Grooved Contact Assembly for Contaminant-Tolerant Power Switching
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Solution Overview
Problem
Contaminants on the mating surfaces of movable and fixed contacts in relays and contactors can prevent or degrade electrical connections, leading to unreliable performance.
Innovation Solution
The use of contacts with non-linear surfaces and grooved mating portions in an electrical assembly, where the grooves extend from top to bottom surfaces, providing multiple contact points that can penetrate contaminants and ensure a reliable connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional flat mating surfaces are used on contacts, then the structure is simple and easy to manufacture, but contaminants on the surface prevent reliable electrical connection
Solution Approach 1:
The contact surface is segmented into multiple grooves that divide the mating surface into distinct sections. This segmentation allows the contact to engage at multiple points along the grooves, ensuring that contaminants on any single point do not prevent overall electrical connection. The grooves create multiple engagement zones that independently contribute to the electrical pathway.
Solution Approach 2:
The contact surface transitions from a two-dimensional flat plane to a three-dimensional structured surface with grooves. This dimensional change creates depth and variation in the mating surface, allowing the contact to engage along the length of the grooves rather than at a single point, thereby bypassing surface contaminants through the vertical dimension.
2Reliability
If a single contact point is used between contacts, then the structure is simple, but contaminants can easily interfere with the electrical connection
Solution Approach 1:
The single contact point is segmented into multiple contact points distributed along the grooved surfaces. Each groove creates additional engagement points where the contacts meet, transforming one vulnerable contact point into multiple redundant contact points that collectively ensure reliable electrical connection even when contaminants are present.
Data Source
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AI summary
An electrical assembly 10 is adapted for switching power to a circuit having a power source. The electrical assembly 10 includes a housing 20 with current carrying contacts 20, 22 disposed in the housing. The current carrying contacts 20, 22 have engagement ends 32 with non-linear surfaces 34. A coupling member 44 is provided in the housing 20. The coupling member 44 has mating portions 48 for engaging the non-linear surfaces 34 of the current carrying contacts 20, 22. The mating portions 48 have grooves 70 provided thereon which extend from top surfaces 72 of the mating portions 48 toward bottom surfaces 74 of the mating portions 48. As the electrical assembly 10 is moved to a closed position, the grooves 70 of the mating portions 48 of the coupling member 44 are moved into engagement with the non-linear surfaces 34 of the contacts 20, 22, resulting in multiple contact points being provided between the non-linear surfaces 34 of each respective contact 20, 22 of the current carrying contacts 20, 22 and edges 78 of each respective groove 70 of the grooves 70 of the mating portions 48.