Adjustable Short-Stroke Button Assembly for Consistent Activation Gap
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Solution Overview
Problem
Existing short stroke button assemblies in automotive vehicles and keypads suffer from loose fits and unwanted activations due to mismatched tolerances, leading to noise and inconsistent tactile responses.
Innovation Solution
A short stroke button assembly with a connector system featuring radial recesses and projections to maintain angular position, allowing for precise adjustment via torque tools, ensuring consistent activation gaps and tactile responses across multiple assemblies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional button assemblies are used with standard tolerances, then manufacturing is simple and cost-effective, but the assembly components have loose fit leading to noise and poor user feeling
Solution Approach 1:
The connector incorporates an adjustable length mechanism that allows dynamic modification of the connector length to compensate for tolerance variations. This enables the assembly to adapt to different tolerance conditions while maintaining proper fit and activation gap, resolving the contradiction between simple manufacturing and reliable fit precision.
Solution Approach 2:
The invention changes the parameter of connector length to compensate for tolerance accumulation. By providing an adjustable connector whose length can be modified within a range, the system can adapt to different manufacturing tolerances and maintain the correct activation gap without requiring extremely tight tolerances on all components.
2Reliability
If conventional button assemblies are used with standard tolerances, then manufacturing is simple, but the switch experiences extensive preload causing unwanted activation
Solution Approach 1:
The adjustable connector length allows the assembly to be tuned during manufacturing or assembly to achieve the correct preload condition. This dynamic adjustment capability enables proper switch activation characteristics without requiring complex manufacturing processes or extremely tight tolerances on all components.
Solution Approach 2:
The invention incorporates preliminary adjustment capability into the connector design, allowing the activation gap and preload to be set before final assembly. This preliminary action ensures correct switch activation characteristics are established during assembly rather than requiring post-assembly adjustment or risking unwanted activation.
3Manufacturing precision
If tolerance chains are reduced to improve precision, then activation gap consistency improves, but manufacturing complexity and cost increase
Solution Approach 1:
The adjustable connector acts as an intermediary element that absorbs tolerance variations from other components. By providing an adjustment mechanism in the connector, the system can compensate for tolerance accumulation in the button, switch, and housing without requiring tight tolerances on all components, thus maintaining activation gap consistency without increasing overall manufacturing complexity.
Solution Approach 2:
The invention changes the connector length parameter to compensate for variations in other components. This single parameter adjustment in the connector can offset tolerance variations from multiple other parts, achieving consistent activation gaps without requiring tight tolerances across the entire assembly and avoiding increased manufacturing complexity.
4Reliability
If individual button adjustment mechanisms are added, then tactile response consistency improves, but device complexity and manufacturing cost increase
Solution Approach 1:
The adjustable connector provides a dynamic adjustment mechanism that can be incorporated into the standard assembly process. By integrating the adjustment capability into the connector itself rather than adding separate adjustment mechanisms to each button, the invention achieves consistent tactile response while maintaining manufacturing simplicity.
Solution Approach 2:
The adjustable connector serves multiple functions: it connects the button to the switch, accommodates tolerance variations, and provides adjustment capability for precise activation gap setting. By combining these functions into a single component, the invention achieves consistent tactile response without adding separate adjustment mechanisms that would increase manufacturing complexity.
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
The invention relates to a short stroke button assembly (2), in particular for use in an automotive vehicle, comprising a housing (3), a button (4) held in said housing (2) and apt to be moved axially in the activation direction along an activation axis (A), at least one switch (5) corresponding to said button (4), having an active state and an Inactive state separated by an activation gap (L) along said activation axis (A), and preloaded to normally maintain said inactive state, and at least one connector (8) disposed along said activation axis (A) between said button (3) and said switch (5). In order to adjust the assembly in a simple way and precisely to maintain its inactive state corresponding to or lower than the activation gap (L) said connector (8) comprises a first member (81) and a second member (82) displaceable angularly about and axially along said activation axis (A) with respect to said first member (81), and means to maintain the relative angular position between said first member (81) and said second member (82) when the torque between said first member (81) and said second member (82) about said activation axis (A) Is below a predefined threshold, wherein said first member (81) comprises at least one protrusion (814) extending along said activation axis (A) and said second member (82) further comprises at least one substantially helical surface (824) cooperating with said protrusion (814), The invention also relates to a keypad (1) comprising a number of such short stroke button assemblies (2).