US3523471A - Precision torque release and part marking wrench - Google Patents

Description

Aug. ll, 1970 I c. J. LANCE 3.523,471

PRECISION rvPORQUE! RELEASE AND PART MARKING WRENCH Filed Nov. 8, 1967 2 Sheets-Sheet l CHRlSTOPHER JAMES LANCE ATTORNEY S c. J. LANCE Aug. 11, 15W() A PRCISION 'PORQUE RELEASE AND PART MARKING 'WRENCH Filed Nov. 8, 1967 2 Sheets-Sheet 2 l NVENTOR CHRISTOPHER JAMES LANCE bm mm www mm ATTORNEYS United States Patent O 3,523,471 PRECISION TORQUE RELEASE AND PART MARKING WRENCH Christopher James Lance, Royal Oak, Mich., assigner of fifty percent to Ivan F. Belknap, Den-oit, Mich. Filed Nov. 8, 1967, Ser. No. 681,423

ABSTRACT OF THE DISCLOSURE A high precision-type torque release or torque limiting wrench is disclosed which has extremely simple provisions to mark a threaded part which is tightened by the wrench at the instant that the exact intended maximum torque has been applied to the part, and precisely simultaneously with the cessation of application of torque to the part.

As a wrench, per se and without reference to its uniquely associated marking means, the tool shown herein is of a generally conventional type. However, its builtin marking structure is, pursuant to the improvement, directly associated with an operated by a pivotal torque applying arm of the wrench, which arm conventionally carries a torque-applying head engageable through a socket-type chuck or like sort of driver with the threaded part to be taken up.

The marking means may be of a pneumatically actuated type, in which power to effect an instantaneous marking of the part, at a desired torque break limit designed into the wrench, derives through an appropriate valve connected between an air pressure source and a plunger unit which applied the mark. Equivalent iluid pressure drivers are contemplated.

In the alternative, the control may be an electric solenoid type, including a suitable switch through which a solenoid coil is energized at the instant the critical break torque is reached, thereby operating, in the manner of an armature, a plunger type device of one sort or another which applies the mark. Other alternative controls are contemplated which are equivalent to the pneumatic and electrical versions.

In any of the possible alternative forms, it is of the essence of the invention that the control provisions, fluid pressure, electrical or mechanical, be in turn responsive directly to the shift of a torque applying arm (or other member constituting a part of the wrench and movable at the instant the intended torque break limit is reached), with a corresponding instantaneous and direct application of motivating power to the marking component of the wrench.

BACKGROUND OF THE INVENTION Field of the invention The wrench finds application in many settings, as in automotive, aircraft and related production lines, mass production or otherwise, in which a very important consideration is than an identically equal maximum designed torque be applied to each of a number of threaded fasteners (bolts, nuts, screws and the like) of any given assembly or a number thereof in course of handling. The desire and intent is that there shall be no perceptible variations at all in the torque to which the fastener part is finally taken up. It follows that possibly unequal localized and dangerous stressing of secured and securing parts is safely avoided.

More particularly, in the use of torque limiting wrenches in mass production or assembly it is highly desirable that an inspector, without making individual manual wrench-check-ups of each of a possibly large number of CTI Mice

Description of the prior art The patents to R. G. Woods No. 2,274,638 of May 1,

1956, No. 2,897,704 of Aug. 4, 1959 and No. 3,016,773 of Ian. 16, 1962, all show torque limiting or release wrenches of the general type involved in the present tool, but llacking marking means of any sort such as is an important factor in the combination which is herein shown and claimed.

The patent to Hines et al. No. 3,009,371 of Nov. 21, 1961, deals with part marking means incorporated in a torque release wrench, but these provisions are of a highly complex and expensive nature, as compared with the simplicity, compactness and low production cost of the direct action marker means of the invention, all coupled with precision of response to de-torsioning.

SUMMARY yOF THE INVENTION The invention resides in a combined torque limiting and part marking wrench which is basically constituted by a very few, extremely simple yet reliable operating components. These, in the general manner of Woods 2,743,638 and 3,016,773, identified above, comprise an elongated tubular handle having a torque transmitting arm pivotally mounted therein, with a torque applying head rigidly connected to an outer end of the arm; a plunger slidably mounted within the handle adjacent an opposite end of the latter and biased toward the torque arm by adjustable spring means; and a simple pivot dcvice operatively interconnecting the plunger with the adjacent end of the arm. Typically, this is clfectuated in such manner that the torque arm shifts when the value of the torque exerted on a threaded part (representing a load) engaged by the -wrench head reaches a value sufficient to overcome the plunger-applied spring force acting through the pivot device on the torque applying arm. The line of torque transmission to the head breaks, signaling to the operator that the desired maximum torque has been reached and further elort should end.

Directly associated with this type of wrench, as at its tubular handle and at its torque applying head, the invention contemplates a unit by which a mark of one sort or another is applied to the threaded part exactly simultaneously with the interruption of torque transmission. This unit includes a member directly engaged and operated by the shifted torque arm, or some other member shiftable in the Wrench, rather than in response to an involved and expensive operating line of parts. The unit may include a valve controlling the application of uidpressure operating force to a marker-carrying plunger, or the control may comprise a simple electrical onoff switch similarly actuated by the torque transmitting arm or equivalent member of the tool and governing the drive of the marker, as through a solenoid.

The nature of the marker and the particular mark applied to the part may of course also vary. Thus, the marker may be a plunger driven punch acting to locally deform and permanently identify the part visually as being acceptable. Alternatively, the marker may be a ballpoint and cartridge type of paint or ink applicator.

In the case of an electrically acting actuator unit, it may be powered from an appropriate line source, usually through transformer means, or by any of a number of available types of battery sources. A strictly mechanical line of direct action from the wrench to its marker is also contemplated.

BRIEF` DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan view, partially broken away and in longitudinal horizontal, and in the main axial, crosssection, illustrating an embodiment of the wrench of the invention in which the intended mark is applied to the tightened bolt or like part through the agency of valvecontrolled pneumatic or other uid pressure powered means, this embodiment being one in which the part is permanently marked by deformation;

FIG. 2 is a fragmentary view of the wrench of FIG. l in side elevation, being partially broken away andin vertical section on line 2 2 of FIG. 1;

FIG. 3 is a fragmentary side elevation of a modified adaptation of the -wrench of FIGS. l and 2, in which the mark is applied by a ballpoint pen type of cartridge unit, this embodiment also optionally incorporating a horizontally acting actuator unit for the marker which may, as in the wrench of FIGS. 1 and 2, be tiuid pressure-powered: however, electrical solenoid operation is also contemplated;

FIG. 4 is a top plan view, partially broken away and in horizontal section, as in FIG. 1, illustrating a further modified embodiment employing an electrically powered and controlled solenoid type of marking unit, plus additional electrical connections to a recording device (if this be deemed desirable), this wrench being further equipped to handle both right and left hand threaded parts;

FIG. 5 is a fragmentary view in vertical cross-section on broken line 5-5 of FIG. 4;

FIG. 6 is a fragmentary schematic view in side elevation and somewhat lesser scale of a wrench similar to that of FIGS. 4 and 5, partially broken away and in vertical cross-section but utilizing a paint or ink cartridge unit as the marker; and v FIG. 7 is a more or less schematic top plan view of a still further modified wrench embodying battery means as the source of marking power.

DESCRIPTION OF PREFERRED EMBODIMENTS Reference being had to FIGS. 1 and 2, the embodiment 10 of the precision torque release and marking wrench shown therein is generally similar in its torque limiting aspect to the -wrench of Woods 2,743,638: this is true both in regard to its main structural features and the operation thereof in taking up a threaded part, such as the bolt B appearing FIG. 2 hereof. Accordingly, these features and their operation need but brief description.

Wrench 10 comprises an elongated tubular, housinglike operating handle 12 of cylindrical cross-section which slidably receives a cylindrical plunger 14. A coil compression spring 15 acts against plunger 14 to oppose movement of the latter to the left, as viewed in FIG. 1. Spring 15 is backed by an abutment disk 16, which is in turn sustained rearwardly by an adjustable screw 17 threaded axially in an end portion 18 of handle 12.

A11 elongated torque transmitting arm 20 is pivotally mounted on a transverse axis within handle 12, as by a pin 21 adjacent the forward or right-hand end of the latter, as viewed in FIG. 1; and a small floating type pivot member 22 is disposed between the left-hand end of arm and the right-hand end of the spring-sustained torque plunger 14. The pivot 22 acts sensitively in the fashion described in Woods 2,743,638 when arm 20 shifts pivotally under a critical break torque of a maximum designed value, the member 22 rocking laterally and causing plunger 14 to yield to the left and arm 20 to swing laterally. This is of course accompanied by the break of the line of torque transmission to bolt B, in the usual manner.

Specific structural aspects of the pivot 22 constitute no part of the present invention, and the use of any equivalent type of responsive coupling or coupling member is contemplated. Furthermore, the arrangement may be such as to permit the drive of bolt B only in response to clockwise swing of the lwrench, as viewed in FIG. l, or it may be such as to respond to both clockwise and counter-clockwise swing of handle 12, as illustrated and described in the last-mentioned patent. This is the case in the embodiment of FIGS. 4 and 5 hereof wherein the part B may be marked regardless of the direction of its threading.

Torque transmitting arm 20' carries, externally of tubular handle 12 and to the right (FIG. 1) of its pivotal axis at pin 21, the usual torsion head, generally designated 24. This head will usually be of a pawl and ratchet type familiar to` the industry. A pneumatic cylinder unit, generally designated by the reference numeral 26, is applied to head 24, being serviced by a control valve unit 28 operatively connected thereto and mounted on the tubular handle of wrench 10.

The wrench is shown as operating a tubular socket 29 mated over the hex-head of bolt B, this socket having a square axial opening 30 at its top upwardly mating a male formation 31 of the same cross-section which is integral with the bottom of a generally T-sectioned operator '32. This operator is pawl and ratchet-engaged, in a known manner and by means not shown, by the torque head 24 of wrench 10, with an appropriate bottom washer 33 fixed on head 24 sustaining operator 32 from beneath. The latter is cylindrical at its main body portion where torque is received, being conventionally received in a cylindrical counterbore 34 of head 24. Thus, indexing movement of handle 12 in a clockwise direction (FIG. 1) transmits clockwise torque through operator 32 and socket 29 to bolt B. As indicated above, head 24 may posses known refinements, for example as are shown in Woods 2,897,704, to transmit the torque both clockwise and counterclockwise. These features constitute no part of the present invention.

The pneumatic cylinder unit 26 includes a radially outwardly flanged base member or plate 36 (FIG. 2) having a cylindrical, reduced diameter bottom extension 37 which pilots in a cylindrical top recess or counterbore 37 in operator 32. Screws 3-8 secure the base 36 of unit 26 to head 24, said unit indexing with the head in the ratcheting action of the wrench. An upright pressure cylinder 39 is seated in a top recess in base member 36, the cylinder being capped by a top plate 40 into which the upper end of the cylinder is recessed; `and the three cylinder and plate parts 36, 39 and 40y are rigidly held in assembly by vertically elongated studs 41.

Cylinder 39 receives a cylindrical plunger head 42 on the top of an elongated rod 43 which is slidably received in aligned bores 44 and -45 of the cylinder base 36 and the operator 32, respectively; and a coil compression spring 46 is disposed between plunger head 42 and base member 36.

Downwardly of the operator extension 31, and normally within the confine of the torque-applying socket 29, the plunger rod 43 is equipped, in the embodiment of FIGS. 1 and 2, with a suitable punch `47 having a part-indenting tip 48 at its bottom, the action of which is, upon pressurization of the cylinder 39', to provide a permanent visual indicium that the bolt B, or other part operated upon, has been taken up to an exact desired extent. The punch 47 of the embodiment of FIGS. l and 2 may, if desired, be replaced by some other type of marker leaving a less permanent signal.

As illustrated in FIGS. 1 and 2, cylinder unit 26= is pneumatically pressurized at the instant of reaching the break value of torque, with resultant swing of wrench arm 20, through a flexible pressure line or tube 50, which is attached to unit 26 by means of a suitable fitting 51 threaded in an opening in cylinder plate 40. The tube 50* is similarly connected through an L-tting 52 toan opening in the side of a housing 53 of the valve unit 28; the housing being suitably mounted directly to the side of the tubular wrench handle 12, as by means of a threaded iitting 54 (FIG. 1) received in an opening in the handle at a substantial distance rearwardly, or to the left, of the pin 21 pivoting arm 20` to the handle.

Valve 28 is a simple On-Ot`r' type, being equipped with a llexible pressure tube or line I55 connecting it to a source of pneumatic pressure (not shown); and an operating element or button 56 of valve unit 28 is exposed within the tubular handle at a point relatively closely adjacent the torque arm 20 in a neutral, non-shifted position of that arm.

The operation of the kwrench embodiment is believed evident from the foregoing description. Upon the torque reaching the break value when the wrench is manipulated clockwise as viewed in FIG. 1, arm 20 swings instantaneously counterclockwise about its pivotal axis 21, interrupting the line of torque transmission to socket 29 and simultaneously depressing the operating button -56 of valve 28. The latter instantaneously pres surizes tube 50 and cylinder unit 26 from the pressure source, with the result that the punch 47 (or equivalent marking device on plunger rod 43) is driven in opposition to spring 46 to place the desired mark on the part B.

FIG. 3 illustrates a modi-lied embodiment of the principle of the invention, the marker of which may be considered to be a pneumatically operated one, although hydraulic, electrical or mechanical control are also contemplated. Here a cylinder unit 58 is appropriately mounted upon the top of the handle 12 of the wrench, which is generally designated 'by the reference` numeral 60; and an elongated operating stem 61 projects axially and horizontally from the end of the cylinder 58. Upon pressurization or equivalent powering of the latter, stem 61 is driven to the right, as viewed in FIG. 3, which action may be in opposition to suitable internal spring means of the cylinder, as in the embodiment of FIGS. 1 and 2.

The torque applying head 24 of tool 60 slidably receives (in the manner of the arrangement of FIG. 2) a vertically elongated plunger rod 62, which rod terminates above the head 24 in an enlarged tappet 63. Rod 62 should be urged upwardly to a predeterminedly limited elevation, as by spring means 64, and when the operating stem 61 is driven to the right (FIG. 3) it engages the top of tappet 63 in the manner of a cam or wedge to drive plunger rod 62 downwardly. The latter is shown in this instance as being equipped with a cartridge device 65 to place the desired mark in paint, ink, cement, or glue on the bolt or like part B. Indentation of the latter by a punch is also contemplated. In addition it should be appreciated that the marking device may contain a threaded sealer, such as the type sold under the trademark Loc-Tite, which is engageable with the threaded nut and which seals the threaded fastener extending through the nut after the nut is torqued as required.

FIGS. 4 and 5 illustrate one version of a bidirectionally indexable precision torque wrench and solenoid-operated marker assembly, generally designated [by the reference numeral 66. Inasmuch as the basic operating structure of this wrench may well be, and is shown as, identical to that of the embodiment of FIGS. 1 and 2, corresponding features have been designated by corresponding reference numerals, primed, and further description thereof is dispensed with Wrench 66 has an electrically energizable solenoid unit fixedly secured atop torque applying head 24', which will include an appropriate reversible pawl and ratchet drive device (not shown) of known sort between the head and the operator 32. The connection of unit 67 is shown as being effected at a flanged base 68 of the unit, using screws 69 threaded into the top of head 24'.v

Base 68 has a central bore 70 coaxially aligned above the top counterbore 37 in the operator 32'; and an alongated plunger rod 72 is slidably received in the central bore 45 of operator extension 31'.

The upper end of rod 72 extends into operator counterbore 37 and base bore 70, terminating just beneath the lower end of an armature plunger 75 of solenoid unit 67. This plunger member is slidable in the annular flanged spool or core 76 on which a solenoid coil 77 is Wound, the armature member 75 having 'an integral enlarged head 78 to limit its downward stroke. Solenoid unit 67 is preferably encased and shielded by an inverted housing 79 suitably aixed to the top of torque applying head 24'; and terminals of coil 77 receive electric leads -80 and 81, which are brought out of the housing, preferably through suitable grommet means of a known type (not shown).

As shown in FIGS. 4 and 5, the electrical circuitry of the wrench 66 includes a small, normally open push ibutton type microswitch 82 suitably mounted on a side of the tubular handle 12 of the tool and encased and shielded by a housing 83. A push button element 84 of switch 82 projects through an opening 85 in handle 12 into position for operation to close the contacts of switch 82 when the break value of torque is reached and arm 20 swings counterclockwise (as viewed in FIG. 4) about its pivotal axis at 21. Wiring lead 80 is connected to one terminal of the switch; lead 81 is connected to an appropriate electric power source (not shown), for example a step-down transformer; and a third lead 86 is connected to a second terminal of switch 82, thus completing this particular solenoid circuit.

Upon closure of switch 82, solenoid unit 67 is energized, thus driving its armature plunger 75 down onto marker rod 72 and, through the agency of the punch 87 on the latter, applying the desired acceptance indicium to the top of bolt B. As before, a non-indented type of mark may be applied.

In certain installations it may be desirable to effect a permanent record of the number of checks for torquecorrectness that have ben made for any given structure under assembly or the like. To this end, the wiring leads 80, r81 of wrench 66 are connected by wires 83, 84, respectively, to a suitable and known type of recording device 86, as shown in FIG. 4, so that each electrical impulse energizing the solenoid unit 67 correspondingly energizes device 86 to make a permanent record, which should reflect a check on each and every one of a possibly large number of threaded fasteners B of an assembly.

As indicated above, the wrench embodiment 66 is one in which both clockwise and counterclockwise swings of its torque arm 20 may take place, for example, in operating on right and left-hand threaded fasteners. In such a unit, the switch means 82 and associated wiring are duplicated at the opposite side of tubular handle 12', with corresponding conections to solenoid coil 77 and to the recorder 86, if one is utilized. In the interest of simplicity, such switch and wiring means are designated in FIG. 4 by reference numerals which correspond to those set forth above, but are primed.

FIG. 6 of the drawings illustrates an embodiment 92 of the wrench of the invention which is in the main similar to that just described, so that corresponding reference numerals are employed to designate corresponding parts. In this form the marking device is shown as being a ballpoint pen and cartridge unit 93 carried by a plunger 94, this plunger 'being operated through the solenoid unit 67 in the same manner as the punch 87 of the embodiment of FIGS. 4 and 5.

Assuming that the tools 66 and 92 are operated under switch control from a power line, possibly involving ap propriate transformer provisions, the improvement of the invention also contemplates an embodiment, such as generally designated 96 in FIG. 7, whose electrical energy source is built in. Thus, one or more simple batteries may constitute a battery power unit 97 ixedly secured to the tubular handle 12' of the tool 96. Such batteries are widely and inexpensively available, for example of a rechargeable nickel-cadmium type, or of the phototlash, alkaline or ashlight types. One terminal of battery unit 97 is connected by a lead 98 to a terminal of switch 82, the second terminals of the battery unit 97 and the switch being electrically connected to the solenoid unit 67 by the respective leads 80 and 81.

While the invention has been illustrated and described as embodied in a wrench having a torque-applying head at one end of a torque-sensing arm, it is to be understood that the principle of the invention may well also ind ap- .plication in other related tools, such as, for example, a Spanner wrench.

What is claimed is:

1. A combined type of torque applying, limiting and marking wrench, comprising means to apply a given, predeterminedly limited torquing force to an object and terminate said application when the force limit is reached, including an elongated tubular operating member having an elongated, rigid but yieldably-acting torque arm swingable therein about an axis transverse of its length, said arm being means to drivingly connect it to said object, means controlling termination of the application of force by said first named means; and a unit responsive to direct engagement by said arm to apply a mark to said object simultaneously with the termination of application of said force, said unit including an element mounted by said tubular member and directly engaged by said torque arm 'upon said termination.

2. The wrench of claim 1, in which said means drivingly connecting said torque arm to the object includes a rotatable torque applying head on said arm, said head having means to drivingly connect it to the object, at least a part of said marking unit being mounted on said head.

3. The tool of claim 1, in which said unit is a fluid pressure operated one.

4. The tool of claim 1, in which said unit is an electrically operated one.

5. The wrench of claim 2, in which said unit is a fluid pressure operated one.

6. The wrench of claim 2, in which said unit is an electrically operated one.

7. A combined type of torque applying, limiting and marking wrench, comprising means to apply a given, predeterminedly limited torquing force to an object and terminate said application when the force limit is reached, including a yieldably-acting, movable member having means to drivingly connect it to said object; and a unit responsive to direct engagement by said member to apply a mark to said object simultaneously with the termination of application of said force, said yieldably-acting member being a torque arm, said unit comprising a control element directly contacted and operated by said torque arm when the limit is reached, and an operating connection between said control element and another part of said marking unit to activate the latter to apply said mark, said torque arm being internally housed by said first-named means, said operating connection between said control element and said part of the marking unit being substantially instantaneously responsive to said termination of application of the torquing force, said means drivingly connecting said torque arm to the object including a rotatable torque applying head on an end of said arm, said head having means to drivingly connect it to the object, at least a part of said marking unit being mounted on said head, said unit being a fluid pressure operated one in which said head-mounted part of the marking unit comprises a liuid pressure-operated cylinder, said marking unit further comprising a control valve mounted on said arm-housing means and having tubular pressure-transmitting means communicating the valve with said cylinder.

8. The wrench of claim 6, in which said head-mounted part of the marking unit comprises a solenoid, said element of said marking unit being a switch mounted on said tubular member and having wiring means electrically connecting the switch with said solenoid.

9. The wrench of claim 7, in which said pressure-transmitting means is exible to permit rotation of said cylinder with said head.

10. The wrench of claim 8, in which said wiring means is flexible to permit rotation of said solenoid with said head.

11. The tool of claim 1, in which said unit has means visually identifying the object by deforming the latter.

12. The tool of claim 1, in which said unit has means visually identifying the object by applying paint or ink to the latter.

13. The wrench of claim 2, in which said marking unit has means marking the part by deforming the latter.

14. The wrench of claim 7, in which said marking unit hasmeans marking the part of deforming the latter.

15. The wrench of claim 8, in which said marking unit has means marking the part by deforming the latter.

16. The wrench of claim 2, in which said marking unit has means marking the part by applying paint or ink to the latter.

17. The wrench of claim 7, in which said marking unit has means marking the part by applying paint or ink t0 the latter.

18. The wrench of claim 8, in which said marking unit has means marking the part by applying paint or ink to the latter.

References Cited UNITED STATES PATENTS 1,131,225 3/1915 Farkell 8l-52.3 1,748,218 2/1930 Groves 81-53 1,985,916 1/1935 Coates et al. 8l-52.5 2,756,622 7/1956 La Belle 81-52.4 2,897,704 8/1959 Woods 81-52.4 2,901,934 9/1959 Dunham 81-53 2,996,940 8/1961 Van Hoose 81-52.4 3,009,371 11/1961 Hines et al 81-53 3,060,763 10/1962 Neufeld et al 81-52.4 X 3,202,021 8/ 1965 Livermont 81-52.4 3,389,623 6/1968 Gill 8l-52.3

JAMES L. JONES, IR., Primary Examiner U,S. C1. X.R. 7 3-139

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