US2492470A

US2492470A - Torque-reducing wrench

Info

Publication number: US2492470A
Application number: US631619A
Authority: US
Inventors: George B Farkas
Original assignee: American Locomotive Co
Current assignee: American Locomotive Co
Priority date: 1945-11-29
Filing date: 1945-11-29
Publication date: 1949-12-27
Anticipated expiration: 1966-12-27

Description

. Dec. 27, 1949 G. B. FARKAs 2,492,470

TORQUE-REDUC ING WRENCH Filed Nov. 29, 1945 i 2 Sheets-Sheet 1 FlG. l.-

G60/9e B, Farkas ATT Dec. 27', 1949 B, FARMS 2,492,470 9 f* TORQUE-REDUCING WRENCH i Filed Nov. 29, 1945 2 Sheets-Sheet 2 INVENTOR Gear 6B, Farkas l M60 8% l RNEY PatentedA Dec. 27, 1949 UNITED STATES TORQUE-RE-DUCING WRENCH George B. Farkas, Jackson Heights, N. Y., as-

signor to American Locomotive Company, New York, N. Y., a corporation of New York Application November 29, 1945, Serial No. 631,619

(Cl. ill- 53) 1 Claim.

This invention relates to a torque-reducing wrench, and more particularly to such a -wrench havingatorque indicator. Y

An object of the present invention is to provide a wrench which has a torque reducer, enabling a man to turn a threaded fastener, such as a nut or a setscrew, to tighten it, or loosen it when tightened, by applying less manual force than required when using a conventional straight wrench to perform the same task.

A further object is to provide a torque reducer Wrench, as aforesaid, having a lever with a socket for receiving the fastener and a torque reducer having a member xed against movement toward the lever and a member connected at one end to the lever and having a threaded connection at its other end with the iirst mentioned member, one of the members being rotatable about the axis of the threaded connection for turning the lever.

A further object is to provide a wrench as aforesaid, having a lever with a socket for receiving the fastener, and a torque reducer for turning the lever, having a support adapted to abut a stationary part of the structure to which the fastener is applied, a member abutting the support and adapted to be rotated relative thereto, and means connected at one end to the lever and having a threaded connection at its other end with the member whereby the lever is turned during rotation of the member.

Another object is to provide a wrenchas aforesaid having a torque-indicating crank or handle for operating the torque reducer whereby the force being exerted upon the fastener can be determined.

Other and further objects of this invention will appear from the following description, the accompanying drawings and the appended claim.

Referring to the drawings forming a part of this application, Figure 1 is an end v iew of a structure, parts being broken away, having fasteners of a type adapted to be tightened by the wrench of the present invention, the wrench being shown in operative position with its lever at starting position, the position of the lever at the end of its travel being indicated in dot-dash lines; Fig. 2 is a foreshortened end view of a torque-indicating handle forming a part of the wrench, taken from the right of Fig. 1; Fig. 3 is a view of the wrench lever and associated parts taken from the left ofv Fig. 1;' Fig. 4 is an enlarged end view of the supporting member of the torque reducer, taken from the left of Fig. l; Fis. 5 `Yis a section on the linev V-V 55 of Fig. 4; Fig. 6 is an enlarged axial section through the rotatable member of the torque reducer; Fig. 7 is an enlarged axial section through a cable-fastening device; Fig. 8 is an end view of the cable-fastening device taken from the right of Fig. 7; Fig. 9 is a view, similar to Fig. 1, showing anotherembodiment of the invention, applied to a different type of structure, which is shown fragmentarily, the lever being shown at the end of its travel and its starting position being indicated in dot-dash lines; Fig. 10 is an endl view of thel lever of Fig. 9, with associated parts, taken from the left thereof; Fig. l1 is an :endview of the supporting member of the torque vreducer of Fig. 9, taken from the right thereof; Fig. l2 is an enlarged view of a plate for preventing rotation of the torque reducer screw, the screw being shown in section; Fig. 13 is aview, similar to Fig. 9, showing another embodiment of the invention, parts being shown in section, the lever being shown at the end of its travel and the vangle of swing being indicated in dot-dashy lines; Fig. 14 is an inverted plan of the leverof Fig. 13; Fig. 15 is an end View vof ithe supporting member of the torque reducer of Fig. 13,. taken from the right thereof; and Fig. 16 is van enlarged axial section through the rotatable member of the torque reducer of Fig. 13.

The wrench shown in Fig. 1 is indicated generally bythe reference numeral I. It is shown, by Wayof example, in starting position for tightening set screws 2, having square heads 3, which screws are threaded in threaded orices 4 (only part ofthe screws being assembled) in a semicircular clamp ring 5. of .a conventional heat exchanger, the clamp ring being utilized for tightly pressing the head 6 of the heat exchanger in place. The heat exchanger forms no part of the present `invention and no further description thereof is deemed necessary.

vThe wrench includes a lever l, a torque reducer 8,. and a pressureor torque-indicating crank or handlev S. The lever 'i at its axis has apart I0 provided with a socket II which is adapted to fit on the heads 3. A triangular arm I2,open through its middle portion, is integral with the part I6 and has a curved outer face or edge I3 spaced radially of the axis of the socket II. Face I3 contains a groove I4 extending from one end thereof to the other end thereof. At one. end of theface I3, the left end as viewed inFig.Y 1,'a right angular shoulder I5 is formedl inthe .lever and a block I6 is secured in. this, 511911.16181; by welds Il. Block I6 has a 3 tapered bore I8 with its small end adjacent and in line with the groove I4.

The torque reducer includes a support I9, a rotatable member 20, a non-rotatable screw 2| and a flexible wire cable 22.

The support I9 is of block formation and has two circular holes 23 adapted to be imposed on two adjacent heads 3 at a distanceiromthe fastener to be tightened,v as is Vclearly shown in Fig. 1. The support is provided with a -bore 24 having portions :of two diierent diameters proi-*i viding a shoulder 25 which is disposed-at the..

side of the support remote from thelever' 'l' (the forward side).

The rotatable member 2D-1i's tubularlandmhasff its end 26 (rear end) disposed in lthe'v shouldered member 20 in line with the bore 24. Bore'2'I'has1-- threads 28 adjacent the support I9. The other end of the rotatable member hasnwelded thereina iitting 29A provided withf-fa square'center socket 3E.

The screw 2| is externally threadedthroughout its length and is screwedat vone -end'finto the threads 28. A fitting 3| havingan'internally threaded bore 32 is screwed onto'the .other er1-'d of the screw 2|. This1tting'alsofhasfa tapered chamber 33 provided with a groove'34 in its defining face. One end ofthe cable-22 Ais disposed in this chamber and secured to the ttingin any usual way as by zinc or other suitable'metal'wh'ich lls the chamber around the end ffof -thecable therein and fills the groove 34,'f'rmlysecur-ing the tting and cable together. l-A lock nut 35- is threaded on the screw 2| `against `the ttingrto prevent the screw 2| from turningout'of-thefite ting when the rotatable rnemberf is .rotaterlrV The cable 22 at its forward end'is vxsecured-n the bore I3 of the block 'I'Iiinra mannersimilfar to that described in connection-wwth-fits.attachment to the tting 3|. v

In normal starting position A'as shown infligk l, the cable 22 engages the entire `groovel-I 4 'but ars-the lever swings the cable 'straightensLout at its fior -1 ward end and leaveslthe #groove I4d'jacent .the tting 3 I. Where it is desired to providea lever for dierent size or diierent lshaped'fastenerfheads; the arm I2 at its axis may be adaptedtoire'ceive any one of a set of socket members ofappropriate sizes and shapes. O-nthe` other vhand'ffinsu'ch cases another lever having a suitablelsocketuna;7 be attached to the torque reducer-screw 2l.: :In such case, the nut 35.is loosened,'.thescrewt unscrewed from the tting 3| f'andfthen the sub-' f' stitute lever attached to the screw 2 :a reversal of this procedure.

The torque reducer vmaybe operate'drby a con-f ventional wrench or any suitable meansfbut it is preferably operated by the 'torque-indicating crank 9, as shown, so that the torque applied can be determined. The crank 9 may-be ofarfymake commercially available and the'. typical l' design includes a boss 36 having a fsquare-ffttingl 31- disposed in socket 3|), a heavyl'butirlexible arm'Ss. extending from the boss at'right anglest'oth'ero;1 tatable member 20, a needle 7.39"securedl-tothe boss and extending inline witlr-the-arm'f38, tand an extension 4U securedtof-the other endotth'e arm. A right angle plate 4Iis secured by means' .of one leg 42 thereof to the:exter'isiio'n'4Il=7djaai cent its connection with the-arml38andatfriglit angles to the arm." The ether-leg"f43iproects outwardly from the extensionl andi-is lpr'rivi'dedl wtha slot UI` throughI-whichtheneedle @fpm-tjects. The upper end of the needle cooperates with a scale 45 to indicate the torque being applied. The leg 43, outwardly of the slot, is bent to provide a curved retaining wall 46 for the needle, the slot thus forming a guide for the needle.

The operation of the wrench is as follows:

Tof tighten 'a screw f2, the1wrench2:is placed substantially in the position 'shown 'in Fig. l with the forward edge of the lever at right angles to the screw 2|. This is presuming the screw 2 has been tightened by a straight Wrench somewhat'l'ess than is nally desired, it being the purpose-of the:v torque reducing Wrench to give :ther'screw 2 its-final and usually predetermined degree vof tightening. This initial tightening should preferablyY dispose the head of the screw 2 angularly as shown in Fig. l.

the placing of the wrench in this position, the tightening force is 'most eiectively applied. Tolmaintain this--eiecti-ven-ess as the-:tightening proceeds; the lever '-'I should notbe iturned.toa position beyond that shownin dot and dash lines. If `further tightening is required; the`v lever I should be removedA from the 4screw 2, the member 20 reversely rotated back'oizthe screw 2|and the lever l'I again mounted on the 'screw 2- at Papwproximately the position shownfin Fig.'l 1, where; upon the tightening procedureis continued. The forwardpoint offcontact of the cable 22 :withthe arm'l for suitable-effectiveness should-'continue in a line throughthe axis of the lever atzirght angles to the screw 2|. Thisv conditionwill be maintained `until the lever :is turned to'itswdot and dash position.

The rotating `of memberl to turn theilevers accomplished in an obviousrmanner by turning the :crank-9.' The needle. will indicate'the. force being applied, due tothe bending ofrthe. crank arm, until finally the force -being indicated-corere'sponds to the desired tightening vof the screw 2 as'predetermined. This insures thatthescrewv will not be'tightened beyond the' critical point;

Thewrench is similar on opposite sides so that it -mayfbe`- reversed'to loosenr a scr-ewfZ byithe aforesaid procedure. They wrenchrsh-own in 'Figsz 1-8 is particularly adapted. to be' employedr where it '-is most convenient; and where there s sufT 'cient room, to have the lever withinrthewuter periphery'of thestructureto which the :fastener is being applied.

Ordinarily the.' screw :2| and `.therefore thecable 22', will have no tendency to turnduring'theturne ing ofthe member 2U, but shouldsuchi'nnde sirable turning tendto take placa-it maybefpre-L' vented by placing a straight wrench onthe :tting 3I1'and lett'i'nglit Abear against theheadi. :Org if desired; the :torque-reducinglwren'ch may lcvep'ro.A` videdilwithl means preventing turning of'th'escrew 2| relative tolthelsupport I3.v .Such la meansi is shown'l 'in' connection withftheA embodimentuof Figs. 'i9-l2andlit will` be understood that' this means can Salso fbei incorporated.in- Lthe -emfbodla' mentor Figs. 1-8 if desired;

The wrench aforedescribed enables "one 'mani-to manually turn a fastener-'which he Icould inotiturn with' arr-ordinary straight wrench, .th'e controlling factor"he`re= being the torque reducer whichV ire-v quires a large @amount `of rotatilontoffeiectl'a smalllamount of rotation otthelevere; J

The-wrench I' shownlin Figs. l9-12'is especially adapted-to'- be'used where it lis desirable 'to have the'lever "I' disposed outside'of-i-h'el circumferenceof `thelstructur'e to which thefrastenerr is being applied. 21 The lever- I 'distinguishes fromthe' lever 'l mainly in having a deep indentation 41 in the forward end wall to clear the fastener2 next to the fastener 2 being tightened, as is clearly shown in Fig. 9. The fasteners 2' are hexagonal nuts on bolts 48 passing through the flange 49 of a pipe 50. Because of the pipe 59, the lever l must extend outwardly from the circumference of the flange instead of inwardly asin Fig. 1.

The support i9 distinguishes from the support I9 in having an extension 5| in which the bore 24' and shoulder 25 are formed. Furthermore a plate 52 is secured to the portion of the support facing the lever 'i' by tap screws 53. This plate has an orifice 5d through which the screw 2| extends. The screw 2| distinguishes from the screw 2E by having a longitudinally extending slot 55 and the plate 52 has a tooth 58 extending into the orifice 54 and disposed in the slot 55. The

tooth 56 prevents the screw 2| from turning L when the rotatable member is rotated.

Parts of the wrench of Figs. 9-12 corresponding to like parts of the wrench of Figs. 1-8 are indicated by like references with an accent added. The plate 52 can be employed in the embodiment of Figs. 1-8 if desired, as aforesaid, in which case the screw 2| would have a slot similar to the screw 2 I.

The operation of the wrench of Fig. 9 is similar to that of Fig. 1. The lever is shown in its extreme forward position and the dot and dash lines indicate the preferred initial position.

The structure of Fig. 13 is similar to that of Fig. 9 and the Wrench of Figs. 13-16 is associated with the structure in a similar manner. Like parts of the structure and corresponding parts of the wrench are indicated by the same reference numerals with an accent added. The crank is similar to the crank of Fig. 9 but the other parts of the wrench of Fig. 13 each differ somewhat from the previously described corresponding parts of the wrench of Fig. 9.

The lever 1 has a part I0 provided with a socket II" suitable for hexagonal nuts, bolts, or the like. The lever further has a curved arm I2 having a fork 51 at its outer end, aligned orices being formed in the branches of the fork. The rotatable member 20" has a convexly spherical end 26". In other respects it is similar to the member 20. The support I9" has the two holes 23" and an extension 5| but the extension is provided with a bore 58 and the face of the support adjacent the member 20 is provided with a spherical seat 59, for receiving the end 26" in place of the shoulder 25 for the end 28'.

The screw 2| has an eye 60 on its end adjacent the lever, and this eye is disposed between the branches of the fork and pivotally secured thereto by a pin 6|. Screw 2| can angle in bore 58, the bore having a somewhat larger diameter than the screw 2|", the joint formed by the spherical end 26 and its seat 59 permitting this angle. The eye 60 prevents the screw 2|" from rotating with the rotatable member 20 but permits the aforesaid angling.

The operation of the wrench of Fig. 13 is similar to the operation of the wrench of Fig. 9. The arm i is provided with a pronounced recess or indentation for the same purpose as the indentation il and is shown in its extreme forward position, and the dot and dash lines indicate the angle of swing of the arm l from its preferred initial position. n

In Figs. 1 and 9 it will be noted that the screws 2| and 2| respectively are associated with their respective levers 'I and 'I' to maintain a desirable constant leverage during the turning of the fasteners, and this is substantially so with the wrench of Fig. 13, when swung through the angle shown.

While there have been hereinbefore described approved embodiments of this invention, it will be understood that many and various changes and modifications in form, arrangement of parts and details of construction thereof may be made without departing from the spirit of the invention, and that all such changes and modifications as fall within the scope of the appended claim are contemplated as a part of this invention.

The invention claimed and desired to be secured by Letters Patent is:

A manually-operable torque-reducing wrench for tightening and loosening a row of threaded fasteners such as nuts and bolts, comprising a socket for turning one of said fasteners; a lever connected to said socket for turning same having an arcuate groove it its outermost edge; a stationary member adapted to be anchored on at least two other of said fasteners spaced angularly from said one fastener, said member having a bore directed toward said lever; a flexible cable connected at one end to the end of said lever remote from said stationary member and seating in said groove; threaded means connected at one end to the other end of said cable and extending at its other end through said bore; a rotary member abutting said stationary member at the side thereof remote from said lever and being threaded on said threaded means; and a hand operated crank for turning said rotary member for drawing said lever toward said stationary member.

GEORGE B. FARKAS.

REFERENCES CITED The following references are of record in the file of this [patent:

UNITED STATES PATENTS Number Name Date 378,299 Finch Feb. 21, 1888 452,237 Robinson May 12, 1891 732,017 Whiteside June 23, 1903 769,814 Buiford et al Sept. 13, 1904 1,169,670 Naylor Jan. 25, 1916 1,355,597 Fahrner Oct. 12, 1920 1,778,055 Alinder et al Oct. 14, 1930 2,311,225 Grable Feb. 16, 1943 2,385,591 Sturtevant Sept. 25, 1945