US621271A - mcculloch - Google Patents

Description

N0- 62 ,27l. Patented Mar. I4, I899.

J. \MOCULLUCH.

ROCK DRILL.

(Application filed July 23, 1898.)

(No Model.) 3 Sheets-Sheet 1.

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UNITED STATES PATENT @EETCE.

JAMES MCOULLOCH, OF PORTREATH, ENGLAND.

ROCK-DRILL.

SPECIFICATION forming part of Letters Patent No. 621,271, dated March 14, 1899.

Application filed July 23,1898. Serial No. 686,708. (No model.)

To aZZ whom it may concern.-

Be it known that I, JAMES MoCULLooH, engineer, a subject of the Queen of Great Britain, residing at Portreath, in the county of Cornwall, England, have invented certain new and useful Improvements in and Relating to Rock-Drills, of which the following is a specification.

This invention relates to rock-drills, and has reference more particularly to a convenient and reliable arrangement of valve for distributing the motive fluid to the cylinder of the drill. According to the said invention the distributing-valve, which may have a rocking motion, is actuated by a wing or vane working fluid-tight in a suitable chamber. The arrangement is such that as the piston of the drill travels to and fro it covers and uncovers suitable subsidiary ports and passages in the drill-casing, thereby admitting motive fluid alternately to opposite sides of the wing or vane and so causing the latter to swing from side to side and operate the valve. at the proper times.

In order that the invention may be clearly understood and readily carried into effect, I will proceed to describe the same more fully by aid of the accompanying drawings, in which- 4 Figure 1 is a plan of the salient portion of my improved rock-drill. Figs. 2 and 3 are elevations of the same from opposite sides. Figs. 4 and 5 are respectively longitudinal and transverse sections through the center of the valve. Fig. 6 is a vertical section on the line 00 9c of Fig. ,4, and Fig. 7 is a section on the line y y of Fig. 5.

a is the distributing-valve, which in the present instance is of cylindrical form and is provided with grooves a for the reception of packing to render the valve stean1-tight,while at the same time allowing it to turn or rock freely on its axis.

a is the wing or vane whereby the rocking movement is imparted to the valve. This win g or vane works fluid-tight, after the manner of a piston, in a recess or cavity a in the wall of the valvemhest a and is operated by motive fluid, the admission and exhaust of which are controlled by the drill-piston in a manner which will be hereinafter described. The valve is shorter than the valve-chest a and a space or chamber a is left at one end. The opposite end of the valve is provided outside the valve-chest with a ring or collar a having a projection ad, which serves as a handle or trigger to enable the valve to be operated when necessary independently of the motive fluid-as, for instance, in starting the drill or when (as sometimes happens in the case of all drills when the rock contains slides or fissures) the bit sticks or fitchers in the hole.

I), Fig. 1, is the exhaust pipe or bend into which the space a opens. The said pipe has a flange b, which is interposed between the valve-chest and a loose ring or collar Z2 Suitable tightening-nuts b on bolts or studs b projecting from the said valve-chest, enable the flange to be clamped tightly up against the said valve-chest in any direction to which the operator may require or wish to turn the exhaust. The exhaust from the cavity a and from the drill-cylinder is concentrated into the pipe I) or bend, thus having one exhaust to the atmosphere in any direction desired.

0 is the supply-pipe for the steam, compressed air, or other motive fluid. This pipe terminates in a pair of inlet-ports c in the valve-chest cover.

Cl 61 are the exhaust-ports of the valve, and e isthe inlet-port thereof, which'is situated midway between the said exhaust-ports and extends diametrically across the valve, whereas the exhaust-ports open only on that face of'the valve next the cylinder, their other ends opening into the exhaust-chamber a The aforesaid arrangement of passages serves when the valve is operated to open a pair of passages f f, leading to opposite ends of the drill-cylinderf alternately to pressure and exhaust.

cl and e are the subsidiary passages which serve for the fluid operating the wing or vane I 0. These passages extend from the inner wall of the drill-cylinder to the cavity a in which the wing or vane works, and open into the said cavity on opposite sides of the vanes. The ends of the subsidiary passages, which open into the cylinder, are so arranged that the piston in its travel uncovers one of them at the end of its forward stroke and the other at the end of its backward stroke.

f is an exhaust-passage leading from the exhaust-chamber a to the cylinder. The end of this passage is situated midway between the passages d and c, and the piston is so constructed that it puts one of the latter into communication with the said passage f at the same time that it opens the other to the interior of the cylinder. For this purpose the piston is constructed in the following mannerthat is to say, it comprises four rings g g g 9 so arranged that one pair is situated at one end and the other pair at the opposite end of the piston. Between each pair of rings is an annular groove or recess g for the ordinary packing-rings of the piston. lhe portion of the piston between the rings g g is of reduced diameter, and the space 9 around it is kept constantly open to exhaust by means of the passage f, but is brought alternately into communication with the aforesaid passages (Z' and 0'. By this construction the piston not only performs its main function in operating the drill, but it also serves as a valve to control the flow of fluid to and from the cavity a. Thus when the piston is operating the spaces on each side of the wing or vane a receive motive fluid from the cylinder and are opened to exhaust alternately, so that the wing or vane is caused to swing from side to side of the chamber a thus reversing the valve after each stroke of the piston.

Obviously in some cases I may employ a tapered valve instead of a plain cylindrical valve, or I may arrange the valve in any desired position relatively to the cylinder instead of transversely thereto, as in the example shown in the drawings.

Having thus explained my invention, what I claim as new, and desire to secure by Letters Patent ot' the'United States, is

1. In a rock-drill the combination with a cylinder and valve-chest, the latter having passages for motive fluid leading from the valve-chest to the ends of the cylinder, of a rotary distributing-valve having a wing or vane adapted to oscillate in a pressure-chamber, said valve having a central live-pressure port between two exhaust-ports, a supplychamber for live fluid having ports communicating with the live-pressure port in the valve alternately, and means for admitting working fluid from the drill-cylinder to the pressure-chamber in which the valve-wing oscillates at the proper times to operate said valve, substantially as described.

2. In a rock-drill, the combination with a rotary distributing-valve having a wing or vane and provided with a live-fluid port between two exhaust-ports, of a piston having an annular space between its ends and the valve alternately communicates, passages leading from the interior of the cylinder to' opposite sides of the chamber in which the valve-wing oscillates, a piston having an annular space between'its ends, an exhaust-passage constantly communicatng with said annular space, and two live-fluid passages from the valve-chamber to the ends of the cylinder,-

substantially as described.

4. In a rock-drill, the combination of a rotary valve, a casing for the same, a wing or vane working fluid-tight in a recess in said casing, a flange at one end of said valve and a projection on said flange for operating the valve by hand, substantially as described.

5. In a rock-drill, the combination of a 1'0- tary valve, means for operating the valve by fluid from the working cylinder, a valve-casing for said valve having a space or cavity at one end thereof, an'exhaust-pipe connected to said casing and opening into said space, and a subsidiary exhaust-passage leading from the space or cavity to the middle of the piston, substantially as described.

6. In a rock-drill the combination with a rotary distributing-valve having a wing or vane to oscillate in a chamber in the valvecasing, said valve being provided with a central live-fluid port between two exhaust-ports, of a cylinder having two live-fluid passages from the valve-chamber to the ends of said cylinder, passages from the interior of the latter to opposite sides of the wing-chamber, a central exhaust-passage between the said passages, a piston having an annular recess between its ends constantly in communica-.

tion with the said exhaust-passage, and an exhaustspace or cavity at one end of the valveeasing, substantially as described.

In testimony whereof I have hereunto set my hand, in presence of two subscribing witnesses, this 14th day of June, 1898.

JAMES MCOULLOCII. Witnesses:

ARTHUR A. BERGIN, S. WINLO IIOAR.

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