US389170A

US389170A - rogers

Info

Publication number: US389170A
Authority: US
Publication date: 1888-09-04
Anticipated expiration: 1905-09-04

Description

2 Sheets-Sheet 1.

(No Model.)

0. D. ROGERS.

MACHINE FOR ROLLING SCREW THREADS. No. 389,170.

Patented Sept. 4, 1888.

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MACHINE FOR ROLLING SCREW THREADS.

N0. 389,170. Patented Sept. 4, 1888.

\NVEN TClFh Jiifa qns UNITED. STATES PATENT OFFICE.

CHARLES D. ROGERS, OF PROVIDENCE, RHODE ISLAND, ASSIGNOR TO THE AMERICAN SCREW COMPANY, OF SAME PLACE.

MACHINE FOR ROLLING SCREW-THREADS.

SPECIFICATION forming part of Letters Patent No. 389,170, dated September 4, 1888.

Application filed May 18, 1888. Serial No. 274,277. (No model.)

To all whom, it may concern: the die in the direction of the spiral groove Be it known that I, CHARLES D. RoGERs, a and ultimately squeezed out at the point, citizen of the United States, residing at Provithereby producing imperfect screw-threads. deuce, in the county of Providence and State These defects in previous machines are avoid- 5 5 of Rhode Island, have invented certain new ed by the combined use of straight acting and and useful Improvementsin Machines for Rollguiding dies, where the ribs of each die have ing Screw-Threads; and I do hereby declare the peculiar relation to the ribs of the other the following to be a full, clear, and exact dewhich I have adopted. scription of the'invention, such as will enable The accompanying drawings, representinga 6o others skilled in the art to which it appertains machine for rolling threads upon wood-screws to make and use the same, reference being had embodying my improvements, are as follows: to the accompanying drawings, and to letters Figure 1 represents a plan view of a maor figures of reference marked thereon,which chine having both dies mounted to travel back form a part of this specification. and forth. Fig. 2 is a plan view of a machine 6 My improvements herewith relate to the in which one die travels back and forth and construction of straight dies having ribbed the other is stationary. Fig.3isatransverse faces placed opposite each other, so as to roll sectional view taken on linear m of Fig. 2 when the blank between them in a machine which the dies are opposite each other. Fig. 4: is a imparts a reciprocal motion to one of such dies, front view, enlarged, of the acting-die. Fig. 0 while the other remains stationary and acts as 5 is a cross-sectional view of both dies, the a back-rest, or in a modification of such maacting die being cut at the line a; 1'. Fig. 6 is chine which imparts a reciprocal motion to a similar sectional view taken on line 0 0. both dies in opposite directions, one of such Fig. 7 is a cross-sectional view taken on line dies only being employed to form the thread, W W, and Fig. 8 is an enlarged sectional view 2 while the other acts as a back-rest or guide. showing the relative arrangement of the Some of the machines for rolling screwthread-forming ribs and the ribs of the backthreads heretofore in use roll the blank berest die. tween two cylindrical dies rotating in the same The frame A of the machine may be of any direction, as in the patent to John Sheldon, convenient form to support'the dies andmech- 8o 0 No. 315,319, dated April 7, 1885, in which case anism for producing a reciprocating motion of guiding devices are required to retain the one or both of them. Such mechanism is well blank in proper relation to the dies. Other known and may be varied as desired. In the machines employ pairs of straight dies facing machine shown in the drawings the shaft S, each other, both acting upon the blank to form by means of the crank b and the connectingthe thread, as in my United States Patent No. rod 0, moves the cross-head m back and for- 370,353, of September 20, 1887, in which case ward. The threading die B, being firmly any minute disarrangement of the reciprocatbolted to the cross-head,Fig. 1, represents these ing mechanism or lack of adjustment between reciprocal parts in duplicate, the dies B and the two dies in the pair may produce a dis- B both being movable. 0 o torted thread. Other machines employ a ro- The blank h is fed through the inclined tating cylindrical die to form the thread, as ways m, and, entering the space between the ing' a hollow cylindrical die placed outside and ends of the dies, as represented in Figs. 1 and around the acting one as a rest to the blank, as 2, is rolled between them, and by the pressure in the patent to Clark and Harvey, No.306,132, of the ribs of the acting-die B the thread is 45 dated October 7, 1884. In this form of conformed upon the blank, which is held in posistruction a transverse section of the inner surtion by the back-rest B. face of the stationary die forms a larger circle The peculiarity of the straight dies which I than the periphery of theacting die, and the use is shown in Figs. 4;, 5, 6, 7, and 8. The face blank in being rolled between these two surof the acting die B is provided with a series of mo 50 faces of unequal length is liable to be twisted inclined parallel ribs, 0, which have a Vshape and distorted, or the metal is plowed along by at the beginning (see Fig. 5) and for portions of their length, and are then transformed into ridges, having the cross-section of truncated wedges gradually increasing in breadth upon the face to the end. The die B, whether arranged, as in Fig. 1, to move, or, as in Fig. 2, to remain stationary, is provided with aseries of inclined parallel ribs upon its face similar, but reversedly inclined, to those upon the face of the acting die B. These ribs for a portion of their length are also Vshaped in cross-section, and are then transformed into ridges whose crosssections are truncated wedges having faces progressively increasing in width to the end of the die; but the sides of theribs upon this die are less inclined relatively to each other than the side walls of the corresponding ribs upon the acting die B, for the purpose and with the effect of preventing the sides of the ribs upon the die B from acting upon the metal of the blank to form the thread, which is shaped by the action of the die B only, thus restricting the function of the die B to acting as a rest only. This feature of the die is shown exaggerated in Fig. 8.

I claim as my invention t 1. In a machine for rolling threads on screwblanks, a straight die having formed upon its acting face a series of inclined parallel ribs, which for portions of their length are V-shaped in cross section, and are then transformed into ridges whose cross sections are truncated wedges having faces progressively increasing in width from the point where they commence to take the truncated form to the end of the ribs, in combination with a straight back rest or die having upon its face a series of inclined parallel ribs similar in form to the series of reve'rsely inclined parallel ribs upon the acting die, but of less area in cross-section, and thereby adapted to bear only upon the core of ascrew-blank rolled between it and the acting die, as described.

2. In a machine for rolling screw-th reads on sorew-blanks,a straight die,substantially as described, in combination with a straight backrest having formed upon its face aseries of incline'd parallel ribs, which are similar to the series of reversedly inclined parallel ribs formed upon the acting die, excepting that the sides of the ribs which constitute the walls of the recesses between the ribs upon the backrest are less inclined relatively to each other than the sides of the corresponding portions of the ribs of the acting die.

In testimony whereof I have affixed my signature inpresence of two witnesses.

CHARLES D. ROGERS.

Witnesses:

CHARLES HANNIGAN, GEO. H. REMINGTON.