Cable Termination Wedge Prevents Slippage Without Severing
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Solution Overview
Problem
Existing cable termination methods, especially for multi-stranded cables in inaccessible locations, face issues with slippage under high tensile forces and require costly and time-consuming resin application, and often necessitate severing the cable for maintenance, which is undesirable.
Innovation Solution
A cable termination apparatus comprising a frustoconical inner plug and semicircular socket pieces that form a tapered center bore, allowing selective attachment and wedging of the plug into the bore under tensile force, preventing slippage without severing the cable.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a clamp or high strength epoxy or polyester resin is used to hold the end connector to the cable, then the connection is initially secure, but slippage occurs when high tensile forces are applied
Solution Approach 1:
The patent employs a conical wedge shape (curved geometry) where the wedge taper angle is specifically designed to be less than the angle of repose of the resin material. This curved geometric relationship ensures that under tensile load, the frictional force generated by the normal pressure exceeds the applied force, preventing slippage while maintaining connection strength
Solution Approach 2:
The invention changes the geometric parameters of the wedge (taper angle) and material properties (resin angle of repose) to create an optimal relationship where the wedge geometry ensures self-locking under load. By controlling the taper angle to be less than the angle of repose, the system transforms the application of tensile force into increased normal pressure and friction, converting the loading condition into a self-reinforcing mechanism
2Reliability
If resin coupling is used to terminate the cable, then the connection is secure, but additional installation time and effort are required to inject resin, bleed air, and allow curing
Solution Approach 1:
The resin is pre-loaded into the end connector before the cable is inserted. This preliminary preparation eliminates the need for time-consuming resin injection, air bleeding, and curing wait time during actual installation. The cable is simply inserted into the pre-filled connector, and the wedge geometry provides immediate mechanical engagement
Solution Approach 2:
The invention skips the traditional multi-step resin application process (injection, air bleeding, curing wait) by using pre-loaded resin and immediate mechanical wedging. The installation is rushed through by simply inserting the cable, which simultaneously engages the mechanical wedge and activates the pre-loaded resin, eliminating lengthy intermediate steps
3Reliability
If a cone and socket type strength termination with a small hole is used, then the end connector is securely held, but the cable must be severed during maintenance, which is costly and time-consuming
Solution Approach 1:
The end connector is segmented into modular components: an outer connector body, an inner wedge element, and a cable retention mechanism. This segmentation allows the connector to be disassembled and the cable to be removed and reinstalled without damaging the central core or requiring complete severing, enabling easy maintenance while maintaining secure holding
4Ease of repair
If the cable is severed during maintenance to replace the end connector, then the connector can be replaced, but the central core containing optical fiber and control wire is damaged, which is costly and time-consuming
Solution Approach 1:
The connector design segments the cable retention function from the central core, using an outer connector body and inner wedge mechanism that grip the cable strands without damaging the central optical fiber and control wire core. This allows the connector to be replaced while leaving the valuable cable core intact
Solution Approach 2:
The inner wedge acts as an intermediary element between the connector body and the cable strands. It provides the gripping force necessary for secure connection while being removable without damaging the cable core, serving as a sacrificial or reusable intermediate component that protects the valuable central core during installation and maintenance
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
The solution provides secure and reliable cable termination without slippage, allowing for maintenance without severing the cable, reducing installation time and costs, and maintaining the integrity of the cable connection.
Implementation Method 1
Tensile force exerted on the cable termination apparatus by the cable strands wedges the inner plug into the center bore
Data Source
AI summary
A cable termination system and method include providing an outer socket having a frustum shaped socket interior tapering from a base to a top opening. The outer socket is comprised of two semicircular socket pieces, each forming a portion of a complete circumference of the outer socket. A plurality of elongate cable strands extend through the socket interior with individual strands circumferentially spaced to form a single layer of strands at the base opening. A frustoconical inner plug is inserted into the socket by a compressive force exceeding a maximum tensile force of the stranded cable for holding the cable in the socket without slippage when a tensile force is applied between the cable and the outer socket. The inner plug includes a plurality of longitudinally extending, laterally separate plug subassemblies.