A thermal protector includes: a first terminal and a second terminal that are provided at both ends in a longitudinal direction and connected to an external circuit; an insulation block that holds the first terminal and the second terminal; a fixed contact and a movable contact capable of coming into contact with each other; a movable plate having the movable contact provided at a leading end; and a bimetal engaged with the movable plate. Each of the first terminal and the second terminal has a main body, an extension, and a slit. The main body of the first terminal and the main body of the second terminal lie in a first plane, and a fixed contact support part of the extension and a movable plate support part of the extension lie in a second plane. An angle formed by the first plane and the second plane is an acute angle.

A thermal protector includes: a first terminal and a second terminal that are provided at both ends in a longitudinal direction and connected to an external circuit; an insulation block that holds the first terminal and the second terminal; a fixed contact and a movable contact capable of coming into contact with each other; a movable plate having the movable contact provided at a leading end; and a bimetal engaged with the movable plate. Each of the first terminal and the second terminal has a main body, an extension, and a slit. The main body of the first terminal and the main body of the second terminal lie in a first plane, and a fixed contact support part of the extension and a movable plate support part of the extension lie in a second plane. An angle formed by the first plane and the second plane is an acute angle.

A circuit breaker device includes a bimetallic overcurrent protection element which is configured to be placed in series with an integrated replaceable fuse. The replaceable fuse may be faster-acting than the bimetallic overcurrent protection element, and may be higher-rated than the bimetallic overcurrent protection element. The circuit breaker device may include an electrically isolated terminal stud having a height sufficient to retain the replaceable fuse thereon, the electrically isolated terminal stud not directly connected to the bimetallic overcurrent protection element, so that current can only flow through the bimetallic overcurrent protection element when a replaceable fuse comprising an intact fuse element is supported on the electrically isolated terminal stud.

A circuit breaker device includes a bimetallic overcurrent protection element which is configured to be placed in series with an integrated replaceable fuse. The replaceable fuse may be faster-acting than the bimetallic overcurrent protection element, and may be higher-rated than the bimetallic overcurrent protection element. The circuit breaker device may include an electrically isolated terminal stud having a height sufficient to retain the replaceable fuse thereon, the electrically isolated terminal stud not directly connected to the bimetallic overcurrent protection element, so that current can only flow through the bimetallic overcurrent protection element when a replaceable fuse comprising an intact fuse element is supported on the electrically isolated terminal stud.

A current cut-off device includes a plate-shaped terminal piece having a contact, a movable piece including an elastic portion formed in a plate shape so as to be elastically deformed and a movable contact arranged at one end portion of the elastic portion and having the movable contact so as to be pressed against and in contact with the contact, and a thermally actuated element which biases the movable piece by deforming in accordance with a temperature change and causes a state of the movable piece to be shifted from a conductive state in which the movable contact is in contact with the contact to a cut-off state in which the movable contact is separated from the contact. When the state of the movable piece is shifted from the conductive state to the cut-off state, as the movable contact moves, it gets over the contact.

A current cut-off device includes a plate-shaped terminal piece having a contact, a movable piece including an elastic portion formed in a plate shape so as to be elastically deformed and a movable contact arranged at one end portion of the elastic portion and having the movable contact so as to be pressed against and in contact with the contact, and a thermally actuated element which biases the movable piece by deforming in accordance with a temperature change and causes a state of the movable piece to be shifted from a conductive state in which the movable contact is in contact with the contact to a cut-off state in which the movable contact is separated from the contact. When the state of the movable piece is shifted from the conductive state to the cut-off state, as the movable contact moves, it gets over the contact.

A breaker includes a fixed piece having a fixed contact, a movable piece having an elastically deformable elastic portion and a movable contact formed at a tip portion of the elastic portion and pushed to contact with the fixed contact, a thermally actuated element deformable according to a temperature change to shift the state of the movable piece from a conductive state to a cut-off state, and a case accommodating the fixed piece, the movable piece, and the thermally actuated element. The movable piece is cantilevered by the case on a base end portion side of the elastic portion, the elastic portion includes a first narrow portion having a smaller width dimension in a short direction perpendicular to a longitudinal direction of the elastic portion than the base end portion, and the first narrow portion has an arc-shaped contour in plan view from a thickness direction of the elastic portion.

A breaker includes a fixed piece having a fixed contact, a movable piece having an elastically deformable elastic portion and a movable contact formed at a tip portion of the elastic portion and pushed to contact with the fixed contact, a thermally actuated element deformable according to a temperature change to shift the state of the movable piece from a conductive state to a cut-off state, and a case accommodating the fixed piece, the movable piece, and the thermally actuated element. The movable piece is cantilevered by the case on a base end portion side of the elastic portion, the elastic portion includes a first narrow portion having a smaller width dimension in a short direction perpendicular to a longitudinal direction of the elastic portion than the base end portion, and the first narrow portion has an arc-shaped contour in plan view from a thickness direction of the elastic portion.

A circuit breaker and method for operating a circuit breaker. The circuit breaker includes a first and a second breaker terminal, a bimetal stripe, a first conduction line, a switch with a first and a second contact, a triggering device mechanically coupling the bimetal stripe to the switch, a magnet and a detection device comprising a magnetic field sensor configured to detect a magnetic field of the magnet. The first conduction line is electrically coupled to the first breaker terminal and to the first contact and is wound around the bimetal stripe. The magnet is connected to at least one of the bimetal stripe, the triggering device and the switch.

A circuit breaker and method for operating a circuit breaker. The circuit breaker includes a first and a second breaker terminal, a bimetal stripe, a first conduction line, a switch with a first and a second contact, a triggering device mechanically coupling the bimetal stripe to the switch, a magnet and a detection device comprising a magnetic field sensor configured to detect a magnetic field of the magnet. The first conduction line is electrically coupled to the first breaker terminal and to the first contact and is wound around the bimetal stripe. The magnet is connected to at least one of the bimetal stripe, the triggering device and the switch.