Folding Trolley Frame With Rotatable Linkages for Stable Loads
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Solution Overview
Problem
Existing cart designs face challenges in achieving stable load capacity and convenient folding, with methods like lengthening cross diagonal rods or parallel connecting cross diagonal rods leading to instability, increased size, and poor support.
Innovation Solution
A frame design featuring side frame bodies with first and second folding assemblies, a middle connector, linkage connector, first and second linkages, and bottom frame transverse tubes, allowing for stable connections and easy folding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the cross diagonal rods of the chassis are lengthened to increase the cart length in the left and right direction, then the cart length in the left and right direction is increased, but the vertical cross diagonal rods become greater than the vertical rods on the sides after folding, which is inconvenient for storage, and the stability of the bottom structure is lowered, resulting in lower load capacity
Solution Approach 1:
The bottom frame member is divided into multiple segments: side frame bodies, bottom frame transverse tubes, middle connector, and linkage connectors. This segmentation allows the structure to achieve both extended length and compact folding, as each segment can be independently positioned and connected through rotatable joints.
Solution Approach 2:
The bottom frame transverse tubes are rotatably connected to the side frame bodies and middle connector, creating dynamic joints that enable the structure to transition between extended and folded states. This dynamic connection allows the cart to maintain stability in both configurations.
2Length of moving object
If multiple sets of cross diagonal rods are parallel connected to increase the cart length in the left and right direction, then the cart length is increased, but numerous and large voids are formed in the chassis, resulting in mediocre support effect and poor carrying capacity
Solution Approach 1:
The side frame bodies and bottom frame transverse tubes are merged into an integrated structure with the middle connector and linkage connectors. This merging eliminates the voids created by parallel cross diagonal rods while maintaining the extended length, as the components work together as a unified load-bearing structure.
Solution Approach 2:
The middle connector and linkage connectors act as intermediaries that connect the side frame bodies and bottom frame transverse tubes, providing structural support and eliminating the need for numerous cross diagonal rods. This intermediary connection achieves both extended length and strong support effect.
3Length of moving object
If the cross diagonal rods are lengthened to achieve increased cart length, then the cart length is increased, but the vertical cross diagonal rods protrude more in the up and down direction after folding, which is not convenient for storage
Solution Approach 1:
The rotatable connections between bottom frame transverse tubes, side frame bodies, and middle connector enable dynamic folding that reduces the vertical dimension. The structure can transition from an extended horizontal configuration to a compact folded configuration, minimizing storage volume.
Solution Approach 2:
The segmented structure with multiple rotatable joints allows different parts of the frame to fold at different angles and positions, enabling the overall vertical size to be minimized while maintaining the extended length when in use.
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 provides enhanced stability, increased load capacity, and improved folding convenience by ensuring the frame remains compact when folded, with better support and reduced vertical size protrusion.
Implementation Method 1
one end portion of each bottom frame transverse tube is rotatably connected to the middle connector, and the other end portion of each bottom frame transverse tube is rotatably connected to a corresponding one of the side frame bodies
Implementation Method 2
a first linkage, one end portion of the first linkage is rotatably connected to the middle connector and the other end portion of the first linkage is connected to the linkage connector; and second linkages that are arranged at an angle, one end portion of each second linkage is rotatably connected to a corresponding one of the linkage connectors and the other end portion is rotatably connected to a corresponding one of the side vertical tubes
Data Source
AI summary
A frame includes a central connector, the central connector is oppositely connected to bottom frame transverse pipes in the direction of side frame bodies, one end of each bottom frame transverse pipe is rotatably connected to the central connector, and the other end is rotatably connected to a side frame body; swing pipe connectors, the swing pipe connectors are arranged in the direction in which the central connector faces first folding assemblies; first swing pipes, one end of each first swing pipe is rotatably connected to the central connector, and the other end-of the first is rotatably connected to the swing pipe connector; and second swing pipes arranged by an angle, one end of each second swing pipe is rotatably connected to the swing pipe connector, and the other end of the second swing pipe is rotatably connected to a side vertical pipe.