COLLET MECHANISM AND METHOD OF MOLDING CANNULA TO A SYRINGE BARREL

• US 20100270702A1
• Filed: 01/15/2009
• Published: 10/28/2010
• Est. Priority Date: 01/15/2008
• Status: Active Grant

• Current Assignee: West Pharmaceutical Services Incorporated
• Original Assignee: West Pharmaceutical Services Incorporated
• Inventors: Baker, John, Zelkovich, Matthew J., Kuhn, Todd E., Roussel, Paul, Lunquist, Jon
• Granted Patent: US 8,496,862 B2
• Time in Patent Office: Days
• US Class Current: 264/278
• CPC Class Codes: A61M 5/343 Connection of needle cannula to needle hub, or directly to syringe nozzle without a needle hub A61M5/322 takes precedence
• CPC Class Codes: B29C 2045/14139 positioning inserts having a part extending into a positioning cavity outside the mould cavity
• CPC Class Codes: B29C 45/14065 Positioning or centering articles in the mould
• CPC Class Codes: B29C 45/14311 using means for bonding the coating to the articles B29C45/14795 takes precedence
• CPC Class Codes: B29C 45/14426 Coating the end of wire-like or rod-like or cable-like or blade-like or belt-like articles
• CPC Class Codes: B29L 2031/7544 Injection needles, syringes

Abstract

A collet mechanism that holds a cannula during molding of a syringe includes first and second arms that form an internal cavity. Each arm has a proximal end and a distal end. The first and second arms are in a closed position when the distal ends are moved toward the internal cavity and are in an open position when the distal ends are positioned away from the internal cavity. First and second cannula guides respectively are mounted proximate the distal ends of the first and second arms and extend into the internal cavity. The first and second cannula guides clamp a portion of the cannula to hold the cannula when the first and second arms are in the closed position.

Claims

1. A collet mechanism for holding a cannula during molding of a syringe, the collet mechanism comprising:

first and second arms forming an internal cavity, each arm having a proximal end and a distal end, the first and second arms being in a closed position when the distal ends are moved toward the internal cavity and being in an open position when the distal ends are positioned away from the internal cavity;

first and second cannula guides respectively mounted proximate the distal ends of the first and second arms and extending into the internal cavity, the first and second cannula guides clamping a portion of the cannula to hold the cannula when the first and second arms are in the closed position.

2. The collet mechanism of claim 1, wherein the first and second cannula guides are positioned opposite each other.

3. The collet mechanism of claim 1, wherein the first and second cannula guides are spaced away from the cannula when the first and second arms are in the open position.

4. The collet mechanism of claim 1 further comprising third and fourth arms, each arm having a distal end and a cannula guide mounted proximate the distal end.

5. The collet mechanism of claim 1, wherein a position of the first and second cannula guides is adjustable with respect to the first and second arms and the internal cavity such that the force with which the first and second cannula guides contact the cannula is adjustable.

6. The collet mechanism of claim 1, wherein the first and second cannula guides contact the cannula at a position spaced away from a tip of the cannula with a predetermined force such that the cannula is not damaged and the sharpness of the tip of the cannula is not altered when the first and second arms are in the closed position.

7. The collet mechanism of claim 1, wherein a surface of each of the first and second cannula guides is sloped, the sloped surfaces each having an indentation formed therein.

8. The collet mechanism of claim 7, wherein the indentations abut the cannula when the first and second arms are in the closed position.

9. The collet mechanism of claim 1, wherein the cannula guides are biased toward the closed position.

10. A method of manufacturing a syringe comprising the steps of:

placing a cannula having a beveled tip onto a recessed tip of a core member;

placing a mold over the core member, the mold having a tapered receiving port at least partially surrounding at least a portion of the cannula;

inserting a collet mechanism having at least two cannula guides through the mold and over the beveled tip of the cannula, a distal end of the collet mechanism being guided by the tapered receiving port to move the collet mechanism into a closed position wherein the cannula guides clamp a portion of the cannula to hold the cannula generally in alignment with a longitudinal axis of the collet mechanism and with a longitudinal axis of the core member;

injecting polymeric material into the mold;

allowing the polymeric material to cool until substantially solidified over at least a proximal end of the cannula;

removing the collet mechanism from the mold such that the cannula guides release the cannula;

removing the mold; and

removing the syringe and attached cannula from the core member.

11. A cannula having an outer diameter in the range of 0.0080 to 0.0165 inches for attachment to a tip of a polymeric syringe barrel molded over the cannula, at least a portion of a proximal end of the cannula having a plurality of notches formed on an outer surface.

12. The cannula of claim 11, wherein at least a portion of the proximal end has a textured or roughened surface.

13. The cannula of claim 11, wherein the notches extend radially and are axially spaced apart from each other.