Sliding Rail Lock Structure With Shift Restrictor Against Bounce Release

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Solution Overview

Problem

Conventional sliding devices for automobile seats fail to ensure reliable locking and are prone to unintended locking release, especially due to vertical vehicle bounce, and excessive engagement force can lead to operation failures.

Innovation Solution

A sliding device with a lock mechanism that includes a rotatable engagement member, a first urging member, an operation member, and a shift restrictor, where the engagement member is kept in the locking position without excessive force, and can be released only with an applied operation force, using a lever plate with a first locking protrusion to prevent unintended release.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the wedge angle of lock tooth is decreased to increase friction force, then engagement force is improved, but operation feeling deteriorates and operation failure may occur

Engineering Contradiction:
Improveengagement forceVSAvoidoperation feeling
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The locking system is segmented into multiple lock teeth (first lock tooth and second lock tooth) arranged at different positions. Each lock tooth engages with corresponding locking holes independently, distributing the locking function across multiple elements rather than relying on excessive force from a single tooth with large friction.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different lock teeth are positioned at different locations along the upper rail, with each having its own engaging relationship with the lower rail. This local distribution of locking functions allows the system to achieve reliable locking without requiring excessive engagement force from any single tooth, thereby maintaining good operation feeling.

Inventive Principle:
Principle #3Local quality

2Reliability

If engagement force is increased to prevent unintended locking release, then reliability is improved, but operation complexity increases

Engineering Contradiction:
Improvelocking reliabilityVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The spring member continuously applies urging force to the locking member in advance, maintaining it in the locking position where lock teeth are engaged with locking holes. This preliminary action ensures that the locking mechanism is always prepared to prevent unintended release without requiring complex additional structures.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The spring member acts as an intermediary element that provides continuous urging force to maintain the locking state. This simple elastic intermediary prevents unintended locking release through continuous force application rather than through complex mechanical interlocking or excessive engagement force.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If lock tooth fitting is made too close to ensure friction force, then engagement force is improved, but operation failure occurs

Engineering Contradiction:
Improveengagement forceVSAvoidoperation reliability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

Multiple lock teeth are segmented along the upper rail at different positions, each engaging with corresponding locking holes. This segmentation allows the system to achieve sufficient total engagement force without requiring each individual tooth to have excessive friction, thereby avoiding operation failure while maintaining reliable locking.

Inventive Principle:
Principle #1Segmentation

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 effectively prevents unintended locking release without increasing the engagement force, maintaining reliable locking and reducing production costs and weight by integrating the lever plate and shift restrictor within the sliding device.

Implementation Method 1

a spring member that urges the locking member in a locking direction

Methodology Applied
Scientific EffectElastic force: Elasticity

Implementation Method 2

decrease a wedge angle of each lock tooth... for ensuring a friction force between the lock tooth and the lock hole with the aim of improving an engagement force

Methodology Applied
Scientific EffectFriction force: Friction

Data Source

PatentEP4088966B1Sliding device
Publication Date: 2024.10.09 DELTA KOGYO CO LTD
  • EP4088966B1 patent drawingFigure 1
  • EP4088966B1 patent drawingFigure 2
  • EP4088966B1 patent drawingFigure 3

AI summary

Provided is a sliding device which can avoid unintended locking release without depending on an excessive engagement force of an engagement member. The sliding device (1) includes a lock mechanism (20) that locks an upper rail (3) to a lower rail (2). The lock mechanism (20) includes: an engagement member (5) that shifts in the upper rail between a locking position and a release position; a first urging member (11) that gives an urging force to the engagement member (5) in a direction from the release position to the locking position; and an operation member (7) for shifting the engagement member (5) from the locking position to the release position. The operation member (7) comprises a shift restrictor (7c) that keeps the engagement member (5) from shifting to the release position when the engagement member (5) is in the locking position.