Abstract: A positioning system for controlling the rotation of a shaft or other member through a defined angular increment. The system includes a rotor which may be coupled in torque transmitting communication with the shaft, and a an indexing assembly for driving the rotor. The indexing assembly includes a slide or other follower which is operably coupled to a first actuator, which may be hydraulically or other otherwise fluid-powered, and to a biasing member, which may be a second actuator, which is also operably coupled to the first actuator. The first actuator is actuable to move the follower and, in turn, a pawl from a locking position to a release position, and to engage another pawl with the rotor effecting the rotation thereof in a rotary direction through the angular increment. The first actuator is de-actuable to return, responsive to the biasing member, the pawls and follower to their original positions.

Abstract: A positioning system for controlling the rotation of a shaft or other member through a defined angular increment. The system includes a rotor which may be coupled in torque transmitting communication with the shaft, and a an indexing assembly for driving the rotor. The indexing assembly includes a slide or other follower which is operably coupled to a first actuator, which may be hydraulically or other otherwise fluid-powered, and to a biasing member, which may be a second actuator, which is also operably coupled to the first actuator. The first actuator is actuable to move the follower and, in turn, a pawl from a locking position to a release position, and to engage another pawl with the rotor effecting the rotation thereof in a rotary direction through the angular increment. The first actuator is de-actuable to return, responsive to the biasing member, the pawls and follower to their original positions.

Abstract: The control surface drive has three shafts. The shafts are rotatably coupled by four universal joints. Mechanisms are provided to guide the shafts as outboard wing sections are moved between folded and unfolded positions. Rotary coupling between the inboard and outboard control surface drives is maintained during folding motion of the outboard wing sections.

Abstract: An actuator of the type used in aircraft flight controls and similar applications is combined with a fail-passive electrohydraulic control system (11) that affords the usual actuator response to electrical input commands during normal operation, and responds to any of a number of possible failure conditions to dispose the actuator in a passive or neutral failure mode. The passive-failure mode allows the actuator (15) to remain in the last-known valid position or move in response to an external force such as provided by a redundant backup actuator thereby avoiding a possibly dangerous flight condition that can result from a "hard over" actuator response to a failure condition.