Injection device

• US 7,195,613 B2
• Filed: 03/26/2002
• Issued: 03/27/2007
• Est. Priority Date: 03/27/2001
• Status: Expired due to Term

• Current Assignee: Sanofi-Aventis Deutschland GmbH (Sanofi )
• Original Assignee: Dca Design International Ltd.
• Inventors: Woolston, Robert
• Primary Examiner(s): MENDEZ, MANUEL A
• Application Number:
  US10/471,729
• Publication Number:
  US 20040097879A1
• Time in Patent Office: 1,827 Days
• Field of Search: 604/65, 604/66, 604/67, 604/131, 604/154, 604/156, 604/315, 128/DIG.1, 128/DIG.12, 128/DIG.13
• US Class Current: 604/154
• CPC Class Codes: A61M 2005/31518 designed to reduce the overall size of an injection device, e.g. using flexible or pivotally connected chain-like rod members
• CPC Class Codes: A61M 2005/3152 including gearings to multiply or attenuate the piston displacing force
• CPC Class Codes: A61M 5/24 Ampoule syringes, i.e. syringes with needle for use in combination with replaceable ampoules or carpules, e.g. automatic ampoules or carpules A61J1/06
• CPC Class Codes: A61M 5/31511 Piston or piston-rod constructions, e.g. connection of piston with piston-rod A61M5/5066 takes precedence
• CPC Class Codes: A61M 5/31553 without axial movement of dose setting member
• CPC Class Codes: A61M 5/31563 interacting with a displaceable stop member
• CPC Class Codes: A61M 5/31575 using scaling up or down transmissions, e.g. gearbox
• CPC Class Codes: A61M 5/3158 performed by axially moving actuator operated by user, e.g. an injection button
• CPC Class Codes: A61M 5/31585 performed by axially moving actuator, e.g. an injection button

Abstract

Injection devices are known for the self administration of medicament by patients, in which the medicament is typically contained within a cartridge located within the injection device. It is a problem that injection devices should be small enough to fit into a jacket pocket or a hand bag without difficulty. Also, the injection device must be of a size that enables a piston or the like used to drive the cartridge bung within the cartridge to be moved both to a maximum dispense position within the cartridge and to be fully withdrawn from the cartridge to allow for replacement of the cartridge. A drive mechanism for an injection device is disclosed in which a piston 42 comprises a first piston part 44 guided for linear movement to selectively drive a bung 18 and a second piston part 46 connected for pivoting movement with respect to the first piston part 44.

Claims

1. A drive mechanism for an injection device, comprising:

a piston that is successively moved in relation to a first end of a medicament cartridge containing a medicament selectively to drive a bung closing a first end of the medicament cartridge into the medicament cartridge to expel medicament through a delivery member located at a second end of the medicament cartridge, the piston further comprising;

a first piston part guided for linear movement to selectively drive the bung; and

a second piston part connected for pivoting movement with respect to the first piston part,

wherein the piston is driven through a dispense gear by a dosing shaft.

2. A drive mechanism according to claim 1, further comprising a transmission mechanism between a dial dose mechanism and the piston.

3. An injection device incorporating a drive mechanism according to claim 2.

4. A drive mechanism according to claim 2, wherein the transmission mechanism comprises a dose setting mechanism connected to drive the piston through the dispense gear.

5. An injection device incorporating a drive mechanism according to claim 4.

6. A drive mechanism according to claim 4, wherein the dose setting mechanism comprises a spline connecting the dosing shaft to the dial dose mechanism, the dosing shaft having an abutment surface at one end.

7. An injection device incorporating a drive mechanism according to claim 6.

8. A drive mechanism according to claim 6, wherein a button has a stop surface for abutment with the abutment surface of the dosing shaft.

9. An injection device incorporating a drive mechanism according to claim 8.

10. An injection device incorporating a drive mechanism according to claim 1.

11. An injection device according to claim 10, further comprising a drive means selectively to drive the bung having a button displaceably housed in the injection device.