Multi-stage hydraulic pump
A multi-stage manual hydraulic pump comprising a plurality of cylinders in tandem. A block holds each cylinder assembly. One or more cylinders are the high volume stage, one or more cylinders are the medium volume stage and the final cylinders are the low volume, high pressure stage. The pump utilizes check valves built into flow tubes that control the direction of fluid. A spring and piston in each high volume block automatically turns off the vacuum and flow of fluid to each cylinder at a designated pressure. At the point of highest pressure only the smallest cylinder or cylinders are pumping fluid, where the effort expended is significantly reduced. A multi-stage manual hydraulic pump having a pump handle adapted to pump fluid to a high pressure in trench shoring, comprising a plurality of cylinders of decreasing volume, each cylinder having a cylinder piston, all of said cylinder pistons mechanically connected together, and mechanically connected to the pump handle, each of the higher volume cylinders having a block containing means to disable each higher volume cylinder at succeeding preset higher pressures by preventing the flow of fluid to the cylinder at the designated pressure being reached, the lowest volume cylinder reaching the highest pressure, said disabling means comprising a spring and piston adapted to prevent the flow of fluid to the cylinder at the preset pressure being reached, further comprising two fluid inlet ports, the first port carrying fluid to the low volume, high pressure cylinder and to a set of flow tubes leading to each of the cylinder blocks and the second port carrying fluid to a set of flow tubes leading to each of the higher volume cylinders, means to connect the pump in a container of fluid, means to connect the fluid output of the pump to the shoring.
Shanghai Kaida Pump Mfg. Co., Ltd.