Working cylinder

• US 6,010,485 A
• Filed: 09/17/1997
• Issued: 01/04/2000
• Est. Priority Date: 09/20/1996
• Status: Expired due to Fees

• Current Assignee: Novo Nordisk A/S
• Original Assignee: Novo Nordisk A/S
• Inventors: Jensen, Jens M.o slashed.ller, Buch-Rasmussen, Thomas, Poulsen, Jens Ulrik, Ljunggreen, Henrik
• Primary Examiner(s): Coggins, Wynn Wood
• Assistant Examiner(s): NGUYEN, ANH TUAN TUONG
• Application Number:
  US08/932,354
• Time in Patent Office: 839 Days
• Field of Search: 604/183, 604/191, 604/207, 604/246, 604/236, 604/247, 604/248, 604/256, 604/221, 604/226, 604/228, 604/30, 604/32
• US Class Current: 604/191
• CPC Class Codes: A61M 5/204 connected to external reservoirs for multiple refilling
• CPC Class Codes: A61M 5/31525 Dosing burettes, pipettes B01L3/02
• CPC Class Codes: A61M 5/31555 by purely axial movement of dose setting member, e.g. during setting or filling of a syringe
• CPC Class Codes: A61M 5/31561 using freely adjustable volume steps
• CPC Class Codes: A61M 5/3158 performed by axially moving actuator operated by user, e.g. an injection button
• CPC Class Codes: A61M 5/31595 Pre-defined multi-dose administration by repeated overcoming of means blocking the free advancing movement of piston rod, e.g. by tearing or de-blocking

Abstract

The present invention relates to a drug delivery system, comprising a reservoir from which set doses are apportioned, a dose setting mechanism by which the relative position of two elements is changed by a distance proportional to a set dose, and a push button by activation of which an element is moved a distance corresponding to the distance proportional to the set dose, further comprises a working cylinder having an open end into which a plunger fits, and a closed end at which an inlet and an outlet port connect the space beneath the plunger with an inlet communicating with the reservoir and an outlet communicating with a drug delivery member, respectively. Valves means at the inlet and outlet control the passages from the reservoir to the working cylinder and from the working cylinder to the drug delivery member, respectively. The cylinder with the plunger, and the injection member are independently exchangeable, disposable parts.

Claims

1. A drug delivery system comprising:

a reservoir from which set doses are apportioned;

a working cylinder having a cylinder wall and open and closed ends;

a plunger having an inner end fitting in said working cylinder, wherein said plunger extends out of said open end and defines, between said inner end and said closed end of said working cylinder, a chamber, and wherein said cylinder wall has inlet and outlet openings communicating with said chamber;

means for connecting said inlet opening and said reservoir for fluid communication therebetween, wherein said plunger can be drawn outwardly relative to said working cylinder to draw a set dose from said reservoir into said chamber, and can be pushed back into said working cylinder to expel the set dose through said outlet opening;

a drug delivery member mounted on said working cylinder so as to be in communication with said outlet opening;

wherein said plunger is rotatable within said working cylinder; and

wherein said plunger inner end includes a valve surface which, in a first rotational position of said plunger, blocks said outlet opening but not said inlet opening, and which, in a second rotational position of said plunger, blocks said inlet opening but not said outlet opening, whereby the rotational position of said plunger can be controlled so that said outlet opening is blocked, and said inlet opening is free, when said plunger is moved outwardly relative to said working cylinder to draw a set dose into said chamber, and said outlet opening is free, and said inlet opening is blocked by said valve surface, when the plunger is moved inwardly in said working cylinder to expel the set dose.

3. A drug delivery system according to claim 1, wherein said drug delivery member is a high pressure jet nozzle.

2. A drug delivery system according to clam 1, wherein said reservoir, the working cylinder and plunger combination, and said drug delivery member are independent, exchangeable parts.

4. A drug delivery system according to claim 2, wherein said drug delivery member is a high pressure jet nozzle.