| 摘要 |
934,166. Boring earth &c. INGERSOLLRAND CO. Feb. 27, 1962 [Feb. 27, 1961], No. 7610/62. Class 85. [Also in Group XXIII] In a drill comprising a casing 10 and a reciprocating hammer 12 striking a tool 14, the hammer and the tool have passages 18, 16 for drilling fluid, and a conduit 20<SP>1</SP> is resiliently connected to the hammer or the tool and is adapted to telescopically engage the tool or the hammer. In the " down the hole drill " shown a resilient sleeve 22 is interposed between the conduit and the hammer. A conduit 26 resiliently fixed to the valve cage 28 is adapted to telescopically engage in the passage in the hammer. In a modification a single conduit resiliently connected to the piston extends beyond the ends of the piston to engage the passages in the cage and the tool. |
