Four-Bar Stroller Frame Lock Mechanism for Compact Safe Folding
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Solution Overview
Problem
Conventional stroller frames have complex folding mechanisms that can lead to accidental folding, taking up a large area and being difficult to store, posing safety risks and convenience issues.
Innovation Solution
A stroller frame with a four-bar linkage structure and a lock mechanism at the pivot joint between the upper and lower support members, allowing for flexible folding and locking, featuring a lock mechanism with an engaging member and elastic members to prevent accidental folding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the stroller frame uses a conventional folding mechanism, then the stroller can be folded for storage, but the folding operation is complicated and prone to accidental folding
Solution Approach 1:
The folding mechanism is segmented into distinct functional components: a lock mechanism with locking and unlocking states, a four-bar linkage structure with specific pivot points, and an operating member. This segmentation allows each component to perform its specific function reliably, reducing the complexity of the overall operation while maintaining safety.
Solution Approach 2:
The lock mechanism automatically engages and disengages through the four-bar linkage structure's motion. When the stroller frame is folded or expanded, the linkage structure naturally drives the locking member to engage with the locking groove, providing self-locking functionality without requiring additional manual intervention, thus preventing accidental folding.
2Ease of operation
If the stroller frame is designed to be foldable, then storage convenience is improved, but the folded size is large and storage difficulty increases
Solution Approach 1:
The four-bar linkage structure enables the support members to nest closely together when folded. The parallel connection between the locking member and the operating member, combined with the linkage geometry, allows the frame to collapse into a compact configuration where components occupy minimal space, significantly reducing the folded volume for easier storage.
Solution Approach 2:
The folding mechanism transforms the stroller frame from a three-dimensional expanded structure to a compact folded state by utilizing angular changes at the pivot joints. The four-bar linkage converts linear folding motion into rotational movement at multiple joints, achieving compact packaging in multiple dimensions simultaneously.
3Reliability
If the lock mechanism is designed to secure the expanded frame, then safety is improved, but the mechanism complexity increases
Solution Approach 1:
The lock mechanism is merged with the four-bar linkage structure, sharing common components such as the locking member that serves both as part of the linkage and as the locking element. The operating member is integrated into the existing support member structure, reducing the number of separate components and simplifying the overall mechanism while maintaining reliable locking functionality.
Solution Approach 2:
The locking member serves multiple functions: it acts as a structural component of the four-bar linkage, provides the locking function by engaging with the locking groove, and simultaneously serves as a reference point for the operating member. This multi-functionality reduces the need for separate dedicated locking components, simplifying the overall mechanism.
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 frame can be safely and easily folded, reducing its size for convenient storage, while preventing accidental folding and ensuring stability in the expanded state.
Implementation Method 1
a first elastic member connected to the engaging member and configured to provide an elastic force for the engaging member to engage with the fixing member
Implementation Method 2
a second elastic member connected to the operating member and configured to provide an elastic force for the operating member to engage with the disengaging member to unlock the lock mechanism
Data Source
Figure 1
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AI summary
A stroller frame (100) includes a front leg (10), a bottom tube (30), a rear leg (20), an upper support member (40) and a lower support member (50). The front leg (10), the bottom tube (30), the lower support member (50) and the upper support member (40) are pivotally connected to each other to form a four-bar linkage structure. The rear leg (20) is connected to an end of the bottom tube (30). A lock mechanism (60) is disposed at a pivot joint between the upper support member (40) and the lower support member (50). The lock mechanism (60) is able to lock the upper support member (40) and the lower support member (50) at an expanded angle, such that the front leg (10) is able to be expanded with respect to the bottom tube (30). The lock mechanism (60) is unlocked to release the upper support member (40) and the lower support member (50), such that the front leg (10) is able to be folded with respect to the bottom tube (30).