Injection device

• US 6,994,692 B2
• Filed: 03/26/2002
• Issued: 02/07/2006
• Est. Priority Date: 03/27/2001
• Status: Active Grant

• Current Assignee: Sanofi-Aventis Deutschland GmbH (Sanofi )
• Original Assignee: Dca Design International Ltd.
• Inventors: Langley, Christopher Nigel, Woolston, Robert
• Primary Examiner(s): SIRMONS, KEVIN C
• Application Number:
  US10/471,730
• Publication Number:
  US 20040092877A1
• Time in Patent Office: 1,414 Days
• Field of Search: 604/131, 604/135, 604/151, 604/246, 604/152, 604/154, 604/155
• US Class Current: 604/151
• CPC Class Codes: A61M 2005/14506 mechanically driven, e.g. spring or clockwork
• 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 5/14566 with a replaceable reservoir for receiving a piston rod of the pump
• CPC Class Codes: A61M 5/20 Automatic syringes, e.g. with automatically actuated piston rod, with automatic needle injection, filling automatically A61M5/142 , A61M5/46 take precedence; hypodermic projectiles F42B12/54
• 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 5/31558 using scaling up or down transmissions, e.g. gearbox
• CPC Class Codes: A61M 5/31575 using scaling up or down transmissions, e.g. gearbox
• CPC Class Codes: A61M 5/31578 based on axial translation, i.e. components directly operatively associated and axially moved with plunger rod

Abstract

Injection devices are known for the self administration of a medicament by patients. The medicament is typically contained within a cartridge located within an 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. Concurrently, the injection device must be of a size that enables a piston used to drive a cartridge bung within the cartridge to both to a maximum dispense position within the cartridge and to be fully withdrawn from the cartridge to allow for replacement of the cartridge.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 comprising a piston member (10), a semi rigid belt (12) connected at a first end to the piston member (10), a belt drive means to drive the semi rigid belt (12) and a dose setting mechanism to control the driving of the semi rigid belt (12) in which the belt drive means comprises a first cable means (22) connected at a first end to a second end of the semi rigid belt (12) and at a second end to a first spool (24). An injection device comprising such a drive mechanism is also disclosed.

Claims

1. A drive mechanism for an injection device in which a piston is successively moved in relation to a first end of a medicament cartridge containing a medicament selectively to drive a bung closing the 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 drive mechanism comprising:

a piston member,

a semi-rigid belt connected at the first end to the piston member,

a belt drive means to drive the semi-rigid belt and

a dose setting mechanism to control the driving of the semi-rigid belt,

wherein the belt drive means comprises a first cable means connected at the first end to a rotatable spool and at the second end to a fixed point on the housing, guide means within which the semi-rigid belt is adapted to be guided, a stopper movably located within the guide means, such that rotation of the spool causes the first cable means to move the stopper within the guide means to drive the semi-rigid belt.

2. A drive mechanism for an injection device according to claim 1, wherein the dose setting mechanism comprises a dose dial button, a dose setting spindle, a dog to release the dose, a dose setting wheel, a first roller or pulley, a second cable means connected between the dose setting wheel and the first roller or pulley, and a second roller or pulley held against the second cable means between the dose setting wheel and the second wheel by a spring means.

3. A drive mechanism for an injection device according to claim 2, wherein the dial dose button is connected to the dose setting spindle by a spline.

4. An injection device having a housing, the injection device comprising a drive mechanism according to claim 2.

5. An injection device according to claim 4, wherein the housing has an opening in which a retaining pin of the dose dial button may be releasably retained.

6. An injection device according to claim 5, wherein the housing is provided with a plurality of guide means for the semi-rigid belt.

7. An injection device according to claim 4, wherein the housing is provided with a plurality of guide means for the semi-rigid belt.

8. An injection device having a housing, injection device comprising a drive mechanism according to claim 1.