Pull-Out Guide Spring Bar Locking to Prevent Slippage and Jamming

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Solution Overview

Problem

Existing pull-out guides with rails and rolling elements face issues with low holding forces, slippage, and wear due to rigid locking mechanisms, which lead to ineffective fixation and potential jams.

Innovation Solution

A pull-out guide with integrally formed spring bars on the rails allows for releasable fixation by applying forces perpendicular to the rail's longitudinal direction, using the spring bar's clamping or latching mechanism to enhance holding forces and prevent slippage, eliminating the need for additional components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a rigid locking mechanism with a locking embossment is used, then the structure is simple, but the holding forces are low and slippage occurs

Engineering Contradiction:
Improvelocking mechanism structureVSAvoidholding forces
Core Design Contradiction:
Device complexityVSForce

Solution Approach 1:

The locking mechanism transitions from a rigid state to an elastic state by introducing a spring element. The spring bar can deform elastically under load, allowing it to maintain continuous contact with the rolling element and provide sustained holding forces without slippage, while still maintaining structural simplicity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The locking mechanism becomes dynamic through the spring bar that can move and deform. The spring element adapts its position and force application based on the operational state, providing active compensation for wear and play between components, thereby maintaining reliable locking forces throughout the service life.

Inventive Principle:
Principle #15Dynamics

2Device complexity

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

Engineering Contradiction:
Improvelocking mechanism structureVSAvoidlocking forces durability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The spring bar's elastic properties allow it to compensate for wear between the rolling element and the locking surface. As wear occurs, the spring can deform further, maintaining adequate contact pressure and locking forces throughout the component's service life, thereby extending the functional duration.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The dynamic spring mechanism continuously adapts to wear by adjusting its deformation state. This active compensation ensures that the locking forces remain reliable over time, preventing the degradation that occurs with rigid locking mechanisms where wear directly reduces contact pressure.

Inventive Principle:
Principle #15Dynamics

3Device complexity

If a rigid locking mechanism is used, then the structure is simple, but jamming can occur if the rolling element hits the embossment unfavorably

Engineering Contradiction:
Improvelocking mechanism structureVSAvoidsmooth movement
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The spring bar's elasticity allows it to deform and absorb impact shocks when the rolling element encounters the locking surface. This cushioning effect prevents hard impacts that could cause jamming, while the spring's recovery force ensures the locking action remains effective.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The spring element provides beforehand cushioning by being pre-loaded in an elastic state. When the rolling element contacts the locking surface, the spring absorbs the impact energy through elastic deformation, preventing the unfavorable hits that would cause jamming in rigid systems.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

4Force

If additional locking components are added to increase holding forces, then the holding forces improve, but the device complexity increases

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

Solution Approach 1:

The spring bar combines multiple functions into a single component: it provides the locking force, compensates for wear, cushions impacts, and maintains continuous contact with the rolling element. This integration achieves high holding forces without requiring multiple separate locking components.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The spring bar serves multiple functions simultaneously: it acts as a locking element, a cushioning element, a wear-compensation mechanism, and a force-application device. This multi-functionality delivers enhanced holding forces while avoiding the complexity of multiple specialized components.

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

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 elastic design of the spring bars provides increased holding forces and prevents blocking, ensuring reliable and durable fixation of the rail in various positions, suitable for applications in furniture and household appliances.

Implementation Method 1

a spring bar (10) that is formed integrally with one of the rails (2; 5) and is movable by one of the rolling elements (13). As a result, the rolling element (13) can be clamped or latched in place via the spring bar (10) by applying forces perpendicular to the longitudinal direction of the rails (2; 5) through the spring bar (10)

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

The holding forces are predetermined by the clamping forces of the movable, in particular bendable, spring bar (10), and blocking of the pull-out guide is prevented by the elastic design of the spring bar (10)

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP4378354A1Pull-out guide
Publication Date: 2024.06.05 PAUL HETTICH GMBH & CO KG
  • EP4378354A1 patent drawingFigure 1A~1B
  • EP4378354A1 patent drawingFigure 2A~2B
  • EP4378354A1 patent drawingFigure 3~4

AI summary

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