Acute-Angle Caster Pockets for Stable Dolly Stacking
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Solution Overview
Problem
When dollies with casters are stacked, they tend to lean significantly if all roll in the same direction due to the offset swivel axis of the casters, leading to misalignment and instability.
Innovation Solution
The dolly design features caster-receiving pockets on the deck surface oriented at an acute angle relative to the dolly's edges, allowing casters to align properly when stacked, with optional tapering to accommodate different wheel sizes, ensuring vertical alignment and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If dollies are stacked with conventional caster-receiving pockets, then the casters can roll freely within the pockets, but the stack develops significant lean and misalignment
Solution Approach 1:
The patent changes the angular parameter of the caster-receiving pockets from conventional orientations (parallel to dolly edges) to acute angles relative to the end edges and side edges. This parameter change ensures that when casters roll within the pockets, they maintain alignment with the dolly's edges, preventing stack lean while preserving caster mobility.
Solution Approach 2:
The caster-receiving pockets are designed with asymmetric angular orientations - each pocket is at an acute angle relative to the adjacent dolly edges. This asymmetric configuration ensures that casters on opposite sides of the dolly converge toward the center when rolled, creating a self-aligning mechanism that maintains vertical stack alignment.
2Ease of manufacture
If caster-receiving pockets are oriented parallel to dolly edges, then stacking is simple, but casters roll in the same direction causing significant stack lean
Solution Approach 1:
The patent modifies the angular parameter of the pockets from parallel orientation to acute angles relative to dolly edges. This change maintains manufacturing simplicity while achieving precise stack alignment, as the acute angle orientation causes casters to naturally converge toward the dolly center when rolled.
3Ease of operation
If casters are allowed to roll freely in conventional pockets, then ease of movement is improved, but alignment consistency deteriorates
Solution Approach 1:
By changing the pocket angle parameter to acute angles relative to dolly edges, the patent maintains free caster rolling for ease of movement while ensuring that the rolled position automatically aligns with the dolly's edge geometry, achieving consistent alignment across stacked dollies.
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
This design prevents the upper dolly from rolling relative to the lower one, maintaining a vertical stack and ensuring consistent alignment, even when casters of varying sizes are used, thereby enhancing stability and ease of stacking.
Implementation Method 1
the casters on the lifted side edge of the upper dolly also rotate slightly due to gravity to an orientation close enough to alignment with the caster-receiving pockets
Data Source
AI summary
A dolly includes a deck having a support surface and a plurality of casters below the deck. The deck includes a plurality of caster-receiving pockets formed in an upper surface of the deck. The caster-receiving pockets are aligned with the casters, such that the casters of an identical dolly could be received in the caster-receiving pockets. The caster-receiving pockets are oriented at an acute angle relative to the end edges and side edges of the dolly. When stacked, the dollies are more consistently aligned and the stack is vertical.