Branched Tube Cold-Expanded Joint for Fire Protection
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Solution Overview
Problem
Existing methods for forming branches in tubes, such as those used in fire protection installations, are cumbersome and difficult to implement in pre-installed tubes, especially in hard-to-access areas, requiring cutting or complex access to the outer face of the tube.
Innovation Solution
A branched tube design featuring a main tubular body with an additional tubular body inserted through a hole, where the additional body has a flared mouth that is cold-expanded to create a leak-tight joint, allowing for easy insertion and connection of new branches without cutting the main tube, and includes features like a support surface, sealing gaskets, and end joining means for secure attachment and interconnection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a clamp device is used to fasten a branch around a pre-installed tube, then the branch can be incorporated into pre-installed tubes, but the device becomes cumbersome and requires access to the entire outer face of the tube
Solution Approach 1:
Instead of fastening the branch from the outside of the tube as in conventional clamp devices, the invention inverts the approach by inserting the additional tubular body through a hole drilled in the tube wall and fastening it from the inside. The mouth of the additional tubular body is flared inward to engage with the inner face of the tube wall, eliminating the need to access the entire outer face of the tube.
Solution Approach 2:
The invention extracts the fastening operation from the outer face of the tube and relocates it to the inner face. By drilling a hole through the tube wall and inserting the additional tubular body, the fastening action is taken out from the cumbersome external clamp application and performed internally through hole expansion, reducing access requirements.
2Adaptability or versatility
If cutting is used to interpose a T-shaped length between two tube lengths, then the branch can be incorporated, but the process becomes complicated and difficult for pre-installed tubes
Solution Approach 1:
The invention performs preliminary action by pre-forming the additional tubular body with a flared mouth that is designed to be inserted through a hole and expanded internally. This preliminary preparation of the additional tubular body eliminates the need for complex cutting and assembly operations required by T-shaped lengths, as the additional body is simply inserted and expanded in place.
Solution Approach 2:
The invention replaces the mechanical cutting and assembly system with a hole expansion system. Instead of cutting the tube and assembling T-shaped lengths with mechanical fasteners, the invention uses a simple hole drilling operation followed by mechanical expansion of the additional tubular body's mouth, substituting a complex mechanical assembly process with a simpler expansion process.
3Strength
If the mouth of the additional tubular body is flared to fasten it to the main tube, then a secure connection is achieved, but the material must be deformable without causing cracks
Solution Approach 1:
The invention applies parameter changes by carefully controlling the deformation parameters during the flaring process. The mouth of the additional tubular body is flared with controlled expansion ratios and deformation rates that remain within the elastic and plastic deformation limits of the material, avoiding excessive stress that would cause cracking. The geometry of the flared mouth is optimized to distribute stresses evenly.
Solution Approach 2:
The invention applies beforehand cushioning by designing the additional tubular body with appropriate material selection and geometric features that cushion the deformation process. The material is chosen to have suitable ductility and toughness to accommodate the flaring operation, and the wall thickness and mouth geometry are designed to distribute deformation stresses, preventing stress concentration that would lead to cracking.
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 easy incorporation of new branches into pre-installed tubes, including those in difficult-to-access locations, without cutting the main tube, providing a secure and leak-tight connection for forming complex tubing circuits and integrating devices like sprinklers in fire protection systems.
Implementation Method 1
a mouth, also tubular, which passes through the hole and is flared, for example said mouth being cold-expanded after the insertion thereof into the main tubular body
Implementation Method 2
the entire perimeter of the mouth is expanded by plastic deformation of said mouth, which is continuous
Implementation Method 3
fastening said flared mouth by the compression the additional tubular body exerts on the main tubular body
Data Source
Figure 1~3a
Figure 3b~3c
Figure 3d~3e
AI summary
The invention relates to a branched tube (1) that enables the incorporation of additional devices into a conduit, such as sprinklers in a fire protection installation, and a method for forming a branch in a tubular body. The branched tube (1) comprises a main tubular body (2) and at least one additional tubular body (3) fitted in a leak-tight manner into a hole (5) formed in the wall (6) of said main tubular body, the additional tubular body comprising a support surface (7) applied onto the outer face (6a) of the main tubular body wall and a mouth (8), which passes through the hole and is cold-flared, the additional tubular body fastening the main tubular body by compression.