HYDRAULICALLY DRIVEN SLEDGE HAMMER Russian patent published in 2014 - IPC B21J7/28 

FIELD: machine building.

SUBSTANCE: proposed hammer comprises anvil block with posts whereat hammer block is fitted to displace thereat. Pumping accumulator-free hydraulic drive with actuating cylinder is mounted at said posts. Hydraulic cylinder rod end is connected to hydraulic pumps via main check valve. Hydraulic drive incorporates two rigidly interconnected three-position hydraulic control valves. One of said hydraulic control valves is arranged between hydraulic pumps and said main check valve to communicated said pumps with drain line for their discharge. Another one of said hydraulic control valves changes over the connection between hydraulic cylinder piston and rod ends and drain line. Working fluid is drained from cylinder rod end via piston end to allow discharging of hydraulic pumps under whatever operating conditions that required no high-pressure fluid flow rate.

EFFECT: higher efficiency, fast operation.

1 dwg