Abstract: A method and apparatus for controlling a ventilation damper unit utilizing a direct coupled two-position rotary damper actuator with a DC solenoid is disclosed. The actuator acts to rotate the output coupling, and in turn, the damper shaft to open the damper. After approximately 95 degrees +/−3 degrees of output coupling rotation, a limit switch is activated and a DC solenoid equipped with a full way bridge rectifier extends to a brake rotor to lock the damper into position. Simultaneously power is shut-off to the actuator motor assembly to reduce electrical consumption. Upon complete power failure to the actuator unit, such as during a fire and smoke emergency, the DC solenoid is spring returned allowing the damper to be spring returned to a closed position, thus preventing flow of air and smoke through a building and starving a fire of oxygen.

Abstract: There is a balanced plug valve with a contour shaped wall. The contour shaped wall forms a gap with an edge of a balanced plug. Fluid is able to flow through an input port, through the balanced plug, through the gap, and out an output port. The shape of the contour and the relative position of the balanced plug to the contour shaped wall affect the modulation of the rate of the fluid flow through the gap, and thus, through the valve. Multiple possible variations of the dimensions of the contour shaped wall make possible a multitude of flow rate verses valve stroke relationships. Further, the use of a balanced valve decreases friction forces on the plug which allows for smaller, more efficient, and more economical valve actuators.

Abstract: A throttle valve includes a one-piece valve body defining a transverse flow passage and an actuation device cavity. The throttle valve includes a valve assembly having a shaft which extends through the flow passage and which is mounted to the valve body via a pair of aligned passages formed in the walls of the valve body defining the flow passage. One of the aligned passages establishes communication with the actuation device so as to enable the valve shaft to be assembled to the valve body through the actuation device cavity. A pole carrier is mounted to the valve shaft and a pair of pole members are secured to the pole carrier. An electromagnetic actuation device is mounted within the actuation device cavity and is operable on the pole members in a contactless manner to impart rotation to the valve shaft through the pole members and the pole carrier upon energization of a coil assembly associated with theelectromagnetic actuation device.

Abstract: A stem seal having first and second wiping members circumjacent a stem is disposed within a bore. A lubricant-bearing ring is disposed about the stem within the bore between the wiping members, under compression therefrom. Projections from the wiping members intrude into the lubrication ring so as to depress the central surface areas thereof. Similar projections are used to center a coil spring against one of these seal members and against an additional seal member. By forming the lubricant ring of open-cell loam or mesh construction, superior lubricant bearing capacities may be achieved.

Abstract: A PC Card includes a printed wiring board with an edge-card connector formed integral therewith. Wiring of the printed wiring board connects the edge-card connector to components on the printed wiring board. Connection is established to the printed wiring board via the edge-card connection for testing and programming of components on the PC Card.

Abstract: A brushless DC motor is controlled by determining a speed of the motor and a line voltage supplying drivers of the motor. Based upon these determined values and predetermined motor performance data, a maximum PWM on-time is determined for drive signals supplied to windings of the motor. This maximum PWM on-time thereby limits motor torque output to a predetermined maximum. Stopping the motor is performed in sequential phases including a loaded generator phase, an active braking phase and a holding phase. During holding, the amount of energy supplied to the motor is reduced to the point just before slippage such that holding energy is minimized. Upon power failure, the motor is driven toward a spring return home position overcoming static friction that may prevent the spring return mechanism from functioning properly. These techniques are applied to a motor in an actuator.

Abstract: A brushless DC motor is controlled by determining a speed of the motor and a line voltage supplying drivers of the motor. Based upon these determined values and predetermined motor performance data, a maximum PWM on-time is determined for drive signals supplied to windings of the motor. This maximum PWM on-time thereby limits motor torque output to a predetermined maximum. Stopping the motor is performed in sequential phases including a loaded generator phase, an active braking phase and a holding phase. During holding, the amount of energy supplied to the motor is reduced to the point just before slippage such that holding energy is minimized. Upon power failure, the motor is driven toward a spring return home position overcoming static friction that may prevent the spring return mechanism from functioning properly. These techniques are applied to a motor in an actuator.

Abstract: A brushless DC motor is controlled by determining a speed of the motor and a line voltage supplying drivers of the motor. Based upon these determined values and predetermined motor performance data, a maximum PWM on-time is determined for drive signals supplied to windings of the motor. This maximum PWM on-time thereby limits motor torque output to a predetermined maximum. Stopping the motor is performed in sequential phases including a loaded generator phase, an active braking phase and a holding phase. During holding, the amount of energy supplied to the motor is reduced to the point just before slippage such that holding energy is minimized. Upon power failure, the motor is driven toward a spring return home position overcoming static friction that may prevent the spring return mechanism from functioning properly. These techniques are applied to a motor in an actuator.

Abstract: An adaptive controller is provided for controlling the velocity of a ram in an injection molding apparatus during the injection stage of the molding cycle. The controller includes two sets of parameters. The first set define an open-loop control equation for controlling the ram velocity. The second set of parameters define a closed-loop control equation for controlling the ram velocity. Control of the ram, during the injection stage, is partitioned into discrete segments, wherein the open-loop control equation governs during the first portion of each segment, and the closed-loop equation governs during the latter portion of each segment. Both control equations are designed to drive the ram at a set, target velocity. At the end of each segment, a processor evaluates the actual ram velocity with the set, target velocity. Based upon this evaluation, the first and second set of parameters are modified to improve the ram performance and efficiency on the subsequent injection cycle.

Abstract: A switched reluctance generator that can be used in an air cycle machine, where the generator uses the energy from the shaft of the air cycle machine to provide a back-up power supply to the magnetic bearings supporting the shaft. The generator includes circuitry for comparing the non-commutated excitation current with a command signal to regulate the excitation current, thereby regulating the generator output voltage.

Abstract: A backup bearing for use with magnetic bearings to support a rotating shaft in the event that the magnetic bearings fail due to the loss of electric power. The backup bearing includes a housing and a fluid film bearing element which is adapted to passively float in the housing and with the shaft during normal operation of the magnetic bearings and which is adapted to support the rotating shaft on a film of fluid if the magnetic bearings fail.

Abstract: An adaptive controller is provided for controlling the transition, in an injection molding apparatus, from the injection stage to the packing stage. The controller operates by controlling the velocity of the ram during the injection stage, and controlling the ram pressure during the packing stage. The controller anticipates the transition from the injection stage to the packing stage by monitoring the ratio of pressure to velocity. The divergence of this ratio forecasts the onset of the packing stage. At this time, a pressure relief valve is preset in anticipation of the packing stage, to prevent a pressure spike during the transition period. The flow control valve is held constant during the transition.

Abstract: A plurality of electromagnetics in an array surround a shaft, with current controlled in the coils of the electromagnets to support the shaft at a desired position approximately centered between the electromagnets. Shaft position sensors provide feedback to a control system for modulating the current to the electromagnet coils, which are arranged in pairs on opposite sides of the shaft. A drive circuit for each coil includes first and second switching transistors which connect the coil to the power supply to transfer a current pulse to the coil. A pair of circulating diodes begin conducting when the transistors turn off, and return power to the supply. A control circuit for the drive circuits interleaves on and off intervals for the coils in the electromagnet pairs so that one coil of the pair is being switched off at about the same time as the other coil of the pair is being switched on.

Abstract: A position sensor includes a coil of small diameter litz wire wound around a ferrite rod. The rod is secured in the end of a ceramic support and an end cap is secured on the other end of the rod to form a bobbin section on which the coil is wound. Two palladium silver strips are formed axially along the length of the support extending from the bobbin section to near the base of the support. Two free ends of the coil are formed into strain relief loops and soldered to the strips. Lead wires of comparatively larger diameter are also soldered to the strips but near the base of the support. The strips establish electrical continuity between the coil and the lead wires while separating the end portions of the coil from the lead wires so as to prevent the lead wires from inducing stress into the relatively fragile coil wires.

Abstract: A force motor includes an electromagnetic rotary actuator and a governor cup for use in the fuel system of an internal combustion engine to permit a desired fuel flow to pass to the engine. The rotary actuator includes a cylindrical housing over which two coils are wound. The magnetic field generated by applying direct current to the coils interacts with a permanent magnet rotor field to rotate an output shaft against the biasing force of a return spring. A governor cup includes a magnet permitting magnetic engagement of the fuel rod to the governor cup. The rotation of the output shaft is translated into linear movement of the fuel rod by a linkage. The rotary actuator has constant output torque characteristics for a given current level to permit the fuel rod to be correctly positioned for the desired fuel flow.

Abstract: A control circuit for a gearmotor is located internal to a plastic gearbox to reduce handling damage and damage resulting from exposure to the environment. The control circuit includes a metal track which provides an electrical conductive path for input power to an electric motor and electrical components and thereby eliminates the need for a printed circuit board. The metal track includes a plurality of alternative control circuits paths, the appropriate circuit being chosen during assembly of the gearmotor by selectively piercing knock-out tabs in the metal track. The metal track includes locking receptacles for receiving switch and d.c. motor electrical terminals and further includes crimping receptacles for receiving electrical component lead wires. The metal track is located on the internal surface of the plastic gearbox cover by integrally molded posts and is secured to the cover by ultrasonically or heat staking the posts.

Abstract: The rotor of a shaded-pole motor carries a braking ring with a radially projecting stop lug adapted to coact with a pivoted pawl to brake the rotor to a stop when the motor is de-energized. The pawl carries a pole piece which, upon energization of the motor, is magnetically attracted toward the stator thereof to cause the pawl to pivot to a released position clear of the stop lug. The braking mechanism requires relatively few components, and those components may be used universally either with a motor with a clockwise rotatable rotor or a motor in which the rotor rotates in a counterclockwise direction.

Abstract: An electric motor acts through a gear train to rotate an output shaft in one direction while a torsion spring rotates the shaft in the opposite direction when the motor is de-energized. When the output shaft stops abruptly at a limit position after being rotated by the spring, a lost-motion drive connection permits the output gear of the drive train to rotate relative to the shaft in order to dissipate kinetic energy through the gear train and to avoid impact loading of the gear train and the motor.

Abstract: An air cycle machine for producing a supply of cooled air and including a compressor rotor fixed to a shaft which is driven by a turbine rotor, the turbine serving to expand air which is pressurized by the compressor. Magnetic bearings support the shaft radially in a housing for rotation about a precisely established axis while a magnetic thrust bearing keeps the shaft in a precisely fixed axial position. The housing and the bearings are constructed as two split sections to permit the housing and the bearings to be separated radially and facilitate repair and/or replacement of the shaft and other internal components.

Abstract: An air cycle machine for producing a supply of cooled air and including a compressor rotor fixed to a shaft which is driven by a turbine rotor, the turbine serving to expand air which is pressurized by the compressor. Magnetic bearings support the shaft radially in a housing for rotation about a precisely established axis while a magnetic thrust bearing keeps the shaft in a precisely fixed axial position. The housing and the bearings are constructed as two split sections to permit the housing and the bearings to be separated radially and facilitate repair and/or replacement of the shaft and other internal components.