Napkin Folding Machine with Vertical Feed and Spacer Compression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing napkin manufacturing machines have a large longitudinal footprint and require complex mechanisms to exert pressure on the stack for cutting, which complicates the folding and cutting process.
Innovation Solution
The introduction of spacer elements with fingers that support the stack downstream of the folding cylinders, allowing for compression and efficient cutting without the need for complex disengagement mechanisms, by inserting into circumferential slots on the cylinders and supporting the stack until it can be conveyed to a platform for further processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If folding cylinders are arranged along a vertical rotation axis with horizontal feed direction, then the machine can fold napkins in a zig-zag motion, but the machine requires a significant longitudinal footprint and the cylinders must exert significant thrust on the advancing stack for the blade to penetrate it
Solution Approach 1:
The patent reorients the folding cylinders from a vertical rotation axis with horizontal feed to a horizontal rotation axis with vertical feed. This dimensional change allows the stack to be compressed vertically by gravity and the weight of subsequent layers, eliminating the need for complex horizontal compression mechanisms and reducing the machine's longitudinal footprint.
Solution Approach 2:
Instead of pushing the stack horizontally against a blade with significant thrust, the invention inverts the approach by allowing the stack to be fed vertically downward under its own weight and the weight of subsequent layers, with the blade cutting from the side. This inversion eliminates the need for significant cylindrical thrust and reduces the longitudinal footprint.
2Length of stationary object
If folding cylinders are oriented along a horizontal axis with vertical feed direction, then the machine structure is simplified, but the separators must be disengaged from guiding means downstream of the blade while upstream separators remain integral with the guiding means
Solution Approach 1:
The patent extracts the compression function from the folding cylinders and assigns it to dedicated compression rollers positioned downstream of the blade. This separation allows the folding cylinders to focus solely on folding while the compression rollers handle stack compression, simplifying the overall mechanism and eliminating complex disengagement requirements for separators.
Solution Approach 2:
The invention introduces compression rollers as intermediary elements between the folding cylinders and the blade. These rollers serve as mediators that compress the stack locally where needed, allowing separators to remain integral with the guiding means throughout the process, thereby eliminating the complex disengagement mechanism required in the prior art.
3Force
If significant thrust is exerted by cylinders on the advancing stack, then the blade can penetrate the stack for cutting, but the machine requires complex mechanisms to maintain appropriate pressure
Solution Approach 1:
The patent employs self-service compression by allowing the weight of the advancing stack and subsequent layers to automatically compress the stack against the blade. This eliminates the need for complex motorized pressure mechanisms, as the system uses its own weight and the natural flow of material to generate the required compressive force for clean cutting.
Solution Approach 2:
The invention uses the weight of subsequent stack layers as a counterweight to provide continuous compression on the stack being cut. As new layers are fed onto the rollers, their weight automatically compresses the underlying stack, maintaining consistent pressure without requiring additional actuation mechanisms.
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 solution reduces the machine's footprint and simplifies the folding and cutting process by providing consistent pressure on the stack, enabling efficient napkin formation and cutting without the need for complex mechanisms, improving operational efficiency.
Implementation Method 1
As the sheet passes through the cylinders, it is folded in a zig-zag motion... arranging itself downstream of the cylinders in a stack which... is pressed against a blade
Implementation Method 2
the stack... is pressed against a blade, which cuts the stack into two identical portions
Implementation Method 3
spacer elements with fingers are provided, which, being movable so as to be placed under the folding cylinders, are adapted to support the stack in the downward feed motion
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A machine (9) for folding, cutting, and stacking napkins comprises a feeding station (10), at least one pair of folding rollers (14) pivoting about horizontal rotational axes and provided with circumferential slots, a blade (16), and a pair of spacers (18), having fingers (20) configured to support the napkins (13) stably downstream of the blade (16), with respect to a horizontal plane perpendicular to the direction of travel, the folding rollers (14) being provided with circumferential slots (15) for inserting the spacers (18).