GB624221A - Improvements in or relating to fluid operated rock drills - Google Patents

Abstract

624.221. Percussive drills. INGERSOLLRAND CO. June 16, 1947, No. 15808. Convention date, July 23, 1942. [Class 124] In a fluid actuated rock drill a passage is provided from the exhaust port to a cavity in the drill body communicating with the drill hole and a valve is arranged selectively to prevent exhaust fluid passing to atmosphere, to cause the piston and distributing valves to assume positions for charging one end of the piston chamber and permit the pressure fluid to flow from such end of the piston chamber through the passage and into the cavity. As shown, pressure fluid enters a drill body through a valve 55 and is fed to either side of a piston 27 through distributing valves 40 and ports 41 and 42, finally exhausting through a port 26 and a valve 60. A passage 58 leads from the exhaust port to a cavity 31. Fig. 1 shows the normal operating position of the drill. If it is desired to blow out the drill hole the valve 60 is moved to the position of Fig. 2 which opens the face 44 of the distributing valve to atmosphere, causes the piston to assume a position in the front of its chamber and allows the pressure fluid to pass through the passage 58 into the cavity 31, finally to the drill hole through the passage 34 in the steel 33. Liquid may be supplied to the drill hole by the tube 52.