US2920518A - Toggle-joint wrench with cam release means - Google Patents

Description

Jan. 12, 1960 e. M LA POINTE TOGGLE-JOINT WRENCH WITH CAM RELEASE MEANS Filed Sept. 10, 195'? 2 Sheets-Sheet l Jan. 12, 1960 6. M. LA POINTE TOGGLE-JOINT WRENCH WITH CAM RELEASE MEANS 2 Sheets- S heet 2 Filed Sept. 10, 1957 Patented Jan. 12, 1960 TOGGLE-JOINT WRENCH WITH CAM RELEASE MEANS Gabriel M. La Pointe, Worcester, Mass.

Application September 10, 1957, Serial No. 683,150

3 Claims. (Cl. 81--370) as a toggle joint. This toggle joint acts to lock the movable jaw against a work piece centered between the jaws with such force that considerable effort is required to break or release the toggle joint so as to efiect releasing of the work piece.

Heretofore various various types of quick release mechanisms have been invented and incorporated in lever jaw wrenches to facilitate unlocking of the jaws. Although such quick release mechanisms are well known and have gained some measure of acceptance, they have not been entirely satisfactory. One common objection is that considerable effort is still required to effect releasing of the jaws. Another objection is that they materially increase the cost of the wrench. A further objection is that they become inoperative or are broken easily under arduous use. Still another great objection is that the operators fingers are easily injured if not properly placed on the wrench. An additional objection is that the quick release mechanism requires or occupies too much space so that it can not be embodied in a relatively small, e.g. seven inch, lever jaw wrench.

Accordingly, the principal object is to provide a lever jaw wrench having .an improved quick release mechanism which avoids the objections attendant to conventional quick release mechanisms and which is capable of being operated by only one hand of the user. A more specific object of this invention is to provide a lever jaw wrench comprising pivotally connected stationary and movable jaws, a handle fixed to the stationary jaw, a lever pivotally connected at one end to the movable jaw, a link, means pivotally connecting one end of the link to said lever intermediate the ends of said lever, means supporting the opposite end of said link in pivotal relation with said handle, said link and lever together constituting a toggle joint effective to hold the movable jaw fixed relative to the stationary jaw when the pivot of said link and lever is forced slightly beyond the line running from the pivot of said lever'and said movable jaw to the pivot of said link and said handle, and a secondary handle pivoted to said lever provided with means for forcing said link-lever pivot to jaw unlocking position.

Another specific object of this invention is to provide a lever jaw wrench comprising a stationary jaw and a movable jaw secured in pivotal relation to said stationary jaw, a handle fixed to said stationary jaw, a lever pivotally connected at one end to said movable jaw, a link pivotally connected at one end to an intermediate portion of said lever and supported at the opposite end in pivotal relation with said handle, said link and lever together constituting a toggle joint effective to force the movable jaw toward the stationary jaw when the pivot of said link and lever is forced toward said handle, a secondary handle pivoted to said lever, and means operated by said secondary handle and engaging said link for forcing the pivot of said link and lever away from said handle whereby to move the movable jaw away from the stationary jaw.

Other objects and many of the attendant advantages of this invention will become readily apparent as reference is had to the following detailed specification when considered together with the accompanying drawings where- Fig. 1 is a view in elevation of a preferred embodiment of the present invention with certain parts broken away and shown in section;

Fig. 2 is a view in elevation of the same embodiment looking from left to right in Fig. 1;

Fig. 3 is a sectional view taken along line 33 of Fig. l;

Fig. 4 is a view in elevation of a second form of the present invention taken from the same vantage point as in Fig. l; and

Fig. 5 is a view in elevation looking from left to right in Fig. 4.

Looking now to Figs. 1, 2 and 3, the first form of the invention comprises an elongated handle 2 formed of sheet metal and bent at 4 in the form of a U-shaped channel so as to provide a pair of opposed substantially parallel sides 6 and 8. Welded to the top end of the handle and extending between opposed sides 6 and 8 is a steel jaw 10 preferably formed by casting or forging. -Attached to jaw 10 is a hardened steel gripping block 12. Secured to the upper end of the handle by means of a pivot pin 14 is a movable jaw 16 provided with a second hardened steel gripping block 18. A tension spring 20 connected at one end to a lug 22 formed in movable jaw 10 and at the other end to a hook 24 formed in the handle 2 urges the movable jaw 16 away from the stationary jaw 10.

A lever 28 formed of sheet metal and bent at 30 so as to form a pair of opposed sides 32 and 34 is pivotally connected at one end to the movable jaw 16 by means of a pivot pin 36. Extending between sides 32 and 34 and attached to lever 28 intermediate its ends by a pivot pin 38 is a link 40 formed of metal rod stock. The link 40 is of rectangular cross-section. The opposite end of the link 40 is provided with an enlarged rounded head 44. This rounded head bears against the end of an adjusting bolt or screw 48 which is screwed into a threaded socket 50 secured to the bottom end of the elongated handle 2. The opposed sides 6 and 8 of the handle 2 are bent around the socket 50 and hold it fixed to the handle. provided with an enlarged knurled head 52 by which it can be easily grasped and turned.

Pivotally secured to the lever 28 is an auxiliary handle 54 formed of sheet metal and bent at 56 .to form opposed sides 58 and 60. The auxiliary handle is secured to lever 28 by means of a pivot pin 62'. The pivot pin is fixedly secured to the auxiliary handles sides 58 and 60 and is rotatable relative to the lever 28. Between the sides of lever 28 the pivot pin 62 is cut away so as to be approximately semi-circular in cross-section and so as to provide a flat cam surface 64 adapted to bear against the edge 66 of link 40.

The curved edge surface 56 of the auxiliary handle overlaps the curved edge surface 30 of lever .28, so that when the auxiliary handle is moved in the direction of the fixed handle 2, it will force the lever 28 to rotate in the same direction. In other words, the auxiliary handle 54 in one direction of movement is adapted to The opposite end of the adjusting screw 48 is Vance it toward. the jaws, decreasesathe ,spacingbetween Qth .j-aws.

1The,,.general relative positionsbfdeven 28 1and link 40 whenjthe. jaws. are. in open positiontzis shown inabmken lines inFig. 1. "Closing of the Wrench is effected by moving auxiliary handles54=toward fixedhandle: 2. This .pivots lever-:28 vtowardhandle Landdorcesthempper. .end

' of link 40 to move inwardly -.toward-.the.=handle12. tT-he :pivot pin-38.1:noves: in line-with pivotppin 361 and? the point of contact of head 44: ofthe=1ink withescrew-48. Broken line y y. in Fig. l runs-from, pivot 36 10? the point of contact of head 44 and screw 48. Pivotpin;38 :passesqacross-line y,y.-;-and=-when thei-center of pin 38 .haspassedslightly .beyondi linei -y-,-.-y,a I il'miS? stopped due to the engagement of the surface 64 of.pin262-iwith the edge of 1ink40. With pivot:pin- 38-.slightly to one side of center, the toggle joint is locked.

To release the toggle joint, qthe auxiliarythandle 54 :is ;moved away from the fixed handle:2. -As-it moves .away from handle, 2,'it pivots relative-to lever28. When this occurs, pivot pinv 62 rotates @and'the edge between :its fiat. surface-64 and its curved surface bears against the edge of the link, forcingthelbottom end of lever 28 away from :the link torelease the toggle joint, .where- .upon spring 20, pullsthe jaw 10 to open position. .In releasing the toggle joint pivot pin 62 functions as a cam. The surprising ease with which the toggle joint is broken is due to the mechanical advantage provided by thelength of. the. auxiliary actingasalever to rotate the pivot pin 62. In practicelitthas. been: found that. the toggle joint. can be released bytthe' fingers 1 f the hand holding the wrench with ease. Whereas conventional ten inch lever jaw wrenches usually'require. approximately twelve pounds force to'breakxthe toggle joint, it has been found .;that: as. little asone-quarter of::a pound .of force is required to. break thetoggle joint of. the wrench illustrated ainfg'igs; 1 03.

The 'secondform ofzzthe. invention is quite similar to the; form;.alreadyadescribed. In this form of the invention, the linki40a'sisvslightly curved. This is different from-the link '40 of Fig.: lawhich isa straight bar. The ;auxiliary:handle-5.4a"in Fig. 4 is pivotally secured to the lever; 28a byameans of a pivot pin 62 n which is of circular rcross-section throughout its length. However, also at- .tac'hedto the auxiliary'handle'isa second pin 70. This 'pin extends throughthe.sideS32a and34a of lever 28a, the sidesv each ibeingtprovided-with an arcuate slot 72.

When the auxiliary handle 54a :is moved from the :dotted line position to the'position shown in full lines (Fig. '4), lever 28a and' link-40a arepivoted toward .handle 2a,:moving1the-jaw 16a toward jaw 10a. As the center of pivot 38a passes through the line 'y1-y1 corresponding to" line y-yof Fig. 1, link 40a is engaged by pin.62a and/or pin '70. When this occurs the toggle joint is locked. -It is not necessarythat pin 62a and pin '70 bothengage the edge 66a'of the link to lock the toggle joint;-= either one or both "may be positioned to engage the link.

When it is=desired toopen'the wrench, the auxiliary handle 54a is'moved awayfromthe fixed handle' 2a. -As it moves, it rotates relative-to the lever 28a'forcingthe :pin"70sagainst=theedge- 66a of the link. The -pin acts *as a cam to move the bottom end oflever z8a awayfrom es'the link. This moves the center of 'piv0t' 38a back-in line with line y1y1, breaking the toggle joint, whereupon spring20a pulls jaw'16a' to open position. The toggle joint is broken with substantially the same ease as the toggle joint of the embodiment of Fig. 1.

It is believed obvious that the two embodiments employ the same principles of operation. In both cases a pin acts as a cam against't-he link to break the toggle joint when the auxiliary handle is moved away from the fixed handle andfiaivots about the' lever. The only difference is that incnecase; thepirt'that functions as a cam is the.sarne,..pint-'by twhichathe-aauxiliaryt handle is pivoted to the lever and in the other case the pin which acts-against th linl is separate'from thepin which; pivotally secures thmauxiliaryuhandle tothe lever.

It is to be noted that' the links'40 and 40.1 are not physically secured to the screws 48 and 48a. Obviously they could be secured to a pivot block piloted on or restingmagainst....thenadjusting .screw, l. as. shown in US. IPatentL No..2,59.0,750,'..issued. March 25, 1952. .In. the

illustrated embodiments the links are prevented from movingout of .contactwith the screw bolts by the sides 6.and'Softbfixedhandle. The sides of the fixed handle curve .inward.-.toward each other at their edges. just .enough. lOpPICVCIlL theahead 44 from moving-out from ibetweenthe-sides ofwthehandle. In practice the. adjust- ..ingascrewais.alwaynengaged by the rounded end of the Hlink, r egardless ofnthe, position of the movable jaw.

.The wrenchlmay beanade of various typesof steel.

.,.Because..-.of.sits.1particular. construction, it is cheap seasytoa manufaeture= and assemble.

The quick release .mechanism-x-is not only; superior to other ,quick. release mechanisms heretofore embodied in lever jawwrenches, but .itI isasalsot strong -easyato assemble, andv does not take opp.1anys.spaceiaoralimit pperation of the wrench. The

force required 10% releaseathe toggle joint canlbe varied by.changing.thegzposition.ofthe pivot pin and can-be adjusted tto- .as.-little= asuone quarter of a pound so.that

the wrench canbe opened and closed withone hand.

Obviouslymany; modifications and variations ofiithe present invention. are; possible in the light of the above teachings. .Thereforait is to be, understood that .the inventionisnotilimited:in its application to the details of construction :and arrangement-of parts as specifically described I orillustrated, ;and Lthat-within I the scope of .the appended claims .itcmay; be practiced otherwise :than -a specifically. described.or.-illustrated.

I I .claim:

1. A lever jaw wrench comprising pivotally: connected stationary andzmovable jaws, a,handle fixed :to the stationary :jaw, a..lever;.pivotallyconnected at one: end-r10 the movable jaw;-.a:1ink,:means pivotally connectingnone end. of the linki-tmsaidxlever intermediate the :ends. offsaid .1ever,-.meansssupporting;the opposite end. of saidlinl-in --pivotal relation with saidrfixedhandle, saidxlinkand lever together constituting ma: toggle joint effective iOZ hold the movable jaw fixed-relative to :the stationary jaw'when nthe pivotof said link:and-"said leveris forced .slightly -be- 'yondithelinerunning. fromthe pivot of said lever andsaid movable .jaw to thesf'pivot' of saidv link .and' said fixed handle; a secondaryii handle, and a pivot pin connecting one end of said-second'aryhandle to said lever, said pivot pin shaving aT flat cam surface engageable" with said link when said-pivot: of saidllink and lever is moved slightly beyond said line to a position where said toggle jointis effective .to hold-saidmov'able jaw fixed relative tosaid stationary jaw, andoperable against said link to shift said pivot of said linkand -lever 'to the other side-of said line when-*saidsecofldarYhandle is rotated relative v:to said lever away from -said' fixed handle.

2. 'A lever jaw wrench comprisingpivotally' connected stationary-and movable jaws, a handle fixed to'the'sta- 'tionaryi jaw, a lever pivotally-connected at one end'to ithe'movable jaw,' a link,"meanspivotally connectingone end 'of the 'link tosaiddever intermediate the-"ends "of said-leverymeans supportingthe opposite end ofisaid' liilk in pivotal relation with said fixed handle, said link and lever together constituting a toggle joint effective to hold the movable jaw fixed relative to the stationary jaw when the pivot of said link and said lever is forced slightly beyond the line running from the pivot of said lever and said movable jaw to the pivot of said link and said fixed handle, a secondary handle, and a pivot pin connecting said lever with one end of said secondary handle whereby said secondary handle functions as an extension of said lever, said pivot pin being fixed to said secondary handle and rotatable relative to said lever, said pivot pin having a flat cam surface engageable 'With said link for forcing the pivot of said link and lever away from said fixed handle across said line to jaw-unlocking position when said secondary handle is pivoted relative to said lever in a direction away from said fixed handle.

3. A lever jaw wrench comprising a first jaw, a first elongated handle affixed to said first jaw, a second jaw pivotally secured to said first handle, a tension spring connected to said first handle and said second jaw normally urging said second jaw to open positon relative to said first jaw, a lever pivotally connected at one end to said second jaw, said lever having a U-shaped cross section defined by two opposed side walls and a third connecting wall, a link, a first pivot pin pivotally connecting one end of said link to an intermediate portion of said lever, means supporting the opposite end of said link in pivotal relation with said first handle, said link and lever together constituting a toggle joint effective to pivot said second jaw toward and away from said jaw when said first pivot pin is forced toward and away from said first handle, a

second handle, at least a portion of said second handle having a U-shaped cross section formed by two opposed side walls and a third connecting wall, said lever having its free end located within one end of said secondary handle with the side walls and connecting wall of said second handle overlapping the corresponding walls of said lever, and a second pivot pin pivotally connecting said portion of said second handle with the free end of said lever, said second pivot pin having its opposed ends fixedly secured to the side walls of said second handle, said second pivot pin also extending through the side walls of said lever in rotatable relation thereto, the portion of said pin located between the side walls of said lever having a flat cam surface engageable with said link for forcing said first pivot pin away from said first handle to unlock said ja ws when said second handle is rotated relative to said lever in a direction away from said first handle.

References Cited in the file of this patent UNITED STATES PATENTS 2,523,385 Mead Sept. 25, 1950 2,590,750 Burns Mar. 25, 1952 2,627,774 Walter Feb. 10, 1953 2,705,899 Berger Apr. 12, 1955 2,800,823 Tugend July 30, 1957 FOREIGN PATENTS 1,100,105 France Mar. 30, 1955

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