Abstract: A circuit breaker having means for varying the thermal rating characterized by a circuit breaker mechanism including a releasable cradle for automatically tripping contacts to an open position in response to overload current conditions. A trip bar movable in response to movement of a bimetal element and the tie bar including a movably mounted member having an inclined surface for adjusting the spacing between the bimetal element and the movable member.

Abstract: A variable frequency vibration isolator for isolating vibrations between a base and a load having relative displacement of each other characterized by a pair of coil springs in series with a connector between them. The connector is journally mounted for axial movement in response to spring vibrations. Locking means including a timing circuit for clamping and unclamping the connector against movement, so as to improve vibration isolation at frequencies higher than approximately 2f.sub.n while substantially improving the performance at lower frequencies.

Abstract: An electrical contact material characterized by a pressed and sintered powder of silver composite with about 5 weight percent of graphite fibers.

Abstract: Fluid-cooled electrical apparatus characterized by a new and improved pump for circulating the fluid within the apparatus. The pump has a motor portion in fluid communication with a pump portion, non-electrically conductive bearings supporting a common shaft between the two portions. The bearings being comprised of a polyamideimide thermoplastic resin.

Abstract: The kinetic energy generated by the rapidly moving contact and coupled operating mechanism of a tripped circuit breaker or similar apparatus is dissipated by a compressible shock-absorbing assembly comprising a loose stack of freely-movable magnetized metal plates which is mounted in laterally-extending position on a stationary upstanding part of the breaker and is struck by a lever fastened to the main operating shaft of the breaker operating mechanism. The metal plates are freely movable toward and away from one another and are so magnetized that adjacent plates repel one another. The plates are accordingly normally spaced from each other and produce a series of sequentially-occurring impacts and collisions between the plates and the advancing striker lever when the breaker is tripped.

Abstract: A circuit interrupter responsive to abnormal currents in conductors of an electrical distribution system characterized by a circuit breaker mechanism for opening and closing separable contacts and which mechanism comprises a releasable member operable between latched and unlatched positions, trip means comprising a bimetal element and a trip bar movable to unlatch the circuit breaker mechanism and biased in the latched position, the trip bar having a surface facing and spaced from the bimetal element which surface is slanted at an oblique angle to the longitudinal axis of the trip bar, and manually adjustable knob connected to the trip bar for sliding the trip bar longitudinally to vary the space between the bimetal element and the trip bar surface in accordance with a desired thermal rating.

Abstract: A circuit breaker having a trip delay mechanism characterized by a variable magnetic air gap that is adjustable to permit time delay at low level overcurrents to avoid nuisance tripping during motor starting.

Abstract: A circuit breaker with electrical disconnect means characterized by a solenoid operator for moving a handle of a circuit breaker between ON and OFF positions. The solenoid operator includes a movable electromagnet and a movable armature for actuating the handle, an interlock switch serially connected to the electromagnet and a manual operator for overriding the solenoid operator by opening a circuit through the interlock switch.

Abstract: A circuit breaker structure having an adjustable magnetic trip unit characterized by an insulating housing containing a circuit breaker mechanism having separable contacts and containing a trip unit comprising a magnetic device responsive to overload current conditions for separating the contacts, the magnetic device having an armature and a calibrating screw for calibrating an air gap between the armature and an associated magnet, the trip unit also including a cam for varying the tension of the spring and the cam having spaced indexing indentations and an associated ball in the frame for rolling engagement with the cam surface and for seating in any indentation to provide positive settings of the spring tension.

Abstract: A terminal base assembly for an electric meter characterized by an insulating base with a jaw terminal for receiving a mating blade terminal of a meter, an electric conductor for conducting current to the jaw terminal, a mounting clip for releasably mounting the jaw terminal in the hole and including offset side walls adjacent to facing walls of the hole and in face-to-face contact with the opposite sides of the jaw terminal, and fastening means securing the jaw terminal, the electric conductor, and the mounting clip together.

Abstract: A double-acting chemical operator drive assembly having a pair of pistons that are secured to the ends of a single piston rod and cooperate with a pair of power cylinders provide a positive drive for opening and closing the separable contacts of a circuit interrupter when the pistons are sequentially actuated by high-pressure gas generated by chemical propellant charges. The power cylinders are spaced apart and aligned with one another and the piston rod extends through open ends of the power cylinders. This eliminates the need for shaft seals and simplifies the manufacture and maintenance of the drive assembly. The operator drive assembly is coupled to the operating mechanism of the circuit interrupter by a yoke that is secured to an exposed medial part of the piston rod and then to a tie bar by a pair of drive rods.

Abstract: A circuit breaker with a magnetic circuit for delaying the trip function and characterized by a dual variable magnetic circuit air gap which allows a time delay at low level overcurrents, such that motor starting transient currents do not prematurely trip the circuit breaker.

Abstract: An integral circuit interrupter characterized by an assemblage of interconnected electrical units including a circuit breaker, a thermal-magnetic overcurrent detector, an electromagnetic actuator, and a modular sensor; the circuit breaker comprising first and second separable contacts and a releasable lever for releasing the first contact to an open position when the detector trips the lever in response to a first predetermined current condition; the electromagnetic actuator for moving the second contact to an open position; the modular sensor for monitoring current flow and for actuating only the electromagnetic actuator in response to a second predetermined current condition; and the electromagnetic actuator being operable from a remotely controlled source.

Abstract: A circuit breaker apparatus characterized by a molded case containing a circuit breaker structure for opening and closing a circuit which structure comprises a releasable lever operable between latched and unlatched positions corresponding to open and closed circuit conditions, latch means including a latch lever for the releasable lever, interconnected toggle connected to the latch lever and that are biased to the unlatched position of the lever, and a movable trip bar responsive to predetermined overcurrents and having a projection contacting the toggle links for holding the links in the unbiased position.

Abstract: An arc-heated plasma lance characterized by an elongated tubular housing containing arc heater ports for producing a plasmic jet at one end of the housing and service ports for providing electric power, gas, and coolant fluid to the arc heater ports, and the service means extending into the housing from the other end.

Abstract: An electrical boot for the bus bar joints of electrical metal-clad switchgear is taught. The boot is formed by taking a piece of heat shrinkable material, disposing it over a joint or similar construction, heating and shrinking the material so that it shrinks to the shape of the joint or construction in question while at the same time, providing on two opened edges thereof a clamped chill bar which does not allow those portions to cohere to each other so that the boot may be removed after the formation process and easily disposed upon a bus bar joint located within the tight confines of a metal-clad switchgear cabinet. The process may be utilized to form metal-clad switchgear having bus bars with a heat-shrunk insulating boot on the joints thereof. Furthermore during the production process, a bolt envelope simulating template or jig may be utilized to fill out the area on the finalized boot which roughly corresponds to the outer dimensions of the bolt and nut arrangement.

Abstract: A circuit interrupter characterized by an assemblage of interconnected electrical units including a circuit breaker, a current limiting structure, a contactor, and a motor controller which units are fitted together detachably into a compact unit, in which the controller controls the contactor and the circuit breaker in response to a predetermined current condition, and in which the circuit interrupter includes a single pair of separable contacts.

Abstract: A current limiting circuit breaker characterized by pairs of stationary and movable contacts with the movable contacts connected in series; an arc-extinguishing chamber including arc guide rails associated with each pair of contacts and in side-by-side relationship; manually operable means for opening and closing the circuit through the contacts; current-limiting electromagnetic means for opening the contact; and linkage means between the manually operable and electromagnetic means for enabling opening of the contacts by the electromagnetic means without tripping the manually operable means.

Abstract: A circuit breaker with a force generate shunt characterized by a circuit breaker structure between spaced conductors with a fixed contact on one conductor and a movable contact on a contact arm that is movable between open and closed positions. A flexible shunt connected between the arm and the other conductor which shunt includes folded-over shunt portions that generate repulsion magnetic forces for pressing the closed contacts together and for expediting the contact arm open.

Abstract: An electrical switching device characterized by an enclosure containing a switch operable between ON and OFF positions by a handle releasably lockable in the OFF position; the handle being disposed between the enclosure and a handle guard, the guard having an opening, the handle having a tab engaging a shoulder surface in the opening when in the OFF position; an interlock plate for releasably latching an enclosure cover in place and the plate being releasable by movement of the handle in the OFF position; and the handle being movable to the ON position only by manipulation of the interlock plate, whereby accidental movement of the handle is avoided.