Switch Device Snap Action Mechanism Fatigue Resistance
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Solution Overview
Problem
Conventional switching devices experience reduced lifespan due to metal fatigue at contact portions caused by shock during circuit changes, which affects the device's longevity.
Innovation Solution
A switching device design incorporating a snap action mechanism with a coupling member and extension spring, where the coupling member clamps the movable and first drivers, and the extension spring is attached to both the first drive member and second driver, reducing stress on the coupling portions and enhancing fatigue resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional snap device with sliding contact is used to achieve circuit switching, then circuit changeover synchronization is achieved, but metal fatigue accumulates at contact portions reducing device lifespan
Solution Approach 1:
The patent extracts the harmful sliding contact mechanism and replaces it with a point-contact snap action mechanism. The movable contact portion directly contacts the fixed contact portion through rotational movement rather than sliding, eliminating the continuous friction and metal fatigue accumulation that occurs with sliding contacts.
Solution Approach 2:
Instead of using sliding motion to achieve contact changeover, the patent inverts the approach by using rotational snap action. The movable contact rotates about a pivot point to make and break contact with the fixed contact, transforming the harmful sliding friction into a beneficial rotational mechanism with minimal contact wear.
2Reliability
If multiple circuits are synchronized through conventional sliding contact mechanism, then circuit changeover reliability is improved, but shock during switching accelerates metal fatigue
Solution Approach 1:
The patent employs dynamic snap action mechanism where the movable contact rotates rapidly between two stable positions (first and second contact positions). This dynamic rotational movement enables synchronized circuit changeover while minimizing the duration and intensity of shock forces compared to conventional sliding mechanisms.
Solution Approach 2:
The patent changes the motion parameter from linear sliding to rotational movement. By rotating the movable contact about a pivot point, the contact force is applied more efficiently and the transition is completed more quickly, reducing the shock duration and improving fatigue resistance while maintaining synchronization reliability.
3Productivity
If sliding contact portions are used for circuit switching, then multiple circuits can be changed over simultaneously, but contact portion lifespan is reduced due to continuous friction
Solution Approach 1:
The patent uses snap action to rush through the contact transition in a single rapid rotational motion. The movable contact skips directly from one stable position to another through the pivot point, completing the circuit switching instantly rather than gradually sliding. This reduces the total contact time and friction accumulation, extending contact portion lifespan while maintaining high switching speed.
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 design significantly increases the fatigue limit of movable contacts, leading to a longer lifespan and reduced variation in synchronization timing during circuit changes.
Implementation Method 1
an extension spring of which one end is attached to a portion of the first drive member and another end is attached to a portion of the second driver
Implementation Method 2
a fulcrum that serves as a pivot point is formed on one end side of a given first driver and in which a given movable contact from among the movable contacts is provided on another end side of the given first driver
Implementation Method 3
a fulcrum that serves as a pivot point is formed on one end side of a given first driver and in which a given movable contact from among the movable contacts is provided on another end side of the given first driver
Implementation Method 4
The coupling member includes clamping portions each of which passes through holes provided through a given first driver and a given movable contact and each of which clamps the given first driver and the given movable contact
Data Source
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AI summary
A switching device according to one embodiment includes a housing, an operation member, a plurality of fixed contacts, a plurality of movable contacts, and a snap action mechanism for causing the movable contacts to operate. The snap action mechanism includes a plurality of first drivers in each of which a fulcrum that serves as a pivot point is formed on one end side of a given first driver and in which a given movable contact from among the movable contacts is provided on another end side of the given first driver; a second driver in which a pressing member to be pressed through the operation member is formed on one end side of the second driver and in which fulcrums that serve as pivot points are each formed on another end side of the second driver; a coupling member integrally coupling the plurality of first drivers to constitute a first drive member; and an extension spring of which one end is attached to a portion of the first drive member and another end is a portion of the second driver. The coupling member includes clamping portions each of which passes through holes provided through a given first driver and a given movable contact and each of which clamps the given first driver and the given movable contact.