Method for attaching metallic flanges to thermal plastic ducts

Patent metadata

Field	Value
Publication number	US-10350796-B2
Application number	US-201214434659-A
Country	US
Kind code	B2
Filing date	Oct 9, 2012
Priority date	Oct 9, 2012
Publication date	Jul 16, 2019
Grant date	Jul 16, 2019

Abstract

A method is provided for connecting a fitting to a reinforced thermoplastic duct including inserting a first end of the fitting having a plurality of barbs into an end of the duct. A clamp is installed around the duct. The duct is heated to a temperature greater than a glass transition temperature of a thermal plastic material used to form the duct. The duct is restructured to include a plurality of protrusions positioned between the plurality of barbs of the fitting.

First claim

The invention claimed is:

1. A method for connecting a fitting to a reinforced thermoplastic duct comprising:
inserting a first end of the fitting having a plurality of barbs into an end of the duct, wherein a maximum external diameter of the first end is less than an initial minimum internal diameter of the duct;
installing a clamp around the duct after inserting the first end into the end of the duct;
heating the duct to a temperature greater than a glass transition temperature of a thermoplastic material used to form the duct after installing the clamp around the duct;
restructuring the duct to include a plurality of protrusions positioned between the plurality of barbs of the fitting via the heating of the duct to the temperature greater than the glass transition temperature;
allowing the duct to cool to a temperature below the glass transition temperature; and
removing the clamp from the duct after the duct is cooled to the temperature below the glass transition temperature.

2. The method according to claim 1 , wherein the clamp restrains movement of the duct relative to the fitting.

3. The method according to claim 1 , wherein the clamp applies a compressive force the duct.

4. The method according to claim 1 , wherein the clamp is installed concentrically around the end of the duct and the first end of the fitting.

5. The method according to claim 1 , wherein the clamp has a melting temperature greater than the glass transition temperature of the duct.

6. The method according to claim 1 , wherein the fitting has a melting temperature greater than the glass transition temperature of the duct.

7. The method according to claim 3 , wherein the force applied by the clamp when the duct is heated to a temperature greater than a glass transition temperature causes the barbs of the fitting to dig into an interior surface of the duct and the duct to flow into a plurality of grooves formed between the plurality of barbs.

8. The method according to claim 1 , wherein the plurality of protrusions are permanently formed in the duct.

9. The method according to claim 7 , wherein the plurality of protrusions are complementary to the plurality of grooves.

10. The method of claim 1 , wherein the fitting is formed from a metal material.

Assignees

• Wysocki Gary R
• Hamilton Sundstrand Corp

Inventors

• Wysocki Gary R

Classifications

• F16L47/24

  for joints between metal and plastics pipes · CPC title

• B29C66/723

  being multi-layered (B29C66/7292, B29C66/72941 take precedence) · CPC title

• B29C66/8322

  Joining or pressing tools reciprocating along one axis · CPC title

• B29C66/30325

  making use of cavities belonging to at least one of the parts to be joined · CPC title

• B29C66/5344

  said single elements being substantially annular, i.e. of finite length, e.g. joining flanges to tube ends (B29C66/5346 takes precedence) · CPC title