Microswitch Contact Bridge Rotary Self-Cleaning Mechanism
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Solution Overview
Problem
Microswitches with movable and fixed contacts experience contact dirt accumulation, leading to unreliable current flow due to undefined contact bridge movement and frictional sequences during switching, which complicates self-cleaning mechanisms.
Innovation Solution
The contact bridge is designed to perform a rotary movement about an axis parallel to its longitudinal extent, ensuring a positively guided frictional movement between contacts, with levers and abutments facilitating consistent rubbing action for effective self-cleaning, and springs for compensating misalignments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the contact bridge is mounted on the plunger by means of springs to enable relative movement for self-cleaning, then contact cleaning capability is improved, but the position definition and force transmission during switching deteriorate
Solution Approach 1:
The contact bridge is designed to perform a rotary movement about an axis of rotation running parallel to its longitudinal extent during switching. This dynamic motion transforms the static spring-mounted connection into a controlled rotational mechanism that provides both self-cleaning through frictional movement and defined position control through the axis of rotation
Solution Approach 2:
The invention changes the movement parameter from linear floating motion to rotational motion. By defining a specific axis of rotation and controlling the rotational path, the system achieves both cleaning (through transverse friction) and position definition (through the constrained rotational path) simultaneously
2Reliability
If the contact bridge is allowed to move freely with springs for self-cleaning, then contact dirt removal is improved, but the sequence of movements at opposing contacts becomes undefined
Solution Approach 1:
The contact bridge executes a controlled rotary movement that defines the sequence of contact make and break. The rotation about a parallel axis ensures that opposing contacts follow a predetermined sequence, eliminating the randomness of free floating motion while maintaining self-cleaning through friction
Solution Approach 2:
The axis of rotation acts as an intermediary that mediates between the spring force and the contact movement. It translates the spring's pushing force into a controlled rotational sequence, ensuring both cleaning action and defined movement sequence at opposing contacts
3Reliability
If frictional movement between contacts is increased for better cleaning, then contact purity is improved, but excessive wear on contacts occurs
Solution Approach 1:
The rotary movement provides sufficient frictional cleaning action during the switching process without excessive force. The controlled rotation ensures cleaning is achieved through the necessary friction while the motion is limited to what is required for effective cleaning, preventing excessive wear
Solution Approach 2:
The self-cleaning action occurs continuously with each switching operation through the rotary movement. The frictional cleaning is integrated into the normal switching cycle, providing ongoing contact maintenance without requiring separate cleaning operations that might cause excessive wear
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 ensures reliable self-cleaning of contacts with each switching process, guaranteeing consistent current flow by maintaining identical frictional paths and preventing excessive wear, thereby enhancing the microswitch's operational reliability.
Implementation Method 1
a positively guided frictional movement takes place transversely to the longitudinal extent of the contact bridge
Data Source
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AI summary
The invention relates to a microswitch with at least two contact points, each with a moveable contact and a fixed contact, wherein the moveable contacts are arranged on a contact link, the contact link is capable of being moved by means of a plunger and can be moved over from a first switching position, in which contact points are open, into a second switching position, in which contact points are closed. During use of the microswitch, dirt may be deposited on the contacts, this having a disruptive effect on the microswitch, and in the worst case scenario, results in there no longer being a current flow in the closed position of the contact points. The intention is therefore to provide a microswitch with reliable self-cleaning. In this regard, the invention provides that the contact link is mounted in such a way that the contact link performs a rotary movement about an axis of rotation, which runs parallel to the longitudinal extent of said contact link, during closing and opening of the contacts, as a result of which a forced frictional movement transversely with respect to the longitudinal extent of the contact link takes place between the mutually opposite contacts of each contact point.