Plessey Incorporated

Gec-marconi Aerospace Inc.

Smiths Industries Actuation Systems Inc.

Eugene E Shube

Valentin G Barba

David J Crook

Reese Randolph Smith, Iii

David J C Crook

Methods and apparatus for generating a linear vibratory output force having a variable amplitude. The force is generated by the cooperation of four rotating eccentric masses that are grouped in two pairs of two masses. The masses in each pair are counter-rotating (i.e., they rotate at the same speed but in opposite directions). The phase relationship between the two pairs is adjustable. For example, the phase of one pair can be advanced while the phase of the other pair is retarded by an equal amount, thereby changing the amplitude of the output force without changing the direction along which the force acts, and also without changing its frequency if desired.

Vibration control system

An electromechanical actuator is disclosed having either a rotary output or a linear output for moving an external load, the actuator having at least two drive motors, a synchronizer connected to the outputs of the drive motors, a differential mechanism combining the outputs of the drive motors, and a quick release mechanism connected to the differential mechanism and the actuator output, the quick release mechanism releasing support of the external actuator load in response to an internal actuator jam and maintaining support or the external actuator load in response to an external actuator overload.

Fail-free actuator assembly

An electro-mechanical actuator has two motors which normally operate at the same speed and combine (sum) to move a load via a rotary actuator output member. If the motors begin to operate at different speeds, this indicates that the system has failed, and the output member is automatically decoupled from the remainder of the actuator. This leaves the output member free to rotate relative to the remainder of the actuator. The speeds of the motors are monitored by a differential mechanism which produces a rotary output proportional to the average of the two motor speeds. This average is normally the same as the speed of the output member. Decoupling of the output member occurs when this average deviates from the output member speed.

A mechanical actuator assembly which automatically releases the load controlled by the actuator when the actuator jams or otherwise fails. The actuator assembly has two kinetic energy sources, the outputs of which are normally summed for application to the load. A monitoring device monitors the two kinetic energy outputs. When the relationship between those outputs deviates substantially from a predetermined relationship, the load is disconnected from the actuator assembly.

An authority limiter includes an input shaft clutched to an output shaft. The output shaft is geared to a motor. Opto-sensors, variable resistors or Hall effect devices provide control signals to a current source supplying power to the motor. Different amounts of opposing torque are applied by the motor dependent upon the positioning of a disc, mechanically attached to the output shaft, that is sensed by the detecting devices. By sensing various angular deviations from a null position, scheduled degrees of torque are applied to the input and output shafts. In another embodiment, the disc is coupled to the output shaft by an auxiliary clutch. When the electrical power is removed from both clutches and the motor, a rotational centering means moves the disc back to a null position with respect to the limiter. Fault monitoring circuitry is provided to disengage the authority limiter when a fault occurs. Finally, solid state switches are provided for interfacing with the aircraft and for enablement of associated devices or satisfactory engagement of the clutch.

Authority limiter

An authority limiter includes an input shaft clutched to an output shaft. The output shaft is geared to a motor. Opto-sensors provide control signals to a current source supplying power to the motor. Different amounts of opposing torque are applied by the motor dependent upon the positioning of a disc, mechanically attached to the output shaft, effecting the optical path in the opto-sensors. In another embodiment, the opto-sensor control is replaced by an electro-mechanical mechanism which senses various thresholds corresponding to angular positions of the coupled input and output shafts.

An electromechanical actuator is disclosed that is capable of high-speed and high force operation having a movable ram member that is biased toward executing a mechanical motion. A solenoid disengages a locking brake that via one input to a differential transmission triggers a high power mechanical stored energy to cause the ram member to execute its motion. A d.c. motor is connected to the other input of the differential transmission and provides an alternate to release the locking brake in the event of failure of the solenoid. Upon reversal of the polarity of the power supply to the motor, the ram member is reset.

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Elmont, NY, United States of America

Eugene E Shube