Abstract: A device to provide for mechanical motion between a locking element in a hydraulic actuator to an external indication device, comprises:(a) a housing defining a first generally longitudinally extensive passage, and a lock element in longitudinal alignment with the first passage,(b) a lever located to pivot in that first passage, the lever having first extent projecting toward the lock element which constrains pivoting of the lever,(c) and structure mounting the lever for such pivoting and defining a fluid barrier, whereby fluid at one side of the barrier closest to said first passage and lock element is isolated from communication with second extent of the lever at the opposite side of the barrier, and whereby motion of the locking element relatively away from the housing relieves said constraint of lever pivoting.

Abstract: A mechanical locking device includes multiple components that must move before axial travel of a load exerting component becomes unblocked. Such elements include a main lock means that is radially movable to unblock said axial travel; axially movable holder means that blocks radial movement of the main lock means; radially movable trigger means that blocks axial movement of the holder means; and release structure blocking radial movement of the trigger means. At least one and preferably both of the main lock means and of the trigger means comprises multiple elements spaced apart about the device axis for independent radial movement, such elements typically being caged for such independent movement.