| 摘要 |
<p>1,075,298. Percussive drills. GEBR. BOHLER & CO. A.G. Jan. 17, 1966 [Jan. 21, 1965], No. 2185/66. Heading B4C. A pneumatically-actuated percussive rock drill assembly comprises a drill 1 connected to a variable-length support 2 by an articulated joint 3 in which an air supply bore is formed, the controls 17, 33 for the drill and support being mounted close to the top of the drill. A rotary valve member (6, Figs. 2 and 3) is mounted in a tubular member (5) forming the pivot of the joint and is provided with a gear (7) meshing with a pinion (19) connected to a pivoted arm 18. The valve member (6) is formed with a port (102) adapted, when the arm is rotated by a lever 33, to communicate a compressed air feed (101) with passages (104), (105) leading to the rock drill. The air to the support is controlled by a valve member (16) rotatably mounted in an arm 15 the valve being rotated by a handle 17 so as to direct the air from the supply feed (101) to one or other side of a piston 21 in the support via various passages (114), (127), (154) in the arm 15 and ports (122), (115), (156), (161), (165) in the valve 16. If it is desired to lower the support rapidly, an exhaust valve (31), (32) may be actuated by a finger-operated plunger (30). In order to direct compressed air to the drill bit for flushing purposes, the valve (6) is rotated, by the lever 33, to a position in which air is fed to a cylinder housing a piston (35, Fig. 5), the piston having a stem (36) which abuts a ball valve (37). Upon opening the ball valve, a separate supply of air is fed through a pipe (38) and passages (180), (181), (183), (184) to a hole through the drill bit.</p> |
