Printing Machine Reversing Unit Acceleration Mechanism
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Solution Overview
Problem
Existing printing machines that perform duplex printing impose a heavy load on sheets and roller pairs, leading to potential damage and deterioration, and require additional mechanical components like clutch mechanisms to mitigate this issue.
Innovation Solution
A printing machine design that includes a reversing unit which switches the sheet back and accelerates it to a higher circulation transfer speed after a temporary stop, eliminating the need to pull the sheet out of the roller pair in a high-speed section, thereby reducing the load on sheets and roller pairs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If acceleration is performed by pulling out the sheet from the roller pair in an upstream-side section by the roller pair in the high-speed section, then the circulation transfer speed is achieved, but a heavy load is imposed on the sheet and the roller pairs causing damage and deterioration
Solution Approach 1:
The circulation route is divided into a low-speed section and a high-speed section. The sheet is transferred at printing transfer speed in the low-speed section and then accelerated to circulation transfer speed in the high-speed section. This segmentation allows acceleration to occur in a dedicated zone rather than throughout the entire circulation route, reducing the load on sheets and rollers while maintaining high productivity.
2Reliability
If a clutch mechanism is added to mitigate the heavy load on sheets and roller pairs, then the reliability is improved, but the device complexity increases due to additional mechanical components
Solution Approach 1:
The roller pairs in the high-speed section are driven at different speeds depending on the section. The circulation transfer unit accelerates the sheet from printing transfer speed to circulation transfer speed in the high-speed section, while the low-speed section maintains printing transfer speed. This dynamic speed adjustment eliminates the need for clutch mechanisms while protecting sheets and rollers from excessive load.
3Productivity
If the sheet is accelerated from printing transfer speed to circulation transfer speed in the high-speed section, then the productivity is maintained, but the load on the sheet transfer mechanism increases
Solution Approach 1:
The circulation route is divided into low-speed and high-speed sections. Acceleration from printing transfer speed to circulation transfer speed occurs only in the high-speed section, while the low-speed section maintains the lower printing transfer speed. This segmentation concentrates the acceleration load in a specific zone, allowing the sheet transfer mechanism to handle high speeds only where necessary for productivity, while reducing overall mechanical stress.
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 design reduces the load on sheets and roller pairs, prevents damage, and minimizes the need for additional mechanical components, while maintaining high productivity and efficiency in duplex printing operations.
Implementation Method 1
a roller pair which transfers the sheet while nipping the sheet is driven at the circulation transfer speed. When the sheet reaches the high-speed section, the sheet is pulled out from a roller pair in an upstream-side section by the roller pair in the high-speed section.
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A printing machine (1) includes a printing unit (3) which performs printing while transferring a sheet P at a printing transfer speed, a circulation transfer unit (4) which receives the sheet after simplex printing and transfers the sheet by reversing the sheet upside down, during duplex printing; and a paper refeed unit (2) which refeeds, to the printing unit, the sheet transferred by the circulation transfer unit after simplex printing, wherein the circulation transfer unit includes a reversing unit (42) which receives the sheet at the printing transfer speed, reverses the sheet upside down by switching back the sheet and accelerates the sheet up to a circulation transfer speed which is higher than the printing transfer speed when sheet transfer is restarted after temporal stop in the switching back, and a horizontal transfer unit (43) which transfers the sheet switched back by the reversing unit, at the circulation transfer speed.