US2486755A - Rockable outer-jaw pipe wrench having slidable inner jaw actuated by rotatable handle - Google Patents

Description

J. A. MITCHELL ROGKABLE OUTER-JAW PIPE WRENCH HAVING SLIDABLE INNER-JAW ACTUATED BY ROTATABLE HANDLE 2 Sheets-Sheet 1 T NM Filed Dec, 30, 1947 INVENTOR. I JZ/We'w flJZ/fC/Ze Nov. 1, 194% J. A. MiTCHELL ROCKABLE OUTER-JAW PIPE WRENCH HAVING SLIDABLE INNER-JAW ACTUATED BY ROTA'IABLE HANDLE Filed Dec. 50, 1947 2 Sheets-Sheet 2 Patented Nov. 1, 1949 UNIT ED RCKAIBLEOU'IER-J AW BIPEWVRTEN'CH HAV- ING SLIDABIiE I INNER LIA-W AGTUATEDBY -;'ROTATABLE eHANDLE James A.IMitchell,' LittleRo'ck, Ark.

. Application December 30, 1947-;iSe1-ial No. 794,641

.2 Claims. 1

'lhiszinvention relates to improvements in pipe wrenches and moreparticul-arly to a quick-adjustable. pipe wrench for holding or turning i cylindricalzbodies of various sizes.

.wltsisrramong theobjectsof the invention to provide an ..impro.ved pipe Wrench which is quickly; adjustable. to grip cylindrical bodies of various :sizes; is :locked in adjusted condition against .iaccidental slippage, automatically tightens-upon; a;:cylindrica1 body disposed between thew-jaws thereof when subjected to body turning pressure is quickly-and-easily freed-from its=turningengagement.with a cylindrical body by .-a.- short backwardmovement of the handle which-.forces the jaws .of the wrench apart and eliminates-sticking, is .strong and durable in construction, and is economical to manufacture.

.Other objects .and advantages will become apparentlfroma consideration, of the following .description inconjunction with the accompanying. drawings, wherein:

Figure 1 is a longitudinal elevation of apipe wrench illustrative-of the invention.

.Figure 2 isatop plan view of the wrench i1- lustrated in Figure 1.

Figure 3 is a transverse cross-section onan enlarged scale taken substantiallyv on the line 3-1-3 .of Figure 1.

.Figure' 4..is afside elevation on an enlarged scaleof a fragmentary portion of the wrench showing the partsin a different operative positionifrom thatillustrated in Figure 1. and havingvportionsbroken away and shown in crosssections to better illustrate .the construction thereof.

Figure is a view similar to.'Figure 4 showing the parts of the wrench in a still difierent operative" position and with additional parts broken awayand-shownin cross-section.

Figuret is a view similar to Figures4 and 5 but showing the parts 'of the'wrench'in a differentposition from that shown in Figures 4 and *5.

Figure 7 is an end elevation of a bracket'cons'tituti-n'g'*an'operative component of the wrench.

*With continued reference to the drawings, the improved pipe wrench comprises in general, a screw shaft-l0 having a tubularycylindrical; coaxialhandle- -l l on one end thereof; a bracket l2' -journa-led on the end ofthe screw shaft opposite thehandle, an outer jaw member 13 pivotally *connected to the bracket and an inner jaw member l4 slidably supported by the bracket and pivotally and'slidably connected to the outer jaw "member '13.

z FI 1 1e-,'screw ishaft1 110 is" provided at-the5 end thereof opposite the handle l I with. a cylindrical, c-oaxialarbor "i5 of reduced .diameter and-a screwethreaded section I Eds secured on this. arbor between 1: the--ends thereof and drivingly .6011- nected with. thearborby. suitable means :such

assthe. keys? and. keyways cl 1;. and 18 @particularly illustratedzin Figure 3.

aBracket member 42 is. a generally rectangular 'bodyihaving a pair-of spaced-apart, apertured substantiallyparallel legs .19 and 20in which the arbor -l5--isjournaled theeleglfl being disposed between ,the screw-threaded section .1 6 :and .the adjacent .end of the.threadedvportion .of the screwrshafmhas is: clearlyil-lustrated in Figure 5. This bracket furtherhasa .cur-Ved top portion 2|. candle. .bottom .portion, 22,. the .two l'egs and the top and bottom portionbeingspacedapart to provide. va substantially square aperture in :the bracket which receives the screw-threadedisection-JB. Theouter .end of the arbor l5ispreferably. beaded vover. as indicated vat-23-to secure the-arbor inlthe bracket. Thetop portion 2| of the'bracket. isprovided .at the. end thereof opposite Lthe. screw. .shaftwith an apertured lug 24 extendinglbeyondthe endof-the arbor i5 and receiving a transverse. .pin 25 .the ends of which provides opposite shoulders.disposedone: at each side of the .lug and .the bottom portion 22 of the [bracket is provided with .a longitudinal guideway 26 substantially parallel to the axisv of screw shaft ill, and with an inclined camnotch 27 whichis directed toward .the handle-end of the screw shaft at an angle of. approximately .45 degrees tothe screw shaft axis.

Theo'utenjaw member l3. has a straight shank 28 of rectangulancross-section from. one end of which the outer .jaw 29 extends substantially perpendicular .tothe shank. Theinner face of this outer jawif29 is.serrated -or toothed, as indicated at '30, to securely. grip a cylindrical body to which the wrenchsis applied. At its end opposite the jaw"29"the shank '28.,is extended into a pair These abutments 33 are located at the side of pin 25 adjacent the handle end of screw shaft I0 and bear against the respective ends of the pin under certain operating conditions of the wrench, as will be later explained.

The inner jaw member I4 has an elongated rack bar 34 slidably received in the guideway 26 of the bracket and held by this guideway constantly in mesh with the threads of the screw shaft in. It is here pointed out that the screw shaft threads have a very steep pitch, approximating an angle of 45 degrees, so that the rack bar 34 is rapidly advanced and retracted upon rotation of the screw shaft. An inner jaw 35 is provided at the end of rack bar 34 adjacent the outer jaw 29 and a pair of spaced-apart apertured cars 35 extend from this jaw past the shank 28 of the outer jaw, straddling the shank, and a pin 3'! is secured at its ends in these apertured ears at the side of shank 28 opposite the inner jaw 25 to pivotally and slidably connect the inner jaw member to the shank of the outer jaw member. The surface of the end of the inner jaw member adjacent the shank is curved to provide a cam surface 38 and the inner face of the inner jaw 35 is provided with serrations or teeth 39 to I firmly grip an object, such as the cylindrical body 40 shown between the wrench jaws in Figure 1.

The leg 20 of bracket [2 is provided with a pair of tapered stops 4| disposed one at each side of the bracket leg and engageable in corresponding notches 42 provided in the plates 3| respectively at this location and the end of the rack bar 34 opposite inner jaw 35 is slidably secured to the screw shaft by a metal loop 43 surrounding the screw shaft and secured at its ends to the corresponding end of the rack bar by suitable means, such as the pegs or rivets 14.

The operation of the wrench is substantially as follows:

In applying'the wrench to a cylindrical object such as a pipe section 40, the outer jaw 29 is hooked over the object and the handle I l is then rotated to turn screw shaft II) to advance the rack bar 34 until the inner face of the inner jaw 35 is also brought into contact with the object. The outer and inner jaws 29 and 35 then bear against the opposite sides of the cylindrical object with a suificient amount of pressure to set the wrench or cause it to firmly grip the object when force is applied to handle H to rotate the object. Before the application of object rotating force to the handle H, the stops (H are spaced from the bottom of the corresponding notches 32, as illustrated in Fig. 4. Pin 32 is also spaced from the inner end of notch 21. When the handle is moved clockwise, asviewed in Figure 1, the inner jaw pivots relative to the shank of the other jaw upon the cam surface 38, carrying with it the screw shaft It and bracket l2, and abutments 33 are brought into contact with the corresponding ends of pin 25. With the pin 25 in operative contact with the abutments 33, a leverage is exerted between the location of this contact and the location of the contact of the threads of the screw shaft with the teeth of the rack bar which leverage tends to pull the outer jaw inwardly toward the inner jaw to provide a gripping action of the wrench. This movement is limited by contact of tapered stops 4| with the bottoms of notches 62 so that the force will not be sufilcient to crush an object such as a cylindrical pipe joint. When the turning force is released and the wrench backed up for another bite, pin 32 moves outwardly innotch 21 thereby separating the inner and outer jaws and freeing them on the pipe.

The wrench is easy to adjust, may be operated very quickly and firmly grips a cylindrical object, such as a pipe joint when pipe-turning force is applied to the handle thereof. It is also extremely rugged in construction and is not easily damaged in use.

The invention may be embodied in other specific forms without departing from the essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, and the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed is:

1. A pipe wrench comprising a screw shaft having a coaxial tubular handle at one end and a pair of spaced-apart arbor portions adjacent the opposite end thereof; a rectangular bracket having spaced-apart legs journaled on said arbor portions, a lug extending beyond the adjacent end of said screw shaft, a guideway extending therethrough parallel to said screw shaft, a machined cam notch therein at the side of said guideway remote from said screw shaft, and a pair of tapered stops disposed one at each side of said guideway; an outer jaw member having a straight shank, a jaw extending from one end of said shank substantially perpendicular thereto, a pair of substantially-parallel, spaced-apart plates extending from the end of said shank opposite said jaw and straddling said bracket, said plates having apertures therein at the location of the cam notch in said bracket, and a pair of inclined abutments disposed one at the inner side of each of said plates at the location of said lug; oppositely disposed shoulders on said lug respectively engageable with said abutments; a pin extending through said cam notch and secured at its ends in said plate apertures; and an inner jaw member having a rack bar slidable in said bracket guideway and held in mesh with said screw shaft; a jaw on one end of said rack bar substantially perpendicular thereto, a pair of apertured ears on said jaw straddling said shank; and a pin secured at its ends in said ears and disposed at the side of said shank opposite said inner jaw, whereby said inner jaw is adjustably movable relative to said outer jaw by rotation of said screw shaft and said jaws are relatively moved to J provide a gripping action by pressure of said abutments against said lug shoulders.

2. A pipe wrench comprising an exteriorly threaded screw shaft having a coaxial, cylindrical handle on one end, a bracket journaled on said screw shaft'at the opposite end thereof and having a guideway in spaced relation beneath and substantially parallel to the axis of said screw shaft, an outer jaw member including a shank, an outer jaw on the distal end of said shank, and a pair of spaced-apart plates on the proximal end of said shank rockably straddling said bracket, a lug and an inclined abutment connection between each of said plates and said bracket disposed on each side of said screw axis, and an inner jaw member including a rack bar positioned below the axis of said screw shaft and slidable in said bracket guideway, said rack bar having teeth on its upper side meshing with the threads of said screw shaft, an inner jaw on the end of said rack bar adjacent said outer jaw, and a loop on said inner jaw slidably and pivotally embracing the outer jaw and limiting rocking movement be- The following references are of record in the file of this patent:

6 I UNITED STATES PATENTS tween the inner and outer jaws Number Name Date 392500 Armstrong et a1. Nov. 6, 1888 JAMES MITCHELL 5 566,299 Downey Aug. 25, 1896 1,637,590 Robinson Aug. 2, 1927 REFERENCES CITED 1,774, 23 Anderson Aug. 26. 1930

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