Drive mechanism for injection device

Abstract

The invention relates to a drive mechanism for an injection device for setting and dispensing a dose of a medicament, comprising:-an inner body (20) fixable within a housing (10) of the injection device (1), the inner body (20) comprising an elongate shaft (20a) extending in an axial direction (z) and having an external thread (21), -a tubular display member (60; 160) having an internal thread (61) that engages with the external thread (21) of the inner body (20), and-a dose member (70) that is able to apply a dose relative to the external thread (21) of the display member (60; 160) is axially displaced between a dose setting position (S) and a dose dispensing position (D),-wherein the display member (60; 160, 160; 260) comprises at least one blocking member (66) which is movable in an axial direction (z) between a blocking position (B) and a release position (R) and which is movable relative to a blocking thread (27; 227), in which the blocking thread (27; 227) and the external thread (21; 221) have the same pitch, and wherein the display member (60; 160) can be moved relative to the inner body (20; 220) in the inner body (20; 220) and a distal zero dose location (Z) on the inner body (20; 220),-wherein, when in a blocking position (B), the blocking member (66) is rotated between a proximal maximum dose position (M) on the dose member (70) and the blocking thread (27; 227) to block axial displacement of the dose member (70) from the dose setting position (S) towards the dose dispensing position (D), and wherein a distal end (27a) of the blocking thread (27, 227) is axially engaged with the inner body (20; 220) is positioned offset in the proximal direction (5) from the distal zero-dose position (Z) by an offset of between 10% and 60% of the axial distance between the distal zero-dose position (Z) and the proximal maximum-dose position (M).

Description

[0001] In one aspect, the present invention relates to a drive mechanism for an injection device, such as a pen-type injector for setting and dispensing a dose of a medicament. In particular, the present invention relates to an injection device that provides a minimum dose mechanism, i.e. a dose setting and dispensing mechanism, which is operable to dispense a dose only when the dose exceeds a predefined minimum threshold. Background Art

[0002] Injection devices for setting and dispensing single or multiple doses of liquid medicaments are well known in the art. Typically, such devices have substantially similar uses to ordinary syringes.

[0003] Injection devices, in particular pen-type injectors, must meet many user-specific requirements. For example, in the case of a patient suffering from a chronic disease such as diabetes, the patient may be physically weak and may also have impaired vision. Therefore, a suitable injection device specifically intended for home medication needs to be robust in structure and should be easy to use. Furthermore, the handling and general control of the device and its components should be clear and easy to understand. Furthermore, the dose setting and dose dispensing procedures must be easy to operate and must be unambiguous.

[0004] Typically, such a device comprises a housing comprising a cartridge holder adapted to receive a cartridge at least partially filled with a medicament to be dispensed. Such a device further comprises a drive mechanism, which typically has a displaceable piston rod adapted to operatively engage with a piston of the cartridge. By means of the drive mechanism and its piston rod, the piston of the cartridge can be displaced in a distal direction or dispensing direction and thus a predefined amount of medicament can be expelled via a piercing assembly which will be releasably coupled to a distal section of the housing of the injection device.

[0005] The medicament to be dispensed by the injection device is provided and contained in a multi-dose cartridge. Such a cartridge generally comprises a glass barrel which is sealed in the distal direction by means of a pierceable seal and further sealed in the proximal direction by a piston. For a reusable injection device, an empty cartridge can be replaced by a new cartridge. In contrast, a disposable injection device will be discarded when the medicament in the cartridge has been dispensed or used up.

[0006] Documents WO 2014 / 033197 A1 and WO 2014 / 033195 A1 disclose disposable and reusable drug delivery devices for selecting and dispensing a plurality of user-variable doses of a medicament. These devices include a housing, a cartridge holder for holding a cartridge containing the medicament, a piston rod displaceable relative to the cartridge holder, a driver coupled to the piston rod, a display member indicating a set dose and coupled to the housing and the driver, and a button coupled to the display member and the driver.

[0007] Document WO 2012 / 049140 A1 describes a dose setting mechanism having a clutch nut that is threadedly engaged with the distal end of the clutch and further engaged with the dose dial sleeve via an internal ratchet. Document WO 2012 / 049139 A1 describes a clutch blocker that includes an external thread that is threadedly engaged with a clutch plate. The axial travel of the clutch plate will tend to cause the clutch blocker to rotate unless its keying feature extends in the first path of the dual-state path to prevent rotation. Document US2013 / 0289518 A1 describes another principle for implementing a minimum dose size. Here, a spiral and axial combined clutch path is described, which has a spiral portion and an axial portion on the inner surface of the outer body. Document WO 2012 / 049138 A1 describes a minimum dose setting mechanism based on a separate threaded insert located between the dose dial sleeve and the housing.

[0008] For some applications, it may be advantageous to limit the minimum dose of a drug that can be delivered from the device, as well as the maximum dose. This may, for example, ensure that only a therapeutically effective dose can be administered. This functionality may be particularly relevant to drug combinations, where a minimum amount of the combined drug is required to ensure adequate delivery of one element of the combination to be therapeutically effective, while allowing for some variation in dose that may be important for other elements in the combination.

[0009] In some applications it may be advantageous to provide a device which allows delivery of only one fixed dose value and which also allows a 'priming' operation to be performed before administration of each dose.

[0010] Another application may be for therapies where a series of discrete, non-sequential pre-fixed doses of a medicament may be required. For example, a series of doses may be required to meet the therapeutic needs of different user groups, or to allow individual users to deliver different doses at different times of the day (e.g., in the morning or evening).

[0011] EP 3 256 194 B1 A drive mechanism for an injection device, the drive mechanism providing a minimum dose function. Another object is that the drive mechanism also provides a maximum dose function. Such a drive mechanism may allow pre-priming of the device, thereby enabling the user to dial and deliver a small amount of medicament, typically 2 International Units (IU), to check that flow is occurring correctly through a needle assembly, which is releasably attached to the distal dispensing end of the device.

[0012] However, the restriction to a fixed minimum dose reduces the flexibility that may be required for certain categories of patients, for example, patients at the beginning of treatment may desire a titration range, where the dose most suitable for the patient remains to be determined. Further, a fixed minimum dose may result in wasting a considerable amount of product in the cartridge that cannot be used.

[0013] Purpose of the Invention

[0014] It is therefore an object of the present invention to provide a drive mechanism for an injection device which provides a fixed dose functionality whilst retaining the flexibility of selecting a variable dose.

[0015] The embodiment of the desired minimum and / or maximum and / or variable dose function should be able to be realized by modifying only a limited number of existing device components. Another object is to modify the minimum and maximum and / or variable dose value or dose size individually by changing only a single or only a few components of the device. Therefore, the minimum and / or maximum and / or variable dose function of the device or its drive mechanism should be able to be configured by interchanging only one or a few components of the device or its drive mechanism. Another object is that the improved drive mechanism is generally applicable to various drive mechanisms and injection devices. Specifically, the improved drive mechanism should be equally applicable to disposable injection devices and reusable injection devices. Summary of the invention

[0016] This object is achieved by a drive mechanism for an injection device having the features of claim 1 .

[0017] In a first aspect, the present invention relates to a drive mechanism for an injection device. The injection device is operable to set and distribute a plurality of variable-size doses of a medicament, usually by injection. The drive mechanism of the injection device includes mechanically interengaged components that require a distal thrust to be applied to a piston of a cartridge filled with a liquid medicament. The drive mechanism includes an internal body that can be fixed in a housing of the injection device. The internal body includes at least an elongated shaft that extends in an axial direction (z) and has an external thread. The external thread is a helical thread and has a constant or variable pitch in the axial direction. The internal body can be fixed in the housing in an immovable manner. Therefore, the internal body can be axially and rotationally fixed in a tubular or cylindrical housing of the injection device. The internal body and the housing can also be formed as one piece. Therefore, the internal body can be a part of the housing.

[0018] The drive mechanism further comprises a tubular display member having an internal thread that engages or cooperates with the external thread of the inner body. When rotated in a spiral manner, the tubular display member can be axially displaced relative to the inner body, specifically relative to its elongated axis. Typically, the pitch and friction of the threaded engagement of the display member and the inner body causes the display member to begin to rotate when it is subjected to an axial force relative to the inner body.

[0019] In addition, the drive mechanism comprises a dose member, which can be axially displaced relative to the display member between a dose setting position (S) and a dose dispensing position (D). The dose member can be rotatable relative to the inner body. The dose member can also be axially displaceable relative to the inner body. Typically, the dose member can be rotated along a spiral path relative to the inner body for setting a dose. In addition, the dose member can be axially displaceable relative to the inner body in a non-rotational manner for dispensing a dose. The dose member and the display member can be selectively engaged in rotation, usually by means of a clutch, in a manner that the rotational engagement between the dose member and the display member is locked or released.

[0020] In dose setting mode, the clutch is normally closed so that the torque applied to the dose member is transmitted to the display member, which, when it is threadedly engaged with the inner body, is axially displaced in unison with the dose member relative to the inner body. For dose dispensing, the clutch between the display member and the dose member can be released so that the display member can rotate when returning to its initial position, while the dose member undergoes a purely translational displacement. Thus, during dose dispensing, the dose member can be rotationally locked to the inner body, while the display member is free to rotate relative to the display body and therefore relative to the dose member.

[0021] According to a particular embodiment of the drive mechanism, the rotational display member or the translationally displaced dose member is operably engaged with the piston rod for driving the piston rod in a distal dose dispensing direction during dose dispensing thereby displacing the piston of the cartridge in distal direction.

[0022] The display member further comprises at least one blocking member, and this at least one blocking member can move and / or be flexible between blocking position (B) and release position (R) in the axial direction.The blocking member can engage with the blocking structure on the outer circumference of the inner body.Usually, the blocking structure is located on the outer circumference of the elongated shaft of the inner body.The radial extension of the blocking structure overlaps or is substantially equal to the radial extension of the external thread of the elongated shaft usually.In other embodiments, the radial extension of the blocking structure can exceed the radial extension of the external thread.

[0023] At least one blocking member of the display member is capable of rotating a predetermined number of turns relative to the inner body, i.e. performing a relative dose setting movement. Due to the threaded engagement of the display member and the inner body, this relative rotation causes a relative axial displacement of the display member and the inner body between a zero dose position (Z) of the at least one blocking member on the inner body and a maximum dose position (M) of the at least one blocking member on the inner body. Typically, if the dose member is in its dose setting position (S), the zero dose position (Z) of the at least one blocking member on the inner body is the most distal position of the at least one blocking member, and if the dose member is in its dose setting position (S), the maximum dose position (M) of the at least one blocking member on the inner body is the most proximal position of the at least one blocking member.

[0024] When in the blocking position (B), the blocking member is axially engaged with the dose member and the blocking structure. In this blocking position, the dose member is effectively blocked and therefore cannot be axially displaced relative to the inner body or relative to the dose member from the dose setting position towards the dose dispensing position. Therefore, when the blocking member of the display member engages the blocking structure of the inner body (which may typically occur during the dial or spiral rotation movement during dose setting), the blocking member is used to block the corresponding axial displacement of the dose member by effectively preventing the axial displacement of the dose member relative to the display member and / or relative to the body or housing. In this blocking state, the clutch between the dose member and the display member is effectively locked in a closed configuration, so that the drive mechanism remains in a dose setting mode, characterized in that the dose member is in the dose setting position (S) relative to the display member.

[0025] According to the blocking member and the blocking structure, in particular, the mutual engagement of the geometric shape and the extension of the blocking structure, the dose dispensing can be effectively blocked for a predefined range of dose sizes. In this way, a minimum threshold and a maximum threshold can be defined, and the dose dispensing is effectively blocked and prevented between these thresholds. According to the present disclosure, the axial position of the distal end of the blocking thread on the inner body is positioned to be offset from the distal zero dose position (Z) in the proximal direction, and the offset is between 10% and 60% of the axial distance between the distal zero dose position (Z) and the proximal maximum dose position (M). In an embodiment, the axial position of the distal end of the blocking thread on the inner body is positioned to be offset from the distal zero dose position (Z) in the proximal direction, and the offset is between 20% and 30% of the axial distance between the distal zero dose position (Z) and the proximal maximum dose position (M), for example, up to 25%. The dose setting range between the zero dose position (Z) of the at least one blocking member on the inner body and the maximum dose position (M) of the at least one blocking member on the inner body is typically between 60 IU and 100 IU, for example 80 IU, the minimum threshold defining the maximum dose value of the titration range, i.e. the variable settable dose, which far exceeds the dose used for the priming procedure (i.e. for example 2 IU or 3 IU).

[0026] In other words, the axial position of the distal end of the blocking structure or blocking thread on the inner body defines the maximum size of a variable dose, which can be selected and dispensed individually, for example, for titration reasons or for a pre-filling procedure. In addition, this titration or variable dose range can be used if the amount of medicament in the cartridge is lower than the dose intended to be dispensed. In this case, the dose intended to be dispensed can be split between the remaining amount in the cartridge set and dispensed in the first step, a new (full) cartridge is inserted into the device after the first step, or a new device with a full cartridge is used to set and dispense the remaining part of the dose intended to be dispensed in the second step.

[0027] As long as the blocking member is axially separated from the blocking structure and as long as the blocking member is located distally of the distal end of the blocking structure, the blocking member remains in the released position. This is typically the case when the display member and therefore the entire drive mechanism is in a zero set dose configuration, i.e. when the blocking member is in its distal zero dose position (Z), or when the dose is set within a titrated or variable dose range. When the dose is set to exceed this lower threshold, the blocking member engages with the blocking structure. This prevents it from flexing in the distal direction, or it actually flexes slightly in the proximal direction in order to block a distally directed dispensing displacement of the dose member.

[0028] By the above-mentioned drive mechanism for injection device, the setting of variable titration dose is allowed within the first lower dose range, wherein standard titration allows flexibility of administration at the beginning of treatment, and since all doses are injectable within this dose range, it allows dose splitting and minimizes drug waste. Further, the second range (e.g., maintenance range) ensures the simplicity of dose dialing and safe administration under a pre-set fixed dose exceeding the variable titration dose. The function of pre-setting a fixed dose in the second dose range is realized by arranging a blocking member on the display member and arranging a blocking structure on the internal body. The positions of the sections of the blocking structure on the internal body define which doses are deliverable and which doses are blocked. According to the present disclosure, the distal end of the blocking structure is arranged so as to allow setting of, for example, a variable titration dose of up to 20 units, while a higher dose above 20 units can be dispensed only in pre-set fixed dose steps of, for example, 10 units each time. In other words, the patient can select and dispense a variable dose between 0 and 20 units or a higher dose in 10 unit increments, ie, 30 units, 40 units, 50 units, 60 units, 70 units, or 80 units.

[0029] In an embodiment of the drive mechanism, at least one blocking member of the display member can be rotated relative to the inner body between a distal zero dose position (Z) on the inner body and a proximal maximum dose position (M) on the inner body by between 1.080° (three full turns) and 2.160° (six full turns), for example 1.440° (four full turns) or 1.800° (five full turns).

[0030] The blocking member can be flexed in the axial direction in response to the engagement with the blocking structure. In addition, the blocking member flexed in the axial direction can be supported and mechanically strengthened by the blocking structure to provide a fairly strong and robust axial abutment for the dose member. Alternatively, the blocking member can also be axially engaged with the blocking structure without axially flexing. In this non-flexed state, it is simply prevented from moving axially relative to the blocking structure. Therefore, even in this non-flexed but engaged configuration, the blocking member engaged with the blocking structure is axially constrained or axially fixed relative to the housing in at least one axial direction (usually in the distal direction). When engaged with the blocking structure, the blocking member can also be axially engaged with the dose member, and then the dose member is also axially constrained or axially fixed relative to the housing.

[0031] Typically, the blocking member engages on the proximal side of the blocking structure such that if a user attempts to dispense a dose, the blocking member cannot be deflected distally by the dose member when engaged with the blocking structure.

[0032] According to an embodiment, the blocking structure includes a blocking thread on the elongated shaft of the inner body. The blocking thread can extend between the turns of the external thread of the inner body, but can also be axially separated from the external thread on the shaft. The blocking thread and the external thread have the same pitch. Usually, the blocking thread, and therefore the turn of the blocking thread, can be axially positioned in the middle between adjacent turns of the external thread of the inner body, in particular its elongated shaft. Since the blocking thread and the external thread have the same pitch, and since the blocking thread and the external thread are axially offset, when the display member is spirally rotated relative to the inner body during the dose dial operation, the blocking member remains in its blocking position during engagement with the blocking thread.

[0033] Typically, the axial extension of the blocking thread is shorter than the overall axial extension of the external thread. As seen in the axial direction, the blocking thread can be located within the external thread so that both the proximal and distal ends of the blocking thread are located in an axial region limited by the proximal and distal ends of the external thread. In alternative embodiments, and depending on the axial position of the internal thread of the display member relative to the axial position of the blocking member, it is also conceivable that the proximal and / or distal ends of the blocking thread are located outside the proximal or distal ends of the external thread.

[0034] When the display member rotates relative to the inner body, the blocking member can be flexed in the axial direction when it engages with one end of the blocking thread. Then, when the blocking member slides along the blocking thread, it can remain flexed, and when it passes the opposite axial end of the blocking thread, it returns to its release position. When the blocking member has passed the proximal end of the blocking thread during the dose increment rotation of the display member relative to the inner body, the blocking member can be axially flexed by the dose member when the dose member is advanced distally in the axial direction to distribute the dose. In this state, the dose member is free to displace in the axial direction relative to the display member by a distance sufficient to release the clutch between the display member and the dose member. When the clutch is released, the device switches to the dose dispensing mode and the dose dispensing program can begin.

[0035] According to another embodiment, the blocking member comprises a flexible arm extending in a tangential direction around the circumference of the display member. The flexible arm of the blocking member may be arc-shaped and may follow the contour of the side wall of the display member. In order to provide an axial flexure or axial deformation of the blocking member relative to the display member, the blocking member is arranged at an axial end of the display member or in a recess of the side wall, in which the blocking member is free to bend elastically or pivot in the axial direction. The flexible arm does not necessarily have to extend exactly tangentially and perpendicularly to the axial direction of the tubular display member. It is generally conceivable that the flexible arm extends at an angle relative to the tangential or circumferential direction and the axial direction of the display member.

[0036] Typically, the flexible arm is formed integrally with the display member. The flexible arm may include a base portion formed integrally with the blocking member, from which the flexible arm extends toward the free end. Due to the flexibility of the material and the geometry of the flexible arm, in particular its free end is flexible, pivotable or displaceable in the axial direction, so as to switch between its blocking position and its release position. Implementing the blocking member as a flexible arm substantially coinciding with the outer circumference of the display member is a fairly space-saving and cost-effective solution. In addition, the integrated embodiment of the blocking member integrated into the display member only requires modification of one component of the drive mechanism, and does not require assembly of additional components.

[0037] This also works with respect to the blocking structure. The blocking structure can be implemented into the inner body without providing a separate component. The general functionality and behavior of the minimum dose function can be modified by using a suitably configured blocking structure. Modification of the minimum dose function only requires replacing the inner body component with the first blocking structure with a different inner body having an alternative blocking structure.

[0038] In another embodiment, the blocking member includes a radially inwardly extending projection at the free end section of the flexible arm to engage with the blocking structure. In this way, the modification of the display member to implement the blocking member has no effect on the components arranged at the outer circumference of the display member or along the outer circumference of the display member of the injection device or the drive mechanism. In addition, by means of the radially inwardly extending projection, the free end of the flexible arm of the blocking member can be axially displaced when it engages with the blocking thread of the blocking structure. Further, by means of the inwardly extending projection, when axially abutting or axially engaging with the blocking structure, the free end of the blocking member can be axially supported and axially constrained. Then, when axially abutting or axially engaging with the blocking structure, any force directed to the distal side transmitted from the dose member to the display member is offset by the axial abutment of the inwardly extending projection of the blocking member. According to the comparison of the slope and geometry of the outer thread of the outer thread of the inner body with the geometry of the blocking structure or the slope, the degree of axial displacement or axial deflection of the free end of the blocking member can be modified and controlled.

[0039] According to another embodiment, the blocking member comprises at its free end section an abutment facing in the axial direction to axially abut with a corresponding abutment of the dose member. Typically, the abutment of the blocking member may face in the proximal direction to axially abut with a correspondingly shaped distally facing abutment of the dose member. The distal abutment of the dose member may coincide with the distal end of the dose member. It is also conceivable that the dose member and the display member are arranged in a somewhat spiral or nested manner.

[0040] In a typical embodiment, the dose setting position of the dose member coincides with the proximal position of the dose member relative to the display member. Depressing the dose member in the distal direction advances the dose member into the dose dispensing position. In such an embodiment, the abutment of the blocking member usually faces the proximal direction. When the blocking member is in the release position, there may be a small axial gap between the abutment of the blocking member and the corresponding abutment of the dose member. In the release position, the dose member is freely displaced in the distal direction relative to the display member to reach the dose dispensing position. Alternatively, when in the release configuration, the blocking member can also be in axial abutment with the dose member. Then the blocking member and the blocking structure can be disengaged. In short, when in the release configuration, the dose member can be displaced distally relative to the housing.

[0041] The blocking member does not necessarily have to be displaced or flexed in the axial direction, since the blocking member engages with the blocking structure of the elongated shaft of the inner body. It is also conceivable that when the blocking member and the blocking structure engage with each other, the blocking member remains non-flexed but is inhibited from flexing in the distal direction. In such an embodiment, the blocking member may even be in permanent axial engagement with the abutment of the dose member. When in the released position, the blocking member is then still in axial abutment with the dose member, but due to being released from the blocking structure, the blocking member is then free to flex or pivot in the distal direction, so that the dose member can be axially displaced to initiate the dispensing of the dose.

[0042] When in the blocking configuration, the dose member is axially engaged and in axial abutment with the blocking member, which is further in axial abutment with the blocking structure. In this way, any distally directed force exerted on the dose member is counteracted and transferred to the blocking structure and thus to the housing.

[0043] In another embodiment, the axial position of the proximal end of the blocking structure on the elongated axis of the inner body defines a minimum size of the therapeutic dose. The above blocking of the dose member is maintained until the display member is further dialed to disengage and release the blocking member. When the display member is dialed above a maximum threshold value consistent with the minimum size of the therapeutic dose, the engagement of the blocking member and the blocking structure is released so that the dose member is no longer prevented from being displaced in the distal direction. Once a desired size of the therapeutic dose exceeding the predefined minimum size has been set, the drive mechanism is operable to start a dispensing procedure.

[0044] According to another embodiment, the distal end of the blocking structure or blocking thread is chamfered. In this way, the blocking member, in particular its radially inwardly extending protrusion directly engaged with the blocking thread mechanically, performs a small axial displacement according to the angle of the chamfered distal end of the blocking thread as the blocking member and the blocking thread engage with each other during dose setting.

[0045] By means of the chamfered distal end, a smooth and reliable engagement of the blocking member with the blocking thread can be achieved when the radially inwardly extending protrusion of the blocking member passes over the end of the blocking thread. Similar to the distal end, the proximal end of the blocking thread may also be chamfered to provide a smooth and reliable engagement with the blocking member when dialing down or in the dose decrementing direction to deselect a dose.

[0046] In another embodiment, and when the display member is rotated in the dose increment direction, the projection of the blocking member slides on the chamfer of the distal end of the blocking thread to flex the free end section of the blocking member from its release position toward its blocking position. Alternatively, the projection slides on the chamfer to axially abut against the proximal edge of the blocking thread. When the projection of the blocking member passes the chamfered end of the blocking thread, the blocking member slides along the proximal edge of the blocking thread and thus remains in axial abutment with the blocking thread, thereby preventing the blocking member from being displaced relative to the distal end of the blocking thread. In one embodiment, the blocking member remains flexed and remains in axial abutment with the blocking thread in the proximal direction because the outer thread of the elongated shaft of the blocking thread and the inner body has the same lead.

[0047] In this way, the blocking member is axially supported by the proximal edge of the blocking thread as long as the blocking member is engaged with the blocking thread. Any axial and distally directed forces acting on the blocking member, for example caused by the dose member, are directly supported and transferred to the blocking thread and thus to the inner body. In this way, a fairly direct axial force transfer can be provided between the dose member and the inner body, thereby providing the user with a fairly intuitive and direct mechanical feedback that a distally directed displacement of the dose member is actually prevented.

[0048] The location of the axial support provided to the blocking member by the proximally facing edge of the blocking thread in the blocking state is also beneficial because the flexible portion of the blocking member does not have to withstand or counteract large axial forces. Thus, the blocking member can be designed with a thin or fine structure so that a desired degree of flexibility can be achieved for low dispensing forces.

[0049] When the blocking member is located proximal to the proximal end of the blocking thread, a dose can be dispensed because the blocking member is no longer axially engaged with the blocking structure. To dispense a dose, the dose member is axially displaced in the distal direction, which in turn causes the blocking member to flex in the distal direction, thereby allowing the clutch between the dose member and the display member to be released. When the clutch has been released, when the display member is rotated in the dose decrementing direction during dose delivery, the protrusion of the blocking member can slide distally beyond the distally facing edge of the blocking thread when the blocking member passes the proximal end of the blocking thread in the distal direction.

[0050] During dose delivery, the geometry and design of the blocking member and the blocking structure make the radially inwardly extending projection of the free end section of the blocking member slide along the distally facing edge of the blocking thread. The projection does not necessarily have to slide along the distal edge. It may be beneficial that it can be separated distally from the distally facing edge of the blocking structure. However, it is axially separated from the proximal edge of the blocking thread. At the beginning of the dose dispensing program, under the action of the dose member that is advanced distally, the blocking member performs a distally directed displacement or a distally directed pivoting. Then, the radially inwardly extending projection of the blocking member slides along the distally facing edge of the blocking thread, but does not engage with its proximal facing edge.

[0051] During dose dispensing, the blocking member, in particular its radially inwardly extending projection, will pass the proximal end of the blocking structure of the inner body in the distal direction. In the event that the dose member is then released to abruptly interrupt the dispensing procedure, the projection of the blocking member may axially abut against the distally facing edge of the blocking thread. If the dose member is released, the blocking member cannot be flexed proximally because it is constrained by the blocking thread. Therefore, when the dose member is again pressed distally, dispensing may continue.

[0052] In another embodiment, the display member comprises a number sleeve and a dial sleeve. The at least one blocking member is located on the dial sleeve, or the at least one blocking member is formed integrally with the dial sleeve. Typically, the number sleeve and the dial sleeve are permanently rotationally and axially locked to each other. Typically, the number sleeve of the display member is threadedly engaged with the external thread of the inner body.

[0053] The division of the display member into two separate parts (number sleeve and dial sleeve) facilitates the injection molding of these individual parts and their assembly in the drive mechanism. The number sleeve is the part of the display member provided with consecutive numbers or symbols indicating the actual set dose size on its outer circumference. According to the spiral movement or position of the external thread relative to the inner body, the corresponding number on the number sleeve is shown in the aperture of the window in the outer body of the housing of the injection device.

[0054] The color of the dial sleeve may be different from the color of the number sleeve. In addition, the dial sleeve may be made of or consist of a different injection moldable plastic material than the number sleeve. Thus, at least one blocking member or all blocking members of the blocking mechanism may be located on or integrally formed with the dial sleeve. Because the dial sleeve does not need to be printed or coated with dose indicating numbers or markings, more material options are available.

[0055] For example, the dial sleeve and therefore at least one blocking member attached thereto or formed integrally therewith may be made of a plastic material such as polyoxymethylene (POM). Such plastic materials are difficult to print, but provide desirable mechanical properties in terms of durability, flexibility and stability, in particular with respect to the at least one blocking member. Thus, by dividing the display member into two separate sleeves, namely the number sleeve and the dial sleeve, and by providing at least one blocking member or all blocking members on the dial sleeve, an optimized plastic material may be selected for manufacturing the dial sleeve and its blocking members. Such plastic material does not need to meet any printing requirements or restrictions and may be mechanically optimized with respect to the mechanical needs and requirements of the at least one blocking member.

[0056] According to another embodiment, the inner body may include a first maximum dose stop and optionally a second maximum dose stop at its outer circumference to engage with the first maximum dose stop and the second maximum dose stop extending radially inwardly of the display member, respectively. When the display member reaches the maximum dose position, the first maximum dose stop of the inner body and the display member and optionally also the second maximum dose stop engage with each other and simultaneously. The maximum dose position limits the amount of medicament to be injected by a single dose dispensing action. Typically, the maximum dose size can be limited to, for example, 60 IU, 80 IU, 120 IU. The mutually corresponding maximum dose stops of the inner body and the display member typically extend axially and radially. In this way, as long as the maximum dose position has been reached, the tangentially facing stop surfaces engage with each other and abut against each other.

[0057] Providing two axially separated pairs of maximum dose stops provides improved and well-defined stop functionality. In this way, the stopping force for inhibiting the dose member from rotating past the maximum dose configuration can be split into two pairs of axially separated dose stops. As a result, the overall design of the dose stops can be reduced, in particular their size. Moreover, the mechanical load between the mutually engaged dose stops of the display member and the inner body is reduced compared to embodiments using only one pair of dose stops.

[0058] According to another embodiment, the maximum dose stop of the display member facing the tangential direction is located on the free end section of the blocking member. The abutment at the free end section of the blocking member can face the proximal direction so that the flexible arm of the blocking member comprises an L-shaped structure in some way. It is generally conceivable that the maximum dose stop of the display member, in particular the maximum dose stop of the display member located proximally, is located on the free end section of the blocking member. Typically, this maximum dose stop faces the base portion of the flexible arm of the blocking member, where the flexible arm engages the display member. In this way, the flexible arm is subjected to a tensile force directed in the tangential direction because its maximum stop engages with a correspondingly shaped maximum stop of the inner body. The tensile force extends substantially parallel to the L-shaped extension of the flexible arm. Any stopping force or torque to be transmitted between the flexible arm and the maximum dose stop of the display member will not damage the mechanical integrity of the flexible arm. Due to the orientation and position of the stop face of the flexible arm, the arm can be designed as a relatively thin and flexible structure while being able to transmit considerable forces and / or torques under tension.

[0059] In another embodiment, the blocking thread comprises at least one recess, interruption or gap, and the at least one recess, interruption or gap has a size suitable for receiving the blocking member and / or its radially inwardly extending projection. In this way, the drive mechanism can be configured as a fixed dose drive mechanism, by which only one or several doses of a predetermined size can be distributed. The circumferential or tangential size of the one or more gaps defines the dose size that can be distributed by the device. The tangential size of the at least one gap is at least as large as the blocking member or its radially inwardly extending projection that actually passes through the gap in the blocking thread when initiating the dose dispensing program. Several gaps that are tangentially and / or axially separated from each other along the blocking thread can exist. Thus, only when the tangential position of the corresponding gap overlaps or axially coincides with the actual position of the blocking member or its projection, it is possible to perform dose dispensing. If the blocking thread comprises at least two recesses having a size for receiving the blocking member and / or its radially inwardly extending protrusion, two adjacent recesses may be spaced apart from each other by between 10% and 20%, for example 12.5%, of the axial distance between the distal zero dose position (Z) and the proximal maximum dose position (M).

[0060] By means of the present invention and solely by means of a specific design and geometry of the blocking structure or blocking thread, the drive mechanism can be configured to allow only doses of specific or discrete sizes to be set and dispensed.

[0061] According to another embodiment, the drive mechanism comprises a piston rod and a tubular driver, both of which extend in an axial direction. The piston rod generally comprises a first external thread engaged with an internal thread of an inner body. In this way, the rotation of the piston rod in the dispensing direction causes the piston rod to be advanced to the distal side relative to the inner body and therefore relative to the cartridge axially constrained in the housing of the injection device. In addition, the piston rod comprises a second external thread that is counter-rotated compared to the first external thread, wherein the second external thread is threadedly engaged with the internal thread of the driver. In this way, the axial but non-rotational displacement of the driver in the distal direction causes the rotation of the piston rod, which is advanced in the distal direction during the dose dispensing due to the threaded engagement with the internal thread of the inner body. Therefore, during the dose dispensing, the driver performs a pure translational non-rotational movement directed to the distal side. For dose dispensing, the driver is generally rotationally locked to the inner body. The driver can be connected to a spline in the inner body so that the driver is prevented from rotating relative to the body during the dose dispensing process, but is freely axially displaced relative to the body.

[0062] In the dose setting configuration, the driver may be rotationally locked or rotationally coupled to the display member so as to follow the helical movement of the display member relative to the inner body. In the dose setting mode, the splined engagement of the driver and the inner body is cancelled or released. Instead, the driver is free to rotate according to a helical path that coincides with the threaded engagement of the driver and the piston rod, so that the driver can be axially displaced in the proximal direction relative to the inner body and relative to the piston rod, which is stationary relative to the inner body during dose setting.

[0063] By means of the two threads of the piston rod in counter-rotation, a displacement conversion ratio between the driver and the distal displacement of the piston rod can be implemented. Thus, a relatively large axial displacement requiring relatively small dispensing forces can be transferred into a relatively short displacement of the piston rod utilizing relatively large dispensing forces.

[0064] According to another embodiment, the dose member is permanently splined with the driver. The driver in turn can be selectively rotationally locked to the inner body by displacing the dose member into the dose dispensing position. When the dose member is in the dose setting position, the driver is no longer rotationally locked to the body but is free to rotate relative to the body, for example by means of a ratchet or clicker pawl engagement, by which the rotation of the driver relative to the body produces an audible and tactile click, thereby indicating to the user that the subsequent discrete step of dose setting actually occurred.

[0065] The driver and the display member may be axially engaged directly or indirectly via axial engagement of the dose member with both the driver and the display member.

[0066] According to another embodiment, the dose member and the display member can be selectively rotationally locked and released via a clutch. When the dose member is in the dose setting position, the clutch rotationally engages the dose member and the display member. Therefore, in the dose setting position, the rotation of the dose member is also transmitted to the corresponding rotation of the display member. Typically, the dose member or at least a portion thereof protrudes proximally from the proximal end of the display member. The rotation of the dose member in the dose increment direction simultaneously displaces the dose member and the display member in the proximal direction to extend proximally from the inner body of the injection device or from the housing.

[0067] When the dose member is switched or depressed into its dispensing position, the clutch between the display member and the dose member is released. In the dispensing position or dispensing configuration, the dose member can be axially displaced distally in a non-rotating manner relative to the inner body. At the same time, the dose member, the driver, and the display member are axially engaged. Depressing the dose member or applying a dispensing force directed distally to the dose member thus causes a distally directed helical torsional motion of the display member and a distally directed translation of the driver to introduce a driving torque to the piston rod.

[0068] The dose member and the driver are permanently rotationally locked.For example, the dose member and the driver may be splined together such that during dose dispensing the dose member is prevented from rotating by the driver being rotationally locked to the inner body.

[0069] In another aspect, the present invention further relates to an injection device for setting and dispensing a dose of medicine. The injection device is generally configured as a pen-type injector. The housing comprises an elongated housing and a cartridge, which accommodates and receives a drive mechanism as described above, and the cartridge is arranged in the housing and filled with a liquid medicament. The cartridge is generally positioned and accommodated by a cartridge holder forming a distal portion of the housing of the injection device. When the injection device is implemented as a disposable device, the cartridge holder and the proximal housing component are generally permanently interconnected. When implemented as a reusable device, the cartridge holder is releasably connected to the proximal housing portion to provide access to the cartridge for cartridge replacement and to enable a reset operation of the drive mechanism.

[0070] In the present context, the distal direction points to the direction of the dispenser and the device, wherein a needle assembly with a preferably double-tipped injection needle is provided, which needle assembly is to be inserted into biological tissue or into the skin of a patient for the delivery of a medicament.

[0071] The proximal end or proximal direction refers to the end of the device or its parts which is farthest from the dispensing end. Typically, an actuation member is located at the proximal end of an injection device which is directly operable by a user to rotate for setting a dose and which is operable to be depressed in the distal direction for dispensing a dose.

[0072] The terms "drug" or "medicament" are used synonymously herein and describe a pharmaceutical preparation comprising one or more active pharmaceutical ingredients or a pharmaceutically acceptable salt or solvate thereof and optionally a pharmaceutically acceptable carrier. In the broadest sense, an active pharmaceutical ingredient ("API") is a chemical structure that has a biological effect on humans or animals. In pharmacology, a drug or medicament is used to treat, cure, prevent, or diagnose disease or to otherwise enhance physical or mental health. A drug or medicament may be used for a limited duration, or periodically for a chronic disorder.

[0073] As described below, a drug or medicament may include at least one API or a combination thereof in different types of formulations for treating one or more diseases. Examples of APIs may include small molecules (having a molecular weight of 500 Da or less); polypeptides, peptides, and proteins (e.g., hormones, growth factors, antibodies, antibody fragments, and enzymes); carbohydrates and polysaccharides; and nucleic acids, double-stranded or single-stranded DNA (including naked and cDNA), RNA, antisense nucleic acids (such as antisense DNA and RNA), small interfering RNA (siRNA), ribozymes, genes, and oligonucleotides. Nucleic acids may be incorporated into molecular delivery systems (such as vectors, plasmids, or liposomes). Mixtures of one or more drugs are also contemplated.

[0074] The drug or medicament can be contained in a primary package or "drug container" suitable for use with a drug delivery device. The drug container can be, for example, a cartridge, a syringe, a reservoir or other solid or flexible vessel, which is configured to provide a suitable chamber for storing (e.g., short-term or long-term storage) one or more drugs. For example, in some cases, the chamber can be designed to store the drug for at least one day (e.g., 1 day to at least 30 days). In some cases, the chamber can be designed to store the drug for about 1 month to about 2 years. It can be stored at room temperature (e.g., about 20 ° C) or refrigerated temperature (e.g., about -4 ° C to about 4 ° C). In some cases, the drug container can be or can include a dual-chamber cartridge, which is configured to store two or more components (e.g., API and diluent, or two different drugs) of the pharmaceutical preparation to be applied separately, one of which is stored in each chamber. In such a case, the two chambers of the dual-chamber cartridge can be configured to allow mixing between two or more components before and / or during distribution to the human or animal body. For example, the two chambers may be configured so that they are in fluid communication with each other (e.g., via a conduit between the two chambers) and allow the user to mix the two components if desired prior to dispensing. Alternatively or in addition, the two chambers may be configured to allow mixing when dispensing the components into a human or animal body.

[0075] The drugs or medicaments contained in the drug delivery devices as described herein can be used to treat and / or prevent many different types of medical disorders. Examples of disorders include, for example, diabetes or complications associated with diabetes (such as diabetic retinopathy), thromboembolic disorders (such as deep vein or pulmonary thromboembolism). Further examples of disorders are acute coronary syndrome (ACS), angina pectoris, myocardial infarction, tumors, macular degeneration, inflammation, hay fever, atherosclerosis and / or rheumatoid arthritis. Examples of APIs and drugs are examples as described in the following manuals: such as Rote Liste 2014 (for example, but not limited to, main group 12 (antidiabetic drugs) or 86 (oncology drugs)) and Merck Index, 15th edition.

[0076] Examples of APIs for treating and / or preventing type 1 or type 2 diabetes or complications associated with type 1 or type 2 diabetes include insulin (e.g., human insulin, or human insulin analogs or derivatives); glucagon-like peptide (GLP-1), GLP-1 analogs or GLP-1 receptor agonists, or analogs or derivatives thereof; dipeptidyl peptidase-4 (DPP4) inhibitors, or pharmaceutically acceptable salts or solvates thereof; or any mixtures thereof. As used herein, the terms "analogs" and "derivatives" refer to polypeptides having a molecular structure that can be formally derived from the structure of a naturally occurring peptide (e.g., the structure of human insulin) by deleting and / or exchanging at least one amino acid residue present in a naturally occurring peptide and / or by adding at least one amino acid residue. The added and / or exchanged amino acid residues can be codable amino acid residues or other naturally occurring residues or purely synthetic amino acid residues. Insulin analogs are also referred to as "insulin receptor ligands." In particular, the term "derivative" refers to a polypeptide having a molecular structure that is formally derived from the structure of a naturally occurring peptide (e.g., the structure of human insulin), wherein one or more organic substituents (e.g., fatty acids) are bound to one or more amino acids. Alternatively, one or more amino acids present in the naturally occurring peptide may have been deleted and / or replaced by other amino acids (including non-encodable amino acids), or amino acids (including non-encodable amino acids) have been added to the naturally occurring peptide.

[0077] Examples of insulin analogs are Gly(A21), Arg(B31), Arg(B32) human insulin (insulin glargine); Lys(B3), Glu(B29) human insulin (insulin glulisine); Lys(B28), Pro(B29) human insulin (insulin lispro); Asp(B28) human insulin (insulin aspart); human insulin in which the proline at position B28 is replaced by Asp, Lys, Leu, Val or Ala and in which the Lys at position B29 may be replaced by Pro; Ala(B26) human insulin; Des(B28-B30) human insulin; Des(B27) human insulin and Des(B30) human insulin.

[0078] Examples of insulin derivatives are, for example, B29-N-myristoyl-des(B30) human insulin, Lys(B29)(N-tetradecanoyl)-des(B30) human insulin (insulin detemir, ); B29-N-palmitoyl-des(B30) human insulin; B29-N-myristoyl human insulin; B29-N-palmitoyl human insulin; B28-N-myristoylLysB28ProB29 human insulin; B28-N-palmitoyl-LysB28ProB29 human insulin; B30-N-myristoyl-ThrB29LysB30 human insulin; B30-N-palmitoyl-ThrB29LysB30 human insulin; B29-N-(N-palmitoyl-γ-glutamyl)-des(B30) human insulin, B29-N-ω-carboxypentadecanoyl-γ-L-glutamyl-des(B30) human insulin (degludec insulin, ); B29-N-(N-lithocholyl-γ-glutamyl)-des(B30) human insulin; B29-N-(ω-carboxyheptadecanoyl)-des(B30) human insulin and B29-N-(ω-carboxyheptadecanoyl) human insulin.

[0079] Examples of GLP-1, GLP-1 analogs and GLP-1 receptor agonists are e.g. lixisenatide Exendin-4 A 39-amino acid peptide produced by the salivary glands of the Gila monster), liraglutide Semaglutide, tasmoglutide, albiglutide Dulaglutide rExendin-4, CJC-1134-PC, PB-1023, TTP-054, Langlenatide / HM-11260C (Efpeglenatide), HM-15211, CM-3, GLP-1Eligen, ORMD-0901, NN-9423, NN-9709, NN-9924 , NN-9926, NN-9927, Nodexen, Viador-GLP-1, CVX-096, ZYOG-1, ZYD-1, GSK-2374697, DA- 3091, MAR-701, MAR709, ZP-2929, ZP-3022, ZP-DI-70, TT-401 (Pegapamodtide), BHM-034. MOD-6030, CAM-2036, DA-15864, ARI-2651, ARI-2255, Telportide (LY3298176), Bamadutide (SAR425899), Exenatide-XTEN, and Glucagon-Xten.

[0080] Examples of oligonucleotides are: Cholesterol-reducing antisense therapeutics for the treatment of familial hypercholesterolemia or RG012 for the treatment of Alport syndrome.

[0081] Examples of DPP4 inhibitors are linagliptin, vildagliptin, sitagliptin, denagliptin, saxagliptin, berberine.

[0082] Examples of hormones include pituitary hormones or hypothalamic hormones or regulatory activity peptides and their antagonists, such as gonadotropins (follicle-stimulating hormone, luteinizing hormone, chorionic gonadotropin, tocopherol), growth hormone (somatropin), desmopressin, terlipressin, gonadorelin, triptorelin, leuprorelin, buserelin, nafarelin and goserelin.

[0083] Examples of polysaccharides include glycosaminoglycans, hyaluronic acid, heparin, low molecular weight heparin or ultra low molecular weight heparin or derivatives thereof, or sulfated polysaccharides (e.g., polysulfated forms of the above polysaccharides), and / or pharmaceutically acceptable salts thereof. An example of a pharmaceutically acceptable salt of a polysulfated low molecular weight heparin is enoxaparin sodium. An example of a hyaluronic acid derivative is Hylan GF 20 A sodium hyaluronate.

[0084] As used herein, the term "antibody" refers to an immunoglobulin molecule or an antigen binding portion thereof. Examples of antigen binding portions of immunoglobulin molecules include F (ab) and F (ab') 2 fragments, which retain the ability to bind antigens. The antibody can be a polyclonal antibody, a monoclonal antibody, a recombinant antibody, a chimeric antibody, a deimmunized antibody or a humanized antibody, a fully human antibody, a non-human (e.g., mouse) antibody or a single-chain antibody. In some embodiments, the antibody has effector functions and can fix complement. In some embodiments, the ability of the antibody to bind to Fc receptors is reduced or there is no such ability. For example, the antibody can be an isotype or subtype, an antibody fragment or a mutant, which does not support binding to Fc receptors, for example, its Fc receptor binding region has been mutated or deleted. The term "antibody" also includes antigen binding molecules based on tetravalent bispecific tandem immunoglobulins (TBTI) and / or dual variable region antibody-like binding proteins with cross-binding region orientation (CODV).

[0085] The term "fragment" or "antibody fragment" refers to a polypeptide (e.g., antibody heavy chain and / or light chain polypeptide) derived from an antibody polypeptide molecule, which does not include a full-length antibody polypeptide, but still includes at least a portion of a full-length antibody polypeptide that can bind to an antigen. Antibody fragments may include cleavage portions of full-length antibody polypeptides, but the term is not limited to such cleavage fragments. Antibody fragments that can be used in the present invention include, for example, Fab fragments, F(ab')2 fragments, scFv (single-chain Fv) fragments, linear antibodies, monospecific or multispecific antibody fragments (such as bispecific, trispecific, tetraspecific and multispecific antibodies (e.g., diabodies, triabodies, tetrabodies)), monovalent or multivalent antibody fragments (such as bivalent antibodies, trivalent antibodies, tetravalent antibodies and multivalent antibodies), mini antibodies, chelated recombinant antibodies, triabodies or biabodies, intracellular antibodies, nanobodies, small modular immunopharmaceuticals (SMIPs), binding domain immunoglobulin fusion proteins, camelized antibodies and antibodies containing VHH. Other examples of antigen-binding antibody fragments are known in the art.

[0086] The term "complementarity determining region" or "CDR" refers to short polypeptide sequences within the variable region of both heavy and light chain polypeptides that are primarily responsible for mediating specific antigen recognition. The term "framework region" refers to amino acid sequences within the variable region of both heavy and light chain polypeptides that are not CDR sequences and are primarily responsible for maintaining the correct positioning of the CDR sequences to allow antigen binding. Although the framework region itself is typically not directly involved in antigen binding as known in the art, certain residues within the framework region of certain antibodies may be directly involved in antigen binding or may affect the ability of one or more amino acids in the CDR to interact with the antigen.

[0087] Examples of antibodies are anti-PCSK-9 mAb (eg, alirocumab), anti-IL-6 mAb (eg, salilumab), and anti-IL-4 mAb (eg, dupilumab).

[0088] Pharmaceutically acceptable salts of any API described herein are also contemplated for use in a drug or medicament in a drug delivery device. Pharmaceutically acceptable salts are, for example, acid addition salts and basic salts.

[0089] Those skilled in the art will appreciate that modifications (additions and / or removals) may be made to the various components, formulations, apparatuses, methods, systems and embodiments of the API described herein without departing from the overall scope and spirit of the invention, and that the invention encompasses such modifications and any and all equivalents thereof.

[0090] An example drug delivery device may involve a needle-based injection system as described in Table 1 of Section 5.2 of ISO 11608-1:2014(E). As described in ISO 11608-1:2014(E), needle-based injection systems can be broadly divided into multi-dose container systems and single-dose (partially or completely emptied) container systems. The container may be a replaceable container or an integral non-replaceable container.

[0091] As further described in ISO 11608-1:2014(E), a multiple-dose container system may involve a needle-based injection device with a replaceable container. In such a system, each container contains multiple doses, the sizes of which may be fixed or variable (pre-set by the user). Another multiple-dose container system may involve a needle-based injection device with an integral non-replaceable container. In such a system, each container contains multiple doses, the sizes of which may be fixed or variable (pre-set by the user).

[0092] As further described in ISO 11608-1:2014 (E), a single dose container system can relate to a needle-based injection device with a replaceable container. In an example of such a system, each container holds a single dose, thereby discharging the entire deliverable volume (completely emptying). In another example, each container holds a single dose, thereby discharging a portion of the deliverable volume (partially emptying). Also as described in ISO 11608-1:2014 (E), a single dose container system can relate to a needle-based injection device with an integral non-replaceable container. In an example of such a system, each container holds a single dose, thereby discharging the entire deliverable volume (completely emptying). In another example, each container holds a single dose, thereby discharging a portion of the deliverable volume (partially emptying).

[0093] It will be further clear to those skilled in the art that various modifications and variations may be made to the present invention without departing from the spirit and scope of the present invention. Further, it should be noted that any reference numerals used in the appended claims should not be construed as limiting the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0094] In the following, embodiments of the drive mechanism and the injection device are described in detail with reference to the accompanying drawings, in which:

[0095] Figure 1 shows a perspective external view of an injection device,

[0096] Figure 2 An isolated and abstract illustration of a display member and a dose member is shown,

[0097] Figure 3a is an isolated stereogram of the interior subject,

[0098] Figure 3b is an isolated perspective view of an alternative embodiment of an inner body,

[0099] Figure 4 shows the interaction of the blocking member with the blocking structure prior to engagement when setting a dose,

[0100] Figure 5 Shown according to Figure 4 a configuration in which the display member is further rotated in the dose increasing direction,

[0101] Figure 6 Shown according to Figure 5 and the interaction of the barrier member with the dose member,

[0102] Figure 7 showing a configuration in which the blocking member disengages the blocking structure when a minimum size of the therapeutic dose has been set,

[0103] Figure 8 shows the configuration of the device during dose dispensing,

[0104] Fig. 9 The maximum dose configuration of the display member is shown,

[0105] Fig.10 A cross section showing the display components and the internal body is shown,

[0106] Fig.11 It is a three-dimensional cross-sectional view showing the interior of a component.

[0107] Fig.12 shows a first embodiment of a drive mechanism in an initial configuration,

[0108] Fig.13 Shown according to Fig.12 The drive mechanism of is in the maximum setting dose configuration,

[0109] Fig.14 is based on Fig.12 and Fig.13 An exploded view of the components of the drive mechanism,

[0110] Fig.15 is a three-dimensional cross-sectional view of the interface between the inner body and the piston rod,

[0111] Fig.16 A cross section showing the interface between the driver and the inner body,

[0112] Fig.17 is a perspective view of the outer circumference of the shaft portion of the dose member,

[0113] Fig.18 shows that the ratchet-like protrusions of the driver coincide with correspondingly shaped receptacles on the outer circumference of the dose member,

[0114] Fig.19 instruct Fig.18 but the dose member and the driver are axially displaced,

[0115] Fig. 20 An isolated perspective view of the last dose nut is shown,

[0116] Fig.21 is the cross section of the interface between the final dose nut and the internal body,

[0117] Fig. 22 The last dose nut is shown threadedly engaged with the threaded portion of the driver,

[0118] Fig.23 The clutch between the display member and the dose member is shown in an engaged state,

[0119] Fig.24 Shown according to Fig.23 The clutch is in the released configuration,

[0120] Fig.25 shows that the flexible arm of the display member is about to engage with the toothed profile of the dose member,

[0121] Fig.26 shows the mutual engagement of the flexible arm with the toothed profile,

[0122] Fig. 27 shows an exploded view of another embodiment of an injection device, which is of a reusable type,

[0123] Fig.28 Shown according to Fig. 27 The dial sleeve of the display component,

[0124] Fig.29 Shown according to Fig. 27 The proximal end of the display member,

[0125] Fig.30 is based on Fig. 27 Isolated view of the distal drive portion of

[0126] Fig.31 An isolated view of the coupling is shown,

[0127] Fig.32 An isolated view of the last dose nut is shown,

[0128] Fig.33 The proximal driver portion is shown,

[0129] Fig.34 The clutch of the dose member is shown,

[0130] Fig.35 is an isolated view of the near side sounder part,

[0131] Fig.36 is an isolated view of the far side sounder portion,

[0132] Fig.37 A proximal portion of a dose member is shown, and

[0133] Fig.38 is a partial cross-sectional view of the drive mechanism when the drive mechanism is assembled in the injection device. DETAILED DESCRIPTION

[0134] Figure 1 A drug delivery device 1 in the form of an injection pen is shown. The device has Figure 1 The far end shown on the left in the figure, and the Figure 1 The component or part of the drug delivery device 1 is at the proximal end of the right side. Fig.14 The drug delivery device 1 comprises an outer housing portion 10, an inner body 20, a piston rod 30, a driver 40, a last dose nut 50, a display member 60, a dose member 70, a cartridge 80, and a cap 120, i.e. a total of nine separate components. Fig.14 As shown, the needle arrangement including the needle seat 2 and the needle cover 3 can be provided as a replaceable additional component. Figures 12 to 26 The general concept and structure of the drive mechanism shown is similar to the mechanism disclosed in WO 2014 / 033197 A1, which is incorporated herein by reference.

[0135] The outer housing part 10 is a generally tubular element having a distal portion forming a cartridge holder 11 for receiving a cartridge 80 and a proximal portion forming an outer body 12. In one embodiment, the outer housing part 10 is transparent, wherein the outer body 12 is provided with an opaque layer 13. Fig.14 In the embodiment, the opaque layer 13 covers most of the outer body 12 except for the transparent window 14. An orifice 15 may be provided on the cartridge holder 11. Further, the cartridge holder 11 has a thread 16 or the like at its distal end for attaching the needle hub 2.

[0136] The inner body 20 is a generally tubular member having different diameter regions. The inner body 20 is received in the outer body 12 and permanently fixed therein to prevent any relative movement of the inner body 20 relative to the outer body 12. An external thread 21 is provided on the outer surface of the shaft portion 20a of the inner body 20. Further, a spline 22 is provided on the inner surface of the inner body 20, such as Fig.21 As shown. Fig.15 It can be seen that the inner body 20 has internal threads 23 near its distal end.

[0137] The piston rod 30 is an elongated element with two external threads 31, 32 of counter-rotation, which overlap each other. One of these threads 31 engages the internal thread 23 of the inner body 20. A disc-shaped bearing 33 is provided at the distal end of the piston rod 30. Fig.14 As shown, the bearing 33 can be attached to the piston rod 30 as a one-piece component via a predetermined breakpoint. This allows the bearing 33 to be separated from the piston rod 30 so that the bearing 33 remains seated on the distal end of the piston rod 30 to allow relative rotation between the bearing 33 and the piston rod 30.

[0138] The driver 40 is a generally tubular element having regions of different diameters. The distal region of the driver 40 has an external thread 41. The inner surface of the driver 40 has an internal thread 42, such as Fig. 22 As shown, the internal thread engages one of the external threads 32 of the piston rod 30. The driver 40 surrounds the piston rod 30 and is at least partially located within the inner body 20. The driver 40 has at least one proximal opening 43 or slit, which will be explained in more detail below. Further, the resilient finger 44 is formed by Fig.12 and Fig.13 The U-shaped cutout shown on the skirt of the driver 40 is provided on the driver 40. The finger 44 is allowed to flex in the axial direction and engage the dose member 70. In addition, as shown Fig.18 and Fig.19The flexibly hinged projection 45 shown is provided on the driver 40 by a similar cutout on the skirt of the driver 40. The projection 45 may be allowed to flex radially inwardly and is provided with lateral tabs 46. The projection 45 engages the splines 22 of the inner body 20.

[0139] The last dose nut 50 is disposed between the inner body 20 and the driver 40. The outer ribs 51 of the nut 50 engage the splines 22 of the inner body 20. Fig. 20 As shown, the internal thread 52 of the nut engages the external thread 41 of the driver 40. As an alternative, splines and ribs may be provided on the interface between the nut 50 and the driver 40, and threads may be provided on the interface between the nut 50 and the inner body 20. As a further alternative, the nut 50 may be designed as a half nut, for example. Further, in Fig. 20 In the embodiment of the present invention, four rotation hard stops 53 are provided on the nut 50 for interacting with corresponding stops 47 located at the proximal end of the thread 41 on the driver 40.

[0140] The display member 60 is a generally tubular element having an internal thread 61 that engages the external thread 21 of the inner body 20. Thus, the display member 60 is interposed between the inner body 20 and the outer body 12. A series of numbers are provided (e.g., printed) on the outer surface of the display member 60. These numbers are arranged on a spiral line so that only one number or a few numbers can be seen in the through window 14 of the outer body 12. As will be explained in more detail below, the display member 60 is attached to the driver 40 to prevent relative axial movement but allow relative rotation.

[0141] The zero-unit rotation hard stop formed by the stop wall 62 of the display member 60 and the corresponding stop surface 24 on the inner body 20 is shown in Figures 3 and Fig.11 The stopper defines a distal zero dose position Z of the display member 60 relative to the inner body 20. Fig.11 Also shown are maximum dose (e.g. 80 units) rotational hard stops formed by stops 63a and 63b at the distal and proximal ends of the display member 60 and corresponding stops 25a, 25b on the outer circumference of the inner body 20 or in the threads 21. The stops define a proximal maximum dose position M of the display member 60 relative to the inner body 20. Thus, the user is prevented from dialing below zero units and above, for example, 80 units.

[0142] The dose member 70 has a proximal end with, for example, a serrated flange or dose button 71 or an outer skirt, allowing the user to easily grip and dial the dose member 70. A sleeve-like portion 72 of reduced diameter of the dose member 70 extends in the distal direction 4 and is inserted into the driver 40 such that limited relative axial movement is allowed, but relative rotation is prevented. This is achieved by a rib 73 on the sleeve-like portion 72, which is guided in the proximal opening 43 of the driver 40, as shown in FIG. Fig.13 In the sleeve-like portion 72 of the dose member 70 a recess 73a is provided which substantially has the profile of the projection 45 and its lateral flaps 46 .

[0143] The clutch C is provided between the display member 60 and the dose member 70 by means of corresponding teeth 64 and 74. Fig.23 and Fig.24 If the teeth 74 of the dose member 70 engage the teeth 64 of the display member 60, these components will be rotationally locked. The resilient finger 44 of the driver 40 biases the dose member 70 in the proximal direction 5 of the device 1, i.e. in the direction engaging the clutch teeth 64, 74. The clutch C can be released by causing the dose member 70 to axially resist the bias of the finger 44 relative to the display member 60, thereby allowing relative rotation.

[0144] Further, the dispensing click is provided by the flexible arm 65 on the display member 60 and a toothed profile 75 on the inside of the dose button 71 of the dose member 70 . Fig.25 and Fig.26 Such a sounding piece is shown.

[0145] The cartridge 80 comprises a pre-filled, necked-down cartridge reservoir 81, which may be typically made of glass. A rubber-type stopper 82 or bung is located at the proximal end of the cartridge reservoir 81, and a pierceable rubber seal (not shown) is located at the other distal end. The rubber seal is held in place using a crimped annular metal cap 83. The cartridge 80 is disposed within the cartridge holder 11, with the bearing 33 of the piston rod 30 abutting against the stopper 82.

[0146] Fig.14 A cap 120 is shown attached to the distal end of the device 1 , covering the cartridge holder 1 1. The cap 120 may be releasably snapped onto the outer housing 10, and may be removed to use the device 1 .

[0147] In the following, the functioning of the disposable drug delivery device 1 and its components will be explained in more detail.

[0148] In order to use the device, the user must select a dose. Figure 1 and Fig.12In the starting (resting) state shown, the display member 60 indicates to the user the number of the dialed dose. The number of the dialed units can be observed through the dose window 14 on the outer body 12. Due to the threaded engagement between the display member 60 and the inner body 20, the dose member 70 is rotated in a clockwise manner so that the display member 60 is wound out of the device and the number of units to be delivered is displayed incrementally.

[0149] During dose setting, the dose member 70, the driver 40 and the display member 60 are rotationally locked together via the clutch teeth 64, 74. Further, the dose member 70, the driver 40 and the display member 60 are axially coupled. Thus, during dose setting, these three components are wound out of the outer housing 10.

[0150] The clockwise rotation of the dose member 70 causes the driver 40 to rotate so that the driver is advanced along the piston rod 30, which remains fixed during the entire dialing process. The projection 45 and the spline 22 form a click arrangement that provides tactile and audible feedback to the user when the dose is dialed. The click arrangement also has the function of defining discrete positions of the display member 60 when dialing and providing a method for locking the rotation of the driver 40 and the dose member 70 when administering. Therefore, during dialing, during dose setting, the dose member 70 is in an axial position relative to the driver 40 so that the pocket or recess 73a is radially located inside the projection 45. Therefore, the projection 45 is allowed to flex radially inward to overcome the spline 22, thereby providing tactile and audible feedback to the user. Fig.16 The flexible protruding arms 45 are shown positioned between the splines 22 which are, for example, 15° apart.

[0151] At the maximum settable dose of 80 units, Figures 3 and Fig.11 The stop features 63a, 63b and 25a, 25b are shown to engage to prevent further rotation. The last dose nut 50 provides a function of recording the total number of units dispensed. The nut 50 locks the device 1 at the end of the use period so that no more medication can be dialed or dispensed by the user. The last dose nut 50 and the driver 40 are connected via the threaded interface 41, 52, as explained above. Further, the last dose nut 50 is as shown. Fig.21 As shown, the nut 50 and the inner body 20 are permanently rotationally locked together. The rotation of the driver 40 during dialing causes the nut 50 to be advanced along the threads 41 of the driver 40. The nut 50 is always free to slide axially within the inner body 20, which allows the nut 50 to be advanced. Fig. 22 The change in pitch shown towards the final dose axially accelerates advancement of the nut 50 towards the end-of-use locked condition.

[0152] In the end of use state, the stop features 53 of the last dose nut 50 contact corresponding features 47 on the driver 40. Any torque transmitted by these stop features 47 is reacted by the spline contact with the inner body 20.

[0153] With the desired dose dialed, the device 1 is ready for dose dispensing. This essentially requires pushing the dose member 70, which disengages the clutch teeth 64, 74. As described above, when a dose is dialed, the dose member 70 is "biased" and engages the clutch features 64, 74 that rotationally lock the driver 40, dose member 70, and display member 60 together, as shown in FIG. Fig.23 When the proximal button portion of the dose member 70 is pressed, the clutch features 64, 74 are disengaged, as shown. Fig.24 As shown, relative rotation between the display member 60 and the dose member 70 is possible. In all cases, the driver 40 and the dose member 70 are rotationally locked together by the engagement of the rib 73 and the opening 43. Therefore, when the clutch 64, 74 is disengaged, i.e. the dose member 70 is depressed or pushed in the distal direction, the dose member 70 and the driver 40 are rotationally locked together, and the dose member 70, the driver 40, and the display member 60 are still axially coupled.

[0154] At the same time, relative axial movement of the dose member 70 with respect to the driver 40 causes the pocket or recess 73 to be displaced with respect to the projection 45. Hence, the projection 45 is prevented from flexing inwardly as the tab 46 rests on a non-recessed area of ​​the sleeve portion 70a of the dose member 70. Fig.18 and Fig.19 A comparison of shows this activation of the locking feature, thereby preventing the flexible protruding arm 45 from overcoming the spline 22 when the dose member 70 is pressed. In this state, the driver 40 and the dose member 70 are rotationally constrained to the inner body 20, so if the spline 22 is in contact with the dose member 70, the driver 40 and the dose member 70 are rotationally constrained to the inner body 20. Fig.16 The device shown is axially aligned, preventing any rotation relative to the outer housing 10. Alternative embodiments are also conceivable with torsion splines 22. Here, the torsion splines are used to cause a rotation of the driver when the driver undergoes a distal displacement during dose dispensing.

[0155] With the desired dose dialed, the dose member 70 may be depressed and the piston rod 30 driven forward to dispense drug from the cartridge 80. The interaction of the mating threads between the piston rod 30, the driver 40 and the inner body 20 provides a mechanical advantage, for example 2:1 in the example shown. Fig.12 The initial new device is shown in the zero dose configuration, while Fig.13 The device 1 is shown with 80 units dialled before the dose member 70 is pushed.

[0156] During dose dispensing, the dispensing clicker is active, which includes the dose member 70 and the display member 60. The dispensing clicker mainly provides the user with audible feedback that the drug is being dispensed. Fig.25 and Fig.26 As shown, the interaction between the flexible arm 65 on the display member 60 and the toothed profile 75 on the button flange 71 provides this dispensing click. Relative rotation is only allowed in one direction. This occurs when these parts are decoupled during dispensing and a click is generated for each unit.

[0157] exist Figures 2 to 11 In the description, the minimum dose mechanism or minimum dose function of the drive mechanism is generally explained. Figure 2 and Fig.12 It can be clearly seen from the comparison that Figure 2 The shape of the dose member 70 shown is similar to that shown in FIG. Figures 12 to 26 The overall shape of the dose member 70 shown in the embodiment of FIG. 1 is slightly different. However, the overall functionality of the dose member 70 and its interaction with all other components, in particular with the display member 60 and the driver 40, is at least similar or even identical to that described above in conjunction with FIG. Figures 12 to 26 The interaction explained by Figures 2 to 11 In the illustration of FIG. 5 , the piston rod 30 , the driver 40 and the last dose nut 50 are omitted for the sake of clarity.

[0158] The inner body 20 includes an elongated shaft 20a, as shown in FIG3. An external thread 21 is provided along the outer circumference of the elongated shaft, which is threadedly engaged with a radially inwardly extending thread feature or internal thread 61 of the display member 60, such as Fig.11 As shown. In addition, the elongated shaft 20a includes a blocking structure 26. In the present embodiment, the blocking structure 26 includes a blocking thread 27, which extends axially between the turns of the external thread 21. The blocking structure 26, and thus the blocking thread 27, terminates in the distal direction 4 with distal ends 26a, 27a. The blocking structure 26 terminates in the proximal direction 5 with proximal ends 26b, 27b. Therefore, the blocking thread 27 terminates in the proximal termination direction 5 with the proximal end 27b. As shown in FIG. Figure 3a As shown, the distal end 27a and the proximal end 27b of the blocking thread 27 are located within the axial extension of the external thread 21. The axial offset between the blocking thread 27 and the external thread 21 is approximately half the pitch of the external thread 21. The lead of the blocking thread 27 is substantially or completely equal to the lead of the external thread 21.

[0159] like Figure 2As shown, the display member 60 comprises a stepped depression at its proximal portion 60b, which is received in a sleeve-like dose member 70 having a tubular shaft 70a extending in the distal direction 4 from a dose dial or dose button 71. The proximal portion 60b and the dose member 70 can be selectively rotationally engaged by means of a clutch C, such as in combination with Fig.23 and Fig.24 For simplicity, the proximal portion 60b of the display member 60 is not shown. Figures 4 to 11 Further shown in.

[0160] The display member 60 includes at least one blocking member 66, such as Figure 4 As shown. The blocking member 66 comprises a flexible arm extending in a tangential direction and, as seen in an axial projection, coinciding with the side wall 60a of the display member 60. The blocking member 66 comprises a base portion 66c, by which the blocking member 66 engages with the side wall 60a of the display member 60. A tangential slit 66a or a corresponding gap is provided between the blocking member 66 and the axially adjacent side wall portion 60a, through which the blocking member 66, in particular its free end 66b, is free to flex or deform in the axial direction (z). Therefore, the side wall 60a of the display member 60 comprises a recess that is large enough to support the blocking member 66 and allow its flexure or displacement directed to the distal side or to the proximal side.

[0161] like Fig.11 As shown, the free end 66b of the blocking member 66 includes a protrusion 67 extending radially inward. The protrusion 67 has a rib-like shape and extends substantially parallel to the internal thread 61. The protrusion 67 is particularly suitable for cooperating or engaging with the blocking thread 27 on the outer circumference of the inner body 20. Figure 4 and Figure 5 As can be seen in FIG. 6 , the blocking member 66 comprises an L-shaped structure having a long side extending tangentially and a short side extending axially in the proximal direction. At the proximal end of the free end 66 b of the blocking member 66, two fork-like abutment portions 68 are provided, which are adapted to axially engage with the distally facing abutment portion 76 of the dose member 70, as shown in FIG. Figure 6 The abutment portion 68 is arranged radially outward of the support surface 69, which extends proximally from the proximal end of the abutment portion 68. Figure 2 and Figure 6 As shown in the various configurations of , the support surface 69 is constrained by the inwardly facing side wall of the dose member 70 so as to provide an effective axial guidance between the mutually corresponding axial abutments 68 , 76 of the blocking member 66 and the dose member 70 .

[0162] The distal ends 26a, 27a are axially spaced from the stop 24 at the distal end of the external thread 21 by the length of the display member 60 from its distal end to the at least one blocking member 66 and by an additional axial space that defines the size of the variable dose range or titration dose range, i.e., the distal end 27a of the blocking thread 27 defines the maximum size of the variable titration dose, while the axial position of the proximal end 27b of the blocking thread 27 defines the minimum value of the fixed dose that can be set by the injection device 1 and subsequently dispensed.

[0163] Typically, the blocking member 66 can assume different axial positions on the inner body 20 depending on the amount of relative rotation of the display member 60 relative to the inner body 20. In the initial configuration, before setting a dose or when the drive mechanism is in the zero dose configuration, the display member 60 is in its most distal position on the inner body 20. This position is referred to as the distal zero dose position Z. On the other hand, the most proximal position assumed by the display member 60 on the inner body 20, i.e. the position where the maximum dose is selected, is referred to as the proximal maximum dose position M.

[0164] In the depicted embodiment, the axial position of the distal end 27a of the blocking thread 27 on the inner body 20 (i.e. the position defining the maximum size of the variable titration dose) is offset from the distal zero dose position Z in the proximal direction 5 by between 20% and 30%, for example up to 25%, of the axial distance between the distal zero dose position Z and the proximal maximum dose position M. However, the position may be positioned closer to the distal zero dose position Z or closer to the proximal maximum dose position M, for example between 10% and 60% of the axial distance between the distal zero dose position Z and the proximal maximum dose position M. Typically, the display member 60 is rotatable relative to the inner body 20 between the distal zero dose position Z on the inner body 20 and the proximal maximum dose position M on the inner body 20 by a predetermined number of turns, for example four or five full turns, corresponding to a relative rotation of 1.440° or 1.800°.

[0165] In the initial configuration, before setting a dose or when the drive mechanism is in the zero-dose configuration Z, the blocking member 66, in particular the protrusion 67 thereof, has not yet engaged with the blocking thread 27, as shown in FIG. Figure 4 In this initial configuration, the blocking member 66, in particular the projection 67 thereof, is located distally of the distal end 27a of the blocking thread 27. Thus, the dose member 70 can be moved in the distal direction to disengage the clutch C and initiate the dispensing procedure as described above.

[0166] When the display member 70 is further rotated in the dose incrementing direction relative to the inner body 20, the projection 67 of the blocking member 66 engages the chamfered distal end 27a of the blocking thread 27. Due to the chamfer 27c, the projection 67 undergoes a slight displacement in the proximal direction 5, thereby pivoting the blocking member 66 with its free end in the proximal direction 5. In this way, the axial size of the gap 66a is enlarged at least in the region of the free end section 66b, and the abutment 68 of the free end section 66b approaches the corresponding abutment 76 of the dose member 70. When the projection 67 has passed the chamfer 27c, it is pushed in the proximal direction 5 by the proximally facing edge 27e of the blocking thread 27.

[0167] In this configuration, the abutment 68 of the free end 66b of the blocking member 66 axially abuts or is very close to the abutment 76 of the dose member 70, thereby inhibiting and blocking the displacement of the dose member 70 relative to the inner body 20 and relative to the display member 60 directed distally. In this way, the clutch C remains locked and the device 1 cannot be switched to the dispensing mode. As long as the blocking member 66 is engaged with the blocking thread 27 or the blocking structure 26, this axial abutment and blocking configuration between the blocking member 66 and the dose member 70 is maintained. Therefore, the blocking member cannot flex because it is engaged with the blocking thread. Because the dose member is abutted with the blocking member, the dose member cannot be displaced distally to initiate dispensing.

[0168] When the flexible blocking member 66 is axially engaged with the proximally facing edge 27e of the blocking thread 27, any axially directed force transmitted via the dose member 70 is directly transmitted to the inner body 20 via the blocking member 66. Due to this relatively short and fairly direct load path between the dose member 70 and the inner body 20, a firm and strong blocking action can be provided. In this blocking configuration, there is inherently only very little flexibility, which might otherwise confuse the user. With the blocking member abutting the blocking thread 27 axially proximally and further abutting or in close proximity to the dose member 70 axially distally, the blocking member is axially sandwiched between the dose member 70 and the inner body 20. In this way, the axial blocking of the dose member 70 is relatively free of play or slack that might confuse the user.

[0169] Only when the display member 60 is further rotated in the dose increment direction, the blocking member 66 is disengaged from the blocking structure 26 (i.e., the blocking thread 27), so that the blocking member 66 relaxes and returns to its unbiased initial state. Figure 7 Here, the projection 67 has just passed the proximal end 27b of the blocking thread 27. Thus, the blocking member 66, in particular its free end section 66b, is displaceable or flexible in the distal direction 4 under the action of the distally advancing dose member 70 or simply by relaxing to its natural unbiased state.

[0170] exist Figure 8 , a configuration is shown in which the drive mechanism has dispensed several units so that the remaining amount of medicament to be dispensed is less than a predetermined minimum dose size. When the drive mechanism performs a dose dispensing procedure, the blocking member 66 is in its release position R and is deflected in the distal direction due to the distal displacement of the dose member 70 and is then in the dose dispensing position D. When the display member 60 is rotated in the dose decrementing direction during dose dispensing, the blocking member 66 passes along the distal side of the blocking thread 27d, as shown in FIG. Figure 8 shown.

[0171] When the blocking thread 27 is approached from the proximal side during dose dispensing, the projection 67 is positioned near the distally facing edge 27d of the blocking thread 27. Figure 8 In the illustrated configuration, the blocking member 66 is also effectively prevented from pivoting or flexing in the proximal direction 5 in case the dispensing procedure should be interrupted. Hence, in case the dose dispensing procedure should be continued, the blocking member does not prevent the dose member 70 from being displaced into its dose dispensing position D. Even if the blocking member 66 and the dose member 70 reach axial abutment before the dose member 70 reaches the dose dispensing position D, the blocking member 66 is free to be at least slightly displaced in the axial distal direction 4 and dispensing can thus be reinitiated.

[0172] In this case, the clutch C between the dose member 70 and the display member 60 is opened or released, and dispensing can continue. In other words, the blocking member 66, in particular its free end section 66b, remains stuck on the distal side of the blocking thread 27. Then, even when the display member 60 should be in a position below the predefined minimum dose value, the user can continue to dispense the dose.

[0173] Despite Figures 2 to 11 Only a single blocking member 66 is shown, it is generally conceivable that two or even more blocking members 66 are provided around the circumference of the display member 60. If two or more blocking members are provided, an equal number of blocking threads will be required.

[0174] exist Fig. 9 A maximum dose configuration is illustrated in FIG. 6 , wherein a maximum dose stop 63b located on a tangentially facing side wall of the blocking member 66 tangentially abuts a correspondingly shaped stop 25b of the inner body.

[0175] The arrangement of the inner body 20 and the display member 60 includes two pairs of mutually corresponding stops. As shown in FIG. 3 , the inner body 20 includes a distal maximum stop 25 a and a proximal maximum stop 25 b. The two stops extend radially outward from the circumference of the elongated shaft 28 of the inner body 20 and include abutment surfaces facing in a tangential direction. The corresponding abutment surfaces coincide with radial and axial planes. The display member 60 also includes at least one proximal maximum dose stop 63 b and at least one distal maximum dose stop 63 a, as shown in FIG. Fig.11 As shown. Fig.11 In the illustrated embodiment, two distal maximum dose stops 63a are provided, which cooperate and engage with correspondingly shaped dose stops 25a on the inner body 20. When the display member 60 has reached the maximum dose configuration, the mutually corresponding stops 25a, 25b, 63a, 63b engage simultaneously, i.e. the display member 60 is in the proximal maximum dose position M. The mutually engaged stops 25a, 25b, 63a, 63b then prevent any further dose increment rotation of the display member 60 relative to the inner body 20.

[0176] It is usually sufficient to provide only one pair of maximum dose stops (e.g. 25a, 63a). Two pairs of mutually corresponding maximum dose stops 25a, 25b, 63a, 63b reinforce each other. Therefore, the load expected on the corresponding blocking member when reaching the blocking configuration is lower than when only one pair of mutually corresponding stops (e.g. 25a, 63a pairs) is implemented. This has the advantage that the stop feature can be designed to be smaller than otherwise. This not only saves space, but also helps to assemble the device, i.e. when the display member 60 is screwed onto the inner body 20. Relatively small stops 25a, 25b, 63a, 63b are less prone to breakage or damage during assembly.

[0177] Since the minimum and maximum deliverable dose volumes depend only on the geometry and overall design of the inner body 20, its blocking threads 27, and the position of the maximum dose stops 25a, 25b, different device types can be easily configured for various applications. Likewise, different dose sizes can be easily implemented by changing only one component. Since the minimum dose feature and the maximum dose feature do not protrude beyond the basic envelope of the inner body, it is fairly straightforward to implement the minimum dose and maximum dose functions, as well as a wide range of different device configurations, using common automated assembly equipment.

[0178] exist Figure 3b , an alternative embodiment of an inner body 220 is shown having a blocking structure 26 having the same Figure 3aThe blocking thread 27 shown is slightly different from the blocking thread 227. The blocking thread 227 has several recesses 227a, 227b, 227c, 227d or interruptions, which define discrete dose sizes to be uniquely dispensed by means of a corresponding drive mechanism. The blocking thread 227 extends almost completely along the axial extension of the shaft 20a. Only when the position of the blocking member 66 overlaps axially and / or tangentially with the position of one of the recesses 227a, 227b, 227c, 227d, the dose member 70 and therefore the blocking member 66 can be displaced in the distal direction 4 to initiate the dispensing action.

[0179] The tangential and axial positions of the recesses 227a, 227b, 227c, 227d define discrete dose sizes for which dose dispensing is uniquely possible. The injection device can be transformed from a device allowing individually set variable-sized doses to a fixed-dose device, or vice versa, simply by modifying or replacing the inner body 20 having the blocking thread 27 with another inner body 220 having a different blocking thread 227.

[0180] The recesses 227a, 227a, 227c, 227d are positioned so that two adjacent recesses are spaced apart from each other by between 10% and 20%, for example 12.5%, of the axial distance between the distal zero dose position Z and the proximal maximum dose position M. This corresponds to, for example, 10 units.

[0181] Although Figures 12 to 26 The embodiment shown relates to a disposable injection device, but according to Figures 27 to 38 An alternative embodiment of the invention relates to a reusable injection device. Also for simplicity, reference is made to Figures 1 to 11 The minimum dose function described is Figures 12 to 38 No further display.

[0182] Unless otherwise stated, according to Figures 27 to 38 A reusable example with Figures 12 to 26 The same or similar parts are indicated by the same or similar reference numerals compared to the embodiment of the present invention. In the case of changes in parts compared to the disposable embodiment, the similar parts are assigned reference numerals increased by 100. Figures 27 to 38 The overall concept and structure of the drive mechanism shown are similar to the mechanism disclosed in WO 2014 / 033195A1, which is incorporated herein by reference. Figures 1 to 11 The same applies to the implementation and adjustment of the minimum dose function described above. Figures 27 to 38 Embodiment of the invention.

[0183] In this embodiment, the actuator 140 is a generally tubular element having three parts 141, 142, 143 in the embodiment shown in the figure. Fig. 27 , Fig.30 , Fig.31 ,and Fig.33 . The driver 140 comprises a distal drive sleeve 141, a proximal drive sleeve 142, and a coupler 143. The distal drive sleeve 141 engages with the piston rod thread 32 to drive the piston rod 30 through the inner body 20 during dose delivery. The distal drive sleeve 141 is also permanently connected to the coupler 143, which in turn is releasably engaged to the proximal drive sleeve 142 by a reset clutch feature. The two halves 141, 142 of the drive sleeve are rotationally and axially connected during dialing and dispensing, but are rotationally decoupled during the device reset process so that they can rotate relative to each other.

[0184] Fig.33 The illustrated proximal drive sleeve 142 supports components of the clicker 100 and sleeve-like clutch 90 and transfers rotational movement from the dose member 70 to the coupler 142 and distal drive sleeve 141. The tooth features 147 at the distal end of the proximal drive sleeve 142 engage with the reset clutch features on the coupler 143 to connect the two halves of the drive sleeve during dialing and dispensing. During reset, these teeth 147 are disengaged.

[0185] Several splines are provided on the outer surface of the proximal drive sleeve 142, which engage with the distal clicker portion 101 to prevent relative rotation during dialing and dispensing. Additional splines located in the middle region of the proximal drive sleeve 142 engage with the clutch 90 components. They can be arranged to be non-rotationally symmetrical so that the individual clicker components cannot be accidentally assembled upside down.

[0186] The proximal portion of the proximal drive sleeve 142 has four arms or fingers 148. Hook-shaped bearing surfaces 149 are present on the underside of the flange segments on the ends of the flexible fingers 148, as shown in FIG. Fig.33 The flexible fingers 148 are separated by gaps or slots which allow space for the dose member 70 to snap onto the clutch 90 and also enable the fingers to flex inwardly during assembly of the proximal drive sleeve 142 to the dial sleeve 162. After assembly, the hooks 149 retain the proximal drive sleeve 142 relative to the dial sleeve 162 under the reaction force of the spring 103.

[0187] During dispensing, the dose member 70 depresses the spring 103 via the clutch 90 and the clicker component, and the spring 103 reacts to the proximal drive sleeve 142 through the coupling 143, which then applies an axial load to the dial sleeve 162 through the bearing surface 149. This axial load drives the dial sleeve 162 and therefore the number sleeve 161 back into the body of the device along the helical thread of the inner body 20 until the zero dose stop surface 62 on the number sleeve 161 contacts the inner body 20.

[0188] Fig.31 The coupling 143 shown couples the two halves of the drive sleeve 140 together rotationally during dialing and dispensing, while allowing them to be uncoupled during resetting. The coupling 143 must also transfer the last dose stop load from the proximal drive sleeve 142 to the distal drive sleeve 141. Two sets of teeth are provided in the coupling 143 for engaging teeth 146 and teeth 147, respectively. The coupling 143 snaps onto the distal drive sleeve 141, allowing limited relative axial movement relative to the proximal drive sleeve 142.

[0189] Display member 160 is a generally tubular element, which is composed of a number sleeve 161 and a dial sleeve 162, which are snapped together during assembly to constrain the two components axially and rotationally, so that they act as an integral piece. The dial sleeve 162 is assembled to the number sleeve 161 so that once assembled, relative movement is not allowed. These parts are made into separate components so that they can be molded and assembled. Moreover, although the number sleeve 161 is preferably white, to produce a contrast of, for example, black dosage numbers, the color of the dial sleeve 162 can be selected to conform to aesthetics or may be used to distinguish between drug types.

[0190] At the proximal end, the dial sleeve 162 has internal clutch features 165 that engage with the clutch member 90 during dialing and disengage from the clutch during dispensing. During dialing and when the zero dose stop and the maximum dose stop are engaged, these clutch features 165 rotationally lock the dial sleeve 162 to the clutch 90. When the dose member 70 is depressed, these clutch features disengage to allow the clutch 90 to move axially while the dial sleeve 162 and the number sleeve 161 rotate back to the zero unit starting position.

[0191] The dial sleeve 162 is rotated out during dialing by its engagement with the clutch 90 and the number sleeve 161, and rotated back during dispensing under the axial force applied by the proximal drive sleeve 142 to the flange-like bearing surface 166 on the proximal end of the dial sleeve, as shown in FIG. Fig.29This bearing surface 166 engages with the flexible arm 148 of the proximal drive sleeve 142 during dispensing. When the maximum dose has been dialed, two diametrically opposed faces 167 may engage with the outer body 10, thereby forming a maximum dose stop surface.

[0192] The central sleeve-like portion of the dose member 70 is provided with four arms 173 having hook-like snap features 174 at their respective distal ends. The arms 173 form a spline surface that engages with the clutch 90 to transfer torque from the dose member 70 to the dial sleeve 162 and the proximal drive sleeve 142 through the clutch. The snap features 174 engage apertures on the clutch 90 and are designed with angled undercuts to maintain engagement when an axial load is applied to pull the dose member 70 out of the pen-type body 10. The spaces between the arms 173 define pockets that give clearance for the flexible arms 148 of the proximal drive sleeve 142 to slide freely relative to the dose member 70 and the clutch 90 when the dose member 70 is depressed and released during dose dispensing.

[0193] The tubular clutch 90 is provided between the display member 160 and the dose member 70. The clutch fixes and holds the dose member relative to the dose member 70 and when the dose member 70 is depressed during dispensing, they travel axially together relative to the proximal drive sleeve 142, disengaging the clutch teeth 95 from the dial sleeve clutch teeth 165. It also transfers torque from the dose member 70 to the proximal drive sleeve 142 and transfers the dial and zero and maximum dose stop loads from the dose member 70 to the dial sleeve 162 and number sleeve 161 via the clutch teeth.

[0194] The drive sleeve splines 91 provided on the inner surface of the clutch engage with the proximal drive sleeve 142. At the distal end face, a clutch biasing tooth 92 is provided, which cooperates with a similar tooth 109 on the proximal clicker portion 102 to ensure that in the unrestricted button ejection position (dose dialed), the clutch is biased to the proximal clicker portion 102 under the biasing action of the clutch spring 103, thereby ensuring that the dose number displayed on the display member is correctly and clearly displayed to the user. The height of the tooth 92 is shallow to prevent the proximal clicker portion 102 from engaging with the splines on the proximal drive sleeve 142 during dialing. Four snap apertures 93 are used to retain the snap features 174 of the dose member 70. The clutch has splines 94 near its proximal end, which lock to the inner body 20 when the dose member 70 is pressed down at the end of dispensing to prevent the user from rotating the dose member 70 below the zero dose position.

[0195] The clutch teeth 95 engage with the clutch teeth 165 of the dial sleeve 162 to rotationally couple the dose member 70 to the number sleeve 161 via the clutch. During dispensing, the clutch 90 is moved axially to disengage these clutch teeth 95, thereby releasing the dial sleeve 162 to rotate back into the device, while the clutch 90 and therefore the driver 140 are moved axially to dispense a dose.

[0196] The clicker 100 includes a distal clicker portion 101, a proximal clicker portion 102, and a spring 103. The spring 103 is used to bias the dose member 70 so that the dose member 70, specifically its proximal button portion, pops up at the end of dosing, reengages the clutch 90 with the dial sleeve 162, and prepares for dialing. Further, the spring provides a spring force for the clicker component to provide audible and tactile feedback to the user, and also provides a pawl position for the number sleeve 161. In addition, it keeps the two halves 141, 142 of the drive sleeve in rotational engagement during dialing and dispensing, while allowing them to disengage during device resetting.

[0197] The distal clicker portion 101 is permanently splined to the proximal drive sleeve 142 and engages with the proximal clicker portion 102, which in turn is splined to the inner body 20. During dialing, as the drive sleeve is rotated relative to the inner body 20, the two clickers 101, 102 rotate relative to each other under the compressive force of the clutch spring 103. This force, combined with the clicker teeth formed on the end face of each clicker, provides a click sound and also a detent dialing position.

[0198] During dispensing, the two clickers 101, 102 are pressed together under the axial dispensing load applied by the user to the dose member 70, and this prevents relative rotation between the proximal drive sleeve 142 and the inner body 20, thereby driving the piston rod 30 forward to deliver the dose. The splines 104 on the inner bore always rotationally couple the distal clicker portion 101 to the proximal drive sleeve 142, but allow free axial movement when the dose member 70 is depressed during dispensing and when the two clickers are stacked one above the other during dialing. The profiles of the clicker teeth 105, 106 on the distal clicker portion 101 and the proximal clicker portion 102 are identical and cross over each other under the compression load from the spring 103 during dialing.

[0199] The proximal clicker portion 102 is permanently splined to the inner body 20 by external splines 107, which prevent relative rotation with the inner body 20 during dialing and dispensing, provide a click sound during dialing, and rotationally lock the proximal drive sleeve 142 during dispensing. When the dose member 70 is depressed, additional cylindrical splines 108 also rotationally couple the proximal clicker portion 102 to the proximal drive sleeve 142, which prevents the user from dialing past 80 units when the dose member 70 is depressed. In addition to the main clicker teeth 106, the proximal clicker portion 102 also has clutch biasing teeth 109 on the opposite end face. These teeth cooperate with similar teeth 92 on the clutch 90 to ensure that in the unconstrained button ejection position (dose dialed), the clutch is rotationally biased by the proximal clicker portion 102 under the biasing action of the clutch spring 103.

[0200] The cartridge bias spring 110 is assembled in two parts, a lower first part and an upper second part, one after the other. The spring combination is used to apply an end load to the cartridge 80 at the extreme tolerance values ​​so as to bias it forward onto the end face of the collar in the cartridge holder 11. This ensures that when the user removes and attaches the needle, the friction between the needle cannula and the septum of the cartridge 80 does not cause the cartridge 80 to move axially relative to the cartridge holder 11. The bias spring 110 is also used to provide a force that the user must work against to connect the cartridge holder 11, and this can increase the tactile feedback of the bayonet joint between the cartridge holder 11 and the inner body 20. The spring 100 is also used to eject the cartridge holder when the cartridge holder 11 is not correctly attached in a fixed position, thereby highlighting this error to the user.

[0201] During dose setting, the dose member 70, the driver 140, and the display member 160 are rotationally locked together via the clutch 90. Further, the dose member 70, the driver 140, and the display member 160 are axially coupled. Therefore, during dose setting, these three components are wound out of the outer body 12. The clockwise rotation of the button dose member 70 causes the driver 140 to rotate on a spiral path, so that the driver is advanced along the piston rod 30, and the piston rod remains fixed during the entire dialing process. When the dose is dialed, the sound piece arrangement 100 provides tactile and audible feedback to the user. At the maximum settable dose of 80 units, the stop features 12 and 67 engage to prevent further dialing.

[0202] With the desired dose dialed, the device 1 is ready for dose dispensing. This requires pushing the proximal button portion of the dose member 70, which will cause the clutch 90 to disengage from the dial sleeve 162, thereby allowing relative rotation between the display member 160 and the dose member 70. In all cases, the driver 140 and the dose member 70 are rotationally locked together by the engagement of the arm 173 and the finger 148 and by the spline 91 engaging the corresponding spline on the proximal drive sleeve 142. Therefore, when the clutch 90 is disengaged from the dose member 70 and the driver 140 is rotationally locked with the dose member 70, the driver 140 and the display member 160 are still axially coupled.

[0203] When a dose is dispensed, the dose member 70 and clutch 90 move axially relative to the mechanism compressing the clutch spring 103. Because the proximal clicker part 102 is splined to the inner body 20, and the distal clicker part 101 is rotationally locked to the proximal clicker part 102 by the axial load of the clicker teeth 105, 106, the drive sleeve 140 and clutch 90 parts of the mechanism are forced to move axially, while the dial sleeve 162 and number sleeve 161 are free to rotate back into the outer housing 10. The interaction of the mating threads between the piston rod 30, the driver 140 and the inner body 20 provides a mechanical advantage of, for example, 2:1.

[0204] In other words, the axially advancing driver 40 causes the piston rod 30 to rotate, which advances the piston rod 30 due to the threaded engagement of the piston rod 30 with the inner body 20. During dose dispensing, the dispensing clicker 168, 71 is active, which involves the dose member 70 and the display member 160. The dispensing clicker primarily provides an audible feedback to the user that a medicament is being dispensed.

[0205] When dispensing of a dose is complete, when the user withdraws force from the end of the dose member 70 , the clutch spring 103 pushes the dose member 70 proximally, causing the teeth 165 and 95 to reengage between the clutch and the dial sleeve.

[0206] The resetting of the device begins by removing the cartridge holder 11 and replacing the empty cartridge with a full cartridge 80. When the cartridge holder 11 is reattached, the bung of the new cartridge 80 contacts the bearing 33, thereby pushing the piston rod 30 back into the housing. Initially, the piston rod 30 is screwed into the inner body 20, thereby overcoming the biasing force of the spring 103 and causing the coupling 143 to axially disengage from the proximal drive sleeve 142. Once disengaged, the coupling 143 is free to begin rotating with the distal drive sleeve 141, and continues to do so, so that the cartridge holder 11 is moved axially to engage with the inner body 20. Therefore, the distal drive sleeve 141 rotates relative to the proximal drive sleeve 142, which is still rotationally restricted in the inner body 20 because the clicker parts 101 and 102 are pressed together by the compression spring 103.

[0207] When the distal drive sleeve 141 is rotated, the last dose nut 50 is reset to its (distal) starting position. The last dose nut 50 is threadedly engaged with the outer thread 144 of the distal drive sleeve 141. Coupling the cartridge holder 11 to the inner body 20 causes the mechanism to be retracted due to the bayonet structure, thereby allowing the proximal drive sleeve 142 to reengage with the coupler 143 and thus with the distal drive sleeve 141.

[0208] It should be noted here that the combination Figures 1 to 11 The minimum dose function described can also be implemented or actually used in combination with Figures 27 to 38 The reusable device is implemented.

[0209] The display member 160 is used together with the injection device 1 and according to Figures 27 to 38 The drive mechanism of the present invention comprises a number sleeve 161 and a dial sleeve 162 when implemented together. The dial sleeve 162 is provided with a ratchet arm 168 near the proximal end, and further has a bearing surface 166 and a clutch feature 165 to selectively engage with the teeth 95 of the clutch 90. The number sleeve 161 and the dose sleeve 162 are permanently and mutually engaged. The distal section of the dial sleeve 162 is located within the proximal section of the number sleeve 161. Therefore, the side wall 181 of the number sleeve 161 at least encloses the distal portion of the side wall 182 of the dial sleeve 162.

[0210] Mutually corresponding recesses 184 and protrusions 185 are provided on radially overlapping portions of the number sleeve 161 and the dial sleeve 162. In an embodiment, at least two recesses are provided near the proximal end of the number sleeve 161, which engage with and receive radially outwardly extending protrusions on the distal section of the side wall of the dial sleeve 162. In this way, a snap-fit ​​engagement is obtained between the number sleeve 161 and the dial sleeve 162. Therefore, the dial sleeve 162 is permanently rotationally and axially locked to the number sleeve 161, and vice versa.

[0211] In one embodiment, two blocking members 66 are provided at the proximal end of the number sleeve 161. The radially inwardly extending projections 67 of the blocking members 66 each extend through an aperture in the side wall of the dial sleeve 162. In this way, the projections 67, and therefore the blocking members 66, extend radially through the side wall of the dial sleeve 162 so as to directly engage with the blocking structure 26 on the outer circumference of the inner body 20. The longitudinal or axial extension of the aperture is large enough to allow and support axial displacement of the blocking member 66 relative to the dial sleeve 162 and relative to the number sleeve 161 when in the release configuration R.

[0212] In the release configuration R, the protrusion 67 of the blocking member 66 is located distally of the blocking structure 26 and thus distally of the blocking thread 27. In other words, the blocking member 66 may be aligned with an intersection or gap of the blocking thread 27. In the release position or release configuration R, the dose member 70 is movable in the distal direction 4, thereby pushing the flexible blocking member 66 in the distal direction.

[0213] In the blocking position B, the projection 67 of the blocking member 66 is located on the proximal side of the blocking structure 26. Here, the distal edge 67d of the projection 67 faces the proximal edge 27e of the blocking thread 27. In this blocking position B, the blocking member 66 is in axial abutment with the blocking structure 26. The blocking member 66 cannot be displaced in the distal direction 4. The distally directed dispensing force acting on the dose member 70 is transmitted into the blocking member 66 via the abutments 76 and 68. Said force is reacted by the mutual axial abutment of the correspondingly shaped proximal edge 27e and the distal edge 67d, thereby preventing and hindering a distally directed displacement of the blocking member 66.

[0214] In another embodiment of the display member, the same interaction and positive engagement is implemented between the number sleeve and the dial sleeve and between the dose member 70, the blocking member 66 and the inner body 20. The only difference is that the blocking member 66 is located on the dial sleeve instead of on the number sleeve 161. Here, the dial sleeve and / or the number sleeve includes an aperture of a recess, similar to the aperture of the dial sleeve 162, to support and provide a direct mechanical interaction between the blocking member 66 and the blocking structure 26.

[0215] In this embodiment, the number sleeve and the elastic blocking member 66 can be made of different materials. Since the number sleeve is usually provided with numbers or symbols on its outer circumference to indicate the size of the dose in the window 14 of the outer body 12, a material particularly suitable for printing or coating can be selected and used for the number sleeve. For the blocking member 66 and the rotary dial sleeve formed integrally with the blocking member 66, different plastic materials can be selected, which provide desired or optimized mechanical properties for the elastic deflection of the blocking member 66. For example, the rotary dial sleeve and the blocking member 66 can be made of POM.

[0216] List of Reference Numerals

[0217] 1 Injection device

[0218] 2 Needle Seat

[0219] 3 Cover

[0220] 4 Distal direction

[0221] 5 Proximal direction

[0222] 10 Housing

[0223] 11 Cartridge holder

[0224] 12 external subjects

[0225] 13th floor

[0226] 14 Window

[0227] 15 Orifice

[0228] 16 Thread

[0229] 20 Internal body

[0230] 20a Shaft

[0231] 21 External thread

[0232] 22 Spline

[0233] 23 Internal thread

[0234] 24 Stopper

[0235] 25a, b Stopper

[0236] 26 Blocking structure

[0237] 26a Distal

[0238] 26b Proximal

[0239] 27 Blocking Thread

[0240] 27a Distal

[0241] 27b Proximal

[0242] 27c Chamfer

[0243] 27d Distal edge

[0244] 27e Nearside edge

[0245] 30 Piston rod

[0246] 31 External thread

[0247] 32 External thread

[0248] 33 Bearings

[0249] 40 Drive

[0250] 41 Thread

[0251] 42 Internal thread

[0252] 43 Opening

[0253] 44 Fingers

[0254] 45 Protrusion

[0255] 46 Wings

[0256] 47 Stopper

[0257] 50 Final Dose Nuts

[0258] 51 External ribs

[0259] 52 Internal thread

[0260] 53 Stopper

[0261] 60 Display component

[0262] 60a Side wall

[0263] 60b Proximal part

[0264] 61 Internal thread

[0265] 62 Stopper

[0266] 63a Stopper

[0267] 63b Stopper

[0268] 64 teeth

[0269] 65 Flexible Arm

[0270] 66 blocking member

[0271] 66a Slit

[0272] 66b Free end

[0273] 66c Base part

[0274] 67 Protrusion

[0275] 67d Distal edge

[0276] 68 Adjacent part

[0277] 69 Support surface

[0278] 70 Dosage member

[0279] 70a Sleeve part

[0280] 71 Dose dial / dose button

[0281] 72 sleeve-shaped portion

[0282] 73 Ribs

[0283] 73a recess

[0284] 74 teeth

[0285] 75 Tooth profile

[0286] 76 Adjacent part

[0287] 80 Cartridges

[0288] 81 Storage

[0289] 82 plug

[0290] 83 Curled Metal Cap

[0291] 90 Clutch

[0292] 91 Spline

[0293] 92 teeth

[0294] 93 Orifice

[0295] 94 spline

[0296] 95 teeth

[0297] 100 Sound Components

[0298] 101 Far side sounder

[0299] 102 Near side sounder

[0300] 103 Clutch spring

[0301] 104 Spline

[0302] 105 Sounding parts teeth

[0303] 106 Sounding teeth

[0304] 107 Spline

[0305] 108 Spline

[0306] 109 teeth

[0307] 110 Cartridge bias spring

[0308] 120 Cap

[0309] 140 Driver

[0310] 141 Distal drive sleeve

[0311] 142 Proximal drive sleeve

[0312] 143 Connector

[0313] 144 Thread

[0314] 145 Stopper

[0315] 146 teeth

[0316] 147 teeth

[0317] 148 Flexible fingers

[0318] 149 Hook

[0319] 160 Display component

[0320] 161 Number Sleeve

[0321] 162 dial sleeve

[0322] 165 Clutch Features

[0323] 166 Support surface

[0324] 167 Stopper

[0325] 168 Ratchet Arm

[0326] 173 Arm

[0327] 174 snap feature

[0328] 220 Internal body

[0329] 227 Blocking Thread

[0330] 227a recess

[0331] 227b recess

[0332] 227c concave part

[0333] 227d concave part

[0334] Z Distal zero dose position

[0335] M Proximal maximum dose position

Claims

1. A drive mechanism for an injection device for setting and dispensing a dose of a medicament, the drive mechanism comprising: an internal body (20; 220) which can be fixed inside the housing (10) of the injection device (1), the internal body (20; 220) comprising an elongated shaft (20a) extending in an axial direction (z) and having an external thread (21), - a tubular display member (60; 160) having an internal thread (61) engaging with the external thread (21) of the inner body (20), and a dose member (70) which is axially displaceable relative to the display member (60; 160) between a dose setting position (S) and a dose dispensing position (D), - wherein the display member (60; 160) comprises at least one blocking member (66) which is movable in an axial direction (z) between a blocking position (B) and a release position (R) and which is engageable with a blocking thread (27; 227) which extends axially on the elongated axis (20a) of the inner body (20; 220), wherein the blocking thread (27; 227) and the outer thread (21; 221) have the same pitch, and wherein the at least one blocking member (66) of the display member (60; 160) is rotatable relative to the inner body (20; 220) by a predetermined number of turns between a distal zero dose position (Z) on the inner body (20; 220) and a proximal maximum dose position (M) on the inner body (20; 220), - wherein, when in the blocking position (B), the blocking member (66) axially engages with the dose member (70) and the blocking thread (27; 227) to block axial displacement of the dose member (70) from the dose setting position (S) towards the dose dispensing position (D), and - wherein the axial position of the distal end (27a) of the blocking thread (27, 227) on the inner body (20; 220) is positioned to be offset from the distal zero dose position (Z) in the proximal direction (5), the offset being between 10% and 60% of the axial distance between the distal zero dose position (Z) and the proximal maximum dose position (M).

2. The driving mechanism according to claim 1, wherein: The axial position of the distal end (27a) of the blocking thread (27, 227) on the inner body (20; 220) is positioned to be offset from the distal zero dose position (Z) in the proximal direction (5), the offset being between 20% and 30%, for example up to 25%, of the axial distance between the distal zero dose position (Z) and the proximal maximum dose position (M).

3. A drive mechanism according to any one of the preceding claims, wherein: At least one blocking member (66) of the display member (60; 160) is rotatable relative to the inner body (20; 220) between a distal zero dose position (Z) on the inner body (20; 220) and a proximal maximum dose position (M) on the inner body (20; 220) by between 1.080° and 2.160°, for example 1.440° or 1.800°.

4. A drive mechanism according to any one of the preceding claims, wherein: The blocking thread (227) includes at least one recess (227a, 227a, 227c, 227d) sized to receive the blocking member (66) and / or a radially inwardly extending protrusion thereof.

5. The driving mechanism according to claim 4, wherein: The blocking thread (227) comprises at least two recesses (227a, 227a, 227c, 227d) having a size suitable for receiving the blocking member (66) and / or its radially inwardly extending protrusion, and wherein two adjacent recesses (227a, 227a, 227c, 227d) are spaced apart from each other by between 10% and 20%, for example 12.5%, of the axial distance between the distal zero dose position (Z) and the proximal maximum dose position (M).

6. A drive mechanism according to any one of the preceding claims, wherein: The blocking member (66) includes a flexible arm extending in a tangential direction along the circumference of the display member (60; 160).

7. A drive mechanism according to any one of the preceding claims, wherein: The blocking member (66) includes a radially inwardly extending protrusion (67) at a free end section (66b) to engage with the blocking thread (27).

8. A drive mechanism according to any one of the preceding claims, wherein: The blocking member (66) comprises, at its free end section (66b), an abutment (68) facing in the axial direction (z) for axially abutting with a corresponding abutment (76) of the dose member (70).

9. A drive mechanism according to any one of the preceding claims, wherein: The axial position of the proximal end (27b) of the blocking thread (27) on the inner body (20; 220) defines a minimum size of the therapeutic dose.

10. The drive mechanism according to any one of claims 7 to 9, wherein: The distal end (27a) of the blocking thread (27; 227) is chamfered, and wherein, when the display member (60; 160) is rotated in the dose increment direction, the protrusion (67) of the blocking member (66) slides along the chamfer (27c) of the distal end (27a) of the blocking thread (27; 227) i) flexing the free end section (66b) of the blocking member (66) in the proximal direction (5) from its release position (R) towards its blocking position (B), or ii) axially abuts a proximally facing edge (27e) of the blocking thread (27; 227).

11. The drive mechanism according to claim 10, wherein: When the display member (60; 160; 260) is rotated in the dose dispensing direction and the blocking member (66) is in the release position (R), when the blocking member enters the blocking thread (27; 227), as the blocking member (66) passes the proximal end (27b) of the blocking thread (27; 227), the protrusion (67) of the blocking member (66) slides along the distal edge (27d) of the blocking thread (27; 227).

12. A drive mechanism according to any one of the preceding claims, wherein: The display member comprises a number sleeve and a dial sleeve, and wherein the at least one blocking member (66) is positioned on the dial sleeve, or wherein the at least one blocking member (66) is formed integrally with the dial sleeve.

13. A drive mechanism according to any one of the preceding claims, wherein: The inner body (20) includes at least a first maximum dose stop (25a, 25b) at its outer circumference to engage with first and second radially inwardly extending maximum dose stops (63a, 63b) of the display member (60; 160) respectively when the display member (60) reaches a maximum dose position.

14. The drive mechanism according to any of the preceding claims, further comprising a piston rod (30) and a tubular driver (40) extending in an axial direction (z), wherein: The piston rod (30) comprises a first external thread (31) engaging with an internal thread (23) of the inner body (20; 220) and comprises a counter-rotating second external thread (32) engaging with an internal thread (42) of the driver (40), and wherein the dose member (70) is permanently splined to the driver (40), the driver being selectively rotationally lockable to the inner body (20; 220) by displacing the dose member (70) into the dose dispensing position (D), and wherein the dose member (70) and the display member (60; 160) are selectively rotationally lockable and releaseable via a clutch (C), the clutch rotationally engaging the dose member (70) and the display member (60; 160) when the dose member (70) is in the dose setting position (S) and the clutch rotationally releasing the dose member (70) and the display member (60; 160) when the dose member (70) is in the dose dispensing position (D).

15. An injection device for setting and dispensing a dose of a medicament, the injection device comprising: - a housing (10) which accommodates a drive mechanism according to any one of the preceding claims, - A cartridge (80) arranged in the housing (10) and filled with a liquid medicament.

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