Drug delivery device provided with a one-way mechanism

• US 6,585,699 B2
• Filed: 03/30/2001
• Issued: 07/01/2003
• Est. Priority Date: 04/13/2000
• Status: Expired due to Term

• Current Assignee: Novo Nordisk A/S
• Original Assignee: Nna/S
• Inventors: Moller-Jensen, Peter, Moller-Jensen, Jens, Aasmul, Soren, Poulsen, Jens Ulrik, Christensen, Lars Hofmann, Ljunggreen, Henrik
• Primary Examiner(s): Casler, Brian L.
• Assistant Examiner(s): WILLIAMS, CATHERINE SERKE
• Application Number:
  US09/822,162
• Publication Number:
  US 20020004651A1
• Time in Patent Office: 823 Days
• Field of Search: 604/207, 604/209, 604/210, 604/211, 604/218, 604/220, 604/224, 604/246, 222/309, 222/325
• US Class Current: 604/207
• CPC Class Codes: A61M 2005/31518 designed to reduce the overall size of an injection device, e.g. using flexible or pivotally connected chain-like rod members
• CPC Class Codes: A61M 2005/31588 electrically driven
• CPC Class Codes: A61M 5/31501 Means for blocking or restricting the movement of the rod or piston A61M5/5013 takes precedence
• CPC Class Codes: A61M 5/31511 Piston or piston-rod constructions, e.g. connection of piston with piston-rod A61M5/5066 takes precedence
• CPC Class Codes: A61M 5/31543 piston rod reset means, i.e. means for causing or facilitating retraction of piston rod to its starting position during cartridge change
• CPC Class Codes: A61M 5/3156 using volume steps only adjustable in discrete intervals, i.e. individually distinct intervals
• CPC Class Codes: A61M 5/31585 performed by axially moving actuator, 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

A drug delivery device comprising a housing (1) with a drug container (2) being provided with delivering means comprising a piston (5) for expelling a drug (4) from the drug container (2). The housing (1) further comprising a displaceable piston rod (6) abutting the piston (5) of the drug container (2) and rotating means being in engagement with the piston rod (6), said rotating means being provided with a one-way mechanism. The one-way mechanism comprises a helical spring (12) wound tightly around an axle (11), one end of said helical spring (12) being fixed in relation to the housing (1), the other end of the helical spring (12) being in a free state.

Claims

1. A drug delivery device comprising:

a housing with a drug container, the drug container having a delivering means comprising a piston for expelling a drug from the container, the housing further comprising a displaceable piston rod abutting the piston of the drug container, a rotating means being in engagement with the piston rod, the rotating means being provided with a one-way mechanism,

wherein the one-way mechanism comprises a helical spring wound around an axle, the spring having one end of the spring being fixed in relation to the housing and a second end, and

the drug delivery device further comprising a release button that is able to displace the second end of the helical spring in a direction unwinding the helical spring.

2. A drug delivery device according to claim 1, wherein the piston rod is provided with a toothing and is in engagement with a piston rod drive wheel provided with a complementary toothing, the piston rod drive wheel being mount on an axle.

3. A drug delivery device according to claim 2, wherein the piston rod is flexible and is position partly around the piston rod drive wheel.

4. A drug delivery device according to claim 3, wherein a guiding face is provided in the housing, the flexible piston rod being position between the guiding face and the piston rod drive wheel.

5. A drug delivery device according to claim 1 wherein the drug delivery device is provide with an exchangeable drug container.

6. A drug delivery device according to claim 1, wherein the drug delivery device is an injection syringe.

7. A drug deliver device comprising:

a. a drug container having a piston

b. a housing;

c. a piston rod, at least a portion of which is linearly displaceable, the piston rod abutting the drug container piston;

d. a rotateable element coupled to the piston rod so that linear displacement of the piston rod in a first direction cause rotation of the element in a corresponding first direction and linear displacement of the piston rod in a second direction causes rotation of the element in a corresponding second direction;

e. a ratchetless means for substantially restricting rotation of the rotateable element in the corresponding first direction while allowing rotation in the corresponding second direction, thereby restricting linear displacement of the piston rod in the first direction but allowing linear displacement in the second direction.

8. The drug delivery device of claim 7, further comprising a release for releasing the ratchless means thereby allowing rotation of the rotateable element in two directions.

9. The drug delivery device of claim 7, wherein the ratchetless means comprises a spring, comprises a helically wound spring.

10. The drug delivery device of claim 7, wherein the ratchetless means is coupled to the rotateable element via a frictional force between the ratchless means and the rotateable element.

11. The drug delivery device of claim 10, wherein the rotateable element is a piston rod drive wheel.

12. A drug delivery device comprising:

a. a piston rod, at least a portion of which is linearly displaceable;

b. a rotateable element coupled to the piston rod so that rotation of the element in a first direction causes corresponding movement of the piston rod in a corresponding first direction and rotation of the element in a second direction causes movement of the piston rod in a corresponding second direction;

c. an axle fixed to the rotateable element, the axle having a cylindrical shape and an outside diameter;

d. a wound spring having an inside surface having a diameter, the diameter of the inside surface in a relaxed state that being smaller than the outside diameter of the axle, the spring having a first end fixed to the housing and a second that is free to move relative to the axle, the spring being rotatably coupled to the axle by a frictional force between the axle and the spring'"'"'s inside surface, and

e. wherein the spring is orientated with respect to its winding so that the frictional coupling force between the axle and the spring'"'"'s inner surface increases to a level sufficient to prevent substantial rotation of the axle in the first direction when a force is applied to the rotateable element to rotate it in the first direction, thereby substantially preventing rotation of the rotateable element in the first direction and linear displacement of the piston rod in the corresponding first direction.

13. The drug delivery device of claim 12, wherein the spring is a helical spring.

14. The drug delivery device of claim 12, further comprising a means for partially unwinding the spring without rotating the axle.

15. The drug delivery device of claim 13, further comprising a means for partially unwinding the spring without rotating the axle.

16. The drug delivery device of claim 12, wherein the rotateable element rotates about an axis that is perpendicular to at least a portion of the piston rod.

17. The drug delivery device of claim 12, further comprising a cartridge containing an injectable medication, the cartridge having a first end that is covered with a pierceable membrane and a moveable piston and a medication holding space located therebetween, the piston abutting the piston rod.

18. The drug delivery device of claim 12, further comprising a release means for partially unwinding the spring.

19. The drug delivery device of claim 14, wherein the piston rod is a flexible piston rod.

20. The drug delivery device of claim 18, wherein the release is a button that abuts the second end of the spring.