Piston Rod Drive System for a Drug Delivery Device

• US 20140058320A1
• Filed: 12/22/2011
• Published: 02/27/2014
• Est. Priority Date: 12/23/2010
• Status: Abandoned Application

• Current Assignee: Novo Nordisk Health Care AG (Novo Nordisk A/S)
• Original Assignee: Novo Nordisk Health Care AG (Novo Nordisk A/S)
• Inventors: Hansen, Soeren Kjellerup
• Application Number:
  US13/995,335
• Publication Number:
  US 20140058320A1
• Time in Patent Office: Days
• US Class Current: 604/89
• CPC Class Codes: A61M 2005/2433 Ampoule fixed to ampoule holder
• CPC Class Codes: A61M 2005/2444 by thread
• CPC Class Codes: A61M 2005/3104 Caps for syringes without needle
• CPC Class Codes: A61M 2005/31508 provided on the piston-rod
• 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 2205/582 by tactile feedback
• CPC Class Codes: A61M 2205/583 by visual feedback
• CPC Class Codes: A61M 5/002 Packages specially adapted therefor, e.g. for syringes or needles, kits for diabetics needle protection, e.g. caps, A61M5/3202; for sharps A61B50/3001
• CPC Class Codes: A61M 5/2448 comprising means for injection of two or more media, e.g. by mixing
• CPC Class Codes: A61M 5/31505 Integral with the syringe barrel, i.e. connected to the barrel so as to make up a single complete piece or unit
• 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 5/31596 comprising means for injection of two or more media, e.g. by mixing
• CPC Class Codes: A61M 5/347 rotatable, e.g. bayonet or screw A61M5/344 takes precedence

Abstract

A piston rod drive system is provided comprising a main body adapted for coupling with a reservoir, a user operable activation element operatively coupled with the main body and configured to move axially and rotationally relative to the main body between a first position and a second position, and a piston rod element operatively coupled with the activation element and the main body and configured to move axially and non-rotationally relative to the main body in response to the activation element being moved between the first position and the second position.

Claims

1. A piston rod drive system (10) for a drug delivery device, the piston rod drive system (10) comprising:

a main body (1) adapted for coupling with a reservoir,

a user operable activation element (2) operatively coupled with the main body (1) and configured to move axially and rotationally relative to the main body (1) between a first position and a second position, and

a piston rod element (3) operatively coupled with the activation element (2) and the main body (1) and configured to move axially and non-rotationally relative to the main body (1) in response to the activation element (2) being moved between the first position and the second position.

2. A system according to claim 1, wherein the activation element (2) is further configured to move axially and non-rotationally relative to the main body (1) between the second position and a third position.

3. A system according to claim 2, wherein the piston rod element (3) is further configured to move axially and non-rotationally relative to the main body (1) in response to the activation element (2) being moved between the second position and the third position.

4. A system according to claim 1, wherein

the main body (1) comprises

a first engagement structure (12) and

a second engagement structure (16),

the activation element (2) comprises

a third engagement structure (23) adapted to cooperate with the first engagement structure (12) to enable a relative rotational motion between the main body (1) and the activation element (2), and

a fourth engagement structure (24), and

the piston rod element (3) comprises

a fifth engagement structure (34) adapted to cooperate with the fourth engagement structure (24) to enable a relative rotational motion between the activation element (2) and the piston rod element (3), and

a sixth engagement structure (35) adapted to cooperate with the second engagement structure (16) to enable a relative axial and non-rotational motion between the main body (1) and the piston rod element (3).

5. A system according to claim 4, wherein the first engagement structure (12) comprises a first inner thread structure and the third engagement structure (23) comprises a mating first outer thread structure, and wherein the fourth engagement structure (24) comprises a second inner thread structure and the fifth engagement structure (34) comprises a mating second outer thread structure.

6. A system according to claim 5, wherein the pitch of the second outer thread structure is greater than the pitch of the first inner thread structure.

7. A system according to claim 5, wherein the second engagement structure (16) comprises a key and the sixth engagement structure (35) comprises a keyway.

8. A system according to claim 5, wherein the first inner thread structure terminates in a stop surface (14) structured to abut with a leading face (28) of the first outer thread structure when the activation element (2) and the piston rod element (3) are brought to a specific relative axial position.

9. A system according to claim 8, wherein the stop surface (14) constitutes a portion of an axial groove (15), and wherein the first outer thread structure comprises a circumferentially limited thread segment which is adapted to travel in the axial groove (15) between the stop surface (14) and an end-of-use position to displace the activation element (2) non-rotationally relative to the main body (1).

10. A system according to claim 8, wherein the activation element (2) comprises a sleeve member (22) adapted to surround at least a portion of the piston rod element (3), and wherein the sleeve member (22) comprises an opening (25) and the piston rod element (3) comprises a flexible arm (32) with a latching protrusion (33) biased to move into the opening (25) when the activation element (2) and the piston rod element (3) reach the specific relative axial position.

11. A drug delivery device comprising:

a reservoir (5) comprising an outlet (53), a proximal end portion, a first piston (6) arranged between the outlet (53) and the proximal end portion, a second piston (7) arranged between the first piston (6) and the proximal end portion, and a transfer arrangement adapted to enable fluid transfer from one side of the first piston (6) to the other, and

a piston rod drive system (10) according to claim 1.

12. A drug delivery device comprising:

a reservoir (5) comprising an outlet (53), a proximal end portion, a first piston (6) arranged between the outlet (53) and the proximal end portion, a second piston (7) arranged between the first piston (6) and the proximal end portion, and a transfer arrangement adapted to enable fluid transfer from one side of the first piston (6) to the other, and

a piston rod drive system (10) according to claim 3, wherein the main body (1) comprises a first inner thread structure (12) terminating in a stop surface (14), the activation element (2) comprises a first outer thread structure (23) configured for mating engagement with the first inner thread structure (12), and a second inner thread structure (24), and the piston rod element (3) comprises a second outer thread structure (34) configured for mating engagement with the second inner thread structure (24), and wherein the pitch of the first inner thread structure (12) and the pitch of the second inner thread structure (24) are configured such that the piston rod element (3) is displaced axially relative to the main body (1) a distance corresponding to the second piston (7) being brought to abutment or non-releasable engagement with the first piston (6) when a leading face (28) of the first outer thread structure (23) is moved from a pre-activation position into abutment with the stop surface (14).