Dosing device with maximum dose limitation

Abstract

A drug delivery device with maximum dose limitation comprises a shell, a dose cylinder used for setting dose is installed in the shell, a lens capable of observing dose setting is installed on the shell in a buckling mode, a blocking strip is arranged at the buckling portion of one side of the lens, and a limiting groove is formed in the other side of the lens. And the outer surface of the dose cylinder is provided with a stop part which can be matched with the barrier strip to limit the maximum dose setting. According to the invention, the barrier strip arranged on the lens is matched with the stop part of the dosage cylinder for limiting, so that the limiting reliability is ensured, that is, when the barrier strip is propped against the stop part, the dosage cylinder cannot continuously rotate to increase the dosage no matter how large the rotating force is applied.

Description

Technical Field

[0001] The present invention belongs to the technical field of drug delivery devices, and particularly relates to a drug delivery device with a maximum dose limit. Background Art

[0002] With the development of insulin pen technology, the current requirements for insulin pens already include: (1) capable of multiple small-dose injections, generally capable of injecting at least 5 times with a maximum single injection dose of (60 IU); (2) convenient for adjusting the single injection dose, with an adjustment range of 0 - 60 IU and high adjustment accuracy (up to 1 IU); (3) when adjusting the dose, it can be visually calibrated, or the pen can emit a sound to facilitate self-operation by patients with poor eyesight or even blindness; (4) during injection, the operation is simple, and the pen will also emit a sound during the injection process to indicate that the injection process is in progress.

[0003] CN117224781A discloses a drug delivery device with settable and callback doses, including a cartridge holder. The rear end of the cartridge holder is connected to a housing. A screw is installed in the housing and is used to move forward during injection to deliver the drug according to the set dose; a rotor, threadedly connected to the screw, is used to rotate and drive the screw to move axially forward during injection; a rotating shaft, the front end of which is connected to the inside of the rear end of the rotor, is used to drive the rotor to rotate during injection and can axially move relative to the rotor, and can cooperate with the screw to control the final dose setting during the axial movement; a differential nut, installed outside the rear end of the rotating shaft, is used for differential adjustment and driving the axial movement of the rotating shaft; a differential screw, fixed in the housing and arranged between the differential nut and the dose setting cylinder, is threadedly connected to both the differential nut and the dose setting cylinder; a dose setting cylinder, which can engage with the bushing and drive the bushing to rotate during injection, and is also used to drive the differential nut to rotate synchronously; a bushing, connected to the inside of the rear end of the rotating shaft, is used to drive the rotating shaft to rotate during injection. When setting the dose, when the dose setting cylinder moves, the meshing teeth on the dose setting cylinder and the meshing teeth on the bushing slide and cooperate to make a sound for dose setting, which is very unfriendly to users with inconvenient hearing, so the dose is easily exceeded the maximum dose during setting. And this patent does not involve the maximum single dose limit structure. Summary of the Invention

[0004] Aiming at the problems existing in the above background art introduction, the purpose of the present invention is to provide a drug delivery device with a maximum dose limit that can prevent over-dose setting and ensure the stability of dose setting.

[0005] The technical solution adopted by the present invention is:

[0006] A dosing device with a maximum dose limit, comprising a housing, a dose cylinder for setting the dose is installed inside the housing, a lens for observing the dose setting is snap-fitted on the housing, a stop bar is provided at a snap-fitting portion on one side of the lens, and a stop portion that can cooperate with the stop bar to limit the maximum dose setting is provided on the outer surface of the dose cylinder. In the present invention, the cooperation between the stop bar provided on the lens and the stop portion of the dose cylinder is used for limitation, ensuring the reliability of the limitation, that is, when the stop bar abuts against the stop portion, no matter how much rotational force is applied, the dose cylinder cannot continue to rotate to increase the dose.

[0007] Further, the stop bar extends along both ends of the snap-fitting portion, and the end of the snap-fitting portion protrudes from the side surface of the stop bar.

[0008] Further, the stop portion is provided with a groove for accommodating the snap-fitting portion. When the stop portion abuts against the stop bar, the snap-fitting portion enters the groove opening to ensure the reliability of the abutment.

[0009] Further, a screw, a rotor, a rotating shaft, a differential nut, a fixed cylinder, and a bushing are installed inside the housing. A push plate is installed at the front end of the screw. The rotor is threadedly connected to the screw and is used to rotate and drive the screw to move axially forward to convey the drug during injection, and can cooperate with the fixed cylinder to make an injection sound; the fixed cylinder is fixed inside the housing and is arranged between the differential nut and the dose cylinder. The fixed cylinder is threadedly connected to both the differential nut and the dose cylinder for differential adjustment, and is rotatably connected to the rotor and axially limits the rotor; the front end of the rotating shaft is connected to the inside of the rear end of the rotor and is used to drive the rotor to rotate during injection, and it can axially move relative to the rotor. The rotating shaft can cooperate with the screw to control the final dose setting during the axial movement process; the differential nut is installed inside the dose cylinder and can rotate synchronously with the dose cylinder and drive the rotating shaft to move axially; the bushing is connected to the inner side of the rear end of the differential nut and axially moves under the drive of the differential nut; a clutch tooth is installed between the bushing and the dose cylinder. The clutch tooth is fixedly connected to the bushing, and the clutch tooth is meshed with the dose cylinder. The clutch tooth can cooperate with the dose cylinder to make a dose setting sound during axial movement, and is meshed with the dose cylinder during injection and is driven by the dose cylinder to rotate synchronously with the bushing; a dose button for driving the dose cylinder to rotate is installed inside the rear end of the dose cylinder.

[0010] Further, protruding one-way ratchet teeth are provided on the outer surface of the rotor, and notches are evenly distributed in a ring on the inner ring of the fixed cylinder. The one-way ratchet teeth cooperate with the notches during rotation to make an injection sound.

[0011] Further, meshing teeth are evenly distributed axially on both the dose cylinder and the clutch tooth. When the dose cylinder rotates, the meshing teeth on the dose cylinder and the meshing teeth on the clutch tooth slide and cooperate to make a dose setting sound.

[0012] Further, the rotor is axially grooved-connected to the rotating shaft, the rotating shaft is axially grooved-connected to the bushing, and the differential nut is axially grooved-connected to the dosing cylinder. The rotating shaft is circumferentially ring-connected to the differential nut, and the differential nut is circumferentially ring-connected to the bushing.

[0013] Further, a flange is provided at the rear end of the screw, and a step is provided inside the front end of the rotating shaft. The flange and the step can be in contact and limit to control the final dose setting.

[0014] Further, a cover plate is fixedly installed at the end of the fixed cylinder. A return knob is meshed with the cover plate. The return knob is sleeved outside the screw. A return spring is provided between the return knob and the cover plate. When the return knob is disengaged from the meshed state, the screw can be driven to move back to its original position under the drive of the return spring.

[0015] Further, the outer shell is connected to the rear end of the cartridge holder. A medicine core is installed in the cartridge holder. A detachable pen cap is provided at the front end of the cartridge holder.

[0016] Compared with the prior art, the significant advantages of the present invention include:

[0017] 1. The dosing cylinder and the lens cooperate to limit the maximum dose setting;

[0018] 2. During the axial movement of the rotating shaft, it can cooperate with the screw to control the final dose setting and prevent sub-dose injection;

[0019] 3. The dose setting process and the injection process are realized through the cooperation of components between the dosing cylinder, the fixed cylinder, the differential nut, the rotating shaft, the bushing, and the rotor. The structure is simple and reasonable;

[0020] 4. The rotor and the fixed cylinder cooperate to inject and make a sound to remind the user of the injection dose;

[0021] 5. The dosing cylinder and the clutch teeth cooperate to make a sound to remind the user of the dose setting.

[0022] 6. After the screw is returned to its original position by the return knob, the medicine core can be replaced and used continuously. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is an exploded structural schematic diagram of the present invention.

[0024] Figure 2 is a sectional structural schematic diagram of the present invention in the natural state.

[0025] Figure 3 is a sectional structural schematic diagram of the present invention in the dose adjustment state.

[0026] Figure 4 is a sectional structural schematic diagram of the present invention in the dose injection state.

[0027] Figure 5 Schematic structural view of the lens and the dose cylinder when the maximum dose of the present invention is locked.

[0028] Figure 6 Schematic cross-sectional view of the lens and the dose cylinder when the maximum dose of the present invention is locked.

[0029] Figure 7 Schematic structural view of the dose cylinder of the present invention.

[0030] Figure 8 Schematic structural view of the lens of the present invention.

[0031] In the figure: 1. Differential nut; 2. Dose cylinder; 21. Stopping part; 22. Protruding teeth; 23. Groove; 3. Cartridge holder; 4. Rotor; 5. Dose button; 6. Clutch; 7. Injection spring; 8. Clutch teeth; 9. Screw; 10. Fixed cylinder; 11. Return spring; 12. Return knob; 13. Cover plate; 14. Bushing; 15. Rotating shaft; 16. Lens; 161. Buckling part; 17. Outer shell; 18. Pen cap; 19. Pusher plate; 20. Stop bar. Detailed implementation manners

[0032] The present invention will be further described below in conjunction with specific embodiments, but the present invention is not limited to these specific implementation manners. Those skilled in the art should recognize that the present invention covers all alternative solutions, improvement solutions, and equivalent solutions that may be included within the scope of the claims.

[0033] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "clockwise", "counterclockwise", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more, unless otherwise clearly defined.

[0034] In the present invention, unless otherwise clearly defined and limited, terms such as "installed", "connected", "joined", "fixed", etc. shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] In the present invention, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.

[0036] See Figure 1-8 , this embodiment provides a drug delivery device with a maximum dose limit, including a housing 17. A dose cylinder 2 for setting the dose is installed inside the housing 17. A lens 16 for observing the dose setting is snap-fitted on the housing 17. A stop bar 20 is provided at a snap-fitting portion 161 on one side of the lens 16. A stop portion 21 that can cooperate with the stop bar 20 to limit the maximum dose setting is arranged on the outer surface of the dose cylinder 2. In the present invention, by the cooperation between the stop bar 20 provided on the lens 16 and the stop portion 21 of the dose cylinder 2, the reliability of the limit is ensured, that is, when the stop bar 20 abuts against the stop portion 21, no matter how large a rotational force is applied, the dose cylinder 2 cannot continue to rotate to increase the dose. The stop bar 20 extends along both ends of the snap-fitting portion 161, and the ends of the snap-fitting portion 161 protrude from the side surface of the stop bar 20. The stop portion 21 is provided with a groove 23 for accommodating the snap-fitting portion 161. When the stop portion 21 abuts against the stop bar 20, the snap-fitting portion 161 enters the opening of the groove 23 to ensure the reliability of the abutment.

[0037] In this embodiment, the outer shell 17 is connected to the rear end of the cartridge holder 3. A medicated core is installed in the cartridge holder 3. A detachable pen cap 18 is provided at the front end of the cartridge holder 3. A screw 9, a rotor 4, a rotating shaft 15, a differential nut 1, a fixed cylinder 10, and a bushing 14 are installed in the outer shell 17. A push plate 19 is installed at the front end of the screw 9. The rotor 4 is threadedly connected to the screw 9 and is used to rotate and drive the screw 9 to axially move forward to convey the drug during injection, and can cooperate with the fixed cylinder 10 to inject and generate sound. The fixed cylinder 10 is fixed in the outer shell 17 and is disposed between the differential nut 1 and the dose cylinder 2. The fixed cylinder 10 is threadedly connected to both the differential nut 1 and the dose cylinder 2 for differential adjustment, is rotatably connected to the rotor 4 and axially limits the rotor 4. The front end of the rotating shaft 15 is connected to the rear end inside the rotor 4 and is used to drive the rotor 4 to rotate during injection, and can axially move relative to the rotor 4. The rotating shaft 15 can cooperate with the screw 9 to control the final dose setting during the axial movement process. The differential nut 1 is installed inside the dose cylinder 2 and can rotate synchronously with the dose cylinder 2 and can drive the rotating shaft 15 to axially move. The bushing 14 is connected to the inner side of the rear end of the differential nut 1 and axially moves driven by the differential nut 1. A clutch tooth 8 is installed between the bushing 14 and the dose cylinder 2. The clutch tooth 8 is fixedly connected to the bushing 14. The clutch tooth 8 is meshingly connected to the dose cylinder 2. The clutch tooth 8 can cooperate with the dose cylinder 2 to generate sound for dose setting during axial movement, and is meshed with the dose cylinder 2 during injection, and then the dose cylinder 2 drives the clutch tooth 8 and the bushing 14 to rotate synchronously. A dose button 5 capable of driving the dose cylinder 2 to rotate is installed inside the rear end of the dose cylinder 2. An injection spring 7 is provided between the dose button 5 and the bushing 14.

[0038] In this embodiment, a clutch 6 is provided between the dose button 5 and the dose cylinder 2. A protruding tooth 22 is provided at the end of the dose cylinder 2. An engaging internal tooth that cooperates with the protruding tooth 22 is provided inside the clutch 6. A ratchet tooth is provided on the clutch 6. An inner ring ratchet tooth that cooperates with the ratchet tooth is provided in a circle inside the dose button 5. The dose button 5 is circumferentially and annularly connected to the clutch 6. When the engaging internal tooth meshes with the protruding tooth 22, rotating the dose button 5 can drive the dose cylinder 2 to rotate to achieve dose adjustment. During injection, the clutch 6 is separated from the dose cylinder 2, and the dose cylinder 2 can freely rotate to achieve dose injection. When the dose cylinder 2 cannot rotate after the drug is injected, due to the provision of the clutch 6, continuing to rotate the dose button 5 and the clutch 6 will spin in place. Thus, no matter how much force is applied, the force is unloaded by the clutch 6 and cannot break through the resistance to continue to achieve dose setting, thereby controlling the incorrect setting of the dose.

[0039] Specifically, the outer surface of the rotor 4 in this embodiment is provided with protruding one-way ratchet teeth. The inner ring of the fixed cylinder 10 is evenly provided with notches. The one-way ratchet teeth cooperate with the notches during rotation to inject and generate sound. The one-way ratchet teeth limit the rotation direction of the rotor 4 to only rotate counterclockwise. It is possible to set that each rotation of a unit will emit a prompt sound to remind the user of the injection dose. The meshing teeth are evenly arranged axially on both the dose cylinder 2 and the clutch teeth 8. When the dose cylinder 2 rotates, the meshing teeth on the dose cylinder 2 and the meshing teeth on the clutch teeth 8 are in sliding fit for dose setting and sound generation. The rotor 4 is axially grooved-connected to the rotating shaft 15, the rotating shaft 15 is axially grooved-connected to the bushing 14, and the differential nut 1 is axially grooved-connected to the dose cylinder 2. The rotating shaft 15 is circumferentially ring-connected to the differential nut 1, and the differential nut 1 is circumferentially ring-connected to the bushing 14. Among them, the axial groove connection is a structure in which a rib or rib platform cooperates with a long strip-shaped groove, and the circumferential ring connection of two sections is a structure in which a ring rib or ring platform cooperates with a ring groove or ring rib. The circumferential ring connection between the rotor 4 and the fixed cylinder 10 restricts the axial movement of the rotor 4, and the rotor 4 can rotate relative to the fixed cylinder 10. The circumferential ring connection between the rotating shaft 15 and the differential nut 1 drives the rotating shaft 15 to move axially through the differential nut 1, and the rotating shaft 15 and the differential nut 1 can rotate relative to each other. The rear end of the screw 9 is provided with a flange, and the front end inside of the rotating shaft 15 is provided with a step. The flange and the step can be in contact for limit control of the final dose setting.

[0040] In this embodiment, a cover plate 13 is fixedly installed at the end of the fixed cylinder 10. A return knob 12 is meshingly connected to the cover plate 13. The return knob 12 is sleeved outside the screw 9. A return spring 11 is arranged between the return knob 12 and the cover plate 13. When the return knob 12 is disengaged from the meshing state, it can drive the screw 9 to move back to its original position under the drive of the return spring 11.

[0041] When adjusting the dose of the present invention: Rotate the dose knob 5, and the dose cylinder 2 and the differential nut 1 will rotate synchronously and move upward, and the bushing 14, the clutch teeth 8, and the rotating shaft 15 will move upward at the same time. At this time, the clutch teeth 8 will jump and make a sound (in the natural state, the clutch teeth 8 and the dose cylinder 2 are in a biting state). When the single maximum dose is adjusted, the rotation of the dose cylinder 2 is blocked by the blocking strip 20 on the lens 16.

[0042] When injecting the dose of the present invention: Press the dose knob 5, and the clutch 6 will disengage from the dose cylinder 2. The three teeth of the rotating shaft 15, the clutch teeth 6, and the dose cylinder 2 will bite. At this time, the rotating shaft 15, the clutch teeth 6, the differential nut 1, and the bushing 14 will rotate and move downward along with the dose cylinder 2. The bushing 14 will drive the rotor 4 to rotate, and the rotation of the rotor 4 causes the screw 9 to move axially forward.

[0043] When replacing the medicine core of the present invention: after removing the medicine core, the teeth of the knob 12 and the teeth of the cover plate 13 are disengaged from the engagement. The knob 12 can be rotated freely. When rotating, the screw rod 9 is driven to rotate and can return to its original position. After reaching the position, install the medicine core and it can be used again.

[0044] The dose cylinder 2 of the present invention cooperates with the lens 16 to define the maximum dose setting; the rotating shaft 15 can cooperate with the screw rod 9 during the axial movement to control the final dose setting and prevent sub-dose injection; the dose setting process and the injection process are realized through the cooperation of the components between the dose cylinder 2, the fixed cylinder 10, the differential nut 1, the rotating shaft 15, the bushing 14, and the rotor 4, and the structure is simple and reasonable; the rotor 4 cooperates with the fixed cylinder 10 to make a sound during injection to remind the user of the injection dose; the dose cylinder 2 cooperates with the clutch teeth 8 to make a sound to remind the user of the dose setting. After returning the screw rod 9 to its original position by retracting the knob 12, replace the medicine core and continue to use.

Claims

1. A drug delivery device with a maximum dose limit, comprising a housing (17), a dose cartridge (2) for setting a dose being mounted in the housing (17), and a lens (16) for observing the dose setting being mounted on the housing (17), characterized in that: A stopper (20) is provided at a buckling portion (161) on one side of the lens (16), and a stopper (21) capable of cooperating with the stopper (20) to limit a maximum dose setting is provided on the outer surface of the dose barrel (2).

2. A drug delivery device with a maximum dose limit according to claim 1, characterized in that: The blocking bar (20) is provided with the buckling portion (161) extending along both ends, and the end of the buckling portion (161) protrudes from the side surface of the blocking bar (20).

3. A drug delivery device with a maximum dose limit according to claim 2, characterized in that: The stopper (21) is provided with a groove (23) for accommodating the buckle portion (161); when the stopper (21) abuts against the stop bar (20), the buckle portion (161) enters the opening of the groove (23).

4. A drug delivery device with a maximum dose limit according to claim 1, characterized in that: The housing (17) is provided with a screw (9), a rotor (4), a rotating shaft (15), a differential nut (1), a fixed cylinder (10), and a bushing (14). A push plate (19) is installed at the front end of the screw (9). The rotor (4) is threadedly connected to the screw (9) for rotating and driving the screw (9) to move axially forward to deliver the drug during injection, and can cooperate with the fixed cylinder (10) to produce injection sound. The fixed cylinder (10) is fixed in the housing (17) and arranged between the differential nut (1) and the dosage cylinder (2). The fixed cylinder (10) is threadedly connected to the differential nut (1) and the dosage cylinder (2) for differential adjustment, and is rotationally connected to the rotor (4) and axially limits the rotor (4). The front end of the rotating shaft (15) is connected to the rear end of the rotor (4) for driving the rotor (4) to rotate during injection, and can move axially relative to the rotor (4). The shaft (15) can cooperate with the screw (9) to control the final dose setting during the axial movement; the differential nut (1) is installed on the inner side of the dose barrel (2) and can rotate synchronously with the dose barrel (2) and can drive the rotating shaft (15) to move axially; the bushing (14) is connected to the inner side of the rear end of the differential nut (1) and moves axially under the drive of the differential nut (1); a clutch tooth (8) is installed between the bushing (14) and the dose barrel (2), the clutch tooth (8) is fixedly connected to the bushing (14), the clutch tooth (8) is meshed with the dose barrel (2), the clutch tooth (8) can cooperate with the dose barrel (2) to make a sound when moving axially, and mesh with the dose barrel (2) during injection and is driven by the dose barrel (2) to rotate synchronously with the bushing (14); a dose button (5) that can drive the dose barrel (2) to rotate is installed in the rear end of the dose barrel (2).

5. A drug delivery device with a maximum dose limit according to claim 4, characterized in that: The outer surface of the rotor (4) is provided with protruding one-way ratchets, and the inner ring of the fixed cylinder (10) is provided with evenly distributed notches, and the one-way ratchets cooperate with the notches to produce injection sound during the rotation process.

6. A drug delivery device with a maximum dose limit according to claim 4, characterized in that: The dosage barrel (2) and the clutch tooth (8) are evenly provided with meshing teeth in the axial direction, and when the dosage barrel (2) rotates, the meshing teeth on the dosage barrel (2) and the meshing teeth on the clutch tooth (8) slide and cooperate with each other to produce a dosage setting sound.

7. A drug delivery device with a maximum dose limit according to claim 4, characterized in that: The rotor (4) and the rotating shaft (15), the rotating shaft (15) and the bushing (14), and the differential nut (1) and the dosage barrel (2) are all connected by axial grooves, and the rotating shaft (15) and the differential nut (1), and the differential nut (1) and the bushing (14) are all connected by circumferential rings.

8. A drug delivery device with a maximum dose limit according to claim 4, characterized in that: The rear end of the screw (9) is provided with a flange, and the front end of the rotating shaft (15) is provided with a step. The flange and the step can contact and limit to control the final dose setting.

9. A drug delivery device with a maximum dose limit according to claim 4, characterized in that: A cover plate (13) is fixedly mounted on the end of the fixed cylinder (10), and a retraction knob (12) is meshedly connected to the cover plate (13). The retraction knob (12) is sleeved outside the screw rod (9), and a retraction spring (11) is arranged between the retraction knob (12) and the cover plate (13). When the retraction knob (12) is out of meshing state, the screw rod (9) can be driven by the retraction spring (11) to move back to its original position.

10. A drug delivery device with a maximum dose limit according to claim 1, characterized in that: The housing (17) is connected to the rear end of the pen core frame (3), a medicine core is installed in the pen core frame (3), and a detachable pen cap (18) is provided at the front end of the pen core frame (3).

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