Adaptive cartridge holder for a drug delivery device

Abstract

A cartridge holder adapted to receive a cylindrical cartridge having a circumferential proximal edge. The proximal end of the cartridge holder includes an opening allowing insertion of the cartridge, and a pair of circumferentially arranged flexible support arms. Each support arm has a free end with a protrusion extending into the opening, the flexibility of which allows the protrusion to be removed from the opening. A free space is provided distally on the flexible support arm, allowing movement of the support arm in a distal direction. A distally oriented axial force applied to the flexible arm moves the protrusion to engage with the circumferential edge of the inserted cartridge, subsequently bending the flexible arm into the free space, thereby applying a force on the circumferential edge of the cartridge to move the distal outlet end of the cartridge to engage with the distal portion of the cartridge holder.

Description

Technical Field

[0001] The present invention generally relates to a cartridge holder adapted to receive a cylindrical cartridge having a circumferential proximal edge, the cartridge holder being adapted for use in combination with a drug delivery device intended for subcutaneous introduction of a fluid drug formulation. Background Technology

[0002] The disclosure of this invention primarily mentions subcutaneous needles intended for patients to administer fluid pharmaceutical preparations subcutaneously, such as for treating diabetes by delivering insulin or GLP-1 drugs, or for treating growth disorders by delivering growth hormone; however, these are merely exemplary uses of the invention.

[0003] Medication delivery devices in the form of injection devices have greatly improved the lives of patients who must self-administer medications and biologics. These devices can take many forms, ranging from simple, disposable devices—mere ampoules with injection tools—to highly complex, electronically controlled instruments with numerous functions. Regardless of their form, they have proven to be powerful aids in helping patients self-administer injectable medications and biologics. They also greatly assist caregivers in administering injectable medications to those unable to perform self-injection.

[0004] In particular, pen-type injection devices have proven to provide an accurate, convenient, and often discontinuous way to administer drugs and biologics such as insulin or GLP-1 drugs.

[0005] Typically, injection devices use pre-filled cartridges containing the target drug, such as 1.5 ml or 3.0 ml of insulin or a GLP-1 formulation. The cartridge is usually a generally cylindrical, transparent glass cylinder with a distal bottleneck and an opposing proximal opening. The distal bottleneck has a distal opening sealed by a needle-piercing septum, and the proximal opening houses an elastomeric piston arranged to be moved by the drug delivery mechanism of the injection device. Injection devices are generally classified into two types: "durable" devices and "disposable" devices. Durable devices are designed to allow the user to replace one cartridge with another, typically replacing an empty cartridge with a new one. In contrast, disposable devices contain an integrated cartridge that cannot be replaced by the user; the entire device is discarded when the cartridge is empty.

[0006] The portion of an injection device that receives and holds the cartridge is traditionally referred to as a cartridge retainer, primarily used to position and securely hold the cartridge relative to the piston rod of the dispensing mechanism. Axial fixation is particularly important for dosing accuracy. Accordingly, a “complete” cartridge retainer includes a cylindrical body portion, a distal portion that engages with the distal portion of the cartridge, and a proximal portion that engages with the proximal portion of the cartridge. However, the term “cartridge retainer” is generally used to refer to a tubular member integrally formed with the body portion and the distal portion and having a proximal opening through which the cartridge is inserted distally. The cartridge retainer containing the cartridge is then mounted onto the body portion of the injection device (i.e., the portion including the dispensing mechanism), which then engages with the cartridge. This forms the cartridge retainer assembly.

[0007] Alternatively, the cylindrical body portion of the cartridge holder may be formed from a distal tubular extension of the body portion of the injection device into which the cartridge is inserted proximally, i.e., "front-loading". The cartridge holder is closed by a distal closure device, which may be, for example, a simple "stopper" portion or a more complex actuable closure mechanism.

[0008] In another alternative, the cartridge holder forms a complete, independent subassembly, in which the cartridge is completely enclosed, and is subsequently mounted on the main body of the injection device. Such an assembly may also include a portion of the dispensing mechanism, such as a piston rod, which then engages with the remaining piston rod drive mechanism, see, for example, EP 1 458 440.

[0009] It can be seen that for durable injection devices, the cartridge holder is installed using a releasable coupling device; while for disposable pre-filled devices, the cartridge holder is permanently mounted to the device body. Because the manufacturing tolerances of glass cartridges are relatively large, for example, for a length of 0.5 mm, the cartridge holder must be able to accommodate this variation. Therefore, for durable devices, the cartridge is typically held in place axially by a resiliently deformable device (e.g., a spring or flexible arm as disclosed in US 2012 / 0143143). US 2009 / 0312715 discloses a durable cartridge holder that includes a distal centering structure. In contrast, for disposable devices, a plastically deformable joining structure can be used, for example, in the form of an extrusion rib that engages with the circumferential edge of the cartridge. However, if a given cartridge is too large in the axial direction or has defects in the glass properties, it may actually break during installation. To address this issue, WO 2016 / 156387 discloses a cartridge retainer in which the compression rib has been repositioned to act on the cartridge neck, which is typically able to withstand greater forces during compression rib deformation.

[0010] The aforementioned cartridge holders are typically designed to hold glass cartridges that do not include a coupling device that allows direct connection to an injection device. However, if the cartridge is made of a polymer material, the coupling device can be integrally formed with the cartridge itself, thus eliminating the need for a traditional cartridge holder.

[0011] Other examples of cartridge / syringe holders are disclosed in US 9,713,678, US 2019 / 060579 and US 2022 / 370729.

[0012] US 11,654,252 discloses a fixing device adapted to receive a syringe with a radially outwardly projecting flange in its proximal portion, and having an opening for receiving the syringe and a proximal surface for contacting a distally facing surface of the flange. A flexible fixing arm has: a first radially outwardly extending portion that allows the flange to pass through; and a second radially inwardly extending free arm portion adapted to prevent proximal movement of the flange (and thus the syringe), the flexible arm allowing the syringe to be inserted across the flexible arm. The fixing arm is preferably not under, or hardly under, elastic stress.

[0013] In view of the foregoing, an object of the present invention is to provide components, devices, and methods that allow for the secure and reliable mounting of a drug-filled cartridge in a cartridge holder for a drug delivery device in an economical and efficient manner. A specific object of the present invention is to provide means for the secure and reliable mounting of a drug-filled glass cartridge in a disposable drug delivery device in an economical and efficient manner. Summary of the Invention

[0014] In the disclosure of this invention, embodiments and aspects that achieve one or more of the above-described objectives or that will achieve objectives as will become apparent from the following disclosure and the description of exemplary embodiments will be described.

[0015] In a first aspect of the invention, a cartridge holder is provided adapted to receive a cartridge containing a drug with an axially movable piston, the cartridge including a distal outlet portion, a cylindrical body portion, and a proximal portion having a circumferential edge. The cartridge holder includes a body portion adapted to receive the cartridge and define a reference axis, a distal portion adapted to engage and support the distal portion of the cartridge, and a proximal portion adapted to engage and support the proximal portion of the cartridge. The proximal portion includes: a proximal opening allowing insertion of the cartridge into the cartridge holder; at least one circumferentially arranged flexible support arm having a free end with a protrusion extending (e.g., radially) into the proximal opening, the flexibility of the arm allowing the protrusion to be removed from the proximal opening; and free space distal to the flexible support arm allowing movement of the support arm in a distal direction.

[0016] In use, a cartridge of appropriate size is inserted into the cartridge body through the proximal opening, such that the at least one protrusion is positioned proximal to the circumferential edge of the cartridge. When a distally oriented axial force is applied to the at least one flexible arm, the protrusion moves to engage with the circumferential edge of the cartridge, subsequently causing the at least one flexible arm to bend into free space, thereby applying force to the circumferential edge of the cartridge and moving the distal outlet end of the cartridge to engage with the distal portion of the cartridge holder.

[0017] As can be seen, in order for the flexible arm to spring back, thereby positioning the protrusion aligned with the circumferential edge of the cartridge, the dimensions of the cartridge holder should be determined to accept a cartridge axial length within a given tolerance range. Accordingly, a given cartridge with the maximum permissible axial length will be received in the cartridge holder without axial clearance, thus the protrusion initially contacts the circumferential edge of the cartridge.

[0018] This arrangement provides a compact cartridge holder in which a given conventional cartridge can be axially fixed, and elastic and / or plastic deformation is absorbed by at least one flexible arm, thereby reducing the magnitude of the force exerted on the cartridge rim by protrusions acting directly on the cartridge rim.

[0019] In practice, the distally oriented axial force applied to the at least one flexible arm must be applied at a position between the base of the flexible arm and the free end with the protrusion, so that the arm can deform into free space, for example, in the middle.

[0020] In an exemplary embodiment, the proximal portion forms a circumferential edge, and the at least one flexible arm has a proximal-facing edge that constitutes part of the circumferential edge. In practice, each flexible support arm, corresponding to the flexible support arm with a free end portion, will have a gap in the edge. Furthermore, depending on the actual design of the cartridge holder, the circumferential edge can be more or less arranged in a given transverse plane. This allows for axial cartridge holding functionality with minimal impact on the outer diameter of the cartridge holder. Accordingly, the proximal portion can be generally cylindrical, and the at least one flexible support arm, except for the protrusion, constitutes part of this cylinder.

[0021] The cartridge holder is adapted to receive a cartridge containing a drug, wherein the main body portion and the proximal portion having a circumferential edge have a generally circular cross-section, and the circumferential edge of the proximal portion of the cartridge is correspondingly generally circular.

[0022] In an exemplary embodiment, two or three equidistant flexible support arms are provided.

[0023] The cartridge holder can be provided in combination with a correspondingly defined cartridge containing a drug, the cartridge being disposed within the cartridge holder, and the at least one flexible support arm protrusion being disposed proximal to the circumferential edge of the cartridge. In this configuration, depending on the actual length of a given cartridge, the one or more flexible arm protrusions may or may not engage the distal circumferential edge of the cartridge; that is, the cartridge may or may not be permitted to move slightly axially.

[0024] The cartridge holder can also be provided in combination with a correspondingly defined drug-containing cartridge and a drug delivery device engine portion, forming a drug delivery device adapted to dispense a drug dose from the distal outlet end of the drug-filled cartridge. In such a combination, the cartridge is arranged in the cartridge holder, the at least one flexible support arm protrusion is arranged proximal to the circumferential edge of the cartridge, the cartridge holder is mounted to the drug delivery device engine portion, and the drug delivery device engine portion includes a mounting structure that axially engages the at least one flexible arm to deform and move it into the free space.

[0025] In an exemplary embodiment, the drug delivery device engine portion includes: a drug dispensing mechanism comprising an axially movable piston rod adapted to engage and axially move the cartridge piston to dispense a drug dose; and a drive mechanism for distally moving the piston rod. The drug delivery device engine portion may be adapted to dispense a preset or user-settable dose of drug.

[0026] In a second aspect of the invention, a method of assembling components of a drug delivery device is provided. The method includes the steps of: (i) providing a drug-containing cartridge with an axially movable piston, the cartridge including a cylindrical body portion, a distal outlet portion, and a proximal end having a circumferential edge; (ii) providing a cartridge holder including: a body portion adapted to receive the cartridge and define a reference axis; a distal portion adapted to engage and support the distal end of the cartridge; and a proximal portion adapted to engage and support the proximal end of the cartridge, the proximal portion including: a proximal opening allowing insertion of the cartridge into the cartridge holder; at least one circumferentially arranged flexible support arm having a free end with a protrusion extending into the proximal opening, the flexibility of the arm allowing the protrusion to be removed from the proximal opening; and a free space distal to the flexible support arm allowing movement of the support arm in a distal direction; and (iii) providing a drug delivery device housing adapted to mount the cartridge holder, including a mounting structure adapted to axially engage the at least one flexible arm. The method further includes the following steps: (iv) inserting the cartridge through the cartridge opening into the cartridge holder, thereby moving the at least one flexible support arm protrusion outward and then inward, the flexible support arm protrusion being positioned proximal to the circumferential edge of the cartridge; and (v) mounting the cartridge holder to the delivery device housing, the mounting structure thereby axially engaging the at least one flexible arm to bend it into the free space, thereby applying a distally oriented axial force on the cartridge via the at least one flexible support arm protrusion.

[0027] In the method of assembling components of the drug delivery device, the provided cartridge may include a distally inwardly angled neck for outwardly moving the at least one flexible support arm protrusion when the cartridge is inserted through a proximal opening of the cartridge holder. The provided drug delivery device housing may include a drug dispensing mechanism with a distal piston rod that engages with the cartridge piston when the cartridge holder is mounted to the delivery device housing. A piston washer may be positioned between the distal piston rod and the cartridge piston, either above the piston or attached to the distal piston rod prior to assembly.

[0028] As used herein, the term "medicine" is intended to encompass any drug-containing, flowable pharmaceutical agent, such as a liquid, solution, gel, or fine suspension, that can be passed in a controlled manner through a delivery device such as a hypodermic needle. The drug may have glycemic control effects, such as human insulin and its analogues, as well as non-insulin drugs such as GLP-1 and its analogues. Attached Figure Description

[0029] Embodiments of the present invention will now be described with reference to the accompanying drawings, wherein: Figure 1A drug delivery device with a needle unit is shown. Figure 2 The drug delivery device 1, with the needle unit replaced by a cap, is shown in a cross-sectional view. Figure 3 It shows Figure 1 and Figure 2 An exploded view of the components of the drug delivery assembly. Figure 4A and Figure 4B They are shown respectively Figure 3 Perspective and cross-sectional views of the cartridge holder. Figure 5A and Figure 5B They are shown respectively Figure 3 Perspective and cross-sectional views of the drive nut. Figures 6A-6C They are shown respectively Figure 3 Perspective and cross-sectional views of the shell components. Figure 6D and Figure 6E A sectional view shows details of the structure surrounding the tower-like shell. Figure 7A and Figure 7B They are shown respectively Figure 3 Perspective and cross-sectional views of the actuator. Figure 8 It shows Figure 3 A perspective view of the return spring. Figure 9A and Figure 9B They are shown respectively Figure 3 Perspective and cross-sectional views of the control components. Figure 10A and Figure 10B They are shown respectively Figure 3 Perspective and cross-sectional views of the driving component. Figure 11 It shows Figure 3 A perspective view of the piston rod. Figure 12 It shows Figure 3 A perspective view of the drive spring. Figure 13A and Figure 13B They are shown respectively Figure 3 Perspective and cross-sectional views of the spring seat component. Figure 14 Shown in cross-sectional view Figure 2 For better visibility, the cap, cartridge, cartridge holder, and return spring of the drug delivery device have been removed. Figure 15 A detailed view of the proximal cross-section of the drive spring arranged in the spring seat is shown. Figure 16 A detailed cross-sectional view of the distal side of the drive spring arranged in the spring seat is shown. Figure 17 A detailed cross-sectional view of the actuator locking flexible finger that engages with the housing locking stop surface is shown. Figures 18A-18F A series of perspective views illustrate the movement of the actuator protrusions and control components relative to the housing tower portion during drug dosing and delivery. Figure 19A and Figure 19B They are shown respectively Figure 3 Perspective and cross-sectional views of the protective structure. Figure 20A and Figure 20B They are shown respectively Figure 3 Perspective and cross-sectional views of the needle holder component. Figure 21A and Figure 21B The following are examples of methods for using... Figure 1 Perspective and cross-sectional views of the container of the needle unit. Figure 22 The arrangement in Figure 21A In the container Figure 1 Cross-sectional view of the needle unit. Figures 23A-23J A series of cross-sectional views illustrate the installation, actuation, and removal of the needle unit on the drug delivery device. Figure 23CX and Figure 23GX The corresponding Figure 23C and Figure 23G The sectional view, and Figures 24A-24C A series of cutaway perspective views show the movement of the shield and needle hub relative to the housing indicator opening during needle unit actuation.

[0030] In the accompanying drawings, similar structures are mainly represented by similar reference numerals. Detailed Implementation

[0031] When terms such as “upper” and “lower,” “right” and “left,” “horizontal” and “vertical” or similar relative expressions are used below, these terms refer only to the accompanying drawings and do not necessarily refer to actual use. The term “distal” refers to the portion of an element, component, or device that faces the user’s skin surface during use, and the term “proximal” refers to the opposite portion. Accordingly, for conventional pen-type drug delivery devices, the needle is positioned distally, while the end-mounted release button is positioned proximally. The figures shown are schematic representations, and therefore the configurations of different structures and their relative dimensions are intended for illustrative purposes only. When the term “component” or “element” is used for a given part, it generally indicates that the part is a single part in the described embodiment; however, the same component or element may alternatively include multiple sub-components, just as two or more described parts may be provided as a single part, for example, manufactured as a single injection-molded part. The term “component” does not mean that the described part must be able to be assembled during a given assembly procedure to provide a single or functional component, but is merely used to describe parts grouped together as being more functionally related.

[0032] See Figure 1 The image shows a drug delivery device 1 with a needle unit 2 mounted on it. The device has a generally tubular configuration that defines a universal reference axis. Figure 2 A cross-sectional view shows a drug delivery device 1 in which the needle unit is replaced by a cap. In the illustrated embodiment, the cap fits snugly onto the distal portion of the drug delivery device, thus preventing the simultaneous installation of the needle unit. The drug delivery device includes a distal cartridge holder portion 3 in which a cartridge filled with drug is disposed, a proximal portion 4 including a drive spring system, and an intermediate portion 5 including a control system. A piston rod is axially arranged in the device and adapted to be driven by the spring to move distally to expel a certain amount of fluid drug through the mounted needle unit; the axial stroke of the piston rod is controlled by the control system. Figure 2 The actuator return spring is not shown.

[0033] exist Figure 3 The exploded view shows the various components of the drug delivery device and needle unit. The drug delivery device includes a tubular housing 400 having a proximal engine portion 401 and a distal cartridge portion 402. The distal cartridge portion 402 is adapted to house a cartridge holder 300 in which a cartridge 390 is disposed, the cartridge including a distal outlet end with a needle-piercing diaphragm, a proximal circumferential edge 391, and an axially displaceable piston 392 (see [reference needed]). Figure 17A piston washer 395 is disposed within the cartridge and engages with the proximal surface of the piston. The actuator 500 includes a cylindrical proximal portion 501 from which a pair of legs 502 extend distally, interposed between the housing and the cartridge holder. A drive nut 600 is mounted within the housing and adapted to receive the piston rod 650 in a threaded engagement manner. The piston rod is non-rotatably received in the distal tubular portion 802 of a drive member 800 adapted to be rotated by a pre-tensioned drive spring 890 disposed in the proximal portion 801 of the drive member, the proximal end of which is anchored to the housing via a spring seat 900. A control member 700 is splinedly engaged with the tubular portion 802 of the drive member and adapted to move axially to engage and disengage with the housing, thereby controlling the rotation of the drive member. A large-diameter return spring 590 is arranged to provide a distally oriented biasing force on the actuator. The drug delivery device is adapted to receive a needle unit at its distal end, the needle unit including a needle hub 100 with a needle 101 disposed within a protective member 200. When the needle unit is not mounted on the drug delivery device, a cap 490 can be mounted to cover the cartridge portion 402. The various components will be described in more detail below. The needle unit will be described later in the description of the drug delivery device.

[0034] The cartridge holder 300 has a generally cylindrical configuration with a larger proximal opening 301 and a smaller distal opening. The proximal opening 301 allows cartridge insertion, while the distal opening allows a hollow needle to be inserted through the diaphragm of the mounted cartridge. The distal end includes a needle unit mount in the form of a cartridge mount 310, which has a pair of opposing partially circumferential flange portions 311 adapted to receive a pair of flexible needle hub connecting arms (see below). Adjacent to the flange portions is a portion 312 with a lower and / or less inclined release flange, allowing the needle hub connecting arms to easily disengage. The cylindrical body portion includes a pair of opposing longitudinal openings 315, allowing the user to inspect the contents of the cartridge and the position of the cartridge piston. Each opening is surrounded by a radially extending window wall 316 adapted to engage with a corresponding window 416 in the housing 400. This window wall includes a plurality of indicator lines 317 arranged to align with the cartridge piston, thereby indicating to the user the amount of remaining dose. Alternatively, an indicator bridge may span the window. The proximal end of the cartridge includes a pair of opposing circumferentially extending flexible support arms 320, each support arm 320 having a free end with a protrusion 321 extending radially into the opening 301. The flexibility of the arm allows the protrusion to move radially out of the opening to allow cartridge insertion. A free space 322 is provided distal to the flexible support arm, allowing the support arm to deform into this free space when engaged with the housing pressure edge 437 during assembly, thereby eliminating axial play (see below) of the installed cartridge. The flexible arm, together with a adjacent portion of the cartridge holder, forms a proximal edge 323 of the cartridge holder, the gap of which corresponds to the free end of the flexible arm. In the illustrated embodiment, this edge is generally arranged in a transverse plane.

[0035] The drive nut 600 includes a generally tubular body portion 610 with internal threads 611 adapted to engage with corresponding threads on the piston rod 650. The drive nut includes a first pair of opposing, distally oriented flexible mounting fingers 620 adapted to be received in corresponding nut grooves in a central portion of the housing. Each finger has a small flexible finger 621 that allows the drive nut to snap into the housing—with a small axial play at this stage. The fingers are slightly outwardly oriented to ensure proper contact with the nut grooves during subsequent securing of the drive nut in the housing, for example, by applying laser energy through an opening in the housing (see below). The drive nut further includes a second pair of opposing, circumferentially extending flexible fingers 630, each finger 630 being inclined proximally to provide a distally oriented biasing force during assembly.

[0036] like Figure 6A , Figure 6B and Figure 6CAs shown, the generally tubular housing 400 includes a proximal engine portion 401, a distal cartridge portion 402, and a distal, generally cylindrical tower-like portion 430 disposed within the engine portion. In the illustrated embodiment, both the distal and proximal portions have a hyperelliptical cross-section with n = 2.5 and a ≠ b. The distal portion of the tower-like portion is connected to the housing via a pair of opposing bridge portions 440, forming a pair of openings between them to provide an axial passage for the actuator leg 502 (see below) between the cartridge and the engine portion. Each bridge portion 440 is provided with a proximal-extending locking rib 447 adapted to engage with an actuator triangular indexing position (see below). Adjacent proximal-facing ribs 448 provide axial support for the actuator. The cartridge portion 402 includes a distal indicator opening 405, a pair of opposing windows 410, and a pair of opposing distal shroud slots 415 adapted to receive corresponding shroud mounting ribs 245 (see below). A pair of opposing inwardly projecting and distally facing locking stop surfaces 407 are provided proximally on the inner surface, along with a pair of opposing proximally extending irreversible point of reversibility (PONR) flexible arms 408, each flexible arm 408 having a proximal PONR stop surface 409 (see below). Figure 6D A pair of opposing snap-fit ​​protrusions 403 adapted to engage with cap 490 are provided on the outer surface. Engine section 401 includes a distal pair of opposing nut openings 406 that allow access to the drive nut mounting point during assembly, for example, allowing the drive nut to be secured to the housing using a laser beam; and a proximal pair of opposing flexible snap-fit ​​fingers 420 that allow the spring seat 900 to be securely mounted in the housing, thus forming part of the housing, each snap-fit ​​finger including an inwardly projecting snap hook 421. A plurality of inner axial ribs 404 provide radial support for actuator 500 and actuator return spring 590. Tower member includes a pair of opposing axially oriented inner nut grooves 432 adapted to receive drive nut mounting fingers 620. The distal edge of the tower member forms a pair of opposing partially circumferential support flanges 431 adapted to be received in the proximal opening 301 of the cartridge holder. Each support flange is associated with a radially extending pressure edge 437 (see...). Figure 6EAssociated with this, the pressure edge 437 is adapted to engage and deform with the flexible arm of the cartridge holder when the cartridge holder is inserted into the housing (see below). The tower-like member further includes a proximal-oriented helical control surface 433, the end of which connects to an axially oriented stop edge (or stop surface) 434 extending distally to form a groove 435 on the helical surface. A central inner circumferential stop flange 438 adapted to engage with the drive member 800 is provided within the tower-like member. A stop protrusion 439 is provided proximal to the stop flange, serving as a second rotational stop for the control member. In the illustrated embodiment, an indicator opening 405 is provided, but a second opposing opening may also be provided.

[0037] like Figure 7A and Figure 7B As shown, actuator 500 includes a cylindrical proximal portion 501 from which a pair of legs 502 extend distally. The cylindrical portion includes a distal outer circumferential spring support flange 510 adapted to engage with a return spring 590, and an inner actuator protrusion 516 and a locking flange 511, the latter providing axial stop for a control member helical flange 710 (see below), thus serving as a locking mechanism for control member 700. A pair of serrated clutch portions 517 are provided on the distal edge of the cylindrical portion, each clutch portion 517 forming two triangular indexing positions adapted to engage with housing locking ribs 447 in an initial position and an actuated rotational position, respectively, thereby providing an anti-rotation clutch upon engagement. Each actuator leg 501 includes a proximal outwardly projecting flexible locking finger 520, which has a proximal-facing locking surface 521 at its proximal free end, the locking surface 521 being adapted to engage with a housing locking stop surface 407. Each actuator leg 501 further includes a proximal axially oriented PONR wedge structure 530 having a distal-facing stop surface 531, the stop surface 531 being adapted to engage with a proximal-facing PONR housing stop surface 409. Each actuator leg includes, at its distal end, a distally located a distally located actuating surface 523 adapted to engage with a needle guard 200, and an adjacent inclined release surface 524 adapted to engage with a needle hub 100.

[0038] Figure 8 The helical return spring 590 shown is typically unwound, but to prevent tangling during manufacturing, it has distal, central, and proximal tightly wound sections.

[0039] like Figure 9A and Figure 9BAs shown, the generally tubular control member 700 includes an outer helical flange 710 for controlling the axial movement of the control member relative to the housing. This helical flange includes: a distal helical surface 713 adapted to engage with a helical surface 433 on the tower-like member; a proximal helical surface 719 adapted to engage with the distal end of the actuation protrusion 516; and a longitudinally extending control edge 714 (acting as a control surface) connecting the end of the helical flange 710 and adapted to engage with a stop edge 434 on the tower-like member of the housing. An axially oriented release flange 716 is arranged on the outer surface of the control member, rotatably aligned with the control edge 714. The control edge 714 extends in the distal direction to form a sharp latch 715 adapted to sit abut against a slot 435 in the tower-like member. A large portion of the helical flange 710 has a larger first diameter, while the cut-out portions 711 on each side of the control edge 714 have a smaller diameter corresponding to the height of the control edge, allowing the actuator protrusion 516 to pass axially. The control member further includes a distally oriented helical edge 720, the end of which connects to an axially oriented second control edge 729 adapted to engage with a tower-shaped stop protrusion 439. The inner surface of the control member includes a pair of opposing spline ridges 730 adapted to engage with corresponding spline grooves in the drive tube. At the distal end, and aligned with the spline ridges, a pair of opposing stop flanges 735 are arranged, adapted to engage with a piston rod stop surface 655.

[0040] like Figure 10A and Figure 10B As shown, the drive member 800 includes a proximal cylindrical spring housing portion 801 and a distal drive tube portion 802. The drive tube portion includes, at its distal end, a pair of internally opposing, axially oriented drive flanges 810 adapted to engage with a piston rod drive recess. Along the length of the drive tube portion, a pair of opposing spline grooves 830 are provided, adapted to engage with corresponding control member spline ridges 730. As described below, the spline grooves may include friction structures to prevent the control members from sliding freely on the drive member tube portion 802. The spring housing 801 includes, at its distal end, an inner circumferential flange forming a circumferential recess 820 adapted to receive the distal end of the drive spring, the recess including an elongated snap-fit ​​opening 821 adapted to receive a distal hook of the drive spring. The spring housing includes a pair of opposing flexible arms 822 that slightly protrude into the interior of the spring housing, the arms being adapted to engage with the spring during assembly and hold it axially in place. An outer circumferential support flange 823 is provided at the proximal end to ensure concentricity between the drive member 800 and the spring seat 900, and a circumferentially oriented and outwardly protruding flexible ratchet finger 825, the free end of which is adapted to rotatably engage the circumferential ratchet surface 915 on the spring seat 900.

[0041] Figure 11 A piston rod 650 is shown, which includes a thread 651 and a pair of opposing drive grooves 652 along its length. The proximal end includes a distally facing stop flange 655 adapted to engage with a control member stop flange 735. The distal end 654 is adapted to engage with a piston washer 395, which, in the illustrated embodiment, is a flat disc. Alternatively, the piston washer may have a proximal-facing centering device adapted to engage with the distal end of the piston rod; for example, the piston washer and the distal end of the piston rod may have corresponding snap-fit ​​connections.

[0042] like Figure 12 The drive spring 890 shown is a tightly wound helical spring with no gaps between adjacent windings, and includes a distal hook 891 arranged in the axial plane and a proximal hook 892 arranged in the transverse plane.

[0043] like Figure 13A and Figure 13B As shown, the spring seat 900 includes a proximal planar end face 901, from which extend an outer circumferential skirt 902, an inner circumferential skirt 910 having a distal support edge 912 for the proximal end of the return spring 590, and a central tower portion 920 providing internal support for the drive spring. The inner surface of the inner skirt includes, distally, a circumferential ratchet surface 915 adapted to engage with a clicker finger 825. The inner skirt further includes a pair of opposing snap-fit ​​openings 911 adapted to engage with a housing snap-fit ​​finger hook 421. Between the inner skirt and the central tower portion is a pair of opposing, distally extending fingers 930, each finger including a longitudinally extending free spring edge 932 adapted to engage with the proximal hook 892 of the drive spring in an axially sliding engagement manner. The sliding engagement allows the spring seat to be inserted into the housing after the spring has been tensioned, just as the spring hook can slide on the edge of the spring when the spring shortens during the release of tension.

[0044] The various components of the drug delivery device 1 have been described. Figure 14 A cross-sectional view of the assembled device is shown. For clarity, the cartridge holder, cartridge, and return spring have been removed; however, the aforementioned components are still present. Figure 2As can be seen in the image. More specifically, a tensioned drive spring 890 is arranged in a spring housing 801 and provides rotational force to the piston rod 650 via a drive tube portion 802, thereby achieving distal axial movement through threaded engagement with a drive nut 600. The drive tube portion 802 is splinedly engaged with a control member 700, so that the drive tube portion 802 is prevented from rotating as long as the control member is in its rotational "parked" position, where the control member control edge 714 engages with the tower-shaped stop edge 434 (see below). The control member is released from the parked position when the actuator member is moved proximally by the needle unit guard, causing the control member to move proximally (see below).

[0045] Figure 15 The diagram shows in detail how the proximal hook 892 of the drive spring engages with the longitudinally extending free spring edge 932 in an axial sliding engagement manner. Figure 16 The diagram shows in detail how the distal hook 891 of the drive spring rotates to engage with the snap opening 821. Figure 17 The diagram shows in detail how the locking finger 521 engages with the housing locking surface 407 to prevent accidental axial movement of the actuator. The piston rod 650, which engages with the cartridge piston 392 via a piston washer 395, is also shown.

[0046] The illustrated embodiment can be assembled according to the following steps: (i) inserting the drive nut 600 into the housing, engaging it in place with axial play; (ii) inserting the control member 700 into the housing tower, aligning the stop edge and the control edge; (iii) inserting the actuator 500, positioning the leg within the cartridge portion of the housing, with the cylindrical proximal portion 501 surrounding the control member and the housing tower, and a shoulder on the inner wall of the housing used to deflect the leg inward, thereby allowing it to move into the cartridge portion; (iv) inserting the drive tube portion 802 of the drive member into the housing tower; (v) inserting the return spring 590, engaging the actuator spring support flange 510 distally, while temporarily holding it in place proximally by the housing snap-lock finger hook 421; (vi) inserting the piston rod 650 into the drive tube, rotating the drive tube 180 degrees back and forth to allow the piston rod thread to engage with the drive nut thread; and (vii) inserting the drive spring 890 into the spring housing 801. (viii) The drive spring distal hook is rotated into the snap-fit ​​opening 821, and (ix) the spring seat 900 is partially inserted into the housing and rotated to tension the drive spring, whereby during the initial rotation, one of the spring edges 932 engages with the drive spring proximal hook 892. The spring seat is then moved fully into the housing, whereby it snaps into the housing snap-fit ​​finger hook 421, thereby displacing the return spring, which then sits against the spring seat distal support edge 912, while the clicker finger 825 engages with the ratchet surface 915. The cartridge 390 is inserted into the cartridge holder, and the piston washer is placed on the cartridge piston. The housing cartridge portion is slightly elliptical to allow insertion into the cartridge holder, so that the window wall 316 snaps into the housing window 416, while the flexible cartridge support arm 320 engages with the pressure edge 437 and deforms into the free space 322 on the distal side of the arm, thereby eliminating axial play of the installed cartridge. In addition to forcing the cartridge case to engage with the distal portion of the cartridge case holder, the cartridge case holder is also forced distally to engage with the housing, for example, forcing the distal end of window wall 316 to engage with the distal end of housing window 416, thereby eliminating axial play between the cartridge case and the housing. Simultaneously, piston washer 395 engages with the distal end of piston rod, thereby causing piston rod and drive nut to move slightly proximally, eliminating gaps between piston rod and piston washer, and (xii) fusing drive nut to housing by applying a laser beam, for example, through housing nut opening 406. As a final step, a label (not shown) is affixed to the proximity portion of housing to cover the snap-lock and nut opening. In an alternative embodiment, a modified piston washer is snapped onto a modified piston rod, and then the cartridge case holder is inserted into the housing, preventing the piston washer from dislodging before being engaged by the piston rod.

[0047] Before referring to the description needle unit, the following will be consulted. Figures 18A-18FDescribe the operation of the drug delivery device (when actuated by the needle unit). Since the drug delivery device can only deliver a drug dose via the installed needle unit when released, the two units together can be referred to as forming a combined drug delivery system.

[0048] When the needle unit is mounted on the cartridge mount 310, the actuator leg 502 is engaged by the needle unit needle seat 100 and the guard 200, thereby rotating the actuator from the initial locked position (here: 20 degrees) to the actuated unlock position, in which (i) the locking finger 521 is no longer aligned with the housing locking surface 407, which allows the actuator to subsequently move proximally, (ii) the PONR wedge 530 is aligned with the housing PONR flexible arm 408, and (iii) the anti-rotation clutch 517 moves from its initial position to its actuated position, which will be described in more detail below in conjunction with the mounting of the needle unit.

[0049] More specifically, Figure 18A (Partially) the device is shown in its pre-drug administration state after the needle unit has been installed. The control member 700 is in its most distal position, with the control edge 714 engaging the tower-shaped stop edge 434. This prevents the drive spring from rotating the drive tube 802, as the control member and drive tube are splined together. Additionally (not shown), a second control edge 729 engages with the tower-shaped stop protrusion 439. The actuation protrusion 516 has been rotated to align with the release flange 716.

[0050] When the user inserts the needle of the needle unit subcutaneously (see below), the needle guard resists the force of the return spring, causing the actuator to move proximally, thereby moving the actuator actuation protrusion 516 past the control edge 714 and engaging the distal end of the control member release flange 716. As the locking flange 511 moves together with the actuator protrusion 516, the control member can move proximally. When the needle guard (and thus the control member) has moved to its proximal position, the control member control edge 714 has moved to disengage from axial engagement with the tower-shaped stop edge 434 (see below). Figure 18B This allows the control member and the drive tube 802, which is splined to it, to rotate, which causes the piston rod to rotate and move distally, thereby discharging the drug. During the rotational movement of the drive member, a clicking sound is produced as the clicker finger 825 rotates relative to the ratchet surface 915.

[0051] Before the ejection mechanism is released, the actuator PONR wedge 530 has moved past the housing PONR stop surface (thanks to the flexibility of the PONR flexible arm 408), which prevents the actuator and therefore the needle guard from returning to its initial position. Accordingly, if the user pulls out the inserted needle at this time, the unreset needle guard will indicate to the user that the device's actuation is "in progress" and an injection should be administered. Additionally, the PONR arrangement prevents the return spring from applying force to the control member via the activation protrusion 516. If this were allowed, friction would be generated, slowing dose delivery.

[0052] When the control member 700 begins to rotate, the helical flange 710 moves into the gap between the helical end face 433 of the tower-shaped member and the distal end of the actuating protrusion 516. These three structures form a threaded connection, thereby ensuring that the control member moves distally during rotation (see...). Figure 18C ).

[0053] Figure 18D The state is shown just before the end of the dose. The control member control edge 714 approaches and engages with the tower-shaped stop edge 434, while the control member release flange 716 approaches the actuation protrusion 516. Finally, the control edge and the stop edge engage with each other, and rotation and outward drug delivery reach the final state. Simultaneously, the release flange 716 has rotated the actuation protrusion 516 (and thus the connector) back to its initial rotation-locked position (see...). Figure 18E ).

[0054] It should be noted that in this final state, the actuating protrusion 516 aligns with the flange cutout 711, which allows the control member to move proximally. For example, if the device is used in an inverted orientation, it will move due to gravity, causing the control edge 714 to move axially until it disengages from the tower-shaped stop edge 434, thus allowing the control member 700 to continue rotating and thus expel further dose. To prevent such gravity-induced conditions, the spline engagement 730, 830 between the control member and the drive tube can be provided with a friction structure whose frictional force can be easily overcome by the energy provided by the drive spring, but not by gravity. Alternatively, the control member can include an integrated return spring, or an additional helical spring can be provided between the two components.

[0055] When the user withdraws the needle from the skin, the actuation protrusion 516 aligns with the flange incision 711, allowing the return spring to move the actuator (see...). Figure 18FThis also causes the needle guard to move distally to its initial distal position. During this axial movement, the actuator locking fingers 521 rotate to align with the housing locking surface 407; however, due to their flexibility, they may extend beyond the locking surface. Conversely, during the final rotation of the actuator, the PONR wedge 530 moves to disengage from the housing PONR stop surface 409. As the actuator moves distally, the locking flange 511 (in...) Figure 18F Hidden in the middle, see also Figure 18A Re-engage the control member flange 710, thereby moving the control member back to its initial distal position (see...). Figure 18F The sharp snap 715 rests against the tower-shaped slot 435, while the serrated clutch portion 517 re-engages the housing to reactivate the anti-rotation clutch in its initial rotating position.

[0056] In this state, the control member 300, actuator 500, and drive member 800 have returned to their initial positions, the piston rod has moved distally corresponding to the preset dose size, and the drive spring has responded to the single-dose release tension. When the intended dose number (e.g., 4 doses) has been discharged, the piston rod has moved to its furthest position, where the piston rod stop surface 655 is positioned very close to the control member stop flange 735, preventing further actuation of the control member. Alternatively, a stop surface between the piston rod and the nut can prevent further rotation of the piston rod, thereby preventing activation of the device.

[0057] In the exemplary embodiments described above, an axially oriented stop edge and an axially oriented control edge are provided, allowing the control member to rotate 360 ​​degrees between disengaging and re-engaging with the stop edge. In an alternative embodiment (not shown), two stop edges spaced 180 degrees apart are provided, allowing the correspondingly improved control member to rotate 180 degrees between disengaging and re-engaging with the stop edge. In another alternative (not shown), three stop edges spaced 120 degrees apart are provided, allowing the correspondingly improved control member to rotate 120 degrees between disengaging and re-engaging with the stop edge. Such improvements to the drug delivery device described above can be adapted to deliver 8 or 12 fixed-volume doses, instead of 4 as disclosed.

[0058] As described below for the needle unit, in this state, the needle guard is locked in its distal position, thus preventing the dosing engine from being released, which provides protection against double dosing. To allow for further dose delivery, a new needle unit must be installed.

[0059] For example, such as Figure 6AAs shown, the distal end of the housing includes an indicator opening 405. When the needle unit needle seat assembly 100 rotates during actuation, the indicator portion on the needle seat assembly moves to align with the indicator opening, indicating that a drug dose has been dispensed.

[0060] The components and operation of the drug delivery device itself have been described in detail. The needle unit and its operation will be described in detail below.

[0061] like Figure 1 and Figure 3 As shown, the drug delivery device 1 is adapted to receive a protected needle unit 2, which includes: a needle hub 100 adapted to be mounted on a corresponding mounting seat on the drug delivery device; a hypodermal hollow needle 101 mounted in the needle hub and including a sharp, free distal portion adapted to be inserted subcutaneously through the user's skin and a sharp, free proximal portion adapted to be inserted through a puncturable cartridge septum; and a shield member 200 in which the needle hub is disposed. The hypodermal hollow needle 200 includes beveled proximal and distal ends and is disposed in a needle hub hole and secured in place by, for example, adhesive. The needle unit is provided as a needle assembly, which further includes a container 280 (see...). Figure 22 The container 280 is adapted to receive a needle unit in an assembled state, the container having an open end adapted to be sealed with a flexible foil member, thereby providing a sealed, sterile interior for the needle unit when provided to the user.

[0062] needle unit Figure 1 A needle unit 2 is shown mounted on an injection device 1 adapted to releasably receive the needle unit. In the illustrated embodiment, the shield has an externally elliptical cross-sectional configuration, allowing it to be received in a correspondingly formed distal opening of the injection device 3. Alternatively, other non-circular designs, such as square or triangular, may be used, or the needle unit may be circular, with its direction of rotation provided by a cooperating guide structure.

[0063] As will be apparent from the following detailed description of exemplary embodiments of the needle unit, the functionality of the unit depends on the rotational movement between the needle hub and the shield, regardless of the external configuration of the shield.

[0064] As will be explained in more detail below, the needle hub 100 (hereinafter also referred to as the "hub" or "needle hub assembly") and the shield assembly 200 (hereinafter also referred to as the "shield") include multiple interacting structures that allow the shield and the needle hub to move axially and rotate relative to each other in a controlled manner during the use and operation of the needle unit. In the embodiments described below, the shield is rotationally locked relative to the cartridge mount, while the needle hub is axially locked relative to the cartridge mount when the needle unit is mounted on the cartridge mount. The rotational movement of the needle hub is controlled by the axial movement of the shield relative to the cartridge mount, and thus relative to the needle hub.

[0065] As will be explained in more detail below, the container and shield components include interacting structures that allow the container to be used efficiently and user-friendly as a tool for installing and removing needle assemblies during use. The shield, needle hub, and container typically consist of pairs of opposing functional structures; however, any suitable number of such structures, such as one, two, or three, can be used.

[0066] like Figure 19A and Figure 19B As shown, the shield 200 has a generally tubular configuration, having a circumferential outer wall 210, a proximal opening with a circumferential edge 211, and a distal surface 201 with a smaller distal opening 212, from which a tower-like structure protrudes axially inward. In the illustrated embodiment, the tower-like structure includes a circumferential skirt portion 215 from which a first pair and a second pair of opposing arms extend proximally and are rotated 90 degrees. The skirt portion includes free clamping edge portions 216 between the arms. The first pair of longer arms are in the form of flexible assembly arms 220, each arm having a hook 225 at its proximal free end, the hook 225 having a distally facing axial stop surface 221 adapted to engage with a corresponding proximal-facing stop surface 121 (see below) on the pin seat tower-like portion, and a proximal-facing ramp surface 222 used during the assembly of the pin unit. The second pair of shorter arms takes the form of flexible control arms 230, each arm having a hook 235 at its proximal free end. This hook 235 has a proximal ramp surface 231 and a distal control surface 232, which are adapted to engage, respectively, a distal ramp surface and a proximal control surface (see below) on the needle seat tower portion. At the proximal end, the shield includes opposing pairs of inner actuating ribs 213 adapted to engage with the corresponding flexible needle seat arms (see below). The actuating ribs 213 also serve to lock the connecting arm (see below) and center the generally circular needle seat at the center of the hyperelliptical shield, thereby ensuring stability of axial and rotational movement between the needle seat and the shield during operation. The shield further includes a pair of opposing locking ribs 217 on its inner wall surface, each rib having a proximal locking surface 218 adapted to engage with a corresponding locking surface on the needle seat. The locking rib extends proximally into a lower torque rib 219, which is adapted to engage with a torque flange (see below) on the needle hub. The shield wall 210 further comprises a pair of externally opposing mounting ribs 245 adapted to engage with corresponding shield grooves 415 in the housing, a pair of opposing windows 240 adapted to allow outward movement of the needle hub connecting arm (see below), and a first indicator opening 241 and a second indicator opening 246. In the illustrated embodiment, the first indicator opening 241 is "open" because, for design reasons, the shield edge 211 includes cutouts for structures in a drug delivery device.

[0067] like Figure 20A and Figure 20B As shown, the needle hub 100 includes a distal tower portion 110 and a proximal skirt portion 120. The distal tower portion 110 includes a central hole 111 adapted to receive a hypodermic needle. At the distal end, the tower portion includes three pairs of opposing functional surfaces adapted to cooperate with corresponding surfaces on the shield: (i) a pair of proximal-facing stop surfaces 121 adapted to engage a distal-facing stop surface 221 on the shield assembly arm; (ii) a pair of distal-facing ramp surfaces 131 adapted to engage a proximal-facing ramp surface 231 on the shield; and (iii) a pair of inclined proximal-facing control surfaces 132 adapted to engage a distal-facing control surface 232 on the shield during operation. At the proximal end, the tower portion includes a pair of opposing snap-fit ​​recesses 135 adapted to engage with a control arm hook portion 235. The skirt-like portion 120 includes a pair of opposing, proximal-extending flexible connecting arms 126, each arm having an outer surface 123 adapted to engage with an actuating rib 213 within the housing during operation, and an inwardly facing snap-fit ​​connecting ridge 127 disposed at the free proximal end of the connecting arm and adapted to engage with a corresponding connecting structure on the cartridge mount 310. The skirt-like portion further includes a pair of distally-facing locking surfaces 118 adapted to engage with the proximal-facing housing locking surface 218 during operation. The skirt-like portion further includes: a pair of radially projecting, opposing locking release flanges 114 adapted to engage with an actuator leg release surface 524; a pair of radially projecting, opposing torque flanges 119 adapted to engage with a housing torque rib 219; and a pair of opposing indicator cutouts 115. Torque interfaces may also be located on other portions of the housing and needle hub, such as between the assembly arm and the needle hub tower portion.

[0068] like Figure 21A and Figure 21B As shown, the container 280 has a generally tubular configuration, having a superelliptical circumferential outer wall 281, a proximal opening with a circumferential flange 282, and a closed distal end 283. A tower-like structure 285 and a pair of opposing snap-lock fingers 290 extend axially inward from the distal end 283. Each snap-lock finger includes an outwardly oriented snap-lock protrusion 296 adapted to releasably engage the tower-like clamping edge portion 216 of the shroud to provide a snap-lock connection. The container further includes a plurality of internal support ribs 286 on the distal side, which are adapted to engage with and support the outer surface of the shroud when the shroud is arranged in the container. When the shroud is installed in the container, the proximal portion provides a circumferential space 299 between the container and the shroud (see...). Figure 22This allows a correspondingly shaped drug delivery housing portion to be received within the needle unit during its attachment to the drug delivery device.

[0069] During assembly, a hollow hypodermic needle 101 with beveled proximal and distal ends is positioned in the needle hub hole and secured in place by means of, for example, adhesive, providing a free distal portion 102 and a free proximal portion 103. The needle hub 100 is then inserted into the shield 200, with the stop surface 121 and the ramp surface 131 rotatably aligned with the shield stop surface 221 and shield ramp surface 231, respectively, allowing the shield stop surface to snap into the needle hub stop surface 121. The needle hub connecting arm 126 is also rotatably aligned with the shield actuating rib 213. In the illustrated embodiment, the proximal end of the needle hub is positioned slightly proximal to the proximal edge 211 of the shield. The assembled needle unit is then inserted into a container, with the container snap-locking finger 290 engaging with the shield tower-shaped clamping edge portion 216. Figure 22 As seen, an axial gap is provided between the proximal end of the container tower-shaped member and the distal end of the needle tower-shaped member. As a final assembly step, a flexible foil member (not shown) is attached to the proximal flange 282 of the container, thereby sealing the interior for subsequent sterilization. Figure 22 The needle assembly is shown in cross-sectional view prior to the attachment of the sealing foil, with the needle unit located in the container.

[0070] The following will refer to Figures 23A-23J To describe the different features and aspects of the above-mentioned needle unit and container combination, Figures 23A-23J The diagram shows a needle unit mounted on a corresponding drug delivery device, operated to allow subcutaneous injection of a certain amount of fluid drug, and subsequently removed from the drug delivery device. Figures 24A-24C The indicator function is also shown.

[0071] After the user removes the flexible sealing foil from the container 280, the container is intended to be used as a tool for mounting the needle unit onto the drug delivery device 1 with the corresponding cartridge mount 310, see [link to relevant documentation]. Figure 23A In the illustrated embodiment, the cartridge mount is positioned proximal to the distal end of the cartridge portion 402 of the drug delivery device housing, with a circumferential space between the cartridge holder 300 and the housing. This circumferential space is adapted to receive the proximal portion of the shield 200 in a non-rotational engagement via cooperating mounting ribs 245 and shield grooves 415. In the illustrated embodiment, the non-circular design allows the user to easily rotate the needle assembly relative to the drug delivery device to correctly orient it to either of its two possible rotational positions.

[0072] Initially, the locked needle hub connecting arm 126 engages with the cartridge mount connecting flange portion 311, which allows the container to push the shroud forward to an axial position where the shroud actuating rib 213 does not engage with the outer surface 123 of the flexible needle hub arm, see [link to relevant documentation]. Figure 23B The control arms 230 can bend freely outward to allow movement of the proximal shield, but they will not engage with the ramp surface 131. It should be noted that... Figure 23B In the image, these two structures appear to overlap due to drawing constraints. Alternatively, a gap can be provided between these two structures.

[0073] The container ensures that the user can firmly push the shroud and needle hub to engage with the cartridge mount, allowing the free proximal portion 103 of the needle to penetrate the cartridge diaphragm 394, and the flexible needle hub connecting arm 126 to first move radially outward in the receiving shroud window 240, and then radially inward to engage with the corresponding snap-fit ​​connecting flange 311 on the cartridge mount, see [link to relevant documentation]. Figure 23C .

[0074] During the axial coupling movement of the needle unit, the needle seat locking release flange 114 engages with the inclined leg release surface 524 on the spring-biased actuator leg 502. Initially, the actuator moves axially until the anti-rotation clutch portion 517 moves to disengage from the housing, allowing the actuator to be rotated by the axial movement of the needle seat. To counteract the torque applied to the needle seat during actuator rotation, the needle seat is supported by a shield (which is non-rotatably coupled to the housing 400) via the torque flange 119 engaging with the torque rib 219. Subsequently, the shield actuator rib 213 engages with the leg actuation surface 523 of the actuator leg 502 and moves axially together with the locking release flange 114. Depending on the actual design of the different components, the actuator can be fully rotated (here: 20 degrees) during needle unit installation. Alternatively, the final rotation of the actuator can occur when the actuator is subsequently allowed to move distally by the return spring 590.

[0075] When the needle hub engages with the cartridge mount, the axial mounting movement of the needle unit ceases, indicating to the user that the needle unit has been mounted on the cartridge needle hub. When the user stops pushing the cartridge (or begins to pull it out), the spring-biased actuator leg 502 pushes the shroud 200 slightly distally until the distally facing axial stop surface 221 on the shroud assembly arm engages with the corresponding proximal facing stop surface 121 on the needle hub tower portion. The control arm 230 moves back to its initial position. Simultaneously, the clutch portion 517 re-engages with the housing locking rib 447 in the actuated rotation position. As the shroud moves distally, the shroud actuation rib 213 moves to engage with the outer surface 123 of the flexible needle hub arm, preventing radial outward movement. This securely locks the needle hub 100 to the cartridge mount 310, corresponding to the actuated needle hub engagement lock state, in which the mounted needle unit cannot be removed from the drug delivery device. See [link to relevant documentation]. Figure 23D .

[0076] As the user pulls the container 280 further distally to remove it completely, the container snap-fit ​​connector 296 disengages from the shield 200. Once the container is completely removed, the drug delivery device with the needle unit is ready for use. Figure 23E As shown. In this state, the housing indicator opening 405 is aligned with the first indicator opening 241 of the shield and the needle hub indicator cutout 115. Therefore, the needle hub skirt 120 is not visible to the user (see...). Figure 24A ).

[0077] As the user pushes the needle unit toward the skin surface, the shield 200 is pushed proximally, allowing the distal end 103 of the subcutaneous needle to be inserted. During the initial proximal movement of the shield, the ramp surface 231 on the flexible control arm 230 is pushed past the ramp surface 131 of the needle seat tower. As the shield moves further proximally to its fully retracted position, the shield actuator rib 213 pushes the pair of actuator legs 502 proximally, thereby releasing the drug delivery device ejection mechanism and initiating the subcutaneous injection as described above, see [link to relevant documentation]. Figure 23F As can be seen, the actuator leg 502 acts both as a locking actuator for the needle hub connector and as a release member of the dispensing mechanism. During external drug delivery, the shield is held in its fully retracted position by the latches 135, 235. In this state, the housing indicator opening 405 aligns with the shield second indicator opening 246 and the needle hub indicator cutout 115. Therefore, the needle hub skirt 120 is not visible to the user (see...). Figure 24B ).

[0078] After the clicking sound stops and the dose has thus been completely expelled, the user withdraws the needle unit from the skin surface, allowing the spring-biased actuator leg 502 to push the shield actuation rib 213, thereby moving the shield 200 distally to its fully extended position, once again covering the distal portion 103 of the needle. During this movement, the control surface 232 on the control arm 230 will engage with the proximal-facing inclined control surface 132 on the needle seat tower (see... Figure 20A This engagement will force the needle hub 100 to rotate as the shield is rotated and locked to the drug delivery device, see [link / reference]. Figure 23G In the illustrated embodiment, the needle hub is rotated 45 degrees relative to the shield; please compare... Figure 23CX and Figure 23GX .

[0079] During the rotation of the needle hub relative to the shield, multiple structures are moved to engage and disengage from each other.

[0080] (i) As the needle hub rotates, a portion of the needle hub skirt 120 adjacent to the needle hub cutout 115 aligned with the housing indicator opening 405 rotates to align with that opening, thus becoming visible to the user (e.g., by having a contrasting color), indicating that the needle unit has been used and, accordingly, a dose of medication has been dispensed. During medication dispensing, when the shield is in its retracted position, the shield second indicator opening 246 aligns with the housing indicator opening 405 (see...). Figure 24C ).

[0081] (ii) As the needle hub rotates, the flexible needle hub connecting arm 126 rotates until it disengages from the shield actuating rib 213, thereby allowing the connecting arm to move radially outward, see [reference]. Figure 23H This removes the needle hub 100 from the cartridge mount 310. To reduce the force required to detach the needle hub connecting arm from the cartridge mount, the needle hub connecting arm is rotated to a position on the cartridge mount with a lower and less inclined release flange portion 312.

[0082] (iii) Since the needle is fixed in the needle hub, it will rotate with the rotating needle hub; however, it may not be desirable for the needle to rotate when fully inserted subcutaneously. Accordingly, the needle hub and shield can be designed to have axial “play” before the shield control surface 232 engages with the inclined needle hub control surface 132, which allows the needle to be at least partially withdrawn from the skin before rotation begins. In practice, the later the rotation begins, the steeper the inclination of the needle hub control surface must be.

[0083] (iv) Prior to operation of the needle unit, the pair of locking ribs 217 on the inner surface of the shield are axially movable, allowing the shield to move from its extended position to its retracted position. When the needle holder rotates, the pair of distally facing locking surfaces 118 rotate to align with the proximal end 218 of the locking ribs 217, thereby preventing repeated retraction of the shield and thus preventing the use of the needle unit, providing a safety lock. See also... Figure 19B and Figure 20A Accordingly, the locking surface should be designed to withstand relatively large forces to prevent the needle unit from reactivating, for example, if the pen-type device is dropped onto a hard surface or in a misuse scenario. Furthermore, if the drug delivery device, as in this embodiment, is released by the shield, the shield lock will also act as a dual-dose prevention device.

[0084] (v) In the illustrated embodiment, the container is also intended to be used as a tool for removing the needle unit, see [link to example]. Figure 23IWhen the user reattaches the container, the container snap-fit ​​connector 296 engages the shield 200. The container snap-fit ​​connector is designed with a release force greater than that required to axially pull the ridge 127 of the flexible needle hub connector arm to disengage from the cartridge mount release flange 312. This allows the needle unit to be removed from the cartridge mount, which is securely held in the container, and then safely disposed of. See [link to relevant documentation]. Figure 23J Because the needle unit is locked to the container via a snap-fit ​​connector, and its proximal end is located at a certain distance inside the container and surrounded only by a small area of ​​free space, removing the needle unit from the container will be difficult.

[0085] (vi) When the needle holder rotates, the locking release flange 114 is rotated to be misaligned with the actuator leg release surface 524, which prevents a used and locked needle unit from being used to release the actuator lock.

[0086] Alternative embodiments: In the embodiments described above, when the needle hub rotates relative to the cartridge mount, the flexible connecting arm 126 is rotated to align with the inclined release flange 312, thereby allowing the needle hub connecting arm to easily disengage. This encourages the user to remove the needle unit without using the container. To encourage the user to use the container, the release flange could be modified to require a greater release force, making it more difficult to simply grasp and pull the shroud to disengage from the needle hub mount. To allow this, the snap-fit ​​connection between the container and the shroud must be able to transmit the required force; however, this may not be ideal because the same snap-fit ​​connection should be designed to allow easy removal of the container after the initial needle unit installation.

[0087] Accordingly, a needle assembly may be provided comprising a snap-fit ​​coupling between a container and a shield, the snap-fit ​​coupling being actuable between a first state and a second state, in which a needle unit can be removed from the container using a first magnitude of force, and in a second state, in which a second, larger magnitude of force can be used to remove the needle unit from the container. The assembly can be operated between these two states by rotational movement of the needle holder within the shield. A detailed description of such an arrangement is described in common pending application EP 23174814.6, which is incorporated herein by reference.

[0088] In the embodiments described above, the indicator is incorporated into the drug delivery housing and operated by the rotational movement of the needle hub. Although the actuation of the indicator is controlled by the needle unit, the placement of the indicator window 405 on the housing is designed to associate the indicator with the operation of the device itself, thus indicating that a drug dose has been dispensed, which occurs when the shield has returned to its extended and now locked position.

[0089] However, it may be desirable to mount the indicator on the housing so that it directly indicates that the needle module has been used and is now locked. Accordingly, instead of the device housing, the housing may have an indicator window, and the needle holder may have an indicator surface that is not initially aligned with the window but moves to be aligned with the window when the needle holder is rotated after use.

[0090] In the above description of exemplary embodiments, different structures and devices for providing the functions of different components have been described to a degree that will be readily understood by a skilled reader. The detailed construction and specifications of the different components are intended for the purposes of a normal design procedure performed by a skilled person following the routes set forth in this specification.

Claims

1. A cartridge holder (300) adapted to receive a cartridge (390) containing a drug and having an axially movable piston (392), the cartridge comprising a distal outlet portion, a cylindrical body portion, and a proximal portion having a circumferential edge (391), the cartridge holder comprising: - A main body portion adapted to receive the cartridge and define a reference axis. - Suitable for engaging and supporting the distal portion of the distal outlet portion of the cartridge, and - A proximal portion adapted to engage and support the proximal portion of the cartridge. The proximal portion includes: - A proximal opening (301) that allows the cartridge case to be inserted into the cartridge case holder along the reference axis. - At least one circumferentially arranged flexible support arm (320) having a free end with a protrusion (321) extending into the proximal opening, the flexibility of the arm allowing the protrusion to be removed from the proximal opening, and - In the free space (322) on the distal side of the flexible support arm, the support arm is allowed to move in the distal direction.

2. The cartridge holder of claim 1, wherein the proximal portion forms a circumferential edge (323), and the at least one flexible support arm (320) has a proximal-facing edge that forms part of the circumferential edge.

3. The cartridge holder as claimed in claim 1 or 2, adapted to receive a cartridge (390) containing a drug, wherein the main body portion and the proximal portion having a circumferential edge have a generally circular cross-section, wherein: - The circumferential edge (323) of the near side of the cartridge is approximately circular.

4. The cartridge holder as claimed in any one of claims 1-3, wherein the proximal portion is generally cylindrical, and the at least one flexible support arm, in addition to the protrusion, forms part of the cylinder.

5. A cartridge holder as claimed in any one of claims 1-4, which is combined with a correspondingly defined cartridge containing a drug, the cartridge being disposed in the cartridge holder, wherein the at least one flexible support arm protrusion (321) is disposed proximal to the circumferential edge (391) of the cartridge.

6. The cartridge holder as claimed in any one of claims 1-4, wherein it is combined with the following components: - The corresponding definition of a cartridge containing a drug (390), and - The drug delivery device engine section, which together form a drug delivery device adapted to dispense a dose of drug from the distal outlet end of a cartridge filled with drug. in: - The cartridge (390) is disposed in the cartridge holder (300), and the at least one flexible support arm protrusion (321) is disposed near the circumferential edge (391) of the cartridge. - The cartridge holder is mounted to the engine section of the drug delivery device, and - The drug delivery device engine section includes a mounting structure (437) that axially engages the at least one flexible arm (320) to deform and move it into the free space.

7. The combination as defined in claim 6, wherein the drug delivery device engine portion comprises: - A drug dispensing mechanism comprising an axially movable piston rod (650) adapted to engage and axially move the cartridge piston (392) to dispense a dose of drug. - Drive mechanism (800, 890) for moving the piston rod distally.

8. The combination as defined in claim 7, wherein the drug delivery device engine portion is adapted to dispense a preset or user-configurable dose of drug.

9. A method for assembling components of a drug delivery device, comprising the following steps: (i) A cartridge containing a drug with an axially movable piston is provided, the cartridge comprising a cylindrical body portion, a distal outlet portion, and a proximal portion having a circumferential edge (391). (ii) Provide a cartridge holder (300) comprising: - A main body portion adapted to receive the cartridge and define a reference axis. - Suitable for engaging and supporting the distal portion of the cartridge case, and - A proximal portion adapted to engage and support the proximal portion of the cartridge, comprising: - A proximal opening (301) that allows the cartridge case to be inserted into the cartridge case holder along the reference axis. - At least one circumferentially arranged flexible support arm (320) having a free end with a protrusion (321) extending into the proximal opening, the flexibility of which allows the protrusion to be radially removed from the proximal opening, and - In the free space (322) at the distal end of the flexible support arm, the support arm is allowed to move in the distal direction. (iii) A drug delivery device housing (400) suitable for mounting the cartridge holder is provided, which includes a mounting structure (437) suitable for axially engaging the at least one flexible arm. The method further includes the following steps: (iv) Inserting the cartridge case (390) through the proximal opening (301) of the cartridge case holder into the cartridge case holder (300) thereby moving the at least one flexible support arm protrusion (321) outward and then inward, the flexible support arm protrusion thereby being positioned proximal to the circumferential edge (391) of the cartridge case, and (v) The cartridge holder (300) is mounted to the delivery device housing (402, 416), wherein the mounting structure (437) thereby axially engages the at least one flexible arm (320) to bend it into the free space (322), thereby applying a distally oriented axial force on the cartridge (390) via the at least one flexible support arm protrusion (321).

10. The method of assembling components of a drug delivery device as claimed in claim 9, wherein: - The provided cartridge (390) includes a distally inwardly inclined neck for radially moving the at least one flexible support arm protrusion (321) when the cartridge is inserted through the proximal opening of the cartridge holder.

11. The method of assembling components of a drug delivery device as claimed in claim 9 or 10, wherein: - The provided drug delivery device housing (400) includes a drug dispensing mechanism (800, 890) with a piston rod (650) having a distal end (654) which engages with the cartridge piston (392) when the cartridge holder is installed into the delivery device housing.

12. The method of assembling components of a drug delivery device as claimed in claim 11, wherein a piston washer (395) is positioned between the distal end of the piston rod (654) and the cartridge piston (392).

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