Pen type injector

Abstract

The pen type injector comprises a shell, an adjusting column, a transmission column, a guide column and a screw rod, and a view window is formed in the side body of the shell; the adjusting column is arranged on the inner side of the shell and is in threaded connection with the shell, spirally-arranged dosage scales are arranged on the periphery of the adjusting column, and a knob is connected to the far end of the adjusting column; the transmission column is arranged on the inner side of the adjusting column, the near end of the transmission column is in clutch connection with the adjusting column, and the far end is connected with a button through a supporting column. The guide column is arranged on the inner side of the transmission column and is in sliding joint with the transmission column, and the guide column is limited to only rotate in one direction; and the screw rod is arranged on the inner side of the guide post and is in threaded connection with the guide post. The driving mechanism of the pen type injector has fewer parts, the whole structure is simpler, and the risk of unstable driving is reduced while the cost is reduced; the transmission parts on all the parts are dispersed, and the problems that the assembly difficulty is increased due to the fact that the transmission parts are excessively concentrated at the same position, and the transmission stability is poor due to stress concentration are solved.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, in particular to a pen-type injector for manual drug injection. Background Art

[0002] Diabetic patients need to control their condition by injecting insulin. The invention of the insulin injection pen eliminates the need to use a syringe to extract insulin from the insulin bottle. It uses a pre-filled injection pen to directly implement the injection, which improves the convenience of insulin injection and makes it easier for diabetic patients to operate it themselves.

[0003] Insulin manufacturers generally use cartridges for pen injectors to pre-fill insulin medication, which is then assembled by the patient into the injection pen for injection. The vials used for pen injectors are cartridges, such as Figure 17 As shown, this is a cartridge bottle. The inner side of the borosilicate glass bottle body A is cylindrical, and a rubber piston B is inserted to seal it. The bottle is filled with medicine C. The injection pen pushes the rubber piston B to push a quantitative amount of medicine C out of the bottle mouth a (in conjunction with a special needle accessory) and inject it into the patient's body.

[0004] At present, there are many similar injection pens on the market. Although these insulin injection pen products are convenient for patients to use to a certain extent, the applicant found after research that the injection drive structure of such products is relatively complex. Due to the basic requirement of portability, the size of insulin injection pen products is destined to be limited. However, the complex injection drive structure brings considerable challenges to product design and assembly, such as the number of parts, assembly operations, drive stability, etc., which invisibly increase production costs.

[0005] Therefore, it is still necessary to conduct research and development in order to obtain an insulin pen that meets all regulatory requirements and is easy for patients to operate and use. Summary of the Invention

[0006] The object of the present invention is to provide a pen-type injector which reduces production costs and facilitates operation and use by patients by optimizing and improving the drive structure.

[0007] The purpose of the present invention is achieved by the following technical solutions: A pen-type injector comprising: The housing has a viewing window on its side; an adjusting column, disposed on the inner side of the housing and threadedly connected thereto, the outer circumference of the adjusting column being provided with a spirally arranged dosage scale, and the distal end of the adjusting column being connected to a knob; A transmission column is arranged on the inner side of the adjustment column, wherein the proximal end of the transmission column is connected to the adjustment column by a clutch, and the distal end of the transmission column is connected to a button through a support column; A guide post is provided inside the drive post and is in sliding engagement therewith, and the guide post is restricted to rotate in only one direction. A screw is provided inside the guide post and is threadedly connected thereto, and the screw is used to provide an injection force for a target object.

[0008] In an alternative embodiment, the pen-type syringe is configured such that rotating the knob counterclockwise presets the injection dose, during which the screw remains stationary; and the screw can be driven forward by pressing the button until the injection dose returns to zero and then stops.

[0009] In an alternative embodiment, a thick screw groove extending axially is provided inside the housing. A thick thread that mates with the thick screw groove is provided on the outer side of the proximal end of the adjusting post, and the distal end extends outside the housing and is connected to the knob.

[0010] In an alternative embodiment, a first tooth portion is provided on the inner side of the proximal end of the adjusting post, and a second tooth portion opposite to the first tooth portion is provided on the proximal end of the drive post. Wherein, when the knob is rotated counterclockwise, the first tooth portion can rotate relative to the second tooth portion and touch it to produce a tooth clicking sound; and after pressing the button, the first tooth portion can engage with the second tooth portion and rotate synchronously in the clockwise direction.

[0011] In an alternative embodiment, the proximal end of the support post abuts against the drive post, and an extension portion is provided at the distal end; wherein, the extension portion is connected to the button and can cooperate with the knob to form a spring groove, and a spring is provided in the spring groove.

[0012] In an alternative embodiment, a rib is provided on the inner side of the drive post, and a groove extending axially is provided on the outer side of the guide post, and the rib is in sliding engagement with the groove.

[0013] In an alternative embodiment, an internal thread that mates with the screw is provided on the inner side of the proximal end of the guide post, and a guide ring is provided at the distal end of the screw, and the guide ring is in sliding fit with the guide post.

[0014] In an alternative embodiment, a first ratchet is provided at the proximal end of the housing, and a first ratchet pawl is provided at the proximal end of the guide post, and the first ratchet is in contact and cooperation with the first ratchet pawl, causing the guide post to rotate only in the clockwise direction.

[0015] In an alternative embodiment, a lens is provided at the viewing window, and the lens is used to magnify the dose scale.

[0016] In an optional solution, a cartridge holder is further included, wherein the proximal end of the cartridge holder is provided with a needle, and the distal end is provided at the proximal end of the shell and cooperates therewith to form a chamber for fixing the medicine bottle.

[0017] In an optional solution, both ends of the cartridge holder are detachably connected to the needle and the housing, and a strip opening is provided on the side of the cartridge holder.

[0018] In an optional solution, the screw is provided with a second ratchet that can be slidably engaged therewith, the proximal end of the housing is provided with a sleeve portion, and the sleeve portion is provided with a second pawl; The second pawl contacts and cooperates with the second ratchet only when the refill holder is mounted on the sleeve portion, so as to limit the freedom of rotation of the screw.

[0019] In an optional solution, the screw is provided with at least one section along the axial direction, and the center of the second ratchet is provided with a non-circular hole that matches the second ratchet.

[0020] In an optional solution, a first ratchet and a socket portion are integrally formed at the proximal end of the shell; a first tooth portion is integrally formed at the proximal end of the adjustment column; a second tooth portion and a rib are integrally formed at the proximal end of the transmission column; and a first pawl is integrally formed at the proximal end of the guide column.

[0021] In an optional solution, the first ratchet and the first tooth portion each extend toward each other and form a limiting block and a matching block respectively; When the injection dose returns to zero, the limiting block can just abut against the matching block.

[0022] In an optional solution, a pen cap is provided on the pen core holder.

[0023] Compared with the prior art, the beneficial effects of the present invention include at least: 1. The drive mechanism has fewer parts and a simpler overall structure, which reduces costs and the risk of unstable driving.

[0024] 2. The transmission parts on each component are relatively dispersed, avoiding problems such as increased assembly difficulty caused by the transmission parts being too concentrated in the same position and transmission stability caused by concentrated force.

[0025] 3. The syringe can prevent the screw from retreating due to vibration or repeated operation through the cooperation of the second ratchet and pawl, ensuring the reliability of the injection dosage accuracy.

[0026] 4. It supports reuse and the dressing change operation is simple and convenient, which effectively reduces the cost of use and reduces equipment waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a three-dimensional schematic diagram of the pen-type syringe of the present invention.

[0028] Figure 2 is a three-dimensional schematic diagram of the pen-type syringe after removing the pen cap.

[0029] Figure 3 is Figure 2 axial sectional view of

[0030] Figure 4 is a partial structural schematic diagram of the pen-type syringe of the present invention.

[0031] Figure 5 is an assembly structural schematic diagram of the outer shell and the adjustment column.

[0032] Figure 6 is a three-dimensional structural schematic diagram of the adjustment column.

[0033] Figure 7 is an assembly structural schematic diagram of the adjustment column and the transmission column.

[0034] Figure 8 is a three-dimensional structural schematic diagram of the transmission column.

[0035] Figure 9 is an assembly structural schematic diagram of the guide column with the outer shell and the transmission column respectively.

[0036] Figure 10 is a three-dimensional structural schematic diagram of the guide column.

[0037] Figure 11 is a drive structural schematic diagram of the pen-type syringe of the present invention.

[0038] Figure 12 is Figure 4 sectional view along the A-A direction.

[0039] Figure 13 is an assembly structural schematic diagram of the screw rod, the second ratchet wheel and the guide column.

[0040] Figure 14 is Figure 4 sectional view along the B-B direction.

[0041] Figure 15 is a disassembled structural schematic diagram of the screw rod and the second ratchet wheel.

[0042] Figure 16 is an assembly structural schematic diagram of the pen core holder and the outer shell.

[0043] Figure 17 is a structural schematic diagram of the medicine bottle.

[0044] In the figure: 1. Outer shell; 101. Visual window; 102. Coarse screw groove; 103. First ratchet; 104. Socket part; 105. Second pawl; 1051. Fitting surface; 106. Avoidance opening; 107. L-shaped groove; 1071. Insertion section; 1072. Locking section; 1073. Stop rib; 108. Limiting block; 2. Adjusting column; 201. Dose scale; 202. Coarse thread; 203. First tooth part; 204. Fitting block; 3. Driving column; 301. Second tooth part; 302. Convex rib; 4. Guide column; 401. Groove; 402. Internal thread; 403. First pawl; 5. Screw; 501. Cutting surface; 502. Guide ring; 6. Knob; 7. Support column; 701. Extension part; 8. Button; 9. Spring; 10. Lens; 11. Cartridge holder; 1101. Slot opening; 1102. Clamping block; 12. Needle; 13. Medicine bottle; 1301. Piston; 14. Second ratchet; 1401. Non-circular hole; 15. Pen cap. Detailed implementation manners

[0045] Now, the exemplary embodiments will be described more comprehensively with reference to the accompanying drawings. However, the exemplary embodiments can be implemented in various forms and should not be construed as limited to the embodiments set forth herein; on the contrary, these embodiments are provided so that the present invention will be more complete and comprehensive, and the concept of the exemplary embodiments will be fully conveyed to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and thus their repeated description will be omitted.

[0046] The words expressing positions and directions described in the present invention are all illustrated by taking the accompanying drawings as examples, but can be changed according to needs, and all the changes made are included in the protection scope of the present invention.

[0047] First, the relative positions of the components are described: The proximal end involved in this application can be understood as the end closer to the injection position, and correspondingly, the distal end is the end farther from the injection position. In addition, the operating state refers to the use of the pen-type syringe, including the injection dose preset stage and the injection stage. The dressing change state refers to the stage when the cartridge holder 11 is separated from the outer shell 1.

[0048] See Figures 1 to 12As shown, the present application discloses a pen-type syringe, which can be used for injecting medicaments at subcutaneous, intramuscular, intravenous and other sites, and the medicaments include but are not limited to insulin.

[0049] As Figure 2 and Figure 3 shown, the pen-type syringe generally includes a housing 1, a driving mechanism partially built into the housing 1, a cartridge holder 11 connected to the proximal end of the housing 1, and a needle 12 connected to the proximal end of the cartridge holder 11. In the present application, the cartridge holder 11 is compatible with a 3-ml standard vial 13 (cartridge), and after being assembled to the housing 1, it forms a chamber for fixing the vial 13. During use, operating the driving mechanism can inject the medicament through the needle 12 into the target site of the subject.

[0050] From Figure 1 and Figure 2 it can be seen that the housing 1, as the handheld part of the syringe, is preferably a circular tube structure, and a viewing window 101 is provided on its side. An arrow is provided at the center line position of the viewing window 101 for alignment with the dose scale 201, so as to accurately control the injection dose of the medicament. In one example, the viewing window 101 is arranged at the distal end of the housing 1 to prevent interference with the holding part and affect dose reading.

[0051] Figure 3 shows the specific structure of the driving mechanism built into the housing 1. The mechanism mainly includes components such as an adjustment column 2, a transmission column 3, a guide column 4, and a screw 5. Among them, the adjustment column 2, the transmission column 3, and the guide column 4 are all circular tube structures.

[0052] Specifically, as Figure 5 shown, the adjustment column 2 is arranged inside the housing 1 and is threadedly connected thereto. In one example, a thick thread groove 102 extending axially is provided inside the housing 1, and a thick thread 202 cooperating with the thick thread groove 102 is provided on the outer side of the proximal end of the adjustment column 2. In the present application, the adjustment column 2 is defined as: counterclockwise rotation can make it retreat relative to the housing 1, and after being pressed, the adjustment column 2 can advance spirally (clockwise) relative to the housing 1.

[0053] Continuing to look at Figure 6 shown, a spirally arranged dose scale 201 is provided on the outer periphery of the adjustment column 2. The dose scale 201 corresponds to the viewing window 101, and its scale range can be 1-60 units (each unit corresponds to 0.01 ml), and the adjustment column 2 can be set to correspond to 1 unit dose per 12° of rotation. In addition, a knob 6 is connected to the distal end of the adjustment column 2. The knob 6 can be rigidly connected to the adjustment column 2 by means of a buckle or the like, so as to facilitate controlling the rotation of the adjustment column 2 to preset the injection dose.

[0054] Referring to Figure 7 and Figure 8As shown, the drive column 3 is disposed inside the adjustment column 2. Its proximal end is in clutch connection with the adjustment column 2, and its distal end is connected to a button 8 through a support column 7. In this application, the drive column 3 selectively engages with the adjustment column 2. Specifically, the two are separated during the injection dose presetting stage, and no transmission action occurs during this period. Only when entering the injection stage, the drive column 3 can form a rigid connection with the adjustment column 2 and achieve synchronous rotation. In one example, a first tooth portion 203 is provided on the inner side of the proximal end of the adjustment column 2, and a second tooth portion 301 is provided on the proximal end of the drive column 3. And the second tooth portion 301 can be elastically engaged with the first tooth portion 203 under the action of an elastic member (such as a spring 9). Note that the acting force exerted by the elastic member is small, and without additional pressure, this acting force does not limit the relative rotation between the first tooth portion 203 and the second tooth portion 301. When the knob 6 is rotated counterclockwise, the adjustment column 2 rotates accordingly but the drive column 3 does not rotate. During this period, the first tooth portion 203 rotates relative to the second tooth portion 301 and touches it to emit a tooth sound similar to "click click click click", indicating that the injection dose presetting adjustment is in progress. Behind the button 8, the pressure causes the first tooth portion 203 and the second tooth portion 301 to engage, and the adjustment column 2 and the drive column 3 form a rigid connection, causing the adjustment column 2 to drive the drive column 3 to advance synchronously in a clockwise spiral while advancing in a clockwise spiral.

[0055] Continue to look at 9 and Figure 10 As shown, the guide column 4 is disposed inside the drive column 3 and is in sliding engagement therewith to ensure synchronous rotation between the two. In one example, a rib 302 is provided on the inner side of the drive column 3, and an axially extending groove 401 is provided on the outer side of the guide column 4; wherein, the rib 302 is in sliding engagement with the groove 401 to ensure no jamming in the axial movement.

[0056] In addition, the guide column 4 is restricted to rotate only unidirectionally, such as only in the clockwise direction. In one example, a first ratchet wheel 103 (see Figure 5 ) is provided at the proximal end of the housing 1, and a first pawl 403 (see Figure 10 ) is provided at the proximal end of the guide column 4; wherein, the first ratchet wheel 103 is in contact and cooperation with the first pawl 403, causing the guide column 4 to rotate only in the clockwise direction. Note that in this application, the connection force between the first ratchet wheel 103 and the first pawl 403 needs to be greater than the acting force exerted by the elastic member on the adjustment column 2 to ensure that during the injection dose presetting stage, the adjustment column 2 cannot drive the drive column 3 to rotate, and only a phenomenon similar to "tooth skipping" can occur and a tooth sound can be emitted.

[0057] Such as Figure 11As shown, the screw 5 is arranged inside the guide post 4 and is threadedly connected thereto. In one example, an internal thread 402 that mates with the screw 5 is provided inside the proximal end of the guide post 4. In addition, a guide ring 502 is provided at the distal end of the screw 5, and the guide ring 502 is slidably mated with the guide post 4 to ensure the stability of the movement of the screw 5. When the guide post 4 rotates clockwise, the screw 5 can be automatically advanced under its drive, thereby providing a pushing force for a target object such as the piston 1301 of the medicine bottle 13. Among them, the advancing speed of the screw 5 can be approximately 0.5 mm / s ± 0.05 mm to achieve a better injection effect.

[0058] See Figures 2 to 11 As shown, the steps of using the pen-type syringe are as follows: S1. Load the medicine bottle 13 into the pen cartridge holder 11 and fix the pen cartridge holder 11 to the housing 1; S2. Rotate the knob 6 counterclockwise to preset the injection dose until the required dose scale 201 appears in the viewing window 101 and stop. During this period, the first ratchet 103 and the first pawl 403 cooperate to circumferentially lock the guide post 4, causing the screw 5 to remain stationary. However, the second tooth portion 301 of the transmission post 3 can contact the first tooth portion 203 of the adjustment post 2 and make a tooth sound for prompting; S3. Press the button 8. The second tooth portion 301 of the transmission post 3 forms a rigid connection with the first tooth portion 203 of the adjustment post 2 under the action of pressure. At the same time, the adjustment post 2 rotates forward clockwise under the cooperation of the coarse thread 202 and the coarse thread groove 102 until the injection dose returns to zero and stops. During this period, the transmission post 3 rotates clockwise synchronously with the adjustment post 2; S4. Under the cooperation of the rib 302 and the groove 401, the guide post 4 rotates clockwise synchronously with the transmission post 3 and drives the screw 5 to move forward through the internal thread 402 at the proximal end; S5. The screw 5 pushes the piston 1301 and extrudes a specific dose of medicine from the bottle and injects it into the target site of the object through the needle 12.

[0059] The focus of this application is mainly to improve the design of the driving mechanism of the syringe. From the above description, it can be seen that compared with the traditional driving structure, the driving mechanism has fewer components and a more concise overall structure. While reducing costs, it reduces the risk of unstable driving. On the other hand, the transmission parts (such as teeth, grooves, threads, etc.) on each component are relatively dispersed, which is beneficial for the assembly design because it can avoid problems such as increased assembly difficulty caused by the transmission parts being too concentrated in the same position and transmission stability problems caused by concentrated stress, thereby improving the driving stability.

[0060] See Figure 7As shown, in some embodiments, the proximal end of the support column 7 abuts against the transmission column 3, which is used to support the transmission column 3 and ensure its circumferential rotation. Preferably, at least one of the proximal end of the support column 7 and / or the distal end of the transmission column 3 may be provided with a smooth and wear-resistant coating or an arc structure (not shown), thereby reducing friction and improving the smoothness of the rotation of the transmission column 3.

[0061] The distal end of the support column 7 is provided with an extension 701, which extends outside the adjustment column 2 and is connected to the button 8. The slightly longer design enables the button 8 to form a certain pressing gap with the knob 6 axially after assembly, so as to avoid the influence of the knob 6 on the pressing operation. In addition, the extension 701 also cooperates with the knob 6 to form a spring groove, and a spring 9 is arranged in the spring groove, which is used to apply a force to the transmission column 3 to form a separable effect with the adjustment column 2.

[0062] See Figure 5 、 Figure 6 and Figure 11 As shown, in some embodiments, the first ratchet 103 and the first tooth part 203 each extend towards each other and respectively form a limit block 108 and a mating block 204. Among them, when the injection dose returns to zero, the limit block 108 can just abut against the mating block 204, thereby accurately defining the zero position and effectively preventing the adjustment column 2 from retreating beyond the limit and affecting the accuracy of the subsequent preset injection dose.

[0063] See Figure 3 and Figure 11 As shown, in some embodiments, a lens 10 is provided at the viewing window 101. The lens 10 is preferably a convex lens, which can play a role in magnifying the dose scale 201 while providing dust protection, facilitating identification and observation. Generally, the magnification of the lens 10 is approximately about 1.5 times to ensure the clear visibility of the dose scale 201.

[0064] See Figure 2 As shown, in some embodiments, a strip hole 1101 is provided on the side of the cartridge holder 11. The strip hole 1101 is arranged axially to observe the remaining amount of the medicament in the vial 13 in real time.

[0065] In addition, the proximal end of the cartridge holder 11 is detachably connected to the needle 12. The detachable needle 12 design can adapt to different injection requirements and effectively prevent the contamination problem that may be caused by replacing different medicaments. Combining Figure 16 As shown, in the present application, the needle 12 can be fixed to the proximal end of the cartridge holder 11 by means of threads.

[0066] Similarly, the distal end of the cartridge holder 11 is detachably connected to the outer shell 1 to facilitate the replacement of the medicine bottle 13. As an example, a socket part 104 is provided at the proximal end of the outer shell 1, and an L-shaped groove 107 is provided on the socket part 104; correspondingly, a clamping block 1102 is provided on the inner side of the distal end of the cartridge holder 11. The clamping block 1102 can be quickly connected by rotating and mating with the L-shaped groove 107. More specifically, the L-shaped groove 107 includes an insertion section 1071 and a locking section 1072, and a retaining rib 1073 is provided in the locking section 1072. After the clamping block 1102 is transferred from the insertion section 1071 to the locking section 1072, it can be limited by the retaining rib 1073, so as to improve the fixing effect after connection. And the retaining rib 1073 also has a certain anti-misoperation effect. Due to its existence, when the cartridge holder 11 needs to be separated from the socket part 104, reverse rotation needs to overcome the resistance of the retaining rib 1073, that is, a greater force is required to remove the clamping block 1102 from the L-shaped groove 107, so as to prevent the cartridge holder 11 and the outer shell 1 from loosening, and the reliability is better.

[0067] In a further design, referring to Figures 1 to 16 as shown, the pen-type syringe of the present application further includes a second ratchet wheel 14 and a second pawl 105. Among them, the second ratchet wheel 14 is provided inside the socket part 104, and a non-circular hole 1401 is provided at its center, such as Figure 15 the rectangular hole shown, and a part of the screw rod 5 slides through this non-circular hole 1401. The second pawl 105 is provided on the socket part 104 and can elastically deform radially. Combining Figure 16 it can be understood that the interaction between the second ratchet wheel 14 and the second pawl 105 is actually controlled by the cartridge holder 11. The second pawl 105 only contacts and cooperates with the second ratchet wheel 14 during the period when the cartridge holder 11 is installed on the socket part 104 to limit the rotational freedom of the screw rod 5. Specifically, in the operating state of the pen-type syringe, since the cartridge holder 11 is sleeved on the socket part 104 of the outer shell 1, the second pawl 105 will radially contract inward under the pressure of its inner wall, causing it to contact and lock the second ratchet wheel 14. And because the non-circular hole 1401 of the second ratchet wheel 14 restricts the screw rod 5 (only axial movement is allowed between the two, and circumferential rotation is not allowed), this causes the screw rod 5 to only move axially forward under the control of the driving mechanism during the period when the medicine in the syringe is not consumed, and will not retreat due to vibration or repeated operation, thus affecting the accuracy of the injection dose. And the existence of the second ratchet wheel 14 further improves the stability of the movement of the screw rod 5. In the medicine-changing state, since the cartridge holder 11 needs to be separated from the outer shell 1, after removing the cartridge holder 11 on the socket part 104, the second pawl 105 automatically expands radially outward and separates from the second ratchet wheel 14. At this time, the second ratchet wheel 14 is allowed to rotate freely. By reversing the second ratchet wheel 14 or the screw rod 5, the screw rod 5 can be retracted to the initial position, waiting to be used again after assembling a new medicine bottle 13.

[0068] Referring toFigure 4 and Figure 14 As shown, in some embodiments, the sleeve portion 104 is provided with a relief opening 106, and the second pawl 105 is located within the relief opening 106 to ensure that the second pawl 105 can elastically deform in the radial direction. Furthermore, the second pawl 105 is provided with a protruding mating surface 1051 on the side away from the second ratchet wheel 14. This mating surface 1051 is convex and has inclined guide surfaces on both sides to facilitate mating with the inner wall of the refill holder 11.

[0069] See also Figure 13 As shown, in some embodiments, the proximal end of the screw 5 is detachably connected to the piston 1301 to facilitate drug replacement operations. For example, the proximal end of the screw 5 is provided with a quick connector, and the distal end of the piston 1301 is provided with a corresponding quick interface. The quick connector and the quick interface correspond to each other and can be quickly connected in a plug-and-pull manner.

[0070] See also Figure 15 As shown, in some embodiments, the screw rod 5 is provided with at least one cut surface 501 along the axial direction. For example, cut surfaces 501 are provided on both sides of the screw rod 5 along the axial direction, resulting in a cross-section of the screw rod 5 having a rectangular structure. Accordingly, the non-circular hole 1401 is a rectangular hole that matches the cross-section of the screw rod 5. This allows the screw rod 5 to only move axially relative to the second ratchet wheel 14, but not to rotate axially.

[0071] See also Figures 5 to 10 As shown, in some embodiments, the proximal end of the housing 1 is integrally formed with a first ratchet 103 and a socket portion 104, the proximal end of the adjustment column 2 is integrally formed with a first tooth portion 203, the proximal end of the transmission column 3 is integrally formed with a second tooth portion 301 and a rib 302, and the proximal end of the guide column 4 is integrally formed with a first pawl 403. The integral molding allows each transmission component to be directly integrated into the corresponding part, facilitating assembly while reducing the number of parts and lowering production costs.

[0072] In some embodiments, a soft rubber cover is provided on the side of the housing 1 facing away from the viewing window 101. The soft rubber cover has a wavy structure that fits the knuckles, thereby increasing friction and improving grip comfort.

[0073] In some embodiments, a pen cap 15 is provided on the pen core holder 11 , and the two can be fixed in an interference manner, thereby protecting the puncture needle 12 and / or the medicine bottle 13 .

[0074] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Without departing from the principles and spirit of the present invention, those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the invention, and all such changes should fall within the scope of protection of the claims of the present invention.

Claims

1. A pen-type syringe, characterized in that, Comprising: A housing (1) with a viewing window (101) provided on its side; An adjustment column (2) provided inside the housing (1), a dose scale (201) being provided on the outer periphery of the adjustment column (2), and a knob (6) being connected to the distal end; A transmission column (3) provided inside the adjustment column (2), the proximal end of the transmission column (3) being in clutch connection with the adjustment column (2), and the distal end being connected to a button (8) through a support column (7); A guide column (4) provided inside the transmission column (3), and the guide column (4) being restricted to rotate only unidirectionally; A screw (5) provided inside the guide column (4), the screw (5) being used to provide a bolus injection force for a target object.

2. The pen-type syringe according to claim 1, characterized in that, The pen-type syringe is configured such that: the knob (6) is rotated counterclockwise to preset the injection dose, during which the screw (5) remains stationary; and the screw (5) can be driven to move forward by pressing the button (8) until the injection dose returns to zero and then stops.

3. The pen-type syringe according to claim 1, characterized in that, A coarsely threaded groove (102) extending axially is provided inside the housing (1); A coarsely threaded portion (202) that mates with the coarsely threaded groove (102) is provided on the outer side of the proximal end of the adjustment column (2), and the distal end extends outside the housing (1) and is connected to the knob (6).

4. The pen-type syringe according to claim 1, wherein, A first tooth portion (203) is provided on the inner side of the proximal end of the adjustment column (2), and a second tooth portion (301) opposite to the first tooth portion (203) is provided on the proximal end of the transmission column (3); Wherein, when the knob (6) is rotated counterclockwise, the first tooth portion (203) can rotate relative to the second tooth portion (301) and touch it to produce a tooth sound; and after the button (8) is pressed, the first tooth portion (203) can engage with the second tooth portion (301) and rotate synchronously in the clockwise direction.

5. The pen-type syringe according to claim 1, characterized in that, The proximal end of the support column (7) abuts against the transmission column (3), and an extension portion (701) is provided at the distal end; wherein, the extension portion (701) is connected to the button (8) and can cooperate with the knob (6) to form a spring groove, and a spring (9) is provided inside the spring groove.

6. The pen-type syringe according to claim 1, characterized in that, A rib (302) is provided on the inner side of the transmission column (3), a groove (401) extending axially is provided on the outer side of the guide column (4), and the rib (302) is in sliding engagement with the groove (401).

7. The pen-type syringe according to claim 1, characterized in that, An internal thread (402) that mates with the screw (5) is provided on the inner side of the proximal end of the guide column (4), a guide ring is provided at the distal end of the screw (5), and the guide ring is in sliding fit with the guide column (4).

8. The pen-type syringe according to claim 1, characterized in that, A first ratchet (103) is provided at the proximal end of the housing (1), a first ratchet pawl (403) is provided at the proximal end of the guide column (4), and the first ratchet (103) is in contact fit with the first ratchet pawl (403), causing the guide column (4) to rotate only in the clockwise direction.

9. The pen-type syringe according to claim 1, characterized in that, A lens (10) is provided at the viewing window (101), and the lens (10) is used to magnify the dose scale (201).

10. The pen-type syringe according to claim 1, characterized in that, It further includes a cartridge holder (11), a needle (12) is provided at the proximal end of the cartridge holder (11), and the distal end is disposed at the proximal end of the outer shell (1) and cooperates with it to form a chamber for fixing a medicine bottle (13).

11. The pen-type syringe according to claim 10, characterized in that, Both ends of the cartridge holder (11) are detachably connected to the needle (12) and the outer shell (1) respectively, and a slot opening (1101) is provided on the side of the cartridge holder (11).

12. The pen - type syringe according to claim 10, characterized in that, A second ratchet wheel (14) which is slidably engaged with the screw (5) is provided on the screw (5), a socket part (104) is provided at the proximal end of the outer shell (1), and a second pawl (105) is provided on the socket part (104); Wherein, the second pawl (105) is in contact and cooperation with the second ratchet wheel (14) only during the period when the cartridge holder (11) is installed on the socket part (104) to limit the rotational freedom of the screw (5).

13. The pen-type syringe according to claim 12, characterized in that, At least one cut surface (501) is axially provided on the screw (5), and a non-circular hole (1401) which is matched with it is provided at the center of the second ratchet wheel (14).

14. The pen-type syringe according to claim 1, characterized in that, A first ratchet wheel (103) and a socket part (104) are integrally formed at the proximal end of the outer shell (1); A first tooth part (203) is integrally formed at the proximal end of the adjusting column (2); A second tooth part (301) and a rib (302) are integrally formed at the proximal end of the transmission column (3); A first pawl (403) is integrally formed at the proximal end of the guiding column (4).

15. The pen-type syringe according to claim 14, characterized in that, The first ratchet wheel (103) and the first tooth part (203) extend towards each other respectively and form a limiting block (108) and a mating block (204); Wherein, when the injection dose returns to zero, the limiting block (108) can just abut against the mating block (204).

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