Abstract: A spring assembly is provided for a yoke assembly of an electrical switching apparatus including a housing, separable contacts enclosed by the housing, and an operating mechanism structured to open and close the separable contacts. The operating mechanism includes a pole shaft. The yoke assembly is coupled to the pole shaft and is movable among first and second positions corresponding to the separable contacts being closed and open, respectively. The spring assembly includes a number of first springs having a first spring rate and being coupled to the yoke assembly, and a number of second springs having a second spring rate and being coupled to the yoke assembly. The second spring rate is different than the first spring rate. The number of first springs and the number of second springs bias the yoke assembly toward the second position.

Abstract: A circuit controller for selectively connecting a power source to a load includes a switching mechanism, which selectively connects the power source to the load and switches a current which flows through the switching mechanism, and a substantially radiant energy dissipating positive temperature coefficient current limiter for limiting the current which flows through the switching mechanism. The switching mechanism includes a current sensor, which senses the current flowing through the switching mechanism and provides a sensed current value, and a switching controller for disconnecting the power source from the load whenever the sensed current value is above a predetermined current value. The switching mechanism may include a contactor having separable contacts which are responsive to the switching controller. The current limiter may have a first resistance which results from a first series current, and a higher second resistance which results from a second series current.

Abstract: A contactor for selectively connecting at least one alternating current (AC) power line to a load and sourcing an AC current having periodic zero crossings includes a fixed contact; a movable contact mechanism; an operating mechanism for engaging and moving the movable contact to an open position in the absence of a closing signal; and a synchronized opening mechanism for disabling the closing signal in synchronization with a zero crossing of the AC current. The operating mechanism is disengaged from the movable contact, in a closed position, by a gap having a predetermined length in order that the contacts are separated at the AC current zero crossing. The contactor may further include a vacuum bottle for enclosing the fixed and movable contact therein. The movable contact may be carried within the vacuum bottle by a bottle stem which protrudes from the bottle and has a surface for engagement by the operating mechanism.

Abstract: Apparatus for monitoring power consumed from anywhere along the conductors in an ac power distribution system includes a housing with through passages through which the conductors extend. Toroidal coils mounted within the housing concentrically with the through passages sense the current in the conductors. Elongated electrically conductive screw fasteners threaded into support blocks mounted on a printed circuit board within the housing extend radially into the through passages to penetrate insulation on the conductors and to electrically contact and mechanically clamp the conductors thereby simultaneously providing a voltage tap and locking the housing to the conductor.

Abstract: An improved PTC current limiting composition has been provided which comprises a chemically cross-linked thermosetting polyester resin and conductive particles dispersed in the resin. The thermosetting polyester resin is selected from the group consisting of polyethylene glycol fumarate, polypropylene glycol adipate fumarate, neopentyl glycol isophthalate fumarate, and neopentyl glycol phthalate fumarate. The conductive additive particles are selected from the group consisting of graphite and/or carbon black. The composition exhibits PTC behavior when cross-linked by a vinyl monomer selected from the group consisting of styrene, vinyl toluene and tertiary butyl styrene. Curing proceeds by free-radical addition across double bonds of the thermosetting polyester resin and is initiated by organic peroxides. Initial gelation which causes cross-linking but not final curing takes about 0.5 to 4 hours at a temperature of about 25.degree. C. to 125.degree. C. The final cure takes about 0.

Abstract: A circuit controller for selectively connecting a power source to a load includes a non-overcurrent protective electrical switching mechanism and a conductive polymer current limiter connected in series with the load for limiting the current which flows through the switching mechanism whenever the power source is selectively connected to the load. The conductive polymer current limiter may include a plurality of parallel conductive polymer positive temperature coefficient (PTC) resistors. The circuit controller may include an electrical switching mechanism which, under short circuit conditions, remains selectively connected to the load. The short circuit current which is limited by the conductive polymer current limiter continues to flow through the electrical switching mechanism. The switching mechanism may include a contactor having separable contacts, and may further include a circuit interrupter, in order to provide a separate circuit disconnection mechanism.

Abstract: A multipole circuit breaker, for example, a three pole circuit breaker, can detect a condition when less than all of the phases are open circuited to trip the circuit breaker. This reduces the tripping time and hence risk of damage to the electrical load. The circuit breaker includes a thermal trip unit and a phase sensitivity assembly that is interlocked with the bimetals included with the thermal unit. The phase sensitivity assembly includes one or more levers, responsive to the deflection of a bimetal corresponding to the open circuited phase resulting from cooling action of a bimetal relative to the other bimetals. The relative displacement of the cooling bimetal is used to either trip or reduce the tripping time of the circuit breaker.

Abstract: A molded case circuit breaker is provided with a magnetic trip unit which includes an armature assembly and a multi-turn magnetic coil assembly. The magnetic coil assembly is formed to occupy substantially the same volume as a single-turn magnetic coil. The added turns in the magnetic coil increase the attraction force on the armature to essentially lower the electric current value at which the magnetic unit trips the circuit breaker. By utilizing a multi-turn magnetic coil assembly which occupies the same space as the single-turn magnetic coil, the same frame size can be used for both single-turn magnetic coils, and multi-turn magnetic coils without the need to locate the thermal unit outside of the molded case circuit breaker.

Abstract: A thin film electroluminescent (TFEL) edge emitter module and packaging assembly is composed of a TFEL edge emitter module including an electroluminescent (EL) stack having a linear array of spaced-apart pixels with light-emitting front edges, an enclosure defining a sealed cavity which encloses at least a portion of the EL stack so as to sealably enclose the array of pixels in a contaminant-free environment, a thermally expansive and contractive liquid substantially filling the sealed cavity, and a cavity capacity expansion and contraction mechanism disposed in the enclosure in communication with the cavity and the liquid therein. In response to thermal expansion of the volume of the liquid filling the cavity, the capacity expansion and contraction mechanism is operable to change from a first condition toward a second condition and thereby increase the liquid-holding capacity of the enclosure cavity.

Abstract: A traction elevator system including an elevator car driven by a drive arrangement having electrically isolated high and low speed components. Fixed AC and controllable DC voltages are selectively applied to the high and low speed components, respectively, at predetermined portions of the run, to control the drive torque to provide smooth operation of the elevator car.

Abstract: An elevator system including an elevator car mounted for movement in a building to serve the floors therein. The deceleration control for stopping the elevator car accurately at a selected floor, regardless of load and direction of the elevator car, continuously adjusts the braking torque to provide the desired velocity versus time pattern, and the desired distance versus time pattern, wherein both the deceleration distance and the deceleration time are fixed quantities.

Abstract: An internally pressurized hermetically clad fuel element for a nuclear reactor having a sealed collapsible capsule within the fuel element plenum. The capsule is controllably collapsed in a buckling mode with increases in plenum pressure to maintain the fuel element pressure substantially constant throughout its operating life.