Collapsible Furniture Leg Assembly With Anti-Jam Telescopic Alignment
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Solution Overview
Problem
Existing collapsible outdoor furniture designs often jam during the collapsing process due to premature movement of upper leg segments relative to lower segments, leading to incomplete telescopic engagement and hindered size reduction.
Innovation Solution
A collapsible leg assembly with a central linkage and control links that ensure proper alignment and telescopic engagement of upper and lower leg segments, using spring-biased detent buttons for easy disassembly and a control link mechanism to prevent jamming by maintaining upper leg segments in extended positions until coaxial alignment is achieved.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If upper leg segments are allowed to move freely during collapsing, then the collapsing process is simpler, but the furniture jams due to premature movement and incomplete telescopic engagement
Solution Approach 1:
The control link mechanism performs preliminary alignment of the upper and lower leg segments before telescopic engagement occurs. The control link maintains the upper leg segment in an extended position during the initial collapsing movement, ensuring proper coaxial alignment is achieved before the segments engage telescopically, thereby preventing premature engagement and jamming
Solution Approach 2:
The control link acts as an intermediary mechanism between the upper and lower leg segments. It controls and coordinates their relative movement during the collapsing process, ensuring that the upper segment moves only after proper alignment is achieved, thus mediating the interaction to prevent jamming while maintaining reliable telescopic engagement
2Device complexity
If solid legs are used, then the furniture is simpler to construct, but the collapsed size is larger and portability is reduced
Solution Approach 1:
The leg is divided into multiple segments - specifically an upper leg segment and a lower leg segment - that can collapse relative to each other. This segmentation allows the leg to reduce in length during collapse while maintaining structural integrity, achieving a compact collapsed size without requiring complex construction
Solution Approach 2:
The upper leg segment is designed to telescope within the lower leg segment during collapse, similar to nested dolls. This nesting arrangement allows the furniture to achieve minimal collapsed size by housing one segment within another, significantly reducing the volume of the collapsed article while maintaining simple construction
3Volume of moving object
If telescopic leg segments are used, then the collapsed size is minimized, but the mechanism becomes more complex and may jam
Solution Approach 1:
The control link serves multiple functions: it aligns the upper and lower leg segments, controls the timing of telescopic engagement, prevents premature movement, and ensures smooth collapsing operation. This multi-functionality reduces the need for additional separate mechanisms, keeping the overall device complexity manageable while achieving minimal collapsed size
Solution Approach 2:
The control link mechanism is designed to automatically perform alignment and coordination of the telescopic segments during the collapsing process. The mechanism self-regulates the movement sequence through its geometric configuration and mechanical constraints, eliminating the need for external control systems or complex actuation mechanisms
Data Source
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AI summary
Collapsible articles of furniture are provided which have at least one leg assembly which includes a first leg and a second leg. The first leg has a first upper leg segment and a first lower leg segment coupled to the upper leg segment by a first link and the second leg has a movable second upper leg segment and a fixed second lower leg segment coupled to the upper leg segment by a second link. The two links are pivotally connected to each other for movement between an open position wherein the first and second legs cross each other to form a generally X- shaped configuration and a closed position wherein the upper and lower leg segments are aligned with each other and the upper leg section of the first leg is received within the lower leg section of the second leg and is aligned with and telescopically received within the lower leg section of the first leg. The pair of control links pivotally supported in a space between the link plates move in response to movement of the plates prevent telescopic connection between the upper and lower leg segments and prevent the upper leg segments from being telescopically received within the lower leg segments until a predetermined condition of alignment between the upper and lower leg segments has been attained.