Hydraulic load lifting device - has telescopic hydraulic cylinders designed so that inner and outer parts function simultaneously

摘要

The hydraulic load lifting device has two or more telescopic hydraulic cylinders which have their operations synchronised in order to lift the common load platform. Each telescopic hydraulic cylinder (16) has a piston (18) with a hollow piston rod (24). This hollow piston rod (24) forms a cylinder (26) for a second piston (27) which has its upper ene connected to the load platform (90). The annular space (22) between the inner and outer cylinders is initially filled with hydraulic fluid. In order to raise the load platform hydraulic fluid is supplied at pressure to the inlet (30) and forces the piston (18) upwards. As this piston rises the volume of the annular space (22) is reduced so that hydraulic fluid is forced into the inner cylinder (26) through holes (25) in the cylinder wall. The inner piston (27) is then forced upwards ismultaneously with the main piston (18). USAE - Lifting heavy loads.