Stroller Wheel Folding Mechanism with Independent Operating Handle

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Solution Overview

Problem

Existing manually operated carts, such as baby strollers, face challenges with complex and force-intensive folding mechanisms that couple wheel folding with the collapsing of the carrier frame, limiting flexibility and ease of use.

Innovation Solution

A separate manually manipulable operating handle allows independent folding of the front and back wheels, enabling them to be positioned either for driving or stowing without affecting the carrier frame's position, using a force-transmitting device with tie rods and sleeve elements to facilitate simultaneous folding and unfolding of the wheels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the folding mechanism is coupled to the collapsing of the carrier frame, then the structure is simplified, but the flexibility and ease of operation deteriorate

Engineering Contradiction:
Improvefolding mechanism structureVSAvoidwheel positioning flexibility
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The folding mechanism is separated from the carrier frame collapsing mechanism into independent systems. The operating handle controls wheel folding through a dedicated force-transmitting device with tie rods, while the carrier frame can be collapsed independently. This segmentation allows wheels to be folded or unfolded without necessarily collapsing the carrier frame, providing greater operational flexibility.

Inventive Principle:
Principle #1Segmentation

2Strength

If the folding mechanism requires significant hand force, then the structural strength is maintained, but the ease of operation deteriorates

Engineering Contradiction:
Improvefolding mechanism durabilityVSAvoidwheel folding effort
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

A force-transmitting device comprising tie rods and sleeve elements acts as an intermediary between the operating handle and the wheels. The tie rods transmit the user's input force efficiently to pivot the wheels, while the sleeve elements guide the motion. This intermediary mechanism amplifies the user's input force, reducing the effort required to fold or unfold the wheels while maintaining structural durability.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If the operating handle is integrated into the carrier frame, then the device complexity is reduced, but the ease of operation deteriorates due to soiled wheels

Engineering Contradiction:
Improvehandle integrationVSAvoidhandle accessibility
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The operating handle is extracted from the carrier frame structure and positioned separately above the wheels. This allows the user to operate the folding mechanism without touching the soiled wheels or the carrier frame, improving hygiene and ease of operation. The handle remains functionally connected to the wheels through the force-transmitting device with tie rods, maintaining mechanical efficiency while improving user accessibility.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP3127775B1cart
Publication Date: 2019.10.02 E H B CONSULTING GMBH
  • EP3127775B1 patent drawingFigure 1~2
  • EP3127775B1 patent drawingFigure 3
  • EP3127775B1 patent drawingFigure 4

AI summary

A cart (1), in particular a baby stroller, comprising a bottom frame (2), at least two back wheels (3) and at least one front wheel (4) mounted to the bottom frame (2), a carrier frame (5) mounted to the bottom frame (2), the carrier frame (5) being arranged for carrying a carrier element, in particular a child seat (6), a collapsing mechanism (12) for bringing the carrier frame (5) from a carrying position into a collapsed position and a folding mechanism (19) for folding the at least two back wheels (3) and the at least one front wheel (4) from a drive position into a stow position, characterized in that the folding mechanism (19) comprises an operating handle (20) separate from the carrier frame (5) such that the at least two back wheels (3) and the at least one front wheel (4) may be folded into the stow position independently of the collapsing mechanism (12) for bringing the carrier frame (5) into the collapsed position.