GB190115824A - Improvements in Direct-acting Reciprocating Engines. - Google Patents

Abstract

15,824. Lake, H. H., [Ingersoll-Sergeant Drill Co.]. Aug. 6. Undercutting &c. - Relates to direct - acting reciprocating engines, such as are used for coal picks, in which the main distributing-valve is operated by a portion of the motive fluid distributed by an auxiliary valve, which itself is operated by fluid distributed by the main valve. Fig. 1 shows a vertical section through the motor portion of a coal-cutting machine, and Fig. 2 shows a plan with the valve-chest and valves removed. The main valve e works over the ports 16 ... 19, and the auxiliary valve over the ports 10 ... 12, both in the same chest, and each furnished with actuating-pistons j. These work in cylinders with which the passages 14, 15. 22, 25 communicate. The main cylinder a has exhaust passages 17, 26 opening into the cylinder at some distance from the ends, and supply passages 20, 23, the supply passages each being fitted with non-return valve n. The valve e has a cavity 28 wide enough to uncover a portion of the ports 17 and 19 together, and has lap for a part of its width at 24 sufficient to keep the exhaust port 19 permanently closed to admission. In action, the free exhaust allows a rapid movement of the piston to take place at the beginning of the stroke, thus leading to a lowering of the pressure in the valve-chest and a consequent delay in the throwing over of the valve e until the pressure rises again on the passage of the main piston b past the ports 27. Also, owing to the length of the exhaust cavity 28, the exhaust from one end of the cylinder a begins before the admission to the other. Through communication from end to end of the cylinder is prevented by the closure of the exhaust ports by the piston b.