Abstract: A system for controlling the rotational position of a solar collector trough includes a hydraulic cylinder having an output end and a linkage assembly. The linkage assembly includes at least one linkage member and a pair of pivot arms attached to the at least one linkage member. The pair of pivot arms is defined by a first pivot arm and a second pivot arm, each arm being pivotally attached to the at least one linkage member and the trough. The first and second pivot arms form respective parallel horizontal first and second pivot axes enabling the trough to be entirely movable over an angular range of motion extending over 180 degrees based totally on the linear movement of the output end of the hydraulic cylinder and in which an actuator control circuit controls the relative displacement of the cylinder output end.

Abstract: A system for controlling the rotational position of a solar collector trough includes a hydraulic cylinder having an output end and a linkage assembly. The linkage assembly includes at least one linkage member and a pair of pivot arms attached to the at least one linkage member. The pair of pivot arms is defined by a first pivot arm and a second pivot arm, each arm being pivotally attached to the at least one linkage member and the trough. The first and second pivot arms form respective parallel horizontal first and second pivot axes enabling the trough to be entirely movable over an angular range of motion extending over 180 degrees based totally on the linear movement of the output end of the hydraulic cylinder and in which an actuator control circuit controls the relative displacement of the cylinder output end.

Abstract: An electro-hydrostatic actuator having a sealed housing filled with a dielectric fluid. A motor driven pump and electronics for controlling the pump are all immersed in the fluid. The pump is arranged to deliver fluid from the housing to a hydraulic cylinder to control the positioning of the piston rod. A solenoid operated valve is integrated as a bypass or tip valve for quick fail safe position. The actuator is ideally suited to control various types of plunger valves. In one embodiment of the invention, the hydraulic cylinder is located outside of the housing and in another embodiment the cylinder is located inside of the housing.

Abstract: An electro-hydrostatic actuator unit that contains a sealed pressurized housing filled with a dielectric fluid. A bi-directional motor is immersed in the fluid and drives a gear pump for exchanging fluid via a control circuit between the chambers of a bi-directional hydraulic actuator in response to an input from a controller. The chambers are separated by a piston and a piston rod is connected to an external load such as a plunger type valve. A failsafe circuit is also provided which is arranged to override the control circuit in the event a failsafe condition is detected by the unit controller. The failsafe circuit contains a motor driven pump that provides high pressure fluid from the pressurized reservoir to an accumulator. Valves are arranged to shut down the control circuit and deliver fluid from the accumulator to one of the cylinder chambers to rapidly move the actuator to a desired failsafe position.

Abstract: An electromechanical linear actuator that contains an electric servo motor mounted within a compact housing. A thermally conductive path of travel is provided to efficiently transfer heat out of the housing into the surrounding ambient. A further mechanism is provided for holding the stator windings of the motor in undisturbed contact with the inner wall of the housing when the motor is subjected to thermal stress. The motor is arranged to linearly position a push rod through means of a ball screw unit. The ball screw nut and the push rod ride on bearings within guideways to insure that the push rod tracks along a linear path of travel.

Abstract: An electric valve actuator with a failsafe device for a rotary type valve that is coupled to a drive shaft screw by means of a clutch. A cam cylinder is secured to the drive shaft screw and is also connected to the stem of the valve. A cam follower is slidably mounted upon the drive shaft and traces a cam profile form in the cylinder as the cylinder turns. A series of torsion springs are connected to the cylinder so that the springs are wound into a loaded condition as the cam cylinder moves from a valve closed position to a cam opening position. In the event of a power failure while the valve is opened, the clutch disengages the motor from the drive shaft and the springs unwind quickly to move the cam cylinder toward the valve closing position. At this time the motion of the cylinder is controlled by the cam follower which regulates the valve closing sequence.

Abstract: An electric valve actuator with a failsafe device for a rotary type valve that is coupled to a drive shaft screw by means of a clutch. A cam cylinder is secured to the drive shaft screw and is also connected to the stem of the valve. A cam follower is slidably mounted upon the drive shaft and traces a cam profile form in the cylinder as the cylinder turns. A series of torsion springs are connected to the cylinder so that the springs are wound into a loaded condition as the cam cylinder moves from a valve closed position to a cam opening position. In the event of a power failure while the valve is opened, the clutch disengages the motor from the drive shaft and the springs unwind quickly to move the cam cylinder toward the valve closing position. At this time the motion of the cylinder is controlled by the cam follower which regulates the valve closing sequence.

Abstract: An electro-hydrostatic actuator having a sealed housing filled with a dielectric fluid. A motor driven pump and electronics for controlling the pump are all immersed in the fluid. The pump is arranged to deliver fluid from the housing to a hydraulic cylinder to control the positioning of the piston rod. A solenoid operated valve is integrated as a bypass or tip valve for quick fail safe position. The actuator is ideally suited to control various types of plunger valves. In one embodiment of the invention, the hydraulic cylinder is located outside of the housing and in another embodiment the cylinder is located inside of the housing.

Abstract: An electromechanical linear actuator that contains an electric servo motor mounted within a compact housing. A thermally conductive path of travel is provided to efficiently transfer heat out of the housing into the surrounding ambient. A further mechanism is provided for holding the stator windings of the motor in undisturbed contact with the inner wall of the housing when the motor is subjected to thermal stress. The motor is arranged to linearly position a push rod through means of a ball screw unit. The ball screw nut and the push rod ride on bearings within guideways to insure that the push rod tracks along a linear path of travel.

Abstract: An electromechanical valve that includes a cylindrical housing having a first axially disposed chamber containing a valve body and a spool reciprocally mounted in the body for movement along the axis of the housing. A second chamber is located within the housing adjacent to the first chamber which contains a voice coil actuator having a coil holder that is coupled to the spool so that the spool moves linearly when a current is applied to the coil. Materials having a high thermal conductivity are placed in the voice coil actuator for rapidly transmitting heat energy generated in the coil to the housing so that the energy is dissipated into the surrounding ambient before it can damage the actuator.

Abstract: A quick acting bi-stable actuator having a piezoelectric trigger for moving the snap actuator past its snap over equilibrium that includes a stem that is mounted for axial reciprocation in a pair of bearings and a bi-stable snap over actuator centrally attached to the stem for movement therewith. The rim of the snap over actuator is loosely held within a cavity so that the snap over actuator is generally radially disposed with regard to the axis of the stem. A piezoelectric actuator is arranged to support the snap over actuator close to one of its snap over equilibrium positions and acts as a trigger when energized to move the snap over actuator past the critical equilibrium point whereby the snap over actuator moves rapidly to a second stable position. This, in turn, moves the stem axially from a first home position to an extended position to actuate a valve or the like.

Abstract: Apparatus for safely installing and removing spring loaded failsafe valve actuators. The apparatus includes a frame that retains a compression spring in a loaded condition between a cover plate fastened to the top wall of the frame and a spring seat slidably contained inside the frame. The spring seat is attached to the valve stem for moving reciprocally therewith between a closed and an open position. The stem is connected to the extendable rod of a remotely controlled actuator that is mounted in the cover plate and arranged to move the stem between the closed and open positions. In the event the actuator fails while the valve is in an open position, the compressed failsafe spring is released to rapidly close the valve.

Abstract: Apparatus primarily for use in seating and unseating a valve by turning the valve stem between a fully opened and fully closed position. In one form of the invention, a lever arm attached to the valve stem is connected at one corner of a triangular shaped crank arm by a link. A second corner of the crank arm is rotatably mounted on a fixed shaft and the third corner is connected to an actuator. The shaft, the link and a pivot point on the distal end of the lever arm and are all brought into alignment along a common axis when the valve is in a fully closed position. Moving the actuator in the opposite direction breaks the alignment between the link and the crank arm and pulls the lever arm toward a valve opening position.

Abstract: A fluid friction controller that includes an outer member having a first friction control surface and an inner member having a second friction control surface. The control surfaces coact to define an elongated orifice that diverges from its entrance toward its exit. The length of the orifice is related to the angle of divergence so that the flow of a fluid passing therethrough remains attached to the control surfaces and the dynamic pressure in the flow does not exceed the static pressure at any point along the length of the orifice.

Abstract: A throttling valve that has an outer ring unit having a plurality of superimposed cylindrical shaped outer throttling rings that define a series of annular passages between the rings. An inner ring unit also having a plurality of superimposed cylindrical shaped inner throttling rings is adapted to movably support the inner rings within the annular passages to establish elongated flow orifices between the adjacent surfaces of the rings. The geometry of each orifice is arranged so that the fluid in transit remains attached to the control surfaces of each orifice and to insure that the static pressure along the length of the orifice remains above the dynamic pressure. The tip region of each orifice is provided with a diverging flow section to further insure quiet performance along the entire length of the orifice.