| 摘要 |
FIELD: construction, applicable for trenchless laying and replacement of underground pipe-lines. ^ SUBSTANCE: a reciprocating striker is positioned in the casing of the pneumatic percussion mechanism. The air-distributing system of the mechanism includes the front and rear working chambers, inlet and exhaust valves and a fixture for closing and opening of the exhaust channels made in the form of a spring-loaded end face stopper coupled to a tractive member. At actuation of the pneumatic percussion mechanism, before the supply of compressed air, the exhaust channels are closed, they are opened after the inner cavities of the pneumatic percussion mechanism are filled with compressed air. ^ EFFECT: provided automatic cyclic action of the pneumatic percussion mechanism. ^ 3 cl, 3 dwg |
