US50576A - Improvement in rock-drills - Google Patents

Description

UNITED STATES PATENT OFFICE.

EDWARD J. GRAHAM, OF PHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT IN ROCK-DRILLS.

Specification forming part ot' Letters Patent No. 50,576, dated October 24, 1865 antedated October 6, 1865.

To all 'whom it may concern.-

Be it known that I, EDWARD J. GRAHAM, ot' Philadelphia, Pennsylvania, have invented an Improved Rock-Drill; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, and to the letters of reference marked thereon.

My improved rock-drill is of tubular form, and has on its face sets ot' cutting-edges, arranged substantia-lly as described hereinafter, so that the edges of one set may strike the rock across the incisions made by the edges ot' the adjacent set, and so that a rapid penetration of the rock may be insured.

1n order to enable others to make and use my invention, I will now proceed to describe its construction and operation.

On reference to the accompanying; drawings, which form a part ot this specification, Figure l is vertical section of my improved rock-drill; Fig. 2, an exterior view; Fig. 3, a view ofthe cutting endofthedrill, Fig.4,a view showing the combination of the drill with a sand-pump; Fig. 5, a modilication of the cutting-edges of the drill.

The drill A is made of steel or of iron with a steel cutting end, and is of the tubular form represented in the drawings, the exterior being largest in diameter at the lower end, and gradually tapering to the shoulder a, and the portion b above the latter being reduced in diameter for attachment tothe boring-bar, which may be screwed into or otherwise secured to the drill.

In the annular face of the drill, which will be best observed on reference to Fig. 3, are cut a series ot' V-shaped grooves in such a manner as to form four sets ot" V-shaped cutting-edges, there being in the present instance live such edges, numbered 1, 2, 3, 4, and 5, in each set.

The cutting-edges ot' each set are arranged parallel to each other and toa radial line drawn from the center of the face ot' the drill to the edge of the same, and the cutting-edges ot' one set are arranged at right angles to those ot' the adjacent set.

Rockdrills with V-shaped cutting edges have been heretofore made; but the edges have been so arranged as to coincide with a series A of radial lines, in consequence of which the cutting-edges, as the'tool was turned, invariably struck the rock in the same lines-a defeet which my arrangement ot' cutting-edges has been designed to obviate.

It will be evident that one set ot' cuttingedges cannot strike the rockin the incisions previously made by another set ofthe cutting' edges unless the rod be turned exactly onequarter round, which must be avoided in the use ot` my improved drill, the turning of the latter being such that one set of cutting-edges will strike the rock in lines crossing previous incisions made by another set. By this action ot' the cutting-edges a more rapid chipping away of the rock is insured than when the edges are arranged radially.

l have found in practice that in the use ot' my improved rock-drill no central core ot' rock coinciding with the central opening of the drill remains, thejar of the drill and the inner cor-- ners ot' the .cutting-edges tending to shatter this central portion of the rock into small pieces.

The drill may be used in the simple form illustrated inthe drawings, in which case the detritus may be removed from time to time after the withdrawal of the drill by the usual sand-pump; or the said pump may bc attached to and combined with the drill, the detritus passing upward through the interior of the drill and through the valve of the pump, as will be readily understood on reference to the view Fig. 4';

It will he evident that three sets only of cuttingedges, Fig. 5, may be used, and that l'or boring large holes there may be live, or even more, sets of cutting-edges.

I claim as my invention and desire to secure by Letters Patent- The within-described tubular drill, having 011 its face sets of cutting-edges, arranged sub* stantially as and for the purpose described.

In testimony whereot'l have signed my name to this specification in the presence of two subscribin g witnesses.

ED WARD J. GRAHAM Witnesses:

CHARLES E. FOSTER, HENRY HoWsoN.

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