US738416A - Drilling-engine. - Google Patents

Description

PATENTED SEPT. 8, 1903.

J. B. DAMAS'.

DRILLING ENGINE.

APPLICATION FILED MAY 26, 1903.

NO MODEL.

Patented September 8, 1903.

PATENT OFFICE.

JOHN B. DAMAS, OF SONORA, CALIFORNIA.

DRlLLlNG-ENGINE.

SPECIFICATION forming part of Letters Patent No.738,416, dated September 8, 190,3. Applicant 'sied May 2s. 190e. serial No. 158,823. (No model.)

To all whom, it may concern:

4Be it known that I, JOHN B. DAMAS, a citizen of the United States, residing at Sonora,

county of Tuolumne, State of California, have invented an Improvement in Drilling and Like Reciprocating Engines; and Ihereby declareathe following to be a full, clear, and exact description of the same.

My invention relates to a reciprocating engine such as is employed for drillingr and like purposes. Y

It consists of a cylinder having a doubleended piston reciprocating therein, the rod of said piston connecting at one end with the drill or other striking device, and in conjunction therewith of a valve having ports by which steam is admitted alternately at either end of the cylinder, and a second port and passage connecting with the cylinder at the rear end and serving to act as a cushion to prevent the piston from striking the rear end of the cylinder. In conjunction with this is a tilting or oscillating fulcrumed lever pivoted in a centrally-disposed chamber and having its lower separated ends so disposed withrelation to the reduced central portion of the piston that the enlarged heads of the piston serve to alternately tilt the lever and move the valve at the instant when the piston arrives at either end of its stroke.

My invention also comprises details of construction, which will be more fully explained by reference to the accompanying drawings, in which- Figure l is a longitudinal vertical central section of my engine with valve opened to admit steam into left end of cylinder. Fig. 2 is a section in same plane with valve opened to admit steam into right end of cylinder.

Reciprocating engines which are operated without crank or iiy-wheel are especially used for impelling rock-drills and like perforating or striking mechanism, and by reason of there being no crank tolimit the length of stroke it is necessary to provide some means for preventing the piston striking the ends of the cylinder, and especially the rear end, since the forward impulse of the piston is communicated directly with the vdrill or striker, and the impact of the striker against the rock or other face takes place before the piston reaches the frontend of the cylinder.

It is therefore only necessary to provide a means for preventing the piston striking the rear end of the cylinder, and this is the object of my invention.

As shown in the drawings, A is a cylinder having a double-ended and packed piston 2 movable within it. This piston has a central portion 3 of smallerdiameter than the ends, and this central portion is connected with the exhaust-chamber of the engine. 4 is a lever fulcrumed or pivoted within this central chamber, and the lower ends of the lever are separated, as shown, and project into the path of the piston in such a manner that they are contiguous to the smaller central portion of the piston, and when the piston reaches either end of itstravel it strikes one of these 1ever ends, and thus tilts the lever upon its pivot. The upper end of the lever enters a socket or open-ing in the slide-valve 5, which valve is movable upon a suitable seat and within a valve-chamber, (shown at 5*.) The forward end of the cylinder is connected by port 6 with the corresponding end of the valve-seat, and at the otherend are two ports7 and 8, which act, respectively, as steaminlet and exhaust ports. The valve has a D-port or single chamber l1 made in its lower surface corresponding with the steam-port 6, and it has a B-port or two chambers 9 and 10 at the opposite or' rear end which correspond with the ports 7 and S. Depressed channels 12 and l2a are made transversely across the ends of the valveseat, and the valve is movable so as to project over these channels alternately, and when in the position shown in Fig. l the chamber 1l at the left end of the valve is in such position that it connects the depression 12 and the port 6, so as to admit steam into the left end of the cylinder, and thus force the piston toward the rear end. When the valve is in this position, the chamber l0 at the opposite end of the valve connects the port S with thecentral chamberin which the lever 4 oscillates, and through this chamber steam from the rear end of the cylinderis eX- hausted and escapes through the exhaustport 13, the two closely-packed fitting heads of the piston preventing any passage of steam at those points. While the valve is in this IOC position, the chamber 9 of the valve covers Athe port 7 and at each end rests upon and makes a tight joint with the valve-seat, so that there can be no escape of steam through the port 7. Consequently when the right end of the piston 2 has passed the exhaust-port S there will be a body of 'steam inclosed between this port and the rear head of the cylinder, and as this steam cannot escape through the port 7 it forms a cushion which prevents the piston striking the rear head of the cylinder, no matter at what speed it may be driven.

When the piston has reached the rear end of its stroke, the shoulder between the smaller portion 3 of the piston and the enlarged p0rltionv2 at the left end will strike the left pro- Y jection of the Ytilting lever 4 and will move it about its pivot, so as to moveV the valve V5 into the position shown in Fig. 2. In this position the chamber 1l at the left end of the valve connects the port 6 with the exhaustpassage 13 through the central chamber, and the chamber 9 will stand in the position to connect the depression 12 at the right end of the valve-seat with the port 7, which now becomes a steam-inlet port, admitting steam at the extreme right end of the cylinder, and as the steam which was previously cushioned at that end of the cylinder still remains there is no loss by what is termed clearance. This position of the valve brings the chamber l0 into such position that it covers the port 8, the ends of the chamber tting upon the surface of the valve-seat, and thus preventing any passage of steam through the port 8 while the piston is moving toward the left end of the cylinder. By this construction it will be seen that the port 8 serves only to exhaust steam from the right end of the cylinder, and while this is taking place the port 7 is closed, so that the space between the ports 7 and 8 Within the cylinder serves to retain the cushioning-steam, but as soon as the -position of the valve has been changed the port 7 becomes the steam-inlet port, and these ports thus alternate, one acting as the exhaust and the other as the steam-port.

The back ofthe valve may have a projection or rib, asl shown at 14, and this rib is adapted to travel against the interior top of the valve-chamber, so as to insure the valve always traveling closely against its seat and preventing its being forced up by the impact of the piston against the cushioning-steam which might otherwise act through the port 7 into the temporarily-closed chamber 9.

The piston-rod 16 extends through the front end of the cylinder and has connected with it the drill or other implement-carrying head 17, through which the power of the piston is applied to strike the blow. The drill may be revolved by any suitable or Well-known ratchet mechanism, which is not here shown, as forming no part of my present invention.

Having thus described myinvention, what I claim, and desire to secure by Letters Patent, is-

1. The combination in a reciprocating engine and the cylinder thereof, of a doubleheaded piston having a central section of less diameter than the ends, a valve slidable upon 7o a valve-seat, said valve having a D-port in the under side at the front end and a B-port in the under side at the rear end, a centrallydisposed chamber between the cylinder and valve-chamber, a lever pivoted within said chamber having the lower ends projecting into the cylinder so as to be alternately tilted by the movement of the piston, a socket in the valve-face with which the upper end of the lever engages to reciprocate the valve, a single port connecting the front end of the valve-chamber with the front end of the cylinder, and two separate ports entering the rearV end of the cylinder, onewo'fV said ports serving to admit steam and the other to exhaust the steam upon the return stroke of the piston.

2. A reciprocating engine consisting of a cylinder, a double-ended piston fitting therein, a valve-chamber .having a seat, a valve slidable on said seat having a single chamber at the front and two chambers at the rear end, depressions at each end of the valveseat over which the ends of the valve are alternately moved to connect the outer end chambers of the valves alternately, with steam-ports leading to the ends of the cylin-l der, a second port connecting with the rear end of the cylinder, said second port communicating through the second chamber of the valve with the exhaust when the valve is in position to receive steam from the opposite' end, and the iirst port temporarily closing the rear steam-port whereby a cushion is formed within the cylinder between the two rear ports.

3. A reciprocating engine consisting of a cylinder, a piston having heads at opposite ends tting the cylinder and an intermediate connection of smaller diameter forming shoulders between itself and the heads, a valve movable within the valve-chamber having a single 'chamber formed in the front end, a port connecting the valve-seat with the front end of the cylinder, means for reciprocating the valve to alternately connect its forward chamber with the steam-port, and with a centrally-located exhaust-port, a steam-port extending from the valve-seat to the rear end of the cylinder, and a similarly-located ex- 12o haust-port opening into the cylinder at a distance from the steam-port, chambers formed in the rear end of the valve corresponding with the steam and exhaust ports, one of said chambers alternately opening and closing the 125 exhaust-port, and the other chamber similarly opening and closing the steam-port.

In witness whereof I hereunto set my hand.

IOO

JOHN B. DAMAS.

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