Injection device

• US 20010053893A1
• Filed: 05/11/2001
• Published: 12/20/2001
• Est. Priority Date: 05/18/2000
• Status: Active Grant

• Current Assignee: Novo Nordisk A/S
• Original Assignee: Novo Nordisk A/S
• Inventors: Larsen, Andre
• Granted Patent: US 6,716,198 B2
• Time in Patent Office: Days
• US Class Current: 604/207
• CPC Class Codes: A61M 2005/202 cocking means, e.g. to bias the main drive spring of an injector
• 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 5/31553 without axial movement of dose setting member
• CPC Class Codes: A61M 5/31583 based on rotational translation, i.e. movement of piston rod is caused by relative rotation between the user activated actuator and the piston rod

Abstract

An injection device for injecting set doses from an ampoule (2) mounted in the device, which doses are set by operation of a dose setting button (7) by which operation elastic torsion rods (14) positioned parallel with the longitudinal axis of the device are twisted. By the dose setting a torque is transmitted from the dose setting button (7) to the rods (14) through gear transmissions comprising a toothing (11) carried by a tubular (8) part coupled to the dose setting button (7) to rotate with this button. The toothing (11) engages pinions (13) fixed to the proximal ends of the torsion rods (14), which are made from a super elastic material, which can stand a deformation larger than 2% without being permanently deformed.

Claims

1. An injection device for injecting set doses from an ampoule mounted in the device, which doses are set by operation of a dose setting button by which operation an elastic member is deformed to store an amount of energy which can be released to inject the set dose, characterised in that the elastic member is a torsion rod which is twisted by the operation of the dose setting member.

2. An injection devices according to

claim 1

, characterised in that the rod is positioned parallel with the longitudinal axis of the device.

3. An injection devices according to

claim 2

, characterised in that a torque is transmitted from the dose setting button to the rod through a gear transmission.

4. An injection device according to

claim 3

, characterised in that the gear transmission comprises a toothing carried by the dose setting member to rotate with this member, which toothing engage a pinion fixed to the proximal end of the torsion rod.

5. An injection device according to

claim 4

, characterised in that the toothing carried by the dose setting button has a larger diameter than has the pinion at the proximal end of the rod.

6. An injection device according to anyone of the preceding claims, characterised in that the torsion rod is made from a super elastic material which can stand a deformation larger than 2% without being permanently deformed.