Claims
- 1. A circuit protection device to be connected into a circuit presenting a given load resistance, the circuit protection device comprising:
- first and second terminals to be electrically connected into the electrical circuit, each terminal comprising a current carrying extension, a terminal blade and a female-style terminal extension;
- flexible conductive current-feeding arms having inner and outer end portions, the inner end portions thereof being electrically connected respectively to the current-carrying extensions of the terminals, the outer end portions of said current-feeding arms being cantilevered and flexible with respect to the inner end portions thereof; and,
- a PTC current-limiting element positioned between the flexible outer end portions of the current-feeding arms, the PTC element including a layer of a PTC material having conductive opposite faces, the conductive opposite faces being in electrical contact with the flexible outer end portions of the current-feeding arms so that the PTC material carries current between the outer end portions of the current-carrying arms, the PTC material conducting a given range of currents presenting a given low resistance value and when current flow therethrough reaches a given trip level, the resistance thereof increases to a high resistance value to limit current in the circuit, wherein each of the current-feeding arms and the associated current-carrying extension and terminal blade thereof are cut from a single piece of metal.
- 2. The circuit protection device of claim 1, wherein both of said current-feeding arms and the associated current-carrying extensions and terminal blades thereof are cut from the same piece of metal.
- 3. The circuit protection device of claims 1 or 2, wherein the associated terminal blades and current-carrying extensions thereof are cut from a thick portion of the single plate of metal and the current-feeding arms are cut from a thin portion of the single plate of metal.
- 4. A circuit protection device to be connected into a circuit presenting a given load resistance, the circuit protection device comprising:
- first and second terminals, each terminal comprising a current-carrying extension, a terminal blade, and a female-style terminal extension;
- flexible current-feeding arms cantilevered and projecting in opposite directions from the current-carrying extensions of the terminals, respectively;
- a PTC element electrically connected between the current-feeding arms so that the PTC element carries current flowing between the terminals, when a normal current passes between the terminals, the PTC element has a low resistance and, when heated by the passage of a higher trip current passing between the terminals, the PTC element will expand to flex the current-feeding arms, permitting the PTC element to have a large resistance and limit current flow in the circuit; and,
- a housing having an opening to allow access to the female-style terminal extensions.
- 5. The circuit protection device of claim 4, wherein the current-feeding arms are spaced from the housing a sufficient distance such that the current-feeding arms will not contact the housing during expansion of the PTC element.
- 6. The circuit protection device of claim 4, wherein the housing comprises a top portion and a bottom portion, the top portion having a plurality of tabs which mate with corresponding openings in the bottom portion to secure the top and bottom portions of the housing around the terminals, the current feeding arms and the PTC element.
- 7. A circuit protection device to be connected into a circuit presenting a given load resistance, the circuit protection device comprising:
- first and second terminals, each terminal comprising a current-carrying extension, a terminal blade, and a female-style terminal extension;
- flexible current-feeding arms having inner and outer end portions, the inner end portion of the current-feeding arms respectively being electrically connected to the current-carrying extensions;
- a plurality of PTC elements positioned between the current-feeding arms, at least two of the PTC elements connected in parallel to one another; and,
- the first and second terminals, the flexible current-feeding arms and the plurality of PTC elements contained within a housing, and wherein there is located, between the plurality of PTC elements, a heat sink-forming body in electrical and thermal contact with one of the current-feeding arms.
- 8. The circuit protection device of claim 7, wherein when a normal current passes through the plurality of PTC elements, the PTC elements have a low resistance, and when a higher trip current which is to be limited by the circuit protection device flows through the plurality of PTC elements, the PTC elements expand causing the current-feeding arms to flex and the resistance of the PTC elements to increase to a high resistance, thus limiting current flow in the circuit in which the device is connected.
- 9. The circuit protection device of claim 7, wherein the plurality of PTC elements includes two outermost PTC elements and each of the current-feeding arms forms a substantially Z-shaped member, each Z-shaped member including an intermediate section and outer sections extending in opposite directions at opposite ends of the intermediate section, one of the outer sections of one of the Z-shaped members extending along and being electrically connected to one of the outermost PTC elements and one of the outer sections of the other Z-shaped member extending along and being electrically connected to the other outermost PTC element.
- 10. A circuit protection device to be connected into a circuit presenting a given load resistance, the circuit protection device comprising:
- first and second terminals, each terminal comprising a current-carrying extension, a terminal blade, and a female-style terminal extension;
- a pair of flexible skived electrodes having inner and outer end portions, the inner end portions thereof being electrically connected respectively to the current-carrying extensions of the terminals, the outer end portions of the flexible skived electrodes being cantilevered and flexible with respect to the inner end portions thereof; wherein the flexible skived electrodes have a microgrooved inner surface, and
- a PTC element sandwiched between and in electrical contact with the flexible skived electrodes so that the PTC element carries current between the flexible skived electrodes, the PTC element conducting a given range of currents presenting a given low resistance and when current flow therethrough reaches a given trip level the resistance thereof increases to a high resistance value to limit current in the circuit.
- 11. The circuit protection device of claim 10, wherein when current flow through the PTC element reaches a given trip level, the PTC element expands, causing the skived electrodes to flex.
RELATED APPLICATIONS
This application is a continuation-in-part of U.S. application Ser. Nos. 08/474,331, filed on Jun. 7, 1995, now U.S. Pat. No. 5,682,130, and 08/480,124, also filed on Jun. 7, 1995, now U.S. Pat. No. 5,663,861.
US Referenced Citations (16)
Foreign Referenced Citations (2)
Number |
Date |
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0 242 902 A2 |
Oct 1987 |
EPX |
0 259 179 A2 |
Mar 1988 |
EPX |
Related Publications (1)
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Date |
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480124 |
Jun 1995 |
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Continuation in Parts (1)
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474331 |
Jun 1995 |
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