US729647A - Tap. - Google Patents

Description

PATENTED JUN HZ 1903.

J No. 729,647. y

F. J. NU-TTING.

' TAP.

APPLICATION FILED 00123, 1902.

lilO MODEL.

UNITED. STATES Patented June 2, 1903.

PATENT OFFICE.

FREDERICK J. NUTTING, OF DAYTON, OI IIO, ASSIGNOR TO THE NATIONAL AUTOMATIC TOOL CO., DAYTON, OHIO.

TAP.

SPECIFICATION forming part of Letters Patent No. 729,647, dated June 2, 1903. Application filed October 23, 1902. Serial No. 129,426. (No model.) I

To all whom it may concern:

Be it known that I, FREDERICK J. NUTTING, a citizen of the United States, residing at Dayton, in the county of Montgomery and State of Ohio, have invented certain new and useful Improvements in Taps and I do declare the following to be a fulLclear, 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, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification.

This invention relates to improvements in taps for drilling screw-threaded openings and possesses the novel and advantageous features hereinafter described and claimed.

The objects of my invention are, first, to provide a tap with a reamer attached thereto, sothat a hole may be reamed and tapped in one operation, and, secondly, to provide an implement of the above character which possesses thestructural features hereinafter described and claimed.

Preceding a detail description of the invention, reference is made to the accompaning drawings, of which Figure 1 is a vertical longitudinal elevation of my improved tap, showing the tap-j aws c011- tracted. Fig. 2 is a vertical longitudinal midsectional elevation of the same, showing the tap-jaws expanded. Fig. 3 is a sectional elevation showing the tap-jaws contracted, as shown in Fig. 1. Fig. 4. is a transverse section on the line 00 a: of Fig. 2. Fig. 5 is a detached view of the retaining band or ring.

In a detail description of the invention similar reference characters indicate corresponding parts.

A designates a headwhich has four longitudinal grooves B on diametricallyopposite sides, that receive four tap-jawsC, said jaws being pivoted therein at D. These tap-jaws have on their outer exposed sides,at theends opposite to their pivots, cutting-teeth E, which during the rotation of the headfA cutscrewthreads in a well-known manner. The said tap-jaws are adapted to-receiveexpanding and contracting movements, respectively, through the expanding-rod F and the cupped contracting or collapsing cone G. The cone G is essentially not an integral part of the rod F, for the reasonsthat it would be impracticalto construct the rod and the cone as integral parts, and, further, by making the cone detachable it may be replacedwhen usage renders it unserviceable. The extreme end of the enpanding'rod F is reduced in diameter at a as compared with the portion lying within the hub of the head, and adjacent to said reduced portion a there is an annular tapering or cam surface I). In the outward or expanding movement of said rod F this tapering surface I), coming in contact with the tapering surfaces 0 on the jaws and thence in contact with the straight surfaces 0 of said jaws causes said jaws-to ride upon the surface of the larger diameter of the rod F, and thereby expand said jaws to their outer or operating position, as shown in Fig. 2. The collapsing or contracting cone G is made fast upon the smaller portion of the rod F by means of the nut H or otherwise. The interior tapering surface e of said cone inthe inward or upward movement of the rod F contracts or draws inwardly the tap-jaws C to the position shown in Fig. 3.- The ends of said jaws adjacent to the cone Gare recessed, as at g, to enable the rim of the cone to enter as the surface 6 moves against the tapering surface f of the jaws. So In this connection it will be observed that the tapering surfaces 0 and f are provided upon opposite edges of what may be properly termed an inwardly-proj ecting offset of each tapjaw, which oifset is of tapering form. I is a retaining-band, which surrounds the head and is secured thereto at a suitable point along said head by means of countersunk screws I. This band is designed to prevent the tap-jaws C from moving out of their openings B to an unnecessary extent. In the expanding movement of the said jaws they have the necessary room to move in by means of the rccesses'l at opposite points of said retaining-band.

The head A is provided with an exteriorl screw-threaded portion A, which screws into a shaft A, thejsaid shaft being mounted in a journal B and driven by a suitable gearing, as shown. The outer or lower end of the mo head A has secured thereto a reamer which operates to cut the opening in advance of the thread-cutting operation of the tap, so that the hole is reamed and tapped in one operation. The head A is provided with a series of concavities or recesses K, which lie on one side of the cutting-teeth E and receive the shavings or cuttings from said teeth during the operation of the tap. The expanding-rod F may be operated longitudinally in any suitable manner to spread the tap-jaws O or to bring the contracting-bone G in a position to close said jaws.

The operation of the tap is briefly described as follows: The s ime is adjusted by lowering or moving out the rod F to the position as shown in Fig. 2, which, as before stated, spreads the tap-jaws O to their outer or operative position. The material to be operated upon is elevated or moved against the reamer J, which cuts the opening for the tap. The tap-jaws, entering said opening in their eX- panded position, cut the threads, after which the rod F is moved in an opposite position to bring the contracting-cone G against the surfaces f of said jaws and the largest part of the rod F away from the surfaces 0 of said jaws. The tool is then removable by lowering the material operated upon.

Having described my invention, I claim A thread-cutting tool comprising a longitudinally-grooved rotatable body having a central opening therethrough and provided at one end with a reamer formed with an opening in axial alinement with that through the body, a series of tap-jaws pivotally supported at one end in the grooves of the body, and each of said jaws being provided upon the inner side thereof, and at or contiguous to its swinging end, with an inwardly-projecting offset of a tapering form with separate inclines or bevels inclining in the same direction, a retaining band encircling the head and the series of jaws therein, a reciprocatory expanding rod movable in the openin g through the head and provided at a point contiguous to one end with an annular conesurface for engagement With the inclines or bevels at one edge of the offsets of the jaws, and a cupped cone detachably mounted on one extremity of the rod and having a bearing within the reamer-opening, said cupped cone being designed to take over the offsets of the taps and engage with the inclines or bevels at the opposite edge of such oifsets.

In testimony whereof I affix my signature in presence of two Witnesses.

FREDERICK J. NUTTING.

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