Hydraulic pile driver with flow diverter valve - closes at given velocity causing flow deceleration which gives ram piston driving force

摘要

The mechanism derives a translatory force from a quantity of decelerating liquid and may be used for pile driving or like operations. It comprises a tube(12, 13), pump impeller(19) for introducing liquid at one end of the tube, a piston(14) at the other end, piston return means(16-18), and flow diversion means(29). A valve(34) is provided which shuts-off the diversion of flow when a given velocity is reached thus decelerating it and thereby forcing the piston outwards. Hydraulic means (44, 43, 38) return the valve to its normally open position.