Cable Drum Nipple Chamber for Secure Window Regulator Assembly

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Solution Overview

Problem

Existing cable drive devices for window regulators in motor vehicles face challenges in reliable assembly of the traction cable on the cable drum, particularly in securely inserting the cable nipple into the nipple chamber, leading to assembly errors due to mismatched sizes and difficulty in automated insertion.

Innovation Solution

The cable drive device incorporates a cable drum with a central receiving opening and a nipple chamber featuring a limiting element, such as an oval or teardrop-shaped rib, which securely engages the cable nipple, preventing it from sliding out and ensuring reliable assembly through a snap-like or clip-like mechanism, utilizing an electric motor with a reduction gear for efficient operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the nipple chamber is made larger than the rope nipple to facilitate insertion, then the insertion process becomes easier, but the rope nipple can slip out of the nipple chamber during assembly

Engineering Contradiction:
Improveease of insertionVSAvoidretention of rope nipple
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The nipple chamber is designed with an asymmetric cross-sectional shape that does not match the circular cross-section of the rope nipple. The chamber has a flattened side with a reduced width section that creates a mechanical interference fit, preventing the circular rope nipple from slipping out while still allowing insertion from one direction.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent introduces an intermediate geometric feature (the flattened asymmetric section of the nipple chamber) that mediates between the rope nipple and the drum body. This intermediate structure provides both the clearance needed for insertion and the mechanical constraint needed for retention.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If automated insertion of the rope nipple is implemented, then assembly efficiency increases, but the precision requirements for alignment and positioning become more stringent

Engineering Contradiction:
Improveassembly efficiencyVSAvoidalignment precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The asymmetric shape of the nipple chamber provides inherent alignment guidance for automated insertion systems. The unique non-circular cross-section ensures that the rope nipple can only be inserted in the correct orientation, eliminating the need for complex alignment procedures while maintaining high assembly efficiency.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The geometric design of the nipple chamber enables self-alignment during automated insertion. The asymmetric flattened section automatically guides the rope nipple into the correct position as it is being inserted, reducing the precision requirements for the automated insertion system.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4015848B1Cable drive device of a motor vehicle
Publication Date: 2024.02.14 BROSE FAHRZEUGTEILE GMBH & CO KG
  • EP4015848B1 patent drawingFigure 1
  • EP4015848B1 patent drawingFigure 2~3
  • EP4015848B1 patent drawingFigure 4

AI summary

The invention relates to a cable drive device (8) of an adjustment system (1) of a motor vehicle, comprising an actuator (11) and a cable drive housing (9) in which a cable drum (10) rotatably coupled to the actuator (11) with a wound-up traction cable (5) is received, wherein the cable drum (10) has on at least one end face (10b, 10c) for receiving a cable nipple (24a, 24b) attached to the traction cable (5) a nipple chamber (23, 25) with a chamber opening (27) and with spaced-apart chamber walls (28), and wherein the nipple chamber (23, 25) has on at least one of the chamber walls (28) a limiting element (29) which the cable nipple (24a, 24b) engages when inserted through the chamber opening (27) into the nipple chamber (23, 25).