Cassette subassembly for a cassette unit

Abstract

A cassette subassembly for a cassette unit configured to be removably connected to a drive unit to form a drug delivery device, the cassette subassembly comprising: a housing having a proximal housing end and a distal housing end; a delivery member cover protruding from the proximal housing end and configured to be moved linearly relative to the housing; and a locking member disposed axially fixed relative to the housing, the locking member configured to be rotated relative to the delivery member cover from a first position to a second position.

Description

[Technical Field]

[0001] The present disclosure relates generally to drug delivery devices. [Background technology]

[0002] Some reusable medication delivery devices may have a hybrid design that includes a disposable first unit that holds a syringe or a medication cartridge equipped with a needle, etc., and a reusable second unit that includes a power pack, etc. The power pack may include a plunger rod that is spring-loaded, motor-driven, or gas-driven.

[0003] The first unit may include a linearly movable needle cover that covers the needle when in a first position and is linearly movable to a second position in which the needle is exposed. This configuration presents a risk of accidental needle sticks if the needle cover is unintentionally moved to the second position. Summary of the Invention [Means for solving the problem]

[0004] Therefore, according to a first aspect of the present disclosure, there is provided a cassette subassembly for a cassette unit configured to be removably connected to a drive unit to form a medication delivery device, the cassette subassembly comprising: a housing having a proximal housing end and a distal housing end; a delivery member cover protruding from the proximal housing end and configured to be moved linearly relative to the housing; and a locking member arranged axially fixed relative to the housing, the locking member being configured to be rotated from a first position to a second position relative to the delivery member cover, wherein the locking member has a proximal-facing radial surface and the delivery member cover has a distal-facing radial surface, the proximal-facing radial surface being axially aligned with the distal-facing radial surface when the locking member is in the first position and facing the distal-facing radial surface, and the proximal-facing radial surface being circumferentially offset relative to the distal-facing radial surface when the locking member is in the second position.

[0005] When the locking member is in the first position, i.e., when the proximally facing radial surface is axially aligned with the distally facing radial surface and faces the distally facing radial surface, the delivery member cover is prevented from moving from the extended position to the retracted position relative to the housing.

[0006] When the locking member is in the second position, i.e., when the proximally facing radial surface is circumferentially offset relative to the distally facing radial surface, the delivery member cover is permitted to move from the extended position to the retracted position relative to the housing.

[0007] The linear movement of the delivery member cover is controlled by the rotational position of the locking member, and thus the locking member can prevent unintended linear movement of the delivery member, such as exposing the delivery member, such as a needle.

[0008] In this 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 part / end" is used, it refers to the part / end of the delivery device or part / end of a member of the delivery device that is positioned 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.

[0009] When the term "proximal portion / proximal end" is used, it refers to the part / end of the delivery device or the part / end of a member of the delivery device that is positioned closest to the dose delivery site during use of the drug delivery device.

[0010] Additionally, the terms "longitudinal," "longitudinally," "axially," or "axial" typically refer to a direction extending along a device or along a component of a device from the proximal end to the distal end in the direction of the longest extension of the device and / or component.

[0011] Similarly, the terms "transverse," "transverse," and "transversely" refer to a direction generally perpendicular to the longitudinal direction.

[0012] Additionally, the terms "periphery," "circumferential," or "circumferentially" refer to the periphery or circumference relative to an axis, typically a central axis extending in the direction of the longest extension of the device and / or component.

[0013] Similarly, "radial" or "radially" refers to a direction extending radially relative to an axis, and "rotational," "rotational," and "rotationally" refer to rotation relative to an axis.

[0014] According to one embodiment, the locking member is positioned radially outward of the delivery member cover.

[0015] According to one embodiment, the locking member is annular, a retaining ring, or has a semicircular shape.

[0016] According to one embodiment, the delivery member cover has an axially extending rib, the distal end face of the rib forming a distally facing radial surface, and the locking member has a shelf structure forming a proximally facing radial surface and a distally extending axial passage circumferentially adjacent the shelf structure, the axial passage being configured to receive the rib when the locking member is in the second position.

[0017] According to one embodiment, the locking member has an axially extending rib, the proximal end face of the rib forming a proximally facing radial surface, and the delivery member cover has a shelf structure forming a distally facing radial surface and a proximally extending axial passage circumferentially adjacent the shelf structure, the axial passage being configured to receive the rib when the locking member is in the second position.

[0018] According to one embodiment, the shelf structure includes a radial shelf surface and a protrusion extending axially from the radial shelf surface, the protrusion being disposed circumferentially of the locking member between the radial shelf surface and the axial passage, whereby rotation of the locking member to the second position may be prevented when the delivery member cover is axially pushed toward the retracted position.

[0019] According to one embodiment, the delivery member cover is rotationally locked to the housing.

[0020] According to one embodiment, the outer surface of the delivery member cover has a periphery with a non-circular cross-sectional shape, and the housing has an inner surface with a cross-sectional shape corresponding to the non-circular cross-sectional shape, the cross-section being taken through the longitudinal axis of the cassette subassembly.

[0021] According to one embodiment, the delivery member cover has an outer surface provided with a first structure, and the housing has a second structure, the first structure configured to engage with the second structure to prevent relative rotation between the delivery member cover and the housing.

[0022] According to one embodiment, the first structure is an axial rib and the second structure is an axial passage, or the first structure is an axial passage and the second structure is an axial rib.

[0023] One embodiment comprises a fastening structure configured to engage with a mating fastening structure of the drive unit.

[0024] According to one embodiment, the fastening structure forms one part of a bayonet connection or forms one part of a screw connection.

[0025] According to one example, the fastening structure is disposed on an outer surface of the housing.

[0026] Alternatively, the cassette subassembly may include a rear member configured to be axially and rotationally fixed relative to the housing, the fastening structure being disposed on an outer surface of the rear member.

[0027] According to one example, the locking member has an outer surface provided with a first helical track or a first rib. The drive unit, in this example, may include a second rib configured to run on the first helical track or a second helical track configured to receive the first rib. The cassette unit including the cassette subassembly can then be linearly inserted into the drive unit without rotation, with the first helical track or first rib acting as part of a cam structure that causes rotation of the locking member from the first position to the second position. The cassette unit including the cassette subassembly can then include, for example, a snap-fit structure configured to engage with the drive unit using a snap-fit connection.

[0028] One embodiment includes a drug container retainer disposed on the housing and configured to be moved by the drive unit from a distal position to a proximal position relative to the housing when the cassette subassembly is connected to the drive unit.

[0029] According to one embodiment, the drug container holder has an outer surface provided with a radially outwardly extending slope, and the housing has an inner surface provided with a radially inwardly extending slope positioned proximal to the radially outwardly extending slope, and facing the radially outwardly extending slope when the drug container holder is in a distal position.

[0030] The radially outwardly extending ramp surface is configured to move past the radially inwardly extending ramp surface when the medicament container retainer is subjected to a proximally directed axial force greater than a threshold value.

[0031] According to a second aspect, there is provided a cassette unit for a medication delivery device comprising the cassette subassembly of the first aspect.

[0032] According to a third aspect, there is provided a medication delivery device comprising the cassette unit of the second aspect and a drive unit configured to be removably connected to the cassette unit.

[0033] In general, all terms used in the claims should be interpreted according to their ordinary meaning in the art unless expressly defined otherwise herein. All references to "a, an / the member, device, component, means, etc." should be openly interpreted as referring to at least one instance of the member, device, component, means, etc. unless expressly stated otherwise.

[0034] Specific embodiments of the inventive concept will now be described, by way of example, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0035] [Figure 1] 1 is a perspective view of an example of a cassette unit for a medication delivery device. [Figure 2] FIG. 2 is an exploded view of the cassette unit in FIG. [Figure 3] FIG. 10 is a perspective view of a delivery member cover and a locking member. [Figure 4]FIG. 2 is a perspective view of a locking member and a rear member. [Figure 5] FIG. 10 is a longitudinal cross-sectional view of the cassette unit with the drug container holding portion in a distal position. [Figure 6] FIG. 10 is a longitudinal cross-sectional view of the cassette unit with the drug container holding portion in a proximal position. [Figure 7] 10 is a front perspective view of the cassette unit when the locking member is in a first position. FIG. [Figure 8] FIG. 10 is a perspective view of the cassette unit when the locking member is in a second position. [Figure 9] FIG. 10 is a perspective view of the cassette unit when the locking member is in a second position. [Figure 10] FIG. 10 is a perspective view of the cassette unit after drug delivery, with the housing, locking member, and back member removed and the delivery member cover shown in transparency. [Figure 11] FIG. 10 is a perspective view of another example of a cassette subassembly of the present invention, wherein the cassette subassembly includes a housing, a locking member, a rear member, and a cap. [Figure 12] FIG. 12 is an exploded view of the cassette unit in FIG. [Figure 13] FIG. 12 is a perspective view of FIG. 11 showing only the delivery member cover and locking member. [Figure 14] FIG. 10 is a cross-sectional view of another example of a cassette subassembly of the present invention, wherein the cassette subassembly includes a housing, a locking member, and a rear member. [Figure 15] FIG. 15 is a cross-sectional view of the cassette subassembly as shown in FIG. 14 with the housing, locking member, and back member. DETAILED DESCRIPTION OF THE INVENTION

[0036] The inventive concepts will now be described more fully hereinafter with reference to the accompanying drawings, in which illustrative embodiments are shown. However, the inventive concepts may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the inventive concepts to those skilled in the art. Like reference numerals refer to like elements throughout this description.

[0037] The present disclosure relates to a cassette subassembly for a cassette unit, the cassette unit being for a medication delivery device.

[0038] The cassette subassembly includes a housing, a delivery member cover linearly movable in the housing, and a locking member configured to be rotated from a first position to a second position relative to the delivery member cover.

[0039] In a first embodiment, the locking member has a proximally facing radial surface and the delivery member cover has a distally facing radial surface that are axially aligned and face each other when the locking member is in the first position, such that the locking member in the first position prevents distal movement of the delivery member cover.

[0040] In a second embodiment, the locking member has a distally facing radial surface and the delivery member cover has a proximally facing radial surface that are axially aligned and face each other when the locking member is in the first position, such that the locking member in the first position prevents proximal movement of the delivery member cover.

[0041] The proximally-facing radial surface is circumferentially offset from the distally-facing radial surface when the locking member is in the second position. Thus, the delivery member cover is free to linearly move when the locking member is in the second position. Specifically, in the first embodiment, the delivery member cover is free to linearly move in the distal direction when the locking member is in the second position, and in the second embodiment, the delivery member cover is free to linearly move in the proximal direction when the locking member is in the second position.

[0042] The cassette unit and the drive unit configured to be mechanically removably connected to the cassette unit form a medication delivery device.

[0043] The medication delivery device can be, for example, an automatic injection device or a manual injection device.

[0044] The cassette unit may form the front or proximal part of the medication delivery device and the drive unit may form the rear or distal part of the medication delivery device.

[0045] The cassette unit may be disposable, and the drive unit may be reusable.

[0046] The cassette unit is configured to hold the medication container, and the drive unit is configured to empty the contents of the medication container by mechanical means, such as a spring-loaded plunger rod, a motor-driven plunger rod, or a gas-driven plunger rod.

[0047] Examples of cassette subassemblies will now be described with reference to Figures 1 to 10 in the context of a primary example cassette unit.

[0048] Figure 1 shows a perspective view of an example of a cassette unit 1 for a drug delivery device. Figure 11 shows a perspective view of another example of a cassette unit 1' for a drug delivery device.

[0049] The cassette unit 1; 1' includes a housing 3. The housing 3 has a proximal housing end 3a and a distal housing end 3b shown in Figures 2 and 12. The housing 3 has a proximal opening disposed at the proximal housing end 3a.

[0050] The cassette unit 1;1' comprises a delivery member cover 5;5';5''. The delivery member cover 5;5';5'' is partially disposed in the housing 3. The delivery member cover 5;5';5'' protrudes proximally from a proximal opening of the housing 3.

[0051] In one example, the delivery member cover 5;5' is configured to be rotationally locked relative to the housing 3. The delivery member cover 5;5' can have, for example, an outer surface having a periphery with a non-circular cross-sectional shape, the cross-section being taken perpendicular to the longitudinal axis of the delivery member cover 5;5'. The housing 3 can have a corresponding non-circular cross-sectional shape. The proximal opening, in particular, can have a corresponding non-circular cross-sectional shape.

[0052] Alternatively, the delivery member cover 5'' is rotatable relative to the housing 3 within a certain rotation angle about the longitudinal axis, depending on the design.

[0053] Alternatively, the delivery member cover 5;5';5" may be provided with a first structure and the housing may be provided with a second structure that are configured to engage with each other to prevent the delivery member cover 5;5' from rotating relative to the housing at all, or to prevent the delivery member cover 5" from rotating relative to the housing beyond a certain angle of rotation about the longitudinal axis. One of the structures may be, for example, a rib and the other may be an axial passage configured to engage with the rib.

[0054] The delivery member covers 5;5';5'' are movable from an extended position to a retracted position relative to the housing 3. The delivery member covers 5;5';5'' are biased towards the extended position.

[0055] The delivery member cover 5;5';5'' may be arranged to move from the retracted position back to the extended position, so that the delivery member cover 5;5';5'' is, according to one example, locked and cannot be moved back to the retracted position.

[0056] The cassette unit 1 is provided with locking members 7; 7'. The locking members 7; 7' may be, for example, annular, may be circlips, or may have a semicircular shape.

[0057] The locking members 7; 7' are fixed to the housing 3 in the axial direction.

[0058] The locking members 7;7' are configured to be rotated relative to the delivery member cover 5;5';5''. The locking members 7;7' are configured to be rotated relative to the housing 3.

[0059] The locking member 7;7' is configured to be rotated from a first position shown in Figures 1, 11, and 14-15 to a second position shown in Figure 8. In the first position, axial movement of the delivery member cover 5;5';5" is prevented by the locking member 7;7'. In the second position, axial movement of the delivery member cover 5;5';5" is no longer prevented by the locking member 7;7'. In the first embodiment, in the first position, the locking member 7 prevents the delivery member cover 5 from moving to the retracted position. In the second position, the delivery member cover 5 is permitted to move from the extended position to the retracted position. In the second position, the locking member 7 no longer prevents the delivery member cover 5 from moving to the retracted position.

[0060] In the second embodiment as shown in Figure 13, in a first position, the locking member 7' prevents the delivery member cover 5' from moving to the extended position. In a second position, the delivery member cover 5' is permitted to move to the extended position. In the second position, the locking member 7' no longer prevents the delivery member cover 5' from moving to the extended position.

[0061] It should be noted that the locking member can also prevent the delivery member cover from axially moving in both the distal and proximal directions relative to the housing. For example, a circumferential groove may be disposed in the wall of the locking member. The circumferential groove defines the aforementioned proximally and distally facing radial surfaces of the locking member. The delivery member cover may include a protrusion positioned within the circumferential groove of the locking member when the locking member is in the first position. The groove may include a notch at one end such that the protrusion of the delivery member cover can move out of the groove through the notch. In this example, when the locking member is in the second position, the protrusion of the delivery member cover moves away from the groove such that axial movement of the delivery member cover is no longer impeded by the locking member. The housing 3, the delivery member cover 5; 5', and the locking member 7; 7' form or form part of a cassette subassembly.

[0062] In another example, the cassette unit 1 optionally comprises a drug container holder 9;9' extending axially inside the housing 3. The drug container holder 9;9' is configured to hold or accommodate a drug container such as a syringe.

[0063] In one example, initially, when the delivery member cover 5 is in the extended position and the locking member 7 is in the first position, the medicament container holder 9 is held in the distal position. The medicament container holder 9 is configured to be moved axially in the proximal direction to the proximal position when the medicament container is subjected to a proximal force greater than a threshold. This typically occurs when the cassette unit 1 is mechanically connected to a drive unit.

[0064] Alternatively, the medicament container holder 9' may be fixed to the housing 3, i.e. the container holder is axially immovable relative to the housing 3.

[0065] 2 and 12 show exploded views of the cassette unit 1 in the first and second embodiments, respectively. The illustrated housing 3 comprises a distally extending axial housing leg 3c provided with a radially flexible tab 3d extending radially outward.

[0066] The delivery member cover 5;5';5'' has a proximal circumferentially closed portion 5a;5a''. The proximal circumferentially closed portion 5a may have a non-circular cross-sectional shape in a section perpendicular to the longitudinal axis of the delivery member cover 5;5'. In another example, the delivery member cover 5'' includes a flange 5b'' extending from the proximal circumferentially closed portion 5a'' in a direction transverse to the longitudinal axis, as shown in FIG. 14. In a preferred example, the flange 5b'' has a diameter larger than the diameter of the proximal opening of the housing 3 so as to limit the distance of movement of the delivery member cover 5'' in the distal direction relative to the housing 3. Furthermore, in one example, the delivery member cover 5 is formed as a single component, as shown in FIG. 2. Alternatively, the delivery member cover 5'' is formed by multiple components attached to each other. For example, the delivery member cover 5'' may be formed by a proximal portion 50'' and a distal portion 51'' that are attached to one another, such as by snap fastening, as shown in FIG.

[0067] The delivery member cover 5;5';5'' has axially extending legs 5b extending distally from a proximal circumferentially closed portion 5a. Each axially extending leg 5b is provided with a respective radially inwardly extending projection 5c, such as a pin.

[0068] The cassette subassembly comprises a resilient member 11 configured to bias the delivery member covers 5; 5'; 5" towards the extended position. The resilient member 11 may be a spring, such as a coil spring, as shown in Figure 14.

[0069] A drug container 13, such as a syringe, can be placed in the drug container holder 9; 9'. The drug container 13 can include a liquid container 13a including a stop 14 and a delivery member, such as a double-rimmed needle 13b. The double-rimmed needle 13b can be covered by a proximal flexible tube and a distal flexible tube. In one example, as shown in FIGS. 5-6, the double-rimmed needle 13b is configured to attach to the liquid container 13a when the drug container holder 9g moves proximally relative to the double-rimmed needle 13b. Alternatively, the double-rimmed needle 13b' can be integrated into the proximal end of the liquid container 13a', as shown in FIG. 14.

[0070] In another example, the illustrated cassette unit 1 includes a rotating portion 15. The rotating portion 15 is disposed around the drug container holding portion 9. In this example, the delivery member cover 5 is disposed radially outward of the rotating portion 15. The rotating portion 15 has a guide structure 15a including a helical track and an axial track disposed adjacent to the helical track in the circumferential direction. During use, each radially inwardly extending protrusion 5c of the delivery member cover 5 is disposed to cooperate with the respective guide structure 15a. When the delivery member cover 5 is moved from the extended position to the retracted position, the radially inwardly extending protrusions 5c run on the respective helical track. This causes the rotating portion 15 to rotate because the delivery member cover 5 is rotationally locked relative to the housing 3. When the delivery member cover 5 is returned to the extended position, the radially inwardly extending protrusions 5c run back toward the proximal end of the rotating portion in a respective one of the axial tracks. The axial tracks are provided with respective flexible elements through which the radially inwardly extending protrusions 5c can pass when the delivery member cover 5 is moved proximally. However, the flexible elements will prevent the delivery member cover 5 from moving back to the retracted position when the delivery member cover 5 returns to the extended position. Thus, the delivery member cover 5 is locked in the extended position after use.

[0071] In a preferred example, the cassette subassembly includes a rear member 17. The rear member 17 may be annular, circlip-shaped, or have a semicircular shape. The rear member 17 is disposed around the distally extending axial housing leg 3c. A radially flexible tab 3d of the housing 3 is configured to engage a snap-fastening connection with the rear member 17. Thus, the rear member 17 and the housing 3 are axially and rotationally fixed relative to one another. In this example, a medication container may be inserted into the housing 3 from the distal end of the housing either during the cassette unit manufacturing process or by a distributor of the cassette unit or a user such as a patient, pharmacist, or other caregiver. It should be noted that, as in the previously mentioned example, the rear member may be a separate component attached to the housing. Alternatively, the rear member 17 is integral with the housing, depending on manufacturing process options.

[0072] Figure 3 shows a perspective view of the delivery member cover 5;5" of the first embodiment and the locking member 7 of the first embodiment. According to an example, the locking member 7 is configured to be arranged radially outside the delivery member cover 5;5".

[0073] In one example, the delivery member cover 5 has one or more axially extending ribs 5d. The one or more axially extending ribs 5d are provided on the outer surface of the delivery member cover 5. In this example, each axially extending rib 5d is disposed on the outer surface of an axially extending leg 5b.

[0074] Axially extending rib 5d has a distal end face that defines a distally facing radial surface 5e.

[0075] Locking member 7 includes a shelf structure 7a having one or more radial shelf surfaces, each of which has a proximally facing radial surface 7b extending radially inward from the inner surface of locking member 7.

[0076] The locking member 7 has a distally extending axial passage 7c that is positioned next to the shelf structure 7a in the circumferential direction of the locking member 7. The axial passage 7c extends distally relative to the shelf structure 7a.

[0077] The shelf structure 7a has one or more protrusions or ridges 7d extending axially from a proximally-facing radial surface 7b. Each protrusion 7d extends proximally from the proximally-facing radial surface 7b. Each protrusion 7d is disposed circumferentially of the locking member 7 between the proximally-facing radial surface 7b and the axial passage 7c. The one or more protrusions 7d are configured to prevent the locking member 7 from rotating relative to the delivery member cover 5 when the delivery member cover is pushed distally. The circumferential distance between adjacent protrusions 7d is large enough to receive an axially-extending rib 5d therebetween.

[0078] When locking member 7 is in the first position, axially extending rib 5d is axially aligned with proximally facing radial surface 7b or protrusion 7d. Thus, distally facing surface 5e is axially aligned with and faces proximally facing radial surface 7b or the protrusion, preventing delivery member cover 5 from moving from the extended position to the retracted position.

[0079] When the locking member 7 is in the second position, the axially extending rib 5d is axially aligned with the axial passage 7c. The axial passage 7c has a circumferential width dimension configured to receive the axially extending rib 5d. Thus, the delivery member cover 5 can be moved to the retracted position, with the axial passage 7c now receiving the axially extending rib 5d.

[0080] As an alternative to the above design, the locking member may be provided with axially extending ribs on its inner surface, and the delivery member cover may be provided with a shelf structure and axial passages on its outer surface.

[0081] Alternatively, the distally facing surface 5e" is defined by the distal end of the delivery member cover 5", as shown in Figure 15. In this example, no protrusions 7d are disposed on the locking member 7. In this example, the shelf structure 7a of the locking member 7 comprises a proximally facing radial surface 7b and an axial passage 7c.

[0082] As another alternative, the locking member may be located radially inward of the delivery member cover. In this case, the outer surface of the locking member may be provided with ledges and axial passages, and the inner surface of the delivery member may be provided with axially extending ribs. A variation is to provide axially extending ribs on the outer surface of the locking member and ledges and axial passages on the inner surface of the delivery member cover.

[0083] The locking member 7 shown in Figure 3 has an outer surface provided with formations 7e extending radially outwardly of the locking member that are configured to engage corresponding recesses in the drive unit.

[0084] Alternatively, Figure 13 shows a perspective view of a second embodiment of a delivery member cover 5' and a second embodiment of a locking member 7'. According to an example, the locking member 7' is configured to be arranged radially outward of the delivery member cover 5'.

[0085] The delivery member cover 5' has one or more protrusions 5d'. The one or more protrusions 5d' are provided on the outer surface of the delivery member cover 5'. In this example, each protrusion 5d' is located on the outer surface of an axially extending leg 5b.

[0086] The projection 5d' has a distal end face that defines a proximally facing radial surface 5e'.

[0087] Locking member 7' includes a shelf structure 7a'. Shelf structure 7a' has one or more radial shelf surfaces, each of which is a distally facing radial surface 7b'. Each distally facing radial surface 7b' extends radially inward from the inner surface of locking member 7'.

[0088] Locking member 7' has a proximally extending axial passage 7c' that is positioned adjacent shelf structure 7a' circumferentially about locking member 7'. Axial passage 7c' extends proximally relative to shelf structure 7a'. In one preferred example, shelf structure 7a' extends helically. In this example, distally facing radial surface 7b' is a helical surface, as shown in FIG. 13.

[0089] When locking member 7' is in the first position, protrusion 5d' is axially aligned with distally facing radial surface 7b', such that proximal facing surface 5e' is axially aligned with and faces distally facing radial surface 7b', thereby preventing delivery member cover 5' from moving to the extended position.

[0090] When the locking member 7' is in the second position, the protrusion 5d' is axially aligned with the axial passage 7c'. The axial passage 7c' has a circumferential width dimension configured to receive the protrusion 5d'. Thus, in this case, the delivery member cover 5' can be moved to the extended position by the elastic member 11 or the like, or can be manually pulled by a user, with the axial passage 7c' receiving the protrusion 5d'.

[0091] As an alternative to the above design, the locking member may be provided with protrusions on its inner surface and the delivery member cover may be provided with a ledge structure and axial passage on its outer surface.

[0092] As another alternative, the locking member may be located radially inward of the delivery member cover. In this case, the outer surface of the locking member may be provided with a ledge structure and an axial passage, and the inner surface of the delivery member may be provided with a protrusion. A variation is to provide the protrusion on the outer surface of the locking member and the ledge structure and axial passage on the inner surface of the delivery member cover.

[0093] As with the first embodiment, the locking member 7' shown in Figure 13 has an outer surface provided with formations 7e extending radially outwardly of the locking member that are configured to engage corresponding recesses in the drive unit.

[0094] 4 shows the locking member 7 and the rear member 17. The rear member 17 is disposed coaxially with the locking member 7. The rear member 17 is disposed distally relative to the locking member 7. It should be noted that the interaction between the locking member and the rear member will be described in detail below by way of a first embodiment as an example. However, the rear member 17 can be used in both the first and second embodiments as mentioned above, since the rear member 17 is configured to provide a safety mechanism to releasably lock the locking member from rotating from the first position to the second position before the cassette unit is connected to the drive unit.

[0095] The locking member 7 has a distal locking member end 7f provided with an axial recess 7g (as shown in FIGS. 4 and 13). The rear member 17 has a proximal rear member end 17a provided with a radially flexible structure 17b. The radially flexible structures 17b may be, for example, wedge-shaped with radial dimensions increasing in a direction toward the proximal rear member end 17a. Each radially flexible structure 17b may be provided with an axially extending end tab 17c configured to be received in a respective axial recess 7g of the locking member 7. This rotationally secures the locking member 7 to the rear member 17 in a first position. The rear member 17 is rotationally and axially secured to the housing 3. When the cassette unit 1 is inserted into and connected to the drive unit, the radially flexible structures 17b are pressed radially inward by the inner wall of the opening in the drive unit. This causes the axially extending tabs 17c to bend radially inward and disengage from their respective axial recesses 7g. The locking member 7 is therefore set to rotate freely from the first position to the second position.

[0096] The rear member 17 includes a fastening structure 17d configured to engage a mating fastening structure on the drive unit. Fastening structure 17d, in this example, is a radially outwardly extending structure on the rear member that is axially aligned with radially outwardly extending structure 7e on the locking member when the locking member 7 is in the first position. The radially outwardly extending structure on the rear member forms one part of a bayonet connection, the other part of which is provided on the drive unit.

[0097] When the cassette unit 1 is connected to the drive unit, the distal end of the cassette unit 1, including the locking member 7 and the rear member 17, is inserted into the proximal opening of the drive unit. The proximal opening of the drive unit has an inner surface provided with a radial recess configured to receive and guide one of the fastening structure 17d and the radially outwardly extending structure 7e of the locking member when the cassette unit 1 is inserted into the proximal opening of the drive unit. The radial recess has an axial length corresponding to the axial length of the radially outwardly extending structure 7e of the locking member such that the fastening structure 17d is axially positioned beyond the axial recess in the distal direction when the cassette unit 1 is inserted into the drive unit. When in this position, the cassette unit 1 can be rotated relative to the drive unit. Because the radially outwardly extending structure 7e of the locking member is disposed in the radial recess, the radially outwardly extending structure 7e of the locking member maintains a fixed position relative to the drive unit, the locking member 7 is released, and the rear member 17 and the housing 3 are rotated relative to the drive unit and the locking member 7. This causes the cassette unit 1 to be locked to the drive unit by the bayonet connection. The locking member 7 is in the middle of rotation between the cassette unit 1 and the drive unit set to the second position.

[0098] Alternatively, the locking member may be provided with a radially flexible structure and an axially extending end tab at the proximal locking member end, and the housing, particularly a radially outwardly extending flange disposed proximally relative to the locking member, may be provided with an axial recess configured to receive the axially extending end tab when the locking member is in the first position.

[0099] Instead of forming one part of a bayonet connection, the fastening structure may, for example, form one part of a screw connection.

[0100] Returning to the first embodiment, as described above, in one example in which the shelf structure 7a of the locking member 7 includes a protrusion 7d, the protrusion 7d of the locking member 7 is configured to prevent rotation of the locking member 7 relative to the delivery member cover 5. Thus, when a user inserts the cassette unit 1 into the drive unit and pushes the delivery member cover 5 distally relative to the housing 3 but has not yet rotated the cassette unit 1 relative to the drive unit, and the user then pushes the delivery member cover 5, the axially extending rib 5d will be radially aligned with the protrusion 7d, thereby preventing rotation of the locking member 7 relative to the delivery member cover 5. The delivery member cover 5 is rotationally fixed to the housing as described above, whereby, when the axially extending rib 5d is radially aligned with the protrusion 7d, the locking member 7 will be prevented from rotating relative to the delivery member cover 5. As mentioned above, the locking member 7 is prevented from rotating relative to the drive unit by the radial recess of the drive unit, and as a result, the user will not be able to rotate the cassette unit relative to the drive unit. This gives the user an indication (from the inability to attach the cassette unit to the drive unit) that the delivery member cover 5 should not be pressed before the cassette is properly attached to the drive unit.

[0101] 5 shows a longitudinal section of the cassette unit 1 in its initial default state, with the drug container holder 9 located distally relative to the housing 3. In this case, the septum sealing the liquid container 13a is intact.

[0102] The drug container holding portion 9 has an outer surface provided with a slope 9a extending radially outward. The housing 3 has an inner surface provided with a slope 3e extending radially inward. When the drug container holding portion 9 is in the distal position, the slope 3e extending radially inward is disposed proximal to the slope 9a extending radially outward and faces the slope 9a extending radially outward.

[0103] The radially outwardly extending ramp 9a is configured to move past the radially inwardly extending ramp 3e when the medication container holding portion 9 is subjected to a proximal axial force greater than a threshold value. Thus, the configuration of ramps 9a and 3e prevents proximal movement of the medication container holding portion 9 until a sufficiently large proximal axial force acts on the proximal end face of the medication container holding portion 9.

[0104] 6, the medicament container holder 9 is being pushed further into the housing 3, i.e., in the proximal direction, by a proximal axial force greater than a threshold value. The medicament container holder 9 has reached its proximal position. The liquid container 13a has therefore also moved proximally with the medicament container holder 9. The distally directed needle of the double-beveled needle 13b has pierced the septum as a result of the distal flexible tubing being compressed and pierced by the distally directed needle.

[0105] When the cassette unit 1 is connected to the drive unit, the drug container holding portion 9 is moved from a distal position to a proximal position by an internal structure such as a motor frame disposed in the drive unit.

[0106] Figures 7 and 15 show the cassette unit 1 of the first embodiment when the locking member 7 is in a first position, and Figures 8-9 show the cassette unit when the locking member 7 is in a second position. In Figure 9, the housing 3 has been removed to better show the axial alignment of the axially extending rib 5d of the delivery member cover 5 with the axial passage 7c of the locking member 7.

[0107] 10 shows the cassette unit 1 in a locked state when the delivery member cover 5 has returned to the extended position. The delivery member cover 5 has been made transparent to show the interaction between the rotating part 15 and the delivery member cover 5. One of the flexible elements 15c of the rotating part 15 is shown positioned distal to the radially inward extending protrusion 5c to prevent the delivery member cover 5 from moving back to the retracted position.

[0108] Additionally, in another example, the cassette subassembly includes a cap 6 that is removably attached to the proximal end 3a of the housing 3, as shown in FIGS.

[0109] The cassette subassemblies and cassette units described herein can be used to treat and / or prevent one or more of many different types of diseases, including, but not limited to, rheumatoid arthritis, inflammatory bowel disease (e.g., Crohn's disease and ulcerative colitis), hypercholesterolemia, diabetes (e.g., type 2 diabetes), psoriasis, migraines, multiple sclerosis, anemia, lupus, atopic dermatitis, asthma, nasal polyps, acute hypoglycemia, obesity, anaphylaxis, and allergies. Exemplary drugs that may be included in the drug delivery devices described herein include, but are not limited to (by non-limiting examples of associated diseases in parentheses), etanercept (rheumatoid arthritis, inflammatory bowel disease (such as Crohn's disease and ulcerative colitis)), evolocumab (hypercholesterolemia), exenatide (type 2 diabetes), secukinumab (psoriasis), erenumab (migraine), alirocumab (rheumatoid arthritis), methotrexate (amethopterin) (rheumatoid arthritis), tocilizumab (rheumatoid arthritis), interferon beta-1a ( Drug delivery devices described herein include, but are not limited to, pharmaceutical formulations comprising any of the drugs described herein, such as, but not limited to, pharmaceutical formulations comprising a drug listed herein (or a pharmaceutically acceptable salt thereof) and a pharmaceutically acceptable carrier.

[0110] Pharmaceutical formulations containing the agents listed herein (or pharmaceutically acceptable salts of the agents) may contain one or more other active ingredients, or may be the only active ingredient present.

[0111] The inventive concept has been primarily described above with reference to certain examples. However, as will be readily appreciated by those skilled in the art, other embodiments besides those disclosed above are equally possible within the scope of the inventive concept as defined by the appended claims.

[0112] Some aspects of the present invention are defined by the following clauses.

[0113] 1. A cassette subassembly for a cassette unit (1) configured to be removably connected to a drive unit to form a medication delivery device, comprising: a housing (3) having a proximal housing end (3a) and a distal housing end (3b); a delivery member cover (5) projecting from the proximal housing end (3a) and configured to be linearly moved relative to the housing (3); a locking member (7) arranged axially fixed relative to the housing (3), the locking member (7) being configured to be rotated relative to the delivery member cover (5) from a first position to a second position; Equipped with the locking member (7) has a proximally facing radial surface (7b) and the delivery member cover (5) has a distally facing radial surface (5e); the proximal-facing radial surface (7b) is axially aligned with and faces the distal-facing radial surface (5e) when the locking member (7) is in the first position; A cassette subassembly, wherein the proximally facing radial surface (7b) is circumferentially offset relative to the distally facing radial surface (5e) when the locking member (7) is in the second position.

[0114] 2. A cassette subassembly as described in clause 1, wherein the locking member (7) is disposed radially outward of the delivery member cover (5).

[0115] 3. A cassette subassembly according to clause 1 or 2, wherein the locking member (7) is annular, a retaining ring or has a semicircular shape.

[0116] 4. A cassette subassembly described in any one of clauses 1 to 3, wherein the delivery member cover (5) has an axially extending rib (5d) whose distal end face forms a distally facing radial surface (5e), and the locking member (7) has a shelf structure (7a) forming a proximally facing radial surface (7b) and a distally extending axial passage (7c) circumferentially adjacent to the shelf structure (7a), the axial passage (7c) being configured to receive the rib (5d) when the locking member (7) is in the second position.

[0117] 5. A cassette subassembly described in any one of clauses 1 to 3, wherein the locking member (7) has an axially extending rib, the proximal end face of the rib forming a proximally facing radial surface, and the delivery member cover (5) has a shelf structure forming a distally facing radial surface and a proximally extending axial passage circumferentially adjacent the shelf structure, the axial passage being configured to receive the rib when the locking member (7) is in the second position.

[0118] 6. A cassette subassembly as described in clause 4 or 5, wherein the shelf structure (7a) comprises a radial shelf surface and a protrusion (7d) extending axially from the radial shelf surface, the protrusion (7d) being positioned circumferentially of the locking member (7) between the radial shelf surface and the axial passage (7c).

[0119] 7. A cassette subassembly according to any one of clauses 1 to 6, wherein the delivery member cover (5) is rotationally locked relative to the housing (3).

[0120] 8. A cassette subassembly as described in clause 7, wherein the outer surface of the delivery member cover (5) has a periphery with a non-circular cross-sectional shape, and the housing (3) has an inner surface with a cross-sectional shape corresponding to the non-circular cross-sectional shape, the cross-section being taken through a longitudinal axis of the cassette subassembly.

[0121] 9. The cassette subassembly of clause 7, wherein the delivery member cover (5) has an outer surface provided with a first structure, and the housing has a second structure, the first structure configured to engage with the second structure to prevent relative rotation between the delivery member cover (5) and the housing (3).

[0122] 10. The cassette subassembly of clause 9, wherein the first structure is an axial rib and the second structure is an axial passage, or the first structure is an axial passage and the second structure is an axial rib.

[0123] 11. A cassette subassembly according to any one of clauses 1 to 10, comprising a fastening structure (17d) configured to engage with a mating fastening structure of the drive unit.

[0124] 12. A cassette subassembly as described in clause 11, wherein the fastening structure (17d) forms one part of a bayonet connection or forms one part of a threaded connection.

[0125] 13. A cassette subassembly as described in any one of clauses 1 to 12, comprising a drug container holder (9) disposed in the housing (3) and configured to be moved by the drive unit from a distal position to a proximal position relative to the housing (3) when the cassette subassembly is connected to the drive unit.

[0126] 14. A cassette subassembly as described in clause 13, wherein the drug container holding portion (9) has an outer surface provided with a radially outwardly extending slope (9a), and the housing (3) has a radially inwardly extending slope (3e) positioned proximal to the radially outwardly extending slope (9a), and has an inner surface facing the radially outwardly extending slope (9a) when the drug container holding portion (9) is in a distal position.

[0127] 15. A cassette unit (1) for a medication delivery device comprising a cassette subassembly according to any one of clauses 1 to 14.

[0128] 16. A cassette subassembly for a cassette unit (1) configured to be removably connected to a drive unit to form a medication delivery device, comprising: a housing (3) having a proximal housing end (3a) and a distal housing end (3b); a delivery member cover (5) projecting from the proximal housing end (3a) and configured to be linearly moved relative to the housing (3); a locking member (7) arranged axially fixed relative to the housing (3), the locking member (7) configured to be rotated relative to the delivery member cover (5) from a first position in which axial movement of the delivery member cover is prevented by the locking member (7) to a second position in which axial movement of the delivery member cover is no longer prevented by the locking member (7); a rear member (17) disposed distally relative to the locking member (7), the rear member (17) being provided with radially flexible structures (17b) with axially extending end tabs (17c) that are received by respective axial recesses (7g) of the locking member (7) when the locking member (7) is in the first position such that the locking member (7) is rotationally fixed in the first position relative to the rear member (17); Equipped with A cassette subassembly, wherein the radially flexible structure (17b) is configured to be pushed radially inward by an inner wall of the drive unit when the cassette unit (1) is inserted into and connected to the drive unit so that the radially flexible structure (17b) is disengaged from the axial recess (7g) of the locking member (7).

[0129] 17. A cassette subassembly as described in clause 16, wherein the locking member (7) is disposed radially outward of the delivery member cover (5).

[0130] 18. A cassette subassembly according to clause 16 or 17, wherein the locking member (7) is annular, a retaining ring or has a semicircular shape.

[0131] 19. A cassette subassembly according to any one of clauses 16 to 18, wherein the delivery member cover (5) is rotationally locked relative to the housing (3).

[0132] 20. A cassette subassembly as described in clause 19, wherein the outer surface of the delivery member cover (5) has a periphery with a non-circular cross-sectional shape, and the housing (3) has an inner surface with a cross-sectional shape corresponding to the non-circular cross-sectional shape, the cross-section being taken through a longitudinal axis of the cassette subassembly.

[0133] 21. A cassette subassembly according to any one of clauses 16 to 20, wherein the rear member (17) comprises a fastening structure (17d) configured to engage with a mating fastening structure of the drive unit.

[0134] 22. A cassette subassembly as described in clause 21, wherein the fastening structure (17d) forms one part of a bayonet connection or forms one part of a threaded connection.

[0135] 23. A cassette subassembly according to any one of clauses 16 to 22, wherein the rear member (17) has a proximal rear member end (17a) provided with a radially flexible structure (17b).

[0136] 24. The cassette subassembly of clause 23, wherein the radially flexible structure (17b) is wedge-shaped having a radial dimension that increases in a direction toward the proximal rear member end (17a).

[0137] 25. The locking member (7) has a proximally facing radial surface (7b) and the delivery member cover (5) has a distally facing radial surface (5e), the proximal facing radial surface (7b) being axially aligned with and facing the distally facing radial surface (5e) when the locking member (7) is in the first position; A cassette subassembly according to any one of clauses 16 to 24, wherein the proximal-facing radial surface (7b) is circumferentially offset relative to the distal-facing radial surface (5e) when the locking member (7) is in the second position.

[0138] 26. A cassette subassembly according to any one of clauses 16 to 24, wherein the locking member has a distally facing radial surface and the delivery member cover has a proximally facing radial surface, the proximally facing radial surface being axially aligned with the distally facing radial surface when the locking member is in a first position and facing the distally facing radial surface, and the proximal facing radial surface being circumferentially offset relative to the distally facing radial surface when the locking member is in a second position.

[0139] 27. The cassette subassembly of clause 26, wherein the distally facing radial surface of the locking member is a helical surface.

[0140] 28. A cassette subassembly according to any one of clauses 16 to 27, wherein the cassette subassembly comprises a resilient member (11), the resilient member (11) being configured to bias the delivery member cover (5) towards the extended position.

[0141] 29. A cassette unit (1) for a medication delivery device, comprising a cassette subassembly according to any one of clauses 16 to 28.

[0142] 30. A medication delivery device comprising a cassette unit (1) according to clause 29 and a drive unit configured to be connected to the cassette unit (1). [Explanation of symbols]

[0143] 1,1´ cassette unit 3. Housing 3a Proximal housing end 3b Distal housing end 3c Axial housing legs 3D Tab 3e Radial inward slope 5, 5´, 5´´ Delivery member cover 5a, 5a´´ Proximal circumferentially closed part 5b Axial extending leg 5b´´ flange 5c Protrusion extending radially inward 5d Axially extending rib 5d´ protrusion 5e Distally facing radial surface 5e´ Proximally facing radial surface 5e´´ Distal facing surface 6 Caps 7, 7´ Locking member 7a, 7a´ Shelf structure 7b Proximally facing radial surface 7b´ Distally facing radial surface 7c Axial passage extending distally 7c´ Proximally extending axial passage 7d protrusion, protuberance 7e Structure extending radially outward 7f Distal locking member end 7g Axial recess 9, 9´ Drug container holding part 9a Radial outwardly extending slope 11 Elastic member 13. Medicine containers 13a, 13a´ Liquid container 13b, 13b´ double edged needles 14 Stop part 15 Rotating part 15a Guidance structure 15c Flexible Element 17 Rear member 17a Proximal posterior end 17b Radially flexible structure 17c Axially extending end tab 17d Fastening structure 50´´ proximal 51´´ distal

Claims

1. 1. A cassette subassembly for a cassette unit (1) configured to be removably connected to a drive unit to form a medication delivery device, comprising: a housing (3) having a proximal housing end (3a) and a distal housing end (3b); a delivery member cover (5) protruding from the proximal housing end (3a) and configured to be linearly moved relative to the housing (3); a locking member (7) arranged axially fixed relative to the housing (3), the locking member (7) being configured to be rotated relative to the housing (3) from a first position in which axial movement of the delivery member cover is prevented to a second position in which the axial movement of the delivery member cover is no longer prevented; a rear member (17) disposed distally relative to said locking member (7), said rear member (17) being provided with radially flexible structures (17b) with axially extending end tabs (17c) that are received by respective axial recesses (7g) of said locking member (7) when said locking member (7) is in said first position such that said locking member (7) is rotationally fixed relative to said rear member (17) in said first position; Equipped with a cassette subassembly configured to be pushed radially inward by an inner wall of the drive unit when the cassette unit (1) is inserted into and connected to the drive unit, so that the radially flexible structure (17b) is disengaged from the axial recess (7g) of the locking member (7).

2. 2. The cassette subassembly of claim 1, wherein the locking member (7) is arranged radially outward of the delivery member cover (5).

3. 3. A cassette subassembly according to claim 1 or 2, wherein the locking member (7) is annular, a retaining ring or has a semicircular shape.

4. A cassette subassembly according to any one of claims 1 to 3, wherein the delivery member cover (5) is rotationally locked relative to the housing (3).

5. 5. The cassette subassembly of claim 4, wherein the outer surface of the delivery member cover (5) has a periphery with a non-circular cross-sectional shape, and the housing (3) has an inner surface with a cross-sectional shape corresponding to the non-circular cross-sectional shape, the cross-section being taken through a longitudinal axis of the cassette subassembly.

6. A cassette subassembly according to any one of claims 1 to 5, wherein the rear member (17) comprises a fastening structure (17d) configured to engage with a mating fastening structure of the drive unit.

7. A cassette subassembly according to claim 6, wherein the fastening structure (17d) forms one part of a bayonet connection or forms one part of a threaded connection.

8. A cassette subassembly according to any one of claims 1 to 7, wherein the rear member (17) has a proximal rear member end (17a) provided with the radially flexible structure (17b).

9. 9. A cassette subassembly according to claim 8, wherein said radially flexible structure (17b) is wedge-shaped with a radial dimension that increases in a direction towards said proximal rear member end (17a).

10. the locking member (7) has a proximal-facing radial surface (7b), and the delivery member cover (5) has a distal-facing radial surface (5e), the proximal-facing radial surface (7b) being axially aligned with and facing the distal-facing radial surface (5e) when the locking member (7) is in the first position; 10. A cassette subassembly according to claim 1, wherein the proximal facing radial surface (7b) is circumferentially offset relative to the distal facing radial surface (5e) when the locking member (7) is in the second position.

11. 10. The cassette subassembly of claim 1, wherein the locking member has a distally facing radial surface, and the delivery member cover has a proximally facing radial surface, the proximally facing radial surface being axially aligned with and facing the distally facing radial surface when the locking member is in the first position, and the proximally facing radial surface being circumferentially offset relative to the distally facing radial surface when the locking member is in the second position.

12. The cassette subassembly of claim 11 , wherein the distally facing radial surface of the locking member is a helical surface.

13. 13. The cassette subassembly of claim 1, wherein the cassette subassembly comprises a resilient member (11), the resilient member (11) configured to bias the delivery member cover (5) towards an extended position.

14. A cassette unit (1) for a medication delivery device comprising a cassette subassembly according to any one of claims 1 to 13.

15. A medication delivery device comprising a cassette unit (1) according to claim 14 and a drive unit configured to be connected to said cassette unit (1).

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