METHOD OF ADVANCING DIRECTION CONTROL IN PERCUSSION-ACTING DEVICE FOR DRIVING HOLES IN GROUND Russian patent published in 1998 - IPC

FIELD: construction engineering. SUBSTANCE: this relates to pneumatically-powered devices which can be used for driving holes in ground for laying underground service lines without digging trenches. According to method, hole-driving device is turned in required driving direction due to single-side braking of device body which is asymmetric in longitudinal cross-section. This is achieved by local changing of coefficient of friction along axial and cylindrical surfaces between contacting surfaces of device body and ground. Device for realization of its advance direction control method has following components: axially symmetric cylindrical body, striker with reciprocating motion, mechanism for changing direction of advancing in the form of several elastic balloons located around body circumference with individual supply of working medium such as compressed air. Elastic balloons are arranged in zone of contact between device body and ground. Aforesaid operating procedure and embodiment of device allow for efficient control of advancing direction and for driving hole in required direction. EFFECT: higher efficiency. 11 cl, 11 dwg