US1348366A - Wrench - Google Patents

Description

R. LEHNHOFF.

WRENCH.

APPLICATION FILED PM! 23, 1919.

Patented Aug 3, 1920.

RUDOLPH LE NH FF, or. BURNHAM, ILLInoIs. L

. f wnmacn.

To all ivhom it may concern Be it known that I, RUDOLPH Lnrnfnorr, a citizen of the United States, residin of Illinois, have invented acertain new and useful Improvement in Wrenches, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification. 7

My invention relates to improvements in wrenchesand has special reference to an improved monkey wrench.

The object of my invention is to provide a wrench of the character known as monkey wrench which can bereadily manipulated to permit the movable jaw to be drawn out a back 11 and open at its-front.

freely, in which the said jaw shall be automatically withdrawn, and which shall be so constructed that the automatic retractionof the jaw can be readily controlled to permit it to be retracted substantially instantaneously or to be retracted slowly.

A further object of m invention is to provide a wrench of the c aracter outlined,

in which the cooperating screw and worm for relative movement of the two jaws of the wrench shall be normally locked in engaging relation and shall have a simple trigger release.

My invention consists in a wrench having two relatively movable jaws, screw means for adjusting said jaws, trigger means for releasing the screw means for permitting the free relative movment of the jaws,-;spring means for closing the jaws and means" for controlling the action of the spring in closing the jaws.

My invention also consists in the several features of construction and in the combinations and relations of parts whereby I am enabled to attain the above-mentioned and other objects and L all as hereinafter described, and particularly pointed out in the appended claims; 1

For a clear understanding of my invention, attention isdirected to said drawings, in which: i

Figure 1 is a longitudinal sectional view substantially on the line 1-1 of Fig. 3 and showing the two jaw members on the wrench in closed relation and side elevation;

at i. Bnrnham, in the county of Cookand tate I Application filed May 23, 1919. Serial No. 299,1 94.

Fig.2 is a view similar to 1 but showingvthe jaws of the wrench separated; and

igs. 3 and 1 are detailed cross-sectional views taken substantially on the lines.33 and 4-4 of Fig. 1.

The wrench comprises the two main members 5 and 6, the member 5 being provided with a jaw 7 and the member 6 with a 00- operating jaw 8. These members are arranged parallel with each other and the member 5 withits jaw 7 can be moved lon- .Speciflcat1on of Letters Patent. v Patented Aug, 3,1920. 1

gitudinally relatively to the member 6 to vopen the wrench as shown in Fig. 201; to

close the wrench as shown in Fig. 1.

To hold the members parallel and permit longltudinal movement I provide a sheet metal U-shaped casing 9 having sides 10 and Thiscasing receives the members 5 and 6 between its sides and its sides are rigidly secured to the member 6 by'rivets 12 and 13 and provides inclose the jaws 7 and 8,'which are thus free to engage the article upon which the wrench is to be used. I close the rear end of the casing by a filler end block 14, which is of providea pivotally mounted block 16 which is mounted at its rear end on the rivet 13 so thatit can swing from and toward the member5. Y c

For the purpose oflocking the member5 with its jaw '7'relativelyfitothe member 6 and its jaw 8 so that the'jaws cannot separate, in use, I provide aworm screw 18 rotatably carried by the block 16 and adapted to the housing in which the member 5 is longitudinally movable. This casing does not tween its rear end and the filler block 14 I be swung with the block into and out of.

mesh with a screw rack 19 which I form on mounted in the member 16 at the forward end of thenotch 20 and its rear end passes -through a'hole 22 which I provide in the filler block 14. The rear end-of the'shaft 21 projects beyond the block 14 and I se-.

cure a knurled head or button 23 on the outer end of the shaft and by which the worm screw 18 can be rotated to adjust the jaws "from and toward each other when the screw is in mesh with the rack. W v

I pivotally mount the block 16 as described so that I can release the rack from the screw, as shown in Fig. 2 to permit the.

quick and free relative movement of the outer 'aw 7 to open the wrench and its free inwar movement to close the wrench.

' For swinging the block. 16 on its pivot and the screw into and out of mesh with the rack, I provide a trigger lever 24 pivotally mounted between its ends to the sides of the casing on the pivot 25 and having one. end 26 arranged to engage in a notch 27 in the forward end .of the'block 16 and 1 so arranged that, when-the triggeris swung Tao in on its pivot.

on its'pivot the block will be swung out or To lock the screw in the rack I provide an inwardl'y'extending abutment 28 on the trigger and a cooperating outwardly extending projection 29 onathe free end of the block 16. The abutment 28 is in the path of the projection 29 as themember 16 swings out and prevents the swingingof the member 16 until thetrigger has been swung on 1 its pivot sufiicient "to permitv the projection 29 to :pass the abutment 28 as shown in Fig. 2. Y

It is to be noted that theline of pressure of the contact of the'projection 29 against the abu-tment'28 passes substantially through the pivot 25 of the trigger 24 and that consequently the'lockin'g pressure doesnot tend to rotate the trigger and release the, worm.

There is sufficient clearance between the end .26 of the trigger. 24 and'the walls of the .notch to permit the trigger to swing the abutment 28 out of the path of the projec tion 29 before the same contacts with the outerend thereof. The trigger 24 is nor- 'mally held in a locking position by a flat spring 30 mounted. in anopening 21 provided in the'rear end of the member 6 and having'its free end clampe'd'ina slot 32 provided in the member 6. T he spring 30 bears at -its'free'e'nd upon the finger :end 33 of the trigger 24 and tendsito hold said end outwardly, as shown in Fig. 1, where it can be conveniently pressed by the finger of' th user to release the worm and .rack.

In order to cause the wvoifm' 18 to be moved inwardly in advanceof. the engagement of the abutment 28 and-projection 29, I provide a light spring 30 substantially parallel withthe spring 30' and longenough so that its fre'eend projects between the proj'ection 29 and abutment 28 and formed to bear upon the-outer endof the projection 29 to yieldingly hold the block 16 swung inwardly' as far "as the engagement of the trigger therewith will permit. In consequence far enough of this the clearance between the end 26 of the trigger 24 and the walls of the notch 27 ,the'block16, with the worm 20, is swung inwardly quick enough so that the-projection 29 clears the abutment 28 as the trigger swings back to locking position.

To cause themember 5 to be automatically retracted once it has been drawn out, as shown'in Fig. 2, I provide a compression spring 34 mounted in an elongated notch 35 which I provide. in the backedge of the shank 17 of the. member 5. The forward end 36 of the pring 34 abuts a projection 37 secured to the-rear wall 11 of the casing 9 and the rear end 38*of the spring '34 abuts a projecting pa'rt 39 of the shank 1,7 of the member 5,'cons'equently when themember 5 is Withdrawnthe spring 'is compressedand tends to push the member 5 back again.v

I make the spring 34 tapered as shownso that I canmake the notch 35 correspondingly tapered in orderthatthe shank 17 at the forward end of the notch 35 will be as strong as possible. .I- guide this spring upon a rod 40 which is somounted at its forward end in the projection-37 that its rear end is threaded'through a ho1e'41 in the projection 39.' I makethe forward .end 'of the rod smallerthanthe rear end to accommodate the smaller diameter'of the spring at this end and 'I providea shoulder '42 on the rod against which the-projection 39 contacts to limit the outward movement of the jaw 7.

I Once the 'jaw -7 has been drawn out the spring34 will retract it unlessthe member is held either by being placed upon the article, as a nut upon which it is to be used or is held in some other way. The means which I provide to control the retraction of the jaw 7 consists of a pin 43 freely'movable in an opening 44 in the member6 and pro 'vided with ahead 45 at its inner end adapted to frictionally engage the adjacent edge :x

. of the shank 17. of. the member- 5. This fi'ic-.

tional engagement is caused the further inward movement. of 'the free end of the spr ng 30 after the trigger has been swung spring 34to retract the member 5 until the "j aws substantially fit the article engaged.

It isobvious that if, he relieves the pini 43 of all pressure the member5' will be into release the worm. from the stantaneously retracted with the whole force of the spring 34, it is also obvious that by maintaining some frictional" engagement between the pin 43 and the member 5 the retraction of the member 5 can be controlled as desired. If a highly finished article is to be engaged, 1t might mar it to have the member 5 retracted with a hammer-like blow. Having allowed the member 5 to be withdrawn so that the aws are in position to engage the article, the trigger is entirely relieved and the worm is forced back into contact the rack by the spring 30 and the cooperating projections 28 and 29 lock the worm in mesh. It is obvious, if at this time the worm should not enter freely into the rack, that a slight rotation of the worm by means of the knurled head or button 23 will cause the thread of the worm to mesh with the teeth of the rack and the worm would then be forced into mesh by the spring 30. If the wrench does not now fit the nut or bolt head closely enough the jaws can readily be adjusted by rotating the worm 18 by means of the knurled head or button 23*to cause the desired engagement of the jaws upon the article being manipulated As many modifications of my invention will readily suggest themselves to one skilled in the art I do not limit or confine my in vention to the specific sctructures herein shown and described;

I claim:

1. In a wrench of the kind described, two relatively movable members, a screw and rack connection for relatively moving members and for holding them in relatively adjusted positions, trigger means for locking the screw in the rack and for swinging the screw out of the rack, a spring resisting Separation of the jaws of the wrench, and a friction member movable by; said trigger for controlling the closing action of said spring.

2. In a wrench of the kind described, a

, screw and rack for relatively moving the I two aw members to ad ust the aws, means for releasing the screw and rack, means normally locking the screw and rack in engaging relation, a spring for yieldingly resisting the separation of the jaws, and

means for applying friction between the two lever engaging in a. slot in the free end of said block for releasing the screw from the rack, and cooperating parts on the block and lever alined with the ivot of said lever for locking the screw in t e rack.

4;. A wrench comprising two, relatively movable members, each carrying a jaw, a

rack on one member and a cooperating screw carried by the other member for relatively moving said members, a spring yieldingly holding the jaws against separation, a pivoted block in which the screw is rotaotably mounted, means for locking the block with thescrew and rack in mesh, means for unlocking and swinging said block on its pivot to release the screw from the rack, and means for frictionally engaging the two members to control the action of the spring in closing the jaws.

5. In a wrench of the kind described, two relatively movable members each having a jaw, a rack on one member and a cooperate ing rotatable screw carried by the other member for relatively moving said members and for holding them against relative movement, a spring tending to close said j aws together, a pivoted'block in which the screw is mounted, a pivoted trigger for releasing the screw from the rack, the trigger having three operating positions, and adapted in one position to lock the screw in the rack, in an intermediate position to lift the screw out of the rack, and means .en-

gageable by the trigger in its third posi tion for trictionally engaging the rack member to prevent the retraction of the rack member by said s ring.

In witness whereof I hereunto subscribe my name this 17th day of May, 1919.

RUDOLPH LEHNHOFF.

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