Folding Pulling Cart Scissor Frame for Wider Interior Space
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Solution Overview
Problem
Existing portable foldable pulling carts suffer from reduced interior width due to the configuration of scissor mechanisms that require adjacent connecting rods to be aligned coaxially, limiting the internal space.
Innovation Solution
A portable folding pulling cart with a folding frame comprising two first scissor mechanisms and two second scissor mechanisms, where the upper ends and lower ends of the scissor units are connected through separate pivoting points, and the connecting rods are connected to different pivot positions, allowing for a wider internal space and improved connection strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If adjacent connecting rods of the two first scissor units are horizontally arranged and pivotally connected at upper ends through a single shaft, then the scissor mechanism can be simplified, but the width of the upper seat must exceed the sum of outer diameters of the two connecting rods, resulting in reduced interior width
Solution Approach 1:
The patent divides the connection function into two separate seats (first upper seat and second upper seat) instead of using a single shaft. The first upper seat connects the first connecting rods while the second upper seat connects the second connecting rods, allowing independent positioning and reducing the overall width requirement.
Solution Approach 2:
The patent transitions from a single-point connection (coaxial pivot) to a distributed two-point connection system. By separating the connection points into two distinct seats positioned at different locations, the design utilizes spatial distribution to reduce the width footprint while maintaining structural integrity.
2Device complexity
If a single shaft is used to connect adjacent connecting rods, then the connection structure is simpler, but the connection strength is reduced and assembly is more difficult
Solution Approach 1:
The connection function is segmented into two separate seats (first upper seat and second upper seat), each handling one connecting rod. This segmentation allows for stronger, more reliable connections compared to a single shaft, while maintaining structural simplicity through modular design.
Solution Approach 2:
The patent introduces seat structures as intermediary components between the connecting rods and the frame. These seats act as mediators that provide robust connection points, facilitating both strong connections and easy assembly/disassembly operations.
3Area of stationary object
If the upper seat width is reduced to increase interior width, then the interior space is improved, but the connection stability may be compromised
Solution Approach 1:
The connection system is segmented into two independent seats, each providing stable connections for individual connecting rods. This segmentation allows the upper seat width to be reduced while maintaining connection stability through distributed, reliable connection points.
Solution Approach 2:
The patent applies local quality by providing targeted connection strength at specific pivot points rather than requiring uniform width throughout. The first upper seat and second upper seat are positioned to provide localized stability where needed, allowing overall width reduction without compromising critical connection stability.
Data Source
AI summary
A portable folding pulling cart includes a pulling cart frame. The pulling cart frame includes a folding frame and a wheel mechanism configured to be mounted on the folding frame. The folding frame includes two first scissor mechanisms arranged at intervals in a left-and-right direction and two second scissor mechanisms arranged at intervals in a front-and-rear direction. Each of the two first scissor mechanisms includes at least two first scissor units, and each of the two second scissor mechanisms includes at least one second scissor unit. An upper part of one of connecting rods of adjacent two first scissor units is bent. The upper ends of the adjacent two first scissor units are respectively pivotally connected to two upper pivoting points, and the lower ends of the adjacent two first scissor units of the at least two first scissor units are respectively pivotally connected to two lower pivoting points.