Cartridge accommodating assembly and injection apparatus

Abstract

The present application relates to a cartridge accommodating assembly and an injection apparatus. The cartridge accommodating assembly comprises a housing, a distal end of a medicament vial being connected with a needle cap covering a needle; an end cover, the end cover comprising an elastic clamping arm, and the elastic clamping arm being capable of cooperating with the needle cap to form a snap-fit connection; and a restricting element, located inside the housing and capable of moving relative to the housing from a first position to a second position. When the cartridge accommodating assembly is in an empty state without accommodating the medicament vial, the restricting element is maintained at the first position; when the cartridge accommodating assembly is in an assembled state in which the medicament vial is accommodated and assembled into the injection apparatus, the restricting element is maintained at the second position. When the restricting element is in the first position, the elastic clamping arm is allowed to form or disengage a snap-fit connection with the needle cap; and when the restricting element is in the second position, the elastic clamping arm is prevented from forming or disengaging a snap-fit connection with the needle cap. The present application facilitates a user in pulling the end cover out from a distal end of the housing while removing the needle cap from the distal end of the medicament vial.

Description

Drug cartridge housing assembly and injection device Technical Field

[0001] This application relates to the technical field of injection devices, and in particular to a cartridge receiving assembly and an injection device. Background Technology

[0002] An injection device is used to inject medication contained within it into a patient through a needle at the injection site. It typically includes a housing, a vial, and a delivery assembly. The vial is housed within the housing and includes a body, medication contained within the vial, a needle at the distal end of the vial, and a movable piston at the proximal end of the vial. The delivery assembly actuates the movable piston to push the medication from the vial through the needle into the patient. To prevent the needle from being exposed to air, a needle cap is removably fitted onto the vial, and correspondingly, the distal end of the injection device typically has an end cap that allows the needle cap to be removed.

[0003] Specifically, the end cap is located at the distal end of the housing and is detachably connected to the housing. The end cap includes an elastic locking arm that extends into the housing and engages with the needle cap. The elastic locking arm includes an axially extending cantilever and a latch that protrudes radially inward at the end of the cantilever. Correspondingly, the needle cap has a locking portion that engages with the latch. During assembly, the elastic locking arm of the end cap and the needle cap move closer together. The latch on the cantilever abuts against the outer wall of the needle cap, causing the cantilever to elastically deform outward. When the latch moves to the position corresponding to the locking portion of the needle cap, the cantilever returns to its original position under the action of elastic restoring force, thereby enabling the latch and the locking portion to engage and form a locking connection. The user can then remove the needle cap by pulling out the end cap.

[0004] However, when the user pulls out the end cap, the latch on the cantilever is also subjected to the reaction force of the needle cap engagement part. Since the cantilever can undergo elastic deformation, the reaction force on the latch is transmitted to the cantilever, which may cause the cantilever to deform. This will cause the engagement connection between the elastic latch on the end cap and the needle cap to fail, so that the needle cap is not removed in this process, causing inconvenience to the removal of the needle cap. Summary of the Invention

[0005] One of the purposes of this application is to provide a cartridge receiving assembly that can prevent the elastic retaining arm from detaching from the needle cap due to the reaction force of the needle cap during actual use of the injection device, thereby making it convenient for the user to remove the needle cap from the far end of the medicine bottle while pulling out the end cap from the far end of the housing.

[0006] The second objective of this application is to provide an injection device that includes the cartridge receiving assembly provided in the first objective above, which allows the user to remove the needle cap from the distal end of the vial while simultaneously pulling out the end cap from the distal end of the housing.

[0007] One of the objectives of this application is to adopt the following technical solution:

[0008] A cartridge receiving assembly for an injection device, comprising:

[0009] The housing is used to contain the medicine bottle, and the distal end of the medicine bottle is connected to a needle cap that covers the needle tip;

[0010] An end cap is detachably connected to the distal end of the housing, and the end cap includes an elastic locking arm that can engage with a needle cap to form a locking connection.

[0011] A limiting element is located within the housing and is movable relative to the housing from a first position to a second position;

[0012] Specifically, when the cartridge receiving assembly is in an empty state without containing a medicine bottle, the limiting element is maintained in a first position; when the cartridge receiving assembly is in an assembled state containing a medicine bottle and assembled into an injection device, the limiting element is maintained in a second position.

[0013] When the limiting element is in the first position, the elastic locking arm is allowed to engage or disengage with the needle cap; when the limiting element is in the second position, the elastic locking arm is prevented from engaging or disengaging with the needle cap.

[0014] By adopting the above technical solution, when the cartridge receiving assembly is in an empty state where the medicine bottle is to be installed, the limiting element is in the first position. At this time, the elastic locking arm is allowed to engage or disengage with the needle cap, which facilitates the user to install the medicine bottle into the housing and make the needle cap at the distal end of the medicine bottle engage with the elastic locking arm of the end cap. When the cartridge receiving assembly is in the assembled state of containing the medicine bottle and assembling it into an injection device, the limiting element is in the second position. At this time, the elastic locking arm is prevented from engaging or disengaging with the needle cap, which facilitates the user to remove the needle cap from the distal end of the medicine bottle while pulling out the end cap from the distal end of the housing.

[0015] Furthermore, the radial movement distance required for the elastic arm to undergo radial elastic deformation during the engagement or disengagement of the elastic arm and the needle cap is defined as D. The limiting element is provided with a limiting part, and the radial distance between the limiting part on the limiting element in the second position and the elastic arm is defined as d, where d < D.

[0016] Furthermore, the end cap also includes a cover body that covers the distal end of the housing, the elastic latch arm includes a cantilever and a latch on the cantilever, the cantilever extends axially from the cover body toward the proximal end, the latch extends radially inward, and the latch includes a first surface and a second surface that are axially opposite each other, the first surface being closer to the cover body than the second surface; the second surface is inclined toward the cover body in the direction of radial inward extension of the latch.

[0017] By adopting the above technical solution, during the process of the elastic locking arm of the end cap engaging with the needle cap at the far end of the medicine bottle, the two approach each other along the axial direction. The far end of the needle cap first contacts the second surface of the buckle and slides relative to each other, which facilitates the radial outward elastic deformation of the cantilever.

[0018] Furthermore, the first surface is inclined toward the cover body in the direction of its inward radial extension along the buckle.

[0019] The first surface of the buckle is used to engage with the needle cap. By adopting the above technical solution, when the end cap is pulled out, the first surface of the buckle is subjected to the reaction force of the needle cap engaging part, which is biased towards the inward radial direction. Therefore, it is not easy for the elastic locking arm to undergo radial outward elastic deformation.

[0020] Furthermore, the first surface is inclined in a direction away from the cover body in the direction that extends radially inward along the buckle.

[0021] By adopting the above technical solution, after the end cap is injection molded, the core can be pulled out from the direction away from the cap body. During the core pulling process, the first surface of the buckle is subjected to a reaction force that is biased towards the outward radial direction, which can cause the elastic buckle arm to undergo radial outward elastic deformation, thereby completing the core pulling action.

[0022] Furthermore, it also includes an elastic element for providing a holding force to maintain the limiting element in a first position, and the elastic element undergoes elastic deformation when the limiting element moves from the first position to a second position.

[0023] Furthermore, the end cap is provided with a positioning plane, which is used for the needle cap to abut against each other to limit the axial position of the end cap and the needle cap, and when the positioning plane abuts against the needle cap, the elastic locking arm and the needle cap form a locking connection.

[0024] Furthermore, the limiting element in the first position is further away from the end cap than the limiting element in the second position.

[0025] Furthermore, an axial guide structure is provided between the limiting element and the end cap, the axial guide structure being used to guide the limiting element and the end cap to move axially relative to each other.

[0026] The second objective of this application adopts the following technical solution:

[0027] An injection device includes a vial, a delivery assembly, and a cartridge receiving assembly as described above. The vial is housed within the housing, and a needle cap at the distal end of the vial engages with a resilient locking arm of the end cap to form a locking connection. The delivery assembly is located within the housing on the proximal side of the vial and is used to provide a holding force to maintain the restraining element in a second position.

[0028] By adopting the above technical solution, it is convenient for users to pull the end cap out of the far end of the housing and remove the needle cap from the far end of the medicine bottle at the same time.

[0029] Furthermore, the housing includes an upper shell and a lower shell that are engaged, the limiting element is housed in the lower shell, and the pushing assembly is housed in the upper shell. When the upper shell and the lower shell are engaged, the pushing assembly provides an external force for the limiting element to move from a first position to a second position.

[0030] In summary, this application includes at least the following beneficial effects:

[0031] When the cartridge housing assembly is in an empty state with the medicine bottle to be installed, the limiting element is in the first position. At this time, the elastic locking arm is allowed to engage or disengage with the needle cap, which facilitates the user to install the medicine bottle into the housing and to engage the needle cap at the distal end of the medicine bottle with the elastic locking arm of the end cap. When the cartridge housing assembly is in the assembled state of containing the medicine bottle and assembling it into an injection device, the limiting element is in the second position. At this time, the elastic locking arm is prevented from engaging or disengaging with the needle cap, which facilitates the user to remove the needle cap from the distal end of the medicine bottle while pulling out the end cap from the distal end of the housing. Attached Figure Description

[0032] Figure 1 is an exploded view of the medicine cartridge container assembly and the medicine bottle in an embodiment of this application;

[0033] Figure 2 is a schematic diagram of the engagement connection between the end cap and the needle cap in an embodiment of this application;

[0034] Figure 3 is a schematic diagram of the medicine container assembly in an embodiment of this application, where no medicine bottle is loaded and the limiting element is in the first position;

[0035] Figure 4 is a schematic diagram of a medicine bottle being loaded in a medicine container assembly in an embodiment of this application, with the limiting element in the first position;

[0036] Figure 5 is a schematic diagram of a medicine bottle being loaded in a medicine container assembly in an embodiment of this application, with the limiting element in the second position;

[0037] Figure 6 is a schematic diagram illustrating the radial distance d of the limiting element in the second position in an embodiment of this application;

[0038] Figure 7 is a cross-sectional view of the housing shown in an embodiment of this application;

[0039] Figure 8 is a structural schematic diagram showing the limiting element in an embodiment of this application;

[0040] Figure 9 is a schematic diagram of the structure of the cartridge holder shown in the embodiment of this application;

[0041] Figure 10 is a structural schematic diagram of the end cap shown in an embodiment of this application;

[0042] Figure 11 is a cross-sectional view showing the end cap in an embodiment of this application;

[0043] Figure 12 is a schematic diagram showing the inner limiting part and axial groove of the limiting element in an embodiment of this application.

[0044] Explanation of reference numerals in the attached drawings: 1. Shell; 11. Inner shell; 12. Outer shell; 121. Axial guide rib; 13. First chamber; 14. Second chamber; 15. Axial channel; 2. End cap; 21. Elastic locking arm; 211. Cantilever; 212. Snap; 2121. First surface; 2122. Second surface; 22. Cap; 23. Axial protruding rib; 24. Central column; 241. Positioning plane; 3. Restricting element; 31. Cylindrical body; 311. Axial groove; 32. Axial extension arm; 321. Guide groove; 33. First section; 34. Second section; 341. Restricting part; 4. Cartridge holder; 41. Axial guide groove; 42. Guide boss; 43. Outer wall boss; 5. Elastic element; 6. Medicine bottle; 7. Needle cap; 71. Engaging part. Detailed Implementation

[0045] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0046] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, features defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0047] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0048] To prevent the needle from being exposed to air, a needle cap is detachably fitted onto the vial to cover the needle. Correspondingly, the distal end of the injection device is typically equipped with an end cap that allows the needle cap to be removed. The end cap is located at the distal end of the housing and is detachably connected to it. The end cap includes a resilient locking arm that extends into the housing and engages with the needle cap. The resilient locking arm includes an axially extending cantilever and a latch that protrudes radially inward at the end of the cantilever. Correspondingly, the needle cap has a locking portion that engages with the latch. During assembly, the resilient locking arm of the end cap approaches the needle cap, and the latch on the cantilever abuts against the outer wall of the needle cap, causing the cantilever to elastically deform outward. When the latch moves to the position corresponding to the locking portion of the needle cap, the cantilever returns to its original position under the action of elastic restoring force, thereby allowing the latch and locking portion to engage and form a locking connection. The user can then remove the needle cap simultaneously by pulling out the end cap. However, when the user pulls out the end cap, the latch on the cantilever is also subjected to the reaction force of the needle cap engagement part. Since the cantilever can undergo elastic deformation, the reaction force on the latch is transmitted to the cantilever, which may cause the cantilever to deform. This will cause the engagement connection between the elastic latch on the end cap and the needle cap to fail, so that the needle cap is not removed in this process.

[0049] This application discloses a cartridge container assembly, which serves as an assembly component for an injection device. It can prevent the elastic locking arm 21 from detaching from the needle cap 7 due to the reaction force of the needle cap 7 during actual use of the injection device, thereby facilitating the user to remove the needle cap 7 from the far end of the medicine bottle 6 while pulling out the end cap 2 from the far end of the housing 1.

[0050] It should be noted that the cartridge containing assembly involved in this application can accommodate the medicine bottle 6, and after accommodating the medicine bottle 6, it can be assembled with other components to form an injection device for users to inject drugs. The aforementioned medicine bottle 6 includes a bottle body, a drug placed inside the bottle body, a needle located at the distal end of the bottle body, and a movable piston located at the proximal end of the bottle body. Furthermore, in the embodiments of this application, "proximal end" refers to the end closer to the user's operating part, and "distal end" refers to the end farther from the user's operating part. Specifically, in subsequent embodiments, "distal end" refers to the end closer to the patient's injection site during use, and the direction between the proximal end and the distal end is defined as the axial direction.

[0051] Furthermore, for ease of subsequent description, the state in which the cartridge receiving assembly does not yet contain the medicine bottle 6 is defined as the empty state of the cartridge receiving assembly, and the state in which the cartridge receiving assembly contains the medicine bottle 6 and is assembled with other components to form an injection device is defined as the assembled state of the cartridge receiving assembly.

[0052] Referring to Figures 1 to 4, the cartridge housing assembly includes a housing 1, an end cap 2, and a limiting element 3. The housing 1 is generally cylindrical and has opposing distal and proximal ends. The housing 1 houses a vial 6, with a needle cap 7 covering the needle tip connected to the distal end of the vial 6. The end cap 2 is detachably connected to the distal end of the housing 1 and can close the distal opening of the housing 1. The end cap 2 includes a resilient locking arm 21 that engages with the needle cap 7 to form a locking connection. Furthermore, the limiting element 3 is located within the housing 1 and can move relative to the housing 1 from a first position to a second position under external force. Figure 3 is a schematic diagram of the cartridge container assembly without the medicine bottle 6 and the limiting element 3 in the first position, corresponding to the empty state of the aforementioned cartridge container assembly; Figure 4 is a schematic diagram of the cartridge container assembly with the medicine bottle 6 loaded and the limiting element 3 in the first position, the cartridge container assembly in this state can be used for further assembly with other components; Figure 5 is a schematic diagram of the cartridge container assembly with the medicine bottle 6 loaded and the limiting element 3 in the second position, the limiting element 3 in this state can be locked with the housing 1 and maintained in the second position, or it can be held in the second position by other components (not shown) used for assembling the injection device, and it also corresponds to the assembled state of the aforementioned cartridge container assembly.

[0053] Referring to Figures 3 to 5, when the cartridge case receiving assembly is in an empty state, the limiting element 3 is in a first position relative to the housing 1; when the cartridge case receiving assembly is in an assembled state, the limiting element 3 is in a second position relative to the housing 1. Furthermore, the radial movement distance required for the elastic locking arm 21 to undergo radial elastic deformation when it forms an engaging or disengaging connection with the needle cap 7 is defined as D. The foregoing indicates that, theoretically, the radial movement distance required for the elastic locking arm 21 to undergo radial elastic deformation when it forms an engaging connection with the needle cap 7 is at least D, and also indicates that, theoretically, the radial movement distance required for the elastic locking arm 21 to undergo radial elastic deformation when it disengages from the needle cap 7 is at least D.

[0054] Accordingly, referring to Figures 3 and 4, when the limiting element 3 is in the first position, the elastic locking arm 21 is allowed to undergo radial elastic deformation with a radial movement distance of d1, where d1 ≥ D. That is, the elastic locking arm 21 is allowed to form an engaging connection with the needle cap 7 or to disengage from the engaging connection. Thus, in the empty state of the cartridge housing assembly, the medicine bottle 6 can be installed into the housing 1 and the needle cap 7 at the distal end of the medicine bottle 6 can engage with the elastic locking arm 21 of the end cap 2 to form an engaging connection.

[0055] Referring to Figures 5 and 6, when the limiting element 3 is in the second position, the elastic locking arm 21 is prevented from undergoing radial elastic deformation with a radial movement distance of d2, where d2 < D. That is, the elastic locking arm 21 is prevented from forming an engaging connection or disengaging connection with the needle cap 7. Thus, when the cartridge containing assembly is assembled into an injection device, the needle cap 7 at the distal end of the vial 6 and the elastic locking arm 21 of the end cap 2 can maintain a stable engaging connection, so that the user can remove the needle cap 7 from the distal end of the vial 6 while pulling out the end cap 2 from the distal end of the housing 1.

[0056] It is understood that during the process of the elastic arm 21 engaging with the needle cap 7 and during the process of the elastic arm 21 disengaging from the engagement, the elastic arm 21 will undergo radial elastic deformation. The radial movement distance required for the elastic arm 21 to undergo radial elastic deformation during the engagement and disengagement of the engagement is the same. In the foregoing, this radial movement distance is defined as D.

[0057] It should be noted that the ability of the limiting element 3 to move from the first position to the second position relative to the housing 1 indicates that the limiting element 3 can change its position relative to the housing 1, without limiting the specific form of movement of the limiting element 3 relative to the housing 1. In this embodiment, the limiting element 3 is configured to be able to translate axially relative to the housing 1 and move from the first position to the second position; in some other specific embodiments, the limiting element 3 is configured to be able to move helically relative to the housing 1 and move from the first position to the second position; in other specific embodiments, the limiting element 3 is configured to be able to rotate relative to the housing 1 and move from the first position to the second position. Furthermore, in specific embodiments where the limiting element 3 translates axially or moves helically relative to the housing 1, the first position of the limiting element 3 can be configured to be farther away from the end cap 2 than the second position, such that the movement of the limiting element 3 from the first position to the second position is a movement toward the end cap 2; in other embodiments, the movement of the limiting element 3 from the first position to the second position can also be a movement away from the end cap 2.

[0058] It is understandable that the housing 1 is used to contain the medicine bottle 6. The internal dimensions of the housing 1 can be set to match the medicine bottle 6, or other built-in components that are configured to match the outer diameter of the medicine bottle 6 can be added inside the housing 1.

[0059] Referring to Figures 1 and 7, in some embodiments, the housing 1 includes an inner shell 11 and an outer shell 12. The inner shell 11 has an inner cavity for defining the position of the medicine bottle 6 within the housing 1. It is understood that, in some specific examples, the inner cavity may be configured to fit the outer wall of the medicine bottle 6 so that the inner cavity of the inner shell 11 directly defines the position of the medicine bottle 6 within the housing 1; alternatively, the inner cavity may be set to be larger than the outer wall of the medicine bottle 6, and other components may be added between the inner cavity and the medicine bottle 6 to define the position of the medicine bottle 6 within the housing 1.

[0060] Referring to Figures 1 and 7, in some specific examples, the cartridge housing assembly also includes a cartridge support 4 that passes through the inner cavity of the inner shell 11. The cartridge support 4 is generally cylindrical in shape, and the outer wall size of the cartridge support 4 is adapted to the inner wall size of the inner shell 11, and the inner wall size of the cartridge support 4 is adapted to the outer wall size of the medicine bottle 6, thereby defining the position of the medicine bottle 6 in the shell 1.

[0061] Meanwhile, in some examples of the above embodiments, the limiting element 3 can be axially translated relative to the housing 1, specifically, the limiting element 3 and the housing 1 can form a direct or indirect axial guiding engagement.

[0062] Referring to Figure 7, the outer wall of the inner shell 11 and the inner wall of the outer shell 12 are connected by two symmetrical inner edges, such that the space between the inner shell 11 and the outer shell 12 is divided by the position of the inner edges into a first chamber 13 at the proximal end and a second chamber 14 at the distal end. The interval between the two symmetrically arranged inner edges forms two axial channels 15 between the first chamber 13 and the second chamber 14. Correspondingly, referring to Figure 8, the limiting element 3 is an axially extending strip structure, and the limiting element 3 includes a cylindrical body 31 and two symmetrically arranged axially extending arms 32. The axially extending arms 32 extend axially from the cylindrical body 31 towards the proximal end, and the axially extending arms 32 pass through the axial channels 15 from the second chamber 14 at the distal end to the first chamber 13 at the proximal end. The maximum position that the limiting element 3 can move towards the proximal end relative to the shell 1 is limited by the abutment of the inner edge against the proximal end face of the cylindrical body 31. In some specific examples, the axial guiding fit between the limiting element 3 and the shell 1 can be achieved by the cooperation of the axial delay arm and the axial channel 15.

[0063] Referring to Figure 1, in some more specific examples, the limiting element 3 indirectly forms an axial guiding engagement with the housing 1 via the cartridge holder 4. Referring to Figures 8 and 9, the proximal outer wall of the cartridge holder 4 has an axially extending axial guide groove 41. Correspondingly, the proximal inner wall of the housing 12 has an axial guide rib 121 that can be embedded in the axial guide groove 41. The engagement of the axial guide groove 41 and the axial guide rib 121 forms an axial guiding engagement between the cartridge holder 4 and the housing 1. Simultaneously, the outer wall of the section of the cartridge holder 4 between the proximal and distal ends has an outwardly radially extending guide boss 42. Correspondingly, the limiting element 3 includes two symmetrically arranged axially extending arms 32, each having a guide groove 321 that engages with the guide boss 42, thereby achieving an axial guiding engagement between the cartridge holder 4 and the limiting element 3. Furthermore, in this embodiment, the two ends of the guide groove 321 are closed in the extension direction to realize the farthest and nearest ends when the limiting element 3 and the cartridge holder 4 move relative to each other in the axial direction; at the same time, during the assembly of the sleeve holder and the limiting element 3, the two axial extension arms 32 of the limiting element 3 can move away from each other so that the guide boss 42 can be embedded in the guide groove 321.

[0064] It should be noted that the limiting element 3 can maintain the first position when the cartridge containing assembly is in an empty state, and can be moved from the first position to the second position by external force. This means that the limiting element 3 is directly or indirectly connected to the housing 1 in an elastic manner, so that the limiting element 3 can be maintained in the first position by elastic force, and when the limiting element 3 is subjected to external force, the elastic element in the elastic connection can undergo elastic deformation, allowing the limiting element 3 to change position.

[0065] Referring to Figures 1, 7 to 9, in some embodiments where the limiting element 3 is axially translated relative to the housing 1, the drug containing assembly further includes an elastic element 5, which is an axially extending linear spring. The distal end of the elastic element 5 abuts against the proximal end face of the inner housing 11, and the proximal end of the spring abuts against the outer wall boss 43 of the cartridge holder 4. The elastic force of the elastic element 5 is transmitted to the limiting element 3 through the abutment between the guide boss 42 on the cartridge holder 4 and the proximal end wall of the guide groove 321 of the axially extending arm 32 on the limiting element 3, so as to maintain the limiting element 3 in a first position relative to the housing 1. At the same time, when the limiting element 3 is subjected to an external force toward the distal end, the limiting element 3 drives the cartridge holder 4 to move toward the distal end and compresses the elastic element 5, so that the limiting element 3 can move from the first position to a second position closer to the distal end.

[0066] Further, referring to Figures 10 and 11, in some embodiments, the end cap 2 further includes a cover body 22 that covers the distal end of the housing 1. There are two elastic locking arms 21, each including a cantilever 211 extending axially from the cover body 22 towards the proximal end and a latch 212 located on the cantilever 211. Referring to Figures 3 to 5, for ease of subsequent description, the area where the cantilever 211 and latch 212 are located when the end cap 2 is installed at the distal end of the housing 1 is the engaging area; the limiting element 3 is sleeved around the elastic locking arms 21 of the end cap 2, and an axial guiding structure is provided between the limiting element 3 and the end cap 2 to guide the relative movement between the limiting element 3 and the end cap 2. Referring to Figures 10 and 12, the inner wall of the distal end of the limiting element 3 is provided with an axial groove 311. Correspondingly, the outer wall of the elastic locking arm 21 of the end cover 2 is provided with an axial protrusion 23 that cooperates with the axial groove 311. The axial guiding structure between the limiting element 3 and the end cover 2 is realized through the cooperation between the axial protrusion 23 and the axial groove 311.

[0067] Referring to Figures 4 and 5, the limiting element 3 includes a first section 33 and a second section 34 distributed along the axial direction. When the limiting element 3 is in the first position, the first section 33 of the limiting element 3 is located at the radial periphery of the engaging activity area, and the radial distance between the inner wall of the first section 33 and the elastic locking arm 21 is d3, where d3 ≥ D, allowing the elastic locking arm 21 to engage or disengage with the needle cap 7. When the limiting element 3 is in the second position, the second section 34 of the limiting element 3 is located at the radial periphery of the engaging activity area. Referring to Figure 12, the inner wall of the second section 34 is provided with a limiting part 341 corresponding to the position of the buckle 212. The limiting part 341 is configured as a protrusion extending radially inward, and the radial distance between the limiting part 341 and the elastic locking arm 21 is d, where d < D, preventing the elastic locking arm 21 from engaging or disengaging with the needle cap 7.

[0068] Referring to Figure 11, the latch 212 extends radially inward and includes a first surface 2121 and a second surface 2122 that are axially opposite each other. The first surface 2121 is closer to the cover 22 than the second surface 2122, and the second surface 2122 is inclined towards the cover 22 in the direction of radial extension of the latch 212. Correspondingly, referring to Figure 2, the proximal end face of the needle cap 7 serves as the engaging portion 71 that cooperates with the latch 212 to form an engaging connection. During the engagement connection between the needle cap 7 and the end cap 2, the elastic latch arm 21 of the end cap 2 approaches the needle cap 7, and the latch 212 on the cantilever 211 abuts against the outer wall of the needle cap 7, causing the cantilever 211 to undergo radial elastic deformation outward. When the latch 212 moves to the position corresponding to the engaging portion 71 of the needle cap 7, the cantilever 211 returns to its original position under the action of elastic restoring force, thereby enabling the latch 212 and the engaging portion 71 to cooperate to form an engaging connection. Furthermore, in some specific examples, the end cap 2 is also provided with a central post 24, the distal end face of the central post 24 serving as a positioning plane 241. The positioning plane 241 is used for the needle cap 7 to abut against each other to define the axial position of the end cap 2 and the needle cap 7. When the positioning plane 241 abuts against the needle cap 7, the buckle 212 and the engagement part 71 of the needle cap 7 are positioned correspondingly to achieve the engagement connection between the elastic locking arm 21 of the end cap 2 and the needle cap 7.

[0069] Furthermore, when the elastic locking arm 21 on the end cap 2 engages with the needle cap 7 to form a locking connection, the second surface 2122 of the latch 212 abuts against the engaging portion 71. When the user pulls the end cap 2 further away from the outer shell 12, the second surface 2122 of the latch 212 transmits force to the engaging portion 71 of the needle cap 7, thereby simultaneously pulling out the needle cap 7. Further, in some embodiments, the first surface 2121 is inclined away from the cap body 22 in the direction of the inward radial extension of the latch 212; this causes the reaction force of the first surface 2121 of the latch 212 from the engaging portion 71 of the needle cap 7 to be biased towards the inward radial direction, thus making it less likely for the elastic locking arm 21 to undergo radially outward elastic deformation. In other embodiments, to facilitate the injection molding and core pulling demolding of the end cap 2, the first surface 2121 can also be inclined towards the cap body 22 in the direction of the inward radial extension of the latch 212.

[0070] This application also discloses an injection device that allows the user to remove the end cap 2 from the distal end of the housing 1 while simultaneously removing the needle cap 7 from the distal end of the medicine bottle 6.

[0071] Specifically, the injection device includes a vial 6, a delivery assembly, and the aforementioned cartridge receiving assembly. The vial 6 is housed within the housing 1, and the needle cap 7 at the distal end of the vial 6 engages with the elastic locking arm 21 of the end cap 2 to form a locking connection. The delivery assembly is located within the housing 1 on the proximal side of the vial 6 and is used to push a movable piston to inject the medication in the vial from the needle into the patient's body. Simultaneously, the delivery assembly provides a holding force to maintain the restraining element 3 in a second position.

[0072] In some embodiments, the housing 1 of the injection device is an integral structure. In the actual assembly process, the end cap 2 and the limiting element 3 are first installed at the far end of the housing 1 to form the aforementioned cartridge receiving assembly, and at this time the cartridge receiving assembly is in an empty state. Then, the medicine bottle 6 is inserted into the housing 1 from the near end of the housing 1. Then, the pushing assembly is inserted into the housing 1 from the near end of the housing 1, and the pushing assembly during the installation process pushes the limiting element 3 from the first position to the second position. Finally, the near end of the housing 1 is closed to obtain the injection device.

[0073] In other embodiments, the housing 1 of the injection device has a split structure, that is, the housing 1 includes an upper shell and a lower shell that are connected. In the actual assembly process, the end cap 2 is installed at the far end of the lower shell, and the limiting element 3 is installed in the lower shell to form the aforementioned empty cartridge receiving assembly. At the same time, the pushing component is installed in the upper shell to form the upper assembly. Then, the medicine bottle 6 is inserted into the lower shell from the near end of the lower shell, and then the upper assembly is connected to the cartridge receiving assembly. During the connection process, the pushing component in the upper assembly pushes the limiting element 3 from the first position to the second position, and finally the injection device is obtained.

[0074] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A cartridge housing assembly for use in an injection device, characterized in that, include: The housing is used to contain the medicine bottle, and the distal end of the medicine bottle is connected to a needle cap that covers the needle tip; An end cap is detachably connected to the distal end of the housing, and the end cap includes an elastic locking arm that can engage with a needle cap to form a locking connection. A limiting element is located within the housing and is movable relative to the housing from a first position to a second position; Specifically, when the cartridge receiving assembly is in an empty state without containing a medicine bottle, the limiting element is maintained in a first position; when the cartridge receiving assembly is in an assembled state containing a medicine bottle and assembled into an injection device, the limiting element is maintained in a second position. When the limiting element is in the first position, the elastic locking arm is allowed to engage or disengage with the needle cap; when the limiting element is in the second position, the elastic locking arm is prevented from engaging or disengaging with the needle cap.

2. The cartridge case receiving assembly according to claim 1, characterized in that, The radial movement distance required for the elastic arm to undergo radial elastic deformation during the engagement or disengagement of the elastic arm and the needle cap is defined as D. The limiting element is provided with a limiting part, and the radial distance between the limiting part on the limiting element in the second position and the elastic arm is defined as d, where d < D.

3. The cartridge case receiving assembly according to claim 1, characterized in that, The end cap further includes a cover body that covers the distal end of the housing. The elastic latch arm includes a cantilever and a latch on the cantilever. The cantilever extends axially from the cover body toward the proximal end. The latch extends radially inward. The latch includes a first surface and a second surface that are axially opposite each other. The first surface is closer to the cover body than the second surface. The second surface is inclined toward the cover body in the direction of radial extension of the latch inward.

4. The cartridge case receiving assembly according to claim 3, characterized in that, The first surface is inclined toward the cover body in the direction of the inward radial extension of the buckle.

5. The cartridge case receiving assembly according to claim 3, characterized in that, The first surface is inclined in a direction away from the cover body in the direction that extends radially inward along the buckle.

6. The cartridge case receiving assembly according to claim 1, characterized in that, It also includes an elastic element for providing a holding force to maintain the limiting element in a first position, and the elastic element undergoes elastic deformation when the limiting element moves from the first position to a second position.

7. The cartridge case receiving assembly according to claim 1, characterized in that, The end cap is provided with a positioning plane, which is used to allow the needle cap to abut against each other to limit the axial position of the end cap and the needle cap. When the positioning plane abuts against the needle cap, the elastic locking arm and the needle cap form a locking connection.

8. The cartridge case receiving assembly according to claim 1, characterized in that, The limiting element in the first position is further away from the end cap than the limiting element in the second position.

9. The cartridge case receiving assembly according to claim 1, characterized in that, An axial guide structure is provided between the limiting element and the end cap, the axial guide structure being used to guide the limiting element and the end cap to move axially relative to each other.

10. An injection device, characterized in that, The device includes a vial, a push assembly, and a cartridge receiving assembly as described in any one of claims 1 to 9, wherein the vial is housed within the housing, and a needle cap at the distal end of the vial engages with the resilient locking arm of the end cap to form an engaging connection, the push assembly is located within the housing on the proximal side of the vial, and the push assembly is used to provide a holding force for maintaining the restraining element in a second position.

Images