US2574834A

US2574834A - Pipe wrench

Info

Publication number: US2574834A
Application number: US778590A
Authority: US
Inventors: John R Leonard
Original assignee: Individual
Current assignee: Individual
Priority date: 1947-10-08
Filing date: 1947-10-08
Publication date: 1951-11-13
Anticipated expiration: 1968-11-13

Description

NOV. 13, 1951 LEONARD 2,574,834

PIPE WRENCH Filed Oct. 8. 1947 JozwnzzvmD Patented Nov. 13, i951 when STTES PIPE WRENCH JohnR. Leonard, Washington, C. Application oetobers, 1947,'SerialNo.778;590 i cases.- (01. 81-1919.)

This invention relates to a pipe Wrench.

One of the objects (of the invention is .to provide a pipe wrench which can get a fast .grip on a pipe that lies close to :a wall, without the necessity of any part of the wrench being interposed between the pipe and wall.

In the conventional pipe wrench the initial fast grip is Qbtainedby' rotating the wrench through an arc of considerable magnitude. .When working with such a wrench 'upon a pipe which is close to the wall, th'e working arc may not be substantially greater-than 180,which arc is. fully occupied by the jaws of the wrench whenthey are first placed astride the pipe so that there is no room for any turning movement of the wrench in order to get the initial hold on the pipe. Consequently; in such situations it is necessary to break away some of the plaster behind the pipe, ;so that one of the jaws can be placed back of the pipe, leaving some room at the front through which the wrench can be turned for gripping and turning the pipe. l H p The present invention provides a pipe wrench which takes up all lost motion upon being moved rectilinearly to an -einbracing position relative to the pipe, until it is in firm contact-therewith, from which position abiting grip-is immediately securedat the beginning of the turningrm ovemerit, the major part of theturning movenient being usefully employed in turning the pipe.

Another object of the invention .is vto provide a pipe wrench of the type described,- thejaws of which are tapered to'ward thirfree ends .forwardly of the normal turning center of the wrench, to increase the turning are when wo'rking upon a pipe close to a surface which-nor nlally would obstruct the wrench.

A further object of the invention is to provide a pipe wrench as described, in which upon initial turning movement of the wrench in a tightening direction, the jaws tilt to positions of tangency to the pipe, forward of the normal diametrical points of tangenc'y at which they engage the pipe prior to tightening movement, thereby reducing the width of the mouth. of the wrench to less thanthediameter 6f the pipe, so that" the pipe is positively prevented from slipping forward in the jaws, ensuring immediate seizure'of the pipe and maintenance of the grip until the wrench is reversely turned in a release direction. a v

Other objects of the invention will appear as the following description of a preferred and practicalembo'diment thereof proceeds.

In the drawings:

Figure 1 is aside sectional view of v a wrench embodying the principles or the invention, in its initialp'osition with respect to a pipe:

Figure 2 i a side elevation, partly in -sectiony showing the pipe entered between the jaws, but

not gripped;

Figure 3 is taisirr'iilar view showing the pipe is the movable member 4 havinga movablewiawl 5, complementary to .the fixed jaw}, said movable jaw. being integral jwithwan adjl ting stem 6, and being disposed substantially;at,right, angles thereto. The handlez preferably extends inia direction perpendicular to the stemdi, that vis,

in a general direction opposite to the mouth ofthe wrench. I V g V I 'Ihestem 6 has a series of concave teeth fl on its back face engageable with a worm 8, ,by m n f wh h th width of th cia oneti e is adjusted. T e wr n his re er y madeto akeo ytwo sizes. p nipejpr mar lv o minimi e the requisite engt o the m V6 sgth t. th latter w l p o t undu ytw en ad u e il a s all p p and sec ndar te r y n th wrench from being usedon a pipe tqo large forits str n h and ecomin brok through h of an extension on its handle v p I H V The stem 6 is slidable through a; guide in the body ,I. Said guide hastwo-aligned portionss and vtermed apart. The u 'en qr i l 94 a channel; openat the front. The lower portion lll is a close d bore. Flfhefie f .5 .is of uniform os ct o lth e hel t th ex e fi of ts .tqol per oa. e n rov ed. wi h sntran Side, fflfis forming channels ll; w ich fit about projecting i s l e ili "ii i li fin 9 he 'iml' ifi sides ofthe fguide channel {land the guide bore lh e inner b ck wall or the guideportions Sand 10 he inthe same I engaged by the toothed rar face of theQstein 6 The body 1 between the ptruans'ejafid later the Stem guide tilni guide channel!) and theifin'r front face of the guide bore I'll. It is forrfid' a recess [3,

opening initsjrrentra',wi er thanitl'iewidth of said guide marina and giiid bore; and exten ing depthwise, that is, inja direction toward the handle, asumcie'nt distance to housethe a with freedom r tn wofn n to rotate 'in. said recess. Above the recess [3 the guidechannel ne and are slidably 9 has a narrow slot [4 extending depthwise, and below said recess l3 the guide bore has a similar slot 15, said slots opening into the recess l3. These slots are to receive the aligned trunnions I6 and H of the worm 8, and terminate at such a point as to position the worm with only its thread extending into the path of the teeth 1 of the stem 6. The body I has aligned openings [8, through its opposite sides, exposing the sides of the worm, giving access for its manipulation.

In assembling the wrench, in the first instance the worm is introduced from the front into the recess l3 with its trunnions in the slots l4 and I5, and pushed back until the trunnions engage the ends of said slots. This positions the worm with its thread extending into the path of the stem 6 of the movable member 4. Next, the stem 6 is introduced into the guide groove 9 and pushed down until its toothed back face contacts the thread of the worm. Then the worm is turned, screwing the stem 6 down until it enters the guide bore 10, passes therethrough, and projects from the lower end thereof. An end plate [9 is provided, having the same cross-sectional shape as the stem 6, but no thread teeth on its rear face, which is screwed congruently onto the projecting end of the stem 6, making the movable member inseparable from the fixed member. The body or fixed member I is of greater thickness than the diameter of the worm in those regions which surround the openings l8, so that the worm is below the plane of the sides of the fixed member and protected from being battered through misuse.

The jaws 3 and 5 are formed with curved inner faces 20 and 2|, respectively, that of the upper jaw being concave and that of the lower jaw being convex. Toothed

jaw members

22 and 23 having correspondingly curved outer faces, slide along the respective curved faces 20 and H of the upper and lower jaws, being retained and guided by

dovetail tracks

24 and 25, formed on the respective jaws 5 and 3, slidably supported by complementary dovetail grooves on the

respective jaw members

22 and 23. The tracks terminate short of the free ends of the jaw members, so that they will not become marred by chance contact with the work in the use of the wrench. The curvature of the interfaces between the jaws and jaw members'extends in an upward direction throughout the range of sliding movement of the jaw members; that is, said grooves are struck from radii which lie beyond the range of travel of the jaw members in a direction toward the closed end of themouth of the wrench. The toothed faces 26 and 21 are straight, the upper toothed face 26 being chordal with respect to the grooved face 20, while the lower toothed face is tangential with respect to the curved face 2!. Consequently, the upper jaw member 22 tapers toward its outer end, said outer end being thin, while the jaw member 23 tapers towards its inner end, its outer end being thick. Both toothed faces in the course of operation of the wrench deviate slightly from a relation of mutual parallelism. As the

jaw members

22 and 23 move inwardly upon the respective upwardly curved guide tracks, the toothed face of each tilts in a clockwise direction, and as said jaw members move outwardly, their toothed faces tilt counterclockwise.

The upper jaw member 22 is normally held in a neutral position by a spring 28, inserted in a bore in the slidable jaw and projected into the' apex of a V-shaped notch in the upper jaw member. Fromthis position, said jaw member can 4 move either inward or outward. When in new tral position, its outer end is slightly inward with respect to the outer end of the jaw 5, so that its thin end is protected and reinforced by the overhang of said jaw.

The lower jaw member 23 is normally held in its foremost position by means of a spring 29, mounted in a bore in the fixed jaw 3 and projecting into a notch in the lower jaw member. From thisposition the lower jaw member is yieldable inwardly. There is ample clearance between the inner ends of the jaw members and the adjacent structure which constitutes the closed end of the wrench mouth to permit the necessary range of sliding movement of the jaw members.

When in normal inactive position, as shown in Figure 1, the toothed face 2-6 of the upper jaw member 22 is inclined slightly downwardly toward the plane of the toothed face 21 of the lower jawmeinber 23. The lower jaw member normally projects outwardly beyond the upper jaw member, being complementary to the overhanging end of the movable jaw 5.

The wrench operates as follows: First, the mouth of the wrench is closed until its outer end is just too small to admit the pipe, as in Figure 1. Then the wrench is pressed against the pipe and pushed astride it by a rectilinear movement, the upper jaw being pressed radially'towarcl the pipe to favor the movement of the upper jaw member preferentially to the lower jaw member. The first action is that the pipe pushes the upper jaw member back, causing it to ride up on its curved track. This widens the jaw mouth, since as the upper jaw member moves back, it also moves upwardly. Also, its toothed face tilts in a clockwise direction, admitting the pipe into the mouth of the wrench. The pipe may be introduced as far into the mouth as may be desired, at least until the diameter of the pipe is some little distance inwardly of the end of the upper jaw member 22, as shown in Figure 2. There will never be a space between the pipe and jaw members, for the upper jaw member constantly thrusts forwardly in a wedge-like manner, automatically taking up any looseness between the jaw members and pipe.

Due to the fact that the lower jaw member projects beyond the upper jaw member, the point of tangency of the pipe with the toothed face 21 is quite a distance inwardly from the end of the lower jaw member.

Up to this time, no turning movement has been imparted to the wrench, but the toothed faces of both jaw members are in firm contact with the pipe, due to the automatic outwardly directed wedging action of the upper jaw member. Now the wrench is turned in a clockwise direction. The immediate result of this movement is to force the upper jaw member outwardly and the lower jaw member inwardly. Since the upper jaw member moves down-hill when moving outwardly, while the lower jaw member moves up-hill in moving inwardly, the toothed faces 26 and 21 of the respective jaw members will move towards one another, forcibly embedding their teeth more or-less into the pipe according to its hardness, to obtain a biting grip. In moving down-hill, the free end of the upper jaw member tilts downward, while in moving up-hill, the free end of the lower jaw member tilts upward. This mutual convergence of the jaws narrows the mouth of the wrench to a width less than the diameter of the pipe, as shown in Figure 3, and prevents the pipe from slipping from the jaws, even though the toothed faces may be somewhat worn or clogged. The fact that the wrench cannot escape from the pipe eliminates a danger hazard, par..- ticularly when working on an overhead pipe.

Upon release of the wrench, the upper jaw member is urged inward, while the lower jaw member is urged outward, the biting grip upon the pipe being released so that the wrench turns freely about the pipe, but the upper jaw member is constantly biased wedgingly outward by the spring 28, so that both jaw members are maintained in firm contact with the wrench during its reverse movement, enabling the wrench to immediately pick up its biting grip when it is pulled in a clockwise direction.

While I have in the above description disclosed what I believe to be a preferred and practical embodiment of the invention, it will be understood by those skilled in the art that the specific details of construction and arrangement of parts, as shown, are by way of example and not to be construed as limiting the scope of the invention.

What I claim as my invention is:

1. Pipe wrench having upper and lower jaws defining themcuth of the wrench, the confronting faces of said jaws being upwardly curved in a direction from'their free ends towards the closed end of the wrench mouth, the curvature of the upper jaw being concave and that of the lower jaw being convex, longitudinal track means on said curved faces, upper and lower jaw members having complementary curved faces engaging the curved faces of said jaws, longitudinally slidable thereupon and retained by said track means, the opposite faces Of said jaw members being planiform and toothed and so disposed with respect to the respective curved faces as to mutually converge toward their forward ends when the upper jaw member is in a forward position and the lower jaw member in a rear position,

and being mutually slightly divergent toward their forward ends when both are in their forward positions.

2. Pipe wrench having upper and lower jaws defining the mouth of the wrench, the confronting faces of said jaws being upwardly curved in a direction from their free ends toward the closed end of the wrench mouth, the curvature of the upper jaw being concave and that of the lower jaw being convex, longitudinal track means on said curved faces, upper and lower jaw members having complementary curved faces engaging the curved faces of said jaws, longitudinally slidable thereupon and retained by said track means, the opposite faces of said jaw members being planiform and toothed and so disposed with respect to the respective curved faces as to mutually converge toward their free ends when the upper jaw member is in a forward position and the lower jaw member is in a rear position, and being mutually slightly divergent toward their free ends when both are in their forward positions, a spring yieldably holding said upper jaw member in a neutral position from which it can move forward or rearwardly, and a spring yieldably'holding said lower jaw member in its foremost position.

3. Pipe wrench having upper and lower jaws defining the mouth of the wrench, the confronting faces of said jaws being upwardly curved in a direction from their free ends towards the closed end of the wrench mouth, the curvature of the upper jaw being concave and that of the lower jaw being convex, longitudinal track means on said curved faces, upper and lower jaw members having complementary curved faces engaging the curved faces of said jaws, longitudinally slidable thereupon and retained by said track means, the opposite faces of said jaw members being planiform and toothed and so disposed with respect to the respective curved faces as to mutually converge toward their free ends when the upper jaw member is in a forward position and the lower jaw member is in a rear position, and being mutually slightly divergent toward their free ends when both are in their forward positions, a spring yieldably holding said upper jaw member in a neutral position from which it can move forward or rearwardly, and a spring yieldably holding said lower jaw member in its foremost position, said jaws being each externally convergent toward its free end, the forward end of said upper jaw member being thin and when in foremost position being overhung by the free end of said upper jaw, the forward end of said lower jaw member being thick and when in foremost position extending beyond the free end of said lower jaw.

4. Pipe wrench comprising a fixed member including a lower jaw, and a cooperating movable member adjustable with respect to said fixed member and including an upper jaw, said jaws defining the mouth of the wrench, the confronting faces of said jaws being upwardly curved in a direction from their free ends toward the closed end of the wrench mouth, the curvature of the upper jaw being concave and that of the lower jaw being convex, longitudinal track means on said curved faces, upper and lower jaw members having complementary curved faces engaging the curved faces of said jaws, longitudinally slidable thereupon and retained by said track means, the opposite faces of said jaw members being planiform and toothed, and so disposed with respect to the respective curved faces as to mutually converge toward their free ends when the upper jaw member is in forward position and the lower jaw member in a rear position, and being mutually slightly divergent toward their free ends when both are in their forward positions, a spring yieldably holding said upper jaw member in a neutral position from which it can move forward or rearward and a spring yieldably holding said lower jaw member in its foremost position, said jaws being each externally convergent toward its free end, the forward end of said upper jaw member being thin and when in foremost position being overhung by the free end of said upper jaw, the forward end of said lower jaw member being thick, and when in its foremost position extending beyond the free end of said lower jaw.

JOHN R. LEONARD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 454,896 Adams June 30, 1891 577,770 Martin Feb. 23, 1897 595,473 Hall Dec. 14, 1897 955,893 Miller Apr. 26, 1910 1,048,380 Youngguist Dec. 24, 1912 1,148,410 Smith July 27, 1915 1,344,573 Barnes June 22, 1920 1,362,481 Dobbins Dec. 14, 1920 1,396,982 Ward Nov. 15, 1921