GB190113277A - Improvements in Percussive Rock Drills, Direct Acting Pumps and Engines. - Google Patents

Abstract

13,277. Daw, Z. W. June 29. Rock drills, percussive. Relates to improvements in percussive rock drills, direct-acting pumps, and engines, in which the distributing-valves are actuated from the main piston by fluid pressure or by tappets, especially those of the class described in Specifications No. 8873 and 11,216, A.D. 1890, No. 11,607, A.D. 1893, No. 18,284, A.D. 1894, No. 10, 101, A.D. 1896, and No. 1748, A.D. 1900, and consists of the addition of expansion valves. As shown in Fig 3, a separate valve 27, 28 is used for each end, and, in Fig. 10, a single valve 27 serves. The valves are worked by the pistons 25, 26 connected by passages 21, 21<1>, 22, 22<1> to the ends and centre of the main cylinder, so as to be opened to supply and exhaust by the travel of the main piston 1. In Fig. 10, only the exhaust passages 21, 22 are used, and the main supply pressure is admitted direct to the valve pistons through small passages 34, 35. Small openings 30, 31 through the valves allow fluid to pass when they are closed in order to open them, or springs may be used. The position of the valve pistons may be adjusted by screw plugs 32 and lock-nuts 33. The expansion valves may be worked by tappets instead of fluid pressure.