Coupling

Abstract

A coupling for attaching to an end of a tube, pipe, conduit or other round solid or hollow section. The coupling includes an inner body and a collar to be provided around the inner body. The inner body has an interior bore passing through at least a portion thereof to receive a tube and the bore has one or more interior annular protuberances extending into the bore. When the collar is provided around the inner body it applies a circumferential compressive force to deform the inner body such that the one or more annular protuberances engage the tube or the like to seal with it.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is continuation of U.S. patent application Ser. No. 11 / 836,180, filed Aug. 9, 2007, which is a continuation of International Application No. PCT / GB06 / 000035, filed Feb. 17, 2006, which application designated the United States, and which application claims priority to Great Britain Patent Application No. 0502954.0, filed Feb. 25, 2005, and Great Britain Patent Application No. 0515165.9, filed Jul. 22, 2005, the disclosure of each of which applications is expressly incorporated herein by reference.BACKGROUND OF THE INVENTION[0002]The present invention relates to a coupling for attaching tubes, pipes, conduits and other round sections to other such items and / or other systems.[0003]Initially this invention has been developed within the instrumentation tube fittings industry. However, the invention is capable of being utilised within many other applications outside of this environment. Other applications may include shipbuildi...

AI Technical Summary

Benefits of technology

"The invention provides a new type of coupling for attaching to a tube or pipe. The coupling has an inner body with interior annular protuberances that deform when a tube or pipe is inserted, creating a seal with it. The coupling requires only two parts, reducing manufacturing costs and making assembly easier. The interior annular protuberances have a cutting surface to breach the skin of the tube or pipe, making a better seal and resistance to axial removal. The collar applies a circumferential compressive force to deform the body, providing a secure and reliable seal. The coupling is suitable for tubes or pipes with different tolerances and can be used with tubes or pipes that have not been precisely squared. The interior annular protuberances may be replaced with screw threads or other methods of engagement. The collar and inner body have complimentary camming surfaces that act together to deform the body. The new coupling provides a better seal and resistance to axial removal than conventional ferrules."

Problems solved by technology

The following problems are associated with these designs:

This in itself can cause issues as traditional hardening methods such as nitriding induces carbon into the material, which reduces the surfaces corrosion resistance.

Incorrect tube preparation can cause major problems within the assembly of the fitting and this is one aspect that the manufacturer has no control over.

Longitudinal scratches on the tube can cause leak paths with these fittings.

Basic tube handling commonly causes these scratches.

These minor surface defects are often manually removed prior to assembly, which adds to the assembly time.

Due to the requirement of enhanced materials it is accepted that compression fittings manufactured from austenitic stainless steel are not suitable for use within certain environments and do not comply with the National Association of Corrosion Engineers (“NACE”) standards.

This is seen by a limitation within certain fields such as the automotive industry.

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