Microswitch Spring Tongue Design for Friction Reduction
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Solution Overview
Problem
Electrical switches, such as microswitches, face challenges in achieving high switching reliability and cost-effectiveness due to complex structures and high friction hysteresis, which lead to increased costs and potential functional deterioration.
Innovation Solution
The design incorporates a buckled spring leaf as a return device and a second spring tongue with a curved shape to reduce contact friction, eliminate the need for a sliding guide, and enhance switching accuracy, featuring a stable contact spring position and balanced spring forces, with a rolled-up hollow section contact area and an angled armature for improved switching behavior.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sliding guide is used to accommodate the contact spring in the direction of actuation, then the contact spring is mechanically guided and contact friction is minimized, but the switch structure becomes complex and costs increase
Solution Approach 1:
The patent removes the sliding guide component from the switch structure. Instead of using a separate guide mechanism, the contact spring is directly accommodated in the actuating element with its longitudinal axis parallel to the actuation direction, eliminating the need for additional guiding components and simplifying the overall structure while maintaining reliable operation.
Solution Approach 2:
The contact spring is divided into functionally distinct regions: a first spring tongue designed as a return device subjected to compressive stress, and a second spring tongue designed as a changeover switch for the contact area. This segmentation allows each portion to perform its specific function optimally without requiring complex overall guidance mechanisms.
2Reliability
If the contact spring is mechanically guided to minimize contact friction, then contact friction is reduced, but friction hysteresis deteriorates the switch function
Solution Approach 1:
Instead of guiding the contact spring laterally to minimize friction, the patent inverts the approach by aligning the contact spring's longitudinal axis parallel to the actuation direction. The spring is compressed and extended along its own axis, transforming the friction mechanism from lateral sliding to axial compression, which reduces friction hysteresis and improves switching function.
3Manufacturing precision
If a guide is formed to accommodate the contact spring, then the contact spring position is controlled, but the switch becomes structurally complex and production costs increase
Solution Approach 1:
The guiding function for the contact spring is merged into the actuating element structure itself. The actuating element is designed with a cavity that directly receives and positions the contact spring, combining the housing and guide functions into a single component. This integration eliminates separate guide parts, simplifies manufacturing, and reduces production costs while maintaining precise contact spring positioning.
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
This design simplifies the switch structure, reduces production costs, and enhances long-term functionality by minimizing wear and vibration, ensuring high switching reliability and accuracy while maintaining a stable contact position.
Implementation Method 1
the first spring tongue designed as a return device for the actuating element is a buckled spring leaf that is subjected to compressive stress at least in its longitudinal direction
Implementation Method 2
the spring tongues having contact areas on surface areas of the armature facing away from one another
Data Source
Figure 1~2
Figure 3~4
AI summary
The switch has contact springs (4) transferred into different switching positions by an actuating element and arranged at an anchor formed as an electrical contact. Spring tongues (6, 7) are arranged at a closed spring frame (5). One spring tongue is formed as a resetting unit for the actuating element. Another spring tongue controls switching functions of a contact region (9) of the springs. The tongues are engaged at surface regions of the anchor in a supporting manner such that the springs exhibit stable position during actuation, where the surface regions are turned away from each other.