Residual-Current Breaker Tripping Mechanism With Shared Pivot Latch
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Solution Overview
Problem
The tripping process in existing residual-current circuit breakers is unstable due to a shifting acting point of the thrust of a reset plate on a latch, leading to variable tripping forces.
Innovation Solution
A leakage protection unit with an optimized structure, featuring a tripping mechanism where the reset plate and latch share a pivot shaft, ensuring a stable pushing point and preventing mutual slippage between locking and locked parts, thereby stabilizing the tripping force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the reset plate and latch are configured with separate pivot shafts, then the structure allows independent movement, but the acting point shifts causing unstable tripping force
Solution Approach 1:
The patent merges the pivot shafts of the reset plate and latch into a single shared pivot shaft. This combining of previously separate components eliminates the acting point shift problem while maintaining the necessary independent movement capability through the coordinated rotation of both components around the common pivot axis.
Solution Approach 2:
The shared pivot shaft serves multiple functions: it acts as the rotation axis for both the reset plate and the latch, providing a stable reference point for force transmission while enabling the coordinated action of both components. This multi-functional design eliminates the need for separate pivot shafts and their associated mounting structures.
2Ease of operation
If the reset plate pushes the latch at a variable acting point, then the mechanism can accommodate movement, but the tripping force becomes unstable
Solution Approach 1:
The patent preliminarily positions the reset plate and latch on the shared pivot shaft such that their relative angular positions are fixed. This preliminary configuration ensures that when the electromagnetic tripper actuates the reset plate, the pushing point on the latch remains at a predetermined, stable location, eliminating variable acting points while maintaining smooth operation.
3Ease of manufacture
If the locking part and locked part have loose fit, then assembly is easier, but mutual slippage occurs reducing reliability
Solution Approach 1:
The patent applies local quality by designing the locking part and locked part with specific geometric features (such as tapered surfaces or precision-machined contact areas) that concentrate the latching force at critical locations. This localized precision ensures a secure fit without requiring tight tolerances throughout the entire component, balancing assembly ease with latching reliability.
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 optimized structure enhances the stability of the tripping force and reliability of the tripping process by maintaining a consistent pushing point and preventing slippage, thus improving the overall performance of the residual-current circuit breaker.
Implementation Method 1
a first electromagnetic tripper that are installed in the base... the reset plate is disposed at a side of the first electromagnetic tripper to receive a push from an output rod of the first electromagnetic tripper
Implementation Method 2
The leakage protection unit detects leakage current in the circuit through a zero-sequence current transformer. Then, through signal processing of a control circuit board, a voltage output from the control circuit board causes a tripper push rod in the leakage protection unit to be pushed out (induced electromotive force induced by the zero-sequence current transformer is output to the tripper)
Implementation Method 3
One end of the first elastic member acts on the base, and another end of the first elastic member acts on the reset plate, to maintain contact between the reset plate and the output rod of the first electromagnetic tripper by means of an elastic force of the first elastic member, and to realize rotation reset of the reset plate
Data Source
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AI summary
A leakage protection unit and a residual-current circuit breaker. The leakage protection unit comprises a base (1), and a handle (2), a tripping mechanism (50), and a first electromagnetic tripper (8) that are mounted in the base (1). Both the handle (2) and the first electromagnetic tripper (8) are in linkage connection with the tripping mechanism (50), so as to respectively drive manual closing and tripping opening of the tripping mechanism (50); and in the tripping mechanism (50), a reset plate (7) and a latch (6) share a pivot shaft (R), such that when the reset plate (7) rotates to unlock the latch (6), a pushing action point of the reset plate on the latch (6) does not deviate, and the unlocking of a locking part (61) and a locked part (51) does not slide mutually, thereby improving the stability of a tripping force and the reliability of a tripping process.