Cylinder Vacuum Cleaner Castor Geometry for Stable Steering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Cylinder vacuum cleaners exhibit poor manoeuvrability due to inertial 'understeer' and instability when changing direction, and conventional rear castors either compromise directional stability or get jammed against obstacles.
Innovation Solution
A cylinder vacuum cleaner design featuring a front swivel castor with a positively-raked swivel axis and wheels that co-rotate with the hose, and rear castors with a negatively-raked swivel axis and positive trail, allowing for improved steering stability and obstacle avoidance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the hose is attached directly to the main body and the front castor trails behind, then the structure is simple, but the cleaner exhibits inertial understeer and poor manoeuvrability when changing direction
Solution Approach 1:
The patent merges the hose connection point with the front castor assembly, specifically attaching the hose to the castor frame rather than the main body. This integration ensures the hose and castor move together as a unified system, eliminating relative motion between them and preventing inertial understeer during directional changes.
Solution Approach 2:
The castor frame acts as an intermediary element between the hose and the main body. By connecting the hose to the rotating castor frame rather than directly to the main body, the system allows the hose to naturally follow the castor's rotation, providing smooth directional transitions without the need for complex hose routing mechanisms.
2Reliability
If the swivel axis is positioned vertically, then the castor structure is simple, but the cleaner becomes unstable and the castor may jam against obstacles
Solution Approach 1:
The patent changes the geometric parameter of the swivel axis from a vertical orientation to a positively-raked orientation. This angular modification creates a trailing action where the castor naturally follows the direction of motion, improving steering stability and preventing the castor from jamming against obstacles during operation.
3Adaptability or versatility
If rear castors have zero rake for free-swiveling, then obstacle avoidance is improved, but directional stability is compromised
Solution Approach 1:
The patent applies different swivel axis configurations to different locations on the cleaner: the front castor has a positively-raked swivel axis for stability during forward motion, while rear castors have a negatively-raked swivel axis that allows greater freedom of movement for obstacle avoidance. This localized differentiation optimizes both directional stability and adaptability.
Data Source
AI summary
A cylinder vacuum cleaner comprising a main body which is fluidly connected to a suction hose used to pull the main body forwards along a floor, and a front swivel castor for supporting the main body on the floor, the front castor comprising a frame mounted for rotation about a swivel axis and one or more wheels mounted on the frame, the hose being connected to the frame for co-rotation with the frame about the swivel axis, wherein the swivel axis is positively raked.