Abstract: An electric fuse is comprised of a tubular fuse casing formed of an electrically insulating material. A first conductive component is attached to a first end of the casing and a second conductive component is attached to a second end of the casing. A first conductive path is formed through the tube between the first and second conductive components. The conductive path includes a fusible element having a first resistance. A second conductive path is formed along the exterior of the tubular fuse casing. The second conductive path is in parallel to the first conductive path and has a second resistance greater than the first resistance. The second conductive path includes an indicator component. The indicator component is comprised of first layer comprised of a colored material, and a second layer comprised of an electrically conductive material deposited onto the first layer. The second layer has a region of increased resistance.

Abstract: A fuse comprising a tubular fuse casing and first and second conductive ferrules located on the exterior of the casing at opposite ends thereof. The second ferrule has an opening therethrough. A first short circuit fusible element is attached to the first ferrule, and a heater is attached to the second ferrule. A time delay over-current trigger mechanism electrically connects the first fusible element and the heater to each other in series in an electrical path between the conductive ferrules. The mechanism is connected to receive heat from the heater and to mechanically interrupt the electrical path when the heater heats up under low over-current conditions. An indicator mechanism is provided for indicating when the electrical path between the conductive ferrules is interrupted. The indicator mechanism is comprised of an indicator movable from a first position wherein the indicator is substantially within the casing to a second position wherein a substantial portion of the indicator is outside the casing.