Collapsible Handcart with Hinged Chassis and Retractable Ends
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional beach handcarts occupy excessive storage space due to their non-collapsible design, making them inconvenient for transportation and storage.
Innovation Solution
A collapsible handcart with a hinged chassis, retractable ends, and a telescopic handle that can be compactly folded for storage, featuring pivotally mounted quadrilaterals and elbows to facilitate a compact collapse, allowing the cart to be stored in a narrow space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the handcart is designed with a fixed non-collapsible frame, then structural strength and stability are improved, but storage space requirement increases
Solution Approach 1:
The handcart frame is divided into multiple collapsible quadrilateral sections with pivots at each corner. These segmented sections can be folded together to reduce storage volume while maintaining structural integrity during use. The segmentation allows the frame to transition between an expanded load-bearing configuration and a compact storage configuration.
Solution Approach 2:
The handcart employs dynamic quadrilateral linkages with pivots that allow the frame to change shape. The sides include one or more quadrilaterals with pivots at each corner that can rotate and fold, enabling the structure to adapt between stable operational form and compact storage form. This dynamic structure maintains strength when needed while minimizing volume during storage.
2Volume of moving object
If the handcart uses a collapsible design with moving parts, then storage space is reduced, but device complexity increases
Solution Approach 1:
The collapsible ends are received within respective frames of the chassis when collapsed, creating a nested configuration. The quadrilateral sections fold inward and stack upon each other, with the ends nesting within the chassis frames, achieving compact storage without requiring additional external storage structures.
Solution Approach 2:
The handcart features asymmetric quadrilateral linkages with strategically positioned pivots of different lengths and configurations. The sides include quadrilaterals with pivots at each corner arranged asymmetrically to facilitate smooth collapsing motion while maintaining structural stability when expanded. This asymmetric design optimizes the collapsing mechanism to be both compact and structurally sound.
3Volume of moving object
If the quadrilaterals are designed to pivot at each corner, then collapsing compactness is improved, but manufacturing precision requirements increase
Solution Approach 1:
The pivots are designed with local quality variations, where each pivot point has specific dimensional characteristics optimized for its position in the quadrilateral linkage. The pivots at different corners may have different radii, mounting configurations, or clearance tolerances tailored to their specific functional requirements, allowing compact folding while accommodating reasonable manufacturing variations.
Solution Approach 2:
The quadrilateral linkages incorporate adjustable parameters such as pivot spacing, link lengths, and hinge angles that can be optimized during manufacturing. By carefully selecting these parameters, the design achieves compact collapse while being tolerant of normal manufacturing tolerances, reducing the need for extremely high precision assembly.
Data Source
AI summary
The present invention relates to a collapsible handcart. The handcart includes a collapsible chassis. Retractable ends are provided for retracting toward the chassis. The collapsible chassis may include a pair of hinged front and back frames which collapse together. Advantageously, the frames may be collapsed together which causes the ends to come together whilst remaining substantially upright. Preferably, a user can simply lift the center of the chassis and the ends roll toward each other.