Circuit Breaker Close Latch Interlock Decoupling Shock
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Solution Overview
Problem
Existing electrical switching apparatus, such as circuit breakers, face issues with unintended discharge of stored energy due to shock and vibration, which can cause the closing spring to discharge unintentionally, leading to safety concerns and inefficiencies.
Innovation Solution
A close latch interlock assembly is designed where the mass of the interlock assembly is not coupled to the close D-shaft, featuring a pivotably coupled close D-shaft, an actuator, a release member, and a transfer link that cooperates to prevent unintended movement and discharge, with a visual indicator to ensure the circuit breaker is ready to close before discharging the closing spring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the close block link is coupled to the close D-shaft, then the interlock assembly can prevent unintended discharge, but the mass coupling increases susceptibility to shock and vibration causing unintended movement
Solution Approach 1:
The patent extracts the mass of the interlock assembly from the close D-shaft by introducing a decoupling mechanism. The transfer link connects the release member to the close D-shaft without directly coupling the interlock assembly mass, thereby removing the harmful mass coupling while preserving the interlock function against unintended discharge
Solution Approach 2:
The patent segments the connection between the interlock assembly and the close D-shaft by introducing intermediate elements (transfer link, release member). This segmentation allows the interlock assembly to maintain its protective function while isolating its mass from the close D-shaft, reducing susceptibility to shock and vibration
2Reliability
If the close button is kept depressed or components move due to shock/vibration, then unintended discharge occurs, but adding more restrictive measures increases device complexity
Solution Approach 1:
The patent introduces a transfer link as an intermediary element between the release member and the close D-shaft. This mediator enables the interlock function to prevent unintended discharge while simplifying the overall structure by avoiding direct complex couplings between the interlock assembly and the close D-shaft
Data Source
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AI summary
A close latch interlock assembly is provided for an electrical switching apparatus, such as a circuit breaker, which includes a stored energy mechanism, such as a closing spring. The close latch interlock assembly includes a close D-shaft (202) pivotable between a latched and unlatched positions corresponding to the closing spring being chargeable and discharged, respectively. An actuator (204) is movable between an unactuated position corresponding to the close D-shaft being disposed in the latched position, and an actuated position corresponding to the close D-shaft being movable toward the unlatched position. A release member (206) cooperates with the actuator and is pivotably coupled to the first end of a transfer link. The second end (212) of the transfer link (208) extends toward the close D-shaft. When the actuator is moved toward the actuated position, it moves the release member, thereby moving the transfer link and pivoting the close D-shaft toward the unlatched position.