Medical delivery device having air shot means

• US 20070016143A1
• Filed: 06/08/2006
• Published: 01/18/2007
• Est. Priority Date: 12/08/2003
• Status: Active Grant

• Current Assignee: Novo Nordisk A/S
• Original Assignee: Novo Nordisk A/S
• Inventors: Miller, Thomas, Thogersen, Klaus, Groth, Lars, Bulow, Martin
• Granted Patent: US 9,044,548 B2
• Time in Patent Office: Days
• US Class Current: 604/208
• 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 5/3146 Priming, e.g. purging, reducing backlash or clearance
• CPC Class Codes: A61M 5/31535 Means improving security or handling thereof, e.g. blocking means, means preventing insufficient dosing, means allowing correction of overset dose
• CPC Class Codes: A61M 5/31541 Means preventing setting of a dose beyond the amount remaining in the cartridge
• 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 5/31551 including 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
• CPC Class Codes: A61M 5/31585 performed by axially moving actuator, e.g. an injection button

Abstract

An air shot or priming mechanism for an injection pen. The injection pen comprises a cartridge-holder and a housing. The cartridge-holder interacts with a nut-member capable of driving the piston rod forward when relatively rotated. The cartridge-holder is rotational coupled to the housing such that rotation of the cartridge-holder relatively to the housing causes the nut-member and the piston rod to rotate relatively, thus the relative angular rotation between the cartridge-holder and the housing determines the size of the air shot so performed.

Claims

1. A delivery device (1) for delivering a fluid medicament, comprising

A cartridge-holder (10) for supporting a cartridge (5) containing the fluid medicament to be delivered,

A housing (20) having the cartridge-holder (10) coupled to a distal end,

A piston rod (50) having an outer thread, and

A piston rod drive (40, 60) to drive the piston rod (50) in a longitudinal direction including:

a) A piston rod guide (40) engaging the piston rod (50) to allow axially displacement but not rotation of the piston rod (50) in relation to the piston rod guide (40) and

b) A nut member (60) which is not longitudinal displaceable in the housing (20) having an inner thread (63) mating the thread of the piston rod (5),

wherein rotation of the piston rod guide (40) and the nut member (60) relatively to each other drives the piston rod (50) in the longitudinal direction

Wherein in that,

the cartridge-holder (10) is rotational coupled to the housing (20) and operational coupled to the piston rod drive (40, 60) such that the piston rod guide (40) or the nut member (60) are rotated when the cartridge-holder (10) and the housing (20) are relatively rotated whereby the piston rod (5) is driven in the longitudinal direction in order to expel a predetermined air shot dose.

2. A delivery device (1) for delivering a fluid medicament according to claim 1, wherein the relative rotational movement possible between the cartridge-holder (10) and the housing (20) and is limited such that the size of the air-shot dose is predetermined by this limitation.

3. A delivery device (1) for delivering a fluid medicament according to claim 2, wherein the housing (20) is provided with an opening 24 and the cartridge-holder (10) is provided with a limiter (14) such that the movement of the limiter (14) in the opening (24) defines the possible angular movement between the cartridge-holder (10) and the housing (20).

4. A delivery device (1) for delivering a fluid medicament according to claim 3, wherein the nut-member (60) comprises a distal part (64) carrying a number of distal ratchet pawls (67) and a proximal part (66) carrying a number of proximal ratchet pawls (68), the distal part (64) and the proximal part (66) being connected by an intermediate part (65).

5. A delivery device for delivering a fluid medicament according to claim 4, wherein the distal ratchet pawls interfaces a cartridge holder ratchet (17) provided on the interior surface of the cartridge holder (10)

6. A delivery device for delivering a fluid medicament according to claim 5, wherein the proximal ratchet pawls (68) interfaces a second ratchet (28) provided on the interior surface of the housing (20).

7. A delivery device for delivering a fluid medicament according to claim 6, wherein the cartridge holder ratchet (17) slides over the distal ratchet pawls (67) when the cartridge holder (10) is rotated in a first direction and that the cartridge holder ratchet (17) engages the distal ratchet pawls (67) when the cartridge holder (10) is rotated in a second opposite direction.

8. A delivery device for delivering a fluid medicament according to claim 7, wherein the engagement between the cartridge holder ratchet (17) and the distal ratchet pawls (67) rotates the nut member (60) simultaneously with the rotation of the cartridge holder (10) and that the piston rod (50) is rotational locked to the housing (20) through a one-way coupling (70).