Fuente: WIPO "rice" 113,692. Oxley, A. J. Rice-, (Oxley, M. K. Rice-). March 20, 1917. Alarms operated by fusible devices.-An automatic fusible-plug temperature alarm comprises a plunger n pressed by a spring e against a plug of fusible material c contained in a cup b attached to a metal casing a screwed into a part of a machine &c., for example an engine water-jacket or bearing. To enable the freedom of movement of the plunger to be tested, a recess o is provided in the plug into which the correspondingly-shaped end of the plunger sinks when it is rotated. The plunger is provided at its outer end with an electrically insulated head g having a conducting-band h normally making contact with spring tongues l, m, which may be in the ignition circuit of an internal-combustion engine. The band may be continued upwards at two parts so that no alarm is given when the plunger is lowered for testing. The plug c may be composed of layers of different fusibility, the first causing an alarm to be given, and the next causing the plunger to break the ignition circuit and stop the engine. The head of the plunger may be arranged to complete a circuit when the plug fuses, and the device may cut off the supply of fuel or other substance to the machine on which it is used.