US1326807A - Charles ralph townsend and joseph george skinner - Google Patents

Description

C R. TOWNSEND AND J. G. SKINNER.

CLAMPING DOG.

APPLICATION FILED JUNE 13. 191B.

Patented Dec. 30, 1919.

Wemsqs/K CHARLES RALPH TOWNSEND AND JOSEPH GEORGE SKINNER, 0F BIRMINGHAM,

ENGLAND.

GLAMIF'ING-IDO G.

Specification of Letters Patent.

Patented Dec. 30, 1919.

Application filed June 13, 1918. Serial No. 239,906.

To all whom it may concern:

Be it known that we, CHARLEs RALPH TOWNSEND and JosEPH GEORGE SKINNER, subjects of the Kin of Great Britain, residing at Caxton House, Great Charles street, in the city of Birmingham, county of Warwick, England, have invented certain new and useful Improvements in and Connected with Clamping-Dogs, of which the following is a specification.

The invention provides the hereinafter described and claimed improvements in and connected with clamping dogs or devices used for many purposes but generally used to hold work to beds, tables, and face plates of machines, obviating the necessity of setting and of using pack-up pieces.

Usually such a dog or device is a fiat or irregular shaped rigid piece through a slot in which a clamping bolt passes, and when using same it is invariably necessarv to packup with loose pieces of different thicknesses. Such packing up is tedious, often very difficult, and always mechanically bad, as no matter how arefully performed the chances are that the position of the work will shift on final screwing up of the clamping bolt, freouently necessitating resetting.

The dog or device according to the invention embodies a rigidly built piece having three curved co-acting surfaces, two of which constitute feet for gripping, and the other of which provides an elevated bolt-pulling up abutment disposed between said feet. Looked at sidewise said dog or device is substantially arch shape, the feet of the arch being the gripping feet, aforesaid, and the elevated surface the crown of the arch, or part adjacent forming the pulling up abutment. The curvings of the three surfaces extend sidewise of the dog or device said surfaces transversely being preferably without curvature. The curves of the feet provide convexity, but the curve of the abutment may be either convex or concave. One foot may be longer than the other, but preferably the curves thereof are alike as to radii. The bolt may pass freely through a slot in the dog or device arranged between the feet to engage either a washer contacting the abutment or a block or piece rocking on the abutment, said washer or piece provid ing flat surface for the nut f the bolt to pull up against and being shaped at its contacting face to the shape of the abutment.

The invention is represented by the accompanying drawing in which Figure 1 is a side elevation and Fig. 2 a plan of the device.

The dog or device is composed of rigidly built pieces or sections 6 and 6 each pr0- vided with three curved co-acting surfaces 7, g and it. Each dog or device section is substantially arch-shape sidewise and the surfaces 7 and 9 provide convex feet and the surface it a convex crown or pulling up abutment for the bolt (5. The curvings are sidewise only of the dog or device, said surfaces transversely having no curvature.

The curved surface it co-acting with the curved surfaces f and g is provided by the lower halves of opposite transverse holes a and 0, formed through the dog or device body between the feet to provide bearings for trunnions n 0 of a rocking bl0ck,'?, working in the slot Z and through a hole 2', in which a pulling up bolt is adapted to pass. This dog is built up of three pieces, the one the pivoted block 2' and the others the two halves c c of the dog or device body, which halves are put together at machined facings, c, and riveted up, at e c, with the block between them so that the latter is always a permanent part of the dog or device.

The co-acting curved surfaces f, g and h are true ones, preferably machined or ground so as not to have any irregularities, same being transversely parallel with each other. Said surfaces may be slightly roughened or matted.

A dog or device according to the invention in addition to being self setting, and pulling up true in all conditions within its range of thickness grip is free from slip, so that once the work is adjusted by a partial pulling up the final screwing up of the bolt will not cause any shifting. Further said dog or device has no set positions being infinitely variable within its range of thicknessgrip and has no adjustment requiring skill.

Having now described our invention what we claim and desire to secure by Letters Patent is 1. A clamping dog comprising a rigid body structure having convex gripping feet,

and a block applied to said body structure between the feet and having trunnions engaging parts of the body structure and also provided with a hole therethrough for the reception of a bolt.

2. A clamping dog comprising a rigid body structure having convex gripping feet, and a block applied to said body structure between the feet and having trunnions engaging parts of the body structure to problock being retained in association as a part of the dog and having an opening therethrough for the reception of a bolt.

3. A clamping dog comprising a rigid body structure having convex gripping feet vide a rocking movement for the block the CHARLES RALPH TOWNSEND. JOSEPH GEORGE SKINNER.

Witnesses GEO. FUERY, D. LEAKER.

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