| 摘要 |
PCT No. PCT/GB86/00780 Sec. 371 Date Aug. 13, 1987 Sec. 102(e) Date Aug. 13, 1987 PCT Filed Dec. 19, 1986 PCT Pub. No. WO87/03924 PCT Pub. Date Jul. 2, 1987.Soil displacement hammer for driving holes in the ground, comprising a substantially cylindrical body (5), a soil displacement head (1) at a forward end of the body, a longitudinally reciprocable striking member (12) housed within the body, and an anvil member (13) within the body adjacent its forward end and adapted to receive hammer blows from the striking member to cause the body to be driven forward. A retractable baffle member (4) is mounted adjacent the forward end of the body and is moveable between a retracted position in which it does not project from the body so that the soil displacement hammer describes a straight path in the ground, and an extended position in which it projects transversely from one side of the body to cause the soil displacement hammer to describe a curved path in the ground. The invention also provides a method of tracking such a soil displacement hammer in the ground. |
