Abstract: A time delay fuse including a fuse casing, terminals located on the exterior of the casing, a hollow electrically insulated inner core having first and second holes in the walls thereof, a fusible element that makes electrical connection to the terminals and is disposed on the surface of the core such that the length of the element is greater than the distance between the terminals, the element passing through the holes, and a material that is deposited on a portion of the element passing through the interior of the core and lowers the melting temperature of that portion.

Abstract: A fuse including a tubular casing, first and second blade-shaped terminals extending from respective sides of the casing, a short circuit fusible element attached to the first terminal, a heater attached to the second terminal, and a time delay overcurrent trigger mechanism electrically connecting the fusible element and the heater to each other in series in an electrical path between the blade-shaped terminals, the mechanism being connected to receive heat from the heater and to mechanically interrupt the electrical path when the heater heats up under low overcurrent conditions.

Abstract: An electric fuse, in particular an electric time-lag fuse, comprising a tubular casing, a pair of terminal elements, a granular arc-quenching filler, and a pair of parallel fusible elements inside the casing interconnecting the pair of terminal elements. Each of the pair of fusible elements has a plurality of juxtaposed points of reduced cross-section. Juxtaposed points of reduced cross-section support an M-effect causing overlay thereon. Each of the M-effect causing overlays extends from a pair of juxtaposed points of reduced cross-section in opposite directions longitudinally of said pair of fusible elements. A substantially E-shaped member of a solid gas-evolving material having three arms is associated with said pair of fusible elements. One of said three arms is interposed between said pair of fusible elements at the region thereof where the juxtaposed points of reduced cross-section are located.

Abstract: The process of circuit interruption by an electric fuse can be initiated either by a protracted overload, or by a major fault current of large proportions. This invention is concerned with the latter kind of fault currents.A substantially U-shaped gas-evolving structure is inserted between parallel rows of fusible elements. The two parallel arms of that structure are positioned close to the terminal elements of the fuse. A tie member interconnecting the two arms is positioned substantially out of the arcing zone and parallel to a generatrix of the fuse casing. On occurrence of a major fault current, the gas evolved from the arms protects the terminal elements of the fuse. It also tends to quench the follow current, i.e. the current which flows through the hot fulgurite after a successful interruption of a major fault current.