Plastic Pipe Mechanical Fitting With Visible Lock and Hermetic Seal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for connecting plastic pipes for natural gas transmission require specialized skill and tooling, or compromise on seal and axial strength integrity, failing to meet industry demands for robust and reliable connections.
Innovation Solution
A mechanical fitting system using a spigot device with a sleeve assembly that includes a gripper ring and compression collar, allowing for easy installation and high-integrity sealing by leveraging the viscoelastic properties of the pipe, with gripper rings radially expanding to engage the pipe wall and a compression collar ensuring a hermetic seal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fusion methods are used to connect plastic pipes, then gas tight seal is achieved, but specialized skill and tooling are required
Solution Approach 1:
The patent replaces thermal fusion processes with a mechanical connection system consisting of a spigot inserted into the pipe end and a sleeve telescoped over the spigot. The mechanical gripper rings compress the pipe wall radially inwardly to create a hermetic seal without requiring heat or specialized fusion equipment, thereby maintaining seal integrity while eliminating the need for specialized skill and tooling.
Solution Approach 2:
The patent introduces intermediate components (spigot, sleeve, and gripper rings) that mediate between the pipe ends to be connected. These intermediaries provide the sealing and gripping functions mechanically, replacing the direct thermal fusion process and enabling easier installation while maintaining reliability.
2Ease of operation
If telescopical inter-fitting parts with dynamic seals are used, then connection is achieved, but seals are exposed to foreign material and axial pull characteristics are insufficient
Solution Approach 1:
Instead of exposing seals to the external environment where they contact foreign material, the patent inverts the approach by having the gripper rings compress the pipe wall from the outside inwardly. The sealing action occurs at the interface between the gripper rings and pipe wall, protected from external contaminants, while still achieving the necessary seal integrity.
Solution Approach 2:
The patent applies different functional qualities to different parts of the connection system: the gripper rings provide radial compression for sealing, the spigot provides structural support and alignment, and the sleeve provides protection and telescopic movement. This local differentiation of functions optimizes each component for its specific role, improving overall reliability while maintaining ease of operation.
3Ease of operation
If metal inserts with compression sleeves are used, then connection is achieved, but high integrity seal and axial strength are not met
Solution Approach 1:
The patent employs a composite connection system where the spigot, sleeve, and gripper rings work together as an integrated assembly. The gripper rings compress the pipe wall to create both a hermetic seal and a strong mechanical bond that resists axial pull forces. This composite approach achieves high integrity sealing and strength while maintaining ease of assembly.
Solution Approach 2:
The gripper rings are pre-configured on the spigot in a relaxed state before installation. During installation, as the sleeve is telescoped over the spigot, the gripper rings are automatically compressed radially inwardly against the pipe wall, creating the seal and grip before final assembly is complete. This preliminary action ensures proper seating and compression without requiring additional steps.
4Reliability
If wedge-driven teeth are used to deform hose wall, then connection is achieved, but tedious work and insufficient sealing are required
Solution Approach 1:
The patent replaces the complex wedge-driven teeth mechanism with a simpler telescopic sleeve system that compresses gripper rings radially inwardly. This mechanical substitution eliminates the need for wedges and teeth while achieving equivalent or superior sealing capability through uniform radial compression, thereby reducing assembly complexity.
Solution Approach 2:
The gripper rings are designed to be dynamically compressible, transitioning from a relaxed state during assembly to a compressed state during operation. This dynamic property allows the rings to be easily installed in a relaxed configuration and then automatically compressed to the gripping and sealing position as the sleeve is telescoped, simplifying assembly while maintaining high seal capability.
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
Provides a reliable, easy-to-install connection that meets industry standards for integrity and durability, resisting axial forces and ensuring hermetic sealing, even under ground shifts and thermal changes.
Implementation Method 1
a radially inwardly contractible gripper ring device retained in the gripper ring chamber, biased outwardly against the bearing surface and constructed to, when received over the spigot, cooperate with the spigot to form an annulus to receive the wall of the pipe
Implementation Method 2
A compression collar is received in the compression cavity and formed on the proximal end to abut the pusher shoulder and on the distal end to engage the gripper ring device
Implementation Method 3
As the spigot device pushes the gripper ring device distally relative to the sleeve, the bearing surface drives the gripper ring device radially inwardly to grip the wall of the pipe
Data Source
AI summary
A fitting for a pipe includes a cylindrical sleeve including at least one observation through window, a spigot disposed concentrically within the cylindrical sleeve and having an outer surface sized to fit within a proximal end of the pipe, wherein the cylindrical sleeve is movable with respect to the spigot in a proximal direction to a sealed position and a locking assembly interposed between the cylindrical sleeve and the spigot to lock the cylindrical sleeve to the spigot in the sealed position. The at least one observation through window provides a view of at least a portion of the locking assembly to determine whether the cylindrical sleeve is locked in the sealed position.