Abstract: A circuit breaker mechanism comprises a line terminal, a load terminal and a set of contacts between the terminals. A fixed contact is connected to the line terminal, and a moving contact is connected to the load terminal via a conductive frame and a load sensing element. The moving contact is fixed to a contact carrier which is supported pivotably on conductive pins which are electrically connected to the frame. A spring urges the contact carrier into snug engagement with the conductive pins. The arrangement obviates the need for a flexible conductive pig-tail to form a current path between the contact carrier and the frame, simplifying the construction and improving the performance of the circuit breaker. With this arrangement, the current path extends from the line terminal to the moving contact, through the contact carrier, through the conductive pins, to the conductive frame and through the load sensing element to the load terminal.

Abstract: A switch mechanism such as a circuit breaker includes a trip indicator mechanism. The switch mechanism includes a switch contact and a rocker movable between a first position in which the contacts are closed, a second position indicating that an electrical fault has occurred, in which the contacts are open, and a third position in which the switch mechanism has been reset and the contacts are open. The rocker preferably comprises two rocker members hinged together with one of the rocker members having a step formation between a front face and an end face. The step formation carries an instruction regarding resetting of the mechanism and lies substantially flush with the front panel of the circuit breaker housing, with the face of the first rocker member standing partially proud of the front panel, when the rocker is in the second position. The mechanism allows a user to distinguish between manual switching off of the circuit breaker and tripping due to a fault.

Abstract: A switch actuator mechanism, for example for use with a circuit breaker, includes a rocker which has first and second rocker members which are hinged together. The rocker members have flat front faces which are movable between a condition in which they lie flat in the same plane, and a second position in which the faces are inclined relative to one another, with one rocker member standing proud of the housing of the switch or circuit breaker. Fingers on one of the rocker members engage a link of the circuit breaker mechanism to open or close its contacts. A spring loaded latching mechanism locks the rocker members alternately in their first and second conditions with successive operations of the mechanism.

Abstract: A circuit breaker mechanism comprises a coil which surrounds a tube in which a magnetic core can move against the urging of a spring. An armature is located adjacent the coil and moves transversely relative to the axis of the coil, with a head portion of the armature being attracted towards a pole piece of the mechanism, while a foot portion of the armature is attracted to the magnetic core. The armature is pivoted to a magnetic frame at a point between the head and foot portions, so that the magnetic force between the head portion and the pole piece is counteracted to some extent by the magnetic force between the foot portion and the magnetic core. This in turn depends on the position of the magnetic core in the tube, and the setting of an adjuster mechanism which spaces the foot portion closer to or further away from the core in use. The adjuster mechanism allows the instantaneous tripping characteristic of the mechanism to be adjusted in use.

Abstract: A circuit breaker 10 includes a housing and an operating mechanism 12 contained within the housing. An indicating arrangement is carried by the operating mechanism 12 and is displaceable relative to the housing under the action of the operating mechanism 12 for indicating the status of the operating mechanism 12.

Abstract: A ground fault interrupter 10 includes a core 12. Two load current-carrying wires 14, 16 pass through the core 12. A primary coil 44 is carried on the core 12 for sensing a current imbalance in the wires 14, 16. An auxiliary coil 18 is wound on the core 12. A pair of back-to-back zener diodes 20 is connected in series with the coil 18 to supply current to the coil 18 when an applied voltage exceeds a predetermined value between wires 14 and 16 or between either one of the and ground.