Elastomer Keypad Carrier Layout for Clear Snap-Switch Feedback
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Solution Overview
Problem
Existing keypad designs with elastomeric support mats fail to provide satisfactory tactile and auditory feedback when using snap switches, as the structural design does not effectively transmit the necessary vibrations and noise for a high-quality user experience.
Innovation Solution
The keypad design features four clamping points around the housing cover recesses with spring tongues that extend along the outer circumference of the pushbuttons, providing increased spring length and pre-tensioning through clamping lugs to enhance tactile and auditory feedback by damping vibrations and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If pushbuttons are combined into a single elastomeric carrier mat, then assembly conditions are simplified, but tactile and auditory perception of snap switch actuation deteriorates
Solution Approach 1:
The elastomeric carrier is segmented into multiple independent support receptacles, each capable of individually supporting a pushbutton. This segmentation allows each pushbutton to be isolated and independently actuated against the snap-action switch, enabling proper tactile and auditory feedback while maintaining the simplified assembly benefits of a unified carrier structure.
2Ease of operation
If pushbuttons are arranged individually on an elastomeric carrier plate, then tactile perception can be adapted, but the switching click perception remains unsatisfactory and pushbuttons cannot be combined into a single unit
Solution Approach 1:
Multiple individually supported pushbuttons are merged into a single elastomeric carrier unit through the unified carrier structure. The carrier integrates multiple support receptacles and fastening points into one piece, allowing all pushbuttons to be combined into a single structural unit while maintaining the individual tactile characteristics of each button through its dedicated support receptacle.
3Ease of manufacture
If pushbuttons are mounted on a common support with spring tongues, then production is simplified, but tactile and auditory perception of switching operations deteriorates
Solution Approach 1:
Each support receptacle in the elastomeric carrier is designed with localized fastening characteristics tailored to its specific pushbutton. The fastening points and spring tongue configurations are optimized locally at each receptacle to provide appropriate tactile and auditory feedback, rather than using a uniform mounting approach across all pushbuttons.
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 allows for a more pronounced tactile and auditory perception of snap switch operations, improving the overall user experience by enhancing the structural unit's ability to transmit vibrations and noise, resulting in a more satisfying keypad interaction.
Implementation Method 1
The vibrations triggered by the actuation of a snap-action switch, which are transmitted via the snap-action switch to the respective pushbutton and from the pushbutton to the support clamped between the housing and the housing cover, cause structure-borne noise that cannot replicate the desired, comparatively quiet, low-reverberation click sound expected when actuating a high-quality keypad with pushbuttons guided with largely zero play. The inventive mounting of the pushbuttons by spring tongues of the elastomer support can at least dampen, if not suppress, vibrations that distort the desired click sound
Implementation Method 2
The pushbuttons locally assigned to the snap-action switches on the circuit board arranged in the housing can, due to the elastic properties of the carrier mat, be displaced in the cover recesses against the respective snap-action switches in order to establish the respective electrical switching connections on the circuit board
Data Source
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AI summary
A housing is described with a keypad consisting of pushbuttons (4) inserted into recesses (13) of a housing cover (5) and of an elastomeric carrier connecting the pushbuttons (4) to each other, which is clamped between the housing (1) and the housing cover (5), and with a circuit board (2) provided in the housing (1) which includes snap switches (3) that can be actuated by the pushbuttons (4).To ensure advantageous tactile and auditory perception of the switching operations, it is proposed that the carrier form four clamping points (8) for the pushbuttons (4) distributed around the recesses (13) of the housing cover (5), arranged in pairs opposite each other, as well as spring tongues (9) extending from the clamping points (8) to receive the pushbuttons (4), that ribs (10) projecting from the opposing clamping points (8) towards each other, and that the spring tongues (9) connecting the ends of the ribs to the pushbuttons (4) extend between the associated clamping points (8) and the pushbuttons (4) along the outer circumference of the pushbuttons (4).