US120351A - Improvement in holders for screw-cutting dies - Google Patents

Description

Y Patented 0ct,24,1871.

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UNITED STATES PATENT OFFICE.

BENJAMIN L. WALKER, OF SING SING, NEW YORK.

Specification forming part of Letters Patent No. 120,351, dated October 24, 1871.

To all whom it may concern:

Be it known that I, BENJAMIN L. WALKER, of Sing Sing, in the county of Westchester and State of New York, have invented a certain new and useful Improvement in Holders for Screw- Cutting Dies while being tapped or cut; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawing forming part of this specification, and in which- Figure l represents a front viewoimyimproved holder with dies therein; Fig. 2, an end view of the same 5 and Fig. 3, a transverse section through the line .r a: in Fig. l.

Similar letters of reference indicate corresponding parts throughout the several figures.

My invention relates to a holder for tapping or cutting the screw-threads in dies, or for recutting the latter by means ofa master tap iirmly held by any suitable tool-holder7 and centered in relation with the dies, as by a tool-holder adjustable in a straight course along the shears of a lathe, while the dies are rotated by a mandrel in concentric position therewith; and the invention consists in a novel construction of the dieholder, whereby provision is made for setting or adjusting the dies so that they may be set and retained true in various directions for the passage ofthe master tap through them. Dies thus cut are truer and more perfect than when cut in the ordinary way.

Referring to the accompanying drawing, A represents the frame of the die-holder provided with a central back socket or extension b for attachment ofthe holder to a revolving mandrelas, for insta-nce, a lathe-chuck is carried and driven. Said frame is formed of a back, sides, and ends, the one c of which latter may be removably attached so as to open and close to fa cilitate the entry and release of the dies and their clamping-strips. A convenient provision for this purpose is to secure the end piece c as by screws d d, and to make a slot, e, in the end piece c, so that by simply slackening the olie screw which fits through said slot, the end piece c may be swung to one side from the other screw as a center of motion when it is desired to open the frame. B B are the dies and O O the clampingstrips, which latter are beveled on their inner sides to conform with the bevel of the dies, and are iitted so as to be capable of adjustment across or from side to side and within the holder. Both dies are secured at their sides and adjustable laterally in common by these clamping strips which may extend the full length of the interior ofthe irame, but not so that they bind, and with provision for their lateral adjust-nient at different points, as by adj Listing and clamping-screws j' f. The dies B B are adjustable lengthwise within these strips, and clamped at their ends by means of end-screws g g. To set the dies inline on their faces a rocker, l), having an eye in its center, is caused to bear, as by projections h h, on both dies and made adjustable from opposite ends by screws Ai z' iitted to enter the sides of the frame. By these combinations of devices the dies may be set and kept exactly truc and in perfect line every way as re quired.

What is here claimed, and desired to be secured by Letters Patent, is-

1. The combination of the frame A, with its end screws gg, the clamping-strips C O with their side-adjusting and clampingscrews ff, and the rocker D adjustable as by screws i z', substantially as specified.

2. The frame A, constructed with a swinging opening end piece, c, slotted as at e, and secured by a bolt or bolts, in combination with the adj ustable clamping-strips O (l, essentially as herein set forth.

BENJ. L. WALKER. Witnesses:

G. B. HUBBELL,

EDGAR GREEN. (14.)

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