Temperature controlled circuit interrupter

• US 5,995,350 A
• Filed: 06/24/1998
• Issued: 11/30/1999
• Est. Priority Date: 06/24/1998
• Status: Expired due to Fees

• Current Assignee: BSafe Electrix, Inc.
• Original Assignee: Robert Z. Kopelman
• Inventors: Kopelman, Robert Z.
• Primary Examiner(s): JACKSON, STEPHEN W
• Application Number:
  US09/104,455
• Time in Patent Office: 524 Days
• Field of Search: 361/103-106, 361/115, 337/103, 337/113
• US Class Current: 361/103
• CPC Class Codes: H01H 1/504 by thermal means
• CPC Class Codes: H02H 3/04 with warning or supervision in addition to disconnection, e.g. for indicating that protective apparatus has functioned watching of pilot wires H02H1/0084; protection of protective arrangements H02H7/008; indication of the state of electronic switches H03K17/18
• CPC Class Codes: H02H 5/047 using a temperature responsive switch

Abstract

A temperature sensitive circuit interrupting arrangement includes a temperature controlled relay that will open to disconnect a load, such as a common household appliance or utensil, from a power source when the amount of heat produced by any one of a plurality of electrically conductive items coupling power from the power source to the load causes a sensed temperature to rise above a pre-determined safety limit temperature. The rise in the sensed temperature may be due to a poor (resistive) contact, an over-current condition due to a malfunction of the load, or other common causes. The circuit interrupting arrangement may be incorporated in many forms of electrical devices including male plugs, female sockets, switches, dimmers, multi-outlet power strips, power cords, and ground fault interrupters.

Claims

1. A heat sensing circuit interrupter to enable a load to be selectively coupled to or disconnected from a power source in accordance with a level of a sensed temperature, the power source connected to the load with current carrying conductors including at least a hot conductor and a neutral conductor, the hot conductor having a hot conductor source side and a hot conductor load side, the circuit interrupter comprising:

a) a temperature controlled relay operable between a closed state when the sensed temperature is below a predetermined limit temperature, thereby enabling the coupling of the load to the power source by connecting the hot conductor source side and hot conductor load side, and an open state when the sensed temperature is above the predetermined limit temperature, thereby electrically disconnecting the load from the power source by disconnecting the hot conductor load side from the hot conductor source side;

b) the temperature controlled relay configurable to cool when in the open state due to a loss of heat resulting from an interruption of a flow of current through at least one of a plurality of electrically conductive means employed to couple the load to the power source, and once the temperature controlled relay is of a temperature that is below the predetermined limit temperature, the relay re-assumes the closed state thereby enabling reconnection of the load to the power source; and

c) thermal conduction means employed to thermally couple the temperature controlled relay to the current carrying conductors to enable heat produced thereby to be sensed by the temperature controlled relay.

2. The circuit interrupter according to claim 1, wherein the circuit interrupter is configured to maintain the temperature controlled relay in the open state until the power source is electrically disconnected therefrom to enable cooling of the relay to a temperature below the predetermined limit temperature, so as to cause the temperature controlled relay to again assume the closed state.

3. The circuit interrupter according to claim 2, wherein the temperature controlled relay is maintained in the open state by heat produced by a resistive heating element proximal to the relay that is energized when the temperature controlled relay is in the open state.

4. The circuit interrupter according to claim 2, wherein the temperature controlled relay is suitably situated proximal to each of the plurality of current carrying conductors that are employed to couple the load to the power source, and wherein the plurality of current carrying conductors include a ground connector.

5. The circuit interrupter according to claim 4, wherein the thermal conduction means comprises, at least in part, a volume of a thermally conductive potting material employed to thermally couple at least a portion of each of a plurality of the current carrying conductors to the temperature controlled relay.

6. The circuit interrupter according to claim 5, wherein the potting material is provided by a thermal epoxy.

7. The circuit interrupter according to claim 1, further including an indication means to indicate when the load has been electrically disconnected from the power source as a result of the sensed temperature rising above the predetermined limit temperature.

8. The circuit interrupter according to claim 7, wherein the temperature controlled relay is maintained in the open state by heat produced by a resistive heating element proximal to the relay that is energized when the temperature controlled relay is in the open state, and wherein the indication means that indicates when the load has been disconnected from the power source further indicates the need to disconnect the circuit interrupter from the power source to enable the temperature controlled relay to cool and return to the closed state.

9. The circuit interrupter according to claim 8, wherein the indication means is provided by at least one of:

a) an audio sounder that emits an audio alarm, either continually or intermittently, to alert nearby persons; and

b) a light emitting element that is observable by a nearby person.

10. A heat sensing circuit interrupter that is interposed between a load and a power source, and arranged to sense an increase in temperature, either directly or indirectly, by sensing heat produced by the flow of current through any of a plurality of current carrying conductors which couple the load to the power source, the current carrying conductors including a hot conductor and a neutral conductor, the circuit interrupter comprising:

a) a thermal relay assembly including a temperature controlled relay configured to close and enable the coupling of the load to the power source when a sensed temperature associated with at least one of the current carrying means is below a predetermined limit temperature, and open to disconnect the load from the power source by disconnecting-the hot conductor when the sensed temperature rises above the predetermined limit temperature, all current carrying conductors extending through the thermal relay assembly;

b) the thermal relay assembly configured to maintain the temperature controlled relay open with an occurrence of an over-temperature event until the power source is electrically disconnected from the thermal relay assembly to enable sufficient cooling thereof, at which point the temperature controlled relay will close; and

c) thermal conduction means arranged to enable heat produced by any of the electrical current carrying conductors to be sensed by the temperature controlled relay.

11. The circuit interrupter according to claim 10, wherein the temperature controlled relay is suitably situated proximal to portion of each of a plurality of current carrying conductors composing, at least in part, the current carrying means, which are employed to couple the load to the power source to enable the relay to readily sense heat resulting from the flow of current through any of the current carrying means.

12. The circuit interrupter according to claim 11, wherein the temperature controlled relay is positioned immediately adjacent to a portion of each of the plurality of current carrying conductors.

13. The circuit interrupter according to claim 10, further including an indication means to indicate when the load has been disconnected from the power source as a result of the sensed temperature rising above the predetermined limit temperature, and to possibly further indicate the need to disconnect the power source from the temperature controlled relay to enable the temperature controlled relay to cool and close.

14. The circuit interrupter according to claim 10, wherein the thermal conduction means is provided by a material that is not electrically conductive.

15. The circuit interrupter according to claim 14, wherein the thermal conduction means is provided by air.

16. The circuit interrupter according to claim 10, wherein the thermal conduction means comprises a potting material that is employed to thermally couple at least a portion of each of the plurality of the current carrying conductors to the temperature controlled relay.

17. The circuit interrupter according to claim 16, wherein the thermal conduction material is provided by a thermal epoxy.

18. The circuit interrupter according to claim 10, wherein the temperature controlled relay is maintained open by heat produced by a resistive heating element proximal to the temperature controlled relay that is energized when the relay opens.