Moveable contact arm releases latch plate engagement in a circuit breaker

Patent metadata

Field	Value
Publication number	US-9576753-B2
Application number	US-201514740545-A
Country	US
Kind code	B2
Filing date	Jun 16, 2015
Priority date	Jun 16, 2015
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

A contact system of a circuit breaker includes a fixed contact. The contact system also includes a moveable contact arm assembly comprising at least one moveable contact arm having a moveable contact thereon, the moveable contact arm moveable to define a closed condition and a blow open condition. The contact system further includes a carrier assembly operatively coupled to the moveable contact arm. The contact system yet further includes a latch plate operatively coupled to the carrier assembly. The contact system also includes a trip shaft operatively coupled to the carrier assembly, the trip shaft having a non-circular region defining an engagement surface disposed in contact with the latch plate in the closed condition. The contact system further includes a biasing portion of the moveable contact arm configured to rotate the trip shaft out of engagement with the latch plate and into the blow open condition.

First claim

What is claimed is:

1. A contact system of a circuit breaker comprising:
a fixed contact;
at least one moveable contact arm assembly comprising a moveable contact arm having a moveable contact thereon, the moveable contact arm moveable to position the moveable contact into engagement with the fixed contact to define a closed condition and out of engagement with the fixed contact to define a blow open condition;
a carrier assembly operatively coupled to the moveable contact arm;
a latch plate operatively coupled to the carrier assembly;
a trip shaft operatively coupled to the carrier assembly, the trip shaft having a non-circular region defining an engagement surface disposed in contact with the latch plate in the closed condition; and
a biasing portion of the moveable contact arm disposed proximate the trip shaft in the closed condition and configured to rotate the trip shaft out of engagement with the latch plate and into the blow open condition.

2. The contact system of claim 1 , wherein the non-circular region comprises a semi-circular geometry, the engagement surface of the non-circular region comprising a curved portion of the semi-circular geometry.

3. The contact system of claim 1 , wherein the biasing portion of the moveable contact arm comprises a protrusion extending from the moveable contact arm toward the trip shaft.

4. The contact system of claim 1 , wherein the contact system retains the contacts in the closed condition at electromagnetic force levels lower than a threshold level and moves the circuit breaker into the blow open condition upon reaching the threshold level.

5. The contact system of claim 1 , wherein the moveable contact arm comprises a first end and a second end, the moveable contact arm pivotable about an axis located proximate the second end.

6. The contact system of claim 5 , wherein the moveable contact disposed on the moveable contact arm is located closer in proximity to the first end than the second end of the moveable contact arm.

7. The contact system of claim 5 , wherein the carrier assembly is operatively coupled to the moveable contact arm with a carrier shaft positioned coaxially with the axis located proximate the second end of the moveable contact arm.

8. A circuit breaker having a mechanism portion, a contact system portion and an arc chamber portion, the circuit breaker comprising:
a first coupling member operatively coupled to a drive link of the mechanism portion, the first coupling member rotatable about a first shaft;
a second coupling member pivotably coupled to the first coupling member and to a second shaft;
a plurality of fixed contacts;
a moveable contact arm assembly comprising a plurality of moveable contact arms, each of the plurality of moveable contact arms having a moveable contact disposed thereon, the moveable contact arm moveable to position each moveable contact into engagement with a respective fixed contact of the plurality of fixed contacts to define a closed condition and out of engagement with the plurality of fixed contacts to define a blow open condition;
a carrier assembly operatively coupling the plurality of moveable contact arms to each other;
a latch plate operatively coupled to the carrier assembly and to the second shaft;
a trip shaft operatively coupled to the carrier assembly, the trip shaft having a non-circular region defining an engagement surface disposed in contact with the latch plate in the closed condition; and
a biasing portion of one of the plurality of moveable contact arms, the biasing portion disposed proximate the trip shaft in the closed condition and configured to rotate the trip shaft out of engagement with the latch plate.

9. The circuit breaker of claim 8 , wherein the non-circular region comprises a semi-circular geometry, the engagement surface of the non-circular region comprising a curved portion of the semi-circular geometry.

10. The circuit breaker of claim 8 , wherein the biasing portion comprises a protrusion extending from one of the plurality of moveable contact arms toward the trip shaft.

11. The circuit breaker of claim 8 , wherein interaction of the latch plate, trip shaft, and biasing portion facilitates retention at electromagnetic force levels lower than a threshold level and moves the circuit breaker into the blow open condition upon reaching the threshold level.

12. The circuit breaker of claim 8 , wherein each of the plurality of moveable contact arms comprises a first end and a second end, each of the plurality of moveable contact arms pivotable about an axis located proximate the second end.

13. The circuit breaker of claim 12 , wherein the moveable contact disposed on each of the plurality of moveable contact arms is located closer in proximity to the first end than the second end.

14. The circuit breaker of claim 12 , wherein the carrier assembly is operatively coupled to the plurality of moveable contact arms with a carrier shaft positioned coaxially with the axis located proximate the second end of the plurality of moveable contact arms.

15. The circuit breaker of claim 8 , wherein the carrier assembly comprises a plurality of separation brackets operatively coupled to each other and to the second shaft, each of the plurality of separation brackets disposed adjacent at least one of the plurality of moveable contact arms, the circuit breaker further comprising:
a first end plate located at a first side of the carrier assembly and operatively coupled to the second shaft; and
a second end plate located at a second side of the carrier assembly and operatively coupled to the second shaft.

16. The circuit breaker of claim 15 , wherein the latch plate is operatively coupled to the first end plate and disposed between the first end plate and one of the plurality of separation brackets.

17. The circuit breaker of claim 16 , further comprising an additional latch plate operatively coupled to the second end plate and disposed between the second end plate and one of the plurality of separation brackets.

18. The circuit breaker of claim 15 , further comprising at least one spacer disposed between the second coupling member and one of the plurality of separation brackets.

19. The circuit breaker of claim 18 , wherein the at least one spacer comprises a first spacer and a second spacer, the first spacer disposed between a first side of the second coupling member and a first separation bracket, the second spacer disposed between a second side of the second coupling member and a second separation bracket.

Assignees

• Gen Electric

Inventors

• Babu Triplicane Gopikrishnan
• Babu Maddela Rajesh
• Narayanan Janakiraman
• Narayanasamy Soundararajan
• Tamboli Tanmay Pralhad

Classifications

• H01H9/20

  Interlocking, locking, or latching mechanisms · CPC title

• H01H2205/002

  fixed to operating part · CPC title

• H01H3/46 Primary

  using rod or lever linkage, e.g. toggle · CPC title

• H01H3/54 Primary

  Mechanisms for coupling or uncoupling operating parts, driving mechanisms, or contacts · CPC title

• H01H3/38

  using spring or other flexible shaft coupling · CPC title