Pen-type injector

• US 7,905,867 B2
• Filed: 03/02/2004
• Issued: 03/15/2011
• Est. Priority Date: 03/03/2003
• Status: Active Grant

• Current Assignee: Sanofi-Aventis Deutschland GmbH (Sanofi )
• Original Assignee: Dca Design International Ltd.
• Inventors: Wimpenny, Steven, Veasey, Robert Frederick, Langley, Christopher Nigel
• Primary Examiner(s): Sirmons; Kevin C
• Assistant Examiner(s): PATEL, SHEFALI DILIP
• Application Number:
  US10/790,025
• Publication Number:
  US 20050113765A1
• Time in Patent Office: 2,569 Days
• Field of Search: 604/187, 604/246, 604/131, 604/207, 604/181, 604/208, 604/209, 604/210, 604/211, 604/218, 604/224
• US Class Current: 604/209
• CPC Class Codes: A61M 2205/581 by audible feedback
• CPC Class Codes: A61M 2205/582 by tactile feedback
• 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 5/2422 using emptying means to expel or eject media, e.g. pistons, deformation of the ampoule, or telescoping of the ampoule
• 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 5/31526 by means of stepwise axial movements, e.g. ratchet mechanisms or detents
• CPC Class Codes: A61M 5/31528 by means of rotational movements, e.g. screw-thread mechanisms
• CPC Class Codes: A61M 5/31533 Dosing mechanisms, i.e. setting a dose administrating mechanisms A61M5/31565
• 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 5/3156 using volume steps only adjustable in discrete intervals, i.e. individually distinct intervals
• 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
• CPC Class Codes: A61M 5/31593 Multi-dose, i.e. individually set dose repeatedly administered from the same medicament reservoir

Abstract

A pen-type injector is improved so that a user may select a delivery dose of medicinal product from a multidose cartridge. The injector includes a housing. a cartridge containing medicinal product retained within a housing, a piston rod, a dose selecting member to select a dose of medicinal product to be expelled, and a drive member to expel the selected dose of medicinal product. The housing is formed unitary so that the dose selecting member and the drive member are moveably retained within the housing. The injector may include ratchet means associated with the insert to ensure the piston rod only rotates in a single direction through the insert, a button located on the drive sleeve, and clutch means which upon depression of the button prevents rotation between the dose dial sleeve and the drive sleeve.

Claims

1. A pen-type injector, comprising:

a housing;

a piston rod having a screw thread and rotatable in only one direction relative to the housing;

an insert located in the housing threadedly engaged with the piston rod;

a ratchet associated with the insert configured to allow the piston rod to rotate only in a single direction through the insert;

a dose dial sleeve rotatable with respect to the housing and the insert;

a drive sleeve which is axially displaceable but not rotatable with respect to the piston rod;

a button located on the drive sleeve and rotatable with respect to the drive sleeve; and

clutch means which upon depression of the button prevents rotation between the dose dial sleeve and the drive sleeve.

2. An injector according to claim 1, characterized in that the injector further comprises a nut which is rotatable with respect to the drive sleeve and axially displaceable but not rotatable with respect to the dose dial sleeve.

3. An injector according to claim 2, characterized in that the nut is provided on a helical thread provided on the drive sleeve and is located between the drive sleeve and the dose dial sleeve, the dose dial sleeve and the nut being splined together by spline means to prevent relative rotation between the nut and the dose dial sleeve.

4. An injector according to claim 1, characterized in that the insert comprises a web having an opening, a first cylindrical portion extending from a first side of the web, a second cylindrical portion extending from a second side of the web and a third cylindrical portion extending from a second side of the web.

5. An injector according to claim 1, characterized in that the dose dial sleeve comprises a first section of first diameter and a second section of a second diameter, wherein the insert and an inner surface of the first section include inter-engaging features to provide a helical thread between the insert and the dose dial sleeve.

6. An injector according to claim 1, characterized in that the dose dial sleeve comprises a first cylindrical portion rigidly connected to a second generally cylindrical portion, wherein an inner surface of the first portion of the dose dial sleeve and an outer surface of a third cylindrical portion of the insert include inter-engaging features to provide a helical thread between the insert and the dose dial sleeve.

7. An injector according to claim 6, characterized in that the second generally cylindrical portion comprises a first cylindrical section and a second cylindrical section connected by a shoulder, the first section being rigidly keyed to an inner surface of the first portion of the dose dial sleeve, and the second section having an outer diameter equal to an outer diameter of the housing.

8. An injector according to claim 1, characterized in that an outer surface of the dose dial sleeve includes graphics and wherein the housing is provided with an aperture or window through which a portion of the graphics may be viewed.

9. An injector according to claim 1, characterized in that the drive sleeve comprises a first part of first diameter located between the insert and the piston rod and a second part of second diameter located between the piston rod and the dose dial sleeve, an internal surface of the drive sleeve being splined to the piston rod such that relative rotation between the drive sleeve and the piston rod is prevented while longitudinal displacement is permitted.

10. An injector according to claim 1, characterized in that the drive sleeve further comprises a central receiving area having a peripheral recess, and wherein the button being of generally “

T”

shaped configuration has a stem that is retained within the receiving area by co-operation between a peripheral bead provided on the stem retained in a peripheral recess provided in the central receiving area.

11. An injector according to claim 10, characterized in that the central receiving area includes at a first end a centrally located domed part.

12. An injector according to claim 1, characterized in that the clutch means comprises a plurality of radially extending longitudinally directed teeth provided respectively on the dose dial sleeve and the drive sleeve.

13. An injector according to claim 1, characterized in that clicker means are provided between the dose dial sleeve and the drive sleeve, the clicker means comprising a plurality of longitudinally extending teeth and a flexible toothed member, one of the plurality of teeth and the toothed member being provided on the dose dial sleeve, the other of the plurality of teeth and the toothed member being provided on the drive sleeve, wherein relative rotation between the dose dial sleeve and the drive sleeve causes the flexible toothed member to ride over the teeth to produce a series of clicks.