WO2015148242A1

WO2015148242A1 - Lightweight, hinged self-closing container covers and elastomer springs for use with such covers

Info

Publication number: WO2015148242A1
Application number: PCT/US2015/021370
Authority: WO
Inventors: Michael D. Grissom
Original assignee: Popseal, Llc
Priority date: 2014-03-27
Filing date: 2015-03-19
Publication date: 2015-10-01
Also published as: US20150274355A1

Abstract

Light weight, hinged, self-closing container covers using springs to self-close are provided. Several cover designs having gates that may be circular or non-circular and may occupy up to almost 100% of the surface of the cover are implemented using springs placed on the exterior of the cover or on the interior of the cover (i.e., inside the container). The dynamics of the gate behavior may be controlled by choosing the properties of the materials from which the springs are comprised. Elastomer springs and combination flex and torsion springs are particularly well suited for comprising the invention and their properties may readily be manipulated to control gate behavior. The gates may be implemented with a toggle action or permanent open action where desired.

Description

LIGHT WEIGHT, HINGED, SELF-CLOSING CONTAINER COVERS

USING SPRINGS TO SELF-CLOSE

Related Applications:

This application claims the benefit of U.S. Patent Application No. 14/226,898, filed March 27, 2014, and U.S. Patent Application No. 14/306,272, filed June 17, 2014.

FIELD OF THE INVENTION

The invention pertains to container covers and, more particularly, to lightweight, self-closing container covers having frangible seams surrounding reclosable gates, where the reclosable gates occupy a large percentage of the area of the container cover and are supported by springs.

BACKGROUND OF THE INVENTION

For many years, manufacturers of cans, particularly aluminum beverage containers, have searched for a way to replace the pull-tab opening mechanisms that are ubiquitous in the beverage industry. Despite their ubiquity, pull-tab opening mechanisms have two deficiencies. First, with some pull-tab designs, the tab may fall into the beverage container and potentially become a swallowing hazard. Second, once opened, pull-tab opening mechanisms are not easily resealed. Beverages, particularly carbonated beverages like beer and soft drinks, rapidly lose their effervescence as the entrained carbon dioxide is released from the beverage and passes through the open container cover and into the air.

Additionally, pull-tab opening mechanisms typically require at least some finger/hand strength to open the container. The opening process may present difficulties to potential users who do not possess sufficient finger/hand strength. Also, pull-tab covers of the prior art are process intensive in their manufacture and require a quantity of metal (generally aluminum) that might be reduced in a better design. It would therefore be desirable to create a container cover that is easy to open, that includes a large gate, and that eliminates the possibility that any portion of the pull- tab opening mechanism may detach from the container and fall into the contents. It would be further desirable to create a reclosable cover that prevents carbon dioxide from escaping from the beverage into the surrounding air. It would still be further desirable to make the container cover lightweight, so as to minimize the amount of material needed to form the cover and any associated spring. It would be further desirable to provide self-closing covers using elastomer springs placed either internally (i.e., within the container) or externally on the outside cover surface.

SUMMARY OF THE INVENTION

The present invention provides lightweight container covers that have self-closing gates or dome areas that are operatively connected to outer portions of the cover by a spring.

A unique tri-fold seam including a frangible seam portion forms a flange that works cooperatively with the spring to implement three modes of operation of the openable gates. In a first mode, after the gate is initially opened by downward directed pressure, for example a tap on the dome or gate by the heal of a person's hand, the gate returns to a closed position. In a second mode, increased downward pressure on the gate pushes it further into the container to which the novel cover is attached, whereat a toggle operation locks the gate in an open position. An action such as swirling the container contents against the gate overcomes the toggle and the gate again returns to a closed position. In a third mode, if the gate is pushed even further downward, the toggle mechanism is defeated; the spring is forced past its elasticity limit; and the gate remains permanently open.

The novel covers of the present invention eliminate the pull tab construction of the prior art and allow a comparable container to be produced using less material than prior art containers. However, the covers of the present invention may be fabricated to be compatible with current production equipment and practices.

Provided herein are multiple designs for the springs that are included in the present invention. Although the container covers disclosed herein may be constructed using a variety of springs, elastomer springs and combination flex-torsion springs are particularly well-suited to comprise the present invention. Accordingly, multiple designs for elastomer springs and combination flex-torsion springs are provided herein, including extremely narrow designs that allow the container cover's gate to occupy nearly 100% of the cover area inside or outside the chuck walls.

It is therefore an object of the invention to provide a lightweight, reclosable cover for a container that utilizes springs, and particularly elastomer and combination flex- torsion springs (though other types of springs may also comprise the invention), to effect reclosing.

It is a further object of the invention to provide a lightweight, self-closing cover for a container wherein the spring may be disposed on either the outer surface of the container and cover or disposed on the inner surface of the container and cover.

It is an additional object of the invention to provide a lightweight, self-closing cover for a container that provides three modes of operation of the gate: a first mode allowing the gate to close upon release of the downward pressure upon it; a second mode (toggle mode) wherein the gate remains open when the downward pressure is released but recloses when tapped or otherwise stimulated; and a third mode where the gate remains permanently open.

It is a further object of the invention to provide a lightweight, reclosable cover for a container wherein the gate may occupy at least 90% of the cover area inside or outside the chuck walls.

It is still a further object of the invention to provide a lightweight, reclosable cover for a container that may be formed using smaller amounts of aluminum or other material than container covers of the prior art. It is yet another object of the invention to provide a lightweight, reclosable cover for a container that may be attached to containers using existing machinery without needing to modify such machinery.

BRIEF DESCRIPTION OF THE DRAWINGS

Various objects, features, and attendant advantages of the present invention will become more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:

FIGURE 1 A is a side elevational, cross-sectional, schematic view of a cover using an elastomer spring in accordance with the invention;

FIGURE 1 B is an enlarged view of a portion of the cover of FIGURE 1 A;

FIGURE 1 C is an enlarged view of another portion of the cover of FIGURE 1 A;

FIGURE 1 D is a top plan, schematic view of the cover of FIGURE 1 A;

FIGURE 1 E is a partial side perspective, cross-sectional, schematic view of the cover of FIGURE 1 A;

FIGURES 2A - 2H are partial side elevational views of the top of FIGURE 1 A in various stages of initial opening and subsequent self-closing;

FIGURE 3A is a side elevational, cross-sectional, schematic view of a cover using an elastomer spring disposed on an external chuck wall in accordance with the invention;

FIGURE 3B is an enlarged view of a portion of the cover of FIGURE 3A;

FIGURE 3C is an enlarged view of another portion of the cover of FIGURE 3A; FIGURE 3D is a top plan, schematic view of the cover of FIGURE 3A;

FIGURE 3E is a partial side perspective, cross-sectional, schematic view of the cover of FIGURE 3A;

FIGURES 4A - 4D are partial side elevational views of the top of FIGURE 3A in various stages of initial opening and subsequent self-closing;

FIGURE 5A is a side elevational, cross-sectional, schematic view of a cover using an internal elastomer spring disposed on an inner surface of the cover;

FIGURE 5B is an enlarged view of a portion of the cover of FIGURE 5A;

FIGURE 5C is an enlarged view of another portion of the cover of FIGURE 5A;

FIGURE 5D is a bottom plan, schematic view of the cover of FIGURE 5A;

FIGURE 5E is a partial side perspective, cross-sectional, schematic view of the cover of FIGURE 5A;

FIGURES 6A - 6E are partial side elevational views of the cover of FIGURE 5A in various stages of initial opening and subsequent self-closing;

FIGURE 7A is a side-elevational, schematic view of an external flush elastomer spring that may be pre-formed and cured;

FIGURE 7B is a side-elevational, schematic view of the elastomer spring of FIGURE 7A with adhesive applied to respective left and right adhesive-receiving walls; FIGURES 7C - 7L show a series of partial side elevational, cross-sectional, schematic views of a portion of a container cover having the elastomer spring of FIGURE 7A installed with the gate at various stages of opening and re-closing;

FIGURE 8A is a side elevational, cross-sectional, schematic view of another internal elastomer spring; FIGURE 8B is a side elevational, cross-sectional, schematic view of a self-closing container using elastomer spring of FIGURE 8A to provide the restorative force for the reclosing; FIGURES 8C and 8D show detailed partial views of flange portions of the cover of FIGURE 8B;

FIGURE 8E is a bottom plan, schematic view of the container cover of FIGURE

8B;

FIGURE 8F is a bottom, perspective, schematic view of the cover of FIGURE 8E;

FIGURE 8G is an enlarged, detailed view of a portion of the cover of FIGURE 8F; FIGURE 8H is a partial side perspective, cross-sectional, schematic view of the cover of FIGURE 8A;

FIGURES 8I - 8M show a series of partial side elevational, cross-sectional, schematic views illustrating five sequential steps involved in opening and subsequently re-closing the container cover of FIGURES 8B - 8G;

FIGURES 9A - 9F show detailed side elevational, cross-sectional, schematic views of the flange region of the container cover of FIGURES 8B - 8G in various stages of opening and closing, including a toggle mode;

FIGURE 10A is a top plan, schematic view of a cover having a center domed external elastomer hinge;

FIGURE 10B is a side elevational, cross-sectional, schematic view of the cover of FIGURE 10A;

FIGURE 10C is a partial side elevational, cross-sectional, schematic view of the cover of FIGURE 10A;

FIGURE 10D is a side perspective, view of the cover of FIGURE 10A; FIGURE 10E is a side elevational, cross-sectional, schematic view of the cover of FIGURE 10B but with the cover crimped to side walls of a container;

FIGURE 10F is a side elevational, cross-sectional, schematic view of the cover of FIGURE 10A in an unopened state;

FIGURE 10G is a side elevational, cross-sectional, schematic view of the cover of FIGURE 10F in a partially open state; FIGURE 1 1 A is a side elevational, cross-sectional, schematic view of a light weight, hinged self-closing container cover having a combination flex and torsion spring in accordance with the invention;

FIGURES 1 1 B and 1 1 C are enlarged portions of the light weight, hinged self- closing container cover having a combination flex and torsion spring of FIGURE 1 1 A;

FIGURE 1 1 D is another enlarged portion of the light weight, hinged self-closing container cover of FIGURE 1 1 C before separation; FIGURE 1 1 E is another enlarged portion of the light weight, hinged self-closing container cover of FIGURE 1 1 C as separation begins;

FIGURE 1 1 F is a bottom plan view of the cover of FIGURE 1 1 A showing the location of the hinged spring;

FIGURE 12 is a side elevational, cross-sectional, perspective, schematic view of the light weight, hinged self-closing container cover having a combination flex and torsion spring of FIGURE 1 1 A; FIGURES 13A and 13B are top and bottom perspective, schematic views of combination flex and torsion spring attached to cover of FIGURE 1 1 A;

FIGURE 14A is a bottom plan, schematic view of a hypothetical container top having a gate and six beaks spaced equidistant along a frangible seam; FIGURES 14B - 141 are side elevational, cross-sectional, schematic views of the simplified light weight, hinged, self-closing container cover of FIGURE 1 1 A in various opening and reclosing; FIGURE 14J is an enlarged portion of the cover of FIGURE 14D showing the interaction of the combination flex and torsion spring and showing a flange formed by the tri-fold seam;

FIGURE 14K is a partial side elevational, cross-sectional view of a portion of the cover of FIGURE 14A showing a detailed schematic view of one of the beaks;

FIGURE 15A is a top plan, schematic view of a container cover having a large (approximately 90% or larger) gate; FIGURE 15B is a partial side elevational, cross-sectional view of the cover of

FIGURE 15A;

FIGURE 15C is an enlarged portion of the view of FIGURE 15B showing a detailed view of the triple fold flange showing the frangible seam/tear line;

FIGURE 15D is a partial side elevational, cross-sectional view of the cover of FIGURE 15A showing a triple fold seam contained within a chuck wall, and with a closed gate; FIGURE 15E is a partial side elevational, cross-sectional view of the cover of

FIGURE 15D showing a triple fold seam contained within a chuck wall, and with a gate partially open;

FIGURE 15F is a partial side elevational, cross-sectional view of the cover of FIGURE 15D showing a triple fold seam contained within a chuck wall, and with a gate fully open;

FIGURE 16A is a bottom perspective, schematic view of a first embodiment of a combination flex-torsion spring for use in conjunction with the cover of FIGURE 15A; FIGURE 16B is a bottom plan view of the cover of FIGURE 15A with the combination flex-torsion spring of FIGURE 16A coupled thereto;

FIGURE 17A is a bottom perspective, schematic view of an alternative embodiment of a combination flex-torsion spring for use in conjunction with the cover of 15A; and

FIGURE 17B is a bottom plan view of the cover of FIGURE 15A with the combination flex-torsion spring of FIGURE 17A coupled thereto.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention provides for lightweight, reclosable container covers that utilize springs to allow the cover to self reclose once it has been initially opened (the terms "lightweight" and "light weight" are used interchangeably throughout this application). In my previous work, light weight, self-closing covers having several sizes and configurations were disclosed. However, none of the previously disclosed designs allowed for large gate openings; for example, gate openings that covered 90% or more of the cover real estate within or including the outer chuck walls. As used herein, the term "large gate openings" is used to refer to gate openings of approximately 90% or more of the surface area of the cover included within the chuck walls or, in some cases, including the chuck walls. It should be noted, however, that gate sizes even larger than 90% are possible by careful spring design and integrating at least a portion of the spring inside the raised (or depressed) ridge that is a chuck wall. The container covers of the present invention may be designed such that, once the cover is attached to an associated container, chuck walls may be located on the exterior of the associated container or located in the interior of the associated container. As such, springs may be located within exterior chuck walls or within interior chuck walls. The term "within the chuck walls" refers to designs where the spring and associated mechanisms are located within the cover space defined by the perimeter chuck wall but not physically inside a chuck wall. Two types of springs, elastomer springs and combination flex-torsion springs, work particularly well to comprise the present invention. However, it will be apparent to those skilled in the art that other types of springs may also comprise the invention. Consequently, the invention is not considered limited to the examples chosen for purposes of disclosure herein. Rather, the invention covers all changes and

modifications which do not constitute departures from the true spirit and scope of the invention.

Elastomer Springs

There are many advantages in forming the present invention's springs from an elastomer material. First, elastomer springs are lighter in weight than metal springs while providing the same functionality. In addition, elastomer springs are significantly less expensive than their metallic counterparts. Also, assembly time for covers that utilize elastomer springs is typically shorter compared to the assembly time for covers that utilize metallic springs. Furthermore, metallic springs may fail and become disconnected from a container top, which presents a safety risk. Elastomer springs at least reduce or, at best, eliminate such safety risks. Technically, elastomers are polymers with viscoelasticity (i.e., "elasticity"). These materials typically exhibit low values of Young's modulus as well as high failure strain compared with other materials. The term elastomer, derived from elastic polymer, is often used interchangeably with the term "rubber". Each of the monomers which link to form the elastomers is usually made of carbon, hydrogen, oxygen and/or silicon.

Elastomers are amorphous polymers existing above their glass transition temperature, so that considerable segmental motion is possible.

Elastomers or elastomer materials have several physical properties that must be evaluated to determine their suitability for use as material from which to form the elastomer springs which comprise some examples of the present invention.

First is cure shrinkage percentage. Cure shrinkage percentage for elastomers may range from a fraction of one percent to what the industry calls "unmeasurable." The elastomeric materials from which springs for the present invention are formed must exhibit a sufficient shrinkage percentage such that an elastomer spring is able to pull a gate portion of a container cover back to the self-closed position with enough force to create a complete seal between mating flanges (i.e., fully self-closed). If the elastomer does not sufficiently shrink when cured, the weight of the gate will prevent complete self- closing.

Another physical property that must be considered is adhesion strength.

Container covers, especially those designed for the food and beverage industry, are typically formed from aluminum having a protective coating. A strong bond between the elastomer spring and the container surface (whether coated with aluminum or another material) is necessary. An etchant may be mixed with the elastomer to increase the strength of the bond.

Another mechanical property of the elastomer that must be considered when choosing an elastomer from which to form elastomer springs is percent elongation. Percent elongation is a measurement that represents how much an elastomer can be elongated or stretched before it comes to a rather abrupt stop. For example, an elastomer with a 100% elongation can be stretched one full length beyond its normal "resting state" length before the elongation process stops. Thus, an elastomer that is stretched to 50% has been elongated to a length equal to 1 .5 times its resting state length.

The tear strength for the elastomer must be considered. Tear strength defines the force required to physically tear the cured elastomer. The force required to physically tear a particular elastomer is typically far greater than the force required to stretch the elastomer to its percent elongation limit.

Finally, cure time is also important, especially if elastomer springs are to be applied to container covers in a high speed production environment. It will be recognized that properties other than the five properties discussed above may also be important for a specific elastomer material or for a specific geometry of a particular elastomer spring.

One material found suitable for forming elastomer springs for use with self- closing container covers is Catalog Number US-SRB-201 -HE fast cure silicone rubber parts binder provided by Silicone Technologies of Ogdensburg, New York, USA. The US-SRB-201 -HE material is intended for applications demanding very high elongation percentages (over 1 000%). When cured, the elastomer resists weathering, ozone, moisture, UV, and high temperatures. Further, US-SRB-201 -HE works well in manual and automatic dispensing equipment.

Another material found suitable for constructing elastic polymer springs or hinges suitable for use with self-closing covers is a heat cured silicone adhesive, Catalog Number RTV-6445 provided by GE Bayer Silicones (now part of Momentive

Performance Materials, headquartered in Columbus, Ohio, USA). RTV-6445 is a heat cured silicone elastomer having an elongation limit of approximately 625%.

It will be recognized by those of skill in the art that numerous other materials exist which are suitable to comprise springs for the present invention and any suitable material may be substituted for the materials cited for purposes of disclosure herein.

Consequently, the invention should not be considered limited to the materials chosen for purposes of disclosure. Rather, the patent is intended to include any suitable elastomers from which the elastomer springs, in accordance with the invention, may be formed. As described hereinbelow, an elastomer spring may be placed on an external surface of a cover or, alternately, the elastomer spring may be placed on or adjacent to an inner surface of the cover.

Referring first to FIGURE 1 A, reference number C1 generally shows a side elevational, cross-sectional, schematic view of a cover having an external elastomer spring in a "button top" configuration.

Cover C1 is shown before attachment to a container represented by partial container side structure 1 18a, 1 18b. Cover C1 is shown with its gate in a sealed (i.e., unopened) state. Further, cover C1 is a simplified design used to illustrate the operation of the elastomer spring. More complex covers using other elastomer springs are described and discussed in more detail hereinbelow.

Cover C1 consists of a seaming panel 102 (best seen in FIGURE 1 D)

surrounding a central gate or dome 1 08. Seaming panel portions 102a, 1 02b have respective distal ends 104a, 104b that are adapted for attachment to upstanding walls 1 18a, 1 1 8b of a container and adapted to form a peripheral seal, not shown. Note that any container or portion thereof shown or discussed herein forms no part of the present invention and is shown and/or discussed only to better describe cover C1 .

In the cross-sectional view of FIGURE 1 A, distal ends 104a, 104b; seaming panel portions 102a, 1 02b; panel portions 1 20a, 120b; countersinks 1 16a, 1 16b; and flanges 106a, 106b are labeled for purposes of discussion. However, cover C1 is typically a circular structure best seen in FIGURE 1 D and distal end 1 04, seaming panel 1 02, panel 120, countersink 1 16, and flange 106 are continuous, circular structures - at least until the initial opening of gate 1 08.

Distal ends 104a, 104b of seaming panel portions 102a, 102b, respectively, form what is commonly known in the industry as a curl. Proximal ends, not specifically identified, of seaming panel portions 102a, 102b are each contiguously connected to respective panel portions 120a, 120b. Panel portions 1 20a, 120b terminate in respective countersinks 1 1 6a, 1 16b. Another panel portion 126a, 126b joins respective

countersinks 1 1 6a, 1 16b to respective tri-fold separable seams forming flanges 1 06a, 106b, respectively. Flanges 106a, 106b are shown in detailed portions 122a, 122b in FIGURES 1 B and 1 C, respectively, and are discussed in more detail hereinbelow.

A gate or dome 108 occupies the central region of cover C1 and is surrounded by seaming panel 1 02 (FIGURE 1 D). Gate 108 in the simplified cover C1 occupies approximately 80% or more of the top surface of cover C1 . It will be recognized by those of skill in the art that the novel construction may be implemented where gate or dome 108 ranges in size from substantially 100% of the cover surface down to very small sizes creating small apertures.

Chuck walls 1 14a, 1 14b define respective countersunk regions 1 16a, 1 1 6b.

Panel sections 126a, 126b are surrounded by countersinks 1 16a, 1 16b and fill the space between countersinks 1 16a, 1 16b and respective tri-fold flanges 106a, 1 06b. An external button top elastomer spring 1 12 is disposed substantially atop tri-fold flange 106a and connecting panel portion 126a and gate 108. Spring 1 12 provides support and closure force for gate 108 after the gate has been initially opened. Referring now also to FIGURES 1 B and 1 C, there are shown enlarged drawings of portions 122a, 122b of flanges 1 06a, 106b, respectively. Of particular interest is the coined frangible seam 1 1 0a, 1 10b formed in flanges 1 06a, 106b. Frangible seam 1 10a, 1 10b defines a tear line completely around gate 108 that allows separation of gate 108 from panel 126 as gate 108 of cover C1 is "opened". Frangible seams 1 1 0a, 1 10b are typically formed using a coining process. However, it will be recognized by those of skill in the art that alternate formation processes may be utilized.

The concept of "beaks" has been discussed extensively in my prior work, United States Patent No. 8,21 5,513, included herein by reference. Beaks, so named for their tapered, pointed shape, or other similar structures, none shown, are provided at one or more points along the frangible seam 1 10a, 1 10b to facilitate an initial rupture of the frangible seam. Providing beaks or similar structures reduces the applied force required to open the container by separating the frangible seam (i.e., the tear line). With larger, round gates - such as those disclosed in some iterations of the present invention - the necessity for more than two beaks is envisioned. A preliminary analysis indicates that five (5) to seven (7) beaks disposed circumferentially around large round gates proximate the frangible seam may be required to ensure proper opening (see, for example, beak locations 1 156 located circumferentially around cover 1 100 in FIGURE 14A). However, different cover designs may require more or less beaks.

Referring now also to FIGURES 1 D and 1 E, there are shown top plan schematic and partial side perspective schematic views, respectively of cover C1 of FIGURES 1 A, 1 B, and 1 C. In FIGURES 1 D and 1 E, the relationship of each of the components and features described hereinabove with respect to FIGURES 1 A, 1 B, and 1 C may readily be seen. The width of gate 108 is represented by arrow 128. In FIGURE 1 E, the relationship of external button top elastomer spring 1 12 to the remainder to the structure of cover C1 may readily be seen.

Referring now also to FIGURES 2A - 2H, there are shown a series of side elevational, cross-sectional, schematic views of a cover having an external elastomer spring in the external "button top" configuration of FIGURE 1 A in various stages of opening and self-closing. Table I provides a percentage of elongation of elastomer spring 1 12 and an angle of rotation of gate 108 relative to a horizontal reference line 130, where line 130 hypothetically connects an upper point of the frangible seam 1 1 0a to a lower point of the frangible seam 1 10b. Angle of rotation is indicated by reference number 138.

Table I

In FIGURE 2A, a downward directed force (typically supplied by the heel of a person's hand) has been exerted on gate 108 as shown by arrow 132. In response to this downward force, frangible seam 1 1 0 has ruptured and the remainder of flange 1 06a has moved downward carrying gate 108 downward into what would be an interior region of a container, not shown, to which cover C1 would be attached. Reference number 134 denotes the gap between the edges of frangible seam 1 1 0a. As may be seen by the relationship of lines 138 and reference horizontal line 130, gate 108 has rotated approximately -5^Q. This motion has caused elastomer spring 1 12 to be slightly elongated (approximately 0.1 %). Frangible seam portion 1 10b has not yet ruptured.

In FIGURE 2B, continued downward directed force on gate 108 has caused further downward travel of the remainder of flange 106 and gate 1 08. Consequently, gap 134 has widened. Gate 108 has now rotated approximately -10°. The continued downward movement has further elongated elastomer spring 1 12 by approximately 0.5%. Frangible seam portion 1 10b has still not begun to rupture.

In FIGURE 2C continued downward directed force on gate 1 08 has caused even further downward travel of the remainder of flange 106 and gate 1 08. Gap 134 has now widened even further. Gate 108 has now rotated approximately -20° and elastomer spring 1 12 has been elongated approximately 200%. Frangible seam portion 1 1 0b has still not begun to rupture.

In FIGURE 2D, frangible seam 1 10b has ruptured and the remaining portion of flange 106b has started to travel downward as indicated by gap 136. Gate 108 is now rotated to a -30^Q angle relative to reference horizontal line 130. Gap 134 has stopped widening. Elastomer spring 1 12 has now been elongated to its maximum extent (i.e., approximately 300%, in this example). In FIGURE 2E, the dynamics of the movement of gate 108 change. Once frangible seam portioni 10b has ruptured, elastomer spring 1 12 contracts and begins to pull the remaining portion of flange 106a upward, thereby closing gap 134. The elongation of spring 1 12 shrinks to approximately 200% and the angular orientation of gate 108 shifts, moving from -30° in FIGURE 2D to a 10° in FIGURE 2E. However, as the left edge of gate 108 rises, the right edge of gate 1 08 continues downward.

In FIGURE 2F, frangible seam portion 1 10a has returned to its original, unopened position and gap 1 34 has shrunk to substantially zero. Gap 1 36 has opened as the right edge of gate 108 continues downward to create an angle of rotation of approximately 20°. The elongation of elastomer spring 1 1 2 has dropped to approximately 0.3%.

In FIGURE 2G, an upward directed restoring force 140 is exerted on gate 108 by elastomer spring 1 12. In response to this upward directed force 140, the right edge of gate 108 has started to move upward. In FIGURE 2G, the elongation of elastomer spring 1 12 has shrunk to approximately 0.2% and the rotation angle of gate 108 has been reduced to approximately 8°.

In FIGURE 2H, cover C1 has completely reclosed and substantially resealed as both portions of the frangible seam 1 10a, 1 1 0b have reclosed. The elongation of elastomer spring 1 12 has become zero (i.e., no elongation) and the angle of rotation of gate 108 has also become zero. Line 138 has become coincident with horizontal reference line 1 30.

In the formation process of elastomer springs (such as elastomer spring 1 12), elastomer shrinkage during the curing process creates an important gate closing bias in the spring. This bias is sufficient to support the weight of a severed gate and firmly hold the gate in a tightly closed position. A typical shrinkage during curing is approximately 0.005%, a seemingly small amount but sufficient to provide the necessary force to hold a severed gate in a tightly closed condition. It will be recognized that elastomer raw materials having different curing shrink rates may be chosen for different spring designs and placements. Consequently, the invention is not considered limited to a particular cure shrinkage rate. Rather, the invention is intended to include any suitable cure shrinkage rate in addition to the approximately 0.005% chosen for purposes of disclosure.

It will be recognized that operation of opening and self-reclosing gate 108 as shown in FIGURES 2A - 2H and described in the attending descriptions is controlled by the design of cover C1 . The primary control over the function of gate 108 is the material choice for elastomer spring 1 12. In this example, an elastomer having a maximum percentage of elongation of 300% has been chosen. In FIGURE 2D, the maximum elongation is reached. Consequently, no further downward travel of the left edge of gate 108 is possible and the downward directed force 132 is transferred to the right edge of gate 108, thereby causing frangible seam portion 1 1 0b to rupture. As the right edge of gate 108 is ruptured, elastomer spring 1 1 2 immediately begins contracting and begins pulling the left edge of gate 108 upward until the left edge of gate 108 is returned to approximately its unopened position and frangible seam portion 1 10a is closed.

If a material with a higher percentage of elongation (i.e., >300%) had been chosen, the downward travel of the left edge of gate 108 could have been deeper into an interior region of the container to which cover C1 is attached. The greater downward travel could cause splashing of the container contents. The choice of elastomer, specifically the percentage of elongation, thus substantially affects the performance of the container covers disclosed herein which include elastomer springs. Referring now also to FIGURE 3A, reference number C2 generally shows a side elevational, cross-sectional, schematic view of a cover having an external elastomer spring disposed inside an external chuck wall in accordance with the invention.

Cover C2 is shown in a sealed (i.e., unopened state) and before attachment to a container represented by partial sides 318a, 31 8b. Further, cover C2 is a simplified design used to illustrate the operation of an elastomer spring disposed in a chuck wall. Additional covers using other elastomer springs and spring configurations are described and discussed in more detail hereinbelow. Cover C2 consists of a seaming panel 302 (best seen in FIGURE 3D) connected to a sloping panel 320 surrounding a central gate or dome 308. Seaming panel portions 302a, 302b have respective distal ends 304a, 304b that are adapted for attachment to upstanding walls 318a, 318b of a container and adapted to form a peripheral seal, not shown. Again, note that any container or portion thereof shown or discussed herein forms no part of the present invention and is shown and/or discussed only to better describe cover C2. While in the cross-sectional view of FIGURE 3A, seaming panel portions 302a, 302b; distal ends 304a, 304b; and panel portions 320a, 320b are labeled for purposes of discussion, cover C2 is typically a circular structure best seen in

FIGURE 3D and seaming panel 302, distal end 304, and panel 320 are continuous, circular structures - at least until initial opening of gate 308.

Distal ends 304a, 304b of seaming panel portions 302a, 302b, respectively, form what is commonly known in the industry as a curl. Proximal ends, not specifically identified, of seaming panel portions 302a, 302b connect to respective sloping panel portions 320a, 320b that terminate in respective tri-fold separable seams forming flanges 306a, 306b, respectively located in chuck walls or countersinks, not specifically identified. Flanges 306a, 306b are shown in detailed portions 322a, 322b in FIGURES 3B and 3C, respectively, and are discussed in more detail hereinbelow. A gate or dome 308 occupies the central region of cover C2 surrounded by tri- fold seam 316 (FIGURE 3D). Dome 308 in the simplified cover C2 occupies

approximately 80% or more of the top surface of cover C2. It will be recognized by those of skill in the art that gate or dome 308 may range in size from substantially 1 00% of the cover surface down to very small sized apertures.

An external elastomer spring 312 is disposed substantially inside an external chuck wall forming a portion of tri-fold flange 306a connecting panel portion 320a and gate 308. Elastomer spring 31 2 provides support and closure force for gate 308 after the gate has been opened. Referring now also to FIGURES 3B and 3C, there are shown enlarged drawings of portions 322a, 322b of flanges 306a, 306b, respectively. Of particular interest is the coined frangible seam 31 0a, 310b formed in flanges 306a, 306b. Frangible seam 310a, 310b defines a tear line completely around gate 308 that allows separation of gate 308 from panel 320 as gate 308 of cover C2 is "opened." Frangible seam 310a, 31 0b is typically formed using a coining process. However, it will be recognized by those of skill in the art that alternate formation processes may be utilized.

Referring now also to FIGURES 3D and 3E, there are shown top plan schematic and partial side perspective schematic views, respectively, of cover 02 of FIGURES 3A, 3B, and 30. In FIGURES 3D and 3E, the relationship of each of the components and features described hereinabove with respect to FIGURES 3A, 3B, and 30 may readily be seen. The width of gate 308 is represented by headed line 328. In FIGURE 3E, the relationship of external chuck wall elastomer spring 312 to the remainder to the structure of cover 02 may readily be seen.

Referring now also to FIGURES 4A - 4D, there are shown a series of side elevational, cross-sectional, schematic views of a cover 02 having an external elastomer spring in the external chuck wall configuration of FIGURE 3A in various stages of opening and self-closing. Table II provides a percentage of elongation of elastomer spring 312 and an angle of rotation of gate 308 relative to a hypothetical horizontal reference line 330 connecting frangible seam points 310a and 310b. Angle of rotation is indicated by reference number 338.

Table II

FIGURE 4A shows gate 308 prior to the rupturing of frangible seam 310a, 310b and before any significant elongation of elastomer spring 312. Horizontal reference line 330 is still level. In FIGURE 4B, a downward directed force has been exerted on gate 308 as shown by arrow 332. In response to this downward force 332, frangible seam 310a has ruptured and the remainder of flange 306a has moved downward carrying gate 308 downward into what would be the interior region of a container, not shown, to which cover C2 would be attached. Reference number 334 denotes the gap between the edges of frangible seam 310a. As may be seen by the relationship of line 338 and reference horizontal line 330, gate 308 has rotated approximately -6^Q. This motion has caused elastomer spring 312 to be slightly elongated (approximately 150%). Frangible seam portion 31 0b has not yet ruptured.

In FIGURE 4C, the dynamics of the movement of gate 308 change. Once frangible seam portion 310b has ruptured, elastomer spring 312 contracts and begins to pull the remaining portion of flange 306a upward thereby closing gap 334. The elongation of spring 312 shrinks to approximately 1 0% elongation and the angular orientation of gate 308 shifts, moving from -6° in FIGURE 4B to +6° in FIGURE 4C. As the left edge of gate 308 rises, the right edge of gate 308 continues downward.

In FIGURE 4D, cover C2 has completely reclosed and substantially resealed as both portions of the frangible seam 310a, 31 0b have reclosed. The elongation of elastomer spring 312 has become zero (i.e., no elongation) and the angle of rotation of gate 308 has also become zero. Line 338 has become coincident with horizontal reference line 330.

As previously stated hereinabove, elastomer shrinkage during the curing process creates an important gate closing bias in the spring that is sufficient to support the weight of a severed gate and firmly hold that gate in a tightly closed position. The invention is not considered limited to a particular cure shrinkage rate. Rather, the invention is intended to include any suitable cure shrinkage rate in addition to the approximately 0.005% chosen for purposes of disclosure.

As explained with regard to cover C1 , the primary control over the function of gate 308 is the material chosen for elastomer spring 31 2. In this example, an elastomer having a maximum percentage of elongation of 150% has been chosen. In FIGURE 4B, the maximum elongation is reached. Consequently, no further downward travel of the left edge of gate 308 is possible and the downward directed force 332 is transferred to the right edge of gate 308, thereby causing frangible seam portion 310b to rupture. As the right edge of gate 308 is ruptured, elastomer spring 31 2 immediately begins contracting and begins pulling the left edge of gate 308 upward until, eventually, spring 312's contraction force pulls both the left and right edges of gate 308 to their respective unopened positions and frangible seam portions 310a, 310b are closed.

As noted with regard to cover C1 , if a material with a higher percentage of elongation (i.e., >150 %) had been chosen, the downward travel of the left edge of gate 308 could have been deeper into an interior region of the container to which cover C2 was attached and thus could have caused splashing of the container's contents.

Referring now also to FIGURE 5A, reference number C3 generally shows a side elevational, cross-sectional, schematic view of a cover having an internal elastomer spring in accordance with the invention.

Cover C3 is shown before attachment to a container, not shown, and in a sealed (i.e., unopened) state. Further, cover C3 is a simplified design used to illustrate the operation of the elastomer spring. More complex covers using other elastomer springs are described and discussed in more detail hereinbelow.

Cover C3 consists of a panel 526 (best seen in FIGURE 5D) surrounding a central gate or dome 508. Panel portions 502a, 502b have respective distal ends 504a, 504b that are adapted for attachment to upstanding walls 518a, 518b of a container. Distal ends 504a, 504b are further adapted to form a peripheral seal, not shown, between upstanding walls 518a, 518b and respective distal ends 504a, 540b of seaming panel 502a, 502b, respectively. Again, any container or portion thereof shown or discussed herein forms no part of the present invention and is shown and/or discussed only to better describe cover C3. While in the cross-sectional view of FIGURE 5A, seaming panel portions 502a, 502b; distal ends 504a, 504b; and panel portions 520a, 520b are labeled for purposes of discussion. However, cover C3 is typically a circular structure (best seen in FIGURE 5D) and seaming panel 502, distal end 504 and panel 520 are continuous, circular structures - at least until initial opening of gate 508.

Distal ends 504a, 504b of seaming panel portions 502a, 502b, respectively form what is commonly known in the industry as a curl. Proximal ends, not specifically identified, of seaming panel portions 502a, 502b each terminate in respective countersinks 51 6a, 516b. In turn, sloped panels 520a, 520b are connected to respective tri-fold separable seams forming flanges 506a, 506b. Flanges 506a, 506b are shown in detailed portions 522a, 522b in FIGURES 5B and 5C, respectively, and are discussed in more detail hereinbelow.

A gate or dome 508 occupies the central region of cover C3 surrounded by panel 526 (see FIGURE 5D). Dome 508 in the simplified cover C3 occupies approximately 80% or more of the surface of cover C3. It will be recognized that the novel construction may be implemented where gate or dome 508 ranges in size from substantially 100% of the cover surface down to very small size apertures.

Panel sections 526a, 526b are surrounded by countersinks 516a, 516b and fill the space between countersinks 516a, 516b and gate 508.

An elastomer spring 512 is disposed on a lower (i.e., internal) surface of panel 526a and attached to both a lower surface of panel 526a and to a lower portion of flange 506a (i.e., the portion below frangible seam 51 0a). Spring 51 2 provides support and closure force for gate 508 after the gate has been opened.

Referring now also to FIGURES 5B and 5C, there are shown enlarged drawings of portions 522a, 522b of flanges 506a, 506b, respectively. Of particular interest is the coined frangible seam 51 0a, 510b formed in flanges 506a, 506b. Frangible seam 510a, 510b defines a tear line completely around gate 508 that allows separation of gate 508 from panel 526 as gate 508 of cover C3 is "opened." Frangible seam 510a, 51 0b is typically formed using a coining process. However, it will be recognized by those of skill in the art that alternate formation processes may be utilized.

Referring now also to FIGURES 5D and 5E, there are shown top plan schematic and partial side perspective schematic views, respectively, of cover C3 as shown in FIGURES 5A, 5B, and 5C. In FIGURES 5D and 5E, the relationship of each of the components and features described hereinabove with respect to FIGURES 5A, 5B, and 5C may readily be seen. The width of gate 508 is represented by headed line 528. In FIGURE 5E, the relationship of internal elastomer spring 512 to the remainder of the structure of cover C3 may readily be seen. Referring now also to FIGURES 6A - 6E, there are shown a series of side elevational, cross-sectional, schematic views of the cover C3 having the internal elastomer spring 512 of FIGURE 5A in various stages of opening and self-closing. Table III provides a percentage of elongation of internal elastomer spring 512 and an angle of rotation of gate 508 relative to a hypothetical horizontal reference line 530 connecting an upper point of the frangible seam 510a to a lower point of the frangible seam 51 Ob. Angle of rotation is indicated by reference number 538.

Table II I

In FIGURE 6A, a downward directed force exerted on gate 508 as shown by arrow 532 has not yet been sufficient to rupture frangible seam 510a, 510b.

In FIGURE 6B, a sufficient downward directed force 532 has been exerted on gate 508 to rupture frangible seam 51 0a and move the remainder of flange 506a and the left edge of gate 508 downward into what would be an interior region of a container, not shown, to which cover C3 would be attached. Reference number 534 denotes the gap between the edges of frangible seam 51 0a. As may be seen by the relationship of line 538 and reference horizontal line 530, gate 508 has rotated approximately -1 0^Q. This motion has caused internal elastomer spring 512 to be slightly elongated (approximately 50%). Frangible seam portion 510b has not yet ruptured.

In FIGURE 6C, continued downward directed force 532 on gate 508 has caused further downward travel of the remainder of flange 506a and gate 508. Consequently, gap 534 has widened. Frangible seam 51 0b has now ruptured and gate 508 is floating freely, constrained only by elastomer spring 512. Gate 508 is now substantially horizontal (i.e., 0- rotation) but is now moved downward into what would be the interior of a container to which cover C3 would be attached. Internal elastomer spring 512 has now begun to contract and is elongated by approximately 20%. In FIGURE 6D, internal elastomer spring 51 2 has further contracted such that its elongation percentage is now 0.0% (i.e., no elongation). As a result, the left edge of gate 508 has returned to its unopened position and gap 534 has closed. The right edge of gate 508, however, remains in an "open" position, represented by gate 508's 9° angle of rotation.

In FIGURE 6E, cover C3 has completely reclosed and substantially resealed as both portions of the frangible seam 510a, 51 0b have reclosed. The elongation of internal elastomer spring 512 has become zero (i.e., no elongation) and the angle of rotation of gate 508 has also become zero. Line 538 has become coincident with horizontal reference line 530. An upward directed force provided by internal elastomer spring 512 now holds gate 508 in a tightly sealed position.

In the examples of elastomer springs 1 12, 312, 51 2, it is assumed that the springs may be formed and/or cured in situ. In a high speed can filling and sealing operation, such in situ placement and curing of any elastomer spring may be

impractical.

Referring now also to FIGURE 7A, there is shown a side-elevational, schematic view of an external flush elastomer spring 700 that may be pre-extruded and cured and then machine-applied to a container cover. Spring 700 has a roughly triangular shape with a left adhesive-receiving surface 702a and a right adhesive-receiving surface 702b.

A slit 704 is disposed in the left side of spring 700 below a lower edge of left adhesive-receiving wall 702a. Slit 704 leads to an open central area 706 from an outside surface, not specifically identified, of spring 700.

A flange receiving region 708 is disposed adjacent a hook tip 724. Referring now also to FIGURE 7B, there is shown spring 700 of FIGURE 7A with adhesive, shown schematically at reference numbers 710a, 71 0b, applied to respective left and right adhesive-receiving walls 702a, 702b. Adhesive 710a, 710b may be applied to spring 700 at the time the spring is manufactured. If adhesive 71 0a, 710b is applied when spring 700 is manufactured, an optional protective coating, not shown, may be placed over adhesive 710a, 710b to prevent drying of the adhesive or prevent contaminating debris from clinging to the tacky surface of adhesive 71 0a, 710b. In alternate embodiments, adhesive, not shown, may be applied to specific areas of a container cover prior to placing spring 700 into place. This may be accomplished using a variety of materials and techniques believed to be well known to those of skill in the art.

Referring now also to FIGURES 7C - 7L, there are shown a series of partial side elevational, cross-sectional, schematic views of a portion of a container cover having elastomer spring 700 installed. The depicted cover portions each show a portion of a gate 712 and a portion of a surrounding panel 714. Also shown is a tri-fold seam or flange represented by reference number 71 8. A frangible seam 716 is placed in gate portion 712.

As seen in FIGURE 7C, elastomer spring 700 is sized and configured to fit between outer portions of gate 712 and panel 714 so that the elastomer spring's top surface, not specifically identified, is substantially flush with the gate 712 and

surrounding panel 714, both of which elastomer spring 700 is attached to. As may readily be seen, left and right adhesive receiving surfaces 702a, 702b of a non- elongated elastomer spring 700 conform to respective surfaces, not specifically identified, of gate 712 and surrounding panel 714, respectively.

In FIGURE 7D, a downward directed force 720 applied to gate 712 causes gate 712 to move downward, thereby stretching elastomer spring 700. As may be seen, central open area 706 and flange engaging region 708 are both compressed. As seen in FIGURE 7E, continued downward force 720 causes further downward travel of gate 71 2 with consequent further elongation of elastomer spring 700. As seen in FIGURE 7E, central open area 706 and flange engaging region 708 are both now almost completely compressed. As seen in FIGURE 7F, continued downward force 720 causes further downward travel of gate 71 2 with consequent further elongation of elastomer spring 700. The elongation of elastomer spring 700 allows flange engaging region 708 to slide past bottom 718 of the tri-fold flange, thereby positioning flange engaging region 708 for toggle mode. As seen in FIGURE 7G, as elastomer spring 700 relaxes, flange engaging region 708 is pulled upward to encircle and retain bottom 718 of the tri-fold flange. Once region 708 of elastomer spring 700 is in this position, the so-called toggle mode for the container top is set.

As seen in FIGURE 7H, once region 708 of elastomer spring 700 is in the position seen in FIGURE 7G, elastomer spring 700 continues to exert an upward force on the flange, represented by bottom of flange 718. Because elastomer spring 700 is not compressible, the force caused by its contraction separates frangible seam 71 6 and forms a gap 728. Once gap 728 is formed, the contents of the container (e.g., soda, beer, etc.) may be oscillated or swirled in the container so as to apply force 726 to the inside of gate 71 2.

In FIGURE 7I, the oscillated container contents continue to apply a force to the inside of gate 71 2 (thereby generating upward directed force 726). Likewise, elastomer spring 700 continues to contract toward its original position (as seen in FIGURE 7C). As a result, gate 71 2 continues its upward movement and gap 728 opens further.

In FIGURE 7J, once flange engaging region 708 is clear of bottom of flange 718 of the tri-fold seam, elastomer spring 700 now supplies the upward directed force 726 that continues to move gate 712 upward.

And in FIGURE 7K, elastomer spring 700 snaps back into its relaxed shape (i.e., 0.0% elongation) and gap 728 closes.

Finally, in FIGURE 7L, gate 712 is returned to a closed position thereby effectively re-sealing the contents of the container.

Referring now also to FIGURE 8A, there is generally shown at reference number 800 a side elevational, cross- sectional, schematic view of another elastomer spring. Elastomer spring 800 is intended as an internal spring for a cover C4 having a toggle mode.

Elastomer spring 800 has a body 802 divided generally into an upper body portion 804 and a lower body portion 806. Body 802 has a hole 808 disposed therei An elongated tail 810 proceeds from lower body portion 806. A slot 812 separates tail 810 from upper body portion 804.

Upper body portion 804 has a flange-receiving area 814 on a right side thereof.

Elastomer spring 800 is formed such that tail 810 provides a counter clockwise (CCW) bias attempting to always exert an upward, CCW force on a lower surface of gate 826. Referring now also to FIGURE 8B, there is shown a side elevational, cross- sectional, schematic view of a self-closing container using elastomer spring 800 to provide the restorative force for the reclosing.

A gate or dome 826 is surrounded by a panel 838, shown as panel portions 838a, 838b in the cross-sectional view of FIGURE 8B. As seen in FIGURE 8E, panel 838 is a continuous circular structure. Between gate 826 and panel 838 is a trifold flange 824, shown as flange portions 824a, 824b. Flanges 824a, 824b include frangible seam 828a, 828b that separates gate 826 from panel 838. Panel 838 is connected to countersinks 830 that are, in turn, connected to panel

832, again shown as panel portions 832a, 832b. Panel 832 is, in turn, connected to seaming panel 820, shown as seaming panel portions 820a, 820b having respective distal ends 822a, 822b. Elastomer spring 800 is fitted against a lower surface of panel portion 838a and fastened thereto with adhesive 846 (best seen in FIGURE 9A). Spring tail 810 is fastened to a lower surface of gate 826 with adhesive 848 (also best seen in FIGURE 9A). Referring now also to FIGURES 8C and 8D, there are shown detailed partial views of flange portions 824a, 824b respectively at reference numbers 834a, 834b.

Referring now also to FIGURE 8E, there is shown a top plan, schematic view of the container cover of FIGURE 8B. The relative positions of all the structures discussed in conjunction with FIGURES 8A and 8B may readily be seen. In addition, the width of gate 826 is shown by headed line 840.

Referring now also to FIGURE 8F, there is shown a bottom perspective, partial side perspective, schematic view of the cover of FIGURES 8B - 8E.

Referring now also to FIGURE 8G, there is shown an enlarged detail of a portion of the cover of FIGURE 8F. Referring now also to FIGURE 8H, there is shown a partial side perspective, cross-sectional, schematic view of the cover of FIGURE 8A.

Referring now also to FIGURES 8I - 8M, there are shown a series of side elevational, cross-sectional, schematic views illustrating five steps involved in opening and subsequently re-closing gate 826 of container cover C4.

In FIGURE 8I, the cover is unopened. A hypothetical horizontal reference line 842 shows that both sides of frangible seam 828 (i.e., frangible seam portions 828a, 828b) as well as both edges of gate 826 are at the same elevation (i.e., gate 826 is level). A downward directed force represented by arrow 844 has not yet been sufficient to rupture frangible seam 828a.

In FIGURE 8J, downward directed force 844 has caused the rupture of the frangible seam (in this example, having ruptured seam portion 828a). The left edge of gate 826 has dropped, causing primarily the spring tail portion 810 of spring 800 to be elongated and reference line 842 has an upward slope relative to flange portion 824a.

In FIGURE 8K, continued downward pressure 844 has now caused frangible seam portion 828b to rupture and gate 826, while substantially horizontal, has now been pressed downward into the container, not shown, to which cover C4 is attached. It should be noted that spring tail 810 is still significantly elongated.

In FIGURE 8L, it may be seen that once frangible seam portion 828b ruptures, spring tail 810 contracts pulling the left edge of gate 826 upward until frangible seam portion 828a is reclosed. Note that the right edge of gate 826 is still downwardly depressed and reference line 842 now has a downward slope relative to frangible seam portion 828a.

Finally, as seen in FIGURE 8M, the restoring force provided by a relaxing elastomer spring 800 has caused the right edge of gate 826 to be raised to substantially its original, unopened position and frangible seam portion 828b is reclosed.

FIGURES 81 - 8M have illustrated a five step "see-saw" sequence for the initial opening of the container using elastomer spring 800. Once initially opened and re- closed, the container may repeatedly be opened and reclosed. With the design of elastomeric spring 800, the container cover may be operated in a so-called toggle mode.

Referring now also to FIGURES 9A - 9F, there are shown detailed side elevational, cross-sectional, schematic views of the flange region of a container cover in various stages of opening and closing, including a toggle mode (FIGURE 9D) wherein gate 826 is retained in a fully open state until deliberately oscillating (e.g., swirling) the container contents to force gate 826 out of the toggle mode lock. In FIGURE 9A, adhesive regions 846 and 848 may be seen adhering elastomer spring 800 to panel region 838a and gate 826. Although not clearly shown in FIGURE 9A, frangible seam 828a has been previously ruptured (i.e., the container opened) and gate 826 has returned to a self-closed position as shown. The CCW bias discussed above is applied to gate 826 by spring tail 810 as indicated by arrow 850. The constant upward force provided by the CCW bias holds gate 826 in a closed position as shown.

In FIGURE 9B, a downward force 844 against gate 826 causes downward movement of gate 826 with the subsequent deflection of spring tail 810. Downward force 844 overcomes the CCW bias of elastomer spring 800. Bottom of flange 824a (see FIGURE 9A) rotates toward flange receiving portion 814 of elastomer spring 800 for eventual capture and retention thereby. Additional CCW arrow 844 shows a second region of CCW rotation and/or CCW bias force development.

In FIGURE 9C, continued downward pressure 844 causes additional downward movement of gate 826 and deflection of spring tail 81 0. Pivot point 852, around which gate 826 rotates, has shifted to a point near the bottom of flange portion 828a. Flange 824a has rotated almost into flange receiving portion 814 of elastomer spring 800. Rotation of gate 826 is now around a new pivot point 854 (best seen in FIGURE 9E). At this point of rotation of gate 826, flange 824a is almost captured by flange receiving region 814 of elastomer spring 800.

In FIGURE 9D, as a result of the rotation of gate 826 in response to continued downward force 844, seam receiving region 814 of elastomer spring 800 has completely captured and retained flange 824a. Spring tail 810 is maximally deflected and, because of the angle of gate 826, the force on gate 826 retains flange 824a in flange receiving portion 814 of elastomer spring 800. As long as no external force is applied, gate 826 is held open.

In FIGURE 9E, an internal force 860 applied against the inside surface of gate 826 forces flange portion 824a out of flange receiving region 814. Such an internal force is typically generated by oscillating (e.g., swirling, etc.) the contents of the container so as to splash or slosh the contents against the inside surface of gate 826.

In FIGURE 9F, once flange 824a is released from flange receiving portion 814 of elastomer spring 800, the restoring force provided by contraction of elastomer spring 800 (particularly spring tail 810), in cooperation with any continued oscillation of the container contents, brings gate 826 upward toward its initial position as shown is FIGURE 9A. Referring now also to FIGURE 10A, there is shown a top plan view of a cover designated C5 having a center domed external elastomer hinge 1000 that is so-called "manufacturing center registration compliant." The design shown in FIGURE 10A allows an offset gate 1 014 larger than the openings possible with center rivet designs of the prior art. In addition, the size and placement of center domed external elastomer hinge 1000 interacts well with the upper lip 1042 (FIGURE 1 0K) of a consumer 1040 (FIGURE 10L) drinking from the container, not specifically identified, to which cover C5 is attached. This process is best illustrated in FIGURE 10K.

Referring now also to FIGURE 10B, there is shown a side elevational, schematic view of the cover of FIGURE 10A. The center domed external elastomer hinge 1000 is attached to both gate 1 014 and surrounding panel 1010 by adhesive 1022, readily seen in FIGURE 10B. Also visible in FIGURE 10B are flanges 1012a, 1 012b and frangible seam 1016a, 1016b. Reference number 1 024 identifies a section of cover C5 shown in FIGURE 10B.

Referring now also to FIGURE 10C, the area identified by reference number 1024 in FIGURE I0B is shown in more detail.

Referring now also to FIGURE 10D, there is shown a perspective view of cover C5.

Referring now also to FIGURE 10E, there is shown the side elevational, cross- sectional, schematic view of cover C5 where cover C5 is attached to container sides 1026a, 1 026b with a respective crimp 1028a, 1028b. Neither container sides 1026a, 1026b nor crimps 1028a, 1028b form any part of the present invention. Such container sides and crimps are shown merely to show cover C5 in its intended operating environment.

Referring now also to FIGURES 10F - 10J, there are shown a series of side elevational, cross-sectional, schematic views of cover C5 in various stages of being opened and subsequently self-closing after opening.

In FIGURE 10F, cover C5 is shown prior to initial opening. In FIGURE 10G, in response to downwardly directed force 1030, frangible seam

1016a has ruptured and the left edge of gate 1014 has moved downward. In the process of moving downward, a gap 1034 is formed. Note that frangible seam 1016b has not yet ruptured. A horizontal reference line 1032 is provided to indicate the angle of gate 1014 relative to its original, closed position.

In FIGURE 10H, in response to continued downwardly directed force 1030, gap 1034 has possibly widened slightly and frangible seam 1016b has now ruptured creating a right gap 1036. Gate 1014 is lower than its original position (i.e., the position in FIGURE 10F) and appears to be approximately parallel to horizontal reference line With the frangible seam 1016 (represented by frangible seam 1016a, 1016b) completely ruptured, the center domed external elastomer hinge 1000, previously elongated and otherwise stretched from its original shape as seen in FIGURES 10G and 10H, begins to return to its original shape. As shown in FIGURE 101, the restorative force provided by the return of spring 1000 to its original shape exerts an upward force shown as arrow 1038 and the left side of gate 1014 is pulled upward closing gap 1034.

Finally, as seen in FIGURE 10J, the right side of gate 1016 is also pulled upward to close gap 1036. The gate 1014 has now self-closed and the container is effectively resealed.

Referring now also to FIGURE 10K, a partial schematic view of a face 1040 representing a consumer of the contents of the container is shown. Another useful feature of center domed external elastomer hinge 1 000 is that it is placed on the cover in a location that the upper lip 1042 of consumer 1040 contacts while drinking from the container. Because frangible seam 1016 has previously been completely ruptured as described hereinabove, a gentle force by upper lip 1 042 of consumer 1040 succeeds in pressing gate 1014 of cover C5 inward, thereby allowing liquid or other content, not shown, through the opening 1044 of cover C5.

Combination Flex-Torsion Springs

In addition to elastomer and various other types of springs, combination flex- torsion springs are also well-suited to comprise the present invention. Flex-torsion springs exhibit two modes of operation: that of a traditional flex spring combined with that of a traditional torsion spring. Multiple combination flex-torsion spring designs are provided herein.

Flex springs generate their restorative force by moving in a single plane. A force applied to a flex spring pushes it from an original position to a new position. Assuming that the spring has not been pushed beyond its elastic limit and deformed, once the force is released, the spring attempts to return to its original position and, in the process, provides a restorative force. The size of the flex spring and the material from which it is made determine the amount of restorative force that the spring can generate. Spring designs that generate restoring forces from more than one modality of operation - for example, the flex-torsion spring disclosed in the designs of the present invention - may be constructed more compactly. In such designs, only a portion of the restoring force is derived from the flexing action of the spring. Another portion of the restoring force is derived from the twisting/untwisting motion of a torsion component of the flex-torsion spring. Consequently, springs having compact flex portions and thin, curved elongated arms extending outwardly from the central or flex portion of the flex- torsion spring may be constructed. The thin, curved elongated arms that may move with a twisting motion may provide a large portion of the restoring force necessary to close, for example, the gate of a large gate self-closing cover.

Referring first to FIGURE 1 1 A, reference number 1 100 generally shows a side elevational, cross-sectional, schematic view of a simplified light weight, hinged, self- closing container cover having a combination flex-torsion spring. Cover 1 100 is shown before attachment to a container, not shown, and in a sealed (i.e., unopened) state. Further, cover 1 100 is a simplified design used to illustrate the operation of the combination flex and torsion spring. More complex covers using combination flex-torsion springs are described and discussed hereinbelow.

Cover 1 100 consists of a seaming panel shown as seaming panel segments 1 102a, 1 102b having respective distal ends 1 104a, 1 104b forming a so-called curl. Distal ends 1 104a, 1 104b are adapted for attachment to upstanding walls 1 18a, 1 18b (see FIGURE 14B) of a container, not shown, thereby forming a peripheral seam or seal, not specifically identified.

Like with the foregoing discussion involving elastomer springs, it should be noted that any container discussed or shown forms no part of the present invention and such containers when shown or discussed are presented only to better describe cover 1 100. Intermediate sloping panel segments 1 134a, 1 134b connect seaming panel segments 1 102a, 1 1 02b to outer countersink walls 1 1 14a. Countersinks 1 1 1 6a, 1 1 1 6b are formed by the connection of outer countersink walls 1 1 14a to respective inner countersink walls 1 1 14b. Inner countersink walls 1 1 14b connect to respective top panel portions 1 136a, 1 136b that, in turn, connect to respective tri-fold seams 1 1 06a, 1 106b.

A tri-fold seam 1 1 12 surrounds a central gate or dome 1 108.

While in the cross-sectional view of FIGURE 1 1 A, seaming panel portions 1 102a, 1 102b; distal ends 1 104a, 1 104b; intermediate sloping sections 1 134a, 1 134b; and top panel portions 1 136a, 1 136b are labeled for purposes of discussion, cover 1 1 00 is typically a circular structure and the aforementioned components thereof (as well as other components) are, in reality, continuous circular structures (best seen in FIGURE 1 1 F) - at least until gate 1 108 is opened.

Flanges 1 106a, 1 106b are shown in more detail in FIGU RES 1 1 B and 1 1 C, respectively, and are discussed in more detail hereinbelow.

As noted with regard to the gates of previously discussed container covers C1 - C5, while gate 1 108 of container cover 1 100 is shown as a substantially flat surface, it will be recognized by those of skill in the art that gate 1 108 may be replaced by an upwardly (or, in alternate embodiments, downwardly directed) curvilinear structure as shown in alternate gate or dome 1 108'.

A combination flex-torsion spring 1 1 12 provides support and closure force for gate 1 108 after the gate has been opened. Flex-torsion spring 1 1 1 2 may be formed from the same material from which the remainder of cover 1 100 and the container are formed, typically aluminum. A typical aluminum alloy found suitable for the application is 5052-H 19 and a thickness in the range of approximately .006 to .007 inch. It will be recognized by those of skill in the art that other materials, other aluminum alloys, and other material thicknesses may be substituted to meet particular operating circumstance or design. Consequently, the invention is not considered limited by the alloy or thickness range chosen for purposes of disclosure. Rather, the invention is intended to include other metals, alloys, and thicknesses. Referring now also to FIGURES 1 1 B and 1 1 C, there are shown enlarged drawings of portions of tri-fold flanges 1 106a, 1 1 06b, respectively. Of particular interest is the coined frangible seam 1 1 1 0a, 1 1 10b formed in respective flanges 1 1 06a, 1 1 06b. Frangible seam 1 1 10a, 1 1 10b defines a tear line completely around gate 1 108 that allows separation of gate 108 from panel 1 1 02 as gate 1 108 of cover 1 100 is "opened". While frangible seams 1 1 10a, 1 1 10b are typically formed using a coining process, it will be recognized by those of skill in the art that alternate formation processes may be utilized. The opening process is discussed in more detail hereinbelow. Referring now also to FIGURE 1 1 D, there is shown an additional cross-sectional, schematic view of the seam of FIGURE 1 1 C. Frangible seam 1 1 10b is thinned adjacent curved structures 1 1 50a, 1 150b forming an indentation 1 152 in frangible seam 1 1 10b. As depicted in FIGURE 1 1 D, frangible seam 1 1 10b has not yet begun to rupture. Referring now also to FIGURE 1 1 E, there is shown an additional cross-sectional, schematic view of the seam of FIGURE 1 1 C, but in FIGURE 1 1 E frangible seam 1 1 10b has begun to rupture adjacent curved structures 1 150a, 1 150b. Portions 1 154a, 1514b are shown separated with respect to one another. Referring now also to FIGURE 1 1 F, there is shown a bottom plan, schematic view of cover 1 100. Notable in FIGURE 1 1 F are optional fasteners or stakes 1 144 and 1 146. First and second optional fasteners or stakes 1 144 attach opposing arcuate side arms 1 126a, 1 126b to gate 1 108 through a corresponding one of optional holes 1 130a, 1 130b. Another optional fastener or stake 1 146 throughhole 1 122 in central portion 1 120 (not shown) fastens spring 1 1 12 to panel 1 136. Holes 1 130a, 1 130b, and 1 1 22 are best seen in FIGURES 13A and 13B.

Referring now also to FIGURE 12, there is shown a side elevational, cross- sectional, perspective, schematic view of simplified light weight, hinged, self-closing container cover 1 100. In FIGURE 12, the relationship of combination flex-torsion spring 1 1 12 to the panel 1 136 and gate 1 108 is better illustrated.

Referring now also to FIGURES 13A and 13B, there are shown top and bottom perspective, schematic views of combination flex-torsion spring 1 1 1 2. Spring 1 1 12 has a substantially flat square central portion 1 1 20, typically having a central hole 1 122 therethrough. Central portion 1 120 has an inward facing camming detent structure 124 disposed on a front edge, not identified, perpendicular to the flat surface, not identified, of central portion 1 120. Inward facing refers to the direction toward the center of cover 1 100. The functions of camming detent structure 1 1 24 are discussed in more detail hereinbelow.

A pair of opposing arcuate side arms 1 1 26a, 1 126b project outward from respective sides of the flat portion of central portion 1 1 20. Opposing arcuate side arms 1 126a, 1 126b have a short curved section 1 1 32a, 1 132b, respectively, adjacent central portion 1 120 that allows the major surface of each arcuate side arm to be raised to approximately the same height as that of camming detent structure 1 124.

Each of opposing arcuate side arms 1 1 26a, 1 126b has a flattened portion 1 1 28a, 1 128b adjacent their respective distal ends, not specifically identified. Flattened portions 1 128a, 1 128b may be off-set or stepped up or down to a different plane from the remainder of side arms 1 126a and 1 126b. An optional through hole 1 130a, 1 130b may be centrally located on respective flattened portions 1 128a, 1 128b. Referring now also to FIGURE 14A, there is shown a bottom plan, schematic view of a hypothetical container top having a gate 1 108 with six beaks 1 158

equidistantly spaced around a frangible seam 1 1 10. Frangible seam 1 1 10 separates gate 1 108 from an adjacent panel 1 136 at locations 1 156. As may be seen in FIGURE 14K, frangible seam 1 1 10 is surrounded by weakened areas 1 148.

FIGURE 14K is a partial side elevational, cross-sectional view of a portion of the cover of FIGURE 14A. FIGURE 14K shows a detailed schematic view of one of the beaks 1 1 58 shown in FIGURE 14A (in FIGURE 14A, beak locations 1 156 are dispersed around the perimeter of gate 1 108). FIGURES 14A and 14K show that frangible seam or tear line 1 1 10 is surrounded on each side by weakened areas 1 148.

As mentioned, beak structures having many different shapes, sizes, and dispositions capable of facilitating an initial rupture of frangible seam 1 1 10 will be recognized by those of skill in the art. Consequently, the invention is not considered limited to any particular quantity or a particular shape, size, or orientation of a beak structure. The invention is intended to include any and all suitable replacement structures for the beaks, including those disclosed in the previously mentioned 513 patent. With larger, especially round gates in accordance with the invention, the downwardly directed opening force applied to gate 1 1 08 may strike gate 1 108 in a number of different locations. The number of beak locations 1 1 56 (six in the example chosen for purposes of disclosure) allows the rupture of frangible seam 1 1 10 to start proximate the beak 1 158 nearest the point of impact. This helps to ensure gate 1 108 will open in response to sufficient downward directed force, regardless of where on gate 1 108 such force is applied. The rupture of frangible seam 1 1 10 typically proceeds both clockwise and counterclockwise from the point of initial rupture until the entire frangible seam 1 10 has ruptured. FIGURE 1 1 A and FIGURE 12 show cover 1 100 in an unopened condition.

Referring now to FIGURES 14B - 141, there are shown a series of side elevational, cross-sectional, schematic views of the simplified light weight, hinged, self-closing container cover 1 100 of FIGURE 1 1 A illustrating steps of the initial opening and self- closing of cover 1 100. Note that container sides 1 1 1 8a, 1 1 18b are partially shown in FIGURE 14B. As previously stated, container walls 1 1 18a, 1 1 18b form no part of the present invention.

In operation, cover 1 100 is first opened by a downward pressure on gate 1 108 as indicated by arrow 1 140. As previously discussed, downward pressure is typically supplied by the heel of a person's hand, not shown, opening the container. In FIGURE 14B it may readily be seen that frangible seam 1 1 10a has started to rupture at a point shown by arrow 1 160 in response to downward force indicated by arrow 1 140. Note that frangible seam 1 1 10b is as yet unaffected by the downward pressure indicated by arrow 1 140.

In FIGURE 14C, the rupture of frangible seam 1 1 10a continues and the left edge of gate 1 108 has moved further inward into the container represented by container side walls 1 1 1 8a, 1 1 18b. Note that frangible seam 1 1 10b is still unaffected by the downward pressure indicated by arrow 1 140. In FIGURE 14D, the rupture of frangible seam 1 1 10a continues and the left edge of gate 1 108 has moved still further inward into the container represented by container side walls 1 1 18a, 1 1 18b. Note that frangible seam 1 1 1 0b is still unaffected by the downward pressure indicated by arrow 1 140.

In FIGURE 14E, frangible seam 1 1 1 0b has finally ruptured at a position shown by arrow 1 1 62 and the left edge of gate 1 108 begins to rise upward, pivoting on the heel of the palm the person opening the container in response to a restoring force provided by flex-torsion spring 1 1 12. The gap in frangible seam 1 1 10 has begun to close.

In FIGURE 14F, the gap at location 1 162 continues to widen in response to continued downward force and the left edge of gate 1 108 continues to rise in response to a restoring force provided by flex-torsion spring 1 1 1 2. The gap in frangible seam 1 1 10a continues to close.

In FIGURE 14G, frangible seam 1 1 10a returns to an original position as shown by arrow 1 164.

In FIGURE 14H, downward pressure shown at arrow 1 140 is removed and an upward (i.e., restoring force) supplied by flex-torsion spring 1 1 12 moves the right edge of gate 1 108 upwards in a direction shown by arrow 1 166.

Finally in FIGURE 14I, the gate 1 1 08 is returned to a position similar to its unopened position (FIGURE 1 1 A) and the gate effectively reseals the container cover 1 100.

Referring now also to FIGURE 14J, once curved portion 1 148 is engaged in camming detent structure 1 124, gate 1 1 08 is permanently held in that open position (i.e., the gate is in toggle mode).

It is possible using the design principles illustrated hereinabove to construct container covers wherein the gate covers substantially 100% (i.e., 90% or more) of the area of the container within or including the chuck walls. Referring now also to FIGURE 15A, there is shown a top plan, schematic view of a cover having a large gate, generally at reference number 1200. Cover 1200 has a central gate 1 204 having a width shown by arrow 1206. Gate 1204 is surrounded by a tri-fold seam 1 210. Tri-fold seam 1210 is surrounded by countersink 121 8 and countersink 1218 is, in turn, surrounded by panel 1216. A peripheral seam, not shown, is formed adjacent and/or including a curl 1208 when cover 1200 is attached to a container body, not shown.

Referring now also to FIGURE 15B, there is shown a partial side elevational, cross-sectional view of the cover 1200 of FIGURE 15A, wherein tri-fold flange seam 1210 is contained within tri-fold flange 1 21 2. An enlarged detail of tri-fold flange 1 212 is shown in FIGURE 15C.

Referring now also to FIGURES 15D, 1 5E, and 15F, there are shown partial side elevational, cross-sectional views of the cover of FIGURE 15A, wherein a tri-fold flange 1212 is contained inside the chuck wall perimeter defined by countersink 1218, and gate 1204 is shown closed, partially open, and fully open, respectively.

Because of the extremely limited space imposed by a "large" gate (e.g., approximately 90% or more), spring design becomes critical. The combination flex- torsion springs for use in these designs have many constraints on their size.

Nonetheless, such springs still need to perform the necessary different reclosure functions.

Referring now also to FIGURE 16A, reference number 1220 generally shows a bottom perspective, schematic view of a design for a combination flex-torsion spring suitable for use with a large gate, self-closing cover.

Combination flex-torsion spring 1220 has a central portion 1222. Central portion 1222 has a rear curved portion 1224 adapted to conform to the curvature of tri-fold flange 1210 and a front flat portion 1226. A throughhole 1228 is placed in front, flat portion 1 226.

A pair of opposing arcuate side arms 1230a, 2130b extends from each edge of central portion 1 222. Each of opposing arcuate side arms 1230a, 1230b has a flattened region 1232a, 1232b, respectively, at the distal ends thereof. Each flattened region 1232a, 1 232b has an elongated through hole 1234a, 1234b, respectively. A pair of toggle tabs 1236a, 1236b extends upward from respective pair of opposing arcuate side arms 1230a, 1230b. Toggle tabs 1236a, 1236b are respectively disposed approximately half way along opposing arcuate side arms 1230a, 1 230b. Referring now also to FIGURE 16B, there is shown a bottom plan view of the cover 1200 of FIGURE 15A with the combination flex-torsion spring 1220 of FIGURE 16A coupled thereto. A fastener or stake, not shown, may be placed in throughhole 1228 and through the gate 1 204. The fastener or stake is used to ensure proper registration of combination flex-torsion spring 1220 during its attachment to cover 1200 during the manufacturing of cover 1200.

Adhesive 1238 proximate each of through holes 1 234a, 1234b is used to fasten flattened tip regions 1232a, 1232b to seaming panel, not specifically identified. Unlike the embodiment shown in FIGURES 15A - 15F using a combination flex-torsion spring (for example, spring 1 1 12 of FIGURES 13A and 13B), in FIGURE 16B there is no space to use a mechanical fastener or stake to attach flattened tip regions 1232a, 1 232b to panel 1210. Consequently, adhesive or similar fastening system must be used to replace fasteners or stakes 1 144 (see Figure 1 1 F). Optional holes 1234a, 1234b allow any excess adhesive 1238 placed under flattened tip regions 1232a, 1232b to escape through the holes 1234a, 1234b. In addition, holes 1234a, 1234b may be used as a port to allow UV curing energy to reach the adhesive. Any suitable adhesive may be utilized in addition to UV-curable adhesives.

In operation, cover 1200 is opened by a directed downward pressure on gate 1204 as shown by arrow 1 140 (see, e.g., Figures 4B-4G), typically applied at or near the center of gate 1204. Upon application of directed downward pressure, frangible seam 1212 ruptures, thereby allowing gate 1204 to rotate downward into an interior region of the container, not specifically identified and forming no part of the invention, to which cover 1200 is attached. Rotation of gate 1 204 must overcome the elastic resistive force provided by flex-torsion spring 1 220. The resilient force of the combination flex-torsion spring 1220 is provided by the flexing of the spring central portion 1222 relative to the opposing arcuate side arms 1230a, 1230b. Upon release of the directed downward pressure, the combination flex-torsion spring 1220 retains sufficient memory to restore gate 1204 to a closed position. Once the frangible seam 1 21 2 has been ruptured, a small amount of force is sufficient to re-open the gate 1204 and access the contents. The pressure of a person's lip, not shown, against the top of the gate 1 204 is sufficient to re-open the gate 1204 thereby allowing a user to drink from the container (as explained above with reference to FIGURE 10K). Upon further application of a directed downward force, gate 1204 may be further rotated downward and toward the central portion 1222 of the combination flex- torsion spring 1220. When the gate has opened through a sufficient angle with respect to panel 1202 (the angle is not specifically identified), the exterior perimeter of the gate, not shown, is pushed past the tips of toggle tabs 1236a, 1236b. Once this is accomplished, the toggle tabs 1236a, 1236b marginally engage the upper peripheral surface of the exterior perimeter of gate 1 204 and provide sufficient resistive force in opposition to the spring memory provided by the flexing of spring central portion 1222. In this position, the gate 1204 is latched open, making it possible to drink from the container or pour the contents out of the container. Subsequent closing of gate 1204 may be accomplished by moving the container in a circular motion such that the interior liquid pushes against the bottom of the gate 1204 and releases the gate 1204 from the marginal engagement of the toggle tabs 1236a, 1236b.

Upon the application of additional force directed downward and toward the spring central portion, the gate 1 204 may be opened beyond the angle required to engage the toggle tabs 1236a, 1 236b, to a position that flexes the spring central portion 1 222 beyond its elastic limit, allowing the container to remain permanently open.

Referring now also to FIGURE 17A, reference number 1250 generally shows a bottom perspective, schematic view of an alternate design for a combination flex-torsion spring suitable for use with a large gate, self-closing cover.

Combination flex-torsion spring 1250 has an elongated central portion 1 252. Central portion 1252 has a rear, curved portion (i.e., flange encircling portion) 1254 adapted to conform to the curvature of tri-fold flange 1210, not shown in FIGURE 7. Spring 1 250 also has a front, tongue-like flat portion 1256. A throughhole 1 258 is placed proximate the tip of front, flat, tongue-like flat portion 1256.

One of a pair of opposing arcuate side arms 1260a, 1260b extends from each side of central portion 1252. Each of opposing arcuate side arms 1260a, 1 260b has a flattened region 1262a, 1262b, respectively, at the distal ends thereof. Each flattened region 1262a, 2162b has an elongated through hole 1264a, 1264b, respectively.

A pair of toggle tabs 1266a, 1266b extends upward from respective ones of the pair of opposing arcuate side arms 1260a, 1 260b. Toggle tabs 1266a, 1266b are respectively disposed approximately half way along opposing arcuate side arms 1260a, 1260b.

Referring now also to FIGURE 17B, there is shown a bottom plan view of the cover 1200 of FIGURE 15A with the combination flex-torsion spring 1250 of FIGURE 17A coupled thereto. A fastener or stake 1270 is placed in throughhole 1258 and through the gate 1204. Fastener or stake 1270 is used to ensure proper registration of combination flex-torsion spring 1 250 during its attachment to cover 1200 during the manufacturing and/or assembly of cover 1200.

Adhesive 1268 proximate each of elongated through holes 1264a, 1264b is used to fasten distal ends 1262a, 1262b to the panel 1202 surrounding gate 1 204.

The operation of cover 1200 with a combination flex-torsion spring 1 250 is almost identical to the operation of cover 1200 equipped with combination flex-torsion spring 1220 described in detail hereinabove. Consequently, the opening of cover 1200 using combination flex-torsion spring 1 250 is not further described herein.

Referring now also to FIGURE 18, reference number 1 300 generally shows novel implementation of combination flex-torsion spring of 1250 of FIGURE 17A.

Combination flex-torsion spring 1300 is implemented by bending a length of spring wire 1320 to fashion all the structural features of combination flex-torsion spring 1250. The equivalent to spring central portion 1252 of spring 1250 is included within the area enclosed by dashed oval 1302.

Flange encircling section 1254 of combination flex-torsion spring 1250 is shown at reference number 1304 and is implemented as curved bends 1304 in spring wire 1320. Flat portion of central portion 1256 of combination flex-torsion spring 1250 is actually space 1 306 between the wire portions, not specifically identified, that connects flattened region that contains hole 1308 corresponding to hole 1258 of combination flex- torsion spring 1250.

Opposing arcuate side arms 1310a, 1 310b are analogous to opposing arcuate side arms 1 260a, 1260b of combination flex-torsion spring 1 250.

Spring wire 1320 may be flattened to form flattened tip regions 1312a, 1312b that correspond to flattened tip regions 1262a, 1262b of combination flex-torsion spring 1250.

Optional elongated holes 1314a, 1314b in flattened portions 1312a, 1312b, respectively, correspond to elongated holes 1264a, 1264b in combination flex-torsion spring 1250.

Finally, structures analogous to toggle tabs 1266a, 1266b are formed at regions 1316a and 1316b in spring wire 1320.

By choosing the spring characteristics of spring wire 1 320, the performance of combination flex-torsion spring 1 300 may match the performance of combination flex- torsion spring 1250, but at a considerable savings in manufacturing cost. In use, combination flex-torsion spring 1 300 provides a direct "drop-in" replacement for combination flex-torsion spring 1 250.

Referring now also to FIGURE 19A, reference number 1330 generally shows a top perspective, schematic view of another implementation of a wide flex spring.

Wide flex spring 1330 has a central portion 1332. A flange accepting section 1334 is disposed rearward of a front tip, not specifically identified, and having a through hole 1 336 therein.

Two slots 1342a, 1342b separate a pair of shortened opposing arms 1338a, 1338b from central portion 1332. A pair of toggle tabs 1340a, 1340b is disposed on the front edges of respective shortened opposing arms 1338a, 1338b.

Referring now also to FIGURE 19B, there is shown a bottom plan, schematic view of a cover 1346 utilizing combination flex-torsion spring 1330.

Hole 1 336 in the tip of central portion 1332 allows central portion 1332 to be attached to a gate 1344 by means of a fastener or stake, not shown, fastened therethrough. In alternate embodiments, an adhesive or other alternate fastening method may replace the fastener or stake to secure central portion 1332 to oval, offset gate 1344.

In operation, combination flex-torsion spring 1330, in conjunction with cover 1346, behaves very much the same as the operation of covers 1200 with either spring 1220 or spring 1250. This operation is described hereinabove and such operational details are not further discussed or described with regard to combination flex-torsion spring 1330 and cover 1346.

Since other modifications and changes varied to fit particular operating requirements and environments will be apparent to those skilled in the art, the invention is not considered limited to the examples chosen for purposes of disclosure, and covers all changes and modifications which do not constitute departures from the true spirit and scope of this invention. Having thus described the invention, what is desired to be protected by Letters

Patent is presented in the subsequently appended claims.

Claims

What is claimed is:

1 . A self-closing cover for a container, comprising: a) an openable gate disposed in said container cover, said gate being surrounded by a frangible seam; b) a panel surrounding said frangible seam; and c) a spring having a first portion affixed to said gate and a section portion affixed to said surrounding panel, whereby, in response to a force applied to an outer surface of said gate, said frangible seam is ruptured thereby freeing said gate from said surrounding panel and moving at least a portion of said gate downward, and upon removal of said externally applied force, said spring returns said gate to its original closed position effectively resealing said container cover.

2. The self-closing cover for a container as recited in claim 1 , wherein said spring is comprised of elastomer.

3. The self-closing cover for a container as recited in claim 1 , wherein said spring is comprised of a combination flex and torsion spring.

4. The self-closing cover for a container as recited in claim 1 , wherein said container cover is configured to receive an externally applied downward force proximate a central portion of said gate.

5. The self-closing cover for a container as recited in claim 2, wherein said elastomer spring is disposed in one the configurations selected from the group: an external top button configuration, an internal configuration, an external configuration, within an interior chuck wall, and within an exterior chuck wall.

6. The self-closing cover for a container as recited in claim 2, wherein said gate has a geometric center, said geometric center being disposed in one of the locations selected from the group: coincident with a center of said container cover and non- coincident with a center of said container cover.

7. The self-closing cover for a container as recited in claim 2, wherein said elastomer spring is disposed in one of the locations selected from the following group: on an external surface of said container cover and on an internal surface of said container cover.

8. The self-closing cover for a container as recited in claim 2, wherein said elastomer spring is formed and cured in one of the locations selected from the group: in situ, and external to said cover.

9. The self-closing cover for a container as recited in claim 3, wherein said combination flex and torsion spring comprises: a) a central portion having a pair of opposing side edges, a front edge, a rear edge, and a means for fastening said central portion to a surface of said cover; b) a pair of elongated, arcuate arms, each having a proximal end and a region adjacent a distal end thereof; a first said pair of elongated, arcuate arms being attached to a first said pair of opposing side edges and extending outwardly therefrom; a second of said pair of elongated, arcuate arms being attached to a second of said pair of opposing side edges and extending outwardly therefrom; and c) a camming structure operatively connected to said central portion proximate said front edge of said central portion.

10. The self-closing cover for a container as recited in claim 4, wherein said container cover is configured to receive said externally applied downward force delivered by a heel of a person's hand.

1 1 . The self-closing cover for a container as recited in claim 9, wherein the combination flex and torsion spring comprises a pair of detent tabs operatively attached to the respective pair of arcuate elongated arms such that a first pair of said detents is attached to the first pair of arcuate elongated arms and a second of said pair of detent tabs is attached to the second pair of arcuate elongated arms.

12. The self-closing cover for a container as recited in claim 9, wherein the central portion of said combination flex and torsion spring further comprises an elongated, tongue-like forward projecting flex spring portion extending from said front edge of said central portion.

13. The self-closing cover for a container as recited in claim 9, wherein said combination flex and torsion spring is formed from a thin piece of aluminum.

14. The self-closing cover for a container as recited in claim 1 1 , wherein the combination flex and torsion spring's camming structure comprises a portion sized and configured to capture and retain a portion of at least one of said pair of detent tabs when a gate of a container cover to which said combination flex and torsion spring is attached is opened and moved to a predetermined position.

15. The self-closing cover for a container as recited in claim 1 2, wherein said elongated, tongue-like forward projecting flex spring portion comprises a distal end having a throughhole therethrough.

16. The self-closing cover for a container as recited in claim 1 2, wherein the combination flex and torsion spring further comprises: a) at least one through hole in at least one of the locations selected from the group: said distal region of said first pair of elongated arcuate arms; said distal region of said second of said pair of elongated, arcuate arms; a distal end of said forward facing flex spring portion; and said central region; and b) means for fastening at least one portion of the combination flex and torsion spring at which a through hole is located to a portion of the container cover.

17. The self-closing cover for a container as recited in claim 1 3, wherein said thin piece of aluminum comprises one of the forms selected from the group: an aluminum sheet and an aluminum spring wire.

18. The self-closing cover for a container as recited in claim 1 3, wherein said thin piece of aluminum comprises a 5052-H 10 aluminum alloy.

19. The self-closing cover for a container as recited in claim 1 3, wherein said piece of aluminum has a thickness in the range of approximately 0.006 inches to 0.007 inches.

20. The self-closing cover for a container as recited in claim 1 6, wherein said means for fastening comprises at least one selected from the following group: a fastener, a stake, and an adhesive.