| 摘要 |
991,533. Percussive drills. J. HEMMLER, [trading as RIKO - WERKZEUGE ING. JAKOB HEMMLER]. May 9, 1963, No. 18332/63. Heading B4C. An electromotively drivable pneumatic percussive drill comprises a cylinder 11 having therein a percussion body 13 movable by means of a piston 12 into engagement with a tool shaft 14, the cylinder being provided with air compensating apertures 17, 18 and the percussion body with a bore 19. The cylinder is surrounded by a casing 15 thereby forming an annular chamber 16 communicating with the cylinder 11 via the apertures 17, 18. In operation, when the piston is reciprocated, the air is moved between the front of the percussion body 13 and the rear of the piston 12 via the apertures 17, 18. The bore 19 in the body 13 serves to replenish the air cushion formed between the piston and body.
|
