Cassette unit subassembly for a drug delivery device

Abstract

A cassette unit subassembly for a medication delivery device comprises a body portion extending along a longitudinal axis from a proximal end to a distal end, a delivery member guard coaxially mounted on the body portion and axially movable relative to the body portion along the longitudinal axis, and a locking member mounted on the body portion, the locking member being movable relative to the delivery member guard between a locked position and an unlocked position, the locking member having a distally oriented surface adjacent to the proximally oriented surface of the delivery member guard in the locked position, and the distally oriented surface of the locking member being circumferentially spaced apart relative to the longitudinal axis from the proximally oriented surface of the delivery member guard in the unlocked position.

Description

[Technical Field]

[0001] The present disclosure relates generally to a cassette unit sub-assembly for a medicament delivery device, such as a reusable autoinjector or injector having two detachable parts, and in particular to a sub-assembly for locking a delivery member guard of such a unit prior to use. [Background technology]

[0002] Drug delivery devices, such as manual pen injectors or auto-injectors, are commonly known for self-administration of medication by patients without formal medical training. For example, a patient suffering from diabetes may require repeated injections of insulin, or a patient may require regular injections of other types of medication, such as growth hormone.

[0003] Some drug delivery devices have two parts that are interconnected during use: one part often receives a drug container, such as a cartridge or syringe, that contains the drug, and this part can usually be called a cassette or cassette unit, and the other part often includes a drive for actuating the release of the drug.

[0004] Drug delivery devices designed in this way are generally reusable: the cassette is the disposable part, and the other parts, including the drive unit, are usually reusable parts. The drive unit may include a power unit such as a spring or a motor, and can therefore be reused for multiple drug deliveries.

[0005] Medication delivery devices are generally designed with a delivery member guard to protect the medication delivery member (such as a needle or spray nozzle) used to deliver medication to the end user from contamination and to protect the end user from injury by the medication delivery member.

[0006] It is common to find a locking mechanism / device for locking the delivery member guard to prevent distal movement of the delivery member guard after use, typically to lock the delivery member guard in the end-of-use position. Prior to use, the delivery member guard is often protected by a cap to stop the user from accidentally pressing the delivery member guard and exposing the medication delivery member. However, it is understood that alternative solutions for protecting the medication delivery member prior to use may also be advantageous. Summary of the Invention [Means for solving the problem]

[0007] The invention is defined by the appended claims, to which reference should be made.

[0008] In the present disclosure, when the term "distal direction" is used, it refers to the direction pointing away from the dose delivery site during use of the drug delivery device. When the term "distal portion / end" is used, it refers to the portion / end of the delivery device, or the portion / end of a member thereof, which is located furthest from the dose delivery site during use of the drug delivery device. Correspondingly, when the term "proximal direction" is used, it refers to the direction pointing towards the dose delivery site during use of the drug delivery device. When the term "proximal portion / end" is used, it refers to the portion / end of the delivery device, or the portion / end of a member thereof, which is located closest to the dose delivery site during use of the drug delivery device.

[0009] Additionally, the terms "longitudinal," "longitudinally," "axially," or "axial" refer to a direction extending from the proximal end to the distal end, typically along a device or component thereof, in the direction of the device and / or component's longest elongation.

[0010] Similarly, the terms "transverse," "lateral," and "transversely" refer to directions generally perpendicular to the longitudinal direction.

[0011] Additionally, the terms "circumferential," "circumferential," or "circumferentially" refer to the circumference or direction of circumference relative to an axis, typically a central axis extending in the direction of greatest elongation of the device and / or component. Similarly, "radial" or "radially" refers to a direction extending radially relative to an axis, and "rotation," "rotational," and "rotationally" refer to rotation relative to an axis.

[0012] Thus, there is provided a cassette unit subassembly for a medication delivery device, the subassembly comprising: a body portion extending along a longitudinal axis from a proximal end to a distal end; a delivery member guard coaxially mounted on the body portion and axially movable relative to the body portion along the longitudinal axis; and a locking member mounted on the body portion, the locking member being movable relative to the delivery member guard between a locked position and an unlocked position, the locking member having a distally directed surface adjacent to the proximally directed surface of the delivery member guard in the locked position, and the distally directed surface of the locking member being circumferentially spaced apart relative to the longitudinal axis from the proximally directed surface of the delivery member guard in the unlocked position.

[0013] The locking member is configured to lock the delivery member guard against proximal movement relative to the body portion when the locking member is in a locked position, and to unlock the delivery member guard so that the delivery member guard is free to move proximally relative to the body portion.

[0014] Thus, the subassembly provided by the present invention can releasably prevent the medication delivery guard from moving relative to the body portion by positioning the locking member in a locked or unlocked position.

[0015] Thus, proximal movement of the delivery member guard can be used to trigger another operation of the medication delivery device, such as priming, needle attachment, allowing the end user to attach the medication delivery member, or in some cases as a second safety design. For example, a delivery member guard safety mechanism may be present on a cassette unit including a delivery member guard and a medication delivery member. This safety mechanism is designed to prevent the delivery member guard from moving to a distal position prior to use until the cassette unit of the medication delivery device is properly assembled with the other parts of the medication delivery device, thereby preventing the end user from accidentally injuring themselves or contaminating the delivery member. However, when the end user assembles the two parts of the medication delivery device together, the end user may sometimes push the delivery member guard distally, causing the delivery member guard to suddenly move distally when the safety mechanism is released, potentially causing the end user to come into contact with the delivery member. In such cases, the proximal movement of the delivery member guard may be a secondary safety design, for example, the delivery member guard cannot be moved distally without first being moved to a proximal position, or the delivery member guard cannot be moved distally a distance long enough to expose the medicament delivery member. Thus, the medicament delivery member is not exposed to the end user unless (i) the cassette unit is properly assembled with the rest of the medicament delivery device, and (ii) the end user has not pushed the delivery member guard distally (and therefore the delivery member guard cannot be moved to the proximal "free to move" position).

[0016] Preferably, according to another embodiment, the locking member is rotatable relative to the delivery member guard about the longitudinal axis between a locked position and an unlocked position.

[0017] Alternatively, according to another embodiment, the locking member is linearly slidable relative to the delivery member guard in a direction transverse to the longitudinal axis from a locked position to an unlocked position.

[0018] Preferably, according to another embodiment, the locking member is a removable pin configured to slide linearly relative to the delivery member guard in a direction transverse to the longitudinal axis to be removed from the delivery member guard.

[0019] Alternatively, according to another embodiment, the locking member is radially bendable relative to the longitudinal axis and the delivery member guard from a locked position to an unlocked position.

[0020] Preferably, according to another embodiment, the locking member is a clip that is radially bendable relative to the delivery member guard from a locked position to an unlocked position.

[0021] Preferably, according to another embodiment, the locking member is a removable clip configured to be detached from the delivery member guard when flexed from a locked position to an unlocked position.

[0022] Preferably, according to another embodiment, the cassette unit subassembly includes a biasing member disposed between a first distally facing surface of the delivery member guard and a proximally facing surface of the body portion.

[0023] According to another embodiment, the delivery member guard includes a ledge extending radially relative to the longitudinal axis, the first distally directed surface of the delivery member guard being defined by a portion of the ledge.

[0024] Preferably, according to another embodiment, the delivery member guard comprises a protrusion extending radially relative to the longitudinal axis, the proximally directed surface of the delivery member guard being part of the protrusion.

[0025] Preferably, according to another embodiment, the protrusion extends radially away from the ledge.

[0026] Preferably, according to another embodiment, the locking member comprises a tubular body that surrounds a portion of the delivery member guard.

[0027] According to another embodiment, the locking member comprises a ledge extending circumferentially with respect to the longitudinal axis along a portion of the inner surface of the tubular body of the locking member, the distally directed surface of the locking member being part of the ledge.

[0028] Alternatively, according to another embodiment, the locking member comprises a recess extending circumferentially with respect to the longitudinal axis along a portion of the inner surface of the tubular body of the locking member, the recess facing radially towards the longitudinal axis, and the distally directed surface of the locking member being part of the recess.

[0029] Preferably, according to another embodiment, the cassette unit subassembly comprises an actuator attached to the body portion and configured to move relative to the body portion in the direction of the longitudinal axis between a proximal position and a distal position, the actuator comprising an elongated body portion, and the actuator comprising an interaction portion extending from the elongated body portion of the actuator towards the distal end of the body portion.

[0030] Preferably, according to another embodiment, the delivery member guard is movable relative to the body portion between a distal trigger position and a proximal post-use position, the delivery member guard comprising a second distally directed surface.

[0031] According to another embodiment, the actuator includes a proximally directed lockout surface, and a second distally directed surface of the delivery member guard is adjacent to the proximally directed lockout surface of the actuator when the delivery member guard is in the proximal, post-use position.

[0032] Alternatively, according to another embodiment, the cassette unit subassembly includes an inner housing configured to be disposed within the delivery member guard and the actuator, the inner housing including a proximally directed lockout surface adjacent to a second distally directed surface of the delivery member guard when the delivery member guard is in the proximal, post-use position.

[0033] According to another embodiment, the actuator is positioned between a proximally directed lockout surface of the inner housing and a second distally directed surface of the delivery member guard in a direction transverse to the longitudinal axis when the delivery member guard is not in the proximal post-use position.

[0034] Preferably, according to another embodiment, the actuator comprises a proximally directed retention surface that abuts the distally directed surface of the body portion when the actuator is moved axially from the proximal position to the distal position.

[0035] Preferably, according to another embodiment, the interaction portion of the actuator protrudes from the distal end of the body portion when the actuator is in the distal position.

[0036] According to another embodiment, a cassette unit subassembly of the present invention can be used in a cassette unit for a medication delivery device, the cassette comprising: a delivery member cover assembly secured to a proximal end of a body portion and rotatably releasable relative to the body portion, the delivery member cover assembly comprising: a tubular outer cap, an inner cap at least partially surrounded by the tubular outer cap, and a clutch member rotatably secured to the inner cap and positioned longitudinally between the tubular outer cap and the delivery member guard, the clutch member including a clutch biasing member, the clutch member being axially movable relative to the outer cap between a relaxed position and a tensioned position, the tubular outer cap being axially secured to the inner cap and rotatable relative to the inner cap, the tubular outer cap including a plurality of engaging members, the clutch member including a plurality of opposing engaging members, the plurality of engaging members abutting the plurality of opposing engaging members when the clutch biasing member is in the tensioned position.

[0037] Preferably, according to another embodiment, the plurality of engagement members of the tubular outer cap are a plurality of protrusions, the plurality of protrusions extending radially inwardly with respect to the longitudinal axis from an inner surface of the tubular outer cap.

[0038] According to another embodiment, the plurality of opposing engagement members of the clutch member are a plurality of opposing projections that extend radially outward from an outer surface of the inner cap relative to the longitudinal axis.

[0039] Alternatively, according to another embodiment, the plurality of opposing engaging members of the clutch member are a plurality of slots, the plurality of slots facing radially outward relative to the longitudinal axis from the outer surface of the inner cap.

[0040] Preferably, according to another embodiment, the clutch member comprises a proximal connector and a distal connector, the clutch biasing member being positioned longitudinally between the proximal connector and the distal connector, the distal connector adjacent the proximal end of the delivery member guard, and the proximal connector releasably adjacent a distally directed surface on the inner surface of the tubular outer cap.

[0041] According to another embodiment, the plurality of opposing engagement members of the clutch member are arranged on an outer surface of the distal connector.

[0042] Alternatively, according to another embodiment, the plurality of opposing engagement members of the clutch member are arranged on an outer surface of the proximal connector.

[0043] According to another embodiment, the plurality of opposing engagement members comprise bendable arms extending partially about the longitudinal axis.

[0044] Preferably, according to another embodiment, the body portion includes a bayonet connector on an exterior surface of the body portion for attachment to a portion of a medication delivery device.

[0045] Preferably, according to another embodiment, the body portion includes a snap-fit connector on an exterior surface of the body portion for attachment to a portion of a medication delivery device.

[0046] Preferably, according to another embodiment, the locking member comprises a flange, the flange protruding from an outer surface of the body portion, the flange being longitudinally aligned with the bayonet connector of the body portion.

[0047] Another embodiment of the present invention provides a cassette unit subassembly for a medication delivery device, the cassette unit subassembly comprising: a body portion extending along a longitudinal axis from a proximal end to a distal end; a delivery member guard coaxially mounted on the body portion and biased proximally to move axially relative to the body portion from a distal position to a proximal position; and a locking member attached to the body portion, the locking member being movable relative to the delivery member guard between a locked position and an unlocked position, the locking member being configured to lock the delivery member guard in the distal position when the locking member is in the locked position.

[0048] Preferably, according to another embodiment, the locking member is rotatable relative to the delivery member guard about the longitudinal axis between a locked position and an unlocked position.

[0049] Preferably, according to another embodiment, the locking member comprises a distally directed surface that faces the proximally directed surface of the delivery member guard in the locked position, and the distally directed surface of the locking member is away from the proximally directed surface of the delivery member guard in the unlocked position.

[0050] Preferably, according to another embodiment, the delivery member guard comprises a protrusion extending radially relative to the longitudinal axis, the proximally directed surface of the delivery member guard being part of the protrusion.

[0051] Preferably, according to another embodiment, the actuator is configured to be moved by the delivery member guard along the longitudinal axis relative to the body portion.

[0052] Preferably, according to another embodiment, the actuator comprises an interaction portion configured to interact with a portion of the medication delivery device including a cassette unit having a cassette unit subassembly.

[0053] Preferably, according to another embodiment, the delivery member guard is movable relative to the body portion between a distal trigger position and a proximal post-use position, and the actuator is configured to lock the delivery member guard in the proximal post-use position when the delivery member guard moves from the distal trigger position to the proximal post-use position.

[0054] Preferably, according to another embodiment, the cassette unit subassembly of the present invention can be used together with a cassette unit for a drug delivery device, wherein in addition to the cassette unit the drug delivery device comprises a drive unit, and the cassette unit is releasably attached to the drive unit of the drug delivery device.

[0055] Preferably, according to another embodiment, the cassette unit of the present invention can be used with a medication delivery device comprising a reusable drive assembly, the reusable drive assembly comprising a tubular housing extending along a longitudinal axis from proximal and distal ends, and the cassette unit is releasably attached to the reusable drive assembly via bayonet connections on the inner surface of the proximal end of the reusable drive assembly and on the outer surface of the distal end of the body of the cassette unit.

[0056] According to another embodiment, an inner surface on the proximal end of the reusable drive assembly includes a bayonet groove and an outer surface on the distal end of the body portion of the cassette unit includes a bayonet protrusion.

[0057] Another aspect of the present invention provides a cassette unit subassembly for a medication delivery device, the subassembly comprising: a housing extending along a longitudinal axis between a proximal end and a distal end; a delivery member guard telescopically arranged at the proximal end of the housing; and an actuator axially movable and rotatable relative to the delivery member guard, the delivery member guard comprising an interaction portion configured to rotate and axially move the actuator relative to the housing through interaction with a chamfer arranged on the actuator.

[0058] Preferably, according to another embodiment, the interaction portion is a protrusion or a distally directed arm.

[0059] Preferably, according to another embodiment, the actuator comprises an actuator body and a track arranged on a wall of the actuator body.

[0060] Preferably, according to another embodiment, the track comprises a first track extending in the direction of the longitudinal axis and a second track including a chamfer.

[0061] Preferably, according to another embodiment, the track is formed by a notch, or a recess, or a plurality of transversely extending ledges arranged on the body of the actuator.

[0062] Preferably, according to another embodiment, the drug delivery device is an injection device, an inhalation device, or a medical nebulizer.

[0063] Preferably, according to another embodiment, the medication delivery device cassette unit is for housing a medication container.

[0064] Preferably, according to another embodiment, the drive unit comprises a drive section for actuating the medicament contained in the medicament container housed in the cassette unit.

[0065] Preferably, according to another embodiment, the subassembly comprises a distal cap attachable to the distal end of the body portion.

[0066] Preferably, according to another embodiment, the distal cap is part of the body of the subassembly.

[0067] Preferably, according to another embodiment, the distal lid includes a lid body portion shaped to correspond to the shape of a medication container received within the body portion.

[0068] Preferably, according to another embodiment, the body portion includes a tubular portion.

[0069] Preferably, according to another embodiment, the distal cap comprises an opposing ramped surface configured to interact with the ramped surface of the actuator when the actuator is moved axially by the delivery member guard.

[0070] Preferably, according to another embodiment, the second track comprises a lockout portion, and the protrusion of the delivery member guard is configured to move into the lockout portion with distal movement of the delivery member guard toward a proximal post-use position of the delivery member guard.

[0071] Preferably, according to another embodiment, the protrusions are arranged on a bendable portion of the delivery member guard or the distal frame of the lockout portion of the actuator is bendable.

[0072] Preferably, according to another embodiment, the actuator comprises a locking tab configured to move into a locking notch in the distal lid together with distal movement of the delivery member guard towards its proximal post-use position.

[0073] Preferably, according to another embodiment, the distal lid comprises a container support for supporting a medicament container received within the body portion, the container support comprising a proximally oriented surface.

[0074] Preferably, according to another embodiment, the container support is a bendable arm.

[0075] Preferably, according to another embodiment, the bendable arms of the container support may be formed by cutouts on the lid body, which are open in a direction transverse to the longitudinal axis.

[0076] Preferably, according to another embodiment, the bendable arm may extend distally from the lid body portion.

[0077] Preferably, according to another embodiment, the proximally directed surface of the container support is formed on the inner surface of the bendable arm or at the distal tip of the bendable arm.

[0078] Preferably, according to another embodiment, the container support is configured to be used to prevent axial movement of a drug container received within the main body portion in a distal direction and / or to accommodate received drug containers having different dimensions, e.g., specific lengths and / or widths, with respect to engineering tolerances.

[0079] Preferably, according to another embodiment, a medication delivery device comprising a subassembly according to the present invention may be operated by a method comprising the step of connecting a cassette unit to a drive unit.

[0080] Preferably, according to another embodiment, the method includes the step of connecting the cassette unit to the drive unit by rotating the cassette unit relative to the drive unit about a longitudinal axis.

[0081] Preferably, according to another embodiment, the method includes the steps of rotating the locking member relative to the body portion from a locked position to an unlocked position, moving the delivery member guard proximally along the longitudinal axis relative to the body portion, compressing the clutch biasing member from a relaxed position to a tensioned position due to the proximal movement of the delivery member guard, and rotating the outer cap together with the inner cap about the longitudinal axis relative to the body portion to remove the delivery member cover assembly from the body portion through engagement between the multiple engaging members and the multiple opposing engaging members.

[0082] Preferably, according to another embodiment, the method includes the steps of inserting a distal end of a body portion of the cassette unit into a proximal end of a housing of the drive assembly, rotating the cassette unit relative to the housing of the drive assembly along the bayonet connection, and rotating the body portion of the cassette unit relative to the locking member about the longitudinal axis while rotating the cassette unit relative to the housing of the drive assembly along the bayonet connection.

[0083] In general, all terms used in the claims should be construed according to their ordinary meaning in the art unless expressly defined otherwise. All references to "elements, devices, components, means, etc." should be openly construed as referring to at least one instance of that element, device, component, means, etc. unless expressly stated otherwise.

[0084] Embodiments of the inventive concept will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0085] [Figure 1] 1 is a schematic perspective view showing a medication delivery device having a cassette unit and a drive unit for the medication delivery device; FIG. [Figure 2] 2 is a schematic exploded view showing a subassembly for a cassette unit of the medication delivery device of FIG. 1. FIG. [Figure 3] 3 is a schematic perspective view showing a locking member of the subassembly of FIG. 2 and a main body of the subassembly of FIG. 2. FIG. [Figure 4A] 4 is a schematic perspective view showing the locking member of FIG. 3 in a different embodiment. [Figure 4B] 4 is a schematic perspective view showing the locking member of FIG. 3 in a different embodiment. [Figure 5] 3 is a schematic perspective view of a delivery member guard of the subassembly of FIG. 2. FIG. [Figure 6A]3A-3C are schematic distal views showing the delivery member guard of the subassembly of FIG. 2 and the locking member of the subassembly of FIG. 2 in two examples, when the locking member is in a locked position and an unlocked position. [Figure 6B] 3A-3C are schematic distal views showing the delivery member guard of the subassembly of FIG. 2 and the locking member of the subassembly of FIG. 2 in two examples, when the locking member is in a locked position and an unlocked position. [Figure 6C] 3A-3C are schematic distal views showing the delivery member guard of the subassembly of FIG. 2 and the locking member of the subassembly of FIG. 2 in two examples, when the locking member is in a locked position and an unlocked position. [Figure 6D] 3A-3C are schematic distal views showing the delivery member guard of the subassembly of FIG. 2 and the locking member of the subassembly of FIG. 2 in two examples, when the locking member is in a locked position and an unlocked position. [Figure 6E] 3A-3C are schematic distal views showing the delivery member guard of the subassembly of FIG. 2 and the locking member of the subassembly of FIG. 2 in two examples, when the locking member is in a locked position and an unlocked position. [Figure 6F] 3 is a schematic perspective view showing the actuator of the subassembly of FIG. 2 and the distal lid of the subassembly of FIG. 2. [Figure 6G] 3 is a schematic perspective view showing the actuator of the subassembly of FIG. 2 and the distal lid of the subassembly of FIG. 2. [Figure 7] 3 is a schematic perspective view showing another example of a distal lid of the subassembly of FIG. 2 and a body portion of the subassembly of FIG. 2. FIG. [Figure 8] 8 is a schematic perspective view showing the distal cap of FIG. 7, a distal portion of the delivery member guard of the subassembly of FIG. 2, and a biasing member of the subassembly of FIG. 2. [Figure 9] 3 is a schematic perspective view of a delivery member guard of the subassembly of FIG. 2 and an actuator of the subassembly of FIG. 2. FIG. [Figure 10] 10 is a schematic perspective view of the delivery member guard of FIG. 9 and the actuator of FIG. 9. FIG. [Figure 11A]10 is a schematic cross-sectional view of the delivery member guard of FIG. 9 and the actuator of FIG. 9. [Figure 11B] 10 is a schematic cross-sectional view of the delivery member guard of FIG. 9 and the actuator of FIG. 9. [Figure 12A] 10 is a schematic cross-sectional view showing the delivery member guard of FIG. 9 and the actuator of FIG. 9 when assembled with the distal cap of FIG. 7 and the biasing member of FIG. 8. [Figure 12B] 10 is a schematic cross-sectional view showing the delivery member guard of FIG. 9 and the actuator of FIG. 9 when assembled with the distal cap of FIG. 7 and the biasing member of FIG. 8. [Figure 13] FIG. 8 is a schematic perspective view showing the distal lid of FIG. 7. [Figure 14A] 10 is a schematic side view of the distal lid of FIG. 7 and the actuator of FIG. 9. [Figure 14B] 10 is a schematic side view of the distal lid of FIG. 7 and the actuator of FIG. 9. [Figure 15A] 10 is a schematic side view of the delivery member guard of FIG. 5, the distal cap of FIG. 7, and the actuator of FIG. 9. [Figure 15B] 10 is a schematic side view of the delivery member guard of FIG. 5, the distal cap of FIG. 7, and the actuator of FIG. 9. [Figure 16] 3 is a schematic perspective view showing an actuator of the subassembly of FIG. 2 in another example. [Figure 17] 6 is a schematic perspective view of the delivery member guard of FIG. 5 and the inner housing of the subassembly of FIG. 2. [Figure 18A] 18 is a schematic perspective view of the inner housing of FIG. 17, the delivery member guard of FIG. 5, and the actuator of FIG. 16. [Figure 18B] FIG. 18B is a schematic cross-sectional view of FIG. 18A. [Figure 18C] 18 is a schematic perspective view of the inner housing of FIG. 17, the delivery member guard of FIG. 5, and the actuator of FIG. 16. [Figure 19A] 18 is a schematic perspective view of the inner housing of FIG. 17, the delivery member guard of FIG. 5, and the actuator of FIG. 16. [Figure 19B]18 is a schematic perspective view of the inner housing of FIG. 17, the delivery member guard of FIG. 5, and the actuator of FIG. 16. [Figure 19C] 6D is a schematic diagram illustrating an operational sequence of the interaction between the actuator of FIG. 6F, the distal cap of FIG. 6G, and the delivery member guard of FIG. 6C. [Figure 19D] 6D is a schematic diagram illustrating an operational sequence of the interaction between the actuator of FIG. 6F, the distal cap of FIG. 6G, and the delivery member guard of FIG. 6C. [Figure 19E] 6D is a schematic diagram illustrating an operational sequence of the interaction between the actuator of FIG. 6F, the distal cap of FIG. 6G, and the delivery member guard of FIG. 6C. [Figure 19F] 6D is a schematic diagram illustrating an operational sequence of the interaction between the actuator of FIG. 6F, the distal cap of FIG. 6G, and the delivery member guard of FIG. 6C. [Figure 19G] 6D is a schematic diagram illustrating an operational sequence of the interaction between the actuator of FIG. 6F, the distal cap of FIG. 6G, and the delivery member guard of FIG. 6C. [Figure 19H] 6D is a schematic diagram illustrating an operational sequence of the interaction between the actuator of FIG. 6F, the distal cap of FIG. 6G, and the delivery member guard of FIG. 6C. [Figure 19I] 6D is a schematic diagram illustrating an operational sequence of the interaction between the actuator of FIG. 6F, the distal cap of FIG. 6G, and the delivery member guard of FIG. 6C. [Figure 19J] 6D is a schematic diagram illustrating an operational sequence of the interaction between the actuator of FIG. 6F, the distal cap of FIG. 6G, and the delivery member guard of FIG. 6C. [Figure 20] FIG. 10 is a schematic side view showing a cassette unit equipped with a drug delivery member set. [Figure 21] 21 is a schematic exploded view of the subassembly of FIG. 2 with the drug delivery member set of FIG. 20. FIG. [Figure 22A] FIG. 21 is a schematic perspective view of the drug delivery member set of FIG. 20. [Figure 22B] FIG. 21 is a schematic perspective view of the drug delivery member set of FIG. 20. [Figure 23]21 is a schematic perspective view showing the inner cap of the drug delivery element set of FIG. 20. FIG. [Figure 24] 21 is a schematic distal view showing the clutch member of the drug delivery element set of FIG. 20. FIG. [Figure 25A] FIG. 21 is a schematic perspective view of the drug delivery member set of FIG. 20. [Figure 25B] FIG. 21 is a schematic perspective view of the drug delivery member set of FIG. 20. [Figure 26A] FIG. 10 is a schematic perspective view showing an outer cap and an inner cap of another example of a drug delivery member set. [Figure 26B] FIG. 10 is a schematic perspective view showing an outer cap and an inner cap of another example of a drug delivery member set. DETAILED DESCRIPTION OF THE INVENTION

[0086] 1-36D show a cassette unit subassembly for a medication delivery device. The term "cassette unit subassembly" is sometimes abbreviated to "subassembly" herein. Note that the terms "cassette unit subassembly" and "subassembly" are used interchangeably herein. A cassette unit is typically used with a medication delivery device having two removable parts, as shown in FIG. 1. The first part of the medication delivery device, i.e., cassette unit 2, typically houses a medication container, such as a syringe or cartridge, in which a medication is contained. The syringe or cartridge may be made of glass or plastic. The syringe or cartridge may include a rubber stopper sealing the distal end of the syringe or cartridge and a septum or medication delivery member with a rubber sheath sealing the proximal end of the syringe or cartridge. Alternatively, the syringe or cartridge may be collapsible with only the septum or medication delivery member with a rubber delivery member sheath sealing the proximal end of the syringe or cartridge.

[0087] The second part of the medication delivery device, i.e., the drive unit 1, typically includes a drive for actuating the medication contained in the medication container in a proximal direction of the medication delivery device, where it is expelled to the end user. The drive unit 1 may include a plunger rod for pushing the medication container. In one example, the stopper of the medication container may thus be moved proximally relative to the other parts of the medication container. In another example, the plunger rod may crush the medication container by pushing the medication container proximally relative to the cassette unit 2. The drive unit 1 also includes a power source, such as a spring, a gas canister, or a motor-driven gear set, for moving the plunger rod proximally of the medication delivery device. Central to the concepts described herein are cassette unit subassemblies for the medication delivery device, rather than the drive unit, and various different types of drive units may be used with cassette units having the subassemblies described herein. As such, the drive unit will not be described comprehensively.

[0088] The subassembly of the present invention comprises a body portion 20, 20' extending along a longitudinal axis L from a proximal end to a distal end, a delivery member guard 21, 21', 21" coaxially mounted on the body portion and axially movable relative to the body portion 20, 20' along the longitudinal axis, and a locking member 22, 22', 22" mounted on the body portion 20, 20'. The locking member 22, 22', 22" is movable relative to the delivery member guard 21, 21', 21" between a locked position and an unlocked position. The locking member 22, 22', 22" comprises a distally directed surface adjacent to the proximally directed surface of the delivery member guard 21, 21', 21" in the locked position, and the distally directed surface of the locking member 22, 22', 22" is circumferentially spaced apart relative to the proximally directed surface of the delivery member guard 21, 21', 21" in the unlocked position.

[0089] In a preferred embodiment, the body portions 20, 20' may be formed as generally tubular components that are shaped to accommodate most common drug containers, allowing the subassembly to keep the drug delivery device compact. However, the body portions may be formed in any other suitable shape that can accommodate a drug container.

[0090] As shown in FIGS. 1 and 2 , the main body 20 is configured to house a medication container within an outer shell 200. If visibility of the medication container is required, the outer shell 200 may include a window 201 aligned with the medication container, allowing an end user to observe the medication through the window 201. On the other hand, the outer shell 200 may be transparent, in which case the main body does not require a window. The cassette unit 2 is configured to be releasably attached to the drive unit 1 through a releasable connection between the main body 20 and the drive unit when the end user plans to perform a medication delivery operation. The main body 20 includes a connector configured to connect with a mating connector on the drive unit 1. In one example, the connector and the mating connector can form a bayonet connection, meaning that one of the main body 20 and the drive unit 1 includes a bayonet protrusion, and the other of the main body 20 and the drive unit 1 includes a bayonet recess / notch. For example, the outer body portion 20 may include a bayonet connector 202 on the outer shell 200 of the body portion 20, such as a bayonet protrusion as shown in Fig. 2, and the drive unit 1 includes a counter bayonet connector 11, such as a bayonet recess as shown in Fig. 1. In this example, the body portion 20 is configured to be axially inserted into a proximal portion of the drive unit 1 along the longitudinal axis L through the bayonet connector 202 and the counter bayonet connector 11, and then the body portion 20 needs to be rotated relative to the drive unit 1 about the longitudinal axis L so that the cassette unit 2 is properly attached to the drive unit.

[0091] Alternatively, the connection between the body portion 20 and the drive unit 1 may be another suitable connection, such as a snap-fit or threaded connection, or the cassette unit may be fully received within the drive unit, in which case the portion of the drive unit for receiving the cassette unit may be a form-fit connection for releasably receiving the cassette unit. If the cassette unit is fully received within the drive unit, the shape of the body portion may depend on the shape of the portion of the drive unit for receiving the cassette unit.

[0092] The subassembly of the present invention includes a delivery member guard 21, 21', as shown in Figures 2, 5, and 6C. The delivery member guard 21, 21' includes a front shield 210, 210' configured to protrude from the proximal end of the main body portion 20. The front shield 210, 210' is configured to shield a medication delivery member that is integral with or attachable to a medication container when the medication delivery device is used by an end user. In a preferred example, the front shield 210, 210' is a tube-shaped element having an opening at the proximal end of the front shield 210, 210', such that the front shield 210, 210' of the delivery member guard 21, 21' is coaxially mounted on the main body portion 20 and axially movable relative to the main body portion 20 along the longitudinal axis L between a distal position and a proximal position. Similarly, the front shield 210, 210' of the delivery member guard is shaped similarly to the main body portion 20 to make the device compact, although the delivery member guard may be formed in any other suitable shape that may be axially movable relative to the main body portion 20 along the longitudinal axis L.

[0093] Delivery member guard 21 includes arms 211 extending from the distal end of front shield 210 toward the distal end of body portion 20 of the subassembly. Preferably, delivery member guard 21 includes protrusions 214, as shown in FIG. 5 , extending radially relative to longitudinal axis L. Delivery member guard 21 optionally includes a ledge 212 disposed on the distal end of the delivery member guard. In a preferred example, protrusions 214 extend radially relative to longitudinal axis L away from ledge 212. Delivery member guard 21 optionally includes a window portion 213 configured to be aligned with window 201 on outer shell 200 of body portion 20. Window portion 213 can be an opening or a portion formed of a transparent material.

[0094] In a preferred example, the delivery member guard 21 is partially disposed within the main body 20, i.e., the delivery member guard 21 is partially disposed within the outer shell 200 of the main body 20. In this example, preferably, the arm 211 and the protrusion 212 are completely disposed within the main body 20, and the front shield 210 protrudes completely or partially from the proximal end of the main body 20 so that the front shield 210 can cover the medication delivery member. In one example, the arm 211 of the delivery member guard 21 is configured to interact with a part of the drive unit 1 of the medication delivery device comprising the subassembly of the present invention. For example, after the cassette unit 2 comprising the subassembly is assembled to the drive unit 1, further distal movement of the delivery member guard 21 can move the arm 211 into the drive unit 1 to release a plunger rod connected to a power source, such as a spring, a gas canister, or a motor, or to switch on the power source.

[0095] The subassembly includes a locking member 22, as shown in FIGS. 2-4B. The locking member 22 is attached to the body 20. The locking member 22 may be removably or non-removably attached to the body 20. The locking member 22 includes a body 220. In a preferred embodiment, the body 220 of the locking member 22 is a tubular body 220. The locking member 22 is movable relative to the body 20 between a locked position and an unlocked position. As shown in FIGS. 4A-4B, the locking member 22 includes a distally oriented surface adjacent to the proximally oriented surface of the delivery member guard 21, 21′ in the locked position, and the distally oriented surface of the locking member 22 is spaced apart from the proximally oriented surface of the delivery member guard 21, 21′ in the unlocked position. In a preferred embodiment, the proximally oriented surface of the delivery member guard 21, 21′ is defined by a protrusion 214.

[0096] The subassembly of the present invention is configured such that when locking members 22, 22', 22" are in the locked position, delivery member guard 21, 21', 21" is locked in a distal position, and when locking members 22, 22', 22" are in the unlocked position, delivery member guard 21, 21', 21" is released from the distal position, such that when delivery member guard 21, 21', 21" is subjected to a proximal force, delivery member guard 21, 21', 21" can move to the proximal position.

[0097] In one example, locking members 22, 22', 22" are rotatably mounted to body portion 20, 20' between a locked position and an unlocked position. In this example, locking member 22 includes a flange 221 as shown in FIG. 3 for purposes of mounting locking member 22 to body portion 20. In this example, as shown in FIG. 3, flange 221 includes an enlarged portion 221a and a transverse portion 221b. Transverse portion 221b extends between enlarged portion 221a and body portion 220 of locking member 22. In this example, body portion 20 includes an assembly track 203 formed by a notch / recess on the distal end of body portion 20. Preferably, 1, the assembly track 203 is located on a distal portion of the outer shell 200 of the body portion 20. The assembly track 203 comprises a longitudinal portion 203a and a transverse portion 203b. The longitudinal portion 203a is a longitudinal notch / recess on the distal end of the body portion 20, and the transverse portion 203b is a transverse notch / recess on the distal end of the body portion 20. The longitudinal portion 203a of the assembly track 203 comprises a distal end and a proximal end. The transverse portion 203b of the assembly track 203 comprises a first circumferential end and a second circumferential end. The proximal end of the longitudinal portion 203a is connected to the first circumferential end of the transverse portion 203b of the assembly track 203.

[0098] The dimensions of the longitudinal portion 203a and the transverse portion 203b, as viewed transversely to the longitudinal axis L, are greater than the dimensions of the transverse portion 221b of the flange 221 of the locking member 22, but are smaller than the dimensions of the enlarged portion 221a of the flange 221 of the locking member 22.

[0099] During assembly, the locking member 22 is configured to be attached to the main body 20 through the flange 221 of the locking member 22 and the assembly track 203 of the main body 20. The transverse portion 221b of the flange 221 of the locking member 22 faces the distal end of the longitudinal portion 203a of the assembly track 203, is inserted into the longitudinal portion 203a through the distal end of the longitudinal portion 203a, is moved along the longitudinal portion 203a of the assembly track 203 from the distal end of the longitudinal portion 203a to the proximal end of the longitudinal portion, and is moved along the transverse portion 203b of the assembly track 203 from a first circumferential end of the transverse portion 203b into the transverse portion 203b of the assembly track 203 until it is blocked at the second circumferential end of the transverse portion 203b.

[0100] Body portion 220 of locking member 22 is sized to match the dimensions of the distal end of outer shell 200, such that body portion 220 of locking member 22 can be snugly received within the distal end of outer shell 200 after assembly. Alternatively, the dimensions of longitudinal portion 203a and transverse portion 203b are smaller than the dimensions of enlarged portion 221a of flange 221 of locking member 22, such that transverse movement of locking member 22 relative to body portion 200 is blocked by enlarged portion 221a.

[0101] In a preferred example, the enlarged portion 221a of the flange 221 protrudes from the outer surface of the distal end of the outer shell 200 of the main body 20. In one example, the bayonet connector 202 of the main body 20 is a bayonet protrusion. The flange 221, specifically the enlarged portion 221a of the flange 221, is longitudinally aligned with the bayonet connector 202 of the main body 20, as shown in FIG. 3 . The enlarged portion 221a of the flange 221 may have a circumferential length that is generally equal to or slightly smaller than the circumferential length of the bayonet connector 202. When the bayonet protrusion 202 moves toward the longitudinal portion of the opposing bayonet connector 11, the enlarged portion 221a of the flange 221 can also move toward the longitudinal portion of the opposing bayonet connector 11. However, when the bayonet protrusion 202 moves to the circumferential portion of the opposing bayonet connector 11, the enlarged portion 221a of the flange 221 can remain only in the longitudinal portion of the opposing bayonet connector 11. Therefore, when the bayonet protrusion 202 rotates along the circumferential portion of the opposing bayonet connector 11, the main body 20 and the delivery member guards 21, 21' are rotated relative to the locking member 22. Therefore, the rotation to connect the cassette unit 2 to the drive unit 1 rotates the locking member 22 relative to the delivery member guards 21, 21' from the locked position to the unlocked position.

[0102] It should be noted that, alternatively, for the purpose of attaching the locking member to the body portion, the body portion 20 can be provided with a circumferential slot therein instead of the assembly track as described above. Thus, the locking member can be snap-fit into the circumferential slot of the body portion 20. It should be noted that if the assembly method for attaching the locking member to the body portion is changed, the above-mentioned components involved in the assembly can also be changed depending on the selected assembly method. Furthermore, the transverse portion 221b of the flange 221 of the locking member 22 is primarily designed for the assembly method, and therefore the flange 221 can be modified to have only the enlarged portion 221a.

[0103] In one example, body portion 220 of locking member 22, 22′, 22″ is a tubular body portion 220. Tubular body portion 220 of locking member 22, 22′, 22″ surrounds a portion of delivery member guard 21, 21′. For example, tubular body portion 220 can be a generally cylindrically shaped element or a generally semi-cylindrical shaped element. In one example, the locking member includes a ledge 222, 222′ extending circumferentially with respect to the longitudinal axis along a portion of the inner surface of tubular body portion 220 of locking member 22, as shown in FIGS. 4A-4B and 6C-6E, and the distally directed surface of the locking member is part of ledge 222, 222′.

[0104] Bump 222 may extend only circumferentially about the longitudinal axis along a portion of the inner surface of tubular body 220 of locking member 22, as shown in FIG. 4A . In this example, the unlocked position is defined by the location of breakaway portion 223 of bulge 222 on the inner surface of tubular body 220 of locking member 22 relative to the remainder of bulge 222, as shown in FIG. 4A . Breakaway portion 223 represents the portion where bulge 222 stops continuing to extend circumferentially about longitudinal axis L. Thus, after protrusion 214 is aligned with the breakaway portion in the direction of longitudinal axis L, protrusion 214 can move freely in the direction of the longitudinal axis without being blocked by bulge 222. Protrusion 214 of delivery member guard 21, 21′ is configured to move along bulge 222 of locking member 22 when locking member 22 moves from the locked position to the unlocked position. After protrusion 214 disengages from ledge 222 or contacts broken portion 223 of ledge 222, delivery member guard 21, 21′ is free to move proximally relative to main body portion 20 of the subassembly. Alternatively, ledge 222′ can extend both circumferentially about the longitudinal axis and in the longitudinal axis direction. In this example, ledge 222′ can be helically shaped, as shown in FIGS. 6C-6E . Helically shaped ledge 222′ extends helically from the distal end to the proximal end toward the proximal direction of cassette unit 2. In this example, protrusions 214, 214′, 214″ of delivery member guard 21, 21′, 21″ are configured to move along helically shaped ledge 222′ of locking member 22 when locking member 22 moves from the locked position to the unlocked position. After the protrusions 214, 214' have moved from the distal end of the helical shaped ledge 222' to the proximal end of the helical shaped ledge 222', the delivery member guards 21, 21' are free to move proximally of the body portion 20 of the subassembly. The exact location that defines the unlocked position of the locking member 22 will depend on the design of the medication delivery device comprising the subassembly of the present invention.In this example, even if the end user rotates the locking member 22 to the unlocked position, the end user can still change their mind and rotate the locking member back to the locked position. Note that the protrusion 214' may include a proximally oriented angled surface.

[0105] Alternatively, locking member 22 includes a recess extending circumferentially relative to longitudinal axis L along a portion of the inner surface of tubular body 220 of locking member 22. The recess faces radially toward longitudinal axis L. The distally facing surface of the locking member is part of the recess, and protrusion 214 of delivery member guard 21, 21′ is configured to protrude into the recess. In this example, protrusion 214 of delivery member guard 21, 21′ is blocked from movement in either a distal or proximal direction relative to body 20 of the subassembly when locking member 22 is in the locked position. Similarly, the recess includes a breakout similar to the above example to define an unlocked position of locking member 22.

[0106] FIG. 6A shows locking member 22 in the locked position. When locking member 22 is in the locked position, protrusion 214 of delivery member guard 21, 21′ rests on / moves along ledge 222 of the locking member, thereby locking delivery member guard 21, 21′ in a distal position, i.e., delivery member guard 21, 21′ is prevented from moving toward the proximal end of body portion 20 relative to locking member 22. FIG. 6B shows locking member 22 in the unlocked position. In this example, locking member 22 rotates about longitudinal axis L relative to delivery member guard 21, 21′ because, in the example where ledge 222 is a partially circular ledge, as shown in FIG. 4A , locking member 22 extends only partially along the inner surface of tubular body portion 220 of locking member 22. When protrusion 214 of delivery member guard 21, 21′ is no longer aligned with a portion of ledge 222 in the direction of longitudinal axis L, the distally directed surface of locking member 22 is spaced apart from the proximally directed surface of delivery member guard 21, 21′. Thus, the position where protrusion 214 of delivery member guard 21, 21′ is fully offset from a portion of ledge 222 in the direction of longitudinal axis L defines an unlocked position of locking member 22. Thus, the exact unlocked position of locking member 22 can be defined by selection of the length of ledge 222, which depends on design requirements.

[0107] The movement of the delivery member guard 21, 21′ from the distal position to the proximal position can be used as an “unlocking” mechanism for the cassette unit 2 to prevent damage or contamination of the medication delivery member caused, for example, by the user accidentally touching it or dropping it to the ground. For example, the delivery member guard 21, 21′ may be able to move to a second distal position when the delivery member guard 21, 21′ has already moved from the distal position to the proximal position; further details regarding this initiation mechanism will be described later. Alternatively, the movement of the delivery member guard 21, 21′ from the distal position to the proximal position can be used in cassette units that require the end user to self-attach the medication delivery member. For example, the end user may need to self-attach a pen needle to the cassette unit. In this example, the delivery member guard should initially be in a distal position so that an end user can attach a pen needle to the cassette unit, and as the end user attaches the pen needle to the cassette unit, the end user can move the locking member 22 from the locked position to the unlocked position so that the delivery member guard 21, 21′ can move from a distal position to a proximal position, such that the attached pen needle can be covered by the delivery member guard 21, 21′, for example, by simply being pulled by the user or pushed by a biasing member or resilient structure. Alternatively, if the subassembly is used in a cassette unit having a pre-assembled medication delivery member set, the proximal movement of the delivery member guard 21, 21′ from its distal position can be used to allow the user to manipulate the medication delivery member set to load the medication delivery member; this alternative will be described in more detail below.

[0108] In a preferred example, a safety mechanism may be provided to prevent an end user from accidentally removing the cassette unit 2. As shown in Figures 33 to 36D, the safety mechanism is provided by providing the tubular body portion 220 of the locking member 22 with a notch / recess 220a' that opens in a direction transverse to the longitudinal axis L and a locking tab 20a' extending from the wall of the body portion 20'. The notch / recess 220a' is configured to face radially toward the distal end 20b' of the locking tab 20a'.

[0109] In this example, the body portion 20′ includes a locking tab 20a′ extending distally from a wall of the body portion 20′ to a distal end 20b′ of the locking tab 20a′. The locking tab 20a′ is bendable. As shown in FIGS. 36A-36D, when an end user attaches the cassette unit 2 to the drive unit 1 via the bayonet connection as described above (the sequence of actions indicated by arrow S), the body portion 20′ rotates relative to the locking member 22′ (as indicated by arrow R3 in FIGS. 36B-36C). The distal end 20b′ of the locking tab 20a′ is relatively biased radially inward toward the longitudinal axis L (as indicated by arrow Z in FIG. 36C) by the tubular body portion 220 of the locking member 22′ when the body portion 20′ rotates relative to the locking member 22′, as shown in FIGS. 36B-36C. When cassette unit 2 is properly attached to drive unit 1, distal end 20b' of locking tab 20a' is radially aligned with notch / recess 220a' of locking member 22' such that locking tab 20a' is bent radially outward about longitudinal axis L and positioned in notch / recess 220a', as shown in FIG. 36D. When locking tab 20a' is within notch / recess 220a', locking member 22' and body portion 20' are prevented from rotating relative to one another.

[0110] As described above, the enlarged portion 221a of the locking member 22' will remain in the longitudinal portion of the opposing bayonet connector 11 of the drive unit 1 when the bayonet protrusion of the main body portion is within the circumferential portion of the opposing bayonet connection portion of the drive unit 1, which means that the cassette unit 2 is properly attached to the drive unit 1. Therefore, when the locking member 22' and the main body portion 20' are prevented from rotating relative to each other as described above, the cassette unit 2 cannot be removed from the drive unit 1 via the bayonet connection portion.

[0111] In a preferred example, the locking tab 20a' includes a protrusion 20c' extending from an outer surface of the locking tab 20a' in a direction transverse to the longitudinal axis L. In this example, when an end user wishes to remove the cassette unit 2 from the drive unit 1, the end user can press the protrusion 20c' radially inward relative to the longitudinal axis L, which causes the locking tab 20a' to deflect radially inward relative to the longitudinal axis L. This causes the distal end 20b' to move out of the notch / recess 220a' of the locking member 22'. Once the distal end 20b' has moved out of the notch / recess 220a' of the locking member 22', the locking member 22' and the main body 20' can rotate relative to each other, thereby allowing the cassette unit 2 to be removed from the drive unit 1 by rotating the cassette unit 2 along the bayonet connection.

[0112] In a preferred example, the subassembly includes a distal lid 24, 24' as part of the body portion 20 of the subassembly, as shown in Figures 6G and 7-8. The distal lid 24, 24' is configured to be fixedly attached to the distal end of the body portion 20, for example, by a snap fit between a snap opening 204 on the body portion 20 and a snap arm 241, 241' on the distal lid 24, 24', thereby blocking movement of the drug container in a distal direction relative to the body portion 20. The distal lid 24 may also be fully or at least partially received within a longitudinal portion 203a of the assembly track 203 such that the locking member 22 may only be rotatable relative to the body portion 20 along a transverse portion 203b of the assembly track 203. In this example, the distal lid 24 includes a proximally extending arm 242 configured to fit within the longitudinal portion 203a of the assembly track 203.

[0113] The shape of the distal lid 24, 24′ typically depends on the shape of the distal end of the main body portion 20. As shown in FIGS. 2, 6G, and 7, the distal lid 24, 24′ includes a lid body portion 240, 240′, which may be formed according to the shape of a drug container to be received in the main body portion 20; for example, the lid body portion 240, 240′ includes a tubular portion. Furthermore, the distal lid 24, 24′ typically includes an opening 240a axially aligned with a portion of the distal end of the drug container, and when the cassette unit 2 is attached to the drive unit 1, a plunger rod can pass through the opening 240a and act on the drug container to deliver the contained drug.

[0114] In one example, distal cap 24 may include a curved opening / slot 240b (when viewed axially) that allows an arm of delivery member guard 21 or an interacting portion 251 of actuator 25 (described later) to pass through the curved opening / slot 240b and protrude into drive unit 1. In another example, distal cap 24 may be generally rectangular or oval in shape. In this example, an arm of delivery member guard 21 or an interacting portion 251 of actuator 25 may pass through a space between the distal end of body portion 20 and the end of distal cap 24.

[0115] It should be noted that the cassette unit subassembly may be used with a medication delivery device that is triggered by a button, for example, arranged at the distal end of the drive unit 1 or on a side body wall of the drive unit 1. In this example, neither the delivery member guard nor the actuator was involved in triggering the medication delivery operation. Therefore, the distal lid does not need to include a curved opening / slot.

[0116] The distal lid 24, 24' optionally includes a label, such as an RFID tag, barcode, QR code (registered trademark), or mechanical code, for including information about the cassette unit 2 or the contained medications, so that a reader in the drive unit 1 may obtain the information for further use.

[0117] The distal lid 24 optionally includes a container support 245 for supporting a drug container received within the main body portion 20. The container support 245 includes a proximally-facing surface. In one example, the container support 245 is a bendable arm 245. The bendable arm 245 may be formed by a notch on the lid body portion 240 that is open in a direction transverse to the longitudinal axis L; alternatively, the bendable arm 245 may extend distally from the lid body portion 240. In this example, the container support 245 can prevent distal axial movement of a drug container received within the main body portion 20. The proximally-facing surface of the container support 245 may be formed on an inner surface of the bendable arm or may be formed at a distal tip of the bendable arm. The container support 245 may also be used to accommodate different dimensions of the received drug container, for example, a drug container having a specific length and / or width, based on engineering tolerances.

[0118] The subassembly of the present invention optionally includes a biasing member 23 disposed between a first distally-directed surface of the delivery member guard 21, 21′ and a proximally-directed surface of the body portion 20. The biasing member 23 can be a spring or a bendable arm. The biasing member 23 is configured to bias the delivery member guard 21, 21′ toward the proximal end of the body portion 20. In one example, the first distally-directed surface of the delivery member guard 21, 21′ is defined by a portion of a ledge 212, 212′. In examples where the subassembly includes a distal lid 24, 24′, the proximally-directed surface 243 of the body portion 20 can be disposed on the distal lid 24, 24′, as shown in FIG. 8 . Alternatively, the body portion can be configured with an inner ledge extending along the inner surface of the body portion, such that the proximally-directed surface is disposed on the inner ledge.

[0119] The subassembly of the present invention optionally includes an actuator 25 movable relative to the body portion 20 along the longitudinal axis L between a proximal position and a distal position, as shown in FIG. 2 . In a preferred example, the actuator 25 includes an elongate body portion extending along the longitudinal axis L between a proximal end and a distal end. The actuator 25 includes an interaction portion 251, a retention portion 252, and a distal notch 253. In a first example, as shown in FIG. 9 , the actuator 25 further includes a second notch 254 and a third notch 255. In a second example, as shown in FIG. 16 , instead of the second notch 254 and the third notch 255, the actuator 25 includes a recess 255′ arranged on the outer surface of the elongate body portion of the actuator 25. The difference between the two examples of actuator 25 relates only to the lockout mechanism for delivery member guard 21, i.e., the mechanism that prevents delivery member guard 21 from moving distally relative to main body portion 20 after cassette unit 2 has been used, which will be described in detail later.

[0120] The interacting portion 251 of the actuator 25 is configured to interact with components of the drive unit 1 of the medication delivery device, including the subassembly. For example, the drive unit 1 may include a motor, a motor drive gear, a plunger rod, and a mechanical switch for switching on the motor. The interacting portion 251 of the actuator 25 may contact the mechanical switch when the delivery member guard 21 moves distally relative to the body 20 and the drive unit 1, moving the switch and switching on the motor. In this case, if the switch is designed to face toward the proximal end of the drive unit 1, the switch may be disposed within a slot in the drive unit 1 (to prevent unintentional contact), and the interacting portion 251 may be a rod with a diameter that can be inserted into such a hole and press the switch. Alternatively, the switch may be disposed on the inner surface of the drive unit 1. In this case, the interacting portion 251 may be an arm that protrudes radially outward, so that the interacting portion 251 can press or reverse the switch when aligned with or moved past the switch. In this example, the arm 211 of the delivery member guard 21 may not protrude into the drive unit 1 of the medication delivery device including the subassembly. In this example, the delivery member guard 21 comprises a second distally oriented surface preferably arranged on the distally oriented surface of the arm 211. The second distally oriented surface is configured to interact with an actuator 25. As shown in Figure 10, the actuator 25 is movably mounted to the delivery member guard 21.

[0121] Actuator 25 is initially positioned in its proximal position. As shown in FIGS. 11A, 12A, and 19A, actuator 25 is in its proximal position when delivery member guard 21 is locked in the distal position. Arm 211 of delivery member guard 21 is adjacent to distal edge 253a of first notch 253 of actuator 25. Delivery member guard 21 is released and moves to the proximal position when locking member 22 is in the unlocked position and the delivery member guard receives a force biasing it in the proximal direction. As shown in FIGS. 11B and 12B / 19B, actuator 25 is in its proximal position when delivery member guard 21 is in the proximal position. Next, arm 211 of delivery member guard 21 moves proximally into second notch 254 of actuator 25. The arm 211 of the delivery member guard 21 may be bendable radially about the longitudinal axis L such that the arm 211 can bend and move over a ledge between the first notch 253 of the actuator 25 and the second notch 254 of the actuator 25. Alternatively, the ledge between the first notch 253 of the actuator 25 and the second notch 254 of the actuator 25 may be bendable radially about the longitudinal axis L such that when the delivery member guard 21 moves proximally relative to the body portion 20, the arm 211 can deflect the ledge and move over the ledge of the actuator 25 from the first notch 253 of the actuator 25 to the second notch 254 of the actuator 25.

[0122] When the arm 211 of the delivery member guard 21 is within the second notch 254 of the actuator 25, the arm of the delivery member guard 21 is adjacent to the distal edge 254a of the second notch 254, and further distal movement of the delivery member guard 21 can move the actuator 25 from a position proximal to the actuator 25 to a position distal to the actuator 25, as shown in Figure 15A. Thus, as the actuator 25 moves from its proximal position to its distal position, the interacting portion 251 of the actuator 25 moves into the drive unit 1 of the medication delivery device and can interact with components within the drive unit 1.

[0123] In another example, the actuator 25 is configured to be retained in its distal position. In this example, the body portion 20 includes a retaining portion that provides a distally oriented surface adjacent to the proximally oriented retaining surface of the actuator 25 when the proximally oriented retaining surface of the actuator 25 is moved beyond the retaining portion of the body portion. In this example, as shown in FIGS. 13 and 14A-14B , the retaining portion 242 a of the body portion 20 may be arranged on an inner surface of the proximally oriented arm 242 of the distal lid 24. The proximally oriented retaining surface of the actuator 25 is defined by the retaining portion 252 of the actuator 25. A design such as that described in this example may be used with a medication delivery device including a drive unit that uses distal movement of the interacting portion 251 of the actuator 25 to switch on a set of control electronics, such that when the end user moves the delivery member guard 21 and the actuator 25 distally relative to the body portion 20, the control electronics are switched on and only switched off after the cassette unit 2 including the subassembly is removed from the drive unit 1. In this example, actuator 25 is retained in its distal position even if delivery member guard 21 is again moved proximally relative to body portion 20, as shown in Figure 15B. Furthermore, when actuator 25 is retained in its distal position, interacting portion 251 of actuator 25 thus protrudes from distal lid 24, such that a visual and / or tactile indication can be provided to the end user when removing cassette unit 2 from drive unit 1 to indicate that cassette unit 2 has been used.

[0124] To initiate operation of the medication delivery device comprising the drive unit 1 and the cassette unit 2, the delivery member guard 21 is moved by the end user to a distal trigger position toward the drive unit 1. This distal movement of the delivery member guard 21 exposes the medication delivery member that connects with the contained medication and may trigger the drive unit 1 to output a force to the contained medication. Thus, when the delivery member guard 21 is in the distal trigger position, the medication delivery member is exposed to the user. This distal movement of the delivery member guard 21 can be performed by pressing the proximal end of the front shield 210 of the delivery member guard 21 against the medication delivery site.

[0125] In examples where the subassembly includes the biasing member 23, the biasing member 23 is configured to bias the delivery member guard 21 in a proximal direction relative to the body portion 20 of the subassembly. After the drug delivery operation is performed, the end user may remove the drug delivery device from the drug delivery site, and thus the biasing member 23 may bias the delivery member guard 21 in a proximal direction relative to the body portion 20 so that the front shield 210 of the delivery member guard 21 can shield the drug delivery member.

[0126] Thus, the delivery member guard 21 is biased to the proximal post-use position by the biasing member 23. The proximal post-use position may be the proximal position of the delivery member guard 21 as described above, or may be a second proximal position than the proximal position of the delivery member guard 21 described above, depending on the design of the medication delivery device. For example, if the medication delivery member of the medication delivery device is configured to move beyond its initial position in a proximal direction of the medication delivery device after use, such as in a medication delivery device with an automatic needle insertion mechanism, the delivery member guard may be moved to the second proximal position as the proximal post-use position.

[0127] 15B , when delivery member guard 21 is moved to the proximal, post-use position, actuator 25 is held in its distal position, such that arm 211 of delivery member guard 21 moves into third notch 255 of actuator 25. The actuator preferably includes a proximally-directed lockout surface 255a disposed on a distal edge 255a of third notch 255 such that when delivery member guard 21 is in the proximal, post-use position, the second distally-directed surface of delivery member guard 21 abuts proximally-directed lockout surface 255a of actuator 25. Thus, further movement of delivery member guard 21 in the distal direction relative to body portion 20 is prevented.

[0128] As shown in FIG. 16 , in a second example of actuator 25, the subassembly includes inner housing 26. As shown in FIG. 17 , inner housing 26 is radially disposed relative to the longitudinal axis between delivery member guard 21 and actuator 25. Inner housing 26 is secured to body portion 20. Inner housing 26 includes body portion 260 having a distal notch 261. In this example, recess 255′ of actuator 25 is configured to block arm 211 of delivery member guard 21 from moving into notch 261 of inner housing when actuator 25 is in its proximal position, as shown in FIGS. 18A-18B . Arm 211 of delivery member guard 21 is adjacent to a distal edge of recess 255a′ of actuator 25 when delivery member guard 21 is in the proximal position. As delivery member guard 21 moves actuator 25 to a position distal of actuator 25, actuator 25 is held in that distal position by body portion 20, such that when delivery member guard 21 moves to a proximal, post-use position, arm 211 of delivery member guard 21 can move into notch 261 of inner housing 26, as shown in FIG. 18C . In this example, the second distally-directed surface of delivery member guard 21 is adjacent to the proximally-directed surface on distal edge 261 a of notch 261 in inner housing 26. Thus, further movement of delivery member guard 21 in the distal direction relative to body portion 20 is prevented.

[0129] In another example, the actuator 25′ includes an actuator body 250′ and a track. The track includes a first track 251′ and a second track 252′. The first and second tracks 251′, 252′ are arranged on a wall of the actuator body 250′. The first and second tracks 251′, 252′ are configured to interact with protrusions arranged on the delivery member guard. In a preferred example, the delivery member guard 21′ preferably includes a protrusion 211′ extending from the wall of the delivery member guard 21′ in a direction transverse to the longitudinal axis L, as shown in FIG. 6C. In this example, the actuator 25′ is rotatable relative to the delivery member guard 21′ about the longitudinal axis L. As shown in FIG. 19C, the protrusion 211′ of the delivery member guard 21′ is initially positioned within the first track 251′ of the actuator 25′ when the locking member 22 is in the locked position. When locking member 22 is in the unlocked position, protrusion 211' can move in the proximal direction (arrow P) with delivery member guard 21', thus entering second track 252' of actuator 25' when delivery member guard 21' is in its proximal position (dashed arrow), as shown in FIG. 19D. The proximal end of first track 251' optionally comprises a sloped surface facing the distal end of actuator 25'. Alternatively, the proximal end of protrusion 211' of delivery member guard 21' optionally comprises a sloped surface facing the proximal end of actuator 25'. When delivery member guard 21' is moved distally (arrow D) relative to body portion 20, protrusion 211' of delivery member guard 21' moves along longitudinal portion 252a' of second track 252' toward chamfered surface 252b', and actuator 25' can be rotated (arrow R1) and moved axially (arrow A) distally relative to body portion 20 by delivery member guard 21', as shown in Figures 19E-19F. Actuator 25' can be configured with one or more interaction parts for interacting with drive unit 1, similar to interaction part 251 described above.

[0130] Optionally, actuator 25′ includes a ramp 254″ configured at a distal end of actuator 25′, as shown in FIG. 6F. Ramped surface 254″ is angled with respect to longitudinal axis L and configured to interact with an opposing ramp on distal lid 24′, as shown in FIG. 19G; such interaction between ramp 254″ of actuator 25′ and the opposing ramp can thus facilitate rotation (arrow R2) between actuator 25′ and delivery member guard 21′ (actuator 25' can be easily rotated by delivery member guard 21'. Second track 252' optionally includes a lockout portion 252c' to provide a delivery member guard lockout mechanism. In this example, as shown in FIG. 19I, after delivery member guard 21' is moved to a proximal, post-use position, protrusion 211' of delivery member guard 21' moves into lockout portion 252c' with distal movement of delivery member guard 21'. In this example, protrusion 211' is located at a bendable portion of delivery member guard 21', e.g., a bendable adapter. The actuator 25' should be configured to have a lockout portion 252c' that interacts with the protrusion 211' of the delivery member guard 21' and a distal frame of the lockout portion 252c' of the actuator 25' that is bendable. Additionally, the actuator 25' optionally includes a locking tab 253' configured to move into the locking notch 246' of the distal lid 24' when the delivery member guard 21' is moved to the proximal, post-use position, as shown in FIGS. 6F-6G and 19J. It should be noted that at least one of the above-described arrangements for the delivery member guard lockout mechanism is sufficient to activate the delivery member guard lockout mechanism when the delivery member guard 21, 21' is moved to the proximal, post-use position. However, multiple of the above-described arrangements for the delivery member guard lockout mechanism can be used together. For example, the second track 252' of the actuator 25' can have a lockout portion 252c' that interacts with the protrusion 211' of the delivery member guard 21' and a locking tab 253' that interacts with the locking notch 246' of the distal lid 24'.

[0131] In another example, as shown in Figures 19K-19L, instead of a ramp 254" for interacting with a locking notch, the actuator 25' includes a distal track 256' and the distal lid 24' includes a protrusion 247' positioned within the distal track. When the delivery member guard 21, 21' moves distally relative to the actuator 25', the actuator 25' rotates as described above. The distal track 256' also facilitates rotation of the actuator 25' due to interaction between the distal track 256' and the protrusion 247' of the distal lid 24', as shown in Figures 19M-19N.

[0132] Figure 19M shows a second track 252', and the path of movement of the protrusion 211' of the delivery member guard 21, 21' moves along the second track as shown by the arrow in Figure 19M when the delivery member guard 21, 21' moves distally relative to the body portion and then moves back proximally relative to the body portion. Meanwhile, as shown in Figure 19N, the protrusion 247' of the distal lid 24' moves relative to the actuator 25' along a distal track 257' (path of movement shown by the arrow in Figure 19N). In another example, instead of the locking tab 253' on the actuator 25' and the locking notch 246' on the distal lid 24' described above, the actuator 25' includes a distal notch / recess 257a' for retaining the actuator 25'. In this example, after the distal notch / recess 257a' of the actuator 25' is aligned with the protrusion 247' of the distal lid 24', i.e., after the protrusion 247' is positioned within the distal notch / recess 257a', the distal lid 24' and the actuator 25' are secured to one another along the longitudinal axis L. It should be noted that the protrusion could be located on the body portion rather than the distal lid.

[0133] It should be noted that the first and second tracks may be formed by notches or recesses on the body of the actuator, or by bulges extending from the body of the actuator in a direction transverse to the longitudinal axis L. Additionally, the protrusions on the delivery member guard may be replaced by distally directed arms arranged on the delivery member guard. For example, a distally directed arm extends from the front shield of the delivery member guard distally of the housing, with the distal end of the distally directed arm configured to act on a chamber in the second track of the actuator, thereby rotating the actuator when the delivery member guard moves distally relative to the actuator along the longitudinal axis L. In this example, lockout portions of the first and second tracks of the actuator are not required in the subassembly of the present invention.

[0134] It should be noted that the delivery member guard lockout mechanism may in some cases be important from a regulatory perspective of the medication delivery device, but not from a mechanical standpoint - the disclosed delivery member guard lockout mechanism is merely an optional feature to the invention as applied. Many variations of delivery member guard lockout mechanisms are known that can be implemented in the subassemblies of the invention without substantial modification of the subassemblies.

[0135] Furthermore, in a preferred example, a slot may be arranged on the actuator 25′ for assembly purposes. As shown in FIGS. 19O to 19P, a slot 258′ on the actuator 25′ is provided. The protrusion 211′ of the drug delivery device 21′ and the protrusion 247′ of the distal cap 24′ are both inserted into the slot 258′ and moved a linear distance to the assembly position (indicated by arrow X in FIG. 19O; the distance depends on the dimensions of the components). After the protrusion 211′ of the drug delivery device 21′ and the protrusion 247′ of the distal cap 24′ are placed in the assembly position, the actuator 25′ may be twisted (arrow Y in FIG. 19P), and then the protrusion 211′ of the drug delivery device 21′ and the protrusion 247′ of the distal cap 24′ are placed in the first and second tracks 251′, 252′.

[0136] It should be noted that the actuators 25, 25' are only related to the delivery member guard lockout mechanism and / or trigger mechanism by distal movement of the delivery member guard. As mentioned above, the delivery member guard lockout mechanism may in some cases be important from a regulatory aspect of the medication delivery device, but is not important from a mechanical point of view, and the cassette unit subassembly may be used with medication delivery devices that are triggered by a button on the drive unit 1. Thus, the actuators 25, 25' are only an optional feature for the initial locking mechanism of the delivery member guard achieved by the subassembly of the present invention, i.e., the locking member and the delivery member guard.

[0137] The subassembly of the present invention can be operated by an end user by attaching the cassette unit 2 to the drive unit 1, preferably through a bayonet connection between the cassette unit 2 and the drive unit, and releasing the delivery member guards 21, 21', 21" to move proximally relative to the medication delivery device by moving the locking members 22, 22', 22" from a locked position to an unlocked position relative to the delivery member guards 21, 21', 21", preferably by rotating the locking members 22, 22', 22" relative to the delivery member guards 21, 21', 21" while the end user rotates the cassette unit 2 to the drive unit 1 to connect the cassette unit 2 to the drive unit 1 through the bayonet connection.

[0138] The subassembly of the present invention may be used with a cassette unit 2 having a pre-assembled drug delivery member set 3, 3', 3", as shown in Figures 20, 26A and 27. The pre-assembled drug delivery member set 3, 3', 3" is fixed to the proximal end of the main body portion. For example, the pre-assembled drug delivery member set 3, 3', 3" can be attached to the main body portion. Alternatively, in examples where the cassette unit 2 includes an inner housing, the pre-assembled drug delivery member set 3, 3', 3" can be attached to the inner housing. Further, in an example where the cassette unit 2 includes a support unit for receiving and / or supporting a drug container configured to be arranged within the main body portion 20, the pre-assembled drug delivery member set 3, 3', 3" can be attached to the support unit. In one example, the pre-assembled drug delivery member set 3, 3', 3" includes a tubular outer cap 30, 30', 30", an inner cap 31, and a clutch member 32, 32', as shown in Figures 21 and 28. The inner cap 31 is configured to be releasably attached to the cassette unit 2 and can be removed from the cassette unit 2 by rotating the cassette unit 2 relative to the main body portion 20. Preferably, the inner cap 31 is configured to completely cover the drug delivery member.

[0139] The tubular outer caps 30, 30', 30" at least partially surround the inner cap 31. The clutch members 32, 32' are positioned longitudinally between the proximal ends of the delivery member guards 21, 21', 21" and the drug delivery member set 3. The clutch members 32, 32' are positioned radially between the tubular outer caps 30, 30', 30" and the inner cap 31 with respect to the longitudinal axis L. The clutch members 32, 32' include clutch biasing members 320, 320' which are axially movable with respect to the outer caps 30, 30', 30" between a relaxed position and a tensioned position. The tubular outer cap 30, 30', 30" is axially fixed to the inner cap 31 and is rotatable relative to the inner cap 31. For example, the inner cap 31 includes a proximal annular recess 311, and the tubular outer cap 30, 30', 30" includes a proximal gripper 302 that engages with the proximal recess 311 of the inner cap 31, as shown in FIG. 22B. The clutch member 32, 32' is rotatably fixed to the inner cap 31. For example, the inner cap 31 may include a grip portion 312, and the inner surface of the clutch member 32, 32' may include an opposing grip portion 322a having a shape corresponding to the grip portion 312 of the inner cap 31, as shown in FIG. 24.

[0140] The tubular outer cap 30, 30', 30" includes a plurality of engaging members 301, 301'. In a preferred example, the plurality of engaging members 301, 301' of the tubular outer cap 30, 30', 30" are a plurality of protrusions extending radially inward with respect to the longitudinal axis L from the inner surface of the tubular outer cap 30, 30', 30" respectively. The clutch member 32 includes a plurality of opposing engaging members 33, as shown in FIG. 24. The plurality of opposing engaging members 33 may be a plurality of protrusions or slots facing radially outward with respect to the longitudinal axis L from the outer surface of the clutch member 32. The plurality of engaging members 301, 301' abut the plurality of opposing engaging members 33 when the clutch biasing member is in the tensioned position, as shown in FIGS. 25B and 26B.

[0141] In a preferred example, the clutch members 32, 32' include proximal connectors 321, 321' and distal connectors 322, 322'. The proximal and / or distal connectors may be ring-shaped or may be formed by multiple bracket-shaped elements. The clutch biasing members 320, 320' are longitudinally positioned between the proximal connectors 321, 321' and the distal connectors 322, 322'. The distal connector 322, 322' abuts the proximal end of the front shield 210, 210" of the delivery member guard 21, 21', 21", and the proximal connector 321, 321' releasably abuts a distally directed surface on the inner surface of the tubular outer cap 30, 30', 30". In another example, the plurality of opposing engagement members 33 of the clutch member 32, 32' are arranged on the outer surface of the distal connector 322, 322', as an example shown in FIG. 24; alternatively, the plurality of opposing engagement members of the clutch member are arranged on the proximal connector. In another example, the plurality of opposing engagement members 33 comprise bendable arms 331 extending partially about the longitudinal axis L, as shown in FIG. 24. In this example, when the plurality of engagement members 301 of the tubular outer cap 30 abut the plurality of opposing engagement members 33 of the clutch member 32 and the outer cap is rotated in a predetermined direction, a tactile and / or audible indication may be provided to the end user. This indication may be defined as an incorrect or correct operating indication, depending on the design.

[0142] The tubular outer caps 30, 30', 30" are rotatable relative to the inner cap 31, and therefore rotation of the tubular outer caps 30, 30', 30" can be transmitted to rotation of the inner cap 31 only when the plurality of engaging members 301, 301' of the tubular outer caps 30, 30', 30" are adjacent to the plurality of opposing engaging members 33 of the clutch members 32, 32'.

[0143] 25A , when clutch biasing member 320 is in the relaxed position, the plurality of engaging members 301 of tubular outer cap 30 are spaced apart from the plurality of opposing engaging members 33 of clutch member 32. As delivery member guard 21, 21′ moves from its distal position to its proximal position, delivery member guard 21, 21′ moves clutch biasing member 320 to its tensioned position. Thus, the plurality of engaging members 301 of tubular outer cap 30 are adjacent to the plurality of opposing engaging members 33 of clutch member 32.

[0144] It should be noted that in the above example, delivery member guard 21, 21' reaches its proximal position while tubular outer cap 30, 30' is still attached to the subassembly. On the other hand, delivery member guard 21, 21' may also be arranged such that delivery member guard reaches its proximal position only when tubular outer cap 30, 30', 30" is completely removed from the subassembly. The latter example may be more suitable for a subassembly arranged to allow a user to reverse rotate the locking member from an unlocked position to a locked position.

[0145] As described above, the subassembly of the present invention is arranged and configured so that the locking members 22, 22', 22" release the delivery member guards 21, 21', 21" from locking at a position distal to the delivery member guards 21, 21', 21" only when the end user has properly assembled the cassette unit 2 to the drive unit 1 of the medication delivery device. Therefore, when the cassette unit 2 comprises the pre-assembled medication delivery member set 3, 3', 3" as described above, the end user can remove the outer cap 30, 30', 30" and the inner cap 31 only when the cassette unit 2 is properly assembled to the drive unit 1. In a preferred example, the clutch members 32, 32' can be removed from the cassette unit 2 together with the removal of the inner cap 31 and the outer cap 30, 30', 30" due to engagement between the outer surface of the inner cap 31 and the inner surface of the clutch members 32, 32'.

[0146] Also, the delivery member guard 21" can be configured such that the delivery member guard 21" reaches its proximal position only when the tubular outer cap 30" is completely removed from the subassembly.

[0147] In this example, protrusion 222" of locking member 22' can be either a helical protrusion or a circumferential protrusion as described above. As shown in FIGS. 31-32B, notch 222a" is disposed within protrusion 222". Thus, when an end user attaches cassette unit 2 to drive unit 1, protrusion 214" of delivery member guard 21" moves along protrusion 222". When protrusion 214" disengages from protrusion 222", protrusion 214" moves into notch 222a" along with delivery member guard 21" moving from a distal position to a proximal position. When protrusion 214" moves into notch 222a", rotation between delivery member guard 21" and locking member 22" is blocked.

[0148] Thus, when the delivery member guard 21″ is moved to the proximal position, the delivery member guard 21″ moves the clutch biasing member 320′ to its tension position. Thus, the protrusion 214″ moves into the notch 222a″. Because relative rotation between the delivery member guard 21″ and the locking member 22″ is blocked and the delivery member guard 21″ cannot rotate with respect to the main body 20 (as described above), the end user cannot remove the cassette unit 2 from the drive unit 1 before the outer cap 30″ is removed. When the outer cap 30″ is removed, the delivery member guard 21″ moves to the proximal position and the protrusion 214″ moves proximally from the notch 222a″. Thus, the end user can remove the cassette unit 2 from the drive unit 1.

[0149] In another example, the pre-assembled drug delivery member set 3" further comprises an adapter 34, as shown in FIG. 28. The adapter 34 comprises an adapter body 340. The adapter body 340 is rotatably and axially fixed to the inner cap 31. The adapter body 340 may be cylindrical as shown in FIG. 28, which may make the drug delivery device more compact. Alternatively, the adapter body 340 may be of any suitable shape depending on the design of the pre-assembled drug delivery member set 3". The adapter further comprises a track 341, which may be a recess / notch in the wall of the adapter body 340. In this example, the clutch member 32' is radially disposed between the tubular outer cap 30" and the adapter body 340. In this example, the clutch member 32' comprises a track follower 322b' positioned in a track 341 of the adapter 34. The track follower 322b' may be a protrusion extending from the inner surface of the distal connector 322', as shown in FIG. 29.

[0150] As described above, when delivery member guard 21" is moved to the distal position, delivery member guard 21" moves clutch biasing member 320 to the tensioned position of clutch biasing member 320'. In a preferred example as shown in Figures 30A-30D, the delivery member guard 21" is configured to move the distal connector 322' of the clutch member 32' in a distal direction relative to the inner cap 31 and the adapter 34. Thus, the track follower 322b' is moved into the track 341 and is moved along the track 341 of the adapter 34 by the front shield 210" of the delivery member guard 21". The track 341 comprises a circumferential section and a longitudinal section. In this example, when the delivery member guard 21" is moved to a proximal position, the delivery member guard 21" moves the track follower 322b' into the circumferential section of the track 341. If the end user plans to remove the outer cap 30", the end user can rotate the outer cap 30" together with the clutch element 32", and the inner cap 31 will not rotate because the track follower 322b' is in the circumferential section of the track 341. When the track follower 322b' is aligned with the longitudinal section of the track 341, the delivery member guard 21" moves the track follower 322b' into the longitudinal section of the track 341, so that when the end user rotates the outer cap 30" relative to the main body 20, the outer cap 30" can be removed, as described above.

[0151] In this example, the protrusion 214" of the delivery member guard 21" is configured to be positioned within the notch 222a" when the track follower 322b' is in the longitudinal section of the track 341. Thus, the end user is prevented from removing the cassette unit 2 from the drive unit 1 only when removing the outer cap 30".

[0152] The inventive concept has been described above solely with reference to certain examples. However, as will be readily apparent to those skilled in the art, embodiments other than those disclosed above are equally possible within the scope of the inventive concept as defined by the appended claims. [Explanation of symbols]

[0153] 1 Drive unit 2 Cassette unit, locking tab, main body 3. Drug delivery component set 3' Drug delivery component set 3" Drug Delivery Component Set 11 Opposite bayonet connector 20 Main body 20' Main body 20a' locking tab 20b' distal end 20c' protrusion 21 Delivery member guard 21' Delivery member guard, drug delivery device 21" Delivery Element Guard 22 Locking member, flange 22' Locking element 22" locking member 23 biasing member 24 distal operculum 24' distal lid 25 Actuators 25' Actuator 26 Inner housing 30 Tubular outer cap 30' Tubular Outer Cap 30" Tubular Outer Cap 31 Inner cap 32 Clutch parts 32' Clutch member 33 Counter engaging member 34 Adapter 200 outer shell 201 Window 202 Bayonet connector, bayonet protrusion 203 Assembly Truck 203a Longitudinal section 203b Transverse section 204 Snap Opening 210 Front Shield 210' Front Shield 211 Arm 211' Protrusion 212 protrusion 212' protrusion 213 Window part 214 Protrusion 214" protrusion 220 Main body, tubular main body 220a' Notch / Recess 221 flange 221a Enlarged section 221b Transverse section 222 protrusion 222' protrusion 222" protrusion 222a" notch 223 broken part, broken part 240 Lid body part 240' Lid body 240b opening / slot 241 Snap Arm 241' Snap Arm 242 Arm 242a Retaining part 243 Surface 245 Container support, bendable arm 246' Locking notch 247' Protrusion 250' Actuator body 251 Interaction part 251' First Track 252' Second Track 252 Holding part 252a' Longitudinal section 252b' Chamfered surface 252c' Lockout section 253 Distal notch, first notch 253' Locking Tab 253a distal edge 254 Second Notch 254' slope 254" slope 254a Distal edge 255 Distal edge, third notch 255a Proximally Oriented Lockout Surface 255' depression 256' distal track 257' distal track 257a' Distal notch / recess 258' Slot 260 Main body 261 Distal notch 301 Engagement member 301' Engagement member 302 Proximal Gripper 311 Proximal annular recess 312 Grip part 320 Clutch biasing member, clutch member 320' Clutch biasing member, clutch member 321 Proximal Connector 321' Proximal Connector 322 Distal Connector 322' Distal Connector 322a Opposite grip part 322b' Track Follower 331 Bendable Arm 340 Adapter body 341 trucks L longitudinal axis

Claims

1. 1. A cassette unit subassembly for a medication delivery device, comprising: a body portion (20) extending along a longitudinal axis (L) from a proximal end to a distal end; a delivery member guard (21) coaxially mounted on said body portion (20) and axially movable relative to said body portion (20) along said longitudinal axis (L); a locking member (22) attached to the main body (20), the locking member (22) is movable relative to the delivery member guard (21) between a locked position and an unlocked position; the locking member (22) comprises a distally directed surface that is adjacent to a proximally directed surface of the delivery member guard (21) in the locked position; the distally directed surface of the locking member (22) is spaced circumferentially about the longitudinal axis (L) from the proximally directed surface of the delivery member guard (21) in the unlocked position; The delivery member guard (21) comprises a protrusion (214) extending radially with respect to the longitudinal axis (L), and the proximally directed surface of the delivery member guard (21) is part of the protrusion (214). Cassette unit sub-assembly.

2. 1. A cassette unit subassembly for a medication delivery device, comprising: a body portion (20) extending along a longitudinal axis (L) from a proximal end to a distal end; a delivery member guard (21) coaxially mounted on said body portion (20) and axially movable relative to said body portion (20) along said longitudinal axis (L); a locking member (22) attached to the main body (20), the locking member (22) is movable relative to the delivery member guard (21) between a locked position and an unlocked position; the locking member (22) comprises a distally directed surface that is adjacent to a proximally directed surface of the delivery member guard (21) in the locked position; the distally directed surface of the locking member (22) is spaced circumferentially about the longitudinal axis (L) from the proximally directed surface of the delivery member guard (21) in the unlocked position; a biasing member (23) disposed between a first distally directed surface of the delivery member guard (21) and a proximally directed surface of the body portion (20); The delivery member guard (21) includes a ledge (212) extending radially relative to the longitudinal axis (L), and the first distally directed surface of the delivery member guard (21) is defined by a portion of the ledge (212). Cassette unit sub-assembly.

3. 3. A cassette unit subassembly according to claim 1 or 2, wherein the locking member (22) is rotatable relative to the delivery member guard (21) about the longitudinal axis (L) between the locked position and the unlocked position.

4. 2. The cassette unit subassembly of claim 1, further comprising a biasing member (23) disposed between a first distally directed surface of the delivery member guard (21) and a proximally directed surface of the main body portion (20).

5. 3. The cassette unit subassembly of claim 2, wherein the delivery member guard (21) comprises a protrusion (214) extending radially with respect to the longitudinal axis (L), and the proximal-facing surface of the delivery member guard (21) is part of the protrusion (214).

6. 6. The cassette unit subassembly of claim 5, wherein said protrusion (214) extends radially away from said ledge (212).

7. 2. The cassette unit subassembly of claim 1, wherein the locking member (22) comprises a tubular body (220) surrounding a portion of the delivery member guard (21).

8. 8. The cassette unit subassembly of claim 7, wherein the locking member (22) comprises a protrusion (222, 222') extending circumferentially with respect to the longitudinal axis (L) along a portion of the inner surface of the tubular body portion (220) of the locking member (22), and the distally directed surface of the locking member (22) is part of the protrusion (222, 222').

9. A cassette unit (2) for a medication delivery device, comprising the cassette unit subassembly of claim 1, a delivery member cover assembly (3) secured to the proximal end of the body portion (20) and rotatably releasable with respect to the body portion (20); The delivery member cover assembly (3) comprises: a tubular outer cap (30); an inner cap (31) at least partially surrounded by the tubular outer cap (30); a clutch member (32) rotatably secured to the inner cap (31) and positioned longitudinally between the tubular outer cap (30) and the delivery member guard (21); the clutch member (32) includes a clutch biasing member (320), the clutch member (32) being axially movable relative to the outer cap (30) between a relaxed position and a tensioned position; the tubular outer cap (30) is axially fixed to the inner cap (31) and is rotatable relative to the inner cap (31); the tubular outer cap (30) includes a plurality of engaging members (301), and the clutch member includes a plurality of opposing engaging members (33); The cassette unit (2) has a plurality of engaging members (301) adjacent to the plurality of opposing engaging members (33) when the clutch biasing member (320) is in the tension position.

10. 10. The cassette unit of claim 9, wherein the plurality of engagement members (301) of the tubular outer cap (30) are a plurality of protrusions or slots, and the plurality of protrusions extend radially inward from the inner surface of the tubular outer cap (30) with respect to the longitudinal axis, or the plurality of slots face radially outward from the outer surface of the inner cap (31) with respect to the longitudinal axis.

11. 11. A cassette unit as described in claim 10, wherein the plurality of opposing engagement members (33) of the clutch member (32) are a plurality of opposing protrusions (33), and the plurality of opposing protrusions (33) extend radially outward from the outer surface of the clutch member (32) with respect to the longitudinal axis.

12. 10. The cassette unit of claim 9, wherein the clutch member (32) comprises a proximal connector (321) and a distal connector (322), the clutch biasing member (320) is positioned longitudinally between the proximal connector (321) and the distal connector (322), the distal connector (322) is adjacent to the proximal end of the delivery member guard (21), and the proximal connector (321) is releasably adjacent to a distally directed surface on the inner surface of the tubular outer cap (30).

13. 13. The cassette unit according to claim 12, wherein the plurality of opposing engagement members (33) of the clutch member (32) are arranged on an outer surface of the distal connector (322).

14. 10. A cassette unit according to claim 9, wherein said plurality of opposing engagement members (33) comprise bendable arms (331) extending at least partially around said longitudinal axis (L).

15. A medication delivery device comprising the cassette unit (2) of claim 9 and a reusable drive assembly (1), The reusable drive assembly (1) comprises a tubular housing extending from a proximal end and a distal end along the longitudinal axis (L); A drug delivery device in which the cassette unit (2) is releasably attached to the reusable drive assembly (1) through bayonet connections (11) on the inner surface of the proximal end of the reusable drive assembly (1) and on the outer surface of the distal end of the main body of the cassette unit (2).

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