A thermally responsive switch is provided with a sealed container having a housing and a cover plate secured to the housing; a couple of conductive thermal pins inserted into a couple of through holes provided on the cover plate and secured by an insulative filler; a stationary contact secured to one of the conductive thermal pins inside the container; a heater having one end connected to the other of the conductive terminal pins inside the container and the other end connected to the cover plate; a thermally responsive plate having one end connected to the housing and being configured to invert a direction of curvature thereof at a predetermined temperature; and a movable contact provided on the other end of the thermally responsive plate. The through holes are configured by cylindrical portions, only the cylindrical portions, the filler, and the conductive terminal pins being covered by an insulative resin.

A temperature-dependent switch has a temperature-dependent switching mechanism arranged in a housing having an upper part and a lower part. A first contact area is arranged on an inner side of the upper part and a second contact area is arranged internally in the lower part. The switching mechanism comprises a current transfer element, a bimetallic snap-action disc and a movable contact area. The moveable contact area is connected to the current transfer element and interacts with the first contact area, the bimetallic snap-action disc lifting off the movable contact area from the first contact area depending on the temperature of the bimetallic snap-action disc. A resistance ring is arranged between the upper part and the lower part and is electrically in series with the current transfer element between the first and second contact areas when the switch is in its closed state.

A temperature-dependent switch has a temperature-dependent switching mechanism, a housing accommodating the switching mechanism, two first connections between which first connections the switching mechanism makes or interrupts an electrically conductive connection depending on the temperature of said switching mechanism, and a heating resistor that is arranged on an outside of the housing and is connected electrically in series with the two connections. The heating resistor is a sheet-like metal part that is welded to the housing and carries a further connection.

A protection device includes a movable arm, a fixed terminal, and a bimetallic member, and a casing that accommodates them, the bimetallic member is located either above or below the movable arm, one end of the bimetallic member applies force to one end of the movable arm, thereby holding one end of the movable arm and the fixed terminal in contact.

A breaker comprises: a first terminal piece on which a fixed contact is formed; a movable piece having a movable contact, for pressing the movable contact against the fixed contact so as to contact therewith; a thermally-actuated element deforming with a change in temperature and moving the movable piece so that the movable contact is separated from the fixed contact, and a second terminal piece electrically connected to the movable piece. The movable piece is provided, within a contact portion contacting with the second terminal piece, with a protrusion projecting toward the thermally-actuated element.

A circuit breaker 1 comprises: a fixed-contact piece 2 with a fixed contact 21; a movable-contact piece 4 with a movable contact 41; a thermal actuator element 5 thermally transformable to move the movable-contact piece; a PTC thermistor 6 for conducting electricity between the movable-contact piece 4 and the fixed-contact piece 2; a main body 71 of a package provided with a holding recess 73 housing the above-mentioned components; and a cover 81 hermetically covering the holding recess 73. The fixed-contact piece 2 is embedded between an internal wall 74 and an external wall 75 of the main body 71. The PTC thermistor 6 is housed in an opened hollow 73d. In a planar view of the circuit breaker, a through-hole 76 penetrating through the external wall 75 overlaps with the opened hollow 73d, but does not overlap with the centroid O of the opened hollow 73d.

In a temperature-dependent switch having a switching mechanism that has a movable contact part which cooperates with a stationary counter contact and is moved by a spring part to which the movable contact part is electrically conductively connected, the switching mechanism produces an electrically conductive connection between the stationary counter contact and a second counter contact in a temperature-dependent manner. The switch is provided with an arc-shielding plate, which has no mechanical function, is arranged on an upper surface of the spring part and covers sections thereof.

A heat-reactive switch includes an airtight container with a housing and a lid plate, two conductive terminal pins fixed in through-holes in the lid plate, a fixed contact point fixed on one of the conductive terminal pins, a heater connected to the other conductive terminal pin and to the lid plate, a heat-reactive plate connected to the housing internal surface, the bending direction becoming inverted at a predetermined temperature, and a mobile contact point provided at the end of the heat-reactive plate. A heating element has a plurality of serpentine portions made from a metal plate in ribbon form, disposed between the lid plate and the heat-reactive plate so as to be parallel thereto. At least two of the serpentine portions are disposed to face each other while sandwiching the conductive terminal pin. Each portion follows the inner peripheral surface of the housing and have planar portions facing each other.

A base member includes a terminal fixing part for blocking an entire surface of an opening part of a housing at a position further inner than an opening end part of the housing when the base member is inserted in the housing. A first electrode part formed by a tip part of two bent stages that are composed of a horizontal part, a vertical part, and a horizontal part and configured by bending a portion of a part of the fixed side fixed a conductive member, which is continuous with a first external connection terminal, in a direction perpendicular to a continuous direction.

A movable flat surface portion, which rises in conjunction with the upward movement of a facing surface, first causes an edge of the movable flat surface portion to abut a flat surface portion, second brings an entirety of a surface of the movable flat surface portion into intimate contact with the fixed flat surface portion as a result of the movable flat surface portion acting against elastic resistance thereof in accordance with upward inertia, third forms, in accordance with a restoring force resulting from the elastic resistance thereof, a gap in the intimate contact with the fixed flat surface portion in a manner such that the forming of the gap starts with an end side continuous with the end of the facing surface, and fourth stabilizes a position shape such that the edge of the movable flat surface portion is a portion that ultimately comes into contact with the fixed flat surface portion.