Pneumatic Baffle Sheet Stacking System for Jam Prevention
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Solution Overview
Problem
In cut sheet finishing systems, the interaction of the lead edge of incoming sheets with a stacked surface leads to uneven surfaces due to curl and ink/toner buildup, causing sheets to roll over and jam, especially with longer or lighter sheets, where mechanical corrugation is ineffective, and active shutters increase complexity and cost.
Innovation Solution
A pneumatic baffle system uses a thin layer of high-velocity air between the sheet and a baffle, employing the Bernoulli Effect to lift the sheet and maintain it above the stack, ensuring consistent feeding and registration by adjusting air flow based on sheet length and weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If mechanical corrugation rolls are used to provide beam strength to sheets, then sheet stability is improved, but the effectiveness decreases for longer, lighter sheets and when lead edge is deflected by baffles or guides
Solution Approach 1:
The patent replaces mechanical corrugation rolls with a pneumatic system that uses air pressure differentials to provide beam strength to sheets. The pneumatic baffle system uses a fan to generate airflow that creates pressure differences, lifting and supporting the sheet lead edge without physical contact, thereby eliminating the mechanical contact that causes deflection and loses effectiveness for longer, lighter sheets.
Solution Approach 2:
The patent employs pneumatic principles by using a fan to generate airflow through a baffle structure. The airflow creates pressure differentials that lift and support the sheet, providing the necessary beam strength. The system includes a fan, baffle with inlet and outlet openings, and uses air pressure to maintain sheet position without mechanical contact.
2Manufacturing precision
If active shutters are used to collate sheets on a flat surface, then sheet registration is improved, but device complexity and cost increase significantly
Solution Approach 1:
The patent extracts the sheet support function from the stacking mechanism by using a pneumatic baffle system that operates independently. The baffle system provides beam strength and registration without requiring active shutter mechanisms, thereby reducing complexity while maintaining registration precision.
Solution Approach 2:
The patent replaces active mechanical shutters with a pneumatic system that uses air pressure differentials to collate and register sheets. The fan-driven airflow creates the necessary forces to hold sheets in place without mechanical contact, eliminating the need for complex active shutter mechanisms.
3Productivity
If sheets are fed directly onto a compiled stack, then stacking speed is improved, but the uneven surface causes sheets to roll over and jam
Solution Approach 1:
The patent introduces a pneumatic baffle as an intermediary between the sheet and the compiled stack. The baffle system uses airflow to lift and support the sheet lead edge, preventing direct contact with the uneven stack surface that causes rolling and jamming, while maintaining high stacking speed.
Solution Approach 2:
The patent replaces mechanical support structures with a pneumatic system that uses air pressure to prevent sheet rolling. The fan-generated airflow creates upward forces that counteract the tendency of sheets to roll over the uneven stack surface, eliminating jams without reducing stacking speed.
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
The pneumatic baffle system effectively prevents sheets from rolling over and jamming by maintaining the lead edge of sheets above the stack, even for longer or lighter sheets, without the need for additional mechanical support, ensuring consistent registration and reducing complexity and cost.
Implementation Method 1
A thin layer of high velocity air is applied between the top side of the sheet and a baffle while the sheet is simultaneously fed by and held within a feed roll nip. The layer of high velocity air that follows a horizontal bottom surface of the baffle and the high velocity air 'lifts' the sheet (Bernoulli Effect) to the boundary layer of air flowing over the baffle.
Implementation Method 2
The layer of high velocity air that follows a horizontal bottom surface of the baffle and the high velocity air 'lifts' the sheet (Bernoulli Effect) to the boundary layer of air flowing over the baffle.
Data Source
AI summary
A sheet stacking tray that includes a single pneumatic baffle which uses the pressure differential caused by the flow of air across a horizontal planar surface of the pneumatic baffle to hold the lead edge of sheets driven by an input nip into the sheet stacking tray above a stack especially for longer and lighter weight sheets as they are driven by the input nip to a registration wall.