Abstract: An electromagnetic operator includes first and second coils wound coaxially. An armature partially surrounds the coils for channeling flux during energization of the coils. The armature may be formed of a bent plate and secured to a ferromagnetic support. A control circuit applies energizing signals to the coils during operation. Both coils are energized during an initial phase of operation. One of the coils is subsequently released or de-energized automatically. A timing circuit removes current from the second coil after a variable time period. The time period may be a function of the configuration of the timing circuit, such as an RC time constant, and of the energizing signal.

Abstract: In a MEMS device employing a beam supported by transverse arms, potential bowing of the transverse arms caused by fabrication processes, temperature or local self-heating from resistive losses is accommodated by flexible terminations of the transverse arms. Alternatively, this bowing is controlled so as to provide selective biasing to the beam or mechanical advantage in the sensing of beam motion.

Abstract: Stationary contact structures for an electrical contactor include a base plate portion, a riser portion and a turnback portion. The riser portion extends substantially perpendicularly from the base plate portion and a stationary contact pad is disposed directly above the riser, reducing the occurrence of mutually opposing flux during closure of movable contacts in the device. A current carrying extension may extend beyond the riser for carrying current during steady state operation. In such case, separate current carrying paths are defined in the stationary contact for transient and steady state operation. The portions of the structure are formed by processes, such as extrusion, which permit the desired geometry to be obtained between the base plate and riser. The turnback portion may descend towards the base plate portion to introduce arcs into an elevated position in a splitter plate stack.

Abstract: A system and method for detecting ground fault currents in multi-phase power systems. The system and method utilize a gapped core having a central opening. The central opening allows the multiple conductors, e.g. three conductors, to pass therethrough as a group. A sensor, such as a Hall generator, is disposed in the gap of the core and provides an output signal when the current flowing through the multi-phase conductor is unbalanced. The signal output is designed to be proportional to the detected ground fault current.

Abstract: An electromagnetic operator includes first and second coils wound coaxially. An armature partially surrounds the coils for channeling flux during energization of the coils. The armature may be formed of a bent plate and secured to a ferromagnetic support. A control circuit applies energizing signals to the coils during operation. Both coils are energized during an initial phase of operation. One of the coils is subsequently released or de-energized automatically. A timing circuit removes current from the second coil after a variable time period. The time period may be a function of the configuration of the timing circuit, such as an RC time constant, and of the energizing signal.

Abstract: An electromagnetic operator includes first and second coils wound coaxially. An armature partially surrounds the coils for channeling flux during energization of the coils. The armature may be formed of a bent plate and secured to a ferromagnetic support. A control circuit applies energizing signals to the coils during operation. Both coils are energized during an initial phase of operation. One of the coils is subsequently released or de-energized automatically. A timing circuit removes current from the second coil after a variable time period. The time period may be a function of the configuration of the timing circuit, such as an RC time constant, and of the energizing signal.

Abstract: An electromagnetic operator includes first and second coils wound coaxially An armature partially surrounds the coils for channeling flux during energization of the coils. The armature may be formed of a bent plate and secured to a ferromagnetic support. A control circuit applies energizing signals to the coils during operation. Both coils are energized during an initial phase of operation. One of the coils is subsequently released or de-energized automatically. A timing circuit removes current from the second coil after a variable time period. The time period may be a function of the configuration of the timing circuit, such as an RC time constant, and of the energizing signal.

Abstract: An electrical contactor includes an electromagnetic operator which may be powered by either AC or DC power. For use with AC power, a rectifier circuit converts AC waveforms to DC waveforms and applies the converted power to DC one or more DC coils. The rectifier circuitry applies DC power directly to a bus. A pair of coils may be used, such as separate pickup and holding coils. The pickup coil may be de-energized after an initial phase of operation. To permit rapid release of the holding coil, a control circuit interrupts an induced current path through the coil upon removal of power from the bus.

Abstract: A candy dispenser that provides a message when a piece of candy is dispensed is provided with a housing adapted to hold candy, an actuating member, a candy dispensing mechanism that releases a piece of candy from the housing when the actuating member is moved and a message mechanism having a plurality of different messages associated therewith. The message mechanism includes a spinner that spins from a first radial position to a second and apparently random radial position when the actuating member is moved. The spinner includes visual indicators corresponding to a characteristic of the piece of candy.

Abstract: A circuit interrupter provides a conducting path between two conductors and interrupts the conducting path in response to overcurrent conditions in the conductors. The interrupter includes a magnetic core around which the conductors are disposed. Each conductor is electrically coupled to an arc runner and a spanner is biased into contact with the arc runners to compete a conducting path between the conductors. A secondary response mechanism is provided adjacent to the core and includes arms extending around the core and a magnetic body. In response to overcurrent conditions of a first magnitude the body of the secondary response mechanism is attracted to the core causing the arms to displace the spanner out of contact with the arc runners. In response to overcurrent conditions of a second magnitude, such as due to direct short circuits, the spanner is repelled rapidly to a non-conducting position and the secondary response mechanism is attracted to the core to hold the spanner in the non-conducting position.

Abstract: A curved wire spring clamp which distributes bending stresses linearly based on the distance from the point of load application while maintaining torsional integrity. Bending stresses are distributed by providing apertures which change the effective width of the spring along its length. In the preferred embodiment the apertures approximate a triangular cantilever and are centrally placed along each leg portion near a constrained curved portion of the spring to change the spring's bending characteristics and distribute the bending stress more evenly throughout the length of the spring thereby reducing the peak bending stress level as compared with an equivalent spring design without apertures.

Abstract: A method for interrupting electrical power between two conductors is provided, including biasing an electrically conductive element into a conducting position between two contact regions of the conductors. The contact regions are preferably portions of arc runners coupled to the conductors. The conductors surround a magnetic core that generates an electromagnetic field due to current in the conductors. The conductive element is repelled to a non-conducting position by the electromagnetic field in response to an overcurrent condition in the conductors. A secondary response mechanism is moved in response to the overcurrent condition to maintain the conductive element in the non-conducting position. For more gradually occurring overcurrent conditions, the secondary response mechanism is attracted toward the core, displacing the conductive element to the non-conducting position.

Abstract: A circuit interrupter provides a conducting path between two conductors and interrupts the conducting path in response to overcurrent conditions in the conductors. The interrupter includes a magnetic core around which the conductors are disposed. Each conductor is electrically coupled to an arc runner and a spanner is biased into contact with the arc runners to compete a conducting path between the conductors. A secondary response mechanism is provided adjacent to the core and includes arms extending around the core and a magnetic body. In response to overcurrent conditions of a first magnitude the body of the secondary response mechanism is attracted to the core causing the arms to displace the spanner out of contact with the arc runners. In response to overcurrent conditions of a second magnitude, such as due to direct short circuits, the spanner is repelled rapidly to a non-conducting position and the secondary response mechanism is attracted to the core to hold the spanner in the non-conducting position.

Abstract: A bar code reader mirror oscillator is disclosed herein. The oscillator includes a permanent magnet having first and second poles of opposite polarity and an electromagnet having a core with first and second pole locations. The permanent magnet is fastened to a mirror carrier resiliently mounted to a frame to oscillate about a rotational axis, wherein the electromagnetic core is fastened to the frame so that the poles of the permanent magnet are equidistant from the pole locations of the electromagnet. This oscillator configuration directs substantially all of the energy applied to the electromagnet to the production of oscillatory motion in the associated reader mirror.

Abstract: An optical code reader having an improved mirror support is disclosed herein. The optical code reader is of the type which scans a code with a light beam and determines the information embodied in the code by decoding signals representative of the portions of the light beam reflected from the code. The scanning motion of the light beam is produced by a mirror supported for oscillation at a predetermined frequency. In particular, the mirror is supported by a shaft which is supported relative to the frame of the reader by two sets of four U-shaped springs. One set of springs is fasted between the first end of the shaft and the frame and the second set is fastened between the second end of the shaft and the frame. This spring configuration supports the mirror and shaft for oscillation about a desired rotational axis without the use of bearings.

Abstract: A V-band coupling for use on an explosion-proof enclosure. The V-band coupling includes a V-band having a toughened layer along its interior surfaces for gripping the flanges on the enclosure which the V-band engages when it is installed on the enclosure. The roughened layer results in an increased coefficient of friction between the V-band and flanges which is effective for reducing the load experienced by the trunnion joints of the coupling during explosion events thereby allowing the explosion-proof enclosure to withstand high internal pressures without system failure.

Abstract: A magnetic pickup tool includes an elongated, flexible, tubular, conductive shaft connected to a handle at one end and to an electromagnet at the other end. The handle is an electrically conductive tube housing batteries and a push-button switch for connecting one battery terminal to the housing, the other battery terminal being connected to an insulated conductor which runs through the shaft for connection to one terminal of the electromagnet, which is provided with telescoping inner and outer pole pieces. A first tubular metal coupler electrically connects the handle to the shaft. A second metal tubular coupler has a diametrically slotted end which is received telescopically between the electromagnet pole pieces in contact with each, the electromagnet coil terminals being accommodated in the slot, the other end of the connector telescopically receiving the adjacent end of the shaft in contact therewith.

Abstract: A torque wrench has a battery-powered sensing circuit which produces a torque signal proportional to the level of the torque applied. A reference signal corresponding to a predetermined torque level is subtracted from the torque signal to produce a difference signal which is, in turn, compared with a compensation signal which is proportional to the rate of change of the torque signal and is produced by differentiating the torque signal. When the value of the difference signal exceeds the value of the compensation signal, an indicator is triggered to produce a tactile indication, the indication being produced prior to the time that the torque signal reaches the reference level by a predetermined time period.

Abstract: The one-piece, open-end wrenching head includes two substantially equal-length jaws with a throat recess therebetween. The jaws respectively include driving surfaces spaced apart a distance slightly greater than the across-flats dimension of an associated hexagonal fastener, with each driving surface having a length no greater than the length of one of the flat sides of the associated fastener and having a serrated region thereon. The distance from the deepest part of the throat to an imaginary line connecting the distal ends of the jaws is approximately 0.86 times the across-flats dimension of the fastener.

Abstract: Self-adjusting pliers for single-handed manual manipulation will automatically adjust to positions of positive gripping and holding of any size workpiece within the size range defined by the maximum opening between the jaw portions of the pliers, which jaw portions respectively extend parallel to jaw portion axes. Upon closure from the maximum opening, parts first undergo a sliding action along an axis until the workpiece is engaged and then a pivoting action. The plier handles have bearing surfaces inclined at angles in predetermined ranges to the sliding axis and to the jaw portion axes to facilitate shifting from the sliding action to the pivoting action.