Injection device

• US 20060258988A1
• Filed: 07/28/2004
• Published: 11/16/2006
• Est. Priority Date: 11/03/2003
• Status: Active Grant

• Current Assignee: Haselmeier AG (Sulzer AG)
• Original Assignee: Haselmeier GmbH (Sulzer AG)
• Inventors: Gabriel, Jochen, Keitel, Joachim
• Granted Patent: US 8,747,367 B2
• Time in Patent Office: Days
• US Class Current: 604/181
• CPC Class Codes: A61M 2005/202 cocking means, e.g. to bias the main drive spring of an injector
• CPC Class Codes: A61M 2205/581 by audible feedback
• CPC Class Codes: A61M 2205/582 by tactile feedback
• CPC Class Codes: A61M 5/20 Automatic syringes, e.g. with automatically actuated piston rod, with automatic needle injection, filling automatically A61M5/142 , A61M5/46 take precedence; hypodermic projectiles F42B12/54
• CPC Class Codes: A61M 5/31551 including axial movement of dose setting member
• CPC Class Codes: A61M 5/31558 using scaling up or down transmissions, e.g. gearbox
• CPC Class Codes: A61M 5/31561 using freely adjustable volume steps
• CPC Class Codes: A61M 5/31563 interacting with a displaceable stop member
• 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

An injection apparatus has a barrel (50) that is adapted to receive a container (108) with injection fluid (110). It further comprises a piston rod (98), provided with a thread (100), for expelling injection fluid (110) from such a container (108), which piston rod (98) is guided relative to the barrel (50) in the axial direction (112, 114). Additionally provided is a threaded part (122) whose thread (120) is in engagement with the thread (100) of the piston rod (98), which threaded part (122) is rotatable relative to the piston rod (98) and relative to the barrel (50) in order to set an injection dose, and, during an injection operation, is prevented from rotating relative to the piston rod (98).

Claims

1. An injection apparatus comprising:

a barrel (50) configured to receive a container (108) containing injection fluid (110);

a piston rod (98) provided with a thread (100), for expelling injection fluid (110) from such a container (108), which piston rod (98) is guided relative to the barrel (50) in the axial direction (112, 114);

a threaded part (122) formed with a thread (120) which is in engagement with the thread (100) of the piston rod (98), the threaded part (122) being rotatable relative to the piston rod (98) and relative to the barrel (50) in order to set an injection dose, said threaded part moving axially, during a setting operation, relative to the piston rod (98) and relative to the barrel (50); and

wherein

said threaded part (122) is, during an injection operation, non-rotatable relative to the piston rod (98) and relative to the barrel (50), and therefore moves axially in an infection direction, relative to said barrel (50).

2. The injection apparatus according to claim 1, further comprising

a setting member (76), rotatably arranged in the barrel (50), the barrel (50) and setting member (76) together having a combined length whose magnitude corresponds, prior to setting of an injection dose, to a predetermined initial length,

a relative rotation between the barrel (50) and the setting member (76) serving to increase the combined length and to set an injection dose,

that combined length being returnable back to the initial length during an injection, likewise by a relative rotation between the barrel (50) and setting member (76).

3. The injection apparatus according to claim 2,

wherein a follower (128) is provided which is coupled to the setting member (76) in such a way that a rotational motion of the setting member (76), that occurs in order to set an injection dose, is transferred to the follower (128);

and

a rotational motion of the setting member (128) that occurs in the context of an injection, is not transferred to the follower (128).

4. The injection apparatus according to claim 3,

wherein the threaded part (122) is connected to the follower (128) in such a way that a rotational motion of the follower (128), but not an axial displacement of the follower (128) relative to the barrel (50), is transferred to the threaded part (122).

5. The injection apparatus according to claim 2, further comprising

a pushing member (66) which is connected to the barrel (50) via a first drive connection and to the setting member (76) via a second drive connection,

one of these drive connections being configured as a second thread (86, 94) and the other drive connection as an axial guidance system (64, 70), so that the pushing member (66) moves relative to the barrel (50) in a predetermined direction when the setting member (76) is moved, likewise in that predetermined direction, by means of a rotation relative to the barrel (50).

6. The injection apparatus according to claim 2, further comprising

a third thread (62, 74), arranged between the barrel (50) and setting member (76), for length adjustment.

7. The injection apparatus according to claim 6,

wherein the pitches of the three threads are coordinated with one another in such a way that during the setting of an injection dose, the motion of the pushing member (66) in a predetermined direction is of at least the same magnitude as the motion of the threaded part (122) in that direction.

8. The injection apparatus according to claim 6,

wherein portions of the setting member (76) that are located adjacent the third thread (52, 74) are provided with scale values (78) for displaying the injection dose that is set.

9. The injection apparatus according to claim 8,

wherein the barrel (50) is provided with a window (52) for displaying at least one of the scale values (78).

10. The injection apparatus according to claim 6,

wherein the second thread (86, 94) and the third thread (62, 74) have identical thread directions.

11. The injection apparatus according to claim 10,

wherein the thread pitch of the third thread (62, 74) is greater in absolute value than the thread pitch of the second thread (86, 94).

12. The injection apparatus according to claim 10,

wherein the thread direction of the first thread (100, 120) corresponds to that of the third thread (62, 74).

13. The injection apparatus according to claim 12,

wherein the thread pitch of the first thread (100, 120) is smaller in absolute value than the thread pitch of the third thread (62, 74).

14. The injection apparatus according to claim 5,

wherein the pushing member (66) is provided on its proximal side with a contact member (69) which is configured for contact against a distal side (125) of the threaded part (122) in order, during an injection, to displace the piston rod (98) via the threaded part (122) in the proximal direction, and to expel injection fluid (110) from the container (108).

15. The injection apparatus according to claim 3, further comprising

a controllable coupling (84, 136) which, in a closed state, enables transfer of torque from the setting member (76) to the follower (128).

16. The injection apparatus according to claim 15,

wherein the controllable coupling (84, 136) is so configured that it transfers the rotational motion of the setting member (76) to the follower (128) during the setting of an injection dose.

17. The injection apparatus according to claim 15,

wherein the controllable coupling (84, 136) is so configured that it does not transfer a rotational motion of the setting member to the follower (128) during an injection.

18. The injection apparatus according to claim 15,

wherein the controllable coupling (84, 136) is implemented so that it is opened by means of an operation occurring at the beginning of an injection.

19. The injection apparatus according to claim 15,

wherein the controllable coupling (84, 136) is implemented so that after completion of an injection, it returns to the closed state;

and

remains closed during dose setting, in order to transfer to the threaded part (122) a rotation of the setting member (76) that is accomplished in order to set the dose.

20. The injection apparatus according to claim 5,

wherein the second thread (86, 94) is implemented as a second drive connection for the pushing member (66).

21. The injection apparatus according to claim 5,

wherein the thread pitches of the first, second, and third threads are dimensioned such that, durinq the setting operation, a rotation of the setting member (76) has substantially no influence on the location of the piston rod (98) relative to the housing (50).

22. The injection apparatus according to claim 2,

further comprising a torsional spring (148), which is arranged in such a way that energy is stored in it when a dose is set, and energy is released from it during an injection operation.

23. The injection apparatus according to claim 22, wherein

the torsional spring (148) is arranged between the setting member (76) and the pushing member (66), a relative rotation between those parts modifying the torque generated by the torsional spring (148).

24. The injection apparatus according to claim 23,

wherein the torsional spring (148) is joined nonrotatably but axially displaceably to the pushing member (66).

25. The injection apparatus according to claim 1,

wherein a detent connection (64, 131) is provided between

the part (50) and

a part (122) connectable via a controllable coupling (84, 136) to the setting member (76).

26. The injection apparatus according to claim 25,

wherein there is provided in the barrel (50) a spline set (64) that coacts with a detent member (131) that is axially displaceable relative to the barrel (50), in order to produce rotational detent positions that are independent of the relative axial locations of the detent member (131) and barrel (50).

27. The injection apparatus according to claim 25,

wherein the detent connection (64, 131) is implemented in such a way that, by means of a first predetermined minimum torque, it is adjustable in a rotation direction that increases the injection dose, and, by means of a second predetermined minimum torques it is adjustable in a rotation direction that decreases the injection dose.

28. The injection apparatus according to claim 27,

wherein the first and the second predetermined minimum torques are of substantially equal magnitude.

29. The injection apparatus according to claim 26,

wherein the detent connection (64, 131) is implemented in such a way that, by means of a first predetermined minimum torque, it is adjustable in a rotation direction that increases the injection dose, and by means of a second predetermined minimum torque, it is adjustable in a rotation direction that decreases the injection dose.

30. The injection apparatus according to claim 3, further comprising

a pushing member (66) which is connected to the barrel (50) via a first drive connection and to the setting member (76) via a second drive connection,

one of these drive connections being configured as a second thread (86, 94) and the other drive connection as an axial guidance system (64, 70), so that the pushing member (66) moves relative to the barrel (50) in a predetermined direction when the setting member (76) is moved, likewise in that predetermined direction, by means of a rotation relative to the barrel (50).