Patent ID: 12251538

DETAILED DESCRIPTION

References made in the following regarding directions are made in the context of the drawing and can naturally vary if the viewing position is changed. Moreover, similar parts or parts having similar functions will be referred to in the following using the same feature and/or reference numeral.

FIGS.1A and1Bshow side views of an autoinjector10. The autoinjector10is a medical instrument that serves the purpose of administering a single dose of medicament M. The autoinjector10can not only be used by medical staff, but also by a patient themselves to administer the medicament M.

The autoinjector10has a housing12with a syringe window14(seeFIG.1A) present therein. A pre-filled syringe16is arranged within the housing12and visible via the syringe window14. The pre-filled syringe16is filled with the medicament M.

A needle guard18(see e.g.FIG.2A) is arranged at a proximal end28of the autoinjector10. The needle guard18has the function of protecting a patient from a needle34(see e.g.FIG.3B) before and after use of the autoinjector, i.e. in a storage state and in a lock-out state of the autoinjector10.

In this connection it should be noted that the terms proximal and distal refer to the position of the needle34relative to a patient with proximal meaning closest to a main mass of the body of a patient and distal meaning it is more distant from the main mass of the body of a patient.

FIG.1Bshows a status indicator window20in which a first part outer surface50of a drive chassis24of the autoinjector10is visible.

A cap70is arranged at the proximal end28of the autoinjector10disposed opposite to a distal end30of the autoinjector10. The cap70covers both the needle34and the needle guard18in the storage state of the autoinjector10.

FIGS.2A and2Bshow the autoinjector10ofFIGS.1A and1Bwith the cap70removed and the needle guard18moved distally, i.e. moved away from the proximal end28, and into the autoinjector10. The distal movement of the needle guard18into the autoinjector also brings about an engagement of a release mechanism40(see e.g.FIGS.4A,4B and4C).

On engaging the release mechanism40, the drive chassis24(see alsoFIG.3) is moved proximally and a dispensing limb22thereof moves a plunger26through the pre-filled syringe16in order to dispense the medicament M via the needle34.

In this connection it should be noted that the plunger26can be a part separate from the dispensing limb22and can be pre-arranged within the pre-filled syringe and configured to be engaged by the dispensing limb22.

In other designs of the autoinjector10, the plunger26can be a part of the dispensing limb22.

FIG.2Ashows the presence of the dispensing limb22, the drive chassis24and the plunger26in the syringe window14following the movement of the drive chassis24in the proximal direction, i.e. at an end of dose state of the autoinjector10.

FIG.2Bshows a second part outer surface52of the drive chassis in the status indicator window20.

In the drawings shown above, the status indicator window20on the side of autoinjector10shows a device status in clear, binary form, which is likely to be very useful particularly to naïve users. Before (and possibly during) dispense, the colour displayed through the window is printed on the drive chassis24(see alsoFIG.3. At the end of the dispense, the moulded colour (indicated with the hashed lines) of the drive chassis24is displayed through the status indicator window20. Other configurations of display, for example employing graphics to indicate that dispense is in progress, icons or text, are possible.

Moreover, before dispensing, the dispensable fluid volume of the medicament M is clearly visible through the syringe window14that is formed as a large wrap-around window in the housing12. The geometry of this window14is intended to maximise the viewing angle for the user.

The progress of the dispense can also be viewed through the window20as a movement of the plunger26and of the drive chassis24is visible through the syringe window14.

At the end of dispense, the syringe window14is filled with the drive chassis24and the plunger26to provide additional visual indication that the autoinjector10has been used. This means that two forms of different visual indication of the end of dose are present. The part of the drive chassis24visible through the syringe window14could include a surface decoration or marking, e.g. printed in a different colour to provide further visual communication of the end of the dose.

FIG.3shows the drive chassis24. The drive chassis34comprises the dispensing limb22and a trigger limb32. The trigger limb32and the dispensing limb22are arranged in parallel to one another. The drive chassis24is a component that is configured to move in a straight line within the housing in order to drive the medicament M out of the pre-filled syringe on activation of the autoinjector10.

The trigger limb32and the dispensing limb22are arranged in an at least generally U-shaped manner respectively in a U-shaped manner and are connected to one another at a distal end38of the drive chassis24via a web42, i.e. axially offset from one another in the transverse direction T with a length of the trigger limb32being longer than a length of the dispensing limb22.

In this connection it should be noted that in other designs the dispensing limb22can also have the same length as the trigger limb32or even be longer than the trigger limb32.

A plunger support44is arranged at an end of the dispensing limb22remote from the web42. The plunger support44is configured to engage the plunger26that moves through the pre-filled syringe16, i.e. the plunger support44is configured to act on the pre-filled syringe16of the autoinjector10via the plunger26that is arranged within the pre-filled syringe16.

A trigger arm36is arranged to extend proximally from the trigger limb32in both a transvers direction T and a radial direction R relative to an axial direction A, with the axial direction A extending in parallel to the trigger limb32. The trigger arm36is arranged extending from the trigger limb32in a direction remote from the distal end38.

The trigger arm36is fixedly attached to the trigger limb32and moveable relative to the trigger limb32.

The trigger arm36is connected to the trigger limb at a position corresponding to a length of the trigger limb32corresponding to 20 to 80% of a length of the trigger limb32from the distal end38.

In this connection it should be noted that the drive chassis24is formed in one piece, i.e. the trigger limb32, the dispensing limb22, the plunger support44and the trigger arm36are integrally formed in one piece, preferably from one and the same material, e.g. in the same injection mold, or, if manufactured by additive manufacturing techniques, in one production cycle.

The drive chassis24can be installed in the autoinjector10shown in connection withFIGS.1A and1B and2A and2B. The drive chassis24may then be linearly guided within the housing12of the autoinjector upon moving10the autoinjector10from a storage state into a dispensing state of the autoinjector.

For this purpose the drive chassis24can have first and second guiding aids46,48cooperating with corresponding structures present within the housing12. In the present example the first and second guiding aids46,48are formed by first and second grooves46′,48′ that respectively extend in the axial direction A along the dispensing limb22respectively the trigger limb32. The first and second grooves46′,48′ cooperate with lugs164,228(see e.g.FIG.10ArespectivelyFIG.13G) present on an inside wall of the housing12.

Alternatively the drive chassis24can comprise lugs cooperating with corresponding grooves in the housing12as the first and second guiding aids46,48.

Alternatively, the trigger limb32and the dispensing limb22can be shaped in such a way that they cooperate with guide structures present within the housing12, by way of example, the trigger limb32and the dispensing limb22can have a round outer shape in a cross-section therethrough perpendicular to the axial direction A, with the round outer shapes of the trigger limb32and the dispensing limb22then being guided in complementary shaped parts of the housing12.

In the storage state the trigger arm36is held at a stop feature54(see e.g.FIG.4A). Upon moving the autoinjector from the storage state into the dispensing state of the autoinjector, the trigger arm36is deflected out of engagement from the stop feature54. For this purpose the trigger arm36is moveable relative to the trigger limb32, i.e. the position of the trigger arm36can be moved relative to the trigger limb32.

In this connection it should be noted that the stop feature54is arranged at a height along the axial direction A of the housing12corresponding to a length of 45% of the length of the housing12from the distal end30of the autoinjector10.

In this connection it should be noted that the stop feature54can be arranged at a height along the axial direction A of the housing12selected in the range of 30 to 70% of the length of the housing12from the distal end30of the autoinjector10.

In this connection it should be noted that the trigger arm36is configured to move radially in the radial direction R and transversely in the transverse direction T with respect to the trigger limb32.

The trigger limb32has an outer surface49comprising the first part outer surface50(hashed surface) and the second part outer surface52(black outer surface). The first and second part outer surfaces50,52are present at a transverse side of the trigger limb32, i.e. pointing in the transverse direction T. The first and second part outer surfaces50,52are visible via the status indicator window20in different states of use of the autoinjector10.

Specifically, as indicated inFIG.1B, the first part outer surface50is visible via the status indicator window20in the storage state of the autoinjector10and the second part outer surface52is visible via the status indicator window20in the dispensing state towards an end of dose and in the lock-out state of the autoinjector10following an end of dose.

A first limb of the U-shaped drive chassis24is formed by the dispensing limb22and a second limb of the U-shapes drive chassis24is formed by the trigger limb32.

A distal end of the syringe window14is arranged at approximately the same height as a distal end of the status indicator window20. The syringe window14and the status indicator window20are arranged in a part of the housing12where an inner body80and an outer body82(seeFIGS.4A,4B and4C) overlap. The third part of the drive chassis24that may be visible in the syringe window14is the dispensing limb22in addition to which the plunger26of the pre-filled syringe16is also visible.

In this connection it should be noted that the first and second parts50,52of the drive chassis24are not visible in the syringe window14.

So that a user (not shown) can distinguish between the different states of use, i.e. between the first and second part outer surfaces50,52, the appearances of the first and second part outer surfaces50,52differ from one another, i.e. these are different from one another.

In the present example the second part outer surface52comprises a marking printed thereon in the form of a hashed structure, other kinds of surface decorations and/or markings can be employed. The first part outer surface50is e.g. formed in the same colour as the remaining drive chassis24, however, can also have some other colour comprise some form of surface marking and/or decoration or other form of visual indicator.

By way of example words such as “full and/or ready” and “empty and/or used” could printed on the first and second part outer surfaces50,52. Additionally and/or alternatively the first and second part outer surfaces50,52can be coloured differently from one another, e.g. in red or green or the like.

The autoinjector10shown inFIGS.4A to4Ccomprises the needle guard18the removable cap (onlyFIG.4A), the pre-filled syringe16arranged within the housing12, a drive spring74, a lock-out spring76, and a removable needle shield78(RNS).

FIG.4Ashows the autoinjector10ofFIG.1Ain the storage state,FIG.4Bshows the autoinjector10ofFIG.1Ain the activated state shortly before the dispensing state, andFIG.4Cshows the autoinjector10ofFIG.1Ain the lock-out state.

In the storage state of the autoinjector10, a cap70is installed at the proximal end28of the autoinjector10. On removal of the cap70, the needle guard18of the autoinjector10becomes accessible.

The needle guard18is mounted axially moveable in the housing12for movement between the storage state, the dispensing state and the lock-out state. The needle guard18adopts different axial positions relative to the housing12in each one of the storage state, the dispensing state and the lock-out state.

As indicated inFIG.4B, the needle guard18is moved in the distal direction along the axial direction A to make the needle34accessible from the outside, i.e. so that a patient can insert the needle34into his skin.

The needle guard18can be moved automatically in the distal direction along the axial direction A as the patient moves the autoinjector10towards the injection point, as the contact with the patients' skin will automatically move the needle guard into the housing12of the autoinjector10. For this purpose the needle guard18is configured to be axially moved in the distal direction between the storage state and the dispensing state.

Upon moving the needle guard from the storage state into the dispensing state the lock-out spring76is biased between the needle guard18and an inner body80of the housing12.

Once a medicament M has been administered, i.e. dispensed from the autoinjector10, the needle guard18is configured to be axially moved in the proximal direction between the dispensing state and the lock-out state on removing the autoinjector10from the injection site. This movement of the needle guard18is automatically brought about by a relaxation of the lock-out spring76.

The housing12is a two-part housing formed of the inner body80and an outer body82that are fixed in position relative to one another and that are snap fit to one another via a connection72.

As shown inFIG.4B, the connection72is formed by a nose188formed at the inner body that is configured to latch to a window190formed in the outer body82.

In this connection it should be noted that the connection72can also be brought about via a different kind of connection. For example, the nose188can be formed at the outer body82and project towards the inner body80and engage the window190then formed at the inner body80, alternatively different forms of connector can be used to form the connection72.

The trigger arm36is actuated on by the needle guard18of the autoinjector10upon moving the autoinjector10from the storage state into the dispensing state of the autoinjector10. As can be seen from a comparison ofFIGS.4A and4B, the trigger arm36is deflected in the transverse direction T. Moreover, the trigger arm36is also deflected in the radial direction R.

The drive spring74is arranged within the housing12of the autoinjector10. The drive spring74is specifically arranged between a distal housing wall84and the drive chassis24. More specifically the drive spring74is arranged between the distal housing wall84of the outer body82and within the trigger limb32of the drive chassis24. In order to fix a position of the drive spring74this can be arranged at a projection86projecting proximally from the distal housing wall84of the outer body82.

The drive spring74is received within a passage140formed in the trigger limb36of the drive chassis24. This means that the trigger limb36is configured to receive the drive spring74. In the present example, the passage140has a cylindrical shape that is complementary to an outer shape of the drive spring74.

As can be seen from a comparison ofFIGS.4A, and4BwithFIG.4Cthe drive spring74is relaxed in comparison to the other two states in the lock-out state. This is because a release of the engagement between the trigger arm36and the stop feature54permits a proximal movement of the drive chassis24relative to the housing, i.e. relative to the inner and outer bodies80,82under relaxation of the previously biased drive spring74.

The drive spring74also biases the trigger arm36in the storage state of the autoinjector10with respect to the housing12of the autoinjector10by urging this against the stop feature54by the inherent spring bias of the drive spring74.

The drive spring74is further configured to drive the plunger support44of the drive chassis of the autoinjector10into the pre-filled syringe16. This is due to the fact that the drive chassis24is linearly guided within the housing12and is permitted to move proximally once the trigger arm36is released from its engagement with the stop feature54.

The needle guard18surrounds the needle34of the pre-filled syringe16in the storage state and in the lock-out state. Once the cap70is removed and the autoinjector10has been moved into the dispensing state, the needle guard18does not surround the needle34of the pre-filled syringe16.

As indicated inFIGS.4A to4C, the autoinjector10further comprises the lock-out spring76that is arranged between the needle guard18and the housing12, more specifically between the inner body80and the needle guard18.

The lock-out spring76is biased between an end wall88of the needle guard18and a proximal end92of the inner body80. The end wall88is arranged proximally with respect to the inner body80and the drive chassis24.

Moreover, the needle guard18comprises a projection90projecting distally from the proximal end28. The lock-out spring76is arranged at the projection90, in particular, the projection90projects into the lock-out spring76.

The needle guard18is configured to compress the lock-out spring76upon moving between the storage state and the dispensing state. This is possible as the lock-out spring76abuts a proximal end92of the inner body80of the autoinjector10and the projection90is guided through an aperture91present in the inner body80.

Following a use of the autoinjector10and removal of the autoinjector from an injection site, the needle guard18is configured to be moved by a relaxation of the lock-out spring76between the dispensing state and the lock-out state in a proximal direction.

In this connection it should be noted that the projection90could also be disposed at the inner body80such that it projects towards the proximal end28of the needle guard18. If this option is selected, then a length of the projection90has to be adapted such that the projection does not prevent movement of the needle guard in the distal direction and/or such that it does not project beyond the needle guard18in the dispensing state so as to not come into contact with a patient's skin, e.g. if it cooperates with an aperture (not shown) of the needle guard18.

In the storage state of the autoinjector10, the needle guard18is arranged at a first axial position. In the dispensing state the needle guard18is arranged at a second axial position and in the lock-out state the needle guard18is arranged at a third axial position. The first, second and third axial positions respectively differ from one another, with the third axial position being more proximal than the first and second axial positions and the first axial position being more proximal than the second axial position with respect to the housing12.

In this connection it should be noted that the third axial position can be the same or very similar to the first axial position in other designs of the autoinjector10.

This means that an outer length of the autoinjector10with the cap70removed is longest in the lock-out state, shortest in the dispensing state and of medium length in the storage state.

FIG.5Ashows a perspective view of the removable cap70. The cap70is of single piece design. The needle guard18is configured to cooperate with the cap70via one or more snap-fit connections94, wherein each snap fit connection94comprises a protruding edge96(see e.g.FIG.6) cooperating with a corresponding snap-fit area98.

In this connection it should be noted that each of the following components can be respectively integrally formed in one piece, preferably from one and the same material, e.g. in the same injection mold, namely the outer body82, the inner body80, the drive chassis24, the needle guard18, the cap70, and/or the needle shield78.

As shown inFIG.5A, the removable cap70has a base100. The cap70tapers outwardly in the region of the base100such that the base100of the cap70has a larger outer diameter than the remaining cap70. This is particularly beneficial as the base100can act as a stand for the autoinjector10in the storage state of the autoinjector10.

A needle guard facing end102of the cap70comprises a needle shield holder104at an end of the cap70disposed opposite to the base100. The needle shield holder104is configured to hold the removable needle shield78covering the needle of the pre-filled syringe16in the storage state of the autoinjector10.

The inner wall106of the needle shield holder104further comprises two windows112. A respective one of the inwardly facing projections108is arranged at each of the windows112.

Two recesses114are formed in the inner wall106of the needle shield holder104of the cap70. The recesses are arranged between respective parts of the needle shield holder104having the windows112.

The needle shield holder104projects distally from the base100of the cap70and is surrounded by an outer wall116of the cap70. An inner surface118of the outer wall116of the cap70comprises several ribs120.

As indicated inFIG.5B, a front end122of the needle guard18is arranged within an opening124of the cap70. The opening124is formed between the outer wall116of the cap70and the needle shield holder104.

The ribs120are configured to press radially inwardly, i.e. in the radial direction R, and transversely inwardly, i.e. in the transverse direction T, against the needle guard18in the storage state of the autoinjector10.

As also shown inFIG.5Bthe removable needle shield78is arranged within the needle shield holder104. For this reason an inner wall106of the needle shield holder104comprises inwardly facing projections108at the needle guard facing end102that engage a syringe facing surface110of the needle shield78.

As indicated inFIG.6the protruding edges96are provided at an outer surface126of the needle guard18. The snap-fit areas98are provided at the inner surface118of the cap70.

The snap-fit connection94holds the cap70in place in the storage state of the autoinjector. The cap70is removably connected to the needle guard18and, on removal of the cap70, the needle shield78is also removed from the autoinjector10, as the projections108of the cap press on the syringe facing surface110of the removable needle shield78to entrain the removable needle shield in the proximal direction on removal of the cap70.

In order to permit an as compact as possible design of the autoinjector10, an inner surface128of the outer body82comprises a groove130in which one of the protruding edges96can axially move relative to the outer body82on an axial movement of the needle guard18.

Similarly, an inner surface132of the inner body80comprises a further groove134in which a further one of the protruding edges96can axially move relative to the inner body80on an axial movement of the needle guard18relative to the housing12.

The snap-fit projection96thereby forms detent features on the needle guard18that engage with corresponding features on the cap in order to provide a tight axial fit between the components following assembly.

A reverse arrangement of the detent features can also be possible, e.g. snap-fit areas can be present at the housing12and corresponding snap-fit projections could be present at the cap70.

The proximal side of these detent features (snap-fit projections96) on the needle guard is relatively steep, i.e. the proximal side of the snap-fit projections96is steeper than the distal side of the snap-fit projections96in the axial direction, so that once the cap70is removed, if the user attempts to re-attach it, the force to re-engage the detent features is high enough to cause the needle guard18to be moved distally until the detent features are hidden within the housing12.

In this way, re-attachment of the detent features will not be possible (although the cap can be held in place by the engagement of the RNS78and the syringe glass). The distance by which the needle guard18is moved in order to hide the detent features is designed to be less than the distance required to trigger dispense, so that attempted re-attachment of the cap70in this way does not trigger dispense.

When the cap70is attached to the autoinjector10, i.e. to the needle guard18via the snap-fit connection94, the cap70prevents axial movement of the needle guard18when attached to the needle guard18in the storage state.

As further indicated inFIG.6the outer wall116of the cap70contacts an outer wall136of the housing12in the storage state of the autoinjector10. The outer wall116of the cap70and the outer wall136of the housing12do not overlap in an axial direction A of the autoinjector10. Moreover, the outer wall116of the cap70and the outer wall136of the housing12radially overlap in the storage state of the autoinjector10.

It should be noted in this connection that the outer wall136of the housing is the outer wall136of the outer body82forming a part of the two-part housing12.

Clip features in the form of the projections108on the cap70act on the distal surface of the rigid needle shield (RNS)78to grip onto it and remove it from the pre-filled syringe16when the cap70is pulled off by the user.

In this connection it should be noted that a ‘three plate tool’ construction can be used to mould the cap70, including the clip features (projections108) in a single component in a common injection mold (not shown) where state of the art devices typically construct similar caps from two or more separate components.

The projections108are supported by the needle guard18during removal of needle shield78, helping to prevent them from splaying outwards and disengaging, as the needle shield holder104is biased radially inwardly by the needle guard18.

FIGS.7A to7Cshow part sectional views of the autoinjector10, with a part of the housing12removed, such that one can see components of the needle guard18, the drive chassis24, the pre-filled syringe16and the housing12on activating the autoinjector10.

These Figures illustrate a distal movement of the needle guard18into the housing12and how this then engages the release mechanism40comprising the trigger arm36and the stop feature54before the drive chassis24is moved proximally in order to administer the medication M stored in the pre-filled syringe16.

The needle guard18comprises a plunger arm142as part of the release mechanism40of the autoinjector10. The plunger arm142extends distally from the front end122of the needle guard18.

As can be seen the relative position of the plunger arm142relative to the housing12varies and a distance the needle guard18projects beyond the housing12at the proximal end28reduces betweenFIGS.7A to7C.

FIGS.8A to8Cshow detailed views of the different positions of the release mechanism40of the autoinjector10corresponding to the views shown inFIGS.7A to7C.

FIG.8Ashows an enlarged view of the components of the release mechanism40of the autoinjector10which comprises the trigger arm36of the drive chassis24, and the stop feature54present in an opening138of the housing12with which the trigger arm36cooperates.

In this connection it should be noted that the opening138of the housing12is indicated as a through-going opening, i.e. it is open both at an outer wall of the housing12as well as an inner wall of the housing12. It should however be noted that it can also be formed as a recess in the inner wall of the housing12such that it does not go through the wall of the housing12.

The drive chassis24is mounted in the housing12, the drive chassis24is biased with respect to the housing12via the drive spring74. The drive chassis24is further fixed with respect to the housing12and a movement relative to the housing12in the storage state of the autoinjector10via the trigger arm36that is held at the opening138.

In the storage state of the autoinjector10, the drive spring74biases the trigger arm36in the axial direction A against the stop feature54. The trigger arm36is present at the right hand side in the opening138(of the present Figure).

In order to activate the autoinjector10and to release the drive chassis24for its proximal movement, the autoinjector10comprises the release mechanism40.

The release mechanism permits relative movement between the needle guard18and the drive chassis24. This relative movement is achieved by an axial movement of the needle guard18towards the drive chassis24which releases the fixing of the drive chassis24with respect to the housing12on activation of the autoinjector10.

For this purpose the plunger arm142is configured to cooperate with the trigger arm36of the drive chassis24for activation of the release mechanism40. Upon moving the plunger arm142in the distal direction the plunger arm142contacts and thereby deflects the trigger arm36in the transverse direction T as indicated by the arrow B and a comparison of the position of the trigger arm36relative to the opening138shown inFIGS.8A to8C.

The plunger arm142of the needle guard18comprises a blocking rib144. The blocking rib144is configured to block a radial movement of the trigger arm36when the plunger arm142contacts the trigger arm36.

In this connection it should be noted that the blocking rib144is also configured to block a radial movement of the trigger arm36during the storage state prior to the plunger arm142contacting the trigger arm36due to an axial movement of the needle guard18.

In order to engage the trigger arm36, the plunger arm142comprises a cam162. The cam162has an engagement surface146configured to engage the trigger arm36. The engagement surface146projects from the cam162of the plunger arm142at a position adjacent to the blocking rib144in the transverse direction T such that it faces the trigger arm36.

The trigger arm36comprises a web148. The web148extends axially (proximally) below the projection154from the trigger arm36and provides a contact surface in the transverse direction T facing the cam162of the plunger arm142for engagement with the cam142following axial (distal) movement of the needle guard18.

On distally moving the needle guard18, the engagement surface146engages the web148. This means that the web148and the engagement surface146are provided to further facilitate the contact between the trigger arm36and the plunger arm142.

In one embodiment (not shown), the web148can comprise a deflection surface150inclined with respect to the trigger arm36relative to the axial direction A, i.e. a movement direction of the drive chassis24.

In this connection it should be noted that the deflection surface150can be inclined with respect to the axial direction A at an angle selected in the range of 0 to 40°, especially in the range of 5 to 350 and most preferably in the range 10 to 30°.

The engagement surface146is also inclined with respect to a movement direction of the drive chassis24, i.e. with respect to the axial direction A. The engagement surface146is inclined to gradually deflect the trigger arm36in the direction transverse to the axial direction A of movement of the needle guard18in order to shift the trigger arm36from the right hand side of the opening138ofFIG.8Ato the left hand side of the opening138ofFIG.8C.

In this connection it should be noted that the engagement surface146can be inclined with respect to the trigger arm36at an angle selected in the range of 5 to 50°, especially in the range of 7 to 30° and most preferably in the range 8 to 20°.

In this connection it should be noted that the engagement surface146and the web148are arranged to face one another in a cooperating manner.

When the engagement surface146contacts the web148respectively the deflection surface150, the trigger arm36is configured to be moved, in particular disengaged, from the stop feature54, through a deflection in the direction of the arrow B.

The opening138at which the stop feature54is arranged comprises a surface152that has a convex shape. The trigger arm36is configured to cooperate with the convex surface152of the stop feature54.

For this purpose the trigger arm36comprises a projection154engaging the stop feature54. The projection154is configured to cooperate with the opening138by engaging into this and by resting on the surface152of the stop feature54at least in the storage state of the autoinjector10.

The web148is arranged at a surface of the trigger arm36different from a surface at which the projection154of the trigger arm36is arranged. The projection154is arranged to project radially from the trigger arm36, whereas the web148is arranged to project transversely from the trigger arm36.

FIG.8Cshows a state in which the engagement surface146of the blocking rib144of the plunger arm142has moved distally in the axial direction A beyond the axial position of the projection154, the trigger arm36has been deflected in the transverse direction T towards the left hand side of the opening138and also radially inwardly in the radial direction R and out of engagement with the stop feature54.

FIG.8Cshows the state in which the needle guard18has been moved distally with respect to the previous figures, i.e. the autoinjector10is illustrated in the dispensing state just before the drive spring74urges the drive chassis24proximally in the axial direction A, as the trigger arm36has been released from engagement with the stop feature54.

FIG.9Ashows a front view of the opening138ofFIG.8Bwhere the projection154is arranged at an apex160of the surface152.

As discussed in the foregoing, the stop feature54comprises the convex surface152formed by first and second planar surfaces156,158inclined with respect to one another. The first and second planar surfaces156,158adjoin one another at the apex160formed therebetween.

In this connection it should be noted that an angle of inclination between the first and second planar surfaces156,158is selected in the range of 110 to 175°, preferably in the range of 120 to 170° and especially in the range of 130 to 165°.

In this connection it should further be noted that an angle between the first planar surface156and the axial direction A is selected in the range of 0 to 50°, especially in the range of 1 to 30° and most preferably in the range of 2 to 20°.

In this connection it should further be noted that an angle between the second planar surface158and the axial direction A is selected in the range of −20 to 20°, especially in the range of −10 to 10° and most preferably in the range of −5 to 5°.

The apex160forms an overhauling angle the trigger arm36faces on activation of the autoinjector10in order to shift this from the storage state into the dispensing state.

In this connection it should be noted that the faces of the trigger arm can preferably be inclined and angled in such a way that the inclination and angle matches the angles and inclinations of the first and second planar surfaces156,158. In this way a contact area between the first and second planar surfaces156,158can be maximised providing an improved attachment between the respective surfaces particularly in the storage state.

FIG.9Ashows a first view of the release mechanism40having the trigger arm36ofFIGS.8A to8Ccooperating with the stop feature54.FIG.9Bshows a second view of the release mechanism40and especially the cooperation of the trigger arm36with the stop feature54in a view perpendicular to that shown inFIG.9A.

In the storage state the blocking rib144is configured to block a radial movement of the trigger arm36, as it forms a wall against which the trigger arm36abuts in the event that the trigger arm36is urged radially inwardly in a non-permitted manner, e.g. from the outside of the opening138when the plunger arm142contacts the trigger arm36.

In this storage state the drive spring74urges the drive chassis24in the axial direction A and the drive chassis24is axially held in position at the opening138via the protrusion154of the trigger arm36.

More specifically, the protrusion154is so to say held in the acute space formed by the first planar surface156of the stop feature in the opening, as to move the trigger arm36, this not only has to be moved in the transverse direction T but also distally in the axial direction A.

Once the needle guard18is moved towards the drive chassis24upon moving the autoinjector10from the storage state into the dispensing state, the plunger arm142via the engagement surface deflects the trigger arm36, i.e. via the deflection surface150of the web148, both distally in the axial direction A by lifting the web148distally in the axial direction A and pushing the web148transversely in the transverse direction T.

Once the projection154of the trigger arm36has passed the apex160, the spring force of the drive spring74causes the drive spring74to relax and urge the drive chassis24proximally in the axial direction A and the trigger arm36out of engagement from the opening138as indicated e.g. inFIG.8Cor shown inFIG.4C.

Moreover, once the engagement surface146of the plunger arm has deflected the trigger arm36in the transverse direction T this can also be deflected radially inwardly in the radial direction R. As is shown inFIG.4B, this is because the transverse deflection of the trigger arm36by the engagement surface146, moves the trigger arm36out of possible engagement from the blocking rib144of the plunger arm142, so that the trigger arm can then also deflect radially inwardly in the radial direction R past the blocking rib144.

Prior to dispensing, the trigger arm36of the drive chassis24is biased into engagement with the axial stop feature54in the outer body82of the housing12.

Under the action of the axial force from the drive spring74on the drive chassis24, the trigger arm36is discouraged from moving either transversely or radially inwards by:the negative inclined contact surface156of the outer body82of the housing12,friction acting against them,the angle of the trigger arm36, andthe stiffness of the trigger arm36.

In this connection it should be noted that this geometry may require the drive chassis24to be slightly lifted and therefore the drive spring74to be slightly compressed in order to disengage the trigger arm36. However, sufficient robustness (i.e. protection against accidental triggering) can be achieved purely by a combination of the load and frictional coefficient of the surfaces of the stop feature54and of the trigger arm36in contact. If the frictional coefficient is high enough, even a negatively inclined holding surface (opposite to that shown in the diagram) can be functional.

The blocking rib144on the needle guard18also prevents the trigger arm36from moving radially inwards. It would also be feasible to add further blocking rib features (not shown) to the needle guard to prevent transverse movement of the trigger arm36. These transverse blocking rib features would be arranged such that, during the initial displacement of the needle guard18on actuation, they axially disengage from and release transverse movement of the trigger arm36.

FIG.8Ashows the storage position of the release mechanism40in the storage state. The dispensing process is triggered by pressing the needle guard18against the user's skin so that it is displaced distally relative to the outer body82of the housing12.

The angled engagement surface146of the cam162of the needle guard18contacts the trigger arm36and translates its projection154transversely over the apex160of the stop feature54in the outer body82of the housing12.

Once the projection154of the trigger arm36is over the apex160of the stop feature54, it engages a steeper slope of the second planar surface158that, under the action of the drive spring74, causes the trigger arm36to continue to deflect and eventually disengage the stop feature54also in the radial direction without further contact from the needle guard18.

FIG.8Bshows the release mechanism40at the point of triggering, in one optional embodiment, after a short transverse movement, the trigger arm36contacts the outer body82with a further angled face that forces it to move radially inwards until they disengage entirely from the stop feature54.

In an alternative embodiment, the cross-section profile of the trigger arm36tends to create a radial movement of the projection154(to enable disengagement) when the arm36is moved transversely.

Once fully disengaged, the drive chassis24advances towards the pre-filled syringe16to engage the plunger26and starts to dispense medicament M under the action of the drive spring74.

FIG.8Cshows the released position of the release mechanism40. The overhauling convex surface152of the stop feature54of the outer body82of the housing12and the radial lead-in of the trigger arm36increases the axial load bearing contact area (which in turn minimises stress for a given drive spring74force) while simultaneously requiring only a short travel to trigger. This short travel to trigger tends to reduce the triggering force input required of the user, with the drive spring74actually contributing a large part of the triggering energy.

FIG.10Ashows a view of the position of the needle guard18of the autoinjector10relative to the inner body80of the housing12in the storage state of the autoinjector10.FIG.10Bshows a view of the position of the needle guard18of the autoinjector10relative to the housing12in the lock-out state.

The drive chassis24is likewise inserted into the inner body80. The inner body80comprises the lug164cooperating with the second groove48′ of the drive chassis24as the second guiding aid48that enables a linear guidance of the drive chassis24within the inner body80of the housing12.

The needle guard18comprises a protrusion166cooperating with an elongate hole168present in the inner body80, to ensure a linear guidance of the needle guard18relative to the inner body80.

The needle guard18further comprises an anti-pull off feature170. The anti-pull off feature170being configured to prevent a removal of the needle guard from the proximal end of the housing12.

For this purpose the elongate hole168comprises a proximal stop172that prevents the protrusion166from being moved proximally beyond the stop172and hence the stop172acts as the anti-pull off feature170of the needle guard18.

In this connection it should be noted that the elongate hole168is dimensioned such that it is complementary to the shape of the protrusion166and such that it defines a linear movement range of the needle guard16relative to the inner body80.

This means that a width of the elongate hole168perpendicular to the axial direction A can be selected such that it is complementary to a width of the protrusion perpendicular to the axial direction A.

Moreover, a length of the elongate hole168between the proximal stop172and a distal stop192in parallel with the axial direction A can be selected to correspond to a movement range along the axial direction of the needle guard18.

The inner body80further comprises a first cut-out174. The first cut-out174being configured to cooperate with a clip arm184and a lock-out arm186of the needle guard18.

Specifically as shown inFIG.10A, the clip arm184cooperates with a first portion180of the first-cut-out174and the lock-out arm186is configured to cooperate with a second portion182of the first cut-out174.

The first and second portions180and182of the first cut-out respectively have a rectangular shape, directly adjoin one another and are offset along the axial direction A with respect to one another.

The inner body80further comprises a second cut-out176that is axially arranged adjacent to the first cut-out174and is separated from the first cut-out174by a bar178. The second-cut-out176is configured to cooperate with the lock out arm186.

In this connection it should be noted that the second cut-out is configured to only cooperate with the lock-out arm186and thus not with the clip arm184. This is made possible due to the offset between the first and second portions180,182.

In this connection it should further be noted that the lock-out arm comprises an engagement portion220that is configured to engage a corresponding cut-out176.

In the embodiment shown the engagement portion220has a ramp222via which it can overcome the bar178on being moved proximally from the first cut-out174to the second cut-out176and a planar portion224that is configured to drop into the second cut-out176and then to act as an abutment that prevents a distal movement of the needle guard18out of the lock-out state beyond the bar178.

As indicated the first cut-out174can be present at the same side of the inner body80as the elongate hole168. The first cut-out174can also be present at a side different from the side at which the elongate hole168is arranged. It is further possible that two first cut-outs174and/or two elongate holes168are provided that are then arranged at oppositely disposed sides of the inner body80(see e.g.FIGS.14A to14J).

As also indicated inFIGS.10A and10B, the nose188of the connection72is present at the inner body80. The nose188cooperates with the window190shown e.g. inFIGS.4A to4Cto form the connection72.

The function of the needle guard18before dispensing is as follows:

The needle guard spring, i.e. the lock-out spring76(that is biased against the inner body80) applies a proximal force to the needle guard18. The needle guard18is axially retained within the inner body80by its clip arm184. The needle guard lock-out arm186is in clearance to the inner body to avoid long term creep affecting subsequent lock-out robustness.

As the needle guard18is pressed during dispense by the user, the clip arm184moves up within the first cut-out174, more specifically within the first portion180of the first cut-out174, in the inner body80. Towards the end of the dispense stroke of the drive chassis24(but before an end of dose click (seeFIGS.11A and11B), to avoid the associated losses occurring at the same time and reducing the minimum output force from the drive chassis24), the drive chassis24contacts a chamfer226of the clip arm184of the needle guard18thereby, deflecting and holding the clip arms184radially inwards. The chamfer226aids in the deflection of the clip arm184in the radial direction R.

Once a user removes the needle34and thereby the needle guard18from the skin, the needle guard18extends linearly proximally under the action of the lock-out spring76. Because the clip arm184is deflected radially inwards by the drive chassis24, it does not engage with an inner body assembly stop feature194during this return travel. Instead, the needle guard18continues to extend until its lock-out arm184engages with the bar178of the inner body80in an extended position to lock the needle guard18from being able to move in the distal direction. The bar178separates the first cut-out174from the second cut-out and the lock-out arm184is moveable within the first-cut out174during use and prior to lock-out of the needle guard18.

Moreover, the protrusion166prevents the needle guard18from being moved more proximally, in the lock-out state as it engages the proximal end of the elongate hole168acting as the anti-pull off feature170.

FIG.10Bshows the extended position of the needle guard18following dispense and the lock-out clip186engages the bar178. In the fully extended position, the lock-out arm186of the needle guard18engages with the bar178of the inner body80to provide a mechanical lockout against depression of the needle guard18, thus protecting the user from the risk of needle stick.

FIG.11Ashows a view of the autoinjector10in the dispensing state at end of dose, andFIG.11AB shows an enlarged view of part of the autoinjector10in the dispensing state at the end of dose.

The trigger limb32further comprises at least a first part56of an audible end of dose feedback member58in the shape of a click arm56. The first part56, i.e. the click arm56, is formed by a nose60, optionally having a generally triangular outer shape, formed at an end of a tongue62, projecting from the trigger limb32.

The tongue62projects from the trigger limb32in the region of a recess64formed in the outer surface49of the trigger limb32. An opening68of the recess64faces in the radial direction R.

The inner body80of the housing12further comprises at least a second part66of the audible end of dose feedback member58(see e.g.FIG.11B).

The second part66of the audible end of dose feedback member58comprises a distal surface196and a proximal surface198surrounding an inner body recess206.

In this connection it should be noted that the positioning of the respective first and second parts56,66of the audible feedback member58could be reversed, i.e. the recess206could be provided at the drive chassis24, whereas the tongue62could be provided at the inner body80. It should also be noted that each one of the drive chassis24and the inner body80could comprise a respective first and second part56,66of the audible feedback member58which cooperate with a respective other one of the first and second part56,66of the audible feedback member58provided at the other component, i.e. the inner body80has both a recess and a tongue each cooperating with a respective one of a tongue and a recess at the drive chassis24.

On use of the autoinjector10, the trigger limb32is moved by the drive spring74in the axial direction A during dispensing, the first part56of the audible end of dose feedback member58is then deflected in the transverse direction T towards the drive spring74.

This is achieved as an inclined surface200of the end of dose feedback member58is deflected by a distal inner housing end204of the inner housing80. This can be aided as the distal inner housing end204can be chamfered towards the distal wall84of the housing12.

The audible end of dose feedback member58is configured to emit a sound once the material has been dispensed from the autoinjector, i.e. once a click surface202of the nose60attached to the latching tongue62engages the distal surface196of the inner body recess206by moving in the transverse direction T outwardly

The positions of the first and second parts56,66of the audible feedback member58are selected such that the audible click occurs once the plunger26reaches or is about to reach its final position in the pre-filled syringe16.

Thereby the audible end of dose feedback member58is configured to emit a sound between the drive chassis24and the housing12once the material has been dispensed from the autoinjector10.

Thus, towards the end of dose, the nose60of the drive chassis24engages with a ramp of the inner body80, i.e. the chamfered distal inner housing end204which deflects the tongue62radially inwards. Near the end of travel, nose60drops through the inner housing recess206in the inner body80, rapidly releasing its deformation and creating an audible click (either by virtue of contact with another component surface or purely acceleration in the air).

FIGS.12A to12Fshow various views of an example of the cap70of the autoinjector10.

FIG.12Ashows a perspective view of the removable cap70. The cap70is of single piece design. The needle guard18is configured to cooperate with the cap70via one or more snap-fit connections94.

FIGS.12B and12Cshow respective side views of the cap indicating sectional lines C:C, D:D and E:E of the respective sections shown inFIGS.12D to12F.

The windows112shown inFIG.12Bhave an at least generally rectangular shape with rounded edges.

The recesses114shown in theFIG.12Chave the shape of a slot with a rounded end and separate the windows112.

In this connection it should further be noted that the provision of the windows112at the needle shield holder104also provide a respective tooling lead-in surface that enables ejection of the cap70from the injection mold tool.

FIG.12Dshows a section through the cap70taken along the sectional line C:C ofFIG.12B.The ribs120are provided at the inner surface118of the cap70only in a region where the needle shield holder104is not present within the cap70.

As indicated in the section shown inFIG.12Etaken along the sectional line D:D ofFIG.12B. The space provided within the needle shield holder104for receiving and holding the removable needle shield78covering the needle of the pre-filled syringe16in the storage state of the autoinjector10is visible.

An inner shape of the needle shield holder104is shaped complementary to an outer shape of the removable needle shield78to aid an as compact a design as possible of the cap70and to permit a reliable removal of the removable needle shield78on removing the cap70from the autoinjector10.

Moreover, the opening124of the cap70is formed between the outer wall116of the cap70and the needle shield holder104. The dimensions of the opening are selected in dependence on the dimensions of the part of the needle guard that is to be inserted into the opening in the storage state to the autoinjector10.

The needle shield holder104projects distally from the base100of the cap70and is surrounded by the outer wall116of the cap70. The inner surface118of the outer wall116of the cap70comprises several ribs120. These ribs are configured to press against the front end122of the needle guard18when this is arranged within the opening124.

As indicated in the section shown inFIG.12Ftaken along the sectional line E:E ofFIG.12C, the ribs120project inwardly into the opening124of the cap70. The ribs120are distributed over the inner surface118in order to hold the front end122of the needle guard18.

The inner wall106of the needle shield holder104further comprises the two windows112, with a respective one of the inwardly facing projections108being arranged at each of the windows112.

Two recesses114are formed in the inner wall106of the needle shield holder104of the cap70. The recesses are arranged between respective parts of the needle shield holder104having the windows112.

The snap-fit areas98of the cap70are provided at the inner surface118of the cap70and a first snap-fit area208is formed within some of the ribs120of the cap, whereas a second snap in area210is formed in a region of the cap70free of ribs120.

The cap70is of single piece design and an end face in a proximal surface of the cap70at the base100does not comprise a hole.

FIGS.13A to13Jshow various views of an example of the outer body82of the autoinjector10.FIGS.13A and13Bshow respective perspective views from two sides of the outer body82, whereasFIGS.13C to13Fshow respective side views of the outer body82,FIG.13Gshows a section taken along the sectional line C:C ofFIG.13F,FIG.13Hshows a section taken along the sectional line D:D ofFIG.13E, andFIG.13Ishows a top view of the outer body82.

FIG.13Jshows a section taken along the sectional line E:E ofFIG.13E. The lug228configured to engage the second groove48′ forming the second guiding aid48is visible the inner surface132of the outer body82.

In contrast to the embodiment shown in connection with the previous figures, the outer body82comprises two stop features54present at either side of the outer body82in the respective windows40as indicated inFIGS.13A,13C and13E.

Moreover, the projection86projecting from the distal wall84of the outer body82of the housing12is visible inFIG.13G. It is arranged at the same transverse position as the trigger limb32of the drive chassis24, as it is intended to be inserted into the passage140of the drive chassis24on assembly of the autoinjector10.

In this connection it should be noted that the drive chassis24is a component that can be configured to move in a straight line within the housing12in order to drive the medicament M stored in the pre-filled syringe16arranged within the housing12out of the pre-filled syringe16on activation of the autoinjector10by entraining the plunger26of the pre-filled syringe26.

FIGS.14A to14Jshow various views of an example of the inner body80of the autoinjector10.FIGS.14A and14Bshow respective perspective views from two sides of the inner body80. The distal housing end204having the recess formed thereat are shown at the top ofFIGS.14and14b.

FIGS.14C to14Fshow respective side views of the inner body80,FIG.14Gshows a section taken along the sectional line F:F ofFIG.14E,FIG.14Hshows a section taken along the sectional line E:E ofFIG.14F,FIG.14Ishows a top view of the inner body80andFIG.14Jshows a section taken along the sectional line G:G ofFIG.14E.

The inner body80is configured to cooperate with the outer body82ofFIG.13and with the needle guard18shown in the following inFIGS.15A to15J. The inner body80has two first cut-outs174, two second cut-outs176and two elongate holes168arranged at oppositely disposed sides of the inner body80and configured to engage corresponding parts of the needle guard18.

FIGS.15A to15Jshow various views of an example of the needle guard18of the autoinjector10, it is configured to cooperate with the inner body80ofFIGS.14A to14J, for this purpose it includes two protrusions166cooperating with a respective one of the elongate holes168, two lock-out arms186cooperating with a respective one of the first and second cut-outs174,176separated by a respective bar178, and two respective clip-arms184engaging the respective first cut-outs174and the trigger limb32of the drive chassis24.

Moreover, the needle guard18also comprises a single plunger arm142having two blocking ribs144and two cams shaped in the manner described in the foregoing. The blocking ribs144are configured to cooperate with the drive chassis24discussed in connection withFIGS.17A to17Lwhen inserted into the housing12comprising the outer body82discussed in connection withFIGS.13C to13Jand the inner body80discussed in connection withFIGS.14A to14J. It should also be noted that the blocking ribs144are arranged at opposite sides of the plunger arm142.

FIGS.15A and15Bshow respective perspective views from two sides of needle guard18, whereasFIGS.15C and15Fshow respective side views of the needle guard18,FIG.15Gshows a section taken along the sectional line D:D ofFIG.15E,FIG.15Hshows a section taken along the sectional line E:E ofFIG.15F,FIG.15Ishows a top view of the needle guard1880andFIG.15Jshows a section taken along the sectional line F:F ofFIG.15E.

FIGS.16A to16Kshow various views of an example of the needle shield78of the autoinjector10. The needle shield78has a needle receptacle212at an end thereof comprising the syringe facing surface110. The syringe facing surface110is arranged opposite to a front end214of the needle shield78. The needle shield78has outer dimensions configured to be received in the needle shield holder104and inner dimensions adapted to receive the needle34of the pre-filled syringe16.

FIGS.16A,16B,16F and16Eshow various perspective views from above and below of the needle shield78,FIGS.16C,16F,16G and16Hrespective side views of the needle shield78,FIG.16Ishows a section taken along the sectional line B:B ofFIGS.16G and16Jshows a view from the front end214andFIG.16Kshows a section taken along the sectional line C:C ofFIG.16G.

The section B:B ofFIG.16Iindicates that the needle receptacle212is shaped complementary to the needle34of the pre-filled syringe16. The function of the needle shield78is to protect the needle34from external influences.

FIGS.17A to17Lshow various views of an example of the drive chassis24of the autoinjector10. The drive chassis24has two trigger arms36each with its respective components as discussed in the foregoing, a single audible feedback member58arranged at a side of the drive chassis24.

FIGS.17A,17Bshow perspective views of the drive chassis24, whereasFIGS.17C to17Fshow different side views of the drive chassis24.FIG.17Gshows a section taken along the section line E:E ofFIG.17Ethrough the dispensing limb22having the plunger support44.

FIG.17H, shows a section taken along the sectional line F:F ofFIG.17Ethrough the trigger limb32indicating the passage140formed therein.

FIG.17Ishows a section taken along the sectional line G:G ofFIG.17Fshowing the parallel arrangement of the dispensing limb22and the trigger limb32.

FIG.17Jshows a top view of the drive chassis24with the projections154of the trigger arms36projecting radially outwardly from the drive chassis24.

FIG.17Kshows a section taken along the sectional line D:D ofFIG.17EandFIG.17Lshows a section taken along the sectional line C:C ofFIG.17Eat a height of the drive chassis24where the two projections154are positioned relative to the trigger arms36.

FIG.17Dand f by way of example show that the trigger limb32comprises a lip216at an end disposed opposite to the web42. The lip216is configured to engage the clip arms184formed at the needle guard18.

The lip216comprises two tips218, with each tip218being configured to engage a respective one of the clip arms184formed at the needle guard18.

It should also be noted that the first and second guiding aids extend proximally from the web42, with the second groove48′ extending directly from the web42and the first groove46′ begin offset from the web42.

In the foregoing the mechanism elements of a disposable auto-injector10to dispense medicament M from the pre-filled syringe (PFS)16are described. The design disclosed permits state of the art features to be incorporated into a small physical package using a very small number of low cost components and a very simple process, compared to the state of the art.

The auto-injector device disclosed includes an assembly surrounding a pre-filled syringe (PFS)16that contains medicament M. Typically, such devices are single-use and intended for administration by a patient (i.e. self-administration) or carer.

At point of use, the user removes the protective Cap70from the proximal end of the autoinjector10, positions the autoinjector10at the injection site (typically the skin of the thigh or belly) and presses the autoinjector10axially in a proximal direction, to achieve needle insertion of the needle34into the skin and to initiate dispense.

Energy from a helical compression drive spring74is released to displace the plunger26within the PFS16and deliver the medicament M to the patient. An audible click notifies the patient that dispense has started. In this connection it should be noted that such an audible click can be generated when the trigger arm36cooperates with the stop feature54on triggering the release mechanism40upon moving the autoinjector10from the storage state to the dispensing state. The progress of dispense can be monitored by the user as a change in position of the PFS plunger26and mechanism plunger within the large wrap-around ‘syringe window’14.

The user is notified when the dose is complete by an audible click emitted from the autoinjector10and a change in the colour displayed within a unique ‘status indicator window’20. The autoinjector10can then be removed from the injection site, allowing the sprung needle guard18to extend to a locked position under the action of a separate helical compression spring76to cover the needle34. In this locked position, the needle guard18covers the needle34and protects the patient or a further person from needle34stick injuries.

The mechanism described utilises a parallel drive arrangement where the axis of the drive spring74is offset from the axis of the PFS16, rather than passing into the bore of the PFS16as is common in the prior art. This arrangement has a number of advantages:The length of the autoinjector10can be minimised so that it is largely determined by the PFS16length and plunger26travel.It allows flexibility in the specification of the drive spring74(e.g. to increase or reduce the force it applies or make other modifications to improve the efficiency of manufacturing), since its geometry is not constrained by the PFS16bore diameter.It allows improved access to components and features, where a tubular arrangement often necessitates a number of concentric (or at least co-axial) components that move relative to each other, which can then be challenging to connect with each other in the optimal way. The improved access further allows simpler interactions between components to create features for triggering, feedback and lock-out which tend to avoid the need for additional parts or complex mechanisms.

The simplicity of the mechanism results in a reduced number of components, which in turn helps to minimise the number of wall thicknesses required and hence device width and depth.

Due to the disposable nature of single-use auto-injectors10, it is considered advantageous to minimise autoinjector10complexity, material usage, package size and assembly complexity in this way, as this all tends to reduce cost and environmental impact by:Reducing the volume of raw materials used,Reducing the cost of manufacturing equipment and the assembly process,Reducing the volume required in transport and storage, which can be particularly expensive when low temperatures are required.

The disclosed invention achieves this simplicity and small size whilst incorporating state of the art user features and adding innovative new user features.

Enumerated Embodiments

1. An autoinjector10comprising:a housing12,a pre-filled syringe16mounted in the housing12and fixed relative to the housing12, and a needle guard18mounted axially moveable in the housing12for movement between a storage state, a dispensing state and a lock-out state in which states the needle guard18adopts different axial positions relative to the housing12,wherein the needle guard18is configured to be axially moved in a distal direction between the storage state and the dispensing state andwherein the needle guard18is configured to be axially moved in a proximal direction between the dispensing state and the lock-out state.2. The autoinjector10according to embodiment 1, wherein the needle guard18surrounds a needle34of the pre-filled syringe16in the storage state and in the lock-out state.3. The autoinjector10according to embodiment 1 or embodiment 2, wherein the needle guard18does not surround a needle34of the pre-filled syringe16in the dispensing state.4. The autoinjector10according to one of embodiments 1 to 3, further comprising a lock-out spring76arranged between the needle guard18and the housing12.5. The autoinjector10according to embodiment 4, wherein the needle guard18is configured to compress the lock-out spring76upon moving between the storage state and the dispensing state.6. The autoinjector10according to embodiment 4 or embodiment 5, wherein the needle guard18is configured to be moved by a relaxation of the lock-out spring76between the dispensing state and the lock-out state.7. The autoinjector10according to one of embodiments 1 to 6, wherein the needle guard18comprises one or more lock-out arms186.8. The autoinjector10according to embodiment 7, wherein the one or more lock-out arms186comprise an engagement portion220that is configured to engage a corresponding cut-out176in the housing12of the autoinjector10in the lock-out state.9. The autoinjector10according to one of embodiments 4 to 8 and embodiment 7, wherein two or more lock-out arms186are provided, with the lock-out spring76being arranged between the two or more lock-out arms186.10. The autoinjector10according to one of embodiments 1 to 9, wherein the needle guard18comprises an anti-pull off feature170cooperating with the housing12.11. The autoinjector10according to one of embodiments 1 to 10, wherein the needle guard18comprises a plunger arm142for activation of a release mechanism40of the autoinjector10.12. The autoinjector10according to embodiment 10 and embodiment 11, wherein the anti-pull off feature170is arranged at the plunger arm142.13. The autoinjector10according to one of embodiments 10 to 12, wherein the anti-pull of feature170comprises a protrusion166that engages a hole168present in the housing12.14. The autoinjector10according to one of embodiments 1 to 13, further comprising a drive chassis24, the drive chassis24being mounted in the housing12, the drive chassis24being biased with respect to the housing12, the drive chassis24further being fixed with respect to the housing12and a movement relative to the housing12in a storage state of the autoinjector10.15. The autoinjector10according to embodiment 14 and of embodiments 7 to 13, wherein the drive chassis24is configured to engage the one or more clip arms184to deflect these radially inwardly away from the housing12in the dispensing state.16. The autoinjector10according to embodiment 14 or embodiment 15 and one of embodiments 11 to 13, wherein the plunger arm142is configured to cooperate with a trigger arm36of the drive chassis24for activation of a release mechanism40of the autoinjector10.17. The autoinjector10according to one of embodiments 14 to 16, wherein an axial movement of the needle guard18towards the drive chassis24releases the fixing of the drive chassis24with respect to the housing12on activation of the autoinjector10.18. The autoinjector10according to embodiment 16 or embodiment 17, wherein the axial movement of the needle guard18is configured to deflect the trigger arm36in a direction transverse to the axial movement.19. The autoinjector10according to one of embodiments 16 to 18 and one of embodiments 11 to 15, wherein the plunger arm142is configured to deflect the trigger arm36in a direction transverse to the axial movement of the needle guard18.20. The autoinjector10according to one of embodiments 1 to 19, wherein the needle guard18comprises a blocking rib144.21. The autoinjector10according to embodiment 20 and one of embodiments 16 to 19, wherein the blocking rib144is configured to block a radial movement of the trigger arm36.22. The autoinjector10according to one of embodiments 1 to 21, wherein the needle guard18further comprises cam162having an engagement surface146.23. The autoinjector10according to one of embodiments 16 to 21 and embodiment 22, wherein the engagement surface146is configured to engage the trigger arm36.24. The autoinjector10according to embodiment 23, wherein the trigger arm36comprises a web148and the engagement surface146engages the web148of the trigger arm36.25. The autoinjector10according to one of embodiments 21 to 24 and embodiment 20, wherein the engagement surface146projects from the blocking rib144.26. The autoinjector10according to embodiment 24 or embodiment 25, wherein the web148comprises a deflection surface150inclined with respect to a movement direction of the drive chassis24.27. The autoinjector10according to one of embodiments 22 to 26, wherein the engagement surface146is inclined with respect to a movement direction of the drive chassis24.28. The autoinjector10according to embodiment 26 and embodiment 27, wherein the engagement surface146and the deflection surface150are inclined with respect to a movement direction of the drive chassis24in a cooperating manner.29. The autoinjector10according to embodiment 28, wherein the engagement surface146is inclined to deflect the trigger arm36in the direction transverse to the axial direction of movement of the needle guard18.30. The autoinjector10according to one of embodiments 14 to 29, further comprising a drive spring74, with the drive spring74being configured to drive the drive chassis24towards the needle guard18after activation of the autoinjector10.31. The autoinjector10according to one of embodiments 1 to 30, wherein the needle guard18is configured to cooperate with a cap70via one or more snap-fit connections94.32. The autoinjector10according to embodiment 31, wherein each snap fit connection comprises a snap-fit projection96cooperating with a corresponding snap-fit area98.33. The autoinjector10according to embodiment 32, wherein the needle guard18comprises one or more snap-fit projections96.34. The autoinjector10according to embodiment 32 or embodiment 33, wherein one or more snap-fit projections96are provided at an outer surface126of the needle guard18.35. The autoinjector10according to one of embodiments 32 to 34, wherein an inner surface128,132of the housing12comprises one or more grooves130,134in which one or more of the snap-fit projections96can axially move relative to the housing12upon axial movement of the needle guard18.36. The autoinjector10according to one of embodiments 31 to 35, wherein a front end122of the needle guard18is arranged within an opening124of the cap70.37. The autoinjector10according to one of embodiments 31 to 36, wherein an outer wall116of the cap70contacts an outer wall136of the housing12in the storage state of the autoinjector10.38. The autoinjector10according to embodiment 37, wherein the outer wall116of the cap70and the outer136wall of the housing12do not overlap in an axial direction of the autoinjector10.39. The autoinjector10according to embodiment 37 or embodiment 38, wherein the outer wall116of the cap70and the outer wall136of the housing12radially overlap in the storage state of the autoinjector10.40. The autoinjector10according to one of embodiments 1 to 39, wherein the housing12is a two-part housing12comprising an inner body80and an outer body82.41. The autoinjector10according to one of embodiments 1 to 40, further comprising a drive chassis24mounted in the housing12, the drive chassis24being biased with respect to the housing12, the drive chassis24further being fixed with respect to the housing12and for a movement relative to the housing12in a storage state of the autoinjector10, the drive chassis24moving relative to the housing12on dispensing a material from the pre-filled syringe16.42. The autoinjector10according to embodiment 41, wherein the autoinjector10is configured to generate an audible end of dose feedback between the drive chassis24and the housing12once the material has been dispensed from the autoinjector10.43. The autoinjector10according to one of embodiments 1 to 42, further comprising a drive chassis24mounted in the housing12, the drive chassis24being biased with respect to the housing12by a drive spring74, the drive chassis24further being fixed with respect to the housing12and a movement relative to the housing12in a storage state of the autoinjector10.44. The autoinjector10according to embodiment 43, wherein the drive chassis24comprises a trigger arm36engaging a stop feature54present in the housing12in the storage state of the autoinjector10for fixing the drive chassis24with respect to the housing12.45. The autoinjector10according to embodiment 44, wherein the trigger arm36is configured to be disengaged from the stop feature54on activation of the autoinjector10.46. The autoinjector10according to one of embodiments 1 to 45, further comprising a needle shield78covering a needle34of the pre-filled syringe16in a storage state of the autoinjector10, the axially moveable needle guard18arranged to cover the needle34of the pre-filled syringe16at least after use of the autoinjector10and to move relative to the pre-filled syringe16during use of the autoinjector10, as well as a removable cap70in which the needle guard18is stored in the storage state of the autoinjector10.47. The autoinjector10according to embodiment 46, wherein the cap70is removably connected to the needle guard18in the storage state of the autoinjector10, and wherein, on removal of the cap70, the needle shield78is also removed from the autoinjector10.48. The autoinjector10according to one of embodiments 1 to 47, further comprising a drive chassis24mounted in the housing12, the drive chassis24being biased with respect to the housing12and being fixed with respect to the housing12in a storage state of the autoinjector10.49. The autoinjector10according to embodiment 48, further comprising a status indicator window20arranged at the housing12via which the drive chassis24is visible from the outside, with the status indicator window20showing a first part50of the drive chassis24in the storage state of the autoinjector10and a second part52of the drive chassis24after use of the autoinjector10, with the first and second parts50,52of the drive chassis24being distinguishable from one another.50. The autoinjector10according to one of embodiments 1 to 49, further comprising a drive chassis24, the drive chassis24comprising a dispensing limb22and a trigger limb32, wherein a plunger26is arrangeable at a proximal end of the dispensing limb22and a trigger arm36is arranged extending proximally from the trigger limb32.51. The autoinjector10according to embodiment 50, wherein the trigger limb32and the dispensing limb22are arranged in parallel to one another respectively at least essentially in parallel to one another and are connected to one another at a respective distal end side of the dispensing limb22and the trigger limb32via a web42.52. An autoinjector10, optionally in accordance with one of embodiments 1 to 51, the autoinjector10comprising:a housing12,a pre-filled syringe16mounted in the housing12,a drive chassis24mounted in the housing12, the drive chassis24being biased with respect to the housing12, the drive chassis24further being fixed with respect to the housing12and for a movement relative to the housing12in a storage state of the autoinjector10, the drive chassis24moving relative to the housing12on dispensing a material from the pre-filled syringe16, andwherein the autoinjector10comprises an audible feedback member58is configured to generate an audible end of dose feedback between the drive chassis24and the housing12once the material has been dispensed from the autoinjector10.53. The autoinjector10according to one or more of the preceding embodiments, wherein drive chassis24comprises a first part56of the audible feedback member58that engages a second part66of the audible feedback member58arranged at the housing12to generate the audible end of dose feedback.54. The autoinjector10according to one or more of the preceding embodiments, wherein the housing12comprises a recess208and the drive chassis24engages the recess208to generate the audible end of dose feedback.55. The autoinjector10according to embodiment 53 and embodiment 54, wherein the first part56of the audible feedback member58of the drive chassis24engages the recess208to generate the audible end of dose feedback56. The autoinjector10according to one or more of the preceding embodiments, wherein the housing12comprises a chamfered distal inner housing end204on an inner surface132thereof.57. The autoinjector10according to embodiment 56, wherein the chamfered distal inner housing end204deflects a part of the drive chassis24radially inwardly as this moves from the storage state to an end of dose state.58. The autoinjector10according to embodiment 57 and one of embodiments 53 to 56, wherein the chamfered distal inner housing end204deflects the first part56of the audible feedback member58radially inwardly as the drive chassis24moves from the storage state to an end of dose state.59. The autoinjector10according to embodiment 58,wherein the chamfered distal inner housing end204is configured to deflect the first part56of the audible feedback member58radially inwardly before the first part56of the audible feedback member58engages the recess208.60. The autoinjector10according to one or more of the preceding embodiments, wherein the audible end of dose feedback comprises an audible click.61. The autoinjector10according to embodiment 60, wherein the audible click is brought about by at least one of a contact between two components56,66and an acceleration of a component56.62. The autoinjector10according to embodiment 60 or embodiment 61 and one of embodiments 57 to 59, wherein the audible click is generated by a radially outwardly directed relaxation of the radially inwardly deflected part56of the drive chassis24.63. The autoinjector10according to one or more of the preceding embodiments, wherein the drive chassis24further comprises a plunger support44for engaging a plunger26of the pre-filled syringe16.64. The autoinjector10according to embodiment 63 and one of embodiments 55 to 62, wherein the first part56of the audible feedback member58extends from the drive chassis at a part of the drive chassis24different from the plunger support44.65. The autoinjector10according to one or more of the preceding embodiments further comprising a drive spring74mounted between the drive chassis24and the housing12.66. The autoinjector10according to embodiment 65 and one of embodiments 63 and 64, wherein a relaxation of the drive spring74drives the plunger support44towards the plunger26of the pre-filled syringe16after activation of the autoinjector10.67. The autoinjector10according to embodiment 66, wherein the drive spring74is arranged within a part of the drive chassis24comprising the first part56of the audible feedback member58, in particular in a passage140.68. The autoinjector10according to one or more of the preceding embodiments, wherein the housing12is a two-part housing comprising an inner body80and an outer body82.69. The autoinjector10according to embodiment 68, wherein the inner body80and the outer body82are fixed in position relative to one another.70. The autoinjector10according to embodiment 68 or embodiment 69, wherein the inner body80and the outer body82are connected to one another via a connection72.71. The autoinjector10according to embodiment 70, wherein the connection72is formed by a nose188engaging a window190.72. The autoinjector10according to embodiment 71, wherein the nose188is formed at the inner body80and engages the window190formed at the outer body82.73. The autoinjector10according to embodiment 68 and one of embodiments 54 to 72, wherein the inner body80comprises the recess208.74. The autoinjector10according to one or more of the preceding embodiments, wherein the inner body80comprises one or more cut-outs174,176and/or holes168that are configured to cooperate with one or more corresponding parts184,186,166of the needle guard18.75. The autoinjector10according to one or more of the embodiments 68 to 74 and one or more of the embodiments 54 to 66, wherein the drive spring74is arranged between the outer body82and the drive chassis24.76. The autoinjector10according to one or more of the preceding embodiments, wherein the drive chassis24is of generally U-shaped design and comprises a dispensing limb22as well as a trigger limb32.77. The autoinjector10according to one or more of the preceding embodiments, wherein the drive chassis24, the first part56of the audible feedback member58and the plunger support44are formed in one piece from the same material.78. An autoinjector10, optionally in accordance with one or more of the preceding embodiments, the autoinjector10comprising:a housing12in which a pre-filled syringe16is arranged,a drive chassis24mounted in the housing12, the drive chassis24being biased with respect to the housing12by a drive spring74, the drive chassis24further being fixed with respect to the housing12and a movement relative to the housing12in a storage state of the autoinjector,the drive chassis24comprising a trigger arm36engaging a stop feature54present in the housing12in the storage state of the autoinjector10for fixing the drive chassis24with respect to the housing12, andwherein the trigger arm36is configured to be disengaged from the stop feature54on activation of the autoinjector10.79. The autoinjector10according to one or more of the preceding embodiments, wherein the stop feature54comprises an opening138.80. The autoinjector10according to one or more of the preceding embodiments, wherein the stop feature54comprises a convex surface152.81. The autoinjector10according to embodiment 80, wherein the trigger arm36is configured to cooperate with the convex surface152of the stop feature54.82. The autoinjector10according to one or more of the preceding embodiments, wherein the trigger arm36comprises a projection154engaging the stop feature54.83. The autoinjector10according to embodiment 82, wherein the projection154is configured to cooperate with the opening138.84. The autoinjector10according to one of embodiments 82 or embodiment 83, wherein the projection156is configured to cooperate with the convex surface152.85. The autoinjector10according to one or more of the preceding embodiments, wherein the trigger arm36comprises a web148projecting therefrom.86. The autoinjector10according to embodiment 85 and embodiment 84 or embodiment 83, wherein the web148is arranged at a surface different from a surface at which the projection154is arranged.87. The autoinjector10according to one or more of the preceding embodiments, further comprising a needle guard18, wherein an axial movement of the needle guard18towards the drive chassis24releases the fixing of the drive chassis24with respect to the housing12.88. The autoinjector10according to embodiment 87, wherein the needle guard18comprises a blocking rib144.89. The autoinjector10according to embodiment 87 or embodiment 88, wherein the needle guard18engages the trigger arm36on axially moving toward the drive chassis24.90. The autoinjector10according to one of embodiments 87 to 89 and embodiment 85, wherein the needle guard18comprises an engagement surface146configured to engage the web148of the trigger arm36.91. The autoinjector10according to embodiment 88 or embodiment 89 and embodiment 90, wherein the engagement surface146projects from the rib.92. The autoinjector10according to one of embodiments 80 to 86, wherein the web148comprises a deflection surface150inclined with respect to a movement direction of the drive chassis24.93. The autoinjector10according to one of embodiments 85 to 87, wherein the engagement surface146is inclined with respect to a movement direction of the drive chassis24.94. The autoinjector10according to embodiment 92 and embodiment 93, wherein the engagement surface146and the deflection surface150are inclined with respect to a movement direction of the drive chassis24in a cooperating manner.95. The autoinjector10according to one of embodiments 78 to 94, wherein the drive spring74is configured to drive the drive chassis24towards the needle guard18after activation of the autoinjector10.96. The autoinjector10according to one or more of the preceding embodiments, wherein the drive chassis24further comprises a plunger support44for engaging a piston of the pre-filled syringe16.97. The autoinjector according to embodiment 96, wherein a relaxation of the drive spring74drives the plunger support44towards the plunger26of the pre-filled syringe16.98. The autoinjector according to one of the preceding embodiments, wherein the drive chassis24is of generally U-shaped design.99. The autoinjector according to one or more of the preceding embodiments, wherein the trigger arm36, the drive chassis24and the plunger support44are formed in one piece from the same material.100. An autoinjector10, optionally in accordance with one or more of the preceding embodiments, the autoinjector10comprising a pre-filled syringe16arranged within a housing12of the autoinjector10, a needle shield78covering a needle34of the pre-filled syringe16in a storage state of the autoinjector10, an axially moveable needle guard18arranged to cover the needle34of the pre-filled syringe16at least after use of the autoinjector10and to move relative to the pre-filled syringe16during use of the autoinjector10, as well as a removable cap70in which the needle guard18is stored in the storage state of the autoinjector10, wherein the cap70is removably connected to the needle guard18in the storage state of the autoinjector10, and wherein, on removal of the cap70, the needle shield78is also removed from the autoinjector10.101. The autoinjector according to one or more of the preceding embodiments, wherein the needle guard18is connected to the cap70via one or more snap fit connections94.102. The autoinjector according to embodiment 101, wherein each snap fit connection94comprises a snap-fit projection96cooperating with a corresponding snap-fit area98.103. The autoinjector according to embodiment 102, wherein one or more snap-fit projections96are provided at an outer surface126of the needle guard18.104. The autoinjector according to embodiment 101 or embodiment 102, wherein one or more snap-fit areas98are provided at an inner surface of the cap70.105. The autoinjector according to one or more of the preceding embodiments, wherein an outer wall116of the cap70contacts an outer wall136of the housing12in a storage state of the autoinjector10.106. The autoinjector according to embodiment 105, wherein the outer wall116of the cap70and the outer wall136of the housing12do not overlap in an axial direction of the autoinjector10.107. The autoinjector according to embodiment 105 or embodiment 106, wherein the outer wall116of the cap70and the outer wall136of the housing12radially overlap in the storage state of the autoinjector10.108. The autoinjector according to one or more of the preceding embodiments, wherein the cap70prevents axial movement of the needle guard18when attached to the needle guard18in the storage state.109. The autoinjector according to one or more of the preceding embodiments,wherein the needle shield78is arranged within an inner wall of the cap70in the storage state of the autoinjector10.110. The autoinjector according to one or more of the preceding embodiments, wherein a front end of the needle guard18is arranged within an opening124of the cap70.111. The autoinjector according to one or more of the preceding embodiments, wherein a front end122of the needle guard18is arranged within an opening124of the cap70and wherein the opening124is formed between the outer wall116of the cap70and the inner wall of the cap70.112. The autoinjector according to one or more of the preceding embodiments, wherein a front end122of the needle guard18is arranged within an opening124of the cap70and wherein the front end122of the needle guard18comprises the one or more snap-fit projections96.113. The autoinjector according to one or more of the preceding embodiments, wherein an inner surface128,132of the housing12comprises one or more grooves130,134in which one or more of the snap-fit projections96can axially move relative to the housing12on a movement of the needle guard18.114. The autoinjector according to one or more of the preceding embodiments, wherein the axially moveable needle guard18is arranged to move relative to the housing12during use of the autoinjector10.115. The autoinjector according to one or more of the preceding embodiments, wherein the cap70is of single piece design.116. The autoinjector according to one or more of the preceding embodiments, wherein the cap70comprises inwardly facing projections108at a needle guard facing end102that engage a syringe facing surface110of the needle shield78.117. The autoinjector according to one or more of the preceding embodiments, wherein the inner wall106of the cap70comprises two windows112.118. The autoinjector10according to embodiment 116 and embodiment 117, wherein each projection108is arranged at a window112.119. The autoinjector10according to one or more of the preceding embodiments, wherein recesses114are formed in the inner wall of the cap70.120. The autoinjector10according to one or more of the preceding embodiments, wherein an inner surface118of the outer wall116of the cap70comprises one or more ribs120.121. The autoinjector10according to one or more of the preceding embodiments, wherein the cap70comprises a stand of the autoinjector10.123. The autoinjector10according to one or more of the preceding embodiments, wherein an axial movement of the needle guard18in the direction of the pre-filled syringe16brings about an engagement of the release mechanism40of a plunger26of the pre-filled syringe16for dispensing a material stored in the pre-filled syringe16.124. An autoinjector10, optionally according to one or more of the preceding embodiments, the autoinjector10comprising:a housing12in which a pre-filled syringe16is arranged,a drive chassis24mounted in the housing12, the drive chassis24being biased with respect to the housing12and being fixed with respect to the housing12in a storage state of the autoinjector10,a status indicator window20arranged at the housing12via which the drive chassis24is visible from the outside, with the status indicator window20showing a first part50of the drive chassis24in the storage state of the autoinjector10and a second part52of the drive chassis24after use of the autoinjector10, with the first and second parts50,52of the drive chassis24being distinguishable from one another.125. The autoinjector10according to embodiment 124, wherein the status indicator window20is formed by an elongate slot extending radially around a part of the housing12.126. The autoinjector10according to embodiment 124 or embodiment 125, wherein the first and second parts50,52of the drive chassis24are distinguishable from one another due to a difference in colour, a printed label applied at a surface of the drive chassis24, a text applied on the surface49of the drive chassis24and/or an icon displayed in the surface of the drive chassis24.127. The autoinjector10according to according to one or more of the preceding embodiments, further comprising a syringe window14via which the pre-filled syringe16is visible from the outside.128. The autoinjector10according to embodiment 127, wherein the syringe window14shows a content filled in the pre-filled syringe16in the storage state of the autoinjector10.129. The autoinjector10according to embodiment 127 or embodiment 128, wherein the syringe window14shows at least one of a plunger26arranged within the pre-filled syringe16and a part of the dispensing limb22in the pre-filled syringe16after use of the autoinjector10.130. The autoinjector10according to one of embodiments 127 to 129, wherein the syringe window14is arranged in the housing12.131. The autoinjector10according to one of embodiments 127 to 130, wherein the syringe window14is of elongate shape and a length of the elongate shape extends in an axial direction of the autoinjector10.132. The autoinjector10according to one of embodiments 127 to 131, wherein the syringe window is arranged transverse to the status indicator window20.134. The autoinjector10according to one of embodiments 127 to 132, wherein the syringe window shows a different part of the drive chassis24in comparison with the status indicator window20.135. The autoinjector10according to one or more of the preceding embodiments, wherein the drive chassis24comprises a trigger arm36engaging an opening138in the housing12in the storage state of the autoinjector10.136. The autoinjector10according to one or more of the preceding embodiments, further comprising a needle guard18, wherein an axial movement of the needle guard18towards the drive chassis24releases the fixing of the drive chassis24with respect to the housing12.137. The autoinjector10according to embodiment 136, wherein the needle guard18comprises a plunger arm142.138. The autoinjector10according to embodiment 136 or embodiment 137, wherein the needle guard18engages the trigger arm36on axially moving toward the drive chassis24.139. The autoinjector10according to embodiment 137 or embodiment 138, wherein the plunger arm142of the needle guard18engages the trigger arm36on axially moving toward the drive chassis24.140. The autoinjector10according to one or more of the preceding embodiments, further comprising a drive spring74mounted between an end of the housing12and the drive chassis24.141. The autoinjector10according to embodiment 140, wherein the spring is configured to drive the drive chassis24towards the needle guard18after activation of the autoinjector10.141. The autoinjector10according to one or more of the preceding embodiments, wherein the drive chassis24further comprises a plunger support44for engaging a piston of the pre-filled syringe16.142. The autoinjector10according to embodiment 139 or embodiment 140 and embodiment 141, wherein the relaxation of the drive spring74drives the plunger support44towards the piston of the pre-filled syringe16.143. The autoinjector10according to one or more of the preceding embodiments, wherein the drive chassis24is of generally U-shaped design.144. The autoinjector10according to one or more of the preceding embodiments, wherein the trigger arm36, the drive chassis24and the plunger support44are formed in one piece from the same material.145. An autoinjector10, optionally according to one or more of the preceding embodiments, comprising a drive chassis24, the drive chassis24comprising a dispensing limb22and a trigger limb32, wherein a plunger26is arranged at a proximal end of the dispensing limb22and a trigger arm36is arranged extending proximally from the trigger limb32, wherein the trigger limb32and the dispensing limb22are arranged in parallel to one another respectively at least essentially in parallel to one another and are connected to one another at a respective distal side of the dispensing limb22and the trigger limb32.146. An autoinjector10according to embodiment 145, wherein the trigger limb32, the dispensing limb22, the plunger support44and the trigger arm36are integrally formed in one piece.147. An autoinjector10according to embodiment 145 or embodiment 146, wherein the trigger arm36is biased with respect to a housing12of the autoinjector10in a storage state of the autoinjector10.148. The autoinjector10according to one or more of the preceding embodiments, wherein the trigger arm36is deflected upon moving the autoinjector10from a storage state into an activated state of the autoinjector10.149. The autoinjector10according to one or more of the preceding embodiments, wherein the trigger arm36is actuated on by a needle guard18of the autoinjector10upon moving the autoinjector10from a storage state into an activated state of the autoinjector10.150. The autoinjector10according to one or more of the preceding embodiments, wherein the plunger support44is configured to act on a pre-filled syringe16of the autoinjector10.151. The autoinjector10according to one or more of the preceding embodiments, further comprising a drive spring74.152. The autoinjector10according to embodiment 151, wherein the drive spring74is arranged within a housing12of the autoinjector10between a distal housing wall84and the drive chassis24.153. The autoinjector10according to embodiment 152, wherein the drive spring74biases the trigger arm36in a storage state of the autoinjector10with respect to the housing12of the autoinjector10.154. The autoinjector10according to one of embodiments 151 to 153, wherein the drive spring74is configured to drive the plunger26of the autoinjector10in a pre-filled syringe16of the autoinjector10.155. The autoinjector10according to one or more of the preceding embodiments, wherein the drive chassis24is linearly guided within a housing12of the autoinjector10upon moving the autoinjector10from a storage state into an activated state of the autoinjector10.156. The autoinjector10according to one or more of the preceding embodiments, wherein the trigger arm36is configured to move radially and transversely with respect to the trigger limb32.156. The autoinjector10according to one or more of the preceding embodiments, wherein the trigger arm36is configured to cooperate with a stop feature54arranged at the housing12in a storage state of the autoinjector10.158. The autoinjector10according to one or more of the preceding embodiments, wherein the trigger limb32and the dispensing limb22are arranged in an at least generally U-shaped manner respectively in a U-shaped manner.159. The autoinjector10according to one or more of the preceding embodiments, wherein the trigger limb32further comprises at least a first part56of an audible end of dose feedback member58.160. The autoinjector10according to embodiment 159, further comprising a housing12, wherein the housing12further comprises at least one second part66of the audible end of dose feedback member58, optionally wherein the housing12is formed by an outer body82and an inner body80and one of the inner body80and the outer body82comprises the at least one second part66of the audible end of dose feedback member58.161. The autoinjector10according to embodiment 159 or embodiment 160, wherein the first and second parts56,66of the audible end of dose feedback members58are formed by a recess208and a latching tongue62configured to cooperate with the recess208.162. The autoinjector10according to one of embodiments 159 to 161, wherein the audible end of dose feedback member58is configured to emit a sound once the material has been dispensed from the autoinjector10.163. The autoinjector10according to one of embodiments 159 to 162, wherein the audible end of dose feedback member58is configured to emit a sound between the drive chassis24and the housing12once the material has been dispensed from the autoinjector10.164. The autoinjector10according to one or more of the preceding embodiments, wherein the inner body80further comprises a first cut-out174, with the first cut-out74being configured to cooperate with a clip arm184and a lock-out arm186of the needle guard18.165. The autoinjector10according to embodiment 164, wherein the inner body80further comprises a second cut-out176, with the second cut-out being configured to cooperate with the lock-out arm186of the needle guard18.166. The autoinjector10according to one or more of the preceding embodiments, wherein the drive chassis24further comprises a second trigger arm36.167. The autoinjector10according to embodiment 166, wherein the second trigger arm36is arranged at a side of the drive chassis24disposed opposite to the first trigger arm36.168. The autoinjector10according to one or more of the preceding embodiments, wherein the trigger limb32comprises a passage140formed therein.169. The autoinjector10according to embodiment 168, wherein the passage140is configured to receive at least a part of the drive spring74.170. The autoinjector10according to one or more of the preceding embodiments, wherein the trigger limb32comprises a lip216at an end disposed opposite to the web42.171. The autoinjector10according to embodiment 170, wherein the lip216is configured to engage clip arms184formed at the needle guard18.172. The autoinjector10according to embodiment 170 or embodiment 171, wherein the lip216comprises two tips218, with each tip218being configured to engage a respective one of a clip arm184formed at the needle guard18.173. The autoinjector10according to one or more of the preceding embodiments, wherein the needle shield78comprises a needle receptacle212configured to receive the needle34of the pre-filled syringe16.174. The autoinjector10according to one or more of the preceding embodiments, wherein the cap70comprises a needle shield holder104that is configured to receive the needle shield78.175. The autoinjector10according to one or more of the preceding embodiments, wherein the needle guard18further comprises one or more lock-out arms186.176. The autoinjector10according to embodiment 175, wherein the one or more lock-out arms186are configured to cooperate with the inner body80.177. The autoinjector10according to embodiment 175 or embodiment 176, wherein the one or more lock-out arms186are configured to engage one or more bars178of the inner body80in the lock-out state.178. The autoinjector10according to one of embodiments 175 to 177, wherein the one or more lock-out arms186are configured to engage a respective one of one or more cut-outs176of the inner body80in the lock-out state.179. The autoinjector10according to one of embodiments 175 to 178, wherein the one or more lock-out arms186are configured to engage one or more further cut-outs174of the inner body80in the dispensing state and in the storage state.180. The autoinjector10according to one or more of the preceding embodiments, wherein the needle guard18further comprises one or more clip arms184.181. The autoinjector10according to embodiment 180, wherein the one or more clip arms184are configured to cooperate with a respective one of one or more cut-outs174of the inner body80in the dispensing state.182. The autoinjector10according to embodiment 180 or embodiment 181, wherein the one or more clip arms184are deflected inwardly and abut an inner surface132of the inner body80in the lock-out state.183. The autoinjector10according to one of embodiments 180 to 182, wherein the one or more clip arms184are configured to be deflected inwardly by the drive chassis24on a proximal movement of the drive chassis24.184. The autoinjector10according to one or more of the preceding embodiments, wherein the needle guard18further comprises a plunger arm142.185. The autoinjector10according to embodiment 184, wherein the plunger arm142comprises one or more blocking ribs144arranged at a distal end thereof.186. The autoinjector10according to embodiment 185, wherein the plunger arm142comprises two blocking ribs144, with the two blocking ribs144being arranged oppositely disposed to one another.187. The autoinjector10according to embodiment 185 or embodiment 186, wherein the one or more blocking ribs144are configured to block a radial movement of the trigger arm36in the storage state.188. The autoinjector10according to one of embodiments 184 to 187, wherein the plunger arm142comprises one or more cams162.189. The autoinjector10according to embodiment 188, wherein the one or more cams162are configured to engage the one or more trigger arms36of the drive chassis24on activation of the autoinjector10.190. The autoinjector10according to embodiment 189, wherein the one or more cams162are configured to entrain the one or more trigger arms36of the drive chassis24in the transverse direction T upon activation of the autoinjector10.191. The autoinjector10according to one or more of the preceding embodiments, wherein the needle guard18comprises one or more protrusions166cooperating with a respective one of one or more elongate holes168present in the inner body80.192. The autoinjector10according to embodiment 191, wherein the one or more protrusions166are provided to ensure a linear guidance of the needle guard18relative to the inner body80.193. The autoinjector10according to one or more of the preceding embodiments, wherein the needle guard18further comprises one or more anti-pull off features170.194. The autoinjector10according to embodiment 193, wherein the one or more anti-pull off features170are configured to prevent a removal of the needle guard18from the proximal end of the housing12.195. The autoinjector10according to embodiment 194, wherein the inner body80comprises one or more elongate holes168each having a proximal stop172, wherein the proximal stop172prevents a respective one of the protrusions166from being moved proximally beyond the stop172.196. The autoinjector10according to one or more of the preceding embodiments, wherein the inner body80of the housing12further comprises at least a part66of an audible end of dose feedback member58.197. The autoinjector10according to embodiment 196, wherein the part66of the audible end of dose feedback member58comprises an inner body recess206having a distal surface196and a proximal surface198surrounding the inner body recess206.198. The autoinjector10according to one or more of the preceding embodiments, wherein the inner body80comprises one or more cut-outs174,176.199. The autoinjector10according to embodiment 198 and embodiment 196 or 197, wherein the one or more cut-outs174,176are arranged at an end of the inner body80disposed opposite to the second part66of the audible end of dose feedback member58.200. The autoinjector10according to one or more of the preceding embodiments, wherein the outer body82comprises one or more stop features54.201. The autoinjector10according to embodiment 200, wherein each stop feature54is provided at a respective opening138.202. The autoinjector10according to embodiment 200 or embodiment 201, wherein the respective stop feature54is a component of a respective release mechanism40of the autoinjector10.203. The autoinjector10according to one or more of the preceding embodiments, wherein an outer surface49of the trigger limb32comprises a first and a second part outer surface50,52whose appearance differ from one another.204. A method of activating an autoinjector10, optionally according to one or more of the preceding embodiments, the method comprising the steps of:releasing a snap-fit connection94between a cap70and a needle guard18;axially moving the cap70away from the needle guard18; and thereby simultaneously removing a needle shield78from a pre-filled syringe16.205. A method of assembling an autoinjector10, optionally according to one or more of the preceding embodiments, the method comprising the steps of:providing a pre-filled syringe16,providing a needle shield78,covering a needle34of the pre-filled syringe16with the needle shield78; andinserting the needle shield78and needle34into a cap70.