GB812315A - Improvements in rock drilling mechanisms - Google Patents

Abstract

812,315. Portable drilling-machines. ATLAS COPCO A.B. April 23, 1957 [May 15, 1956], No. 12932/57. Class 83 (3). [Also in Group XXIII] A pneumatic rockdrilling assembly comprises a rotary or rotary and percussive pneumatic rock drill co-operating with a feeding device, the back head of the drill having a main cylindrical control valve 13 for the drill motor operating in a first cylindrical bore parallel to the drill axis, and an auxiliary valve 18 operating in a second cylindrical bore parallel to the drill axis to control compressed air to the feeding device, the back head also being provided with a handle 11 offset relative to the levers 16, 21, operating the valves. The valves are on one side of a plane 12 passing through the centres of fixing- bolts 8, the valve 13 also controlling flushing water to a flushing tube 5. The feeding device may be as described in Specification 767,814, [Group XXIII]. The handle 11 is on the opposite side of the plane 12 to the valves, so that the valve-levers 16, 21 may be operated without releasing hold of the handle. The valve 13 is so arranged that, on initial movement into the operating position, water is admitted to the flushing passages before the motor is started. The valve 13 may also be operated to blow air alone through the flushing passages without other operation of the drill, and in the " stop " position may allow a reduced stream of air to pass through the duct 5.