Patent ID: 12233247

DETAILED DESCRIPTION

The injection device1as shown inFIG.1comprises a housing10of tubular and elongated shape. The injection device1may be configured as a prefilled disposable injection device. Alternatively, it may be configured as a reusable injection device.

The injection device1comprises a distal end to which a needle assembly15can be affixed. An injection needle of the needle assembly15can be protected by an inner needle cap16and further by an outer needle cap17. The distal end of the injection device1is further covered by a protective cap18that is releasably engageable with the housing10of the injection device1. When attached to the injection device1the protective cap18covers a portion of the housing of the injection device1that is also denoted as a cartridge holder14. The cartridge holder14is configured to accommodate a cartridge6filled with a medicament. The cartridge6comprises a tubular-shaped barrel25. The barrel25is sealed in distal direction2by means of a pierceable seal26.

Towards the proximal direction3the barrel6is sealed by a displaceable piston7. The piston7is displaceable in distal direction2by means of a piston rod20of a drive mechanism8of the injection device1expelling a predefined amount of the medicament from the cartridge and through the injection needle of the needle assembly15. The pierceable seal26is configured as a septum and is pierceable by a proximally directed tipped end of the needle assembly15. Furthermore, the cartridge holder14comprises a threaded socket28at its distal end to threadedly engage with a correspondingly threaded portion of the needle assembly15. By attaching the needle assembly15to the distal end of the cartridge holder14the seal26of the cartridge6is penetrated thereby establishing a fluid transferring access to the interior of the cartridge6.

The proximal portion or the main housing10of the injection device1is configured to house and to accommodate a drive mechanism8the entirety of which is illustrated inFIGS.4and5. Here, the drive mechanism8is a combined drive mechanism8and dose setting mechanism9. The drive mechanism8is configured to set and to dispense a dose of the medicament. Here, the drive mechanism8may coincide with a dose setting mechanism9. In the following reference is made to the drive mechanism8.

Operation of the injection device1is as follows. For setting of a dose a user has to trigger a release member100,101, in form of a first and a second release button102,103. As illustrated inFIG.17the release members100,101each comprise a release button102,103that is located in a recess19, hence in a through opening of a sidewall13of the housing10as indicated inFIG.23. The release member100,101belong to an interlock84that is configured to keep a dose tracker60in a retracted position or in an initial position i as shown inFIG.18. The dose tracker60comprises a dose button61that is substantially flush with a proximal end face of the housing10when in the initial position i. The dose tracker60is biased in proximal direction3by a spring80as shown inFIG.16. By activating the at least one release member, typically, e.g. by depressing both release members100,101simultaneously, the interlock84between the dose tracker60and the housing10is deactivated or abrogated and the dose tracker60is free to become displaced in proximal direction3under the action of the spring80. The dose tracker60is slidably engaged with the housing10. It is prevented from rotating relative to the housing10. The dose tracker60is configured to slide from the initial position i towards the activation position a as it is apparent from a comparison ofFIG.18andFIG.19.

In the activation position a as shown inFIG.19the dose tracker60is depressible, e.g. by a thumb of a user in distal direction2so as to advance the piston rod20in the distal direction2for displacing the piston7relative to the cartridge6. In this way a predefined amount of the medicament can be expelled from the cartridge6. For dispensing of the dose the dose tracker60is operably engaged with a piston rod20. The drive mechanism8serves to transfer a distally advancing sliding motion of the dose tracker60into a rotational movement of the piston rod20, which due to a threaded engagement with the housing10advances in distal direction2accordingly.

When the dose tracker60or the dose button61returns into the initial position as illustrated inFIG.18the interlock84is automatically reactivated so as to keep the dose tracker60in the initial position i against the action of the spring80. A distally directed displacement of the dose tracker60acts against the force exerted by the spring80. The spring80is hence biased or tensed as the dose tracker60is displaced in distal direction2. When returning and arriving at the initial position i as illustrated inFIG.18the interlock84engages or re-engages. A repeated depression of at least one, typically of both release members100,101disengages the interlock84and enables a repeated displacement of the dose tracker60relative to the housing10in proximal direction3towards the activation position a.

The length of a displacement path of the dose tracker60relative to the housing10between the initial position i as shown inFIG.18and one of the activation positions as shown inFIGS.19to21is correlated to the size of the dose actually set. The more the dose tracker60and the dose button61protrude from the proximal end of the housing10the larger is the size of the dose to be dispensed in the subsequent dose dispensing procedure.

In order to vary a size of a dose the injection device1there is provided a preselector70as illustrated inFIGS.12and15. The preselector70is at least one of longitudinally or rotationally displaceable relative to the housing10. It is translationally or rotationally displaceable relative to the housing10between at least two preselection positional states. With the example as currently illustrated the preselector70is rotatable relative to the housing10. It is axially fixed to the housing10. In any of at least two preselection positional states the preselector70is fixable to the housing10. For this, the mutual engagement of the preselector70and the housing10may comprise a ratchet mechanism, such as at least one protrusion mechanically engageable with one of at least two or more recesses of corresponding shape.

The preselector70comprises a sleeve section71. It is arranged inside the housing10. An outside facing portion of the sleeve section71faces an inside facing portion of the sidewall30of the housing10. The housing10comprises a preselection window11in a sidewall13of the housing10as illustrated inFIG.18toFIG.21. On the outside surface of the sleeve section71of the preselector70there is provided at least one preselection indication77, e.g. in form of one or several dose indicating numbers, such as 1, 2, 3. Depending on the rotational state of the preselector70relative to the housing10only one of the dose indicating numbers shows up in the preselection window11. As shown inFIG.19a dose of size 1 is currently preselected. InFIG.20a dose of size 2 is preselected and in the configuration ofFIG.21a dose size characterized by a number 3 is preselected.

The numbers or any other type of preselection indication, such as symbols or letters may represent several standard units of the medicament to be dispensed. For instance, a number 1 of a preselection indication77may represent 10 standard units of the medicament. For moving and for rotating the preselector70there is provided a radial recess72in the outside facing surface of the sleeve section71. The recess72is aligned with a through opening78in the sidewall13of the housing10as illustrated inFIG.23. Here, authorized persons, such as caregivers may use a tool to reach through the through opening78and to engage with the recess72of the sleeve section71. Then, and by making use of the tool the preselector70can be rotated with regards to the longitudinal axis z of the elongated housing10as an axis of rotation. Consequently, another preselection indication77will show up in the preselection window11. The through opening78as shown inFIG.23may be covered by a label, an adhesive tape or by a detachable cover so as to prevent unauthorized manipulation of the preselector70.

As illustrated further inFIG.15the preselector70comprises numerous preselector stop features73,74,75. The preselector stop features73,74,75extend in longitudinal direction and may protrude from the sleeve section71in distal direction2. The preselector stop features73,74,75may be provided as stepped sections of a protrusion76that protrudes axially or longitudinally from the sleeve section71of the preselector70.

The stop features73,74,75to be denoted as a first stop feature73, as a second stop feature74and as a third stop feature75each comprise a respective stop face73a,74a,75a. The stop faces73a,74a,75aface in distal direction2. The stop features73,74,75are configured to engage with a correspondingly shaped tracking stop feature63of the dose tracker60. The tracking stop feature63comprises a proximally facing stop face63a.

In an initial configuration as illustrated inFIG.4there is a longitudinal distance and a free space between the tracking stop feature63and any of the preselector stop features73,74,75. This configuration represents the initial position i of the dose tracker60. As the interlock84is released the dose tracker60is subject to a proximally directed advancing motion under the action of the relaxing spring80. The dose tracker60is subject to the longitudinal movement until the stop face63aof the tracking stop feature63gets in axial abutment with one stop face73a,74a,75aof one of the preselector stop features73,74,75.

In the configuration as shown inFIG.5the tracking stop feature63is in axial engagement and axial abutment with the second preselector stop feature74. The proximally facing stop face63ais in direct abutment with the distally facing stop face74a. Since the stop features63,73,74,75are located in a common radial plane and since the dose tracker60is in sliding engagement with the housing10the maximum size of the dose and hence the activation position of the dose tracker60is governed by the longitudinal alignment of the tracking stop feature63with one of the preselector stop features73,74,75. Each stop feature73,74,75comprises a stop face73a,74a,75a, wherein the stop faces of the various stop features73,74,75are axially and tangentially offset with respect to each other.

As illustrated inFIG.15the various preselector stop features73,74,75comprise different elongations in longitudinal or axial direction. The stop faces73a,74a,75aof the stop features73,74,75are also located at an axial offset with respect to each other. If for instance the preselector70is rotated relative to the housing10in such a way that the distalmost stop feature75is aligned with the tracking stop feature63the displacement path of the dose tracker60is comparatively short as seen in proximal direction3until the tracking stop feature63gets in axial abutment with the respective stop feature75.

If another preselector stop feature, such as the preselector stop feature73is in longitudinal alignment with the tracking stop feature63the movement of the dose tracker60from the initial position towards the activation position as illustrated inFIG.21is rather long, which corresponds to a maximum dose size. When the distalmost preselector stop feature75is longitudinally aligned with the tracking stop feature63the smallest preselection indication77, i.e. number 1, shows up in the preselection window11. When the most proximal preselector stop feature73is longitudinally aligned with the tracking stop feature63the largest preselection indication77, i.e. number 3, shows up in the preselection window11.

Starting from the configuration ofFIGS.5and20and when rotating the preselector70in a clockwise direction as seen from the proximal end of the injection device1the proximal most preselector stop feature73becomes aligned with the tracking stop feature63. Accordingly, a free path length for the longitudinal travel of the dose tracker60between the initial position i and the activation position a will be enlarged. When finally arriving in the activation position a as illustrated inFIG.21the dose button61and hence the dose tracker60protrudes even further from a proximal end of the housing10compared to the configuration of the preselector when another preselector stop feature74or75is aligned with the tracking stop feature63.

The housing10further comprises a dose indicating window12in which the momentary state or position of the dose tracker60relative to the housing10is illustrated. In the dose indicating window12a dose size indicator66provided on an outside surface of the dose tracker60shows up. When in the initial position as shown inFIG.18a dose size indicator66may show up in form of an arrow indicating to a user, that the dose tracker60needs to be displaced towards the proximal direction3. When reaching an activation position a as shown in any of theFIG.19to21different or identical dose size indicators66will show up in the dose indicating window12thereby indicating to a user that the injection device1is ready for dispensing and for expelling of the dose of the medicament. Here, the dose size indicators66may show an arrow pointing in the distal direction2.

The injection device1further comprises a support90as shown inFIG.13. The support90is fixed inside the housing10. It serves as a mounting support or mounting platform for several other components of the drive mechanism8. The support90may be also integrally formed with the housing10. For the purpose of assembly of the injection device1it may be beneficial to provide the support90as a separate component to be assembled and fixed inside the housing10.

The support90comprises a body91of elongated shape. Towards a proximal end the body91comprises a radially widened flange section97having two diametrically oppositely located recesses98. The dose tracker60comprises two elongated legs64,65, each of which being longitudinally guided in any one of the recesses98. In this way the dose tracker60is longitudinally displaceable relative to the housing10and relative to the support90. The dose tracker60is allowed to slide relative to the support90in longitudinal direction but is hindered to rotate relative to the support and/or relative to the housing10.

The support90comprises two geometrically opposed and longitudinally extending strut sections92,93each of which having a distal face94. In a final assembly configuration as for instance shown inFIG.23the strut sections92,93are in axial abutment with a threaded insert44or with a radially inwardly extending flange section of the housing10. The threaded insert44is separately illustrated inFIG.6. It may be integrally formed with an inside facing portion of the sidewall13of the housing10. The threaded insert44comprises a sleeve section45through which the piston rod20extends in longitudinal direction. The sleeve section45and hence the threaded insert44comprises an inner thread43that is in threaded engagement with an outer thread23of the piston rod20.

The threaded insert44comprises a radially widening socket section47extending radially outwardly from the sleeve section45. The socket section47is connected to the sidewall13of the housing10. The socket section47forms and comprises a radially outwardly extending shoulder portion48. As illustrated inFIG.23the distal faces94of the strut sections92,93are in axial abutment with the shoulder portion48. In this way the support90can be axially fixed inside the housing10. The elongated legs64,65of the dose tracker60each comprise a distal face67that is configured to get in axial abutment with the shoulder portion48of the threaded insert44when arriving in the initial position i, e.g. at the end of a dose dispensing procedure. In this way the distally directed displacement of the dose tracker60can be blocked and limited thereby terminating a dose dispensing procedure.

The dose tracker60further comprises a tubular or knob-like shaped dose button61having a distally facing support face61a. The dose button61forms a proximal end of the dose tracker60. A distal end face of the dose button61may get in axial abutment with the flange section97of the support90as illustrated for instance inFIG.23in order to limit a distally directed displacement of the dose tracker60and in order to define the initial position i of the dose tracker60.

In the initial position i as shown inFIG.23the support face61ais in axial abutment with the flange section97of the support90. Between the support90and the dose tracker60there is provided the spring80. As illustrated inFIG.23the support90comprises a central bore in which a distal end81of the spring80is located. An opposite end of the spring, hence a proximal end82, is located inside a bore of the dose tracker60or dose button61. The distal end and/or the proximal end81,82of the spring80are either fixed to the support90and to the dose tracker60or they are in abutment with respective abutment faces of the support90and the dose tracker60.

The spring80comprises a helically wound compression spring83. In the initial position of the dose tracker60the spring80is pre-tensioned at least to a predefined degree such that upon release of the interlock84the dose tracker60becomes subject to a proximally directed sliding motion relative to the support90.

The interlock84is illustrated in greater detail inFIGS.12,17and23. It comprises a first engaging structure68b,69bconnected to or integral with the dose tracker60and a second engaging structure109connected to or integral with the at least one release member100,101. The dose tracker60comprises two diametrically oppositely located and longitudinally extending interlock members68,69. The interlock members68,69comprise longitudinally extending straight shaped arms or legs extending axially from a distal end of the dose button61. The interlock members68,69extend substantially parallel to the elongation of the legs64,65of the dose tracker60. As seen in circumferential direction the two interlock members68,69are located tangentially or circumferentially between the diametrically oppositely located legs64,65.

The interlock members68,69each extend through another recess99or through opening provided in the flange section97at the proximal end of the support90. As shown inFIG.17in greater detail the interlock members68,69each comprise an elongated arm68a,69a. Each one of the interlock members68,69comprises an engaging structure68b,69b. In the present example the engaging structures68b,69bcomprise a serrated or toothed surface that is selectively engageable with a correspondingly shaped engaging section109of the release members100,101.

The release members100,101may be integrally formed with the support90. Alternative, they are provided as separate components. The release members100,101and the respective release buttons102,104are provided at a free end of resilient arms106,107of the support90, which arms106,107are deflectable in radial direction. As illustrated inFIG.13the resilient arms106,107are provided and arranged on a flange section104of the support90protruding radially outwardly from the body91of the support90.

The resilient arms106,170extend substantially parallel to the arms68a,69aof the interlock members68,69. That side of the resilient arm106facing towards the interlock member68is provided with an engaging structure109in form of a toothed section configured to releasably engage with the engaging structure68b. That side of the resilient arm107facing towards the interlock member69is also provided with a correspondingly shaped engaging section, in form of a toothed section109. The teeth of the engaging sections68b,69b,109comprise a saw tooth profile thus allowing a distally directed sliding displacement of the dose tracker60relative to the release members100,101and their respective resilient arms106,107.

The saw tooth profile of the engaging structures68b,69b,109is such, that the dose tracker60and hence the interlock members68,69thereof are hindered from a proximally directed sliding displacement as long as the release member100,101, the release buttons102,103and the resilient arms106,107are located in an initial and non-depressed configuration.

As illustrated further inFIG.17the interlock members68,69and hence the elongated arms68a,69aextend in longitudinally direction between the release buttons102,103and the respective resilient arms106,107. In other words the interlock members68,69each extend through a gap between the toothed section109and the corresponding release button102,103. The release buttons102,103are connected to the resilient arms106,107by means of a radially extending connecting piece108as shown inFIG.13. The radial extension of the connecting piece108is larger than a radial thickness of the interlock members68,69, respectively.

By simultaneously depressing both release members100,101and hence both release buttons102,103the respective resilient arms106,107are displaced radially inwardly thereby disengaging the engaging sections109of the release members100,101from the engaging sections68b,69bof the interlock members68,69, respectively. In this way the interlock84is released and the dose tracker60is free to become displaced in proximal direction3under the action of the spring80.

The support90further comprises a distally facing toothed section96. The toothed section96may be provided in the region of or on a flange section95from which the two strut sections92,93extend in distal direction2. The toothed section96is of annular shape and faces in distal direction. The toothed section96comprises a saw-toothed profile.

The piston rod20comprises a pressure foot22that is rotationally supported on the distal end of the piston rod20. In this way the piston rod20is allowed to rotate relative to the pressure foot22when the pressure foot22is in axial abutment with a proximal thrust receiving surface of the piston7of the cartridge6. A detailed view of the piston rod is shown inFIG.6. The piston rod20comprises an outer thread23that is threadedly engaged with the inner thread43of the threaded insert44. Alternative, the piston rod20extends through a threaded bore of the housing10. The piston rod20further comprises two elongated, straight shaped and axially extending grooves21intersecting the outer thread23. As illustrated inFIG.7the oppositely located grooves21are in a splined engagement with radially inwardly extending protrusions38of a driver30.

The driver30comprises a sleeve section31enclosing an axial portion of the piston rod20. The driver30further comprises a radially widened flange32near or at its distal end. The flange30is in axial abutment with a clutch spring40. The clutch spring40as shown inFIG.10is axially sandwiched between a proximal face46of the threaded insert44and the distal end of the driver30.

An opposite end of the driver30, hence the proximal end thereof is provided with a first toothed section36that is in engagement with the toothed section96of the support90. The first toothed section36is also of saw-toothed profile and comprises an annular shape. Both, the first toothed section36and the toothed section96may comprise or form a kind of a crown wheel. Since the first toothed section36and the toothed section96are of saw tooth profile a rotation of the driver38along the first sense of rotation as indicated inFIG.9is permanently prevented.

Since the driver30is in splined engagement with the piston rod20through the protrusion38a back winding or retraction of the piston rod20towards the proximal direction3is effectively impeded and prevented.

A rotation along a second sense of rotation5opposite to the first sense of rotation4is supported and allowed by the engagement of the toothed sections36,96. If a torque along the second sense of rotation5is applied to the driver30the teeth of the first toothed section36will slide along the teeth of the toothed section96of the support90thereby axially tensioning the clutch spring40until the tips of the teeth of the first toothed section36pass respective tips of the teeth of the toothed section96. As soon the mutually corresponding teeth have passed the clutch spring40urges the driver40in proximal direction so that the teeth of the first toothed section36engage with circumferential consecutive teeth of the toothed section96of the support90.

Hence, during a rotation along the second sense of rotation and hence during dispensing of a dose the driver30is subject to a stepwise discrete rotational displacement that is accompanied by a small axial displacement in accordance with the axial height of the teeth of the toothed sections36,96. The driver30further comprises a second toothed section34extending along the outer circumference of the sleeve section31. The second toothed section36comprises teeth of saw toothed shape.

There is further provided a clutch enclosing at least a portion of the driver30. As shown inFIGS.9and10the clutch50comprises a distal face57in axial abutment with the proximal side of the flange32of the driver30. The clutch50comprises an outer thread52that is in threaded engagement with an inner thread62provided on a distal section of the dose tracker.60. The inner thread62is provided on and/or distributed on the two legs64,65of the dose tracker64. In this way a longitudinal sliding displacement of the dose tracker60is transferable into a rotation of the clutch50.

The threaded engagement between the dose tracker60and the clutch50is such that a proximally directed displacement of the dose tracker60relative to the clutch50leads to a rotation of the clutch50along the first sense of rotation4. A displacement of the dose tracker60in distal direction2relative to the clutch50leads to a rotation of the clutch50along the second sense of rotation5. The clutch50further comprises engaging sections55,56as indicated inFIG.8. The engaging sections55,56are provided at ends of resiliently deformable arc-shaped ratchet members53,54provided at a proximal end of the clutch50.

The engaging sections55,56are in permanent engagement with the teeth of the second toothed section34of the driver30. Due to the saw tooth profile of the second toothed section30the ratchet members53,54of the clutch50slide along and relative to the second toothed section34along the first sense of rotation4during the process of dose setting and while the dose tracker is subject to a proximally directed displacement. A rotation of the clutch50along the first sense of rotation4is accompanied by an audible click sound. Such a click sound is generated each time when an engaging section55,56passes a tip of a tooth of the second toothed section34. As the clutch50is rotated along the first sense of rotation4the driver30is and remains in torque proof engagement with the support90by means of the first toothed section36and produced section96. The driver30remains rotationally locked to the housing10.

The free end of each of the ratchet members53,54is in tangential or circumferential abutment with a steep flank of a tooth of the second toothed section34. When subject to a rotation in the second sense of rotation5the engaging sections55remain in abutment with the steep flank of a tooth or several teeth of the second toothed section36thereby transferring a respective angular momentum to the driver30along the second sense of rotation5.

The clutch50is axially or longitudinally sandwiched between the flange section95of the support90and the flange32of the driver30. In this way the clutch50is axially fixed inside the housing10. A proximal face58of the clutch50is in axial abutment with the support90.

Operation of the injection device1is as follows. When handed out to a patient or consumer the injection device1may be ready for dispensing. The injection device may be preconfigured or manufactured in such a way that a priming procedure is not necessary. Alternatively, it is conceivable, that the injection device has to undergo a priming procedure or an air shot so as to make sure that the pressure foot22of the piston rod20is in direct abutment with the piston7of the cartridge6.

A user has to depress the two release members100,101simultaneously. In this way the two sections109thereof and the interlock members68,69disengage and are operably released from each other. The dose tracker60is then free to be displaced in proximal direction3under the action of the releasing spring80. This proximally directed displacement of the dose tracker60continues until the tracking stop feature63of the dose tracker60gets in axial abutment with one of the preselector stop features73,74,75. Then and due to the proximally directed displacement of the dose tracker60the those button61thereof protrudes from a proximal end of the housing10as for instance illustrated inFIG.20. The device is then ready for dispensing or for expelling of a dose of the medicament. In the preselection window11the preselected size of a dose is indicated. In the corresponding dose indicating window12, e.g. two arrows show up thus indicating to the user that the dose button61can now be depressed in distal direction2.

The proximal displacement of the dose tracker60is accompanied by a rotation of the clutch50in the first sense of rotation4as illustrated inFIG.9. The driver30is kept stationary and remains in non-rotational engagement with the support90by the toothed sections36and96. This rotational interlock is further supported by the clutch spring40configured to urge the driver30in a unidirectional torque proof and non-rotative engagement with the support90.

During a dose dispensing procedure in which the dose tracker60is depressed in distal direction2against the action of the spring80the clutch50is subject to a rotation along the second sense of rotation5. The ratchet members53,54of the clutch50and their engaging sections55,56are configured to transfer an angular momentum from the clutch50to the driver30. Insofar the driver30also starts to rotate along the second sense of rotation5. The radially inwardly extending protrusions38of the driver30are in splined engagement with respective longitudinal grooves21of the piston rod20. A rotation of the driver30along the second sense of rotation5therefore transfers into a respective rotation of the piston rod20. Due to the threaded engagement of the piston rod20with the housing10the piston rod20becomes subject to a respective distally directed advancing motion thereby expelling a respective amount of the medicament from the cartridge6.

The longitudinal travel of the dose tracker60relative to the housing10between the initial position i and a respective activation position a is determined by the positional state of the preselector70. The preselector70comprises at least one axially extending protrusion76. As shown inFIG.15the preselector70may even comprise two diametrically oppositely located and symmetrically configured protrusions76each of which having numerous preselector stop features75,74. A bottom of the protrusion76and hence a rim of the sleeve section71of the preselector70may form or comprise another preselector stop feature73. Each of the preselector stop features73,74,75comprises a well-defined stop face73a,74a,75a. One of the stop faces73a,74a,75acan be brought in axial alignment with the tracking stop feature63. The free space between the tracking stop feature63and that particular stop face73a,74a,75athat is in axial alignment with the tracking stop feature63determines the axial distance that the dose tracker60can be displaced between the initial position i and the at least one activation position a.

Modifying of a preselection of a dose requires a rotation of the preselector70with the longitudinal axis of the injection device as an axis of rotation. In this way another one of the preselector stop features73,74,75can be brought in longitudinal alignment with the tracking stop feature63. Since the axial positions of the preselector stop features73,74,75all differ, correspondingly modified longitudinal displacement paths of the dose tracker60can be implemented.

The driver30comprises a driver sleeve section31enclosing an axial portion of the piston rod20. The driver30comprises a radially widened flange32near or at its distal end. The flange32is in axial abutment with a clutch spring40. The clutch spring40as illustrated inFIG.10is axially sandwiched between a proximal face46of the threaded insert44and the distal end of the driver30. The clutch spring40is configured or comprises a compression spring. One end of the clutch spring40is supported by the proximal face46of the threaded insert44and an opposite end of the clutch spring40is in abutment with the flange32of the driver30. The distal end of the clutch spring40may be alternatively in abutment with a proximal face, with a rim or with a radially inwardly extending flange section of the housing10.

As illustrated further inFIGS.6,7and9the driver30comprises a first toothed section36and a second toothed section34at or near a proximal end of the driver30. The first toothed section36is provided at an axial face35, typically at an axial end face35of the driver. It is provided at a proximal axial end face. It is configured to engage with a correspondingly-shaped toothed section96of the support90. The support90is separately illustrated inFIG.13. The first toothed section36is of annular shape and comprises numerous teeth36athat are arranged next to each other along the circumference of the driver sleeve section31. Typically, the teeth36aof the first toothed section36resemble or comprise a hirth toothing, wherein the tips of the teeth36aprotrude in axial direction and wherein the grooves between consecutive teeth36aextend radially with regard to the tubular shape of the driver sleeve section31.

The teeth36aof the first toothed section36comprise a saw tooth profile. Hence, the teeth36aof the first toothed section36each comprise a saw tooth36a. The saw teeth36aof the first toothed section36comprise a steep edge and a shallow or flat edge. As illustrated inFIGS.6and9the steep edges of the teeth36aof the first toothed section36face towards a first sense of rotation or in a first direction4. The shallow or flat edges of the saw teeth36aof the first toothed section36faces towards a second sense of rotation or in a second direction5as illustrated inFIG.9.

The support90comprises a correspondingly-shaped toothed section96as illustrated inFIGS.10and13. The correspondingly-shaped toothed section96also comprises numerous saw teeth that are of substantially identical shape and size compared to the saw teeth36aof the first toothed section36. Since the driver30is biased by the clutch spring40in proximal direction3the first toothed section36provided at the proximal end face35of the driver30is kept in abutment and in engagement with the correspondingly-shaped toothed section96of the support90. Due to the mutually corresponding saw toothed profiles of the first toothed section36and the correspondingly-shaped toothed section96a rotation of the driver30along the first direction4is permanently prevented. A rotation in the opposite, hence along the second direction5is allowed and supported.

When the driver30is rotated in the second direction5the shallow or flat-shaped edges of the first toothed section36and the correspondingly-shaped toothed section96are allowed to slide relative to each other. Such a rotational motion of the first toothed section36relative to the toothed section96of the support90may be accompanied by a slight axial displacement of the driver30in longitudinal direction (z).

As the shallow edges of the teeth36aof the first toothed section36and the correspondingly-shaped toothed section96are subject to a relative sliding displacement in circumferential direction the axial slope of the saw toothed profiles of the teeth of the toothed sections36,96leads to a distally directed sliding motion of the driver30until the crest or tips of the teeth of the mutually engaged toothed sections36,96pass each other. As soon as the tips of the teeth of the mutually corresponding toothed sections36,96have passed, the clutch spring40urges the driver30in proximal direction3so that the tips or crests of the toothed section36engage with the grooves of the correspondingly-shaped toothed section96and vice versa.

The rotation of the driver30along and in the second direction5may be thus accompanied by a back and forth movement of the driver30in longitudinal direction. The stepwise and ratchet-like rotational movement of the driver30relative to the support90and relative to the housing10may be further accompanied by an audible click sound thus providing an audible feedback to the user or healthcare giver that a dispensing or drug delivery operation is currently in process.

When the driver should become subject to a torque along the first direction4the steep edges of the teeth36aof the first toothed section36are and remain in torque-proof engagement with correspondingly-shaped steep edges of the saw teeth of the correspondingly-shaped toothed section96of the support90. In this way a rotation of the driver30along the first direction4is effectively prevented.

Since the driver30is in permanent splined engagement with the piston rod20through the protrusion38a back winding or retraction of the piston rod20along or in proximal direction3is effectively impeded and prevented. A rotation along the second direction5or along the second sense of rotation opposite to the first sense of rotation or direction4is supported and allowed by the engagement of the toothed sections36,96.

The injection device1further comprises a clutch50having a hollow interior59. The clutch50is configured to receive at least a portion of the driver30inside the hollow interior59. At least a portion of the driver sleeve section31and/or a portion of the driver30is arranged inside the hollow interior59of the clutch50. In this way a nested or interleaved configuration of the driver30and the clutch50can be provided. This allows for a rather stable and robust construction of the drive mechanism8of the injection device1.

Moreover, the at least partially nested or interleaved arrangement and configuration enables a rather compact and space saving design of the injection device1. The partially interleaved or nested configuration is also beneficial in that the driver30and the clutch50provide mutual support with regard to a rotation relative to the housing1. For instance, the driver30is mechanically supported by the piston rod20and the interleaved or nested arrangement between the driver30and the clutch50provides a rotational support for the clutch50. Since the clutch50receives at least a portion of the driver sleeve section31the clutch50is rotationally supported by the driver30. This is beneficial for a torque transmitting engagement between the clutch50and the driver30and may reduce mechanical tolerances and backlash between the various components of the injection device1.

As shown inFIGS.9and10the clutch50and in particular a clutch sleeve section51thereof comprises a distal face57in axial abutment with the proximal side of the flange32of the driver30. The clutch50further comprises an outer thread52that is in threaded engagement with an inner thread62provided on a section of the dose tracker60. The inner thread62is provided on and/or distributed on the two legs64,65of the dose tracker60. In this way a longitudinal sliding displacement of the dose tracker60is transferrable into a rotation of the clutch50. The threaded engagement between the dose tracker60and the clutch50is such that a proximally directed displacement of the dose tracker60relative to the housing10or relative to the clutch50leads to a rotation of the clutch50along the first direction4.

An oppositely directed sliding displacement of the dose tracker60in distal direction2relative to the housing10and hence relative to the clutch50leads to a rotation of the clutch50along the second direction5. The clutch50and the dose tracker60are permanently threadedly engaged. Any axial sliding displacement of the dose tracker60relative to the housing10and/or relative to the clutch50transfers into a respective rotation of the clutch50along the first direction or the second direction.

The clutch50is in unidirectional torque transmissive engagement with the driver30. This is achieved by a second toothed section34provided on an outside surface of a sidewall37of the driver sleeve section31. The second toothed section34also comprises numerous saw teeth34aeach of which protruding radially outwardly from the outside surface of the sidewall37as illustrated inFIG.7. The saw teeth34aeach comprise a steep edge facing in or along the first direction4. The saw teeth34aalso comprise a shallow or flat edge facing towards the second direction5.

The second toothed section34may be arranged axially adjacent to the first toothed section. The steep and flat or shallow edges of the teeth36a,34amay be in radial alignment or may flush in radial direction. Hence, the first toothed section36and the second toothed section34comprise an equal number of consecutive teeth.

The clutch50comprises at least one engaging section55,56. Typically and as illustrated inFIG.8the clutch50comprises a first and a second engaging section55,56. The engaging sections56are located at free ends53a,54aof a first and a second ratchet member53,54, respectively. Generally, the clutch50comprises at least one ratchet member53,54that is resiliently deformable in radial direction. In the presently illustrated example the clutch50comprises two ratchet members, namely a first ratchet member53and a second ratchet member54. The ratchet members53,54are provided at a proximal end of the clutch50and hence at a proximal end of the clutch sleeve section51.

A proximal face58of the clutch50is formed by or constituted by the first and the second ratchet members53,54. Each one of the at least first and second ratchet members53,54comprises an arc-shaped geometry that is conformal to a sidewall51aof the clutch sleeve section. Hence, the ratchet members53,54are axially flush with the sidewall51aof the clutch sleeve section51. The ratchet members53,54are integrally formed with the clutch50and hence with the clutch sleeve section51. The clutch50may comprise or may consist of an injection molded plastic component.

The free ends53a,54aof the ratchet members53,54are separated from the clutch sleeve section51by a longitudinal or L-shaped slit in the sidewall51aof the clutch sleeve section51. The engaging sections55,56may comprise radially inwardly extending protrusions to engage with the steep edges of the saw teeth34aof the second toothed section34. However, it may be even sufficient that an end face of the ratchet members53,54gets in engagement with the steep edges of the saw teeth34a.

This may be attained when the outer diameter of the second toothed section34as measured at the tips of the saw teeth34ais slightly larger than an inside diameter of the clutch sleeve section51in the region of the first and second ratchet members53,54. In this way the ratchet members53,54are resiliently deformed radially outwardly when the second toothed section34is located in the free space between the at least two ratchet members53,54.

Alternatively it is conceivable, that the ratchet members53,54are biased radially inwardly so that in an initial configuration the free ends of the ratchet members53,54and hence the engaging sections55,56thereof protrude radially inwardly from the inside surface of the sidewall51aof the clutch sleeve section51. As the clutch50receives the driver30the ratchet members53,54will then be at least slightly biased radially outwardly when engaging with the second toothed section34.

The present example shows resiliently deformable ratchet members53,54. However, the injection device1is by no way limited to resiliently deformable ratchet members. It is also conceivable, that the ratchet members53,54are pivotally supported on the clutch50. They may be pivotable radially outwardly against a restoring force that may be provided by a spring not further illustrated here. In this way, a similar ratchet effect could be attained.

As illustrated inFIG.9the engaging sections55,56are in permanent engagement with the saw teeth34aof the second toothed section34of the driver30. The saw toothed profile of the second toothed section34is selected such, that the ratchet members53,54of the clutch50slide along and relative to the second toothed section34as the clutch50is rotated along the first direction4during a dose setting procedure. Since the driver30is hindered to rotate along the first direction4through the engagement with the support90the driver30cannot follow the rotation of the clutch50that is induced by a proximally directed displacement of the dose tracker60.

The rotation of the clutch50along the first direction4is accompanied by an audible click sound that is generated as the ratchet members53,54pass a tip of the teeth34aof the second toothed section34. A click sound is generated each time when an engaging section55,56passes over a tip of a tooth34aof the second toothed section34thereby providing an audible feedback to the user of the injection device1that a dose setting procedure is in progress. As the clutch50is rotated in the first direction4the driver30is and remains in torque-proof engagement with the support90.

When the clutch50is subject to a rotation in the second direction5the engaging sections55,56remain in abutment with the steep flange or steep edge of the teeth34aof the second toothed section34thereby transferring a respective angular momentum or torque to the driver30along the second direction5. Consequently, the driver30is rotated in the second direction5which rotation is equally transferred to a rotation of the piston rod20.

Due to its threaded engagement with the threaded insert44the piston rod20advances in distal direction2so as to expel the set dose of the medicament from the cartridge6.

The clutch50is axially or longitudinally sandwiched between the flange section95of the support90and the flange32of the driver30. In this way the clutch50is axially constrained inside the housing10. A proximal face58of the clutch50is in axial abutment with the support90or with the support90. The distal face57of the clutch is in axial abutment with a proximal side of the flange32of the driver30. When the dose tracker60is depressed in distal direction2the clutch50may be subject to a distally directed displacement before it starts to rotate due to the threaded engagement with the dose tracker60.

The axially distally directed displacement of the clutch50at the beginning of a dose dispensing procedure is transferred to a respective axial displacement of the driver30since the distal face57of the clutch50is and remains in abutment with the proximal side of the flange32. In this way the first toothed section36may disengage from the toothed section96of the support90. Accordingly, the driver30may start to rotate along the second direction5while being out of contact with the support90. Consequently, a dispensing force to be applied to the dose tracker60in distal direction2can be decreased because there is no longer a friction between the first toothed section36and the correspondingly shaped toothed section96of the support90as long as the dose tracker60is depressed, e.g. by a thumb of a user.

Operation of the injection device1is as follows. When handed out to a patient or consumer the injection device1may be ready for dispensing. The injection device may be preconfigured or manufactured in such a way that a priming procedure is not necessary. Alternatively, it is conceivable, that the injection device has to undergo a priming procedure or an air shot so as to make sure that the pressure foot22of the piston rod20is in direct abutment with the piston7of the cartridge6.

A user has to depress the two release members100,101simultaneously. In this way the two sections109thereof and the interlock members68,69disengage and are operably released from each other. The dose tracker60is then free to be displaced in proximal direction3under the action of the releasing spring80. This proximally directed displacement of the dose tracker60continues until the tracking stop feature63of the dose tracker60gets in axial abutment with one of the preselector stop features73,74,75. Then and due to the proximally directed displacement of the dose tracker60the those button61thereof protrudes from a proximal end of the housing10as for instance illustrated inFIG.20. The device is then ready for dispensing or for expelling of a dose of the medicament. In the preselection window11the preselected size of a dose is indicated. In the corresponding dose indicating window12, e.g. two arrows show up thus indicating to the user that the dose button61can now be depressed in distal direction2.

The proximal displacement of the dose tracker60is accompanied by a rotation of the clutch50in the first sense of rotation4as illustrated inFIG.9. The driver30is kept stationary and remains in non-rotational engagement with the support90by the toothed sections36and96. This rotational interlock is further supported by the clutch spring40configured to urge the driver30in a unidirectional torque proof and non-rotative engagement with the support90.

During a dose dispensing procedure in which the dose tracker60is depressed in distal direction2against the action of the spring80the clutch50is subject to a rotation along the second sense of rotation5. The ratchet members53,54of the clutch50and their engaging sections55,56are configured to transfer an angular momentum from the clutch50to the driver30. Insofar the driver30also starts to rotate along the second sense of rotation5. The radially inwardly extending protrusions38of the driver30are in splined engagement with respective longitudinal grooves21of the piston rod20. A rotation of the driver30along the second sense of rotation5therefore transfers into a respective rotation of the piston rod20. Due to the threaded engagement of the piston rod20with the housing10the piston rod20becomes subject to a respective distally directed advancing motion thereby expelling a respective amount of the medicament from the cartridge6.

The longitudinal travel of the dose tracker60relative to the housing10between the initial position i and a respective activation position a is determined by the positional state of the preselector70. The preselector70comprises at least one axially extending protrusion76. As shown inFIG.15the preselector70may even comprise two diametrically oppositely located and symmetrically configured protrusions76each of which having numerous preselector stop features75,74. A bottom of the protrusion76and hence a rim of the sleeve section71of the preselector70may form or comprise another preselector stop feature73. Each of the preselector stop features73,74,75comprises a well-defined stop face73a,74a,75a. One of the stop faces73a,74a,75acan be brought in axial alignment with the tracking stop feature63. The free space between the tracking stop feature63and that particular stop face73a,74a,75athat is in axial alignment with the tracking stop feature63determines the axial distance that the dose tracker60can be displaced between the initial position i and the at least one activation position a.

Modifying of a preselection of a dose requires a rotation of the preselector70with the longitudinal axis of the injection device as an axis of rotation. In this way another one of the preselector stop features73,74,75can be brought in longitudinal alignment with the tracking stop feature63. Since the axial positions of the preselector stop features73,74,75all differ, correspondingly modified longitudinal displacement paths of the dose tracker60can be implemented.

The injection device1as shown inFIG.24comprises an outer structure that is similar to the structure of the device as described above in connection withFIG.1orFIG.2. The injection device1may be configured as a pre-filled disposable injection device that comprises a housing10to which an injection needle15can be affixed. If not described otherwise, similar or identical components of the device1according toFIG.24are denoted with the like are identical reference numbers as used in connection with the injection device1ofFIG.1orFIG.2.

As shown further inFIG.24, the housing10comprises a dosage window113that may be in the form of an aperture in the housing10. The dosage window113permits a user to view a limited portion of a number sleeve180that is configured to move when a dose dial112is turned or rotated. In this way a visual indication of a currently set dose can be provided. The dose dial112is rotated on a helical path with respect to the housing10when turned during setting and/or dispensing or expelling of a dose.

The injection device1may be configured so that turning the dose dial112causes a mechanical click sound to provide acoustical feedback to a user. The number sleeve180mechanically interacts with a piston in the cartridge6. When the needle15is stuck into a skin portion of a patient, and when the trigger111or injection button is pushed, the insulin dose displayed in display window113will be ejected from the injection device1. When the needle15of the injection device1remains for a certain time in the skin portion after the trigger111is pushed, a high percentage of the dose is actually injected into the patient's body. Ejection of a dose of the medicament may also cause a mechanical click sound, which is however different from the sounds produced when using the dose dial112.

In this embodiment, during delivery of the insulin dose, the dose dial112is turned to its initial position in an axial movement, that is to say without rotation, while the number sleeve180is rotated to return to its initial position, e.g. to display a dose of zero units.

The injection device1may be used for several injection processes until either the cartridge6is empty or the expiration date of the medicament in the injection device1(e.g. 28 days after the first use) is reached.

Furthermore, before using injection device1for the first time, it may be necessary to perform a so-called “prime shot” to remove air from the cartridge6and the needle15, for instance by selecting two units of the medicament and pressing trigger11while holding the injection device1with the needle15upwards. For simplicity of presentation, in the following, it will be assumed that the ejected amounts substantially correspond to the injected doses, so that, for instance the amount of medicament ejected from the injection device1is equal to the dose received by the user.

The expelling or drive mechanism8as illustrated in more detail inFIG.24comprises numerous mechanically interacting components. A flange like support of the housing10comprises a threaded axial through opening threadedly engaged with a first thread or distal thread122of the piston rod120. The distal end of the piston rod120comprises a bearing121on which a pressure foot123is free to rotate with the longitudinal axis of the piston rod120as an axis of rotation. The pressure foot123is configured to axially abut against a proximally facing thrust receiving face of the bung7of the cartridge6. During a dispensing action the piston rod120rotates relative to the housing10thereby experiencing a distally directed advancing motion relative to the housing10and hence relative to the barrel25of the cartridge6. As a consequence, the bung7of the cartridge6is displaced in distal direction2by a well-defined distance due to the threaded engagement of the piston rod120with the housing10.

The piston rod120is further provided with a second thread124at its proximal end. The distal thread122and the proximal thread124are oppositely handed.

There is further provided a driver130having a hollow interior to receive the piston rod20. The driver130may comprise or may form a drive sleeve. The driver130comprises an inner thread threadedly engaged with the proximal thread124of the piston rod120. Moreover, the driver130comprises an outer threaded section131at its distal end. The threaded section131is axially confined between a distal flange portion132and another flange portion133located at a predefined axial distance from the distal flange portion132. Between the two flange portions132,133there is provided a last dose limiting member135in form of a semi-circular nut having an internal thread mating the threaded section131of the driver130.

The last dose limiting member35further comprises a radial recess or protrusion at its outer circumference to engage with a complementary-shaped recess or protrusion at an inside of the sidewall of the housing10. In this way the last dose limiting member135is splined to the housing10. A rotation of the driver130in a dose incrementing direction4or clockwise direction during consecutive dose setting procedures leads to an accumulative axial displacement of the last dose limiting member135relative to the driver130. There is further provided an annular spring140that is in axial abutment with a proximally facing surface of the flange portion133. Moreover, there is provided a tubular-shaped clutch160. At a first end the clutch160is provided with a series of circumferentially directed saw teeth. Towards a second opposite end of the clutch160there is located a radially inwardly directed flange.

The number sleeve180is provided outside of the spring140and the clutch160and is located radially inward of the housing10. A helical groove181is provided about an outer surface of the number sleeve180. The housing10is provided with the dosage window113through which a part of the outer surface of the number180can be seen. The housing10is further provided with a protrusion163or helical rib at an inside sidewall portion of an insert piece162, which helical rib is to be seated in the helical groove181of the number sleeve180. The tubular shaped insert piece62is inserted into the proximal end of the housing10. It is rotationally and axially fixed to the housing10. There may be provided first and second stops on the housing10to limit a dose setting procedure during which the number sleeve180is rotated in a helical motion relative to the housing10. As will be explained below in greater detail, at least one of the stops is provided by a preselector stop feature171provided on a preselector170.

The dose dial112in form of a dose dial grip is disposed about an outer surface of the proximal end of the number sleeve180. An outer diameter of the dose dial112typically corresponds to and matches with the outer diameter of the housing10. The dose dial112is secured to the number sleeve180to prevent relative movement there between. The dose dial112is provided with a central opening.

The trigger111, also denoted as dose button is substantially T-shaped. It is provided at a proximal end of the injection device10. A stem164of the trigger111extends through the opening in the dose dial112, through an inner diameter of extensions of the driver130and into a receiving recess at the proximal end of the piston rod120. The stem164is retained for limited axial movement in the driver130and against rotation with respect thereto. A head of the trigger111is generally circular. The trigger side wall or skirt extends from a periphery of the head and is further adapted to be seated in a proximally accessible annular recess of the dose dial112.

To dial a dose a user rotates the dose dial112. With the spring140also acting as a clicker and the clutch160engaged, the driver130the spring or clicker140, the clutch160and the number sleeve180rotate with the dose dial112. Audible and tactile feedback of the dose being dialed is provided by the spring140and by the clutch160. Torque is transmitted through saw teeth between the spring140and the clutch160. The helical groove181on the number sleeve180and a helical groove in the driver130have the same lead. This allows the number sleeve180to extend from the housing10and the driver130to climb the piston rod120at the same rate. At a limit of travel a radial stop on the number sleeve180engages either with a first stop or a second stop provided on the housing10provided on the pre-selector170to prevent further movement in a dose incrementing direction4. A rotation of the piston rod120is prevented due to the opposing directions of the overall and driven threads on the piston rod120.

The last dose limiting member135keyed to the housing10is advanced along the threaded section131by the rotation of the driver130. When a final dose dispensed position is reached, a radial stop formed on a surface of the last dose limiting member135abuts a radial stop on the flange portion133of the driver130, preventing both, the last dose limiting member135and the driver130from rotating further.

Should a user inadvertently dial beyond the desired dosage, the injection device1, configured as a pen-injector allows the dosage to be dialed down without dispense of the medicament from the cartridge6. For this the dose dial112is simply counter-rotated, in the dose decrementing direction5. This causes the system to act in reverse. A flexible arm of the spring or clicker140then acts as a ratchet preventing the spring140from rotating. The torque transmitted through the clutch160causes the saw teeth to ride over one another to create the clicks corresponding to dialed dose reduction. Typically, the saw teeth are so disposed that a circumferential extent of each saw tooth corresponds to a unit dose.

When the desired dose has been dialed the user may simply dispense the set dose by depressing the trigger111. This displaces the clutch160axially with respect to the number sleeve180causing dog teeth thereof to disengage. However, the clutch160remains keyed in rotation to the driver130. The number sleeve180and the dose dial112are now free to rotate in accordance with the helical groove181.

The axial movement deforms the flexible arm of the spring140to ensure the saw teeth cannot be overhauled during dispense. This prevents the driver130from rotating with respect to the housing10though it is still free to move axially with respect thereto. The deformation is subsequently used to urge the spring140and the clutch160back along the driver130to restore the connection between the clutch160and the number sleeve180when the distally directed dispensing pressure is removed from the trigger111.

The longitudinal axial movement of the driver130causes the piston rod120to rotate through the through opening of the support of the housing10, thereby to advance the bung7in the cartridge6. Once the dialed dose has been dispensed, the number sleeve180is prevented from further rotation by contact of a plurality of members extending from the dose dial112with a corresponding plurality of stops. A zero dose position is finally determined by the abutment of one of axially extending edges of members of the number indicating sleeve180with a corresponding stop of the housing10.

The expelling mechanism or drive mechanism8as described above is only exemplary for one of a plurality of differently configured drive mechanisms that are generally implementable in a disposable pen-injector. The drive mechanism as described above is explained in more detail e.g. in WO2004/078239A1, WO 2004/078240A1 or WO 2004/078241A1 the entirety of which being incorporated herein by reference.

Compared to the injection device as described in any one of the documents WO2004/078239A1, WO 2004/078240A1 or WO 2004/078241A1 the injection device according toFIGS.24to47is further provided with a preselector170;270,370,470,570. The preselector170is displaceable relative to the housing10between at least two preselection positional states in order to define a one of a plurality of activation positions of the dose tracker or to define a maximum dose positional state of the dose tracker150. In the example ofFIG.24the dose tracker150may comprise the number sleeve180having a helical groove181that is in threaded engagement with the housing10or with the insert162that is fixed to the housing10. Here and in the following embodiments the number sleeve180may represent the dose tracker150or may coincide with the dose tracker150.

On an outside surface of the number sleeve180there may be provided consecutive numbers that show up in the dosage window113. Selection and indication of visualization of a dose is modified with the various examples of an injection device as described hereinafter with regards toFIGS.25to47. With the various examples as illustrated inFIGS.25to47the number sleeve180and hence by the dose tracker150is displaceable in unison with a trigger111relative to the housing10for setting as well as for dispensing of the dose of the medicament.

In the example ofFIGS.25to28there is provided a preselector170that is displaceable relative to the housing10between at least two preselection positional states p1and p2. Each preselection positional state p1, p2defines a maximum dose positional state dm for the dose tracker. In the present example the preselector170comprises a preselector sleeve that is rotationally fixed to the tubular shaped housing10.

As shown inFIGS.25to28the preselector170is provided and rotationally supported at a proximal end142of the housing10. It may be rotationally supported on a side wall13of the housing10. For selecting at least one of two available preselection positional states p1, p2the preselector170is rotatable with regard to a rotation axis extending parallel to the longitudinal axis of the housing10. The preselector170is lockable or fixable relative to the housing10in any one of the at least two preselection positional states p1, p2. In this way and when the preselector170is in a first preselection positional state p1the preselector170is hindered and impeded against self-actuated displacement relative to the housing10.

The preselector170comprises a first preselector stop feature171. The preselector stop feature171as illustrated inFIG.27comprises a first groove201. The preselector170further comprises a second preselector stop feature172. The second preselector stop feature172comprises a second groove202. The grooves201,202are provided on an inside facing surface of the sleeve of the preselector170. The dose tracker150comprising a tracking stop feature151. The tracking stop feature151comprises a radial protrusion156protruding radially outwardly from an outside surface of the dose tracker150. Here, the dose tracker150comprises a tracking sleeve155that is rotationally and translationally supported inside the elongated housing10.

Typically, the dose tracker150is in threaded engagement with the housing10. As illustrated inFIG.27and when in the zero dose positional state the tracking stop feature151is located inside a connecting groove204interconnecting the first groove201and the second groove202. One end, e.g. a first end of the first groove201merges into the connecting groove204. A first end of the second groove202also merges into the connecting groove204. The connecting groove204extends at a predefined angle relative to the elongation of the first groove201and the second groove202. Typically, first and second grooves201,202extend parallel to each other. As illustrated, the second groove202comprises a larger longitudinal extension compared to the first groove201. There is also provided a third groove203. Also the third groove203extends parallel to the first groove201and to the second groove202. The third groove203comprises an elongation that is larger than the elongation of the second groove202. As shown further, the second groove202is located between the first groove201and the third groove203.

The connecting groove204comprises an elongation that aligns with and/or coincides with a direction of displacement of the preselector170when the preselector170is displaced between the at least two preselection positional states p1, p2. For transferring and displacing the preselector170from the first preselection positional state p1as illustrated inFIG.25to the second preselection positional state p2as illustrated inFIG.26the preselector170is rotatable relative to the housing10, e.g. in a counterclockwise direction. Accordingly, the connecting groove204extends in circumferential or tangential direction with regards to the tubular shaped housing10or with regards to the tubular shaped preselector170.

As further illustrated inFIGS.25and26the housing10, in particular the sidewall13thereof is provided with a preselection indication143. The preselection indication143comprises numerous numbers or symbols arranged along a displacement path of the preselector170. The preselector170comprises a correspondingly shaped preselection indication175, e.g. in form of an arrow. In each one of the provided preselection positional states p1, p2the preselection indication175of the preselector170aligns with one of the preselection indications143of the housing10.

An alternative implementation is also conceivable here, wherein the preselection indication143comprises a pointer or an arrow and wherein the preselection indication175comprises numerous numbers or symbols arranged along a displacement path of the preselector170. The preselection indication175aligning with a preselection indication143indicates to the user, which one of the preselection positional states p1, p2is actually valid for the injection device1. In the present example there may be provided three or even for preselection positional states. In a first preselection positional state the tracking stop feature151is in alignment with the first groove201. In a second preselection positional state the tracking stop member151is in alignment with the second groove202.

There is also provided an interlock184. The interlock184is connected to one of the housing10and the dose tracker150. The interlock184is further connectable to the other one of the housing and the dose tracker in order to establish a releasable engagement between the dose tracker150and housing10. The interlock184may further comprise or may be operably engaged with a release member190. The release member190is configured to release the interlock184in order to liberate and to enable a movement of the dose tracker150relative to the housing10. The interaction of the interlock184and the release member190is such that the dose tracker150it locked to the housing10when in the initial position i or in the zero dose positional state d0as illustrated inFIG.27. In the present example there is further provided a mechanical energy reservoir in form of a spring144. The spring144comprises a first end145connected to the housing10and the spring144comprises a second end146connected to the dose tracker150. If the release member190is actuated in order to liberate or to release the dose tracker150the dose tracker150starts to rotate relative to the housing10under the action of the relaxing spring144.

As illustrated the spring144comprises a cylindrically wound torsion spring147. The spring144encloses at least a portion of an outside surface of the tracking sleeve155of the dose tracker150. In this way and when released the spring144is configured to induce a torque to the dose tracker150.

In the given preselection positional state p1, p2the preselector170is rotationally fixed to the housing10. Here, the engagement of the tracking stop feature151with one of the grooves201,202,203provides a threaded engagement between the dose tracker150and the housing10. Since the preselector170is translationally or axially fixed to the housing10the dose tracker150is subject to a proximally directed displacement such that a proximal end154of the dose tracker150protrudes from a proximal end of the preselector170and/or from a proximal end142of the housing10when reaching the maximum dose positional state dm as illustrated inFIG.28.

The amount of displacement of the length of a displacement path of the dose tracker150relative to the housing10is indicative and is directly correlated to the size of a dose actually set. The grooves201,202,203each comprise a second end facing away from the connecting groove204. The second end of the grooves201,202,203each provides an end stop for the tracking stop feature151. At the second end each one of the grooves201,202,203comprises a stop face to engage or to abut with a correspondingly shaped stop face of the protrusion156of the tracking stop feature151. Once the tracking stop feature151with its protrusion156reaches the second end of the second groove202as illustrated inFIG.26or28a further displacement of the dose tracker150in a dose incrementing direction, i.e. proximal direction, relative to the preselector170and/or relative to the housing10is effectively impeded and blocked.

Once the maximum dose positional state dm has reached the injection device1is prepared and ready for a dose dispensing procedure. For this, a user has to depress the trigger111in distal direction as described above with regard toFIG.24. During a dispensing procedure the dose tracker150returns into the initial position i and hence back into the zero dose positional state d0. It rotates in a dose decrementing direction5relative to the housing1in accordance and along the helical path provided by the respective grooves201,202,203. When reaching the initial position i as illustrated inFIGS.25and27the interlock184reengages and positionally fixes the dose tracker150to the housing10.

Thereafter the preselector170may the transferred to another preselection positional state in order to vary the size of the dose if required. Otherwise, the preselector170remains in the present preselection positional state. A repeated actuation of the release member190will lead to a release of the interlock184thus enabling a further automated displacement of the dose tracker150from the initial position i to the activation position a. Accordingly, another dispensing procedure can take place.

In the example ofFIGS.25to28the dose tracker150may be in threaded engagement with the housing10only via the tracking stop feature151sliding along the preselector stop feature171of the preselector170. It is generally conceivable, that the insert162as described in connection withFIG.24is replaced by the preselector170. In this way, only minor modifications have to be implemented in the injection device1as described in any of the documents WO2004/078239A1, WO 2004/078240A1 or WO 2004/078241A1 in order to implement a preselection of only a limited number of different dose sizes.

InFIGS.29and30another example of an injection device1is illustrated. Identical or components compared to the example ofFIGS.25to28are denoted with identical reference numbers. Similar components compared to the example ofFIGS.25to28are denoted with respective reference numbers that are increased by 100.

In comparison to the example ofFIGS.27and28the example ofFIGS.29and30comprises an insert162that is fixed to the housing10. The insert162is typically fixed to a sidewall13of the housing10. The insert162is a threaded insert. The insert162comprises a radially inwardly extending protrusion163. The protrusion163may comprise a helical shape. It may be in threaded engagement with an outer thread or with a helical groove181on the outside surface of the dose tracker250. Also here, the dose tracker250may coincide with a number sleeve180. The preselector270is of sleeve-like shape. It is rotationally supported at or near a proximal end of the housing10. The preselector270is axially or longitudinally fixed to the housing10.

The preselector270comprises a preselector stop feature271. The dose tracker250comprises a correspondingly shaped tracking stop feature251. Compared to the example ofFIGS.27and28it is the tracking stop feature251that comprises a first tracking stop feature151comprising a first groove201, a second tracking stop feature152comprising a second groove202and a third tracking stop feature153comprising a third groove203. The grooves201,202,203are connected by a connecting groove204in the same way as described above in connection withFIGS.25to28. The preselector stop feature171comprises a radial protrusion176that is in sliding engagement with one of the grooves201,202,203,204.

InFIGS.28aand28ba modification of the device as illustrated inFIGS.25to28is illustrated. Here, the injection device is equipped with a supplemental clutch166having a recess167to engage with the protrusion156and hence with the tracking stop feature151of the dose tracker150. The supplemental clutch166may comprise a clutch sleeve. The supplemental clutch166may comprise a tubular shaped body with a tubular-shaped sidewall168. The clutch166is attached to the housing10. It may be located on an outside surface of the housing10. It may be displaceable in longitudinal direction relative to the housing10. The clutch166is rotationally fixed to the housing10. The clutch166may be in a splined engagement with the housing10. Hence, the clutch166is hindered to rotate relative to the housing10. The clutch166may be in a longitudinally sliding and rotation inhibiting engagement with the housing10.

In the zero dose positional state d0of the dose tracker150as illustrated inFIG.28athe tracking stop feature151of the dose tracker150and hence the protrusion156is located inside the recess167of the clutch166. The recess167comprises a tangential or circumferential width that substantially matches with the respective size or width of the protrusion156. The width or size of the recess167may be slightly larger than the size of the protrusion so as to enable a smooth insertion of the protrusion156into the recess167. The recess167is open towards the proximal direction3.

The clutch166is axially displaceable in distal direction2against the action of a spring165. One end of the spring165is engaged with the clutch166and the opposite end of the spring165is engaged with the housing10. The spring165may comprise a compression spring. It may be configured to urge or to drive the clutch166in and towards the proximal direction3. As long as the protrusion156is located inside the recess167the mutual engagement of the protrusion156and the recess167hinders the dose tracker150from rotating under the action of the spring144.

The position of the recess167matches and overlaps with the position of the protrusion156as the dose tracker150is in the zero dose positional state d0. By depressing the clutch166in distal direction the recess167is moved in distal direction accordingly. As a consequence, the protrusion156is no longer retained inside the recess167and the dose tracker150becomes free to rotate under the action of the spring144.

The preselector170is axially engaged with the clutch166. It is fixed to the clutch166in axial or longitudinal direction. Any movement of the clutch166in longitudinal or axial direction equally transfers to a respective movement of the preselector170. The preselector170is rotatable relative to the clutch166. In any of its rotational states, the preselector170is rotationally fixable to the clutch and hence to the housing10. The preselector170may be in a kind of a snap-fit engagement or ratchet engagement with the housing10or with the clutch166. This allows and supports a dedicated rotation of the preselector170with the longitudinal axis of the injection device as an axis of rotation, so as to bring one of the preselector stop features171,172,173in axial or longitudinal alignment with the tracking stop feature151as the tracking stop feature is in the zero dose positional state. The rotation of the preselector170relative to the housing10and/or relative to the clutch166may be accompanied by an audible click sound or haptic feedback.

When in the zero dose positional state d0the preselector170is rotatable relative to the housing10as well as relative to the clutch166in order to preselect a dose of a particular size. For instance and as illustrated inFIG.28athe second preselector stop feature172and hence the groove202, in particular the distal end of the preselector stop feature172and the distal end of the groove202, are brought in longitudinal alignment with the recess167and hence with the protrusion156or tracking stop feature151located therein.

Since the preselector170is axially connected to the clutch166, a distally directed displacement of the clutch166equally transfers to a respective distally directed displacement of the preselector170; and vice versa. As a consequence, the tracking stop feature151and hence the protrusion156slides out of the recess167and enters the preselector stop feature172, i.e. the groove202. Through this axial displacement of the preselector170relative to the housing10the protrusion156enters the groove202. The protrusion156is then allowed to slide along the helical path provided by the groove202. In this way the entire dose tracker150becomes subject to a proximally directed screwing motion relative to the housing10as it is free to rotate under the action of the spring144as described above in connection withFIGS.25to28.

At the end of a dose delivery procedure during which the dose tracker150is moved in distal direction2and during which the dose tracker150returns into the zero dose positional state d0the tracking stop feature151and hence the protrusion156re-enters the recess167. As the dose dispensing or injection procedure terminates the mutual engagement of the tracking stop feature151or protrusion156with the recess167hinders the dose tracker150from rotating.

In the example ofFIGS.28aand28bthe release member190may be replaced by the clutch166. Here, the clutch166may provide both, an interlock184as well as a release member190. In the proximal position as indicated inFIG.28athe clutch166provides an interlock184configured to prevent a rotation of the dose tracker150relative to the housing10. In the distal position as indicated inFIG.28bthe clutch166provides a release member190disengaging the interlock184, thus allowing and supporting a rotation of the dose tracker150relative to the housing10.

The clutch166as illustrated inFIGS.28aand28bmay be integrally formed with the clutch160as illustrated inFIG.24. The clutch166may be a portion of the clutch160. In further examples the clutch166and the clutch160may be separate parts.

In the initial position i as illustrated inFIG.29the preselector stop feature271is slidably engaged with the connecting groove204. A rotation of the preselector270relative to the housing10provides an alignment of the preselector stop feature271with one of the grooves201,202,203. After a release of the dose tracker250by actuating the release member190the dose tracker250starts to rotate according to the threaded engagement with the insert162relative to the housing10and hence relative to the preselector170, which is rotationally fixed to the housing10in the respective preselection positional state.

As illustrated inFIG.30the preselector stop feature171, in particular a radially inwardly extending protrusion176as provided on an inside facing sidewall of the sleeve-shaped preselector170slides along the groove202until it reaches a second end of the groove202provided with a stop face for the preselector stop feature171. In this maximum dose positional state dm any further proximally directed displacement of the dose tracker150is blocked through the mutual engagement of the protrusion176with the second end of the groove202. The mode of operation of the device according toFIGS.29and30is comparable if not identical to the mode of operation as described in connection with the device according toFIGS.25to28.

The further example ofFIGS.31and32is somehow similar to the example as described in connection withFIGS.29and30. Also here the dose tracker350comprises a tracking stop feature351. The dose tracker350comprises a tracking sleeve355that is in threaded engagement with the insert162. Also here, the preselector370is of sleeve-like shape. It is also longitudinally or axially fixed to the housing10, in particular to a sidewall13thereof. The preselector370is stationary supported on the housing10or relative to the housing between at least two preselection positional states p1, p2.

The preselector370comprises a first preselector stop feature371, which is implemented as a radial protrusion276protruding radially inwardly from a sidewall of the preselector270. The correspondingly shaped tracking stop feature351of the dose tracker350is provided on an outside surface portion of the tracking sleeve355. The tracking stop feature351comprises a radially outwardly extending protrusion356. For setting of a dose and for transferring the dose tracker350from the initial position i or from the zero dose positional state d0to the activation position a or to the maximum dose positional state dm the dose tracker350rotates in accordance to the threaded engagement with the housing10.

The preselection positional state of the preselector370, hence the orientation of the preselector370with regard to a rotation axis thereof defines the positional state, hence the longitudinal position and/or an orientation of the dose tracker350relative to the housing10at least when the tracking stop feature351abuts with the preselector stop feature371. As illustrated inFIGS.31and32the preselector370may comprise numerous preselector stop features371,372and373, hence a first preselector stop feature371, a second preselector stop feature372and a third preselector stop feature373. The various preselector stop features371,372,373all comprise a radially inwardly extending protrusion376. The various preselector stop features371,372,373are located at a predefined positions at an inside facing sidewall portion of the preselector370. The first and the second preselector stop features371,372may be located at least one of axially and tangentially offset relative to each other.

The preselector stop features371,372,373are located at a predefined and different axial and/or longitudinal positions along the elongation or along the inner circumference of the preselector370. The preselector stop features371,372,373may comprise a flange protruding radially inwardly from the sidewall of the preselector370. The tangential or circumferential extension of the flange may be larger than the tangential or circumferential extent of the correspondingly shaped tracking stop feature351. The tangential or circumferential extension of the preselector stop features371,372,373is shorter than 180°, shorter than 90° or shorter than 45° with respect to the inner circumference of the preselector370.

In this way and depending on the rotational state of the preselector370the tracking stop feature351may pass by at least one of the preselector stop features373and372on its way towards the maximum dose positional state. When reaching the maximum dose positional state the tracking stop feature351axially and/or tangentially engages with that one of the preselector stop features, which, due to the positional state p1, p2of the preselector370is in alignment with the tracking stop feature351.

With the further example according toFIG.33toFIG.36the preselector470is permanently translationally fixed to the dose tracker450. The preselector470is rotatable relative to the dose tracker450. As already described above in connection withFIG.29toFIG.32the dose tracker450is threadedly engaged with the housing10, e.g. via the threaded insert162. Also here, a spring144in form of a torsion spring147is provided in order to provide an automated displacement of the dose tracker450from the initial position i towards and into the activation position a.

In the initial position i the dose tracker450is positionally locked to the housing10by means of the interlock184and the release member190. In the illustrated example the preselector470comprises a sleeve having an inside facing surface that faces towards the outside facing surface of the sidewall13of the housing10. Hence, the preselector470comprises a cup-shaped receptacle to receive a proximal end142of the housing10. Other configurations are also conceivable, wherein at least a distal end of the preselector470is insertable into the sleeve-shaped housing10.

In the example as shown inFIGS.15and36the preselector stop feature471provided on the preselector470comprises a radially inwardly extending protrusion476to engage with the tracking stop feature451. In contrast to the examples as described above the tracking stop feature451is provided on the sidewall13of the housing10. The tracking stop feature451is provided on an outside surface of the sidewall13. There is provided a first tracking stop feature451, a second tracking stop feature452and a third tracking stop feature453. The first tracking stop feature451comprises a first groove201, the second tracking stop feature452comprises a second groove202and the third tracking stop feature comprises a third groove203. All three grooves201,202,203merge into a connecting groove204with a first end. The grooves201,202,204comprise different elongations. The grooves201,202,203extend parallel to each other. The second ends of the grooves201,202,203are located at a longitudinal offset relative to each other. At their second ends the grooves201,202,203each comprise a stop face to abut or to engage with a correspondingly shaped stop face of the protrusion476of the preselector stop feature471.

In this way the elongation of the grooves201,202,203define the maximum dose positional dm of the dose tracker450. Depending on the positional state of the preselector470one of the grooves201,202,203aligns with the tracking stop feature451thereby defining the maximum distance the dose tracker450can move towards the proximal direction3when the interlock184is released. The tracking stop feature451is provided on or in an outside facing surface portion of the sidewall13of the housing10.

The preselector stop feature471protruding radially inwardly from an inside facing section of the sidewall of the preselector470is in permanent engagement with at least one of the grooves201,202,203,204. In the zero dose positional state d0is illustrated inFIG.35the preselector stop feature471, hence the radial protrusion476, is located inside the connecting groove204. By rotating the preselector470relative to the housing10the preselector stop feature471will be aligned with one of the grooves201,202,203. Thereafter and upon releasing of the dose tracker450by actuation of the release member190the spring144induces a rotation of the dose tracker450, which according to the threaded engagement with the housing10is subject to a helical motion relative to the housing10.

The grooves201,202,203extend parallel to the elongation of the housing10. They extend e.g. perpendicular to the elongation of the connecting groove204. Since the preselector470is freely rotatable relative to the dose tracker450but remains axially and longitudinally locked and constrained to the dose tracker450, the preselector stop feature471starts to slide along the selected groove203as soon as the dose tracker is subject to a longitudinal movement relative to the housing10.

The engagement of the preselector stop feature471with the groove203also prevents a rotation of the preselector470relative to the housing10during a dose setting motion of the dose tracker450. When reaching the maximum dose positional state dm, the preselector stop feature470gets in abutment with the second end of the groove203by way of which a further proximally directed displacement of the preselector470is impeded. Due to the permanent longitudinal interlock or engagement between the preselector470and the dose tracker450any further rotation of the dose tracker450is impeded and prevented.

Since the dose tracker450is threadedly engaged with the housing10any further rotation thereof would require a further displacement in longitudinal direction relative to the housing10. This is effectively blocked an impeded when the dose tracker450is in the maximum dose positional state dm. In the maximum dose positional state dm as illustrated inFIG.36the trigger111can be depressed in order to induce a dose dispensing procedure as described above.

Generally, the preselector470may be fixed in the preselection positional states at discrete positions relative to the housing or relative to the dose tracker450. The supported preselection states may correspond to consecutive and complete revolutions of the dose tracker450. In the present example the dose tracker450comprises two or even three tracking stop features451,452,453to engage with the preselector stop feature471. Alternatively, also the preselector470may comprise two or more preselector stop features to engage with the tracking stop feature451,452,453. In this way the maximum dose positional state could be assigned with every half or every third revolution of the dose tracker450relative to the housing10. Furthermore it is conceivable, that two or more tracking stop features451,452,453simultaneously engage with correspondingly shaped two or more preselector stop features471. In this way the mechanical interaction and robustness of the abutment between the dose tracker450and the preselector470can be enhanced and increased.

In the further example of an injection device according toFIG.37toFIG.47the injection device1as illustrated inFIG.24serves as a basis. The injection device24as shown inFIG.37comprises some additional features as will be explained below in order to provide an enhanced functionality of the injection device1as described above.

As illustrated, there is provided an outer housing200encapsulating or accommodating the entirety of the housing10of the injection device1. On the outside of the housing10there is provided the dose tracker550. The dose tracker550as illustrated inFIG.40comprises two components, namely a distal part552and a proximal part553. The distal part552and the proximal part553may be provided as a single-pieced or as an integrally shaped dose tracker550. Only for reasons of assembly of the injection device1the dose tracker550is separated into two separate components.

The distal part552and the proximal part553are permanently and rigidly connected to each other. They are locked with regards to the longitudinal direction (z) as well as with regard to a rotation relative to the housing10. A longitudinal displacement or rotational displacement of one of the distal part552and the proximal part553equally transfers to the other one of the distal part552at the proximal part553.

In the present example the distal part552comprises an at least one or more elongated ribs557extending in longitudinal direction. The ribs557provide a keyed and longitudinally sliding engagement with the outer housing200. The outer housing200may comprise a correspondingly shaped longitudinal groove107in which the rib or ribs557are slidably guided. The dose tracker550is rotationally locked to the outer housing200but is translationally displaceable relative to the housing100in longitudinal or axial direction (z). The dose tracker550also comprises a tracking sleeve555and a tracking stop feature551.

As further illustrated inFIG.40, there is provided a preselector570with a preselector stop feature571. The preselector570comprises a sleeve rotationally supported on an outside facing surface of the dose tracker550. Typically, the distal part552and the proximal part553of the tracking sleeve555are of tubular shape. As illustrated inFIGS.40,46, and47a proximal portion of the distal part552is received in a receptacle at a distal portion of the proximal part553. In the overlapping region the distal part552of the proximal part553are mutually engaged and permanently interlocked.

The preselector570comprises an annular ring or a sleeve with a preselector stop feature571. As illustrated inFIG.40the preselector stop feature571comprises numerous axial recesses in a proximal side of the preselector570. The recesses may form slots of different axial length or of different elongation. A distal end or distal edge of the sleeve of the preselector may form a first preselector stop feature471. The recess501may form a second preselector stop feature572and the further recess502may form a third preselector stop feature573. The recesses501,502comprise different elongations in longitudinal direction as illustrated inFIG.40. Both recesses501,502are open towards the distal end and hence towards the tracking stop feature551. The recesses501,502are located tangentially or circumferentially adjacent and next to each other.

Depending on the rotational position of the preselector570either the first recess501or the second recess502longitudinally aligns with the tracking stop feature551. Since the dose tracker550and hence the tracking stop feature551thereof can only slide in longitudinal or axial direction relative to the housing and since the preselector570is axially or longitudinally fixed to the outer housing200the distance between the tracking stop feature551and a proximal end of the recesses501,502defines a maximum displacement path for the dose tracker550for setting of a dose. Depending on the rotational state, hence depending on the preselection positional state p1, p2of the preselector570the maximum displacement path for the dose tracker550can be modified on demand.

The recesses501,502or slots are configured to receive and to engage the tracking stop feature551protruding radially outwardly from an outside surface of the tracking sleeve555. In the present example the tracking stop feature551comprises a radially outwardly extending protrusion556integrally formed with the distal part552and protruding radially outwardly through a correspondingly shaped recess at a sidewall of the proximal part553. It may likewise be integrally formed with the proximal part553.

The radial extension of the protrusion556matches with the radial extension or radial position of the preselector stop feature571. The preselector570is rotatable between at least two preselection positional states as described above. In any of the preselection positional states the preselector570is rotationally locked to the outer housing200. The preselector570is also permanently longitudinally locked to the housing10. For instance, a proximal end572or edge of the preselector570may be in axial abutment with the outer housing200or with another component of the injection device, e.g. with the release member590that is axially fixed to the outer housing200. In this way the preselector570is locked to the outer housing200with regard to the longitudinal or axial direction.

The injection device1is further provided with an interlock584. The interlock comprises a locking feature575extending through a recess or a through opening of the preselector570. The locking feature575may comprise a spring biased actuator that is depressible in radial direction for temporarily releasing the preselector from the outer housing200. The locking feature575may comprise a screw or the like fastening element that requires a correspondingly shaped tool for temporarily releasing the locking feature575and hence the preselector570from the outer housing200in order to enable a sliding motion or rotation of the preselector570relative to the outer housing200. Depending on the selected preselection positional state of the preselector578a maximum dose positional state dm for the dose tracker550can be defined.

If the preselector570is in a first preselection positional state p1, in which the first recess501longitudinally aligns with the tracking stop feature551the maximum distance the dose tracker550is longitudinally displaceable relative to the outer housing200is shorter compared to a configuration in which the preselector570is in the second preselection positional state p2, in which the second recess502is longitudinally aligned with the tracking stop feature551.

As further illustrated inFIG.40there are provided numerous preselection indications576on an outside surface portion of the preselector570. One preselection indication576always aligns with a preselection window213provided in the outer housing200. As illustrated inFIGS.37and46number 20 shows up in the preselection window213indicating to the user that a preselection of 20 units of the medicament has been pre-selected. Dialing or displacing the preselector570e.g. with the second recess502in alignment with the tracking stop feature551may reveal a larger number, e.g. number 30 in the preselection window213.

The interaction between the release member590and the dose tracker550is illustrated in connection withFIG.41toFIG.45. The release member590comprises an annular ring591comprising numerous catch elements592at an inside facing portion thereof as illustrated inFIG.41. The release member590comprises an annular groove593near a proximal end of the annular ring591. The groove593is positively engaged with a radially inwardly extending fastener214at the outer housing200as illustrated inFIG.47. The fastener214comprises a radially inwardly extending protrusion positively engaged with the groove593. In this way the release member590is freely rotatable relative to the outer housing200but is permanently locked to the outer housing200in longitudinal direction.

In the sequence ofFIGS.42to45only the catch elements592and the proximal portion of the annular ring591are illustrated. An outer section of the annular ring591is cut away or faded away for illustration purpose in order to reveal the mutual engagement of the various catch elements592with radially outwardly extending protrusions562provided on an outside surface portion of the dose tracker550. As illustrated, the protrusions562are of a pin-shaped structure. They extend radially outwardly near a proximal end of the proximal part553. The catch elements592and the protrusions562are regularly and equidistantly arranged along the outer circumference of the dose tracker550and along the inner circumference of the annular ring591, respectively.

The catch elements592extend at a predefined angle relative to the longitudinal direction. Each catch element592comprises a rather straight shaped beveled section594extending in distal direction into a curved section595. The curved section595further extends into an undercut section596. The curved section595extends from the beveled section594into the undercut section596. The curved section595may even overlap with the undercut section596. A free end of the undercut section596is located at a predefined tangential or circumferential distance from the beveled section594. As the protrusion562is displaced in distal direction relative to the release member590it get gets in contact with the beveled section594and slides along the beveled section594until it reaches the curved section595as illustrated by a comparison ofFIG.43andFIG.44.

The curved section595is shaped and describes at least half of a circle or three-quarter of a circle. It describes a circumference of a circle of about 270°. A bottom of the curved section595forms the distal end of the catching element592. Due to the curved section595the button thereof is in longitudinal overlapping configuration with the undercut section596. As the protrusion562is displaced in distal direction and returned towards the zero dose positional state50the release member590is subject to a rotation in accordance to the extension and slope of the beveled section594and the curved section595, respectively. As the protrusion562reaches the bottom of the curved section595it has tangentially entered a free space between the undercut section596and the curved section595.

Releasing of the trigger511in the configuration as shown inFIG.44may enable a small spring-driven proximally directed displacement of the dose tracker550. But then the protrusion562gets in abutment with the undercut section596, thereby impeding any further displacement of the dose tracker550relative to the release member590and hence relative to the outer housing200in proximal direction3.

For release of the dose tracker550the release member590has to be rotated in a clockwise direction. In this way, the undercut section596induces a slight but distinct initial distal displacement of the dose tracker550before the protrusion562enters a free space between the undercut section596and the beveled section594of the catch element592. Due to the regular arrangement of a plurality of catch elements592and protrusions562the protrusions562and catch elements592mutually engage and disengage simultaneously. Once the protrusions562to have disengaged from the catch elements592the dose tracker550is free to slide in proximal direction relative to the outer housing200.

The annular ring591and hence the release member590may be also spring biased, e.g. by a further torsion spring not further illustrated here. In this way, the release member590could be kept in an interlocked configuration as shown inFIG.45. A releasing motion of the release member519may that have to be conducted against the action of such a return spring.

As illustrated inFIG.39in connection withFIG.46orFIG.47there is also provided a spring144implemented as a torsion spring147. The spring144has a first end45permanently connected to the dose tracker550, in particular to its distal part552. Since the dose tracker550is rotationally fixed to the outer housing200the first end45of the spring144is effectively connected to the outer housing200and hence to the housing10. In other words the first end145of the spring144is indirectly connected or coupled to the housing10.

The opposite second end146of the spring144is connected to the dose dial112or to a separate sleeve-shaped fastener216as for instance illustrated inFIG.39. The fastener216is annular shaped and comprises a ring structure. The fastener216is permanently locked or attached to the dose dial112provided at the proximal end of the injection device1. The fastener216may be adhesively attached to the dose dial112. The second end146of the spring144is connected to the fastener216in a torque proof way. Liberating the dose setting mechanism, e.g. by actuating the release member590enables a rotation of the number sleeve180and a respective rotation of the dose dial112. As illustrated further the fastener216comprises a rim217and a recessed portion218on the outside surface of the fastener216. The rim217extends into the recessed portion118via a radial step119or shoulder.

As illustrated inFIG.28the dose tracker550, in particular the proximal part553comprises a radially inwardly extending ledge or rim558that is in axial abutment with the step219. Insofar the rim217is in axial abutment with the rim558. As the spring144induces a dose incrementing rotation of the fastener216and hence of the dose dial112the number sleeve180starts to rotate relative to the housing10. Due to the threaded engagement between the insert162and the number sleeve180the number sleeve180and hence the dose dial112as well as the fastener216become subject to a proximally directed displacement relative to the outer housing200. This proximal displacement of the fastener216is equally transferred to the dose tracker550due to the mutual axial abutment and engagement between the rim217and the rim558.

A spring driven rotation of the number sleeve180therefore transfers to a longitudinal sliding and proximal displacement of the dose tracker550until the tracking stop feature551thereof engages with the preselector stop feature571. As illustrated inFIGS.46and47there is provided a separate trigger511that covers the trigger111of the injection device1. The trigger511is provided and configured to cover the trigger111. The trigger511comprises a larger cross-section compared to the cross-section of the trigger111. The trigger511may be adhesively attached to the trigger111. The trigger511is configured to cover a proximal end of the outer housing200.

InFIGS.48and49a more detailed exemplary implementation of an interlock184and a release member190is illustrated. Here, the interlock184comprises a first locking feature provided on the dose tracker150and further comprises a second locking feature provided on the release member190. The first locking feature is presently implemented as a catch157protruding radially outwardly from the dose tracker150. The catch157may be integrally formed with the dose tracker150. The release member190comprises a correspondingly shaped catch197protruding radially inwardly from the release member190. The catch197may be also integrally formed with the release member190.

The release member190is configured as a pivotable lever191. The lever191is pivotally supported on a pivot axis192. The pivot axis extends in tangential or circumferential direction with regard to the overall geometry of the housing10. The lever191may flush with the outside surface of the sidewall13of the housing10in the initial configuration i as shown inFIG.48.

The lever191comprises the catch197and a depressible end portion at an opposite end. The depressible end portion and the catch197are provided on opposite ends of the lever191. By depressing the depressible end radially inwardly the opposite end and hence the catch197is raised or lifted radially outwardly thus disengaging from the catch157of the dose tracker150as illustrated inFIG.49. The release member190may be further provided with a return spring, presently not illustrated. The return spring may be arranged at the pivot axis192in order to return the release member190into the initial configuration as shown inFIG.48, in which the catch197of the release member190is in axial abutment and in engagement with the correspondingly shaped catch157of the dose tracker150.

The catch157comprises an axial abutment face facing in proximal direction. The catch197comprises a correspondingly shaped axial abutment surface facing in distal direction. In the initial configuration as illustrated inFIG.48the two abutment faces are in axial abutment thus inhibiting a proximally directed displacement of the dose tracker150.

In one embodiment the release member190may comprise a radially outwardly bulged portion193that is configured to become depressed by the user of the device. The radially raised or bulged portion193slightly protrudes from the outside surface of the sidewall13of the housing10. Insofar it provides a haptic feedback to the user that this respective bulged portion193is configured for a radially inwardly directed depression. Once the user depresses the bulged portion193the oppositely located end section of the lever191is raised so that the mutually corresponding abutment faces157,197get out of engagement. As the dose tracker150and hence the interlock184is liberated, the dose tracker150is free to rotate or to move proximally in longitudinal direction under the effect of the spring140as described above, e.g. in connection withFIGS.25to28.

The catch157further comprises a beveled section158. The catch197also comprises a correspondingly shaped beveled section198. The beveled section158of the dose tracker150faces in distal direction2whereas the beveled section198of the release member190faces in proximal direction3. During dose delivery and hence at the end of a dose dispensing procedure the dose tracker150is subject to a distally directed displacement, hence to the left inFIGS.48and49. As the catch157approaches the initial configuration or initial axial position as indicated inFIG.48, the beveled section158slides along the beveled section198. Such a sliding motion is accompanied by the release member198becoming lifted radially outwardly so that the outermost and inner most radial tips of the catches157,197mutually pass by until the axial abutment faces157,197return into an engagement configuration as shown inFIG.48.

If the release member190or its lever191biased by a spring, the catch197is raised or lifted radially outwardly against the action of the respective spring. As soon as the abutment faces197,157get in alignment the lever191snaps into the initial configuration as illustrated inFIG.48under the action of the spring.

InFIGS.50and51a further conceivable implementation of an interlock284and a release member290is illustrated. Here, the dose tracker250comprises an elastic portion256. The elastic portion256may axially protrude from the dose tracker250. Alternatively, it may be integrated into the sidewall of the dose tracker250. It may be separated from a sidewall of the dose tracker along a u-shaped slit. Here, the dose tracker250comprises a catch257correspondingly shaped with a catch297provided at an inside facing portion of the sidewall13of the housing10. The catch257comprises an axial abutment face as described above that faces in proximal direction3. The correspondingly shaped catch297of the housing10comprises a distally facing abutment face to engage with or to abut with the abutment face257.

The catch257and the well as the catch297both comprise a beveled section258,298that enable and induce a slight radially inwardly directed elastic deformation of the elastic portion256as the dose tracker250returns into the initial configuration as illustrated inFIG.50.

The interlock284is formed by the mutually corresponding catches257,297of the dose tracker250and the housing10. In order to release the interlock284there is provided a release member290in form of a depressible button291. The release member290comprises a somewhat planar-shaped or slightly bulged button291integrally formed with a longitudinally extending stem292. The stem292extends radially inwardly and intersect a recess or through opening in the sidewall13of the housing10. The button291slightly protrudes from the outside surface of the sidewall13of the housing10. It is radially displaceably supported on the housing10against the action of a spring295. The spring295is located in a recess293on the outside surface of the sidewall13. The recess293comprises a bottom294that is recessed compared to the outside surface of the sidewall13. The bottom294provides a support for the spring295. An opposite end of the spring295is in abutment with an underside of the button291.

An inner free end299of the stem292protrudes radially inwardly from an inside surface of the sidewall13. The free end299is provided with lateral protrusions296that are separated by distance that is larger than the inner diameter of the recess of the sidewall13through which the stem292extends. In this way, the stem292and the entire button291is hindered from getting pushed out of the housing10under the action of the spring295.

In an initial configuration as illustrated inFIG.50the free end299of the stem292axially overlaps with the elastic portion256of the dose tracker250. By depressing the release member290and hence the button291radially inwardly, the stem292advances downward in the illustration ofFIG.50andFIG.51. Since the free end299is in abutment with an outside surface portion of the elastic portion256such a depression leads to a local and radially inwardly directed deformation of the elastic portion256. The elastic deformation is large enough to bring the catches297,298out of engagement so as to liberate a proximally directed displacement of the dose tracker250.

The examples ofFIGS.48to51are only exemplary for an interlock184,284and a release member190,290and can be generally implemented with any of the examples as illustrated inFIG.1toFIG.47.

List of reference numbers1injection device36atooth2distal direction38protrusion3proximal direction40spring4first direction43inner thread5second direction44threaded insert6cartridge45sleeve section7piston46proximal face8drive mechanism47socket section9dose setting mechanism48shoulder portion10housing50clutch11preselection window51sleeve section12dose indicating window52thread13sidewall53ratchet member14cartridge holder54ratchet member15−needle assembly55engaging section16inner needle cap56engaging section17outer needle cap57distal face18protective cap58proximal face19recess60dose tracker20piston rod61dose button21groove61asupport face22pressure foot62threaded section23thread63tracking stop feature25barrel63astop face26seal64leg28socket65leg30driver66dose size indicator31sleeve section67distal face32flange68interlock member33bore68aarm34toothed section68bengaging structure34atooth69interlock member35axial face69aarm36toothed section69bengaging structure71sleeve section111trigger72recess112dose dial73stop feature113dosage window73astop face120piston rod74astop face121bearing75stop feature122first thread75astop face123pressure foot76protrusion124second thread77preselection indication130driver78through opening131threaded section80spring132flange81distal end133flange82proximal end135last dose limiting member83compression spring140spring84interlock141distal end86retainer142proximal end90support143preselection indication91body144spring92strut section145first end93strut section146second end94distal face147torsion spring95flange section150dose tracker96toothed section151tracking stop feature97flange section152tracking stop feature98recess153tracking stop feature99recess154proximal end100release member153proximal end101release member155tracking sleeve102release button156protrusion103release button157catch104flange section158catch106resilient arm160clutch107resilient arm162insert108connecting piece163protrusion109engaging structure164stem165spring257catch166clutch258catch167recess270preselector168sidewall271preselector stop feature170preselector276protrusion171preselector stop feature290release member172preselector stop feature292stem173preselector stop feature293recess175preselection indication294bottom180number sleeve295spring18groove296protrusion184interlock297catch190release member298catch191lever299free end192pivot axis350dose tracker193bulged portion351tracking stop feature197catch355tracking sleeve198catch356protrusion200outer housing370preselector201groove371preselector stop feature202groove372preselector stop feature203groove373preselector stop feature204connecting groove376protrusion207groove450dose tracker213preselection window451tracking stop feature214fastener452tracking stop feature216fastener453tracking stop feature217rim455tracking sleeve218recessed portion470preselector219step471preselector stop feature250dose tracker476protrusion251tracking stop feature501recess252tracking stop feature502recess253tracking stop feature511trigger255tracking sleeve550dose tracking member256elastic portion551tracking stop feature552distal part553proximal part555tracking sleeve556protrusion557rib558rim562protrusion570preselector571preselector stop feature572preselector stop feature573preselector stop feature572proximal end575locking feature576preselection indication584interlock590release member591annular ring592catch element593groove594beveled section595curved section596undercut sectionp1preselection positionalstatep2preselection positionalstated0zero dose positional statedmmaximum dose positionalstateiinitial positionaactivation position