Westinghouse Electric Corporation

Walter J Kellogg

Glenn R Taylor

Wardell Gary

Birch L DeVault

Allan V Heberling

Kenneth L Paape

Chester W Calvin

Arden L Scott

Samuel K Seneadza

An electrical control apparatus characterized by a pair of separable contacts with electromagnetic means for opening and closing the contacts and including a U-shaped core having spaced legs and a yoke, a permanent magnet across the yoke, and the magnet having a cross-section greater than that of either leg.

Electrical control apparatus with electromagnetic latch

A circuit breaker including an improved means of retaining an arc grid assembly within the arc grid assembly cavity defined by the housing of the circuit breaker. The means of retaining the arc grid assembly within the arc grid assembly cavity is the arc grid assembly has a framework formed of a rigid material that may be temporarily plasticized and is inserted within the arc grid assembly cavity while it is in the temporarily plasticized state, wherein said framework rigid material hardens and is retained by restraining means such as lugs which are placed upon the housing of the circuit breaker which defines the arc grid assembly cavity.

Circuit breaker utilizing improved arc chambers

A circuit comprising a load sensor connected to a multiple rated motor for monitoring the motor load demand and a switching apparatus connected to the source of electrical power for changing the connection of electrical power to the windings of the motor under load in response to the motor load demand.

Circuit for controlling multiple rated motors

A selector switch for use as a pushbutton and rotary switch characterized by a rotatable switch actuator and at least two switch structures, the actuator having a shaft on which a handle is detachably mounted for operation in a plurality of modes to operate the switch structures in different combinations of open and closed conditions, the handle being detachably mounted on the shaft for rotating the cam through one limited sector thereof, and the handle being repositionable on the shaft for rotation through another limited sector thereof.

Convertible selector switch

An indicator light circuit utilizing a single lamp and providing continuous illumination during normal operation and on and off flashing during an emergency condition. The circuit can also provide an indication wherein the lamp is continuously on but pulsating bright and dim. The indicator light circuit can thus provide four visual indications: (1) Off; (2) Normal on; (3) Flashing on and off; and, (4) On, but pulsating bright and dim. The invention is particularly adaptable for use to provide motor running and relay trip indication.

Indicator light circuit providing normal and emergency indication

A switch operator characterized by a tubular base, a tubular member movably mounted within the base, biasing means for holding the member in an inoperative position, a tubular manual knob detachably mounted on the member, the knob having an outer closed end portion, a switch unit including a contact operator adjacent the end of the member opposite the knob, the contact operator being operable by the member upon movement of the knob, and sealing means at least between the tubular base and tubular member.

Switch operator

A circuit is provided for test and operation of indicator lights wherein multiple lights may be tested simultaneously by pushing one button and closing one set of normally open contacts and the individual indicator lights are operated from a circuit utilizing a self-triggering bidirectional thyristor. The test pushbutton and the indicator operating signal circuit operate at a higher voltage, such as 120 volts ac, and the indicator lamp is operated at a low voltage, such as 6 volts ac, providing safety and allowing use of inexpensive incandescent indicator bulbs. One indicator transformer is required for each indicator light. A diode is provided in the test circuit on the high voltage side of each of the indicator transformers to permit a test signal to activate the indicator lamps without affecting the rest of the circuit. The diodes in the test circuit permit only unidirectional current to flow therethrough. The operating signal circuit is also connected to the high voltage side of each transformer, in parallel with the test circuit. A bidirectional thyristor is used to switch the indicator circuit on lighting the indicator lamp and providing circuit isolation. The bidirectional thyristor is connected so to be self-triggering and when current flows in the line to which the thyristor is connected the thyristor is triggered on energizing the transformer and lighting the indicating lamp. The lumination of the indicator lamps when activated through the test circuit is less than the lumination when activated through the normal indicator signal circuit.

Indicator lamp test circuit utilizing bidirectional thyristor switching

A circuit, having protection against current feedback when a component fails, for testing indicator lights whereby multiple lights may be tested simultaneously by pressing one pushbutton and closing one set of normally open contacts. The test pushbutton and the indicator signal operate at a higher voltage such as 120 volts AC and the indicator lamp is operated at a low voltage such as 6 volts, providing safety and allowing the use of inexpensive incandescent indicator bulbs. Only one indicator transformer is required for each indicator light. In one embodiment of the invention a pair of diodes are provided on the high voltage connection to indicator transformer to permit a test signal or a normal operating signal to activate the indicator bulb without affecting the rest of the circuit. A single common return line is used to provide a return line for the test circuit and the operating signal circuit. A transformer diode is connected across the primary of the indicator transformer, and fuses are disposed in series with each of the pair of diode provided on the high voltage side connection to the indicator transformer. When a signal diode or a test diode failure occurs a surge of current flows through the transformer diode and blows the appropriate fuse. The fuse blowing isolates the test circuit from the signal circuit. In another embodiment of the invention a single fuse is provided in the signal line connection to the high voltage side of the indicator transformer. A Zener diode is also provided in series with the transformer diode in a back-to-back relationship. This allows kick back to flow in the primary winding of the transformer which is less than the Zener breakdown level. It is important to allow this inductive kick back to flow for two reasons. One is that transformed to the secondary, it contributes to overall greater brilliance in the lamp and; second is that it tends to demagnetize the iron in the transformer core. However, when either the test or signal diode fails, the potential rises to a value greater than the Zener breakdown level, across the Zener diode and transformer diode which conduct, blowing the associated fuse. This then isolates the test circuit from the signal circuit. The disclosed invention prevents a failure of the test or signal diode from adversely affecting other circuits connected to the signal lamp test circuit.

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Beaver, PA, United States of America

Walter J Kellogg