PROCEDURE FOR ADJUSTMENT OF MATERIALS WITHOUT BADGROUND

摘要

1380097 Rock drills ATLAS COPCO AB 1 Nov 1972 [5 Nov 1971] 50298/72 Heading B3C A rock drill comprises a fluid pressure vanetype motor 1 for rotating the drill rod 63, and a fluid pressure feed motor 4 which may be of the vane type, or may be a fluid-pressure ram, an unloading valve 7 connected to the inlet 35 to motor 4, and arranged to connect inlet 35 to a low pressure source 50 via a valve 52, and conduit 5, when a predetermined resistance against rotation of the drill rod is exceeded, and a device 51, 53, adapted to keep exhaust 33 of the motor at a pressure higher than that of the source, so that reversal of the feed motor is obtained when inlet 35 is connected to the low pressure. Drilling machine 62 is mounted on a carriage 64 which is fed by motor 4 via a chain 65. In operation, when the predetermined resistance to rotation of drill rod 63 is reached, the exhaust pressure at 32 is decreased, so that there is a rapid decrease in pressure in conduit 14, through passages 37, 38, and 39 in a venting valve 9. Actuation of manual valve 52 provides for fluid supply to motor 4 through conduit 6, and there is a rapid reversal of the motor to retract the drill rod. Movement of the drill rod can be provided independently of the operation of motor 1 when fluid is supplied from a source 12 through valves 11, 10, and conduit 14, which supplies motor 4 through valve 7. Check valves and restrictions (80), (81) or (90), (91). Figs. 3 and 4 (not shown) may be placed in the circuit.