Shielded needle unit with operable container coupling

Abstract

The needle assembly comprises a needle unit and a container therefor. The needle unit comprises a needle hub to which a distally projecting needle is attached, and a shield on which the needle hub is positioned. The shield is axially movable between an extended position in which the shield axially covers the distal end of the needle, a retracted position in which the distal end of the needle protrudes from the shield, and coupling means that enable the needle unit to be mounted on a drug delivery device. The assembly comprises a snap coupling between the container and the shield, the snap coupling being actuated between a first engaged state in which the needle unit can be removed from the container using a first amount of force, and a second engaged state in which the needle unit can be removed from the container using a second, higher amount of force.

Description

Technical Field

[0001] The present invention generally relates to a needle unit adapted to be supplied to a user within a container, the needle unit comprising a hollow subcutaneous injection needle intended for subcutaneous introduction of a fluid formulation, the needle unit being adapted to be attached by a user onto a drug delivery device, and the needle unit comprising an axially movable needle shield designed to reduce the risk of accidental needle stick injury. A needle unit having a shielded needle is often referred to as a safety needle, especially when the shield is designed to be locked in place after use. In the field of subcutaneous injection needles, the term "needle" is sometimes used and sometimes the broader term "cannula" may be used.

Background Art

[0002] In the disclosure of the present invention, mainly subcutaneous injection needles intended for use by a patient for subcutaneous administration of fluid drug formulations are referred to, for example, in the treatment of diabetes by delivery of insulin or GLP-1 type drugs, or in the treatment of growth disorders by delivery of growth hormone, but these are merely exemplary uses of the present invention.

[0003] To administer such drugs, a considerable number of different drug delivery systems have been developed over the past 30 years. Drug delivery systems generally take the form of a “pen” device (due to its form) that has a cartridge containing the liquid drug to be injected. The pen device may be a durable type adapted to receive user-replaceable drug cartridges, or it may be a “pre-filled” disposable device provided with cartridges not intended to be replaced by the user. The pen device may be adapted to dispense single or multiple drug doses, and the size of the dose may be user-settable or preset and therefore not adjustable by the user. The dispensing mechanism for driving the fluid drug from the cartridge may be “manual,” with force applied to the pen device as the drug is dispensed. Alternatively, the pen device may be “automatic,” in which case a stretched spring provides energy to the dispensing mechanism. The spring may be compressed during dose setting, for example, as in the FlexTouch® pen offered by Novo Nordisk A / S, or the spring may be pre-compressed and provided to the user with enough energy to dispense one or more preset or user-set doses. As a further alternative configuration, the pen-type device may be motor-driven.

[0004] A common feature of all these diverse types of drug delivery devices is that they must be provided with an injection needle that allows for subcutaneous administration of the drug. The needle may be pre-attached, as is common with single-dose devices, but it has also been proposed to provide pre-attached needles suitable for repeated use with multi-dose devices.

[0005] In the case of multi-dose pen devices, the most common solution is to provide a single-use needle unit that is attached by the user to the pen device before use and is then intended to be discarded after use. The needle unit (also called a “needle module”) typically comprises a hub member adapted to be detachably mounted on the distal end of a cartridge, the hub member carrying a subcutaneous injection needle having a pointed distal end adapted for subcutaneous insertion and a pointed proximal end adapted for insertion into the cartridge through a needle-punctureable septum.

[0006] The problem presented by the handling and disposal of pen needle assemblies is the potential risk of injury from any of the sharp ends of the needle. This is particularly dangerous if it follows penetration of a patient's skin, as the needle may become contaminated and thus spread diseases such as hepatitis and HIV.

[0007] To address this problem, a considerable number of pen-needle units have been developed in which the patient end of the needle is concealed by a spring-loaded and retractably movable shield during and after injection, as disclosed, for example, in WO 01 / 91837, WO 03 / 066141, EP 1 289 587, EP 1 448256, and US 11,497,857.

[0008] If a shielded needle unit is provided, the shield may also be used to release a spring-driven ejection mechanism. Such needle units may typically be formed integrally with a pen-type device for single use, or they may be provided as user-installable needle units, for example, as disclosed in WO2018 / 215605.

[0009] In general, needle units, and by extension, shielded needle units, are conventionally supplied to the user in a sealed container and, after removal of the sealing member, can be used as an installation tool, and subsequently as a removal and disposal tool for used needle units. For example, WO2018 / 215605, mentioned above, discloses a needle unit supplied in a container that can be used as a tool for both the installation and subsequent removal of a used needle unit. More specifically, once supplied to the user, the needle unit is held in place within the container by friction. When the needle unit is used for drug delivery, the shield is returned to a more distal position, allowing the container to snap-engage with the shield when the container is mounted on the shield in order to remove the used and locked needle unit.

[0010] In relation to the above, the object of the present invention is to provide a shielded type of subcutaneous injection needle unit that can be manufactured cost-effectively, provides a high level of safety, and is easy and safe to handle during operation and use. [Overview of the project]

[0011] The disclosure of the present invention describes embodiments and aspects that address one or more of the above-mentioned objectives, or objectives that are evident not only from the following disclosure but also from the description of exemplary embodiments.

[0012] Accordingly, a first aspect of the present invention provides a needle assembly comprising a needle unit and a container adapted to house the needle unit. The needle unit comprises a needle hub, a hollow needle having a pointed distal end mounted within the needle hub and protruding from the needle hub, defining a reference axis, a shield on which the needle hub is fully or partially disposed, and coupling means enabling the needle unit to be mounted on a drug delivery device. The shield is axially movable relative to the needle hub between an initial extended position in which the shield axially covers the distal end of the needle, a retracted position in which the distal end of the needle protrudes from the shield, and a final extended position in which the shield axially covers the distal end of the needle. The assembly further comprises a snap coupling between the container and the shield, the snap coupling being actuated between a first state in which the needle unit can be removed from the container using a first amount of force and a second state in which the needle unit can be removed from the container using a second, higher amount of force.

[0013] In this way, a needle assembly is provided in which the gripping force between the container and the needle unit can be finely controlled and optimized, enabling the container to function as an initial tool for mounting the needle unit onto a drug delivery device and subsequently as a tool for removing the used needle unit, the configuration resulting in a low separation force when the user removes the container from the mounted needle unit and a higher separation force that allows the user to overcome the gripping force between the used needle unit and the drug delivery device. As shown, during normal use, the second higher separation force is not intended to be overcome.

[0014] The snap coupling may include cooperating first and second coupling means, respectively, disposed on the shield of the container, the first coupling means being operable between an initial state corresponding to a first state of the snap coupling and an activated state corresponding to a second state of the snap coupling. The first coupling means is activated from the initial state to the activated state when the shield moves from its extended position to its retracted position and back to its extended position.

[0015] In exemplary embodiments, the first coupling means comprises one or more radially flexible shield snap structures, for example, a pair of opposing snap structures, and the second coupling means comprises a corresponding container snap structure adapted to engage with the shield snap structures. The individual radially flexible shield snap structures may be, for example, thin-walled shield portions or flexible finger structures.

[0016] The first coupling means may further include a blocking means that is movable relative to the flexible shield snap structure, from a non-blocking position that allows radial movement of the flexible shield snap structure corresponding to a first state to a blocked locking position that restricts or prevents radial movement of the flexible shield snap structure corresponding to a second state. The blocking means may be configured to form part of the needle hub.

[0017] In further exemplary embodiments, the first coupling means comprises one or more radially movable shield snap structures, and the second coupling means comprises a corresponding container snap structure adapted to engage with the shield snap structures. At least one of the radially movable shield snap structures may be located on (i) a thin-walled shield portion, or (ii) a flexible finger structure. The first coupling means may further include an actuation means that is movable with respect to the radially movable shield snap structure from an unengaged position corresponding to a first state to an engaged position in which the shield snap structure moves radially outward corresponding to a second state. As shown, a stronger snap coupling may be provided, for example, by making the shield coupling structure stiffer or projecting further outward.

[0018] The needle hub and the shield may rotate relative to each other as the shield moves from its retracted position to its final extended position, thereby the first coupling means is actuated from an initial state to an operating state as the needle hub rotates relative to the shield from an initial position to an operating position. When the shield moves from the retracted position to its final extended position, the shield and the needle hub may rotate relative to each other to a rotation locking position that prevents the shield from being retracted.

[0019] In the alternative configuration, the final extended position of the shield is distal to the initial extended position of the shield, which allows the first coupling means to operate from the initial state to the operational state as the shield moves from the retracted position to the final extended position.

[0020] A similar configuration is used in the shield needle assembly disclosed in WO2018 / 215605 above, where the shield is returned to its most distal final position, allowing the container to snap-engage with the shield. If the coupling operation is based on hub rotation, the initial and final extended positions of the shield relative to the hub will typically be the same.

[0021] In further embodiments, the snap coupling is provided as a needle assembly comprising cooperating first and second coupling means, respectively, disposed on the shield, as described above, however, the second coupling means is operable between an initial state corresponding to a first state of the snap coupling and an activated state corresponding to a second state of the snap coupling. The second coupling means may be configured to be activated from the initial state to the activated state when a container in a first rotational position relative to the shield is removed from the shield and then reattached to the shield in a second rotational position. As shown, in such a simplified arrangement, the operation of the snap coupling involves active manipulation of the shield by the user. To ensure the correct orientation of the container in use, the container and shield (or drug delivery device) may be provided with corresponding markings.

[0022] In certain embodiments, the second coupling means comprises first and second coupling structures, the first coupling structure being adapted to engage with the first coupling means when the container is in a first rotational position relative to the shield, and the second coupling structure being adapted to engage with the first coupling means when the container is in a second rotational position relative to the shield. The coupling structures may take the form of a somewhat "aggressive" snap structure that engages with the shield.

[0023] In a further exemplary embodiment, the coupling means comprises a flexible gripping finger adapted to bend to grip a corresponding coupling structure on a drug delivery device, and a blocking means adapted to block the radial movement of the gripping finger, corresponding to a locked state in which the attached needle unit cannot be removed from the drug delivery device. The flexible gripping finger and the blocking means are movable relative to each other from an initial mounting position in which the radial movement of the gripping finger is possible, to a locked position in which the radial movement of the gripping finger is blocked, thereby preventing the needle unit from being removed from the drug delivery device.

[0024] The flexible gripping fingers and blocking means may be movable relative to each other from a locked position to a released position in which the gripping fingers can move radially, thereby allowing the needle unit to be removed from the drug delivery device by unblocking the coupling means. Furthermore, the flexible gripping fingers and blocking means may be movable relative to each other from the locked position to the released position by the rotational movement of the needle hub relative to the shield. For example, the flexible gripping fingers and blocking means may rotate relative to each other when the shield is moved from its retracted position to its extended position.

[0025] In a further aspect of the present invention, a needle unit adapted to be housed in a container is provided. The needle unit comprises a needle hub; a hollow needle mounted within the needle hub and having a pointed distal end protruding from the needle hub, the hollow needle defining a reference axis; a shield on which the needle hub is fully or partially disposed, the shield being axially movable relative to the needle hub between an initial extended position in which the shield axially covers the distal end of the needle; a retracted position in which the distal end of the needle protrudes from the shield; and a final extended position in which the shield axially covers the distal end of the needle; and coupling means enabling the needle unit to be mounted on a drug delivery device. The needle unit further comprises a container coupling that enables the needle unit to be mounted inside a container; a container coupling that includes one or more radially flexible shield snap structures; and a blocking means that is movable relative to the flexible shield snap structure from a non-blocking position that allows radial movement of the flexible shield snap structure to a blocking position that restricts or prevents radial movement of the flexible shield snap structure.

[0026] The blocking means may be configured to form part of the needle hub, and the needle hub and shield may be configured to rotate relative to each other when the shield is moved from its retracted position to its extended position, thereby rotating the blocking means from a non-blocking position to a blocking position.

[0027] As disclosed above, the needle unit includes coupling means that enable the needle unit to be mounted on a drug delivery device. Accordingly, the latter may include, for example, a cartridge mount as part of a cartridge holder, enabling the needle unit to be mounted in fluid communication with the inside of a cartridge.

[0028] The drug delivery device may comprise a cartridge holder containing a drug-filled cartridge or adapted to receive a drug-filled cartridge, an operable discharge mechanism for discharging a preset or user-set amount of drug from the cartridge, a drive spring for driving the discharge mechanism, and an actuating means for actuating the discharge mechanism, for example, a proximally disposed release button.

[0029] In such an assembly, when the needle unit is attached to the drug delivery device, the shield may be adapted to actuate the discharge mechanism actuating means when the shield moves from the extended position to the retracted position, and when the shield moves from the retracted position to the extended position, the needle unit is actuated to a locked state where the shield cannot retract. This configuration can prevent double actuation of the discharge mechanism with the same needle unit attached.

[0030] The drug delivery device may comprise an actuator associated with the cartridge mount, the actuator being adapted to actuate the coupling means from an initial attachment state to a locked state. The actuator may engage with the shield of the attached needle unit to provide an axially directed force towards the distal end.

[0031] Since the needle is fixed within the hub, the needle will rotate with the rotating hub, but it is not always desirable for the needle to rotate when fully inserted subcutaneously. Accordingly, relative rotational movement between the needle hub and the shield may occur after at least half of the length of the distal end of the needle protruding from the shield is covered by the shield with the shield in its retracted position.

[0032] In all of the embodiments described above, the hollow needle may have a pointed proximal end adapted to be inserted through a needle-penetrating cartridge partition to provide fluid communication between the inside of the cartridge and the distal end exit opening of the needle when the needle unit is mounted on a drug delivery device. To reduce the risk of accidental needle stick injuries, the proximal needle end may be located distal to the nearest portion of the needle hub and / or shield, i.e., the distal needle end is located inside the needle unit.

[0033] The container may have an open end adapted to be sealed with a flexible foil member, thereby providing a sealed, sterile interior for the needle assembly when supplied to the user.

[0034] As used herein, the term “drug” means any drug-containing fluid pharmaceutical that can pass through a delivery means such as a subcutaneous injection needle in a controlled manner, such as a liquid, solution, gel, or microsuspension. Drugs may have blood glucose-controlling effects, such as human insulin and its analogues, as well as non-insulinic effects such as GLP-1 and its analogues. [Brief explanation of the drawing]

[0035] Embodiments of the present invention will be described below with reference to the drawings.

[0036] [Figure 1] Figure 1 shows the components of an exemplary first embodiment of a needle assembly comprising a shield member, a hub member, and a container. [Figure 2] Figure 2 shows a cross-sectional view of the assembled needle assembly from Figure 1, which has a needle unit formed by a shield member and a hub member attached to a container. [Figure 3] Figure 3 shows an alternative embodiment of the needle unit attached to a pen-type device. [Figure 4] Figures 4A and 4B show the shield member of Figure 1 viewed from the proximal end and the distal end, respectively. Figure 4C shows the shield member of Figure 4A in cross-sectional view. [Figure 5] Figures 5A and 5B show the hub member of Figure 1 as viewed from the proximal end and the distal end, respectively. [Figure 6] Figures 6A and 6B show the container of Figure 1 viewed from the proximal end and the distal end, respectively. Figure 6C is a cross-sectional view showing the shield member of Figure 6B. [Figure 7] Figure 7 shows cross-sectional views of the stylus assembly from Figure 1 in different states mounted on the cartridge mount. [Figure 8] Figure 8 shows cross-sectional views of the stylus assembly from Figure 1 in different states mounted on the cartridge mount. [Figure 9] Figure 9 shows cross-sectional views of the stylus assembly from Figure 1 in different states mounted on the cartridge mount. [Figure 10] Figure 10 shows cross-sectional views of the stylus assembly from Figure 1 in different states mounted on the cartridge mount. [Figure 11] Figure 11 shows cross-sectional views of the needle unit of Figure 1 in different states during operation. [Figure 12] Figure 12 shows cross-sectional views of the needle unit from Figure 1 in different states during operation. [Figure 13] Figure 13 shows that the outer portion of the shielding member has cut through the needle unit in Figure 14. [Figure 14] Figure 14 shows cross-sectional views of the needle unit in Figure 1 in different states during operation. [Figure 15] Figure 15 shows a detailed cross-sectional view of the shield locking mechanism. [Figure 16] Figure 16 shows cross-sectional views of the stylus assembly from Figure 1 in different states after being removed from the cartridge mount. [Figure 17] Figure 17 shows a cross-sectional view of the stylus assembly from Figure 1 in a different state after it has been removed from the cartridge mount. [Figure 18] Figure 18 shows a cross-sectional view of the stylus assembly from Figure 1 in a different state after it has been removed from the cartridge mount. [Figure 19] Figure 19 shows an alternative embodiment of a cartridge mount used in combination with the needle unit of Figure 1. [Figure 20] Figure 20 shows a second embodiment of a drug delivery device having an attached needle unit. [Figure 21] Figure 21 shows a cross-sectional view of drug delivery device 1 with the needle unit replaced with a cap. [Figure 22] Figure 22 shows an exploded view of the components of the drug delivery assembly shown in Figures 20 and 21. [Figure 23] Figures 23A and 23B show a perspective view and a cross-sectional view, respectively, of the shield member shown in Figure 22. [Figure 24] Figures 24A and 24B show a perspective view and a cross-sectional view, respectively, of the hub member shown in Figure 22. [Figure 25] Figures 25A and 25B show a perspective view and a cross-sectional view, respectively, of the container for the needle unit shown in Figure 20. [Figure 26] Figure 26 shows a cross-sectional view of the needle unit from Figure 20, which is placed inside the container from Figure 25A. [Figure 27] Figures 27A–27J show a series of cross-sectional views illustrating the installation, operation, and removal of the needle unit on the drug delivery device. Figures 27CX and 27GX show cutaway views of the corresponding Figures 27C and 27G. [Figure 28] Figures 28A-28C show a series of cutaway perspective views illustrating the movement of the shield and needle hub relative to the housing indicator opening during operation of the needle unit.

[0037] In these diagrams, similar structures are primarily identified by similar reference numbers. [Modes for carrying out the invention]

[0038] Where terms such as “up” and “down,” “right” and “left,” “horizontal” and “vertical,” or similar relative expressions are used below, they simply refer to the accompanying diagrams and do not necessarily represent actual usage. The term “distal” refers to an element, assembly, or part of a device that is oriented toward the user’s skin surface during use, and the term “proximal” refers to the opposing part. Accordingly, in conventional pen-type drug delivery devices, the needle is located at the distal end, and the release button attached to the end is located at the proximal end. The diagrams shown are schematic and are therefore intended for illustrative purposes only, as are the configurations of different structures as well as their relative dimensions. Where the term member or element is used for a given component, this generally indicates that in the described embodiment, this component is a single component; however, two or more of the described components may be provided as a single component, for example, manufactured as a single injection-molded part, and alternatively, the same member or element may comprise several subcomponents. The term “assembly” is not intended to imply that the described components are necessarily assembled to provide a single, functional assembly during a given assembly procedure, but is simply used to describe components that are classified together as being more closely related functionally.

[0039] Referring to Figures 1 and 2, a first embodiment of the shielded needle assembly 2 is shown, which comprises a needle hub 100 adapted to be mounted on a corresponding needle attachment on a drug delivery device; a subcutaneous injection hollow needle 101 attached to the hub and having a pointed free distal end portion adapted to be inserted subcutaneously through the user's skin and a pointed free proximal end portion adapted to penetrate a puncturable drug cartridge partition; a shield member 200 on which the needle hub is placed; and a container 280. The needle hub, with the attached needle and shield member, combines to form the needle unit 1. The subcutaneous injection hollow needle 101 has chamfered proximal and distal ends and is positioned within the hub hole and secured in place, for example, by adhesive. The container 280 is adapted to receive the needle unit and thereby form the needle assembly, and the container has an open end adapted to be sealed with a flexible foil member, thereby providing a sealed sterile interior to the needle unit 2 when supplied to the user. In the illustrated embodiment, the proximal end of the needle extends proximal to the nearest portion of the hub, but not proximal to the nearest portion of the shield, which reduces the risk of accidental needle contact.

[0040] Figure 3 shows a needle unit 11 mounted on an injection device 3 adapted to detachably receive the needle unit. In contrast to the circular configurations of the needle units in Figures 1 and 2, Figure 3 shows an exemplary design having an outer square configuration that allows the shield 302 to be received within a correspondingly formed distal cartridge portion 402 of the injection device 3. Alternatively, other non-circular designs, such as oval or triangular, can be implemented. As will be apparent from the following detailed description of exemplary embodiments of the needle assembly, the function of the assembly depends on rotational movement between the hub and the shield, regardless of the outer configuration of the shield.

[0041] As will be described in more detail below, the needle hub 100 (hereinafter also simply referred to as the "hub" or "hub member") and the shield member 200 (hereinafter also simply referred to as the "shield") have several interaction structures that enable the shield and the hub to move axially and rotatably relative to each other in a controlled manner during use and operation of the needle unit. In the embodiments described below, the shield is rotatably locked to the cartridge mount, and the hub is axially locked to the cartridge mount when the needle unit is mounted on the cartridge mount. The rotational movement of the hub is controlled by the axial movement of the shield relative to the cartridge mount and, consequently, to the hub.

[0042] Furthermore, as will be described in more detail below, the container and shield member include several interaction structures that enable the container to be used as an attachment and removal tool for the needle unit during use in an efficient and user-friendly manner. The shield, hub, and container generally have opposing pairs of functional structures, but any preferred number of such structures, e.g., one, two, or three, can be used. The structure and functionality of the needle unit and container will be described with reference to embodiments having a generally circular configuration of the shield and container (see Figures 1, 2, and 4A-18), however the shield and container may have a non-circular configuration, such as shown in Figure 3, where the shield 302 and the drug delivery device housing 402 have a wrinkled configuration.

[0043] As shown in Figures 4A-4C, the shield 200 has a generally tubular configuration, having a circumferential outer wall 210, a proximal skirt portion 202 with a proximal opening having a circumferential edge 211, and a distal end surface 201 with a smaller distal opening 212 from which the tower structure protrudes axially inward. In the illustrated embodiment, the tower structure includes first and second pairs of opposing arms offset by 90 degrees. The first pair of arms are in the form of flexible stop arms 220, each having a distally facing axial stop surface 221 at a proximal free end adapted to engage with a corresponding proximal-facing stop surface on the hub tower portion (see below), and a proximal-facing inclined surface 222 used during the assembly of the needle assembly. The second pair of arms are in the form of flexible control arms 230, each having a proximal-facing inclined surface 231 and a distal-facing control surface 232 at its proximal free end, the surfaces being adapted to engage with the corresponding distal-facing inclined surface and proximal-facing control surface on the hub tower portion, respectively (see below). At the proximal end, the shield comprises a pair of opposing inner block surfaces 213 adapted to engage with the corresponding flexible hub arm (see below). The shield further comprises a pair of opposing locking ribs 214 on the inner wall surface of the shield, each rib having a proximal-facing locking surface 215 adapted to engage with the corresponding locking surface on the hub. The outer wall 210 of the shield is further provided with a pair of opposing flexible coupling arms 240, each arm comprising an inner ridge 241 and an outer ridge 246 at its distal free end, adapted to engage with the corresponding structure on the hub and the container, respectively (see below).

[0044] As shown in Figures 5A and 5B, the hub 100 comprises a distal tower portion 110 having a central hole adapted to receive a subcutaneous injection needle and a proximal skirt portion 120. At the distal end, the tower portion includes three pairs of opposing functional surfaces adapted to cooperate with corresponding surfaces on the shield: a pair of proximal-facing stop surfaces 121 adapted to engage with a distal-facing stop surface 221 on the shield; a pair of distal-facing inclined surfaces 131 adapted to engage with a proximal-facing inclined surface 231 on the shield; and a pair of inclined proximal-facing control surfaces 132 adapted to engage with a distal-facing control surface 232 on the shield during operation. The hub tower further carries a pair of opposing axially extending block flanges 140, each having an outer block edge 141 adapted to engage with a corresponding inner ridge 241 of the shield coupling arm during operation. The skirt portion 120 comprises a disc portion having two opposing part circumferential bearing surfaces 125 that extend proximal and are adapted to engage with a corresponding bearing structure on the shield to ensure stability during axial and rotational movement between the hub and the shield during operation. The skirt portion comprises a pair of opposing proximal-extending flexible coupling arms 126, each having an outer surface 113 adapted to engage with the inner block surface 213 of the shield during operation; an inward-facing snap coupling ridge 127 located at the free proximal end of the coupling arm and adapted to engage with a corresponding coupling structure on the cartridge mount; and a distal-facing locking surface 115 adapted to engage with the proximal-facing shield locking surface 215 during operation.

[0045] As shown in Figures 6A-6C, the container 280 has a generally tubular configuration, having an outer peripheral wall 281, a proximal opening with an outer peripheral flange 282, and a closed distal end 283 from which a tower structure 285 projects axially inward. The container has a stepped configuration with a distal portion of a smaller diameter and a proximal portion of a larger diameter. An inner circumferential ridge structure 286 is positioned between the two portions and is adapted to engage with an outer ridge 246 on the shield flexible coupling arm 240. The remainder of the circumferential ridge functions to support the shield when it is placed inside the container. With the shield installed inside the container, the larger diameter proximal portion provides a circumferential space 299 (see Figure 2) between the container and the shield, allowing the correspondingly shaped drug delivery housing portion to be received therein during the attachment of the needle assembly to the drug delivery device.

[0046] During assembly, a hollow subcutaneous injection needle having inclined proximal and distal ends is placed in the hub hole and fixed in place, for example, by adhesive, thereby providing a free distal end 102 and a free proximal end 103. The hub is then inserted into a shield having stop surfaces 121 and inclined surfaces 131, which are rotatably aligned with the shield stop surface 221 and shield inclined surface 231, respectively, thereby allowing the shield stop surface to snap into engagement with the hub stop surface 121. The hub coupling arm 126 is also rotatably aligned with the shield block surface 213. The assembled needle unit is then inserted into the container by snapping the container rim 286 into engagement with the outer ridge 246 on the shield flexible coupling arm 240. As shown in Figure 2, the container tower 285 abuts against the distal end of the hub tower. In the final assembly step, a flexible foil member is attached to the proximal flange 282 of the container, thereby sealing the interior for subsequent sterilization.

[0047] The following describes the different features and embodiments of the above-mentioned needle unit and container combinations with reference to Figures 7-18, which show needle units mounted on a corresponding drug delivery device, operating to allow a certain amount of fluid drug to be subcutaneously injected and then removed from the drug delivery device.

[0048] After the flexible seal foil is removed from the container 280 by the user, the container can be used as a tool for mounting the needle unit onto the drug delivery device 13 having a corresponding cartridge mount 310. See Figure 7. The drug-filled cartridge 390, having a partition 394, is placed within the cartridge holder 300. In the illustrated embodiment, the cartridge mount is located proximal to the distal end of the drug delivery device housing 402, which has a circumferential space 403 between the cartridge holder 300 and the housing, adapted to receive the proximal portion of the shield in a non-rotational engagement, for example, by cooperating splines or a non-circular shape such as elliptical or square. Such a non-circular design also facilitates the user in rotatably oriented the needle assembly correctly relative to the drug delivery device. As shown in Figure 7, the hub coupling is in an initial mounting state in which the shield block surface 213 does not engage with the outer surface 113 of the flexible hub arm.

[0049] The container ensures that the shield can be firmly pressed by the user to engage with the cartridge mount, thereby allowing the free proximal needle end 103 to penetrate the cartridge partition 394, and the flexible hub coupling arm 126 to move radially outward within the receiving space on the shield and then snap radially inward to engage with the corresponding snap coupling means 311 on the cartridge mount. See Figure 8. In the illustrated embodiment, the drug delivery device is provided with a pair of opposing spring-biased connector members 502, which are initially pressed proximal by the shield periphery 211 over a short distance. During installation, the spline connection between the hub and the shield prevents rotational movement between them.

[0050] When the user stops pushing the container (or begins to pull the container away), the spring-biased connector member 502 pushes the shield 200 slightly distally until the distally facing axial stop surface 221 on the shield tower engages with the corresponding proximal-facing stop surface 121 on the hub tower portion. As the shield moves distally, the shield block surface 213 engages with the flexible hub arm outer surface 113 and moves, thereby preventing its radially outward movement. This securely locks the hub 100 to the cartridge mount 310, corresponding to an operating hub coupling lock state that prevents the mounted needle unit from being removed from the drug delivery device. See Figure 9.

[0051] When the user pulls the container 280 further distally to completely remove it, the container snap coupling ridge engages and disengages the shield 200. In the illustrated embodiment, the shield comprises a pair of flexible coupling arms 240, each having a ridge 246 facing outward at its free end, which is pushed inward by the container snap coupling ridge 286, thereby allowing the container to be easily moved distally. See Figure 10. Once the container is completely removed, the drug delivery device with the attached needle unit 1 becomes usable, as shown in Figure 11. Note that the cross-sectional views in Figures 10-12 are rotated 90 degrees compared to Figures 7-9, so that the inclined surface 231 on the shield flexible control arm 230 can be seen as stationarily engaged with the distally facing inclined surface 131 on the hub tower. Furthermore, due to the rotation, the connector 502 that engages with the proximal end 211 of the shield is not visible. In this state, the shield is in its initial extended position.

[0052] When the user pushes the needle unit toward the skin surface, the shield 200 is pushed proximal, allowing the distal end of the needle 102 to be inserted subcutaneously. During the initial proximal movement of the shield, the inclined surface 231 on the flexible control arm 230 is pressed against the hub tower inclined surface 131. As the shield moves further proximal to its fully retracted position, the distal end of the needle protrudes from the shield corresponding to the needleless length portion 104 (see Figure 12). Simultaneously, the proximal periphery 211 of the shield pushes a pair of connector members 502 proximal (see Figure 9), thereby releasing the drug delivery device discharge mechanism and thereby initiating subcutaneous injection. As shown, the connector members 502 function as both a locking actuator for the hub coupling and a release member for the discharge mechanism. Drug delivery devices having similar release connectors adapted to transmit translational movement from a retractable needle shield to an ejection mechanism are disclosed in WO2021 / 122219 and WO2021 / 122192 and are suitable for adaptation to function with the present needle unit. Alternatively, the ejection mechanism may be released by a manually operated release means on the drug delivery device, such as a proximal push button. Such a push button may be configured to be blocked for operation until released by the proximal movement of the shield.

[0053] After the dose has been completely dispensed, the user withdraws the needle unit from the skin surface, thereby allowing the spring-biased connector 502 to move distally to its fully extended final position, which again covers the distal portion of the needle 102. During this movement, a control surface 232 on the shield control arm 230 (see Figure 4C) engages with an inclined proximal-facing control surface 132 on the hub tower, which rotates the needle hub 100 when the shield is rotatably locked to the drug delivery device. See Figure 13. In the illustrated embodiment, the hub is rotated 45 degrees relative to the shield. In the illustrated embodiment, the initial and final extended positions of the shield relative to the hub are the same.

[0054] During the rotation of the hub 100 relative to the shield 200, several structures engage with each other and move in and out. Note that the cross-sectional views in Figures 16 and 17 below are rotated 90 degrees compared to Figures 14 and 18, which allows us to show the cooperation between the hub block flange edge 141 and the inner ridge 241 of the shield flexible coupling arm.

[0055] (i) When the hub rotates, the flexible hub coupling arm 126 disengages from the shield block surface 213 and rotates, thereby allowing the flexible hub arm to move radially outward. See Figure 14. Thus, the hub 100 is removed from the cartridge mount 310.

[0056] (ii) Once the needle 101 is fixed within the hub 100, the needle will rotate with the rotating hub, but it is not always desirable for the needle to rotate when it is fully inserted subcutaneously. Accordingly, the hub and shield can be designed with axial slack or "play" before the shield control surface 232 engages with the inclined hub control surface 132, which allows the needle to be withdrawn at least partially from the skin before rotation begins. In fact, subsequent rotation should begin with a more abrupt inclination of the hub control surface, and the inclination of the hub control surface should be abrupt.

[0057] (iii) Before the needle unit begins to operate, a pair of locking ribs 214 on the inner surface of the shield move freely in the axial direction, thereby allowing the shield to move from its extended position to its retracted position. As the hub rotates, a pair of distally facing locking surfaces 115 rotate to align with the proximal ends 215 of the locking ribs 214, thereby preventing repeated retraction of the shield and consequently the use of the needle unit, and thereby providing a safety lock. See Figure 15. Accordingly, the locking surfaces should be designed to withstand relatively large forces to prevent the needle unit from restarting, for example, if the pen-type device falls onto a solid surface or in misuse scenarios. Furthermore, if the drug delivery device is shield released, the shield lock also functions as a double dose prevention means.

[0058] (iv) As the hub 100 rotates, a pair of block flange edges 141 rotate to align with the inner ridge 241 of the shield flexible coupling arm, thereby preventing the arm from bending inward. In this state, the actuating needle unit and the locking needle unit can be removed from the cartridge mount by simply grasping and pulling the shield distally (the shield is axially connected to the hub via corresponding stop surfaces 221, 121 on the shield tower and hub tower, respectively; see Figure 14), however, in the illustrated embodiment, the container is also intended to be used as a tool for removing the needle unit; see Figure 16. More specifically, with the shield flexible coupling arm 240 in a blocked state, the container 280 is mounted on the shield by a user applying axial force until the container snap coupling ridge 286 overrides the shield outer ridge 246, for example by ellipsing the container wall; see Figure 17. The container snap coupling is designed to have a release force greater than the release force required to axially separate the flexible hub coupling arm 126 from its engagement with the cartridge mount 310, thereby allowing the needle unit to be removed from the cartridge mount, which is then securely held in the container for safe disposal. See Figure 18. Because the needle unit is locked to the container via the container snap coupling, and its proximal end is positioned at a specific distance inside the container and surrounded only by a small amount of free space, removing the needle unit from the container is difficult for the user.

[0059] Alternative embodiments: As the hub rotates relative to the cartridge mount, this characteristic can be utilized to provide a cartridge mount 360 having different snap coupling characteristics depending on the rotational position of the hub relative to the cartridge mount. More specifically, as shown in Figure 19, the cartridge mount is provided with a first set of snap coupling structures 361 adapted to engage with the hub snap coupling structure to allow the hub to be mounted using a first amount of force, and a second set of snap coupling structures 362 adapted to engage with the hub snap coupling structure to allow the hub to be removed using a second, lower amount of force, wherein the first and second cartridge mount snap coupling structures may be configured to be rotationally offset from each other, for example, by 45 degrees. A given coupling force may be provided, for example, by the inclination of the coupling inclined surface.

[0060] As an alternative to the shield's flexible coupling arm, the shield's outer wall may be provided with a thin wall section that supports a snap projection, allowing the snap projection to bend inward when not blocked by the hub. Such a design provides a cleaner appearance and prevents the potential intrusion of materials that could interfere with the shielding mechanism.

[0061] As a further alternative, the shield coupling may be provided with one or more radially movable shield snap structures, and the container coupling means comprises corresponding container snap structures adapted to engage with the shield snap structures. Such radially movable shield snap structures may be located on a thin-walled shield portion or on a flexible finger structure. The shield coupling means includes an actuation means that is movable with respect to the radially movable shield snap structure from an unengaged position corresponding to a first state to an engaged position in which the shield snap structure is moved radially outward corresponding to a second state. The actuation means may be configured to correspond to the flange 141 described above. As shown, a stronger snap coupling may be provided, for example, by making the shield coupling structure stiffer or projecting further outward.

[0062] As a further alternative configuration, the block mechanism for the shield-container coupling may be dispensed, meaning the hub may not have a structure that engages with the shield-container coupling during operation. In this way, the forces required for removing, attaching, and preventing the container from being removed from the shield during operation are provided solely by the design of cooperating surfaces, such as the inclination of an inclined surface.

[0063] Where a rotating needle hub is desirable, the configuration may include additional components to achieve secure locking in a similar manner. More specifically, the needle unit may be configured to include a hub and a shield coupled to each other to allow only axial movement, the assembly comprising a locking ring rotated by the forward and backward axial movement of the shield relative to the hub during operation, and the components comprising cooperating control surfaces adapted to rotate the locking ring from a non-blocking position to a blocked position as the shield returns from its retracted position to its extended position.

[0064] In a further alternative configuration, the final extended position of the shield is distal to the initial extended position of the shield, which allows the shield coupling means to be activated from the initial state to the operational state as the shield moves from the retracted position to the final extended position.

[0065] A similar arrangement is used in the shielded needle assembly disclosed in WO2018 / 215605 above, where the shield is returned to its most distal final position, allowing the container to snap-engage with the shield. If the coupling operation is based on hub rotation, the initial and final extended positions of the shield relative to the hub will typically be the same.

[0066] In a further alternative configuration, the needle assembly is provided with a snap coupling including cooperating first and second coupling means disposed on the shield and the container, respectively, such that, as described above, the container coupling means is operable between an initial state corresponding to a first state of the snap coupling and an activated state corresponding to a second state of the snap coupling. The container coupling means may be configured to be activated from the initial state to the activated state when the container, which is in a first rotational position relative to the shield, is removed from the shield and then reattached to the shield, which is in a second rotational position. As shown, in such a simplified arrangement, the operation of the snap coupling involves active manipulation of the shield by the user. To ensure the correct orientation of the container in use, the container and shield (or drug delivery device) may be provided with corresponding markings.

[0067] In certain embodiments, the second coupling means comprises first and second coupling structures, the first coupling structure being adapted to engage with the first coupling means when the container is in a first rotational position relative to the shield, and the second coupling structure being adapted to engage with the first coupling means when the container is in a second rotational position relative to the shield. The coupling structures may take the form of a somewhat "aggressive" snap structure that engages with the shield.

[0068] Further embodiments of the shielded needle assembly will be described with reference to Figure 20-28C.

[0069] Referring to Figure 20, a drug delivery device 1003 having a mounted needle unit 1001 is shown. The device preferably has a generally tubular configuration defining a common reference axis. Figure 21 shows a cross-sectional view of the drug delivery device 1003 having a cap and a replaceable needle unit. In the illustrated embodiment, the cap fits snugly onto the distal portion of the drug delivery device and therefore does not allow the needle unit to be mounted simultaneously. The drug delivery device comprises a distal cartridge holder portion 1004 in which a drug-filled cartridge is arranged, a proximal portion comprising a drive spring system 1005, and an intermediate portion comprising a control system 1006. A piston rod is axially positioned within the device and is adapted to be moved distally by a drive spring to discharge a certain amount of fluid drug through the mounted needle unit, the amount of axial movement of the piston rod being controlled by the control system. In Figure 21, the actuator return spring is not shown.

[0070] The exploded view in Figure 22 shows the individual components of the drug delivery device and needle unit. The drug delivery device comprises a tubular housing 1400 having a proximal engine portion 1401 and a distal cartridge portion 1402 adapted to house a cartridge holder 1300 in which a drug cartridge 1390 is arranged, the drug cartridge having a needle-punctureable partition, a proximal circumferential edge, and a distal outlet end having an axially displaceable piston. A piston washer 1395 is disposed within the cartridge and engages with the proximal surface of the piston. The actuator 1500 comprises a cylindrical proximal portion 1501 from which a pair of legs 1502 extend distally between the housing and the cartridge holder. A drive nut 1600 is mounted within the housing and adapted to receive a piston rod 1650 by screw engagement. A piston rod is non-rotatably received within the distal tubular portion 1802 of a drive member 1800, which is adapted to be rotationally driven by a pre-stretched drive spring 1890 disposed within the proximal portion 1801 of the drive member, the proximal end of which is fixed to the housing via a spring base 1900. A control member 1700 is spline-engaged with the tubular portion 1802 of the drive member and is adapted to move axially in and out of engagement with the housing, thereby controlling the rotation of the drive member. A large-diameter return spring 1590 is configured to provide a distally directed biasing force on the actuator. The drug delivery device is adapted to receive a needle unit at its distal end, the needle unit comprising a needle hub 1100 having a needle 1101, and a shield member 200 in which the needle hub is placed. If the needle unit is not mounted on the drug delivery device, a cap 1490 may be mounted to cover the cartridge portion 1402.

[0071] A detailed description of the drug delivery device itself is disclosed in EP 23212595.5, which is incorporated herein by reference. Below, only those parts of drug delivery that directly engage with the needle unit are described.

[0072] As shown in Figures 23A and 23B, the shield 1200 has a generally tubular configuration, having a circumferential outer wall 1210 with a proximal skirt portion 1202, a proximal opening with a circumferential edge 1211, and a distal end face 1201 with a smaller distal opening 1212 from which the tower structure protrudes axially inward. The outer wall, and therefore the proximal skirt portion, also have a circumferential noncircular configuration in the form of a hyperelliptical cross-section in the illustrated embodiment. The tower structure, in the illustrated embodiment, includes a circumferential skirt portion 1215 that extends proximal to first and second pairs of opposing arms with a 90-degree rotational offset. Between the arms, the skirt portion includes a free-gripping edge portion 1216. The first pair of longer arms are in the form of flexible assembly arms 1220, each having a hook portion 1225 at the proximal free end, and a distally facing axial stop surface 1221 adapted to engage with a corresponding proximal facing stop surface 1121 on the hub tower portion (see below), as well as a proximal facing inclined surface 1222 used during assembly of the needle unit. The second pair of shorter arms are in the form of flexible control arms 1230, each having a hook portion 1235 at the proximal free end, and a proximal facing inclined surface 1231 and a distal facing control surface 1232, respectively, the surfaces adapted to engage with the corresponding distal facing inclined surface and proximal facing control surface on the hub tower portion (see below). At the proximal end, the shield comprises a pair of opposing inner operating ribs 1213 adapted to engage with the corresponding flexible hub arm (see below). The actuation rib 1213 also engages the coupling arm (see below) and positions the substantially circular hub at the center of the hyperelliptical shield, thus ensuring stability during axial and rotational movement between the hub and the shield in operation. The shield further comprises a pair of opposing locking ribs 1217 on the inner wall surface of the shield, each rib having a proximal-facing locking surface 1218 adapted to engage with a corresponding locking surface on the hub. The locking ribs proximal to a lower torque rib 1219 adapted to engage with a torque flange on the hub (see below).The shield wall 1210 further comprises an outer pair of opposing mounting ribs 1245 adapted to engage with a corresponding shield slot 1415 in the housing, a pair of opposing windows 1240 adapted to allow outward movement of a hub coupling arm (see below), and a first indicator opening 1241 and a second indicator opening 1246. In the illustrated embodiment, the first indicator opening 1241 is “open” for design reasons, but the shield edge 1211 has a cutout for structures within the drug delivery device. In the illustrated embodiment, a further pair of opposing guide structures 1247 (see Figure 27A) adapted to engage with a corresponding shield guide 1417 in the housing are provided distal to the indicator opening 1246.

[0073] As shown in Figures 24A and 24B, the hub 1100 includes a distal tower portion 1110 having a central hole 1111 adapted to receive a subcutaneous injection needle and a proximal skirt portion 1120. At the distal end, the tower portion has three pairs of opposing functional surfaces adapted to cooperate with corresponding surfaces on the shield: (i) a pair of proximal-facing stop surfaces 1121 adapted to engage with a distal-facing stop surface 1221 on the shield assembly arm; (ii) a pair of distal-facing inclined surfaces 1131 adapted to engage with a proximal-facing inclined surface 1231 on the shield; and (iii) a pair of inclined proximal-facing control surfaces 1132 adapted to engage with a distal-facing control surface 232 on the shield during operation. At the proximal end, the tower portion includes a pair of opposing snap recesses 1135 adapted to engage with a control arm hook portion 1235. The skirt portion 1120 comprises a pair of opposing flexible coupling arms 1126 extending proximal, each arm having an outer surface 123 adapted to engage with the shield's inner operating rib 1213 during operation, and an inwardly facing snap coupling ridge 1127 located at the free proximal end of the coupling arm and adapted to engage with the corresponding coupling structure on the cartridge mount 1310. The skirt portion further comprises a pair of distally facing locking surfaces 1118 adapted to engage with the proximal facing shield locking surface 1218 during operation. In the illustrated embodiment, the skirt portion further comprises a pair of radially projecting opposing drop locking release flanges 1114 adapted to engage with the corresponding actuator leg release surface 1524 (Figure 27CX), a pair of radially projecting opposing torque flanges 1119 adapted to engage with the shield torque rib 1219, and a pair of opposing indicator cutouts 1115. The torque interface may also be located on other parts of the shield and hub, for example, between the assembly arm and the hub tower section.

[0074] As shown in Figures 25A and 25B, the container 1280 has a generally tubular configuration, having a hyperelliptical outer wall 1281 corresponding to the hyperelliptical outer wall of the shield, a proximal opening with a circumferential flange 1282, and a closed distal end 1283 with a tower structure 1285 and a pair of opposing snap-locking fingers 1290 extending axially inward. Each snap-locking finger has an outwardly oriented snap projection 1296 adapted to removably engage with a shield tower grip edge portion 1216 to provide a snap connection. The container further includes a plurality of internal support ribs 1286 adapted to engage with the outer surface of the shield and support the shield when placed inside the container. With the shield installed inside the container, the proximal portion provides a circumferential space 1299 (see Figure 26) between the container and the shield, allowing a drug delivery housing portion of the corresponding shape to be received therein during the attachment of a needle unit to a drug delivery device.

[0075] During the assembly of the hollow subcutaneous injection needle 1101, which has inclined proximal and distal ends, it is positioned within the hub hole and fixed in place, for example, by adhesive, thereby providing a free distal end portion 1102 and a free proximal end portion 1103. In the illustrated embodiment, the needle proximal end portion extends proximal to the tower portion 1110 but not proximal to the nearest portion of the hub 1100, which reduces the risk of accidental needle contact. The hub 1100 is then inserted into the shield 200, which has stop surfaces 1121 and inclined surfaces 1131, respectively, which are rotatably aligned with the shield stop surface 1221 and the shield inclined surface 1231, thereby allowing the shield stop surface to snap into engagement with the hub stop surface 1121. The hub coupling arm 1126 is also rotatably aligned with the shield operating rib 1213. In the illustrated embodiment, the hub proximal end is positioned slightly proximal to the shield proximal edge 1211. Next, the assembled needle unit is inserted into the container by snapping the container snap locking finger 1290 into the shield tower grip edge portion 1216, thereby forming the needle assembly. As shown in Figure 26, an axial gap is provided between the proximal end of the container tower and the distal end of the hub tower. In the final assembly step, a flexible foil member (not shown) is attached to the proximal flange 1282 of the container, thereby sealing the interior for subsequent sterilization. Figure 26 shows a cross-section of the needle assembly 1002 with the needle unit 1001 positioned inside the container 1280 before the sealing foil is attached.

[0076] The following describes the different features and embodiments of the above-mentioned needle unit and container combinations with reference to Figures 27A-27J. Figure 27A-27J shows a needle unit mounted on a corresponding drug delivery device that operates to allow a certain amount of fluid drug to be subcutaneously injected and then removed from the drug delivery device. The indicator function is further illustrated in Figure 28A-28C.

[0077] After the flexible seal foil is removed from the container 1280 by the user, the container is intended to be used as a tool for mounting the needle unit onto the drug delivery device 1001 having a corresponding cartridge mount 1310. See Figure 27A. In the illustrated embodiment, the cartridge mount is positioned proximal to the distal end of the drug delivery device housing cartridge portion 1402, having a circumferential space 1403 between the cartridge holder 1300 and the housing, which is adapted to receive the proximal portion of the shield 1200 in non-rotational engagement by cooperating mounting ribs 1245 and shield slots 1415. In the illustrated embodiment, the non-circular hyperelliptical design of the container, shield, housing outer surface, and inner circumferential space facilitates the user in orienting the needle assembly rotationally correct relative to the drug delivery device in either of its two possible rotational positions.

[0078] Alternatively, the non-circular configuration of the shield, container, and housing may be an asymmetrical form providing one rotational mounting position, an elliptical, oval, or rectangular form providing two rotational mounting positions, a triangular form providing three rotational mounting positions, or a square form providing four rotational mounting positions.

[0079] First, the locked hub coupling arm 1126 engages with the cartridge mount coupling flange portion 1311, thereby allowing the container to push the shield forward in an axial position where the shield operating rib 1213 does not engage with the outer surface 123 of the flexible hub arm. See Figure 27B. The control arm 1230 bends freely outward to allow proximal shield movement, but does not snap onto the inclined surface 1131. Note that in Figure 27B, the two structures are shown superimposed for drawing purposes. Alternatively, a configuration with a gap between the two structures may be used.

[0080] The container ensures that the shield and hub can be firmly pressed by the user to engage with the cartridge mount, thereby allowing the free proximal needle end portion 1103 to penetrate the cartridge partition 1394 and the flexible hub coupling arm 1126 to first move radially outward within the receiving shield window 1240 and then snap inward to engage with the corresponding snap coupling flange 1311 on the cartridge mount. See Figure 27C.

[0081] During the axial coupling movement of the needle unit, the hub drop locking release flange 1114 engages with an inclined leg release surface 1524 on the spring-biased actuator leg 1502. Initially, the actuator is moved axially until the anti-rotation clutch portion 1517 disengages from the housing and moves, thereby allowing the actuator to rotate by the axial movement of the hub. To counteract the torque applied to the hub during the rotation of the actuator, the hub is supported by a shield (non-rotatably coupled to the housing 1400) via a torque flange 1119 that engages with a torque rib 1219. Subsequently, the shield actuator rib 1213 engages with the leg operating surface 1523 of the actuator leg 1502 and moves axially together with the drop locking release flange 1114. Depending on the actual design of the different components, the actuator may be fully rotated (20 degrees here) during the mounting of the needle unit. As an alternative configuration, the final rotation of the actuator may occur when the actuator is then moved distally by a return spring 1590.

[0082] The axial mounting movement of the needle unit stops when the hub engages with the cartridge mount portion, indicating to the user that the needle unit is mounted on the cartridge hub. When the user stops pushing the container (or begins to pull the container away), the spring-biased actuator leg 1502 pushes the shield 1200 slightly distally until the distally facing axial stop surface 1221 on the shield assembly arm engages with the corresponding proximal facing stop surface 1121 on the hub tower portion. The control arms 1230 are moved back to their initial positions. Simultaneously, the clutch portion 1517 re-engages with the housing locking rib 1447 in the operating rotation position. As the shield moves distally, the shield operating rib 1213 moves into a closed engagement with the outer surface 1123 of the flexible hub arm, thereby preventing its radially outward movement. This securely locks the hub 1100 to the cartridge mount 1310, which corresponds to an operating hub coupling lock state that prevents the attached needle unit from being removed from the drug delivery device. See Figure 27D.

[0083] When the user pulls the container 1280 further distally to completely remove it, the container snap coupling 296 engages and disengages the shield 1200. Once the container is completely removed, the drug delivery device with the attached needle unit 1001 becomes usable, as shown in Figure 27E. In this state, the housing indicator opening 1405 aligns with the first indicator opening 241 and the hub indicator cutout 1115 of the shield. Thus, the hub skirt 1120 is not visible to the user (see Figure 28A).

[0084] When the user pushes the needle unit toward the skin surface, the shield 1200 is pushed proximal, allowing the distal end of the needle 1103 to be inserted subcutaneously. During the initial proximal movement of the shield, the inclined surface 1231 on the flexible control arm 1230 is pressed against the hub tower inclined surface 1131. As the shield moves further proximal to its fully retracted position, the shield actuator rib 1213 pushes a pair of actuator legs 1502 proximal, thereby releasing the drug delivery device discharge mechanism, and thereby initiating subcutaneous injection as described above. See Figure 27F. As shown in the figure, the actuator legs 1502 function as both a locking actuator for the hub coupling and a release member for the discharge mechanism. While discharging the drug, the shield is held in its fully retracted position by snap locks 1135, 1235. In this state, the housing indicator opening 1405 aligns with the second indicator opening 246 and the hub indicator cutout 1115 of the shield. Therefore, the hub skirt 1120 is not visible to the user (see Figure 28B).

[0085] After the clicking sound generated by the discharge mechanism ceases and the dose has been completely discharged, the user withdraws the needle unit from the skin surface, thereby allowing the spring-biased actuator leg 1502 to push the shield operating rib 1213, thereby moving the shield 1200 distally to its fully extended position, again covering the distal portion of the needle 1103. During this movement, the control surface 1232 on the control arm 1230 engages with the inclined proximal-facing control surface 1132 on the hub tower (see Figure 24A), which forces the needle hub 1100 to rotate as the shield is rotatably locked to the drug delivery device. See Figure 27G. In the illustrated embodiment, the hub rotates 45 degrees relative to the shield. Compare Figures 27CX and 27GX.

[0086] During the rotation of the hub relative to the shield, several structures move in and out of their engagement with each other.

[0087] (i) As the hub rotates, a portion of the hub skirt 1120 adjacent to the hub cutout 1115 aligned with the housing indicator opening 1405 rotates to align with the opening and is therefore visible to the user (for example, by having a contrasting color), indicating that the needle unit has been used and, accordingly, a dose of the drug has been dispensed. During drug dispensing with the shield in its retracted position, the second indicator opening 1246 of the shield aligns with the housing indicator opening 405 (see Figure 28C).

[0088] (ii) As the hub rotates, the flexible hub coupling arm 1126 rotates away from its engagement with the shield operating rib 1213, thereby allowing the coupling arm to move radially outward (see Figure 27H), and allowing the hub 1100 to be removed from the cartridge mount 1310. To reduce the force required to engage and disengage the hub coupling arm from the cartridge mount, the hub coupling arm is rotated to a position on the cartridge mount having the lower and lower inclined release flange portions 1312.

[0089] (iii) Once the needle is fixed within the hub, it will rotate with the rotating hub, but it is not always desirable for the needle to rotate when it is fully inserted subcutaneously. Accordingly, the hub and shield can be designed with axial "play" before the shield control surface 1232 engages with the inclined hub control surface 1132, which allows the needle to be withdrawn at least partially from the skin before rotation begins. In fact, subsequent rotation should begin with a more abrupt inclination of the hub control surface, and the inclination of the hub control surface should be abrupt.

[0090] (iv) Before the needle unit operates, a pair of locking ribs 1217 on the inner surface of the shield move freely in the axial direction, thereby allowing the shield to move from its extended position to its retracted position. As the hub rotates, a pair of distally facing locking surfaces 1118 rotate to align with the proximal ends 1218 of the locking ribs 1217, thereby preventing repeated retraction of the shield and therefore use of the needle unit, thereby providing a secure lock. See Figures 23B and 24A. Accordingly, the locking surfaces should be designed to withstand relatively large forces to prevent the needle unit from restarting, for example, if the pen-type device is dropped onto a hard surface or in misuse scenarios. Furthermore, if the shield is released in a drug delivery device such as in this embodiment, the shield lock also functions as a double-dose prevention means.

[0091] (v) In the illustrated embodiment, the container is also intended to be used as a tool for removing the needle unit. See Figure 27I. When the user reinstalls the container, the container snap coupling 1296 engages with the shield 1200. The container snap coupling is designed to have a release force greater than the release force required to axially pull the bulge 1127 of the flexible hub coupling arm away from engagement with the cartridge mount release flange 1312, thereby allowing the needle unit to be removed from the cartridge mount portion which is firmly held in the container, and then the needle assembly 1002 can be safely disposed of. See Figure 27J. Since the needle unit is locked to the container via the container snap coupling, and its proximal end is positioned at a specific distance inside the container and surrounded only by a small amount of free space, removal of the needle unit from the container is difficult.

[0092] (vi) As the hub rotates, the drop lock release flange 1114 rotates out of alignment with the actuator leg release surface 1524, thereby preventing the actuator drop lock from being released using the used and locked needle unit.

[0093] Alternative embodiments: In the embodiments described above, when the hub rotates relative to the cartridge mount, the flexible coupling arm 1126 aligns with the rotating and inclined release flange 1312, allowing the hub coupling arm to be easily engaged and disengaged, thereby facilitating the user to remove the needle unit without using the container. To encourage the user to use the container, the release flange may be modified and configured to require a greater release force, which would make it more difficult to simply grab the shield and pull it out of engagement with the hub mount. To enable this, the snap coupling between the container and the shield would need to be able to transmit the required force, but this may be undesirable as the same snap coupling should be designed to allow for easy removal of the container after the initial installation of the needle unit.

[0094] Accordingly, a needle assembly including a snap coupling between a container and a shield may be provided, which is actuated between a first state in which the needle unit can be removed from the container using a first amount of force and a second state in which the needle unit can be removed from the container using a second, higher amount of force. The assembly may be actuated between the two states by the rotational movement of a hub inside the shield. A detailed description of such arrangements is given in concurrently pending application EP 23174814.6, which is incorporated herein by reference.

[0095] In the embodiments described above, the indicator is incorporated into the drug delivery housing and is operated by the rotational movement of the hub. The indicator operation is controlled by the needle unit, but the placement of the indicator window 1405 on the housing is designed to associate the indicator with the operation of the device itself, and thus indicates that a dose of the drug has been dispensed when the shield returns to its extended and locked positions.

[0096] However, instead of directly indicating that the needle module is in use and locked, it may be desirable to provide an indicator on the shield. Accordingly, instead of the device housing, the shield may be provided with an indicator window, and the hub may be provided with an indicator surface that is not initially aligned with the window but moves to align with it as the hub rotates after use.

[0097] The above description of exemplary embodiments has described different structures and means that provide the functionality described for different components to the extent that the concept of the present invention becomes clear to a skilled reader. Detailed structures and specifications for different components are considered to be subject to the usual design procedures performed by those skilled in the art along the lines specified herein.

Claims

1. A needle assembly (2) comprising a needle unit (1) and a container (280) adapted to house the needle unit, wherein the needle unit is - Needle hub (100), - A hollow needle (101) mounted within the needle hub and having a pointed distal end protruding from the needle hub, wherein the hollow needle defines a reference axis, - A shield (200) on which the needle hub is fully or partially disposed, the shield being axially movable relative to the needle hub between an initial extended position that covers the distal end of the needle axially, a retracted position in which the distal end of the needle protrudes from the shield, and a final extended position in which the shield covers the distal end of the needle axially. - A coupling means (126) that enables the needle unit to be attached to the drug delivery device (3), The assembly is provided with snap connections (246, 286) between the container and the shield, and the snap connections are - A first engaged state in which the needle unit can be removed from the container using a first amount of force, A needle assembly comprising: a second engaged state, in which the needle unit can be removed from the container using a second, higher amount of force.

2. The snap coupling comprises cooperating first and second coupling means (246, 286) respectively arranged on the shield, - The first coupling means (246) is operable between an initial state corresponding to the first state of the snap coupling and an operating state corresponding to the second state of the snap coupling. - The first coupling means is a needle assembly that is operated from an initial state to an operational state when the shield moves from its initial extended position to its retracted position and returns to its final extended position.

3. The needle assembly according to claim 2, - The first coupling means comprises one or more radially flexible shield snap structures (240, 246), - A needle assembly comprising a corresponding container snap structure (286) adapted to engage with the shield snap structure.

4. The needle assembly according to claim 3, wherein at least one of the radially flexible shield snap structures is in the form of (i) a thin-walled shield portion, or (ii) a flexible finger structure (240).

5. A needle assembly according to claim 3 or 4, - A needle assembly wherein the first coupling means further comprises a blocking means (141) that is movable relative to the flexible shield snap structure (240) from a non-blocking position that allows radial movement of the flexible shield snap structure corresponding to the first state to a blocking position that restricts radial movement of the flexible shield snap structure corresponding to the second state.

6. The needle assembly according to claim 5, - A needle assembly in which the blocking means (141) forms part of the needle hub (100).

7. The needle assembly according to claim 2, - The first coupling means comprises one or more radially movable shield snap structures (240, 246), - A needle assembly comprising a corresponding container snap structure (286) adapted to engage with the shield snap structure.

8. The needle assembly according to claim 7, wherein at least one of the radially movable shield snap structures is located on (i) a thin-walled shield portion or (ii) a flexible finger structure (240).

9. A needle assembly according to claim 7 or 8, - A needle assembly further comprising an actuation means (141) which is movable relative to the radially movable shield snap structure (240) from a non-engaged position corresponding to the first state to an engaged position in which the shield snap structure is moved radially outward corresponding to the second state.

10. A needle assembly according to any one of claims 2 to 9, - The needle hub (100) and the shield (200) rotate relative to each other when the shield is moved from its retracted position to its final extended position. - A needle assembly in which the first coupling means (246) is operated from an initial state to an operating state when the needle hub rotates from an initial position to an operating position relative to the shield.

11. A needle assembly according to any one of claims 1 to 10, - A needle assembly in which, when the shield (200) is moved from the retracted position to the fully extended position, the shield and the needle hub rotate relative to each other to a rotational locking position in which the shield cannot be retracted.

12. A needle assembly according to any one of claims 2 to 9, - The final extension position of the shield is distal to the initial extension position of the shield. - A needle assembly in which the first coupling means (240, 246) is activated from the initial state to the operating state when the shield moves from the retracted position to the final extended position.

13. A needle assembly according to claim 1, wherein the snap coupling comprises first and second cooperating coupling means, respectively, disposed on the shield, - The second coupling means is operable between an initial state corresponding to the first state of the snap coupling and an operating state corresponding to the second state of the snap coupling. - A needle assembly in which the second coupling means is activated from the initial state to the operating state when the container, which is in a first rotational position relative to the shield, is removed from the shield and then reattached to the shield, which is in a second rotational position.

14. The needle assembly according to claim 13, - The second coupling means includes the first and second coupling structures, - The first coupling structure is adapted to engage with the first coupling means when the container is in the first rotational position relative to the shield, - A needle assembly in which the second coupling structure is adapted to engage with the first coupling means when the container is in the second rotational position relative to the shield.

15. A needle assembly according to any one of claims 1 to 14, wherein the coupling means is - A flexible gripping finger (126) adapted to bend and grip the corresponding coupling structure (311) on the drug delivery device, - Blocking means (213) adapted to block the radial movement of the flexible gripping finger corresponding to a locked state in which the attached needle unit cannot be removed from the drug delivery device, A needle assembly in which the flexible gripping finger and the blocking means are movable relative to each other from an initial mounting position in which the radial movement of the gripping finger is possible, to a locking position in which the radial movement of the gripping finger is blocked, thereby preventing the needle unit from being removed from the drug delivery device.

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