Serrated Electrical Contacts for Ice-Breaking Solenoid Switches
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Solenoid switches in cold climates face operational malfunctions due to ice accumulation on electrical contacts, which acts as an insulator and prevents proper mating, leading to malfunction of connected loads such as electric motors.
Innovation Solution
The implementation of serrated surfaces on both stationary and movable electrical contacts, which create pressure points that break through ice and ensure electrical connection, either by brazing serrated disks onto existing contacts or manufacturing them directly with serrated faces, allowing condensation to pool in valleys and preventing ice formation on peaks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional smooth electrical contacts are used, then the device structure is simple and manufacturing is easy, but ice accumulation on the contact surface prevents proper mating and causes operational malfunction in cold climates
Solution Approach 1:
The contact surface is segmented into multiple serrations or teeth that protrude from the surface. This segmentation creates discrete contact points while maintaining the overall contact surface functionality, allowing the contact to break through ice accumulation and establish reliable electrical connection in cold climates
Solution Approach 2:
The contact surface has non-uniform geometry with localized protruding serrations that concentrate force at specific points. This local quality change enables the contact to penetrate ice accumulation at critical contact points while the rest of the surface maintains its mating function
2Reliability
If serrated surfaces are added to electrical contacts to break through ice, then reliability in cold climates improves, but manufacturing complexity and production difficulty increase
Solution Approach 1:
The contact is manufactured as an integrated piece with serrations formed directly during the molding or machining process, rather than assembling separate components. This segmentation is created in a single manufacturing step, maintaining ease of production while achieving the ice-breaking functionality
Solution Approach 2:
The contact surface geometry is modified by changing the molding parameters or machining parameters to create serrated patterns. By adjusting these parameters during the existing manufacturing process, the serrated feature is added without requiring entirely new manufacturing equipment or processes
Data Source
AI summary
Provided is a solenoid switch of a motor including a solenoid case, a solenoid having at least one control terminal for connection to at least one external control cable, two power terminals for connection to external power cables, two stationary serrated electrical contacts mounted within the solenoid case, where each serrated electrical contact is electrically connected to a corresponding one of the power terminals, two movable electrical contacts coupled to the solenoid and electrically connected to windings of the motor, where each movable electrical contact corresponds to one of the two serrated electrical contacts, and is movable by applied force of the solenoid. In response to a control signal received by the at least one control terminal, the solenoid is energized and moves the two movable electrical contacts to mate with the corresponding two serrated electrical contacts resulting in an electrical connection between the power cables and the motor windings.