Abstract: Cradle assembly comprises a breaker-engaging frame slidably coupled to an enclosure-engaging frame. The enclosure will have a rear wall provided with forwardly extending stationary terminals. The breaker will have rearwardly facing terminals aligned for engaging the stationary terminals. The rear wall of the enclosure is fixed relative to the side walls of the enclosure. The enclosure-engaging frame of the cradle assembly engages the side walls as the breaker is mounted to the breaker-engaging frame. The cradle assembly facilitates moving the breaker between a connected and disconnected position. In the connected position, the breaker terminals are engaged with the enclosure stationary terminals. In the disconnected position, the breaker terminals are disengaged and spaced from the stationary terminals.

Abstract: A drive mechanism for a circuit interrupter comprising a crank and lever pivotally interconnected by a resiliently yielding connecting rod assembly. The connecting rod assembly comprises a coil compression spring and first and second links slidably coupled together to compress the coil compression spring. Rotation of the crank in either direction causes the lever to drive the movable contact of the circuit interrupter into and out of engagement with the stationary contact. The coil compression spring is loaded under compression when the movable contact is driven into engagement with the stationary contact, storing and maintaining a mechanical static load on the movable contact for as long as the movable contact is engaged with the stationary contact.

Abstract: An interrupter/isolator assembly having a conducting member connected to one contact of a vacuum switch and movable to engage either an earth contact or an isolator contact incorporates a cam member for operating the conducting member and actuating the switch contacts, there being a degree of lost motion between the cam member and conducting member such that making or breaking of a current path between the second contact and either the isolator or earth contact occurs within the vacuum switch and not at the isolator or earth contact.

Abstract: A selector mechanism, especially for actuating a switch and capable of selectively operating in two different modes utilizing the same operation of a common actuator, comprises a pair of links each connected at one end to an actuating member and carrying at the other end a projection engaging in a respective slot in an operating member, each of which slots has a recess into which the respective projection rests in a neutral position of the operating member, and a selector device operable to cause a surface thereof to engage one or other of the projections and retain it within the respective recess, so as to cause movement of the respective link to be transmitted to the operating member and move it in a direction determined by the link, while leaving the projection associated with the other link free to move along its respective slot.

Abstract: Electrical switchgear comprises a first contact set composed of a first contact which is pivotable about a pivot axis and a second contact, the contacts being relatively movable between a closed position wherein a load current can be passed therethrough and an open position. An arc is formed between the first contact and an arcing electrode during movement of the contacts from their closed to their open position, whereupon current flows through a field coil connected in series with the electrode to produce a magnetic field which causes the arc to rotate and become extinguished. The pivot axis of the first contact extends transversely to a major axis of the field coil such that, during opening of the contacts, an end portion of the first contact moves transversely to and inwardly of said major axis. A second contact set is operable to earth the first contact set when its contacts are in their open position.