Sheet Ejection Device Alignment via Friction Biasing
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Solution Overview
Problem
Existing sheet ejection devices face challenges in aligning sheets accurately in the conveying direction on a sheet stacking table, particularly at high speeds and under varying environmental conditions, leading to misalignment issues when stacking multiple sheets.
Innovation Solution
A sheet ejection device with a pair of holding members that move sheets to a stacking position, where a friction member corrects misalignment by contacting the uppermost sheet and biasing it against a trailing edge hitting section, ensuring proper alignment and stacking without stopping the sheet conveyance process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If sheets are conveyed at high speed onto the sheet stacking table, then productivity is improved, but sheet alignment precision deteriorates due to deviation during conveyance and dropping time
Solution Approach 1:
The patent applies preliminary action by providing a predetermined dropping distance from the ejection roller to the sheet stacking table. This fixed distance allows the sheet to naturally drop and align itself before stacking, compensating for high-speed conveyance effects and maintaining alignment precision even at increased productivity levels.
2Manufacturing precision
If a gripper is used to hold and move the sheet to the stacking table, then sheet alignment is improved, but the sheet conveyance process must be stopped once, increasing processing time
Solution Approach 1:
The patent extracts the alignment function from the conveyance process itself. Instead of using a gripper to actively move and align the sheet (which would require stopping conveyance), the sheet is ejected continuously and alignment occurs passively during the predetermined dropping phase, eliminating the need to interrupt the conveyance process.
3Manufacturing precision
If existing sheet ejection devices are used to improve alignment, then the mechanism becomes complicated and the device size increases
Solution Approach 1:
The patent segments the sheet handling process into distinct phases: high-speed conveyance phase, predetermined dropping phase for natural alignment, and stacking phase. This segmentation allows each phase to be optimized independently, achieving alignment precision without requiring complex integrated mechanisms.
Solution Approach 2:
The patent applies self-service by allowing the sheet to align itself during the predetermined dropping phase through gravitational force and the natural physics of sheet deformation. No active alignment mechanism is required - the sheet self-corrects its position during the drop, simplifying the overall device structure.
4Productivity
If multiple sheets are stacked on the sheet stacking table, then productivity is improved, but misalignment occurs between stacked sheets
Solution Approach 1:
The patent applies preliminary action to each sheet before stacking by ensuring every sheet undergoes the predetermined dropping distance alignment process individually, even when multiple sheets are being processed. This pre-alignment of each sheet before it reaches the stacking table ensures that batch-stacked sheets maintain proper alignment relative to each other.
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 solution enhances sheet alignment and stacking efficiency, reducing misalignment and maintaining high-speed processing capabilities while preventing sheet dropout and improving productivity in post-processing operations.
Implementation Method 1
a friction member which is provided on one of the pair of the sheet holding members and which comes in contact with an uppermost sheet stacked on the sheet stacking section
Data Source
AI summary
A sheet ejection device including: a sheet stacking section; a sheet trailing edge hitting section; a pair of sheet holding members for holding a sheet or plural sheets placed one on top of another at a sheet holding position, and moving the same to the sheet stacking position; and a friction member that is provided on one of the sheet holding members and that comes in contact with the topmost sheet of the sheets stacked on the sheet stacking section; wherein, when the sheet holding members reach the sheet stacking position, one of the sheet holding members is moved upstream in the sheet ejecting direction, whereby the trailing edge of the held sheet is made to hit against the sheet trailing edge hitting section, and the friction member comes in contact with the topmost sheet, and then the topmost sheet is biased toward the sheet trailing edge hitting section.