Chemically augmented electrical fuse

• US 3,958,206 A
• Filed: 06/12/1975
• Issued: 05/18/1976
• Est. Priority Date: 06/12/1975
• Status: Expired due to Term

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Klint, Robert V.
• Primary Examiner(s): Miller, J. D.
• Assistant Examiner(s): Bell, Fred E.
• Application Number:
  US05/586,286
• Time in Patent Office: 341 Days
• Field of Search: 337/30, 337/142, 337/160, 337/243, 337/295, 337/296, 337/401, 337/404, 337/405
• US Class Current: 337/406
• CPC Class Codes: H01H 2085/466 with remote controlled forced fusing
• CPC Class Codes: H01H 39/00 Switching devices actuated by an explosion produced within the device and initiated by an electric current
• CPC Class Codes: H01H 85/06 characterised by the fusible material H01H85/11 takes precedence
• CPC Class Codes: H01H 85/38 Means for extinguishing or suppressing arc by powder filling H01H85/18; by mechanical tension applied to fusible member H01H85/36

Abstract

A conventional fusible element is combined with exothermic reactive material such as PETN or a ribbon of aluminum-palladium to supply quickly released chemical energy for fast circuit interruption where the circuit-derived electrical energy available for interruption is low. An arc quenching substance preferably surrounds the fusible element. The exothermic reaction is initiated thermally or by supplementary electrical energy from a trigger circuit.

Claims

1. An electrical fuse for fast circuit interruption with low amounts of circuit-derived electrical energy at current levels above the steady-state current comprising

an elongated conductive fusible element having an exothermic reactive material carried by the central portion thereof,

mounting means connected to each end of said fusible element and supporting a surrounding insulating tube, and

a trigger circuit for initiating rapid circuit interruption comprising means for effectively sensing the current in said fusible element, and circuit means responsive to the sensing of a predetermined excessive current level for discharging supplementary electrical energy through a localized portion of said exothermic reactive material to initiate the exothermic reaction.

2. A fuse according to claim 1 further including an arc quenching substance substantially filling the space between said insulating tube and fusible element.

3. An electrical fuse for fast circuit inerruption with low amounts of available circuit-derived electrical energy comprising

an elongated conductive fusible element encasing a slug of diluted pentaerythritol tetranitrate,

mounting means connected to each end of said fusible element and supporting a surrounding insulating tube, and

a solid material having an adsorbed arc quenching electro-negative gas and substantially filling the space between said fusible element and insulating tube, said adsorbed gas being liberated upon rapid exothermic reaction of said pentaerythritol tetranitrate due to excessive current levels in said fusible element to obtain fast circuit interruption.

4. A fuse according to claim 3 wherein said solid material having adsorbed arc quenching gas is a granular zeolite material with adsorbed sulfur hexafluoride.

5. A fuse according to claim 3 further including a trigger circuit for initiating more rapid circuit interruption and comprising means for effectively sensing the current in said fusible element, a source of electrical energy, switch means rendered conductive by the sensing of a predetermined excessive current level, and means for connecting said switch means and source of electrical energy in series to discharge across a localized portion of said slug of diluted pentaerythritol tetranitrate.

6. A fuse according to claim 3 wherein said solid material having adsorbed arc quenching gas is a granular zeolite material with adsorbed sulfur hexafluoride, and further including

a trigger circuit for initiating more rapid circuit interruption comprising means for effectively sensing the current in said fusible element, and circuit means responsive to the sensing of a predetermined excessive current level for discharging supplementary electrical energy through a localized portion of said slug of diluted pentaerythritol tetranitrate.

7. An electrical fuse for fast circuit interruption with low mounts of available circuit-derived electrical energy comprising

an elongated conductive fusible element having a ribbon of aluminum-palladium reactive solid bonded thereto by an insulating layer, and

mounting means connected to each end of said fusible element and supporting a surrounding insulating tube,

said ribbon of aluminum-palladium having a rapid exothermic reaction in response to excessive current levels in said fusible element to obtain fast circuit interruption.

8. A fuse according to claim 7 further including a trigger circuit for initiating more rapid circuit interruption and comprising means for effectively sensing the current in said fusible element, a source of electrical energy, switch means rendered conductive by the sensing of a predetermined excessive current level, and means for connecting said switch means and source of electrical energy in series to discharge across a localized portion of said aluminum-palladium ribbon.

9. A fuse according to claim 8 wherein the fuse is substantially filled with arc quenching insulating oil.

10. A fuse according to claim 7 wherein the fuse is substantially filled with arc quenching insulating oil, and further includes

a trigger circuit initiating initiatin more rapid circuit interruption comprising means for effectively sensing the current in said fusible element, and circuit means responsive to the sensing of a predetermined excessive current level for discharging supplementary electrical energy through a localized portion of said aluminum-palladium ribbon.