WO2015031937A1

WO2015031937A1 - Wrench

Info

Publication number: WO2015031937A1
Application number: PCT/AU2014/000871
Authority: WO
Inventors: Andax Petts
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-09-03
Filing date: 2014-09-03
Publication date: 2015-03-12
Anticipated expiration: 2016-03-03

Abstract

A wrench including: first (11) and second (12) jaw members each having a gripping portion (42) spaced from a leverage portion by an adjustable connector (16) connecting said first and second jaw members and holding them in opposed disposition, said connector providing an adjustable fulcrum allow pivoting of the jaw members relative to one other and allowing adjusting of the distance between the gripping portions for gripping the work piece from a minimum distance at which the first and second jaw members abut one another and a maximum distance; and a handle ( 13) pivotally connected (32) to said first leverage portion and having an engagement means such as a cam (36) on said lever handle (13) for levering the first and second leverage portions apart.

Description

WRENCH

THIS INVENTION relates to a wrench.

The invention has particular application to an adjustable wrench of the type which has opposed gripping jaws. However, it will be appreciated that the invention is not limited to this particular field of use, and may have application to other tools having other kinds of opposed moveable jaws, such as bolt cutters.

Many types of wrench have been provided for gripping a work piece which requires application of torque for rotational movement or holding against rotation. A particularly useful wrench for large work pieces, such as in mining and/or bore drilling is disclosed in my Australian Patent No. 771591 which discloses a wrench having first and second jaw members each having grips for gripping a work piece rotatable about a work axis and a leverage portion spaced from the grips, a handle pivotally connected to the leverage portion of the first jaw member for pivoting movement about a leverage axis parallel to the work axis, a protrusion on handle for engagement with the leverage portion of the second jaw member for urging the first and second leverage portions apart. An adjustable connector is interposed between the gripping portions and the opposed leverage portions for pivotally connecting the first and second jaw members to one another in opposed disposition. The adjustable connector is adjustable to vary the distance between the gripping portions to allow the grips to accommodate different sized articles. For convenience the wrench described in the patent will be referred to hereinafter as "my earlier wrench".

My earlier wrench has been satisfactory in its intended use, but it has been found through usage thereof that there are aspects of its usage and its manufacture and design which could be improved.

The present invention aims to provide a wrench which alleviates one or more of the disadvantages of, and/or provides improvements to, the prior art, particularly my earlier wrench. Other aims and advantages may hereinafter become apparent .

With the foregoing in view, in one aspect, the present invention resides broadly in a wrench for gripping a work piece rotatable about a work axis including:

first and second jaw members having first and second gripping portions for gripping the work piece and first and second leverage portions spaced from said first and second gripping portions respectively;

a handle pivotally connected to said first leverage portion for pivoting movement about a leverage axis parallel to said work axis;

connecting means connecting said first and second jaw members and holding them in opposed disposition, said connecting means being operatively interposed between said respective opposed gripping portions and said opposed leverage portions and being arranged to allow pivoting of one of said jaw members relative to the other;

adjustment means operatively associated with said connecting means for adjusting the distance between the gripping portions from a minimum distance at which the first and second jaw members abut one another and a maximum distance at which the jaws are separated from one another for gripping the work piece of a predetermined maximum size; and

engagement means on said handle for engagement with said second leverage portion for urging said first and second leverage portions apart and consequently said first and second jaw members together.

In another aspect, the invention resides broadly in a wrench for gripping a work piece rotatable about a work axis as hereinbefore described and further including another handle in fixed relationship to and extending from the leverage portion of the second jaw member.

The handles extend substantially at right angles to the work axis. The handles are preferably arranged in operative juxtaposition to each other for gripping of both handles by the hand of a user, and such that the handle pivotally attached to the first jaw member may be pivoted towards the other handle to tighten the grip of the gripping portions and away from the other handle to loosen the grip of the gripping portions . The adjustment means is preferably in the form of a screw in threaded engagement with a threaded passage penetrating diametrically through a pivot pin mounted in the first jaw member. In a preferred form, the adjustment means comprises a nut and bolt assembly, the pivot pin providing the function of the nut. In such form, the screw includes a shaped head which engages with a complementary shaped counterbore in an aperture penetrating the second jaw member. Preferably, the shaped head includes a hemispherical face extending from the shaft or shank of the screw.

Correspondingly, the shaped counterbore is shaped to conform to an inside face of a hemisphere, the shaped head and counterbore performing akin to a ball and socket joint, but with the shaft that extends away from the ball and socket joint being in tension rather that the normal arrangement in which the shaft or member extending away from the ball and socket joint is in a direction which accommodates compression of the shaft or member. In a preferred form, the nut is in the form of a cylindrical pin for receiving the screw. The nut is in pivotal co-operation with a complementary cylindrical housing provided in the jaw member for pivotal movement about an axis parallel to the work axis.

Preferably, the screw includes a transverse projection extending radially from or near the end remote the head to prevent the screw being unscrewed completely from the nut in order to provide the maximum extension of the adjustment means. In a preferred form, the transverse projection is provided in the form of a grub screw or such like extending through a corresponding transverse bore at or near the end of the screw. The wrench may be disassembled into its component parts, firstly by removing the grub screw, and then unscrewing all of the remaining threaded parts to separate them from one another .

Preferably, the nut and bolt assembly is pivotally connected to the first jaw member and the second jaw member includes an aperture for accommodating the screw, and permitting relative, but limited, pivoting movement of the screw within the aperture. Preferably, the screw has a head held captive in a head retaining cavity provided in the second jaw member, and some of the perimeter of the head is exposed on one or both sides of the second jaw member for turning in a similar fashion to a thumb wheel in the same way disclosed in my earlier patent. However, instead of the length adjustable screw, described therein, it has been found that a screw passing through the pivot of the first jaw member, together with the grub screw in the end remote from the head, provides advantages in preventing the jaw members becoming disconnected from one another and adds strength to the mechanism used to adjust the distance between the jaw members.

Preferably, a biasing coil spring is provided with its respective ends engaging the respective jaw members intermediate the engagement means and the length adjustable means of each jaw member respectively. The engagement means is the form of the cam described in my earlier patent. However, it has been found that the shape of the protrusion is better if there is a portion of the engagement face which provides only a very small leverage for relatively large movement of the handle, thereby permitting friction between the faces so engaged to provide braking or locking of the jaw members on the work piece.

Other tool formations may be provided in the mating parts of the jaw members to provide for known functions of similar tools such as pliers and such like, such as wire cutters, pincers and such like.

In order that the invention may be more readily understood and put into practical effect, reference will now be made to the accompanying drawings which illustrate two embodiments of the invention, and wherein:

Fig. 1 is a pictorial view of a one-handled wrench according to the invention gripping a work piece;

Fig. 2 is a detail cross section of the head of the wrench of Fig. 1, but gripping a smaller work piece than that of Fig. 1 ;

Fig. 3 is a cross section of detail 3 of Fig. 2 ;

Fig. 4 is a pictorial view of a two-handled wrench according to the invention; and

Fig. 5 is a cross-section of the wrench of Fig. 4; and Fig. 6 is a cross-section of the head of another single handled wrench similar to that of Fig. 1.

The one-handled wrench 10 illustrated in Figs. 1 to 3 includes a first jaw 11, a second jaw 12 pivotally connected to the first jaw and a handle 13 pivotally connected to the first jaw at a handle pivot 32. The pivotal attachment of the jaws to one another is in effect a double pivot connection, there being a jaw pivot pin 14 mounted in the first jaw and a hemispherical socket 15 in the second jaw which co-operates with a screw 16 which has a head 17 having a hemispherical face 18 proximal to its threaded shaft 19. The threaded shaft is threadedly engaged with a threaded aperture 20 passing diametrically through the jaw pivot pin.

The head of the screw also has a hexagonal socket 21 and a rounded end face 22. The hexagonal socket enables rotation of the screw by an alien key or similar hexagonal tool and the rounded end face is provided to accommodate capturing the head of the screw in the second jaw. The head of the screw is captured in the second jaw by a retainer plate 23 fastened to the second jaw by a fastener 24 being fastened to the second jaw by way of a fastener aperture 25. The retained plate has a penetration 26 therethrough in juxtaposition with the head of the screw to permit the end of an alien key or such like to engage in the hexagonal socket.

The first jaw has an arcuate rebate 27 of a radius selected to provide a close, but clearance fit with the end of the handle which is pivoted thereto, having an arcuate outer face 31. A spring-loaded ball bearing 28 is located in a blind aperture 29 in the arcuate face of the arcuate rebate in the first jaw. The ball-bearing is engageable with an indentation 30 in the top of the handle at or near the end of the arcuate outer face for fixing the handle in an outward disposition with respect to the jaws. A biasing spring 34 is provided in a passage through the second jaw, attached to the second jaw at one end 33 and to the first jaw at the other end 33a to provide a biasing of the jaws to a rest position with respect to one another.

The second jaw has a shaped bearing face 35 in juxtaposition to the handle, and more specifically, a shaped protrusion 36. The shaped bearing face and shaped protrusion are so formed and arranged with respect to the pivot pin connecting the handle to the first jaw member that movement of the handle in the direction of arrow 37 with respect to the first jaw member causes the shaped protrusion to slide along the shaped bearing face and push the bearing face away from the pivot pin. This movement causes the second jaw to rotate in the direction of arrow 38 with respect to the head of the screw and correspondingly the first jaw to rotate in the direction of arrow 39 with respect to the pivot pin. The jaws have sliding mating faces 41, but as the leverage portions of the jaws are pushed away from each other, there is a corresponding closing of the gap between the grips 42 of the j aws .

The two-handled wrench 40 illustrated in Figs. 4 and 5 is the same in nearly all respect as the one-handled wrench of Figs. 1 to 3, with the exception that a second or fixed handle 43 extends rigidly from the second jaw in the same plane as the plane of rotation of the handle 13 pivotally connected to the first jaw.

The other single-handled wrench 60 illustrated in Fig. 6 is the same as that illustrated in Figs. 1 to 3, but includes first jaw finger grip 44 extending outward from above the pivot pin and a detachable portion 45 of the handle 13.

In the present invention, the tube bolt of my earlier wrench has been replaced by a screw, thereby allowing an increase in the size of the adjusting bolt by three times in order to allow greater gripping forces to be applied to work piece gripped by the wrench. Additionally, two wings have been incorporated on the leverage portion of the second jaw member to cover the bottom portion of the first jaw, thus substantially preventing sideways movement of the second jaw. The improved arrangements also has the centre pivot in the first jaw member jaw drilled out to a larger size and double threaded inside and into which a much larger and stronger adjustment bolt may be inserted. The tool of the present invention has a much stronger adjustment bolt than my earlier wrench and because of the double thread now employed, is much faster to adjust.

To allow movement of the adjustment bolt through the centre pivot a space has been hollowed out above the centre pivot to allow the adjustment bolt to wind well past the outside of the centre pivot , into the top jaw, also to allow a certain amount of sideways movement, to give the tool a full range of adjustment.

The adjustment bolt in the wrench of the present invention has a small hole drilled at the threaded end of the bolt in which a pin is inserted after the adjustment bolt has been screwed through the centre pivot. This allows the tool to be adjusted either way, but will not allow the tool to be adjusted any further out than it is designed to do, thus making the tool much safer to use.

On each side of the centre pivot facing to the outside of the tool, a 6 mm hole is provided to allow the pin in the end of the adjustment bolt to be inserted after the bolt has been screwed into the centre pivot, and also to remove it, if necessary. These holes were tapped with a 6 mm thread so the holes could be sealed against moisture and dirt.

A grease nipple can be screwed into these holes and a certain amount of grease or oil can be pumped into the hollowed out section above the centre pivot, to act as an automatic greaser for the adjustment (the adjustment bolt will be lubricated every time the tool is adjusted) . After the grease or oil has been pumped in , the grease nipple may be removed and a plug screwed into the threaded hole to seal against ingress of dust or moisture, thereby providing automatic lubrication incorporated into its moving parts.

The wrench of the present invention can also be locked in place, and this may be useful when holding two pieces of metal in place for welding, or locking on to a solid work piece like a round piece of steel.

The cam is on the handle and serves to close the two jaws on the work piece by being wedged in between the leverage portions on the other side of the pivots from the grips of the jaws. The cam is slightly tapered from the narrow end towards the back of the cam, and when the handle is depressed, the cam moves down between the two wings on the second or lower jaw, and because the cam is thicker towards the back of the cam, it begins to tighten between the wings on the lower jaw. This creates friction on an increasing scale the further the cam is depressed into the wings on the lower jaw, and, if the tool is adjusted correctly, it acts as a brake, locking the tool on to the work piece.

Although the invention has been described with reference to particular examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms within the broad scope and ambit of the invention as defined by the following claims.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1 . A wrench for gripping a work piece rotatable about a work axis including:

2. The wrench according to Claim 1, and further including another handle in fixed relationship to and extending from the leverage portion of the second jaw member.

3 . The wrench according to Claim 2, wherein handles are arranged in operative juxtaposition to each other and extend substantially at right angles to the work axis for gripping of both handles by the hand of a user.

4. A wrench according to any one of the preceding claims, wherein the adjustment means includes a screw in threaded engagement with a threaded passage penetrating diametrically through a pivot pin mounted in the first jaw member.

5. The wrench according to Claim 4, wherein the adjustment means comprises a nut and bolt assembly, the pivot pin providing the function of the nut.

6. The wrench according to Claim 5, wherein the screw includes a shaped head which engages with a complementary shaped counterbore in an aperture penetrating the second jaw member .

7. The wrench according to Claim 6, wherein the shaped head includes a hemispherical face extending from the shaft or shank of the screw and the shaped counterbore is shaped to conform to an inside face of a hemisphere.

8. The wrench according to Claim 4, wherein the adjustment means comprises a nut and bolt assembly, the nut being in the form of a cylindrical pin for receiving the screw.

9. The wrench according to Claim 8, wherein the nut is in pivotal co-operation with a complementary cylindrical housing provided in the jaw member for pivotal movement about an axis parallel to the work axis.

10. The wrench according to Claim 8, wherein the nut and bolt assembly is pivotally connected to the first jaw member and the second jaw member includes an aperture for accommodating the screw, and permitting relative, but limited, pivoting movement of the screw within the aperture.

11. The wrench according to Claim 4, wherein the screw includes a transverse projection extending radially from or near the end remote the head to prevent the screw being unscrewed completely from the nut in order to provide the maximum extension of the adjustment means.

12. The wrench according to Claim 11, wherein the transverse projection is provided in the form of a grub screw or such like extending through a corresponding transverse bore at or near the end of the screw.

13. The wrench according to Claim 12, and wherein the grub screw is arranged to prevent the jaw members becoming disconnected from one another.