Safety controls for tailgate hoist - include twin switches allowing two handed operation only

摘要

The hydraulically operated tailgate hoist has two hydraulic servos to tilt the tailgate between the vertical and horizontal positions and two rams to raise and lower the gate. The servos and rams are controlled by twin switches to ensure that the operator cannot trap his hands, or feet in the mechanism. The failsafe connections for the servo operating relays ensure that if one switch is released the other has to be released before the two switches can be activated again. This prevents jamming of any one switch allowing dangerous one handed control.