Method of forming internal strictures in a tubular member and a bonding connection with an inserted tube

• US 5,203,943 A
• Filed: 12/13/1990
• Issued: 04/20/1993
• Est. Priority Date: 12/13/1990
• Status: Expired due to Fees

• Current Assignee: Graseby Medical Limited
• Original Assignee: 3M Company
• Inventors: Stoen, David M., Ferguson, Raymond L., Nornberg, Jon M.
• Primary Examiner(s): Arola, Dave W.
• Application Number:
  US07/626,826
• Time in Patent Office: 859 Days
• Field of Search: 285/21, 285/22, 285/423, 285/238, 285/369, 285/915, 264/320, 264/322, 156/245, 156/293
• US Class Current: 156/245
• CPC Class Codes: A61M 2039/1027 Quick-acting type connectors
• CPC Class Codes: A61M 39/12 for joining a flexible tube to a rigid attachment
• CPC Class Codes: B29C 57/00 Shaping of tube ends, e.g. flanging, belling or closing; Apparatus therefor , e.g. collapsible mandrels
• CPC Class Codes: B29C 65/02 by heating, with or without pressure
• CPC Class Codes: B29C 65/04 Dielectric heating, e.g. high-frequency welding , i.e. radio frequency welding of plastic materials having dielectric properties, e.g. PVC
• CPC Class Codes: B29C 65/48 using adhesives , i.e. using supplementary joining material; solvent bonding
• CPC Class Codes: B29C 65/4895 Solvent bonding, i.e. the surfaces of the parts to be joined being treated with solvents, swelling or softening agents, without adhesives
• CPC Class Codes: B29C 65/54 between pre-assembled parts
• CPC Class Codes: B29C 65/548 by capillarity
• CPC Class Codes: B29C 66/032 Mechanical after-treatments deburring welded articles B29C37/04
• CPC Class Codes: B29C 66/1222 comprising at least a lapped joint-segment
• CPC Class Codes: B29C 66/1224 comprising at least a butt joint-segment
• CPC Class Codes: B29C 66/5221 for forming coaxial connections, i.e. the tubular articles to be joined forming a zero angle relative to each other
• CPC Class Codes: B29C 66/53261 Enclosing tubular articles between substantially flat elements
• CPC Class Codes: B29C 66/5344 said single elements being substantially annular, i.e. of finite length, e.g. joining flanges to tube ends B29C66/5346 takes precedence
• CPC Class Codes: B29C 66/71 characterised by the composition of the plastics material of the parts to be joined welding bar compositions B29C65/125
• CPC Class Codes: B29K 2027/06 PVC, i.e. polyvinylchloride
• CPC Class Codes: B29L 2031/7148 Blood bags, medical bags
• CPC Class Codes: Y10S 285/915 Mastic

Abstract

A leak-resistant connection between two generally tubular members in which second tubular member is telescopically received in a first generally tubular member. There is at least one integral continuous annular stricture formed in the lumen of the first tubular member for engaging and sealing with the second tubular member. A second, integral stricture of larger profile may be provided as a stop to abut the end of the second tubular member. A method of making the connection is also disclosed. The method includes the step of forming the strictures in the tubular member by inserting a grooved mandril into the lumen of the tubular member and heating and applying pressure to the tubular member to form the strictures in the grooves in the mandril. The tubular member can be conveniently heated with RF energy applied through the mandril.

Claims

1. A method of making a connection between the ends of first and second generally tubular members, the method comprising:

forming at least one continuous annular stricture in the lumen of the first tubular member by inserting a mandril, having at least one circumferential annular groove, into the end of the lumen of the first tubular member;

heating the portion of the first tubular member surrounding the mandril to form an annular projection in the groove in the mandril; and

removing the mandril from the lumen leaving an annular stricture in the lumen of the first tubular member;

inserting the end of the second tubular member into the end of the first tubular member, beyond the stricture, and

bonding the first and second tubular members together.

2. The method of claim 1 wherein the step of bonding the first and second tubular members comprises the steps of applying a solvent to at least one of the interior of the end of the first tubular member and the exterior of the end of the second tubular member before inserting the second tubular member into the first tubular member.

3. The method according to claim 1 wherein the step of heating the first tubular member comprises applying RF energy to the tubular member.

4. The method according to claim 3 wherein the step of heating the first tubular member comprises applying RF energy to the tubular member with the mandril.

5. The method according to claim 1 further comprising the step of pressing the portion of the first tubular member surrounding the mandril against the mandril while heating the first tubular member.

6. The method according to claim 5 wherein the step of pressing the first tubular member against the mandril includes pressing the tubular member against the mandril with at least one die.

7. The method according to claim 1 wherein the portion of the mandril that is inserted into the tubular member is generally tapered.

8. A method of making a connection between the ends of first and second generally tubular members, the method comprising:

forming a first continuous annular stricture in the lumen of the first tubular member, and a second annular stricture in the lumen of the first tubular member, spaced further from the end of the first tubular member than the first stricture, and having a higher profile than the first stricture to abut the end of the second tubular member inserted into the lumen by inserting a mandril, having at least two axially spaced circumferential annular grooves therein, into the end of the lumen of the first tubular member;

heating the portion of the first tubular member surrounding the mandril to form an annular projection in each groove in the mandril; and

removing the mandril from the lumen leaving two annular strictures in the lumen of the first tubular member;

inserting the end of the second tubular member into the end of the first tubular member, beyond the first stricture, until the end of the second tubular member abuts the second stricture, and

bonding the first and second tubular members together.

9. The method according to claim 8 further comprising the step of pressing the portion of the first tubular member surrounding the mandril against the mandril while heating the first tubular member.

10. The method according to claim 9 wherein at least two dies are used to press the first tubular member against the mandril, each die having a recess therein generally complementary to the configuration of the portion of the mandril inserted into the tubular member.

11. The method according to claim 10 wherein the portion of the mandril that is inserted into the first tubular member is generally tapered, and wherein the recesses in the dies have a complementary taper.

12. The method according to claim 8 wherein the groove closest to the distal end of the mandril is deeper than the groove closest to the proximal end of the mandril, to form said stricture with said higher profile.

13. The method according to claim 8 wherein the step of bonding the first and second tubular members comprises the step of applying a solvent to at least one of the interior end of the first tubular member and the exterior end of the second tubular member before inserting the second tubular member into the first tubular member.

14. A method of making an improved tubular member for facilitating leak-resistant connections with other tubular members, the method comprising the steps of:

inserting a mandril having an annular groove into the end of the lumen of the tubular member;

heating the portion of the tubular member surrounding the mandril to form an annular projection in the grove in the mandril, and removing the mandril from the lumen to leave a continuous annular stricture in the lumen of the tubular member.

15. The method according to claim 14 wherein the step of heating the tubular member comprises applying RF energy to the tubular member.

16. The method according to claim 14 further comprising the step of pressing the portion of the tubular member surrounding the mandril against the mandril while heating the tubular member.

17. The method according to claim 16 wherein the step of pressing the tubular member against the mandril includes pressing the tubular member against the mandril with at least one die having a recess therein generally complementary to the configuration of the portion of the mandril inserted into the tubular member.

18. The method according to claim 17 wherein the portion of the mandril that is inserted into the tubular member is generally tapered, and wherein the recess in the die is tapered.

19. The method according to claim 17 wherein the step of heating the tubular member comprises applying RF energy to the tubular member with the mandril and the die.

20. The method according to claim 14 wherein the portion of the mandril inserted into the tubular member has two axially spaced circumferential annular grooves therein for forming two annular strictures in the tubular member.

21. The method according to claim 20 wherein the groove closest to the distal end of the mandril is deeper than the groove closest to the proximal end of the mandril, to form a stricture with a higher profile.