| 摘要 |
965,852. Percussive tools. RAND MINES Ltd., and C. J. IRVING. Nov. 26, 1962 [Dec. 12, 1961], No. 44684/62. Heading B4C. An auxiliary drill steel chuck 1 for a percussive rock drilling machine comprises a body portion externally shaped to be engaged by the drilling machine chuck, the bore 2 being so shaped that when a drill steel is inserted therein a longitudinal passage 15 is formed, and an external water box 16 associated with the chuck and communicating with the bore, the bore being blanked off at its inner end 3 which is adapted to be struck by the piston of the rock drill. The outer surface of the auxiliary chuck 1 is of hexagonal shape for co-operation with the chuck of the machine, the bore 2 being of circular cross-section. A collet 12 is screwed into the lower end of the chuck and is provided with a hexagonal bore corresponding to the shank of the drill steel, the latter being retained by the collet in the chuck with the end of the shank in contact with a surface 7 in the bore 2. The collet may be replaced by a rubber collar located in the chuck 1 and clamped by a screwed cap so that it grips the shank of the drill; alternatively, the collar may be secured to the shank of the drill. The water box 16 is mounted on the auxiliary chuck between a shoulder 9 and a nut 17, water being fed from the box via ports 18, passageway 15, and groove 22, formed either in the surface 7 or end of the drill shank, to a central bore 20 in the drill. The shoulder 9 may be coated with a resilient material in order to act as a buffer against the drill body 10. |
