Process for obtaining a hermetic connection for rigid tube

• US 5,131,145 A
• Filed: 01/30/1990
• Issued: 07/21/1992
• Est. Priority Date: 01/30/1989
• Status: Expired due to Term

• Current Assignee: Parker-Hannifin Corporation
• Original Assignee: Parker Hannifin Rak
• Inventors: Badoureaux, Jean-Pierre
• Primary Examiner(s): Cuda, Irene
• Application Number:
  US07/472,159
• Time in Patent Office: 903 Days
• Field of Search: 29/890.144, 29/890.15, 29/465, 29/512, 29/523, 285/334.5, 285/382, 285/354, 285/349, 72/370
• US Class Current: 29/890.144
• CPC Class Codes: B21D 19/04 shaped as rollers
• CPC Class Codes: B21J 9/025 with rolling or wobbling dies
• CPC Class Codes: B21K 21/12 Shaping end portions of hollow articles
• CPC Class Codes: F16L 19/0283 and having a bell-mouthed shape
• CPC Class Codes: Y10T 29/49435 Flexible conduit or fitting therefor
• CPC Class Codes: Y10T 29/49897 Registering mating opposed tool parts [e.g., registering a punch and a cooperating die]
• CPC Class Codes: Y10T 29/4992 by flaring inserted cup or tube end
• CPC Class Codes: Y10T 29/4994 Radially expanding internal tube

Abstract

In a tube fitting a nut which extends about the end of a tube allows the tube to be threadedly joined to a nipple. The end of the tube is formed in the shape of a collar which retains the nut. The face of the collar is flattened to sealingly meet with an o-ring which resides in an annular recess in the frontal surface of the nipple. The process of forming the collar in the end of the tube includes placing a nut on the tube, gripping the end of the tube with a die, and deforming the end of the tube with a tool of truncated cone-shape move in an advancing, precessing motion. The die is shaped with interior shoulders having the profile of the collar. A socket which forms the back side of the collar can be placed over the tube after the die grips the tube. After the collar formed the dies is removed.

Claims

1. A process for forming a tube fitting of the type having a nut which extends about a tube for joining the tube to a nipple with threads to receive the nut and with a front surface which sealingly mates with a flattened face disposed at an end of the tube, comprising the steps of:

placing a nut about the tube;

gripping the end of the tube with a die having an internal profile of a

deforming the end of the tube gripped in the die to form a collar having the collar shape of the die by means of a tool having a flattened annular area to form the flattened face of the tube and a truncated cone-shaped nose insertable in the tube to guide movement of the tool with respect to the tube and by advancing the tool into the die in an advancing precessing motion.

2. The process of claim 1 which further includes the step of:

placing a socket about the end of the tube in the die so that the socket extends between the collar and the nut after the collar is formed by deforming the end of the tube.

3. The process of claim 2 which further includes the step of:

removing portions of the die form the tube by separating these portions of the die from about the collar of the tube.