Thermal cutout

A thermal cutout comprising a casing (1) of which at least a portion (3) is of heat-conducting material, two terminals (5) carried by an electrically insulating plug (4) secured to the casing, and an electrically conductive moving element (6) maintained in contact with each terminal (5) by a member (8) which is deformable under the action of heat and which is in turn in contact with the heat-conducting portion (3) of the casing (1), said thermal cutout comprising an electrically insulating member (7) translationally displaceable between a normal position wherein said member has a surface portion (18) in contact with the plug (4) and an opposite surface portion in contact with the heat-deformable member (8), and a fused position wherein an end portion (13) of said displaceable member (7) has penetrated into said deformable member (8) and wherein said surface portion (18) opposite to said end portion (13) is spaced from the plug (4), whereby said displaceable member (7) forms an isolating separation between on the one hand the heat-deformable member (8) and on the other hand the terminals (5) and the electrically conductive moving element (6) and allows electrical disconnection between the terminals (5) and the conductive moving element (6), the terminals (5) and the electrically conductive moving element (6) in said normal position being enclosed within an internal cavity (16, 17) delimited by opposite portions of a wall of said plug (4) and of said displaceable member (7).