GB1431383A - Telescopic rock drill feed - Google Patents

Abstract

1431383 Drill feed mechanism GARDNER-DENVER CO 18 June 1973 [14 Dec 1972] 28855/73 Heading B4C [Also in Division B3] A feed mechanism, e.g. for a rotary percussive rock drill, comprises an elongate support 12, an elongate drill guideway 24 mounted on the support for reversible movement therealong, a drill motor 32 mounted on the guideway for reversible movement along the guideway, and power means for moving the guideway along the support and the drill motor along the guideway. A pressure fluid control circuit is provided including series connected first and second valves on the gaideway and support 12, respectively, actuated by projections on the drill motor 32 and the guideway 24, respectively, when the mechanism is fully extended to produce a pressure fluid signal. The support 12 is adapted to be slidably and pivotably supported on the end of a drill boom by guides 13 and a support 14. The support 12 has grooves receiving the edges of a plate 26 attached to the guideway 24, and the guideway has grooves receiving ridges on the drill motor 32. The guideway 24 carries rotary fluid motors 46, 48 which drive power screws 54, 64 rotatably mounted on the guideway. A nut 68 fixed to the support 12 is threaded on the screw 64, and a nut 58 on the motor 32 is threaded on the screw 54 so that operation of the motors 46, 48 causes relative movement of the parts 12, 24 and 32. The support 12 and guideway 24 carry centralizers 42, 40, respectively, for a drill rod 36. As shown in Fig. 6, the motors 46, 48 are connected in parallel in an hydraulic circuit including a reversible pump 87 driven by a motor 86. In one mode of operation the motors 46, 48 are operated together to advance the guideway 24 and drill motor 32. At the forward limits of their advance projections 95 on the motor and 100 on the guideway operate valves 93, 98, respectively, so as to permit the flow of pressurized air from a source via conduits 103, 105, 108 to a control circuit which causes the pump 87 to be reversed. The guideway and motor are thus retracted to rearward positions in which projections 99, 96 carried thereby operate valves 97, 94 to send a further pulse of pressurized air via conduits 101, 104, 109 to the control circuit and so again reverse the pump 87. In a second mode of operation a manually operated valve 89 is moved to isolate the motor 48 and at the same time open a conduit to bypass valve 97. In this case only the motor 32 is fed and retracted, the guideway 24 remaining in its retracted position.