When the pump is switched on, the oil from the pump
extends the cylinder. After full extension, the Check Valve (1)
holds the load in place at which point the pump can be
switched off. To lower the valve, the Solenoid Valve (3) is
energized which opens the flow of oil to tank. The rate of
lowering is adjusted by means of a Flow Control Valve (3).
There is an inbuilt Relief Valve (4) for pump protection in
case of a rise in pressure.
The system is mounted on the framework of the
stacker/scissor lift itself. The compact nature of the
hydraulic system reduces the need for bulky valves and
piping. Solenoid valves are available with a manual override
function to lower the platform in case of power failure.
Due to the load holding nature of the system, there is no
need for the pump to offer continuous duty and hence there
is reduced power consumption.