| 摘要 |
A down-the-hole hammer is described. It comprises an external cylindrical outer wear sleeve (10), an inner cylinder (9) mounted co-axially within the outer wear sleeve (10), a sliding piston (11) mounted for reciprocating movement within the inner cylinder (9) and the outer wear sleeve (10), to strike a hammer bit (40) mounted at the lower end of the outer wear sleeve (10) and an elongate cylindrical air distributor (3) positioned within the hammer assembly. The lower end of the air distributor (3) is positioned substantially concentrically within the upper end of the inner cylinder (9). A shoulder (38) on the air distributor (3) engages the underside of a complementary shoulder (15) on the inner cylinder (9). The top end of the outer wear sleeve (10) is screw-threadably engaged with the lower part of an annular locking member (1), and the top end of the inner cylinder (9) abuts the lower end of the locking member (1) such that the inner cylinder is rigidly mounted in the drill assembly relative to the outer wear sleeve (10) by means of a locking engagement between the air distributor (3) and the-locking member (1). |
