US278517A - derby - Google Patents

Description

(No Model.)

G. MGC. DERBY.

ROCK DRILLING APPARATUS..

PNG. 278,517.

, Patented May 29,1883.

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UNITED STATESA PATENT Quince-,

GEORGE Meo. DERBY, oF NEW Yonk, N. Y.

'hoCK-DRILLING APPARATUS.

SPECIFICATION forming part of Letters Patent No. 278,517, dated May 29, 18183.

l 4 Application tiled November 14, 1882. (No model.)

To all whom fit may concern:

Be it known that I,GEORGE MoU. DERBY, a citizen of the United States, and residing in' the city, county, and State of New York, have invented certain new anduset'ul Improvements in Rock-Drilling Apparatus, ot' which the fol-V lowingis a specification.

y My invention belongs to that class ot' drills denominated tubular,in which the bit or cutting-edge of the drillis formed upon or attached to the end of a tubular steel,and by the action of which an annular section of the rock operated upon is cut away. The advantage of this class is that the labor that would be` expended in pnlverizing the interior is saved. It belongs also to the class` known as reciprocating, which are operated upon the principle of the steam-hammers; These havetheir shank connected to a piston working in a cylinder. Steam or compressed air, being admitted alternately before and behind the piston,forces it rapidly to and fro, causing the drill to strike the rock with great rapidity and force.` The advantage of the reciprocating drill, besides the rapidity of itsoperation, is that it can be used to drill a hole at anyangleto the vertical.

Heretofore, so far as myknowledge extends, i it has notbeen found practicable to operatea tubular drill withthis class of machine, but only drills hav-ing a solid steel` and bit have y been so worked. The diamond `drill is tubular, butis worked onlyby a constant revolution about the axis of the tubo and scratches away the rock without striking.

' The practical difticulties to be' overcome in using a tubular bit on the class of machinedrills above described are, first, to dispose of .the core formed; and, second,to prevent the steels, thus uniting the. classes. f

`My invention consists in pitching up the end or bit of the drill and shapingthe cuttingedges in such` a manner as to rapidly break the rock, and to prevent clogging either on'the outside or inside of theV tubular shank-steel.

advantages of both `It consists, also, in applying a streamof water, air,` or steam to remove the broken material'from the bit, soften the rock,and preserve the temper of the drill. y

In the accompanying drawings, Figure l is a vertical section of a tubular drill embodying my in vention, together with `a device forcom mnnicating reciprocating motion thereto and supplying water or other fluid to the bit of the Yceiving the extremity ot' the drill-shank D,

and to theother extremity of the shank D is secured, in any suitable manner, the tubular drill E, hereinafter described. Theshank D is also tubular, its perforation communicating at one extremity directly with that ofthe rod 0,1and at the other extremity with the interior ofthe tubular drill E.

Surrounding the rod G at its upper extremity is a cylindrical air or Huid chamber, F, with which communicates an inlet-tube, G, for supplying air, steam, or water from any suitable reservoir and under any desired amount ot' pressure. t t

VSuitablepacking-boxes, a andf, surround the piston-rod C at the points where it passes through the heads of the cylinders A and F. Suitable packing' is provided, andV the two cylinders are tirmlyunited by means of suitable pressure-screws, a andf. ,A transverse aperture, c', leads from the exterior ot' the piston-rod C, at a point within the air Vor fluid chamber F, into the center of the same, and

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communicates with the longitudinal perforation c2. The aperture c is at all times Within the cylinder F, and through it the Huid is vforced continuously into the interior of the rock away from the bit of the drill, and thus from the hole, as it is being formed, thereby obviating the difficulties arising from the clogging of the drill, and to prevent the drill from becoming overheated and its temper thereby destroyed.

To provide clearance and keep the drill from lbeing clogged bythe accumulation ot' debris about its extremity near the bit, either upon the inside or outside, it becomes necessary that the cutting-edge ofthe drill should be wider than the steel immediately above it, and I therefore construct the same in substantially the manner shown in Figs. 2, 3, and 4. This construction consists in forming the face of the bit transversely serra-te, as shown lin Fig. 2, and at the same time swelling or expanding it upon its inner and outer edges. By rendering the cutting-edge serrate it will rapidly pulverize the rock against which it is driven, and by constructing the cutting-edges Wider than the steel ot' the drill the dimensions of the-hole formed will be sut'ticient to permit the drill to be reeiprocated without undue friction, and. the size ofthe core of rock cut by the inner edge ot' the drill will be such as to extend within the same without in any mannerintertering with the motion ofthe drill.

For the purpose of conveniently obtaining the required expansion ofthe face ofthe drill, I prefer to form anyy convenient number ot'r transverse wedge-shaped, teeth, e, around the extremity ot' the drill. The inner edges ofthe adjacent teeth meet eachother at their respective bases, as shown at e', and the surplus metal, obtained by forming `the triangular openings between the same, is thrownout uponeach lateral Vsurface ot' the teeth, thus causing the face e2 ot' each tooth to be of greater width than its base. The result of this method of forming the cutting-edge or bit is that it presents to the rock a polygonal `figure, as seen iu Fig. 3, the lines joining the outer ends of the cutting-edges ot' the teeth forming a regular iigure,`the number ot' sides depending upon the number of, teeth. v

The form given tothe face ol' the drill in carrying out my invention will depend both upon the size ot' the hole to be made and the material to be operated upon. If a large hole is tobe made,'it is important to have the core remain unbroken, so that it can be removed in as large pieces or 'sections as possible, thereby saving the power that would benecessary to pulverize it; or it' the rock operated upon is very hard, then it again becomes important to leave the core unbroken. To do thisit'is necessary that the teeth of the drill vbe pitched up both on the inside and outside, as represented in Fig. S-that is, the face of the teeth should extend beyond the surface of the tubular steel both on the inside and ou the outside. In such cases the tubular steel must be nearly as long as the distance the machine feeds. On the other hand, it' the hole to be drilled is small, or it' the rock is soft and easily pulverized, it is not always necessary to pitch up the inside of the teeth in this manner, the pitching up of the outside being sufficient. The drill, then, by its action breaks oft' the core in small sections and soon pulverizesit, the dbris of which is carried away with the rest.

It will be apparent from an inspection of the drawings that the triangular spaces formed between the teeth and extending above their basis provide abundant clearance for the escape ofthe debris. The expansion of the steel commences as near the base ofthe teeth as is expedient for combining the requisiteenlargement and strength.

1 do not herein broadly claim a tubular rock-drill attached to atubular shank, in com-v bination with mechanism for communicating a positive to-'and-fro motion thereto, and for forcing a stream ot' air or water therethrough, as I contemplate embodying the same in an application to be hereafter tiled by me.

I claim as my invention- 1. A tubular rock-.drill having its bitor cutting-ed ge composed ot' wed ge-shaped teeth the cutting-edges ot' which are Wider than their bases, so arranged that lines joining their outer edges shall form a polygon, and having triangular recesses between said teeth and extending above their bases for the escape of dbris.

2. The combination,substantially as hereinbefore set forth, of a tubular rock-drill, a

Vtubular shank rigidly secured to said drill,

mechanism for giving a positive to-and-fro motion to said drill, means, substantially such as described, for supplying air, steam, or water through the interior of said shank and drill to the bit of the drill, and a bit or cuttingedge to said drill, composed of Wedge-shaped teeth the cutting-edges of whichl are wider than their bases, so arranged that lines joining their outer edges shall form a polygon, and having triangular recesses between said teeth and extending above their bases for the escape of dbris.

In testimony whereof I have hereunto subscribed my name this 11th day of November, A. D. 1882. v GEO. MCO. DERBY. Witnesses:

DANIEL W. EDGEooMB,

CHARLES A. TERRY.

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