Rotation Joint Two-Stage Lock to Prevent Accidental Unlocking
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Solution Overview
Problem
Conventional joint structures for household items like baby beds and strollers lack a reliable two-stage locking mechanism, leading to unsafe usage due to easy unlocking by inadvertent touch.
Innovation Solution
A rotation joint structure featuring a fixed joint, movable joint, primary and secondary springs, slide knob, first and second limit members, and a movable rod, which creates a two-stage locking mechanism by extending springs to lock the joint and prevent accidental unlocking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single locking mechanism is used in the conventional joint structure, then the device complexity is reduced, but the reliability of the locking mechanism deteriorates as it can be easily unlocked by inadvertent touch
Solution Approach 1:
The locking mechanism is divided into two independent stages: a first locking mechanism with a first locking block and first locking groove, and a second locking mechanism with a second locking block and second locking groove. This segmentation allows each locking stage to provide independent security, significantly improving overall locking reliability while maintaining reasonable device complexity through modular design
Solution Approach 2:
The first locking mechanism engages first to secure the movable joint to the fixed joint, creating a preliminary locked state. Subsequently, the second locking mechanism engages to provide an additional layer of security. This preliminary action sequence ensures that the joint is securely locked through multiple stages, preventing accidental unlocking while maintaining a systematic approach to complexity management
2Reliability
If a two-stage locking mechanism is implemented, then the reliability and safety of the joint structure is improved, but the device complexity increases due to additional components
Solution Approach 1:
Both locking mechanisms are integrated into a single rotational operation of the movable joint. The first and second locking blocks and grooves are positioned such that one rotational movement simultaneously engages both locking stages, merging the function of two locking mechanisms into a unified operational sequence. This reduces operational complexity while maintaining the reliability benefits of two-stage locking
Solution Approach 2:
The movable joint structure serves multiple functions: it provides the primary rotational connection between fixed and movable joints, incorporates both first and second locking mechanisms for enhanced safety, and enables a single operational interface for engaging both locks. This multi-functionality reduces the need for separate control mechanisms, thereby managing device complexity while improving reliability
3Reliability
If the locking mechanism is designed to be secure against inadvertent touch, then the reliability is improved, but the ease of operation deteriorates as deliberate action is required for unlocking
Solution Approach 1:
The first locking mechanism engages first during the normal locking operation, creating a preliminary secured state. The second locking mechanism then engages subsequently, requiring a deliberate and complete rotational action. This preliminary action sequence ensures that accidental touches cannot easily unlock the joint, while the structured two-stage process remains manageable through clear operational feedback
Solution Approach 2:
The locking mechanism transitions through distinct dynamic states: unlocked, first lock engaged, and both locks engaged. The movable joint rotates through specific angular positions that correspond to each locking stage, providing dynamic operational feedback. This dynamic behavior makes the unlocking process deliberate and controlled, improving reliability while maintaining operational clarity through observable state 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
The two-stage locking mechanism ensures the movable joint is locked solidly and steadily, preventing accidental rotation and enhancing safety by requiring deliberate action for unlocking.
Implementation Method 1
at least one primary spring mounted in the at least one primary receiving slot and having a first end pressing one end of the at least one primary receiving slot and a second end pressing the at least one resting portion
Implementation Method 2
secondary spring mounted in the secondary receiving slot and having a first end pressing the protruding block and a second end pressing one end of the secondary receiving slot
Data Source
AI summary
A rotation joint structure includes a fixed joint, a movable joint, a first limit member, and a second limit member. The fixed base has a locking groove. The movable joint is pivotally connected with the fixed joint. The movable joint has a first slideway and a second slideway connected to each other. The first limit member is movably mounted in the first slideway. The second limit member is movably mounted in the second slideway. When the second limit member is locked in the locking groove, and the first limit member stops the second limit member, the movable joint is locked and cannot be rotated. Thus, the movable joint is disposed at a two-stage locking state.