Abstract: A circuit breaker comprises a housing; a stationary contact mounted in the housing; an operating shaft disposed in the housing and rotatable about a first axis of rotation; and a movable contact including a contact arm pivotally held in the operating shaft for rotation about a second axis of rotation from an on position into a tripped position. By rotating the operating shaft about the first axis of rotation, the contact arm is movable into and out of the on position and an off position. The contact arm further has a terminus including a rounded corner and an adjoining rounded engagement face. There is further provided a structural unit stationarily supported in the housing and comprising a spring having a stationarily supported first end and a second end and a transfer lever having an end pivotally supported for rotation about a third axis of rotation.

Abstract: A motor protection electric switch, and the like, in which contacts are opened and closed by means of a switch latch equipped with an "on" button and an "off" button, with the different positions of the "on" button indicating the switching state of the contacts. A two-armed blocking lever is rotatably mounted on a latch housing of the switch, and disposed between the contact member carrier and the "on" button. One arm of the lever is latched with the "on" button while the other arm thereof is supported at the contact member carrier as long as the contacts are not opened sufficiently far to open a circuit through the contacts of the switch.

Abstract: A method for calibrating a bimetal releaser for a switch, e.g. a motor protection switch, the releaser including a release bridge and a differential bridge which is movable relative to the release bridge, with the ends of the bimetal strips being disposed between the two bridges through the use of calibrating elements. In order to provide a reliably adjusted bimetal releaser and to reduce the costs involved with adjustment, the free release end of each bimetal strip is equipped with a single calibrating element which, when the releaser is in its calibrated state, is fixed to the bimetal strip and, when seen in the direction of movement of the bimetal strip, lies, on the one hand, at the release bridge and, on the other hand, at the differential bridge.