Circuit breakers with moving contact arm with spaced apart contacts

Patent metadata

Field	Value
Publication number	US-9697975-B2
Application number	US-201514698192-A
Country	US
Kind code	B2
Filing date	Apr 28, 2015
Priority date	Dec 3, 2014
Publication date	Jul 4, 2017
Grant date	Jul 4, 2017

Abstract

Circuit breakers with moving contacts having a rocking movement, e.g., heel-toe action, are configured to direct arcing across one of two (first and second) spaced apart contacts on a moving arm to an adjacent arc chute to thereby alleviate deterioration due to arcing and improve conductivity of the first moving contact over time.

First claim

That which is claimed:

1. A circuit breaker comprising:
an arc chute;
a pivotable handle;
a moveable contact arm, the contact arm having first and second cooperating arm members pivotably attached together, wherein the second arm member can move inward, outward and up and down relative to the first arm member, the first arm member having a first end portion attached to the pivotable handle and having a longitudinally spaced apart second end portion attached to the second arm member, the second arm member comprising a free end portion with first and second spaced apart electrical contacts, and wherein, with the handle oriented above the moveable contact arm, the first and second electrical contacts of the second arm member reside inside or adjacent and above the arc chute, with the second electrical contact below the first electrical contact; and
a mechanism spring having an inwardly extending end portion attached to the first arm member at a location that is spaced apart from the second end portion of the first arm member that is attached to the second arm member,
wherein the second arm member is configured to translate the first and second electrical contacts in a rocking action so that the first electrical contact moves away from a first stationary contact after the second electrical contact engages a second stationary contact immediately prior to an arcing event, wherein, with the handle oriented to be above the moveable contact arm, the first electrical contact is held by the second arm member above the second electrical contact facing the first stationary contact and the second electrical contact is held by the second arm member facing the second stationary contact, wherein, when a contact surface of the first electrical contact is in physical contact with the first stationary contact or a contact surface of the second electrical contact is in physical contact with the second stationary contact, planes drawn parallel to the contact surface of the first electrical contact and the contact surface of the second electrical contact intersect at a location between the first and second electrical contacts of the second arm member,
wherein the second arm member has a shape that places the free end of the second arm member a distance forward of the second end portion of the first arm member, and
wherein, in operation, (i) the second arm member moves relative to the first arm member to position the first electrical contact surface forward of the second electrical contact to contact the first stationary contact in an ON position of the circuit breaker for a first electrical contact only contact position and (ii) the second arm member moves relative to the first arm member to position the second electrical contact surface forward of the first electrical contact to contact the second stationary contact for a second electrical contact only contact position when the contact arm rotates toward an OFF position to thereby direct arcs across only the second electrical contact.

2. The circuit breaker of claim 1 , wherein a lower end portion of the first arm member is pivotably directly attached to an upper end portion of the second arm member or is directly attached to a sleeve with a slot that is directly attached to the upper end portion of the second arm member to provide the pivotable attachment, and wherein the circuit breaker further comprises a link that extends from a top portion of the first arm member to the second arm member above the first and second contacts to rotate the second arm member and facilitate a rocking action when the first arm member starts to rotate.

3. The circuit breaker of claim 1 , wherein the second electrical contact of the second arm member resides closer to a lower portion of the arc chute than the first electrical contact and angles downward, wherein the first electrical contact is a continuous use contact, and wherein the second electrical contact engages the second stationary contact while the first electrical contact is spaced apart from the first stationary contact when the contact arm moves toward an “OFF” position and/or in an opening position to thereby direct arcing into the arc chute.

4. The circuit breaker of claim 1 , further comprising a single planar coupler with a curvilinear perimeter directly affixed to the first arm member, the coupler having a slot, wherein the second arm member comprises a slot, and wherein the slot of the coupler and the slot of the second arm member are aligned with a pin extending therethrough and allow the pin to travel inward, outward, upward and downward while the pin remains in the slots to place the second arm member and first and second electrical contacts in different positions to thereby provide the inward, outward, up and down movement of the second arm member relative to the first arm member.

5. The circuit breaker of claim 1 , wherein the first and second electrical contacts both reside in front of the mechanism spring closer to the arc chute than the mechanism spring, wherein the first arm member applies a downwardly extending force vector to the second arm member, the circuit breaker further comprising a resilient member extending down from the first arm member to reside behind the second arm member, and wherein the resilient member applies an upwardly extending force vector to the second arm member.

6. The circuit breaker of claim 5 , wherein the first arm member has a lower end portion with a curvilinear perimeter that faces the upper end of the second arm member, and wherein there is a curvilinear space between the lower end portion of the first member and the upper end of the second arm member, and wherein the circuit breaker further comprises a spring attached to the lower end portion of the first arm member spaced apart from the mechanism spring that transmits the downwardly extending first force vector to the second arm member.

7. The circuit breaker of claim 1 , further comprising a resilient member that extends down from a back surface of the first arm member to reside behind a back surface of the second arm member, wherein the resilient member has first and second linear segments with the second linear segment angularly extending between about 100-160 degrees from the first linear segment, and wherein the first linear segment is attached only to the first arm member and the second linear segment contacts the back surface of the second arm member.

8. The circuit breaker of claim 1 , wherein the second arm member holds the first electrical contact on one corner that resides closer to the handle than the second electrical contact, wherein the second arm member has a downwardly extending leg that holds the second electrical contact below the first electrical contact, and wherein the leg projects outwardly a greater distance than the corner from a primary body of the second arm member.

9. The circuit breaker of claim 1 , wherein the first and second electrical contacts are spaced apart from each other from about 0.030 inches to about 0.234 inches, and wherein the second contact arm member has a primary body shape with a perimeter that extends inward between the first and second electrical contacts to define an open space with a valley medially between the first and second electrical contacts.

10. The circuit breaker of claim 1 , wherein the second arm member comprises an upwardly extending slot, and wherein the circuit breaker further comprises a planar coupler that is directly attached to the first arm member and has an elongate slot, and wherein the coupler slot and the second arm member slot engage a pin that allows the second arm member to move relative to the first arm member through defined positions with the inward, outward, up and down movements.

Assignees

• Eaton Corp

Inventors

• Maloney James Gerard
• Betances Sansur Luis Enrique

Classifications

• H01H9/38 Primary

  Auxiliary contacts on to which the arc is transferred from the main contacts (using arcing-horns H01H9/46) · CPC title

• H01H73/04

  Contacts · CPC title

• H01H1/225

  the supporting member being pivotable · CPC title

• H01H71/2472 Primary

  with rotatable armatures · CPC title

• H01H71/02

  Housings; Casings; Bases; Mountings · CPC title