Short Stroke Reed Switch Button with Stroke-Translating Mechanism
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Solution Overview
Problem
Existing buttons for membrane keyboards and sealed short-travel keyboards face challenges such as complex and costly manufacturing, mechanical stress, oxidation of electrical contacts, limited switching cycles, and unreliable performance in dusty or humid environments due to requiring significant key travel and being susceptible to wear and oxidation.
Innovation Solution
A button design featuring a stroke-translating mechanism with a transmission ratio greater than 1:1, allowing for a small key travel to result in a larger switching travel, using a reed switch and permanent magnet interaction without contact, and a housing to protect components, which decouples key travel from switching travel and is resistant to environmental influences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a button uses reed switch and permanent magnet with direct contactless interaction, then mechanical wear and oxidation are eliminated, but a key travel of several millimeters is required which exceeds the elastic range of membrane keyboards
Solution Approach 1:
A stroke-translating mechanism is introduced as an intermediary between the button and the reed switch. This mechanism includes a button, a carrier unit with the reed switch, and a translating mechanism with a lever that converts small button strokes into larger switching strokes, enabling contactless reed switch operation with minimal key travel
Solution Approach 2:
The translating mechanism uses a lever with rotational movement to dynamically convert the input stroke into a magnified output stroke. The lever rotates around an axis, transforming the small linear displacement of the button into a larger linear displacement of the operating element near the reed switch
2Length of moving object
If conventional electrical contacts are used with snap disk, then button stroke is reduced to a few tenths of a millimeter, but mechanical stress on the snap-action disc limits the number of switching cycles
Solution Approach 1:
The mechanical snap disk contact system is replaced with a magnetic field-based reed switch system. The reed switch uses magnetic attraction between a permanent magnet and magnetized reed contacts to open/close circuits, eliminating mechanical stress on snap-action discs and enabling millions of switching cycles
Solution Approach 2:
A stroke-translating mechanism serves as an intermediary that decouples the small button stroke from the larger switching stroke required by the reed switch, allowing the button to travel only a few tenths of a millimeter while the operating element travels several millimeters to reliably actuate the reed switch
3Length of moving object
If conventional electrical contacts are used, then button stroke is reduced, but contacts are susceptible to oxidation resulting in variable electrical contact resistance
Solution Approach 1:
Physical electrical contacts are replaced with a contactless magnetic field-based reed switch system. The permanent magnet generates a magnetic field that actuates the reed switch reeds without physical contact, eliminating oxidation and ensuring stable switching characteristics over time
Solution Approach 2:
The stroke-translating mechanism acts as an intermediary that allows the button to be pressed with minimal force and travel while still achieving the several millimeter displacement needed for the operating element to reliably trigger the reed switch, protecting the contacts from stress and oxidation
4Object-affected harmful factors
If a sealed button design is used to protect against dust and moisture, then environmental resistance is improved, but manufacturing complexity and cost increase
Solution Approach 1:
A flexible membrane serves as a protective seal enclosing the button, carrier unit, and reed switch assembly. The membrane allows the button to be pressed while protecting the internal components from dust, dirt, and moisture, creating a sealed design without complex manufacturing processes
Solution Approach 2:
The button, carrier unit, reed switch, and sealing membrane are combined into a single integrated sealed assembly. This merging of components simplifies manufacturing and ensures that all internal parts are protected together as one unit from environmental contaminants
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
Enables reliable switching with low wear and cost-effective production, supporting millions of switching cycles while maintaining precise switching states, even in harsh conditions, and is suitable for various applications including membrane keyboards and emergency stop switches.
Implementation Method 1
the contact element and the operating element being designed to interact directly with one another without contact
Implementation Method 2
a reed switch and permanent magnet interaction without contact
Data Source
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AI summary
The push-button switch comprises a carrier unit (1) which is movably connected to a key (2), in which a contact element (3), an operating element (4), and the key are secured at the carrier element. The contact element and the operating element are formed directly interacting with each other in non-contact manner. The key stroke of the key relative to the carrier unit is different from the switching stroke of the operating element relative to the contact element. A stroke-translating mechanism (5) is arranged between the key and the operating element.