Injection Device

• US 20080281275A1
• Filed: 10/31/2007
• Published: 11/13/2008
• Est. Priority Date: 06/16/2000
• Status: Active Grant

• Current Assignee: Novo Nordisk A/S
• Original Assignee: Novo Nordisk A/S
• Inventors: Moller, Claus Schmidt
• Granted Patent: US 8,267,899 B2
• Time in Patent Office: Days
• US Class Current: 604/224
• CPC Class Codes: A61M 2005/3152 including gearings to multiply or attenuate the piston displacing force
• CPC Class Codes: A61M 2205/581 by audible feedback
• 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 5/28 Syringe ampoules or carpules, i.e. ampoules or carpules provided with a needle
• CPC Class Codes: A61M 5/315 Pistons; Piston-rods; Guiding, blocking or restricting the movement of the rod or piston; Appliances on the rod for facilitating dosing ; Dosing mechanisms
• CPC Class Codes: A61M 5/31541 Means preventing setting of a dose beyond the amount remaining in the cartridge
• CPC Class Codes: A61M 5/3155 by rotational movement of dose setting member, e.g. during setting or filling of a syringe
• CPC Class Codes: A61M 5/31551 including 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 5/3158 performed by axially moving actuator operated by user, e.g. an injection button

Abstract

A medication dispensing device with a housing and a member wherein the member is moveable in a distal direction is useful in delivering medication to a patient. A fluid container can be used with the device and often has a moveable piston at one end and an outlet at the other. The member receives a force from a user and drives the piston in the distal direction to expel medication. A intermediate system is disposed between the member and the piston including a gear set that has a pinion in meshed engagement with a rack. The system allows the member to move a greater distance than the piston moves thereby increasing the force on the piston.

Claims

1. A method for expelling medication form an injection device having a rack and pinion transmission that couples an injection button with a piston driver;

the method comprising the steps of;

moving a first rack reward during setting of a dose, the rack remaining in continuous meshed engagement with a pinion causing that to rotate during setting of the dose;

moving the first rack forward during injection of a dose and causing the pinion to rotate in an opposite direction, thereby causing part of the transmission to drive the piston driver forward which in turn moves a piston within a medication cartridge and expels medication from the device.

2. The method of claim 1, further comprising the step of:

rotating a second smaller pinion at the same speed as the pinion of claim 10 during the expelling of the medication,

wherein the second pinion is in continuous meshed engagement with a second rack.

3. The method of claim 2, wherein the first rack moves forward by a distance greater than the piston is drive forward during injection.