Furniture Caster Braking Device with Composite Spring

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Solution Overview

Problem

Existing roller braking devices are either mechanically complex and expensive or have low mechanical resilience, failing to provide a cost-effective and reliable braking solution for preventing unintentional rolling of furniture castors.

Innovation Solution

A roller with a braking device featuring a spring-elastic housing part reinforced by a metal or fiber-reinforced plastic spring element, which increases braking force and mechanical load-bearing capacity, and a housing opening design allowing limited vertical displacement of the axle bolt for effective braking and release.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a simple spring formed in one piece with the plastic housing is used, then the manufacturing cost is reduced, but the mechanical load-bearing capacity and braking reliability deteriorate

Engineering Contradiction:
Improvemanufacturing costVSAvoidbraking reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent combines a plastic housing with a metal spring element to create a composite structure. The metal spring element is embedded in the plastic housing, providing high mechanical load-bearing capacity and braking reliability while maintaining cost-effectiveness through the use of inexpensive plastic for the housing structure.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent merges two different materials (plastic and metal) into a single integrated braking device. The metal spring element is embedded during injection molding to form a unified structure that combines the advantages of both materials: the cost-effectiveness and ease of manufacturing of plastic with the mechanical strength and reliability of metal.

Inventive Principle:
Principle #5Merging (Combining)

2Device complexity

If a spring-elastic housing part connected via web parts is used, then the structural simplicity is improved, but the mechanical load-bearing capacity deteriorates

Engineering Contradiction:
Improvestructural simplicityVSAvoidmechanical load-bearing capacity
Core Design Contradiction:
Device complexityVSStrength

Solution Approach 1:

The patent uses a composite structure where a metal spring element is embedded in the plastic housing to reinforce the spring-elastic housing part. This maintains structural simplicity while dramatically improving the mechanical load-bearing capacity through the high-strength metal component.

Inventive Principle:
Principle #40Composite materials

3Force

If the spring element directly contacts the axle bolt, then the braking force transmission is improved, but noise and wear increase

Engineering Contradiction:
Improvebraking force transmissionVSAvoidnoise and wear
Core Design Contradiction:
ForceVSObject-generated harmful factors

Solution Approach 1:

The patent uses the spring-elastic housing part as an intermediary between the spring element and the axle bolt. The spring element acts on the spring-elastic housing part, which in turn acts on the axle bolt, thereby transmitting the braking force while preventing direct contact between the spring element and axle bolt, thus reducing noise and wear.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 a cost-effective and mechanically reliable braking system that effectively prevents unintentional rolling of furniture castors while maintaining durability and reducing noise and wear.

Implementation Method 1

at least one spring element which interacts with the at least one spring-elastic housing part and increases its braking force effect and/or increases the mechanical load-bearing capacity of the at least one spring-elastic housing part

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the housing opening for the axle bolt allowing limited vertical displacement of the axle bolt

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 3

against which a hub of the at least one wheel frictionally and/or positively rests in the first braking load state of the roller

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3548302B1Caster with braking device
Publication Date: 2022.04.20 GROSS & FROELICH GMBH & CO KG
  • EP3548302B1 patent drawingFigure 1a)~1c)
  • EP3548302B1 patent drawingFigure 2a)~2b)
  • EP3548302B1 patent drawingFigure 3a)~3c)

AI summary

The invention relates to a caster having a housing (10) and an axial pin (16) which is situated in a substantially horizontal housing opening (14, 14') and on which at least one wheel (18, 18') is mounted, having, at the top, a substantially vertical pivot pin opening (12) for accommodating a pivot pin, and having a braking device which brakes the at least one wheel (18, 18') in a first load state and releases the wheel in a second load state, wherein the housing opening (14, 14') for the axial pin (16) allows limited vertical displaceability of the axial pin (16) and the braking device comprises at least one resilient housing part (20, 20') which acts on the axial pin (16). In an alternative embodiment, the invention relates to a caster having a housing (10') and an axial pin (16) which is situated in a substantially horizontal housing opening (14') and on which at least one wheel (18, 18') is mounted, having, at the top, a substantially vertical pivot pin opening (12) for accommodating a pivot pin, and having a braking device which brakes the at least one wheel (18, 18') in a first load state and releases the wheel in a second load state, wherein the braking device comprises at least one resilient housing part. In order to provide a braking device which can be produced cheaply but is nevertheless mechanically reliable, the braking device, in a first variant of the invention, is additionally provided with at least one spring element (28, 28', 28'') which cooperates with the at least one resilient housing part (20, 20') and amplifies the effect of its braking force and/or increases the mechanical load-bearing capacity of the at least one resilient housing part (20, 20'). Alternatively, the substantially horizontal housing opening (14') is provided in a housing part (34) which is elastically vertically displaceable relative to the rest of the housing (14').