US787490A - Groove and thread cutter. - Google Patents

Description

'PATBNTED APR. 18, 1905.

F. B ERSZINSKY'. GROOVE AND THREAD CUTTER.

APPLIOATION FILED NOV. 3, 1903.

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UNITED STATES Patented April 18, 1905.

PATENT OFFICE.

FRIEDRICH BERSZINSKY, OF ESSEN, GERMANY, ASSIGNOR TO DE FRIES & CO., AGTIEN-GESELLSCHAFT, OF DIISSELDORF, GERMANY.

GROOVE AND THREAD CUTTER.

SPECIFICATION forming part of Letters Patent No. 787,490, dated April 18, 1905.

Application filed November 8, 1903. Serial No. 179,687-

To all whmn it may concern;

Be itknown that I, FRIEDRICH BERSZINSKY, a citizen of Germany, residing at Essen, Germany, haveinvented new and usefulImprovements in Groove and Thread Cutters, of which the following is a specification.

This invention relates to an improved apparatus for cutting threads or grooves and spirals for worm and gear wheels, ratchets, and

segments of threads for the breech of guns, &c. The apparatus is so constructed that the cutter can be readily adjusted to the pitch desired and that it is automatically lowered as the depth of the groove cut is to be increased.

In the accompanying drawings, Figure 1 is a front elevation, partly in section, of a lathe embodyingmyinvention; Fig. 2, a plan, partly in section, thereof; and Fig. 3, a cross-section on line A B, Fig. 1.

The letter a represents the cutter, which passes freely through a corresponding slot of a spindle c and is movable within a diametrical groove Z formed in the head Z of a left sleeve section Z). This sleeve is slidably mounted upon the spindle 0 and participates in its rotation by means of a groove-and-feather connection. The cutter (Z is provided with a laterally-projecting pin 0, that engages an eccentric groove (Z in the head a; of a second or right sleeve-section 5, also mounted on spindle 0. At a distance from head 1) the bore of sleeve Z) is enlarged to accommodate a spring g, embracing spindle 0. The right end of said spindle terminates in a tenon 10, that engages a mortised shaft :13, which enters the bore of sleeve Z). By this construction spring g, which bears with one end against shaftw, while its other end bears against an inner shoulder of sleeve 6', will push the latter against sleeve 6. Shaft 02, being supported by a bearing of the head-stock y, receives rotary motion by toothed wheel 2/, and transmits the same through spindle c and sleeve Z) to cutter 0. During the rotation of the sleeve the cutter receives an additional longitudinal movement, according to the pitch of the thread to be out, in the following manner:

Into the bore of slide-rest q is fitted a hub .9, provided at its outer end with a bulged flange or cam Z. Slide-rest q is slitted, asat Q, so that by tightening a pair of clampscrews g hub s is held in position. One side of cam 25 is engaged by a projection Z on flange k of sleeve Z), while its other side is' engaged by a roller m. This roller is pivoted within a housing w, attached to sleeve 6. When spindle c rotates, sleeve 6 and cutter a will thus be reciprocated for a distance corresponding to the bulge of cam 26. In this way the tool a is revolved around the spindle c and is reciprocated along the same to accord With the pitch of the thread desired. In order to gradually deepen the groove at each revolution of the cutter, I provide sleeve Z) with a ratchet-disk at, having teeth 0. The latter are engaged byapawl Z, pivoted at Z to aflange r of shaft :12. The pawl Z is provided with an arm Z, having spring w, that holds pawl Z in engagement with the ratchet a. If sleeve Z) moves to the right, Figs. 1 and 2, the ratchet n will approach flange 1'. This movement causes pawl Z to turn on its pivot against the action of spring 10. During this motion pawl Z, engaging one of the teeth 0, will take along ratchet 01, thus partially rotating sleeve Z). This partial rotation of sleeve 6 causes'a slight advance of the tool (6 by means of eccentric groove (Z and pin 0. If the sleeve 6 moves to the left, the distance between ratchet n and flange r will increase and pawl Z will by spring u; be turned backward to engage a new tooth of ratchet n. In this way the tool is slightly advanced radially outward at each rotation until the groove has the desired depth. When the cutting of the groove has been completed, the machine is arrested and the workholder is advanced to the proper position for cutting the next groove. This being done, the cutter is set back to its initial position by turning sleeve Z) by hand until the cutter is sufficiently retracted and the machine thus set for cutting the next groove.

It Will be seen that the groove cut by my machine gradually increases in depth; but as the advance of the tool during each rotation is very small this increase may be practically ignored.

What I claim is- 1. In a groove-cutter, the combination of a rotatable spindle With a left sleeve rotatable with the spindle and having a diametric groove, means for reciprocating the sleeve, a reciprocable right sleeve having an eccentric groove, means for independently rotating the right sleeve upon the spindle, and a cutter positioned in the diametric groove and having a part engaging the eccentric groove, substantially as specified.

2. In a groove-cutter, the combination of a rotatable spindle with a left sleeve rotatable FRIEDRICH BERSZIN SKY.

WVitncsses:

HERMANN FRoBosE, PETER LIEBER.

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