Ignition Key Switch Snap Spring Mechanism for Arc Reduction
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Solution Overview
Problem
Conventional ignition key switches are prone to sustained arcing due to their sliding contact make and break mechanism, which is susceptible to failure from prolonged arcing, especially when handling high currents and cycles, and lack a compact, high-current snap action mechanism to reduce arcing effects.
Innovation Solution
A compact ignition key switch with a pre-loaded snap spring mechanism that converts rotary motion into linear movement for instantaneous contact switching, using a 'A' or 'C' type snap spring with a force balance mechanism to ensure contacts remain in extreme positions and reduce arcing, and contact tips made of silver tin oxide for improved arc quenching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a sliding contact make and break mechanism is used in conventional ignition switches, then the switch can be operated through key rotation, but sustained arcing occurs leading to contact failure
Solution Approach 1:
The snap action mechanism creates periodic, instantaneous contact making and breaking actions. The spring-loaded contacts are held in one state and then rapidly transition to the other state, creating discrete periodic actions rather than continuous sliding contact. This periodic snap action reduces sustained arcing by minimizing the time contacts spend in intermediate states.
Solution Approach 2:
The snap action mechanism rushes through the contact transition state instantaneously. Instead of slowly sliding through the make and break process, the contacts snap from one position to the other in a single rapid motion. This skipping of the intermediate arcing state significantly reduces contact wear and failure.
2Device complexity
If conventional sliding contact mechanism is used, then the switch structure is simple, but arcing endures for prolonged time causing switch failure
Solution Approach 1:
The mechanism creates periodic snap actions that rapidly transition contacts between states. The spring-loaded system stores energy and releases it in periodic cycles, creating instantaneous contact making and breaking actions that minimize arcing duration with each cycle.
Solution Approach 2:
The snap action mechanism rushes through the contact transition in a single rapid motion, skipping the prolonged intermediate state that causes extended arcing. The spring-loaded contacts transition instantaneously from make to break or vice versa, eliminating sustained arcing exposure.
3Power
If ignition switch is designed for lower voltage and current, then the switch can handle standard automotive electrical systems, but it cannot handle high current applications with extended life cycle
Solution Approach 1:
The snap action mechanism rushes through contact transitions instantaneously, even under high current loads. This rapid transition prevents sustained arcing that would otherwise cause contact erosion and failure during high-power operations, enabling the switch to handle high current with extended life cycle durability.
Solution Approach 2:
The spring-loaded snap action creates periodic, controlled contact transitions that manage high current flows efficiently. The periodic snapping action ensures consistent, rapid contact making and breaking even under high-power conditions, maintaining reliability during extended high-current operation.
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 high-current, compact ignition key switch with reduced arcing and increased durability by ensuring instantaneous contact switching and preventing intermittent contact states, thus extending the switch's life cycle and preventing battery drain.
Implementation Method 1
A pre-loaded snap spring is configured to include a fixed end attached to an anchor and a free end attached to a movable contact
Implementation Method 2
A cam can be utilized to convert a rotary motion at a key interface into a linear movement of a plunger for snap spring blade actuation
Implementation Method 3
contact tips made of silver tin oxide for improved arc quenching
Data Source
AI summary
An ignition key switch apparatus having a compact size, high current capability, and a snap action mechanism. A pre-loaded snap spring can be configured to include a fixed end attached to an anchor and a free end attached to a movable contact operable between normal and actuated positions. A cam can be utilized to convert a rotary motion at a key interface into a linear movement of a plunger for snap spring blade actuation. The unique pre-loaded snap spring generates a fast (e.g., instantaneous) movement from an open to a closed position and vice versa upon application/removal of a load to reduce the effect of arcing on associated contacts and conductors. The pre-loaded snap spring also ensures that the movable contact does not remain in any intermittent position, other than the two extreme positions given at any position of the plunger.