Injection device

• US 5,480,387 A
• Filed: 08/24/1994
• Issued: 01/02/1996
• Est. Priority Date: 07/24/1991
• Status: Expired due to Fees

• Current Assignee: B D Medico SARL
• Original Assignee: Medico Development Investment Company
• Inventors: Bechtold, Herbert, Gabriel, Jochen
• Primary Examiner(s): Rosenbaum, C. Fred
• Assistant Examiner(s): ELGART, VANITHA M
• Application Number:
  US08/295,143
• Time in Patent Office: 496 Days
• Field of Search: 604/187, 604/206-211, 604/218, 604/199, 604/117, 604/232, 604/131, 604/134, 604/135, 604/136, 604/220, 604/191, 604/68, 604/71, 604/72, 604/137, 604/138, 604/139 , 604/156, 604/157, 604/188
• US Class Current: 604/134
• CPC Class Codes: A61M 2005/202 cocking means, e.g. to bias the main drive spring of an injector
• CPC Class Codes: A61M 2005/3131 specially adapted for improving sealing or sliding
• CPC Class Codes: A61M 2205/581 by audible 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 5/24 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 5/31535 Means improving security or handling thereof, e.g. blocking means, means preventing insufficient dosing, means allowing correction of overset dose
• CPC Class Codes: A61M 5/31553 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 5/46 having means for controlling depth of insertion

Abstract

An injection device (10) is adapted to receive a cartridge (11) holding injection fluid (12). This cartridge (11) is displaceable in the proximal direction in the injection device counter to the force of a resetting spring (157). An adjustable-length tappet (80) is biased in the proximal direction by a spring (53), is displaceable in the injection device between a proximal end position and a distal end position, and has a threaded spindle (19) which is guided in the thread (17) of an adjusting member (15), serves to act upon a plunger (23) provided in the cartridge (11), and has a guide member (67) associated with it; the guide member is connected to it in a manner fixed against relative rotation but axially freely displaceably. This guide member (67) is rotatable relative to the housing (100) of the injection device (10) in the distal end position of the tappet (80), but not in the proximal end position thereof.

Claims

1. For combination with

a liquid-containing cartridge (11), wherein the cartridge has a plunger (23) displaceably located therein,

an injection device for injecting a selected dose of a fluid from the cartridge into a subject, when the injection device is located proximally with respect to the subject,

wherein the injection device comprises

a housing (100) dimensioned to receive the cartridge (11);

an adjustable-length tappet (80) which is axially displaceable relative to said housing (100) between a proximal end position and a distal end position thereof, including

a dose-adjusting member (15) located within the housing (100) and having a thread (17), and

a threaded spindle (19) guided in the thread (17) of said dose-adjusting member (15), said threaded spindle (19) being axially aligned with said plunger (23) in said cartridge (11) for acting on said plunger when the cartridge is positioned in the injection device;

a spring means (53) having two ends, which ends are coupled, respectively, to said housing (100) and to said tappet (80) for axially biassing said dose-adjusting member (15) in a proximal direction;

a guide member (67) located in the housing (100), axially slidably located on said threaded spindle (19), and secured against rotation relative to said threaded spindle (19);

rotation-disabling means (92,

     93) for disabling rotation of said guide member (67) relative to said housing (100) when said tappet (80) is in the proximal end position thereof while permitting rotation of the guide member (67) in the distal end position of said guide member (67); and

retaining means (42,

     118) for retaining said dose-adjusting member (15) in a rotational position, selected by a user when setting the dose to be injected by rotating said dose-adjusting member (15) in a setting direction (190), and

wherein said retaining means (42,

     118) is enabled when said tappet (80) is in its distal end position, and is disabled when said tappet (80) is in its proximal end position.

2. The injection device of claim 1, wherein the spring means comprises a spring (53) located between said housing (100) and said dose-adjusting member (15), the biassing force of said spring being variable by rotation of said dose-adjusting member (15);

and

wherein said retaining means (42,

     118), when in the distal end position of said dose-adjusting member (15), permits rotation of said dose-adjusting member (15) relative to said housing (100) only in a predetermined rotational direction and blocks such rotation in the opposite rotational direction.

3. The injection device of claim 2, wherein said dose-adjusting member (15), when in the distal end position, is adjustable by rotation of said dose-adjusting member in a dose-setting direction, beginning at a predetermined rotary position,

wherein said predetermined rotary position acts as a stop at the proximal end position of said dose-adjusting member (15) to limit rotation thereof counter to said dose-setting direction.

4. The injection device of claim 2, wherein said retaining means (42, 118) comprises a pawl (118) and ratchet teeth (42), both disposed between said dose-adjusting member (15) and said housing,

said pawl (118) engaging said ratchet teeth in the distal end portion of the tappet (80).

5. The injection device of claim 2, wherein said retaining means (42, 118) forms a block with respect to rotation of said dose-adjusting member (115) in said opposite rotational direction upon movement of said dose adjusting member (15) from its distal end position to its proximal end position, at least while said guide member (67) is freely rotatable relative to the housing.

6. The injection device of claim 1, further including at least one elastically deformable element (63, 64) located between the guide member (67) and said dose-adjusting member (15);

and

wherein said at least one elastically deformable element is positively coupled to at least one of;

said guide member (67) and said dose-adjusting member (15).

7. The injection device of claim 1, wherein the guide member (16) is provided with at least one engagement element (72), which engagement element, in the proximal end position of said dose-adjusting member (15), is in engagement with at least one further engagement element (93) of the injection device, said further engagement element being substantially complementary with said at least one engagement element (72) and is structurally connected to the housing.

8. The injection device of claim 7, wherein the engagement element (72) of the guide member (67) comprises a first set of longitudinally extending teeth (72);

said at least one further engagement element (93) comprises a corresponding second set of longitudinally extending teeth (93), said second set of teeth (93) being structurally connected to the housing (100) and operatively associated with said first set of teeth for engagement with said first set of teeth at least in the proximal end position of said dose-adjusting member (15).

9. The injection device of claim 8, wherein said retaining means comprises a pawl (118) and ratchet teeth (42),

said retaining means being arranged between said housing (100) and said dose-adjusting member (15),

said pawl (118) engaging said ratchet teeth (42) in the distal end position of said dose-adjusting member;

and

wherein the first set of said longitudinally extending teeth (72) has a tooth pitch angle (α

) compatible with said ratchet teeth (42).

10. The injection device of claim 9, wherein the tooth pitch of the ratchet teeth (42) and the tooth pitch of the first set of longitudinally extending teeth (72) have respective values such that the larger value can be divided integrally by a smaller value.

11. The injection device of claim 9, wherein the teeth of the first set of longitudinally extending teeth (72) are angularly aligned with said retaining means to permit, upon movement of said dose-adjusting member (15) from its distal end position to its proximal end position, substantially rotation-free linear motion of the dose-adjusting member (15) and of the guide member (67).

12. The injection device of claim 1, wherein the threaded spindle (19) is made of plastic material and has longitudinal grooves (29, 30) formed thereon, disposed symmetrically with respect to one another;

and

wherein the guide member (67) includes a guide element (69) in engagement with at least one of said longitudinal grooves (29,

     30).

13. The injection device of claim 1, wherein the threaded spindle (19) is subdivided longitudinally into two visually distinguishable regions (24, 25).

14. The injection device of claim 13, wherein one region (25) of the threaded spindle is colored.

15. The injection device of claim 1, wherein the guide member is positioned for direct contact with at least one of said cartridge (11) and a cartridge holder (148, 162) receiving the cartridge;

and

wherein said guide member (67) guides at least one of the cartridge (11) or the cartridge holder (148,

     162) for proximal movement during an injection process, to thereby move said cartridge or said cartridge holder, respectively, in proximal direction.

16. The injection device of claim 1, further including an actuation device (38) located outside of said housing (100);

and

wherein said dose-adjusting member (15) is coupled to said actuation device (38) for movement, by said actuation device, of said dose-adjusting member from its proximal end position to its distal end position, for tensioning said spring means (53), and for preselecting a desired injection dose when said dose-adjusting member (15) is in the distal end position.

17. The injection device of claim 16, further including a releasable detent device (59, 104), couple with said dose-adjusting member (15) for locking said dose-adjusting member (15) into place when said dose-adjusting member is in the distal end position.

18. An injection device for injecting fluid into a subject, comprising

a housing (100);

at least one of a cartridge holder (148,

     162) and a liquid-containing cartridge (11) axially movable with said housing,

said liquid-containing cartridge having a proximal end portion shaped and dimensioned to receive an injection needle (74) coupled thereto;

spring means (53), for storing energy needed to perform an injection, located in said housing (100), said spring means having one end portion thereof operatively coupled to one of said cartridge and said cartridge holder, and another end portion connected to said housing (100);

retaining means for retaining said spring means (53) in an energy-storing position;

injection-starting means for starting an injection,

said injection-starting means including

first means for releasing, after start of an injection, a first portion of the energy stored in said spring means, and for transferring said released energy to at least one of said cartridge and said cartridge holder, for moving at least one of said cartridge and said cartridge holder, and the injection needle (74) coupled to said cartridge, in a subject-proximal direction without pressing liquid out of the cartridge; and

second means for subsequently releasing a second portion of the energy stored in said spring means (53) when a predetermined axial position, with respect to said housing, of at least one of said cartridge and said cartridge holder is reached during said movement of at least one of said cartridge and said cartridge holder in the subject-proximal direction for then pressing liquid out of said cartridge and through the injection needle coupled to said cartridge.

19. The injection device of claim 18, wherein said spring means (53) is a coil spring (53) which stores a portion of its energy by axial compression, and another portion of the energy by torsional stressing.

20. The injection device of claim 19, wherein said first portion of the energy stored in said coil spring (53) and released to move at least one of said cartridge and said cartridge holder and said needle coupled to said cartridge (11) comprises energy stored in said coil spring by axial compression;

and

wherein said second part of the energy stored in said coil spring (53) and released during injection of liquid out of said cartridge (11) comprises energy stored by torsional stressing.

21. The injection device of claim 18, wherein said device further comprises a dose-adjusting member (15) axially movable within said housing (100) between two end positions, and formed with an internal thread;

a threaded spindle (19) guided in the thread (17) of said dose-adjusting member (15);

and wherein

said first means for releasing a first portion of the energy includes

means for converting the first portion of the energy stored in said spring means into subject-proximal movement of said dose-adjusting member (15), and

means for transferring said proximal movement to at least one of the cartridge and the cartridge holder for moving at least one of the cartridge and the cartridge holder in subject-proximal direction; and

wherein said second means includes means enabled by said proximal movement of the at least one of the cartridge and the cartridge holder for converting said second portion of the energy stored in said second portion of the energy stored in said spring means (53) into rotation of said dose-adjusting member relative to said threaded spindle, said threaded spindle pressing liquid out of said cartridge (11) loaded by axial movement of said threaded spindle.

22. The injection device of claim 21, further including rotation-disabling means coupled to said threaded spindle, for disabling rotation of said threaded spindle relative to said housing when said dose-adjusting member is in a subject-proximal end position.

23. The injection device of claim 21, further including rotation-enabling means coupled to said threaded spindle to enable rotation of said threaded spindle relative to said housing when said dose-adjusting member is in a subject remote or distal end position.