Temperature-dependent switch

A temperature-dependent switch, comprising:

• a first stationary contact, a second stationary contact, and a temperature-dependent switching mechanism having a movable contact member,
• wherein in a first switching position, the switching mechanism presses the movable contact member against the first stationary contact, thereby producing an electrically conductive connection between the first stationary contact and the second stationary contact via the movable contact member, and, in a second switching position, the switching mechanism keeps the movable contact member spaced at a distance from the first stationary contact, thereby disconnecting the electrically conductive connection,
• wherein the temperature-dependent switching mechanism comprises a temperature-dependent snap-action part, which is configured to switch from a geometric low-temperature configuration to a geometric high-temperature configuration upon reaching a switching temperature, and which is configured to switch back from the geometric high-temperature configuration to the geometric low-temperature configuration upon subsequently reaching a reset temperature that is lower than the switching temperature,
• wherein a switching of the temperature-dependent snap-action part from the geometric low-temperature configuration to the geometric high-temperature configuration moves the switching mechanism from the first switching position to the second switching position, thereby opening the switch,
• wherein a closing lock is provided that prevents the switch once having opened from closing again by keeping the switching mechanism in its second switching position,
• wherein the closing lock comprises a fusible medium which is configured to melt when a temperature of the switch exceeds a melting temperature of the medium, to contact, in a molten state, a part of the switching mechanism when the switching mechanism is in the second switching position, and to subsequently solidify again and thereby lock the switching mechanism in its second switching position when the temperature of the switch falls below the melting temperature of the medium again, wherein the melting temperature of the fusible medium is lower than the switching temperature of the temperature-dependent snap-action part.