Injection pen cap and injection pen

Abstract

The utility model provides a kind of injection pen cap and injection pen, including sleeve, end cover and clamping part, clamping part includes first clamping part and second clamping part, second clamping part one end is axially fixed connection with first clamping part, both internal communication to form cavity accommodate needle head;Second clamping part is fixed with the annular arrangement of extension arm in the end away from first clamping part, each extension arm is equipped with reinforcing rib, and reinforcing rib extends to second clamping part from extension arm along the axial direction, at least one group of oppositely arranged extension arm's end and the reinforcing rib on the inner side wall of this extension arm form annular groove, annular groove and the annular boss on injection cylinder sidewall are clamped.The utility model structure is compact, can effectively improve the structural strength of pen cap, effectively improve the molding yield.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, and in particular to an injection pen cap and an injection pen. Background Technology

[0002] In existing injection pen designs, the methods for securing the pen cap or pen casing have significant shortcomings. On the one hand, while threaded screw-on designs are common, the internal and external tapping of these threads is difficult and costly, and the multiple turns of threads can make it difficult to open the cap. After long-term use, the threads are prone to stripping and slipping. Without end-mounted stops, the fixation is not secure enough.

[0003] On the other hand, such as Figure 1 As shown, the pen cap and the injection pen body are assembled via a snap-fit ​​mechanism. The pen cap uses a flexible cantilever snap-fit ​​structure to engage with the injection pen body. While this flexible cantilever snap-fit ​​pen cap is an alternative solution, the flexible cantilever is prone to fatigue bending and damage after repeated opening and closing, and deformation over long-term use can lead to snap-fit ​​failure. Furthermore, during injection molding, the connection between the flexible cantilever and the pen cap body is prone to breakage, or insufficient strength may cause breakage during use, increasing the scrap rate and consequently increasing costs. Moreover, elastic deformation weakens the snap-fit ​​sound, affecting the user's judgment of proper installation. Utility Model Content

[0004] In view of the shortcomings of the prior art described above, the technical problem to be solved by this utility model is to provide an injection pen cap and injection pen to improve the yield and ensure its structural strength.

[0005] This utility model provides an injection pen cap, including a sleeve, an end cap, and a snap-fit ​​component. The snap-fit ​​component includes a first snap-fit ​​portion and a second snap-fit ​​portion. One end of the second snap-fit ​​portion is axially fixedly connected to the first snap-fit ​​portion, and the two are internally connected to form a cavity to accommodate a needle. The second snap-fit ​​portion has annularly arranged extension arms fixedly provided at the end away from the first snap-fit ​​portion. Each extension arm has a reinforcing rib, and the reinforcing rib extends axially from the extension arm to the second snap-fit ​​portion. The ends of at least one set of oppositely arranged extension arms form annular grooves with the reinforcing ribs on the inner sidewall of the extension arm. The annular grooves engage with annular protrusions on the sidewall of the injection cartridge.

[0006] Preferably, the radial dimension of the first snap-fit ​​portion is smaller than the radial dimension of the second snap-fit ​​portion, and the first snap-fit ​​portion connects to the internal communication of the second snap-fit ​​portion to form a first stepped surface, and each reinforcing rib extends axially from the first platform to the extension arm.

[0007] Preferably, the ends of the extension arms are provided with guide ramps.

[0008] Preferably, at least one set of opposing extension arms has a first guide block on its inner sidewall, and the annular protrusion at the end of the injection barrel has a first groove along the axial direction that cooperates with the first guide block.

[0009] Preferably, a second stepped surface is formed at the connection between the outer wall of the first snap-fit ​​portion and the outer wall of the second snap-fit ​​portion, the sleeve passes through the first snap-fit ​​portion and is fitted onto the second snap-fit ​​portion, and the bottom of the sleeve abuts against the second stepped surface.

[0010] Preferably, a second guide block is fixed on the side wall of the first snap-fit ​​portion, and the second guide block extends axially to the second step surface; the end of the sleeve is provided with a second groove that mates with the second guide block along the axial direction.

[0011] Preferably, the end cap is fixedly or detachably connected to the snap-fit ​​member, and the end cap abuts against the sleeve.

[0012] Preferably, a reinforcing plate is fixed between adjacent extension arms, and the reinforcing plate is fixedly connected to an adjacent reinforcing rib. The reinforcing plate extends axially from the first platform to 50% to 65% of the length of the extension arm.

[0013] In another aspect, this utility model provides an injection pen, including the injection pen cap, injection barrel, and driving assembly described in the above embodiments. The injection barrel is connected to the driving assembly, and the injection pen cap is sleeved and snapped onto the injection barrel.

[0014] As described above, the present invention relates to an injection pen cap and an injection pen, which have the following beneficial effects:

[0015] This invention features annularly arranged extension arms at the end of the second locking portion away from the first locking portion. Each extension arm has a reinforcing rib on its inner sidewall, and a reinforcing plate is positioned between the extension arms. The reinforcing ribs and plates increase the structural strength at the connection between the extension arm and the second locking portion. The reinforcing ribs and the ends of at least one set of opposing extension arms form an annular groove, allowing the groove to engage with the sidewall of the injection cylinder. This invention has a compact structure, effectively improving the structural strength of the pen cap and increasing the yield of molded products. Attached Figure Description

[0016] Figure 1 This is existing technology.

[0017] Figure 2 This is a three-dimensional schematic diagram of the cap of an injection pen provided in an embodiment of the present invention.

[0018] Figure 3 This is a three-dimensional cross-sectional view of the cap of an injection pen provided in an embodiment of the present invention.

[0019] Figure 4 This is a schematic diagram of the assembly of the snap-fit ​​component and the sleeve provided in one embodiment of the present utility model.

[0020] Figure 5 This is a three-dimensional schematic diagram of a sleeve provided in an embodiment of the present invention.

[0021] Figure 6 This is a three-dimensional schematic diagram of a snap-fit ​​connector provided in an embodiment of the present invention.

[0022] Figure 7 This is a front view of a snap-fit ​​connector provided in an embodiment of the present invention.

[0023] Figure 8 for Figure 7 The left view.

[0024] Figure 9 for Figure 7 The right view.

[0025] Figure 10 for Figure 7 Top view.

[0026] Figure 11 A first assembly view of an injection pen provided according to an embodiment of the present invention.

[0027] Figure 12 for Figure 11 A magnified view of a portion of the image.

[0028] Figure 13 This is a second assembly view of the injection pen provided in an embodiment of the present invention.

[0029] Figure 14 for Figure 13 A magnified view of a portion of the image.

[0030] Explanation of reference numerals in the attached figures:

[0031] 100. Sleeve; 110. Second groove; 200. End cap; 300. Snap-fit ​​part; 310. First snap-fit ​​part; 311. Second guide block; 320. Second snap-fit ​​part; 321. First step surface; 322. Second step surface; 330. Extension arm; 331. Guide slope; 332. First guide block; 340. Reinforcing rib; 350. Reinforcing plate; 400. Annular groove; 500. Injection cylinder; 510. Annular protrusion; 511. First groove. Detailed Implementation

[0032] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification.

[0033] It should be understood that the structures, proportions, sizes, etc., illustrated in the accompanying drawings of this specification are merely for illustrative purposes to aid those skilled in the art and are not intended to limit the implementation of this utility model. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of this utility model, should still fall within the scope of the technical content disclosed in this utility model. Furthermore, the terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity of description and are not intended to limit the scope of implementation of this utility model. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of implementation of this utility model.

[0034] As shown in the figure Figures 2 to 14As shown, this utility model provides an embodiment of an injection pen cap, including a sleeve 100, an end cap 200, and a snap-fit ​​component 300. The sleeve 100 passes through the snap-fit ​​component 300 and is fitted onto it at one end. The end cap 200 is fixedly connected to or snap-fitted onto the end of the snap-fit ​​component, and the end face of the end cap 200 abuts against the end face of the sleeve 100, making the sleeve 100, end cap 200, and snap-fit ​​component 300 a single unit. The snap-fit ​​component 300 includes a first snap-fit ​​portion 310 and a second snap-fit ​​portion 320. One end of the second snap-fit ​​portion 320 is axially fixedly connected to the first snap-fit ​​portion 310. The two portions can also be integrally formed to reduce assembly steps. The first snap-fit ​​portion 310 and the second snap-fit ​​portion 320 are internally connected to form a cavity for accommodating the needle, providing sufficient space for the needle. The first snap-fit ​​portion 310 and the second snap-fit ​​portion 320 are made of plastic. The second snap-fit ​​portion 320 has annularly arranged extension arms 330 fixed at its end away from the first snap-fit ​​portion 310. These extension arms 330 are elastic. Each extension arm 330 has a reinforcing rib 340 extending axially from the extension arm 330 to the second snap-fit ​​portion 320 to enhance the structural strength of the extension arm 330, preventing breakage at the connection between the extension arm 330 and the second snap-fit ​​portion 320. This also improves the molding yield and reduces costs. In this embodiment, two reinforcing ribs 340 are preferably provided on each extension arm 330, which improves the overall structural strength of the second snap-fit ​​portion 320 and effectively increases the molding yield. Too many reinforcing ribs can reduce the elasticity of the extension arms 330, making it difficult to snap them onto the injection cylinder 500. Therefore, the number of reinforcing ribs 340 can be adjusted according to specific working conditions. At least one set of opposing extension arms has its end forming an annular groove 400 with a reinforcing rib 340 on the inner sidewall of the extension arm. The annular groove 400 engages with an annular protrusion 510 on the sidewall of the injection cylinder 500. Those skilled in the art can determine the number of extension arm sets forming the annular groove 400 based on specific working conditions. It should be noted that the second engaging portion 320, the extension arm 330, and the reinforcing rib 340 are integrally molded, ensuring that the extension arm will not break during injection molding, can withstand frequent bending, and reduces product defect rate.

[0035] During engagement, the sleeve 100 is axially fitted onto the injection cylinder 500. The extension arm 330, where the annular groove 400 is located, is propped open by the annular protrusion 510 until the annular protrusion 510 engages within the annular groove 400, completing the engagement. When engaged, the annular protrusion 510 abuts against the inner wall of the annular groove 400. If further force is applied at this point, the user will feel a tightening under the reaction force. This engagement method determines whether the engagement relies solely on tactile feedback, reducing dependence on the clicking sound.

[0036] In one embodiment, such as Figure 3 , Figure 6 , Figure 7 and Figure 10 As shown, the radial dimension of the first snap-fit ​​portion 310 is smaller than the radial dimension of the second snap-fit ​​portion 320. The first snap-fit ​​portion 310 connects to the internal connection of the second snap-fit ​​portion 320 to form a first stepped surface 321. Each reinforcing rib 340 extends axially from the extension arm 330 to the first stepped surface 321 to strengthen the connection between the extension arm and the second snap-fit ​​portion 320.

[0037] In one embodiment, such as Figure 6 , Figure 8 and Figure 12 As shown, each end of the extension arm 330 is provided with a guide slope 331, which has the same inclination angle as the outer edge slope of the annular protrusion 510. The extension arm 330 is subjected to an axial thrust, causing the guide slope 331 to engage with the outer edge slope of the annular protrusion 510. During movement, the outer edge slope of the annular protrusion applies a vertically upward reaction force to the extension arm, thereby causing the extension arm to overcome its own elasticity and remain in an extended state until the annular protrusion 510 engages within the annular groove 400. The inner wall of the annular groove 400 on the side of the extension arm end is also provided with a guide slope, forming a protrusion. This protrusion engages with the groove adjacent to the annular protrusion, facilitating the disengagement of the annular protrusion 510 from the annular groove 400.

[0038] In one embodiment, such as Figure 3 As shown, a reinforcing plate 350 is fixed between adjacent extension arms 330, and the reinforcing plate 350 is fixedly connected to the adjacent reinforcing rib 340. The reinforcing plate 350 extends axially from the first platform 321 to 50% to 65% of the length of the extension arm 330.

[0039] Specifically, the reinforcing plate 350 and the reinforcing rib 340 can be integrally formed to improve the structural strength of the extension arm. In this embodiment, the reinforcing plate 350 has a restraining effect on the adjacent extension arm 330. If the length of the reinforcing plate 350 is less than 50% of the length of the extension arm 330, the extension arm 330 will have elasticity but insufficient structural strength, and will also result in a low molding yield of the extension arm 330. If the length of the reinforcing plate 350 is greater than 65% of the length of the extension arm 330, the extension arm 330 will have excessive strength, resulting in insufficient elasticity at the end of the extension arm 330, making it difficult to engage the injection cylinder 500. Therefore, in this embodiment, the length of the reinforcing plate 350 is preferably between 50% and 65% of the length of the extension arm 330.

[0040] In one embodiment, such as Figure 6 , Figure 8 and Figure 14As shown, a first guide block 332 is provided on the inner wall of one or more sets of oppositely arranged extension arms. This embodiment is not limited, and the specific configuration can be determined according to the specific working conditions. The annular protrusion 510 at the end of the injection cylinder has a first groove 511 along the axial direction that mates with the first guide block 332. During engagement, the sleeve 100 can be rotated to drive the engagement member 300 to rotate, thereby driving the first guide block 332 to rotate and applying a pushing force to it, so that the first guide block 332 smoothly enters the first groove 511, and the first guide block 332 fits against the bottom wall of the first groove 511. For ease of guidance, the first guide block 332 is provided on a set of oppositely arranged extension arms.

[0041] In one embodiment, such as Figure 4 and Figure 9 As shown, a second stepped surface 322 is formed at the connection between the outer walls of the first snap-fit ​​portion 310 and the second snap-fit ​​portion 320. The sleeve 100 passes through the first snap-fit ​​portion 310 and is fitted onto the second snap-fit ​​portion 320, with the bottom of the sleeve 100 abutting against the second stepped surface 322. The end cap 200 can be connected to the first snap-fit ​​portion 310 by ultrasonic welding or snap-fitting. The end cap 200 abuts against the end of the sleeve 100 to prevent the sleeve 100 from detaching from the second snap-fit ​​portion 320 during use.

[0042] In one embodiment, such as Figure 5 , Figure 9 and Figure 10 As shown, a second guide block 311 is fixedly provided on the side wall of the first snap-fit ​​part, and the second guide block 311 extends axially to the second step surface 322; a second groove 110 that mates with the second guide block 311 is formed at the end of the sleeve axially. When the sleeve 100 is fitted, the second groove 110 is aligned with the second guide block 311, so that the inner bottom surface of the sleeve 100 fits against the second step surface 322, and then the end cap 200 is welded or snapped to the first snap-fit ​​part 310, thereby restricting the sleeve 100 from rotating during use and avoiding affecting the assembly feel.

[0043] In another aspect, this utility model proposes an injection pen, including the pen cap in any of the above embodiments, and also including an injection cylinder and a driving component. The injection cylinder is connected to the driving component, and the pen cap is sleeved and snapped onto the injection cylinder. During repeated use, the pen cap is not easily detached from the injection cylinder.

[0044] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A pen cap for an injection pen, comprising a sleeve (100), an end cap (200), and a snap-fit ​​component (300), characterized in that, The snap-fit ​​component (300) includes a first snap-fit ​​portion (310) and a second snap-fit ​​portion (320). One end of the second snap-fit ​​portion (320) is axially fixedly connected to the first snap-fit ​​portion (310), and the two are internally connected to form a cavity to accommodate the needle. The second snap-fit ​​portion (320) has annularly arranged extension arms (330) fixedly provided at the end away from the first snap-fit ​​portion. Each extension arm (330) is provided with a reinforcing rib (340), and the reinforcing rib (340) extends axially from the extension arm (330) to the second snap-fit ​​portion (320). The end of at least one set of oppositely arranged extension arms forms an annular groove (400) with the reinforcing rib (340) on the inner sidewall of the extension arm. The annular groove (400) snaps with an annular protrusion (510) on the sidewall of the syringe (500).

2. The pen cap of the injection pen according to claim 1, characterized in that, The radial dimension of the first snap-fit ​​portion (310) is smaller than that of the second snap-fit ​​portion (320). The first snap-fit ​​portion (310) connects to the internal communication of the second snap-fit ​​portion (320) to form a first stepped surface (321). Each reinforcing rib (340) extends axially from the first stepped surface (321) to the extension arm (330).

3. The pen cap of the injection pen according to claim 1 or 2, characterized in that, The ends of the extension arms are all provided with guide ramps (331).

4. The pen cap of the injection pen according to claim 1, characterized in that, At least one set of opposing extension arms (330) have a first guide block (332) on their inner sidewalls, and the annular protrusion (510) at the end of the injection cylinder has a first groove (511) that mates with the first guide block along the axial direction.

5. The pen cap of the injection pen according to claim 2, characterized in that, A second stepped surface (322) is formed at the connection between the outer side wall of the first snap-fit ​​part (310) and the second snap-fit ​​part (320). The sleeve (100) passes through the first snap-fit ​​part (310) and is fitted onto the second snap-fit ​​part (320), and the bottom of the sleeve (100) abuts against the second stepped surface (322).

6. The pen cap of the injection pen according to claim 5, characterized in that, A second guide block (311) is fixed on the side wall of the first snap-fit ​​part, and the second guide block (311) extends axially to the second step surface (322); the end of the sleeve is provided with a second groove (110) that cooperates with the second guide block (311) along the axial direction.

7. The pen cap of the injection pen according to claim 1, characterized in that, The end cap (200) is fixed or detachably connected to the snap-fit ​​member (300), and the end cap (200) abuts against the sleeve (100).

8. The pen cap of the injection pen according to claim 2, characterized in that, A reinforcing plate (350) is fixed between adjacent extension arms (330), and the reinforcing plate (350) is fixedly connected to the adjacent reinforcing rib (340). The reinforcing plate (350) extends axially from the first step surface (321) to 50% to 65% of the length of the extension arm (330).

9. An injection pen, characterized in that, The device includes an injection pen cap, an injection barrel, and a drive assembly as described in any one of claims 1 to 8, wherein the injection barrel is connected to the drive assembly, and the injection pen cap is fitted onto and snapped onto the injection barrel.

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