Snap Switch Position Sensing via Elastic Deformation
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Solution Overview
Problem
Existing snap switches face reliability issues due to discrepancies between actuation and actual operation, particularly in terms of durability and noise generation from repeated friction between electrical contacts.
Innovation Solution
The design incorporates a sensing switch and a detecting switch with elastically deformable blades and a cam-shaped actuator to accurately sense and detect the position changes of the pushbutton and tilting driving member, ensuring precise switching states and reducing friction through a modular and simplified conductive unit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If sliding movable contacts are used in the swaying conductive element, then noise generation is reduced, but durability is affected due to repeated frictions between electrical contacts
Solution Approach 1:
The patent extracts the sensing function from the main switching mechanism by introducing a separate sensing switch with elastically deformable blades. This separates the low-friction sensing operation from the high-friction switching operation, allowing sliding contacts to be used in the sensing mechanism without compromising the durability of the main switching contacts.
Solution Approach 2:
The elastically deformable sensing blades act as intermediaries between the pushbutton actuation and the switching mechanism. These blades transmit positional information without requiring direct friction-based contact, thereby reducing wear while maintaining noise reduction benefits of sliding contacts.
2Reliability
If a sensing switch with elastically deformable blades is introduced to accurately sense position changes, then reliability is improved, but device complexity increases
Solution Approach 1:
The patent merges the sensing switch with the existing switching unit by integrating the elastically deformable blades into the same housing and utilizing the same actuation mechanism. The sensing blades are positioned to be actuated by the same pushbutton movement that operates the main switching mechanism, thereby combining sensing and switching functions in a unified structure.
Solution Approach 2:
The elastically deformable sensing blades serve multiple functions: they sense the position of the pushbutton, detect the state of the switching mechanism, and provide mechanical coupling between these elements. This multi-functionality reduces the need for separate dedicated sensing components, thereby limiting the increase in device complexity.
3Reliability
If the pushbutton and tilting driving member positions are accurately detected, then discrepancies between actuation and operation are reduced, but manufacturing precision requirements increase
Solution Approach 1:
The patent utilizes the elastic deformation parameter of the sensing blades to create a compliant sensing mechanism. By allowing the blades to deform elastically within a controlled range, the system can accommodate minor manufacturing variations and tolerances in the positioning of the pushbutton and driving member, thereby reducing the stringency of manufacturing precision requirements while maintaining accurate position detection.
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 solution enhances the reliability and durability of the snap switch by accurately reflecting the actuation positions, reducing noise, and maintaining consistent operation, making it suitable for applications like electronic parking brakes and automotive systems.
Implementation Method 1
at least one elastically deformable conductive sensing blade, said sensing blade being movable between a rest position associated with the pushbutton upper position and an active position associated with the pushbutton lower position
Implementation Method 2
a traction spring having a first end operatively connected to the housing and a second end secured to the swaying element, such that when the pushbutton is in the first upper pushbutton position, the spring is in a first spring position and the spring causes the swaying element to electrically connect a first pair of conductive fixed contacts
Implementation Method 3
the switch comprises a return spring that is disposed between said housing and said pushbutton, in which, when an external force applied to said pushbutton is removed, said pushbutton is returned back to its original said first active position by the return spring
Data Source
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AI summary
The invention proposes a switch comprising an actuation member in the form of a pushbutton (18) comprising an actuating portion (28) being arranged, when an external force is applied to the pushbutton (18), to be moved vertically relative to the housing between a pushbutton upper position and a pushbutton lower position, said pushbutton (18) and a tilting driving member (84) forming a movable mechanical assembly, characterized in that it comprises electrical switching means (100, 200) for generating signals representative of changes of position of the one (18) and/or of the other (84) of the two components of the movable assembly, said electrical switching means including a sensing switch (100) for sensing the changes of position of the pushbutton (18) between its upper position and its lower position, and a detecting switch (200) for detecting the changes of position of the tilting driving member (84) between its upper position and its lower position.