Drive mechanism for an injection device

• US 7,699,815 B2
• Filed: 12/21/2001
• Issued: 04/20/2010
• Est. Priority Date: 12/22/2000
• Status: Expired due to Term

• Current Assignee: Sanofi-Aventis Deutschland GmbH (Sanofi )
• Original Assignee: Dca Design International Ltd.
• Inventors: Woolston, Robert, Day, Shane Alistair, Veasey, Robert Frederick, Langley, Christopher Nigel
• Primary Examiner(s): Sirmons; Kevin C
• Assistant Examiner(s): Gilbert; Andrew M
• Application Number:
  US10/433,782
• Publication Number:
  US 20040054329A1
• Time in Patent Office: 3,042 Days
• Field of Search: 604/131, 604/151, 604/155, 604207-211
• US Class Current: 604/209
• CPC Class Codes: A61M 2005/31588 electrically driven
• CPC Class Codes: A61M 2205/215 Tilt detection, e.g. for warning or shut-off
• CPC Class Codes: A61M 2205/50 with microprocessors or computers
• CPC Class Codes: A61M 2205/6018 providing set-up signals for the apparatus configuration
• CPC Class Codes: A61M 2205/8206 battery-operated
• CPC Class Codes: A61M 5/14244 adapted to be carried by the patient, e.g. portable on the body
• 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 5/31525 Dosing burettes, pipettes B01L3/02
• CPC Class Codes: A61M 5/31546 Electrically operated dose setting, e.g. input via touch screen or plus/minus buttons
• CPC Class Codes: G16H 20/17 delivered via infusion or injection
• CPC Class Codes: Y10S 128/01 Motorized syringe

Abstract

A drive mechanism for an injection device is disclosed in which piston means are selectively driven to expel medicament from within a medicament cartridge. The drive mechanism comprises a drive means associated with a first ratchet member, a second ratchet member associated with the piston means, a housing, the first ratchet member and the second ratchet member being disposed within the housing. The second ratchet member being biased by biasing means toward the first ratchet member. The drive means is actuable reciprocally to drive the first ratchet member in a first angular direction such that the first ratchet member drives the second ratchet member along its longitudinal axis against the biasing means along at least a part of its movement and subsequently drives the first ratchet member and the second ratchet member together in a second angular direction thereby to drive the piston means.

Claims

1. A drive mechanism for an injection device in which piston means are selectively driven to expel medicament from within a medicament cartridge, the drive mechanism comprising:

a drive means associated with a first ratchet member;

a second ratchet member associated with the piston means; and

a housing, wherein

the first ratchet member and the second ratchet member are disposed within the housing,

the second ratchet member being biased by biasing means towards the first ratchet member, in which the drive means is actuable reciprocally to drive the first ratchet member in a first angular direction of rotary motion such that the first ratchet member drives the second ratchet member along its longitudinal axis against the biasing means along at least a part of its movement and subsequently to drive the first ratchet member and the second ratchet member together in a second angular direction thereby to drive the piston means, and

the drive means comprises a rotary solenoid.

2. A drive mechanism according to claim 1, wherein the piston means comprises a lead screw.

3. A drive mechanism according to claim 1, wherein the first ratchet member and the second ratchet member comprise teeth and the first ratchet member drives the second ratchet member along a longitudinal axis of the second ratchet member against the biasing means by pushing the teeth of the second ratchet member away.

4. A drive mechanism according to claim 2, wherein the second ratchet member is attached to a shaft of the lead screw.

5. A drive mechanism according to claim 1, wherein the rotary solenoid has a range of motion of approximately 15°

.