Tiltable Wheelchair Roller Guide Assembly for Compact Folding
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Solution Overview
Problem
Existing tiltable wheelchairs are not foldable, adding weight and increasing footprint, making them difficult to transport and maneuver, and their operation can be cumbersome, especially in pediatric models.
Innovation Solution
A tiltable wheelchair design featuring a tilt seat guide assembly with rollers and a link arm mechanism that allows the seat frame to tilt relative to the base frame, supported by a locking device for stability and adjustability, enabling compact folding and reduced operational effort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a tiltable feature is added to enable seat tilting, then the ability to relieve pressure injuries is improved, but the weight of the wheelchair increases
Solution Approach 1:
The tiltable feature is segmented into separate components: a tilt mechanism assembly with rollers, guide rails, and link arms that can be independently integrated into the wheelchair frame. This allows the tilting function to be added as a modular subsystem rather than redesigning the entire wheelchair structure, thereby minimizing weight increase.
Solution Approach 2:
The seat frame is made dynamically tiltable relative to the base frame through the link arm mechanism and roller assembly. The seat frame can rotate between a horizontal position (for normal seating) and a tilted position (for pressure relief), allowing the wheelchair to adapt its configuration based on operational needs without requiring multiple separate wheelchairs.
2Ease of operation
If a tiltable feature with limiting components is added, then the ability to control seat position is improved, but the footprint of the wheelchair increases
Solution Approach 1:
The tilt mechanism components are nested within the existing wheelchair structure. The roller assembly is positioned within the seat frame, the guide rails are integrated into the base frame, and the link arms connect existing structural elements. This nesting approach allows the tilting functionality to be embedded within the wheelchair's existing spatial envelope without significantly increasing its overall footprint.
3Adaptability or versatility
If manual tilting mechanism is added, then the ability to tilt the seat is improved, but the operational difficulty increases
Solution Approach 1:
The guide rails are designed with a curved or arc-shaped path that guides the roller through a smooth, controlled motion arc during tilting. This curved geometry naturally guides the user's pushing motion and reduces the operational effort required, as the mechanical path is optimized for the tilting motion rather than requiring complex mechanical advantage systems.
Solution Approach 2:
The roller acts as an intermediary element between the user's manual input force and the seat frame tilting action. The roller moves along the guide rail, converting the user's pushing motion into controlled rotational movement of the seat frame. This intermediary mechanism provides mechanical guidance and reduces the direct operational difficulty of manually tilting a heavy seat.
4Length of moving object
If the wheelchair is made compact for pediatric use, then the portability is improved, but the foldability is lost
Solution Approach 1:
The wheelchair frame is designed with localized folding capability at specific points rather than requiring the entire structure to fold. The cross-bar members and frame sections are configured to allow folding at strategic locations, enabling the wheelchair to be collapsed into a compact configuration for storage and transport while maintaining structural integrity during use. This local folding approach preserves compactness without sacrificing the foldability feature.
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 design achieves a lightweight, compact, and easily maneuverable tiltable wheelchair with reduced operational effort, allowing for efficient storage and transport while maintaining stability and ease of use.
Implementation Method 1
a first roller supported in relation to the tilt seat guide assembly for supporting a seat frame for movement in relation to the base frame. The first roller is movable along the tilt seat guide assembly in fore and aft directions to enable tilt of the seat frame in relation to the base frame.
Implementation Method 2
A link arm connected between the base frame and seat frame to urge the seat frame upward and rearward to tilt the seat frame as the first roller moves in a forward direction.
Implementation Method 3
A locking device may be provided for holding the seat frame in a desired position.
Data Source
AI summary
A tiltable wheelchair comprises a tilt seat guide assembly supported in relation to a base frame and a first roller supported in relation to the tilt seat guide assembly for supporting a seat frame for movement in relation to the base frame. The first roller is movable along the tilt seat guide assembly in fore and aft directions to enable tilt of the seat frame in relation to the base frame. A link arm may be connected between the base frame and seat frame to urge the seat frame upward and rearward to tilt the seat frame as the first roller moves in a forward direction. A second roller may be provided to cooperate with a guide rail, which is supported in relation to the tilt seat guide assembly, so as to track the movement of the first roller and prevent lateral translation of the seat frame in relation to the base frame. A locking device may be provided for holding the seat frame in a desired position.