US2374217A - Ratchet measuring wrench - Google Patents

Description

April 1945- V K. R. LARSON EIAL 2,374,217

' RAIFJHET MEASURING WRENCH Filed Sept. 10, 1942 V IN VE NTORS.

KENNETH R. LAWSON.

GEORGEMWAL AVEN. C 2 Q.

7 ATTORNEY.

Patented Apr. 24, 1945 RATCHET MEASURING WRENCH Kenneth R. Larson, Des Plaines, Ill., and George M. Walraven,

Kenosha, Wis.,

assignors to Snap-On Tools Corporation, Kenosha, Wis;

Application September 10, 1942, Serial No. 457,866 7 Claims. (.01. 73-139) flexible torque resisting beam type wherein ratchet mechanisms can more easily be supplied than in torsion type load measuring devices such as illustrated in' the aforesaid copending application for Letters Patent. There has been a long felt want for ratachet torque turning tools, and

theseshould be compact, dependable, and accurate as well as light in weight and effective in operation. This coupled with the fact that the turning head constitutes the torsion resisting element which should be as long and unafiected as possible by any other influences, complicates the adaptation of ratchet mechanisms thereto; A torque wrench of the specified type that presents a ratchet problem is fully described in the above referred to copending application and Letters Patent.

One object of the present invention is to simplify the construction and improve the operation of devices of the character mentioned.

Another object is to incorporate compact, de-

pendable, and durable ratcheting expedients into a nutturning or other type of a torque wrench head member presenting limited space. and special operating instrumentalities.

Still another object is to provide an improved torsion shank and ratchet member embodying a double toothed pawl that is circumferentially spaced to provide registry with an annular'ratchet member comprising part of a sectional turning head.

A further object isto provide a measurin wrench shank with a plurality of circumferentially spaced pawl teeth that are operatively connected' to an actuator to place one or the other of the pawl teeth in and out of registry therewith for operative head turning engagement in selected directions of rotation.

A still further object is to provide a plurality of pawl teeth in a casing attached to a measuring shank concentric to the axis of rotation thereof to comprise a reversible ratchet head with a turning member. 7

Still a further objectis to tprovide aplura'li of pawlteeth operatively connected with an axially positioned actuator for controlled directional engagement with at ratchet head comprising part of a torsion resistin turning member.

An additional object is to provide a plurality of pawl teeth in a head member for selected registry with circumferentially spaced pawl engaging members on a revoluble turning member for engagement by one or the other of the. opposite pawls to constitute a torque indicator actuator element.

Other objects and advantages will appear from the following description of an illustrative em:- bodiment of the present invention.

In the drawing:

Figure 1 is a fragmentary, partly sectional side view in elevation of a measuring wrench having a ratchet mechanism associated therewith in accordance with theteachings of the presentinvention.

Figure 2 is a fragmentary bottom plan view of of the wrench coverplate shown in Figure 1- with the enclosing casing removed therefrom.-

Figure 3 is a fragmentary sectional view in elevation taken substantially along line ILL-III of Figure 2. i

Figure 4 is a fragmentary sectional view take substantially along line IVIV of Figure 3.

Figure 5 is a perspective view of the ratchet member embodying. an element of the structure shown in Figures 1 to 4 inclusive.

Figure 6 is a perspective view of the doubletoothed pawl constituting a complement of the ratchet member shown in Figure 5. v

Figure 7 is a perspective view of the pawl actuator shown in assembled relation with the other instrumentatlies in Figures 1 and 3.

The structure selected for illustration comprises a solid handle member I0 of standard.- construction having an elongated chambered wrench shank or body ll cast or otherwise shaped to present side walls l2 and I3 termin'atingin a semicircular top or head extremity M. The handle I!) with its chambered body H is preferably though not essentially cast from an aluminum alloy so as to possess the desired strength and lightness for convenience and manipulation in nut turning as will appear morefully hereinafter;

It will be observed that the handle shank or body converge in the direction of the'handle F0 and steel plate I! that is shaped to conform with the configuration of the peripherally flanged open side [8 opposite the bottom wall l to confront therewith and serve as a complement thereof. The lower or handle extremity I9 of the chamber I6 is of the same general size and semicircular configuration as the head extremity l4.

Theperipherally flanged open edge [8 of the casing ll extends around the side walls l2-l3 and their semi-circular head and handle extremities l4 and IS. The rigid face or cover plate l! is shaped to correspond with the flanged open edge l8 including its upper and lower semicircular head and handle extremities l4 and L9 to serve as an enclosure therefor and also as a rigid turning arm to which the measuring instrumentalities are attached as will appear more fully hereinafter. A plurality of threaded screw fasteners 20 project through apertures 2i in the rigid cover plate I! to engage correspondingly threaded bores 22 in the peripheral casing edge l8 that extends along the side walls |2--l3 of the handle shank or casing body I l and semicircular ends l4|9, thereby enclosing the chamber 16 and confining the torsion displacing, indicating, and measuring instrumentalities to be described hereinafter.

It should be noted that the handle shank or casing body II and the side walls |2-l3 are provided with a sufiicient number of apertures 2| and threaded bores 22 uniformly spaced along the entire peripheral flange I8 so that the comparatively rigid and load carrying cover plate I! can be effectively attached to the casing body H which is greatly strengthened and reinforced therewith. In fact, the casing ll does not sustain any appreciable turning load and primarily serves to confine the measuring instrumentalities as a protection against foreign substances and impacts. The cover plate H is sufficiently rigid to avoid a flex, distorsion or consequential variation under turning load.

The semi-circular head M of the body ll is provided with a circular recess 23 corresponding substantially in curvature therewith and sized to freely receive a housing or body member 24 of substantially smaller size for free rotation therein. The housing or body member 24 is formed, in this instance, integral with a substantially smaller cylindrical shank 25 that terminates in a somewhat enlarged polygonal shoulder 26 (Figure 3). The polygonal shoulder 26 is formed integral with the shank 25 in axial relation to the housing or body member 24.

The polygonal shoulder 25 registers with a correspondingly sized and shaped opening 21 provided in the cover plate I! coaxially with a circular aperture 28 (Figure 3) provided in the confronting bottom wall I5 of the casing ll. As shown, the housing or body member 24 is confined within the head M of the casing H and is disposed adjacent the bottom l5 for free rotation therein except for the fixed association beterior or interior or both surfaces of the cover I plate I! depending upon the dictates of commercial practice.

The housing or body member 24 has, in this instance,- a circular recess 29 provided axially therein through the bottom end surface 30 thereof. The housing or body member 24 cooperates with an axially disposed work engaging member 32 telescoped in the axial recess 29 thereof for radial confronting relation therewith for connection through a ratcheting mechanism to be hereinafter described. A polygonal wrench socket receiving shank 33 is, in this instance, formed integral with the work engaging member 32 which freely projects through the bore or aperture 28 provided in the bottom wall of the-head I4. The work engaging wrench socket receiving shank 33 projects beyond the bottom I5 of the casing shank H to provide accessibility to fasteners such as nuts for turning to a predetermined degree.

A spring impelled detent 35 of standard construction is provided in a face of the polygonal shank 33 for cooperation with a correspondingly sized and shaped recess providedin a wrench socket or other turning implement that is telescoped thereon for retention thereon against accidental detachment. Wrench sockets or other turning implements (not shown) would normally be provided with a recessed shank shaped and sized to conform with the polygonal shank 33 of the revoluble work engaging member 32 so that the friction exerted by the spring impelled detent 35 would be effective in retaining the turning implement thereon against accidental removal.

It should be noted that the housing or body member 24 is rigidly attached to the cover plate ll that is preferably of rigid and non-yielding material such as steel, while the body or casing shank H may be cast or otherwise shaped from aluminum, in that the housing or body member 24 is mounted for movement relative thereto in sustaining the turning load. The casing ll does not directlycarry any appreciable load. Turning movement is imparted to a fastener such as a threaded nut through a Wrench socket attached to the polygonal shank 33 of the revoluble work engaging member 32, responsive to manually applying force or effort to the handle in in one direction or another.

The revoluble member 32 has an annular shoulder 36 which is intermediate the cylindrical ends 3'|--38 journalled for support in an end bore 39 in the housing 24 and communicating with its internal chamber or recess 29. The other turning member shoulder 38 is journalled in a circular aperture 40 provided in a closure bearing plate 4! that is shaped to correspond with the substantially figure 8 contour of the head chamber or recess 29 that communicates with a pawl chamber or recess 42 provided in the housing orbody member 24. Threaded fasteners 43 retain the closure plate 4| on a correspondingly shaped peripheral shoulder 44 that defines the outline of the head and pawl chambers 2942. 7

To enable ratcheting of the handle ID with the housing or body member 24 in opposed directions to impart intermittent rotation responsive to oscillatory movement of the handle 10, the periphery of the revoluble turning member shoulder 36 is provided with radially extending ratchet teeth 45 cut or otherwise formed for extension therefrom. As shown, the circular pawl recess 42 is provided in the housing or body member 24 to communicate with the chamber 29, it being in longitudinal alignment therewith to receive a correspondingly shaped circular pawl 46 journalled for rotation therein with the periphery thereof partially disposed in the chamber 29.

To this end, the pawl 46 has integral axial aligned hubs 4i and 48 received in correspondingly shaped bores 45 and 56 provided in the housing or body member 24 and closure plate 4|. A circular knob i having a stem 52 with a polygonal end 53 is disposed for reception in a somewhat larger and correspondingly shaped polygonal recess 54 provided axially within the pawl hub 41 to establish fixed connection therewith to constitute a manual rotary adjustment for the pawl 46. A cotter pin 55 extends through an aperture 56 in the knob stem 52 in the inside of the body cover plate I? (Figure 3) to retain the stem end 53 in registry with the pawl recess 54.

To enable ratcheting of the revoluble work engaging member 32 in opposed directions by rotary adjustment of the knob 5! to extreme positions that may be designated on the body closure plate H, the pawl 46 has the periphery thereof interrupted to define confronting pawl teeth 51 and 56. The pawl teeth 51 and 58 are complemental to the ratchet teeth 45 for independent meshing engagement therewith depending upon the rotary position of the pawl 46 which is adjusted by the knob 5! to control the directional rotation of the revoluble member or ratchet wheel 36. The pawl teeth 5! and 58 are sufficiently spaced so that one or the other will be in operative engagement with a ratchet tooth 45 to enable the desired rotary throw of the housing or body member 24 with the closure plate I! for ratcheting purposes, without interference with the inactive pawl tooth. During the ratcheting action, the pawl 45 partially rotates about desired directional ratcheting, a positioning ball or detent 59 is resilientl mounted on a spring 60 confined in a passage 6i provided longitudinally in an elongated extension 62 in the housing member 24 and projecting toward the handle Ill. The passage '6! is in radial communication with the pawl receiving recess 42. The spring 66 urges the positioning detent or ball 56 in the direction of the pawl 46 for engagement with the periphery thereof. To this end, the periphery of the pawl 46 is provided with conical cavities 63' and 64 for reception of the resiliently mounted positioning'ball or detent59. The cavities 63 and 64 are spaced for selective registry with the detent 46 to hold the pawl teeth: '51 and 58, respectively, in meshing engagement with the teeth 45 of the turning member 32', thereby enabling its rotation in a counterclockwise and clockwise direction (viewedfrom Figure 4) responsive' to ratcheting or oscillating the handle It is thus apparent that the knob adjusting member 5| enables the ratchet member. 32 to function in opposed directions with the dual pawl teeth 51-58 easily adjusted for the purpose set forth and without possible accidental displacement owing to the fact that the detent 59 is resiliently urged into the cavities 63 or 64 to retain the pawl 46 in its displaced position to-control the direction of pawl tooth engagement. Consequently, when the wrench handle I 0 with its casing II and cover plate I? are turned to carry the nut turning load, the housing 24 and the revoluble work engaging member 32 are operatively connected together to rotate as aunit through the pawl 46.

However, when the handle I0, casing I I and cover plate I! are momentarily moved back to effect another bite or engagement between the ratchet teeth 45 and the pawl 46, the housing 24', casing II, and cover plate I! rotate relative to the then stationary work engaging member 32 to accomplish ratcheting action. In order to measure the extent to which any fastener such as a threaded nut is applied through the manipulation of the handle ill, the extent of twist sustained by the cylindrical extension 2 5 of the housing member 24 is determined in that this will be uniform for any predetermined applied force and will vary proportionately to the turning load imparted through the handle [0 that'is primarily sustained by the rigid cover plate 11. I

It will be observed that owing to the polygonal shoulder 26 on the shank 25 and the attachment thereof to the cover plate I! in any suitable manner such as welding, any load turning movement applied to the handle 16 will be transferred to the cover plate I! which, in turn, will rotarily displace the housing member 24 with its pawl connected work engaging member 32 which carries a nut or other turning implement. To the end that proportional twist is imparted to the cylindrical extension 25 anchored to the cover plate I! at one extremity 26 and is free to twist at the other extremity 33 responsive to carrying the turning; load, there is movement of the housing 24 proportional to the load on the revoluble member 33. It is to be noted that the torsional stress will mostly be effective in the solid member 25 and to a negligible degree in the work engaging member 32. a

In order to measure the degree of twist or torsion imparted to the revoluble member 25 and work engaging member 32 responsive to'any turning operation, an elongated cylindrical indicator displacing tube 65 is in this instance of uniform diameter, and projects radially through a passage 66 provided in the housing extension 62 for fixed press fitted engagement therein to constitute a single action unit or member therewith. The elongated rod 65 projects longitudinally of the body or casing shank II for confinement therein, although it is oppositely offset at both ends to align with the measuring instrument, as will appear more fully hereinafter.

So that the casing shankmll together with its associated instrumentalities may be as compact as possible, the cylindrical indicator displacing rod 65 is preferably disposed at a slight angle between the extremities B1 and 68 thereof (Figure 1) to avoid contact with either the bottom l5 or cover plate I! and free to circumferentially move or oscillate for a limited extent depending upon the degree of twist imparted to the housing extension 62 or the torsion effect on the shank 25 responsive to carrying the turning load relative to-its polygonal extremity 26 fixed to the cover plate IT.

The elongated indicator displacing tube or rod 65 need only be heavy enough to overcome the friction in the measuring instrumentalities and the load occasioned by their operation without causing any flex in the tube or rod 65. Its di- 'ametrical size, however, may be determined .by

other factors such as the elimination of backlash and conditions of abuse in actual nut turning operations. For that reason, the elongated tube or rod 65 in actual practice may be somewhat heavier than otherwise required merely to carry a comparatively negligible load of operating the measuring instrumentalities without any flex in the rod 65. I

It may be more desirable from a manufacturing standpoint to terminate the elongated cylindrical rod 65 short of the lower circular handle casing formation I9 and cover plate circular extension 69 of the cover plate H, with a reduced portion 10, and joined therewith to a rod extension H of comparatively smaller diameter. To this end, the rod extension II has its upper extremity projecting within an axial bore provided in the lower extremity of the reduced rod portion 10. The upper extremity of the rod extension H is frictionally engaged in the axial bore by means of a tapered tightening nut 12 that threadedly engages a correspondingly tapered and lower threaded extremity 13 of the reduced rod portion to effect rigid connection of the rod extension H with the elongated cylindrical actuating rod 65 for the measuring instrumentalities.

With this arrangement, the rod extension H may be extended or retracted within the axial bore of the reduced rod portion 10 to enable longitudinal adjustment of the rod extension H relative to the indicator mechanism. The longitudinal adjustment of the rod extension II will vary the extent to which the dial mechanism. is actuated or displaced responsive to a predetermined torsional stress imparted to the shank 25 of the interconnected housing and revoluble work engaging members 2432. This enables also the replacement of the rod extension H should occasion demand or should such become impaired in any nut turning operation.

It should be noted that the rod 65 together with its reduced portion 10 and extension 7| function exactly the same even though these were turned or otherwise shaped to constitute an integral unit; however, such construction would be somewhat more expensive from a production standpoint than the coaxial connected rods 6510|l serving as an actuator for measuring instrumentalities when displaced by the twist imparted to the turning member shank 25. The reduced rod extension 11 has a right angularly oifset extremity 14 which is confined within the casing body chamber l6 near the bottom end thereof, for registry with a longitudinally elongated slot provided in a lever 15 that comprises a part of the measuring and indicating instrumentalities 76-11 fully described in the Larson copending application serially numbered 374,361 filed January 14, 1941, which eventuated into Letters Patent N 0. 2,312,104, dated February 23, 1943.

The measuring instrumentalities which are assembled as a unit on the dial casing plate that is attached to the exterior surface of the lower circular extremity B9 of the cover plate'l'l. Consequently, the measurin and indicator mechanism l5l6'l| can be attached to the cover plate I! together with the housing 24, shank 25, revoluble turning member 32 and its torsion displacing rod 65l0'l|. The cover plate I! together with these instrumentalities are, in turn, attached for confinement in the chamber 16 of the body or casing shank l I by mean of fasteners such as the threaded studs 20.

It should be observed that'the lower end of the chamber I6 of the body casing II is outwardly flared to define a circularly flared configuration 19 to conform with the size and shape of the lower extremity 69 of the cover plate I! together with the dial casing plate and its confronting ring 11. It will be apparent from the foregoing arrangement of parts that a manual turning force applied to the handle H] will impart a corresponding turning effect to the ratchet housing or body turning member 24. This creates a slight twist in the turning member extension or shank 25 which can be measured with the advantage procured through the moment arm dial indicator displacing member 65-10'H therebetween.

This turning operation is transmitted to a suitable tool or implement or fastener such as a threaded nut, which requires a predetermined turning load in securing it to the desired degree of tightness for the suitable performance of its intended function. This turning movement and sustained turning load will create a fractional twist in the revoluble member shank or extension 25 primarily between its enlarged annular housing 24 and the poylgonal stationary shoulder 26. This fractional twist created by the torsional effeet on the cylindrical extension 25, will be transest displacement.

As a result, the rod 55-|0'|l will accentuate the twist created in the revoluble head extension 25 to efiectively turn the indicator pointer to an extent proportional to the length of the elongated rod 65-10-H. The measurement of the twist imparted to the revoluble head extension 25 at a point of maximum displacement of the comparatively long twist-translating rods 65'|0ll is an important factor in producing accurate readings. Then, too, the rod 6510--'H need only be heavy enough to overcome the comparatively negligible force required to actuate the measuring instrumentalities, so that comparatively little friction is encountered between the housing 24, its revoluble turnin member 32 and the measuring instrumentalities. This is conducive to accuracy accomplished with utmost simplicity in construction and operation.

With the arrangement of parts above described, the rod 6510-|I comprising a single or' sectional member is of such flexibility as to preclude injury to the dial mechanism in the event the handle I0 is abruptly released or the turning load should fall by virtue of a rupture in the nut or bolt or other instrumentality that is being tightened. The rather flexible rod 65-'lllll and especially the part'H would absorb a substantial part of the shock, without permitting such to damage the dial mechanism or any part thereof under abnormal conditions of abrupt release.

Any back-lash occasioned by the abrupt accidental release of the turning load would ordinarily jar, impair and render permanently defective the measuring instrumentalities, but the rod extension H is sufiiciently flexible to fully absorb this shock.

This is largely if not entirely overcome by the actuator rod extension H which is highly flexible, resilient and possessed of only sufiicient rigidity to overcome the function of the measuring instrumentalities connected thereto. Consequently, the severe stress and strains resulting from any back-lash action, will be absorbed for the most part by the flexing of the actuator rod extension ll and thus protect the measuring instrumentalities under such abnormal conditions of abusive operation. The steel spring wire H is sufliciently rigid to carry the comparatively small load involved in actuating the indicator instrumentalities Without any flex therein and yet sulficiently resilient to absorb any shock created in the abnormal operation of the turning head 32 or shank 25 such as the sudden release of the handle ID with a full load on the turningmember shank 33.

Then. too, the torsional displacement in a torsion-type wrench embodying a comparatively short load turning shank 25, is comparatively small, in that the degree of twist therein would be a minute amount approximating five thousandths of an inch under normal loads. Because the elongated rcd 65-lfl-li actuates the dial mechanism at its extremity which is the point of maximum displacement, this minute torsional displacement of the load carrying shank 25 is appreciably and accentuated at the dial end of the actuator rod H. Even though there was an abrupt release of load, therefore, the backlash in the aforesaid structure would be negligible and the actuator rod 65'l 0-'ll would not be called upon to withstand any appreciable backlash shock which could, however, be absorbed by the resilient actuator extension 'II which is preferably constructed from small diameter spring steel wire. I

With the arrangement of parts above described, it will be apparent that a very simple, inexpensive and highly accurate ratchet torsion measuring wrench has been provided, wherein there are few moving parts and the friction thereof has been reduced to a minimum to preclude variable and inaccurate readings. These features coupled with the fact that the torsional stress created by the turning load is measured at the point of maximum displacement of the elongated dial mechanism actuator rod, eliminates or reduces to a negligible minimum any inaccuracies even at small loads. Whether or not the handle I is a part of the casing I I or the cover plate I! is immaterial as suchconstitutes a mere reversal of parts, and the operation is the same irrespective of the arrangement.

While we have illustrated and described a preferred embodimen of this invention, it must be understood that the invention is capable of considerable variation and modification without departing from the spirit of the invention. We,

chored in one end of said rigid handle member, a casing complemental to said rigid handle member, said work engaging turning head mem-.

ber comprising .a turning load resisting shank anchored in said handlemember and a work turning element projecting through said casing, a ratchet housing fixed to said load resisting shank in said casing, ratchet means in said housingbetween said load resisting shank and said-work turning element, and an elongated rod anchored to said ratchet housing at a point spaced from its anchorage to said rigid handle member, said elongated rod serving to transmit the degree of their load sustaining movement relative to said handle member, said elongated rod extending along said handle member without being under any load stress or strain in transmitting movement of said head member andcalibrated-indieating means operatively connected to the free extremity of said elongated rod to imeasurethe degree of twist occasioned in sustaining turning loads imparted by turning a load with said work engaging member.

2. Ina torque measuring wrench, the combinationwith a rigid handle member, of a casing complemental to said rigid handle member, a turning load resisting shank on said work engaging tuming head member-comprising a cylindrical torsion shank anchored to said handle member, said =torsion shank having a substantially enlarged peripheral shoulder spaced from said handle member for confinement in said casing, said turning headmember including a work engaging shank extension journalled in said casing for rotation relative to said torsion shank,.a housing fixed to the peripheral shoulder of said load resisting shank, ratchet means in said housing. intenposed between said ,torsionand work engaging shanks, an elongated rod anchored to said ratchet housing, a flexible extension on said rod, said 'elongated rod serving to transmit the degree of their load sustaining movement relative .tosaidhandle member, said elongated rod extending along said handle member without being ,under any load stress or strain in transmitting movement of said head member and calibrated indicating means operatively connected to the free extremity of said flexible rod extension to measurethe degree of twist occasioned in sustaining turning loads imparted by said work engaging shank to said torsion shank relative to said handle member.

3. In a torque measuring wrench, the combination with a handle member including a casing rigid cover plate attached to said casing, awork engaging turning head :member comprising a cylindrical torsion shank anchored in said handle member and having a substantially enlarged peripheral shoulder spaced therefrom for confinement in said casing, a housing fixed to the end of said shank, said turning head member including a work engaging shank extension journaled in said torsion shank, ratchet means in. said housing interposed between said torsion and work engaging shanks, an elongated rod fixed at one end to said housing and extending along said casing, and indicating means operatively connected to the free extremity of said rod for displacement responsive to torque applied.

4. In a torque measuring wrench, the combination with a handle member including a casing, of a rigid cover plate attached to said handle member casing, a work engaging head member comprising a cylindrical torsion shank anchored in said handle member, said torsion shank having a substantially enlarged peripheral shoulder spaced from said handle member for confinement in said casing, said turning head member including a work engaging shank extension journalled in the casing of said handle member for axial rotation relative to said torsion shank, a housing fixed to the peripheral shoulder of said torsion shank, ratchet means in said housing interposed between said torsion and work engaging shanks, an elongated rod anchored at one extremity thereof to said ratchet housing to transmit the degree of their load sustaining movement relative to said handle member a comparatively flexible extension on said rod, without being under any load stress or strain in transmitting movement of said head member said elongated rod extending along said rigid cover plate for confinement by said casing, and turning load indicating means operatively connected to the free ex-,

tremity of said flexible rod extension which is displaced responsive to applying force to said rigid cover plate through said handle member.

5. In a torque measuring wrench, the combination with a handle member including a rigid non-yielding plate, of a work engaging turning proximate to one end thereoL'said work engaging head member comprising a uniform shank extending normal to said handle member for connection therewith, an enlarged ratchet housing on the extremity of said shank, said turning head member including a Work engaging shank extension coaxially mounted for rotation in said enlarged housing, reversible ratchet means in said housing and interposed between said torsion shank and said coaxial work engaging shank extension, an elongated rod achored at one extremity thereof to said ratchet housing at a point spaced from the anchorage of its connecting shank to said handle member, to transmit the degree of their load sustaining movement relative to said handle member said elongated rod extending longitudinally of said handle member, without being under any load stress or strain in transmitting movement to said head member said elongated rod terminating in a free highly flexible extremity proximate to the end of said handle member opposite to said work engaging head member, and

' turning load indicating means on said handle head member anchored in said handle member proximate to one end thereof, said work engaging. head member comprising a uniform shank extending normal to said handle member for connection therewith, an enlarged ratchet housing on the extremity of said shank, said turning head member including a work engaging shank extension coaxially mounted for rotation in said enlarged housing, ratchet means in said housing and interposed between said torsion shank and said coaxial work engaging shank extension, an elongated rod anchored at one extremity thereof to said ratchet housing at a point spaced from the anchorage of its connecting shank to said handle member, to transmit the degree of their load sustaining movement relative to said handle member said elongated rod extending longitudinally of said handle member, without being under any load stress or strain in transmitting movement of said head member said elongated rod terminating in a free extremity proximate to the end of said handle member opposite to said work engaging head member, and turning load indicating means on said handle member for operative connection to the free extremity of said elongated rod which is displaced responsive to applying force to said handle member.

6. In a torque measuring wrench, the combination with a handle member including a rigid non-yielding plate, of a work engaging turning head member anchored in said handle member member for operative connection to the free flexible extremity of said elongated rod which is displaced responsive to applying force to said handle member.

'7. In a torque measuring wrench, the combination with a handle member including a rigid non-yielding plate, of a Work engaging turning head member anchored in said handle member proximate to one end thereof, said work engaging head member comprising a uniform torsion shank extending normal to said handle member for connection therewith and adapted to twist in response to torque, an enlarged ratchet housing fixed to the extremity of said shank, said turning head memberincluding a work engaging shank extension coaxially mounted for rotation in said enlarged housing, ratchet means in said housing and interposed between said torsion shank and said coaxial work engaging shank extension, an elongated rod anchored at one extremity to said ratchet housing to project radially of said torsion shank {or rotary movement responsive to any torque twist therein, to transmit the degree of ,their load sustaining movement relative to said handle member said elongated rod extending longitudinally of said handle member, without being under any load stress or strain in transmitting movement of said head member said elongated rod terminating in a free highly flexible extremity proximate to the end of said handle member, and turning load indicating means on said handle member for operative connection to the free flexible extremity of said elongated rod, which is displaced responsive to applying force to said handle member, said elongated rod and flexible extremity being sufficiently rigid to actuate said turning load indicating means and sufiiciently yielding to absorb back-lash occasioned by an abrupt load release on said work engaging turning head member.

KENNETH R. LARSON. GEORGE M. WALRAVEN.

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