Self-Centering Gripper for Paper Rolls Using Spring Compression
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Solution Overview
Problem
Current gripping solutions for material web rolls, such as scissor-type grippers, are inefficient due to their inability to handle varying roll diameters, require excessive space, and lack optimal compression force distribution, leading to radial staggering and increased storage costs in warehouses.
Innovation Solution
A gripper system with adjustable compression force and contact members that can accommodate rolls of varying diameters, equipped with RFID reading capabilities and a self-centralizing mechanism, allowing for safe and efficient handling of multiple rolls with reduced space requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If scissor-type grippers are used to compress rolls, then a grip can be applied to the roll surface, but the gripper requires excessive space and cannot handle varying roll diameters effectively
Solution Approach 1:
The gripper employs a dynamic compression mechanism where the compression force is automatically adjusted based on the roll diameter and weight. The compression member can move vertically to accommodate different roll sizes, and the spring mechanism provides adaptive force that increases with load weight, eliminating the need for fixed-size mechanical structures
Solution Approach 2:
The invention changes the physical parameters of the gripping system by using a spring-based compression mechanism instead of rigid mechanical arms. The compression force parameter is made variable through the spring constant and pre-compression settings, allowing the same gripper to handle rolls from 700mm to 1600mm diameter without structural modification
2Reliability
If compression force mechanism is located above the roll and extended 2.5 to 3 m downwards, then grip can be applied to lowest roll in pile, but the structure becomes massive and economically unviable
Solution Approach 1:
The spring mechanism is positioned above the roll and uses the roll's own weight to compress the spring and generate the gripping force. The system serves itself by converting the gravitational force on the load into the compression force needed for gripping, eliminating the need for heavy mechanical advantage structures or long compression members
Solution Approach 2:
The spring acts as an intermediary element between the compression member and the roll surface. It transmits the compression force over a short distance while accommodating vertical movement, providing reliable grip without requiring the compression mechanism to be physically connected to the lowest roll through long rigid members
3Extent of automation
If scissor mechanisms are used to increase gripping force with load weight, then automatic gripping force adjustment is achieved, but the mechanism requires large space and compression force is not optimal over whole diameter range
Solution Approach 1:
The spring compression mechanism automatically adjusts the gripping force in response to the load weight without requiring complex feedback systems or actuation mechanisms. The spring compresses more under heavier loads, naturally providing proportional gripping force adjustment while occupying minimal space
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 gripper system provides a secure hold for rolls of varying diameters, reduces storage space needs, and enhances RFID reading reliability, enabling efficient roll handling and transportation while maintaining grip integrity during power failures.
Implementation Method 1
a spring 15 is arranged between the lower end of the lifting member 8 and the compression member 6
Implementation Method 2
the friction between the compression member 6 and the roll 1 prevents slipping
Data Source
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AI summary
A gripper for gripping vertical material web rolls (1), such as paper and paperboard rolls, for lifting them in a scissor grip. The gripper is provided with contact members arranged to be positioned against the sides of a roll to be lifted. A gripping force is provided on the contact members (4) at substantially gripping height against the roll to be lifted by tensioning a binder (18) connecting the contact members. The gripper enables transporting a plurality of rolls at the same time.