Rapid Tearing Device for Paper Strip Rewinding
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Solution Overview
Problem
Existing methods for separating continuous paper strips in rewinding machines are complex, often cause paper folds, and result in unnecessary waste, particularly when using buffers or combined actions with the upper winding roll.
Innovation Solution
A device comprising oscillating arms with a transversal blade that collaborates with the cardboard core to tear the paper along perforation lines, minimizing contact with the upper winding roll and reducing waste by using a cam wheel and toothed wheel mechanism to synchronize the tearing action with the core's movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high-pressure fluid blowing is used to tear the continuous strip, then the breakage along the perforated line is achieved, but the device complexity increases and paper folds are generated
Solution Approach 1:
The invention extracts and removes the complex high-pressure fluid blowing system and replaces it with a simple mechanical tearing device consisting of a tearing element that directly acts on the perforated line to achieve breakage, thereby reducing device complexity while maintaining reliable breakage
Solution Approach 2:
The invention replaces the pneumatic system (high-pressure fluid blowing) with a direct mechanical action (tearing element applying force) to achieve the same breaking function, simplifying the system while ensuring reliable breakage along the perforated line
2Reliability
If comb- or buffer-elements are used to block the paper for separation, then the breakage is achieved, but paper folds are generated and device complexity increases
Solution Approach 1:
The invention removes the comb- or buffer-elements that cause paper folds and replaces them with a tearing element that applies direct mechanical force to create clean breaks without generating folds in the paper
Solution Approach 2:
The invention replaces the indirect mechanical action of blocking paper with comb- or buffer-elements with a direct tearing action that applies force perpendicular to the perforated line, achieving breakage without paper folds
3Reliability
If the tearing action varies the rotation rate of winding rolls, then the breakage is achieved, but the device complexity increases
Solution Approach 1:
The invention extracts and removes the complex variable rotation rate control system of winding rolls and replaces it with a simple tearing element that directly creates breaks by applying mechanical force, thereby reducing device complexity while maintaining reliable breakage
Solution Approach 2:
The invention replaces the complex variable speed control system with a direct mechanical tearing action, where the tearing element applies force to the perforated line to achieve breakage without requiring variable rotation rates
Data Source
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AI summary
A rapid tearing device of a strip in a rewinder for the winding of paper around a core (15) to produce a log (12), wherein said rewinder essentially comprises a formation area of the log (12), upstream of which there is a conveyor (13) with pushers (14) for moving cores (15) forward into a channel (16) defined by a series of cradles (17) integral with the structure of the rewinder, and by an upper winding roller (18) which is situated above the channel (16), wherein the upper winding roller (18) collaborates with a lower winding roller (19) positioned almost at the final end of the cradles (17), whereas a third oscillating roller (20) is situated above the lower winding roller (19) and acts as a press with the variation in the dimension of the log (12) being formed between the three mentioned rollers (18, 19 and 20), the device essentially consisting of a blade (24), having the dimension of the width of the rollers (18, 19, 20), which can be moved by actuators (31, 35; 30, 22, 25) between a rest position and an engagement position on a core (15) when the core (15) is unloaded from said conveyor (13) by means of an introducer (34) and introduced into the channel (16) thus blocking, between core (15) and blade (24), the paper (11) which is being unwound.