US499092A - Screw-cutting implement - Google Patents

Description

(No Model.)

B. BOWMAN. SCREW GUTTING IMPLEMENT.

. N0. 4 9,092. Patented June 6,1893.

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UNITED STATES PATENT OFFICE.

REUBEN BOWMAN, OF MIDDLETOWN, PENNSYLVANIA.

SCREW-CUTTING IMPLEMENT.

SPECIFICATION forming part of Letters Patent No. 499,092, dated June 6, 1893.

Application filed January 31, 1893. $erial No. 460.325. (No model.)

To all whom it may concern:

Be it known that I, REUBEN BOWMAN, a citizen of the United States, and a residentof Middletown, in the county of Dauphin and State of Pennsylvania, have invented certain new and useful Improvements in Screw-Outting Implements; and I do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, which form a part of this specification.

My invention relates to improvements in devices for screw-threading taps, bolts, and other similar articles, but is more especially intended for threading taps for cutting threads in pipe couplings or sockets.

The object of the invention is to providea novel construction of die stock and dies, which shall possess superior advantages with respect to utility and efficiency.

The invention consists in the novel construction and combination of parts hereinafter fully described and claimed.

In the accompanying drawings: Figure 1 is a central vertical sectional view of a screw cutting instrument constructed in accordance with my invention. Fig. 2 is a horizontal section, on the line oc0c, Fig. 1. Fig. 3 is a similar section, on the line y-y, Fig. 1. Figs. at and 5 are perspective views of the dies removed from the stock. Fig. 6 is a view of a tap threaded by my improved-device.

In the said drawings, the reference numeral 1 designates the die stock consisting of a metal cube or block having a rectangular aperture extending therethrough. This block is provided with heads 2 at each end secured thereto by screw-bolts or other fastening devices, and each is provided with a circular aperture 3, aligned witb,but of less area than cheaperture in the block.

The reference numeral 4 designates a series of superimposed cutting dies, located in the aperture in the block 1, and confined in place by means of the heads 2. Each of these superimposed dies consists of two plates or. sections of equal area or size, having theirinner faces formed with spaces 5, and cutting threads or teeth in a semi-circular line, as is usual in this class of devices.

Passing through apertures in the blocks at right angles to and communicating with the rectangular aperture, are a number of set screws 6,the inner ends of which bear against one of the edges of each set of dies, by means of which the dies may be adjusted to compensate for any slight variations in the cutting edges or threads, which are liable to occur from continued use. These dies are so arranged with respect to each other, that the cutting threads of one set will alternate with the spaces in the next adjoining set, preventing rounding of the front edge of the tap, which is liable to occur, when what is known as sectional taps are being cut, that is, taps having a series of grooves 7in between them,'

as seen in Fig. 6, which represents a tap cut with an instrument constructed in accordance with my invention. The meeting edges of each set of dies is formed at an angle to the.

edges of the adjoining dies, so as to break joints.

The operation will be readily understood: The tap blank to be threaded is inserted between the dies, and then rotated by any suitable means, and by once passing through the series of superimposed dies, the threads are cut thereon, and the tap is then ready for tempering.

Having thus described my invention, What I claim is- In a screw-cutting instrument, the combination with the stock having a rectangular aperture therein, the heads secured thereto having circular apertures, and the set screws passing through apertures in the stock at right angles to the rectangular aperture and communicating therewith, of the superimposed sets of dies, each set consisting of two plates, the meeting edges of which are at an angle with the adjoining sets, so as to break joints, and each plate or die formed with a series of cutting threads and spaces, alternating the teeth and spaces of the adjoining dies, substantially as described. I

In testimony that I claim the foregoing as my own I have hereunto aflixed my signature in presence of two witnesses.

REUBEN BOWMAN. IVitnesses:

H. B. LAUMAN, J. W. PATTON.

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