Sliding Door Locknut Mechanism for Vibration-Resistant Adjustment

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Solution Overview

Problem

Existing sliding door mechanisms face issues with locknuts that can loosen due to vibration, leading to improper operation or damage, and require precise torque control during assembly, which can be difficult to manage.

Innovation Solution

A sliding door movement mechanism with a locknut designed to resist predefined loads, featuring a cylindrical body without ribs and a hexagonal tightening cavity, requiring a special apparatus for intervention, ensuring secure attachment of the adjustment pin and preventing loosening.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a normal locknut is used to secure the adjustment pin, then the assembly is simple and easy to manufacture, but the locknut can loosen due to vibration leading to improper operation or damage

Engineering Contradiction:
Improvelocknut securityVSAvoidlocknut structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The locknut features an asymmetric design with a cylindrical outer surface that lacks rotational symmetry, combined with a hexagonal tightening cavity. This asymmetric geometry prevents the locknut from rotating freely and requires a specialized intervention apparatus with a matching hexagonal interface, thereby preventing loosening due to vibration while maintaining structural simplicity.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

A specialized intervention apparatus serves as an intermediary tool to tighten and secure the locknut. This apparatus features a hexagonal interface that engages with the locknut's tightening cavity, allowing controlled tightening without requiring the locknut to have complex anti-loosening features. The intermediary tool provides the necessary torque control while the locknut itself remains structurally simple.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a locknut with self-locking features is used to prevent loosening, then the reliability improves, but the device complexity increases

Engineering Contradiction:
Improveanti-loosening capabilityVSAvoidlocknut design
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Instead of incorporating complex self-locking features such as deformed threads or locking collars, the patent uses a simple asymmetric cylindrical shape combined with a hexagonal tightening cavity. This asymmetric geometry inherently prevents rotational loosening while maintaining a simple locknut structure that does not require additional self-locking mechanisms.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The specialized intervention apparatus acts as an intermediary that provides the anti-loosening function externally rather than embedding it within the locknut structure. The hexagonal interface of the apparatus engages with the locknut's tightening cavity, providing controlled tightening and preventing vibration-induced loosening without requiring the locknut itself to have complex self-locking features.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If precise torque control is required during assembly to prevent damage, then the reliability improves, but the ease of manufacture decreases

Engineering Contradiction:
Improveassembly precisionVSAvoidassembly process
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The specialized intervention apparatus serves as a torque-controlling intermediary during assembly. By designing the apparatus with a hexagonal interface that engages the locknut's tightening cavity, the system provides inherent torque control during tightening. This eliminates the need for complex torque monitoring equipment or specialized assembly procedures, as the apparatus itself controls the torque application to prevent over-tightening and component damage.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The locknut and intervention apparatus are designed to work together in a self-regulating manner. The hexagonal tightening cavity and matching apparatus interface create a mechanical relationship that naturally limits the torque that can be applied, preventing over-tightening without requiring external torque monitoring or control systems. The assembly process becomes simpler as the components guide the tightening process themselves.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4585780B1A sliding door movement mechanism
Publication Date: 2025.11.12 FORD OTOMOTIV SANAYI ANONIM SIRKETI
  • EP4585780B1 patent drawingFigure 1~2
  • EP4585780B1 patent drawingFigure 3~4

AI summary

The present invention relates to a sliding door movement mechanism (1), which connects the vehicle body and the sliding door for the free movement of the sliding door in the opening and closing direction within a guide rail, particularly in vehicles with sliding doors.