Baby Carriage Handle Joint Locking Against Accidental Opening

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Solution Overview

Problem

Existing baby carriages with foldable structures face issues where the handle and/or canopy may automatically open during carrying, complicating transportation and storage, especially for air travel.

Innovation Solution

A baby carriage design featuring pivotable handle joints with a limiting part that prevents automatic opening by blocking the pivot movement when folded, using elastic fingers or projections that deform elastically upon exceeding a threshold force to allow smooth unfolding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the baby carriage is designed with a foldable structure to reduce volume for carrying and storage, then the compactness and portability are improved, but the handle or canopy may automatically open during carrying, reducing reliability

Engineering Contradiction:
Improvefolded volumeVSAvoidanti-automatic-opening reliability
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The patent applies preliminary anti-action by designing a limiting part that proactively prevents the handle upper joint from pivoting back to the unfolded state. The limiting part creates a mechanical barrier that counteracts any force that might cause automatic opening during carrying, thus preventing the problem before it occurs rather than reacting to it afterward.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The limiting part serves as an intermediary element between the handle upper joint and the pivoting motion. It mediates the pivoting action by allowing controlled movement during intentional folding while blocking unintended reverse movement during carrying, thus resolving the contradiction between foldability and anti-automatic-opening reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the limiting part is designed to firmly block pivoting motion to prevent automatic opening, then the anti-automatic-opening reliability is improved, but the ease of manual unfolding may be reduced

Engineering Contradiction:
Improveanti-automatic-opening reliabilityVSAvoidunfolding ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The limiting part is designed with dynamic characteristics, being elastically deformable under sufficient force. During normal carrying, it firmly blocks pivoting motion to prevent automatic opening. However, when intentional unfolding force is applied, the limiting part can deform elastically to allow the pivoting motion, thus maintaining both reliability and ease of operation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The limiting part's mechanical properties are designed to change based on applied force. Under normal conditions, it maintains a rigid blocking state. When sufficient unfolding force is applied, its elastic properties allow it to deform and change state from blocking to permitting pivoting, thus resolving the contradiction between firm blocking and easy unfolding.

Inventive Principle:
Principle #35Parameter changes

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

Prevents accidental opening of the handle and canopy during folding and carrying, ensuring ease of transport while maintaining the ability to unfold smoothly when desired.

Implementation Method 1

the elastic finger is elastically deformed to allow the second pivoting part to pivot

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP4408721B1Baby carriage
Publication Date: 2026.04.22 WONDERLAND SWITZERLAND AG
  • EP4408721B1 patent drawingFigure 1
  • EP4408721B1 patent drawingFigure 2
  • EP4408721B1 patent drawingFigure 3

AI summary

A baby carriage has an unfolded state and a folded state, and includes a handle, a front leg, a rear leg. The handle, the front leg and the rear leg may be pivoted to the unfolded state or the folded state with respect to each other. The handle includes a handle upper joint and a handle lower joint, which may be pivoted to the unfolded state or the folded state with respect to each other. The baby carriage also includes a limiting part, and in the folded state, the limiting part prevents the handle upper joint from pivoting towards the unfolded state. The baby carriage can effectively prevent the handle or a canopy from being unfolded when the baby carriage is folded and carried.