US375098A

US375098A - Ghaeles d

Info

Publication number: US375098A
Authority: US
Publication date: 1887-12-20
Anticipated expiration: 1904-12-20

Description

(No Model.) 2 Sheets-Sheet 1.

C. D. ROGERS.

DIE FOB. SWAGING THE POINTS AND THREADS 0P WOOD scRnws.

No; 375,098. Patented Dec. 20, 1887.

m5- Model.) 2 SheetsSheet 2. C. D. ROGERS.

DIE FOR swAGlNG THE POINTS AND THREADS 0? W001) SCREWS. N0. 375,098.

Patented Dec. 20, 1887.

IEII BI INVEN TCIR RG72 arid .sjD j fa qera.

WITNEES ES.

UNITED STATES PATENT OFFICE.

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

DIE FOR SWAGING THE POINTS AND THREADS OF WOOD-SCREWS.

SPECIFICATION forming part of Letters Patent No. 375,098, dated December 20, 1887.

Application filed July 7, 1887. Serial No. 243,671. (No model.)

To aZZ whom it may concern.-

Be it known that 1, CHARLES D. Roenns, a citizen of the United States, residing at Providence, in the county of Providence and State of Rhode Island, have invented certain new and useful Improvements in Methods of Forming and Screw-Threading the Points of WVood- Screws; and I do hereby declare the following to be afull, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, referencebeing had to the accompanying drawings, and to letters or figures of reference marked thereon, which form a part of this specification.

This invention relates to an improved method of shaping and screw-threading the points of wood-screws; and it consists in passin g the blank between dies, the action of which is to first roll or impress a partly-formed thread into the body of the shank, and at the same time roll the rough point of the blank into shape preparatory to being threaded,the continued action of the said dies completely forming the screw-thread both on the shank and pointed portions of the screw.

It also consists in the novel construction of the dies and mechanism for operating them.

Wood-screws as commonly screw-threaded are first passed throughapointing mechanism which gives a proper form to the point of the blank. This operation becomes necessary when the blanks are severed from the rod by shearing or pinching, from the fact that more or less of a burr or fin is left on the point. It is evident that the employment of such pointing mechanism,when in a separate machine, including the attendance of an operator, necessarily increases the cost of manufacture. Moreover, where rolling dies are provided with thread-forming ribs adapted to thread the point of a screw (not previously prepared) coincident with the forming of the thread on the shank of the screw, the reduction of the metal of the pointed end and its consequent elongation produces additional strains upon the dies, the same being due to the opposed action of the metal of the screw in flowing both'laterally and longitudinally at the same time. The screws thus produced are found to be inferior, owing to the fact that the thread on the point is rough, in some instances being only partly finished, while in others the threads are nearly or quite detached at the root from the core, due to the cause stated,wherein, in forming the thread, the unyielding ribs and grooves of the dies retain the stock impressed therein, but the end of the screw while being rolled into shape is elongated, thereby causing the metal to quarrel, as it may be termed.

The object of my improvements is to overcome these disadvantages and produce a superior wood-screw at a reduced cost. These results Iattain by the use of peculiar dies,each of which for a portion of its length at the lower or point-forming portion (and at the entering end thereof) being without grooves and having a form adapted to roll and elongate the pointed end of the blank to a uniform shape. This plain or ungrooved portion merges into acorrespondingly-shaped portion of the die, into which obliquely-arranged grooves uniting with the main threading-grooves are cut, adapted to roll a thread on the screw-point while the screw-shank is being completely threaded.

The dies are provided at the lower contiguous edges with an extension or cutter adapted to sever from the point of the screw any superfluous stock remaining after the thread is formed thereon. I

The shape of the thread forming ribs adapted to produce a solid screw-thread raised from the surface of a screw-blank is shown and claimed in an application for United States Letters Patent, filed by me May 11, 1887, Serial No. 237,824.

In the annexed two sheets of drawings, Figure 1, Sheet 1, represents in elevation the working-face of one of a pair of dies constructed substantially according to my present invention. Fig. 2 is a transverse sectional view, taken through a pair of said dies, corresponding to line 0 0, Fig. 1. Figs. 3 and 4 are similar views taken through linesa: a; and a u of Fig. 1, respectively. Fig. 5 is a perspective view of a headed screw-blank as roughly severed from a rod, as usual. Fig. 6 is asimilar view of the lower portion of a blank, showing fins formed thereon by the action of the cuttingofi' dies. Figs. 7,8, and 9 represent perspective ICO views of the screwblank corresponding to the several stages in rolling the thread by the dies, at the lines 88, com, and are, respectively. Fig. 10 is a plan view of a machine having my improved dies mounted therein and adapted to shape the point of a screw-blank and to roll a screw-thread into the shank and point of the blank. Fig. 11 is a transverse sectional view taken on line .10 or of Fig. 10, viewed from the left. Fig. 12, Sheet 2, is a side elevation of the working-face of my improved die, its lower edge being divided into three parts or seetionsviz., the first part being adapted to roll the point of the blank into proper form preparatory to being threaded and simultaneously with the commencement of the threads on the body of the blank, the second section being constructed and adapted to roll the screw-thread on the pointed portion of the screw, and the third section is composed of a knife or cutter adapted, in" conjunction with its fellow die, to remove any superfluous stock from the tip of the point, which may have been produced during the rolling process. Fig. 13 is a transverse sectional view of a pair of mounted dies provided with such cuttingedge, taken on line at m of Fig. 12; and Fig. 14: is a perspective View of a partly-finished screw, showing superfluous metal extending from the tip thereof as a result of shaping and screw-threading the point.

In the drawings, A, Fig. 1, designates my improved die, made of steel and hardened. The working-face of the die is provided with a series of obliquely-arranged thread-forming ribs, a, separated by grooves 21. The lower edge portion of the die is beveled or angular, as at k. A portion, 1), thereof, for about one third of the length of the die from the entering end (t*, is made smooth or ungrooved. This plain portion is adapted to reduce the roughened point of the blank, as p, Figs. 5 and 6,into the proper symmetrical form necessary, and preparatory to the points engagement with the thread-forming portion 1) of the die about to be described, the superfluous metal, if any, being forced out and extending from the pointof theblank. By means of thus shapiugthe points the time and attendance necessary to produce the same result in another machine or operation are avoided. At the termination of the smooth portion b the ribs for forming the threads on the points commence. These thread-forming ribs and grooves are practically the prolongation of those which form the screw-threads on the body of the screw. It will be observed, referring to Figs. 1 and 12, that a portion of the said ribs to and grooves 12 terminate along the upper edge of the plain or point-shaping porion 12.

Fi g. 10 represents in plan a machine adapted o produce a screw having an automaticallyshaped and screw-threaded point, 12 Fig. 9. Said machine represents one of the dies A secured to the framing 13, while the other die is oppositely mounted in guides g and adapted to reciprocate back and forth in front of the stationary die, by means of a connecting-rod, d, crank c, and revolving shaft m. t indicates an inclined trough or runway adapted to conduct blanks 8 Fig. 5, to the dies while the latter are normally separated, as at the end of the stroke. It is obvious that the dies may be mounted so that both are adapted to travel, in which case the screw will not advance but simply turn on its axis while being submitted to the action of the dies.

The operation is as follows: A blank, 8", roughly pointed, as at pf, Figs. 5 and 6, and having a plain shank, s, terminating at its upper end in a head, it, (nicked, as at n, if desired,) is placed in a vertical position at the left of the stationary die A. Now, by suitable connections, the movable die is forced ahead toward the right, (see arrow-directiom) the dies being so adjusted in relation to each other that the blank is grasped between them at the same instant from opposite sides. The screw is carried along between the dies by the movable one until it passes the rear end of the stationary die, when the screw drops from them through an opening, 25, which conducts it to a receptacle beneath. At the commencement of the operation the ribs a are forced into the metal of the shank s, and as the rolling progresses to form the thread the lower portion, 12, of the dies at the same time transforms the roughened point 1) into an elongated and symmetrical point,p, Fig. 7. The further movement of the die as it carries the screw past the end of the plain portion 1) produces a continnation of the screw-thread 25 from the shank to the end of the screw. The final action of the dies produces a completely-threaded screw, E, substantially as represented in Fig. 9.

In Figs. 12 and 13 the rear portion of the stationary die is provided on its under side with a short cutter, b, which, co-operating with the sharpened edge b of the movable die,

Fig. 13, serves to shear off any superfluous metal or burr, as b Fig. 4-, from the lower end of the screw that may be produced during the rolling process.

Having described my invention, I claim 1. Grooved dies for rolling the threads on screws, each die having a portion of its working-face formed to first reduce and elongate the point portion of the screw-blank to a symmetrical shape by an ungrooved beveled surface, and then to roll a screw-thread on said point, the latter thread being a continuation 'of that simultaneously produced on the body of the screw.

2. The combination, in a screw-threading machine, of two grooved dies, one of which may be stationary, for rolling the thread on screws, each die having a portion of its beveled working-face ungrooved to reduce the point of the screw-blank to a symmetrical shape, and then, by means of ribs and grooves formed in the succeeding portion of the said beveled surface, to roll a sorewihread on the I sever superfluous metal from the tip of the 10 point of the screw. screw.

3. The combination of a pair of thread-forn1- In testimony whereof I have affixed my siging dies, each having a beveled portion of its nature in presence of two Witnesses. 5 Working-face longitudinally un grooved to first shape the point of the blank, and then, by CHARLES ROGERS means of grooves formed in the continuation "Witnesses: of said ungroovecl portion, to roll a screw- CHARLES HANNIGAN, thread thereon, and a cutting-edge adapted to G120. H. REMINGTON.