Reciprocating Probe Plunger Contact Area and Resistance
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Solution Overview
Problem
Conventional spring-loaded contact probes face issues with reduced surface area of contact due to rough surfaces from the extrusion process, leading to increased electrical resistance and inconsistency in contact, which affects reliability, and the plating process struggles to cover crevices and rough surfaces effectively.
Innovation Solution
The solution involves a device with reciprocating conductive bodies and a resilient means that increase the surface area of contact between the plungers without the need for an electrically conducting barrel, using a non-conductive housing with through holes to bias the plungers in opposing directions, allowing for increased contact area and ease of plating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the barrel is made by extrusion process, then the manufacturing is simplified, but the surface becomes rough reducing contact surface area and increasing electrical resistance
Solution Approach 1:
The invention removes the barrel component entirely from the probe structure. The plungers move directly within the non-conductive housing without requiring a separate conducting barrel, thereby eliminating the surface roughness issue caused by extrusion processes while maintaining electrical conductivity through the plunger-to-plunger contact path.
Solution Approach 2:
Instead of plating the rough barrel interior to improve contact, the invention inverts the approach by making the plungers themselves the primary contact surfaces. The non-conductive housing replaces the conducting barrel, and electrical contact is achieved through the abutting plungers rather than through the barrel wall, thus avoiding the plating of rough surfaces altogether.
2Reliability
If galvanic plating is applied to protect against corrosion and reduce resistance, then protection is improved, but crevices and rough surfaces remain hard to plate effectively
Solution Approach 1:
The invention eliminates the barrel component that requires plating, removing the source of the plating problem. By using a non-conductive housing without internal crevices and relying on plunger-to-plunger contact, the design avoids the need to plate complex geometries entirely.
Solution Approach 2:
The invention applies protective coating only where necessary - on the external surfaces of the plungers and housing rather than attempting to coat the entire barrel interior. The critical contact surfaces between plungers receive attention, while non-critical areas are simplified, reducing manufacturing complexity.
3Reliability
If a conventional spring-loaded probe with barrel is used, then electrical contact is provided, but the surface area of contact is reduced due to rough surfaces
Solution Approach 1:
The invention removes the barrel that limits contact surface area. The plungers are exposed to move directly against each other within the non-conductive housing, creating larger contact surfaces between the abutting plungers without the constraint of a narrow barrel interior.
Solution Approach 2:
The invention transitions from contact through the barrel wall (one-dimensional contact path) to direct plunger-to-plunger contact (two-dimensional surface contact). This dimensional change allows for significantly larger contact area between the abutting plungers, reducing electrical resistance.
4Strength
If crimping is used to secure the plunger in the barrel, then the assembly is secured, but an extra manufacturing step is required
Solution Approach 1:
The invention removes the barrel component that requires crimping. The plungers are secured directly within the non-conductive housing using simpler methods such as snap-fits, clips, or adhesive bonding, eliminating the need for complex crimping operations on a metallic barrel.
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 significantly reduces electrical resistance and enhances reliability by increasing the contact surface area between the plungers, simplifies the manufacturing process, and eliminates issues associated with springs and plating on rough surfaces.
Implementation Method 1
a resilient means biasing the first reciprocating conductive body and the second reciprocating conductive body in opposing directions axially away from each other
Implementation Method 2
the first abutting body is slidably abutting the second abutting body, thereby providing electrical conductivity between the first reciprocating conductive body and the second reciprocating body
Data Source
AI summary
A device for providing electrical contact comprises a first reciprocating conductive body having a first abutting body at one end, a second reciprocating conductive body having a second abutting body at one end and a resilient means biasing the first reciprocating conductive body and the second reciprocating conductive body in opposing directions axially away from each other. The first abutting body is slidably abutting the second abutting body, thereby providing electrical conductivity between the first reciprocating conductive body and the second reciprocating body. In another embodiment, the first reciprocating conductive body, the second reciprocating body and at least one securing means are disposed within one of plurality of through holes of an elastic non-conductive housing body. The elastic non-conductive housing body biases the first reciprocating conductive body and the second reciprocating conductive body in opposing directions axially from each other.