Disposable injection pen capable of accurately adjusting dosage

Abstract

The invention provides a disposable injection pen capable of accurately adjusting dosage, which comprises a refill frame, a pen body tube, a piston, a screw rod, a positioner, a transmission rod, a guide sleeve, a transmission connecting rod, a locking ring, a dosage rotating cylinder, a button and a button spring, a cavity for placing medicament is arranged in the refill frame, and the positioner is fixedly arranged at the joint of the refill frame and the pen body tube; the piston is arranged at one end of the screw rod, and the other end of the screw rod penetrates through the positioner and extends into the transmission rod; one end of the transmission rod is rotatably connected with the positioner, and the other end of the transmission rod can axially and movably extend into the transmission connecting rod; the locking ring is arranged in the dose rotating cylinder, the transmission connecting rod penetrates through the locking ring and extends into the dose rotating cylinder, the dose rotating cylinder rotatably penetrates through the guide sleeve and extends into the pen body tube, and the guide sleeve is arranged at the joint of the interior of the pen body tube and the dose rotating cylinder; a button spring is arranged at the tail end of the dosage drum, and one end of the button extends into the dosage drum and is connected with the transmission connecting rod through the button spring; the patient operation difficulty is low, the use experience is good, the product structure is simple, the cost is low, and design and production are easy.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a disposable injection pen capable of accurately adjusting dosage. Background Art

[0002] Injection pens are a common type of drug delivery device. With the advantages of being able to inject quantitatively, being easy to use, and being highly safe, they have become a common device for patients to self-inject at home. In particular, they have been widely used in the delivery of insulin. In terms of subcategories, injection pens can be divided into disposable non-adjustable injection pens, reusable adjustable injection pens, and disposable or disposable adjustable injection pens. Since there are a large number of diabetic patients who need insulin injections, and insulin needs to be injected 1-4 times a day (based on the degree of disease progression), there is a very high demand for pen injectors, including reusable adjustable injection pens and disposable adjustable injection pens. Reusable insulin injection pens have the characteristics of low cost and environmental friendliness. Disposable insulin injection pens with adjustable dosage have great market prospects due to their advantages of being easy to carry, easy to use, clean and hygienic.

[0003] Since the 1950s and 1960s, syringes for daily use by patients who inject insulin have been available abroad, but early versions of these syringes were mostly disposable, non-adjustable dosing devices. Disposable, adjustable-dose medication injection pens became available in the early 2000s and have been continuously updated with technological advancements. Currently, most disposable, adjustable-dose injection pens on the market consist of a medication cartridge, a graduated dose adjustment device, and a rotatable dose button, allowing patients to adjust their injection dose independently. Because these injection devices are only used for injecting one medication, injection pens typically have complex structures, numerous parts, and are difficult to manufacture. Furthermore, during the manufacturing process, defects such as difficult-to-eliminate step differences in the product's joints and uneven surface textures, resulting in noticeable color differences, are common. Furthermore, these pens are primarily designed for diabetic patients with poor eyesight, and typically require other dosage instructions in addition to visible scale indicators.

[0004] Based on this, how to provide an injection pen that has a simple structure, is easy to process, and can serve as a prompt when the patient adjusts the dosage is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] The embodiment of this specification aims to provide a disposable injection pen that can accurately adjust the dosage. The device has a simple structure, mature production and processing technology, low cost, and a sound prompt function.

[0006] The present invention provides a disposable injection pen capable of precisely adjusting the dosage, comprising a cartridge holder, a pen barrel, a piston, a screw, a positioner, a transmission rod, a guide sleeve, a transmission connecting rod, a locking ring, a dosage drum, a button, and a button spring. The cartridge holder is provided with a cavity for placing a medicine, and the positioner is fixedly provided at the connection between the cartridge holder and the pen barrel. The screw has an outer thread on its outer wall, and the positioner has an inner thread on its inner wall that matches the screw's outer thread. The positioner has a buckle on its outer wall, and the pen barrel has a buckle on its inner wall, and the pen barrel has a buckle, and the barrel buckle and the positioner buckle are mutually connected. The piston has a buckle, and one end of the screw has a buckle, and one end of the screw and the piston are mutually connected via the buckle. The piston is provided at one end of the screw, and the other end of the screw passes through the positioner and extends into the interior of the transmission rod. The screw has an axial groove on its outer wall, and the transmission rod has a bump on its inner wall that matches the axial groove on the screw's outer wall.

[0007] One end of the transmission rod extends into the locator and is rotatably connected to the locator, and the other end can be axially moved and extends into the inner cavity of the transmission connecting rod. The inner wall of the transmission connecting rod is axially provided with a protrusion, and the outer wall of the transmission rod is axially provided with a groove and matched with the protrusion on the inner wall of the transmission connecting rod. The transmission connecting rod is axially provided with a sounding tooth; the locking ring is arranged in the dose drum, and the transmission connecting rod passes through the locking ring and extends into the dose drum. The dose drum can be rotatably passed through the guide sleeve and extends into the pen body tube. The guide sleeve is arranged inside the pen body tube and is connected to the dose drum. At the connection between the drums, limit blocks are respectively provided at both ends of the guide sleeve; a buckle is provided on the inner wall of one end of the dose drum, and limit blocks are respectively provided at both ends of the dose drum, which cooperate with the limit blocks at both ends of the guide sleeve, and a button spring is provided at the tail end of the dose drum, and a sounding tooth is axially provided on the inner wall of the dose drum and cooperates with the axial sounding tooth of the transmission connecting rod; the button is provided with a buckle, and is connected to the dose drum through the buckle, and one end of the button provided with the buckle extends into the interior of the dose drum and is connected to the end of the transmission connecting rod through the button spring.

[0008] The transmission rod, the positioner and the pen body constitute a modular component, which adopts modular design and modular assembly; the screw is made of PBT plus glass fiber material, which increases the lubricity and strength of the screw; the transmission connecting rod is made of PA66 plus glass fiber material, which enhances the stability and lubricity of the product.

[0009] The pen body and pen cap are processed by injection molding, wherein the mold is processed by electric spark machining. The processing process includes: first, placing the two halves of the mold side by side and measuring with a dial indicator until there is no error; second, connecting the two halves of the mold to an electrode. When discharging, the two halves of the mold are processed simultaneously as a whole, avoiding errors that may occur when the two halves of the mold are processed separately.

[0010] Preferably, the outer wall of the transmission rod is provided with at least one axial groove, and the inner wall of the transmission connecting rod is provided with a protrusion that matches the axial groove.

[0011] Preferably, the outer wall of the transmission connecting rod is provided with an external thread, and the inner wall of the locking ring is provided with a convex key that cooperates with the external thread of the transmission connecting rod; the inner wall of the dose drum is provided with a protrusion, and the outer wall of the locking ring is provided with a groove that cooperates with the protrusion on the inner wall of the dose drum.

[0012] Preferably, the outer wall of the dose drum is provided with an external thread, and the inner wall of the guide sleeve is provided with a guide sleeve thread that matches the external thread of the dose drum.

[0013] Preferably, the pen body tube is provided with a viewing window, the guide sleeve is fixedly connected to the pen body tube viewing window, and the guide sleeve is provided with a guide sleeve viewing window.

[0014] Preferably, the dose drum is marked with scale values, the scale values ​​have multiple gears, each gear of the dose drum corresponds to each unit of the medicine dose in the cartridge holder, and the total number of gears of the dose drum is equal to the total number of units of the medicine dose.

[0015] Preferably, the positioner is axially provided with two elastic buckle feet, and the end of the refill holder is provided with two tile-shaped elastic clip feet, and the two elastic clip feet are respectively located between the two elastic buckle feet of the positioner, so that the two tile-shaped elastic clip feet and the two elastic buckle feet form a ring.

[0016] Preferably, the end of the transmission rod is provided with an elastic ratchet, and a plurality of ratchets are provided on the circumference of the inner side of the positioner to cooperate with the elastic ratchet at the end of the transmission rod.

[0017] Preferably, the disposable injection pen with precise dosage adjustment includes a large spring, which is sleeved on the outer wall of the transmission rod, the end of the transmission rod is provided with a sounding tooth, and the positioner is axially provided with a sounding tooth, which cooperates with the sounding tooth at the end of the transmission rod.

[0018] Preferably, the end of the refill holder is provided with an external thread, which is detachably connected to the injection needle via a threaded structure.

[0019] Preferably, the disposable injection pen capable of precisely adjusting the dosage comprises a pen cap, and the pen cap is detachably mounted on the outside of the pen core frame.

[0020] The embodiment of this specification provides a disposable injection pen with precise dosage adjustment. By setting a button spring at the button at the tail end, button damping is provided to optimize the patient's comfort when pressing the injection button. When the patient turns the dosage drum to adjust the dosage, a prompt sound emitted by the connection part can be heard, which serves to remind the patient to adjust the injection volume and enhance the patient's user experience. In addition, the device provided by this technical solution has a simple structure and a modular design that can shorten the R&D cycle. The use of modular assembly can standardize production, facilitate processing and assembly, and reduce production costs. The processing method of the mold core can increase the processing accuracy of the product and effectively eliminate the step difference of the product joint line position. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in this application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0022] Figure 1 is an exploded view of an embodiment of the present specification;

[0023] Figure 2 is a schematic diagram of an embodiment of this specification;

[0024] Figure 3 is a cross-sectional view of an embodiment of the present specification;

[0025] Figure 4 is a schematic diagram of a transmission connecting rod according to an embodiment of the present specification;

[0026] Figure 5 is a schematic diagram of a locking ring in an embodiment of this specification;

[0027] Figure 6 is a schematic diagram of a dosage drum in an embodiment of this specification;

[0028] Figure 7 is a schematic diagram of a guide sleeve in the embodiment of this specification;

[0029] Figure 8 Schematic diagram of the screw in the embodiment of this specification;

[0030] Figure 9 This is a structural diagram of a preferred embodiment 1 of a modular component in the implementation manner of this specification;

[0031] Figure 10 This is a structural diagram of a preferred embodiment 2 of a modular component in the implementation manner of this specification;

[0032] Figure 11 is a cross-sectional view of a preferred embodiment 2 of a modular component in the embodiment of this specification;

[0033] Among them, 1-pen core holder, 101-tile-shaped elastic foot, 2-pen body tube, 21-pen body tube window, 22-pen body tube buckle, 23-pen body tube limiting rib, 3-piston, 4-screw, 41-screw groove, 42-screw buckle, 5-locator, 51-elastic buckle foot, 52-locator buckle, 53-ratchet, 53a-locator sounding tooth, 54-locator internal thread, 6-transmission rod, 61-elastic ratchet, 61a-transmission rod sounding tooth, 62-transmission rod groove, 63-transmission rod inner convex block, 7-guide sleeve, 71-guide Sleeve window, 72-guide sleeve thread, 704-guide sleeve limit block, 8-transmission connecting rod, 801-transmission connecting rod external thread, 802-transmission connecting rod inner wall protrusion, 803-transmission connecting rod sounding tooth, 9-locking ring, 901-locking ring convex key, 902-locking ring slot, 10-dose drum, 102-dose drum buckle, 103-dose drum protrusion, 104-dose drum limit block, 105-dose drum sounding tooth, 106-dose drum limit rib, 11-button, 12-button spring, 13-pen cap, 14-large spring. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this specification will be clearly and completely described below in conjunction with the drawings in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0035] like Figure 1-8As shown, the embodiments of this specification provide a disposable injection pen capable of precisely adjusting dosage, comprising a cartridge holder 1, a pen body 2, a piston 3, a screw 4, a positioner 5, a transmission rod 6, a guide sleeve 7, a transmission connecting rod 8, a locking ring 9, a dosage drum 10, and a button 11. The cartridge holder 1 includes a cavity for placing medication, and the positioner 5 is fixedly connected to a pen body clip 22 provided on the pen body 2 via a positioner clip 52. The screw 4 has an external thread on its outer wall, and an internal positioner thread 54 on its inner wall that mates with the external thread of the screw 4. The positioner 5 is threadedly mounted on the screw 4. The screw 4 also has an axial screw groove 41 on its outer wall that mates with a transmission rod internal projection 63 provided on the inner wall of the transmission rod 6. A screw clip 42 is provided at one end of the screw 4. The piston 3 is arranged at the end of the screw 4 close to the refill frame 1. A buckle is also provided on the piston 3 and is connected to the screw 4 through the screw buckle 42. The end of the screw 4 away from the refill frame 1 passes through the positioner 5 and extends into the hollow cavity of the transmission rod 6. The screw 4 can move axially relative to the transmission rod 6 but cannot rotate under the restriction of the screw groove 41; one end of the transmission rod 6 is rotatably connected to the positioner 5, and the other end can move axially and extend into the interior of the transmission connecting rod 8; the locking ring 9 is rotatably sleeved on the outside of the transmission connecting rod 8 and is provided Inside the dose drum 10, the transmission connecting rod 8 passes through the locking ring 9 and extends into the dose drum 10; the guide sleeve 7 is fixedly arranged at the connection between the inside of the pen body 2 and the dose drum 10, and the dose drum 10 can be rotatably passed through the guide sleeve 7 and extended into the pen body 2; a button spring 12 is provided at the tail end of the dose drum 10, one end of the button 11 extends into the interior of the dose drum 10 and is connected to the end of the transmission connecting rod 8 via the button spring 12. A buckle is provided at one end of the button 11, which cooperates with the dose drum buckle 102 provided on the dose drum.

[0036] The outer wall of the transmission rod 6 is provided with at least one axial transmission rod groove 62 , and the inner wall of the transmission connecting rod 8 is provided with a transmission connecting rod inner wall protrusion 802 that matches the transmission rod groove 62 .

[0037] The outer wall of the transmission connecting rod 8 is provided with a transmission connecting rod external thread 801, and the inner wall of the locking ring 9 is provided with a locking ring cam 901 that mates with the outer thread of the transmission connecting rod 8. The transmission connecting rod 8 can rotate and move axially within the locking ring 9 via the external thread 801. The locking ring 9 limits the axial displacement of the transmission connecting rod 8 via the locking key, so that the transmission connecting rod 8 always moves within the locking ring 9 but does not escape from the locking ring 9. The inner wall of the transmission connecting rod 8 is provided with a transmission connecting rod inner wall cam 802, which mates with the transmission rod groove 62. The transmission connecting rod 8 is axially provided with a transmission connecting rod sounding tooth 803, which mates with the sounding tooth 105 of the dosage drum, and when the two rotate relative to each other, they collide and produce sound.

[0038] The inner wall of the dose drum 10 is provided with a dose drum protrusion 103, and the outer wall of the locking ring 9 is provided with a locking ring groove 902 that mates with the dose drum protrusion 103. The outer wall of the dose drum 10 is provided with an external thread, and the inner wall of the guide sleeve 7 is provided with a guide sleeve thread 72 that mates with the outer thread of the dose drum 10. The guide sleeve 7 is threadedly connected to the outer wall of the dose drum 10. A dose drum buckle 102 is provided on the inner wall of one end of the dose drum 10, which mates with the buckle provided on the button 11. A dose drum limiting rib 106 is provided on the inner wall of the dose drum 10, which mates with the locking ring 9 and limits the movement of the locking ring 9. Guide sleeve limiters 704 are provided at the upper and lower ends of the guide sleeve 7. The dose drum 10 also has a dose drum limiter 704 at its upper and lower ends, which mate with the guide sleeve limiters 704 to limit the movement of the dose drum 10 relative to the pen barrel 2. The pen body 2 is provided with a viewing window 21, and the guide sleeve 7 is provided with a guide sleeve viewing window 71 and is fixedly connected to the pen body window 21. The inner wall of the guide sleeve 7 is provided with a guide sleeve thread 72, which cooperates with the external thread of the dose drum 10.

[0039] The dose drum 10 is provided with a scale, and the scale value has multiple gears starting from 0. Each gear of the dose drum 10 corresponds to each unit of the medicine dose in the cartridge holder 1, and the total number of gears of the dose drum 10 is equal to the total number of units of the medicine dose.

[0040] The locator 5 is axially provided with two elastic buckle feet 51, and the corresponding end of the refill holder 1 is provided with two tile-shaped elastic clamping feet 101, and the two elastic clamping feet 101 are respectively located between the two elastic buckle feet 51 of the locator, so that the two tile-shaped elastic clamping feet 101 and the two elastic buckle feet 51 form a ring.

[0041] The end of the refill frame 1 away from the pen body 2 is provided with an external thread for connecting with an external injection needle. The pen cap 13 is detachably sleeved on the outside of the refill frame 1.

[0042] The transmission rod 6, positioner 5, and pen barrel 2 form a modular assembly. The modular assembly in this invention utilizes modular design and assembly. Modular design can shorten R&D cycles, while modular assembly can improve the standardization of product production. During product assembly, the assembled module simply needs to be combined with other components for complete assembly. Different embodiments of the present invention can be achieved by simply replacing the module. This approach improves product assembly efficiency and optimizes production costs.

[0043] The screw 4 in this invention is made of PBT with glass fiber, while the drive connecting rod 8 is made of PA66 with glass fiber. These two materials were selected after extensive testing of various materials, including lubricity, strength, stability, and reliability, and after a comprehensive consideration of material performance and production costs. The use of PBT with glass fiber for the screw 4 enhances lubricity and strength, improving product performance; the use of PA66 with glass fiber for the drive connecting rod 8 increases dimensional stability and improves lubricity. These materials ensure smoother product operation, improve product performance, and reduce production costs.

[0044] Specifically, Example 1 of the present invention is as follows Figure 9 As shown, the end of the transmission rod 6 is provided with an elastic ratchet 61, and a plurality of ratchet teeth 53 are arranged circumferentially inside the positioner 5, which cooperate with the elastic ratchet 61. The transmission rod 6 can move axially relative to the screw rod 4 but cannot rotate. Because the positioner 5 is fixed, the transmission rod 6 rotates relative to the positioner 5 but remains axially stationary. The positioner 5 is connected to the external thread of the screw rod 4 via the positioner internal thread 54. When the transmission rod 6 and the screw rod 4 rotate simultaneously, the screw rod 4 can rotate downward relative to the positioner 5. When the transmission rod 6 rotates relative to the positioner 5, the elastic ratchet 61 and the ratchet teeth 53 provided in the positioner 5 rotate relative to each other, emitting a "clicking" prompt sound.

[0045] Example 2 of the present invention Figure 10-11 As shown, the large spring 14 is sleeved on the outer wall of the transmission rod 6, and the pen body 2 is provided with a pen body limiting rib 23 that contacts and cooperates with the large spring 14 and limits the large spring 14. The end of the transmission rod 6 is provided with a transmission rod sounding tooth 61a, and the locator 5 is provided with a locator sounding tooth 53a along the axial direction to cooperate with the transmission rod sounding tooth 61a. During the injection process, when the transmission rod 6 rotates relative to the locator 5, the transmission rod 6 and the locator 5 are in close contact under the elastic force of the large spring 14. When the transmission rod sounding tooth 61a and the locator sounding tooth 53a rotate relative to each other, a "clicking" prompt sound is emitted under the collision.

[0046] When the patient rotates the dose drum 10 clockwise to increase the injection dose, the guide sleeve threads 72 within the guide sleeve 7 cooperate with the external threads of the dose drum 10, causing the dose drum 10 to extend out of the pen barrel 2 and rotate upward, with the button 11 subsequently moving linearly upward. When the patient rotates the dose drum 10 counterclockwise to decrease the injection dose, the dose drum 10 extends into the pen barrel 2 and rotates downward. During the dose adjustment process, because the transmission rod 6 does not move, the transmission connecting rod 8, constrained by the transmission rod 6, moves only axially and linearly, without rotating. The dose drum 10, manually rotated by the patient, generates relative motion with the transmission connecting rod 8. The transmission connecting rod's sounding teeth 803 and the dose drum's sounding teeth 105, acting under the elastic force of the button spring 12, come into close contact, colliding with each other and producing a "ticking" sound.

[0047] During the process of rotating to adjust the dose, the patient can observe the dose scale required for injection through the pen barrel window 21 and the guide sleeve window 71 and stop rotating to adjust the dose at any time.

[0048] During injection, the patient presses the button 11, and the button 11 contacts the tail surface of the transmission connecting rod 8. The dose drum 10, the transmission connecting rod 8, and the locking ring 9 form a whole and rotate downward; at the same time, the transmission rod 6 is driven to rotate, and the transmission rod 6 drives the screw 4 to rotate. Under the cooperation of the internal thread 54 of the locator and the external thread of the screw 4, the screw 4 rotates downward and pushes the piston 3 to move linearly downward. The piston 3 extends into the refill frame 1 to push the medicine downward, completing the injection.

[0049] When the patient increases the dose, the locking ring 9 rotates with the dose drum 10 due to the interlocking groove on the outer wall of the locking ring 9 and the dose drum protrusion 103 on the inner wall of the dose drum 10. The locking ring key 901 on the locking ring 9 engages with the external thread 801 of the transmission connecting rod, causing the locking ring 9 to rotate upward and rise a corresponding height relative to the transmission connecting rod 8. When the patient decreases the dose, the height of the locking ring 9 relative to the transmission connecting rod 8 is correspondingly retracted as the dose drum 10 moves. During injection, the locking ring 9 and the transmission connecting rod 8 rotate downward simultaneously, and the displacement between the locking ring 9 and the transmission connecting rod 8 during dose adjustment no longer changes.

[0050] After each injection, locking ring 9 rises relative to drive connecting rod 8 by a certain height corresponding to the injected dose. The total travel of locking ring 9 corresponds to the total dose of medicine in cartridge holder 1. During repeated adjustments and injections, locking ring 9 continues to rise until it reaches the top of drive connecting rod 8, completing the injection. When the amount of medicine in cartridge holder 1 is less than the total amount of medicine in the adjustment range of dose drum 10, dose drum 10 can only adjust the adjustment range for the remaining amount of medicine in cartridge holder 1.

[0051] The pen body and pen cap in the present invention are processed by injection molding, wherein the mold is processed by electric spark machining. The processing includes: during the grinding process, the two halves of the mold are also processed at the same time, and the outer shape, the tiger's mouth, etc. are simultaneously ground on the grinder to make the verticality and dimensional accuracy of the two halves of the mold consistent. Before discharging, the two halves of the mold are first placed side by side and measured with a micrometer until the needle of the micrometer does not jump, thereby eliminating the error of the two halves of the mold. When installing the electrode, the two halves of the mold are connected to one electrode together, and the shapes of the two halves of the mold are processed simultaneously under the same processing conditions, which can eliminate the error caused by separate processing of the electrodes. During discharge, the two halves of the mold are also discharged simultaneously, which can eliminate the errors caused by machine tool movement, screw rod gap, etc. when the two halves of the mold are processed separately, and can ensure the consistency of the contour shape of the two halves of the mold. In addition, during the processing, the electrodes are processed using high-precision and high-speed machine tools to ensure that the surface of the electrodes is extremely smooth and the dimensional accuracy is guaranteed. After the electrodes are processed, they need to be delicately polished to ensure that there are no textures or scratches on the surface of the electrodes. The above processing methods avoid uneven texture or color difference on the product appearance.

[0052] In the present invention, by providing a spring and cooperating between the transmission rod 6 and the positioner 5, a sound is emitted under the action of the spring force when the patient rotates the dose drum 10 to adjust the dose, serving as a reminder to the patient to adjust the injection dose. Furthermore, the button spring 12 provides spring damping when the patient presses the button 11, enhancing the user experience of pressing and injecting, and also facilitating adjustment and use by the patient.

[0053] In addition, this embodiment has a simple structure and a small number of parts. It can significantly improve production and processing efficiency through modular design and modular assembly. Through the selection of screw and transmission connecting rod materials, the overall use smoothness and stability of the product are improved, while reducing production costs.

[0054] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In the description of this specification, the description of the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of this specification. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in an appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples, unless they are contradictory. The drawings in this application specification are merely schematic diagrams and do not represent the actual structure of each component.

[0055] The foregoing is merely an example of one or more embodiments of this specification and is not intended to limit the one or more embodiments of this specification. It will be apparent to those skilled in the art that various modifications and variations may be made to one or more embodiments of this specification. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this application shall be included within the scope of the claims.

Claims

1. A disposable injection pen with precise dosage adjustment, characterized in that: The pen cartridge frame comprises a pen barrel, a piston, a screw, a positioner, a transmission rod, a guide sleeve, a transmission connecting rod, a locking ring, a dosage drum, a button and a button spring. The pen cartridge frame is provided with a cavity for placing medicine, and the positioner is fixedly provided at the connection between the pen cartridge frame and the pen barrel. The outer wall of the screw is provided with an external thread, the inner wall of the positioner is provided with an internal thread matching the external thread of the screw, and the outer wall of the screw is provided with a groove along the axial direction; the piston is provided with a buckle and is connected to one end of the screw through the piston buckle, and the other end of the screw passes through the positioner and extends into the interior of the transmission rod; The inner wall of the transmission rod is provided with a protrusion and cooperates with the groove on the outer wall of the screw rod. One end of the transmission rod extends into the positioner and is rotatably connected to the positioner, and the other end can be axially moved into the inner cavity of the transmission connecting rod. The inner wall of the transmission connecting rod is provided with a protrusion along the axial direction, and the outer wall of the transmission rod is provided with a groove along the axial direction and cooperates with the protrusion on the inner wall of the transmission connecting rod. The transmission connecting rod is provided with a sounding tooth along the axial direction; The locking ring is disposed in the dose drum, the transmission connecting rod passes through the locking ring and extends into the dose drum, the dose drum rotatably passes through the guide sleeve and extends into the pen body tube, the guide sleeve is disposed at the connection between the pen body tube and the dose drum, and limit blocks are respectively provided at both ends of the guide sleeve; The inner wall of the dose drum is provided with a buckle, and limit blocks are respectively provided at both ends of the dose drum and cooperate with the limit blocks at both ends of the guide sleeve. The button spring is provided at the tail end of the dose drum, and a sounding tooth is axially provided on the inner wall of the dose drum and cooperates with the sounding tooth of the transmission connecting rod; The button is provided with a buckle and is buckled and connected to the inner wall of the dose drum, and one end of the button extends into the interior of the dose drum and is connected to the transmission connecting rod through the button spring; The transmission rod, the positioner and the pen body tube form a modular component, and the modular component adopts modular design and modular assembly; The screw is made of PBT plus glass fiber material; The transmission connecting rod is made of PA66 plus glass fiber material.

2. A disposable injection pen capable of precisely adjusting dosage according to claim 1, characterized in that: The pen body is processed by injection molding, and the mold core is processed by electric spark machining. The processing process includes: first, placing the two halves of the mold core side by side and measuring with a micrometer until there is no error; second, connecting the two halves of the mold core to an electrode together, and when discharging, the two halves of the mold core are processed simultaneously as a whole.

3. A disposable injection pen capable of precisely adjusting dosage according to claim 2, characterized in that: The outer wall of the transmission rod is provided with at least one axial groove, and the inner wall of the transmission connecting rod is provided with at least one protrusion matched with the axial groove of the outer wall of the transmission rod.

4. A disposable injection pen capable of precisely adjusting dosage according to claim 3, characterized in that: The outer wall of the transmission connecting rod is provided with an external thread, and the inner wall of the locking ring is provided with a convex key that matches the external thread of the transmission connecting rod; the inner wall of the dose drum is provided with a protrusion, and the outer wall of the locking ring is provided with a groove that matches the protrusion on the inner wall of the dose drum.

5. A disposable injection pen capable of precisely adjusting dosage according to claim 4, characterized in that: The outer wall of the dose drum is provided with an external thread, and the inner wall of the guide sleeve is provided with a guide sleeve thread that matches the external thread of the dose drum.

6. A disposable injection pen capable of precisely adjusting dosage according to claim 5, characterized in that: The pen body tube is provided with a viewing window, the guide sleeve is fixedly connected to the viewing window of the pen body tube, and the guide sleeve is provided with a guide sleeve viewing window.

7. A disposable injection pen capable of precisely adjusting dosage according to claim 6, characterized in that: The dose drum is provided with a scale value, and the scale value has a plurality of gears, and each gear corresponds to each unit of the medicine dosage in the cartridge holder, and the total number of gears of the dose drum scale value is equal to the total number of units of the medicine dosage.

8. A disposable injection pen capable of precisely adjusting dosage according to any one of claims 2 to 7, characterized in that: The positioner is axially provided with two elastic buckle feet, and the end of the refill frame is provided with two tile-shaped elastic clamping feet, and the two elastic clamping feet are respectively located between the two elastic buckle feet of the positioner, so that the two tile-shaped elastic clamping feet and the two elastic buckle feet form a ring.

9. A disposable injection pen capable of precisely adjusting dosage according to claim 8, characterized in that: The end of the transmission rod is provided with an elastic ratchet, and a plurality of ratchets are provided on the circumference of the inner side of the positioner to cooperate with the elastic ratchet at the end of the transmission rod.

10. The disposable injection pen capable of accurately adjusting dosage according to claim 8, characterized in that: It includes a large spring, which is sleeved on the outer wall of the transmission rod. The end of the transmission rod is provided with a sounding tooth. The axial direction of the positioner is provided with a sounding tooth, which cooperates with the sounding tooth on the end of the transmission rod.

11. The disposable injection pen capable of accurately adjusting dosage according to claim 1, characterized in that: The pen cap comprises a pen cap and an injection needle, wherein the pen cap is detachably sleeved on the outside of the pen core frame; one end of the pen core frame is provided with an external thread, and the injection needle is detachably connected to the end of the pen core frame.

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