Injection device for injection, especially self-administered injection, of medicament, including mechanisms for nulling and for selecting dosage, especially for use with multi-dose ampules

• US 5,114,406 A
• Filed: 01/18/1990
• Issued: 05/19/1992
• Est. Priority Date: 11/14/1986
• Status: Expired due to Fees

• Current Assignee: B D Medico SARL
• Original Assignee: Wilhelm Haselmeier GmbH & Company
• Inventors: Hambrecht, Gerhard, Nothdurft, Klaus, Bechtold, Herbert, Gabriel, Jochen
• Primary Examiner(s): Apley, Richard J.
• Assistant Examiner(s): Dvorak, Linda C. M.
• Application Number:
  US07/466,999
• Time in Patent Office: 852 Days
• Field of Search: 604/134-139, 604/156, 604/157, 604/186, 604/207-209, 604/211, 604/218, 604/201, 604/228, 604/232
• US Class Current: 604/136
• CPC Class Codes: A61M 2005/1402 Priming
• CPC Class Codes: A61M 2005/206 With automatic needle insertion
• CPC Class Codes: A61M 2005/2407 from the rear
• 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 5/24 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 5/2466 by piercing without internal pressure increase A61M5/2429 takes precedence
• CPC Class Codes: A61M 5/31553 without 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 5/31593 Multi-dose, i.e. individually set dose repeatedly administered from the same medicament reservoir

Abstract

To permit accuracy presetting of a dose for an injection to be ejected from an ampule (12) containing more fluid medication than the dose requires, a plunger (18) which is telescopically received within a tubular element (77) is movable against the customary piston (17) in the ampule for a distance which depends on the extent of telescopic insertion of the plunger stem (18") within the tubular element (77). This extent can be set by a rotary knob or sleeve (56, 65) which rotates the tubular element with respect to the plunger (18); the plunger and tubular element are coupled together by a steeply pitched spiral thread (76), thereby controlling the extent of projection of the combined injection dosing arrangement of plunger (18) and plunger length setting mechanism (77), and hence controlling the amount of medicinal fluid expelled through an injection needle (16) coupled to the ampule (12) at the end of the injection device.

Claims

1. Injection device for performing dosed injections, said injection device defining a proximal end and a distal end, and having

a housing (30, 32) for reception of an ampule or medication container (12) retaining a medicinal fluid, and a fluid expelling piston (17) movable in proximal direction within the ampule;

an injection needle (16) engageable with the proximal end of the ampule and movable with the ampule in proximal direction with respect to the housing, in an injecting direction;

an injection plunger (18) engageable against said piston (17);

a plunger length setting mechanism (77) coupled to said plunger and forming with said plunger an injection dosing arrangement (18-77);

a spring (95) coupled to the injection dosing arrangement (18-77);

user operable spring cocking means (100);

user operable spring release means (42,

     104),

said spring (95), after cocking, moving the plunger (18) of the injection dosing arrangement (18-77), upon release by the spring release means (41,

     104) in engagement with said piston (17) to expel medicament fluid from the injection needle (16),

wherein, in accordance with the invention,

the plunger length setting mechanism (18-77) comprises

a tubular element (77'"'"') having an internal thread;

the injection plunger (18) includes an elongated stem (18") having an external thread (76) matching the internal thread of the tubular element (77) and telescopically receivable therein, and a plunger head (18'"'"') engageable with said piston (17) of the ampule;

means (80, 82,

     83) are provided for restraining relative rotation of the injection plunger (18) with respect to the housing (30,

     32) while permitting axial movement of said injection plunger and said plunger length setting mechanism (77) within the housing; and

user dosage setting means (56,

     65) are provided and engageable with said tubular element (77'"'"') of the plunger length setting mechanism (77) to effect relative rotation of the plunger length setting mechanism (77) and to control the extent of telescopic penetration of the plunger (18) within said tubular element (77'"'"') and hence the overall length of the injection dosing arrangement (18-77) to thereby control the extent of movement of said piston (17) within the ampule upon release of said spring (95) by the spring release means (42,

     104).

2. The device of claim 1, wherein said means for restraining relative rotation of the injection plunger (18) with respect to the housing comprises

an at least partially essentially cylindrical guide element (83) formed with an axial opening therein;

interengaging projection-and-recess means (80,

     82) formed at the outside of said elongated stem (18") and at said elongated opening; and

means (103,

     104) formed on said guide element and coupling said guide element in rotation-inhibited manner to said housing (82).

3. The device of claim 2, wherein said interengaging projection-and-recess means, (80, 82) comprises an axially extending groove or slot (80) extending along said elongated stem (18") of the injection plunger;

and

an internal projection (82) extending into the opening formed in said guide element (83).

4. The device of claim 2, wherein said guide element (83) and said plunger length setting mechanism (77) are in engaged coupled relationship, permitting relative rotation of said plunger length setting mechanism (77) with respect to said guide element, while coupling said guide element and said plunger length setting mechanism (77) together for conjoint axial motion upon axial movement of said plunger length setting mechanism (77).

5. The device of claim 1, wherein said means for restraining relative rotation of the injection plunger (18) with respect to the housing comprises interengaging projection-and-recess means (103, 104, 40, 41) formed, respectively, within said housing and on said guide element.

6. The device of claim 5, wherein said projection-and-recess means comprises a projecting ridge (103) formed on said guide element;

and an internal groove (41) formed on the inside of the housing, slidably engageable by said projecting ridge.

7. The device of claim 1, wherein said internal and external threads within the tubular element (77'"'"') and on the stem (18") of the plunger (18), respectively, are steep-pitch spiral threads.

8. The device of claim 1, including coupling means coupling said user dosage setting means (56, 65, 100) to said plunger length setting mechanism (77).

9. The device of claim 8, wherein said user dosage setting means includes a hand grippable element (100) and a coupling arrangement for tensioning said spring (65) and thereby cocking said injection device.

10. The device of claim 1, further including coupling means coupling the user dosage setting means (56, 65, 100) with said plunger setting mechanism (77), said coupling means (98) comprising at least one of:

a slip or friction coupling;

a one-way of free-wheel coupling;

a torsion or spiral spring coupling.

11. The device of claim 1, wherein said spring (95) comprises a spiral spring coupled to and acting on the tubular element (77'"'"') of the injection dosing arrangement.

12. The device of claim 1, wherein said user operable spring cocking means comprises a latch means (42, 104) retaining the spring (95) and said injection dosing arrangement (18-77) in cocked position;

and wherein said user operable spring release means comprises a release (11) to unlatch said latch means.

13. The device of claim 12, wherein said latch means comprises an opening (42) formed in the housing (32) of the device and an engagement projection (104) fitting into said opening and coupled to said injection dosing arrangement (18-77).

14. The device of claim 13, wherein said housing (32) includes an inner axially extending longitudinal groove or slot (41);

and wherein said projection (104) is slidable within said groove or slot.

15. The device of claim 14, wherein said means for restraining relative rotation of the injection plunger (18) with respect to the housing comprises

an at least partially essentially cylindrical guide element (83) formed with an axial opening therein;

interengaging projection-and-recess means (80,

     82) formed at the outside of said elongated stem (18") and at said elongated opening;

means (103,

     104) formed on said guide element and coupling said guide element in rotation-inhibited manner to said housing (82);

and wherein said projecting (104) is formed on said guide element (83) at a side thereof remote from said opening, and fitting into said groove or slot (41), and providing for longitudinal guidance of said guide element within said housing while restraining said guide element from relative rotation with respect to said housing.

16. The device of claim 1, wherein said dosage setting means (56, 65) includes a ratchet means (48, 49;

52, 53, 54;

56,

     55) having a spring (52) which snaps over ratchet teeth (49) of the ratchet means to provide an audible signal upon rotation of said dosage setting means.

17. The device of claim 16, wherein said dosage setting means (56, 65) includes indicating means (57, 66) for visually indicating a selected dosage.

18. The device of claim 1, wherein said user operable dosage setting means comprises a preselection element (56) and positionable with respect to said housing.

19. The device of claim 18, wherein said user operable dosage setting means further includes a setting element (65);

said preselecting element (56) having an abutment means (58), said setting element being settable on said housing and engageable with said abutment means for positioning the setting element in accordance with the setting of the preselecting element and hence the position of said abutment means (58);

and coupling means (98) coupling the setting element with said injection dosing arrangement (18-77) to control the combined length of the injection plunger (18) and the plunger length setting mechanism (77) and hence the dosage to be injected.

20. The device of claim 19, wherein said housing (30, 32) comprises an elongated, essentially cylindrical structure;

and said preselecting element (56) and said setting element (65), each, are ring means coaxial with, and on said housing.

21. The device of claim 1 further including a return spring (29) located within said housing and coupled to said ampule or medication containing container (12) and resiliently biassing said ampule or medication containing container (12) in a distal direction.

22. The device of claim 1, further including a reception sleeve (20) located within the housing and dimensioned and shaped to receive an ampule or medication containing container (12);

and a return spring (29) located within the housing and biassing said reception sleeve (20) in distal direction,

said reception sleeve being movable counter the force of said return spring in proximal direction under force of said injection spring (95).

23. The device of claim 1, wherein said tubular element (77'"'"') having the internal thread is positioned within said housing for relative axial displacement between a predetermined proximal and position and a predetermined distal end position.

24. The device of claim 23, wherein said spring (95) is positioned between an inner wall of the housing and the outside of said tubular element (77'"'"'), and

said spring being stressed or cocked upon shifting of said tubular element (77'"'"') in said predetermined distal end position.

25. Injection device for performing dosed injections, said injection device defining a proximal end and a distal end, and having

a housing (30, 32) for reception of an ampule or medication container (12) retaining a medicinal fluid, and a fluid expelling piston (17) movable in proximal direction within the ampule;

an injection needle (16) engageable with the proximal end of the ampule and movable with the ampule in proximal direction with respect to the housing, in an injecting direction;

an injection plunger (18) engageable against said piston (17);

a plunger length setting mechanism (77) coupled to said plunger and forming with said plunger an injection dosing arrangement (18-77);

a spring (95) coupled to the injection dosing arrangement (18-77);

user operable spring cocking means (100);

user operable spring release means (42,

     104),

said spring (95), after cocking, moving the plunger (18) of the injection dosing arrangement (18-77), upon release by the spring release means (41,

     104) in engagement with said piston (17) to expel medicament fluid from the injection needle (16),

wherein, in accordance with the invention,

the plunger length setting mechanism (18-77) comprises

a tubular element (77'"'"') having an internal thread;

the injection plunger (18) includes an elongated stem (18") having an external thread (76) matching the internal thread of the tubular element (77) and telescopically receivable therein;

a guide element (83) guiding said elongated stem (18"), and interengaging projection-and-recess means (82,

     80) formed on said guide element and said elongated stem, respectively, to prevent relative rotation of the guide element and the plunger (18) while permitting relative axial movement of the guide element and said plunger;

means (103,

     104) for coupling the guide element (83) with the housing (32) of the device while preventing relative rotation of the guide element and the housing; and

user operable setting means (56, 65,

     100) coupled to the tubular element (77'"'"') of the plunger length setting mechanism for causing and controlling relative rotation (106) between said guide element (83) and said plunger length setting mechanism (77) to selectively control and change the overall length of said injection dosing arrangement (18-77) in accordance with the selected injection dosage.

26. The device of claim 25, wherein said user dosage setting means includes a user operable element (100) coupled to said tubular element (77'"'"') of the plunger length setting mechanism (77).

27. The device of claim 25, wherein said guide element is coupled to said plunger length setting mechanism (77) for axial movement with said plunger length setting mechanism while permitting relative rotation of said plunger length setting mechanism and said guide element.

28. The device of claim 25, wherein said internal and external threads within the tubular element (77'"'"') and on the stem (18") of the plunger (18), respectively, are steep-pitch spiral threads.

29. The device of claim 25, wherein said tubular element having the internal thread is positioned within said housing for relative axial displacement between a predetermined proximal end position and a predetermined distal end position.

30. The device of claim 29, wherein said spring (95) is positioned between an inner wall of the housing and the outside said tubular element (77'"'"'), and

said spring being stressed or cocked upon shifting of said tubular element (77'"'"') in said predetermined distal end position.

31. In an injection device for injecting fluid medication from an ampule or container (12) having an ejection piston (17) for injecting the medication through a needle (16) coupled to the container upon axial movement of the piston,

means for moving said piston including an injection dosing arrangement (18-77) of adjustable length,

said injection dosing arrangement having a tubular element (77'"'"') formed with an inner thread, and a plunger means (18) having an elongated stem (18") formed with an external thread (76) matching said internal thread of the tubular element, said plunger means being engageable with the piston (17) in said ampule or container (12),

comprising, in accordance with the invention,

a guide element (83) rotatably coupled to said tubular element;

a groove or slot (80) extending in axial direction formed in said elongated stem (18");

projecting means (82) on said guide element (83) engageable with said groove or slot (80);

interengaging projection-and-recess means (103, 104;

     41) formed on said coupling element (83) and interiorly of a housing (32) of said device to permit relative longitudinal movement of said guide element within the housing while preventing relative rotation of the guide element (83) with respect to the housing (32); and

means (65,

     100) for rotating said internally threaded tubular element (77), whereby, upon rotation of said tubular element, said plunger means (18) will telescopically move into or out of said tubular element while being guided longitudinally within said housing.

32. The device of claim 31, wherein said internal and external threads within the tubular element (77'"'"') and on the stem (18") of the plunger (18), respectively, are steep-pitch spiral threads.

33. The device of claim 31, further including an injection spring (95) operatively coupled to said injection dosing arrangement (18-77) and positioned for resiliently stressing said injection dosing arrangement (18, 77);

latching means for retaining the spring in stressed condition; and

stress release means acting on said latch means to permit relaxation of the stressed spring and thereby moving said injection dosing arrangement (18-77) in injecting direction against said piston (7).

34. The device of claim 33, wherein said injection spring (95) comprises a spiral spring surrounding said tubular element (77'"'"');

and user operable rotary setting means engageable with one end of said spiral spring, rotation of said setting means transferring rotation to said tubular element when rotated in wind-up direction of the spiral spring, but not transferring rotation when rotated in an opposite direction, whereby said spring will have the dual function of a one-way engagement clutch as well as an injection effecting spring for said injection dosing arrangement (18-77).

35. The device of claim 31, wherein said tubular element having the internal thread is positioned within said housing for relative axial displacement between a predetermined proximal end position and a predetermined distal end position.

36. The device of claim 35, wherein said spring (95) is positioned between an inner wall of the housing and the outside said tubular element (77'"'"'), and

said spring being stressed or cocked upon shifting of said tubular element (77'"'"') in said predetermined distal end position.

37. In an injection device for injecting fluid medication from an ampule or container (12) having

a housing for reception of said ampule or container (12);

an ejection piston (17) for ejecting the medication through a needle (16);

means for moving said piston (17) including an axially movable injection dosing arrangement (18, 77'"'"') of adjustable length, said injection dosing arrangement having

a tubular element (77'"'"') formed with an inner thread, and a plunger means (18) having an elongated stem (18") formed with an external thread (76) matching said internal thread of said tubular element (77'"'"'),

said plunger means being engageable with the piston (17) in said ampule or container (12),

comprising, in accordance with the invention,

means (80, 82, 83,

     104) for restraining relative rotation of said plunger means (18) with respect to the housing (30) while permitting axial movement of said plunger means (18) within said housing (30); and

user dosage setting means (56,

     65) to effect relative rotation between said housing (30) and said tubular element (77'"'"') to control the amount of telescopic extension of said plunger means (18) from said tubular element (77'"'"') and hence the overall length of said injection dosing arrangement (18, 77'"'"').

38. The device of claim 37, wherein said internal and external threads within the tubular element (77'"'"') and on the stem (18") of the plunger (18), respectively, are steep-pitch spiral threads.

39. The device of claim 37, further including an injection spring (95) operatively coupled to said injection dosing arrangement (18-77) and positioned for resiliently stressing said injection dosing arrangement (18, 77);

latching means for retaining the spring in stressed condition; and

stress release means acting on said latch means to permit relaxation of the stressed spring and thereby moving said injection dosing arrangement (18-77) in injecting direction against said piston (7).

40. The device of claim 39, wherein said injection spring (95) comprises a spiral spring surrounding said tubular element (77'"'"');

and user operable rotary setting means engageable with one end of said spiral spring, rotation of said setting means transferring rotation to said tubular element when rotated in wind-up direction of the spiral spring, but not transferring rotation when rotated in an opposite direction, whereby said spring will have the dual function of a one-way engagement clutch as well as an injection effecting spring for said injection dosing arrangement (18-77).

41. The device of claim 37, wherein said tubular element (77'"'"') having the internal thread is positioned within said housing for relative axial displacement between a predetermined proximal end position and a predetermined distal end position.

42. The device of claim 41, wherein said spring (95) is positioned between an inner wall of the housing and the outside of said tubular element (77'"'"'), and

said spring being stressed or cocked upon shifting of said tubular element (77'"'"') in said predetermined distal end position.