Push-to-trip high-amp circuit breaker

5,004,994

07/528,312

May 24, 1990

A low voltage high-amp circuit breaker (20) having a substantially reactangular bimetallic bistable element (41). The bistable element is attached to have one end move from a first normal electrically conductive position to a second non-electrically conductive position. The manual reset circuit breaker includes a manual reset lever (29) and a non-conductive heat resistant extension blade (64) connected to the reset lever via a rotatable shaft (56). The extension blade being positioned adjacent the moveable end of the bistable element and when the element is moved to its second position, the blade is moved to prevent the element from returning to its first conductive position until the circuit breaker is manually reset. A push-to-trip button (80) pushes plate (88) downward causing fingers (84) to move upward lifting bracket (92) to deform bistable element (41) placing the breaker in an open circuit condition.

Korczynski, Jacek M. (Niles, IL); Stack, Thomas J. (Chicago, IL)

Cooper Industries, Inc. (Houston, TX)

What is claimed is

1. A high amperage circuit breaker comprising

a pair of spaced terminals being placed in series with the circuit to be protected;

a heat resistant electrical insulating plastic housing defining a body cavity, said body cavity having a base, a front wall, a rear wall and two side walls

a cover to close said housing;

a rectangular thermally activated bistable mechanical element in said cavity, at least one dimple formed on said bistable element;

a first contact being connected to one of said terminals, said first contact also connected to one end of said bistable element by means wherein the one end of said bistable element always remains stationary with respect to the first contact and in electrical contact with the first contact;

a second electrical contact attached to the other end of said bistable element;

said other end of said bistable element being free to move in a relatively vertical direction;

a third contact electrically connected to said other terminal and being positioned relative to said second contact wherein said second and third contact are normally in electrical contact with each other when the bistable element is in a first position, and said first position being to close the circuit of the circuit breaker;

said bistable element having a predetermined current response to quickly deflect when there is a predetermined over current, said deflection causing said other end of said bistable element to move from said first position to a second position and to cause said second contact to separate from said third contact by a predetermined distance to open the circuit of the circuit breaker;

a reset mechanism to maintain the predetermined distance between said second contact and said third contact until the circuit breaker is manually reset; and

a manual trip means to open the circuit of the circuit breaker.

2. The circuit breaker of claim 1 wherein the bistable element has at least two dimples formed on the upper face and adjacent opposite sides of said bistable element, and said bistable element having a length greater than a width with said width being greater than 1/2 width.

3. The circuit breaker of claim 2 wherein;

a vertical plane passing through a center of said first contact and a center of said contact is perpendicular to a vertical plane passing through centers of said pair of dimples.

4. The circuit breaker of claim 3 wherein;

said first contact being connected to said one end of said bistable element by mechanical stake joint; and

said second electrical contact attached to and extending from the underside of the other end of said bistable element.

5. The circuit breaker of claim 2 wherein the circuit breaker is a manual-reset, low voltage, DC, high-amp, surface mounted circuit breaker.

6. The breaker of claim 2 wherein the circuit breaker is a manual-reset, low voltage, DC, high-amp, through surface mounted circuit breaker.

7. The circuit breaker of claim 1 wherein said circuit breaker is a manual-reset breaker comprising;

a plastic rotatable shaft having one end rotatably mounted in the said cavity base;

said shaft other end extending out of said cover for a predetermined distance;

a pair of longitudinally spaced first and second integral bars extending from said rotatable shaft;

said second bar extending a predetermined distance from said first bar and being sized to provide predetermined electrical insulation, said second bar being in contact with the outer surface of said second contact when the electrical circuit is closed;

a spring attached to said first bar and said housing, said spring exerting a rotational force on said plastic shaft to urge the second bar in contact with and toward said second contact;

wherein when said second and third contacts are separated said shaft rotates to position said second bar between said second and third contacts and electrically separates said second and third contacts from each other.

8. The circuit breaker of claim 2 wherein said circuit breaker is a manual-reset breaker comprising;

said shaft's other end extending out of said cover for a predetermined distance;

9. The circuit breaker of claim 1 wherein;

a blind hole is defined by said cavity base adjacent said rear wall;

said rotatable shaft having said one end rotatably mounted in said blind hole;

said first bar being adjacent the top of said housing;

said second bar being paddle shaped;

10. A circuit breaker as in claim wherein said trip means comprises;

a button;

a plate which is rotatably connected to fingers, such that when said button forces said plate downward said fingers move upward;

a bracket connected to said bistable element near said second contact and interconnected with said fingers so that when said fingers move upward, said bracket moves upward causing said bistable element to deform, opening said second and third contact.

11. A high amperage manual reset D.C. circuit breaker comprising;

a heat resistant electrical insulating plastic housing defining a rectangular central body cavity, with a base, front wall, a rear wall and two side walls;

a blind hole defined by said cavity base adjacent said rear wall;

a pair of spaced terminal bolts extending through said base with a pair of contact nuts being external of said housing, said spaced terminals being placed in series with the circuit to be protected;

an insulating plastic rotatable shaft having one end rotatably mounted in said blind hole and the other end extending out of said housing for a predetermined distance;

a seal placed between said housing and said cover to seal said cover to said housing;

means to permanently attach said cover to said shaft;

a seal ring attached to said cover and said shaft;

a paddle shaped bar extending a predetermined distance from said first bar, said second bar having a relatively straight side, said second bar being sized to provide predetermined electrical insulation.

a generally rectangular thermally activated bistable mechanical element, a pair of dimples formed on an upper surface of and adjacent opposite sides of said bistable element;

a first contact being connected to one of said terminals, said first contact also connected to end of said bistable element by a washer and a mechanical stake joint wherein the one end of said bistable element always remains stationary with respect to the first contact and in electrical contact with the first contact;

a second electrical contact attached to and extending from the underside of the other end of said second electrical contact;

a vertical plane passing through a center of said first contact and a center of said second contact being perpendicular to a vertical plane passing through centers of said pair of dimples;

a third contact electrically connected to said other terminal and being positioned below said second contact, said second and third contact normally begin in electrical contact with each other to close the circuit of the circuit breaker;

said second bar having its side in contact with the outer surface of said second contact when the electrical circuit is closed;

a spring attached to said first bar and said housing, said spring exerting a rotational force on said plastic shaft to urge the second bar in contact with said second contact and toward said second contact;

said bistable element having a predetermined current response to quickly deform when there is a predetermined over current, said deformation causes said other end to vertically rise and to cause said second contact to separate from said third contact by a predetermined distance;

wherein said second and third contacts are separated said spring rotates to position said second bar between said second and third contacts and electrically separate second and third contacts from each other; and

a manual trip means to cause said bistable element to deform, said deformation causes said second contact to separate form said third contact.

337/66; 337/68

H01H 7116

2720416 October 1955 Raleigh
3723929 March 1973 Sitar
4814739 March 1989 Moldovan

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