Injection device

• US 20040176729A1
• Filed: 09/15/2003
• Published: 09/09/2004
• Est. Priority Date: 03/27/2001
• Status: Active Grant

• Current Assignee: Sanofi-Aventis Deutschland GmbH (Sanofi )
• Original Assignee: Dca Design International Ltd.
• Inventors: Woolston, Robert, Langley, Christopher Nigel
• Granted Patent: US 7,794,430 B2
• Time in Patent Office: Days
• US Class Current: 604/207
• CPC Class Codes: A61M 2005/2414 from the side
• 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 5/31541 Means preventing setting of a dose beyond the amount remaining in the cartridge
• 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 5/3158 performed by axially moving actuator operated by user, e.g. an injection button
• CPC Class Codes: A61M 5/31593 Multi-dose, i.e. individually set dose repeatedly administered from the same medicament reservoir

Abstract

Injection devices are known for the self administration of medicament by patients in which the medicaments 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 similar used to drive a 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bung within the cartridge to be moved both to a maximum dispense position within the cartridge and to be fully withdrawn from the cartridge to allow for replacement of the cartridge.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 (48) is successively moved along the first axis to drive a bung (20) into a medicament cartridge (18), a displacement mechanism comprising a dose setting spindle (30) is disposed along a second axis, the second axis being parallel to the first axis, transmission means connected between the dose setting spindle (30) and the piston (20), and displacement means to displace the dose setting spindle (30) with respect to the medicament cartridge (18), a movement of the displacement means in a first direction causing movement of the dose setting spindle (30) and the piston (20) in the first direction.

Claims

1. A drive mechanism for an injection device in which a piston is successively moved along a first axis 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, in which the displacement mechanism comprises a dose setting spindle disposed along a second axis, the second axis being parallel to the first axis, transmission means connected between the dose setting spindle and the piston, and displacement means to displace the dose setting spindle with respect to the medicament cartridge, a movement of the displacement means in a first direction causing movement of the dose setting spindle and the piston in the first direction.

2. A driven mechanism for an injection device according to claim 1, characterised in that the drive mechanism further comprises a dose dial mechanism connected to the dose setting spindle to control rotational movement of the dose setting spindle.

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

4. A drive mechanism for an injection device according to any previous claim, characterised in that the transmission means comprises a drive rack.

5. A drive mechanism for an injection device according to any previous claim, characterised in that the piston comprises a sleeve member connected to the drive rack and a piston member located concentrically within the sleeve member and extending outward from the sleeve member.

6. A drive mechanism for an injection device according to any previous claim, characterised in that the dose setting spindle is provided with counter contacts.

7. An injection device having a main housing incorporating a drive mechanism according to any previous claim.

8. An injection device according to claim 7, characterised in that the displacement means comprises a button located for displacement within a housing of the injection device.

9. An injection device according to claim 8, characterised in that the dose dial mechanism is retained within the button.

10. An injection device according to any of claims 7 to 9 in which the injector device further comprises a secondary housing adapted for displacement with respect to the main housing, is characterised in that the secondary housing is provided with a web for abutment with an abutment surface provided on the transmission means in order to allow the piston to be displaced along the first axis in a direction opposite the first direction.