Pull-Out Guide Spring Bar Clamping to Reduce Slippage and Wear

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Solution Overview

Problem

Existing pull-out guides for household appliances face issues with weak holding forces, slippage, and high wear due to rigid locking mechanisms, which lead to ineffective rail fixation and potential jams.

Innovation Solution

A pull-out guide with integrally formed spring bars on the rails that clamp the rolling element cage, creating frictional forces for secure rail fixation without additional components, using a clamping mechanism that avoids slippage and reduces wear by utilizing elastic design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a rigid locking device with an embossment is used to fix the rail position, then the structure is simple, but the holding force is low and slippage occurs

Engineering Contradiction:
Improvelocking device structureVSAvoidholding force
Core Design Contradiction:
Device complexityVSForce

Solution Approach 1:

The patent replaces the rigid locking mechanism with a dynamic spring bar that can flex and adapt. The spring bar is designed to be elastically deformable, allowing it to dynamically adjust to the rolling element cage and maintain optimal clamping force, thereby increasing holding force while maintaining structural simplicity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the physical state of the locking element from rigid to elastic. By using a spring bar with specific elastic properties, the system can vary the clamping force parameter dynamically, ensuring sufficient holding force without increasing structural complexity.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If a rigid embossment locking device is used, then the structure is simple, but wear is high and locking forces reduce over time

Engineering Contradiction:
Improvelocking device structureVSAvoidlocking force durability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The spring bar's elastic nature allows it to absorb and distribute wear more effectively. Instead of a rigid contact that concentrates stress, the flexible spring bar distributes the contact forces, reducing wear on both the locking device and the rolling element cage, thereby maintaining reliable locking forces over time.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

By changing from a rigid to an elastic material property, the system reduces the contact stress and distributes wear more evenly. This parameter change in material flexibility directly improves the durability and reliability of the locking mechanism over extended use.

Inventive Principle:
Principle #35Parameter changes

3Force

If additional locking components are added to increase holding force, then the holding force is sufficient, but the device complexity increases

Engineering Contradiction:
Improveholding forceVSAvoidnumber of components
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The spring bar integrates multiple functions into a single component: it provides the clamping force, acts as the locking element, and serves as a wear-compensating mechanism. This merging of functions achieves sufficient holding force without adding separate locking components, thereby maintaining device simplicity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The spring bar is designed as a multi-functional element that simultaneously provides structural support, locking force, and wear compensation. This universal component replaces what would traditionally require multiple specialized parts, achieving high holding force while minimizing component count.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Device complexity

If a rigid locking mechanism is used, then the structure is simple, but jams can occur due to unfavorable ball impact

Engineering Contradiction:
Improvelocking device structureVSAvoidoperation smoothness
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The flexible spring bar acts as a shock absorber, dynamically responding to impacts from the rolling elements. Instead of rigidly transmitting impact forces that could cause jamming, the spring bar flexes to absorb the shock, ensuring smooth operation while maintaining the simplicity of the locking structure.

Inventive Principle:
Principle #15Dynamics

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 reliable and durable rail fixation with adjustable holding forces, preventing slippage and jams, while maintaining a compact design suitable for various applications in household appliances and furniture.

Implementation Method 1

the elastic design of the spring bar prevents blockage of the drawer guide

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

forces are applied perpendicular to the longitudinal direction of the rails by the spring bar to the rolling element cage and the other rail, which leads to frictional forces that hold the movable rail

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4378355A1Pull-out guide
Publication Date: 2024.06.05 PAUL HETTICH GMBH & CO KG
  • EP4378355A1 patent drawingFigure 1A~1B
  • EP4378355A1 patent drawingFigure 2A~2B
  • EP4378355A1 patent drawingFigure 3A~3B

AI summary

An extension guide (1) comprises at least two rails (2, 5) movable relative to each other, between which rolling elements (13) held in a rolling element cage (14) are arranged and which can roll on raceways on the rails (2, 5), wherein the rails (2, 5) are detachably held in at least one position by a holding device (9), the holding device (9) comprising at least one spring bar (10) formed integrally with one of the rails (2, 5), by means of which the rolling element cage (14) can be clamped onto the other rail (2, 5). This allows the movable rail to be held in a predetermined position on the stationary rail by simple means.