US434139A

US434139A - Island

Info

Publication number: US434139A
Authority: US
Publication date: 1890-08-12
Anticipated expiration: 1907-08-12

Description

(No Model.) I Y J. U. TAFT.

METHOD OF GROOVING DRILL BLA'NKS. v No. 434,139. Patented Aug. 12, 1890.

UNITED STATES ATENT FFICE.

JEROME C. TAFT, OF PROVIDENCE, RHODE ISLAND.

METHOD OF GRQOVING DRlLL-BLANKS.

SPECIFICATION forming part of Letters Patent No. 434,139, dated August 12, 1890.

- Application filed April 22, 1890- Serial lie. 34:9,006. (N0 modeL) To all whom it may concern:

Be it known that I, JEROME C. TAFT, a citizen of the United States, residing at Provideuce, in the State of Rhode Island, have invented a new and useful Improvement in the Method of Grooving Drill-Blanks, of which the following is a specification.

In the manufacture of grooved drills from a bar of steel having squared ends, by the process of cold-swaging, it has been found that as the result of the said process the end of the grooved drill-blank would be almost invariably split or cracked, thus necessitating the cutting off and loss of aconsiderable portion of the stock; and it is the object of my invention to avoid this difficulty; and to that end my invention consists in providing the drill-blank with atapering or pointed end prior to the complete swaging of the blank to form the clearing-grooves of the drill, as hereinafter set forth.

Figure 1 represents a side View of a cylindrical drill-blank provided with a tapered or pointed end. Fig. 2 represents the grooved drill-blank, formed from the blank shown in Fig. 1 by the process of cold-swaging between sets of oppositely-reciprocated dies. Fig. 3 represents a front elevation of the sets of swaging-dies, by means of which the clearing grooves of the drill-blank may be formed, the grooved blank being shown in transverse section between the dies. Fig. 4 represents a front elevation of a rotary swaging-machine, in which the dies as shown in Fig. 3, can be employed, the front plates which serve to hold the dies in place being removed.

I11 the accompanying drawings, A, Fig. 1, represents a suitable bar of soft steel, which may either first be provided with a pointed end I), or be provided with said pointed end when the blank is partly swaged, as preferred. The pointed blank is to be inserted into the opening a between the sets of oppositely-reciprocating swaging-dies o c d d, which sets of dies are arranged at right angles to each other, and which may be operated simultaneously by engagement with the heaters e e e c of the swaging-machine, as shown in Fig. at, and the clearing-grooves f f of the drill may be formed by gradually closing the reciprocated grooving-dies upon the blank; and to accomplish the formation of the grooves to the best advantage I preferably employ several removable dies of gradually-changing form to carry the clearing-grooves f f to the proper depth from the original cylindrical or other form of the blank; but in some cases the said grooves can be completely made without a change of dies, especially in the manufacture of drills of small size. The pointed end, when made prior to the completed action of the sets of swaging-dies upon the blank, will tend to prevent the cracking of the metal at the end of the blank, by reason of which cracking a considerable loss is entailed in the manufacture.

I claim as my invention The method of grooving drill-blanks, which consists in cold-swaging the blanks between sets of oppositoly-reciprocated swaging-dies to form the clearing-grooves, and providing the drill-blank with a pointed end prior to the complete swaging of the grooves, as set forth.

JEROME C. TAFT. Witnesses: JOHN S. LYNCH, SOCRATES SCHOLFIELD.