Pipe Bending Head for Helical Strip Interlock Formation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for manufacturing helically wound pipes using wrapped material strips face challenges such as the need for clean room conditions for adhesives, imbalance of radial stresses leading to conical shapes, and limitations in pipe length due to internal rollers, which restrict the use of mobile pipe manufacturing in the field.
Innovation Solution
A pipe bending head apparatus with multiple bending heads that deform strips into helical forms using asymmetric interlock features and rollers to apply stress, allowing for plastic deformation of ridges while maintaining the non-ridge portions in elastic deformation, enabling the formation of longer pipes without adhesives and balancing radial stresses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If adhesive is applied to hold the layers of the pipe together, then the pipe structure is retained, but clean room conditions are required which restricts mobile pipe manufacturing in the field
Solution Approach 1:
The patent replaces the chemical bonding mechanism (adhesive) with a mechanical interlocking mechanism. The interlocking features (ridges and grooves) on the strip edges mechanically engage to retain the pipe structure, eliminating the need for adhesives and the associated clean room conditions, thereby enabling mobile field manufacturing
2Ease of manufacture
If self-overlapping strip method is used to form helical shapes, then pipe structure is created, but radial stress imbalance occurs causing conical shape instead of tubular shape
Solution Approach 1:
The patent introduces asymmetric interlocking features (ridges and grooves) on the strip edges that create balanced radial stresses when the strips are wrapped. The asymmetric geometry of the interlocking features distributes the stresses uniformly around the pipe circumference, preventing the conical deformation that occurs with symmetric self-overlapping methods
3Shape
If internal roller is used to resist radial stresses, then radial stress imbalance is addressed, but pipe length is limited which restricts moderate or longer length pipe manufacturing
Solution Approach 1:
The patent replaces the mechanical support system (internal rollers) with a self-balancing interlocking mechanism. The asymmetric interlocking features inherently balance the radial stresses through their geometry, eliminating the need for internal rollers and thereby removing the length limitations imposed by roller support requirements
4Shape
If plastic deformation is applied to achieve desired pipe shape, then pipe shape is formed, but excessive stress is created leading to stress fractures
Solution Approach 1:
The patent applies plastic deformation locally only to the interlocking features (ridges and grooves) on the strip edges, while the main body of the strip remains in the elastic range. This localized plastic deformation creates the necessary interlocking geometry without subjecting the entire strip to excessive stresses that would cause fractures
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
Enables the continuous on-site manufacturing of longer pipes with balanced radial stresses and improved burst strength, eliminating the need for adhesives and countervailing rollers, thus enhancing the flexibility and reliability of pipe manufacturing in the field.
Implementation Method 1
each bending head is arranged to deform a strip of material into a helical form by applying a stress to at least one ridge running longitudinally along the strip of material to provide a plastic deformation of the at least one ridge
Implementation Method 2
A non-ridge portion of each helical strip of material is deformed into a cylindrical shape by elastic deformation
Data Source
AI summary
A bending apparatus for forming a helical strip of material. The bending apparatus comprises at least one bending head and is arranged to deform a strip of material into a helical form by applying a stress to a ridge running longitudinally along the strip of material to provide a plastic deformation of the ridge. The helical form of the helical strip of material is a permanent distortion due to the deformation of the ridge applied by the at least one bending head.