GB1234981A - Improvements in or relating to drilling apparatus - Google Patents

Abstract

1,234,981. Rock drilling apparatus. L. ARCANGELI. 8 April, 1968 [7 April, 1967], No. 16881/68. Heading B4C. [Also in Division B3] A rock drilling apparatus comprises support members 1, 2 for attachment to a vehicle, a housing 6 rotatable relative to the support members about an axle 4, a boom 12 pivotally mounted on an axle 11 journalled in a member 10 which is rotatable relative to the housing 6 about an axle (8) (Fig. 9, not shown) which is perpendicular to the axles 4 and 11. The boom at its free end pivotally carries on an axle 24, an arm 16 on which a cradle 18 is mounted for pivotal movement about an axle 17. An hydraulic arrangement comprising two actuators 25, 26 associated respectively with the axles 11 and 24 is provided for effecting movement of the arm 16 relative to the boom in response to movement of the boom about axle 11. The actuators are connected via connections 25e, 25f by pipes providing a closed hydraulic circuit and each actuator comprises a pair of cylinders 25a, a piston 25b reciprocable in each cylinder, a housing 25d, journalling a stub shaft, integral with each cylinder, and a pinion 25g carried by each stub shaft and meshing with a toothed rack on a piston 25b. The pair of stub shafts associated with each actuator provides the axle 11 or 24. The actuator 25 is fixed to the boom so that when the latter is moved about axle 11 movement of the pistons 25b of that actuator will effect movement of the pistons of the actuator 26 which is fixed to the arm 16 so as to cause movement of the arm about the axle 24. The closed hydraulic circuit may include valves whereby the actuators may be connected in a main hydraulic circuit independently so as to provide independent movement of the boom and arm about axles 11 and 24 respectively. The boom may be of variable length. Hydraulic jacks are provided for effecting movement of the housing 6 about axle 4, movement of the boom about axle 11 and movement of the arm about axle 17, and a worm gear arrangement driven by an hydraulic motor is provided for effecting rotation of the member 10 relative to the housing 6. The cradle 18 slidably carries a feed shell 21 on which a rock drill 22, 23 is slidably mounted. The pistons and cylinders of the actuators may have the same cross-sectional dimensions so the movement of the boom about axle 11 results in equal movement of the arm about axle 24.