Improvement in rock-drilling sviachines
US 165646 A
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Description (OCR text may contain errors)
E. S; WINCHESTER."
Patented July 13, 1875.
7 I vI W? amass.
MPEIERS, PHOTO-LITHDGRAFHEH, WASHINGTCN D 0 EDWARD S. WINCHESTER, OF BOSTON, MASSACHUSETTS.
IMPROVEMENT IN ROCK-DRILLING MACHINES.
Specification forming part of Letters Patent No. 165,646, dated July 13, 1575;- application filed April 30, 1875.
To all whom it may concern Be it known that I, EDWARD S. WINCHES- .TER, of Boston, in the. county of Suffolk and which the following is a specification:
My invention relates to engines for drilling rocks, usually termed rock-drills; and the invention consists in a novel construction of the valve and its ports, to prevent the entrance of foreign substances through them into the steam-passages. It further consists in the combination, with the spring-arms of the valve, of rubber or other elastic material, 'to increase their durability and prevent breakage; and it further consists in a novel construction and arrangement of the parts, whereby the engine is rendered less liable to stop in consequence of the valve not making its full movement, all as hereinafter more fully set forth.
Figure l is a longitudinal section. Fig. 2 is a side elevation of the valve detached; and Fig. 3 is a transverse section of the same, taken on the line :c w of Fig.2.
In rock-drilling engines it often happens that fragments of rock or other foreign material accidentally enter the steam-passage when the hose or pipe is disconnected, and when the engine is started these fragments are driven into the ports or openings of the valve, and, catching between the edges of the valve and the passages in the cylinder, either break the latter or stop the engine, necessitating loss of time and repairs. To obviate this 1 construct my valve as represented in the drawings. As there shown, the passages e, which lead to the ports I), consist of a series of holes of less diameter than the port itself, so that nothing can enter that will not readily escape from the ports b. These holes may be round, as represented, or the may be oval; or they may be united, so as to form a narrow slot, less in size than the port b, though I prefer a series of holes instead of a slot, as they will obviously operate more perfectly to prevent the entrance of solid particles. These holes 6, it will be observed, enter the ports b at nearly a right angle, so that any slender object, such as a nail or small bolt, which might enter the holes 6, cannot work through, as its front end would strike against the wall of the port, which would prevent its further passage. As the passages c are to be made of a size equal to the passages a, leading to the cylinder, it will be seen that any substance that can pass through the openings 6 will pass readily on into the cylinder, where particles of such size cannot create any sudden breakage, and from whence they can be removed at will.
The body of the valve A is cylindrical in form, made solid, and is seated in a correspond-iuglyformed cavity, as shown in Fig. 1. That portion of the surface of the valve between the openings 6 and the ports I), and designated by the letter d in Figs. land 3, is made equal in extent, or greater than the semicircular wall f, against which it works, as shown in Fig. '1, so that, whatever position the valve may occupy, the edge of the openings 6, will never pass the edge of the wall f, and hence any object that will enter the openings 6 cannot be carried past the edge of the walls f, and by that means I guard against accidents from that source.
Another difficulty with this class of engines is their liability to stop at the forward stroke of the piston, in consequence of the drill striking the rock before the piston D has movedfar enough to throw the valve a sufficient distance to admit the steam or air for the reverse stroke. To obviate this difficulty I arrange the inlet-passage O in such a posi-- tion in relation to the broad flat armor lever O of the piston D that the steam or compressed air, as it enters, will strike directly against the arm G, and thus assist to throwit forward, this arrangement being shown in Fig. 1. It will be observed, also, that the groove at the center of the piston D, in which the end of. the arm 0 plays, is of such a size that when the piston has completed its stroke the arm 0 has still a short distance to move in order to complete its stroke, this additional movement of the arm being accomplished by the momentum of the valve and its arm, so that it the piston should stop a little short of its full stroke, the valve will continue its motion until its stroke is completed, thus preventing the engine from stopping, as it otherwise would. On its back stroke there sured, so as to reverse the stroke and insure the continuous operation of the engine. The arm 0 of the valve is made, as represented in the drawings, of a flat piece of steel divided into two separate curved parts, which operate as a spring, so that when struck by the pisr ton there will not be the liability of breakage by the suddenconcussion, and also less jar than there would otherwisebe; and to still further lessen the liability of breaking these spring-arms, and to render them more durable, I interpose between them a piece of rubber, P, as shown in Figs. 1 and 3. Instead of rubber, any other elastic material may be used, such as leather, or even wood, with beneficial results; but I consider rubber best adapted for the desired purpose.
By these several improvements I am enabled to produce an engine that is far less liable to become deranged or stopped, that is more perfect in its operation, and also more durable.
Having thus described my invention, what I claim is- 1. The solid plug-valve provided with the steam-passages 6, less in diameter than the ports I), to prevent the entrance of fragments of rock or other foreign material.
2. The solid plug-valve provided with the ports I), with the steam-passages 0 arranged at right angles thereto, whereby elongated articles entering the passages e are prevented from passing through the ports I), as set forth.
3. In combination with the oscillating valve provided with the arm 0, the inlet-passage 0, arranged to deliver the infiowing steam or air directly against said arm, and thereby assist in completing the full movement of the valve, whereby the engine is prevented from stopping on its forward stroke when the piston stopsv short of its full movement, as set forth.
EDWARD S. WINCHESTER.
Witnesses W. O. DODGE, DONN TWITOHELL.