Stroller Frame Folding Mechanism for Compact Storage

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Solution Overview

Problem

Existing strollers have complex folding mechanisms, large folded sizes, and high production costs, making them inconvenient for daily storage and carrying.

Innovation Solution

A stroller with a novel frame structure and folding mechanism featuring a four-bar linkage and crank slider mechanisms, allowing for one-step unfolding and folding with a compact, flat folded design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If traditional stroller frame structures are used, then structural stability is maintained, but the folded size becomes large and the number of rod pieces increases

Engineering Contradiction:
Improvefolded sizeVSAvoidnumber of rod pieces
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

The stroller frame is divided into functional modules: front support assembly, rear support assembly, connecting rods, and transverse braces. Each module serves multiple functions - for example, the front support both bears weight and enables folding motion, reducing the need for separate structural components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The folding mechanism allows rod pieces to nest within each other during folding. The front support and rear support rotate relative to each other, enabling the frame to collapse into a compact configuration where components occupy overlapping spatial volumes, significantly reducing folded dimensions.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Volume of moving object

If complex folding mechanisms are used, then folded size is reduced, but the folding operation becomes cumbersome and requires multiple steps

Engineering Contradiction:
Improvefolded sizeVSAvoidfolding operation
Core Design Contradiction:
Volume of moving objectVSEase of operation

Solution Approach 1:

Multiple folding actions are merged into a single rotational motion. When the user rotates the front support relative to the rear support, this single action simultaneously triggers the folding of connecting rods, transverse braces, and wheel assemblies, achieving complete folding in one step rather than requiring sequential manipulation of multiple components.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The folding mechanism employs dynamic geometric relationships where rod lengths and connection points are designed to automatically guide the folding sequence. As the front support rotates, the connecting rods and transverse braces naturally follow predetermined paths, enabling smooth one-step folding without requiring the user to manually manipulate multiple joints or locks.

Inventive Principle:
Principle #15Dynamics

3Stability of the object's composition

If multiple rod pieces are used, then structural stability is maintained, but production cost increases

Engineering Contradiction:
Improvestructural stabilityVSAvoidproduction cost
Core Design Contradiction:
Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

Each rod piece is designed to perform multiple functions simultaneously. For example, the front support serves as both a structural load-bearing element and a folding actuator; the connecting rods provide both structural support and guide the folding motion. This multi-functionality reduces the total number of components needed, lowering production costs while maintaining stability.

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

Solution Approach 2:

The stroller frame employs asymmetric rod configurations optimized for specific functions. Rather than using identical symmetric rods throughout, different rod pieces are strategically designed with varying lengths, connection points, and orientations to achieve both structural stability and compact folding capability, reducing material waste and manufacturing complexity.

Inventive Principle:
Principle #4Asymmetry

4Loss of time

If traditional folding structures are used, then folded size is reduced, but the stroller requires plurality of steps for folding operation

Engineering Contradiction:
Improvefolding timeVSAvoidfolding mechanism
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The folding mechanism utilizes dynamic geometric relationships where rod lengths and connection points are precisely designed to automatically guide the folding sequence. As the front support rotates, the connecting rods and transverse braces naturally follow predetermined paths, enabling smooth one-step folding without requiring the user to manually manipulate multiple joints or locks.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The rod pieces and connection joints are pre-configured during manufacturing with specific geometries and pivot points that automatically guide the folding motion. This preliminary design ensures that when folding is initiated, all components follow their predetermined paths, eliminating the need for sequential user actions and reducing folding time to a single motion.

Inventive Principle:
Principle #10Preliminary action

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 stroller can be easily unfolded and folded by one hand, achieving a compact and neat folded state suitable for transportation and carrying, while maintaining structural stability.

Implementation Method 1

a four-bar linkage and crank slider mechanisms, allowing for one-step unfolding and folding

Methodology Applied
Scientific EffectFour-bar linkage: Four-Bar Linkage

Implementation Method 2

a four-bar linkage and crank slider mechanisms, allowing for one-step unfolding and folding

Methodology Applied
Scientific EffectCrank slider mechanism:

Implementation Method 3

the side support on each side comprises a front support, a rear support, a push rod and an upper supporting rod each extending along an up-down direction, an upper portion of the front support and an upper portion of the rear support are pivotally connected with each other

Methodology Applied
Scientific EffectRotation:

Data Source

PatentEP3632772B1stroller
Publication Date: 2023.07.05 GOODBABY CHILD PROD CO LTD
  • EP3632772B1 patent drawingFigure 1
  • EP3632772B1 patent drawingFigure 2
  • EP3632772B1 patent drawingFigure 3~4

AI summary

A stroller, comprises two side supports (100) respectively disposed on the left and right sides, and the side support (100) on each side comprises a front support (1), a rear support (2), a push rod (3), an upper support rod (4), an upper connecting rod (5), a rear connecting rod (6), a lower connecting rod (7), and a sliding member (8) disposed on the rear support (2) and capable of sliding up and down along the length extension direction of the rear support (2), wherein the rear connecting rod (6) is pivotally connected to the upper support rod (4), one end portion of the rear connecting rod (6) is pivotally connected with the sliding member (8), the other end portion of the rear connecting rod (6) is pivotally connected with a lower portion of the upper connecting rod (5), an upper portion of the upper connecting rod (5) is pivotally connected to the push rod (3), one end portion of the lower connecting rod (7) is pivotally connected to the front support (1), and the other end portion of the lower connecting rod (7) is pivotally connected with the sliding member (8). When a stroller frame is folded, the sliding member (8) slides downwardly along the rear support (2), and the upper support rod (4) rotates backward and folds up on a rear side of the rear support (2). The stroller frame can be unfolded or folded by pressing or pulling the push rod (3) with one single hand, and the folded frame is flat and neat, and has a volume small enough for transportation and carrying.