Automotive Flat Cable Termination with Ferrule Crimping
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Solution Overview
Problem
The transition from round-wire harnesses to flat flexible cable systems in automotive electrical distribution systems requires redesigning electronic modules or using specialized adapters, which is labor-intensive and costly, and the thin metal wires in flat cables are prone to damage during handling.
Innovation Solution
The solution involves modifying the end terminations of flat flexible cables by folding the wires into zig-zag strips and crimping them with conductive metal ferrules to match the cross-sectional area of round wires, allowing the use of existing connector components and protecting the wires from damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If flat flexible cable systems are used to reduce system volume and weight, then heat dissipation is improved and mass is reduced, but the terminal ends become damaged during handling
Solution Approach 1:
The patent applies preliminary action by pre-attaching ferrules to the flat cable conductors at the factory before the cables are installed in the vehicle. This preliminary termination protects the conductor ends from damage during subsequent handling, routing, and connection operations, eliminating the need for field workers to manually attach ferrules to delicate flat cable ends.
Solution Approach 2:
The ferrules serve as protective cushions for the thin flat cable conductors. By providing this protective layer beforehand, the conductors are shielded from mechanical damage, bending, and deformation that would otherwise occur during installation and handling, ensuring their integrity throughout the vehicle's service life.
2Volume of moving object
If flat flexible cable systems are used, then system volume and weight are reduced, but existing connector interfaces are incompatible
Solution Approach 1:
The patent changes the physical parameters of the flat cable conductors by attaching ferrules that transform their cross-sectional shape from flat to round. This parameter change enables the conductors to interface with existing round-wire connector designs without requiring redesign of the connectors themselves, thus maintaining compatibility while retaining the volume and weight benefits of flat flexible cables.
Solution Approach 2:
The ferrule acts as an intermediary component between the flat flexible cable system and the existing round-wire connector infrastructure. This intermediary element bridges the incompatibility gap, allowing the new flat cable technology to work with legacy connector designs and avoiding the need for complete system redesign.
3Weight of moving object
If thin metal wire traces are used in flat cables, then mass is reduced, but the wires are easily damaged during handling
Solution Approach 1:
The patent creates a composite structure by combining the thin flat metal conductor with a ferrule. This composite construction maintains the low mass advantage of the thin conductor while adding the mechanical strength and durability of the ferrule, resulting in a hybrid structure that exhibits both lightweight and robust properties.
Solution Approach 2:
The ferrule is placed over the thin flat conductor in a nested configuration, with the conductor inside the ferrule. This nesting arrangement protects the delicate conductor while maintaining a compact structure, allowing the thin wire to benefit from the protective enclosure without significant increase in overall size or mass.
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 approach enables seamless integration of flat flexible cables with existing connector systems, reducing the need for redesign and minimizing wire damage during handling, while maintaining compatibility with round-wire connectors and facilitating efficient heat dissipation.
Implementation Method 1
a ferrule or collar having a cylindrical shape and made of conductive metal with a sufficiently large inside diameter is placed over the folded planar strip and then crimped in order to compress the folded strip
Implementation Method 2
The wire ends may be comprised of very thin sheets (i.e., foil) of copper or aluminum that may be easily damaged, especially when the wire traces extend out from the insulating layers as an unsupported blade or finger
Implementation Method 3
Due to the increase in surface area of a flat wire relative to a round wires usually used in wiring harnesses, heat is more easily dissipated
Data Source
AI summary
An electrical distribution apparatus is adapted for use in a wiring harness of an automotive electrical system. A flat flexible cable has an insulating substrate embedding a plurality of flat wires. The flat cable has a cable end wherein the wires extend as exposed blade fingers, each finger having at least one lateral fold stacking a thickness of the respective finger. A ferrule is crimped over each stacked finger. A plurality of contact bodies each has a coupler end and a crimp end. Each crimped end has a pair of legs crimped onto a respective ferrule. A carrier block has a plurality of bores each receiving a respective coupler end. The carrier block carrying the coupler ends is configured to plug into an electronic module connector in the automotive electrical system.