US2878346A - Flush key electrical switch - Google Patents

Description

March 17, 1959 K. E. ANDREWs ET AL FLUSH KEY ELECTRICAL SWITCH Filed Oct 22'. 1956 '2 Sheets-Sheet l |3 45 INVENTORS 36 KENNETH E. ANDREWS JOHN E. DAVIS Agent March 17, 1 959 K. E. ANDREWS ET AL 2,

FLUSH KEY ELECTRICAL SWITCH Filed Oct. 22, 1956 2 Sheets-Sheet 2 as so F- L J A \jm l A v 683 I 1 INVENTOJS vGD KENNETH E. ANDREWS JOHN E. DAVIS A ent United States Patent FLUSH KEY ELECTRICAL SWITCH Kenneth E. Andrews, Sunland, and John E. Davis, Sherman Oaks, Calif., assignors to Lockheed Aircraft Corporati0n, Bnrbank, Calif.

Application October 22, 1956, Serial No. 617,392

9 Claims. (Cl. 200-167) This invention relates to electrical switches and more particularly to improvements in manually operated snap switches having positive contact action, adaptable for internal illumination and susceptible to be edge-lighted.

In the past it has been difiicult to provide a universal switch which may be internally illuminated, edge illuminated and also have positive contact action. Some conventional types of switches known as toggle switches having a spring loaded toggle arm for operating the switch mechanism purport to include these desirable features but inherent difiiculties have prevented widespread use in many applications. For example, in confined quarters such as an aircraft cockpit, it has been found that passenger or crew member clothing easily catches the protruding toggle arm and may inadvertently cause switch actuation. Also, serious physical damage has been encountered by passengers or crew members hitting or bumping the protruding toggle arm which sometimes proves fatal. Attempts have been made to modify the toggle switch by replacing the toggle arm with a substantially flush panel operating means for closing the switch contacts. However, these attempts have not included means for illuminating the switch, either internally or by edge-lighting, whereby switch actuation is more noticeable or these attempts have not included means for adapting conventional protruding toggle arm switches for actuation by a substantially flush panel operating means.

novel means for illuminating a portion of the operating means which is flush with the supporting panel and which derives its source of light via the panel while maintaining its opposite portion of the operating means darkened.

It is a further object of the present invention to provide illuminating means associated with the operating means i which illuminates the depressed portion of the operating These difiiculties are obviated in the present invention which provides a pivotal substantially flush panel operating means composed of light-transmitting material for operatoing the switch mechanism. In one form of the invention, illuminating means are provided so that depression of one portion of the operating means causes that portion of the operating means to become illuminated while the opposite portion of the operating means remains darkened. Another form of the invention provides a similar operating means mounted in such a fashion so as to convert the depression of the operating means into pivotal action for operating the toggle arm of a conventional toggle switch.

It should be noted that in all forms of the present invention, the operating means is susceptible of edge-lighting since the depressed portion of the operating means remains flush with the supporting panel and may transmit light generated by lamps through the panel.

An object of the present invention is to provide a novel switch which because of its shape, mounting, and position need not extend far beyond the surfaceof a casing or panel for operation. Therefore, .it is less susceptible to being broken or damaged by forcible inadverent actuation by some other object and is less susceptible to injuring personnel in its proximity.

Another object of the present invention is to provide a positive stop arrangement for the switch operating means located directly beneath and in line with the point of application of force and direction of the force so that all strain on the switch mechanism is avoided.

:"Anotherobje'ct of the present invention is to provide a means and provides additional means for preventing the illumination of its opposite portion.

Still a further object of the present invention is to provide means for isolating the switch mechanism from environment conditions such as the presence of moisture, foreign objects, gases, etc. which may surround the switch and which would cause switch activation of conventional switches.

These objects and advantages, and others hereinafter referred to, are obtained by providing the operating means in the form of a pivoted member approximately Y-shaped having a pair of arms and having its pivot point located in the center of the Y, and having the stem of the Y protruding through an opening in a casing engageable with a teeter bar adapted to alternately teeter from one position of rest to another in response to force placed on either arm of the Y-shaped member. The teeter bar is provided with opposing electrical contacts which complete electrical circuits in either position of rest of the teeter bar.

In the accompanying drawings:

Figure l is a perspective view of an electrical switch in accordance with the present invention;

Figure 2 is a sectional view showing the switch of Figure 1 having internally illuminating means;

Figure 3 is a sectional view showing another embodiment of the present invention wherein the operating means is employed to cooperate with a conventional protruding toggle arm of a toggle switch; and

Figure 4 is a sectional view taken in the direction of arrows 4-4 showing a mounting arrangement for the conventional toggle switches and operating means adaptor as shown in Figure 3.

The switch shown in the accompanying drawings, for the purpose of illustartion, is of the flush panel type. In reference to Figure l, a panel 10 is provided having an aperture 11 to receive an electrical switch 12. Switch 12 is carried by a mounting bracket 13 attached to panel 10 by means of a pair of screw and nut arrangements 14. The mounting bracket 13 is provided with a pair of opposing arcuate sections 15 contoured around the switch and a rectangular section 16 joining the pair of arcuate sections. Each arcuate section is provided with a stiffening bead such as bead 17 which strengthens the bracket and resists excessive sideloads from displacing the switch from aperture 11 in the panel.

As shown in Figure 2, electrical switch 12 comprises a base 18 carried within a casing 20 which, in turn, is mounted on the mounting bracket 13 and attached thereto by means of a snap arrangement 21 carried on both sides of casing 20. Base 18 may be composed of suitable insulation material such as rubber for example and serves to hold a plurality of stationary contacts to be described later. The casing substantially follows the contour of mounting bracket 13 by having an arcuate portion 22 supported by a base section 23 which forms a hollow or opening into which a switch operating means projects and in which suitable elements of the switch mechanism may be placed. The top of the casing is provided with angular surfaces 24 and 25 forming an apex A; the surfaces slanting towards the opposing sides of arcuate portion 22.

The operating means may be said to comprise a pivoted member 26 which is substantially Y-shaped, having a pair of arms 27 and 28 attached to a stem 29. Member 26 has its fulcrum located in the center of the Y at the 3 approximate juncture of arms 27 and 28 integral with stem 29. A rod 30 extends from one side of casing to its opposite side and passes through an opening in stem 29 of member 26 at the apex A of the casing. The apex A of the casing thus provides a fulcrum on which member 26 can rock, limited in either direction by the engagement of member 26 with the angular surfaces 24 and 25 of the casing. The stem of member 29 is partiallyhollowed out at 32 in order to accomodate a slidable nub 31 and spring 33 which urges the nub away from the stem.

One of the plurality of electrical contacts of the switch mechanism, such as contact 34, may be considered to be common to other contacts such as contacts and 36 so that the negative side of an electrical circuit (not shown) may be attached to contact 34 while the positive side of the electrical circuit may be connected to contacts 35 and 36 respectively. Contacts 35 and 36 are attached to base 18 by rivets 3'7 and 38 respectively, these latter rivets serving to communicate externally disposed contaets 35 and 36 with the interior of casing 20. Contact 34 is connected to a fulcrum element 39 by means of a rivet 41 which secures element 39 and contact 34 to base 18.

The urging of nub 31 away from stem 29 is resisted by its engagement with a teetering bar 42 adapted to alternately teeter on bar carried by the fulcrum element 39, moving from one position of rest to anotherin response to the pivoting of member 26. The teetering bar is provided with electrical contacts 44 and 45 which complete electrical circuits via contact 34 when either of the teetering bar contacts engages contacts 35 or 36. The teetering bar is provided with a pair of depressions or rounded portions 46 and 47 located on opposite sides of bar 40. These rounded portions are adapted to receive nub 31 alternately as the teetering bar pivots on the fulcrum element rod 40 in response to the outward urging of the nub as the latter travels over the teetering bar.

In order to isolate the switch mechanism from environmental conditions surrounding the switch such as moisture, foreign objects, gases etc., a skirt 48 is attached to the periphery of arms 27 and 28 of member 26 in such a fashion that the skirt interposes between the outside of casing 20 and the inside of arcuate sections 15 associated with the mounting bracket. Construction in this manner allows member 26 to be pivoted with the assurance that skirt 48 will follow the movement from the lower portion of the arcuate portion 22 to the top portion thereof without exposing the interior of the casing containing the switch mechanism to the environment conditions. To insure the sealing of the casing interior, a resilient seal 49 of rubber or felt may be carried by the casing on the outer surface of its arcuate portion 22 to engage with the inside surface of skirt 48.

In order to illuminate the switch to visually represent which electrical circuit is closed with reference to the contacts 44 and 45 carried by the teetering bar, a pair of lamps 50 are provided withinthe hollow of the casing. The lamps are alternately illuminated when either arm 27 or 28 is depressed. Each lamp comprises a bulb 51 and a base 52 slidably mounted in a tubular socket 53 carried by base 18. The sockets 53 are oppositely disposed within the casing and are secured to thebase by a contact 54 attached to positive electrical contacts 35 and 36 respectively. Each socket 53 is suitably electrically isolated from negative terminal contact 34 by an extension or barrier 55 integral with base 18 so that internal arcing between electrical contacts of the switch mechanism will not occur. Each lamp of the pair of lamps St) is yieldingly supported in the unenergized position bya resilient member such as a helical spring 56 interposing between the base 52 of each lamp and socket 53. A lamp contact 57 associated with the base of each lamp completes an electrical circuit when engaged with contact 54.

A leaf spring 58 coiled around rod 30 "is provider! to engage the top of bulb 51 and maintains a slight pressure thereon against thecompression of springs 56 so that the lamps will not leave their respective sockets regardless of the position of the switch. Construction in this manner insures proper alignment of the lamps in their respective sockets. Upon depression of either arm 27 or 28, the depressed arm will engage the top of the bulb and urge the lamp 50 downward through its socket 53 so that contact 57 engages either positive contact 54.

With reference to Figures 3 and 4, another embodiment of the present invention is shown which comprises an operating means 60 employed with the elements of a conventional toggle switch having a casing 61 housing the switch mechanism (similar to the mechanism employed in Figure 2) and a toggle arm 62 for activating the switch mechanism; the toggle arm causing the completion or breaking of electrical circuits connected to positive terminals 63 and 64 with a common negative terminal 65.

The operating means 60 may be said to comprise a pivoted member 66 having a pair of arms 67 and 68 and an aperture 70 located on the bottom side of the operating means. Member 66 has its pivot point located substantially in the center of the member at the juncture of arms 67 and 68 whereby the member may freely pivot within an aperture 71 provided in a panel 72. The surface of member 66 forming aperture 70 is provided with a leaf spring 73 adaptable to provide tension on toggle 1 arm 62 which is received into aperture 70. The tension of spring 73 maintains the firm but movable engagement between the toggle arm and member 66. Spring 73 is provided with a pair of flanges 74 extending exteriorly of aperture 70 on opposing sides of member 66 to engage a pivot rod 75.

The pair of arms 67 and 68 in combination with toggle arm 62 present substantially a Y-shaped configuration wherein pivoting of member 66 causes toggle arm 62' to position the switch mechanism to one .of alternative rest positions. As shown more clearly in Figure 4, pivot rod 75 is rotatably mounted between parallel sides 76 and 77 of a bracket 78. Bracket 78 is supported by the panel by a pair of L-shaped members 79 secured to the panel by means of fasteners 80. Nut and screw arrange ments 81 secure the bracket to the L-shaped member. A base 82 of bracket 78 carries the conventional toggle switch which is attached to the bracket by a pair of nuts 83 threadably engaged with the top of casing 61. A pair of exposed areas 84 associated with opposing sides of member 66 are provided to receive sides 76 and 77 of bracket 78 so that the operating means appears to be flush with the edge of the panel or additional adjacent operating means.

Rotation of operating means 60 by placing a depressing force on either arm 67 or 68 causes the toggle arm 62- electric light source (not shown) remotely located .on

the panel from the operating means. The panels and operating means, in either embodiment, are preferably composed of a light transmitting substance such as plastic ortranslucent acrylic which passes light rays in the direction of arrows 86 in Figure 2 and arrows 87 in Figure 3. These light rays are transmitted to arm 27 of the light transmitting operating means which is substantially flush with the panel surface as shown in Figure 2 or to both arms 67 and 68 of the operating means as shown in Figure 3. To insure that only a desirable portion of the operating means is illuminated, black paint may be used to provide a light absorbing surface 88 to prevent light rays from illuminating the undesirable portion of the operating means.

It is understood that the mounting brackets and panel's may be arranged to accommodate more than-one switch and that additional switches may be mounted adjacent to one another. Indicia may be inscribed on the operating means or panels of either embodiment which are set out more clearly by the illuminated background of operating means and panel.

Having described only typical forms of the invention we do not wish to be limited to the specific detailsherein set forth, but wish to reserve to ourselves any variations or modifications that may appear to those skilled in the art and fall within the scope of the following claims.

We claim:

1. Ina snap switch for mounting through an aperture provided in a panel, the improvement comprising, a bracket secured to the panel about the aperture, a casing mounted on the bracket having a hollow portion,; operating means pivotally carried by the casing, a skirt secured about the periphery of the operating means interposing between the bracket and casing, switch mechanism carried by the casing in the hollow portion thereof and movable to alternatively switch from one position of rest to another; the operating means comprising, a pair of arms occupying the aperture and a stem integrally formed with the arms and protruding a substantial distance into the casing to move the switch mechanism in response to force placed on either arm, spring tension means telescopingly carried by the stem to forcibly engage the switch mechanism, each arm of the pair representing one rest position of the switch mechanism when each arm is substantially flush with the panel, and means limiting the pivotal action of the operating means deter-, mined by the engagement of the skirt with the casing.

2. An illuminating manually operated switch for arrangement through an aperture provided in a panel of light transmitting material comprising, a casing associated with the panel, a fulcrum assembly nested in the casing, switch mechanism carried internally of the casing having a plurality of electrical contacts movable to alternative rest positions about the fulcrum assembly, li ht transmitting operating means occupying the aperture of the panel in close proximity to the panel and pivotally disposed in relation thereto to move the plurality of contacts from one position of rest to their alternative position of rest, a pair of illuminating means resiliently mounted in the casing separated by the switch mechanism for illuminating alternative portions of the operating means representing the rest positions of the electrical contacts, and spring retention means pivotally supported on the casing and engageable with the pair of illuminating means for retaining the illuminating means within the casing acting against the resiliency of the mounting.

3. An illuminating manually operated switch for arrangement through an aperture provided in a panel of light transmitting material comprising, a casing secured to the panel, a fulcrum assembly nested in the casing, switch mechanism carried interiorly of the casing having a plurality of electrical contacts movable to alternative rest positions about the fulcrum assembly; operating means of light transparent material including a pair of arms, each arm associated with alternative rest positions of the plurality of contacts; each arm of the pair representing one rest position of the plurality of contacts when the arm is substantially flush with the panel in close proximity to the panel, means resiliently mounted in the casing in sockets separated by the switch mechanism illuminating each arm of the pair when each arm is substantially flush with the panel, an electrical barrier surrounding the switch mechanism and electrically isolating the mechanism from the illuminating means, and spring retention means pivotally supported on the casing and engageable with the pair of illuminating means for retaining the illuminating means within the casing acting against the resiliency of the mounting.

4. An illuminating manually operated switch adaptable for mounting on a panel of light transmitting material comprising, a casing carried by the panel, operating means of light transmitting material carried by the casing and having a pair of arms being alternately arranged in a substantially flush condition with the panel, in close proximity thereto a fulcrum assembly nested in the easing, switch mechanism carried interiorly of the casing responsive to the pivotal movement of the operating means to teeter about the fulcrum assembly, means carried about the periphery of the operating means and engageable with the casing for limiting the pivotal movement ofthe operating means, and means for illuminating the operating means via the panel whereby the arm of the operating means substantially flush with the panel is illuminated.

5. An illuminating manually operated switch comprising, a casing having a hollow formed the-rein, a substantially Y-shaped member having a pair of arms extending outwardly from a stem integrally formed therein, the Y-shaped member being of light transmitting material and pivotally associated with the casing at an area substantially common to the pair of arms and stem, a fulcrum assembly nested in the hollow of the casing, switching mechanism carried by the casing in the hollow provided therein operably to teeter about the fulcrum assembly, means resiliently and telescopingly associated with the stem for positioning the switching mechanism to alternative rest positions in response to the pivoting movement of the Y-shaped member, illuminating means separated by the switching mechanism for alternately illuminating each arm of the pair, socket mountings carried within the hollow of the casing for holding the illuminating means, a leaf spring pivotally carried on the casing for retaining the illuminating means within the mountings, and one arm of the pair being alternately illuminated when substantially flush with the panel in response to pivotal movement of the Y-shaped member.

6. An illuminating manually operated switch forarrangement through an aperture provided in a panel comprising, a bracket secured to the panel about the aperture, a casing mounted on the bracket having a hollow portion, operating means of light transmitting material pivotally carried by the casing, a fulcrum assembly nested in the hollow of the casing, switch mechanism carried by the casing in the hollow portion thereof and movable to alternatively switch from one position of rest to another position about the fulcrum assembly, a pair of illuminating means separated by the switch mechanism and being alternately operated; the operating means comprising, a skirt attached about its periphery interposed between the bracket and easing, a pair of arms occupying the aperture and a stem protruding a substantial distance into the casing to move the switch mechanism in response to force placed on either arm, each arm of the pair representing one rest position of the switch mechanism when the arm is substantially flush with the panel and illuminated by one of the pair of illuminating means; and means limiting the pivotal action of the operating means determined by the engagement of the skirt of the operating means with the casing.

7. An illuminating manually operated switch for arrangement through an aperture provided in a panel of light transmitting material comprising a casing carried by the panel; switch mechanism in the casing including a teeter member movable between a first position and a second position and electrical contacts controlled by the movement of the member to the first and second positions; an operating means of solid light transmitting material supported in the aperture for pivotal movement comprising, a pair of arms and a stem extending a substantial distance into the casing and operatively associated with the teeter member to move the latter alternately to the first and second positions; a light source carried on the panel for lighting at least one arm of the pair via the panel when the arm is substantially flush with the panel, and light absorbing means carried by one arm of the pair protruding beyond the panel to prevent the'transmissionof light from the panel.

8. An illuminating manually operated switch comprising, a casing having a hollow provided therein, a fulcrum assembly nested in the casing hollow, a switch mechanism carried in the casing hollow having electrical contacts movable to alternative rest positions about the fulcrum assembly, light transmitting operating means pivotally mounted on the casing to move the electrical contacts from one position of rest to their alternative position of rest, and illuminating means located on either side of the switch mechanism and fulcrum assembly and operable by the operating means for alternate illumination representing the rest positions of the contacts, resilient mountings carrying the illuminating means on the casing, and a spring mechanism pivotally carried on the casing engageable with the illuminating means for retaining the illuminating means on their resilient mountlngs.

9. An illuminating manually operated switch comprising, a casing having a hollow provided therein, a fulcrum assembly nested in the hollow of the casing, a switch mechanism including a teeter member supported on the fulcrum assembly and electrical contacts on the teeter; member movable to alternate rest positions about thef fulcrum assembly, a pair of sockets carried on the cas- I ing and separated 'by the switch mechanism, light trans- 1 mitting operating means pivotally mounted on the casing tomove the electrical contacts from one positionof rest to their alternative position of rest, illuminating means movably carried in each socket being operable by the" operating means for alternate illumination representing? the rest positions of the contacts, and spring means pivot'-' ally supported on the casing for retaining the illuminating means within their sockets regardless ofthe position of the operating means.

References Cited in the file of this" patent UNITED STATES PATENTS" I 1,969,263 Gaynor Aug. '7', 1934 2,095,174 Douglas ,Oct. 5=, 1937: 2,377,134 Dietrich May 29, 1945* 2,430,189 Schellman Nov. 4, 1947:

2,749,415 Davis June 5, 1956

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