Screwless Wire Terminal Clamp for Stable Stranded Connections
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrical wire terminations, particularly direct pressure and screw and clamp types, are prone to issues such as wire damage, poor connections, and strand relaxation in stranded wires, leading to increased resistance and overheating, which necessitates re-torquing of terminal screws, thereby increasing costs.
Innovation Solution
The development of a twist lock electrical receptacle with screwless wire terminals that utilize a clamp brace and a force applying member, along with an activating member, to securely clamp wires without the need for screws, ensuring a constant and continuous mechanical connection and reducing the risk of strand relaxation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If direct pressure type terminations are used, then the wire terminal can be simple in structure, but the wire may be cut or nicked causing poor electrical connections
Solution Approach 1:
The wire terminal is divided into multiple functional components: a fixed plate, a movable plate, and a cam member. The fixed plate provides structural support and initial wire positioning, while the movable plate applies clamping force. This segmentation allows each component to perform its specific function optimally without compromising wire integrity.
Solution Approach 2:
The installation process requires preliminary wire stripping and positioning between the plates before the cam member is actuated. This preliminary action ensures the wire is correctly positioned and protected from damage during the clamping process, preventing nicking while maintaining connection reliability.
2Strength
If screw and clamp type terminations are used, then the wire can be securely clamped, but strand relaxation occurs causing increased resistance
Solution Approach 1:
The terminal uses a dynamic cam mechanism that allows the movable plate to be easily actuated during installation to apply clamping force, then locks into a stable position. The cam member's geometric shape provides mechanical advantage, ensuring consistent clamping pressure that prevents strand relaxation over time while maintaining connection stability.
Solution Approach 2:
The cam mechanism is designed to maintain constant clamping pressure on the wire without requiring additional adjustment or torque application. Once the cam is actuated, the geometry of the cam profile automatically maintains the necessary force to prevent strand relaxation, making the connection self-sustaining without re-torquing.
3Reliability
If terminal screws are re-torqued to alleviate strand relaxation, then connection reliability improves, but installation and maintenance costs increase
Solution Approach 1:
The cam-based wire terminal is designed to maintain constant clamping pressure on the wire without requiring additional adjustment or torque application. Once the cam is actuated during installation, the geometry of the cam profile automatically maintains the necessary force to prevent strand relaxation, making the connection self-sustaining without re-torquing.
Solution Approach 2:
The cam mechanism provides continuous clamping force on the wire throughout the operational life of the connection. The mechanical design ensures that the clamping pressure is maintained constantly without interruption or degradation, preventing strand relaxation and eliminating the need for periodic re-torquing operations.
4Reliability
If increasing clamping force is applied to prevent strand relaxation, then connection reliability improves, but wire damage risk increases
Solution Approach 1:
The wire terminal is divided into multiple functional components: a fixed plate, a movable plate, and a cam member. The fixed plate provides structural support and initial wire positioning, while the movable plate applies clamping force. This segmentation allows each component to perform its specific function optimally without compromising wire integrity.
Solution Approach 2:
The installation process requires preliminary wire stripping and positioning between the plates before the cam member is actuated. This preliminary action ensures the wire is correctly positioned and protected from damage during the clamping process, preventing nicking while maintaining connection reliability.
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 provides a reliable and cost-effective electrical connection that minimizes wire damage and strand relaxation, maintaining consistent performance without the need for frequent re-torquing, thus reducing installation and maintenance costs while ensuring efficient electrical conductivity.
Implementation Method 1
The force applying member is movable relative to the clamp brace between a closed position where a wire can be clamped between the force applying member and the clamp brace
Data Source
AI summary
Electrical wiring devices that incorporate screwless wire terminal connections are described. The electrical wiring devices include for example, single and duplex electrical receptacles, locking electrical receptacles, single or multi-pole electrical switches, combination switches and receptacles, plugs for electrical cords, connectors for electrical cords, male and female inlet connectors, pin-in-sleeve connectors and multi-pole or multi-phase control switches. The electrical wiring devices include a plurality of contact assemblies. Each contact assembly includes a wire terminal and an activating member.