GB659688A - Oiling system for percussive tools such as rock drills - Google Patents

Abstract

659,688. Percussive drills. CHICAGO PNEUMATIC TOOL CO., and FOSSUM, H. O. Sept. 5, 1949, No. 22931. [Class 124] A lubricating system in a gas pressure operated percussive drill comprises an oil supply reservoir, an enclosed oil transmission line from the reservoir to a point adjacent gas conducting passages, and a valve in the oil transmission line to check the flow of oil on the sudden pressure drop due to shutting off the operating gas, the valve comprising a sleeve having a tapered portion and a plunger slidable in the sleeve, the plunger being loosely mounted to permit passage of oil between it and the sleeve when in the unseated position. As shown, oil from a reservoir 62 flows through a passage 71, port 72, passage 79, port 81, aperture 82 and into a ratchet gear 15 where it meets the operating gas. Between the port 72 and the passage 79 the oil passes into a recess 73 then through an aperture 78 in a sleeve 74 in which there is a valve 84 seating at 88 where the bore is reduced. The movement of the drill in operation causes the valve to close and open, thus preventing any solid matter from remaining in the pipes. On shutting off power, the rush of oil foam and gas in the passages moves the valve into the closed position and prevents flooding of the tool on restarting.