US3341177A - Wire strainers - Google Patents

Description

Sept; ,1967. R. v. WEI-SE ETAL 3,341,177

WIRE STRAINERS Filed Oct. 29, 1965 2 Sheets-Sheet l Sept. 12, 1967 R. v. WEISE ETAL WiRE STRAINERS 2 Sheets-Sheet 2 Filed Oct. 29, 1965 United States Patent 3,341,177 WIRE STRAINERS Reginald Vincent Weise, Narran Plains, Walgett, New South Wales, Australia Filed Oct. 29, 1965, Ser. No. 505,617 Claims priority, application Australia, Dec. 31, 1964, 53,487/64 2 Claims. (Cl. 254-73) This invention relates to improvements in wire strainers and in particular to improvements in the wire grippers and operating handles for such strainers.

In the specification of my Australian Patent No. 151,406 I have described a wire strainer in which the wire is strained by anchoring one end of the strainer directly to a strainer post or to a loop in the wire and then, by operating a handle to and fro, to cause alternate operation of two wire grippers which alternately grip and release the wire, each gripper upon being released, moving along the wire to re-engage and grip the wire as the movement of the handle is reversed.

Although this wire strainer, which is referred to hereafter as being of the type described, has met with great commercial success, it has had its disadvantages, particularly in regard to the gripping means. These gripping means are cam-like members having convex gripping surfaces which are flat in the plane normal to the major plane of the cam and their gripping action is to squeeze the wire against a concave surface on an adjacent anvil. The drawbacks to this arrangement have been twofold. In the first place, particularly where the softer types of fencing wire are used, the gripping pressure upon the wire between the cam and the anvil has tended to flatten the wire and thus to weaken it. Secondly, the fact that the cam presses the wire into a concave recess has bent the wire into conformity with the concavity so that, particularly where the softer grades of wire are being used, the strain on the wire over .a period tends to straighten out the sinuosities so formed and the wire then may require restraining.

Still a further disadvantage is that when the gripper on the end of the strainer is released to allow the other gripper to move the wire forward, that end of the strainer has to be held on the wire to prevent it from becoming disengaged.

The object of the present invention is to provide in such a wire strainer means which will eliminate the above disadvantages.

According to a general form of the invention, therefore, I provide a wire strainer, of the type described, including wire gripping means comprising two camming members each pivotable into gripping engagement with an anvil or with a wire located on said anvil; said camming members each having a convex gripping surface formed thereon and said gripping surface having a groove, part-circular in cross-section, formed in and around the convexity thereof; said groove being of lesser width than the diameter of the wire to be strained and said anvil each having a planar surface in proximity to said convex gripping surface.

A better understanding of the invention may be obtained from the following description of one preferred form thereof when this is read with reference to the accompanying drawings; it being understood that it is not intended that the invention should be limited by this description but only by the scope of the appended claims.

In the drawings,

FIGURE 1 is a perspective view of a strainer according to a general form of the invention,

FIGURE 2 is a plan view of the strainer of FIGURE 1,

FIGURE 3 is a detail view of one end of the strainer chorage.

The wire strainer consists of an approximately U- shaped bar 11 having an elongated base 12. At one end 13 is formed a hook 14 having an open slot 15 formed therein and at the other end the bar 11 is bent to form an extension 16 which lies substantially parallel with the elongated base 12. The bar 11 is preferably formed from hexagonal sectioned mild steel bar.

On the extension 16 are mounted the wire gripping and straining means. These means include a stop 18 located near the inner end of the extension 16 and secured thereto.

A first flanged block 19 is slidably mounted on the outer end of the extension 16 and a second flanged block 20 is slidably mounted on the extension 16 forwardly of the stop 18. A helical compression spring 17 is mounted on the extension 16 between the stop 18 and the block 20 and a similar spring 17a is inserted between the blocks 19, 20. The spring 17a abuts against an abutment 16a secured to the extension 16.

Finger pieces 21, 22 are rotatably mounted on each block 19, 20 and each includes a convex camming surface 23, 24 which, when the finger pieces 21, 22 are rotated in one direction, are adapted to lock awire 25 between them and the flange, or anvil, 26, 27 on the respective block and, when rota-ted in the other direction, to release the wire 25. l

An operating handle 28 is connected to a lever 29 centrally pivoted at 30' on the stop 18 and is pivotally connected at its opposite ends, by connecting links 31, 32, to the respective finger pieces 21, 22 which are directed in opposite senses on the extension 16.

When the handle 28 is moved in a clockwise direction (as seen in FIGURE 1) it pivots the lever 29 to move the blocks 19, 20 towards each other, the camming surface 23 locking the previously inserted wire 25 against the anvil 26 and the cam-ming surface 24 releasing its pressure on the wire. When the handle 28 is moved in the opposite, or counterclockwise direction, the lever 29 is pivoted to move the blocks 19, 20 away from each other, the camming surface 24 locking the wire against the anvil 27 and the camming surface 23 releasing the wire. As the blocks 19, 20 move in opposite relative direc tions with reciprocation of the handle 28 and lever 29 and as the camming surface on the block moving towards the hook 14 is, in each case, locking the wire 25 between itself and its associated anvil, it will be seen that in whichever direction the handle 28 is being moved, the wire 25 is gripped between the camming surface and anvil on the block .19 or 20 which is being moved towards the hook 14. Consequently, reciprocation of the handle 28 places a continuous and incrementally increasing strain on the Wire 25.

The finger pieces 21, 22, previously referred to, extend substantially normally to the extension 16 when the camming surfaces are in their engaging or locking position. As previously stated, the camming surfaces 23, 24 were previously flat in the direction normal to the major plane of the cams and the anvils 26, 27 were concave to match the convexity of the cams.

In the present invention, however, in order to avoid the previous disadvantages of flattening and kinking of 3 the wire, the form of the cams and associated anvils has been modified.

The anvils 26, 27 are planar on the surface in proximity to the camming surfaces 23, 24 and each cam surface has a part circular groove 33 formed longitudinally around its convexity. This groove 33 is less in width than the wire 25 to be strained, so that it does not bottom in the groove, but is nipped on two portions 34 of its periphery by the opposite edges of the groove 33. By this means a firm grip is obtained without flattening the wire 25, weakening it or noticeably deforming it. Furthermore, due to the planar surfaces of the anvils 26, 27, the wire 25 is not forced into a concavity and accordingly remains straight.

In order to avoid the strainer falling off the wire 25 when the first camming surface 23 is released, the anvil 26 on the block '19 at the free end of the extension 16 has a projection 35 formed on its otherwise flat surface at the upper outer corner thereof. This projection defines a recess 36 in which the wire 25 rests when the camming surface 2-3 is released and so prevents the strainer from becoming dislodged or detached from the wire 25 at that end. The other end is, of course, held in place by the hook 14, either within a loop '37 in the wire as shown in FIGURE 3 or around a post or other anchorage 38, as shown in FIGURE 7.

The operating handle 28 is retractable, and atits operating end, the lever 29 is formed with aboss 38 having a di-ametrical groove 39 in its surface. A hole is formed through the boss and into this is inserted the turned-over end 40 of the operating handle \28. A pin 41 is secured in this turned-over end and is adapted to rest in the groove 39 in the operating lever, into which it is urged by a spring '42. By presing against the spring 42, the pin 41 may be disengaged from the groove 39 and the handle 28 turned so that it lies substantially parallel with the elongated base 12 of the U-shaped bar 11.

What I claim is:

1. A wire strainer comprising a generally U-shaped bar including an elongated base and two upright arms on the base, one of said arms having a free end and including a hook thereat, the other of the arms including an extension extending away from said base substantially parallel thereto, first and second spaced blocks slidably mounted on said extension, each block including a flange having .a planar surface constituting an anvil, a camming member pivotably mounted on each block for gripping a wire located on such anvil, an operating lever pivotably mounted on said extension, and bars connected to said lever and to a respective camming member such that upon pivotal movement of the operating lever in opposite directions, said camming members alternately engage and 'disengage the wire on the anvils While simultaneously moving the blocks towards and away from each other on said extension, each camming member having a convex surface for gripping the wire, and a groove which is part circular in cross-section and which extends along and into said surface, said groove having a width at said surface which is smaller than the diameter of the wire, a stop member secured to said extension proximate the location where it is joined to said other arm, said operating lever being pivotally connected to said stop member, a handle connected to said lever to operate the same, said handle being pivotally connected to said operating lever, and means for locking the handle to the lever in an operating position longitudinally of said lever and means to release it for pivotal movement parallel to said extension to a retracted inoperative position.

2. A wire strainer according to claim 1 comprising a projection on the block furthest from said base, said projection extending normally from the latter said block on the outer side theerof and at the end thereof remote from the other block, said projection defining a recess with the camming member associated with the block carrying the projection for retaining the free end of said extension upon the wire being strained.

References Cited UNITED STATES PATENTS 560,867 5/ 1896 Shepard 25473 746,135 12/ 1903 Obiols 24-134 FOREIGN PATENTS 151,406 5/ 1953 Australia.

672,5 35 10/ 1963 Canada.

WILLIAM PELDMAN, Primary Examiner.

MILTON S. MEI-IR, Examiner.

Claims (1)

1. A WIRE STRAINER COMPRISING A GENERALLY U-SHAPED BAR INCLUDING AN ELONGATED BASE AND TWO UPRIGHT ARMS ON THE BASE, ONE OF SAID ARMS HAVING A FREE END AND INCLUDING A HOOK THEREAT, THE OTHER OF THE ARMS INCLUDING AN EXTENSION EXTENDING AWAY FROM AND BASE SUBSTANTIALLY PARALLEL THERETO, FIRST AND SECOND SPACED BLOCKS SLIDABLY MOUNTED ON SAID EXTENSION, EACH BLOCK INCLUDING A FLANGE HAVING A PLANAR SURFACE CONSTITUTING AN ANVIL, A CAMMING MEMBER PIVOTABLY MOUNTED ON EACH BLOCK FOR GRIPPING A WIRE LOCATED ON SUCH ANVIL, AN OPERATING LEVER PIVOTABLY MOUNTED ON SAID EXTENSION, AND BARS CONNECTED TO SAID LEVER AND TO A RESPECTIVE CAMMING MEMBER SUCH THAT UPON PIVOTAL MOVEMENT OF THE OPERATING LEVER IN OPPOSITE DIRECTIONS, SAID CAMMING MEMBERS ALTERNATELY ENGAGE AND DISENGAGE THE WIRE ON THE ANVILS WHILE SIMULTANEOUSLY MOVING THE BLOCKS TOWARDS AND AWAY FROM EACH OTHER ON SAID EXTENSION, EACH CAMMING MEMBER HAVING A CONVEX SURFACE FOR GRIPPING THE WIRE, AND A GROOVE WHICH

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