Sheet Conveying Device Tray Recess and Pickup Roller Dynamics
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Solution Overview
Problem
Existing sheet conveying devices face issues with excessive load on pickup rollers when conveying sheets of varying sizes, leading to sheet jam and feeding failures, as the current solutions either fail to accommodate different sheet sizes effectively or apply excessive friction, causing mechanical stress and misalignment.
Innovation Solution
The implementation of a sheet conveying device with a tray having a recess and a rotating member that moves between contact and separation positions, accompanied by a positioning member and a preventing member, which adjusts to accommodate sheets of different sizes by altering the position of a restriction member to prevent the operative portion from entering the recess, ensuring proper sheet alignment and reducing mechanical stress on the pickup rollers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the pickup roller is raised away from the friction member when the tray becomes empty, then excessive loads on the pickup roller are reduced, but sheet feeding failures occur when conveying sheets of smaller sizes
Solution Approach 1:
The pickup roller is designed to dynamically change its position between contacting the sheet and being raised away from the friction member. This dynamic adjustment allows the system to adapt to different sheet sizes and tray states, reducing excessive load on the pickup roller while maintaining reliable sheet feeding for smaller sheets through the preventing member mechanism
Solution Approach 2:
The preventing member acts as an intermediary element that controls whether the pickup roller can be raised. When the positioning member detects a small sheet, the preventing member blocks the raising motion, ensuring the pickup roller remains in contact with the sheet for reliable feeding, while allowing raising for larger sheets to prevent excessive load
2Productivity
If the pickup roller contacts the sheet to convey it, then sheets are separated and conveyed one by one, but multiple sheets may be conveyed simultaneously causing multiple sheet feeding
Solution Approach 1:
The friction member is positioned at a specific location on the tray to create localized high friction. This local quality enhancement ensures that the pickup roller can reliably separate and convey one sheet at a time by creating sufficient friction differential between the contacted sheet and underlying sheets, preventing multiple sheet feeding while maintaining conveyance efficiency
3Reliability
If the preventing member blocks the operative portion from entering the recess, then sheet feeding reliability for small sheets is improved, but the device complexity increases
Solution Approach 1:
The preventing member is integrated with the positioning member to form a combined structure. This merging reduces device complexity by consolidating functions into a single component while maintaining the reliability improvement of preventing premature pickup roller raising for small sheets
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 effectively reduces sheet feeding failures by ensuring consistent sheet alignment and minimizing mechanical stress on the pickup rollers, allowing for reliable conveyance of sheets of various sizes without jamming, thereby enhancing the operational efficiency of the sheet conveying device.
Implementation Method 1
sheets are conveyed from the tray to a predetermined conveying direction while being separated one by one by friction
Implementation Method 2
The friction member will reduce the possibility of multiple sheet feeding because the frictional force applied between the tray and the sheets becomes greater than the frictional force applied between the sheets
Data Source
AI summary
A sheet conveying device includes a tray having a bottom surface. The tray holds at least one sheet therein, and has a recess formed in the bottom surface. A rotating member moves between a first position and a second position. In the first position, the rotating member contacts a sheet held in the tray, and in the second position, the rotating member is separated from the tray. The rotating member selectively rotates to convey a sheet held in the tray in a when the rotating member is in the first position. An operative portion moves in and out of the recess in the bottom surface of the tray, and movement of the operative portion corresponds to a movement of the rotating member into the second position.