Method and apparatus for measurement of breakaway and running forces of a plunger in a syringe barrel

• US 6,240,788 B1
• Filed: 02/15/2000
• Issued: 06/05/2001
• Est. Priority Date: 02/27/1999
• Status: Expired due to Fees

• Current Assignee: Bracco Diagnostics Incorporated (Bracco SPA)
• Original Assignee: Bracco Diagnostics Incorporated (Bracco SPA)
• Inventors: Balestracci, Ernest
• Primary Examiner(s): Hughes, S. Thomas
• Assistant Examiner(s): JIMENEZ, MARC QUEMUEL
• Application Number:
  US09/504,100
• Time in Patent Office: 476 Days
• Field of Search: 294/070.1, 294/070.5, 294/070.8, 292/35, 292/39, 292/56, 292/66, 294/265, 294/071, 604/65, 604/66, 604/67, 604/31, 738/620.1, 738/31, 738/56
• US Class Current: 73/862.01
• CPC Class Codes: A61M 2005/3104 Caps for syringes without needle
• CPC Class Codes: A61M 2209/02 Equipment for testing the apparatus
• CPC Class Codes: A61M 5/31513 Piston constructions to improve sealing or sliding
• CPC Class Codes: B67B 7/02 for removing stoppers
• CPC Class Codes: G01L 5/0028 Force sensors associated with force applying means G01L5/0052, G01L5/0057, G01L5/0061 take precedence
• CPC Class Codes: G01N 19/02 Measuring coefficient of friction between materials testing of tyres G01M17/02; determinations of friction coefficient used in vehicle braking or traction control systems B60T8/172
• CPC Class Codes: Y10T 29/4978 Assisting assembly or disassembly
• CPC Class Codes: Y10T 29/49822 by applying force
• CPC Class Codes: Y10T 29/53657 to apply or remove a resilient article [e.g., tube, sleeve, etc.]
• CPC Class Codes: Y10T 29/53683 Spreading parts apart or separating them from face to face engagement

Abstract

Method and apparatus for measuring the breakaway and running forces required to move the plunger from its initial position toward the distal end of the syringe or cartridge barrel.

Claims

1. An apparatus for measuring breakaway and running forces required to move a plunger in a cartridge barrel said cartridge barrel having proximal end stoppered by a slidable plunger therein, and an open tapered distal end wherein said cartridge barrel is pre-filled with an injectable solution, the apparatus comprising:

a housing of generally rectangular configuration having a horizontal bottom portion, a horizontal top portion and two vertical side portions connected to and being integral with said horizontal top portion and said horizontal bottom portion enclosing a space therebetween, said housing being open at its front and back portions thereof;

threaded guidance rods affixed to said vertical side portions extending from said horizontal bottom portion to said horizontal top portion;

an electronically movable horizontal member extending to said vertical side portions engaging said vertical side portions and traveling vertically between said horizontal top portion and said horizontal bottom portion;

electronic drive and control means for moving said movable member and for measuring a force required to move said plunger in said barrel;

a barrel mounting block positioned on said horizontal bottom portion of said housing comprising a cylindrical top portion and a generally rectangular shape bottom portion, said barrel mounting block having a cylindrical inside cavity therein tapered toward the bottom portion and terminating in a bore to receive a cartridge barrel in an upside down position;

a rod having a distal end and a proximal end attached by its distal end to said movable horizontal member, and releasably attached by its proximal end to a plunger;

said electronic drive and control means designed to move said plunger from its stationary position toward the distal end of said cartridge barrel for measuring the breakaway and running forces required to move said plunger in said cartridge barrel.

2. A method of measuring breakaway and running forces required to move a plunger in a cartridge barrel said cartridge barrel having a proximal end stoppered by a slidable plunger therein, and an open tapered distal end wherein said cartridge barrel is pre-filled with an injectable solution, the method comprising:

(a) providing a housing of generally rectangular configuration having a horizontal bottom portion, a horizontal top portion and two vertical side portions connected to and being integral with said horizontal top portion and said horizontal bottom portion enclosing a space therebetween, said housing being open at its front and back portions thereof;

threaded guidance rods affixed to said vertical side portions extending from said horizontal bottom portion to said horizontal top portion;

an electronically movable horizontal member extending to said vertical side portions engaging said vertical side portions and traveling vertically between said horizontal top portion and said horizontal bottom portion;

electronic drive and control means for moving said movable member and for measuring a force required to move said plunger in said barrel;

a barrel mounting block positioned on said horizontal bottom portion of said housing comprising a cylindrical top portion and a generally rectangular shape bottom portion, said barrel mounting block having a cylindrical inside cavity therein tapered toward the bottom portion and terminating in a bore to receive a cartridge barrel in an upside down position;

a rod having a distal end and a proximal end attached by its distal end to said movable horizontal member, and releasably attached by its proximal end to a plunger;

said electronic drive and control means designed to move the plunger from it stationary position toward the distal end of the cartridge barrel and is capable of measuring the breakaway and running forces required to move said plunger in said cartridge barrel;

(b) placing the pre-filed cartridge barrel upside down into said barrel mounting block;

(c) activating said electronic drive and control means to move said plunger from its stationary position toward the distal end of the cartridge barrel; and

(d) measuring by electronic means the breakaway and running forces required to move the plunger in said cartridge barrel.