Hydraulic system for controlling caravan support - has electric pump with safety overload cut=out using pressure switch and pressure relief valve

摘要

When the caravan has been placed in the required position, the system pivots the two stabilising legs which are stowed under the rear end of the van, parallel to its long horizontal axis when the van is being towed. Power is applied to an electric motor which drives a hydraulic pump (4). Fluid is fed from a reservoir (9), via a mechanical shut-off valve (5) to a pipe (2) which supplies the two hydraulic cylinders (1). When the foot has bedded into the ground, the back pressure in the pipe (2) increases and operates a pressure switch (8) to cut off the supply to the pump (4). The user then closes the shut-off valve (5) and the van is ready for use. A feedback loop via a one-way valve (6) and a pressure relief valve (7) provides extra overload protection. When the feet are to be lifted, the pump is rotated in the opposite direction.