Interfolding Roll Grippers for High-Speed Paper Folding Accuracy
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Solution Overview
Problem
Existing folding and interfolding machines face limitations in speed and flexibility due to mechanical and pneumatic systems that cannot operate synchronously at high speeds, leading to inaccurate folds, jamming, and quality issues with varying paper weights, necessitating operation within predetermined speed thresholds.
Innovation Solution
A folding or interfolding unit with first and second rolls featuring mechanical gripping members, suction holes, and a vacuum distribution system that allows precise control over gripping and releasing points, enabling operation at speeds exceeding 300 m/min and accommodating various paper weights.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If mechanical pliers with wedges are used to grip and release sheets, then gripping and releasing functions are achieved, but the system cannot operate synchronously at high speed and requires complex actuation devices
Solution Approach 1:
The patent replaces the complex mechanical actuation system with a pneumatic system. Pneumatic grippers use air pressure to open and close the gripping members, eliminating the need for complex mechanical linkages and wedges. This substitution enables synchronous operation at high speeds while reducing overall system complexity.
Solution Approach 2:
The patent employs pneumatic elements throughout the system - pneumatic grippers for gripping, pneumatic suction for holding sheets, and pneumatic actuators for synchronized movement. This pneumatic approach allows for rapid, synchronized operation of multiple gripping members across different rolls without complex mechanical coupling.
2Reliability
If mechanical pliers are used for gripping, then gripping function is achieved, but the system is very complicated and expensive with frequent maintenance needs
Solution Approach 1:
The patent replaces mechanical pliers with pneumatic grippers that have fewer moving parts and no wear-prone wedges. The pneumatic system uses flexible membranes and air pressure control, eliminating the mechanical wear issues that require frequent maintenance and reduce reliability.
Solution Approach 2:
The patent changes the operating parameters from mechanical force to pneumatic pressure. This allows for more precise and consistent gripping force control through pressure regulation, improving reliability while reducing the complexity of mechanical linkages and actuation mechanisms.
3Speed
If pneumatic suction systems are used to adhere sheets, then adhesion is achieved at determined portions, but the speed is limited to predetermined thresholds due to inertia
Solution Approach 1:
The patent merges pneumatic suction and pneumatic gripping functions into a unified system. The same pneumatic pressure control mechanism is used both to create suction for adhering sheets to the roll and to actuate the gripping members, enabling synchronized high-speed operation that maintains folding accuracy.
Solution Approach 2:
The patent uses periodic pneumatic pulses to control the gripping cycle - suction is applied periodically to adhere sheets, then pneumatic pressure is applied to the gripping members to grip and release at precise moments. This periodic control enables high-speed operation while maintaining synchronization with the folding cycle.
4Adaptability or versatility
If fixed suction roll configuration is used, then adhesion at determined portions is achieved, but adaptability to various paper weights is limited
Solution Approach 1:
The patent introduces adjustable elements that allow the suction roll configuration to be dynamically modified. The positioning of suction holes and gripping members can be adjusted to accommodate different paper weights and types, enabling the system to adapt to various materials without requiring complete system redesign.
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 unit achieves high-speed, accurate folding or interfolding of paper sheets with improved quality and flexibility, avoiding jams and ensuring consistent product quality across different paper weights.
Implementation Method 1
at least one suction hole (16) arranged to cause said sheet of paper (5) to be sucked to introduce the same into said mechanical gripping member (15)
Data Source
AI summary
A folding or interfolding unit of a plurality of sheets of paper comprising a first and a second folding or interfolding roll to fold, or interfold, the plurality of sheets of paper according to a predetermined folding or interfolding configuration, at a folding or interfolding zone. Each folding or interfolding roll comprises a tubular body which rotates about a longitudinal rotation axis oriented along a horizontal direction and a plurality of gripping groups integral in rotation with the tubular body. Each gripping group comprises a mechanical gripping member configured to move, at a gripping point, from a releasing configuration to a gripping configuration, where is arranged to mechanically hold the, or each, sheet up to a releasing point having a second angular position.