Abstract: A breaker includes a fixed metal plate 4, a moving metal plate 6, a bimetal 8, and a heater 9. The fixed plate 4 includes a fixed contact 5 in space 20 of an exterior case 1 including an electrically-insulating case 2 and an exterior metal plate 3. The exterior plate 3 and the fixed plate 4 are arranged at opposed positions, and fixed to the case 2. The bimetal 8 has a convex shape, and is arranged between the heater 9 and the moving plate 6. The case 2 includes first and second outer walls 11A and 11B protruding from the both ends of the case 2. A central part 4B of the fixed plate 4 is fixed to the first outer wall 11A. A part of moving plate 6 is fixed to the second outer wall 11B. The exterior plate 3 closes the opening of the space 20.

Abstract: A thermal and/or magnetic overload trip device for an electrical switching device having multiple poles includes a housing having a housing member configured to receive a plurality of functional elements and being at least partially closable. The overload trip device further including a conductor strap associated with each of the multiple poles, each conductor strap having an associated housing portion, and a rotatable trip shaft configured to rotate between a rest position and an actuating position so as to trip an associated switching mechanism. The overload trip device further including at least one rotatable adjusting element configured to set the at least one of the presettable thermal threshold and the presettable magnetic threshold. Further, the housing member is configured so that the functional elements is insertable therein and is couplable to the housing member.

Abstract: An electrostatic micro switch includes a fixed electrode disposed on a fixed substrate; a movable substrate elastically supported by the fixed substrate, the movable substrate including a movable electrode facing the fixed electrode. The movable substrate includes a semiconductor including a plurality of regions having different values of resistivity and a region of high resistivity is disposed near the movable electrode.

Abstract: A pair of spring mounted masses have sufficient inertia to remain stationary in response to a shock force applied to the housing of a trip assembly in a circuit breaker to block movement of the trip bar and thereby prevent a nuisance trip.

Abstract: A service switching device is described. The service switching device has a thermal release, an electromagnetic release, a switching mechanism with a latching point, a contact point with a moving contact piece and a stationary contact piece. When an over-current condition occurs, the thermal release unlatches the latching point so that the contact points are opened permanently and, when a short-circuit current occurs, the electromagnetic release moves the moving contact piece to the open position. The service switching device has a housing and an associated actuator in the form of a piezoelectric bending strip, which likewise acts on the latching point in order to open the contact point permanently, with a fault current detection device being provided, whose output signal drives the actuator when a fault current occurs.

Abstract: A circuit breaker includes an upper rail mounting device defined by a line terminal having a pair of spaced-apart jaws. A bimetal is adjusted by means of a calibration screw. An aperture is provided in an upper sidewall portion of a base of the circuit breaker for access to the calibration screw by a calibration device. The aperture is positioned so that the calibration device must pass through the jaws of the upper rail mounting device. This ensures that the calibration screw can only be operated when the circuit breaker is disconnected from an electrical supply.

Abstract: The thermal circuit breaker and switch has fixed and movable contacts, and non-conductive contact and trip actuators. The movable contact is provided on the free end of a lever arm that normally biases the movable contact toward its open position. The contact actuator transfers movement from a rocker or operator to the movable contact arm when no overload condition exists. The trip actuator is L shaped and rotates in a socket when engaged by a thermally sensitive bi-metallic element so as to allow one end of the contact actuator to float freely, allowing the movable contact arm's bias to open the circuit. The bi-metallic element is so positioned as to engage and rotate the trip actuator only when the bi-metallic element is deformed due to an overheat condition that occurs with an overcurrent. A compression spring acts between the upstanding legs of the trip actuator and the underside of the rocker thus biasing the rocker to the `off` position and biasing the trip actuator to the `reset` position.

Abstract: In an exemplary embodiment of the invention, a calibration arrangement and process for use in a circuit protective device are presented. An exemplary calibration assembly for use in the calibration process of the present invention includes a split clamp arm having a first opening for receiving and holding a calibration pin and a second opening for receiving an actuator key. A portion of the split clamp arm is divided into a first arm and a second arm by a channel which extends from a first end of the split clamp arm through the first opening and communicates with the second opening. The split clamp arm is opened by inserting the actuator key through the second opening and because of the preferred oblong or rectangular shape of the second opening of the split clamp arm, rotation of the actuator key therein forces the members forming the first opening of the split clamp arm apart from one another.

Abstract: The thermal circuit breaker and switch has fixed and movable contacts, and non-conductive contact and trip actuators. The movable contact is provided on the free end of a lever arm that normally biases the movable contact toward its open position. The contact actuator transfers movement from a rocker or operator to the movable contact arm when no overload condition exists. The trip actuator is L shaped and rotates in a socket when engaged by a thermally sensitive bi-metallic element so as to allow one end of the contact actuator to float freely, allowing the movable contact arm's bias to open the circuit. The bi-metallic element is so positioned as to engage and rotate the trip actuator only when the bi-metallic element is deformed due to an overheat condition that occurs with an overcurrent. A compression spring acts between the upstanding legs of the trip actuator and the underside of the rocker thus biasing the rocker to the `off` position and biasing the trip actuator to the `reset` position.

Abstract: A reduced-size thermal overload relay having a housing (2) that includes three narrow compartments (2k, 2l, 2m) in which are mounted three connector brackets (16,18,20) supporting three flat bimetal members (16j, 18j, 20j). Three narrow cassette heaters (6,8,10) are mounted at the upper part of the housing and held in by a snap-in hold-down device (12) that engages pairs of hooks (6b, 7b) at the lower portions of the heaters. A pushbutton (12a) on the hold-down device extends through a hole (3c) in the front wall of the housing for manual depression to release the heaters for removal. Each bracket (16) is H-shaped having legs (16c, 16d) for mounting it in a housing compartment (2k) and arms (16a, 16b) connected by a platform (16e) to which the upper terminal clip (6d) of the cassette heater is clamped with a screw (16q), the small angles of this platform and terminal clip automatically drawing the flat heater element (6c) into desired spacing with the bimetal member.

Abstract: A secondary circuit breaker for a distribution transformer characterized by electrical inductive apparatus within an oil-filled housing, and circuit interrupter for controlling current flow through the transformer and comprising a releasable latch arm, trip means operable upon overload conditions to release the latch arm, a latch lever between the trip means and the latch arm and comprising the only operable part therebetween, and the latch lever having a cam surface for latching and unlatching the releasable arm.

Abstract: One reed of a pair of parallel reeds has a rod extending to opposite sides of the pair. A bimetallic snap disc can be heated to snap against one end of the rod and thus flex the reed to engage a contact on that reed with a contact on the other reed and thus close a circuit to be controlled. A resilient latch holds that reed in its flexed position, even after the disc cools and snaps back to its normal configuration, until a second snap disc is heated and pushes the rod and reed back to its open-contact position. A selectively operable switch serves to provide electric current to a selected one of a pair of resistance heaters, one heater being near each of the snap discs.