Injection device with dose setting member

Abstract

An injection device (10) comprising: a barrel (12); a plunger rod (14) received in the barrel (12) and comprising N radial protrusions (14A, 14B) arranged successively at different positions along an axis (X) of the barrel (12), where N is an integer greater than or equal to 2; and a dose setting member (16) configured to be removably mounted on the barrel (12) and having N portions (16A, 16B) configured to axially abut sequentially against the N radial protrusions (14A, 14B), respectively, when the plunger rod (14) is axially pressed within the barrel (12), the dose setting member (16) being configured to be moved relative to the barrel (12) between N positions, where the nth radial protrusion (14A, 14B) axially faces the nth portion (16A, 16B) at the nth position, where n is an integer greater than or equal to 1 and less than or equal to N.

Description

[Technical field]

[0001] The present invention relates to injection devices, e.g. medical injection devices such as syringes. [Background technology]

[0002] Today's medical injection devices, such as prefilled syringes, are intended to contain and administer several doses of the same medical injection liquid, but are not always convenient for administering precise doses, such as small amounts (e.g., 1 ml). In addition, a high motive force is required to expel potential air bubbles contained in the medical injection device, which may result in poor administration accuracy of the injected fluid. For example, the injection devices disclosed by US Patent Application Publication No. 5,601,077, US Patent Application Publication No. 9,579,465, and US Patent Application Publication No. 2021 / 0196906 may be difficult to handle or have low accuracy. Furthermore, the structure of such devices may be very complicated. Summary of the Invention [Problem to be solved by the invention]

[0003] Thus, there is a need to provide a reliable, easy-to-use injection device that delivers an accurate dosage and / or exhibits simple construction. [Means for solving the problem]

[0004] An embodiment relates to an injection device including a barrel extending along an axis and defining a reservoir, the barrel including a proximal end and a distal end having an outlet, a plunger rod received within the barrel via the proximal end and configured to move along the axis relative to the barrel, the plunger rod including N radial protrusions arranged successively at different positions along the axis, N being an integer greater than or equal to 2, a dose setting member configured to be attached to the barrel and having N portions configured to be axially adjacent to the N radial protrusions respectively when the plunger rod is moved axially in a first direction (or distal direction) from the proximal end towards the distal end, the dose setting member configured to be moved relative to the barrel between the N positions, the nth radial protrusion axially facing the nth portion at the nth position, n being an integer greater than or equal to 1 and less than or equal to N.

[0005] Axial is the direction defined by the axis of the barrel. Radial is the direction perpendicular to the axis. Circumferential or azimuthal directions correspond to directions describing a ring around the axial direction. The three directions, axial, radial and azimuthal, correspond to directions defined by height, radius and angle in a cylindrical coordinate system, respectively. Additionally, upstream and downstream can be defined with respect to the direction of movement of the plunger rod to expel / deliver the contents of the reservoir when moved in a first direction.

[0006] The distal side is the side of the injection device from which the contents of the reservoir are ejected / delivered, and the proximal side is the side opposite the distal end along the axis and is typically the side that is handled by the user during injection.

[0007] Each nth radial projection may include one or more radially extending projections. Each nth portion may include one or more abutments / shoulders. One abutment / shoulder of the nth portion may be configured to cooperate with one or more projections of the nth radial projections. Some abutments / shoulders of the nth portion may be configured to cooperate with one or more projections of the nth radial projections.

[0008] The radial protrusions are arranged consecutively, i.e., arranged / ordered along the axis from the first radial protrusion (when the plunger rod is mounted in the reservoir) to the Nth radial protrusion, in other words, the nth radial protrusion is between the (n-1)th radial protrusion and the (n+1)th radial protrusion.

[0009] The portions may be arranged contiguously, but this is not required.

[0010] The N portions are configured to be axially adjacent to the N protrusions, respectively, i.e., the first protrusion is configured to be axially adjacent to the first radial protrusion and the second protrusion is configured to be axially adjacent to the second radial protrusion.

[0011] For example, the movement of the dose setting member between two successive positions can be a translation, a rotation, a combination thereof, and the like.

[0012] The plunger rod may be comprised of 2, 3, 4 etc. radial projections and the dose setting member may be comprised of the same number of portions, i.e. 2, 3, 4 etc., and may move between the same number of positions, i.e. 2, 3, 4 etc. In a first position, the first radial projection is axially opposite the first portion and in a second position, the second radial projection is axially opposite the second portion.

[0013] During a single full injection stroke of the plunger rod (i.e. in a first direction), the dose setting member is disposed in succession at first, second, third (if present) etc. positions, with the first, second, third (if present) etc. radial projections axially opposing successive first, second, third (if present) etc. portions. The partial stroke from the initial position of the plunger rod to the abutment of the first radial projection with the first portion corresponds to a first dose (which may be a priming dose), and the partial stroke from the first radial projection to the abutment of the second radial projection with the second portion corresponds to a second dose.

[0014] By moving the dose setting member between different positions a predetermined dose is pre-set, for example in the nth position the injection device is pre-set for the nth injection.

[0015] In other words, the dose setting member is initially placed in a first position. A first delivery (or priming) can then be performed by moving the plunger rod from the initial position (where the reservoir is full and no injection / delivery has yet taken place) until the first radial protrusion abuts against the first portion. The dose setting member can then be moved to a second position. A second delivery (or first injection) can then be performed by moving the plunger rod from the previous position (corresponding to the axial position of the plunger rod at the end of the first injection / delivery, i.e. the position where the first radial protrusion abuts against the first portion) until the second radial protrusion abuts against the second portion.

[0016] The configuration of the injection device allows the user to set the dose simply and reliably by simply moving the dose setting member relative to the reservoir, while the axial tightness of the radial projections and segments ensures a reliable stop means. In addition, the configuration of the radial projections and segments can provide a simple construction.

[0017] In some embodiments, the injection device can be configured such that the nth portion can only abut against the nth radial projection.

[0018] In some embodiments, the dose setting member may be configured to adopt at least one N+1 position, and the plunger rod is axially free relative to the dose setting member.

[0019] For example, when the dose setting member is placed at the N+1 position, the plunger rod can be moved after the Nth injection (when the Nth radial protrusion abuts the Nth portion) or in a second direction opposite to the first direction (or proximal direction) to perform the (N+1)th injection for aspirating / pumping the substance to be injected in the reservoir, e.g., liquid but not necessarily, through the outlet. Alternatively, the medical injector can be pre-filled with the substance to be injected. The injection device is composed of a single N+1 position or multiple N+1 positions, e.g., a first N+1 position for aspirating / pumping the substance to be injected and a second N+1 position for performing the (N+1)th injection. For example, the first N+1 position is an initial position before the 1st position (in this case, the first N+1 position can also be considered as the 0th position), and the second N+1 position is a final position after the Nth position.

[0020] In some embodiments, the dose setting member is removably attached to the barrel.

[0021] In such a configuration, an N+1 dose can be set, which corresponds to the final stroke of the plunger rod from the axial position of the plunger rod at the end of the Nth injection, i.e., from when the Nth radial projection abuts the Nth portion, until the plunger rod abuts a portion of the barrel, e.g., the bottom of a reservoir defined to be in fluid communication with the outlet.

[0022] In some embodiments, the dose setting member may be configured to move radially relative to the barrel between N positions.

[0023] Such radial movement is easy to achieve and can be positively confirmed by the user to ensure that the proper dose is set.

[0024] In some embodiments, the dose setting member may include a radially extending and radially open cutout that is taken into account when the dose setting member is mounted on the barrel and is configured to receive the barrel.

[0025] When the dose setting member is attached to the barrel, the cutout may extend in a plane perpendicular to the axis. The walls extending around or defining the cutout may define a general U-shape. The barrel and plunger rod may be introduced into the cutout via a hole in the U-shape, i.e., the open top of the "U-shape", and extend transversely to the plane in which the "U-shape" extends.

[0026] In some embodiments, the cutout portion can extend along a second axis, and the Nth portions are sequentially positioned at different locations along the second axis.

[0027] When the dose setter is attached to the barrel, the second axis may extend radially. The sections may be arranged / ordered from the first section to the Nth section along the second axis. In other words, the nth section may be between the (n-1)th section and the (n+1)th section.

[0028] In some embodiments, the radial extension of the tth radial protrusion may be greater than the radial extension of the (t-1)th radial protrusion and less than the radial extension of the (t+1)th radial protrusion, if any, where t is an integer greater than or equal to 2 and less than or equal to N.

[0029] In other words, the radial protrusions may be arranged in increasing order from a first radial protrusion to an Nth radial protrusion.

[0030] In some embodiments, all or a portion of the radial projection can have a radial extension that is smaller than the radius of the reservoir, which allows the radial projection to be inserted into the reservoir, into the barrel.

[0031] In some embodiments, each of the radial projections may have an annular shape having a radius, where the radius of the tth radial projection is greater than the radius of the (t-1)th radial projection and less than the radius of the (t+1)th radial projection, and where each segment, if any, defines an axial passage having a minimum radial length, where the minimum radial length of the tth segment is greater than the minimum radial length of the (t-1)th segment and less than the minimum radial length of the (t+1)th segment, and where t, if any, is an integer greater than or equal to 2 and less than or equal to N.

[0032] The annular shape of each radial projection may be continuous, i.e., annular, or discontinuous, e.g., a series of projections or annular portions arranged in an annular or circumferential direction. The radial projections may be arranged from the first radial projection to the Nth radial projection.

[0033] The minimum radial length of the tth portion may be greater than the diameter on the (t-1)th radial projection and less than the diameter of the tth radial projection. The minimum radial length may correspond to a short distance between two opposing walls that define the cutout and extend along the second direction at the tth position.

[0034] In some embodiments, the N portions may be arranged consecutively to have an overall staircase shape, with each portion forming a step in the staircase shape.

[0035] In some embodiments, at least one N+1 position, the dose setting member may define an axial passageway having a minimum radial length greater than the radius of the Nth radial projection.

[0036] In some embodiments, the (t-1)th radial projection may be axially closer to the distal end than the tth radial projection.

[0037] In some embodiments, the barrel may include a radially extending flange, the dose setting member being configured to be slidably mounted to the flange.

[0038] The dose setting member may have one or more grooves that receive all or part of the flange. For example, the flange may form a rib that slidably engages within the groove of the dose setting member. The flange may be of any shape, such as annular, rectangular or elliptical, diamond-shaped, square, oblong, or polygonal with acute or rounded angles.

[0039] In some embodiments, the flange can include a guiding portion configured to slidably guide the dose setting member and a retaining portion configured to maintain the dose setting member in any of the N positions.

[0040] The guide may be comprised of two radially opposing tongues, for example extending along the second axis of the cutout and radially guiding the dose setting member to translate along the second axis when the dose setting member is attached to the barrel.

[0041] For example, the retaining part may cooperate with the dose setting member by a snap fit, For example, the retaining part may form a ratchet configured to engage with a different complementary part of the dose setting member.

[0042] In some embodiments, the injection device may be a medical injector, which may be disposable and / or pre-filled.

[0043] In some embodiments, the injection device may include a removable spray nozzle.

[0044] In some embodiments, the injection device may include a vial adapter, which may be removable.

[0045] An embodiment also relates to a dose setting method for presetting a dose of an injection device prior to injection, the dose setting method comprising providing an injection device according to any one of the embodiments of the present disclosure and moving the dose setting member to any one of N positions such that the nth radial protrusion axially faces the nth portion.

[0046] In some embodiments, the dose setting member may be moved to an nth position to allow for an nth injection.

[0047] In some embodiments, the dose setting member may be removably attached to the barrel and the dose setting method may include removing the dose setting member to set the final dose.

[0048] In some embodiments, the dose setting member may be configured to adopt at least one N+1 position, the plunger rod being axially free relative to the dose setting member, and the dose setting method may comprise moving the dose setting member to any of the at least one N+1 position before setting a first dose for filling the injection device or after completion of the Nth dose to allow the injection device to be emptied.

[0049] An arrangement according to any one of the above embodiments may serve to provide a reliable, easy to use, and / or simple structure and method. [Brief description of the drawings]

[0050] The present disclosure and its advantages can be better understood by reading the detailed description of various embodiments, given by way of non-limiting example, in which reference is made to the accompanying drawings, in which: [Figure 1] FIG. 1 shows an injection device. [Diagram 2] FIG. 2 shows a top view of the dose setting member. [Diagram 3] FIG. 3 shows a side view of the dose setting member. [Figure 4]FIG. 4 shows another view of the dose setting member. [Figure 5A] FIG. 5A shows the different steps for setting up a dose with an injection device. [Figure 5B] FIG. 5B shows the different steps for setting up a dose with an injection device. [Figure 5C] FIG. 5C shows the different steps for setting up a dose with an injection device. [Figure 5D] FIG. 5D shows the different steps for setting up a dose with an injection device. [Figure 5E] FIG. 5E shows the different steps for setting up a dose with an injection device. [Figure 5F] FIG. 5F shows the different steps for setting up a dose with an injection device. [Figure 5G] FIG. 5G shows the different steps for setting up a dose with an injection device. [Figure 6A] FIG. 6A shows a cross-sectional view of the injection device at section VI of FIG. [Figure 6B] FIG. 6B shows a cross-sectional view of the injection device at section VI of FIG. [Figure 7] FIG. 7 shows a top view of a dose setting member according to a first variant. [Figure 8] FIG. 8 shows a side view of a dose setting member according to a first variant. [Figure 9] FIG. 9 shows another view of the dose setting member according to the first variant. [Figure 10A] FIG. 10A shows the different steps for setting a dose with an injection device according to a first variant. [Figure 10B] FIG. 10B shows the different steps for setting a dose with an injection device according to the first variant. [Figure 10C] FIG. 10C shows the different steps for setting a dose with an injection device according to the first variant. [Figure 10D] FIG. 10D shows the different steps for setting a dose with an injection device according to the first variant. [Figure 10E]FIG. 10E shows the different steps for setting a dose with an injection device according to the first variant. [Figure 10F] FIG. 10F shows the different steps for setting a dose with an injection device according to the first variant. [Figure 10G] FIG. 10G shows the different steps for setting a dose with an injection device according to the first variant. [Figure 11A] FIG. 11A shows a cross-sectional view (a cross-section similar to cross-section VI) of an injection device according to a first variant. [Figure 11B] FIG. 11B shows a cross-sectional view (similar to cross-section VI) of the injection device according to the first variant. [Figure 11C] FIG. 11C shows a cross-sectional view (similar to cross-section VI) of the injection device according to the first variant. [Figure 12] FIG. 12 shows a top view of a dose setting member according to a second variant. [Figure 13] FIG. 13 shows a side view of a dose setting member according to a second variant. [Figure 14] FIG. 14 shows another view of the dose setting member according to the second variant. [Figure 15A] FIG. 15A shows the different steps for setting a dose with an injection device according to a first variant. [Figure 15B] FIG. 15B shows the different steps for setting a dose with an injection device according to the first variant. [Figure 15C] FIG. 15C shows the different steps for setting a dose with an injection device according to the first variant. [Figure 15D] FIG. 15D shows the different steps for setting a dose with an injection device according to the first variant. [Figure 15E] FIG. 15E shows the different steps for setting a dose with an injection device according to the first variant. [Figure 15F] FIG. 15F shows the different steps for setting a dose with an injection device according to the first variant. [Figure 15G]FIG. 15G shows the different steps for setting a dose with an injection device according to the first variant. [Figure 16A] FIG. 16A shows a cross-sectional view (similar to cross-section VI) of an injection device according to a second variant. [Figure 16B] FIG. 16B shows a cross-sectional view (similar to cross-section VI) of an injection device according to a second variant. [Figure 16C] FIG. 16C shows a cross-sectional view (similar to cross-section VI) of an injection device according to a second variant. [Figure 16D] FIG. 16D shows a cross-sectional view (similar to cross-section VI) of an injection device according to a second variant. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0051] 1 shows an injection device 10 including a barrel 12, a plunger rod 14, and a dose setting member 16. In this embodiment, the injection device 10 is a medical injector, e.g., a syringe. In this example, the injection device 10 comprises a spray nozzle 18 and a removable vial adapter 20. For example, the injection device 10 can be pre-filled with a powdered drug, a liquid medical ingredient, or other active ingredient, such as a medical drug, a vaccine, etc.

[0052] The barrel 12 extends along an axis X and defines a reservoir 12A therein. The barrel 12 has a proximal end PE and a distal end DE. The distal end DE has an outlet 22. A spray nozzle 18 and a vial adapter 20 are disposed at the distal end DE. The spray nozzle 18 is in fluid communication with the reservoir 12A via the outlet 22. Instead of the spray nozzle 18, a needle may be attached to the distal end DE of the barrel for injecting a medical component into a patient.

[0053] The distal side of the injection device 10 corresponds to the side of the distal end DE, and the proximal side of the injection device 10 corresponds to the side of the proximal end PE.

[0054] In this embodiment, the barrel 12 comprises a radially extending flange 24, which is disposed at the proximal end PE of the barrel 12. As seen in FIG. 5A, the flange 24 has a general diamond shape with rounded angles. In this embodiment, the flange 24 comprises a guide portion GP configured to slidably guide the dose setting member 16 and a retaining portion RP configured to maintain the dose setting member 16 in one of the N positions. The guide portion GP comprises two radially oppositely extending tongues E1 and E2. The retaining portion RP comprises two radially opposite edges E3 and E4. The two tongues E1 and E2 extend along the larger diagonal of the diamond, and the two edges E3 and E4 are disposed at the tow opposite apexes joined by the smaller diagonal of the diamond. In this embodiment, the edges E3 and E4 comprise two ratchets configured to engage different complementary parts of the dose setting member 16, which will be described later. In a variant, the flange can have any shape, for example a circular shape.

[0055] The plunger rod 14 is received in the barrel 12 via a proximal end PE and is configured to move along an axis X relative to the barrel 12. The plunger rod 14 consists of N radial projections 14A, 14B arranged successively at different positions along the axis X, where N is an integer equal to or greater than 2. In this embodiment, N is equal to 2 (N=2). In this example, the plunger rod 14 comprises a pusher portion 15 at its proximal end and a stopper (not shown) at its distal end and arranged in the reservoir 12A. For injection / spraying of the medical component contained in the barrel 12, the end user can apply his thumb to the pusher portion 15 of the plunger rod 14 to facilitate injection / spraying.

[0056] In this embodiment, as shown in FIG. 1 and FIG. 5A-FIG. 5G, the radial extension of the second radial projection 14B is larger than the radial extension of the first radial projection 14A. In other words, the radial extension of the most distal radial projection 14B is larger than the radial extension of the most proximal radial projection 14A. In this embodiment, the radial projections 14A, 14B have an annular shape with a radius, in this embodiment a ring shape, and the radius of the second radial projection 14B (or the most distal radial projection) is larger than the radius of the first radial projection 14A (or the most proximal radial projection). The first radial projection 14A is axially closer to the distal end DE than the second radial projection 14B. In this embodiment, the radius of all the outer radial projections is smaller than the inner radius of the reservoir 12A, so that the reservoir 12A can be inserted into the barrel 12.

[0057] The dose setting member 16 is configured to be attached to the barrel 12. In this example, the dose setting member 16 is configured to be slidably attached to the flange 24. The dose setting member 16 has N portions 16A, 16B configured to sequentially axially urge the N radial protrusions 14A, 14B, respectively, when the plunger rod 14 is axially moved in a first direction (or distal direction) F1 from the proximal end PE toward the distal end DE. The dose setting member 16 is configured to move relative to the barrel 12 between N positions, with the nth radial protrusion axially facing the nth portion at the nth position, where n is an integer between 1 and N, i.e., in this example, between 1 and 2. In this example, the dose setting member 16 is removably attached to the barrel (see in particular Figures 5A and 5F). As shown in Figures 5A-5G, the dose setting member 16 is configured to move radially relative to the barrel 12 between the N portions in a direction perpendicular to the axis X.

[0058] The dose setting member 16 consists of a radially extending and radially open cutout 100, considered when the dose setting member 16 is mounted on the barrel 12, and configured to receive the barrel 12. The cutout 100 extends along a second axis X2, and the Nth portions are successively arranged at different positions along the second axis X2. The walls extending around the cutout 100 define a general U-shape. The barrel 12 and the plunger rod 14 can be introduced into the cutout 100 through the U-shaped hole, i.e. the open top of the "U-shape", extending transversely to the plane in which the "U-shape" extends (see FIG. 5B). When the dose setting member 16 is mounted on the barrel 12, the second axis X2 extends radially, perpendicular to the axis X.

[0059] In this embodiment, the dose setting member 16 comprises an upper portion 26, which may be a top plate, extending in a radial plane perpendicular to the axis X, considered when mounted on the barrel 12. The upper portion 26 is configured to face the distal end of the plunger rod 14 (in this example the pusher portion 15 of the plunger rod 14). The side walls of the U-shaped cutout 100 of the upper portion 26 are configured to receive and cooperate with the plunger rod 14. On either side of the cutout 100, two opposing shoulders are formed in each portion 16A, 16B, which are configured to axially abut against the radial projections 14A, 14B of the plunger rod 14. In this embodiment, the portion 16A comprises two opposing shoulders (in this embodiment radial shoulders) 16A1, 16A2, and the portion 16B comprises two opposing shoulders (in this embodiment radial shoulders) 16B1, 16B2. In this embodiment, each of the portions 16A, 16B defines an axial passage having a minimum radial length, with the minimum radial length RL2 of the second portion 16B being greater than the minimum radial length RL1 of the first portion 16A. The remaining portion of the plunger rod 14 (i.e., the rod of the plunger rod without the radial projection) is received within the cutout 100 and is free to move axially relative to the dose setting member 16. The upper portion 26 may be configured with markings to indicate information regarding the dose at the position. In this embodiment, the portions 16A, 16B are arranged consecutively along the second axis X2, with the last portion 16B being closer to the open top of the "U-shape" than the first portion 16A.

[0060] In this embodiment, the dose setting member 16 comprises a lower part 28, which may be a lower plate, extending in a radial plane perpendicular to the axis X and parallel to the second axis X2. The lower part 28 is configured to face the distal end DE of the barrel 12. The side walls of the U-shaped cutout 100 in the lower part 28 are configured to receive and cooperate with the barrel 12 (or the barrel body). The width of the cutout 100 in the lower part 28 perpendicular to the second axis X2 is constant all along the second axis X2. This width may be larger than the maximum width of the cutout 100 in the upper part 26.

[0061] The upper part 26 and the lower part 28 are adjacent along the axis X (when mounted on the barrel 12) and form a single, identical element. In the opposing side walls of the cutout 100, two opposing grooves 30 are arranged axially between the upper part 26 and the lower part 28. The grooves 30 extend along the second axis X2. An opening 38 is arranged between the two grooves 30, through which the tongue E1 or E2 of the flange 24 can at least partially extend. The grooves 30 are configured to receive at least partially the flange 24 in a slidable manner. The reliefs 32 are arranged in the grooves 30, in this example at the bottom of the grooves 30, and are configured to cooperate with the edges E3 and E4 of the flange 24 by a snap fit. In other words, the reliefs 32 form different complementary parts configured to engage with the edges E3 and E4. The reliefs 32 are arranged in pairs, the two members of the pair facing each other with respect to the second axis X2. In this embodiment, each snap-fit ​​position corresponds to an nth position of the dose setting member 16.

[0062] In this embodiment, the outer edge of the dose setting member 16 is provided with a gripping portion 34 having anti-slip ribs 34A to facilitate handling of the dose setting member 16.

[0063] The dose setting member 16 may be made of polypropylene, polyester, polycarbonate, polypropylene, polyethylene, polyethylene terephthalate, acrylonitrile butadiene styrene, preferably the dose setting member 16 is made of polypropylene.

[0064] In this embodiment, the injection device 10 is configured such that the nth portion can only abut against the nth radial projection.

[0065] A dose setting method for presetting the dose of the injection device 10 prior to injection, which comprises moving the dose setting member 16 to one of N positions such that the nth radial projection axially faces the nth portion, will now be described with reference to Figures 5A to 5G.

[0066] In FIG. 5A, the injection device 10 does not include a dose setting member 16. Reconstitution of the injection liquid can be performed by mixing the prefilled powder with the injection liquid. Alternatively, the injection liquid may be pumped / drawn from an external vial (not shown) containing the injection liquid while the reservoir 12A is initially empty. This can be performed by moving the plunger rod 14 in a direction F2 (or proximal direction) extending along the axis X and from the distal end DE towards the proximal end PE. Alternatively, the injection device 10 can be prefilled with the injection liquid and stored prefilled.

[0067] In Fig. 5B, the dose setting member 16 can be attached to the barrel 12 by radially inserting and sliding the flange 24 into the groove 30 (see arrow I in Fig. 5B and Fig. 6A) and snap-fitting the edges E3, E4, which are considered as the last pair of undulations 32 in the insertion direction (see Fig. 6A). In this position, which is the first position of the dose setting member 16, the first portion 16A faces the first radial projection 14A in the axial direction. The first dose is pre-set. As can be seen in Fig. 6A, in the first position, the tongue E2 extends through the opening 38.

[0068] In FIG. 5C, a first dose, in this embodiment a priming dose used to expel any air bubbles potentially contained within the injection device, is performed by moving the plunger rod 14 in a first direction F1, as shown by arrow II, until the first radial projection 14A abuts against the first portion 16A.

[0069] In Fig. 5D, the dose setting member 16 is then radially moved and slid along the second axis X2 (see arrow III) from the first position to a second position in order to pre-set a second dose corresponding to the first dose to be injected. In this position, the second part 16B faces the second radial projection 14B in the axial direction. In such position, the edges E3, E4 are snap-fitted into the first pair of undulations 32 considered in the insertion direction, as shown in Fig. 6B.

[0070] In Figure 5E, a first injection is performed by moving the plunger rod 14 in a first direction F1, as shown by arrow IV, until the second radial projection 14B abuts against the second portion 16B. Note that the first radial projection 14A does not cooperate with the second portion 16B because the radius of the first radial projection 14A is smaller than the minimum radial length RL2 of the second portion 16B.

[0071] In Fig. 5F, once the first injection is completed, the dose setting member 16 is radially moved and slid along the second axis X2 (see arrow V) and removed from the barrel 12. A third dose is then pre-set, which corresponds to the second dose to be injected, i.e. the dose setting member is removed to set the final dose.

[0072] In FIG. 5G, the plunger rod 14 is moved in a first direction F1 as indicated by arrow VI until a portion of the plunger rod 14 abuts a portion of the barrel 12, and a second injection is performed.

[0073] A first variant of the dose setting member 16' will be described with reference to Figures 7 to 9. The dose setting member 16' is configured to adopt one N+1 position, the plunger rod 14 being axially free relative to the dose setting member 16'.

[0074] The dose setting member 16' according to the first variant is similar to the dose setting member 16 of figures 2 to 4, except for the gripping parts arranged only on the two edges parallel to the second direction X2, and the widened part 16C of the cutout 100 in the upper part 26', which is not provided in the dose setting member 16 of figures 2 to 4. The other parts are identical or very similar and will not be described again but will keep the same reference numbers. It should be noted that the term "wide" is used with respect to the other parts, and that the minimum radial length of the widened part 16C is greater than the radial lengths of the other parts 16A, 16B.

[0075] In this embodiment, the wide portion 16C causes the dose setting member 16' to define an axial passage with a minimum radial length RL3 that is greater than the radius of the Nth radial projection 14B. The wide portion 16C corresponds to the N+1 position of the dose setting member 16'. Compared to the dose setting member 16, the dose setting member 16' of the first variant also comprises two additional undulations 32 (i.e. an additional pair of opposing undulations 32) to allow a snap fit with the flange 24 in the N+1 position. In this embodiment, the wide portion 16C is located in front of the first portion 16A and corresponds to the initial or 0 position. The wide portion 16C is closer to the closed bottom of the "U-shape" than the first portion 16A. The first portion 16A is axially located between the wide portion 16C and the second portion 16B.

[0076] An injection device 10' shown in Figures 10A to 10G corresponds to injection device 10 in which dose setting member 16 has been replaced with a dose setting member 16' according to a first modified example.

[0077] A dose setting method for presetting a dose of the provided injection device 10' before injection, which consists of moving the dose setting member 16' to any one of N positions such that the nth radial projection axially faces the nth portion, will now be described with reference to Figures 10A to 10G.

[0078] In FIG. 10A, the dose setting member 16′ is attached (or pre-attached compared to FIG. 5A) to the barrel 12 and placed in the N+1 or initial position (see also the corresponding snap-fit ​​configuration shown in FIG. 11A). In such a position, no part of the dose setting member 16′ faces axially against the radial projections 14A, 14B and the plunger rod 14 is axially free relative to the dose setting member 16′. Reconstitution of the injection fluid can be performed by mixing the prefilled powder with the injection fluid. Alternatively, the injection fluid may be pumped / drawn from an external vial, not shown, while the reservoir 12A is initially empty. This can be performed by moving the plunger rod 14 in a direction F2 extending along the axis X and from the distal end DE towards the proximal end PE. Alternatively, the injection device 10 can be prefilled with the injection fluid and stored prefilled. In other words, FIG. 10A corresponds to moving the dose setting member 16' to position N+1 before setting the first dose for filling the injection device 10'.

[0079] In Fig. 10B, the dose setting member 16' can move and slide radially along the second axis X2 (see arrow VII) to snap-fit ​​the edges E3, E4 into the second or middle pair of undulations 32 (see Fig. 11B). In this position, which is the first position of the dose setting member 16', the first portion 16A faces the first radial projection 14A in the axial direction. The first dose is preset.

[0080] Figures 10C to 10G are similar to and correspond closely to the steps of Figures 5C to 5G, respectively, and will not be described further. Similarly, Figures 11B and 11C correspond to Figures 6A and 6B, respectively, and will not be described further.

[0081] A second variant of the dose setting member 16'' will be described with reference to Figures 12 to 14. The dose setting member 16'' is configured to adopt two N+1 positions, the plunger rod 14 being axially free relative to the dose setting member 16''. The dose setting member 16'' may be non-removable, but this is not necessarily the case.

[0082] The dose setting member 16'' according to the second variant is similar to the dose setting member 16' of the first variant, except with regard to the arrangement of its parts on the upper part 26''. The other parts are identical or very similar and will not be described again but will retain the same reference numbers.

[0083] The top 26'' of the dose setting member 16'' is successively composed along the second axis X2 of a first N+1 portion or wide portion 16C'', a first portion 16A'', a second portion 16B'' and a second N+1 portion or wide portion 16D'', where the first N+1 portion 16C'' is closer to the open top of the ``U'' than the second N+1 portion or wide portion 16D''. The second N+1 portion 16D'' is closer to the closed bottom of the ``U'' than the first N+1 portion 16C''.

[0084] In this embodiment, the first wide portion 16C'' defines a first axial passageway of the dose setting member 16'' having a minimum radial length RL4 that is greater than the radius of the Nth radial projection 14B. The first wide portion 16C'' corresponds to the first N+1 position of the dose setting member 16''. The second wide portion 16D'' defines a second axial passageway of the dose setting member 16'' having a minimum radial length RL5 that is greater than the radius of the Nth radial projection 14B. The second wide portion 16D'' corresponds to the second N+1 position of the dose setting member 16''. In this embodiment, RL4 is greater than RL5. However, RL4 may be less than RL5 or RL4 may be equal to RL5.

[0085] Compared to the dose setting member 16, the second variant 16'' also comprises four additional undulations 32 (i.e., two additional opposing undulations 32) to enable a snap fit with the flange 24 in the first position and in the second N+1 position.

[0086] The injection device 10'' shown in Figures 15A to 15G corresponds to an injection device 10 in which the dose setting member 16 has been replaced by a dose setting member 16'' according to a second variant.

[0087] A dose setting method for presetting a dose of the provided injection device 10'' before injection, which consists of moving the dose setting member 16'' to any one of N positions such that the nth radial protrusion axially faces the nth portion, will now be described with reference to Figures 15A to 15G.

[0088] Figures 15A to 15E correspond to Figures 10A to 10E, respectively, except for the radial movement of the dose setting member 16'', which is opposite due to the reversal of the order of parts along the second axis X2. Figures 15A to 15E will therefore not be described further. Similarly, Figures 16A to 16C correspond to Figures 11A to 11C, respectively, and will not be described further.

[0089] In Fig. 15F, the dose setting member 16'' is radially moved and slid from the second position to a second N+1 position (see arrow XII). The corresponding snap-fit ​​position is shown in Fig. 16D. This position is the final position of the dose setting member 16'', where the last dose is pre-set. In other words, Fig. 15 corresponds to moving the dose setting member 16'' in the second N+1 position to allow emptying the injection device 10'' after completion of the Nth dose.

[0090] In FIG. 15G, the final injection is performed by moving the plunger rod 14 in the first direction F1 until a portion of the plunger rod 14 abuts a portion of the barrel 12, as indicated by arrow XIII.

[0091] Although the present disclosure has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present disclosure. In particular, the individual features of the various embodiments shown and / or mentioned can be combined in additional embodiments. Accordingly, the present specification and drawings are to be considered in an illustrative and not a restrictive sense.

[0092] Furthermore, all of the features of the disclosed apparatus, either alone or in any combination, can be transferred to the method, and vice versa.

[0093] It is intended that the specification and examples be considered as exemplary only, with the true scope of the invention being indicated by the following claims.

Claims

1. An injection device (10, 10', 10'') comprising: a barrel (12) extending along an axis (X) and defining a reservoir (12A), said barrel (12) having a proximal end (PE) and a distal end (DE) having an outlet (22); a plunger rod (14) received in the barrel (12) via the proximal end (PE) and configured to move along the axis (X) relative to the barrel (12), the plunger rod (14) comprising N radial protrusions (14A, 14B) arranged in succession at different positions along the axis (X), N being an integer equal to or greater than 2; a dose setting member (16, 16', 16'') configured to be removably attached to the barrel (12) and having N portions (16A, 16B) configured to sequentially abut axially against the N radial projections (14A, 14B) when the plunger rod (14) is moved axially in a first direction (F1) from the proximal end (PE) towards the distal end (DE), The dose setting member (16, 16', 16'') is configured to be moved relative to the barrel (12) between N positions, and an nth radial projection (14A, 14B) axially faces the nth portion (16A, 16B) at the nth position, where n is an integer greater than or equal to 1 and less than or equal to N.

2. 2. An injection device (10, 10', 10'') according to claim 1, wherein the nth portion (16A, 16B) is configured to be able to abut only against the nth radial projection (14A, 14B).

3. 3. An injection device (10', 10'') according to claim 1 or 2, wherein the dose setting member (16', 16'') is configured to adopt at least one N+1 position, and wherein the plunger rod (14) is axially free relative to the dose setting member (16', 16'').

4. 4. An injection device (10, 10', 10'') according to any one of claims 1 to 3, wherein the dose setting member (16, 16', 16'') is configured to move radially relative to the barrel (12) between N positions.

5. 5. The injection device (10, 10', 10'') according to any one of claims 1 to 4, wherein the dose setting member (16, 16', 16'') comprises a radially extending, radially opening cut-out portion (100) configured to receive the barrel (12) when the dose setting member (16, 16', 16'') is mounted on the barrel (12).

6. An injection device (10, 10', 10'') as described in claim 5, wherein the cutout portion (100) extends along a second axis (X2) and the N portions (16A, 16B) are arranged consecutively at different positions along the second axis (X2).

7. An injection device (10, 10', 10'') according to any one of claims 1 to 6, wherein the radial extension of the t-th radial protrusion (14B) is greater than the radial extension of the (t-1)-th radial protrusion (14A) and less than the radial extension of the (t+1)-th radial protrusion, where t is an integer greater than or equal to 2 and less than or equal to N.

8. 8. The injection device (10, 10', 10'') according to any one of claims 1 to 7, wherein each of the radial projections (14A, 14B) has an annular shape having a radius, the radius of the t-1st radial projection (14B) being greater than the radius of the t-1st radial projection (14A) and less than the radius of the t+1th radial projection, each of the portions (16A, 16B) defining an axial passage having a minimum radial length, the minimum radial length (RL2) of the t-1st portion (16B) being greater than the minimum radial length (RL1) of the t-1st portion (16A) and less than the minimum radial length of the t+1th portion, wherein t is an integer greater than 2 and less than N.

9. An injection device (10', 10'') as claimed in claims 3 and 8, wherein in the at least one N+1 position, the dose setting member (16', 16'') defines an axial passage having a minimum radial length (RL3, RL4, RL5) greater than a radius of the Nth radial projection (14B).

10. An injection device (10, 10', 10'') according to any one of claims 7 to 9, wherein the (t-1)th radial protrusion (14A) is axially closer to the distal end (DE) than the tth radial protrusion (14B).

11. 11. An injection device (10, 10', 10'') according to any one of claims 1 to 10, wherein the barrel (12) comprises a radially extending flange (24), and the dose setting member (16, 16', 16'') is configured to be slidably mounted on the flange (24).

12. 12. The injection device (10, 10', 10'') according to claim 11, wherein the flange (24) comprises a guiding portion (GP) configured to slidably guide the dose setting member (16, 16', 16'') and a retaining portion (RP) configured to maintain the dose setting member (16, 16', 16'') in one of the N positions.

13. 14. A dose setting method for presetting a dose of an injection device before injection, comprising the steps of: providing an injection device (10, 10', 10'') according to any one of claims 1 to 13; and moving the dose setting member to any one of the N positions such that the nth radial protrusion axially faces the nth portion.

14. 14. The dose setting method according to claim 13, wherein the dose setting member (16, 16') is removably mounted on the barrel, and the dose setting method comprises the step of removing the dose setting member (16, 16') for setting a final dose.

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