US2680396A - Hook-jaw centering means for pipe wrenches - Google Patents

Description

June 8, 1954 c. E. WRIGHT HOOK-JAW CENTERING MEANS FOR PIPE WRENCHES Filed Oct. 12, 1951 r v 0 0 0 0 o v o 0 Q 0 o o 0 o 0 5320202 1 3940 1 .F I INVENTOR. j CLYDE E. WEIGHT H/S A TTOENEY Patented June 8, 1954 UNITED STATES PATENT OFFICE HOOK-JAW CENTERING llIEANS FOR PIPE VVRENCHES Clyde E. Wright, Elyria, Ohio, assignor to The Ridge Tool Company, Elyria, Ohio 2 Claims.

-ment of the hook jaw laterally towards and away from the heel jaw, to center the hook jaw in its housing on the handle by means of springs. Since the hook jaw must also slide longitudinally, the use of such springs has necessitated provision of a stationary guide of some sort against which the spring can .press to hold the jaw in place. One such type of guide and spring arrangement is illustrated in U. S. Patent No. 1,727,623 to William O. Thewes.

The Thewes device has proved useful, but certain disadvantages in its use have appeared. These disadvantages were primarily incurred in the assembly of the device. At such times, the three tongues which formed the internal spring of the device frequently were misaligned, causing difficulty in the assembly and frequent rejection of the spring members as unsatisfactory.

By my invention, I have improved this type of spring so that rejections for mis-alignment of the spring tongue are reduced to practically nothing, and also assembly of the device is made much more easy. This is accomplished by an expedient which causes almost no increase in the cost of manufacturing the device.

A fuller understanding of the invention may be had by reference to the following description and the drawings which form a part of this specification.

Fig. i is a perspective View of the combined spring and guide member embodying my invention;

Fig. 2 is a front elevational view thereof;

Fig. 3 is a side view partly in section of a Wrench utilizing the spring and guide member;

Fig. 4 is a top plan view of the spring guide member alone;

Fig. 5 is a horizontal cross-section taken along the line 55 of Fig. 3.

As stated above, my invention has particular adaptation to use in pipe wrenches. As best shown in Fig. 3, the device of my invention comprises a combined spring and guide member Hi disposed in the opening II in the housing 12 on the handle I3 of a pipe wrench. A hook jaw I4 is slidably disposed in that opening and is adjusted longitudinally toward and away from a heel jaw I 5 by means of a nut it that is threaded on the shank of the hook jaw and engages the lower end of the housing 12. The hook jaw 14 is held centered in the opening 1 l by a combination of two springs. The first of the springs includes a member I ii, and the other is a small compression coil spring 59 disposed in a recess 29 in the housing 52 and which cooperates with the member Hi to provide the desired action or support for the hook jaw.

The member ii) is formed with a body part that embraces the stem part 22 of the hook jaw. One side 23 is in the form of long rectangle slightly curved transversely to provide a close conformation to the shank 22 of the jaw. From this side, a spring tongue 58 is struck from a central region of the rectangle leaving metal on all sides of the opening left by the tongue. This formation is very important. In the prior device, three tongues were formed at this stage. The outer two were supposed to be in alignment, but very frequently they spread apart so far that they could not be assembled into the opening ll. Moreover, if one was bent in the direction of the spring tongue is more than the other, the load on the two tongues was unevenly distributed and there was a tendency of the hook jaw M to become twisted in its opening i I. All of these disadvantages are eliminated by striking the tongue from the central part of the rectangle. At the same time, no additional disadvantages are incurred. By this construction the dimensional tolerances may be held within closer limits, and the manufacturing problem is greatly lessened because there are no plurality of tongues to become bent in various directions causing the disadvantages previously stated.

Extending from the rectangular side 28 is a narrow strap part 25 which lies along the broad side of the hook jaw and is bent at 26 to provide ;a portion .21 that embraces the other edge opposite the side 23. The end 27 of the strap part 25 beyond the bend 25 is again curved to fit the edge of the hook. jaw. It also provides a pad for the spring [9 to seat against. Thus, the spring i9 presses against the force of the spring tongue It on the guide member 18, and neither presses the hook jaw, thus leaving it free to slide.

As can best be seen in Fig. 3, the spring combination is disposed in properly formed recesses in the housing. They engage the shank of the hook jaw and hold it so that it is capable of movement in both forward and backward directions over the heel jaw 15 at the same time its fit with the shank is sufliciently loose that the shank is free to slide longitudinally, under control of the adjusting nut IE, to enable the hook jaw to be moved toward and away from the heel jaw.

In order to retain the main spring member in place, the housing is provided with a recess which includes a top portion that terminates in a shoulder 30 and an enlarged intermediate portion 3! extending for a zone opposite the main part of the tongue it. The side wall is also recessed at 32 to receive the part 25.

In operation the engagement of the part 25 with the recess 32 holds the spring in place and allows the hook jaw to be moved freely. When the wrench is engaged with a pipe, to turn the pipe, the hook jaw pivots in the housing, the teeth moving to the left opposite the heel jaw as viewed in Fig. 3.

This pivot action takes place largely at the lower end of the housing at the point indicated by the arrow X. Resistance to the pivoting action is provided by the combination of the two springs. Pivoting is also facilitated by the nut I6 which engages with the bottom of the housing.

It will be noted that this action can occur until the shank 22 engages with the side of the housing at the heel jaw. At this point, another advantage of the spring is observed. The upper bridging portion -23 of the main spring provides a fiat hardened arcuate surface which shields the housing and the shank of the hook jaw from each other since it engages with the housing just above the shoulder 30. It therefore prevents wear of the housing but also protects the threads on the shank of the hook jaw from being mutilated during rough usage and when the hook jaw is extended so far that the threads are opposite the bridge part 23, which frequently occurs.

Another advantage is also realized at this time. When the hook jaw starts to pivot in the housing, the main resistance to the pivoting effort is the tongue [3. As can be seen the recess 3i in the housing permits free bending or bowing of the tongue, between its ends, into the recess. This enables the tongue to retain its resiliency over a much longer period of time than was heretofore possible.

Although the wrench is intended to be used as a wrench and not intended to be used to strike blows with, it frequently is used in a manner for which it was not intended. The workman usually hammers with the wrench against a pipe or other object, causing an impact against the edge of the wrench below the heel jaw and opposite the housing. This causes a violent pivoting of the hook jaw in the housing. At this time, it will be appreciated that the bridge 23 is most desirable for protecting the parts, and what is important is the fact that the recess 3i particularly at the juncture of the tongue it with the body 23 prevents the hook jaw from hammering the bend out of th tongue and thus causing it to lose its desired form.

It will thus be seen that by my improved construction I have provided a wrench, the parts of which are now economical to manufacture and assemble, and where protection for the parts is provided because of the inbent construction and which constitutes an improvement over the prior art.

Having thus described my invention, I am aware that numerous and extensive departures may be made therefor without departing from the spirit thereof as defined by the appended claims.

I claim:

1. In a pipe wrench having a handle with a heel jaw at one end and a hook jaw housing adjacent the heel jaw, said housing having an opening therethrough substantially parallel to the handle and a hook jaw having a threaded shank extending through said opening and a jaw disposed over the heel jaw, the opening in the housing being sufiiciently large to permit pivoting action of the hook jaw in the housing, the improvement which comprises spring means for holding the hook jaw shank centered in the housing and comprising a longitudinally extending portion shaped for close sliding engagement with a front surface of the hook jaw shank, an arm portion extending transversely from one side of said longitudinal portion so as to lie along a side surface of the shank, and terminating in a curved end engaging a rear surface of the shank, said longitudinal portion being provided with a tongue spaced from an upper and from both side edges of said longitudinal portion, and sloping outwardly from a juncture line spaced below said arm portion, the spacing of said tongue from the upper and side edges of said longitudinally extending portion providing side strips connected by a bridge, said bridge holding the side strips in alignment, and said bridge being disposed between the front surface of said shank and a front interior wall of said housing, whereby said bridge may serve as a buffer during said pivoting action of the hook jaw.

2. In a pipe wrench as recited in claim 1, said housing interior wall confronting said tongue and being provided with a recess extending from above the tip of the tongue to a point below the juncture of the tongue with said longitudinally extending portion, and said recess having sufiicient depth and width to provide for fiexure of the tongue into the recess during said pivoting action.

References case in the file or this patent UNITED STATES PATENTS Number Name Date 1,727,623 Thewes Sept. 10, 1929 1,939,798 Thewes Dec. 19, 1933 2,192,702 Wright Mar. 5, 1940 2,302,633 Ingwer et a1 Nov. 1'7, 1942

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