Automated Welding of Plastic Handles to Metal Canisters

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Solution Overview

Problem

Current methods for attaching plastic handles to metal containers are either excessively expensive and labor-intensive or limited in their ability to handle complex shapes, such as tulip cans, with low production rates and quality issues.

Innovation Solution

A method involving the selection, perforation, and bending of a plastic strip to form a handle, which is then securely fixed to the container using welding, allowing for automated installation on various shapes, including tulip cans, with a machine that unwinds, punches, cuts, and bends the strip to ensure precise and efficient attachment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the first technique (welding lugs or rivets and manually mounting handles) is used, then the handle attachment is secure and reliable, but the production rate becomes very low and labor costs become excessively high

Engineering Contradiction:
Improvehandle attachment reliabilityVSAvoidproduction rate
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent replaces manual mechanical operations (manual handle mounting) with an automated welding system. The welding device automatically welds the plastic handle directly to the metal can body at predetermined positions, eliminating the need for manual lug/rivet installation and handle mounting operations. This substitution maintains attachment reliability through controlled welding parameters while dramatically increasing production speed to 50-75 cans per minute.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If the second technique (automatically unrolling and riveting plastic strip) is used, then the production rate increases to 50 cans per minute, but the handle positioning becomes random and uncontrolled on complex-shaped cans

Engineering Contradiction:
Improveproduction rateVSAvoidhandle positioning precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent employs a programmable control system that automatically determines the precise positioning coordinates for handle attachment based on the can's geometric data stored in memory. The system self-adjusts the welding head position and orientation to accommodate various can shapes (cylindrical, conical, tulip-shaped) without manual intervention. This automated positioning ensures consistent, precise handle placement at predetermined locations while maintaining high production rates of 50-75 cans per minute.

Inventive Principle:
Principle #25Self-service

3Extent of automation

If the second technique (automatically unrolling and riveting plastic strip) is used, then automation is achieved, but the technique is effective only for cylindrical cans and fails on complex shapes like tulip cans

Engineering Contradiction:
Improveautomation levelVSAvoidcan shape adaptability
Core Design Contradiction:
Extent of automationVSAdaptability or versatility

Solution Approach 1:

The patent designs a universal welding apparatus with a programmable control system that can handle multiple can geometries (cylindrical, conical, tulip-shaped, and other complex forms). The system stores geometric data for different can types in memory and automatically adjusts welding parameters, head position, and orientation based on the detected can shape. This multi-functional capability allows the same automated device to precisely attach handles on various can shapes without requiring changeovers or manual reconfiguration.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The welding head is designed with dynamic positioning and orientation capabilities, allowing it to move freely in three-dimensional space and adjust its angle relative to the can surface. The programmable control system dynamically calculates the optimal welding trajectory and parameters based on real-time can geometry detection. This dynamic adaptability enables the automated system to successfully weld handles on complex-shaped cans like tulip cans, where fixed or rigid positioning systems would fail.

Inventive Principle:
Principle #15Dynamics

4Ease of operation

If handles are attached vertically above the opening on tulip cans, then the handle mounting appears simple, but the leverage effect of the tulip causes random positioning and poor attachment quality

Engineering Contradiction:
Improvehandle mounting simplicityVSAvoidattachment quality
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent incorporates a feedback mechanism where the programmable control system continuously monitors the can's position, orientation, and geometry during the welding process. Sensors detect the actual can shape and dimensions, and the control system automatically adjusts the welding head position and parameters in real-time based on this feedback. This closed-loop control ensures that handles are precisely positioned and welded with consistent quality on tulip-shaped cans, eliminating the random positioning problems associated with simple vertical mounting approaches.

Inventive Principle:
Principle #23Feedback

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 method enables high production rates, up to 75 equipped packages per minute, with improved precision and quality, and can handle complex shapes without the drawbacks of existing techniques.

Implementation Method 1

a fixing means is welded into the perforated orifice in each of said ends of the tape

Methodology Applied
Scientific EffectWelding: Welding

Data Source

PatentEP1972562B1Method of fixing a plastic handle to a metal package
Publication Date: 2010.09.29 SABATIER
  • EP1972562B1 patent drawingFigure 1
  • EP1972562B1 patent drawingFigure 2A~3
  • EP1972562B1 patent drawingFigure 4

AI summary

The method involves selecting a portion of a plastic strip (1) of length for forming a plastic handle (A) of a metallic canister (B), and perforating an orifice on the ends of the portion of the strip to receive fixation units e.g. rivet, where the units fix ends on walls of the package. The portion is bent in a horizontal plane using a bending device, and the portion is oriented with respect to walls of the package by displacing the device. A fixation unit is welded on the perforated orifice in two positions on the walls of the package for integrating with the walls so as to form the handle.