US2393681A - Torque wrench - Google Patents

Description

Jan. 29,1946. E. c. HARTLEY TORQUE WRENCH- Filed Nov. 13, 1942 3 Sheets-sheaf, 1

Janfzs, 1946. E H RTLEY 2,393,681

TORQUE WRENCH I Filed Nov. .15, 1942 s Sheets-Sheet 2 Jan. 29, 1946. E. c.. HARTLEY 2,393,681

TORQUE WRENCH Filed Nov. 15, 1942 s Sheets-Sheet s 3 w \.Q M w. Qk

J A 1i l O4 Ww QW N. M

Patented Jan. 29, 1946' TORQUE WRENCH Emmett C. Hartley, Cleveland, Ohio, assignor to The Parker Appliance Company, Cleveland, Ohio, a corporation of Ohio Application November 13, 1942, Serial No. 465,507

(Cl. ill-52.5)

18 Claims.

The invention relates generally to torque wrench structures and primarily seeks to provide a novel torque wrench structure of the clapper type wherein provision is made for automatically releasing the applied torque whenever it reaches a predetermined maximum.

It is well known, of course, that by applying excessive torque to a bolt, nut, coupling element or the like, damage can result, such as the shear, ing of a bolt, stripping of threads, or the bending or other distortion of parts. Such damaging of parts is objectionable even though it is readily discernable and can be readily remedied, but it sometimes happens that the damage resulting from excessive application of torque remains unseen, as when too great torque is. applied to a tube coupling in which a relatively soft tube is clamped, resulting in pinching off of the tube within the coupling, and such unseen damage jeopardizes expensive equipment and human lives. It is the purpose of the present invention to provide an improved wrench structure which will operate efliciently in the application of the proper amount of torque and in which provision is made for guarding against application of an amount of torque which. might result in damaging of parts.

An object of the invention is to provide. an improved torque wrench structure including a handle, a socket mounted fOr turning. movement relative to said handle, and means including a magnet effective for securing the socket to turn with the handle until a predetermined maximum torque load limit is reached and for then releasing the handle and socket connection to discontinue torque application through the handle to the socket.

Another object of the invention is to provide in a wrenchof the character stated, means for varying the maximum effective torque load limit.

Another object of the invention is to provide an improved torque wrench structure in which is included a handle, a socket, a clapper swingably mounted on the handle and operatively connected with the socket, and means for yieldably retaining the clapper in line with the handle during the application of a proper amount of torque and releasable upon application of a predetermined maximum of torque to allow the clapper to swing out of line with the handle.

Another object of the invention is to provide in a wrench of the character stated, clapper retaining means which can be adjusted a greater or lesser distance from the swingable mounting center of the clapper to vary the predetermined maximum of torque application effective to cause the clapper to swing out of line with the handle.

Another object of the invention is to provide a wrench structure of the character stated in which the clapper is swingable to either side. out

of line with the handle, thereby to make the wrench reversible and usable in either direction.

Another o ject of the invention is to pr vide a wrench structure of the character stated including a removable and replaceable socket and means normally effective to retain the socket in operative position and releasable by manipulation of the c apper to free the socket so that it can be removed and replaced with a socket of diiierent gauge.

Another object of the invention is to provide a wrench. structure of the character stated in which the. clapper is held, in line with the handle by yieldable spring means.

Another object of the invention is to provide a wrench structure of the character stated in which the clapper is held in line with the handle by a permanent magnet.

Another object of the invention is to provide a wrench of the character stated in which the clapper means is composed of two clapper olements operatively connected with a single socket member, one element being swingable. out of line with the handle in one. direction. and the other in the. opposite direct o and n whi h is included means for yieldably holding he elements in line with the handle.-

Another object of the invention is to. provide a wrench oi he haracter stated and inluding two clan-per lements as aforesaid. and

in which the yieldable. holding. means: comprises 7 a permanent magnet lyingbetween said. elements and longitudinally-adjustably mounted in the handle, 7

Another object of the invention is to. provide a wrench structure of the character stated in which is included. means for limiting the amount of swinging movement of the clapper means out of line with the handle.

With the above and other objects in view that will hereinafter appear, the nature of the invention will be more fully understood by following the detailed description, the appended claim and the several views illustrated in the accompanying drawings.

In the drawings:

Figure l is a plan view of a torque Wrench embodying the invention.

Figure 2 is a central longitudinal section of the wrench illustrated in Figure 1.

Figure 3 is a view similar to Figure 1, one of the handle structure half sections being removed and the clapper being shown as swung out of line with the handle structure.

Figure 4 is a detailed cross section taken on the line 4-4 on Figure 1,

Figure 5 is a detailed plan view of the spring means for yieldably retaining the clapper in line with the handle structure.

Figure 9 is a detailed vertical cross section taken on the line 9-9 on Figure 7.

Figure 10 is a detailed cross section taken on the line Iii-l on Figure '7.

Figure 11 is a fragmentary plan view of the socket mounting portion of the wrench illustrated in Figure 7 and showing the manner in which the parts may be adjusted to efiect removal of the socket member.

Figure 12 is a detailed perspective view of the socket member removed from its mounting.

Figure-13 is a plan view and Figure 14 is a' central longitudinal section of another modified form of wrench.

In the form of the invention illustrated in Figures 1 through 4 the invention is embodied in a wrench including a handle structure composed of half sections v and 6 removably secured together by screws. A screw 1 secures the sections at one end and passes through a spacer 8, and a screw 9 secures the sections at the other end and passes through a spacer element Iii. By spacing the handle half sections 5 and 6 in the manner stated, openings are provided at each side of the handle structure.

A socket piece I l is pivoted intermediate its ends about the spacer sleeve 8 and carries a socket head l2 at its outer end, said head being open as at 13 so that the socket can be conveniently applied to a coupling element associated with a tube or pipe line. At its inner end or the end thereof extending into the space between the handle structur half sections 5 and 6, the socket piece H is recessed as at M to receive the short arm or actuator end extension I5 of a clapper member l6 swingably mounted in the space between the handle structure half ections in the manner clearly illustrated in Figures 2, 3 and 4.

The clapper member is provided with trunnion pins II spaced a short distance from the end of the actuator arm l5 and which are received in apertures in the handle half sections 5 and 6 in themanner clearly illustrated in Figures 1 and 2 for pivotally mounting the clapper. The clapper includes a channel piece 18 shaped to provide a slide chamber l9 and including inwardly turned flanges 20. See Figures 2, 3 and 4.

A retainer spring element generally designated 2| is slidably mounted in the slide chamber IQ of the clapper member channel piece, and this element includes opposed body portions 22 and 23 connected as at 24 so that they tend to spring apart in the manner illustrated in Figure 6. It will also be observed by reference to Figures 5 and 6 that the body portion 22 of the spring element is equipped with an outwardly projecting detent 25 and laterally projected fingers 26 which engage under the inturned flanges 20 of the channel piece l3. The other portion 23 of the spring element carries a rebent portion which engages at 21 under the inturned flanges 20. When the parts are positioned as illustrated in Figure 2, the detent 25 engages in a longitudinal groove 28 formed in the handle half section 5 and serves to yieldably retain the clapper 16, I8 in line with the handle structure, or in the position illustrated in Figures 1, 2 and 4 of the drawings. The spring element 2| is slidable along the channel piece l8 so as to var the spacing between the detent 25 and the clapper fulcrum H. By thus adjusting the position of the spring element it is possible to vary the degree of resistance to displacement of the clapper l5, l8 out of line with the handle structure set up by the detent 25. In practice, the detent is set for a predetermined maximum torque load, and so long as the wrench is used to apply torque not in excess of the predetermined maximum, the clapper l6, 18 will remain in line with the handle structure as illustrated in Figures 1, 2 and 4. Whenever an attempt is made to appl torque greater than the predetermined maximum for which the wrench has been set by a selective positioning of the spring detent 25, the resistance of the detent 25 will be overcome and the detent will spring out of the handle structure groove 28 and permit the screw 38, and the walls of the aperture are engageable with the stop screw so as to limit outward swinging movement of the clapper I6, I8 in either direction. By thus permitting only a limited amount of outward swinging movement of the clapper l6, It, a definite signaling to the operator of an application of an overload of torque is efiected, and yet it is possible for the operator to continue to apply torque, with care, should he desire to do so, because of the provision of the stop equipment.

In the form of the invention illustrated in Figures 7 to 12, the handle structure is composed of half sections 3| and 32 each of which is recessed as at 33 so as to provide between them a clapper chamber 34 when the sections are removably secured in assembled relation as illustrated in Figures '7 and 8 by screws 35. A clapper member 36 is mounted in the chamber 34, and this clapper member is provided with trunnion pins 31 which form fulcrums in the receiving recesses provided therefor in the handle sections 3| and 32. See Figure 8.

One of the handle sections 3| is provided with a socket mounting head extension 38 formed so as to provide a circular seat 39 for rotatably supporting a socket member 40 which is provided with a flange 4| for engaging said seat.

The socket head 38 is provided with an opening as at 42, and the socket member 4!] includes an opening 43 normally registering with the socket head opening so that the wrench can readily straddle a pipe or tube and be conveniently applied to a nut or coupling element forming a part of a tube or pipe coupling. The handle half section 32 overlies the socket member flange 4! as at 44 and normally serves to retain the socket member against removal from its mounting. See Figures 7, 8 and 11. The clapper member 36 includes a short arm or lever portion 45 extending beyond the fulcrum 37 and which normall engages in a recess 45, formed in the socket member 49 in the manner best illustrated in Figures 7 and 12 of the drawings. The clapper 3 6 is swingable out of one side only of the handle structure, to the left as viewed in Figure 7, and

the head extension 38 is provided with a stop houl er 41- whieh is eifective to limit outward swinging movement of the clapper member in the manner clearly illustrated in Figure 11.

It will be observed by reference to Figure 11 that when the clapper member 36 is swung outwardly to the limit illustrated in Figure 11, the short arm. or actuator extension 45 thereof will be moved out of the socket member recess 45, thus freeing the socket member so that it can be rotated to the position illustrated in Figure, 11. By thus rotating the socket member the opening 43 therein can be brought opposite the retaining edge 44- of the handle half section 32 to provide a clearance which will permit the socket member to be lifted out of its. mounting so that it can be readily replaced by another socket memher having a different size work engaging opening therein.

In this form of the invention a magnet is employed as the. adjustable means for determining the predetermined maximum torque limit. A longitudinal slot 48 is formed between the half sections 3| and, 32 at; the closed edge. of the handle structure, and a permanent magnet 49 is slidably mounted in the handle chamber 34 in position for being engaged by and for releasably holding the clapper member 38 in the manner clearly illustrated in Figure 7. A clamp screw 50 engages the magnet through the slot 48 and serves to secure adjustments of the magnet. It will be obvious that by spacing the magnet greater or lesser distances from the clapper trunnions 31, the predetermined maximum torque load which can be applied by the. wrench. can be varied at will. The magnet will serve to hold the clapper 36 in the position illustrated in full lines in Figure 7 so long as the wrench is used to apply torque less than the. predetermined maximum. Whenever an attempt is made to use the wrench in application of torque greater than the predetermined maximum, the. magnet will suddenly release the clappar and permit it to swing out of line with the handle structure in the manner illustrated in dot and dash lines on Figure 7.

In. Figures. 13 and 14 of the drawings still, another form of the invention is illustrated. In this modified illustration the wrench. handle is composed of half sections and 52 which are recessed as at 53. to provide an intervening clapper chamber 54, and the sections are removably secured together by screws or bolts 55.

The half sections 5| and 52 are provided with complementary grooves or recesses 56 for rotatably receiving the mounting flange 51 of a socketv member 58. The handle structure and the socket member are open as at 59 so as to permit the wrench to straddle a tube or pipe when being applied to a coupling element. In this form of the invention two identical clapper members 60 are provided, they being disposed in parallel spaced relation. in the chamber 54 in the manner clearly illustrated in Figure 13. Each clapper member is provided with trunnions 61 fulcrumed in receiving apertures in the half sections 5| and 52, and

the short arms 62 of the clappers extending beyond the fulorums. 6| are engaged in a recess 63 in the socket member 58. See Figure 13.

A. single. permanent magnet 64 is interposed in the space between the. long arms of the clapper members 51] in position for being simultaneously engaged by both clapperarms at any position of adjustment throughout the length thereof. In order toprovide. for the desired adjustment of the spacing: of the magnet 64 and the. clapper meme her trunnion (ii. the magnet is provided with oppositely projected mounting pins 65 receivable in selected. ones of the plurality of receiving apertures 66; provided centrally longitudinally of the handle sections. It will be observed by reference to Fi res: 1.3- and 141 that. the apertures 65 are disposed in centrally stag ered relation in the respective half sections 5| and 52, and the pins 65 projecting from. the magnet are staggered so that when the pin projecting, from one face of the ma net is engaged, in an aperture in one of the sections, the pin projecting from the opposite face of the magnet will, engage in the next adjacent perture in the other section. The sections must be separated in order to effect adjustments of the magnet, and by reversing the position of the magnet the direction of the projection of the pins thereof can bev selected to cooperate with the novel staggering 01 the receiving apertures in a manner for providing a maximum of possible in dividual adjustments with a minimum of apertures.

In this form of the invention the magnet serves to secure the clappers in line with the handle structure regardless of the direction of the application of the torque and so long as a torque no greater than the predetermined maximum is being applied, and will release one or the other of the clapper arms as soon as torque greater than the predetermined maximum. is applied and permit the arm to swing out of line; with the handle structure in the manner hereinbefore described. In this form of the invention, as in the others, the predetermined maximum of torque load which can be applied by the wrench can be adjusted by varying the spacing between the. magnet 64 and the fulcra 61..

It will be apparent that in all forms of the in-- vention Wrenches are provided which will automatically relieve torque application, or release when the nut or coupling element which is being tightened has been tightened to a predetermined maximum tightness, thus avoiding stripping of threads, shearing of bolts, or the bending or other distortion of parts. The clapper elements, swingable out of line with the handle structures constitute visual means for indicating the fact that greater than the proper amount of torque has. been applied, and the swinging of the clappers out of line with. the handle structures also constitute sensible means felt by the operators hand to indicate when the proper maximum torque has been obtained. Also, in all forms of the invention herein illustrated, means are provided for adjusting the maximum torque limit to suit particular conditions of use, such as the material from which the, bolt or nut is made, or the material of which an article is made which is being clamped by a nut, bolt or coupling element to which. the wrench is applied. The features of the invention herein disclosed, are advantageous because they permit placement of the wrenches in the hands of inexperienced help without fear that they will destroy or damage parts by excessive torqu application.

It is of course to be understood that the details of structure and the arrangement of parts may be variously changed and modified without departing from the spirit and scope of the invention.

I claim:

1. A torque wrench comprising a. handle structure, a socket member mounted on; the handle structure. for movement with or relative thereto, and means forming a movement. imparting connection between the socket member and. the

handle structure and including a permanent magnet effective for securing the socket against movement relative to the handle structure so that the socket member will move with the handle structure until a predetermined maximum torque load has been applied through said socket member and for then releasing the connection to permit a continued movement of the handle structure without imparting movement to the socket member.

2. A torque wrench comprising a handle structure, a socket member mounted on the handle structure for movement with or relative thereto, means forming a movement imparting connection between the socket member and the handle structure and including a permanent magnet efiective for securing the socket against movement relative to the handle structure so that the socket member will move with the handle structure until a predetermined maximum torque load has been applied through said socket member and for then releasing the connection to permit a continued movement of the handle structure without imparting movement to the socket member, and

means enabling adjustment of the torque-load maximum at which said connection release will be effected.

3. A torque wrench comprising a handle structure, a socket member mounted on the handle structurefor movement with or relative thereto, a clapper swingably mounted on the handle struc ture and operatively connected with the socket member, said handle having a recess therein opening through a side thereof and Within which said clapper normally is retained, means in said recess for yieldably retaining the clapper in line with the handle structure and within said recess during the application of torque less than a predetermined maximum of torque load and automatically releasable upon application of torque greater than said predetermined maximum to allow the clapper to swing freely out through the side opening recess out of line with the handle structure and the handle structure to move relative to the socket member without applying torque, and means mounting said yieldable retaining means at variable distances from the swing center of the clapper to vary said predetermined torque load.

4. A torque wrench comprising a handle structure, a socket member mounted on the handle structure for movement with or relative thereto, a clapper swingably mounted on the handle structure and operatively connected with the socket member, means for yieldably retaining the clapper in line with the handle structure during the application of torque less than a predetermined maximum of tor ue load and automatically releasable upon app cation of torque greater than said predetermined maximum to allow the clapper to swing out of line with the handle structure and the handle structure to move relative to the socket member without applying torque, said yieldable retaining means comprising a permanent magnet engageable by and releasable by excessive torque application from said clapper, and means mounting said magnet for adjustment to varied distances from the swing center of the clapper to vary said predetermined torque load.

5. A torque wrench comprising a handle structure, a socket member mounted on the handle structure for movement with said structure or relative thereto, an elongated clapper swingably mounted on the handle structure with its swing center disposed intermediately of the ends thereof and close to one end so as to provide long and short arms on the clapper, means connecting the short arm to the socket member with the long arm normally extending in line with the handle structure, means for yieldably retaining the long arm in line with the handle structure during the application of less than a predetermined maximum of torque load and automatically releasable upon application of torque greater than said predetermined maximum to allow the clapper long arm to swing out or line with the handle structure and the handle structure to move relative to the socket member without applying torque, said yieldable retaining means comprising a permanent magnet engageable by and releasable by excessive torque application from said clapper long arm, and means mounting said magnet for adjustment to varied distances along said long arm toward the fulcrum of the clapperto vary said predetermined torque load.

6. A torque wrench comprising a handle structure, a socket member mounted on the handle structure for movement with said structure or relative thereto, an elongated clapper swingably mounted on the handle structure with its swing center disposed intermediately of the ends thereof and. close to one end so as to provide long and short arms on the clapper, means connecting the short arm to the socket member with the long arm normally extending in line with the handle structure, means for yieldably retaining the long arm in line with the handle structure during the application of less than a predetermined maximum of torque load and automatieally releasable upon application of torque greater than said predetermined maximum to allow the clapper long arm to swing out of line with the handle structure and the handle structure to move relative to the socket memberwithout applying torque, said yieldable means comprising a spring element mutually engageable between the clapper long arm and the handle structure and including a detent, one of said parts mutually engaged by said spring element having an elongated recess in which to receive said detent, and said spring element being adjustable along said long arm and recess to vary said predetermined torque load.

'7. A torque wrench comprising a handle structure, a socket member mounted on the handle structure for movement with said structure or relative thereto, an elongated clapper swingably mounted on the handle structure with its swing center disposed intermediately of the ends thereof and close to one end so as to provide long and short arms on the clapper, means connecting the short arm to the socket member with the long arm normally extending in line with the handle structure, means for yieldably retaining the long arm in line with the handle structure during the application of less than a predetermined maximum of torque load and automatically releasable upon application of torque greater than said predetermined maximum to allow 1e clapper long arm to swing out of line with the handle structure and the handle structure to move relative to the socket member without applying torque, said yieldable means comprising a spring element mutually engageable between the clapper long arm and the handle structure and including a detent, one of said parts mutually engaged by said spring element having an elongated recess in which to receive said detent, said spring element being adjustable along said long arm and recess to vary said predetermined torque load, and said clapper long arm being swingableout of line with the handle structure at opposite sides thereof so as to adapt the wrench for application to work without regard for right or left hand disposition thereof.

8. A torque wrench comprising a handle structure composed of two elongated body sections socured together face to face with portions thereof spaced apart to provide an intervening chamber open at both sides, a socket member mounted on the handle structure for movement with said structure or relative thereto, two elongated olappers disposed side by side in said chamber and each being swingably mounted with its swing center disposed intermediately of the ends thereof and close to one end so as to provide long and short arms, said socket member being recessed to receive said short arms and form a connection with said clappers, said long arms being disposed in parallel spaced relation, and a permanent magnet disposed between the long arms and engaged thereby for securing the long arms in the chamber during the application of torque less than a predetermined maximum and efiective to automatically release one or the other of said long arms upon application of a torque greater than said predetermined maximum to allow the respective long arm to swing out of the chamber and the handle structure to move relative to the socket member without applying torque 9. A torque wrench comprising a handle structure composed of two elongated body sections secured together face to face with portions thereof spaced apart to provide an intervening chamber open at both sides, a socket member mounted on the handle structure for movement with said structure or relative thereto, two elongated clappers disposed side by side in said chamber and each being swingably mounted with its swing center disposed intermediately of the ends thereof and close to one end so as to provide long and short arms, said socket member being recessed to receive said short arms and :form a connection with said clappers, said long arms being disposed in parallel spaced relation, a permanent magnet disposed between the long arms and engaged thereby for securing the long arms in the chamber during the application of torque less than a predetermined maximum and citestive to automatically release one or the other of said long arms upon application of a torque greater than said predetermined maximum to allow the respective long arm to swing out of the chamber and the handle structure to move relative to the socket member without applying torque, and means for securing said magnet at variable distances from the swing centers of the clappers to vary said predetermined torque load 10. A torque wrench comprising a handle structure composed of two elongated body sections removably secured together face to face with portions thereof spaced apart to provide an intervening chamber open at both sides, a socket member mounted on the handle structure for movement with said structure or relative thereto, two elongated slappers disposed side by side in said chamber and each being swingably mounted with its swing center disposed intermediately of the ends thereof and close to one end so as to provide long and short arms, said socket member being recessed to receive said short arms and form a connection with said clappers, said long arms being disposed in parallel spaced relation, a permanent magnet disposed between the long arms and engaged there by for securing the long arms in the chamber during the application of torque less than a predetermined maximum and effective to automatically release one or the other of said long arms upon application of a torque greater than said predetermined maximum to allow the respective long arm to swing out of the chamber and the handle structure to move relative tothe socket member without applying torque, and means for securing said magnet at variable distances from the swing center of the clappers to vary said predetermined torque load, said securing means comprising pins projecting from opposite faces of the magnet and selectively receivable in apertures provided therefor in the handle structure sections along the line of the space between the clapper long arms.

11. In a wrench of the character described, a handle structure having a circular recess therein for removably receiving a socket and a straddle opening extending through a side of said recess, a socket removably and replaceably mounted in said recess and having a straddle opening normally registering with the straddle opening in the handle structure, means on said handle structure normally overlying and retaining the socket in said recess, and releasable means normally holding the socket in effective position with said straddle openings in register, said socket being turnable upon release of said releasable means to present the straddling opening of the socket opposite said retaining means to free the socket for removal out of said recess. 12. A torque wrench comprising a handle structure, a socket member having a fixed pivotal mounting on the handle structure for movement with said handle structure or for pivotal movement relative thereto, a clapper swingably mounted on the handle structure on a pivot spaced from the socket mounting, said clapper being operatively connected with the socket member, said handle having a recess therein opening through a side thereof and extending at least in part along that portion of the handle to be grasped in the hand of a user and within which said clapper normally is retained throughout the full length and breadth thereof, and means in said recess for yieldably retaining the clapper in line with the handle structure and Within said recess during the application of torque less than a predetermined maximum of torque load and automatically releasable upon application of torque greater than said predetermined maximum to allow the clapper to swing freely out through the side opening recess out of line with the handle structure and the handle structure to move relative to the socket member without applying torque.

13. A torque wrench comprising a handle structure, a socket member having a fixed pivotal mounting on the handle structure for movement with said structure or for pivotal movement relative thereto, an elongated clapper swingably mounted on the handle structure with its swing center spaced from the socket mounting and disposed intermediately of the ends of the clapper and close to one end thereof so as to provide long and short arms on the clapper, said handle having a recess therein opening through a side thereof and extending at least in part along that portion of the handle to be grasped in the hand of a user and within which said clapper normally is retained throughout the full length and breadth thereof, means connecting the short arm to the socket member with the long arm normally extending in line with the handle structure and within said recess, and means in said recess for yieldably retaining the long arm in line with the handle structure and Within said recess during the application of less than a predetermined maximum of torque load and automatically releasable upon application of torque greater than said predetermined maximum to allow the clapper long arm to swing freely out through the side opening recess out of line with the handle structure and the handle structure to move relative to the socket member without applying torque.

14. A torque wrench comprising a handle structure, a socket member having a fixed pivotal mounting on the handle structure for movement with said structure or for pivotal movement relative thereto, an elongated clapper swingably mounted on the handle structure with its swing center spaced from the socket mounting and disposed intermediately of the ends of the clapper and close to one end thereof so as to provide long and short arms on the clapper, means connecting the short arm to the socket member with the long arm normally extending in line with the handle structure and alon that portion thereof to be grasped in the hand of a user, and means for yieldably retaining the long arm in line with the handle structure during the application of less than a predetermined maximum of torque load and automatically releasable upon application of torque greater than said predetermined maximum to allow the clapper long arm to swing out of line with the handle structure and the handle structure to move relative to the socket member without applying torque, said clapper long arm being swingable out of line with the handle structure at opposite sides thereof so as to adapt the wrench for application to work without regard for right or left hand disposition thereof.

15. A torque wrench comprising a handle structure, a socket member having a fixed pivotal mounting on the handle structure for movement with said structure or for pivotal movement relative thereto, an elongated clapper swingably mounted on the handle structure with, its swing center spaced from the socket mounting and disposed intermediately of the ends of the clapper and close to one end thereof so as to provide long and short arms on the clapper, means connecting the short arm to the socket member with the long arm normally extending in line with the handle structure and along that portion thereof to be grasped in the hand of a user with no part thereof extending beyond the sides of the handle, and means for yieldably retaining the long arm in line with the handle structure during the application of less than a predetermined maximum of torque load and automatically releasable upon application of torque greater than said predetermined maximum to allow the clapper lon arm to swing out of line with the handle structure and the handle structure to move relative to the socket member without applying torque, said clapper long arm being swingable out of line with the handle structure at opposite sides thereof so as to adapt the wrench for application to work without regard for right or left hand disposition thereof, and means permitting only a limited amount of movement of said long arm out of line with the handle structure in either direction.

16. In a wrench of the character described, a handle member, and a socket member mounted on said handle member for rotational movement relative to said handle structure, an annular ledge on said socket member and a flange on the handle member normally efiective to overlie the socket member ledge and prevent displacement of the socket member from the handle member, said socket member including a tube straddle opening through one side thereof effective when the socket member is turned to a predetermined position to release the efiective overlapping of the flange over the socket member ledge and permit removal and replacement of the socket member.

17. In a wrench of the character described, a handle structure having a circular socket member receiving recess, a selective socket member removably and replaceably mounted on said handle structure having a nut receiving opening therein of selected size and a peripheral recess, means including a lever pivoted on said handle structure and having a short arm normally engageable in the peripheral recess in the socket member for holdnig the socket member against movement relative to the handle structure and determining a single constant effective position of the socket on the handle structure, said lever also having a long arm, and means engaging said long arm and effective upon application of torque less than a predetermined maximum of torque load through said handle structure and socket for causing said handle structure and socket to maintain rigid relation and yieldable upon application of torque greater than said predetermined maximum to permit the handle structure to move relative to the socket Without applying torque, said nut receiving opening when in said effective position bearing constant definite relation to the pivot of said lever whereby said relative movement of handle and socket member will occur at the same torque overload regardless of the size of the nut receiving opening in the selected socket member.

18. In a wrench of the character described, a handle structure having a circular socket member receiving recess and a retaining shoulder overlying a part of said recess, a selective socket member removably and replaceably mounted on said handle structure and including a circular portion rotatably receivable in said recess and a break in its circumference placeable opposite the shoulder to permit removal of the socket member and also having a nut receiving opening therein of selected size and a peripheral recess, means including a lever pivoted on said handle structure and having a short arm normally engageable in the peripheral recess in the socket member for holding the socket member against movement relative to the handle structure and determining a single constant effective position of the socket on the handle structure, said lever also having a long arm, and means engaging said long arm and efi'ective upon application of torque less than a predetermined maximum of torque load through said handle structure and socket for causing said handle structure and socket to maintain rigid relation and yieldable upon application of torque greater than said predetermined maximum to permit the handle structure to move relative to the socket without applying torque, said nut receiving opening when in said effective position bearing constant definite relation to the pivot of said lever whereby said relative movement of handle and socket member will occur at the same torque overload regardless of the size of the nut receiving opening in the selected socket member.

EMMETT C. HARTLEY.

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