Patent ID: 8418955

Claim:
An actuation system for a hydraulically operable aircraft elevator, comprising: two actuators, supplied from at least one hydraulic supply system, of which each is coupled to a load-bearing structural component, and to an elevator displaceable relative to the load-bearing structural component, for the operation of the elevator, a first control valve device, hydraulically connected to the first actuator to control the latter, and a second control valve device, hydraulically connected to the second actuator to control the latter, which devices are respectively supplied from an hydraulic system, a control and monitoring unit functionally connected with the control valve devices, which determines appropriate command signals for the control valve devices, and transmits the signals to the latter to execute appropriate control movements for the operation of the actuators, and a locking device coupled to the first actuator with a locking mechanism to secure an extended position of a pushrod of the first actuator in its locked state, which is hydraulically connected with the first hydraulic system and with the second hydraulic system via an hydraulic OR-circuit, such that in normal operation of at least one of the hydraulic systems, the locking mechanism is in its unlocked state, and such that in the event of the failure of both hydraulic systems the locking mechanism under a minimum pressure secures the extended position of the pushrod of the first actuator.