MEDICAL DEVICE

• US 20120109075A1
• Filed: 03/31/2010
• Published: 05/03/2012
• Est. Priority Date: 03/31/2009
• Status: Active Grant

• Current Assignee: Sanofi-Aventis Deutschland GmbH (Sanofi )
• Original Assignee: Sanofi-Aventis Deutschland GmbH (Sanofi )
• Inventors: Harms, Michael, Raab, Steffen, Stauder, Udo
• Granted Patent: US 9,381,305 B2
• Time in Patent Office: Days
• US Class Current: 604/224
• CPC Class Codes: A61M 2005/3115 spring-assisted
• 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 5/31525 Dosing burettes, pipettes B01L3/02
• 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

Abstract

The medical device comprises a wave spring or wave washer in a mechanism to engage or disengage a first element and a second element. The invention also discloses the use of a multiple wave spring or wave washer comprising at least two waved spring layers in a medical device.

Claims

1. A medical device comprising:

a mechanism;

a first element and a second element of the mechanism;

a coupling device engaging the first element and the second element;

a spring arranged in contact with at least one of the first element and the second element and tending to engage or disengage the first element and the second element; and

the spring being a wave spring or wave washer.

2. The medical device according to claim 1, wherein the spring is formed by a helically curved wire comprising waves in the direction in which the spring force is to be exerted.

3. The medical device according to claim 1, wherein the spring is formed of at least two waved layers of an elastic material mounted one above the other.

4. The medical device according to claim 1, wherein the first element and the second element of the mechanism are nuts and the coupling device is a gear formed by surface structures of the nuts.

5. The medical device according to claim 1, wherein the device is a pen-type drug delivery device or injection device.

6. The medical device according to claim 1, further comprising:

a body;

a receptacle in the body;

a piston movable in the receptacle by means of a piston rod having an axis;

the piston rod going through holes in the first element and the second element of the mechanism;

the first element being engaged with the body in such a manner as to inhibit a rotation of the first element relatively to the body around the axis of the piston rod;

the second element being engaged with the piston rod in such a manner as to generate an axial rotation of the piston rod relatively to the second element when the piston rod is moved along its axis relatively to the second element;

the coupling device engaging the first element and the second element in such a manner as to inhibit a rotation of the second element relatively to the first element around the axis of the piston rod; and

the spring being arranged between the first element and the second element and tending to disengage the first element and the second element.

7. The medical device according to claim 6, further comprising:

the receptacle being provided for a cartridge;

the first element and the second element of the mechanism being engaged when a cartridge is in the receptacle; and

the spring disengaging the first element and the second element when no cartridge is in the receptacle.

8. The medical device according to claim 6 further comprising a receptacle being provided for a cartridge containing a medicament.

9. The medical device according to claim 8, wherein the medicament is a pharmaceutical formulation containing at least one pharmaceutically active compound which comprises at least one human insulin or a human insulin analogue or derivative, glucagon-like peptide (GLP-1) or an analogue or derivative thereof, or exedin-3 or exedin-4 or an analogue or derivative of exedin-3 or exedin-4.

10. The medical device according to claim 6, further comprising:

the piston rod having a screw thread; and

the second element of the mechanism having a thread engaging the screw thread of the piston rod.

11. The medical device according to claim 10, further comprising:

the screw thread of the piston rod being located near the piston;

the piston rod having a further screw thread located at a larger distance from the piston;

a cylindrical operation sleeve surrounding the piston rod; and

the operation sleeve having a thread engaging the further screw thread of the piston rod.

12. The medical device according to claim 11, wherein the screw thread of the piston rod has a smaller pitch than the further screw thread.

13. The medical device according to claim 6, wherein the first element and the second element of the mechanism are disengaged by means of the spring when the piston rod is reset or moved to a starting position.

14. Use of a wave spring or wave washer within a medical device according to claim 1, the wave spring or wave washer having at least two waved turns or waved layers formed of an elastic material in the shape of a waved wire or band.

15. The use of a wave spring or wave washer according to claim 14, wherein the spring is a helically curved wire comprising waves in the direction in which the spring force is to be exerted.

16. The use of a wave spring or wave washer according to claim 14, wherein the spring is formed of a plurality of waved layers of an elastic material mounted sequentially one above another.

17. The use of a wave spring or wave washer according to claim 14, wherein the medical device is a pen-type drug delivery device or injection device.