US1281785A - Power-driven rock-drill. - Google Patents

Description

M. KELLOW.

POWER DRIVEN ROCK DRILL.

APPLICATION FILED .IULYH. 1914.

1,281,785. Patented Oct. 15, 1918.

2 SHEETSSHEET 1.

INVENTOR:

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M. KELLOW.

POWER DRIVEN ROCK DRILL.

APPLICATION FILED JULY 1 I. 1914.

' Patented 0011.15, 1918.

2 SHEET$SHEET 2.

Hun em-es PATENT WERE Moses 'KELLOW, on fPENRHYNDEUDRAETH, WALES.

POWER-DRIVEN ROCK-DRILL.

Letters Patent of the United States granted to mean'd dated the 26th May 1908. No.

888506 andthe 9th June1908, 'NO. 890,065. The 'presentinvention consists in certain improve'ments inj-power- 'drills of this class;

" "particularlyin regardto the mode of connecting 'the motor shaft with. the speedreducinggear, in theconstru'ction of the specd-reducing gearwitha view toinsuring its thorough lubrication',and in the construction o'fthe' beari'ng between the forward extremity of the speed-reducinggear and the e'ndfcov'er of the gear-box.

--In the accompanying drawings, Figure 1 is a part longitudinal section .on the line 2"illu'strating the application of my present improvements to arock-drill of thetype'abovereferred' to. Fig. 2 being a transversesection through the speed-reducing gear taken on the line YY inFig. 1.

The machine viewed as 'a'complete construction consists in a turbine-driven rockdrill wherein the drill rod A and a casing B whereby "it is operated pass through the power-transmitting gear; the latter" being arranged about the part traversed by the section line Y--Y. The casing B is in indirect connection through soeed-reducing gear with the motor shaft 0, the latter being rotated by the turbine D. The opposite extremity of the drill-rod A proiects beyond the left hand end of the casing B and terminates in a piston (not shown) inclosed in a cylinder E. To the back of which piston water under high pressure is admitted for the purpose of forcing the drill-rod forward; the latter being capableof sliding longitudinally through the casing B while rotating with and being rotated thereby. F is the inlet for high pressure water for operating the turbine D, and G is the outlet. There being considerable drag between the drill-rod A and its casing B, a ball-race H is provided between a collar B on the casing reducing gear.

Specification of Letters Patent. :Patented Oct, 15, 1918.

Application filedJ'uly 11, 1914. Serial 110,850,455.

B and the end cover J; this ball bearing servingnot only'toresist the longitudinal thrust ofthe casing B but to center it and its inclosed drill-rod A laterallv. A ballrace is also provided between the turbine. chamber D and the gear-box L for the purpose'of preserving correct alinement and due clearances betweenthe turbine D and other .rotating parts.

The forward extremity of the turbineshaft C, instead of being externally screwthreaded to receive the first pinion of the epicyclic speed-reducing gear as in my prior construction, is screw-threaded internally 'and e'ngages alaterally projecting and externally threaded boss or sleeve b -formed on the face of the pinion Z; of the first speed- Bythese means, the diameter of the pinion is restricted to a minimuma point of primary importance in gears of the type under consideration','seeing that the ratio ot'gear train and reduced velocity of the teeth speed-reduction depends on the diameter of the central' pinion in relation to that of the internally toothed circumscribing ring.

I have found that in running epicyclic gears, such as employed in my prior con- 'struction, at a very high speed, even in an Oil bath', the intermediate wheels in the highspeed train displace lubricant from the setscrews or "studs whereon they rotate, owing to the centrifugal action, and wear badly. To obviate this defect, I employ set-screws or studs 5 of the maximum diameter prac- "ticable, leaving only sufficient metal in each applicable to the machine as a whole is more particularly explained in my co-pending application Ser. No. 139,911 filed Dec. 30, 1916). The set-screws or studs 6 are screwed left-handedly, so that rotation of the wheels upon them only tends to tighten them against their carrier-plate.

The speed-reducing gear is of the wellknown epicyclic type, and being repeated. four times, reduces the speed in four successive stages; From Fig. 2 it will be seen that six intermediate wheels 6 are employed all of which mesh with the central pinion b and with the internally toothed ring I)". The central pinion of the second gear train is screwed into the intermediate wheel-carrier of the first train and so on as regards, the third and fourth trains. The intermediate wheel-carrier of the fourth train is integral with the sleeve B which incloses and actuates the drill-rod A. The set screws or studs whereon the intermediate gear wheels are mounted are formed with shoulders which limit-the distance they can be screwed into the plate and determine the working clearance'allowed for the intermediate wheels between the carrier plate and the heads of theset screws or studs. As already stated, a hole extends from the central cavity 6 to the external surface of each stud or set screw with the effect that the lubricant under the influence of centrifugal force, is drawn from the said central cavity and fed to the bearing surface of the stud or set screw whereon the intermediate wheel is mounted. The internally toothed ring forming the outer member of the speed-reducing gear is held in position by reason of the tightness of its fit in the gear case or may be secured by means of set-screws.

In practice,1have found that side-thrusts are set up in the drill-rodwhich tend to cause rapid wear in the bearing at the forward end of the machine; incorrect aline-.

ment between the drill-rod casing and of the gears resulting, in addition to which lubricant escapes from the gear-box. Moreover the drag upon the drill-casing, due to the heavy feed-pressure, is considerable; and a great deal of wear takes place between the flange of the ,drill rod-casing and the Phosphor bronze plate in the forward end-cover of the machine.

Copies of this patent may be obtained for In the present construction, a ball-bearing H is employed and eliminates any wear in a radial; direction, thus keeping the r0- tating gears in correct position in relation to the fixed internally-toothed gear. This bearing also takes up the end-thrust and thusperforms a two-fold function; a considerable reduction of friction as compared with my previous construction before referred to resulting. In addition to these advantages the roller bearing permits an effective circulation of oil between the various rotating parts. To prevent the escape of oil from the gear-boxL the front end of the drill-casing B is provided with a stuffing-box f and a gland 7.

I claim 1. In a turbine-driven rock-drill, wherein the drill-rod and a casing whereby it is 0perated pass through an epicyclic powertransmission and speed reducing gear, the combination, with a hollow motor-shaft internally'screw-threaded at its forward extremity, of an externally screw-threaded annular projection formedv on the inner part of the face of the first pinion'of the speed:- reducing gear and adapted to engage in the forward extremity of the said motor-shaft, substantially as set forth.

2. Ina turbine-driven rock-drillfwherein I the drill rod and a casing whereby it is op. erated pass through epicyclic power-transmission gear, the herein described means for lubricating the planetary wheels, comprising studs with axial and radial holes forming passages and lubricant being fed, under the influence of centrifugal force, through said passages to the internal Working faces of the said planetary wheels.

i M; KELLow.

Witnesses: V

H. D. JAMESON, O. J. WORTH.

five cents each, by addressing the fcommissioner o1 latentsp 7 Washington, D. G,

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