(19)
(11)EP 2 654 842 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
02.10.2019 Bulletin 2019/40

(21)Application number: 11804559.0

(22)Date of filing:  21.12.2011
(51)International Patent Classification (IPC): 
A61M 5/315(2006.01)
A61M 5/20(2006.01)
A61M 5/32(2006.01)
(86)International application number:
PCT/EP2011/073508
(87)International publication number:
WO 2012/085027 (28.06.2012 Gazette  2012/26)

(54)

AUTO-INJECTOR

AUTOMATISCHER INJEKTOR

INJECTEUR AUTOMATIQUE


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 21.12.2010 EP 10196073
13.01.2011 US 201161432241 P

(43)Date of publication of application:
30.10.2013 Bulletin 2013/44

(73)Proprietor: Sanofi-Aventis Deutschland GmbH
65929 Frankfurt am Main (DE)

(72)Inventors:
  • KEMP, Thomas Mark
    Ashwell Hertfordshire SG7 5NW (GB)
  • BARROW-WILLIAMS, Timothy Donald
    St. Albans Hertfordshire AL3 5NA (GB)
  • EKMAN, Matthew
    Macclesfield Cheshire SK10 1RD (GB)

(74)Representative: Finger, Catrin et al
Liedtke & Partner Patentanwälte Gerhart-Hauptmann-Strasse 10/11
99096 Erfurt
99096 Erfurt (DE)


(56)References cited: : 
WO-A1-2009/007305
WO-A2-2009/098502
US-A1- 2002 095 120
WO-A1-2009/062508
US-A- 2 605 766
US-A1- 2007 112 310
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    Technical Field



    [0001] The invention relates to an auto-injector for administering a dose of a liquid medicament.

    Background of the Invention



    [0002] Administering an injection is a process which presents a number of risks and challenges for users and healthcare professionals, both mental and physical.

    [0003] Injection devices (i.e. devices capable of delivering medicaments from a medication container) typically fall into two categories - manual devices and auto-injectors.

    [0004] In a manual device - the user must provide the mechanical energy to drive the fluid through the needle. This is typically done by some form of button / plunger that has to be continuously pressed by the user during the injection. There are numerous disadvantages to the user from this approach. If the user stops pressing the button / plunger then the injection will also stop. This means that the user can deliver an underdose if the device is not used properly (i.e. the plunger is not fully pressed to its end position). Injection forces may be too high for the user, in particular if the patient is elderly or has dexterity problems.

    [0005] The extension of the button/plunger may be too great. Thus it can be inconvenient for the user to reach a fully extended button. The combination of injection force and button extension can cause trembling / shaking of the hand which in turn increases discomfort as the inserted needle moves.

    [0006] Auto-injector devices aim to make self-administration of injected therapies easier for patients. Current therapies delivered by means of self-administered injections include drugs for diabetes (both insulin and newer GLP-1 class drugs), migraine, hormone therapies, anticoagulants etc.

    [0007] Auto-injectors are devices which completely or partially replace activities involved in parenteral drug delivery from standard syringes. These activities may include removal of a protective syringe cap, insertion of a needle into a patient's skin, injection of the medicament, removal of the needle, shielding of the needle and preventing reuse of the device. This overcomes many of the disadvantages of manual devices. Injection forces / button extension, hand-shaking and the likelihood of delivering an incomplete dose are reduced. Triggering may be performed by numerous means, for example a trigger button or the action of the needle reaching its injection depth. In some devices the energy to deliver the fluid is provided by a spring.

    [0008] US 2002/0095120 A1 discloses an automatic injection device which automatically injects a pre-measured quantity of fluid medicine when a tension spring is released. The tension spring moves an ampoule and the injection needle from a storage position to a deployed position when it is released. The content of the ampoule is thereafter expelled by the tension spring forcing a piston forward inside the ampoule. After the fluid medicine has been injected, torsion stored in the tension spring is released and the injection needle is automatically retracted back to its original storage position.

    [0009] WO 2009/098502 A2 discloses an autoinjector device comprising a drive housing and a syringe housing which can be disconnected to allow insertion of a syringe. A drive mechanism in the drive housing is cocked by means of a cord connected between the drive housing and the syringe housing. The drive mechanism comprises a drive gear rotatably mounted in the drive housing and acting as a rotary crank connected by a connecting rod to a plunger. In use the drive gear is driven by a torsion spring so that the drive mechanism extends the syringe from the syringe housing and expels a dose and then retracts the syringe back into the housing. A firing button releases the drive gear to be driven by the torsion spring but is also engageable as a brake on the rim of the drive gear.

    [0010] WO 2009/007305 A1 discloses an automatic injection device adapted to automatically eject a dose of a medicament by automatically inserting a needle into the skin of a user, ejecting a dose of a medicament through the needle, and subsequently retracting the needle into a housing of the device.

    Summary of the Invention



    [0011] It is an object of the present invention to provide an improved auto-injector.

    [0012] The object is achieved by an auto-injector according to claim 1.

    [0013] Preferred embodiments of the invention are given in the dependent claims.

    [0014] In the context of this specification the term proximal refers to the direction pointing towards the patient during an injection while the term distal refers to the opposite direction pointing away from the patient.

    [0015] An auto-injector for administering a dose of a liquid medicament according to the invention comprises:
    • an elongate housing arranged to contain a syringe with a hollow needle and a stopper for sealing the syringe and displacing the medicament, the elongate housing having a distal end and a proximal end with an orifice intended to be applied against an injection site, wherein the syringe is slidably arranged with respect to the housing,
    • spring means capable of, upon activation, pushing the needle from a covered position inside the housing into an advanced position through the orifice and past the proximal end, operating the syringe to supply the dose of medicament, and covering the needle on removal of the auto-injector from the injection site,
    • activating means arranged to lock the spring means in a pressurized state prior to manual operation and capable of, upon manual operation, releasing the spring means for injection.


    [0016] According to the invention the spring means is a single torsion spring.

    [0017] According to the invention a first gear arrangement and a second gear arrangement are arranged for respectively converting torque from a first end and a second end of the torsion spring into a translative force. The first end is arranged to be groundable in the housing while the second end is configured to act on a plunger through the second gear arrangement for advancing the needle and supplying the dose. The activating means is arranged to block or release the second gear arrangement. When the second gear arrangement is blocked by the activating means the torque from the second end of the torsion spring is also statically resolved in the housing. The first end is releasable from the ground in the housing for causing a translation through the first gear arrangement resulting in the needle getting covered.

    [0018] This translation may be a needle retraction or preferably the advancement of a needle shroud over the needle.

    [0019] The single torsion spring is used for both, inserting the needle and fully emptying the syringe. A major advantage of the torsion spring with gear arrangements is that force is exerted on the stopper and syringe in a smooth manner, whereas a conventional compression spring exhibits a rather abrupt force deployment which may spoil a glass syringe or other parts of the auto-injector.

    [0020] The needle shroud may be arranged in the housing surrounding the syringe and translatable in longitudinal direction, wherein the needle shroud is coupled to the first gear arrangement in a manner to be translated in proximal direction over the advanced needle on release of the first end from the ground in the housing.

    [0021] The torque required to advance the needle shroud may be configured to be less than the torque required to advance the plunger and the stopper. This allows for triggering the shroud advancement at any point during injection without having to ground the second end of the torsion spring in the housing while injection is immediately stopped.

    [0022] According to the invention, the first gear arrangement and the second gear arrangement respectively comprise a first gear member coupled to the respective end of the torsion spring, wherein the first gear member is engaged through a screw thread to a respective second gear member arranged to translate on rotation of the first gear member.

    [0023] The needle shroud may be arranged to be in an initial position protruding from the proximal end of the housing in an initial state interlocked to the activating means for preventing manual operation. The needle shroud may be arranged to be translated in distal direction into the housing into a distal position against the load of a shroud spring when pushed against the injection site. The needle shroud is rotationally fixed to the housing and to the second gear member of the first gear arrangement. In the distal position the needle shroud is arranged to rotationally fix the first gear member to the second gear member of the first gear arrangement and to allow operation of the activating means. The needle shroud is thus used as a skin interlock means requiring a sequence of operation in order to increase needle safety. Furthermore, the needle shroud serves for blocking the first gear arrangement as long as it is maintained pressed against the injection site. When removed from the skin, the needle shroud returns into the initial position under load of the shroud spring thereby releasing the first gear arrangement for advancing the needle shroud further.

    [0024] The activating means may be arranged to be in a splined engagement with the first gear member of the first gear arrangement in the initial state so as to rotationally fix it to the housing, wherein the activating means is arranged to remove this splined engagement on manual operation. This ensures that the first end of the torsion spring is grounded in the housing prior to injection. The activating means cannot be operated before the needle shroud has been depressed. On depression of the needle shroud the already grounded first end of the torsion spring becomes further grounded in the housing through the first gear arrangement. Operating the activating means removes only one of these grounds. This ensures that the needle shroud is only advanced over the needle when the needle shroud is allowed to return to the initial position on removal from the injection site after an injection has been triggered.

    [0025] A clip arrangement may be provided comprising at least one resilient chassis clip attached to the housing. The chassis clip may be engageable proximally behind a shoulder in the plunger in a manner to prevent translation of the plunger in proximal direction. The shoulder may be arranged to flex the chassis clip outwards due to ramped engagement under force in proximal direction applied to the plunger from the second end of the torsion spring through the second gear arrangement. The activation means may comprise an end trigger button arranged at the distal end translatable between a distal position and a proximal position. At least one trigger beam may be arranged on the trigger button in a manner to outwardly support the chassis clip to prevent it from being outwardly deflected when the end trigger button is in the distal position. The trigger beam is arranged to be repositioned on translation of the end trigger button into the proximal position, i.e. depression in a manner to allow outward deflection of the chassis clip thus releasing the plunger for needle insertion and injection. The end trigger button may protrude from the distal end in a manner to be accessible for operation.

    [0026] At least one flexible first beam element may be arranged on the housing, the flexible first beam element arranged to obstruct the path of the end trigger button so as to prevent its depression. A second beam element is arranged on the needle shroud in a manner to deflect the flexible first beam element out of the path of the end trigger button on depression of the needle shroud. This embodiment requires the user to first depress the needle shroud before the end trigger button can be translated.

    [0027] In another embodiment a rib may be arranged in the housing in a manner to obstruct the path of a resilient part of the end trigger button so as to prevent depression of the end trigger button. A lateral trigger button may be laterally arranged on the housing arranged to inwardly deflect the resilient part of the end trigger button in a manner to bypass the rib thus allowing depression of the end trigger button. The needle shroud may be arranged to inwardly support the resilient part of the end trigger button when in the initial position so as to prevent deflection. The inward support of the resilient part of the end trigger button is arranged to be removed on translation of the needle shroud into the distal position. The end trigger button is biased in proximal direction against the housing by a trigger spring. In this embodiment the end trigger button may be hidden inside the distal end so only the lateral trigger button is operated by the user.

    [0028] In yet another embodiment a wrap over sleeve trigger may be arranged over the distal end. The sleeve trigger is translatable in longitudinal direction between a distal position and a proximal position and has at least one locking feature engageable with a respective mating part on the needle shroud in the initial position so as to prevent depression of the sleeve trigger from the distal position into the proximal position. The mating part is arranged to be inwardly withdrawn by a cam feature on translation of the needle shroud into the distal position so as to allow the sleeve trigger to be depressed. The end trigger button exhibits at least one latch feature arranged to abut against a respective stop in the housing so as to prevent depression of the end trigger button. At least one latch actuation boss on the sleeve trigger is arranged to inwardly deflect the latch feature disengaging it from the stop. The end trigger button is biased in proximal direction against the housing by a trigger spring. A wrap over sleeve trigger may ease operation for users with reduced dexterity.

    [0029] The trigger spring and the shroud spring are specified to balance each other's load. I.e. the relative strength of the shroud spring and the trigger spring are arranged such that when the auto-injector is pressed against the injection site the shroud will always move first thereby giving a two step feel to the operation.

    [0030] The screw thread of the first gear arrangement may end with a pitch of zero on its proximal end allowing remaining torque in the torsion spring to be released when the second gear member reaches the zero pitch.

    [0031] A method for operating the auto-injector comprises the steps of:
    • grounding the first end of the torsion spring in the housing and blocking the second gear arrangement in an initial state prior to manual operation of the activating means,
    • releasing the second gear arrangement on manual operation of the activating means so as to translate the plunger in proximal direction for advancing the needle and supplying a dose of medicament from the syringe under torque from the second end of the torsion spring,
    • releasing the first end from the ground in the housing for causing a translation through the first gear arrangement under torque from the first end resulting in the needle getting covered.


    [0032] The first gear arrangement may translate the needle shroud in proximal direction over the advanced needle on release of the first end from the ground in the housing.

    [0033] The needle shroud may be held in an initial position protruding from the proximal end of the housing in the initial state, wherein the needle shroud is interlocked to the activating means for preventing manual operation in the initial state, wherein the needle shroud is translated in distal direction into the housing into a distal position against the load of a shroud spring when pushed against the injection site. The needle shroud is rotationally fixed to the housing and to the second gear member of the first gear arrangement. In the distal position the needle shroud rotationally fixes a first gear member to the second gear member of the first gear arrangement and releases the interlock so as to allow operation of the activating means.

    [0034] The housing may have at least one viewing window for inspecting the syringe.

    [0035] The auto-injector may preferably be used for subcutaneous or intra-muscular injection, particularly for delivering one of an analgetic, an anticoagulant, insulin, an insulin derivate, heparin, Lovenox, a vaccine, a growth hormone, a peptide hormone, a protein, antibodies and complex carbohydrates.

    [0036] Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the scope of the invention as defined by the appended claims will become apparent to those skilled in the art from this detailed description.

    Brief Description of the Drawings



    [0037] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:
    Figure 1
    is an isometric partial section of an auto-injector,
    Figure 2
    shows longitudinal sections of the auto-injector in an initial state,
    Figure 3
    is a longitudinal section of the auto-injector after removal of a protective needle shroud,
    Figure 4
    is a detail view of a distal end of the auto-injector with a trigger button in the situation as in figure 3,
    Figure 5
    is a detail view of the trigger button with an interlock feature to a needle shroud in the situation as in figure 3,
    Figure 6
    is a longitudinal section of the auto-injector after depression of the needle shroud,
    Figure 7
    is an isometric detail view of a shroud follower locked in rotation to a shroud lead screw by depression of the needle shroud,
    Figure 8
    is an isometric detail view of the interlock feature of figure 5 disengaged by depression of the needle shroud,
    Figure 9
    is a longitudinal section of the detail view of figure 8,
    Figure 10
    is a longitudinal section of the auto-injector after depression of the trigger button,
    Figure 11
    is an isometric detail view of the trigger button prior to depression of the trigger button,
    Figure 12
    is an isometric detail view of the trigger button after depression of the trigger button,
    Figure 13
    is another isometric detail view of the trigger button after depression of the trigger button,
    Figure 14
    is another isometric detail view of the trigger button prior to depression of the trigger button,
    Figure 15
    is yet another isometric detail view of the trigger button after depression of the trigger button,
    Figure 16
    is the auto-injector with a syringe advanced for needle insertion,
    Figure 17
    is the auto-injector with the emptied syringe,
    Figure 18
    is the auto-injector on removal from the injection site after the syringe has been emptied,
    Figure 19
    is a detail view in the situation as in figure 18 with the shroud lead screw released for rotation,
    Figure 20
    is the auto-injector with the needle shroud fully advanced for post injection needle safety,
    Figure 21
    is a detail view of the shroud lead screw in the situation as in figure 20,
    Figure 22
    is a detail view of the needle shroud locked in the position as in figure 20,
    Figure 23
    is the auto-injector on removal from the injection site before the syringe has been emptied,
    Figure 24
    is the auto-injector with the needle shroud fully advanced for post injection needle safety after delivery of a partial dose,
    Figure 25
    is an alternative embodiment of the auto-injector with a lateral trigger button,
    Figure 26
    is a detail view of an interlock mechanism between the lateral trigger button, the needle shroud and the end trigger button with the needle shroud depressed,
    Figure 27
    is a detail view of the interlock mechanism with the lateral trigger button depressed and the end trigger button released,
    Figure 28
    is a detail view of the interlock mechanism with the end trigger button translated in proximal direction for releasing the plunger,
    Figure 29
    is an alternative embodiment of the auto-injector with a wrap over sleeve trigger,
    Figure 30
    is a detail view of an interlock mechanism between the sleeve trigger, the needle shroud and the end trigger button during an attempt to translate the sleeve trigger in proximal direction without prior depression of the needle shroud,
    Figure 31
    is a detail view of locking features of the interlock mechanism, and
    Figure 32
    is a sectional detail view of the locking features of the interlock mechanism.


    [0038] Corresponding parts are marked with the same reference symbols in all figures. Detailed Description of Preferred Embodiments

    [0039] Figure 1 shows an isometric partial section of an auto-injector 1 with an elongate housing 2 and a needle shroud 3 for protecting a needle (not shown). A trigger button 4 arranged at a distal end D of the auto-injector 1 may be depressed in a proximal direction P in order to trigger an automatic injection. The trigger button 4 is interlocked with the needle shroud 3 so it cannot be pressed until the needle shroud 3 is pushed into the housing 2 by placing it on an injection site, e.g. a patient's skin and applying pressure. The needle shroud 3 has longitudinal splines 5 engaged in corresponding grooves in the housing 2 for preventing relative rotation of the needle shroud 3 with respect to the housing 2.

    [0040] Figures 2a and 2b are longitudinal sections of the auto-injector 1 in different section planes approximately 90° offset from each other. The auto-injector 1 is in an initial state prior to use. A syringe 7 is partially surrounded and supported at a front end by a syringe carrier 8. Attached at the front end of the syringe 7 is a hollow injection needle 19 for piercing a patient's skin and delivering a liquid medicament stored inside the syringe 7 (syringe and needle are not shown in figure 2b for clarity). Near the distal end of the syringe 7 a stopper 10 is arranged for sealing and containing the medicament. The stopper 10 may be advanced by a plunger 11 in order to expel the medicament M from the syringe 7. The syringe carrier 8 is slidably arranged inside the needle shroud 3. The needle shroud 3 is biased towards a proximal end P by a shroud spring 12 in the shape of an integral compliant polymer beam element integrally moulded with the needle shroud 3 and acting against a first rib 2.1 in the housing 2. The shroud spring 12 could likewise be of a different type, e.g. a compression spring.

    [0041] The plunger 11 exhibits an external plunger lead screw 11.1 and is rotationally fixed to the housing 2 by a torque reaction rod 21 arranged in an axial bore of the plunger 11. The axial bore and the torque reaction rod 21 both have a non-circular profile in order to keep the plunger 11 from rotating, e.g. a square profile or a profile with at least one spline or flat. The torque reaction rod 21 is attached to the housing 2 at the distal end D of the auto-injector 1 through a framework in a distal end cap 22 in such a manner that the torque reaction rod 21 is prevented from rotating relative to the housing 2.

    [0042] The plunger 11 is arranged inside a tubular plunger follower 15, which is engaged to the plunger lead screw 11.1 by at least one ball bearing (not illustrated). The plunger follower 15 is arranged inside a torsion spring 14 which in turn is arranged inside a tubular shroud lead screw 13 with an external shroud lead screw thread 13.1. A tubular shroud follower 9 is arranged around the shroud lead screw 13 and inside a distal part of the needle shroud 3. The shroud follower 9 is engaged to the shroud lead screw 13 by at least one ball bearing (not illustrated).

    [0043] The extension of the needle shroud 3 from the proximal end P is limited by engagement of a pin 9.2 on the shroud follower 9 in a slot hole 3.3 in the needle shroud 3. This engagement also fixes the shroud follower 9 rotationally to the needle shroud 3. The shroud follower 9 is axially fixed to the tubular shroud lead screw 13 by the ball bearing.

    [0044] Axial translation of the shroud lead screw 13 in the proximal direction P is prevented by an external lip 13.4 on the distal end of the shroud lead screw 13 abutting against a step 2.8 in the housing 2. Axial translation of the shroud lead screw 13 in the distal direction D is prevented by an internal flange 13.5 distally bearing against the proximal end of the plunger follower 15. The plunger follower 15 is axially fixed to the housing 2 at its distal end. In the initial state, rotation of the shroud lead screw 13 is prevented by splined engagement with the trigger button 4 (see figure 4). For this purpose the trigger button 4 has an inward boss 4.3 engaged between circumferential outward bosses 13.3 on the shroud lead screw 13.

    [0045] The torque from the proximal end 14.1 of the torsion spring 14 is resolved into the shroud lead screw 13. The torque from the distal end 14.2 is resolved into the plunger follower 15. The torque from the plunger follower 15 is coupled through the ball bearing into an axial force in the plunger 11. In the initial state, axial loads within the plunger 11 are resolved through into the housing 2 by means of a chassis clip arrangement at the distal end D. The chassis clip arrangement comprises two resilient chassis clips 16 fixed to the housing 2. The chassis clips 16 are engaged proximally behind a shoulder 11.2 in the plunger 11 in a manner to prevent translation of the plunger 11 in proximal direction P. Due to ramped engagement the shoulder 11.2 is trying to flex the chassis clips 16 outwards which is prevented by two trigger beams 4.1 on the trigger button 4 respectively arranged between an outward pin on the chassis clip 16 and a rigid support beam 17.

    [0046] The trigger button 4 is locked in a distal position in the initial state to prevent unintended activation of the auto-injector 1. Flexible first beam elements 2.2 integrally moulded with the housing 2 obstruct the motion of the trigger button 4 if attempts are made to depress it (see figures 5, 8). The first beam elements 2.2 are deflected out of the path of the trigger button 4 by a second beam element 3.1 on the needle shroud 3 on axial movement of the needle shroud 3 within the housing 2 (see figures 8, 9) in distal direction D. This is achieved when the proximal end P is pressed against the injection site.

    [0047] In the as delivered initial state a protective needle shield 18 is arranged on the injection needle 19.

    [0048] A sequence of operation is as follows:
    The user removes the protective needle shield 18 from the needle 19. This can be achieved by a device cap engaged with the needle (not illustrated). The needle 19 is a safe distance back within the needle shroud 3 to protect the user from accidental needle stick injuries (see figure 3).

    [0049] The user places and pushes the proximal end P of the auto-injector 1 on the injection site, e.g. a patient's skin. The needle shroud 3 moves in distal direction D into the housing 2 by a small distance (see figure 6). Due to the slot hole 3.3 this translation does not translate the shroud follower 9. The translating second beam element 3.1 flexes the first beam elements 2.2 outwards thus clearing the path for the trigger button 4 and releasing the aforementioned interlock (see figures 8, 9). The moulded shroud spring 12 opposes this motion but is specified such that its spring rate and preload are low enough for this to feel natural. A resilient third beam element 3.2 on the needle shroud 3 is deflected inwards by contact with a ramped second rib 2.3 on the housing 2 on translation of the needle shroud 3. The third beam element 3.2 deflects a fourth beam element 9.1 on the shroud follower 9 into a spline 13.2 on the shroud lead screw 13 (see figures 4, 7).

    [0050] As the shroud follower 9 is rotationally fixed to the housing 2 through its engagement with the needle shroud 3, the fourth beam element 9.1 provides further grounding of the shroud lead screw 13 to the housing 2. As detailed above, the shroud lead screw 13 is already grounded to the housing 2 through a splined engagement with the trigger button 4.

    [0051] When ready to do so, the user depresses the trigger button 4, translating it in proximal direction P (see figures 10, 12, 13, 15). The trigger beams 4.1 on the trigger button 4 are translated with the trigger button 4 in a manner to allow the outward pin 16.1 to enter an aperture 4.2 in the trigger beam 4.1 by the chassis clip 16 being flexed outwards due to ramped engagement with the shoulder 11.2 under the force pulling the plunger 11 in proximal direction P.

    [0052] The plunger 11 moves in proximal direction P towards the stopper 10 driven by rotation of the plunger follower 15. As stated, the plunger 11 is prevented from rotating by the torque reaction rod 21 down its centre. This could be achieved with one or more splines, flats or by using a square shaft as shown in this embodiment. One or more ball bearings provide a low friction contact between the plunger follower 15 and the plunger lead screw 11.1. Depression of the trigger button 4 also removes the splined engagement of the trigger button 4 from the shroud lead screw 13 by translating the inward boss 4.3 out of engagement with the circumferential outward bosses 13.3 (see figure 15). Now, the shroud lead screw 13 is grounded to the housing 2 through the shroud follower 9 only. This means at any point from now, a shroud extension mechanism described below would be triggered if the auto-injector 1 is removed from the injection site, thereby ensuring the needle 19 is covered. The trigger button 4 is locked in a fully depressed position by snaps 4.4 acting against the housing 2 (see figures 13 and 15).

    [0053] The plunger 11 drives the syringe 7 forward by pushing on the stopper 10 thus inserting the needle 19 into the injection site. The subcutaneous injection depth is set by a rear flange 8.1 on the syringe carrier 8 contacting a stop 2.4 in the housing 2 (see figure 16).

    [0054] When the injection depth has been reached the stopper 10 is driven forwards in proximal direction P within the syringe 7, injecting the dose of medicament M. The stopper 10 continues to move until it reaches the end of the syringe 7 thereby fully emptying the syringe 7. This would require the user to hold the auto-injector 1 in place for a sufficient period of time. In this embodiment, the user is asked to keep pressure on the injection site for a short period of time (e.g. approximately 10 seconds), which can be communicated to the user through user instructions. Other options would be observance of moving components within the auto-injector 1, or an audible ratchet detecting movement of the plunger 11.

    [0055] After confirmation that the full dose has been delivered, the user withdraws the auto-injector 1 from the injection site. With withdrawal, the needle 19 is extracted from the skin, and the needle shroud 3 extends under the force of the shroud spring 12 (see figure 18). The third beam element 3.2 is translated back in proximal direction P thus no longer deflecting the fourth beam element 9.1 inwards. Hence the fourth beam element 9.1 flexes outwards again and disengages the shroud follower 9 from the shroud lead screw 13. Therefore torque within the shroud lead screw 13 is no longer resolved through to the housing 2 (see figure19). With the grounding to the housing 2 removed, the torque is now resolved through the ball bearing interface to an axial force on the shroud follower 9. Further movement of the plunger 11 in the proximal direction P is not possible in this situation, so when the shroud follower 9 is released it moves in the proximal direction P pushing the needle shroud 3 further out of the proximal end P of the housing 2 thus completely covering the needle 19 (see figure 20). The shroud lead screw thread 13.1 ends with a pitch of zero on the proximal end allowing any remaining torque in the torsion spring 14 to be released (see figure 21). This makes the auto-injector 1 tamper proof post injection, e.g. if the user tries to dismantle the auto-injector 1.

    [0056] The needle shroud 3 is locked in this extended position by snaps 2.5 within the case 2 (see figure 22).

    [0057] Figure 23 illustrates removal from skin mid injection with the syringe 7 only partially emptied. As the shroud follower 9 disengages from the shroud lead screw 13, the torque within the shroud lead screw 13 is no longer resolved through to the housing 2 but through the ball bearing interface to an axial force on the shroud follower 9. Although the torque from the distal end 14.2 of the torsion spring 14 is still resolved through the plunger 11, the torque required to extend the needle shroud 3 is less than the torque required to forward the plunger 11, hence the distal end 14.2 becomes ground.

    [0058] Figure 24 shows the auto-injector 1 with the needle shroud 3 fully advanced for post injection needle safety after delivery of the partial dose. The zero end pitch of the shroud lead screw thread 13.1 allows the torsion spring 14 to be released preventing further drug delivery.

    [0059] Figure 25 shows an alternative embodiment of the auto-injector 1 with a lateral trigger button 20. The lateral trigger button 20 is an integral part of the housing 2. It may be moulded orthogonal to the housing 2 and then folded into place. However, the auto-injector 1 also comprises the end trigger button 4 of the embodiment illustrated in figures 1 to 24, but hidden inside the distal end D closed by the distal cap 22 attached to the housing 2. A trigger spring 23 in the shape of a small compression spring applies a load between the distal cap 22 and the trigger button 4.

    [0060] The sequence of operation is as described above for the embodiment in figures 1 to 24 except in the following steps:
    The initial position and function of all components is identical with the exception of the button interlock. The lateral trigger button 20 is locked in an extended position in the initial state to prevent unintended activation of the auto-injector 1. A boss 20.1 on the distal end of the lateral trigger button 20 extends through an aperture in the housing 2. In the initial state the boss 20.1 abuts against one of the inward bosses 4.3 on the end trigger button 4 which is inwardly supported by the shroud lead screw 13 and by a distal extension 3.4 on the needle shroud 3 arranged between the inward boss 4.3 and the shroud lead screw 13. Any force applied to the lateral trigger button 20 is therefore statically resolved preventing its depression. The inward boss 4.3 on the end trigger button 4 abuts against a third rib 2.6 in the housing 2 in proximal direction P thus preventing release of the end trigger button 4. When the auto-injector 1 is pressed against the skin, the needle shroud 3 translates within the housing 2 and a window 3.5 in the distal extension 3.4 becomes aligned with the boss 20.1 (see figure 26) allowing the lateral trigger button 20 to be depressed (see figure 27) thereby flexing the inward boss 4.3 inwards into the window 3.5 in such a manner that the inward boss 4.3 comes clear of the third rib 2.6 releasing the end trigger button 4 which is then translated under the action of the trigger spring 23 (see figure 28). This releases the chassis clip 16 resolving the axial load on the plunger 11 as in the embodiment in figures 1 to 24.

    [0061] Figure 29 shows another alternative embodiment of the auto-injector 1 with a wrap over sleeve trigger 24 arranged over the distal end D and extending over roughly half the length of the housing 2. However, the auto-injector 1 also comprises the end trigger button 4 of the embodiment illustrated in figures 1 to 24, but hidden inside the distal end D. A trigger spring 23 applies a load between the sleeve trigger 24 and the end trigger button 4. The load from the trigger spring 23 is balanced by load from the shroud spring 12. The end trigger button 4 exhibits latch features 4.5 initially abutted against a stop 2.7 in the housing 2 (see figures 29 to 32).

    [0062] The sequence of operation is as described above for the embodiment in figures 1 to 24 except in the following steps:
    The initial position and function of all components is identical with the exception of the button interlock. Movement of the trigger sleeve 24 is prevented to avoid unintended activation of the auto-injector 1. If the trigger sleeve 24 is moved, a locking feature 24.1 engages with a mating part 3.6 on the needle shroud 3 guarding against the user grabbing the housing 2 and attempting to operate the trigger sleeve 24 (see figure 30). When the auto-injector 1 is pressed against the skin, the needle shroud 3 translates within the housing 2 and the mating part 3.6 on the shroud 3 is inwardly withdrawn as the resilient third beam element 3.2 runs down a cam on the second rib 2.3 in the housing 2 allowing it to be depressed.

    [0063] When ready to do so, the user translates the sleeve trigger 24 in proximal direction P. As the trigger sleeve 24 translates, a latch actuation boss 24.2 on the sleeve trigger 24 deflects the latch feature 4.5 inwards disengaging it from the stop 2.7 in the housing 2. The end trigger button 4 is then translated under the action of the trigger spring 23. This releases the chassis clip 16 resolving the axial load on the plunger 11.

    [0064] This allows for a forced activation sequence. The intended activation of the auto-injector 1 involves the needle shroud 3 (skin interlock) being depressed prior to the trigger sleeve 24 being translated. Both parts (needle shroud 3 and trigger sleeve 24) are sprung relative to the housing 2 in this embodiment. By careful selection of the spring properties of the shroud spring 12 and the trigger spring 23, the correct sequence can be achieved. If the shroud spring 12 is less stiff than the trigger spring 23, it will compress first when a load is applied between the needle shroud 3 and the trigger sleeve 24. In the case of an end trigger button 4 only as in figure 1 to 24, this is not required as the user holds the housing 2 and is able to move the two parts independently.

    [0065] The embodiment of figures 29 to 32 furthermore allows for a non-return activation sequence, i.e. the embodiment allows the needle shroud 3 to be depressed and the trigger sleeve 24 to be moved up to the point of release of the end trigger button 4 and then released without changing the load paths within the auto-injector 1. I.e. the auto-injector 1 can be placed on the skin and then removed and remain in a safe state. Once the trigger sleeve 24 moves beyond the point of release of the internal end trigger button 4, the auto-injector 1 is activated under the action of the trigger spring 23 and cannot be stopped by the user. This prevents the user partially activating the auto-injector 1 and leaving it in a partially activated state, which would result in the auto-injector firing immediately on the next attempt without requiring the sequenced operation.

    [0066] Furthermore the embodiment demonstrates the ability to convert the auto-injector 1 from an end trigger (figures 1 to 24) to a sleeve trigger (figures 29 to 32) by adding an additional part, thus achieving a platform design.

    [0067] The auto-injector 1 may preferably be used for delivering one of an analgetic, an anticoagulant, insulin, an insulin derivate, heparin, Lovenox, a vaccine, a growth hormone, a peptide hormone, a protein, antibodies and complex carbohydrates.

    List of References



    [0068] 
    1
    auto-injector
    2
    housing
    2.1
    first rib
    2.2
    first beam element
    2.3
    second rib
    2.4
    stop
    2.5
    snap
    2.6
    third rib
    2.7
    stop
    2.8
    step
    3
    needle shroud
    3.1
    second beam element
    3.2
    third beam element
    3.3
    slot hole
    3.4
    distal extension
    3.5
    window
    3.6
    mating part
    4
    trigger button, end trigger button, activating means
    4.1
    trigger beam
    4.2
    aperture
    4.3
    inward boss
    4.4
    snap
    4.5
    latch feature
    5
    spline
    7
    syringe
    8
    syringe carrier
    8.1
    rear flange
    9
    shroud follower, second gear member
    9.1
    fourth beam element
    9.2
    pin
    10
    stopper
    11
    plunger, second gear member
    11.1
    plunger lead screw thread
    11.2
    shoulder
    12
    shroud spring
    13
    shroud lead screw, first gear member
    13.1
    shroud lead screw thread
    13.2
    spline
    13.3
    circumferential outward boss
    13.4
    lip
    13.5
    flange
    14
    torsion spring, spring means
    14.1
    proximal end, first end
    14.2
    distal end, second end
    15
    plunger follower, first gear member
    16
    chassis clip
    16.1
    outward pin
    17
    support beam
    18
    protective needle shield
    19
    injection needle
    20
    lateral trigger button, activating means
    20.1
    boss
    21
    torque reaction rod
    22
    distal end cap
    23
    trigger spring
    24
    sleeve trigger, activating means
    24.1
    locking feature
    24.2
    latch actuation boss
    D
    distal end, distal direction
    M
    medicament
    P
    proximal end, proximal direction



    Claims

    1. Auto-injector (1) for administering a dose of a liquid medicament (M), comprising:

    - an elongate housing (2) arranged to contain a syringe (7) with a hollow needle (19) and a stopper (10) for sealing the syringe (7) and displacing the medicament (M), the elongate housing (2) having a distal end (D) and a proximal end (P) with an orifice intended to be applied against an injection site, wherein the syringe (7) is slidably arranged with respect to the housing (2),

    - spring means (14) capable of, upon activation, pushing the needle (19) from a covered position inside the housing (2) into an advanced position through the orifice and past the proximal end (P), operating the syringe (7) to supply the dose of medicament (M), and covering the needle (19) on removal of the auto-injector (1) from the injection site,

    - activating means (4, 20, 24) arranged to lock the spring means (14) in a pressurized state prior to manual operation and capable of, upon manual operation, releasing the spring means (14) for injection,

    wherein the spring means (14) is a single torsion spring (14), wherein a first gear arrangement (13, 13.1, 9) and a second gear arrangement (15, 11.1, 11) are arranged for respectively converting torque from a first end (14.1) and a second end (14.2) of the torsion spring (14) into a translative force, wherein the first end (14.1) is groundable in the housing (2) while the second end (14.2) acts on a plunger (11) through the second gear arrangement (15, 11.1, 11) for advancing the needle (19) and supplying the dose, wherein the activating means (4, 20, 24) is arranged to block or release the second gear arrangement (15, 11.1, 11) and wherein the first end (14.1) is releasable from the ground in the housing (2) for causing a translation through the first gear arrangement (13, 13.1, 9) resulting in the needle (19) getting covered, wherein the first gear arrangement (13, 13.1, 9) and the second gear arrangement (15, 11.1, 11) respectively comprise a first gear member (13, 15) coupled to the respective end (14.1, 14.2) of the torsion spring (14), wherein the first gear member (13, 15) is engaged through a respective screw thread (13.1, 11.1) to a respective second gear member (9, 11) arranged to translate on rotation of the first gear member (13, 15).
     
    2. Auto-injector (1) according to claim 1, characterized in that a needle shroud (3) is arranged in the housing (2) surrounding the syringe (7) and translatable in longitudinal direction, wherein the needle shroud (3) is coupled to the first gear arrangement (13, 13.1, 9) in a manner to be translated in proximal direction (P) over the advanced needle (19) on release of the first end (14.1) from the ground in the housing (2).
     
    3. Auto-injector (1) according to claim 2, characterized in that the torque required to advance the needle shroud (3) is configured to be less than the torque required to advance the plunger (11) and the stopper (10).
     
    4. Auto-injector (1) according to claim 2, characterized in that the needle shroud (3) is arranged to be in an initial position protruding from the proximal end (P) of the housing (2) in an initial state interlocked to the activating means (4, 20, 24) for preventing manual operation, wherein the needle shroud (3) is arranged to be translated in distal direction (D) into the housing (2) into a distal position against the load of a shroud spring (12) when pushed against the injection site, wherein the needle shroud (3) is rotationally fixed to the housing (2) and to the second gear member (9) of the first gear arrangement (13, 13.1, 9), wherein in the distal position the needle shroud (3) is arranged to rotationally fix the first gear member (13) to the second gear member (9) of the first gear arrangement (13, 13.1, 9) and to allow operation of the activating means (4, 20, 24).
     
    5. Auto-injector (1) according to claim 4, characterized in that the activating means (4, 20, 24) is arranged to be in a splined engagement with the first gear member (13) of the first gear arrangement (13, 13.1, 9) in the initial state so as to rotationally fix it to the housing (2), wherein the activating means (4, 20, 24) is arranged to remove this splined engagement on manual operation.
     
    6. Auto-injector (1) according to one of the claims 1 to 5, characterized in that a clip arrangement is provided comprising at least one resilient chassis clip (16) attached to the housing (2), the chassis clip (16) engageable proximally behind a shoulder (11.2) in the plunger (11) in a manner to prevent translation of the plunger (11) in proximal direction (P), wherein the shoulder (11.2) is arranged to flex the chassis clip (16) outwards due to ramped engagement when a force in proximal direction (P) is applied to the plunger (11), wherein the activation means (4, 20, 24) comprises an end trigger button (4) arranged at the distal end (D) translatable between a distal position and a proximal position, wherein at least one trigger beam (4.1) is arranged on the trigger button (4) in a manner to outwardly support the chassis clip (16) to prevent it from being outwardly deflected when the end trigger button (4) is in the distal position, wherein the trigger beam (4.1) is arranged to be repositioned on translation of the end trigger button (4) into the proximal position in a manner to allow outward deflection of the chassis clip (16).
     
    7. Auto-injector (1) according to claim 6, characterized in that at least one flexible first beam element (2.2) is arranged on the housing (2), the flexible first beam element (2.2) arranged to obstruct the path of the end trigger button (4) so as to prevent its depression, wherein a second beam element (3.1) is arranged on the needle shroud (3) in a manner to deflect the flexible first beam element (2.2) out of the path of the end trigger button (4) on depression of the needle shroud (3).
     
    8. Auto-injector (1) according to claim 6, characterized in that a third rib (2.6) is arranged in the housing (2) in a manner to obstruct the path of a resilient part of the end trigger button (4) so as to prevent its depression, wherein a lateral trigger button (20) is laterally arranged on the housing (2) arranged to inwardly deflect the resilient part of the end trigger button (20) in a manner to bypass the third rib (2.6) thus allowing depression of the end trigger button (4), wherein the needle shroud (3) is arranged to inwardly support the resilient part of the end trigger button (4) when in the initial position so as to prevent deflection, wherein the inward support of the resilient part of the end trigger button (4) is arranged to be removed on translation of the needle shroud (3) into the distal position, wherein the end trigger button (4) is biased in proximal direction against the housing (2) by a trigger spring (23).
     
    9. Auto-injector (1) according to claim 6, characterized in that a wrap over sleeve trigger (24) is arranged over the distal end (D), the sleeve trigger (24) translatable in longitudinal direction between a distal position and a proximal position, the sleeve trigger (24) having at least one locking feature (24.1) engageable with a respective mating part (3.6) on the needle shroud (3) in the initial position so as to prevent depression of the sleeve trigger (24) from the distal position into the proximal position, wherein the mating part (3.6) is arranged to be inwardly withdrawn by a cam feature on translation of the needle shroud (3) into the distal position so as to allow the sleeve trigger (24) to be depressed, wherein the end trigger button (4) exhibits at least one latch feature (4.5) arranged to abut against a respective stop (2.7) in the housing (2) so as to prevent depression of the end trigger button (4), wherein at least one latch actuation boss (24.2) on the sleeve trigger (24) is arranged to inwardly deflect the latch feature (4.5) disengaging it from the stop (2.7), wherein the end trigger button (4) is biased in proximal direction against the housing (2) by a trigger spring (23).
     
    10. Auto-injector (1) according to claim 9, characterized in that the trigger spring (23) and the shroud spring (12) are specified to balance each other's load.
     
    11. Auto-injector (1) according to one of the claims 1 to 10, characterized in that the screw thread (13.1) ends with a pitch of zero on its proximal end allowing remaining torque in the torsion spring (14) to be released when the second gear member (9) reaches the zero pitch.
     


    Ansprüche

    1. Autoinjektor (1) zur Verabreichung einer Dosis eines flüssigen Medikaments (M), aufweisend:

    - ein längserstrecktes Gehäuse (2), das dazu angeordnet ist, eine Spritze (7) mit einer hohlen Nadel (19) und einem Stopfen (10) zum Abdichten der Spritze (7) und Verdrängen des Medikaments (M) zu enthalten, wobei das längserstreckte Gehäuse (2) ein distales Ende (D) und ein proximales Ende (P) mit einer Öffnung hat, die dazu bestimmt ist, an einer Injektionsstelle angelegt zu werden, wobei die Spritze (7) bezüglich des Gehäuses (2) verschiebbar angeordnet ist,

    - ein Federmittel (14), das bei Aktivierung in der Lage ist, die Nadel (19) aus einer abgedeckten Position in dem Gehäuse (2) in eine durch die Öffnung und an dem proximalen Ende (P) vorbei vorgeschobene Position zu schieben, die Spritze (7) zur Ausschüttung der Dosis des Medikaments (M) zu betätigen und die Nadel (19) bei Entfernung des Autoinjektors (1) von der Injektionsstelle abzudecken,

    - ein Aktivierungsmittel (4, 20, 24), das dazu angeordnet ist, das Federmittel (14) vor manueller Betätigung in einem druckbeaufschlagten Zustand zu verriegeln, und dazu in der Lage ist, das Federmittel (14) bei manueller Betätigung für die Injektion zu lösen,

    wobei das Federmittel (14) eine einzelne Torsionsfeder (14) ist, wobei eine erste Getriebeanordnung (13, 13.1, 9) und eine zweite Getriebeanordnung (15, 11.1, 11) angeordnet sind, um jeweils Drehmoment von einem ersten Ende (14.1) und einem zweiten Ende (14.2) der Torsionsfeder (14) in eine Translationskraft umzuwandeln, wobei das erste Ende (14.1) in dem Gehäuse (2) verankerbar ist, während das zweite Ende (14.2) durch die zweite Getriebeanordnung (15, 11.1, 11) auf einen Kolben (11) wirkt, um die Nadel (19) vorzuschieben und die Dosis auszuschütten, wobei das Aktivierungsmittel (4, 20, 24) dazu angeordnet ist, die zweite Getriebeanordnung (15, 11.1, 11) zu blockieren oder zu lösen, und wobei das erste Ende (14.1) von der Verankerung in dem Gehäuse (2) lösbar ist, um eine Translation durch die erste Getriebeanordnung (13, 13.1, 9) zu veranlassen, was dazu führt, dass die Nadel (19) abgedeckt wird, wobei die erste Getriebeanordnung (13, 13.1, 9) und die zweite Getriebeanordnung (15, 11.1, 11) jeweils ein erstes Getriebeglied (13, 15) aufweisen, das an das jeweilige Ende (14.1, 14.2) der Torsionsfeder (14) gekoppelt ist, wobei das erste Getriebeglied (13, 15) durch ein jeweiliges Schraubengewinde (13.1, 11.1) mit einem jeweiligen zweiten Getriebeglied (9, 11) in Eingriff steht, das dazu angeordnet ist, bei Drehung des ersten Getriebeglieds (13, 15) zu translatieren.
     
    2. Autoinjektor (1) nach Anspruch 1, dadurch gekennzeichnet, dass ein Nadelschutz (3) in dem Gehäuse (2) angeordnet ist, der die Spritze (7) umgibt und in Längsrichtung translatierbar ist, wobei der Nadelschutz (3) so an die erste Getriebeanordnung (13, 13.1, 9) gekoppelt ist, dass er bei Lösung des ersten Endes (14.1) von der Verankerung in dem Gehäuse (2) in proximaler Richtung (P) über die vorgeschobene Nadel (19) translatiert wird.
     
    3. Autoinjektor (1) nach Anspruch 2, dadurch gekennzeichnet, dass das zum Vorschieben des Nadelschutzes (3) erforderliche Drehmoment geringer als das zum Vorschieben des Kolbens (11) und des Stopfens (10) erforderliche Drehmoment ausgestaltet ist.
     
    4. Autoinj ektor (1) nach Anspruch 2,
    dadurch gekennzeichnet, dass der Nadelschutz (3) dazu angeordnet ist, in einem Anfangszustand in einer Anfangsposition von dem proximalen Ende (P) des Gehäuses (2) vorzuragen und mit dem Aktivierungsmittel (4, 20, 24) verriegelt zu sein, um manuelle Betätigung zu verhindern, wobei der Nadelschutz (3) dazu angeordnet ist, wenn er gegen die Injektionsstelle gedrückt wird, gegen die Belastung einer Nadelschutzfeder (12) in distaler Richtung (D) in das Gehäuse (2) in eine distale Position translatiert zu werden, wobei der Nadelschutz (3) an dem Gehäuse (2) und an dem zweiten Getriebeglied (9) der ersten Getriebeanordnung (13, 13.1, 9) drehfixiert ist, wobei der Nadelschutz (3) in der distalen Position dazu angeordnet ist, das erste Getriebeglied (13) an das zweite Getriebeglied (9) der ersten Getriebeanordnung (13, 13.1, 9) drehzufixieren und die Betätigung des Aktivierungsmittels (4, 20, 24) zu gestatten.
     
    5. Autoinj ektor (1) nach Anspruch 4,
    dadurch gekennzeichnet, dass das Aktivierungsmittel (4, 20, 24) so angeordnet ist, dass es im Anfangszustand in einem Verkeilungseingriff mit dem ersten Getriebeglied (13) der ersten Getriebeanordnung (13, 13.1, 9) steht, um es an dem Gehäuse (2) drehzufixieren, wobei das Aktivierungsmittel (4, 20, 24) dazu angeordnet ist, diesen Verkeilungseingriff bei manueller Betätigung zu entfernen.
     
    6. Autoinjektor (1) nach einem der Ansprüche 1 bis 5,
    dadurch gekennzeichnet, dass eine Clipanordnung vorgesehen ist, die zumindest einen federnden Gestellclip (16) aufweist, der an dem Gehäuse (2) angebracht ist, wobei der Gestellclip (16) proximal so hinter einer Schulter (11.2) in dem Kolben (11) in Eingriff bringbar ist, dass er eine Translation des Kolbens (11) in proximaler Richtung (P) verhindert, wobei die Schulter (11.2) dazu angeordnet ist, den Gestellclip (16) aufgrund von Rampeneingriff nach außen zu biegen, wenn eine Kraft in proximaler Richtung (P) auf den Kolben (11) ausgeübt wird, wobei das Aktivierungsmittel (4, 20, 24) einen Endauslöserknopf (4) aufweist, der an dem distalen Ende (D) zwischen einer distalen Position und einer proximalen Position translatierbar angeordnet ist, wobei zumindest ein Auslöserträger (4.1) so an dem Auslöserknopf (4) angeordnet ist, dass er den Gestellclip (16) außen stützt, um zu verhindern, dass dieser nach außen ausgelenkt wird, wenn der Endauslöserknopf (4) in der distalen Position ist, wobei der Auslöserträger (4.1) dazu angeordnet ist, bei Translation des Endauslöserknopfs (4) in die proximale Position so umpositioniert zu werden, dass er ein Auslenken des Gestellclips (16) nach außen gestattet.
     
    7. Autoinjektor (1) nach Anspruch 6,
    dadurch gekennzeichnet, dass zumindest ein flexibles erstes Trägerelement (2.2) an dem Gehäuse (2) angeordnet ist, wobei das flexible erste Trägerelement (2.2) dazu angeordnet ist, die Bahn des Endauslöserknopfs (4) zu blockieren, um dessen Niederdrücken zu verhindern, wobei ein zweites Trägerelement (3.1) so an dem Nadelschutz (3) angeordnet ist, dass es das flexible erste Trägerelement (2.2) bei Niederdrücken des Nadelschutzes (3) aus der Bahn des Endauslöserknopfs (4) auslenkt.
     
    8. Autoinj ektor (1) nach Anspruch 6,
    dadurch gekennzeichnet, dass eine dritte Rippe (2.6) so in dem Gehäuse (2) angeordnet ist, dass sie die Bahn eines federnden Teils des Endauslöserknopfs (4) blockiert, um sein Niederdrücken zu verhindern, wobei ein seitlicher Auslöserknopf (20) seitlich an dem Gehäuse (2) angeordnet und dazu angeordnet ist, den federnden Teil des Endauslöserknopfs (20) so nach innen auszulenken, dass die dritte Rippe (2.6) umgangen wird, wodurch ein Niederdrücken des Endauslöserknopfs (4) gestattet wird, wobei der Nadelschutz (3) dazu angeordnet ist, den federnden Teil des Endauslöserknopfs (4) innen zu stützen, wenn er in der Anfangsposition ist, um ein Auslenken zu verhindern, wobei die innere Stütze des federnden Teils des Endauslöserknopfs (4) dazu angeordnet ist, bei Translation des Nadelschutzes (3) in die distale Position entfernt zu werden, wobei der Endauslöserknopf (4) durch eine Auslöserfeder (23) in proximaler Richtung gegen das Gehäuse (2) vorgespannt wird.
     
    9. Autoinj ektor (1) nach Anspruch 6,
    dadurch gekennzeichnet, dass ein Überwurf-Hülsenauslöser (24) über dem distalen Ende (D) angeordnet ist, wobei der Hülsenauslöser (24) in Längsrichtung zwischen einer distalen Position und einer proximalen Position translatierbar ist, wobei der Hülsenauslöser (24) zumindest ein Verriegelungsmerkmal (24.1) hat, das mit einem jeweiligen zusammenwirkenden Teil (3.6) an dem Nadelschutz (3) in der Anfangsposition in Eingriff bringbar ist, um ein Niederdrücken des Hülsenauslösers (24) aus der distalen Position in die proximale Position zu verhindern, wobei der zusammenwirkende Teil (3.6) dazu angeordnet ist, bei Translation des Nadelschutzes (3) in die distale Position durch ein Nockenmerkmal nach innen zurückgezogen zu werden, um zu gestatten, dass der Hülsenauslöser (24) niedergedrückt wird, wobei der Endauslöserknopf (4) zumindest ein Rastmerkmal (4.5) aufweist, das dazu angeordnet ist, an einem jeweiligen Anschlag (2.7) in dem Gehäuse (2) anzuliegen, um ein Niederdrücken des Endauslöserknopfs (4) zu verhindern, wobei zumindest ein Rastbetätigungsbuckel (24.2) an dem Hülsenauslöser (24) dazu angeordnet ist, das Rastmerkmal (4.5) nach innen auszulenken und es mit dem Anschlag (2.7) außer Eingriff zu bringen, wobei der Endauslöserknopf (4) durch eine Auslöserfeder (23) in proximaler Richtung gegen das Gehäuse (2) vorgespannt ist.
     
    10. Autoinj ektor (1) nach Anspruch 9,
    dadurch gekennzeichnet, dass die Auslöserfeder (23) und die Nadelschutzfeder (12) zum Ausgleich der Belastung der jeweils anderen ausgelegt sind.
     
    11. Autoinj ektor (1) nach einem der Ansprüche 1 bis 10,
    dadurch gekennzeichnet, dass das Schraubengewinde (13.1) an seinem proximalen Ende mit einer Steigung von null endet, wodurch in der Torsionsfeder (14) verbliebenes Drehmoment gelöst wird, wenn das zweite Getriebeglied (9) die Steigung null erreicht.
     


    Revendications

    1. Injecteur automatique (1) pour administrer une dose d'un médicament liquide (M), comprenant :

    - un boîtier allongé (2) prévu pour contenir une seringue (7) avec une aiguille creuse (19) et un bouchon (10) pour sceller la seringue (7) et déplacer le médicament (M), le boîtier allongé (2) ayant une extrémité distale (D) et une extrémité proximale (P) avec un orifice destiné à être appliqué contre un site d'injection, la seringue (7) étant disposée de manière à pouvoir coulisser par rapport au boîtier (2),

    - un moyen de ressort (14) capable, lorsqu'il est activé, de pousser l'aiguille (19) d'une position recouverte à l'intérieur du boîtier (2) jusque dans une position avancée à travers l'orifice et au-delà de l'extrémité proximale (P), d'actionner la seringue (7) pour fournir la dose de médicament (M), et de recouvrir l'aiguille (19) lors de l'enlèvement de l'injecteur automatique (1) du site d'injection,

    - un moyen d'activation (4, 20, 24) prévu pour verrouiller le moyen de ressort (14) dans un état pressurisé avant l'actionnement manuel et capable, lors de son actionnement manuel, de libérer le moyen de ressort (14) en vue de l'injection,

    le moyen de ressort (14) étant un ressort de torsion unique (14), un premier agencement d'engrenage (13, 13.1, 9) et un deuxième agencement d'engrenage (15, 11.1, 11) étant prévus pour convertir respectivement un couple provenant d'une première extrémité (14.1) et d'une deuxième extrémité (14.2) du ressort de torsion (14) en une force de translation, la première extrémité (14.1) pouvant être ancrée dans le boîtier (2) tandis que la deuxième extrémité (14.2) agit sur un plongeur (11) par le biais du deuxième agencement d'engrenage (15, 11.1, 11) pour faire avancer l'aiguille (19) et fournir la dose, le moyen d'activation (4, 20, 24) étant prévu pour bloquer ou libérer le deuxième agencement d'engrenage (15, 11.1, 11) et la première extrémité (14.1) pouvant être libérée de son ancrage dans le boîtier (2) pour provoquer une translation par le biais du premier agencement d'engrenage (13, 13.1, 9) entraînant le recouvrement de l'aiguille (19), le premier agencement d'engrenage (13, 13.1, 9) et le deuxième agencement d'engrenage (15, 11.1, 11) comprenant respectivement un premier organe d'engrenage (13, 15) accouplé à l'extrémité respective (14.1, 14.2) du ressort de torsion (14), le premier organe d'engrenage (13, 15) étant en prise par le biais d'un filetage de vis respectif (13.1, 11.1) avec un deuxième organe d'engrenage respectif (9, 11) prévu pour se déplacer en translation lors de la rotation du premier organe d'engrenage (13, 15).
     
    2. Injecteur automatique (1) selon la revendication 1, caractérisé en ce qu'une enveloppe d'aiguille (3) est disposée dans le boîtier (2) entourant la seringue (7) et peut être déplacée en translation dans la direction longitudinale, l'enveloppe d'aiguille (3) étant accouplée au premier agencement d'engrenage (13, 13.1, 9) de manière à être déplacée en translation dans la direction proximale (P) par-dessus l'aiguille avancée (19) lors de la libération de la première extrémité (14.1) de l'ancrage dans le boîtier (2).
     
    3. Injecteur automatique (1) selon la revendication 2, caractérisé en ce que le couple requis pour faire avancer l'enveloppe d'aiguille (3) est configuré pour être inférieur au couple requis pour faire avancer le plongeur (11) et le bouchon (10).
     
    4. Injecteur automatique (1) selon la revendication 2, caractérisé en ce que, dans un état initial, l'enveloppe d'aiguille (3) est prévue pour être dans une position initiale faisant saillie depuis l'extrémité proximale (P) du boîtier (2) et étant emboîtée avec le moyen d'activation (4, 20, 24) pour empêcher un actionnement manuel, l'enveloppe d'aiguille (3), lorsqu'elle est poussée contre le site d'injection, étant prévue pour être déplacée en translation dans la direction distale (D) dans le boîtier (2) jusque dans une position distale à l'encontre de la charge d'un ressort d'enveloppe (12), l'enveloppe d'aiguille (3) étant fixée en rotation au boîtier (2) et au deuxième organe d'engrenage (9) du premier agencement d'engrenage (13, 13.1, 9), l'enveloppe d'aiguille (3), dans la position distale, étant prévue pour fixer en rotation le premier organe d'engrenage (13) au deuxième organe d'engrenage (9) du premier agencement d'engrenage (13, 13.1, 9) et pour permettre l'actionnement du moyen d'activation (4, 20, 24).
     
    5. Injecteur automatique (1) selon la revendication 4, caractérisé en ce que le moyen d'activation (4, 20, 24) est prévu pour être en engagement cannelé avec le premier organe d'engrenage (13) du premier agencement d'engrenage (13, 13.1, 9) dans l'état initial de manière à le fixer en rotation au boîtier (2), le moyen d'activation (4, 20, 24) étant prévu pour supprimer cet engagement cannelé lors de l'actionnement manuel.
     
    6. Injecteur automatique (1) selon l'une des revendications 1 à 5, caractérisé en ce qu'un agencement de pince est prévu, comprenant au moins une pince de châssis élastique (16) attachée au boîtier (2), la pince de châssis (16) pouvant être engagée dans la direction proximale derrière un épaulement (11.2) dans le plongeur (11) de manière à empêcher la translation du plongeur (11) dans la direction proximale (P), l'épaulement (11.2) étant prévu pour faire fléchir la pince de châssis (16) vers l'extérieur sous l'effet de l'engagement en rampe lorsqu'une force dans la direction proximale (P) est appliquée au plongeur (11), le moyen d'activation (4, 20, 24) comprenant un bouton de déclenchement d'extrémité (4) disposé à l'extrémité distale (D) et pouvant être déplacé en translation entre une position distale et une position proximale, au moins une barrette de déclenchement (4.1) étant disposée sur le bouton de déclenchement (4) de manière à supporter vers l'extérieur la pince de châssis (16) pour l'empêcher d'être déviée vers l'extérieur lorsque le bouton de déclenchement d'extrémité (4) est dans la position distale, la barrette de déclenchement (4.1) étant prévue pour être repositionnée lors de la translation du bouton de déclenchement d'extrémité (4) dans la position proximale de manière à permettre une déviation vers l'extérieur de la pince de châssis (16).
     
    7. Injecteur automatique (1) selon la revendication 6, caractérisé en ce qu'au moins un premier élément de barrette flexible (2.2) est disposé sur le boîtier (2), le premier élément de barrette flexible (2.2) étant prévu pour bloquer le trajet du bouton de déclenchement d'extrémité (4) de manière à empêcher son enfoncement, un deuxième élément de barrette (3.1) étant prévu sur l'enveloppe d'aiguille (3) de manière à dévier le premier élément de barrette flexible (2.2) hors du trajet du bouton de déclenchement d'extrémité (4) lors de l'enfoncement de l'enveloppe d'aiguille (3).
     
    8. Injecteur automatique (1) selon la revendication 6, caractérisé en ce qu'une troisième nervure (2.6) est disposée dans le boîtier (2) de manière à bloquer le trajet d'une partie élastique du bouton de déclenchement d'extrémité (4) de manière à empêcher son enfoncement, un bouton de déclenchement latéral (20) étant disposé latéralement sur le boîtier (2), étant prévu pour dévier vers l'intérieur la partie élastique du bouton de déclenchement d'extrémité (20) de manière à contourner la troisième nervure (2.6) pour ainsi permettre l'enfoncement du bouton de déclenchement d'extrémité (4), l'enveloppe d'aiguille (3) étant disposée de manière à supporter vers l'intérieur la partie élastique du bouton de déclenchement d'extrémité (4) lorsqu'il est dans la position initiale de manière à empêcher sa déviation, le support vers l'intérieur de la partie élastique du bouton de déclenchement d'extrémité (4) étant prévu pour être supprimé lors de la translation de l'enveloppe d'aiguille (3) dans la position distale, le bouton de déclenchement d'extrémité (4) étant sollicité dans la direction proximale contre le boîtier (2) par un ressort de déclenchement (23).
     
    9. Injecteur automatique (1) selon la revendication 6, caractérisé en ce qu'un organe de déclenchement de manchon d'enveloppement (24) est disposé par-dessus l'extrémité distale (D), l'organe de déclenchement de manchon (24) pouvant être déplacé en translation dans la direction longitudinale entre une position distale et une position proximale, l'organe de déclenchement de manchon (24) ayant au moins un élément de verrouillage (24.1) pouvant être engagé avec une partie d'accouplement respective (3.6) sur l'enveloppe d'aiguille (3) dans la position initiale de manière à empêcher l'enfoncement de l'organe de déclenchement de manchon (24) de la position distale jusque dans la position proximale, la partie d'accouplement (3.6) étant prévue pour être retirée vers l'intérieur par un élément de came lors de la translation de l'enveloppe d'aiguille (3) dans la position distale de manière à permettre l'enfoncement de l'organe de déclenchement de manchon (24), le bouton de déclenchement d'extrémité (4) présentant au moins un élément de loquet (4.5) prévu pour buter contre une butée respective (2.7) dans le boîtier (2) de manière à empêcher l'enfoncement du bouton de déclenchement d'extrémité (4), au moins un bossage d'actionnement de loquet (24.2) sur l'organe de déclenchement de manchon (24) étant prévu pour dévier vers l'intérieur l'élément de loquet (4.5) en le désengageant de la butée (2.7), le bouton de déclenchement d'extrémité (4) étant sollicité dans la direction proximale contre le boîtier (2) par un ressort de déclenchement (23).
     
    10. Injecteur automatique (1) selon la revendication 9, caractérisé en ce que le ressort de déclenchement (23) et le ressort d'enveloppe (12) sont conçus de manière à équilibrer leur charge mutuelle.
     
    11. Injecteur automatique (1) selon l'une des revendications 1 à 10, caractérisé en ce que le filetage de vis (13.1) se termine avec un pas nul sur son extrémité proximale, permettant au couple restant dans le ressort de torsion (14) d'être libéré lorsque le deuxième organe d'engrenage (9) atteint le pas nul.
     




    Drawing






















































































    Cited references

    REFERENCES CITED IN THE DESCRIPTION



    This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

    Patent documents cited in the description