Medication injection device

Abstract

The invention relates to a drug injection device comprising a cartridge housing accommodating a drug cartridge, a dose setting mechanism and a dose delivery mechanism. The dose setting mechanism comprises a dose setting service member arranged to rotate about said longitudinal axis during drug dose setting. The dose setting mechanism further comprises a final dose setting arrangement to prevent a user from setting a drug dose larger than the remaining drug amount in the cartridge after at least one previous drug dose delivery. The final dose setting arrangement comprises a pinion and a rack, the pinion being arranged coaxially with said longitudinal axis in a fixed axial position relative to the cartridge housing and arranged to rotate about the longitudinal axis together with the dose setting service member during drug dose setting, the rack being movable in a direction parallel to the longitudinal axis when the pinion is rotated. The pinion and the rack have mutually abutting members arranged to abut against each other and prevent further rotation of the pinion after the rack has been moved an axial length related to a predetermined drug amount.

Description

Technical Field

[0001] This invention relates to a drug injection device.

[0002] More specifically, the present invention relates to a drug injection device that allows a user to set a desired dose of a predetermined amount of drug contained in a cartridge and deliver the previously set dose to the injection site. This setting and delivery operation can be repeated until the entire amount of drug contained in the cartridge has been delivered. Background Technology

[0003] Examples of the above-mentioned drug injection devices are described in DE202012001411U1 and US8512296B2. These devices have been praised by users for being compact and user-friendly.

[0004] US10569024B2 and US2019 / 0366007A1 disclose drug injection devices that, in addition to including components configured to allow a user to set a desired dose before delivery, also include components configured to prevent the user from setting a dose exceeding the remaining dose in the cartridge after one or more doses have been delivered. Specifically, in US10569024B2, this overdose is prevented by providing a boss between a stop member fixed to a piston rod and a stop member fixed to a nut member configured to move along the piston rod; however, in US2019 / 0366007A1, the aforementioned overdose is prevented by providing a boss between a nut that moves along a drive shaft and a worm gear fixed to the end of the drive shaft. Summary of the Invention

[0005] The applicant took into account the benefit of preventing users from setting doses greater than the currently available dose in the cartridge.

[0006] Therefore, the applicant designed a drug injection device in which the benefit is achieved through a technical solution that differs from those existing technologies.

[0007] Therefore, the present invention relates to a drug injection device, comprising:

[0008] - A cartridge case, which extends along a longitudinal axis and is configured to contain a cartridge containing a predetermined amount of medicine;

[0009] - Dosage setting mechanism, which is set to set the dosage of drug to be delivered from the cartridge;

[0010] - A dose delivery mechanism configured to deliver a drug dose set by a dose setting mechanism;

[0011] The dosage setting mechanism includes:

[0012] - Dosage setting service component, which is configured to rotate about the longitudinal axis during drug dosage setting;

[0013] - A final dose setting device configured to prevent a user from setting a dose greater than the remaining amount of medication in the cartridge after at least one previous dose delivery, wherein the final dose setting device includes:

[0014] - A pinion, which is arranged coaxially with the longitudinal axis at a fixed axial position relative to the cartridge housing, and is configured to rotate together with the dosage setting service member about the longitudinal axis during drug dosage setting;

[0015] - A rack that meshes with a pinion, which is movable longitudinally parallel to the longitudinal axis as the pinion rotates;

[0016] The pinion and rack have abutting members that are arranged to abut each other after the rack has moved an axial length related to a predetermined amount of medicine, and to prevent the pinion from rotating further.

[0017] In this specification and the presented claims, the terms "axial" and the corresponding term "along the axial direction" are used to refer to the longitudinal direction of the injection device, which corresponds to the longitudinal direction of the cartridge housing, while the terms "radial" and the corresponding term "along the radial direction" are used to refer to any direction perpendicular to the aforementioned longitudinal direction. In particular, when referring to a component that rotates about an axis, the terms "radial" and "along the radial direction" are used to indicate any direction perpendicular to that axis.

[0018] The longitudinal direction from the user's hand operating the injection device during the injection procedure toward the injection site (e.g., the patient's skin) is also referred to herein as the "distal direction," while the longitudinal direction from the injection site toward the user's hand operating the injection device during the injection procedure is also referred to herein as the "proximal direction."

[0019] The term "correlated" is used to describe a relationship of interdependence between two parameters, such as two linear dimensions, or a linear dimension and a volume. This means that the quantity, size, or range of the first parameter is a function of (or varies depending on) the quantity, size, or range of the second parameter, and vice versa.

[0020] The applicant has realized that a pinion-rack connection structure is provided in the drug injection device, wherein, during each dose setting operation, when the dose setting service component drives the pinion to rotate, axial movement of the pinion is prevented relative to the dose setting service component, and the rack moves relative to the cartridge housing due to meshing with the pinion. During any further dose setting operation after the first dose setting operation and the first dose delivery operation, the axial length of the rack movement of the corresponding portion—which depends on the specific dose actually set and delivered each time—makes the total axial length of the rack movement from the first dose setting and delivery operation to the last dose setting and delivery operation dependent on the maximum dispensable amount of drug provided in the cartridge.

[0021] Therefore, the applicant considered that by providing respective abutting members in the pinion and rack, the respective abutting members being configured to abut against each other when the rack has reached the aforementioned total axial length, further rotation of the pinion is prevented (and thus further rotation of the dose setting service member is also prevented), so that during any further dose setting operation after the first dose delivery operation, the dose is equal to the dose volume currently present in the cartridge, thereby preventing the user from setting a dose greater than the still available dose.

[0022] The preferred features of the drug injection device of the present invention are disclosed below, each of which is provided individually or in combination with other preferred features.

[0023] Preferably, the injection device is pen-shaped to allow users to easily carry, pick up, store, and operate the injection device.

[0024] The injection device of the present invention is compact and independent of the provision of a final dose setting device. For example, the size of the injection device may be the same as that of the injection devices of DE202012001411U1 and US8512296B2, which do not include any final dose setting device.

[0025] The injection device can be reusable or disposable, with disposable being the preferred option.

[0026] Preferably, the dosage setting service component does not move along the longitudinal direction during drug dosage setting.

[0027] Preferably, the dose setting service component is configured to move along the longitudinal direction toward the cartridge housing during drug dosing delivery (thereby along the distal direction). Therefore, the dose setting mechanism and the dose delivery mechanism share the same structural component (i.e., the dose setting service component) to facilitate the compactness of the injection device.

[0028] Preferably, the dosage setting service component does not rotate about the longitudinal axis during drug dosage delivery.

[0029] The rotational movement of the dose setting service component during dose setting operations and the axial movement of the dose setting service component during dose delivery operations allow these two operations to be structurally and functionally separated from each other, while sharing the same structural component, namely the dose setting service component.

[0030] Preferably, the rack has a predetermined axial dimension, which is related to the axial length by which the dosage setting service member moves to deliver a predetermined amount of medication.

[0031] This specific configuration allows for the selection of a particular axial dimension of the rack based on the specific amount of medication contained in the cartridge to be used, thereby ensuring that the effective operation of the injection device is identical when using a new cartridge with the same amount of medication.

[0032] Preferably, before setting the first drug dose, the pinion is located at the first free end of the rack near the cartridge housing.

[0033] Preferably, after the final drug dosage is set, the pinion is located at the second free end of the rack opposite to the first free end of the rack.

[0034] Thus, the axial length of the rack from the first dose setting and delivery operation to the last dose setting and delivery operation is equal to the axial dimension of the rack.

[0035] Preferably, the abutting components include a first rotating end stop associated with the pinion.

[0036] Preferably, the abutting components include a second rotating end stop associated with the rack.

[0037] The term "rotating end stop" is used herein to refer to a component that abuts against the other component when at least one of two components rotates about its respective axis of rotation.

[0038] In the injection device of the present invention, the provided rotating end stop member allows for effective prevention of pinion rotation during the last dose setting operation, and correspondingly prevents axial movement of the rack.

[0039] Preferably, the first rotating end stop member is associated with a face of the pinion located on the opposite side of the cartridge case.

[0040] Preferably, the second rotating end stop member is arranged at the second free end of the rack.

[0041] Preferably, the rack is slidably connected to the housing of the drug injection device.

[0042] Preferably, the rack includes an axial guide groove slidably coupled to an axial guide rail disposed on the inner surface of the housing of the drug injection device. This axial coupling allows for easy and precise installation of the rack within the housing and provides an auto-alignment feature that further improves the axial movement of the rack relative to the housing.

[0043] Preferably, the pinion is arranged between the rack and at least one rib, which is formed on the inner surface of the housing on the opposite side to the rack. This rib acts as a limiter for the radial movement of the pinion, preventing it from disengaging from the rack upon impact.

[0044] Preferably, two ribs are provided on the inner surface of the housing on the opposite side relative to the radial plane of the pinion that coincides with the longitudinal center plane of the rack. This arrangement provides a more effective contrast for any possible disengagement movement of the pinion relative to the rack.

[0045] Preferably, the dose setting service component has at least one plane, and the pinion has at least one planar profile portion coupled to the at least one plane of the dose setting service component. This allows for effective rotational coupling between the pinion and the dose setting service component during dose setting operation, and effective sliding coupling between the pinion and the dose setting service component during dose delivery operation.

[0046] In a preferred embodiment, the dosage setting service component is a piston rod extending along the longitudinal axis.

[0047] In these embodiments, preferably, the pinion has a central bore coupled to the piston rod, and the at least one of the planar profiles is defined by a surface portion of the central bore. Attached Figure Description

[0048] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, which are for illustrative purposes and not for limiting purposes. In these drawings:

[0049] Figure 1 A schematic perspective view of an embodiment of the drug injection device according to the present invention;

[0050] Figure 2 Is Figure 1 Obtained from the section marked A in the middle Figure 1 A schematic cross-sectional view of the injection device;

[0051] Figure 3 Is Figure 1 A schematic perspective view of the final dose setting device provided in the injection device in its first setting configuration;

[0052] Figure 4 and Figure 5 yes Figure 4 The final dose setting device is in Figure 4 Schematic perspective views of two different configurations of the device shown;

[0053] Figure 6 yes Figure 4 The final dose setting device is in Figure 5 A magnified perspective view with the same operating configuration, but from the opposite angle;

[0054] Figure 7 yes Figures 3 to 6 A perspective view of the components of the final dose setting device. Detailed Implementation

[0055] Figure 1 and Figure 2 An embodiment of the drug injection device 10 according to the present invention is shown.

[0056] The injection device 10 is pen-shaped and extends along the central longitudinal axis X, such as... Figure 2 As shown.

[0057] The injection device 10 includes a body 12 and a cap 14, the cap 14 being detachably connected to the body 12 at a first free end 12a of the body 12.

[0058] When the body 12 is coupled to the body 12, both the body 12 and the cap 14 extend coaxially with the longitudinal axis X.

[0059] The cartridge housing 16, extending coaxially with the longitudinal axis X, is detachably coupled to the body 12 at its first free end 12a so that it is received within the cap 14 when coupled to the body 12. The cartridge housing 16 is configured to receive a cartridge 17 containing a predetermined amount of medicine to be delivered.

[0060] The main body 12 includes an outer shell 20, which is preferably substantially cylindrical.

[0061] A dose setting mechanism 30 and a dose delivery mechanism 35 are provided inside the housing 20. The dose setting mechanism 30 is configured to allow a user to set the dose of drug to be delivered from the cartridge 17, while the dose delivery mechanism 35 is configured to allow a user to deliver the dose of drug set by the dose setting mechanism 30.

[0062] Since various dose setting structures 30 and dose delivery structures 35 can be anticipated in the injection device 10 of the present invention, they will not be described in detail here. For example, the dose setting mechanism 30 and the dose delivery mechanism 35 can be of the same type described in DE202012001411U1 and US 8512296B2. In this particular case, and as will become clearer from the following description, the dose setting mechanism 30 of the injection device 10 differs from one of the devices in these two prior art documents in that it also includes a final dose setting device 60, such as... Figure 2 As shown, and as referenced below. Figure 3 A more detailed description up to 6.

[0063] The dose setting mechanism 30 and the dose delivery mechanism 35 share a knob 40 located at the second free end 12b of the main body 12 opposite to its first free end 12a, and a dose setting service component arranged inside the housing 20, coaxial with the longitudinal axis X, and having a free end operably connected to the knob 40.

[0064] In the embodiment shown herein, the aforementioned dose setting service component is a piston rod 44 extending coaxially with the longitudinal axis X.

[0065] The knob 40 is configured to be driven by the user rotating clockwise and counterclockwise around the longitudinal axis X to drive the dose setting mechanism 30, and to be driven by the user pushing along the longitudinal (or distal) direction P parallel to the longitudinal axis X to drive the dose delivery mechanism 35.

[0066] The rotation here refers to the rotation of the injection device 10 as follows: Figure 2 When viewing the right side view of the injection device 10 during positioning, that is, when viewing the knob 40 from the side opposite to the side where the cartridge 17 is located, the knob can be rotated clockwise or counterclockwise.

[0067] A clutch device 50 is provided inside the housing 20 to switch the injection device 10 between a dose setting configuration and a dose delivery configuration. In the dose setting configuration, the clutch device 50 is operably connected to a knob 40 and operably connected to a dose setting mechanism 30. In the dose delivery configuration, the clutch device 50 is operably disengaged from the knob 40 and the knob 40 is operably connected to the dose delivery mechanism 35.

[0068] In the dosage setting configuration, the piston rod 44 rotates about the longitudinal axis X and is prevented from moving along the longitudinal direction P, while in the dosage delivery configuration, the piston rod 44 moves along the longitudinal direction P and is prevented from rotating about the longitudinal axis X.

[0069] The piston rod 44 is coupled to the dose setting sleeve 46, which rotates about the longitudinal axis X in both the dose setting and dose delivery configurations. In the dose setting configuration, the rotation of the dose setting sleeve 46 and the piston rod 44 is driven by a clutch device 50, which in turn is driven by a knob 40 rotating about the longitudinal axis X; however, in the dose delivery configuration, the rotation of the dose setting sleeve 46 is generated by an axial thrust applied by the user to the knob 40 along the longitudinal direction P.

[0070] Dosage setting sleeve 46 includes an outer surface 47 (e.g., Figure 1 As shown), it has multiple numbers (or usually labels, not shown), each number being associated with a corresponding dose for all settable doses.

[0071] like Figure 1 As shown, a display window 20a is formed in the housing 20.

[0072] The user rotates knob 40 clockwise or counterclockwise until a value related to the desired dose to be set and delivered is displayed on display window 20a, thus providing the user with a visual indication of the actual dose set. During the dose setting operation, if the user's initial dose setting is greater than or less than the desired dose, rotation in both directions allows the user to set the desired dose.

[0073] After setting the desired dose, the user pushes knob 40 longitudinally P to deliver the dose. Axial movement of knob 40 causes clutch device 50 to switch the injection device 10 from the dose setting configuration to the dose delivery configuration. In the latter configuration, knob 40 is prevented from rotating.

[0074] Stop 55 (e.g.) Figure 2 (As shown) Coupled to the free end of piston rod 44 opposite to knob 40. Stop 55 is initially inserted into cartridge 17, located within cartridge housing 16, at the free end 12a of cartridge 17 positioned relative to the free end 12a of body 12. Due to axial movement of knob 40 during dosage delivery, causing axial movement of piston rod 44, stop 55 moves longitudinally P towards the relative free end of cartridge 17 within cartridge 17, thereby forcing the desired dose to be discharged from cartridge 17 at the relative free end of cartridge 17.

[0075] The final dose setting device 60 is arranged between the dose setting sleeve 46 and the cartridge housing 16 to prevent the user from setting a dose greater than the remaining dose in the cartridge 17 after the previous dose / several doses have been delivered.

[0076] like Figures 3 to 7As shown, the final dose setting device 60 includes a pinion 62 and a rack 66. The pinion 62 is coupled inside the housing 20 and located at a fixed axial position of the housing 20. The rack 66 meshes with the pinion 62 and is slidably coupled to the inner surface of the housing 20.

[0077] like Figure 5 As shown, the fixed axial position of the pinion 62 within the housing 20 is defined by positioning the collar 61a formed at the free end of the spindle 61 of the pinion 62 against the boss surface 21 (the boss surface 21 protrudes radially inward from the inner surface of the housing 20), and positioning the free end portion 61b of the spindle 61 (or the collar 61a) against another boss surface 22 corresponding to the boss (the boss surface 22 protrudes radially inward from the inner surface of the housing 20).

[0078] The pinion 62 is arranged coaxially with the longitudinal axis X and includes a central hole 64 coupled to the piston rod 44.

[0079] The coupling between the pinion 62 and the piston rod 44 causes the piston rod 44 to drive the pinion 62 to rotate during the dose setting operation; while during the dose delivery operation, the piston rod 44 slides axially within the central hole 64.

[0080] To allow rotational coupling between the pinion 62 and the piston rod 44, the piston rod 44 has a longitudinal plane 45, and the central bore 64 has a planar profile portion 65 coupled to the longitudinal plane 45.

[0081] To prevent the pinion 62 from detaching from the rack 66 upon impact, two ribs 63 ( Figure 3 Only one of them can be seen in the middle) is formed on the inner surface of the housing 20 and is located on the portion of the latter that is disposed on the opposite side of the rack 66, so that the pinion 62 is located between the rib 63 and the rack 66. The rib 63 is preferably located on the opposite side of the radial plane that coincides with the longitudinal intermediate plane of the rack 66 relative to the pinion 62.

[0082] Since the pinion 62 is located in a fixed axial position within the housing 20, when the pinion 62 rotates, the rack 66 moves longitudinally P. Preferably, clockwise rotation of the pinion 62 causes the rack 66 to move axially toward the cartridge housing 16, i.e., in the distal direction; while counterclockwise rotation of the pinion 62 causes the rack 66 to move axially toward the dosage setting sleeve 46, i.e., in the proximal direction.

[0083] The axial movement of the rack 66 is achieved by the sliding coupling between the axial guide groove 67 formed in the rack 66 and the axial guide rail 25 provided on the inner surface of the housing 20. The axial guide groove 67 extends in the longitudinal direction X, and the axial guide rail 25 also extends in the longitudinal direction X.

[0084] The rack 66 is designed such that during all dose setting operations performed to deliver the maximum dispensable amount of medicine initially contained in the cartridge 17, the axial length of the movement of the rack 66 is related to the total amount of medicine.

[0085] The rack 66 includes a free end 66a near the cartridge 17 and an opposite free end 66b, such as... Figure 5 and 7 As shown.

[0086] In particular, the rack 66 has a predetermined axial dimension that is equal to or proportional to the axial length of the piston rod 44 that moves to deliver the entire amount of the drug.

[0087] like Figure 6 As shown, the pinion 62 has a rotating end stop member 70 in its surface 62a, which faces the second free end 66b of the rack 66. The rack 66 has a corresponding rotating end stop member 80 at its second free end 66b.

[0088] During the rotation of the pinion 62, and therefore during the axial movement of the rack 66, further rotation of the pinion 62 and thus further axial movement of the rack 66 are prevented when the rotating end stop member 70 abuts against the rotating end stop member 80.

[0089] During operation, the injection device 10 is initially in the dose setting configuration, and the user rotates the knob 40 to set the desired dose to be delivered. During this initial dose setting operation, the knob 40 moves axially in the proximal direction while being rotated. Figure 3 As shown, rack 66 is initially positioned in a first position such that pinion 62 is located at the free end 66a of rack 66, and during the first dose setting operation, rack 66 moves along the longitudinal direction P (i.e., the distal direction) from this first position toward cartridge 17, the axial length of which depends on the specific dose actually set. Once the first dose setting operation is completed, rack 66 is located in a second axial position closer to cartridge 17.

[0090] After this initial dose setting operation, the user pushes the knob 40 along the longitudinal direction P toward the cartridge 17 to deliver the previously set dose. During this initial dose delivery operation, the rack 66 does not move away from the previously reached second axial position.

[0091] After this first dose delivery operation, when the user wishes to set a new desired dose, the user rotates knob 40 to set such a new desired dose. During this new dose setting operation, piston rod 44 remains in the axial position reached at the end of the first dose delivery operation until the new dose setting operation ends, while rack 66 moves toward cartridge 17 by a corresponding axial length, depending on the actual new desired dose set.

[0092] Once this new dosage setting operation is complete, rack 66 is in a new axial position closer to cartridge 17 than its previous second axial position. An example of the new axial position reached by rack 66 is shown below. Figure 4 As shown.

[0093] The user can continue to perform the above dosage setting and dosage delivery operations until all the drug initially contained in cartridge 17 has been delivered.

[0094] Following one or more prior dose setting and dose delivery operations, when a new dose setting operation (referred to herein as the final dose setting operation) results in a dose to be set that is the same as or nearly the same as the amount of drug remaining in cartridge 17, rack 66 reaches an axial position such that pinion 62 is positioned at the second free end 66b of rack 66 opposite the first free end 66a. An example of such an axial position is as follows: Figure 5 and Figure 6 As shown.

[0095] Therefore, from the first dose setting and delivery operation to the last dose setting and delivery operation, the rack 66 moves toward the cartridge 17 by a total axial length, which depends on the total amount of medicine initially supplied in the cartridge 17.

[0096] The user can set (and subsequently deliver) any desired dose until the rotating end stop member 70 of the pinion 62 and the rotating end stop member 80 of the rack 66 abut against each other. This situation is very close to... Figure 6 The situation shown. In particular, relative to Figure 6 As shown, after the pinion 62 rotates slightly further, the rack 66 moves axially a short distance, reaching the desired position. Figure 6 The situation is shown.

[0097] If the user attempts to set a dose greater than the current and actual amount of medicine available in cartridge 17, the rotating end stop member 70 of pinion 62 abuts against the rotating end stop member 80 of rack 66, thus preventing further relative movement between pinion 62 and rack 66, thereby preventing the user from setting such a dose.

[0098] Therefore, users can set the dose equal to the current and actual available amount of medicine in cartridge 17 as the final dose.

[0099] Of course, those skilled in the art can make many modifications and alterations to the invention described above to meet specific and possible requirements, all of which fall within the scope of protection defined by the present claims.

Claims

1. A drug injection device (10), comprising: - A cartridge case (16) extending along a longitudinal axis (X) and configured to house a cartridge case (17) containing a predetermined amount of medicine; - Dosage setting mechanism (30), the dosage setting mechanism (30) is configured to set the dosage of the drug to be delivered from the cartridge (17); - A dose delivery mechanism (40) configured to deliver a drug dose set by the dose setting mechanism (30); The dosage setting mechanism (30) includes: - Dosage setting service component (44); - A final dose setting device (60), the final dose setting device (60) being configured to prevent a user from setting a drug dose greater than the remaining amount of drug in the cartridge (17) after at least one previous drug dose delivery, wherein the final dose setting device (60) comprises: - A pinion (62), which is arranged coaxially with the longitudinal axis (X) at a fixed axial position relative to the cartridge housing (16) and is configured to rotate together with the dosage setting service member (44) about the longitudinal axis (X) during drug dosage setting; - A rack (66) meshing with the pinion (62) is movable along a longitudinal direction (P) parallel to the longitudinal axis (X) when the pinion (62) rotates; The pinion (62) and the rack (66) have mutually abutting members (70, 80) configured to abut against each other after the rack (66) has moved an axial length related to a predetermined amount of medicine, and to prevent the pinion (62) from rotating further. The dosage setting service component (44) and the pinion (62) are connected to each other, such that: During drug dosage setting, the dosage setting service component (44) does not move along the longitudinal direction (P), but rotates about the longitudinal axis (X), thereby dragging the pinion (62) to rotate; During drug delivery, the dose setting service component (44) and the pinion (62) do not rotate, and the dose setting service component (44) moves along the longitudinal direction (P) toward the cartridge housing (16).

2. The drug injection device (10) according to claim 1, wherein, The rack (66) has a predetermined axial dimension, which is related to the axial length by which the dose setting service member (44) moves to deliver the predetermined dose.

3. The drug injection device (10) according to claim 1, wherein, Before the first drug dose is set, the pinion (62) is located at the first free end (66a) of the rack (66) near the cartridge housing (16); and after the last drug dose is set, the pinion (62) is located at the second free end (66b) of the rack (66) opposite the first free end (66a) of the rack (66).

4. The drug injection device (10) according to claim 1, wherein, The abutting components (70, 80) include a first rotating end stop (70) associated with the pinion (62) and a second rotating end stop (80) associated with the rack (66).

5. The drug injection device (10) according to claim 4, wherein, Before the first drug dose is set, the pinion (62) is located at the first free end (66a) of the rack (66) near the cartridge case (16); after the last drug dose is set, the pinion (62) is located at the second free end (66b) of the rack (66) opposite to the first free end (66a), wherein the first rotating end stop member (70) is associated with a face (62a) of the pinion (62) located on the opposite side relative to the cartridge case (16), and the second rotating end stop member (80) is located at the second free end (66b) of the rack (66).

6. The drug injection device (10) according to claim 1, wherein, The rack (66) is slidably coupled to the housing (20) of the drug injection device (10).

7. The drug injection device (10) according to claim 6, wherein, The rack (66) includes an axial guide groove (67) that is slidably coupled to an axial guide rail (25) which is disposed on the inner surface of the housing (20) of the drug injection device (10).

8. The drug injection device (10) according to claim 6, wherein, The pinion (62) is disposed between the rack (66) and at least one rib (63), the at least one rib (63) being formed on the inner surface of the housing (20) on the opposite side to the rack (66).

9. The drug injection device (10) according to claim 1, wherein, The dose setting service component (44) has at least one plane (45), and the pinion (62) has at least one planar profile portion (65), the at least one planar profile portion (65) being coupled to the at least one plane (45) of the dose setting service component (44).

10. The drug injection device (10) according to claim 1, wherein, The dose setting service component (44) is a piston rod (44) extending along the longitudinal axis (X).

11. The drug injection device (10) according to claim 10, wherein, The dose setting service component (44) has at least one plane (45), and the pinion (62) has at least one planar profile portion (65) coupled to the at least one plane (45) of the dose setting service component (44); wherein the pinion (62) has a central hole (64) coupled to the piston rod (44), and the at least one planar profile portion (65) is defined by a surface portion of the central hole (64).

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