US2887922A - Self-adjusting pipe wrench - Google Patents

Description

May 26, RUFF! SELF-ADJUSTING PIPE WRENCH Filed May 1, 1957 INVENTOR.

Everett W 3 av N mm 2,887,922 SELF-ADJUSTING PIPE WRENCH Everett E. Rulf, Camrose, Alberta, Canada Application May 1, 1957, Serial No. 656,453

2 Claims. (Cl. 81-99) This invention relates to pipe wrenches. More particularly, the invention relates to a self-adjusting wrench, adapted for use on pipes and other tubular or solid members of various sizes and cross-sectional shapes.

It is an object of the present invention to provide a pipe wrench that will permit work to be performed on pipe and related workpieces with greater ease and speed than has heretofore been true, andthat will be designed to facilitate the gripping and the rotational movement of pipe even when it is located in relatively inaccessible areas.

It is another object of the present invention to provide a wrench characterized by the ease with which it may be engaged with or disengaged from a pipe, and characterized, further, by a ratchet action of the handle.

It is another object of the present invention to provide on a wrench of the type stated complementary jaws having a particular shape and a particular arrangement of teeth which, taken with the particular axis about which the jaws are relatively swingable, will produce an especially effective gripping action upon the associated workpiece.

For other objects and a better understanding of the invention, reference may be had to the following detailed description taken in connection with the accompanying drawing in which:

Figure 1 is a view of a pipe wrench according to the invention with the jaws in closed position, partly in side elevation and partly in longitudinal section;

Fig. 2 is an enlarged longitudinal sectional view substantially on line 22 of Figure 1 in which portions have been broken away;

Fig. 3 is a fragmentary view similar to Fig. 1 in which the jaws are illustrated in position closed about a pipe, the pipe being shown in transverse section;

Fig. 4 is an enlarged, detail, transverse sectional view substantially on line 4-4 of Fig. 1; and

Fig. 5 is a transverse sectional view through the jaws substantially on line 5-5 of Fig. 1.

Referring now more in detail to the drawing, an elongated tubular handle 10, increased progressively in diameter toward its rear end, has a forwardly projecting longitudinal extension 12 at its front end provided with a longitudinally and centrally extending slot 14 opening upon the top and bottom surfaces of the extension and communicating (see Fig. 1) with the bore of the tubular handles body portion.

Integrally formed upon the front end of extension 12 is a jaw 16, appropriately termed a fixed jaw, having a work-engaging face arcuately curved through slightly more than 180 and formed, over its full length, with symmetrically shaped, transversely extending teeth 24.

Intermediate its ends, extension 12 is integrally formed with upwardly projecting ears transversely aligned to receive between them one end of a movable jaw 22 having a work-receiving recess the wall of which is arcuately curved complementarily to the arcuately bowed face of jaw 16, as shown in Fig. 1. Formed upon the wall of the recess of movable jaw 22 are transversely extending teeth 18 inclined or raked backwardly from the outer end of the jaw 22.

The inner end of the jaw 22 is formd with a short, straight arm portion 26 having a transverse opening aligned with openings of the ears 20 to receive a pivot pin 28. The arm portion 26, below the pin 28, has a depending extension 30 the forward edge of which has a transverse notch 32 receiving a hooked front end 34 of an elongated, contractile spring 36 that extends within the bore of handle 10. Within the handle 10, the spring 36 is threaded onto or coiled about a sleeve 38 the outer surface of which has a helical groove receiving the coils of the spring.

The bore of sleeve 38 is threaded to receive one end of an elongated adjusting screw 40 formed adjacent its other end with a collar 42. The outer end portion 44 of the screw is smooth surfaced, and extends within an axial bore of a cylindrical bushing or block 46 engaged fixedly in the outer end of the bore of tubular handle 10 by means of a set'screw 48 threaded through an opening of the handle into a recess provided in the bushing.

The end portion 44 is connected to a head 50 by means of a cross pin 52, so that the head will rotate with the screw 40. The head 50 projects beyond the rear end of the tubular handle 10 and has a kerf 54 adapted to receive the bit of a screw driver or similar tool, not shown.

By reason of the construction illustrated and described, it is apparent that on rotation of the head 50 in one direction, the screw 40 will rotate relative to the sleeve 38, which is held against rotation by the spring 36. As a result, the sleeve 38 will be shifted axially within the handle 10, causing the spring 36 to be either increased or decreased in tension, depending on the direction of rotation of the screw 40.

In use, the wrench is placed in engagement with a workpiece such as a pipe P. The jaws are engaged about the pipe by lifting the jaw 22 so that the pipe can be extended into the space between the open jaws. The tension of spring 36 may be temporarily decreased to permit this. Alternatively, the pipe may be engaged by and between the jaws through the provision of a nose 56 of the jaw 22. One would place the nose in engagement with the pipe, and exerting a downward pressure upon the wrench, would cause the jaw 22 to be opened due to the fact that the pipe will hold the jaw 22 against downward movement with the remaining parts of the wrench. When the wrench has been shifted downwardly and the jaw 22 opened, the wrench may be moved forwardly slightly to cause the pipe to enter the space between the jaws 16, 22.

In rotating the pipe clockwise in Figure 3, one simply rocks the handle 10 upwardly and downwardly. This produces a ratchet action, that is, on each downward movement of the hanlde 10, jaw 22 will be rocked clockwise in Figure 3. .Since the teeth 18 point in a clockwise direction, they will bite into the surface of the pipe and will cause the same to be rotated with the jaw 22. The teeth 24 will grip the opposed portion of the pipe, and though biting into the surface of the pipe, will do so to a markedly less degree than the teeth 18.

When the handle is swung upwardly, the teeth 18 will ratchet over the surface of the pipe, that is, the pipe will not be rotated counterclockwise, the spring 36 yielding as necessary to permit the slippage of the jaw 22 on the surface of the pipe as the jaw 22 now moves counter clockwise in Fig. 3. The teeth 24 will be designed to slip over the surface of the pipe in these circumstances, this being so by reason of the symmetrical shape of the teeth.

On the next downward movement of the handle 10, the teeth 18 will again bite into the surface of the pipe P to rotate the same.

Patented May 26, 1959 It will be seen that in this way, the pipe can be turned in aselecteddirection withmaximum ease and speed, even if located in a relatively inaccessible area. The wrench is thus designed to speed up the work upon the piping, and is adapted, ofi course, to adjust itself to the particular diameter of the pipe, by reasonof the spring 36. The tension of the spring can be adjusted as necessary, of course, to provide for gripping of pipes of different diameters with the desired degree of force.

The wrench is also characterized by its ease of assembly or disassembly. To remove the upper jaw, one need merely punch out the pin 28, shift the depending extension 30 downwardly out of the slot 14, disengage the spring from the extension, and remove the upper jaw; This permits the upper jaw to be replaced in the event of dulling of the teeth 18, or in the event that a jaw 22 of a. diiferent shape or size is desired.

While various changes may be made in. the detail construction, it shall be understood that such changes shall be within the function and scope of the present invention as defined by the appended claims.

What I claim as new and desire to protect by Letters Patent of the United States is:

1. A self-adjusting pipe wrench comprising, a handle,

a fixed jaw on said handle, a movable jaw pivoted upon 25 said handle for swinging movement toward and away from said fixed jaw, said jaws having confronting work engaging faces, and resilient yielding means connected between the movable jaw and handle and tensioned to normally bias the movable jaw toward the fixed jaw, said handle being of tubular formation and the resilient yielding means extending within said handle, said connection of the resilient yielding means to the handle comprising a threaded member swiveled and extending axially of the handle, and a sleeve having a threaded bore engaging said member, said sleeve being engaged against rotation by the resilient yielding means to place said means under a selected amount of tension responsive to rotation of the member in a correspondingly selected direction.

2. A self-adjusting pipe wrench as in claim 1, said resilient yielding means comprising a coiled, contractile spring, the sleeve having a helical external groove receiving convolutions of the spring to engage the. sleeve and spring with one another in selectedpositions of relative axial adjustment thereof.

References Cited in the file of this patent UNITED STATES PATENTS 566,299- Downey Aug. 25, 1896 937,959 Richards Oct. 26, 1909 1,120,815 Holland Dec. 15, 1914

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