US112759A - Improvement in lathe-dogs - Google Patents

Description

lith %tti5 HENRY K. WHITE, OE CHELSEA, MASSAGHSETTS.

Letters Patent No. 112,759', dated March14,1871.

IMPROVEMENT IN LATHE-DOGS'.

The Schedule referred to in these Letters Patent and making part of the same.

turning lathes, it is customary to fasten one end of thestick by forcing it against a mandrel-dog, having radial teeth, that sink into the wood and hold it fast, or cause it to be heldfast between the dog and the back poppet, so that the stick turns with and by the rotating mandrel.

These teeth are very liable to split the wood, especially when the wood is turned down nearly to them;

and e The object of my invention ist'o so construct the clamping-dog as to insure the wood against any liability to split by the action of the teeth; and for this purpose I make or provide the dog-stock with an encompassing-sleeve or tube, which is internallyscrewthreaded or nut-threaded, and. works upon a male thread on the stock, the front end of the tube being made sharp, so that, when fed up into the plane ofthe ends of the dog-teeth, or slightly projecting beyond them, the saidedge shall strike into the end of the stick to be turned, thereby holding the material, into which the teeth enter, and eieetually preventingit from splitting, although the turning-'tool may cut down to the tube.

It is in this sleeve, encompassing or working upon the stock of the lathe-dog, that my improvement c011- sists The drawing represents, in end view and in side and .sectional-elevation, a lathe-dog (for a wood-turning lathe) embodying my invention.

a denotes the stock of the dog, having formed on its front end the radial teeth or bits'b, (the points or edges of' which are in a plane right angular to the axis of the stock,) at the'center'of which may be a projecting spur or point, c.

As the wood is driven against the end of the dog, these teeth enter the wood parallel to or inline with the grain, and tend to split open the end.

cl denotes the sleeve, preferably made with the nutthread e, and working uponthe screw-thread j', ou the stock.

The front end of the tube has the cutting-edge g, and this edge is preferably kept in or. just in advance of the plane of the front edges of the bits or teeth b by a cheek-nut, h.

The end of the wood being driven upon this front edge, as well as upon the teeth, the grain or fibers of the wood are held together within the ring, and prevent any splitting, either withiu or outside the ring, enabling the wood to be turned down even to the ring without injury or liability of the Woodv to break open. n

As the edge of the sleeve wears 0r becomes dull it can be sharpened, and, as' ground down, can be kept up to the proper plane by the screw-threads and checknut.

A lathe-dog,l having an encompassing-sleeve, the sharpened front edge of which is or may be brought into a plane with the dog-teeth or bits, so that the edge of the sleeve, as well as the edges of the teeth, enter the wood, substantially as described.

Witnesses: HENRY K.' WHITE.

FRANols GoULD, S. B. KIDDER.

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