Injection device

• US 6,454,743 B1
• Filed: 10/30/2000
• Issued: 09/24/2002
• Est. Priority Date: 04/30/1998
• Status: Expired due to Term

• Current Assignee: Bayer Intellectual Property GmbH (Bayer AG)
• Original Assignee: Schering Ag (Merck & Co., Inc.)
• Inventors: Weber, Wilfried
• Primary Examiner(s): Walberg, Teresa
• Assistant Examiner(s): FASTOVSKY, LEONID M
• Application Number:
  US09/674,253
• Time in Patent Office: 694 Days
• Field of Search: 604/131, 604/134, 604/135, 604/136, 604/157, 604/152, 604/232, 600/583
• US Class Current: 604/131
• CPC Class Codes: A61M 2005/206 With automatic needle insertion
• CPC Class Codes: A61M 2005/2086 having piston damping means, e.g. axially or rotationally acting retarders
• 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 5/2033 Spring-loaded one-shot injectors with or without automatic needle insertion multishot dosing syringes A61M5/31525, needle insertion only A61M5/3287
• 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 5/3157 Means providing feedback signals when administration is completed A61M5/20 takes precedence

Abstract

An injection device that is used with a syringe, wherein the injection needle of the syringe is initially introduced into the skin and the injection fluid is injected afterwards. The injection device is essentially driven and controlled by a control sleeve (6) which can be displaced and/or rotated in relation to the housing (7) and which can be moved between a closing and functional position (P1) and an open and safety position (P2). In the closing and functional position, the control sleeve prevents access to the syringe and activates a release device for the injection process. In the open and safety position, a syringe (1) can be removed or inserted. A plurality of components carrying out the injection process (a slide (2) in which the syringe (1) is placed and a plunger (4) that impinges upon the syringe piston) are moved or controlled depending on the movement and position of the control sleeve or supported (for example, an ejection device for the syringe or a signaling device informing that injection has been completed). The device enables full-automatic injection that can be reliably carried out by patients themselves with few handling procedures.

Claims

1. An injection device for actuating a syringe, in particular a disposable syringe, with drive and control means which are held in a housing and which cause the injection operation to take place successively in such a way that first a linear displacement of the syringe (1) with the injection needle takes place for introducing the injection needle into the skin, and then the injection of the injection fluid takes place, and the drive and control means contain a control sleeve (6) which is displaceable between a closing and operating position (P1), which prevents access to the syringe (1) and releases a trigger means for the injection operation, and an opening and securing position (P2), which allows the syringe (1) to be inserted and extracted,

characterized in that the control sleeve (6), over part of its circumference, has a loading orifice (L6) for inserting and extracting the syringe (1), and that it is rotatable between the closing and operating position (P1) and the opening and securing position (P2) by a control angle (a) on the casing surface (M) of the housing (7).

2. The injection device as claimed in claim 1, characterized in that the control sleeve (6) has a substantially cylindrical middle portion (6B), which has the loading orifice (L6).

3. The injection device as claimed in claim 1, characterized in that the housing (7) has an essentially cylindrical middle portion (7B) which has, over part of its circumference, a loading orifice (L7) for inserting and extracting the syringe (1).

4. The injection device as claimed in claim 2 characterized in that the housing (7) has an essentially cylindrical middle portion (7B) which has, over part of its circumference, a loading orifice (L7) for inserting and extracting the syringe (1) and in that the two loading orifices (L6, L7) extend over part of the respective circumference of their associated structural part (6, 7), the circumferential angle (α

1, α

2) of which is greater than 180°

, so that, in the closing and operating position (P1), the syringe (1) is surrounded completely by the housing (7) and the control sleeve (6) and, when the control sleeve (6) is in the opening and securing position (P2) rotated through the control angle (α

) the two loading orifices (L6, L7) are at least partially congruent.

5. The injection device as claimed in claim 1, wherein a first stroke (H1) of a slide (2), in which the syringe (1) is held for introducing the injection needle (13) is provided, within the housing (7), between a locking position (A1) and an advanced position (V1).

6. The injection device as claimed in claim 5, characterized in that a second stroke (H2) of a tappet (4) in the operational axis (F) relative to the slide (2) for injecting the injection fluid is provided, within the housing (7), between a locking position (A2) and an advanced position (V2).

7. The injection device as claimed in claim 6, characterized in that the relative positions of the tappet (4) and slide (2) are defined by a coupling element (8), in such a way that, after the trigger means has been actuated, the second stroke (H2) of the tappet (4) directly follows the first stroke (H1) of the slide (2) and the two strokes (H1, H2) are added together.

8. The injection device as claimed in claim 7, characterized in that, during the first stroke (H1) of the slide (2), the coupling element (8) couples the latter and the tappet (4) to one another via a first catch element (81) in the tappet (4) and, after the first stroke (H1), releases the coupling by means of a second catch element (72) in the housing (7), so that the tappet (4) alone then carries out the second stroke (H2).

9. The injection device as claimed in claim 1, characterized in that the control sleeve (6), housing (7), slide (2) and tappet (4) are designed at least in portions, as cylindrical or hollow-cylindrical portions lying coaxially to one another.

10. The injection device as claimed in claim 9, characterized in that the housing (7) has, in a rear cylindrical handling portion (7A), an annular groove (75), in which a cylindrical control portion (6A) of the control sleeve (6) is guided rotatably.

11. The injection device as claimed in claim 10, characterized in that the control sleeve (6) has a front tapered guide portion (6C) which is held rotatably on the housing (7).

12. The injection device as claimed in claim 1, characterized in that the closing position (P1) and the opening position (P2) are secured by a catch element (77) acting between the housing (7) and control sleeve (6) and by depressions (77A, 77B) in the housing (7) which act in a manner offset relative to one another by the control angle (α

).

13. The injection device as claimed in claim 9, characterized in that the slide (2) is designed, over a first portion (2A) guided in the housing (7), as a hollow cylinder in which the tappet (4) is centrally mounted axially displaceably.

14. The injection device as claimed in claim 13, characterized in that the slide (2) has a U-shaped cross section in a second portion (2B) guided in the housing 10 (7), and a groove-shaped or slit like retention (21) for positioning the syringe collar (12) held in this retention (21) in such a way that the end face of the syringe plunger can be displaced in the injection direction by the tappet (4).

15. The injection device as claimed in claim 9, characterized in that the tappet (4) has, at it send pointing toward the handling portion (7A) of the housing (7), a guide portion (4A) which is guided in the 20 housing (7) and which has the same outside diameter as the first portion (2A) of the slide (2).

16. The injection device as claimed in claim 15, characterized in that a joint drive means for generating the two strokes (H1, H2) by the slide (2) and the tappet (4) is accommodated between the rear end face of the guide portion (4A) of the tappet (4) and the housing rear wall (74).

17. The injection device as claimed in claim 16, characterized in that the drive means is a helical spring (3) arranged coaxially to the longitudinal axis (F).

18. The injection device as claimed in claim 15, wherein a first stroke (H1) of a slide (2), in which the syringe (1) is held for introducing the injection needle (13) is provided, within the housing (7), between a locking position (A1) and an advanced position (V1), and characterized in that a second stroke (H2) of a tappet (4) in the operational axis (F) relative to the slide (2) for injecting the injection fluid is provided, within the housing (7), between a locking position (A2) and an advanced position (V2), and in that there is integrally formed on the rear side of the guide portion (4A) of the tappet (4) at least on securing pawl (41) which, in the opening and securing position (P2), is in releasable engagement with at least one control pawl (53, 54) of the trigger means, said control pawl being displaceable transversely to the longitudinal axis (F), and which holds the tappet (4) in its locking position (A1) counter to the pretension of the helical spring (3).

19. The injection device as claimed in claim 18, characterized in that the trigger means is guided outward through the housing (7) and there forms an actuating button (5) for releasing the securing pawl (41) and, consequently, the two strokes (H1, H2).

20. The injection device as claimed in claim 19, characterized in that the displacement of the actuating button (5) is possible only when the control sleeve (6) is in the closing and operating position (P1).

21. The injection device as claimed in claim 20, characterized in that the cylindrical control portion (6A) of the control sleeve (6) has an edge recess (6A1), through which a nose (5A) of the actuating button (5) can pass in the closing and operating position (P1).

22. The injection device as claimed in claim 15, characterized in that control elements are held in the guide portion (4A) of the tappet (4), said control elements cooperating with profiles which form at least one control cam are formed on the inner casing surface (MI) of the cylindrical control portion (6A) of the control sleeve (6) and which act as control cams (64, 66;

65, 67).

23. The injection device as claimed in claim 22, characterized in that in the control elements consist of at least one lifting bolt (42,43) which loads the control cam portions (64, 67;

65, 66;

68, 69) in such a way that, as a result of rotation of the control sleeve (6) from the closing and operating position (P1), after the execution of the two strokes (H1, H2), through the functional angle into the opening and securing position (P2), the torque applied at the same time is converted via the control cam portions (64, 67;

65, 66;

68, 69) into a linear restoring force counter to the tension force of the helical spring (3), with the result that the tappet (4) and the slide (2) execute a counterstroke (OH) in the housing (7) until in their locking positions (A1, A2), the securing pawls (41) of the tappet (4) come into engagement with the control pawls(53, 54) of the trigger means (5) again.

24. The injection device as claimed in claim 23, characterized in that two lifting bolts (42, 43) of different thickness spring-loaded in the direction of the casing surface (MI) are provided, which are guided by two control cams (64, 67 and 65, 66) arranged so as to be offset vertically in the inner casing surface (MI) in such a way that, in each axial position of the tappet (4), the conversion of the torque of the control sleeve (6) takes place via at least one of the lifting bolts (42, 43).

25. The injection device as claimed in claim 1, characterized in that the control sleeve (6), when in the closing and operating position (P1), allows a view of the syringe (1).

26. The injection device as claimed in claim 25, characterized in that the control sleeve (6) is made at least partially from transparent plastic.

27. The injection device as claimed in claim 1, characterized in that at least some of the essential structural operating parts (2, 4, 6, 7) are formed from plastic.

28. The injection device as claimed in claim 6, characterized in that the acceleration of the slide (2) into its advanced position (V1) during the first stroke (H1) is limited by a rotation damper (100) which is connected to the housing (7) via a rack (101).

29. The injection device as claimed in claim 23, characterized in that the housing (7) has an essentially cylindrical middle portion (7B) which has, over part of its circumference, a loading orifice (L7) for inserting and extracting the syringe (1), and in that there is provided opposite the loading orifice (L7) of the housing (7) an ejection means which, after injection has taken place, lifts the syringe (1) in the direction of the loading orifices (L6, L7) during the opening of the loading orifice (L7) as a result of the rotation of the control sleeve (6) into the opening and securing position (P2).

30. The injection device as claimed in claim 29, characterized in that the ejection means contains an ejection lever (200), one end of which is held pivotably on the slide (2) by means of a pin (201), in such a way that its other end can be moved in the direction of the syringe (1).

31. The injection device as claimed in claim 30, characterized in that, in order to control the movement of the ejection lever (200), the latter has a control boss which, at the end of the first stroke (H1), comes into engagement with a guide track (205) which rises in the direction of the operating axis (F) in a ramplike manner opposite to the injection direction, so that the lifting of the ejection lever (200) takes place during the rotation of the control sleeve (6) into the opening and securing position (P2).

32. The injection device as claimed in claim 31, characterized in that the control boss consists of two sliding bosses (202) which are arranged in a forklike manner on the ejection lever (200) and which are guided in a guide channel (203) narrowing in the stroke direction, until their ends pointing outward in a hooklike manner come into engagement with the lower end of the guide track (205).

33. The injection device as claimed in claim 1, characterized in that a signal means is provided, which is actuated at the end of the second stroke (H2) after injection has taken place.

34. The injection device as claimed in claim 33, characterized in that the signal means consists solely of mechanically acting structural elements.

35. The injection device as claimed in claim 33, characterized in that the signal means generates an acoustic signal.

36. The injection device as claimed in claim 34, characterized in that the signal means generates an acoustic signal and in that the signal is generated by means of a bell (306), the edge region of which is loaded by means of a striking pin (305) in order to generate the signal.

37. The injection device as claimed in claim 36, characterized in that the striking pin (305) is actuated, via a lever arrangement (302), by a tension rod (300) displaceable parallel to the operating axis (F) by the slide (2) and loaded by a spring (309).

38. The injection device as claimed in claim 37, characterized in that the striking pin (305) is secured by means of springs (304, 307) and is loaded in such a way that the bell (306) receives only a short pulse for generating the signal.

39. The injection device of claim 6, characterized in that the tappet (4′

) is coupled via a linear gear to a thrust rod (4″

), which actuates the syringe plunger (14).

40. The injection device of claim 39, characterized in that the ratio of the gear is selected such that the second stroke (H2) of the tappet (4′

) is converted into a stroke in the same direction of the thrust rod (4″

), which corresponds to the injection stroke of the syringe plunger (14).

41. The injection device of claim 40, characterized in that the thrust rod (4″

) is guided parallel to the tappet (4′

) by the slide (2′

).

42. The injection device of claim 41, characterized in that the front portion of the tappet (4′

), at least two gear wheels (Z1, Z2) of different diameter are coaxially secured to one another, of which the first gear wheel (Z1) meshes with a first rack (S1) on the thrust rod (4″

), and the second gear wheel (Z2) meshes with a second rack (S2) on the slide (2′

).

43. The injection device of claim 40, characterized in that the front portion of the tappet (4′

), at least two gear wheels (Z1, Z2) of different diameter are coaxially secured to one another, of which the first gear wheel (Z1) meshes with a first rack (S1) on the thrust rod (4″

), and the second gear wheel (Z2) meshes with a second rack (S2) on the slide (2′

) and in that the diameter of the two gear wheels (Z1, Z2) specifies the ratio of the gear (Z1, Z2;

S1, S2).

44. The injection device of claim 43, characterized in that the front portion of the tappet (4′

) fits in forklike fashion over an arrangement of three gear wheels (Z2A, Z1, Z2B), of which the middle, first gear wheel (Z1) has the larger diameter, and the two outer, second gear wheels (Z2A, Z2B) mesh with two second racks (S2A, S2B).

45. The injection device of claim 42, characterized in that the first rack (S1) is an integral part of the thrust rod (4″

).

46. The injection device of claim 42, characterized in that the second rack or racks (S2;

S2A, S2B) are an integral part of the slide (2′

).

47. The injection device of claim 39, characterized in that the longitudinal axis of the syringe (1) is located parallel to the longitudinal axis (F) of the housing (7).

48. The injection device of claim 41, characterized in that in the front portion of the tappet, a gear wheel is supported which meshes with a first rack on the thrust rod and with a second rack on the injection stroke is twice as long as the stroke of the tappet.