GB296020A - Feed controlling apparatus for percussive tools - Google Patents

Abstract

296,020. Chicago Pneumatic Tool Co., (Assignees of Nell, G. M.). Aug. 23, 1927, [Convention date]. Percussive drills.-The admission of pressure fluid to the space above 'the feed piston b<1> of a stoping or other percussive drill is controlled by a differential valve 9 which is moved into the position shown, that is, to close the passage b<3>, when the operator places his thumb over the open end 14a of a vent passage 14. The drill then descends as air escapes from the piston chamber through passages 13, 16, 18, which action may be more) or' less checked by the provision of a small inlet port 19. The handle is screwed into a tapered socket 8 which may be adjusted about its own axis by means of a cross pin 22 taking into different peripheral sockets 23. Lubricant from a recess 28 in the handle passes to the working parts by passages 30, 32. The main throttle valve 5 controls the pressure fluid inlet 4 supplying both the drill cylinder and the feed piston.