Foldable Rolling Bearing Cage With Snap Lock for Pull-Out Guides

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Solution Overview

Problem

Existing rolling element cages for furniture pull-out guides are limited by their simple geometric shape and require multiple separate work steps for equipping with rolling elements and installation, making the process cumbersome and inefficient.

Innovation Solution

A rolling element cage design featuring two separate side walls with radial plug-in locking mechanisms, including bistable leaf spring elements and snap fasteners, allows for easy assembly and precise positioning, preventing unintended loosening and enabling direct installation onto a guide without pre-lubrication issues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If rolling element cages are designed as one-piece injection molded bodies, then manufacturing simplicity is improved, but geometric shape complexity is limited and assembly complexity increases

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidassembly complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The rolling element cage is divided into two separate side wall components that can be manufactured independently using simple injection molding processes. Each side wall can be produced as a basic geometric shape, avoiding the complexity constraints of one-piece molding. The segmented design allows each component to be manufactured with simpler tools and processes while reducing overall assembly complexity through the plug-in locking mechanism.

Inventive Principle:
Principle #1Segmentation

2Shape

If rolling element cages are designed as separate side walls, then geometric shape complexity is improved, but connection stability may worsen without proper locking mechanisms

Engineering Contradiction:
Improvegeometric shape complexityVSAvoidconnection stability
Core Design Contradiction:
ShapeVSStability of the object's composition

Solution Approach 1:

The plug-in locking mechanism is pre-formed as an integrated feature of each side wall component during injection molding. The locking protrusions and receptacles are built into the basic geometric shapes of the side walls before assembly, ensuring that connection stability is achieved without requiring additional stabilization features or complex post-assembly operations. This preliminary incorporation of locking features maintains connection stability while preserving geometric flexibility.

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If multiple separate work steps are used for equipping and installation, then manufacturing precision is improved, but productivity decreases

Engineering Contradiction:
Improveequipping precisionVSAvoidinstallation efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The design combines the equipping of rolling elements and the installation of the cage into a single integrated operation. The separate side walls with plug-in locking mechanisms allow the cage to be assembled and installed on the rail in one continuous motion, eliminating the need for separate equipping and installation steps. This merging of operations maintains precision through the self-aligning locking features while dramatically improving productivity by reducing the number of discrete work steps.

Inventive Principle:
Principle #5Merging (Combining)

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

This design simplifies the production and installation of rolling element cages, reduces assembly complexity, and allows for targeted lubrication, while preventing connection loosening and reducing component variants through efficient shaping during final assembly.

Implementation Method 1

The bending area has a film hinge, a gap and a bistable leaf spring element

Methodology Applied
Scientific EffectBistable leaf spring element: Metastability

Implementation Method 2

the snap fastener parts consist of a spherical head on one longitudinal edge and of a hollow cylinder on the opposite longitudinal edge, the spherical head being insertable into the hollow cylinder

Methodology Applied
Scientific EffectMechanical fastening: Mechanical Fastener

Data Source

PatentEP2356347B1Rolling bearing cage for a furniture pull-out guide
Publication Date: 2015.04.08 PAUL HETTICH GMBH & CO KG
  • EP2356347B1 patent drawingFigure 1~3
  • EP2356347B1 patent drawingFigure 4~8
  • EP2356347B1 patent drawingFigure 9~11

AI summary

The invention relates to a rolling bearing cage (1, 101) for a furniture pull-out guide, comprising at least two side walls (2, 3) with rolling bearing guides (5), wherein the side walls (2, 3) are connected along at least one of the longitudinal edges (10, 11) thereof by at least one flexible region so as to fold relative to one another, wherein the flexible region comprises detent means (6, 107) by means of which the side walls (2, 3) can be locked in a final position forming the rolling bearing cage (1, 101).