INDUCTIVE HEATING MEANS FOR THERMAL TRIP DEVICE

• US 3,808,572 A
• Filed: 07/12/1973
• Issued: 04/30/1974
• Est. Priority Date: 07/12/1973
• Status: Expired due to Term

• Current Assignee: Siemens-Allis, Inc. (Siemens AG)
• Original Assignee: George Gaskill
• Inventors: Gaskill, George
• Primary Examiner(s): Broome, Harold
• Application Number:
  US05/378,416
• Time in Patent Office: 292 Days
• Field of Search: 337/106,40
• US Class Current: 337/106
• CPC Class Codes: H01H 71/7427 Adjusting only the electrothermal mechanism

Abstract

A transformer type heater for the bimetal trip element of a circuit breaker is provided with an auxiliary magnetic structure including means for diverting heating energy from the transformer secondary to a power dissipating means to thereby control the heating energy acting to heat the bimetal. The power dissipating means consists of a lumped resistor, the value of which may be controlled or set very readily within required tolerances, thereby facilitating the production of an accurately calibrated circuit breaker thermal trip means.

Claims

1. A circuit interrupter having automatic trip means comprising transformer means including a core structure, primary means and secondary means both magnetically coupled to said core, thermal trip means mounted in heat conducting relationship with respect to said secondary means, an auxiliary magnetic structure magnetically coupled to said core structure and including power dissipating means diverting heating energy from said secondary means to control the heating energy acting on the thermal trip means.

2. A circuit interrupter as set forth in claim 1 in which the power dissipating means includes a circuit having a power resistance therein.

3. A circuit interrupter as set forth in claim 2 in which the value of the resistance is adjustable to control the magnitude of heating energy diverted from said secondary means.

4. A circuit interrupter as set forth in claim 2 in which the auxiliary magnetic structure includes an auxiliary secondary means through which the circuit is coupled to the secondary means.

5. A circuit interrupter as set forth in claim 4 in which the resistance is lumped.

6. A circuit interrupter as set forth in claim 5 in which the value of the resistance is adjustable to control the magnitude of heating energy diverted from said secondary means.