Medical disposable pre-filling injection pen

Abstract

The utility model provides a medical disposable pre-filling injection pen. The medical disposable pre-filling injection pen comprises a cylinder body, a pressing assembly, a transmission assembly and an injection assembly, the interior of the cylinder body is divided into an injection cavity and a transmission cavity; the pressing assembly is provided with a pressing head and a rotating cylinder, the rotating cylinder is in threaded connection with the inner wall of the transmission cavity, and an axial locking clamping groove is formed in the inner wall of the bottom end of the rotating cylinder; the transmission assembly comprises a connecting rod, a push rod and a push plate, the push rod is divided into a push part and a stop part from bottom to top, and the bottom end of the push part is connected with the push plate; the connecting rod is provided with a stop head, and the stop part can push the stop head outwards in the radial direction of the barrel body, so that the stop head is connected with the axial stop clamping groove in a clamped mode; the injection assembly is arranged in the injection cavity. According to the medical disposable pre-filling injection pen provided by the utility model, after injection is finished, the stop head is extruded by the stop part to generate irreversible deformation, so that the situation that the used injection pen can be repeatedly used is avoided.

Description

Technical Field

[0001] This utility model belongs to the field of medical device technology, specifically relating to a disposable pre-filled injection pen for medical use. Background Technology

[0002] When treating certain diseases, a syringe is typically used to directly inject medication into the body tissue to achieve an effective treatment. An injection pen is a type of syringe that automatically injects pre-filled liquid medication into the patient's body, meeting the user's need for self-administration and reducing the number of times a patient needs to return for treatment.

[0003] Since patients are not professional medical personnel, injection pens are required to be easy to operate and highly reliable. Existing injection pens consist of a shell and an injection component inside the shell, which injects the medication into the patient's body. After the medication in a single injection pen is used up, the pen needs to be discarded to avoid cross-infection from reuse. Since patients use them at home, to prevent reuse or indiscriminate collection, the pen needs to be damaged after injection. However, current damage methods are mostly due to human error, making it impossible to automatically discard the pen. The extent of human error is uncontrollable, posing a risk of the pen needing repair. Utility Model Content

[0004] This utility model provides a disposable pre-filled medical injection pen, which aims to solve the technical problem that existing injection pens require manual disposal after use, cannot be automatically discarded, and pose a risk of reuse.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0006] A disposable pre-filled injection pen for medical use is provided, comprising:

[0007] The cylinder has openings at both ends, and a partition is provided inside the cylinder to divide the inner cavity of the cylinder into an injection cavity and a transmission cavity. A connection port is provided on the partition.

[0008] The pressing assembly has a pressing head and a rotating cylinder. The rotating cylinder is screwed to the inner wall of the transmission cavity. The pressing head is slidably disposed at the upper end of the rotating cylinder along the axis of the transmission cavity and can push the rotating cylinder downward. The inner wall of the bottom end of the rotating cylinder is provided with an axial stop groove.

[0009] A transmission assembly, placed inside the rotating cylinder, includes a connecting rod, a pushing rod, and a pushing plate. The connecting rod slides circumferentially with the inner wall of the rotating cylinder. The pushing rod is divided into a pushing part and a stopping part from bottom to top. The bottom end of the pushing part is connected to the pushing plate. The pushing part is threadedly engaged with the inner wall of the connecting rod. The outer diameter of the stopping part is larger than the outer diameter of the pushing part. The connecting rod has a mating opening corresponding to the axial stopping groove. A stopping head is provided in the mating opening. The stopping part can push the stopping head radially outward along the cylinder body, so that the stopping head engages with the axial stopping groove to limit the axial displacement of the pushing rod.

[0010] An injection assembly has a cartridge vial, one end of which has a piston located within the injection chamber, and a push plate abuts against the piston of the cartridge vial.

[0011] In one possible implementation, the rotating cylinder includes a digital display, a transmission gear, and a sliding cylinder. The digital display is screwed to the inner wall of the transmission cavity. The bottom inner wall of the digital display has a mating part. The sliding cylinder is located inside the digital display. The transmission gear is located between the mating part and the sliding cylinder. The two ends of the transmission gear are respectively provided with external teeth. The mating part and the sliding cylinder are respectively provided with internal teeth corresponding to the external teeth. The internal teeth mesh with the external teeth at the corresponding ends.

[0012] In one possible implementation, the pressing component further includes:

[0013] A transmission block is located inside the upper end of the digital tube. The upper end of the transmission block is inserted into the pressing head, and the lower end is connected to the sliding tube.

[0014] A bushing, disposed in the transmission cavity and fixedly connected to the cylinder, wherein the inner wall of the bushing is threadedly engaged with the outer wall of the digital tube; and

[0015] An elastic element is connected at both ends to the transmission block and the pressing head, respectively. The elastic element is configured with a preload force to push the pressing head away from the transmission block.

[0016] In one possible implementation, the inner side of the pressing head is provided with a plug-in post, the transmission block is provided with a plug-in sleeve corresponding to the plug-in post, the plug-in post and the plug-in sleeve are plugged into each other, and the elastic element is simultaneously sleeved on the outer periphery of the plug-in post and the plug-in sleeve.

[0017] The bottom outer periphery of the pressing head is provided with an anti-detachment hook, and the inner wall of the digital tube is provided with an anti-retraction groove corresponding to the anti-detachment hook. The anti-detachment hook and the anti-retraction groove are engaged to prevent the pressing head from detaching from the digital tube.

[0018] In one possible implementation, the outer periphery of the digital tube is provided with a threaded groove, and the inner wall of the tube body is provided with an internal thread corresponding to the threaded groove, wherein the internal thread is threadedly engaged with the threaded groove.

[0019] The digital tube has multiple markings on its outer periphery, and a reading port is provided on the tube body.

[0020] In one possible implementation, the medical disposable pre-filled injection pen further includes a pen cap, which covers the cartridge and is connected to the cylinder.

[0021] In one possible implementation, the injection assembly further includes a refill holder with openings at both ends, one end of which is connected to the opening of the injection cavity, and the cartridge is disposed within the inner cavity of the refill holder.

[0022] In one possible implementation, the injection cavity is further provided with a sound-making element, the sound-making element having a perforation in the middle, and the push rod slidingly engaging with the perforation;

[0023] The bottom outer periphery of the connecting rod is provided with an abutment arm, and the sound-making component forms a sound ring corresponding to the abutment arm. The inner wall of the sound ring is provided with a toothed ring, and the abutment arm abuts against the toothed ring. The abutment arm rotates as the connecting rod rotates.

[0024] In one possible implementation, a connecting ring is provided between the digital display and the sliding cylinder, the outer ring of the connecting ring being slidably engaged with the digital display, and the inner ring of the connecting ring being threadedly engaged with the outer wall of the sliding cylinder.

[0025] In one possible implementation, the outer periphery of the connecting ring is provided with a limiting groove extending along its own axial direction, and the inner wall of the digital tube is provided with a limiting protrusion corresponding to the limiting groove. The limiting groove and the limiting protrusion are slidably engaged to restrict the relative rotation between the connecting ring and the digital tube.

[0026] The disposable pre-filled injection pen provided by this utility model, compared with the prior art, features a rotatable connection between the press head and the digital cylinder, and an insertion fit between the digital cylinder and the sliding cylinder. The sliding cylinder drives the connecting rod to rotate, and the push rod slides with the connecting rod. When the patient presses the press head, the digital cylinder rotates, driving the sliding cylinder to rotate, which in turn drives the connecting rod to rotate. The connecting rod then drives the push rod to rotate, causing the push rod to slide along the long axis of the cylinder, thereby pushing the plate to squeeze the cartridge bottle for easy dispensing. After all the liquid in the cartridge bottle has been injected, the stop part of the connecting rod moves to the position of the stop head. The stop head is squeezed by the stop part, resulting in irreversible deformation. The stop head protrudes outward and engages with the axial stop groove, restricting the axial displacement of the push rod. The push rod cannot retract, causing irreversible damage to the injection pen. This prevents the used injection pen from being reused. The compression damage to the push rod and connecting rod is inside the injection pen and cannot be repaired, facilitating the disposal of the injection pen. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 A schematic diagram of the structure of the disposable pre-filled injection pen provided in this embodiment of the utility model;

[0029] Figure 2 for Figure 1 Front cross-sectional view;

[0030] Figure 3 for Figure 2 A cross-sectional view of the pressing component used in the process;

[0031] Figure 4 for Figure 2 The assembly diagram of the digital tube and its body used in the design;

[0032] Figure 5 for Figure 2 The assembly cross-sectional view of the cylinder and bushing used in the process;

[0033] Figure 6 for Figure 2 A schematic diagram of the transmission components used in the process;

[0034] Figure 7 for Figure 6 Cross-sectional view;

[0035] Figure 8 for Figure 2A schematic diagram of the structure of the digital tube used in the design;

[0036] Figure 9 for Figure 8 The side view of the digital tube used in the image;

[0037] Figure 10 for Figure 2 A schematic diagram of the assembly of the transmission gear and the sliding cylinder used in the process;

[0038] Figure 11 for Figure 2 A schematic diagram of the connecting rod used in the process;

[0039] Figure 12 for Figure 2 A schematic diagram of the sound-emitting component used in the process.

[0040] Explanation of reference numerals in the attached figures:

[0041] 1. Cylinder body; 11. Baffle plate; 12. Reading port;

[0042] 2. Pressing assembly; 21. Pressing head; 211. Insertion post; 212. Anti-disengagement hook; 22. Digital display; 221. Axial stop groove; 222. Anti-reverse groove; 223. Threaded groove; 23. Sliding cylinder; 231. Retaining ring; 24. Transmission block; 241. Insertion sleeve; 25. Bushing; 26. Transmission gear; 27. Elastic element; 28. Connecting ring; 281. Limiting groove;

[0043] 3. Transmission assembly; 31. Connecting rod; 311. Stop head; 312. Abutment arm; 32. Push rod; 321. Stop part; 33. Push plate; 34. Sounding component; 341. Gear ring;

[0044] 4. Injection assembly; 41. Cartridge; 42. Pen refill holder;

[0045] 5. Pen cap. Detailed Implementation

[0046] To make the technical problem to be solved, the technical solution, and the beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0047] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. The following description of at least one exemplary embodiment is actually illustrative only and is in no way intended to limit this application or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0048] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways, and the spatial relative descriptions used herein will be interpreted accordingly.

[0049] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Additionally, "multiple" and "several" mean two or more, unless otherwise explicitly specified.

[0050] Please refer to the following: Figures 1 to 12The present invention provides a description of a disposable pre-filled injection pen for medical use. The disposable pre-filled injection pen includes a cylinder 1, a pressing assembly 2, a transmission assembly 3, and an injection assembly 4. The cylinder 1 is open at both ends, and a partition 11 is provided inside the cylinder 1 to divide the inner cavity of the cylinder 1 into an injection chamber and a transmission chamber. A connection port is provided on the partition 11. The pressing assembly 2 has a pressing head 21 and a rotating cylinder. The rotating cylinder is screwed to the inner wall of the transmission chamber. The pressing head 21 is slidably disposed at the upper end of the rotating cylinder along the axis of the transmission chamber and can push the rotating cylinder downwards. An axial stop groove 22 is provided on the inner wall of the bottom end of the rotating cylinder. The transmission assembly 3 is placed inside the rotating cylinder and includes a connecting rod 31, a pushing rod 32, and a pushing plate 33. The connecting rod 31 slides circumferentially with the inner wall of the rotating cylinder. The pushing rod 32 moves downwards from the bottom... The upper part is divided into a pushing part and a stopping part 321. The bottom end of the pushing part is connected to the pushing plate 33. The pushing part is threadedly engaged with the inner wall of the connecting rod 31. The outer diameter of the stopping part 321 is larger than the outer diameter of the pushing part. The connecting rod 31 is provided with a mating port corresponding to the axial stopping groove. A stopping head 311 is provided in the mating port. The stopping part 321 can push the stopping head 311 outward along the radial direction of the cylinder 1, so that the stopping head 311 is engaged with the axial stopping groove 221 to limit the axial displacement of the pushing rod 32. The injection assembly 4 has a cartridge bottle 41. One end of the cartridge bottle 41 with a piston is located in the injection chamber. The pushing plate 33 abuts against the piston of the cartridge bottle 41.

[0051] It should be noted that the terms "upper end" and "bottom end" mentioned in this embodiment refer to the vertical direction shown in the attached drawings.

[0052] It should be noted that in this embodiment, the connecting rod 31 first forms a mating opening corresponding to the axial stop groove 221, and the stop head 311 is located in the mating opening. One end of the stop head 311 is connected to the side of the mating opening. The stop head 311 will not contact the push rod 32 when the injection pen is in normal use. After the medicine in the cartridge bottle 41 is injected, the stop part 321 moves to the position of the mating opening. The stop part 321 can squeeze the stop head 311, so that the stop head 311 moves towards the axial stop groove 221 until it abuts against the axial stop groove 221, forming a snap-fit ​​fixation between the push rod 32 and the digital tube 22.

[0053] It should be noted that the deformation of the stop head 311 is irreversible. After being pushed by the stop part 321, it undergoes inelastic deformation and comes into contact with the axial stop groove 221.

[0054] It should be noted that the digital tube 22 is the digital tube in the existing injection pen. One end is inserted into the tube body 1, and the other end forms a convex ring. The outer circumference of the convex ring is set with scales to facilitate patients to adjust the injection volume themselves.

[0055] In practice, a clearance space is formed between the threads on the outer periphery of the push rod 32, and the stop head 311 extends into the clearance space. The outer diameter of the stop part 321 is larger than the outer diameter of the push rod 32. During the injection process, the stop head 311 will not be squeezed; it will only be pushed outward after it comes into contact with the stop part 321.

[0056] The medical disposable pre-filled injection pen provided in this embodiment, compared with the prior art, has a pressing head 21 rotatably connected to a digital cylinder 22, and a sliding cylinder 23 inserted into and engaged with the digital cylinder 22. The sliding cylinder 23 drives the connecting rod 31 to rotate, and the pushing rod 32 slides with the connecting rod 31. When the patient presses the pressing head 21, the digital cylinder 22 rotates, driving the sliding cylinder 23 to rotate. The rotation of the sliding cylinder 23 drives the connecting rod 31 to rotate, and the connecting rod 31 drives the pushing rod 32 to rotate, causing the pushing rod 32 to slide along the long axis of the cylinder 1. This, in turn, causes the pushing plate 33 to squeeze the cartridge bottle 41, facilitating liquid dispensing. When the cartridge bottle is pressed... After all the liquid in the bottle 41 has been injected, the stop part 321 of the connecting rod 31 moves to the position of the stop head 311. The stop head 311 is squeezed by the stop part 321, causing irreversible deformation. The stop head 311 protrudes outward and engages with the axial stop groove 221, restricting the axial displacement of the push rod 32. The push rod 32 cannot retract, causing irreversible damage to the injection pen. This prevents the used injection pen from being reused. The compression damage to the push rod 32 and the connecting rod 31 is inside the injection pen and cannot be repaired, facilitating the disposal of the injection pen.

[0057] In some embodiments, see Figures 2 to 4 The rotating cylinder includes a digital tube 22, a transmission gear 26, and a sliding cylinder 23. The digital tube 22 is screwed to the inner wall of the transmission cavity. The bottom inner wall of the digital tube 22 is provided with a mating part. The sliding cylinder 23 is located inside the digital tube 22. The transmission gear 26 is located between the mating part and the sliding cylinder 23. The two ends of the transmission gear 26 are respectively provided with external teeth. The mating part and the sliding cylinder 23 are respectively provided with internal teeth corresponding to the external teeth. The internal teeth mesh with the external teeth at the corresponding ends.

[0058] It should be noted that the convex teeth and their corresponding concave teeth can cooperate to form a skip space. The skip space refers to the spatial range in which the chain and gears deviate from their fit during the alignment process due to various reasons, resulting in skipping. When skipping occurs, a sound will be produced to remind the patient to adjust the chain correctly.

[0059] It should be noted that the protruding teeth at both ends of the transmission gear 26 are inclined, which causes the concave teeth on the digital tube 22 to skip with the transmission gear 26 when the patient rotates the digital tube 22 outward, and the digital tube 22 cannot drive the sliding tube 23 to rotate; when injecting, the concave teeth on the digital tube 22 are engaged with the transmission gear 26, and the digital tube 22 drives the sliding tube 23 to rotate.

[0060] In this embodiment, the digital tube 22 inside the rotating cylinder is screwed to the cylinder body 1, which facilitates the stable extraction of the digital tube 22. The digital tube 22 is connected to the sliding cylinder 23 through the transmission gear 26. The transmission gear 26 performs transmission, so that when adjusting the dosage, the digital tube 22 does not drive the transmission gear 26 to rotate, creating a skipping space to remind the patient and facilitate the patient to adjust automatically.

[0061] In some embodiments, see Figures 2 to 4 The pressing assembly 2 also includes a transmission block 24, a bushing 25, and an elastic element 27. The transmission block 24 is located inside the upper end of the digital tube 22, with its upper end inserted into the pressing head 21 and its lower end connected to the sliding cylinder 23. The bushing 25 is located in the transmission cavity and is fixedly connected to the cylinder body 1, with the inner wall of the bushing 25 threadedly engaged with the outer wall of the digital tube 22. The elastic element 27 is connected to the transmission block 24 and the pressing head 21 at both ends, and the elastic element 27 is configured with a preload force to push the pressing head 21 away from the transmission block 24.

[0062] The pressing component 2 provided in this embodiment allows the patient to adjust the injection volume independently. The patient rotates the digital cylinder 2, causing the digital cylinder 2 to move outward or inward relative to the bushing 25. At this time, the transmission tooth 26 engages with the concave tooth on the digital cylinder 22, and the elastic element 27 is compressed, so that the digital cylinder 22 cannot drive the push rod 32 to rotate. The position of the push rod 32 remains unchanged, causing a skipping motion between the concave tooth of the digital cylinder 22 and the transmission tooth 26 to produce a skipping sound prompt. The patient can know that the adjustment is successful when they hear the skipping sound, which makes it convenient for the patient to adjust the dosage.

[0063] The pressing component 2 provided in this embodiment can operate the pressing head 21 to cause a series of interactions between the internal digital cylinder 22, sliding cylinder 23, transmission block 24, elastic element 27 and transmission gear 26, ultimately causing the moving rod 32 to slide, reducing the difficulty of operation for the patient and making it convenient for the patient to perform injection operations independently.

[0064] Optionally, the elastic element 27 can be a spring with good deformation continuity and high elasticity to meet the usage requirements. It can also be a rubber spring, as long as it can drive the sliding cylinder 23 to move.

[0065] In some embodiments, see Figure 2 and Figure 5The inner side of the pressing head 21 is provided with a plug-in post 211, and the transmission block 24 is provided with a plug-in sleeve 241 corresponding to the plug-in post 211. The plug-in post 211 and the plug-in sleeve 241 are plugged into each other. The elastic element 27 is simultaneously sleeved on the outer periphery of the plug-in post 211 and the plug-in sleeve 241. The outer periphery of the end of the pressing head 21 facing the digital tube 22 is provided with an anti-disengagement hook 212, and the inner wall of the digital tube 22 is provided with an anti-retraction groove 222 corresponding to the anti-disengagement hook 212. The anti-disengagement hook 212 and the anti-retraction groove 222 are engaged to prevent the pressing head 21 from disengaging from the digital tube 22. The plug-in post 211 and the plug-in sleeve 241 can guide the extension and retraction direction of the elastic element 27 to ensure the stability of pressing. After the anti-disengagement hook 212 and the anti-retraction groove 222 are engaged, the elastic element 27 cannot push the pressing head 21 out of the digital tube 22, improving the ease of use of the injection pen.

[0066] In some embodiments, see Figure 8 The digital tube 23 has a threaded groove 223 on its outer periphery, and the inner wall of the tube body 1 has an internal thread corresponding to the threaded groove 223, with the internal thread engaging with the threaded groove 223. The digital tube 22 has multiple markings on its outer periphery, and a reading port 12 is provided on the tube body 1. The tube body 1 and the digital tube 23 are threaded together. By turning the digital tube 22, the single movement distance of the push rod 32 can be adjusted, thereby adjusting the injection dose, which is simple to operate. The reading port 12 allows the markings on the digital tube 22 to be displayed on the reading port 12, making it convenient for patients to adjust the single injection dose independently and reducing the difficulty of operation.

[0067] In some embodiments, see Figure 1 and Figure 2 The medical disposable pre-filled injection pen also includes a pen cap 5, which covers the cartridge bottle 41 and is connected to the barrel 1. The pen cap 5, together with the barrel 1, forms a closed environment, isolating the cartridge bottle 41 from the outside world, improving the preservation effect of the drug solution, and preventing the drug solution from being contaminated by impurities in the external environment.

[0068] In some embodiments, see Figure 1 and Figure 2 The injection assembly 4 also includes a cartridge holder 42, which has openings at both ends. One end of the cartridge holder 42 is connected to the opening of the injection chamber, and a cartridge 41 is disposed in the inner cavity of the cartridge holder 42. One end of the cartridge holder 42 is fixed to the end of the cylinder 1 to protect the cartridge 41. When the piston of the cartridge 41 is pushed by the push plate 33, the cartridge 41 will not move, thus improving the stability of the injection.

[0069] In some embodiments, see Figure 2 , Figure 11 and Figure 12The injection chamber is also equipped with a sound-emitting element 34, which has a perforation in the middle. The push rod 32 slides in the perforation. The bottom outer periphery of the connecting rod 31 is provided with an abutment arm 312. The sound-emitting element 34 forms a sound ring corresponding to the abutment arm 312. The inner wall of the sound ring is provided with a toothed ring 341. The abutment arm 312 abuts against the toothed ring 341 and rotates with the connecting rod 31. The push rod 32 and the connecting rod 31 are screwed together. When the connecting rod 31 rotates, the push rod 32 is driven to move along the axis of the cylinder 1, pushing the push plate 33 to perform the injection operation. At the same time as the injection, the abutment arm 312 rotates around the circumference of the connecting rod 31. Since the abutment arm 312 abuts against the toothed ring, the abutment arm 312 will strike the toothed ring 341 when it rotates, producing a sound to remind the patient of the injection progress. This helps the patient to complete the injection operation independently and reduces the difficulty of the operation.

[0070] In some embodiments, see Figure 2 , Figure 3 and Figure 10 A connecting ring 28 is provided between the digital display 22 and the sliding cylinder 23. The outer ring of the connecting ring 28 is slidably engaged with the digital display 22, and the inner ring of the connecting ring 28 is threadedly engaged with the outer wall of the sliding cylinder 23. When the digital display 22 rotates, it can drive the connecting ring 28 to rotate, and the rotation of the connecting ring 28 enables the sliding cylinder 23 to rotate effectively.

[0071] Specifically, a retaining ring 231 is provided on the outer periphery of the end of the sliding cylinder 23 away from the partition 11. The connecting ring 28 can abut against the retaining ring 231 to prevent the sliding cylinder 23 from detaching from the digital cylinder 22. When the patient rotates outward to pull out the digital cylinder 22, the retaining ring 231 moves along the end away from the push plate 33. When the connecting ring 28 and the retaining ring 231 abut against each other, the digital cylinder 22 cannot be pulled out, indicating that the medication in this injection pen has been used up and the injection pen is discarded, avoiding the possibility of reusing the injection pen.

[0072] In some embodiments, see Figure 10 The connecting ring 28 has a limiting groove 281 extending along its own axial direction on its outer periphery. The inner wall of the digital tube 22 has a limiting protrusion corresponding to the limiting groove 281. The limiting groove 281 and the limiting protrusion slide together to restrict the relative rotation between the connecting ring 28 and the digital tube 22. The setting of the limiting groove 281 ensures that the connecting ring 28 can only slide along the axis of the digital tube 22 and cannot rotate circumferentially. During the injection process, the digital tube 22 rotates, the sliding tube 23 rotates, and the connecting ring 28 slides along the limiting protrusion and in a direction away from the cartridge bottle 41. This allows the connecting ring 28 to abut against the retaining ring 231 after all the medicine has been injected.

[0073] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A disposable pre-filled medical injection pen, characterized in that, include: The cylinder has openings at both ends, and a partition is provided inside the cylinder to divide the inner cavity of the cylinder into an injection cavity and a transmission cavity. A connection port is provided on the partition. The pressing assembly has a pressing head and a rotating cylinder. The rotating cylinder is screwed to the inner wall of the transmission cavity. The pressing head is slidably disposed at the upper end of the rotating cylinder along the axis of the transmission cavity and can push the rotating cylinder downward. The inner wall of the bottom end of the rotating cylinder is provided with an axial stop groove. A transmission assembly is placed inside the rotating cylinder. The transmission assembly includes a connecting rod, a pushing rod, and a pushing plate. The connecting rod slides circumferentially with the inner wall of the rotating cylinder. The pushing rod is divided into a pushing part and a stopping part from bottom to top. The bottom end of the pushing part is connected to the pushing plate. The pushing part is threadedly engaged with the inner wall of the connecting rod. The outer diameter of the stopping part is larger than the outer diameter of the pushing part. The connecting rod has a mating port corresponding to the axial stopping groove. A stopping head is provided in the mating port. The stopping part can push the stopping head radially outward along the cylinder body, so that the stopping head engages with the axial stopping groove to limit the axial displacement of the pushing rod. as well as An injection assembly has a cartridge vial, one end of which has a piston located within the injection chamber, and a push plate abuts against the piston of the cartridge vial.

2. The medical disposable pre-filled injection pen as described in claim 1, characterized in that, The rotating cylinder includes a digital tube, a transmission gear, and a sliding cylinder. The digital tube is screwed to the inner wall of the transmission cavity. The bottom inner wall of the digital tube is provided with a mating part. The sliding cylinder is located inside the digital tube. The transmission gear is located between the mating part and the sliding cylinder. The two ends of the transmission gear are respectively provided with external teeth. The mating part and the sliding cylinder are respectively provided with internal teeth corresponding to the external teeth. The internal teeth mesh with the external teeth at the corresponding ends.

3. The medical disposable pre-filled injection pen as described in claim 2, characterized in that, The pressing component also includes: A transmission block is located inside the upper end of the digital tube. The upper end of the transmission block is inserted into the pressing head, and the lower end is connected to the sliding tube. A bushing, disposed in the transmission cavity and fixedly connected to the cylinder, wherein the inner wall of the bushing is threadedly engaged with the outer wall of the digital tube; and An elastic element is connected at both ends to the transmission block and the pressing head, respectively. The elastic element is configured with a preload force to push the pressing head away from the transmission block.

4. The medical disposable pre-filled injection pen as described in claim 3, characterized in that, The inner side of the pressing head is provided with a plug-in post, and the transmission block is provided with a plug-in sleeve corresponding to the plug-in post. The plug-in post and the plug-in sleeve are plugged into each other, and the elastic element is sleeved on the outer periphery of both the plug-in post and the plug-in sleeve. The bottom outer periphery of the pressing head is provided with an anti-detachment hook, and the inner wall of the digital tube is provided with an anti-retraction groove corresponding to the anti-detachment hook. The anti-detachment hook and the anti-retraction groove are engaged to prevent the pressing head from detaching from the digital tube.

5. The medical disposable pre-filled injection pen as described in claim 2, characterized in that, The outer periphery of the digital tube is provided with a threaded groove, and the inner wall of the tube body is provided with an internal thread corresponding to the threaded groove, and the internal thread is threadedly engaged with the threaded groove; The digital tube has multiple markings on its outer periphery, and a reading port is provided on the tube body.

6. The medical disposable pre-filled injection pen as described in claim 1, characterized in that, The medical disposable pre-filled injection pen also includes a pen cap, which is placed over the cartridge and connected to the cylinder.

7. The medical disposable pre-filled injection pen as described in claim 1, characterized in that, The injection assembly also includes a pen refill holder, which has openings at both ends, one end of which is connected to the opening of the injection cavity, and the cartridge is disposed in the inner cavity of the pen refill holder.

8. The medical disposable pre-filled injection pen as described in claim 1, characterized in that, The injection cavity is also provided with a sound-making component, which has a perforation in the middle, and the push rod slides in conjunction with the perforation. The bottom outer periphery of the connecting rod is provided with an abutment arm, and the sound-making component forms a sound ring corresponding to the abutment arm. The inner wall of the sound ring is provided with a toothed ring, and the abutment arm abuts against the toothed ring. The abutment arm rotates as the connecting rod rotates.

9. The medical disposable pre-filled injection pen as described in claim 2, characterized in that, A connecting ring is also provided between the digital display and the sliding cylinder. The outer ring of the connecting ring is slidably engaged with the digital display, and the inner ring of the connecting ring is threadedly engaged with the outer wall of the sliding cylinder.

10. The medical disposable pre-filled injection pen as described in claim 9, characterized in that, The outer periphery of the connecting ring is provided with a limiting groove extending along its own axis, and the inner wall of the digital tube is provided with a limiting protrusion corresponding to the limiting groove. The limiting groove and the limiting protrusion are slidably engaged to restrict the relative rotation between the connecting ring and the digital tube.

Images