Injection Device with Mode Locking Means

• US 20090209920A1
• Filed: 05/03/2007
• Published: 08/20/2009
• Est. Priority Date: 05/18/2006
• Status: Active Grant

• Current Assignee: Novo Nordisk A/S
• Original Assignee: Novo Nordisk A/S
• Inventors: Kvolsbjerg, Bo, Moller, Claus Schmidt, Pedersen, Bennie Peder Smiszek
• Granted Patent: US 9,192,727 B2
• Time in Patent Office: Days
• US Class Current: 604/211
• CPC Class Codes: A61M 2005/2407 from the rear
• CPC Class Codes: A61M 2005/2411 from the front
• CPC Class Codes: A61M 2005/3125 specific display means, e.g. to indicate dose setting
• 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 5/31536 Blocking means to immobilize a selected dose, e.g. to administer equal doses
• 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 5/31553 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 5/31566 Means improving security or handling thereof
• CPC Class Codes: A61M 5/31571 Means preventing accidental administration for automatic syringes A61M5/20
• CPC Class Codes: A61M 5/3158 performed by axially moving actuator operated by user, e.g. an injection button
• 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
• CPC Class Codes: A61M 5/31585 performed by axially moving actuator, e.g. an injection button

Abstract

An injection device comprising a housing, a dose setting member being operable to set a desired dose, a piston rod adapted to cooperate with a piston to cause a set dose to be expelled, and mode locking means. The mode locking means is adapted to be in a first extreme position and in a second extreme position. When the mode locking means is in the first extreme position the piston rod is prevented from cooperating with the piston, and when the mode locking means is in the second extreme position the dose setting member is prevented from being operated to set a dose. The mode locking means is adapted to be in the first extreme position during dose setting and the second extreme position during injection of a set dose. It is ensured that the liquid drug is not inadvertently expelled during dose setting and that blood or other body fluids is not sucked into the injection device during injection. Furthermore, inadvertent changing of the set dose during injection is prevented. The mechanism can readily be applied to injection devices which are not provided with a scale drum.

Claims

1. An injection device comprising:

a housing,

a dose setting member being operable to set a desired dose,

a piston rod adapted to cooperate with a piston to cause a set dose to be expelled from the injection device,

mode locking means adapted to be in a first extreme position, in which the piston rod is prevented from cooperating with the piston, and a second extreme position, in which the dose setting member is prevented from being operated to set a dose,

wherein the mode locking means is adapted to be in the first extreme position during dose setting and in the second extreme position during injection of a set dose.

2. An injection device according to claim 1, wherein the piston rod is prevented from moving in a distal direction when the mode locking means is in the first extreme position.

3. An injection device according to claim 1, wherein the dose setting member is rotationally operable to set a desired dose, and wherein the dose setting member is prevented from performing a rotational movement when the mode locking means is in the second extreme position.

4. An injection device according to claim 1, wherein the mode locking means is further adapted to be in an intermediate position in which the piston rod is prevented from cooperating with the piston, and the dose setting member is prevented from being operated to set a dose, the mode locking means being adapted to be in the intermediate position when being moved between the first and the second extreme positions.

5. An injection device according to claim 1, wherein the mode locking means is provided with a first set of teeth, and wherein the piston rod is operatively connected to a dosing member, the dosing member being provided with a first set of mating teeth, and wherein the first set of teeth and the first set of mating teeth engage when the mode locking means is in the first extreme position.

6. An injection device according to claim 1, wherein the mode locking means is provided with a second set of teeth, and the dose setting member is provided with a second set of mating teeth, and wherein the second set of teeth and the second set of mating teeth engage when the mode locking means is in the second extreme position.

7. An injection device according to claim 1, wherein the mode locking means is rotationally locked to the housing.

8. An injection device according to claim 1, further comprising an injection button being operable to cause the piston rod to cooperate with the piston to cause a set dose to be expelled from the injection device, the injection button being operatively connected to the mode locking means in such a manner that when the injection button is operated to cause a set dose to be expelled from the injection device, the mode locking means is automatically moved from the first extreme position to the second extreme position.

9. An injection device according to claim 1, wherein the mode locking means is adapted to be operated independently of a cylindrical scale drum.