Circuit Breaker Drawer Position Indicator with Lever Mechanism
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Solution Overview
Problem
Existing air circuit breakers face issues with inaccurate position state indication and premature failure of microswitches due to high driving force and rigidity, leading to instability and reduced reliability in remote monitoring and maintenance.
Innovation Solution
The design incorporates a position indicating device with levers and an execution shaft pin that precisely control contact switches, reducing over-stroke and damage by using a knocking fit mechanism and gear surfaces to manage the oscillation stroke, ensuring accurate and reliable three-position state indication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If a supporting plate directly contacts a contact switch to convert position states to on/off outputs, then remote monitoring capability is enabled, but the microswitch suffers from easy damage due to large transmission impact force and high rigidity
Solution Approach 1:
The patent introduces a lever as an intermediary component between the supporting plate and the contact switch. The lever converts the linear motion of the supporting plate into rotational motion, and through the arc-shaped contact surface, it controls the contact switch to open or close. This intermediary mechanism reduces the direct impact force transmitted to the microswitch, thereby extending its service life while maintaining the remote monitoring function.
2Measurement precision
If a rotating shaft directly acts on a microswitch to indicate position states, then position indication is achieved, but the microswitch experiences easy failure due to great acting force and very high rigidity
Solution Approach 1:
The patent uses a lever with an arc-shaped contact surface as an intermediary between the rotating shaft and the contact switch. The lever translates the rotational motion of the shaft into controlled linear motion of the contact switch, reducing the direct acting force on the microswitch while maintaining accurate position indication through the precise geometric relationship of the arc surface.
3Ease of manufacture
If a supporting plate with low linear precision contacts a contact switch, then position conversion is possible, but large over-strokes are generated causing great damage to the contact switch
Solution Approach 1:
The patent employs an arc-shaped contact surface on the lever that serves as a cushioning mechanism. This curved surface gradually guides the supporting plate's motion, absorbing and distributing the impact forces before they reach the contact switch. The arc shape ensures that even with low linear precision in the supporting plate, the contact switch experiences reduced shock and stress, preventing damage while maintaining manufacturing simplicity.
Data Source
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AI summary
A position indicating device of a circuit breaker drawer seat comprises a body switch of a circuit breaker and a handle screw rod assembly and further comprises a position indicating assembly and an indicating drive piece, wherein the body switch of the circuit breaker is detachably installed on a guide rail of the drawer seat, the handle screw rod assembly drives the body switch to linearly move along the guide rail to the three positions where the body switch and the drawer seat are separated, tested and connected, the indicating drive piece is fixed to a small side plate of the body switch, the position indicating assembly comprises three contact switches, three pairs of forward gear and backward gear protruding columns, a separation lever, a test lever and a connection lever, wherein the three contact switches are fixed to a fixing plate of a big side plate of the drawer seat, and the separation lever, the test lever and the connection lever are pivoted to the fixing plate through rotating pair structures. An execution shaft pin on the indicating drive piece is in knocking fit with the corresponding levers of the position indicating assembly when the body switch is moved to the three working positions, so that the separation lever can be driven to be in contact fit with the separation contact switch, the test lever can be driven to be in contact fit with the test contact switch, and the connection lever can be driven to be in contact fit with the connection contact switch.