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US 6,388,553 B1Granted
Conductive polymer current-limiting fuse
AssigneeEaton Corporation
InventorsJohn J. Shea, William K. Hanna
Life of this patent
Estimating the term…
Abstract
Conductive polymer current-limiting fuses. when connected in series with conventional mechanical circuit breakers, exhibit extremely low let-through values. Particularly, conductive polymer current-limiting fuses based on conductive elastomeric material are disclosed which exhibit extremely low let-through values, namely less than 5,000 A2s with a switch current of 1.79 kAp, preferably less than 2,500 A2s, most preferably no more than 2,250 A2s.
Claims5
A current limiting fuse, comprising:
- a body of an electrically conductive, PTC composition, wherein the body defines two substantially parallel surfaces;
- a plurality of electrodes for carrying current through the body, wherein at least one of the plurality of electrodes is in free contact with one of the parallel surfaces;
- a commutation shunt;
- a pressure mechanism which maintains a force perpendicular to the parallel surfaces which force presses the electrodes against the substantially parallel surfaces, wherein the fuse exhibits let through values of less than 5,000 A2s with a switch current of 1.79 kAp;
- wherein the pressure mechanism comprises:
- a cylindrical tube with two open ends, wherein the body is disposed within the cylindrical tube with the parallel surfaces facing the open ends of the tube;
- wherein the plurality of electrodes comprise two threaded copper electrodes each having a silver plated surface for contacting the body;
- and
- wherein the cylindrical tube has groves adjacent the two open ends for threadably engaging the two threaded copper electrodes whereby the two threaded copper electrodes may be threaded into the cylindrical tube and brought to bear against the body.
6 more elements
Dependencies are inferred from the claim text.