US398637A

US398637A - mcculloce

Info

Publication number: US398637A
Authority: US
Publication date: 1889-02-26
Anticipated expiration: 1906-02-26

Description

(No Model.) 7 Sheets-Sheet 1.

J. MoGULLOOI-I. BOOK DRILL.

No. 398,637. Patented Feb. 26, 1889.

flrewior (No Model.) 7- Sheets-Sheet 2.

J. MGGULLOGH.

ROCK DRILL.

No. 398,637. Patented Feb. 26', 1889.

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J. MOGULLOCH.

. ROGK DRILL. No. 398,637. Patented Feb. 26, 1889-.

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(No Model.) 7 Sheets-Sheet 4.

J. MQOULLOOH.

ROCK DRILL.

No. 398,637. Patented Feb. 26,1889.

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ROCK DRILL. No. 398,637. Patented Feb. 26, 1889.

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(No Model.) 7 SheetsSheet 6.

J. MOUULLOOH.

ROGK DRILL. No. 398,637. Patented Feb. 26, 1889.

N, PETERS. Phcio-Lilhog apher, Washmgicn. D.C.

UNTTE STATES PATENT OFFICE.

JAMES MCCULLOCH, OF. MANCHESTER, ENGLAND.

ROCK- DRILL.

SPECIFICATION forming part of Letters Patent No. 398,637, dated February 26, 1889.

Application filed June 29, 1888. Serial No. 278,602. (No model.) Patented in England August 16, 1887, No. 11,192.

1' 0 all whom it 7771M](HUME/ft! Be it known that 1, JAMES MoCULLocH, engineer, a subject of the Queen of Great Britain, and a resident of Manchester, England, have invented new and useful Improvements in Rock-Drills, (for which I have obtained a patent in Great Britain, No. 11,192, bearing date August 16, 1887,) of which the following is a specification, reference being had to the accompanying drawings.

My invention relates to valves and valvegear chiefly designed for rock-drills.

The dist-ributingvalvcs of rock-drills have in some instances been operated by means of a tappet actuated by the piston or piston-rod in its to-and-fro movement. In such cases, however, it has been necessary to use a spring for retaining the valve in position at either extremity of its stroke or movement while not acted upon by the piston or piston-rod, and considerable inconvenience has been occasioned by the failure of the said spring to properly fulfill its function by reason of diminution of its strength or by the friction caused by excessive tightening of the said spring. In other instances the valves of rock-drills have been arranged to be operated by airpressure. This arrangement is unreliable, as the valve is apt to flutter or stick or be rendered inoperative by the entrance of sand, grit, or the like between the working-surfaces, the air-pressure then being insufiicient to overcome the increased resistance to movement of the valve. The springs, moreover, offer great resistance to the movement of the piston and cause considerable wear of the working parts, and when these parts are slightly worn the apparatus will not work properly (the valve not being kept in its f proper place) until the springs are renewed or read usted.

when working underground. In the valveless machine, moreover, the motive fluid is in constant communication with the piston, thereby causing great resistance to the movement of the piston and waste of the fluid.

By my invention I obviate the above-mentioned defects and provide for operating a distributirig-valve in an eificient and reliable manner by the combined action of a tappet or similar device and of iiuitln-essure.

A great amount of trouble 3 and inconvenience is thus caused, especially 5 My said invention comprises, moreover, other improvements, hereinafter set forth.

In the accompanying drawings I have shown how my said invention can be conveniently and advantageously carried into practice.

Figure 1 is a side elevation showing the application of my said invention to a rock-drill. Fig. ,2 is a plan. Fig. 3 is a longitudinal vertical central section. Fig. is a vertical section on the line a w, Fig. Fig. 5 is a vert-i cal section on the line 9; .r, Fig. 3. Fig. 6 is a vertical section on the line 1 y, Fig. 3. Fig. 7 is a vertical section on the line y y, Fig. 3. Fig. 8 is a plan,.and Fig. 9 a section on the line 2 2, Fig. 8, showing a modification hereinafter described. Fig. 10 is a plan; and Fig. 11 is a section on the line .2 .2", Fig. 10, showing a further modification.

Like letters indicate corresponding parts throughout the drawings.

A is the cylinder.

B B are the cvlinder-covers.

C C are the pistons.

D is the pistoirrod.

E is the stop-cock, and F the supply-pipe.

G is the socket for holding the drill H.

I is the bracket carrying the cylinder.

J-is a handle for feeding the drill to or from its work by means of a screw hereinafter referred to.

CL is a valve adapted to be moved by a tappet, b, which is pivoted at b to the cylinder A, and is actuated by a swelling or enlargement, 0, upon the piston-rod D. The air or other fluid delivered through the supply-pipe F and stop-cock E is caused by the tappet valve a to pass alternately through the two channels or passages ct to the extremities of the cylinder A and expands in the said eylinder. Holes (Z (I are formed in the cylinder A, through which the exhaust wili take place. As the piston C passes theupertures d d, the 1 compressed air or other motive fluid behind the piston exhausts through said apertures until the air behind said piston is in a state of equilibrium with the atmospheric air.

Upon the return-stroke of said piston the air piston will be compressed between the piston and cylinder-head. The air thus compressed provides a safe cushion at each end of the i said stroke and prevents damage to the covers 1 thus remainlng 1n the cylinder behind the l B B by the pistons C C. The air compressed, as above described, expands in the returnstroke of the pistons C C, and thereby augments the power or initial pressure tending to move the said pistons. Vhen the pistons O C are performing their forward stroke or niovenient thatis to say, the stroke in which they deliver the cutting-blow of the drill l-I- resistance due to the above-described cushioning does not offer any appreciable opposition to the force of the cutting-blow of the drill except when the pistons travel too far-as, for instance, when the said drill comes in contact with soft places in the rock, or when the apparatus is not keptinp to its proper working position. The atmospheric air is prevented from entering the channels or passages a, through which the moti ve fluid is delivered to-the cylinder A, by valves 6, provided with seatings f. The valves 6 are normally retained closed by springs g. When the atmospheric air is being compressed, as hereinbefore described, in either end Of l lIQ cylinder, the pressure of the said air tends to press the valve 6 in that end of the cylinder A tighter upon its seating f, while the valve 6 in the other end of the said cylinder is opened by the air or other fluid delivered by the tappetvalve a through the passage a, the pressure of the said air or other fluid being sufficient.

to overcome the strength of the spring g. This action takes place alternately at either end of the cylinder.

An important feature of my said invention is the construction and arrangement of the distributing-valve and its adjuncts in such a manner that when the said valve is moved to one end of its stroke to close one of the said ports and open the other port the pressure of the compressed air or other fluid acting upon the said valve will retain the same in position, and thus prevent movement thereof while the projection or enlargement c of the piston-rod D is out of contact with the tappet b. For this purpose I make the said valve as shown and fit it toslide in a cylinder or casing, provided with an oil-hole, a The said valve is provided with recesses or cavities a in which works the extremity o of the tappet b. I moreover provide steel disks a having india-rubber disks a in the center. Against these steel disks the surface of one or the other end of the valve a will be pressed by the tappet b at either extremity of its movement. \Vhen desired, the valve a can be reversed and the extremity b of the tappet I) inserted in the other recess or cavity, (t hen at either extremity of its movement the valve a closes the port through which the compressed air has access to it, so that the said end of the valve is no longer subjected to the pressure, and the compressed air acting upon the remaining surfaces of the valvewill tend to keep it pressedagainst the said disk.

To impart rotary or angular motion to the drill H upon or about its axis at the same time that it delivers its cutting-blow, a spindle, h,

is fitted in the cylinder-cover l3. The spindle h is provided with spiral grooves h, in which are adapted to fit correspondingfeathers or projections upon a bush, 1, fitted in the piston O, which is recessed or hollowed out. for that purpose. A hole or cavity, j, is also provided in the piston-rod D to receive the spindle h durin the inward stroke of the piston. The spindle h is moreoverprovided with a ratchet-wheel, k, with which engages pawls 71, actuated by springs 76 during the outward stroke of the pistons. \Vhen the drill H making its cutting-blow-that to say, when the pistons O O are making their outward stroke-the said pistons, the piston-rod D, an d the drill H are caused to rotate by the action of thcgrooved spindle 71 upon the piston C. Upon the return-stroke the pawls It" do not engage with the ratchet-wheel k, and the latter, with the spindle h, is free to revolve.

The cylinder A is provided with V-shaped projections land is arranged to slide in corresponding grooves, Z", in the bracket I. To feed the said cylinder, and consequently the drill H, to or from its work, I provide a screwthreaded spindle, m, carried in a suitable bearing, m, in the bracket I, and in a bear in g, 171*, in an extension, m of the said bracket. The screw-threaded spindle m is arranged to engage with corresponding threads in nuts 92, attached to the cylinder A. This spindle m is worked by means of the crank-handle J, as above stated. To take up any wear that may take place in the screwthreads upon the spindle m or in the nuts 02, the latter are provided with right and left hand screw-threads n upon the outside of the same. The nuts n are fitted with'a nut, 0, having right'and left hand screw-threads adapted to engage with the external screw-threads upon the said nuts n. Thus by turning the nut 0 any wear can be taken up and the jar to which machines of this kind are liable after a little wear is obviated. Nuts 1) are provided for taking up the wear in the journal m Suitable packing, q, is provided round the piston-rod D and grooved spindle h. Screwthreaded plugs r are provided, by removing which the tappet-valve a can be taken out for inspection or repair. A screw-threaded plug, 8, is also provided to permit access for oiling or inspecting the ratchet-wheel and the pawls I a.

Figs. 8 and 9 illustrate a modification wherein the cylinder A is arranged to slidein a bracket, 1, having at one side a V-shaped groove, 1, in which is adapted to slide the corresponding V-shaped projection, Z, upon the said cylinder. The V-shaped projection upon the other side of the cylinder .is adapted to slide in a recess, 2, provided with a setting-up strip, t. The strip 15' can be set up by means of set-screws u when necessary, so as to take up any wear that may occur.

Figs. 10 and 11 illustrate a modification wherein the bracket I is provided with a movable part or portion, 1', attached to the 1. In a rock-drill or other machine, the com-' bination, with a piston and a tappet operated by said piston, of the valve engaged with said tappet and having pockets in its ends forming chambers for receiving the pressure of motive force to hold it in position, substantially as shown and described.

In a rock-drill or other machine, the coml i11ation,with the cylinder and the doubleended piston, of the exhaust-ports (I, placed at a distance from the ends of said cylinder, and el1eck-valves in the supply-passages for preventing the escape of the air in the ends of the cylinder, substantially as described.

3. In a rock-drill or other machine, the combination, with the cylinder A, bracket I, and screw-threaded spindle m, mounted in said bracket, of sermvthreaded nuts 97-, mounted .on the cylinder and engaging with the spindie, and an auxiliary nut, o, placed around and screwed upon nuts 11, for compensating for the wear'upon said nuts, substantially as described.

I11 testimony whereof I have hereunto signed my name in the presence of two subscribing witnesses.

J. MCCULLOCH.

Witnesses:

I. SUTHERLAND MACKAY, CHARLES J. JAINEY.