Double acting steam or air hammer

1,067,691. Fluid pressure hammers. VSESOIUZNY NAUCHNO-ISSLEDOVATEL 'SKY INSTITUTE STROITEL 'NOVO I DOROZHNOVO MASHINOSTROENIA. April 29, 1965 [Feb. 2, 1964], No. 257/64. Heading B3H. A double-acting steam or air hammer has a differential working piston 2 which also serves to distribute the working fluid between upper and lower cylinder spaces 5, 6 which are interconnected through a one-way valve 8 to allow fluid to pass from the upper to the lower spaces during ascent of the piston. The hammer may be used for driving piles and is actuated by steam or compressed air. An anvil 13 has limited axial movement in slots 18 and is connected by articulated linkage 15 to a throttle device 9 in the main fluid admission valve 12 for reducing the fluid supply during excess movement of the anvil as occurs during piling in soft ground. During ascent of the piston 2 by fluid admitted into space 6, ports 26 are uncovered to allow fluid to pass through ducts 28 in upper space 5. When the pressure therein exceeds a predetermined amount, adjustable valve 8 opens to allow fluid to pass back into space 6. The upstroke of the piston is cushioned by a piston 19 supplied through pipes 23. Exhaust ports 25 are opened by the piston during its downstroke.