Compressed Air Folding System for Print Sheets
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing folding technologies face challenges in adapting to the varying properties of print sheets, such as format, grammage, and frictional values, leading to issues like jamming, reduced quality, and decreased capacity, especially when processing sheets from digital printers with diverse properties.
Innovation Solution
An apparatus and method utilizing a compressed air device with adjustable exit openings, controlled by a unit that changes the time interval, cross-sectional surface, and pressure of the compressed air blast to match the properties of each print sheet, ensuring precise folding and high capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a mechanical folding sword is used to achieve high folding capacity and speed, then folding productivity is improved, but the device requires very precise and involved geometric adjustments and has high device complexity
Solution Approach 1:
The patent replaces the traditional mechanical folding sword with a jet of compressed air to convey the print sheet to the folding rollers. This substitution eliminates the need for complex mechanical adjustments and geometric precision while maintaining high folding capacity. The compressed air jet provides a contactless means of sheet conveyance, reducing mechanical complexity.
Solution Approach 2:
The invention uses a jet of compressed air (pneumatic system) to convey the print sheet horizontally to the folding rollers and another jet to convey the folded sheet away. This pneumatic approach replaces complex mechanical sword systems with simpler air-based conveyance, reducing device complexity while preserving productivity.
2Productivity
If a mechanical folding sword moves at high speed to clear the folding table quickly, then folding productivity is improved, but the print sheet is in an undefined movement state causing jamming risk
Solution Approach 1:
By replacing the mechanical sword with compressed air jets, the system eliminates the rapid reversal of mechanical motion that creates undefined sheet movement. The air jets provide smooth, controlled conveyance without abrupt stops or reversals, keeping the sheet in a defined movement state throughout the process and reducing jamming risk.
Solution Approach 2:
The compressed air acts as an intermediary between the folding table and the folding rollers, providing controlled sheet conveyance. This intermediary allows for smooth acceleration and deceleration of the sheet, preventing the abrupt movement changes that occur with mechanical swords and reducing the risk of jamming.
3Productivity
If a mechanical folding sword is used to fold print sheets, then folding function is achieved, but the structural area required is relatively large and the sword is hard to access
Solution Approach 1:
The use of compressed air jets eliminates the need for a large mechanical sword structure. The air jets can be delivered through nozzles positioned close to the folding line, significantly reducing the structural area required. The system achieves the same folding function with a much more compact arrangement.
Solution Approach 2:
The invention extracts the essential function of sheet conveyance and folding from the bulky mechanical sword structure. By using only the necessary compressed air jets positioned at key locations, the system removes unnecessary structural elements, reducing the overall area required while maintaining folding capability.
4Productivity
If a mechanical folding sword is used to fold print sheets, then folding function is achieved, but the sword is hard to access for maintenance and adjustment
Solution Approach 1:
Replacing the mechanical sword with compressed air jets eliminates complex mechanical components that require maintenance. The air delivery system consists of simple nozzles and tubing that are much easier to access, inspect, and repair compared to a mechanical sword with moving parts, bearings, and adjustment mechanisms.
Solution Approach 2:
The compressed air nozzle system uses simple, inexpensive components that can be easily replaced if needed. Rather than maintaining a complex mechanical sword, the system uses affordable air delivery components that are straightforward to service, improving ease of repair and maintenance.
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 solution enables flexible and cost-effective adaptation to different print sheet properties, improving folding quality and capacity, allowing for efficient processing of sheets with diverse characteristics, including those from digital printers.
Implementation Method 1
a compressed air device, arranged essentially parallel to the rotational axes of the folding rollers on a second side of the guide plane which is essentially arranged opposite the first side of the guide plane, in a region of the folding gap
Implementation Method 2
The print sheet is then gripped by the folding rollers and pulled into the folding gap, formed in-between the rollers and, in the process, is folded and also compressed along the folding line
Data Source
AI summary
An apparatus for folding print sheets includes two folding rollers arranged on one side of a guide plane to define a folding gap. A compressed air device is arranged on the other side of the guide plane in a region of the folding gap. The compressed air device is connected to the compressed air source and to the control unit, and includes an exit opening for the compressed air that is focused onto the folding gap. Control elements can be activated by the control unit to change the time interval during which the at least one exit opening is admitted with compressed air, and/or the cross-sectional surface of the exit opening, and the pressure of the compressed air supplied to the exit opening may also be changed by a different control element, to adapt a compressed air blast to properties of the print sheet made available to the folding gap.