Method and apparatus for flashless tipping of an I.V. catheter

• US 4,661,300 A
• Filed: 03/11/1986
• Issued: 04/28/1987
• Est. Priority Date: 09/12/1984
• Status: Expired due to Term

• Current Assignee: Deseret Medical, Inc. (Becton, Dickinson & Co)
• Original Assignee: Becton, Dickinson & Co
• Inventors: Daugherty, Charles W.
• Primary Examiner(s): Silbaugh, Jan
• Assistant Examiner(s): THEISEN, MARY LYNN F
• Application Number:
  US06/838,739
• Time in Patent Office: 413 Days
• Field of Search: 264/320, 264/322, 264/40.1, 264/40.6, 264/40.7, 264/163, 425/393, 425/383, 425/384, 425/392, 425/397, 425/398, 425/406, 425/145, 425/144, 425/298, 308/30 A, 308/5 R
• US Class Current: 264/40.6
• CPC Class Codes: A61M 25/001 Forming the tip of a catheter, e.g. bevelling process, join or taper
• CPC Class Codes: B29C 33/06 using radiation , e.g. electro-magnetic waves, induction heating
• 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: B29L 2031/7542 Catheters

Abstract

A method and apparatus for tipping one end of an I.V. catheter includes the method steps for use of the apparatus including mounting a catheter to be tipped onto a mandrel supported on a carriage; a die having an interior molding surface, at least one portion of which is tapered according to the tip desired on the catheter, is heated; the carriage is moved along guide bars to the die such that the catheter carrying mandrel moves toward the interior molding surface to define a space, when the carriage is halted the catheter carrying mandrel is biased toward the die space with only sufficient force to cause the heated catheter to flow into the die space and as the catheter melts and flows, the mandrel engages the die thereby defining the edge of the catheter, after which the die and catheter therein are cooled; the carriage is then reversed along the guide bars such that the catheter and mandrel are withdrawn from the die, and the catheter is removed from the mandrel. An apparatus for performing the above described method is also disclosed.

Claims

1. A method of tipping by molding one end of an I.V. catheter, without any flash comprising the steps of;

mounting a catheter to be tipped coaxially over a cantilever support mandrel carried on a carriage whereby said catheter is even with or extends slightly beyond the end of said mandrel,

heating a die having an interior molding surface at least one portion of which is tapered according to the tip desired on said catheter and is open at both ends for allowing flow of catheter material therethrough,

moving said carriage along a guide means toward said die such that said catheter carrying mandrel enters said die and carries said catheter toward engagement with said tapered molding surface,

continuing moving said mandrel into said die and forcing said catheter into the space being established between and by the mandrel and the tapered molding surface of said die,

allowing said catheter to heat and flow in and through said space between the tapered molding surface of the die and the mandrel and flow there through between the end of the mandrel and along the tapered die surface toward said open end,

advancing said flowing heated catheter and carrying mandrel until said mandrel engages said interior tapered molding surface,

severing the flowing tip of said catheter where said mandrel engages said interior tapered molding surface to ultimately define said space and the catheter tip shape as a continuous fine edge and to allow the flow of catheter material beyond said mandrel and to said open end of said die,

cooling said die and said catheter while holding said catheter in said space defined by said mandrel and said tapered die surface,

reversing said carriage along said guide such that said catheter is withdrawn from said die, and

removing said catheter from said mandrel.

2. The method of claim 1 wherein the engaging of said mandrel with said tapered molding surface of said die defines the leading edge of the mandrel to form the flashless tip of said catheter.

3. The method of claim 1 further comprising measuring the temperature of said catheter material during heating and melting to determine the forcing of said catheter into said die.

4. The method of claim 1 comprising measuring the temperature of said die to determine the cooling of said catheter in the space defined between the mandrel and the tapered die molding surface.

5. Apparatus for tipping one end of an I.V. catheter to provide a fine edge for ease of penetration, comprising:

a die defining an interior molding surface therein having at least one portion of which is tapered according to the outer surface of the tip desired on said catheter and being open at both ends for allowing flow of catheter material therethrough,

means for controllably heating said die to a temperature sufficient to cause said catheter material to melt and flow therein and therethrough,

means for cooling said die,

a mandrel for supporting and carrying said catheter thereon in position even with or extending slightly cantilever therefrom,

transport means for supporting and carrying said mandrel and catheter, movable along a predetermined path for inserting said catheter and mandrel toward said die and for removing same from said die following production of the desired tip,

means for biasing said mandrel and said catheter inwardly with respect to said die, with sufficient force first causing said catheter to move inwardly with respect to said die as said catheter is heated to its melting point and begins to flow and then causing said mandrel to touch said die to clip the flow of catheter material which extends slightly cantilever to form a continuous finished edge at the tip of said catheter leaving the catheter end open and allowing the outward flow of the clipped catheter material to pass through said open end of said die.

6. Apparatus as defined in claim 5 wherein said transport means comprises a carriage for supporting and carrying said mandrel, and a frictionless surface for carrying said carriage, said frictionless surface being movable within guide means.

7. Apparatus as defined in claim 5 further comprising a measurement device for determining sufficient flow of said catheter within said die to produce the desired tip thereon, and control means responsive to said measurement device for controlling said heating means and reversible drive means so as to terminate heating of said die and remove said catheter therefrom following production of the desired tip.