Compact Circuit Breaker Snap-Action Mechanism for Arc Suppression
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Solution Overview
Problem
Low-voltage switching devices with manual switch buttons face issues with arc formation and potential damage or fire when high DC voltages or currents are applied, especially during slow contact separation, and existing snap-action switch-off technologies are not suitable for compact devices due to integration challenges.
Innovation Solution
A compact switching device with a snap-action switch-off mechanism that includes a pawl and pawl support for abrupt contact separation, independent of the user's operation speed, using a switching mechanism with a pawl support and a manual shift lever connected via brackets to ensure safe and reliable contact separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If manual switch button is used for closing switching contacts, then the switching device can be operated manually, but the contact separation becomes slow and causes arc formation leading to damage or fire
Solution Approach 1:
The switching mechanism transforms the static manual operation into a dynamic snap-action process. When the manual switch button is released, the spring-driven mechanism automatically accelerates the contact separation from slow manual movement to rapid automatic separation, eliminating arcs while maintaining manual control capability.
Solution Approach 2:
The spring mechanism is pre-charged during the contact closing phase. When the manual switch button is released, this pre-stored energy is immediately released to drive the rapid contact separation, ensuring the switching action occurs before an arc can form.
2Reliability
If snap-action switch-off function is implemented, then contact separation becomes abrupt and safe, but the device requires spring accumulators that are too large for compact housings
Solution Approach 1:
The switching mechanism combines the manual switch button structure with the spring-driven snap-action mechanism into a single integrated assembly. The manual button serves both as the operating interface and as part of the triggering mechanism, eliminating the need for separate spring accumulators and reducing overall device volume.
Solution Approach 2:
The manual switch button performs multiple functions: it initiates contact closing, triggers the snap-action mechanism upon release, and serves as part of the mechanical linkage. This multi-functionality reduces the number of separate components needed, enabling compact housing design.
3Adaptability or versatility
If manual switch button is held in intermediate position, then contacts can be held in intermediate position, but this prevents safe abrupt separation when high current is present
Solution Approach 1:
The mechanical latch provides temporary intermediate positioning capability for low-current applications, but is designed to be overcome by the spring force when high current requires rapid separation. The system accepts that intermediate positioning is not always safe and allows the spring mechanism to override it when needed.
Solution Approach 2:
The spring mechanism is continuously prepared to counteract any intermediate positioning. When high current conditions arise or the manual button is fully released, the pre-charged spring immediately overcomes the latch force to ensure rapid contact separation, preventing arc formation.
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
The invention relates to a shifting device (1) with a contact (6) which is fixed to the housing and a movable contact (4). The shifting device (1) has a shift lock (2) which has a latch (20) and a latch support (22). The latch support (22) has a latching point (24) for latching the latch (20) to the latch support (22). The shifting device (1) further has a manual shifting lever (7) which is connected to the latch (20) by means of a first bracket (37) in order to contact the movable contact (4) with the contact (6) that is fixed to the housing. The shifting device (1) has a sudden disconnect mechanism (40) for manually causing a sudden separation of the contacts (4, 6). According to the invention, the manual shifting lever (7) is additionally equipped with a second bracket (41) such that an actuation of the manual shifting lever (7) releases the latch connection between the latch support (22) and the latch (20) in order to separate the movable contact (4) from the contact (6) which is fixed to the housing.