Abstract: A dual-functional fuse unit, which is responsive to an electric current and an ambient temperature, contains a current sensing fuse and a temperature sensing fuse element. The current sensing fuse is serially connected with and between lead terminals of the fuse unit directly or through an intermediate conductor member. The current sensing fuse or the intermediate conductor member is urged but kept from moving when the temperature sensing fuse element is in a solid state. When the fuse element melts at a specified ambient temperature the urged current sensing fuse or the intermediate conductor member is displaced by the urging force so that the lead terminals are electrically disconnected from each other. In other embodiment, an urged cutter member in the case is normally kept from moving but is driven to sever the element of the current temperature fuse when the temperature sensing fuse element melts at a specified ambient temperature.

Abstract: A circuit breaking element comprising an electrically insulating base member, an organic insulation layer having a low melting point and formed over the surface of the base member, and a metal resistance coating layer formed over the surface of the insulation layer. When the metal resistance coating layer is thermally broken by excessive current passing therethrough, the coating layer completely separates into two portions at opposite sides of the break to completely break a circuit.

Abstract: The present invention discloses an electric safety device in which a fuse element adapted to break a circuit upon passage of an overcurrent and a circuit-breaking conductive member of the heat-sensitive type for preventing overheat are housed in one vessel and are electrically connected to each other, so that the circuit of an electrical appliance can be broken with respect to both overcurrent and overheat.