Harpoon Web Snap-Fit Sliding Bearing Assembly

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Solution Overview

Problem

Existing plain bearing arrangements for children's toys, particularly in baby walkers, face challenges with stability and durability due to increased load and friction, leading to reduced service life and potential instability.

Innovation Solution

A snap-in connection between a sliding bush and a retaining bush with harpoon webs and flange surfaces provides a secure, adaptable, and space-efficient bearing arrangement that absorbs loads with minimal friction, ensuring stability and durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a simple bushing or plain bearing is used in children's toys, then the device complexity is low and ease of manufacture is high, but the reliability and durability are reduced due to increased friction and load

Engineering Contradiction:
Improvebearing durabilityVSAvoidbearing structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The bearing assembly is divided into separate functional components: a sliding bush for low-friction movement and a retaining bush for structural support and positioning. This segmentation allows each component to be optimized for its specific function while maintaining overall simplicity of the assembly process

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The sliding bush is nested within the retaining bush, with the sliding bush positioned inside the retaining bush's inner diameter. This nested configuration allows the smaller sliding bush to provide low-friction surfaces while the larger retaining bush provides structural support, creating a compact and reliable bearing assembly without significant increase in overall size

Inventive Principle:
Principle #7Nested doll (Nesting)

2Stability of the object's composition

If brakes are applied to baby walkers to prevent uncontrolled rolling, then stability is improved, but the friction increases leading to reduced service life of the axle bearing

Engineering Contradiction:
Improvebaby walker stabilityVSAvoidaxle bearing service life
Core Design Contradiction:
Stability of the object's compositionVSDuration of action of stationary object

Solution Approach 1:

The sliding bush acts as an intermediary element between the axle and the retaining bush, providing a low-friction interface that mediates the interaction between the braking force and the bearing structure. This intermediary layer protects the bearing from excessive friction wear while still allowing the brake to function effectively

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The sliding bush changes the friction parameter at the bearing interface by providing a self-lubricating surface. This parameter change reduces the coefficient of friction between the axle and bearing, thereby extending service life while maintaining the stability provided by the brake system

Inventive Principle:
Principle #35Parameter changes

3Reliability

If a snap-in connection with harpoon webs is used between sliding bush and retaining bush, then the reliability and secure positioning are improved, but the manufacturing precision requirements increase

Engineering Contradiction:
Improveconnection reliabilityVSAvoidweb and web guide alignment
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The harpoon webs are designed with an asymmetric geometry featuring barbs that engage with the web guide in a single direction. This asymmetric design provides reliable one-way locking that is tolerant of manufacturing variations, as the barb structure naturally accommodates small misalignments while maintaining secure engagement

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The harpoon web design incorporates inherent compliance and tolerance buffering through the barb structure. The barb geometry is designed to accommodate expected manufacturing variations before engagement, providing a cushioning effect that maintains reliable connection despite variations in web guide alignment during assembly

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

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 enhances the stability and durability of the bearing arrangement, allowing for reliable axial and rotational support while minimizing friction, thus extending the service life and ensuring safe operation of children's toys.

Implementation Method 1

the plain bearing arrangement is capable of reliably absorbing the loads that are to be expected in use in a child's toy and at the same time permitting the axle to slide with little friction in the plain bearing arrangement

Methodology Applied
Scientific EffectFriction reduction: Lubrication

Implementation Method 2

The snap-in connection is easy to assemble and ensures a reliable connection between the sliding bush and the retaining bush

Methodology Applied
Scientific EffectSnap-in connection: Elasticity

Implementation Method 3

the holding area can be held clamped at least partially between a flange face of the sliding bush and a flange face of the retaining bush

Methodology Applied
Scientific EffectClamping force: Mechanical Force

Implementation Method 4

the retaining bush can have at least one web which extends in the direction of the slide bush and can be guided on a web guide of the slide bush

Methodology Applied
Scientific EffectMechanical guidance: Mechanical Force

Data Source

PatentEP3348851B1Sliding bearing assembly for an axle of a childýs toy and the use thereof and a child's toy with sliding bearing assembly
Publication Date: 2019.09.04 HABERMAASS
  • EP3348851B1 patent drawingFigure 1
  • EP3348851B1 patent drawingFigure 2
  • EP3348851B1 patent drawingFigure 3

AI summary

To improve a sliding bearing arrangement for an axle of a child's toy, comprising a sliding bushing designed to be received at least partially in an axle bore and having a receptacle for the sliding support of an axle, and a retaining bushing connected to the sliding bushing by a snap-fit ​​connection and designed to hold the sliding bushing in the axle bore, wherein the retaining bushing has at least one web extending towards the sliding bushing and guided on a web guide of the sliding bushing; in such a way as to ensure a reliable, stable and durable sliding bearing and to allow the simplest possible assembly, it is proposed to design the web at least on one side as a harpoon web, and in particular to hold it in snap-fit ​​engagement with the sliding bushing by means of a harpoon web guide.