Thermal Circuit Breaker Trip Indicator and Reset Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing thermally responsive circuit breakers lack a visual indication of an overload trip condition, making it difficult to determine if the circuit has been tripped due to an overload.
Innovation Solution
A thermally activated circuit interrupter with a cantilever-mounted snap acting disc, a pivot member, latch, trip indication, and reset assembly, where the pivot member rotates to move a trip indicator button into an exposed position when the disc trips, providing visual indication of an overload trip and allowing for manual reset.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a simple thermal circuit breaker design is used, then the device complexity is reduced and ease of manufacture is improved, but visual indication of trip condition is lost
Solution Approach 1:
The patent combines the reset function and trip indication function into a single button assembly. When the button is pressed, it simultaneously resets the latch mechanism and provides visual feedback through its position (extended vs. retracted), eliminating the need for separate indication components and reducing overall device complexity
Solution Approach 2:
The button serves multiple functions: it acts as the reset actuator, provides visual trip indication through its extended position, and mechanically interacts with the latch system. This multi-functionality reduces the number of separate components needed while maintaining both indication and reset capabilities
2Loss of information
If a trip indication mechanism is added to the circuit breaker, then visual indication of overload trip is provided, but device complexity increases
Solution Approach 1:
The indication function is merged with the existing reset button rather than being implemented as a separate mechanism. The button's physical position (extended when tripped, retracted when reset) provides visual indication without requiring additional indication components, thereby avoiding increased device complexity
Solution Approach 2:
The button automatically provides trip indication through its own position without requiring separate indication mechanisms. The mechanical state of the button itself serves as the indication, eliminating the need for additional indicators while maintaining the information display function
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
The solution provides a clear visual indication of an overload trip condition and allows for easy reset, enhancing user safety and operational simplicity while maintaining the thermal responsiveness of the circuit interrupter.
Implementation Method 1
Electric current passing through the disc generates heat thereby raising the temperature of the disc
Implementation Method 2
two latches are integrally formed with respective spring members mounted on the pivot member, the spring members having legs that react against a fixed surface of the housing to provide a bias urging the pivot member to rotate
Data Source
AI summary
A thermally activated circuit interrupter (10) has a cantilever mounted, snap acting thermostatic disc (16) mounting a movable electric contact (18) that is adapted to move between a contacts engaged position and a tripped, contacts disengaged position. A pivot member (24) is rotatably mounted above the thermostatic disc and movably mounts a latch (26d) that is biased by spring arm (26a) against the edge of the free end of thermostatic disc (16) in the contacts engaged position and is moved under the thermostatic disc when the disc moves to the contacts disengaged position. An arm (24b) of the pivot member transfers motion to a trip indicator button (32) pushing the button to an exposed position upon rotation of the pivot member when the thermostatic disc moves to the tripped configuration and the latch moves under the disc. The trip indicator button also serves as a reset button so that upon cooling of the thermostatic disc to the reset temperature, the button can be depressed transferring motion to the arm (24b) of the pivot member thereby moving the latch from under the disc allowing the disc to move to the contacts engaged configuration.