Pivoting Gripping Element for Pipe Joint Restraints
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Solution Overview
Problem
Existing pipe joint restraints require high torque for secure engagement, which is difficult to achieve in outdoor conditions and can lead to seal deflection, and they require multiple configurations for different materials and sizes, increasing inventory needs.
Innovation Solution
The pipe joint restraints feature a gripping element that pivots about a fixed fulcrum relative to the annular gland's centerline, allowing for secure engagement at lower torques and using adaptable gripping elements for various materials, reducing torque requirements and inventory needs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional pipe joint restraints use friction-based gripping elements, then the pipe connection can be secured, but high torque (65-90 foot-pounds) is required which is difficult to achieve in outdoor conditions and can deflect the pipe
Solution Approach 1:
The gripping element is designed to dynamically pivot about a fixed fulcrum in response to hydraulic thrust forces. When thrust forces act on the pipe, the gripping element automatically pivots to increase gripping force, converting the thrust force into enhanced friction without requiring high installation torque. This dynamic adaptation resolves the contradiction by making the connection secure under load while keeping installation simple.
Solution Approach 2:
The invention changes the operational parameters of the gripping element by introducing a fixed fulcrum at a specific distance from the pipe centerline. This geometric parameter change creates a mechanical advantage that reduces the torque required for initial engagement while maintaining secure connection under hydraulic loads through the pivoting action.
2Adaptability or versatility
If multiple configurations of wedges and retainer glands are used to accommodate different pipe materials and sizes, then all pipe types can be serviced, but inventory complexity and manufacturing costs increase
Solution Approach 1:
The gripping element is designed as a universal component that can accommodate different pipe materials (ductile iron, PVC, etc.) and sizes through a single standardized interface. The fixed fulcrum design and standardized pocket configuration allow the same retainer gland and gripping element assembly to work across multiple pipe types, eliminating the need for multiple specialized configurations and reducing inventory complexity.
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 design achieves reliable pipe engagement at lower torques (40-60 foot-pounds) for both metal and polymeric pipes, reducing installation effort and inventory complexity while maintaining a secure seal under hydraulic forces.
Implementation Method 1
A gripping element or wedge is movably supported in the pocket and has a gripping edge, such as a tooth, to frictionally engage the pipe surface when the gripping element is moved to project out of the pocket toward a pipe in the pipe-receiving space
Implementation Method 2
the top wall of the pocket defines a fulcrum fixed a predetermined distance from the axial centerline of the annular retainer gland, with the gripping element being operatively engaged therewith so as to move relative to the fulcrum such that the gripping edge moves toward the centerline of the gland
Data Source
AI summary
A pipe joint restraint (16) includes a pocket (74) having a fulcrum (92) a fixed distance from the centerline (26) of an annular retaining gland (22) and about which a gripping element (76) pivots to move a gripping edge (75) toward the centerline (26) so as to grip a pipe (14) engaged by the gripping element (76) in response to thrust forces on the pipe (14). The length of gripping edge (75) is selected for the material of pipe (14). Adjustable element (78) operatively connects to the gripping element (76) and fulcrum (92) to pivot with the gripping element (76). Adjustable element (78) and may be torqued to a common, predetermined torque whether the pipe (14) is metal or polymeric.