GB998463A - A control system for a feed cylinder for a rock drill - Google Patents

Abstract

998,463. Rock drills. INGERSOLL-RAND CO. Oct. 17, 1961 [Oct. 27, 1960], No. 37216/61. Heading B4C. A control system for a double-acting feed cylinder 14 of a rock drill 10 includes a housing 20 having a fluid supply passage 52, a passage 48 to the chamber 14A of the cylinder and a passage 50 to the chamber 14B of the cylinder. The housing is the handle of the drill which has internal passages connecting the passage 52 with the air supply hose 18, and the passages 48, 50 with the chambers. A valve 90 is slidable to supply and exhaust the chambers, and a valve 74 is rotated to control the pressure of the supply to the chamber 14A. With the valve 90 set, as shown in Fig. 3, and the valve 74 set as shown in Figs. 6 and 7, air is supplied to the chamber 14A, to extend the cylinder, by passages 52, 58, groove 106, passage 60, port 80, chamber 76 of the valve 74 and passage 48, whilst fluid is exhausted from the chamber 14B by passages 50, 54 and outlet 114. Anti-clockwise rotation of the valve 74 (as viewed in Figs. 6, 7) progressively prevents fluid flowing into the chamber 76 and thence to the chamber 14A and progressively opens a port 64 to vent the chamber 14A. Movement of the valve 90 until the groove 106 is directly opposite the passage 58 stops fluid supply to the cylinder. Further movement of the valve 90 to its extreme right-hand position directs pressure fluid from the passages 52, 58 through the groove 106 and passages 54, 50 to the chamber 14B to retract the cylinder, fluid from the chamber 14A being exhausted through the passages 48, 62, the groove 102 and port 43.