Sheet Conveying Device with Tilted Roller for Thick Sheet Damage Reduction
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Solution Overview
Problem
Conventional sheet conveying and discharging devices often damage thick sheets due to excessive elastic bending, leading to indentation and friction, which can degrade image quality.
Innovation Solution
A sheet conveying device with a pair of rotating members, where the second rotating member has a small-diameter and large-diameter portion, allowing tilting of its rotating shaft relative to the first rotating member, disperses the pressing force and reduces contact points to minimize damage during sheet conveyance and discharge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If excessive elastic bending is performed on a thick sheet using conventional rigidity-providing members, then the sheet can be discharged without bending at the leading end, but the sheet can be damaged by indentation and friction, causing image quality to decline
Solution Approach 1:
The second rotating member has different diameter portions at different locations: a small-diameter portion that contacts the sheet for rigidity provision, and a large-diameter portion that does not contact the sheet to avoid damage. This local differentiation allows the same component to simultaneously provide rigidity where needed and avoid damage where harmful contact would occur.
Solution Approach 2:
The second rotating member can tilt relative to the first rotating member, changing its orientation dynamically. This allows the large-diameter portion to move away from the sheet path when needed, reducing contact points and pressing force on thick sheets while maintaining the rigidity-providing function when required.
2Shape
If a rigidity-providing member lifts up the widthwise center portion of a sheet, then the sheet can be discharged onto the tray without leading end bending, but excessive elastic bending damages the sheet through indentation and friction
Solution Approach 1:
The second rotating member applies rigidity locally through its small-diameter portion that contacts the sheet, while the large-diameter portion is positioned to avoid contact. This localized approach provides the necessary shape control without the excessive bending that causes indentation and friction damage across the entire sheet surface.
Solution Approach 2:
The second rotating member is effectively segmented into functional zones: a small-diameter portion for sheet contact and rigidity provision, and a large-diameter portion for non-contact operation. This segmentation allows different parts of the same component to have different functions, providing rigidity where needed while avoiding damage elsewhere.
3Strength
If larger diameter rollers are used to provide rigidity to sheets, then sheets can be conveyed without leading end drooping, but the pressing force concentrates at fewer contact points, increasing friction and potential damage
Solution Approach 1:
The second rotating member uses a small-diameter portion for sheet contact to distribute pressing force over a larger contact area, reducing friction and damage risk. The large-diameter portion is positioned away from the sheet path, preventing force concentration while maintaining adequate sheet rigidity through the smaller contact region.
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 configuration reduces damage to sheets, such as thick papers, by dispersing the pressing force and minimizing indentation and friction, thereby maintaining image quality and preventing sheet jams.
Implementation Method 1
a biasing unit configured to bias the second rotating member toward the first rotating member
Data Source
AI summary
A sheet conveying device includes a first rotating member, a second rotating member, and a biasing unit that biases the second rotating member toward the first rotating member. The first and second rotating members pinch a sheet therebetween and convey the sheet in a sheet conveying direction. The second rotating member includes a small-diameter portion that faces a conveying portion of the first rotating member, and a large-diameter portion at a position axially displaced from the conveying portion. The second rotating member can change its orientation to an orientation where a rotating shaft of the second rotating member is tilted relative to a rotating shaft of the first rotating member as viewed in the sheet conveying direction, thereby moving a position of an end portion of the second rotating member on a side of the large-diameter portion away from the rotating shaft of the first rotating member.