US2704477A

US2704477A - wright

Info

Publication number: US2704477A
Authority: US
Publication date: 1955-03-22
Anticipated expiration: 1972-03-22

Description

March 22, 1955 c. E. WRIGHT 2,704,477

CENTERING AND GUARD SPRING FOR PIPE WRENCHES Filed Sept. 13, 1952 2 Sheets-Sheet 1 INVENTOR.

6 ,4 TI'OPNE Y March 22, 1955 c. E. WRIGHT CENTERING AND GUARD SPRING FOR PIPE WRENCHES 2 Sheets-Sheet 2 Filed Sept. 15, 1952 dill] INVENTOR. /yq e 5 M1? United States Patent CENTERING AND GUARD SPRING FOR PIPE WRENCHES Clyde E. Wright, Elyria, Ohio, assignor to The Ridge Tool Company, Elyria, Ohio Application September 13, 1952, Serial No. 309,429

4 Claims. (Cl. 81-101) This invention relates to improvements in pipe wrenches and more particularly to an improved hook jaw centering spring for pipe wrenches.

It has become common practice to provide in a pipe wrench, a handle which carries at one end a heel jaw and at the same end, offset thereto, a housing having an opening through which a hook jaw extends. It is desirable that the hook jaw move both forward and backward over the heel jaw in order that the proper ratcheting and gripping action with the pipe may be realized. In accomplishing this, the housing opening is usually wider toward the heel jaw end and the hook jaw pivots about a center at approximately that end of the housing remote from the heel jaw end, a nut being threaded on the shank of the hook jaw and bearing against said remote end of the housing.

In recent years it has been customary to make the handle and housing, which are integral, of the softer and lighter metals, such as aluminum or magnesium. In these instances the hook jaw, being of steel, has a tendency to wear the housing, and the nut has a tendency to dig into and mutilate the housing.

The present invention contemplates a spring construction which of itself presents an improved construction easier to make and resistant to breakage. It also guards the inside of the housing against wear from the hook jaw as well as guards against wear from the nut, and provides a resultant distribution of pressure from the nut to the housing over a large area, which pressure would otherwise be localized.

Still other advantages of the invention, and the invention itself will become more apparent from the following description of an embodiment thereof, which description is illustrated by the accompanying drawings and forms a part of the specification.

In the drawings:

Fig. 1 is an elevational view of a wrench of this invention with the housing and handle partly broken away and shown in section to show certain parts which would otherwise be hidden;

Figs. 2 and 3 are side elevational views of the centering springs used in the housing;

Figs. 4 and 5 are face views thereof; and

Fig. 6 is a bottom plan view of one of the springs.

Referring now to the drawings, throughout which like parts are designated by like reference characters, and particularly to Fig. 1 wherein there is illustrated a pipe wrench which includes a handle 10, the upper end of which is provided with a heel jaw 11, held in place by a pin 12 in a manner well known in the art.

The portion to the left will be considered the front, and the part to the right, the back, of the wrench.

Extending backward at the upper end, as viewed in the figure, is a hook jaw housing 14 which is cast integral with the handle. The hook jaw housing is provided with an opening 16 which extends substantially parallel with the handle through the housing from top to bottom. The opening is of generally rectangular cross section, being wider at the top than the bottom, and the front and rear walls are provided with

grooves

17 and 18 respectively.

The opening is adapted to receive a hook jaw which includes the toothed portion 20 that overhangs the heel jaw and a shank part 21, of generally rectangular cross section, which extends through the opening and is provided with threads 22 on the front and rear edges upon which is threaded an adjusting nut 23.

Spaced below the housing is a pair of ears 24 between ice which the shank may slide and which serves as an abutment for holding the nut against movement longitudinally of the housing.

The hook jaw, because of the shape of the opening in the housing, is capable of a limited amount of forward and backward movement over the heel jaw. This enables a better and quicker grip to be obtained on a pipe as well as to allow the ratcheting engagement of the jaws with the pipe in a manner well known in the art.

In order to provide the most efiicient of such action, it is preferable that the hook jaw shank be centered in the opening so that from this position it can move either way.

In this case, this is effected by two improved springs of the invention, one being interposed between the inner wall of the opening in the housing and the front side of the shank, and the other being disposed between the rear edge of the shank and the back wall of the opening.

The springs are alike except for length, the one on the front side preferably being longer because that wall is longer, and the one in back being shorter because the back wall is shorter due to the tapered contour of the v housing which can best be seen in Fig. l.

As can best be seen in Figs. 2 and 4, the spring for the front wall includes a semi-circular base 30 which provides a washer like guard between the nut and the lower surface of the housing, it being notched at 30' to allow the hook jaw shank to pass therethrough. The diameter of the base is substantially equal to the diameter of the nut but may preferably be somewhat larger.

Extending upward from and normal to the base is an upright member 31 which is curved transversely (Fig. 6) in an arc of substantially the same radius as the periphery of the threads 22 on the shank of the hook jaw. This member is adapted to lie against the face of the hook jaw shank and besides guiding the hook jaw shank, prevents the threads of the hook jaw shank from digging into the housing wall.

The upper end of the upright 31 is bent outwardly at 32 which is desirable to enable easier assembly of the hook jaw shank in the housing.

It can be seen that, since the base of the spring is enlarged between the nut and the bottom of the housing, the hook jaw shank is held centered in the housing. This centering action is, however, assisted by a tongue 33 struck from the center part of the upright and which tongue is bent outward away from the upright and seats in the groove 17. The end of the tongue is curved at 33 away from the groove wall.

The other spring is as stated exactly the same except for length. It has a base 35, upright part 36, and a tongue 37 which is bent at 38.

It will be appreciated that the structure of both springs lends itself to a simple stamping operation from a single sheet of metal, which is preferably of some highly resilient metal such as spring steel. It will also be apparent that a dual spring action is present due to each spring base being engaged between the nut and the housing and each spring tongue extending into the groove in the adjacent housing wall. It is to be particularly noted that greater strength for each spring is realized because each upright member is completely closed, being formed by two side strips integral with a top bight strip, which construction is not only stronger than an upright member without such integral bight strip, but which causes the guiding parts to act in unison in guiding the shank.

In operation, the opening through the housing being narrower at the bottom, the tendency of the hook jaw is to pivot forward and backward about a pivot point at or just below the bottom edge of the housing. When the wrench is gripping a pipe, there is a pressure on the hook jaw pulling it in an outward direction and pulling the nut against the bottom side of the housing. It will be apparent then that the hook jaw inclines one way or the other when gripping the pipe, and that as it is turned, the tendency of the hook jaw is to move forward over the heel jaw. The tongue 33 then bends inward toward its upright member, and the upright member moves toward the edge wall. The pressure of the nut against the underside of the housing increases at this time and is distributed by the base 30 over a large area, since the base is of material thickness, preventing the nut from digging into the housing.

When pressure is released, the tongues cause the shank to be again centered in the housing. It will be appreciated that there is some bending in the base. This is particularly apparent at the points 40 which are narrower at the slots. The pads 41, however, remain fiat and absorb the thrust from the nut.

This bending also assists in causing the shank to be returned to an upright position. As a matter of fact, it is contemplated that the

tongues

33 and 37 could be eliminated, and the bending action of the base relied on for maintaining the proper alignment. The tongues are to be preferred, however, because they do assist in maintaining the alignment.

Having thus described the invention in an embodiment thereof, it is appreciated that numerous and extensive departures may be made therefrom without departing from the function or scope of the invention defined in the appended claims.

I claim:

1. A centering and guard spring for a wrench having a housing, a hook jaw having a threaded shank extending through the housing, and a nut for adjusting the hook jaw, comprising a spring steel base portion interposed between the nut and the housing, a guide portion extending into the housing and having a curved portion conforming to the surface of the hook jaw shank, said base having an abutment surface extending outwardly from the junction of said base and said guide portions, and a tongue extending outwardly from the guide portion into engagement with the inner wall of the housing,

2. A centering and guard spring for a wrench having r a housing, a hook jaw having a threaded shank extending through the housing, and a nut for adjusting the hook jaw, comprising a spring steel base portion interposed between an upper surface of the nut and a lower surface of the housing, a guide portion extending into the housing and having a curved portion conforming to the surface of the hook jaw shank, and a tongue extending outwardly from the guide portion into engagement with the inner wall of the housing, said tongue being joined to the guide portion adjacent the base, and the guide por- 1 tion being formed by spaced side strips integral with a bridging top strip.

3. A centering and guard spring means for a wrench having a housing, a hook jaw having a threaded shank extending through the housing, and a nut for adjusting the hook jaw, comprising a pair of spring steel hook jaw shank and nut engaging members disposed on opposite sides of the hook jaw and each including a base portion of semi-circular formation and provided with a notch for the shank of the hook jaw, said base portion being disposed between the nut and the housing, an upright hook jaw guiding portion curved transversely to engage the threaded surface of the hook jaw shank, each base portion having an abutment surface extending outwardly from the junction of said base and said guiding portions, and a tongue struck from the guiding portion of said member and bent outwardly into engagement with the inside wall of the housing.

4. A centering and guard spring means for a wrench having a housing, a hook jaw having a threaded shank extending through the housing, and a nut for adjusting the hook jaw, comprising a pair of spring steel hook jaw shank and nut engaging members disposed on opposite sides of the hook jaw and each including a base portion of semi-circular formation providing spaced pads for contact with an upper surface of the nut and providing a notch for passage of the shank of the hook jaw, said base portion being disposed between the nut and the housing, and an upright hook jaw guiding portion curved transversely to engage the threaded surface of the hook jaw shank and having a tongue struck from said member and bent outwardly into engagement with the inside wall of the housing, said base portion also being necked down between said pads and the upright portion so that said pads are resiliently bendable relative to said upright portion.

References Cited in the file of this patent UNITED STATES PATENTS 1,734,734 Lawson Nov. 5, 1929 1,778,748 Bayrer Oct. 21, 1930 2,192,702 Wright Mar. 5, 1940 2,496,799 Lanckton Feb. 7, 1950