IMPACT-ACTION DEVICE Russian patent published in 1996 - IPC

FIELD: construction and road-building machines; consolidation of ground in under confined conditions; breaking of asphalt-concrete and concrete coatings. SUBSTANCE: device has housing 1 with striker 2, control unit with housing 3, and spool 4 and pressure and return main lines. Two-step control unit spool 4 has circular groove 9 on larger diameter step through which return space 6 communicates with return main line 25. Spool smaller step forms pressure chamber 10 coupled with pressure main line 21. EFFECT: increased efficiency in operation. 1 dwg