Indicator-equipped, dual-element fuse
AssigneeMcGraw-Edison Company
InventorAldino J. Gaia
Life of this patent
Estimating the term…
Abstract
A circuit-interrupting device has a stationary current-conducting member, a movable current-conducting member, a connector which accommodates the adjacent ends of the current-conducting members and which normally holds a mass of heat-softenable alloy in engagement with those adjacent ends, an indicator which is connected to the movable current-conducting member and a spring which can simultaneously move the movable current-conducting member, and the indicator to moved positions whenever the circuit-interrupting device opens the circuit. The adjacent ends of the current-conducting members extend into the connector a distance less than one-half of the minimum distance through which the spring will move the indicator.
Claims15
An indicator-equipped, dual-element, electric fuse which comprises a casing, a current-conducting member disposed within said casing, a second current-conduct member disposed within said casing, heat-softenable alloy which normally maintains said current-conducting members in electrically-conducting relation, an indicator which is disposable in an initial, retracted position or in a moved, extended position, said indicator being held in said initial, retracted position as long as both of said current-conducting members remain intact and said heat-softenable alloy maintains said current-conducting members in electrically-conducting relation, and a spring which will move one of said current-conducting members away from said heat-softenable alloy and will simultaneously move said indicator to said moved, extended position and will thereby simultaneously provide relative movement between said current-conducting members and also will provide relative movement between said one of said current-conducting members and said heat-softenable alloy whenever said heat-softenable alloy softens sufficiently to free said one of said current-conducting members, said casing defining an open area into which said spring can bodily move said heat-softenable alloy, said spring simultaneously moving said one of said current-conducting members and said heat-softenable alloy away from the other of said current-conducting members when said heat-softenable alloy softens sufficiently to free said other of said current-conducting members but continues to remain in holding engagement with said one of said current-conducting members.
An indicator-equipped, dual-element, electric fuse which comprises a casing, a current-conducting member disposed within said casing which will fuse if the temperature thereof is raised to the melting temperature thereof, a second current-conducting member disposed within said casing which will fuse if the temperature thereof is raised to the melting temperature thereof, said second current-conducting member having one end thereof adjacent one end of the first said current-conducting member, a connector adjacent said one ends of both of said current-conducting members, heat-softenable alloy which will soften if the temperature thereof is raised to the softening temperature thereof, said heat-softenable alloy normally holding said one ends of both of said current-conducting members in mechanical engagement and in electrically-conducting relation with said connector, an indicator which is disposable in an initial, retracted position or in a moved, extended position, said indicator being held in said initial, retracted position as long as both of said current-conducting members remain intact and said heat-softenable alloy holds said connector in mechanical engagement and electrically-conducting relation with said one ends of both of said current-conducting members, and a spring which moves said indicator to said moved, extended position and which simultaneously provides relative movement between said connector and at least one of said current-conducting members whenever said heat-softenable alloy softens or either of said current-conducting members fuses.
An indicator-equipped, dual-element, electric fuse which comprises a casing, a current-conducting member which is disposed within said casing and which will fuse if the temperature thereof is raised to the melting temperature thereof, a second current-conducting member which is disposed within said casing and which will fuse if the temperature thereof is raised to the melting temperature thereof, said second current-conducting member having one end thereof adjacent one end of the first said current-conducting member, heat-softenable alloy which has a melting temperature substantially lower than the melting temperature of either of said current-conducting members and which normally holds said one ends of said current-conducting members in mechanical engagement and in electrically-conducting relation, an indicator which is disposed in an initial retracted position or in a moved, extended position, said indicator being held in said initial, retracted position as long as both of said current-conducting members remain intact and said heat-softenable alloy remains in mechanical engagement and electrically-conducting relation with said one ends of both of said current-conducting members, and a spring which maintains both of said current-conducting members and said heat-softenable material under tension, said spring moving said indicator to said moved, extended position and simultaneously providing relative movement between said two current-conducting members and between one of said current-conducting members and said heat-softenable alloy whether said heat-softenable alloy softens or one or the other of said current-conducting members fuses.
Dependencies are inferred from the claim text.