Push-button Switch Member with Spaced Pusher
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Solution Overview
Problem
Conventional pushbutton switch members face issues with positional differences between the metal dome and the rubber switch, leading to a short stroke and degraded touch feeling, and adhesion-related problems with adhesive agents affecting dimensional tolerance and click sensation.
Innovation Solution
A pushbutton switch member design where the pusher is spaced apart from the metal dome's top part, with the outer periphery of the movable contact fixed radially outside the pusher, allowing for a longer stroke and a smooth increase in load to enhance the click feeling by adjusting the deformation distance and adhesion force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the pusher is directly adhered to the top part of the metal dome, then the positioning between the key and metal dome is accurate, but the dimensional tolerance in pushing direction is large due to adhesive agent thickness variation
Solution Approach 1:
The patent introduces a pusher as an intermediary component between the key and the metal dome. The pusher is spaced apart from the top part of the metal dome by a predetermined distance, eliminating the need for adhesive agents. This intermediary structure provides stable dimensional tolerance while maintaining accurate positioning, as the pusher's position is determined by mechanical constraints rather than variable adhesive thickness.
2Reliability
If the pusher is directly adhered to the metal dome, then the positioning is fixed, but the metal dome is unlikely to deform where the adhesive agent exists, resulting in weak click feeling
Solution Approach 1:
The pusher serves as a mediator that transmits force from the key to the metal dome without preventing the dome's deformation. By spacing the pusher apart from the top part of the metal dome, the invention allows the metal dome to deform freely under the pusher, generating a strong click feeling while maintaining stable positioning through the predetermined distance constraint.
3Device complexity
If the rubber switch is simply disposed above the metal dome, then the structure is simple, but a positional difference occurs between the metal dome and rubber switch, leading to short stroke
Solution Approach 1:
The pusher acts as an intermediary that connects the key to the metal dome with a predetermined spacing arrangement. This structure prevents positional differences between components while maintaining relative simplicity. The predetermined distance between the pusher and metal dome top part ensures adequate stroke length, avoiding the short stroke problem caused by direct disposal of components.
4Stability of the object's composition
If adhesive agent is used to adhere the pusher to the metal dome, then the components are fixed together, but the variation in adhesive thickness degrades touch feeling
Solution Approach 1:
The invention extracts and eliminates the adhesive agent from the assembly. By spacing the pusher apart from the metal dome without using adhesive, the patent removes the source of dimensional variation. This extraction approach maintains component fixation through mechanical constraints while ensuring consistent touch feeling不受adhesive thickness variation.
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 achieves a favorable operation feeling with a long stroke and strong click sensation by maintaining the stroke length and ensuring reliable adhesion between the dome-shaped movable contact and the key, improving the overall switch performance.
Implementation Method 1
a switch is turned on through deformation of a metal dome when pushing is externally applied on a central top part of the metal dome
Data Source
Figure 1(A)~1(B)
Figure 2(A)~2(B)
Figure 3
AI summary
[Problem] To provide a pushbutton switch member capable of achieving a favorable operation feeling, a long stroke, and a strong click feeling that should be provided by a dome-shaped movable contact. [Solution] The present invention pertains to a pushbutton switch member including: a dome-shaped movable contact; and an operation key disposed on a protrusion side of the movable contact and contacting with the movable contact. Pushing the operation key toward the movable contact causes the movable contact to electrically connect at least two contacts on a substrate. The operation key includes: a key body; a dome part connected with an outer periphery of the key body and deformable by pushing of the key body toward the substrate; a foot part connected with an outer periphery of the dome part and fixed on the substrate; and a protrusion provided on a top surface of the key body or the outer periphery of the key body, protruding from the top surface of the key body, and deformable by compression during operation of pushing the operation key toward the substrate. The movable contact includes: an upper contact part disposed in contact with a site directly below the key body and configured to contact with a contact of the at least two contacts when the key body is pushed in; and an outer fixing part disposed at the upper contact part or outside of the upper contact part in a radial direction and fixed outside of the key body of the operation key in the radial direction.