Drive mechanism for a medicament delivery device and corresponding medicament delivery device

Abstract

A drive mechanism for a drug delivery device, the device being used to deliver a dose of medication, the drive mechanism comprising: a dose setting assembly (N), a knob (1), a rotatable but non-axially translatable clutch element (2), a rotatable piston rod (3), a drive element (4), and a drive spring (5); the clutch element (2) is rotatably connected to the knob (1) and engages with the dose setting assembly (N); the piston rod (3) has external threads (3.2) and is located inside the clutch element (2); wherein, when the dose is set (1) by means of the knob (1), the clutch element (2) is rotated, causing the drive spring (5) to be loaded, while the drive element (4) and the piston rod (3) remain stationary; and when the dose is delivered, the drive spring (5) is released from... The drive element (4) rotates together with the piston rod (3), which moves axially in the distal direction. The piston rod (3) is hollow and has an internal thread (3.3), and a shaft (21) with an external thread (21.2) is located inside the piston rod (3). The shaft (21) is rotatably engaged with a clutch element (2), such that during the setting of each subsequent dose, the shaft (21) rotates relative to the piston rod (3) and moves axially in the proximal direction, while during dose delivery, the shaft (21) is stationary relative to the piston rod (3). The total translation of the shaft (21) relative to the piston rod (3) caused by setting a limited number of doses is limited by means of a blocking element (B) located on the piston rod and the shaft, respectively. A drug delivery device for delivering a dose of medicine includes the disclosed drive mechanism.

Description

[0001] This application relates to a drive mechanism and a corresponding applicator for delivering a dose of a medicament, particularly a drive mechanism and applicator equipped with a last dose blocking feature. Devices for delivering multiple doses of medication via subcutaneous injection are known in the art, in which the volume of the dose can be pre-selected. The device typically includes a housing comprising a mechanism for axially translating a piston rod and a cartridge housing adapted to receive the medication cartridge. A piston is located within the cartridge, and the translation of the piston by the piston rod causes an appropriate dose of medication to be ejected from the cartridge. Such applicators are particularly useful for patients who require periodic administration of medication doses—especially adjustable doses.

[0002] For example, such a sprayer is described in international application WO99 / 38554A1. Here, the force required to translate the piston rod is applied directly by the user by pressing a button. Alternatively, the force required to translate the piston rod can be applied by a spring, which is preferably loaded by the user, as in sprayers known from documents EP0338806B1, WO2010 / 089418A2, or WO2017 / 064275A1.

[0003] In applicators used to deliver dose-adjustable drugs, it is essential to prevent the possibility that the set dose may exceed the volume of drug remaining in the cartridge. Without this safeguard, there is a risk that the dose delivered by the applicator will be less than the dose desired by the user. For example, WO01 / 19434A1 discloses such a mechanism, which describes a setting mechanism comprising coaxial cylinders, wherein a sleeve is translated between the coaxial cylinders toward a final position in which the sleeve abuts a blocking element with the set dose equal to the remaining dose in the cartridge. In a similar mechanism known from WO2010 / 149209A1, a spherical element is used instead of an annular sleeve. European Patent EP2814547B1 describes a final dose limiting mechanism in which blocking elements move along a closed path curve, the shape of the curve and the speed at which the blocking elements move along the curve being adjusted such that the blocking elements contact each other when the final dose is delivered.

[0004] The purpose of the currently disclosed solution is to provide a drive mechanism with a final dose blocking feature, allowing the automatic dispenser to be precisely set and preferably also to allow for the correction of a single dose. A particular objective is to provide a blocking mechanism that prevents the possibility that the set dose may exceed the volume of the drug in the cartridge.

[0005] In addition, the aim is to provide a reliable final dose block that will not require any necessary modifications to the applicator's setting mechanism and other components, thereby reducing costs and facilitating the manufacture of the applicator.

[0006] Another objective is to create a final dose barrier that can be used in a lightweight, compact applicator. A further objective is to design an automatic applicator with replaceable cartridges, equipped with a drive mechanism featuring a final dose barrier, enabling precise setting and calibration of a single dose.

[0007] In accordance with the above objective, a drive mechanism for a drug applicator is provided, the applicator being used to deliver a dose of drug, the drive mechanism comprising:

[0008] Dosage setting component,

[0009] Knob

[0010] A rotatable but non-axially translational clutch element, which is rotatably connected to a knob and cooperates with a dosage setting assembly.

[0011] A rotatable piston rod with external threads is located inside the clutch element.

[0012] Drive components and drive springs

[0013] in,

[0014] When the dosage is set using a knob, the clutch element is rotated, loading the drive spring while the drive element and piston rod remain stationary. As the dosage is delivered, the drive spring is released, causing the drive element and piston rod to rotate together, with the piston rod axially translating in the distal direction.

[0015] in,

[0016] The piston rod is hollow and has internal threads, and a shaft is located inside the piston rod. The shaft has external threads for engaging with the internal threads of the piston rod. The shaft is rotatably connected to a clutch element such that during the setting of each subsequent dose, the shaft rotates relative to the piston rod and moves axially in the proximal direction, while during dose delivery, the shaft is stationary relative to the piston rod. The total translation of the shaft relative to the piston rod caused by setting a predetermined number of doses is limited by means of blocking elements located on the piston rod and the shaft, respectively.

[0017] Preferably, the shaft is rotatably connected to the clutch element by means of a longitudinal spline.

[0018] The blocking element may include a protrusion on the internal thread of the piston rod and a protrusion on the external thread of the shaft, and the blocking element is adapted to block the rotation of the piston rod relative to the shaft.

[0019] Preferably, the drive element has an orifice with a non-circular cross-section, and the piston rod has a cross-section with a non-circular profile corresponding to the orifice of the drive element.

[0020] A dispensing device is also provided for delivering a dose of medicine. The dispensing device includes:

[0021] case,

[0022] A cartridge case housing adapted to receive cartridges containing medication.

[0023] Dosage setting component,

[0024] Knob

[0025] A rotatable but non-axially translational clutch element, which is rotatably connected to a knob and cooperates with a dosage setting assembly.

[0026] A rotatable piston rod with external threads is located inside the clutch element.

[0027] Drive components and drive springs

[0028] in,

[0029] When the dosage is set using a knob, the clutch element is rotated, loading the drive spring while the drive element and piston rod remain stationary. As the dosage is delivered, the drive spring is released, causing the drive element and piston rod to rotate together, with the piston rod axially translating in the distal direction.

[0030] in,

[0031] The piston rod is hollow and has internal threads, and a shaft is located inside the piston rod. The shaft has external threads for engaging with the internal threads of the piston rod. The shaft is rotatably engaged with a clutch element such that during the setting of each subsequent dose, the shaft rotates relative to the piston rod and translates axially in the proximal direction, while during dose delivery, the shaft is stationary relative to the piston rod. The total translation of the shaft relative to the piston rod caused by setting a predetermined number of doses is limited by means of blocking elements located on the piston rod and the shaft, respectively.

[0032] Preferably, the drive element has an orifice with a non-circular cross-section, and the piston rod has a cross-section with a non-circular profile corresponding to the orifice of the drive element.

[0033] Preferably, the drive element is releasably connected to the dose setting component.

[0034] The blocking element preferably includes a protrusion on the internal thread of the piston rod and a protrusion on the external thread of the shaft, and the blocking element is adapted to block the rotation of the piston rod relative to the shaft.

[0035] The applicator may include an indicating mechanism comprising a control sleeve, a graduated sleeve, and a control nut. The control sleeve has external threads for engaging with the control nut, which is prevented from rotating within a housing and is axially translatable within the housing. The control nut also axially engages with the graduated sleeve, which moves along a helical path during dose setting and dose correction.

[0036] Preferably, the indicator includes an indicator window that displays the currently set dose.

[0037] Preferably, the drive spring is a torsion spring.

[0038] The applicator preferably includes a release mechanism adapted to be in a locked or unlocked state. The release mechanism includes an external activation element, wherein when the release mechanism is in the locked state, the drive element cannot rotate, and when the release mechanism is in the unlocked state, the drive element can rotate. The release mechanism is adapted to be switched from the locked state to the unlocked state by a user.

[0039] The external activation element may include a trigger located on the side wall of the housing, which is prevented from rotating and can be translated axially.

[0040] A preferred embodiment is shown in the accompanying drawings, in which:

[0041] Figure 1 An exploded view of an exemplary automatic pesticide applicator with a disclosed drive mechanism is shown;

[0042] Figure 2 A longitudinal section of a segment of an exemplary automatic applicator with a disclosed drive mechanism is shown;

[0043] Figure 3 A cross-section A-A' of the dose setting component is shown;

[0044] Figures 4a to 4c The diagram illustrates the final dose blocking procedure;

[0045] Figures 5a to 5c The blocking element is shown;

[0046] Figure 6 Various cross-sections of the piston rod used in the applicator are shown;

[0047] Figure 7 A perspective view showing the connection between the drive element and the blocking ring and the toothed ring is shown;

[0048] Figure 8a and Figure 8b The cross-sections of the applicator are shown with the applicator housing connected to the cartridge shell and with the housing separated from the cartridge shell, respectively.

[0049] Figure 9 A longitudinal section of a segment of an alternative automatic applicator with a disclosed drive mechanism is shown;

[0050] Figure 10 A longitudinal section is shown of yet another embodiment of an automatic pesticide applicator with a disclosed drive mechanism.

[0051] In the following description of the embodiments, the distal direction is defined as the direction toward the injection site, and the proximal direction is defined as the direction toward the dose selection knob.

[0052] exist Figure 1 and Figure 2 The exemplary automated drug delivery device shown is designed to deliver multiple doses of medication, the volume of which can be set and calibrated prior to injection. The mechanism for dose setting and calibration is similar to that described in WO2010 / 089418A2. Alternatively, other setting components known in the art can be used, enabling dose amplification and calibration, and allowing a control element to be driven, rotatably coupled to or integrated with the dose selection knob. In particular, alternative setting components may include ratchet, tooth, or ratchet-tooth mechanisms known in the art.

[0053] The applicator is equipped with a disclosed drive mechanism. This mechanism includes a dosage setting component N, a knob 1, and a rotatable but non-axially translatable clutch element 2, which is rotatably connected to the knob 1 and engages with the dosage setting component N. Preferably, the clutch element 2 is engaged with the knob 1 at its proximal end and with the dosage setting component N at its distal end. The mechanism also includes a rotatable piston rod 3, a drive element 4, and a drive spring 5, the rotatable piston rod 3 being located inside the clutch element 2.

[0054] The dosage selection knob 1 is located at the proximal end of the applicator. Knob 1 is connected to clutch element 2 via a spline or another connector that ensures the engagement of these components during rotation. In the described embodiment, knob 1 and clutch element 2 can be rotated, but their axial positions are fixed.

[0055] Arm 2.1 is located at the distal end of clutch element 2, and arm 2.1 engages with dose setting assembly N. Figure 3 A cross-section A-A' of an exemplary dose setting assembly is shown. In the described exemplary applicator, the dose setting assembly N includes a ratchet element 6 (also... Figures 1 to 2 (As shown in the diagram). The ratchet element 6 surrounds the gear ring 7 and the arm 2.1 of the clutch element 2. The gear ring 7 is located at least partially inside the ratchet element 6.

[0056] As mentioned above, the disclosed drive mechanism also includes a rotatable piston rod 3, a drive element 4, and a drive spring 5. (As in...) Figure 1 As shown, the drive element 4 is connected via the non-circular profile of the piston rod 3 and the corresponding orifice 4.1 in the drive element 4 (in Figure 3 and Figure 7 (As shown in the image) is connected to the piston rod 3. The piston rod end component 3.1 is located at the end of the piston rod 3 to increase the contact surface with the cartridge piston. In an alternative embodiment, the piston rod end component 3.1 may be configured and integrated as part of the piston rod.

[0057] The piston rod 3 can be a single, integral component, or it can comprise two or more parts connected in a manner that secures them together. These parts can be interconnected axially or coaxially. Furthermore, the piston rod 3 or its components can be made of polymer or metal. In a piston rod 3 composed of more than one component, all components can be made of the same material or different materials.

[0058] Still referencing Figure 1 and Figure 2 The applicator described in this embodiment also has a housing 8 for connection to the cartridge housing 9. Once the housing 8 is connected to the cartridge housing 9, the two components are rotatably and axially fixed relative to each other. Preferably, the cartridge housing 9 can be detached from the housing 8 to allow for replacement of the drug cartridge. Alternatively, in the case of a disposable applicator, the components can be connected to each other in a non-releasable manner during assembly. The applicator may be equipped with a cap 10 that covers the distal end of the cartridge housing 9 when the cap 10 is placed on the housing 8. A thread 9.1 is formed on the distal end for mounting a needle module comprising a needle through which the drug contained in the cartridge flows. In the disclosed embodiment, the cartridge housing 9 is connected to the housing 8 via a nut 11, which... Figure 1As shown, it has a protrusion 11.1 that mates with the groove 9.2. However, these elements can also be snap-fit ​​connected. In the described applicator, the housing 8 has a protrusion 8.1 to allow the cap 10 to be placed in only one fixed angular position. The cap 10 may be provided with a clamp 10.1, which facilitates the use of the applicator, for example, allowing the applicator to be attached to clothing.

[0059] In a preferred embodiment, the piston rod 3 rotates within the nut 11. The piston rod 3 has an external thread 3.2 that mates with the thread 11.2 of the nut (see...). Figure 2 The nut 11 is rotatably and axially blocked within the housing 8. In an alternative variant, the piston rod 3 is threaded directly onto an integral element of the housing, preferably on an element facing inwards towards the housing. The applicator according to this embodiment also has an indicating mechanism W to indicate the volume of the currently set dose to the user. The indicating mechanism W includes a control sleeve 13, a scale sleeve 12, and a control nut 14. The volume of the dose is indicated by a digital scale 12.1 located on the scale sleeve 12. As the dose increases, the scale sleeve 12 moves along a helical path, and subsequent digits of the scale 12.1 are indicated by a marker 8.2 and appear in an indicating window 8.3, which may be provided with a transparent cover and additional components, such as a lens, to improve the visibility of the set dose. The scale sleeve 12 is rotatably connected to the control sleeve 13, which in this embodiment is integrally formed with the ratchet element 6. In alternative variations, the ratchet element 6 can be a separate component that is rotatably coupled to the control sleeve 13. (As in...) Figure 1 As shown, the control sleeve 13 has threads 13.1 on its outer surface, which engage with a control nut 14 having internal threads. The control nut 14 is axially engaged with the graduated sleeve 12 by means of, for example, a clamping member; the control nut 14 also blocks rotational movement by means of a protrusion 14.1 that can move in a longitudinal groove 8.4 of the housing.

[0060] exist Figure 2 The diagram shows a drive spring 5, which forms part of the drive mechanism of the disclosed applicator. The drive spring 5 is connected at one end to a control sleeve 13 and at the other end is fixed in a spring stop 15, which is fixed within the housing 8. Other methods of mounting the drive spring 5 are also possible; for example, the drive spring 5 may be connected at one end to a ratchet element 6 or a clutch element 2. The other end of the drive spring 5 may also be directly fixed within the housing 8.

[0061] The applicator also has a release mechanism Z to allow rotation of at least one element or drive element in the dose setting assembly. Due to this mechanism, the energy accumulated in the loaded drive spring 5 is not immediately released back. When the release mechanism Z becomes unlocked, the at least one element or drive element in the dose setting assembly is also unlocked, allowing the energy accumulated in the loaded drive spring to be released and the injection to be triggered. In this embodiment, the release mechanism Z includes an external activation element 16 adapted to release the injection; the activation element 16 is axially translatable within the housing 8. Figure 2 and Figure 8b The release mechanism Z is shown in detail. The release mechanism Z also includes a spring 17 located between the activation element 16 and the housing 8. The external activation element 16 is activated by means of... Figure 7 The blocking ring 18, shown in detail, is connected to the drive element 4. A protrusion 18.1 is provided on the outer surface of the blocking ring 18 for engaging with a corresponding recess 4.2 of the drive element 4. Other shapes of the engaging surfaces 18.1 and 4.2 are possible, as long as such other shapes ensure rotational connection between the blocking ring 18 and the drive element 4. In the case where the applicator has a replaceable cartridge, the connection can be releasable. The blocking ring 18 also has a peripheral groove 18.2 adapted to block the blocking ring 18 via a protrusion 16.1 located on the outer activating element 16, which in this embodiment is in the form of a trigger.

[0062] Alternatively, the external activation element 16 may be located at the proximal end of the applicator. Thus, the external activation element 16 may take the form of a button separate from the dose selection knob 1, or the knob 1 itself may constitute the external activation element. Preferably, the external activation element can be released from the dose setting component N during injection.

[0063] exist Figure 2 The diagram shows a bearing 8.5 that enables the drive element 4 to rotate. In the illustrated embodiment, the bearing is integral with the housing 8. Alternatively, the bearing may be formed on a separate component fixed within the housing. A spring 19 is present between the drive element 4 and the gear ring 7 or the bearing 8.5, allowing these elements to be separated for replacement of the cartridge case. A push rod 20 is present, having a protrusion 20.1 on its distal side, thereby abutting the drive element 4 on its proximal side. When the housing 8 is connected to the cartridge case housing 9, the push rod 20 contacts the cartridge case housing 9 via the protrusion 20.1.

[0064] Figure 3 The applicator is shown along the path of the drug delivery system. Figure 2The cross-section of plane A-A' is indicated in the figure, at which the dose setting component N is shown.

[0065] The ratchet element 6 has an external elastic arm 6.1 with a protrusion 6.2, and the clutch element 2 has an inner protrusion 2.2 on its arm 2.1. The gear ring 7 has circumferential teeth 7.1, which are located in... Figure 3 As can be seen, the arm 6.1 of the ratchet element 6 rests on the circumferential tooth 7.1. Between the protrusion 6.2 and the protrusion 2.2 of the clutch element 2, there exists a clearance X that allows these elements to rotate within a limited range. The position of the arm 6.1 on the toothed ring 7 corresponds to the current set dose.

[0066] For example, in particular Figures 4a to 4c as well as Figures 5a to 5c As can be seen, the piston rod 3 contains a threaded shaft 21, which engages with an external thread on the inner surface of the piston rod 3. This external thread is preferably a track 3.3. The shaft 21 is rotatably engaged with the clutch element 2, for example via a spline or another connecting piece that ensures that relative rotation between these elements is prevented.

[0067] Figures 4a to 4c The diagram illustrates how the final dose is blocked. Figure 4a The relative positions of the applicator components are shown before the dosage is set. Knob 1 is rotatably connected to clutch element 2, which in turn is rotatably connected to shaft 21. In the disclosed embodiment, both couplings are spline-type, but other known types of couplings may also be used, such as any corresponding recess and protrusion on the mating elements. Figure 4b The relative positions of the applicator components are shown after the dosage has been set, and Figure 4c The relative positions of the applicator components after injection are shown.

[0068] Figure 5a , Figure 5b and Figure 5c A blocking element B is shown, comprising a blocking protrusion 3.4 on the piston rod 3 and a blocking protrusion 21.1 on the shaft 21. The blocking protrusion 3.4 has a blocking surface 3.5, and the blocking protrusion 21.1 has a blocking surface 21.3. When the dosage is set to equal the volume of the remaining drug in the cartridge, the blocking surface 3.5 contacts the blocking surface 21.3, thereby preventing further relative rotation between the piston rod 3 and the shaft 21.

[0069] Figure 6 Various embodiments of the non-circular cross-section of the piston rod 3 are shown, which mates with the non-circular cross-section of the drive element 4.

[0070] Figure 7 A perspective view of the connection between the drive element 4, the blocking ring 18, and the toothed ring 7 is shown. Figure 7 The diagram shows a non-circular cross-section of the orifice 4.1 in the drive element 4, through which the piston rod 3 passes. In alternative variations, the orifice 4.1 may have a different cross-section, for example, a cross-section corresponding to... Figure 6 The shape of the cross-section of piston rod 3 is shown in the figure.

[0071] Figure 8a A longitudinal section of a segment of the applicator ready for use is shown. The drive element 4 is connected to the toothed ring 7 and the blocking ring 18, allowing the drive element 4, toothed ring 7, and blocking ring 18 to rotate together. The spring 19 is compressed, and the cartridge case 9 contacts the push rod 20. Figure 8b The diagram shows the same cross-section after the housing 8 has been separated from the cartridge case 9 in the case of a variant with a replaceable cartridge. The spring 19 is no longer compressed, and the drive element 4 is separated from the stop ring 18 and the toothed ring 7.

[0072] The operation of the applicator equipped with a drive mechanism according to the preferred embodiment described above will now be described with reference to the figures described above.

[0073] To increase or adjust the dosage, the user rotates knob 1 in one of two directions. Clutch element 2 is rotated by means of knob 1, and thus ratchet element 6 also rotates due to the engagement of protrusions 2.2 and 6.2. Due to this rotation, the elastic arm 6.1 of ratchet element 6 passes over the subsequent tooth 7.1 of the gear ring 7. Passing over the subsequent position on the gear ring corresponds to an overall increase in the dosage volume, which is defined by the size of the gear ring 7. The arm of ratchet element 6 engages with the arm of clutch element 2 via the protrusions 2.2 and 6.2 of the corresponding arm in such a way that, while the arms of the clutch element and the arm of ratchet element 6 slide against each other, during rotation in one direction, the arm 6.1 of ratchet element 6 disengages from the tooth 7.1 of the gear ring, and during rotation in the opposite direction, relative rotation between these elements is blocked. During rotation in the direction of dose correction, as arm 6.1 disengages from tooth 7.1 of the gear ring 7, ratchet element 6 rotates under the force of the drive spring and then re-engages gear ring 7 at a position one tooth 7.1 behind, corresponding to one unit of correction. This is because once arm 6.1 has been moved due to the rotation of ratchet element 6, arm 6.1 is no longer deflected by arm 2.1 of clutch element.

[0074] During dose setting and dose correction, the drive element 4 and the piston rod 3 therewith are restricted from movement via the stop ring 18 through the release mechanism Z described above. The toothed ring 7 connected to the drive element 4 is also stationary. Rotation of the control sleeve 13 causes the drive spring 5 to be loaded and energy to be accumulated in the drive spring 5. During dose correction in one unit, when the arm 6.1 disengages from the toothed ring 7, the drive spring 5 releases a portion of the accumulated energy as the arm 6.1 moves backward by one tooth of the toothed ring 7.

[0075] During dosage setting, the scale sleeve 12 rotates together with the control sleeve 13 due to the anti-rotational connection between the scale sleeve 12 and the control sleeve 13. Because of the threaded connection between the control sleeve 13 and the control nut 14, the rotation of the control sleeve 13 causes axial translation of the control nut 14. The scale sleeve 12 receives the axial movement from the control nut 14, and thus the final movement of the scale sleeve 12 follows a helical path, allowing subsequent digits of the helically arranged scale 12.1 to be visible in the indicator window 8.3. Alternatively, another indicating mechanism can be used in the applicator, for example, the scale may be located directly on the control sleeve 13. In this variation, separate scale sleeve 12 and control nut 14 are not necessary, and this indicating mechanism has a scale arranged in a ring. The applicator may also have other elements providing feedback to the user, such as an indicator confirming the end of injection. Preferably, the indicator can be applied to the scale sleeve 12 and can be seen through a separate window provided in the housing 8 when the injection is complete. The operating range of the indicating mechanism W can be limited to a boundary position by limiting elements known to those skilled in the art. They can operate circumferentially or axially. Depending on the variant of the applicator, the limiting element can be located on the dose setting assembly N, various elements of the indicating mechanism W, or the housing, thereby limiting the operating range of the applicator from its initial position to the maximum dose that can be set at one time.

[0076] To trigger the injection of the set dose of medication, the user moves the outer activating element 16 axially. This causes the protrusion 16.1 to disengage from the blocking ring 18, freeing the entire mechanism from obstruction and allowing the drive spring 5 to release accumulated energy. The drive spring 5 rotates the control sleeve 13 and the ratchet element 6, causing the arm 6.1 of the ratchet element 6 to push against the teeth 7.1, thereby rotating the toothed ring 7. The drive element 4 and the piston rod 3 rotate together with the toothed ring 7. The rotation of the piston rod 3 through the threaded nut 11 causes the piston rod 3 to be translated axially, and thus the cartridge piston is also translated axially, resulting in the ejection of the set dose of medication.

[0077] During injection, the graduated sleeve 12 and control nut 14 return to their initial positions due to the rotation of the drive sleeve. When the activation element 16 is triggered by the user, the axial movement of the activation element 16 causes compression of the spring 17. Upon release of the activation element 16, the spring 17 extends, causing the activation element 16 to return to its initial position. The protrusion 16.1 again blocks the stop ring 18, and the entire mechanism is ready for dose resetting.

[0078] The disclosed drive mechanism has a piston rod 3, which is hollow and has an internal thread 3.3, preferably in the form of a track located on the inner surface of the piston rod. Inside the piston rod is a shaft 21, which has an external thread 21.2 that mates with the internal thread of the piston rod.

[0079] During dose setting and dose correction, the drive element 4 is prevented from rotating by means of the activation element 16 and the retaining ring 18. The piston rod 3, rotatably coupled to the drive element 4, does not rotate and remains stationary. The shaft 21 is rotatably coupled to the clutch element 2, and during the setting of each subsequent dose, the shaft 21 rotates relative to the piston rod 3, thereby moving axially and proximally a defined distance corresponding to the set dose (during dose correction, the shaft 21 rotates in the opposite direction relative to the piston rod 3, thereby moving axially and distally by the action of the clutch element 2). Figure 8b The position of shaft 21 is shown when setting the maximum possible dose in a single delivery. The length of shaft 21 can be selected such that when setting the maximum dose, shaft 21 contacts knob 1, thereby preventing further increases in the set dose. Alternatively, a blocking element to prevent axial translation of shaft 21 during dose setting can be located on clutch element 2, or some other mechanism that limits the maximum dose in a single delivery can be used.

[0080] Because the piston rod 3 is simultaneously rotated and translated distally during each dose delivery, the shaft 21, which engages with the piston rod 3, rotates together with the piston rod 3 and the clutch element 2, and is translated distally with the piston rod 3, thereby maintaining the distance relative to the piston rod 3 corresponding to the delivered dose. Therefore, during the delivery of each subsequent dose, the total axial translation of the shaft 21 relative to the piston rod 3 increases, while the axial position of the shaft 21 relative to the clutch element 2 remains the same as before the dose was set. This situation occurs in… Figure 4c The diagram is shown in the image. To prevent the next dose from being unable to be delivered due to the limited contents of the cartridge, the mechanism is equipped with a blocking element B, which is located on both the piston rod and the shaft. The blocking element B—specifically in… Figures 5a to 5cAs shown in the diagram, the translation range of the limiting axis relative to piston rod 3 is limited, thereby preventing the possibility of setting the next dose after the last dose of drug.

[0081] The blocking element B may specifically include a blocking protrusion 21.1 on the shaft 21 and a blocking protrusion 3.4 on the piston rod 3. The blocking protrusion 21.1 has a blocking surface 21.3, and the blocking protrusion 3.4 has a blocking surface 3.5. When the volume of the currently set dose is equal to the amount of drug remaining in the cartridge, the blocking surface 21.3 of the shaft and the blocking surface 3.5 of the piston rod are abutted to each other, thereby preventing further increase in the dose. When the blocking surfaces 21.3 and 3.5 are further abutted, rotation of the threaded shaft 21—and therefore rotation of the clutch element 2 and the knob 1—is impossible, thus preventing the setting of a dose greater than the amount of drug remaining in the cartridge from being blocked. On the other hand, when the blocking surface 21.3 on the blocking protrusion 21.1 and the blocking surface 3.5 on the blocking protrusion 3.4 are respectively abutted, a reduction in the set dose and injection are possible.

[0082] In a preferred embodiment of the applicator with a drive mechanism, the drive element 4 is releasably engaged with the dosage setting assembly N via a connector having a toothed ring 7; the drive element 4 is also releasably engaged with the release mechanism Z via a connector having a retaining ring 18. This arrangement ensures that when the connector of the drive element 4 is disengaged ( Figure 8b The piston rod 3 can be retracted and the cartridge can be replaced with a new cartridge. To replace the cartridge, the cartridge housing 9 should be disengaged from the nut 11 and the housing 8. The spring 19, no longer compressed, extends and causes the drive element 4 to be pushed away from the gear ring 7 and disengaged from the gear ring 7. The axial translation of the drive element 4 causes the drive element 4 to disengage from the retaining ring 18. Therefore, the drive element 4 can be rotated, causing the piston rod 3, which is engaged with the drive element 4, to also rotate. This allows the piston rod 3 to be retracted to its initial position by rotation of the piston rod 3 in the nut 11. When the piston rod 3 is retracted, the shaft 21, which is blocked from rotation by engagement with the clutch element 2, remains stationary, and therefore the axial position of the piston rod 3 relative to the shaft 21 returns to its initial state after the piston rod 3 has been retracted. When the cartridge housing 9 is re-engaged with the nut and housing 18, the relative axial movement of these elements causes the push rod 20 to translate, which is compressed by the cartridge housing 9. The push rod 20 applies pressure to the drive element 4, which is thus axially translated, thereby applying pressure to the spring 19. The translation of the drive element 4 causes it to re-engage with the stop ring 18 and, via the toothed ring 7, with the dosage setting assembly N, and the applicator is ready for use.

[0083] In an alternative embodiment where the applicator is disposable, the drive element 4 can be integrated with the toothed ring 7.

[0084] Figure 9 A longitudinal section of a segment of an alternative applicator with a disclosed drive mechanism is shown. In the applicator according to this embodiment, any dose setting component and indicating mechanism known in the art can be used. In particular, the dose setting component and indicating mechanism can have... Figure 1 The form shown in the embodiment in Figure 8. Figure 9 In the current embodiment shown, the drive mechanism is also equipped with a drive element 104.

[0085] The applicator also includes an external activation element 116 that engages with a blocking sleeve 118. The blocking sleeve 118 is axially movable; the external activation element 116 and the blocking sleeve 118 together constitute the release mechanism Z'. The blocking sleeve 118 is connected to a toothed ring 107, preferably by means of engaging circumferential protrusions and recesses. Before the axial movement of the external activation element 116, the blocking sleeve 118 prevents rotation of the toothed ring 107, thus blocking the entire mechanism and preventing dose setting and / or correction. Drive elements 104 are connected to the toothed ring 107, preferably by means of engaging circumferential protrusions and recesses, such that these elements are not rotated during dose setting and / or correction, and that these elements rotate during injection. Drug delivery is initiated by the axial movement of the external activation element 116, which in turn applies pressure to the protrusion 118.1 and axially moves the blocking sleeve 118. Due to this translation, the blocking sleeve 118 disengages from the toothed ring 107 and the entire mechanism is unlocked, allowing the energy accumulated in the drive spring to be released and the set dose to be delivered. When injection is triggered, the holder 188.2 of the blocking sleeve 118 moves, applying pressure to the spring 119, causing the spring 119 to compress. When the external activating element 116 is released, the energy accumulated in the spring 119 during the translation of the activating element 116 and the blocking sleeve 118 is released. The spring 119 then applies pressure to the blocking sleeve, causing the blocking sleeve to return to its initial position and re-engage with the toothed ring 107, thereby blocking the entire mechanism ready for re-dosing.

[0086] In a variant where the applicator is disposable and the cartridge can be replaced, the spring 119 is compressed when the cartridge housing is connected to the casing. In this case, the spring 119 is additionally compressed when the blocking sleeve 118 is translated. When the external activating element 116 is released, not all the accumulated elastic energy is released, but only the portion accumulated due to the pressure applied through the blocking sleeve 118 is released.

[0087] To replace the cartridge case, the cartridge case outer shell disengages from the housing, releasing the energy of spring 119, which then applies pressure to push rod 120. Push rod 120 and drive element 104 are connected in such a way that these elements can rotate relative to each other but are axially coupled, preferably by means of a clamping member including protrusion 120.1 and recess 104.1 of the drive element. The pressure of spring 119 causes push rod 120 and drive element 104 to move axially in the distal direction. Therefore, drive element 104 disengages from the freely rotatable toothed ring 107, allowing the piston rod to retract. The cartridge case outer shell, upon re-engaging with the housing, applies pressure to push rod 120, causing push rod 120 to translate in the proximal direction. This translation causes spring 119 to be compressed again and drive element 104 to translate and re-engage with toothed ring 107.

[0088] Figure 10 A longitudinal section of another embodiment of a drug applicator with a disclosed drive mechanism is shown.

[0089] In this embodiment, the activation element includes a button 216 located at the proximal end of the applicator. The button 216 is axially connected to a button sleeve 216A, preferably by means of a connector including a recess and a protrusion at the periphery.

[0090] During dosage setting, clutch element 202 is rotated by means of knob 201, to which clutch element 202 is rotatably engaged. Clutch element 202 is also connected to gear ring 207. Gear ring 207 includes toothed flanges, and clutch element includes teeth that traverse subsequent positions on the toothed flanges during dosage setting. The teeth of clutch element can be operated axially or radially, and can be in the form of ratchet arms. A dispenser with a button 216 located at a proximal end can also be equipped with another dosage setting component known in the art or in… Figure 1The dosage setting assembly is shown in Figure 8. During dosage setting, the drive sleeve 213 and drive spring 205 are rotated, causing elastic energy to accumulate in the drive spring 205. The drive spring 205 is connected to the drive sleeve 213 on one side and to the spring stop 215 on the other side. Alternatively, the drive spring 205 can be connected to the clutch element 202, with the other end of the drive spring 205 directly fixed in the housing. During dosage setting, the mechanism is blocked by means of the connection between the gear ring 207 and the clutch element 202. These two elements are advantageously pressed against each other by means of the spring 219. The button sleeve 216A is releasably connected to the clutch element 202 and remains stationary during dosage setting. The volume of the currently set dosage is indicated on the scale sleeve 212. The applicator according to this embodiment can also be equipped with different indicating mechanisms known in the art. During dosage correction, the clutch element 202 rotates in the opposite direction to the dosage setting direction. The teeth of clutch element 202 pass over subsequent positions on tooth flange 207, but in the reverse order of dosing. During dosing correction, energy accumulates in drive spring 205, which in this embodiment is a torsion spring.

[0091] To initiate dosage delivery, the user presses button 216, causing button sleeve 216A to move axially. During this translation, button sleeve 216A engages with clutch element 202 and applies pressure to gear ring 207, causing gear ring 207 to translate axially in the distal direction. When the teeth of gear ring 207 disengage from the teeth of clutch element 202, the mechanism is unlocked, and drive spring 205 can release accumulated energy, causing the mechanism's components to return to their initial positions. Button sleeve 216A rotatably engages with piston rod 203, for example, by means of a spline or mating planar surface. In the described embodiment, button sleeve 216A serves as a drive element. During dosage delivery, button sleeve 216A rotatably engages with clutch element 202, and button sleeve 216A rotates under the force of drive spring 205. This causes piston rod 203 to be unscrewed through threaded nut 211. When button 216 is released, spring 217 located between button 216 and knob 201 extends, thereby returning the button to its initial position. At the same time, spring 219 presses toothed ring 207 against clutch element 202 and blocks the mechanism again, making the mechanism ready for resetting the dosage.

[0092] The final dose blocking is achieved through the engagement of a threaded shaft 221 located inside a piston rod 203 with internal threads. Shaft 221 is rotatably connected to clutch element 202 via connecting element 222. During dose setting, rotation of clutch element 202 causes shaft 221 to rotate, and shaft 221 is unscrewed in the proximal direction and translated relative to piston rod 203. During dose correction, shaft 221 is translated in the distal direction. During dose delivery, shaft 221 rotates together with piston rod 203 and is translated axially, and the relative positions of shaft 221 and piston rod 203 remain unchanged. The position of shaft 221 relative to piston rod 203 corresponds to the sum of the dose delivered from the cartridge and the currently set dose. When the currently set dose equals the amount of drug remaining in the cartridge, movement of shaft 221 relative to piston rod 203 is blocked by a blocking element advantageously located on these elements, and the user cannot increase the dose further because clutch element 202 cannot be rotated further.

[0093] When the applicator is configured as a reusable device, the user can replace the cartridge with a new one. The applicator has a disengagement element 223 and a toothed ring 224, which is prevented from rotating within the housing. The disengagement element 223 is rotatably connected to a button sleeve 216A, and the disengagement element 223 is connected to the toothed ring 224 in such a way that the disengagement element 223 can be rotated in one direction relative to the toothed ring 224. During dosage setting, the disengagement element rotates together with the button sleeve 216A. Disengagement of the cartridge housing from the housing causes the spring 219 to extend and the disengagement element 223 to separate from the button sleeve 216A. The button sleeve 216A can then rotate freely, allowing the piston rod 203 to be screwed back into the housing. Simultaneously, the threaded shaft 221 is moved to its initial position, thereby allowing the final dosage blocking mechanism to be reset.

Claims

1. A drive mechanism for a drug applicator used to deliver a dose of drug, the drive mechanism comprising: Dosage setting component (N). Knob (1) A rotatable but non-axially translational clutch element (2), said clutch element (2) being rotatably connected to the knob (1) and cooperating with the dose setting assembly (N), A rotatable piston rod (3) having external threads (3.2) is located inside the clutch element (2). Drive element (4) and drive spring (5). in, When the dosage is set by means of the knob (1), the clutch element (2) is rotated, causing the drive spring (5) to be loaded, while the drive element (4) and the piston rod (3) remain stationary. When the dosage is delivered, the drive spring (5) is released, causing the drive element (4) to rotate together with the piston rod (3), which translates axially in the distal direction. in, The piston rod (3) is hollow and has an internal thread (3.3). A shaft (21) is located inside the piston rod (3) and has an external thread (21.2) for engaging with the internal thread (3.3) of the piston rod (3). The shaft (21) is rotatably connected to the clutch element (2) such that during the setting of each subsequent dose, the shaft (21) rotates relative to the piston rod (3) and moves axially in the proximal direction, while during the delivery of the dose, the shaft (21) is stationary relative to the piston rod (3). The total translation of the shaft (21) relative to the piston rod (3) caused by setting a limited number of doses is limited by means of a blocking element (B) located on the piston rod and the shaft, respectively.

2. The mechanism according to claim 1, characterized in that, The shaft (21) is rotatably engaged with the clutch element (2) by means of a longitudinal spline.

3. The mechanism according to claim 1 or 2, characterized in that, The blocking element (B) includes a protrusion (3.4) on the internal thread of the piston rod (3) and a protrusion (2.1) on the external thread of the shaft (21), and the blocking element (B) is adapted to block the rotation of the piston rod (3) relative to the shaft (21).

4. The mechanism according to claim 1, characterized in that, The drive element (4) has an orifice (4.1) with a non-circular cross-section, and the piston rod (3) has a cross-section with a non-circular profile corresponding to the orifice (4.1) of the drive element (4).

5. A drug applicator for delivering a dose of drug, the drug applicator comprising: Shell (8) A cartridge case (9) is provided, which is adapted to receive a cartridge containing a drug. Dosage setting component (N). Knob (1) A rotatable but non-axially translational clutch element (2), said clutch element (2) being rotatably connected to the knob (1) and cooperating with the dose setting assembly (N), A rotatable piston rod (3) having external threads (3.2) is located inside the clutch element (2). Drive element (4) and drive spring (5). in, When the dosage is set by means of the knob (1), the clutch element (2) is rotated, causing the drive spring (5) to be loaded, while the drive element (4) and the piston rod (3) remain stationary. When the dosage is delivered, the drive spring (5) is released, causing the drive element (4) to rotate together with the piston rod (3), which moves axially in the distal direction. in, The piston rod (3) is hollow and has an internal thread (3.3), and a shaft (21) is located inside the piston rod (3). The shaft (21) has an external thread (21.2) for engaging with the internal thread (3.3) of the piston rod (3). The shaft (21) is rotatably engaged with the clutch element (2) such that during the setting of each subsequent dose, the shaft (21) rotates relative to the piston rod (3) and moves axially in the proximal direction, while during the delivery of the dose, the shaft (21) is stationary relative to the piston rod (3). The total translation of the shaft (21) relative to the piston rod (3) caused by setting a limited number of doses is limited by means of a blocking element (B) located on the piston rod (3) and the shaft (21), respectively.

6. The applicator according to claim 5, characterized in that, The drive element (4) has an orifice (4.1) with a non-circular cross-section, and the piston rod (3) has a cross-section with a non-circular profile corresponding to the orifice (4.1) of the drive element.

7. The applicator according to claim 5 or 6, characterized in that, The drive element (4) is releasably connected to the dose setting component (N).

8. The applicator according to claim 5, characterized in that, The blocking element (B) includes a protrusion (3.4) on the internal thread of the piston rod (3) and a protrusion (2.1) on the external thread of the shaft (21), and the blocking element (B) is adapted to block the rotation of the piston rod (3) relative to the shaft (21).

9. The applicator according to claim 5, 6, or 8, characterized in that, The applicator includes an indicator mechanism (W) comprising a control sleeve (13), a scale sleeve (12), and a control nut (14). The control sleeve (13) has an external thread for engaging with the control nut (14), which is prevented from rotating within the housing (8) and is axially movable within the housing (8). The control nut (14) also axially engages with the scale sleeve (12), which moves along a spiral path during dose setting and dose correction.

10. The applicator according to claim 9, characterized in that, The indicator (W) includes an indicator window (9.3) that displays the currently set dose.

11. The applicator according to claim 5, 6, or 8, characterized in that, The drive spring (5) is a torsion spring.

12. The applicator according to claim 7, characterized in that, The drive spring (5) is a torsion spring.

13. The applicator according to claim 9, characterized in that, The drive spring (5) is a torsion spring.

14. The applicator according to claim 10, characterized in that, The drive spring (5) is a torsion spring.

15. The applicator according to claim 5, 6, or 8, characterized in that, The applicator includes a release mechanism (Z) adapted to be in a locked state or an unlocked state. The release mechanism (Z) includes an external activation element (16), wherein the drive element (4) is not able to rotate when the release mechanism (Z) is in the locked state, and the drive element (4) is able to rotate when the release mechanism (Z) is in the unlocked state. The release mechanism (Z) is adapted to be switched from the locked state to the unlocked state by a user.

16. The applicator according to claim 7, characterized in that, The applicator includes a release mechanism (Z) adapted to be in a locked state or an unlocked state. The release mechanism (Z) includes an external activation element (16), wherein the drive element (4) is not able to rotate when the release mechanism (Z) is in the locked state, and the drive element (4) is able to rotate when the release mechanism (Z) is in the unlocked state. The release mechanism (Z) is adapted to be switched from the locked state to the unlocked state by a user.

17. The applicator according to claim 9, characterized in that, The applicator includes a release mechanism (Z) adapted to be in a locked state or an unlocked state. The release mechanism (Z) includes an external activation element (16), wherein the drive element (4) is not able to rotate when the release mechanism (Z) is in the locked state, and the drive element (4) is able to rotate when the release mechanism (Z) is in the unlocked state. The release mechanism (Z) is adapted to be switched from the locked state to the unlocked state by a user.

18. The applicator according to claim 10, characterized in that, The applicator includes a release mechanism (Z) adapted to be in a locked state or an unlocked state. The release mechanism (Z) includes an external activation element (16), wherein the drive element (4) is not able to rotate when the release mechanism (Z) is in the locked state, and the drive element (4) is able to rotate when the release mechanism (Z) is in the unlocked state. The release mechanism (Z) is adapted to be switched from the locked state to the unlocked state by a user.

19. The applicator according to claim 11, characterized in that, The applicator includes a release mechanism (Z) adapted to be in a locked state or an unlocked state. The release mechanism (Z) includes an external activation element (16), wherein the drive element (4) is not able to rotate when the release mechanism (Z) is in the locked state, and the drive element (4) is able to rotate when the release mechanism (Z) is in the unlocked state. The release mechanism (Z) is adapted to be switched from the locked state to the unlocked state by a user.

20. The applicator according to claim 12, characterized in that, The applicator includes a release mechanism (Z) adapted to be in a locked state or an unlocked state. The release mechanism (Z) includes an external activation element (16), wherein the drive element (4) is not able to rotate when the release mechanism (Z) is in the locked state, and the drive element (4) is able to rotate when the release mechanism (Z) is in the unlocked state. The release mechanism (Z) is adapted to be switched from the locked state to the unlocked state by a user.

21. The applicator according to claim 13, characterized in that, The applicator includes a release mechanism (Z) adapted to be in a locked state or an unlocked state. The release mechanism (Z) includes an external activation element (16), wherein the drive element (4) is not able to rotate when the release mechanism (Z) is in the locked state, and the drive element (4) is able to rotate when the release mechanism (Z) is in the unlocked state. The release mechanism (Z) is adapted to be switched from the locked state to the unlocked state by a user.

22. The applicator according to claim 14, characterized in that, The applicator includes a release mechanism (Z) adapted to be in a locked state or an unlocked state. The release mechanism (Z) includes an external activation element (16), wherein the drive element (4) is not able to rotate when the release mechanism (Z) is in the locked state, and the drive element (4) is able to rotate when the release mechanism (Z) is in the unlocked state. The release mechanism (Z) is adapted to be switched from the locked state to the unlocked state by a user.

23. The applicator according to claim 15, characterized in that, The external activation element (16) includes a trigger located on the side wall of the housing (8), the trigger being blocked from rotation and capable of axial translation.

24. The applicator according to claim 16, characterized in that, The external activation element (16) includes a trigger located on the side wall of the housing (8), the trigger being blocked from rotation and capable of axial translation.

25. The applicator according to claim 17, characterized in that, The external activation element (16) includes a trigger located on the side wall of the housing (8), the trigger being blocked from rotation and capable of axial translation.

26. The applicator according to claim 18, characterized in that, The external activation element (16) includes a trigger located on the side wall of the housing (8), the trigger being blocked from rotation and capable of axial translation.

27. The applicator according to claim 19, characterized in that, The external activation element (16) includes a trigger located on the side wall of the housing (8), the trigger being blocked from rotation and capable of axial translation.

28. The applicator according to claim 20, characterized in that, The external activation element (16) includes a trigger located on the side wall of the housing (8), the trigger being blocked from rotation and capable of axial translation.

29. The applicator according to claim 21, characterized in that, The external activation element (16) includes a trigger located on the side wall of the housing (8), the trigger being blocked from rotation and capable of axial translation.

30. The applicator according to claim 22, characterized in that, The external activation element (16) includes a trigger located on the side wall of the housing (8), the trigger being blocked from rotation and capable of axial translation.

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