PERCUSSIVE ACTION MACHINE

摘要

PCT No. PCT/SU86/00141 Sec. 371 Date Aug. 24, 1986 Sec. 102(e) Date Aug. 24, 1986 PCT Filed Dec. 24, 1986 PCT Pub. No. WO88/05115 PCT Pub. Date Jul. 14, 1988.A percussive action machine for changing the shape of solids objects comprises a housing (1) accommodating a hammer (2) capable of reciprocations. A tail piece (3) of the hammer (2) is disposed inside a power cylinder (6) to impart energy thereto during the work stroke of the hammer, the tail piece being capable of engagement with a drive for executing the return stroke of the hammer (2). The machine is also provided with a unit for decelerating the forward travel of the hammer (2) in the form of an annular projection (20) in the midportion of the hammer (2), and a cavity (17) which accommodates this projection (20), and has a hammer deceleration chamber (21) of a cross-section substantially equal to the cross-section of the projection (20). The side surface of either the hammer decleration chamber (21) or the annular projection (20) is tapered.