Swivel Connector for Nonmetallic Conduit with Reduced Nut Diameter
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing swivel fittings for electrical conduit installations face limitations in tight spaces due to large coupling nut diameters and internal obstructions, hindering wire and cable threading and restricting angular adjustability.
Innovation Solution
A swivel coupling design featuring arcuate tubular sections with parallel planar connecting flanges, a coupling nut with a minimum internal diameter, and a stop nut, allowing for easy assembly and adjustment while minimizing bulk and eliminating internal obstructions, facilitating smooth conduit and cable threading.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a coupling nut with large diameter is used to obtain clearance for assembly, then the coupling nut can pass over the radial abutment flange, but the radius of curvature of the fitting is limited and the fitting cannot be used in limited space applications
Solution Approach 1:
The invention divides the coupling mechanism into two separate components: a coupling nut for joining the tubular members and a stop nut for limiting rotation. This segmentation allows the coupling nut to have a smaller diameter that can pass through the abutment flange, while the stop nut provides the necessary rotational limitation without requiring large clearance for assembly.
Solution Approach 2:
The stop nut acts as an intermediary element that provides the rotational stopping function without requiring the coupling nut to have a large diameter. By introducing this separate component, the system achieves both assembly clearance and rotational limitation without the trade-off present in the prior art.
2Ease of manufacture
If the coupling nut has a large diameter to pass over the radial abutment flange, then assembly is possible, but the overall device dimensions are increased and space is consumed
Solution Approach 1:
The coupling and rotation-limiting functions are segmented into separate nuts, allowing the coupling nut to be compact with a diameter that fits through the abutment flange, while the stop nut is positioned separately to provide rotational limitation without increasing the overall device footprint.
Solution Approach 2:
The stop nut is positioned along the axial dimension of the fitting rather than requiring radial clearance. This dimensional change allows the rotation-limiting function to be achieved without increasing the radial footprint of the device, enabling use in tight spatial configurations.
3Strength
If the internal bores of tubular members are not coincident at the radiused flanges, then the structural integrity is maintained, but internal obstructions are created that hinder smooth threading of wires and cables
Solution Approach 1:
The invention applies different geometric qualities to different locations: the abutment flanges have radiused corners for structural integrity and bearing surface, while the internal bores are made coincident at the flange region to provide smooth wire threading. This local differentiation of geometric properties resolves the contradiction between strength and ease of wire installation.
Data Source
AI summary
A swivel coupling for electrical conduit is formed of a pair of arcuate tubular sections joined together at a pair of connecting flanges. A liquid tight seal is provided by an O-ring which seats in registered annular grooves in the face of each flange. A coupling nut tightens the flanges against one another. Formed at the end of one of the sections is a junction box fitting including a threaded nipple which is inserted through an opening of the junction box until a stop nut, positioned on the nipple, engages the box. A tightening nut is engaged over the nipple from the interior of the junction box to secure the swivel coupling to the box. The end of the other tubular section includes a conduit fitting for securing a length of electrical conduit. Because the stop nut is installed after the coupling nut has been advanced past the nipple, a reduced diameter coupling nut may be employed.