Upper pen barrel assembly of injection pen and injection pen

Abstract

The present invention discloses an upper pen barrel assembly of an injection pen and an injection pen, comprising: an upper pen barrel; a dosage adjustment mechanism; a rotating wheel of a driving mechanism located between a driving wheel and a power rod, the inner ring of the rotating wheel being threadedly connected to a screw, the outer ring being able to rotate relative to the upper pen barrel, being connected to a sleeve circumferentially and being able to move relative to the sleeve along an axial direction; the driving wheel and the sleeve being circumferentially limited and rotating, the driving wheel and the screw being circumferentially limited, and the driving wheel and the bottle holder cover being relatively rotatable; the driving wheel and the sleeve being relatively rotating, the bottle holder cover being circumferentially limited to the driving wheel, and the driving wheel circumferentially limiting the screw to rotate with the rotating wheel. In adjusting the dosage of the injection drug, the screw and the sleeve can ensure the stability of the position under the support of the power rod, the bottle holder cover and the rotating wheel, and the rotating wheel can move axially toward the direction close to the button, so that a spacing is generated between the rotating wheel and the upper pen barrel along the axial direction, further improving the stability of the screw position and the stability of the sleeve rotation.

Description

Technical Field

[0001] The invention relates to the technical field of injection pens, in particular to an upper pen barrel component of an injection pen and the injection pen. Background Art

[0002] Insulin injection therapy is the most commonly used treatment method in clinical work, and injection pens for insulin injection have been developed. Injection pen products are divided into reusable injection pens and disposable injection pens. The drug reservoir of a reusable injection pen can be reused and the injection dose can be accurately adjusted by simply replacing the cartridge containing insulin. The disposable injection pen is a "drug-device-in-one" product, and the drug reservoir of the pen body cannot be disassembled. The disposable injection pens currently on the market can be divided into adjustable, quantitative, etc., and can also be divided into automatic and manual types.

[0003] In addition to insulin injections, injection pens can also be used to inject other drugs.

[0004] The injection pen includes an upper pen barrel assembly and a lower pen cap assembly. The upper pen barrel assembly includes a button mechanism, a dose adjustment mechanism and a transmission mechanism. The lower pen cap assembly is used to install a cartridge bottle. Kinetic energy can be stored by operating the dose adjustment mechanism. When the button mechanism is pressed, the kinetic energy stored in the dose adjustment mechanism can be released, and the stopper of the cartridge bottle is pushed by the driving mechanism to achieve drug injection.

[0005] The gap between the sleeve of the current dosage adjustment mechanism and the screw of the transmission mechanism is relatively large, which affects the stability of the sleeve during rotation and the stability of the screw during pushing the stopper of the cartridge bottle, and is not conducive to the use of the injection pen.

[0006] Therefore, how to provide an upper pen barrel assembly for an injection pen to improve the stability of the injection pen during use is a technical problem that needs to be urgently solved by those skilled in the art. Summary of the invention

[0007] In view of this, the present invention provides an upper pen barrel assembly of an injection pen to improve the stability of the injection pen during use. In addition, the present invention also provides an injection pen having the upper pen barrel assembly.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] An upper pen barrel assembly of an injection pen, characterized by comprising:

[0010] An upper pen holder, wherein the upper pen holder is a hollow part;

[0011] A dose adjustment mechanism, the dose adjustment mechanism is used to adjust the dose of the drug to be injected, and the dose adjustment mechanism includes a power rod, a barrel, a sleeve and a torsion spring arranged inside the upper pen barrel; wherein the power rod can rotate relative to the upper pen barrel and can move relative to the upper pen barrel along the axial direction of the upper pen barrel; the barrel is sleeved on the outside of the power rod, and the power rod rotates relative to the barrel, and the barrel is fixed relative to the upper pen barrel; the upper end of the sleeve is circumferentially limitedly connected to the power rod, and the sleeve can move relative to the axial direction of the upper pen barrel; one end of the torsion spring is relatively fixed to the upper pen barrel, and the other end of the torsion spring is connected to the lower end of the sleeve;

[0012] A driving mechanism, the driving mechanism comprising a screw, a bottle holder cover, a rotating wheel and a driving wheel, wherein the screw is located at the lower end of the interior of the upper pen barrel, and the screw and the power rod are arranged along the axial direction of the upper pen barrel; the lower end of the sleeve is sleeved on the outside of the screw, and there is a gap between the sleeve and the screw in the radial direction; the driving wheel is sleeved on the screw, and the bottle holder cover is sleeved on the outside of the driving wheel, and when the sleeve moves to a preset position along the axial direction of the upper pen barrel, the sleeve and the driving wheel can be circumferentially limited and connected;

[0013] The rotating wheel is located between the driving wheel and the power rod, and the inner ring of the rotating wheel is threadedly connected to the screw, and the outer ring of the rotating wheel can rotate relative to the upper pen barrel; the rotating wheel is circumferentially limited and connected to the lower end of the sleeve, and the rotating wheel can produce a displacement along the axis direction of the upper pen barrel relative to the sleeve; during the circumferentially limited connection and rotation of the driving wheel and the sleeve, the driving wheel and the screw are circumferentially limited, and the driving wheel and the bottle rack cover can rotate relative to each other; during the relative rotation of the driving wheel and the sleeve, the bottle rack cover and the driving wheel are circumferentially limited, and the driving wheel circumferentially limits the screw to rotate with the rotating wheel.

[0014] Preferably, in the above-mentioned upper pen barrel assembly, the inner wall of the driving wheel and the screw are unidirectionally stuck in the circumferential direction, the outer wall of the driving wheel and the bottle rack cover are unidirectionally stuck in the circumferential direction, and the bottle rack cover and the screw limit the driving wheel in opposite directions.

[0015] Preferably, in the above-mentioned upper pen barrel assembly, the inner wall of the bottle holder cover has ratchet teeth, and the driving wheel has a limiting protrusion for unidirectionally locking with the ratchet teeth.

[0016] Preferably, in the above-mentioned upper pen barrel assembly, the inner wall of the driving wheel has a wedge block, the circumference of the screw has a plurality of arcuate threads, and a wedge groove is formed between the circumferentially adjacent arcuate threads, the wedge block is used to be clamped in the wedge groove, and one side surface of the wedge groove along the circumference can be restrained and limited by the wedge block, and the other side surface can guide the movement of the wedge block.

[0017] Preferably, in the above-mentioned upper pen barrel assembly, the driving wheel comprises:

[0018] A driving wheel body, the driving wheel body is used to be sleeved on the screw rod, and the inner wall of the driving wheel body has the wedge block; the lower end of the inner part of the sleeve has first gear teeth arranged along the circumferential direction, and the outer ring of the driving wheel body is provided with second gear teeth; when the sleeve moves along the axial direction of the upper pen barrel to a preset position, the first gear teeth mesh with the second gear teeth;

[0019] The wheel edge is arranged on the outer ring of the driving wheel body and is located on a side of the driving wheel body away from the rotating wheel, and the limiting protrusion is arranged on the wheel edge.

[0020] Preferably, in the above-mentioned upper pen barrel assembly, the rotating wheel comprises:

[0021] The inner ring is threadedly connected to the screw;

[0022] The outer ring is rotatable relative to the upper pen barrel, and a gap is formed between the inner ring and the outer ring in a radial direction;

[0023] A connecting section connects the outer ring and the inner ring, and an accommodating space is formed between the connecting section, the inner ring and the outer ring.

[0024] Preferably, in the above-mentioned upper pen barrel assembly, the sleeve includes: arc segments arranged along the circumferential direction, the arc segments are sleeved on the outer side of the screw, and limiting grooves extending along the axial direction of the upper pen barrel are formed between the circumferentially adjacent arc segments, the connecting section is used to be inserted into the limiting groove and can move along the axial direction of the limiting groove, and the arc segment can be inserted into the accommodating space.

[0025] Preferably, in the above-mentioned upper pen barrel assembly, the bottle rack cover is sleeved on the outside of the rotating wheel, and the rotating wheel is threadedly connected to the bottle rack cover, and the bottle rack cover is circumferentially limitedly connected to the upper pen barrel; or in the above-mentioned upper pen barrel assembly, the rotating wheel is threadedly connected to the upper pen barrel, and the bottle rack cover and the rotating wheel are arranged along the circumference of the upper pen barrel.

[0026] Preferably, in the above-mentioned upper pen barrel assembly, the dosage adjustment mechanism further comprises:

[0027] A knob, which is sleeved on the upper end of the upper pen barrel and can rotate relative to the upper pen barrel, and is used to adjust the rotation position of the sleeve;

[0028] The scale plate is sleeved on the outside of the sleeve and can rotate synchronously with the sleeve. During the rotation of the scale plate, the scale plate can move relative to the sleeve along the axis direction of the upper pen barrel. The upper pen barrel has a display window for displaying the scale on the scale plate.

[0029] An injection pen, comprising an upper pen barrel assembly and a lower pen cap assembly, wherein the upper pen barrel assembly is the upper pen barrel assembly described in any one of the above items;

[0030] The lower end of the upper pen barrel of the upper pen barrel assembly is connected to the lower pen cap assembly, and the lower pen cap assembly is used to install a medicine cartridge bottle.

[0031] An upper pen barrel assembly of an injection pen is disclosed in an embodiment of the present invention. By adding a rotating wheel, the screw and sleeve of the injection pen can ensure position stability under the support of a power rod, a bottle holder cover and a rotating wheel during the process of adjusting the injection drug dosage. That is, the screw and the sleeve have three fulcrums coordinated in the axial direction to reduce the shaking of the screw and the sleeve. In addition, during the process of adjusting the injection drug dosage, the rotating wheel can move axially toward a button, so that a spacing is generated between the rotating wheel and the upper pen barrel in the axial direction, further improving the stability of the screw position and the stability of the sleeve rotation. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 It is a front view of the injection pen disclosed in an embodiment of the present invention;

[0034] Figure 2 It is a disassembled diagram of the upper pen barrel assembly of the injection pen disclosed in the embodiment of the present invention;

[0035] Figure 3 for Figure 2 Further decomposition diagram of the local structure in the figure;

[0036] Figure 4 for Figure 3 Further decomposition diagram of the local structure in the figure;

[0037] Figure 5 for Figure 4 Further decomposition diagram of the local structure in the figure;

[0038] Figure 6 for Figure 4 A progressive decomposition diagram of another local structure in the;

[0039] Figure 7 It is a front view of the upper pen barrel assembly of the injection pen disclosed in the embodiment of the present invention;

[0040] Figure 8 for Figure 7 Sectional view in the AA direction;

[0041] Fig. 9 It is a structural schematic diagram of a sleeve of an upper pen barrel assembly disclosed in an embodiment of the present invention;

[0042] Fig.10 It is a structural schematic diagram of a bottle holder cover of an upper pen holder assembly disclosed in an embodiment of the present invention;

[0043] Fig.11 It is a structural schematic diagram of the rotating wheel of the upper pen holder assembly disclosed in an embodiment of the present invention;

[0044] Fig.12 It is a schematic structural diagram of a driving wheel of an upper pen holder assembly disclosed in an embodiment of the present invention;

[0045] Fig.13 The present invention is an assembly diagram of a driving wheel, a bottle holder cover and a screw rod of an upper pen barrel assembly disclosed in an embodiment of the present invention. DETAILED DESCRIPTION

[0046] The invention discloses an upper pen barrel assembly of an injection pen, so as to improve the stability of the injection pen during use. In addition, the invention also discloses an injection pen having the upper pen barrel assembly.

[0047] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0048] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0049] Insulin injection therapy is the most commonly used treatment method in clinical work, and injection pens for insulin injection have been developed. Injection pen products are divided into reusable injection pens and disposable injection pens. The drug reservoir of a reusable injection pen can be reused and the injection dose can be accurately adjusted by simply replacing the cartridge containing insulin. The disposable injection pen is a "drug-device-in-one" product, and the drug reservoir of the pen body cannot be disassembled. The disposable injection pens currently on the market can be divided into adjustable, quantitative, etc., and can also be divided into automatic and manual types.

[0050] In addition to insulin injections, injection pens can also be used to inject other drugs.

[0051] The injection pen includes an upper pen barrel assembly and a lower pen cap assembly. The upper pen barrel assembly includes a button mechanism, a dose adjustment mechanism and a transmission mechanism. The lower pen cap assembly is used to install a cartridge bottle. Kinetic energy can be stored by operating the dose adjustment mechanism. When the button mechanism is pressed, the kinetic energy stored in the dose adjustment mechanism can be released, and the stopper of the cartridge bottle is pushed by the driving mechanism to achieve drug injection.

[0052] In this document, the side where the button mechanism of the injection pen is located is defined as the upper side, and correspondingly, the injection end of the injection pen or the side close to the injection site when in use is defined as the lower side, the length direction of the injection pen is defined as the axial direction, the side close to the center of the injection pen is defined as the inner side, and correspondingly, the side away from the center of the injection pen is defined as the outer side. It can be understood that the use of the above-mentioned directional words is only for the convenience of description and understanding, and does not constitute a limitation on the scope of protection.

[0053] The following combination Figures 1 to 8 The basic structure and operating principle of the injection pen 1000 are described.

[0054] The injection pen 1000 includes an upper pen barrel assembly 100 and a lower pen cap assembly 200 .

[0055] The upper pen barrel assembly 100 includes an upper pen barrel 10, a button mechanism 30, a dosage adjustment mechanism 20 and a driving mechanism 40. The button mechanism 30, the dosage adjustment mechanism 20 and the driving mechanism 40 are sequentially arranged along the axis of the injection pen 1000 from the upper end to the lower end. The upper pen barrel 10 forms the external structure of the injection pen 1000, and the lower end of the upper pen barrel 10 is used for threaded connection with the lower pen cap assembly 200; the dosage adjustment mechanism 20 includes a knob 21 that forms the external structure of the injection pen 1000, and the lower end of the knob 21 is rotatably connected to the upper end of the upper pen barrel 10, for adjusting the injection amount; the button mechanism 30 includes a button 31 that forms the external structure of the injection pen 1000, and the button 31 is connected to the upper end of the knob 21, and the button 31 can move relative to the axial direction of the upper pen barrel 10 to achieve injection of the drug.

[0056] The lower pen cap assembly 200 has a bottle holder for detachably mounting a cartridge bottle. The lower end of the upper pen barrel 10 is sheathed on the upper end of the bottle holder. It should be noted that the cartridge bottle is a container for storing drugs, which is essentially not part of the composition of the injection pen 1000 and is used in conjunction with the injection pen 1000. In application, the cartridge bottle is a replaceable component.

[0057] The button mechanism 30 includes a button 31 , a button housing 32 and a return spring 33 .

[0058] The button 31 is mounted on the button housing 32 and can move relative to the button housing 32 in a direction close to the dose adjustment mechanism 20, and during the movement of the button 31, the reset spring 33 is squeezed, so that the reset spring 33 is elastically deformed. Exemplarily, the button housing 32 is a cylindrical structure, the button 31 is mounted on the upper end of the button housing 32 and can move along the axis of the button housing 32, one end of the reset spring 33 is against or fixedly connected to the button 31, and after the external force applied to the button 31 by the user is cancelled, the button 31 can be reset under the action of the reset spring 33.

[0059] The dose adjustment mechanism 20 includes a knob 21 , a stop bracket 22 , a torsion spring bracket 23 , a dial 24 , a sleeve 25 , a torsion spring 26 , a cylinder 27 and a power rod 28 .

[0060] The upper end of the knob 21 is rotatably mounted on the outside of the button housing 32, and the lower end of the knob 21 is rotatably mounted on the upper pen holder 10, and the surface of the upper pen holder 10 has a display window 111. The upper end of the portion of the knob 21 used to form the accommodating space extends into the button 31 of the button mechanism 30, and the return spring 33 is mounted on the outside of the portion of the knob 21 used to form the accommodating space.

[0061] The stop bracket 22 is sleeved inside the knob 21 , and part of the torsion spring bracket 23 is sleeved inside the knob 21 . In some embodiments, the stop bracket 22 is circumferentially limitedly connected to the knob 21 , and the torsion spring bracket 23 is fixed relative to the upper pen holder 10 .

[0062] In some embodiments, the torsion spring bracket 23 is connected to the stop bracket 22 in a limiting manner. Specifically, the stop bracket 22 can only rotate in one direction relative to the torsion spring bracket 23, but cannot rotate in the reverse direction. In the structural configuration of the injection pen 1000, the stop bracket 22 can rotate forward relative to the torsion spring bracket 23, but cannot rotate in the reverse direction. Exemplarily, the limiting structure between the stop bracket 22 and the torsion spring bracket 137 can be a one-way ratchet ratchet matching structure.

[0063] It can be understood that the reverse rotation of the power rod 28 and the sleeve 25 refers to a rotation in the opposite direction to the aforementioned rotation toward the direction of setting the injection dose, and the reverse rolling of the ball is also a rolling in the opposite direction to the previous direction.

[0064] The power rod 28 is arranged along the axial direction of the injection pen 1000, and the barrel 27 is fitted over the power rod 28. A spiral channel extending along the axial direction of the power rod 28 is formed between the inner barrel wall of the barrel 27 and the outer rod wall of the power rod 28, and the ball is rollably arranged in the spiral channel. The barrel 27 is fixed relative to the upper pen barrel 10, and the power rod 28 rotates relative to the barrel 27. During the relative rotation of the two, the power rod 28 moves along the axial direction of the power rod 28. Specifically, the ball and the threaded channel form a ball screw structure, so that during the rotation of the power rod 28 relative to the barrel 27, the power rod 28 and the barrel 27 move in the axial direction. This part of the content can be referred to the existing known methods, and will not be repeated here.

[0065] The torsion spring bracket 23 is outer-mounted on the cylinder 27, and the torsion spring bracket 23 is relatively fixed to the upper pen barrel 10. The cylinder 27 can be relatively fixed to the upper pen barrel 10 by being relatively fixed to the torsion spring bracket 23. Exemplarily, the relative fixing method of the torsion spring bracket 23 and the upper pen barrel 10 and the relative fixing method of the cylinder 27 and the torsion spring bracket 23 can both adopt the method of clamping structure clamping, which is convenient for disassembly and assembly and is conducive to maintenance.

[0066] The sleeve 25 is arranged along the axis of the injection pen 1000, and the upper end of the sleeve 25 is inserted into the interior of the power rod 28. It can be understood that the power rod 28 is sleeved on the outer side of the upper end of the sleeve 25. The upper end of the power rod 28 abuts against the button 31 and is circumferentially limitedly connected to the knob 21. The lower surface of the power rod 28 abuts against the radial step of the sleeve 25. The lower end of the sleeve 25 is used to install the drive mechanism 40.

[0067] The sleeve 25 is connected to the power rod 28 in a circumferentially limited manner. In other words, the power rod 28 and the sleeve 25 cannot rotate relative to each other, but can rotate together. Under the action of external force, the power rod 28 can rotate relative to the cylinder 27 and drive the sleeve 25 to rotate together. The upper end of the torsion spring 26 is relatively fixed to the torsion spring bracket 23, and the lower end of the torsion spring 26 is connected to the sleeve 25. The connection method between the torsion spring 26 and the sleeve 25 includes but is not limited to a limited connection. The degree of rotation of the sleeve 25 driven by the power rod 28 determines the energy storage size of the torsion spring 26, and the energy storage size of the torsion spring 26 is related to the stroke of the drive mechanism 40 pushing the bottle stopper downward, that is, it is related to the dose of the drug injection.

[0068] The dial 24 is sleeved on the outer side of the upper end portion of the sleeve 25 and the outer side of the torsion spring bracket 23, and the dial 24 and the sleeve 25 are circumferentially limited so that the dial 24 can rotate with the sleeve 25, so that the user can determine the adjusted dosage size through the scale on the dial 24 displayed in the display window 111.

[0069] In combination with the connection relationship of the above-mentioned dosage adjustment mechanism 20, the dosage adjustment process of the injection pen 1000 is described below:

[0070] When the user applies external force to rotate the knob 21, the knob 21 transmits power to the power rod 28, causing the power rod 28 to rotate in the direction of the set injection dosage. During the rotation of the power rod 28, the sleeve 25 can be driven to rotate together, but the cylinder 27 does not rotate, so that the ball can roll in one direction along the spiral channel between the power rod 28 and the cylinder 27. Since the upper end of the torsion spring 26 is relatively fixed to the upper pen barrel 10 through the torsion spring bracket 23, and the lower end of the torsion spring 26 is connected to the sleeve 25, the lower end of the torsion spring 26 rotates with the sleeve 25 to store energy; when the torsion spring 26 rotates to the required injection dosage position, the user stops rotating, and under the action of the circumferential one-way locking of the stop bracket 22 and the torsion spring bracket 23, the power rod 28, the sleeve 25 and the torsion spring 26 can be maintained in this position.

[0071] After adjusting the dosage, the stored energy of the torsion spring 26 can be released by operation, that is, by pressing the button 31, so that the power rod 28 moves toward the lower end along the axis. During the movement of the power rod 28 toward the lower end, the sleeve 25 will be pushed to move toward the lower end, so that the dial 24 and the torsion spring bracket 23 are driven by the torsion spring 26 to move toward the lower end synchronously, so that the stop bracket 22 and the torsion spring bracket 23 are separated in the axial direction, thereby releasing the position lock of the power rod 28, the sleeve 25 and the torsion spring 26. When the power rod 28 and the sleeve 25 rotate in the reverse direction, the cylinder 27 does not move, so that the ball can roll in the reverse direction and reset.

[0072] The above describes the structure of the medication dosage adjustment of the injection pen 1000 . The following describes the specific structure of the driving mechanism 40 involved in the injection process of the injection pen 1000 .

[0073] The driving mechanism 40 includes a bottle holder cover 41 , a rotating wheel 42 , a driving wheel 43 , a screw washer 44 and a screw 45 .

[0074] Among them, Fig.10 As shown, the bottle holder cover 41 includes a barrel section 411 and a barrel bottom section 412 .

[0075] The barrel section 411 is a cylindrical structure, and the inner wall has a thread for engaging with the outer surface of the rotating wheel 42 for transmission. The barrel section 411 has ratchet teeth 413 at one end close to the barrel bottom section 412. The ratchet teeth 413 are evenly arranged along the circumference of the barrel section 411.

[0076] The bottle holder cover 41 is sleeved on the outer side of the lower end of the sleeve 25 , and is located on the inner side of the upper pen barrel 10 . The upper pen barrel 10 is circumferentially limitedly connected to the bottle holder cover 41 , and the bottle holder cover 41 is relatively rotatably connected to the sleeve 25 .

[0077] like Fig.11As shown, the rotating wheel 42 includes an inner ring 421 , an outer ring 422 and a connecting section 423 .

[0078] The rotating wheel 42 is sleeved on the outer surface of the screw 45 and meshes with the screw 45 for transmission. The rotating wheel 42 is close to the lower end of the sleeve 25 and is circumferentially limitedly connected to the end surface of the lower end of the sleeve 25, and the sleeve 25 can be inserted between the rotating wheel 42 and the screw 45. The outer surface of the rotating wheel 42 is threadedly connected to the inner wall of the bottle rack cover 41.

[0079] Specifically, the inner ring 421 of the rotating wheel 42 is sleeved on the outer surface of the screw 45. For example, the inner ring 421 is threadedly connected to the screw 45; the outer ring 422 is threadedly connected to the bottle holder cover 41, and there is a gap between the outer ring 422 and the inner ring 421, and the outer ring 422 and the inner ring 421 are connected by a connecting section 423. In some embodiments, there are two connecting sections 423, which are symmetrically arranged about the inner ring 421, and an accommodation space is formed between the outer ring 422 and the inner ring 421 and between adjacent connecting sections 423. For example, the inner ring 421, the outer ring 422 and the connecting section 423 are integrally formed.

[0080] like Fig. 9 As shown, the lower end of the sleeve 25 includes a first arc segment 251 and a second arc segment 252 along the circumferential direction.

[0081] A limiting groove 253 extending in the axial direction is formed between the first arc segment 251 and the second arc segment 252. The connecting segment 423 of the rotating wheel 42 is inserted into the limiting groove 253, and the first arc segment 251 and the second arc segment 252 can be respectively inserted into two accommodating spaces formed by the two connecting segments 423. The inner walls of the lower ends of the first arc segment 251 and the second arc segment 252 are both provided with first gear teeth 254.

[0082] like Fig.12 As shown, the driving wheel 43 includes a driving wheel body 431 and a wheel rim 432 .

[0083] The driving wheel body 431 of the driving wheel 43 is sleeved on the screw rod 45 and is located on one side of the screw rod 45 close to the lower end of the rotating wheel 42 .

[0084] The inner wall of the driving wheel body 431 has a wedge block 4311, and the outer wall of the driving wheel body 431 has a second gear tooth 4312. The wheel edge 432 is arranged around the circumference of the driving wheel body 431. Exemplarily, the wheel edge 432 is an arc segment, and a limiting protrusion 4321 is arranged at the end of the arc segment, and the limiting protrusion 4321 protrudes in a direction away from the axis of the driving wheel body 431.

[0085] The driving wheel 43 and the inner surface of the bottle rack cover 41 are unidirectionally limited. Specifically, the limiting protrusion 4321 of the wheel edge 432 can abut against the ratchet teeth 413 to achieve unidirectional blocking of the driving wheel 43 and the bottle rack cover 41 in the circumferential direction.

[0086] like Fig.13 As shown, the screw 45 is arranged along the axial direction of the injection pen 1000 and is coaxial with the power rod 28 . The sleeve 25 is sleeved on the outer surface of the screw 45 and there is a gap between the sleeve 25 and the screw 45 .

[0087] The screw rod 45 has multiple arcuate threads 451 in the circumferential direction, which can be understood as a discontinuous thread of the screw rod 45 along the circumferential direction, and a wedge-shaped groove 452 is formed between the arcuate threads 451 adjacent to each other along the circumferential direction. The wedge-shaped block 4311 of the driving wheel 43 is inserted between the arcuate threads 451 adjacent to each other along the circumferential direction, and abuts against the wedge-shaped groove 452, so as to realize the one-way blocking of the driving wheel 43 and the screw rod 45.

[0088] Exemplarily, the wedge block 4311 is used to be clamped in the wedge groove 452, and one side surface of the wedge groove 452 along the circumferential direction can be restrained against the wedge block 4311, and the other side surface can guide the movement of the wedge block 4311, thereby achieving one-way jamming of the screw 45 and the drive wheel 43.

[0089] It should be noted that the jamming direction of the driving wheel 43 and the bottle holder cover 41 is opposite to the jamming direction of the driving wheel 43 and the screw 45. Taking the process of adjusting the drug dosage as the clockwise rotation direction of the sleeve 25, the jamming direction of the driving wheel 43 and the screw 45 is: when the driving wheel 43 rotates counterclockwise, the screw 45 is restricted from rotating relative to the driving wheel 43. It can be understood that the screw 45 cannot rotate clockwise relative to the driving wheel 43. The jamming direction of the driving wheel 43 and the bottle holder cover 41 is: the bottle holder cover 41 restricts the instantaneous clockwise rotation of the screw 45.

[0090] The screw gasket 44 is fixed to one end of the screw 45 away from the power rod 28 and is located on the side of the barrel bottom section 412 away from the barrel section 411 , and can fit and limit the barrel bottom section 412 to prevent the screw 45 from separating from the bottle rack cover 41 .

[0091] In combination with the above structure, the structural relationship of the driving mechanism 40 of the injection pen 1000 during use is described below:

[0092] During the process of the user adjusting the drug dose of the injection pen 1000: the sleeve 25 rotates, and since the rotating wheel 42 and the sleeve 25 are circumferentially limited by the cooperation of the connecting section 423 and the limiting groove 253, the rotating wheel 42 rotates synchronously with the sleeve 25; the rotating wheel 42 is threadedly engaged with the inner wall of the bottle holder cover 41, and during the process of the rotating wheel 42 rotating with the sleeve 25, since the bottle holder cover 41 and the upper pen barrel 10 are axially limited, the bottle holder cover 41 is relatively fixed, and the rotating wheel 42 moves along the axial direction of the bottle holder cover 41.

[0093] During the process of adjusting the drug dosage, the driving wheel 43 is separated from the sleeve 25, so the driving wheel 43 does not rotate; in addition, during the clockwise rotation of the rotating wheel 42, the wedge-shaped groove 452 of the screw 45 will abut against the wedge-shaped block 4311 of the driving wheel body 431 of the driving wheel 43, and the limiting protrusion 4321 of the wheel edge 432 of the driving wheel 43 will abut against the ratchet teeth 413 of the bottle rack cover 41, so that the screw 45 will not rotate with the rotating wheel 42. That is, during the movement of the rotating wheel 42 along the axial direction of the bottle rack cover 41, the screw 45 does not rotate, which can be understood as the rotating wheel 42 moving along the axial direction of the screw 45. When the sleeve 25 rotates to the required drug dosage, the rotating wheel 42 stops moving, and the lower end of the sleeve 25 is inserted into the interior of the rotating wheel 42 and is located between the screw 45 and the rotating wheel 42.

[0094] During the process of injecting the drug: the user presses the button 31, the power rod 28 and the sleeve 25 move downward along the axial direction, the sleeve 25 is released, and during the downward movement of the sleeve 25, the first gear 254 of the sleeve 25 meshes with the second gear 4312 of the drive wheel 43, so that the sleeve 25 and the drive wheel 43 are engaged; under the action of the torsion spring 26, the sleeve 25 and the power rod 28 rotate counterclockwise together, and at the same time drive the drive wheel 43 and the rotating wheel 42 to rotate together; during the rotation of the drive wheel 43, the drive wheel 43 and the screw rod 45 pass through the wedge block 4 311 and the circumferential limit of the wedge-shaped groove 452, and the driving wheel 43 and the bottle rack cover 41 can rotate relatively, so that the driving wheel 43 drives the screw 45 to rotate together; because the rotating wheel 42 is sleeved on the screw 45, and the rotating wheel 42 is threadedly connected with the bottle rack cover 41, under the thread cooperation of the rotating wheel 42 and the bottle rack cover 41, the screw 45 and the rotating wheel 42 move downward along the axial direction together, pushing the bottle stopper downward to achieve drug injection, and the rotating wheel 42 returns to the bottom of the bottle rack cover 41 and abuts against the driving wheel 43, that is, the rotating wheel 42 returns to the initial position. Because the screw and the sleeve will not have a large swing under the action of the fulcrum of the thread adjustment mechanism, the transmission of the screw and the sleeve is more stable, and the hand feel and injection accuracy are increased.

[0095] The present application adds a rotating wheel 42, so that the screw 45 of the injection pen 1000 can ensure the stability of the position during the process of adjusting the injection drug dose under the support of the power rod 28, the bottle holder cover 41 and the rotating wheel 42. In addition, during the process of adjusting the injection drug dose, the rotating wheel 42 can move axially toward the button 31, so that the rotating wheel 42 and the bottle holder cover 41 are spaced axially, further improving the stability of the screw 45 position and the stability of the sleeve 25 rotation.

[0096] In some embodiments, the rotating wheel 42 can also be directly threadedly connected to the upper pen barrel 10, and the rotating wheel 42 and the bottle rack cover 41 are circumferentially arranged and sleeved on the outside of the screw 45, and the bottle rack cover 41 is circumferentially limitedly connected to the upper pen barrel 10, and the connection method of the bottle rack cover 41 and the driving wheel 43 is the same, which will not be repeated here.

[0097] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0098] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An upper pen barrel assembly of an injection pen, characterized in that: include: An upper pen holder, which is a hollow part; The dose adjustment mechanism is used to adjust the dose of the drug to be injected. The dose adjustment mechanism includes a power rod, a barrel, a sleeve and a torsion spring arranged inside the upper pen barrel; wherein the power rod can rotate relative to the upper pen barrel and can move relative to the upper pen barrel along the axis direction of the upper pen barrel; the barrel is sleeved on the outside of the power rod, and the power rod rotates relative to the barrel, and the barrel is fixed relative to the upper pen barrel; the upper end of the sleeve is connected to the power rod in a circumferential limiting manner, and the sleeve can move relative to the axis direction of the upper pen barrel; one end of the torsion spring is fixed relative to the upper pen barrel, and the other end of the torsion spring is connected to the lower end of the sleeve; The driving mechanism includes a screw, a bottle holder cover, a rotating wheel and a driving wheel, wherein the screw is located at the lower end of the upper pen barrel, and the screw and the power rod are arranged along the axial direction of the upper pen barrel; the lower end of the sleeve is sleeved on the outer side of the screw, and there is a gap between the sleeve and the screw in the radial direction; the driving wheel is sleeved on the screw, and the bottle holder cover is sleeved on the outer side of the driving wheel, and when the sleeve moves to a preset position along the axial direction of the upper pen barrel, the sleeve and the driving wheel can be connected in a circumferential limit direction; The rotating wheel is located between the driving wheel and the power rod, and the inner ring of the rotating wheel is threadedly connected to the screw, and the outer ring of the rotating wheel can rotate relative to the upper pen barrel; the rotating wheel is circumferentially limited and connected to the lower end of the sleeve, and the rotating wheel can produce a displacement along the axis direction of the upper pen barrel relative to the sleeve; during the circumferentially limited connection and rotation of the driving wheel and the sleeve, the driving wheel and the screw are circumferentially limited, and the driving wheel and the bottle rack cover can rotate relative to each other; during the relative rotation of the driving wheel and the sleeve, the bottle rack cover and the driving wheel are circumferentially limited, and the driving wheel circumferentially limits the screw to rotate with the rotating wheel.

2. The upper pen barrel assembly according to claim 1, characterized in that: The inner wall of the driving wheel is unidirectionally blocked with the screw in the circumferential direction, the outer wall of the driving wheel is unidirectionally blocked with the bottle rack cover in the circumferential direction, and the limiting directions of the driving wheel by the bottle rack cover and the screw are opposite.

3. The upper pen barrel assembly according to claim 2, characterized in that: The inner wall of the bottle rack cover is provided with ratchet teeth, and the driving wheel is provided with a limiting protrusion for unidirectionally locking with the ratchet teeth.

4. The upper pen barrel assembly according to claim 3, characterized in that: The inner wall of the driving wheel has a wedge block, the screw has multiple arc threads in the circumference, and wedge grooves are formed between the arc threads adjacent to each other in the circumferential direction. The wedge block is used to be clamped in the wedge groove, and one side surface of the wedge groove in the circumferential direction can be restrained against the wedge block, and the other side surface can guide the movement of the wedge block.

5. The upper pen barrel assembly according to claim 4, characterized in that: The driving wheel comprises: A driving wheel body, the driving wheel body is used to be sleeved on the screw rod, and the inner wall of the driving wheel body has the wedge block; the lower end of the inner part of the sleeve has first gear teeth arranged along the circumferential direction, and the outer ring of the driving wheel body is provided with second gear teeth; when the sleeve moves to a preset position along the axial direction of the upper pen barrel, the first gear teeth mesh with the second gear teeth; The wheel edge is arranged on the outer ring of the driving wheel body and is located on a side of the driving wheel body away from the rotating wheel, and the limiting protrusion is arranged on the wheel edge.

6. The upper pen barrel assembly according to claim 1, characterized in that: The rotating wheel comprises: The inner ring is threadedly connected to the screw; The outer ring is rotatable relative to the upper pen barrel, and a gap is formed between the inner ring and the outer ring in a radial direction; A connecting section connects the outer ring and the inner ring, and an accommodating space is formed between the connecting section, the inner ring and the outer ring.

7. The upper pen barrel assembly according to claim 6, characterized in that: The sleeve includes: arc segments arranged along the circumferential direction, the arc segments are sleeved on the outer side of the screw, and limiting grooves extending along the axial direction of the upper pen barrel are formed between the arc segments adjacent to each other along the circumferential direction. The connecting section is used to be inserted into the limiting groove and can move along the axial direction of the limiting groove, and the arc segment can be inserted into the accommodating space.

8. The upper pen barrel assembly according to any one of claims 1 to 7, characterized in that: The bottle rack cover is sleeved on the outer side of the rotating wheel, and the rotating wheel is threadedly connected to the bottle rack cover, and the bottle rack cover is circumferentially limitedly connected to the upper pen barrel; or, The rotating wheel is threadedly connected to the upper pen barrel, and the bottle holder cover and the rotating wheel are arranged along the circumference of the upper pen barrel.

9. The upper pen barrel assembly according to any one of claims 1 to 7, characterized in that: The dosage adjustment mechanism also includes: A knob, which is sleeved on the upper end of the upper pen barrel and can rotate relative to the upper pen barrel, and is used to adjust the rotation position of the sleeve; The scale plate is sleeved on the outside of the sleeve and can rotate synchronously with the sleeve. During the rotation of the scale plate, the scale plate can move relative to the sleeve along the axis direction of the upper pen barrel. The upper pen barrel has a display window for displaying the scale on the scale plate.

10. An injection pen, characterized in that: It comprises an upper pen barrel assembly and a lower pen cap assembly, wherein the upper pen barrel assembly is the upper pen barrel assembly as claimed in any one of claims 1 to 9; The lower end of the upper pen barrel of the upper pen barrel assembly is connected to the lower pen cap assembly, and the lower pen cap assembly is used to install a medicine cartridge bottle.

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