Spirally Wound Pipe Liner Interlocking Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for spirally wound pipe lining, such as those described in AU 746929, face limitations including the need for minimum longitudinal stiffness of the profile, shallow entry angle for larger diameters, and unreliable engagement of locking members due to tension-dependent mechanisms, restricting the range of diameters that can be wound and the reliability of the installation process.
Innovation Solution
A method involving the use of transversely spaced connecting formations on a web that are interlocked during helical winding, with exterior support means applying a radially outward force to pinch the overlapping formations into engagement, eliminating the reliance on profile tension and stiffness, and allowing for the formation of large diameter pipes without an annulus space between the host and new pipes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the profile requires minimum longitudinal stiffness for locking members to engage, then the locking mechanism can function, but the range of usable profiles is limited
Solution Approach 1:
The patent changes the engagement mechanism from tension-dependent to compression-dependent. By applying radial compression forces through guide rollers and support structures, the locking members are forced into engagement regardless of the profile's longitudinal stiffness. This parameter change allows flexible profiles to be used while maintaining reliable locking.
2Reliability
If the entry angle becomes shallower for larger diameters, then the locking members will no longer engage properly, but larger diameter pipes cannot be formed
Solution Approach 1:
The patent applies preliminary compression forces through the guide rollers and radial support structures before the locking members need to engage. This pre-compression ensures that the locking members are already in engagement position when they meet, eliminating the entry angle problem for large diameter pipes.
3Device complexity
If tension in the profile is used to engage locking members, then the mechanism is simple, but engagement becomes unreliable for large diameters
Solution Approach 1:
The patent inverts the engagement mechanism from tension-based to compression-based. Instead of relying on profile tension to push locking members together, radial compression forces are applied through guide rollers and support structures to force the locking members into engagement. This inversion significantly improves reliability for large diameter pipes.
4Productivity
If the liner is wound to maximum diameter to optimise hydraulic efficiency, then hydraulic performance is improved, but the locking members may not engage properly
Solution Approach 1:
The patent applies counteracting radial compression forces through guide rollers and support structures that balance the outward forces on large diameter pipes. This allows the liner to be wound to maximum diameter for hydraulic efficiency while the compression forces ensure locking members remain properly engaged.
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 reliable and intimate contact of the new liner with the host pipe across a wide range of diameters, reducing the need for profile stiffness and ensuring consistent interlocking engagement, thus overcoming the limitations of prior art methods.
Implementation Method 1
applying a radially outwardly directed force against an inner face of the driven web and the support means, thereby pinching the overlapping connecting formations into interlocking engagement
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention provides methods and apparatus for producing a spirally wound pipe or pipe liner, and also to a web for forming a spirally wound pipe or pipe liner. One aspect of the invention provides a method and an associated machine of winding a helically wound pipe from a web (200) having transversely spaced apart connecting formations (310, 320) adapted to interlock when the web is wound in a helical path and adjacent edge portions (300a, 300b) of the web overlap one another, wherein an exterior support means (400) for the connecting formation at the terminus of the pipe being helically wound from the web is provided, and a radially outwardly directed force is applied against an inner face (220) of the web and the support means (400) to pinch connecting formations into interlocking engagement. A further aspect of the invention provides an elongated web (200) comprising a wall portion (210) bound by edge portions (300a, 300b) and adapted to form a pipe by spirally winding said web and joining adjacent said edge portions, wherein a distal end of joined edge portions (330) of the web projecting from the wall portion (210) of the web is less than a spacing distance defined by a spacer rib (350) projecting from the wall portion, when the web is spirally wound and adjacent edge portions are joined together.