CIRCUIT BREAKER WITH BIMETALLIC ELEMENT

• US 3,593,249 A
• Filed: 05/22/1969
• Issued: 07/13/1971
• Est. Priority Date: 05/22/1969
• Status: Expired due to Term

• Current Assignee: Allan R. Sedgwick
• Original Assignee: Allan R. Sedgwick
• Inventors: Sedgwick, Allan R.
• Application Number:
  US04/826,866
• Time in Patent Office: 782 Days
• US Class Current: 337/113
• CPC Class Codes: H01H 2071/088 Terminals for switching devices which make the devices interchangeable, e.g. with fuses
• CPC Class Codes: H01H 71/162 with compensation for ambient temperature
• CPC Class Codes: H01H 73/30 reset by push-button, pull-knob or slide

Abstract

A circuit breaker device of relatively small, compact and simple construction and which may be used as a direct replacement for typical small cartridge fuses currently used in electronic and electrical equipment. The device includes a housing having metal end caps thereon. A spring-biased plunger is coupled with a bimetal strip assembly having a contact on an end thereof, the plunger being electrically coupled with one end cap. The contact normally is coupled with another contact which is electrically connected with the second cap. Current flows through the device from one end cap to the other, and upon the occurrence of current above a predetermined value, at least a portion of the bimetal strip assembly flexes thereby releasing the top contacts. This allows the plunger to withdraw the strip assembly and break the electrical circuit. The bimetal strip assembly may include an ambient temperature compensating section.

Claims

1. A compact circuit breaker device comprising a body member formed of electrical insulating material and having first and second electrical conductors coupled with the ends thereof defining the ends of a current path through said device, the first of said conductors having an opening therein, an elongated plunger member extending into the opening in said first electrical conductor and reciprocable axially within said body member for resetting the device, bimetal strip assembly means affixed to an end of said plunger within said body member, said bimetal strip assembly means including at least a bimetal strip having an electrical contact thereon, spring contact means coupled with said end of said plunger and providing an electrical current path from said first electrical conductor through said bimetal strip to said contact thereon, and a clip member having a contact thereon coupled with said second electrical conductor, said contacts on said bimetal strip and said clip member being normally engaged, but being caused to disengage upon the occurrence of a predetermined current through the first and the second of said electrical conductors and through said bimetal strip.

2. A compact circuit breaker device having an external configuration and dimensions similar to a conventional cartridge-type fuse comprising a body member formed of electrical insulating material and having metal end caps coupled therewith, one of said end caps having an opening therein, a plunger member extending through said opening in said one cap, a bimetal strip assembly coupled with an end of said plunger within said body member, said bimetal strip assembly including at least a bimetal strip having an electrical contact thereon, guide means mounted within said body member and electrically coupled with said one end cap, spring contact means coupled with said end of said plunger and engaging said guide means, and a second electrical contact coupled with the second of said end caps and mounted within said body for engagement with said electrical contact on said bimetal strip.

3. A circuit breaker device as in claim 2 wherein said bimetal strip assembly comprises an ambient compensating bimetal strip having a first end coupled with said first end of said plunger and having a second end coupled with said first named bimetal strip and electrically insulated therefrom, the second end of said first named bimetal strip having said first electrical contact thereon.

4. A circuit breaker device as in claim 3 including heater means mounted about said bimetal strip for heating said bimetal strip upon the occurrence of a current through said breaker device above a predetermined value.

5. A compact circuit breaker device comprising a body member formed of electrical insulating material and having electrically conductive caps on the ends thereof, a first of said caps having an opening therein, plunger means extending into the opening in said first cap, bimetal strip assembly means coupled with a first end of said plunger within said body member, said bimetal strip assembly means including at least a bimetal strip having a first electrical contact thereon, electrical conductor means coupled between said first end of said plunger and said first cap, a second electrical contact, said second electrical contact being electrically coupled with the second of said caps and positioned to allow engagement therewith of said first electrical contact, and a clip member having said second electrical contact thereon, said clip member being electrically coupled with said second cap, said second cap including means for varying the position of said clip member for setting the current tripping level of said breaker device.

6. A compact circuit breaker device comprising a body member formed of electrical insulating material and having electrically conductive caps on the ends thereof, a first of said caps having an opening therein, plunger means extending into the opening in said first cap, bimetal strip assembly means coupled with a first end of said plunger within said body member said bimetal strip assembly means including at least a bimetal strip having a first electrical contact thereon, electrical conductor means coupled between said first end of said plunger and said first cap, guide means coupled with said first cap and extending into said body member, said electrical conductor means comprising a pair of spring contacts mounted on said first end of said plunger and extending into engagement with said guide means, and a second electrical contact, said second electrical contact being electrically coupled with the second of said caps and positioned to allow engagement therewith of said first electrical contact.

7. A compact circuit breaker device having an external configuration and dimensions similar to a conventional cartridge-type fuse comprising a body member formed of electrical insulating material and having metal end caps coupled therewith, one of said end caps having an opening therein, a plunger member extending through said opening in said one cap, a bimetal strip assembly coupled with an end of said plunger within said body member, said bimetal strip assembly including at least a bimetal strip having an electrical contact thereon, guide means mounted within said body member and electrically coupled with said one end cap said guide means comprising a pair of channel members extending into said body, spring contact means comprising a pair of spring contacts respectively engaging said channel members, and a second electrical contact coupled with the second of said end caps and mounted within said body for engagement with said electrical contact on said bimetal strip.

8. A circuit breaker as in claim 7, including electrical heater means mounted in a series with and about said bimetallic strip for heating said bimetallic strip upon the occurrence of a current through said breaker device above a predetermined value.

9. A compact circuit breaker device comprising an elongated body member formed of electrical insulating material and having first and second electrical conductors coupled with the ends thereof defining the ends of a current path through said device, said body member and electrical conductors having a configuration, size and appearance similar to a cartridge fuse, the first of said conductors having an opening therein, an elongated plunger extending into the opening in said first electrical conductor and reciprocal axially within said body member for resetting the device, said plunger member being capable of movement in the direction of the axis of said body member automatically upon a current overload from a set position to an unset position and manually from the unset to the set position, guide means physically retained within said body member and electrically connected with said first electrical conductor, spring contact means within said body member and coupled with an internal end of said plunger member extending within said body member, said spring contact means engaging said guide means for reciprocally guiding said internal end of said plunger member within said body member and electrically coupling said internal end of said plunger member through said guide means with said first electrical conductor, said spring contact means having a pair of contact members, first contact latch means electrically connected to the second of said electrical conductors and positioned within said body member, second contact latch means positIoned within said body member and normally engaging said first contact latch means when said device is in the set position, said second contact latch means being electrically connected through said spring contact means and said guide means to said first electrical conductor and physically connected to said internal end of said plunger member, one of said contact latch members including a bimetallic strip which flexes upon current overload to move said one contact latch member from a latched position to an unlatched position with respect to the other contact latch member for allowing said plunger member to move to said unset position, and means normally urging said plunger member in an axial direction to said unset position whereby excessive current passing through said device causes a heating of said bimetallic strip, resulting flexing of said strip, and unlatching of said first and second contact latch means and an axial movement of said plunger from its set position to an unset position.