Abstract: A proportional control valve has inlet and outlet solenoids controlling the pressurization and evacuation of a chamber between two pistons in a control valve of the rack and pinion opposed-piston type. The control valve can be maintained in fully open, fully closed, or intermediate positions by selectively energizing and de-energizing the solenoids. The solenoids can be of the normally open or normally closed solenoid poppet types depending on whether the control valve is to open, close or maintain its current state in the event of a power failure.

Abstract: A position indicator for a rotary valve actuator has a stator of one color mountable on a housing for the actuator and a rotor of a contrasting color which is connected to the actuator output shaft for rotation with it. The rotor has inner and outer coaxial cylindrical walls with windows in the outer wall. The stator has a hollow cylindrical wall in the space between the rotor walls. When the windows of the rotor and stator are in registration the inner wall of the rotor is visible and the stator is hidden to indicate one position of the actuator output shaft. When the windows of the rotor and stator are out of registration the inner wall of the rotor is hidden by the stator wall which is visible through the rotor window to indicate another position of the actuator output shaft. A circuit actuator and sensor may be mounted on the rotor and stator for generating electrical signals indicative of the actuator output shaft position in addition to the visual indication.

Abstract: A rocker valve for alternately sealing one of two outlet ports is provided with two cylinders in which there are respectively disposed pistons carrying sealing members for longitudinal reciprocation along the extended axes of valve seats respectively surrounding the port openings. The rocker is rotated to urge one piston toward its respective valve seat while permitting the other piston to be retracted from its respective valve seat. An elastomeric diaphragm is mounted between the sealing members mounted on the pistons and the valve seats whereby the sealing members urge the diaphragm against the valve seats during sealing. The longitudinal motion of the pistons prevents skewing of the sealing members during rotation of the rocker arm for maintaining the sealing members parallel to the valve seats throughout the strokes of the pistons.

Abstract: A linear optocoupler is employed to provide a signal which is a galvanically isolated reproduction of the magnitude of an A.C. line voltage and another galvanically isolated signal indicative of a change in the polarity of the line voltage for enabling safe monitoring of a change the A.C. voltage. Actuation of an automatic transfer switch to substitute an emergency source of power for a normal source that has failed may be achieved with the emergency power waveform used to replicate the normal power waveform.

Abstract: A position indication for an actuator of a rotary valve has a rotor of one color mountable on the shaft of the actuator and a stator of contrasting color, each with a plurality of volutes in one-to-one correspondence. The rotor volutes are hidden behind corresponding stator volutes to indicate a closed disposition and extend beyond their corresponding stator volutes to indicate an open disposition of the valve actuator when viewed from a radial direction. Web members on the rotor are rotated into and out of registration with windows in the base and cover of the stator for indicating valve disposition from above. The rotor and stator are congruent to permit the indicator to be inverted depending on the direction of rotation of the valve actuator shaft during opening and closing of the valve.

Abstract: A proportional flow valve wherein inlet fluid pressure urges a main valve member toward a valve seat. A cylindrical bearing ring is mounted on the main valve member and slideable within an axial bore leading from the main valve seat to an outlet port for axially stabilizing the main valve member and limiting pressure differential across the main valve member while the bearing ring is at least partially disposed within the axial bore. The outer circumference of the bearing ring may have circumferential grooves for producing eddy currents and turbulence to enhance the limitation of pressure differential across the main valve member.

Abstract: A digitally controllable valve has a main valve member mounted on a diaphragm for movement sealing and exposing a main valve seat. A flow restriction on the main valve member varies the flow rate as a function of displacement of the main valve member from the main valve seat. Pressure in a reservoir above the diaphragm is controlled by two pilot valves respectively connected to the inlet and outlet ports of the main valve, one of which has fluid passageway with a larger minimum cross sectional area than the other. Both pilots communicate with the reservoir through a single common bleed opening which has an area less than the minimum cross sectional areas of pilot valve flow passageways.

Abstract: A method of and apparatus for actuating an automatic transfer switch for disconnecting a motor load from a normal source of voltage and reconnecting the load to an alternate source of voltage at a time when phase differences between the output voltage of the disconnected motor load and of the alternate source voltage are minimized to prevent excessive in-rush currents to the motor upon reconnection. Actuation of the transfer switch is commenced when the difference in phase between the normal source and alternate source is equal to a predetermined number of degrees depending upon whether the alternate source frequency is greater or less than the normal source frequency.

Abstract: An automatic transfer switch for transferring a load between a normal power source and an alternate power source has a control circuit which senses the movement of the plunger of the switch-actuating solenoid into a position proximate the plunger stop or pole piece and then turns off power to the coil current so that the plunger can be restored to its rest position as the inertia of the switch enables completion of the transfer. Upon interruption of voltage to the coil, the coil is switched in series with a resistance which rapidly dissipates the residual current generated by the collapsing field within the coil to alleviate the braking effect of the residual coil current on the solenoid plunger.

Abstract: A proportional flow valve wherein inlet fluid pressure urges a main valve unit having a main valve member and a surrounding diaphragm toward the valve seat. The diaphragm is connected to the valve body and has a bleed passageway to enable inlet fluid to pass from an inlet port below the main valve unit to a reservoir above it. The area of the main valve unit exposed to the reservoir is substantially greater than the area of the main valve unit exposed to the inlet port. A solenoid actuator determines the position of a pilot valve sealing member which controls the flow of inlet fluid from the reservoir through a pilot opening in the main valve member to an outlet port to selectively relieve the pressure above the main valve unit thereby permitting the main valve unit to move away from the main valve seat.

Abstract: A low-noise solenoid has an armature with a projecting ridge receivable within a groove in a pole piece. As the ridge enters the groove, the magnetic force which opposes a return spring decreases until there is equilibrium whereat the armature remains suspended without impacting upon the pole piece.

Abstract: A solenoid valve has a yoke with reinforcing integral frame members surrounding inlet and outlet connectors molded into a plastic body which encapsulates the solenoid coil and electrical components and forms the valve housing.

Abstract: A two-way cartridge valve for aggressive media has a replaceable module including a main valve seat, a diaphragm sealing member for the valve seat, and a pilot seat. In one embodiment, a leaf spring is employed to bias the diaphragm toward the open position for actuation under conditions of minimal pressure differential. In another embodiment a resilient support is provided for the diaphragm behind the region of engagement with the main seat.

Abstract: A proportional flow valve wherein inlet fluid pressure urges the valve member toward the valve seat. A pressure member, which may be a piston, has an effective area substantially larger than that of the valve member, and is also selectively subjected to inlet fluid pressure to urge the valve member away from the valve seat, so as to open the valve and keep it open. A solenoid actuator determines the position of a pilot valve member which controls the flow of inlet fluid to the pressure member, and hence controls the location of the pressure member and the spacing of the valve member from the valve seat. The position of the pilot valve member, and hence the spacing of the valve member from the valve seat, is proportional to the amount of electric current applied to the actuator.

Abstract: A valve including a valve member having two different stable positions, and a valve operator for shifting the valve member between its two stable positions and holding the valve member in those positions. The valve operator includes a shuttle moveable between two extreme positions corresponding to the two stable positions, respectively, of the valve member. A first spring urges the shuttle toward one of its extreme positions and a second spring, stronger than the first spring, urges the shuttle toward the other of its extreme positions, these movements of the shuttle being transmitted to the valve member. A device, such as an electric solenoid, selectively renders the second spring ineffective with respect to the shuttle, so that when the second spring is ineffective the first spring causes the valve member to assume one of its stable positions, and when the second spring is not ineffective, the second spring causes the valve member to assume the other of its stable positions.

Abstract: A valve having a valve body formed with a chamber with which a plurality of ports in the valve body communicate. At least one of the ports is adapted for connection to a source of pressurized fluid. A rocker valve member is pivotally mounted within the chamber and swings between two extreme positions in which it closes and opens at least one of the ports. A diaphragm within the chamber extends from the periphery of the rocker valve member and the margin of the diaphragm is secured in the valve body. All the ports in the valve body face one side of the diaphragm. An operator, for swinging the rocker valve member between its extreme positions, engages the rocker valve member on the side of the diaphragm opposite the side facing the ports, so that the diaphragm serves to isolate the ports from the operator.

Abstract: An electrical switch contact arrangement having a spring which snaps the movable arcing contact away from the stationary arcing contact at a high rate of speed to open the arcing contacts, but only after the movable main contact has moved through a considerable portion, for example, at least about 50%, of its opening movement away from the stationary main contact. The spring is tensioned as the main contacts open. At an intermediate point during the opening movement of the movable main contact, the moveable main contact positively initiates opening movement of the arcing contacts whereupon the spring snaps the arcing contacts open at a high rate of speed independent of the opening speed of the main contacts.

Abstract: An automatic transfer switch having two sets of phase switches, one set for connection between a normal source of power and a load, and the other set for connection between an emergency power source and the load. The transfer switch includes two pairs of neutral switches, one pair for connection in parallel between the normal source neutral and the load neutral, and the other pair for connection in parallel between the emergency source neutral and the load neutral. The phase switches can operate to provide an "open transition" transfer, wherein the phase switches connecting the load to one source open before closing of the phase switches which connect the load to the other source, or a "closed transition" transfer, wherein the phase switches connecting the load to one source open after closing of the phase switches which connect the load to the other source.

Abstract: A manual operator for opening and closing an electrical switch, including a switch-driving element, a relatively rotatable handle element, and a resilient transmission, e.g., a leaf spring or springs, extending between the two elements. An abutment is fixed to one of the elements and a follower is fixed to the other, the abutment engaging the follower only after the resilient transmission has been tensioned by rotation of the handle element. When the driving element engages a portion of the switch mechanism, initial rotation of the handle causes the resilient transmission to be tensioned and the abutment to engage the follower. Further rotation of the handle is transmitted through the abutment and follower to the driving element to initiate the movement of the switch mechanism, following which the tensioned resilient transmission instantly shifts the switch mechanism through the remainder of its movement to snap the switch open or closed.

Abstract: A solenoid actuator comprising a coil or coils of electrical wire and a plugnut and movable core within the coil(s). A magnetic yoke surrounds the coil(s), the axis of the latter extending across the magnetic circuit defined by the yoke. Relatively large and small permanent magnets are associated with the yoke on opposite sides of the axis, the magnets producing flux in opposite directions. A flux sensor, closer to the small magnet, senses changes in direction of the flux. When the core and plugnut are separated, the large magnet flux predominates throughout the yoke. When the core engages the plugnut, the small magnet flux predominates in its portion of the yoke, this change in flux direction being detected by the sensor. Thus, the sensor can be used to indicate the position of the core with respect to the plugnut.