Disposable injection pen

Abstract

The disposable injection pen comprises a pen shell (1), an injection head mechanism (2) and a trigger mechanism (3), the injection head mechanism (2) comprises a needle cylinder (21) located in the pen shell (1) and a needle head (22) installed at the top of the needle cylinder (21), and a rubber plug (23) is arranged in the needle cylinder (21); the trigger mechanism (3) comprises a protective shell (31) which is arranged in the pen shell (1) and can movably wrap the needle head (22), the bottom of the protective shell (31) movably abuts against a sliding part (32), the sliding part (32) is sleeved with an auxiliary spring (33), the bottom end of the auxiliary spring (33) is fixed to the inner bottom of the pen shell (1), and a push rod (34) with the open bottom is movably connected into the sliding part (32) in a clamped mode. A main spring (35) is connected between the inner top of the push rod (34) and the inner bottom of the sliding part (32), and the triggering mechanism (3) enables the needle head (22) to automatically and quickly pierce into the skin and inject medicine, so that the pain and fear of a user who pierces into the skin by pressing are relieved.

Description

Disposable injection pen Technical Field

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

[0002] The syringe is a commonly used medical device. Conventional syringes only include three core components: a syringe, a needle, and a piston. By pushing the piston, the medicine in the syringe can be easily injected into the body through the needle. However, if it is used in non-medical settings such as home use and is operated by non-medical professionals, it requires injection, medication, and needle removal, and each operation requires certain skills; and after the injection is completed, the exposed needle is dangerous and requires special disposal. Therefore, the automatic injection pen was invented to improve the convenience of injection. With only simple movements, the continuous actions of injection, medication, and needle removal can be achieved. Because its appearance is designed to be pen-shaped, it is convenient to store and hold, so it is also called an injection pen.

[0003] There are many automatic injection pen products with the above functions on the market, but there are still some shortcomings. The injection method mostly relies on manual pressing, which invisibly increases the user's inner fear and makes the user experience very poor.

[0004] Therefore, it is necessary to design a new automatic injection pen to improve safety, reliability and user experience.

[0005] Summary of the Invention

[0006] The purpose of the present invention is to provide an automatic injection pen, in which the trigger mechanism needle tip automatically and quickly penetrates the skin and injects the drug, reducing the pain and fear of the user when pressing the needle tip into the skin.

[0007] The technical solution adopted by the embodiment of the present application to solve the technical problem is: a disposable injection pen, including a pen housing, an injection head mechanism and a trigger mechanism:

[0008] The injection head mechanism includes a syringe located in the pen housing and a needle mounted on the top thereof, and a rubber plug is provided in the syringe;

[0009] The trigger mechanism includes a protective shell provided in the pen case and movably wrapped around the outside of the needle, the bottom of the protective shell movably abuts against a sliding part, the outside of the sliding part is provided with a secondary spring whose bottom end is fixed to the bottom of the pen case, the inside of the sliding part is movably engaged with a push rod with an open bottom, a main spring is connected between the top of the push rod and the bottom of the sliding part, when the protective shell is pressed, the sliding part moves downward, causing the push rod to move upward and push the rubber plug forward; when the injection of the liquid medicine is completed, the push rod is separated from the inner cavity of the sliding part, and the sliding part is bounced to the bottom of the pen case by the main spring and hits to produce a sound of the completion of the injection of the liquid medicine.

[0010] Preferably, the pen shell includes an upper pen shell and a lower pen shell that are fixed together, and protrusions are provided on both sides of the inner wall of the lower pen shell. The protrusions are fixed on the inner wall of the syringe, and avoidance openings adapted to the protrusions are opened on both sides of the protective shell.

[0011] Preferably, the sliding portion includes an outer slider and a main body, guide grooves are provided on both sides of the outer slider, guide plates are longitudinally fixed in the guide grooves, and the main body slides along the guide plates and is inserted into the inner cavity of the outer slider.

[0012] Preferably, both sides of the outer wall of the outer sliding block are provided with retaining ribs, the upper end of the auxiliary spring is pressed against the bottom of the retaining ribs, and the auxiliary spring abuts against the inner bottom of the lower pen housing.

[0013] Preferably, the main body includes a cylinder and arc-shaped connecting plates connected to both sides of the upper part of the cylinder, the upper ends of the two arc-shaped connecting plates are connected to elastic hooks A provided at the opening of the upper end of the outer slider, and the middle parts of the two arc-shaped connecting plates are connected to arc-shaped plug plates with openings facing each other and fixed to the corresponding guide plates.

[0014] Preferably, the push rod is designed to be hollow inside, and both sides of the outer bottom are connected with bosses located in the two guide grooves respectively. The upper surfaces of the two bosses are respectively designed to fit with the side walls of the two arc-shaped connecting plates, and the fitting surfaces are designed to be inclined. When the arc-shaped connecting plate moves downward, the two bosses slide and screw into the corresponding arc-shaped insert plates and contact the guide plates.

[0015] Preferably, a fixed block that is in movably contact with the boss is connected to the opening at the upper end of the outer slider, the upper surface of the fixed block is in movably contact with the lower surface of the elastic hook A, and the inner walls of the lower pen shell are provided with connecting grooves that are adapted to the protruding parts of the two outer walls of the fixed block.

[0016] Preferably, the main spring is fixedly connected between the inner bottom of the cylinder and the inner top of the push rod.

[0017] Preferably, a spring guide pin is fixedly connected to the inner bottom of the cylinder, and the main spring is wound around the outside of the spring guide pin.

[0018] Preferably, a pen cap is clamped on the upper end of the lower pen shell, and the pen cap includes a cap head and elastic hooks B connected to both sides of the inner top thereof, and a needle cap that can movably cover the periphery of the needle head is clamped through the elastic hooks B.

[0019] The advantages of the embodiment of the present application are: the trigger mechanism needle tip automatically and quickly pierces the skin and injects the medicine, reducing the pain and fear of the user pressing the needle tip into the skin. When using, step 1, remove the pen cap, and pull out the needle cap with an elastic hook B connected to the cap head; step 2: a. Press the protective shell to drive the outer slider to move downward and compress the secondary spring, and then the arc-shaped connecting plate in the main body will also move downward, and the boss on the side wall of the lower end of the push rod will rely on the pushing force of the main spring to rotate a certain angle along the inclined surface that fits the arc-shaped connecting plate and enter the inner cavity of the main body, and the push rod Push the rubber stopper to inject the medicine; b. When the injection of the medicine is completed, the push rod is separated from the inner cavity of the main body, and the main body is bounced to the bottom of the upper pen shell by the main spring and hits to produce the end sound of the medicine injection completion; Step 3: After the injection of the medicine is completed, remove the injection pen, and the pre-compressed secondary spring pushes the outer slider and the protective shell to move forward. When the outer slider returns to its original position, the two elastic hooks A on the upper end of the main body are inserted into the two square holes on the side wall of the upper end of the outer slider, and the protective shell is pressed again. Since the elastic hook A of the main body supports the outer slider, it prevents the protective shell from moving, forming an anti-needlestick function. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG1 is a schematic diagram of the external three-dimensional structure of a disposable injection pen provided in an embodiment of the present application;

[0021] FIG2 is a schematic planar cross-sectional view of the assembled disposable injection pen provided in an embodiment of the present application;

[0022] FIG3 is a schematic diagram of a planar cross-sectional structure of a disposable injection pen provided in an embodiment of the present application when completing an injection;

[0023] FIG4 is a schematic diagram of the structure of FIG1 after removing the lower case according to an embodiment of the present application;

[0024] FIG5 is a schematic structural diagram of the connection relationship between the trigger mechanism and the injection head mechanism provided in an embodiment of the present application;

[0025] FIG6 is a schematic diagram of the structure of a trigger mechanism provided in an embodiment of the present application;

[0026] FIG7 is a schematic structural diagram of the connection relationship between the boss and the sliding portion provided in an embodiment of the present application;

[0027] FIG8 is a schematic structural diagram of an outer slider provided in an embodiment of the present application;

[0028] FIG9 is a schematic diagram of the main structure provided by an embodiment of the present application;

[0029] FIG10 is a schematic diagram of the structure of a fixed block provided in an embodiment of the present application;

[0030] FIG11 is a schematic diagram of a push rod structure provided in an embodiment of the present application;

[0031] FIG12 is a schematic structural diagram of the connection relationship between the cylinder, the main spring, and the spring guide pin provided in an embodiment of the present application;

[0032] FIG13 is a schematic structural diagram of the connection relationship between the injection head mechanism and the push rod provided in an embodiment of the present application;

[0033] FIG14 is a schematic structural diagram of a pen cap member provided in an embodiment of the present application.

[0034] In the figure: 1-pen case; 11-upper pen case; 12-lower pen case; 2-injection head mechanism; 21-syringe; 22-needle; 23-rubber plug; 3-trigger mechanism; 31-protective shell; 311-avoidance; 32-sliding part; 321-outer slider; 3211-guide groove; 3212-guide plate; 3213-retaining rib; 322-main body; 3221-cylinder; 3222-arc-shaped connecting plate; 3223-elastic hook A; 3224-arc-shaped plug plate; 33-auxiliary spring; 34-push rod; 341-boss; 35-main spring; 36-fixing block; 37-spring guide pin; 4-pen cap; 41-cap head; 42-elastic hook B; 43-needle cap. DETAILED DESCRIPTION

[0035] The technical solution in the embodiments of the present application is to solve the above problems, and the overall idea is as follows:

[0036] Example 1:

[0037] Please refer to Figures 1 to 14, the disposable injection pen includes a pen housing 1, an injection head mechanism 2 and a trigger mechanism 3:

[0038] The injection head mechanism 2 includes a syringe 21 located in the pen housing 1 and a needle 22 mounted on the top thereof, and a rubber plug 23 is provided in the syringe 21;

[0039] The trigger mechanism 3 comprises a protective shell 31, which is disposed within the pen housing 1 and movably wraps around the exterior of the needle 22. The bottom of the protective shell 31 movably engages a sliding portion 32. The sliding portion 32 is sheathed with a secondary spring 33, the bottom end of which is fixed to the bottom of the pen housing 1. A push rod 34, with an open bottom, is movably engaged within the sliding portion 32. A main spring 35 is connected between the top of the push rod 34 and the bottom of the sliding portion 32. During injection, as shown in FIG3 , when the protective shell 31 is pressed, the sliding portion 32 moves downward, causing the push rod 34 to move upward and push the rubber plug 23 forward. When the injection of the liquid medicine is complete, the push rod 34 disengages the inner cavity of the sliding portion 32, and the sliding portion 32 is rebounded by the main spring 35 to the bottom of the pen housing 1, where it impacts and produces a sound indicating that the injection is complete. Specifically, pressing the protective shell 31 drives the outer slider 321 to move downward and compress the secondary spring 33, and then the arc-shaped connecting plate 3222 in the main body 322 will also move downward, and the two bosses 341 on the lower end side wall of the push rod 34 will rely on the pushing force of the main spring 35 to rotate a certain angle along the inclined surface that fits the arc-shaped connecting plate 322 to enter the inner cavity of the main body 322, and the push rod 34 pushes the rubber plug 23 to inject the medicine; when the injection of the medicine is completed, the push rod 34 is separated from the inner cavity of the main body 322, and the main body 322 is bounced to the bottom of the upper pen shell 11 by the main spring 35 and hits to produce the end sound of the medicine injection completion.

[0040] It should also be noted that the state of the trigger mechanism 3 when not injecting is shown in FIG. 2 , where the bottom of the push rod 34 is stuck inside the sliding portion 32 .

[0041] The pen housing 1 includes an upper pen housing 11 and a lower pen housing 12 that are fixed together. Both sides of the inner wall of the lower pen housing 12 are provided with protruding blocks (not shown). The protruding blocks are fixed on the inner wall of the syringe 21. The lower pen housing 12 and the syringe 21 are fixed together by the protruding blocks. Avoidance openings 311 that are compatible with the protruding blocks are opened on both sides of the protective housing 31. The avoidance openings 311 are shown in Figure 5. The design of the avoidance openings 311 makes it convenient for the protruding blocks to not interfere with the downward movement of the protective housing 31.

[0042] The sliding portion 32 includes an outer slider 321 and a main body 322 . Guide grooves 3211 are provided on both sides of the outer slider 321 . Guide plates 3212 are longitudinally fixed in the guide grooves 3211 . The main body 322 slides along the guide plates 3212 and is inserted into the inner cavity of the outer slider 321 .

[0043] The outer wall of the outer slider 321 is provided with retaining ribs 3213 on both sides, and the upper end of the auxiliary spring 33 is pressed against the lower end of the retaining ribs 3213, and the auxiliary spring 33 contacts the inner bottom of the lower pen housing 12. The design of the retaining ribs 3213 can compress the auxiliary spring 33 when the outer slider 321 moves downward.

[0044] The main body 322 comprises a cylinder 3221 and curved connecting plates 3222 connected to either side of the upper portion of the cylinder 3221. The upper ends of the two curved connecting plates 3222 are each connected to an elastic hook A3223 located at the upper opening of the outer slider 321. Furthermore, a curved insert plate 3224, with openings facing each other and secured to the corresponding guide plate 3212, is connected between the two curved connecting plates 3222. The matching design of the curved insert plates 3224 and the guide plates 3212 in the guide grooves 3211 facilitates the sliding connection and securement of the main body 322 with the outer slider 321. When the curved insert plates 3224 slide to the bottom of the guide plates 3212, as shown in FIG3 , the cylinder 3221 collides with the inner bottom of the upper pen housing 11.

[0045] It should be noted that when not in use, the arc-shaped connecting plate 3222 is tightly pressed against the inner wall of the outer slider 321 . Later, under the push of the main spring 35 , the elastic hook A3223 moves to the inner wall of the outer slider 321 and moves downward along with the arc-shaped connecting plate 3222 .

[0046] The push rod 34 is hollow inside, and its outer bottom is connected to two sides with bosses 341, which are located in two guide grooves 3211. The upper surfaces of the two bosses 341 are designed to fit the side walls of the two curved connecting plates 3222, and the fitting surfaces are inclined. When the curved connecting plates 3222 move downward, the two bosses 341 slide and screw into the corresponding curved insert plates 3224, and come into contact with the guide plates 3212. When the two bosses 341 slide into the curved insert plates 3224, the main spring 35 is in a twisted state. Without external force, the main spring 35 twists the two bosses 341 by a certain angle and moves them into the curved connecting plates 3222. Later, they fit into the two L-shaped limit arms on the fixed block 36, preventing the push rod 34 from moving further upward.

[0047] It should be noted that, in the non-use state, the two bosses 341 are stuck on the inclined surface of the arc-shaped connecting plate 3222 , so that the positions of the push rod 34 and the main body 322 are as shown in FIG. 7 .

[0048] A fixed block 36 is also connected to the opening at the upper end of the outer slider 321, which is in movably contact with the boss 341. The upper surface of the fixed block 36 is in movably contact with the lower surface of the elastic hook A3223, and the inner walls of the lower pen shell 12 are provided with connecting grooves on both sides that are compatible with the protruding parts of the two outer walls of the fixed block 36.

[0049] A main spring 35 is fixedly connected between the bottom of the cylinder 3221 and the top of the push rod 34. The main spring 35 can be used to push the push rod 34 upward to move against the rubber plug 23, thereby promoting the injection of the liquid medicine.

[0050] It should be noted that when the push rod 34 moves into the inner cavity of the main body 322, the main spring 35 extends, thereby pushing the push rod 34 upward and the main body 322 downward along the guide groove 3211. When the final injection of the liquid medicine is completed, as shown in Figure 3, the push rod 34 pushes the stopper 23 against the inner cavity of the syringe 21 near the needle 22, so that the main body 322 hits the bottom of the upper pen shell 11 to produce a sound indicating that the injection of the liquid medicine is completed.

[0051] A spring guide pin 37 is fixedly connected to the bottom of the cylinder 3221, and the main spring 35 is wound around the outside of the spring guide pin 37. The spring guide pin 37 has a guiding effect on the movement of the main spring 35, reducing the bending of the main spring 35 during movement.

[0052] The pen cap 4 is secured to the upper end of the lower pen housing 12. The pen cap 4 comprises a cap head 41 and elastic hooks B42 connected to the inner top on both sides. A needle cap 43, which is adapted to flexibly cover the needle tip 22, is secured to the cap head 41 via the elastic hooks B42. As shown in FIG14 , the elastic hooks B42 secure the needle cap 43 to the cap head 41, thereby securing the needle cap 43 to the needle tip 22.

[0053] When using this application, follow the steps below:

[0054] Step 1:

[0055] Remove the pen cap 4 and pull out the needle cap 43 using the two elastic hooks B42 connected to the cap head 41;

[0056] Step 2:

[0057] a. Pressing the protective shell 31 drives the outer slider 321 downward and compresses the secondary spring 33. Subsequently, the arc-shaped connecting plate 3222 in the main body 322 also moves downward. The two bosses 341 on the lower side wall of the push rod 34, driven by the force of the main spring 35, rotate a certain angle along the inclined surface that fits the arc-shaped connecting plate 3222 and enter the inner cavity of the main body 322. The push rod 34 pushes the rubber plug 23 to inject the liquid medicine.

[0058] b. When the injection of the liquid medicine is completed, the push rod 34 is separated from the inner cavity of the main body 322, and the main body 322 is bounced to the bottom of the upper pen housing 11 by the main spring 35 and strikes to produce the end sound of the liquid medicine injection completion;

[0059] Step 3:

[0060] After the injection of the drug solution is completed, the injection pen is removed, and the pre-compressed secondary spring 33 pushes the outer slider 321 and the protective shell 31 to move forward. When the outer slider 321 returns to its original position, the two elastic hooks A3223 on the upper end of the main body 322 are inserted into the two square holes on the side wall of the upper end of the outer slider 321, and the protective shell 31 is pressed again. Since the elastic hooks A3223 of the main body 322 support the outer slider 321, the protective shell 31 is prevented from moving, forming an anti-needlestick function.

[0061] In addition, it should be noted that this application also has the following advantages:

[0062] High efficiency:

[0063] Lower precision requirements: Compared with the traditional clamping push rod limiter, the unique trigger mechanism 3 of the present invention has lower requirements for product dimensional accuracy. The traditional clamping method requires a part accuracy of + / -0.05mm, while the present invention only requires + / -0.1mm. This improves product production yield and production efficiency. After testing and verification, the reliability is also more stable and reliable than the traditional structure.

[0064] Number of parts: The number of parts of the traditional structure modification pen is 13 to 18, while the number of parts in this application is 11. Thanks to the structural advantages, the number of parts has also been significantly reduced;

[0065] Plastic parts injection cycle: The traditional structure takes a total of about 190 to 210 seconds for all plastic parts injection. The current plastic parts injection cycle of this application is 145 to 165 seconds, which reduces the injection time and increases the efficiency.

[0066] Fewer automatic equipment workstations: As the number of parts decreases, the number of supporting automatic workstations also decreases accordingly, saving resources.

[0067] Short automated assembly cycle: With a simple structure and easy assembly, coupled with a reduced number of parts, the current assembly efficiency of this application is 15-17s / pcs, while the traditional pen assembly is about 18-20s / pcs. In this respect, this application has a significant advantage;

[0068] Stability: After the core components of the present application are assembled, the locking structure of the push rod 34 is unique. After tests such as drops and vibrations, no false triggering phenomenon has been found, and the performance is very reliable;

[0069] The protective shell 31 has a secondary protection function: the protective shell of the present application has a protection force greater than 150N. When the applied force is greater than 150N and the protection function fails, the protective function can be provided again by releasing the applied force;

[0070] Recycling and reuse: Some parts of this application can be recycled and reused, such as the pen cap 4, the pen shell 2, and the auxiliary spring 33, saving social resources.

[0071] Finally, it should be noted that the above embodiments are merely examples for the purpose of illustrating the present invention and are not intended to limit the embodiments. Those skilled in the art will readily appreciate that other variations or modifications based on the above description are possible. It is not necessary and impossible to provide an exhaustive list of all embodiments. However, obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A disposable injection pen, characterized in that: include: Pen case (1); An injection head mechanism (2) comprises a syringe (21) located in the pen housing (1) and a needle (22) mounted on the top thereof, wherein a rubber plug (23) is provided in the syringe (21); The trigger mechanism (3) comprises a protective shell (31) arranged in the pen case (1) and movably wrapped around the outside of the needle (22); the bottom of the protective shell (31) movably contacts with a sliding part (32); the sliding part (32) is sleeved with a secondary spring (33) whose bottom end is fixed to the bottom of the pen case (1); the sliding part (32) is movably engaged with a push rod (34) with an open bottom; a main spring (35) is connected between the top of the push rod (34) and the bottom of the sliding part (32); when the protective shell (31) is pressed, the sliding part (32) moves downward so that the push rod (34) moves upward and pushes the rubber plug (23) forward; when the injection of the liquid medicine is completed, the push rod (34) is separated from the inner cavity of the sliding part (32), and the sliding part (32) is bounced to the bottom of the pen case (1) by the main spring (35) and hits to produce a sound indicating that the injection of the liquid medicine is completed.

2. The disposable injection pen according to claim 1, characterized in that: The pen housing (1) comprises an upper pen housing (11) and a lower pen housing (12) which are fixed by clamping, and protruding blocks are provided on both sides of the inner wall of the lower pen housing (12), and the protruding blocks are fixed on the inner wall of the syringe (21), and avoidance openings (311) adapted to the protruding blocks are opened on both sides of the protective housing (31).

3. The disposable injection pen according to claim 2, characterized in that: The sliding portion (32) comprises an outer sliding block (321) and a main body (322), the outer sliding block (321) is provided with guide grooves (3211) on both sides, a guide plate (3212) is longitudinally fixed in the guide groove (3211), and the main body (322) is slidably inserted into the inner cavity of the outer sliding block (321) along the guide plate (3212).

4. The disposable injection pen according to claim 3, characterized in that: Both sides of the outer wall of the outer sliding block (321) are provided with retaining ribs (3213), the upper end of the auxiliary spring (33) is pressed against the lower part of the retaining ribs (3213), and the auxiliary spring (33) is pressed against the inner bottom of the lower pen housing (12).

5. The disposable injection pen according to claim 4, characterized in that: The main body (322) comprises a cylinder (3221) and arc-shaped connecting plates (3222) connected to both sides of the upper part of the cylinder (3221); the upper ends of the two arc-shaped connecting plates (3222) are connected to elastic hooks A (3223) provided at the upper opening of the outer sliding block (321); and the middle parts of the two arc-shaped connecting plates (3222) are connected to arc-shaped plug plates (3224) with openings facing each other and fixed to the corresponding guide plates (3212).

6. The disposable injection pen according to claim 5, characterized in that: The push rod (34) is designed to be hollow inside, and both sides of the outer bottom are connected with bosses (341) respectively located in the two guide grooves (3211). The upper surfaces of the two bosses (341) are respectively designed to fit with the side walls of the two arc-shaped connecting plates (3222), and the fitting surfaces are designed to be inclined. When the arc-shaped connecting plates (3222) move downward, the two bosses (341) slide and screw into the corresponding arc-shaped plug plates (3224) and contact the guide plates (3212).

7. The disposable injection pen according to claim 6, characterized in that: A fixing block (36) movably in contact with the boss (341) is also connected to the upper opening of the outer sliding block (321); the upper surface of the fixing block (36) movably contacts the lower surface of the elastic hook A (3223); and the inner walls of the lower pen housing (12) are provided with connecting grooves adapted to the protruding parts of the two outer walls of the fixing block (36) on both sides.

8. The disposable injection pen according to claim 7, characterized in that: The main spring (35) is fixedly connected between the inner bottom of the cylinder (3221) and the inner top of the push rod (34).

9. The disposable injection pen according to claim 8, characterized in that: A spring guide pin (37) is fixedly connected to the inner bottom of the cylinder (3221), and the main spring (35) is wound around the outside of the spring guide pin (37).

10. The disposable injection pen according to claim 9, characterized in that: A pen cap member (4) is clamped on the upper end of the lower pen shell (12), and the pen cap member (4) comprises a cap head (41) and elastic hooks B (42) connected to the top of the cap head on both sides, and a needle cap (43) capable of movably covering the periphery of the needle head (22) is clamped on the elastic hooks B (42).

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