Abstract: A circuit breaker includes a handle having OFF, ON and intermediate positions, and an extension. A blocking disk has a spring, and first, second and third surfaces. The handle and disk are co-pivotally mounted. The extension engages the third surface for rotation therewith. A pivot lever includes a first end adapted for engagement with a movable contact arm, and a second end adapted for engagement with the first and second surfaces. The first surface blocks the second end as the handle moves from OFF toward the intermediate position, and releases the second end to the second surface at the intermediate position. The first end blocks movement of the movable contact arm when the first surface blocks the second end, and releases the movable contact arm when the first surface releases the second end, thereby moving a movable contact toward a fixed contact in response to the bias of a spring.

Abstract: A circuit breaker includes a handle having OFF, ON and intermediate positions, and an extension. A blocking disk has a spring, and first, second and third surfaces. The handle and disk are co-pivotally mounted. The extension engages the third surface for rotation therewith. A pivot lever includes a first end adapted for engagement with a movable contact arm, and a second end adapted for engagement with the first and second surfaces. The first surface blocks the second end as the handle moves from OFF toward the intermediate position, and releases the second end to the second surface at the intermediate position. The first end blocks movement of the movable contact arm when the first surface blocks the second end, and releases the movable contact arm when the first surface releases the second end, thereby moving a movable contact toward a fixed contact in response to the bias of a spring.

Abstract: The circuit breaker current/time characteristic value at which the bimetal in a thermal trip assembly actuates a trip mechanism is adjusted by an adjustable coupler that includes first and second pivoted members separately rotatable about a common pivot axis. Deflection of the bimetal by an overload current causes rotation of the first pivoted member, which is coupled by a coupling member extending parallel to the common axis into the second pivoted member which rotates to actuate the trip mechanism. A positioner moves the coupling member toward and away from the common pivot axis to adjust the amount of deflection of the bimetal needed to actuate the trip mechanism.

Abstract: The circuit breaker current/time characteristic value at which the bimetal in a thermal trip assembly actuates a trip mechanism is adjusted by an adjustable coupler that includes first and second pivoted members separately rotatable about a common pivot axis. Deflection of the bimetal by an overload current causes rotation of the first pivoted member, which is coupled by a coupling member extending parallel to the common axis into the second pivoted member which rotates to actuate the trip mechanism. A positioner moves the coupling member toward and away from the common pivot axis to adjust the amount of deflection of the bimetal needed to actuate the trip mechanism.

Abstract: A circuit breaker includes a housing, line and load terminals, first and second circuit breaker mechanisms, an operating handle having on and off positions, and first and second links from the operating handle to the respective first and second operating mechanisms. Each of the circuit breaker mechanisms includes a set of separable contacts in series with the other separable contacts between the line and load terminals, an operating mechanism for moving the corresponding separable contacts between open and closed positions, and a trip mechanism cooperating with the corresponding operating mechanism for moving the corresponding separable contacts from the closed to the open position thereof. The first and second links engage the first and second operating mechanisms to move the first and second separable contacts, respectively, between the corresponding closed and open positions thereof responsive to the on and off positions, respectively, of the operating handle.

Abstract: A circuit breaker embodies with a single electromagnetically actuated plunger two levels of actuation, corresponding to two levels of excessive current or voltage defined by two different airgaps, one at the lower level for triggering the toggle mechanism, the other at the higher level for directly actuating the movable arm through a kicker arm. The preferred embodiment provides a double-ended lever pulled by the plunger at midpoint for actuating the trip bar, and the kicker arm is actuated in an overriding situation by the lever rotating about the trip bar blocked at the end of its initial move.

Abstract: A walking beam for interlocking control devices such as circuit breakers is characterized by a central bracket for supporting, on a mounting plate of the control devices, the beam through its central pin, and a single screw is provided for adjusting the central pin level within the bracket until the plungers at the two ends of the beam are fully engaged with their respective control members, which could be the crossbars of a circuit breaker. Once the walking beam has been properly adjusted, the central pin and the screw are fixed in position with nuts.