Circuit Breaker Trip Indicator Flag Mechanism
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Solution Overview
Problem
Two-position automatic reset circuit breakers lack a reliable trip indicator that can visually signify a trip condition regardless of the operating handle or cradle position, making it difficult to distinguish between tripped and manually turned-off states, especially when handles are padlocked in the ON position.
Innovation Solution
A trip indicator with resilient properties and a unique latching design that includes a flag member with a trip indicia, a first leg to bias the indicia away from view when not tripped, and a second leg to assist the operating handle in moving to the OFF position, ensuring the trip indication remains visible at the housing opening regardless of the mechanism's position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a two-position automatic reset circuit breaker is used, then the device complexity is reduced and automatic resetting is enabled, but the ability to visually distinguish trip condition from manual OFF position is lost
Solution Approach 1:
The trip indicator is segmented into functionally independent components: a flag member with trip indicia, a first leg for visual indication, and a second leg for mechanical assistance. This segmentation allows the indicator to provide persistent visual feedback independent of the cradle position while the cradle performs automatic resetting, resolving the information loss problem without adding complex interdependencies.
Solution Approach 2:
The trip indicator acts as an intermediary between the trip mechanism and the user. It decouples the visual indication function from the mechanical position of the operating handle and cradle, providing reliable trip status information even when the cradle automatically resets to its initial position, thus preventing information loss.
2Device complexity
If the trip indicator is dependent on the cradle position, then the indicator structure is simplified, but the indication disappears when the cradle automatically resets
Solution Approach 1:
The trip indicator is segmented into functionally independent components: a flag member with trip indicia, a first leg for visual indication, and a second leg for mechanical assistance. This segmentation allows the indicator to provide persistent visual feedback independent of the cradle position while the cradle performs automatic resetting, resolving the information loss problem without adding complex interdependencies.
Solution Approach 2:
The trip indicator employs resilient material that allows dynamic movement and maintains indication through elastic deformation. The flag member can be deflected by the cradle during tripping and then returns to its indicating position independently, maintaining reliability even when the cradle resets automatically.
3Reliability
If a resilient material is used for the trip indicator, then the indication can be maintained independently of mechanism position, but the manufacturing precision requirements increase
Solution Approach 1:
The trip indicator employs resilient material that allows dynamic movement and maintains indication through elastic deformation. The flag member can be deflected by the cradle during tripping and then returns to its indicating position independently, maintaining reliability even when the cradle resets automatically.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Provides a clear and persistent visual indication of a trip condition, independent of the circuit breaker's operating mechanism position, and assists the handle in moving from the ON to the OFF position upon tripping, effectively addressing the ambiguity in two-position automatic reset circuit breakers.
Implementation Method 1
The trip indicator is made of a resilient material and, thus, provides a biasing force for assisting movement of the circuit breaker operating mechanism to the desired position in response to a trip condition
Implementation Method 2
In response to the trip condition, the first leg is structured to engage a portion of the housing in order to maintain a viewable trip indication by the flag member, regardless of the position of the operating mechanism
Data Source
AI summary
A trip indicator is for a circuit breaker having a housing including first and second openings, separable contacts and an operating mechanism having an operating handle protruding from the first opening. The trip indicator includes a one-piece flag member with a first end having a trip flag and a second end with first and second integral legs. The first leg biases the trip flag away from the second opening when the separable contacts are not tripped open, and includes a latching portion to maintain the flag in a viewable position to indicate the trip condition regardless of the operating mechanism position. The second leg is disposed proximate first leg and biases the operating handle toward the OFF position, thereby assisting the handle to move from the ON position in response to the trip condition.