Switch having a safety element

A switch, comprising:

• two external terminals for connection to a circuit,
• a temperature-dependent switching mechanism that above a response temperature interrupts and closes, respectively, said circuit when connected,
• said switching mechanism comprising:
• a fixed contact electrically connected to one of said two external terminals, and a moving contact electrically connected to the other of said two external terminals,
• a bimetallic part acting on said movable contact such that the latter is in contact with the fixed contact depending on the temperature of the bimetallic part, and
• a safety element produced from a shape-memory alloy that changes its shape into a high-temperature shape if its temperature reaches a transformation temperature which is above the response temperature, the safety element, in its high-temperature shape, holding the movable contact in a safety position which it retains even if the temperature of the safety element again drops below the transformation temperature,
• wherein the safety element is a tension spring.

A switch, comprising:

• two external terminals for connection to a circuit,
• a temperature-dependent switching mechanism that above a response temperature interrupts and closes, respectively, said circuit when connected,
• said switching mechanism comprising:
• a fixed contact electrically connected to one of said two external terminals, and a moving contact electrically connected to the other of said two external terminals,
• a bimetallic part acting on said movable contact such that the latter is in contact with the fixed contact depending on the temperature of the bimetallic part, and
• a safety element that changes its shape into a high-temperature shape if its temperature reaches a transformation temperature which is above the response temperature,
• wherein the switching mechanism comprises a spring element, clamped at one end, at whose free end the movable contact is arranged;
• and the safety element, in its high-temperature shape acts on the spring element.

A switch, comprising:

• two external terminals for connection to a circuit,
• a temperature-dependent switching mechanism that above a response temperature interrupts and closes, respectively, said circuit when connected,
• said switching mechanism comprising:
• a fixed contact electrically connected to one of said two external terminals, and a moving contact electrically connected to the other of said two external terminals,
• a bimetallic part acting on said movable contact such that the latter is in contact with the fixed contact depending on the temperature of the bimetallic part, and
• a safety element that changes its shape into a high-temperature shape if its temperature reaches a transformation temperature which is above the response temperature,
• wherein the switching mechanism comprises a spring snap disk which carries the movable contact approximately centeredly, and is braced peripherally against a housing part by means of which it is electrically connected to the external terminal;
• and the safety element acts on the spring snap disk.