Automatic injector

Abstract

The invention discloses an automatic injector which comprises a needle tip protection sleeve, a pen body, an anti-mistaken-touch injection assembly and an injector body, the anti-mistaken-touch injection assembly and the injector body are installed in the pen body, the anti-mistaken-touch injection assembly comprises a release part, a release spring, an injection spring, a sound production base and a push rod assembly, and a limiting sliding block is arranged on the release part; a release sliding rail matched with the limiting sliding block is arranged on the sound production base, in the initial state, the limiting sliding block is not clamped into the release sliding rail, in the assembling process, the injection assembly is rotated to enable the limiting sliding block to be clamped into the release sliding rail, and the needle tip protection sleeve can touch the release piece so as to trigger the push rod assembly to move. According to the scheme, installation is convenient and simple, the overall structure is stable and reliable, triggering is sensitive, and safety is high.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to an automatic injector. Background Technology

[0002] Autoinjectors have reduced the difficulty of injection therapy and decreased patient pain, making them popular with many healthcare professionals and patients. However, autoinjectors require a high degree of precision in the assembly of their components.

[0003] Chinese invention patent application CN117618712A discloses an automatic injector, comprising: a pen cap and a front pen barrel; a compression mechanism disposed inside the pen cap and the front pen barrel; and a rear pen barrel. The technical solution of this invention patent application utilizes a limiting block on the surface of the push rod, which rotates, and then a track releases the limiting block. A push rod spring inside the push rod is normally compressed; when the limiting block is released, the compressed spring pushes the push rod to move, which in turn pushes a rubber stopper to move. The stopper then compresses the liquid medication inside the syringe, allowing the medication to flow out from the needle and ultimately into the patient's body. Ultimately, by using simplified components, production costs are reduced, and the stability of the injector is improved, while better meeting customers' requirements for small size. This demonstrates that the structure of automatic injectors is becoming increasingly mature in current applications. Therefore, the spring and push rod structure is becoming increasingly mature in the application of automatic injectors.

[0004] However, the casing and automatic injection assembly of existing auto-injectors are generally designed and manufactured by injection molding companies, while pre-filled syringes are typically manufactured and filled by pharmaceutical companies. The casing and automatic injection assembly are then sent to the pharmaceutical company for final assembly. During transportation, the automatic injection assembly may experience component movement that could trigger the automatic injection mechanism, leading to malfunction. Furthermore, if workers accidentally activate the automatic push mechanism during the production and assembly of the auto-injector, assembly will fail, significantly reducing assembly efficiency. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of the existing technology described above by providing an automatic injector that has the advantages of preventing accidental triggering and being easy to install.

[0006] The technical solution adopted by the present invention to solve its technical problem is as follows: an automatic injector, including a needle tip protective sleeve, a pen body, and an anti-accidental injection component and a syringe installed in the pen body. The rear end of the needle tip protective sleeve extends into the pen body. The anti-accidental injection component includes a sound-generating base and a release member, a release spring, an injection spring, and a push rod assembly installed on the sound-generating base. The release member can restrict the movement of the push rod assembly and the injection spring. The release member is provided with a limiting slider. The sound-generating base is provided with a release slide rail that cooperates with the limiting slider. In the initial state, the limiting slider is not engaged with the release slide rail, and the release member cannot move axially back and forth on the sound-generating base. The outer sides of the release member and the sound-generating base are respectively provided with a front limiting rib and a rear limiting rib. The inner wall of the pen body is provided with an axial limiting groove that matches the front limiting rib and the rear limiting rib. The anti-accidental touch injection component has two states: an initial state and a post-installation state. In the initial state, the anti-accidental touch injection component is not installed in the pen body, the front and rear limiting ribs are not on the same vertical line, and the limiting slider is not engaged in the release rail. After installation, the anti-accidental touch injection component is installed in the pen body, the front and rear limiting ribs are on the same vertical line, and the limiting slider is engaged in the release rail. The end of the axial limiting groove is also provided with a spiral inclined part that allows the release element or the sound-generating base to rotate, so that after the anti-accidental touch injection component is assembled with the pen body, the limiting slider is engaged in the release rail. When installing the anti-accidental injection assembly, the front limiting rib is aligned with the axial limiting groove, and the rear limiting rib is aligned with the spiral inclined portion. After the release member moves a certain distance along the axial limiting groove, the rear limiting rib cooperates with the spiral inclined portion. Then, the anti-accidental injection assembly is moved, and the sound-generating base rotates with the spiral inclined portion and is inserted into the axial limiting groove. At this time, the limiting slider is engaged in the release slide rail, and the rear end of the needle tip protective sleeve extends into the pen body and can push the release member to move axially on the sound-generating base. After the release member moves, it can release the push rod assembly and the injection spring, so that the injection spring drives the push rod assembly to push the syringe. In this solution, the anti-accidental injection component is designed with the limit slider and release rail misaligned during transportation, making it difficult to trigger. When assembling the syringe, the release component at the front of the anti-accidental injection component first engages with the inner wall of the pen body. When the sound-generating base engages with the pen body, it rotates a certain angle along the spiral inclined part at the end of the axial limit groove, allowing the limit slider and release rail in the anti-accidental injection component to cooperate with each other. This makes installation convenient and simple, and the overall structure is stable, reliable, and sensitive to triggering.

[0007] Furthermore, a sound-generating component is also installed on the sound-generating base. An axial limiting groove and an axial limiting strip are provided between the sound-generating component and the sound-generating base to cooperate with each other. The sound-generating component and the sound-generating base can rotate synchronously. The release component, the sound-generating component, and the release spring are axially movable forward and backward on the outer surface of the sound-generating base. The push rod assembly and the injection spring are installed in the inner cavity of the sound-generating base. The two ends of the release spring respectively abut against the release component and the sound-generating component. The release component can restrict the movement of the push rod assembly and the injection spring. The release component is provided with a release spring, and the end of the release spring is provided with the limiting slider. The front end of the sound-generating component is provided with a groove that cooperates with the limiting slider. When the limiting slider is engaged in the groove, the release component cannot move axially on the sound-generating base. The inner wall of the sound-generating component is provided with a release slide rail. Rotating the sound-generating component or the release component can cause the limiting slider to disengage from the groove and engage in the release slide rail. At this time, the release component can move axially on the sound-generating base under external force. The front end of the sound-generating base may also be provided with a limiting block to block the release member, preventing the release member from detaching from the sound-generating base.

[0008] Furthermore, the front end of the sound-generating base is also provided with a front spring plate, which is located behind the limiting block. One end of the front spring plate is connected to the sound-generating base, and the inner and outer sides of the other end are respectively provided with an inner locking block and an outer protrusion. In the initial state, the release member is sleeved on the front spring plate. The inner wall of the release member squeezes the outer protrusion, causing the front spring plate to retract inward. The inner locking block blocks the push rod assembly, thereby restricting the movement of the push rod assembly and the injection spring. After the release member is pushed backward away from the front spring plate by external force, the injection spring pushes the push rod assembly to squeeze the inner locking block, causing the front spring plate to pop outward. The push rod assembly can then be driven forward by the injection spring to assist the syringe in automatic injection.

[0009] Furthermore, the rear end of the sound-generating base is also provided with a collision step and a rear spring. The rear spring is placed on the front side of the collision step. One end of the rear spring is connected to the sound-generating base, and the outer side of the other end is provided with a protruding rear spring block. The push rod assembly abuts against the inner side of the lower spring. The rear spring block blocks the sound-generating component, so that a collision gap is formed between the rear end of the sound-generating component and the collision step. When the injection spring pushes the push rod assembly away from the inner side of the rear spring, the rear spring can retract inward and lose its blocking function. The release spring will push the sound-generating component to collide with the collision step, emitting a "click" prompt sound to remind the user that the injection is over.

[0010] Furthermore, the push rod assembly includes a push rod and a push rod linkage. The push rod has a locking hole that engages with the inner locking block. The inner cavity of the sound-generating base has a first sliding groove. The push rod linkage is slidably mounted on the first sliding groove and can abut against the inner side of the rear spring. The push rod linkage has a second sliding groove. The top end of the push rod extends out of the front end of the push rod linkage, and the bottom end of the push rod is slidably mounted in the second sliding groove. The first and second sliding grooves ensure that the push rod linkage and the push rod have radial constraints within the inner cavity of the sound-generating base, preventing them from rotating and ensuring their sliding stability. The top of the second sliding groove has a limit position. The two ends of the injection spring abut against and connect the push rod and the sound-generating base, respectively. When the injection spring pushes the bottom end of the push rod to the limit position, the injection spring will push the push rod and the push rod linkage to slide forward synchronously. Designing the push rod assembly as a telescopic structure can greatly reduce the length requirements of the device.

[0011] Furthermore, to ensure that the injection spring is not easily bent or deformed and thus does not affect its use, the push rod assembly also includes a spring bracket. The push rod has an inner cavity, and the injection spring and spring bracket are located in the inner cavity. The injection spring is sleeved on the spring bracket, with one end of the injection spring abutting against the push rod and the other end abutting against the spring bracket.

[0012] Furthermore, to ensure the stability of the push rod linkage installation, the push rod linkage is also provided with a linkage spring. One end of the linkage spring is connected to the push rod linkage, and the outer wall of the other end is provided with a linkage elastic block. The linkage elastic block is gradually thickened from front to back. The sound-generating base is provided with a locking hole that matches the linkage elastic block. Since the third elastic block is gradually thickened from front to back, the linkage elastic block can disengage from the locking hole under force. The cooperation between the linkage elastic block and the locking hole is mainly to provide a simple positioning and fixation for the connection between the push rod linkage and the sound-generating base, ensuring that the push rod linkage will not be displaced along the first slide groove due to shaking during installation and transportation. However, when subjected to a sufficiently large driving force from the injection spring, the linkage elastic block and the locking hole will fail, allowing the push rod and the push rod linkage to slide forward together.

[0013] Furthermore, the automatic injector of this design also includes a refill holder installed inside the pen body. The pen body has a hollowed-out or transparent window, and the refill holder is installed in the window. A refill holder clip is provided between the refill holder and the pen body for mutual cooperation and fixation. The refill holder has a medicine cartridge for installing the injector inside. The inner wall of the pen body has a protective sleeve groove. The front end of the needle tip protective sleeve extends out of the pen body, and the rear end of the needle tip protective sleeve extends into the pen body. The rear end of the tip protective sleeve is equipped with a protective sleeve spring. The outer side of the spring has a protective sleeve locking block that can engage with the protective sleeve sliding groove. The locking block is tapered from back to front, facilitating the insertion of the tip protective sleeve into the pen body. The outer end of the pen refill holder has a stop block that presses against the inner side of the spring. This stop block ensures a tight fit between the locking block and the sliding groove, preventing the spring from deforming even under external force, thus preventing the assembled tip protective sleeve from being pulled out of the pen body. The rear end of the tip protective sleeve also has a limiting hole. The pen refill holder has a refill holder spring, and the spring has an elastic positioning block that engages with the limiting hole. This elastic positioning block can disengage from the limiting hole under external force. This elastic buckle prevents the tip protective sleeve from wobbling during transportation, but the elastic positioning block has sufficient deformation capacity to not hinder the user's ability to squeeze the tip protective sleeve during use.

[0014] Furthermore, the automatic injector of this design also includes a pen cap. The needle end of the injector is provided with a safety cap. The pen cap is fitted onto the front end of the pen body and covers the front end of the needle tip protective sleeve. There is a pen cap elastic buckle that cooperates and fixes the pen cap to the pen body. There is a cylindrical buckle inside the pen cap that extends into the pen body and fastens the safety cap. In this way, when the pen cap is pulled out, the safety cap of the injector is also pulled out at the same time, which greatly facilitates the use.

[0015] Compared with the prior art, the beneficial effects of this invention are as follows: In this solution, the anti-accidental injection component is designed with a misaligned limit slider and release rail during transportation, preventing easy triggering. During assembly of the syringe, the release element at the front end of the anti-accidental injection component first engages with the inner wall of the pen body. When the sound-generating base engages with the pen body, it rotates a certain angle along the spiral inclined portion at the end of the axial limit groove, causing the limit slider and release rail in the anti-accidental injection component to cooperate. This solution is easy and simple to install, and the overall structure is stable and reliable, with sensitive triggering and high safety. When using the syringe, the user removes the pen cap, holds the pen body against the injection section, and presses down. The needle tip protective sleeve moves downward relative to the pen body. As the needle tip protective sleeve moves downward, it pushes the release element downward simultaneously, releasing the push rod. As the push rod moves forward, the limit rib at its bottom drives the push rod linkage to move forward a certain distance, at which point the sound-generating element is released. After the user hears a "click" sound or confirms the injection is complete via the visual window, hold the syringe for ten seconds and then remove it from the body. At this time, the release mechanism will receive the longitudinal force of the injection spring, returning it to its initial position (the positions of the sound-emitting element, push rod, and push rod linkage remain unchanged). The needle tip protective sleeve will also be pushed back to its original position by the release mechanism, protecting the needle tip. During the release mechanism's reset process, because the sound-emitting element has moved backward, the limiting slider will collide with and deform against it. After reset, the limiting slider will pop out of the release rail and will press against the end of the sound-emitting element. Therefore, the release mechanism is locked, preventing a second injection and protecting the syringe needle tip to prevent secondary injury to the user. Attached Figure Description

[0016] Figure 1a This is a front view of the overall structure of Embodiment 1 of the present invention;

[0017] Figure 1b for Figure 1a Diagram of tangent section in the middle AA section;

[0018] Figure 1c for Figure 1b Diagram of tangent section in the middle BB line;

[0019] Figure 2a This is a perspective view of the overall structure of the anti-accidental injection component in the initial state according to Embodiment 1 of the present invention;

[0020] Figure 2b This is a front view of the overall structure of the anti-accidental injection component in the initial state according to Embodiment 1 of the present invention;

[0021] Figure 2c for Figure 2b Diagram of tangent section in the middle DD section;

[0022] Figure 2e This is a perspective view of the overall structure of the anti-accidental injection component of Embodiment 1 of the present invention after being rotated 45°;

[0023] Figure 2d This is a front view of the overall structure of the anti-accidental injection component of Embodiment 1 of the present invention after being rotated 45°;

[0024] Figure 2f This is a schematic diagram of the section cut by the BB tangent in 2b;

[0025] Figure 2g for Figure 2f Diagram of cross section with CC tangent;

[0026] Figure 3 This is a three-dimensional structural diagram of the release element and the sound-generating element according to Embodiment 1 of the present invention;

[0027] Figure 4 This is a three-dimensional structural diagram of the sound-generating base according to Embodiment 1 of the present invention;

[0028] Figure 5a This is a front view structural diagram of the sound-generating base according to Embodiment 1 of the present invention;

[0029] Figure 5b for Figure 5a Diagram of cross section with KK tangent;

[0030] Figure 6a This is a front view of the initial state of the anti-accidental injection component of Embodiment 1 of the present invention, showing the sound-emitting base and push rod assembly in tandem.

[0031] Figure 6b for Figure 6a Diagram of tangent section in JJ;

[0032] Figure 7 This is a three-dimensional structural diagram of the push rod assembly according to Embodiment 1 of the present invention;

[0033] Figure 8 This is a cross-sectional view of the push rod assembly according to Embodiment 1 of the present invention;

[0034] Figure 9 This is a three-dimensional view of the overall structure of the anti-accidental injection component in operation after being triggered, according to Embodiment 1 of the present invention.

[0035] Figures 10a-10d This is a schematic diagram of the installation steps in Embodiment 1 of the present invention;

[0036] Figure 11 for Figure 10b Enlarged view of the area marked A in the middle;

[0037] Figures 12a-12d This is a schematic diagram illustrating the usage principle and steps of Embodiment 1 of the present invention;

[0038] Figure 13 This is an exploded view of the structure of Embodiment 2 of the present invention. Detailed Implementation

[0039] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be noted that the following specific embodiments are merely representative embodiments of the present invention, and the specific methods, apparatuses, conditions, materials, etc., exemplified are not intended to limit the present invention or the corresponding specific embodiments.

[0040] In addition, the terms "front", "front end", and "front part" in the text refer to the end towards the injection needle, while "rear", "rear end", and "rear part" refer to the opposite direction, that is, the end towards the base cap.

[0041] Example 1

[0042] In this embodiment, for structural stability, the upper spring, lock hole, release spring, spring, and irregular recess are all arranged symmetrically from left to right. However, in practical applications, users can adjust the number and position of these structures according to the actual situation to achieve the functions of these structures.

[0043] An automatic injector, such as Figures 1a to 1c As shown, the device includes a needle tip protective sleeve 4, a pen body 1, and an anti-accidental injection component 2 and a syringe 3 installed within the pen body 1. The needle tip protective sleeve 4 triggers the anti-accidental injection component 2, which then squeezes the syringe 3 to complete the injection. The anti-accidental injection component 2 is designed to be rotatable. Initially, the anti-accidental injection component 2 is not rotated and cannot trigger automatic injection. When the anti-accidental injection component 2 is rotated a certain angle, it becomes a triggerable automatic injection component. After the triggerable automatic injection component 2 is installed in the pen body 1, the needle tip protective sleeve 4 triggers the anti-accidental injection component 2 to squeeze the syringe 3 to complete the injection.

[0044] like Figures 2a to 9As shown, the anti-accidental injection assembly 2 includes a release element 21, a release spring 22, an injection spring 23, a sound-generating element 24, a sound-generating base 25, and a push rod assembly. The sound-generating base 25 consists of a base 251 and a cap 252, with the cap 252 sealing the bottom opening of the base 251. The base 251 has an inner cavity. The push rod assembly includes a push rod 261 and a push rod linkage 262, which are installed in the inner cavity. The top and bottom of the base 251 have push rod assembly openings and a bottom opening, respectively. The cap 252 is installed at the bottom of the base 251 and seals the bottom opening. A rear limiting rib 2102 is provided on the outer side of the cap 252. The outer surface of the base 251 is formed with a first shaft portion 25101, a second shaft portion 25102, a third shaft portion 25103, and a fourth shaft portion 25104, the outer diameter of which gradually increases from front to back. A first step portion is formed between the first shaft portion 25101 and the second shaft portion 25102, a second step portion is formed between the second shaft portion 25102 and the third shaft portion 25103, and a collision step portion is formed between the third shaft portion 25103 and the fourth shaft portion 25104. The front part of the release member 21 is movably sleeved on the first shaft portion 25101, and a front limiting rib 2101 is provided on the outer side of the release member 21. The rear part of the sound-generating element 24 is movably sleeved on the third shaft part 25103. The two ends of the release spring 22 respectively abut against the release element 21 and the sound-generating element 24. The rear part of the release element 21 is provided with a release element rear sleeve, and the front part of the sound-generating element 24 is provided with a sound-generating front sleeve. The outer diameter of the release element rear sleeve is not greater than the inner diameter of the sound-generating front sleeve. The release element rear sleeve can be inserted into the sound-generating front sleeve. The side wall of the release element rear sleeve is provided with a release spring piece 211, and one end of the release spring piece 211 is connected to... Following the release element, the other end of the release spring 211 is provided with a limiting slider 2111. The outer surface of the limiting slider 2111 protrudes beyond the inner diameter of the front sleeve of the sound-generating element, but the limiting slider 2111 does not protrude beyond the outer diameter of the front sleeve of the sound-generating element. The front inner wall of the front sleeve of the sound-generating element is provided with a groove 241, and the inner wall of the front sleeve of the sound-generating element is provided with a release slide rail 242. The front inner wall of the front sleeve of the sound-generating element is provided with a transition groove connecting the groove 241 and the release slide rail 242 to facilitate the rotation of the limiting slider 2111. The sound-generating element 24 and the sound-generating base 25 are provided with mutually cooperating axial limiting grooves and axial limiting strips, and the sound-generating element 24 and the sound-generating base 25 can rotate synchronously.The sound-generating base 25 has a front spring plate 2513 at the first shaft portion 25101. One end of the front spring plate 2513 is connected to the first stepped portion, and the inner and outer sides of the other end are respectively provided with an inner locking block 25131 and an outer protrusion 25132. The push rod 261 has a first locking hole 2611 and a second locking hole 2612 along its length direction, which cooperate with the inner locking block 25131. In the initial state, the front part of the release member 21 is sleeved on the front spring plate 2513. The inner wall of the release member 21 presses against the outer protrusion 25132, causing the front spring plate 2513 to retract inward. The inner locking block 25131 is engaged in the first locking hole 2611, thereby restricting the movement of the push rod assembly and the injection spring 23.

[0045] like Figure 2a As shown, the release spring 211 and the groove 241 are located on the same vertical line, while the front limiting rib 2101 and the rear limiting rib 2102 will be located on different vertical lines. The limiting slider 2111 is inserted into the groove 241, and the end face of the limiting slider 2111 contacts and engages with the end face of the sound-generating element 24. The release element 21 and the sound-generating element 24 are fixedly arranged and cannot move relative to each other. Figure 2dAs shown, when the release element 21 or the sound-generating element 24 is rotated, the release spring 211 and the groove 241 are no longer on the same vertical line. At this time, the front limiting rib 2101 and the rear limiting rib 2102 will be on the same vertical line. The limiting slider 2111 retracts inward as the release spring 211 is subjected to force. When the limiting slider 2111 is inserted into the release slide rail 242, the release spring 211 rebounds, making the limiting slider 2111 and the release slide rail 242 in close contact. At this time, the release element 21 and the sound-generating element 24 are movable and can move relative to each other. After the release member 21 moves towards the rear end under the action of external force and leaves the front spring 2513, the injection spring 23 pushes the push rod 261 forward to squeeze the inner locking block 25131, causing the front spring 2513 to pop outward. The push rod 261 can then continue to move forward under the drive of the injection spring 23 to assist the syringe in automatic injection. When the injection spring 23 drives the push rod 261 to the maximum injection stroke, the second locking hole 2612 will reach the position of the inner locking block 25131. After the injection is completed and the external force is lost, the release member 21 will also be pushed back to the position of the front spring 2513 under the action of the release spring 22, locking the inner locking block 25131 into the second locking hole 2612 to assist in locking the push rod assembly. In fact, the fixing of the push rod assembly can also be determined according to factors such as the elasticity of the release spring 22 and the length of the push rod 261. The inner wall of the pen body 1 is provided with an axial limiting groove 101 that matches the front limiting rib 2101 and the rear limiting rib 2102. The end of the axial limiting groove 101 is provided with a spiral inclined part 102 that allows the release member 21 or the sound-generating member 2524 to drive the sound-generating base 25 to rotate, so that after the anti-accidental injection component 2 is assembled with the pen body 1, the limiting slider 2111 is inserted into the release slide rail 242. Specifically, when installing the anti-accidental injection component 2, the front limiting rib 2101 is aligned with the axial limiting groove 101, and the rear limiting rib 2102 is aligned with the spiral inclined part 102. After the release member 21 moves a certain distance along the axial limiting groove 101, the rear limiting rib 2102 cooperates with the spiral inclined part 102. Then, the anti-accidental injection component 2 is moved, and the sound-generating base 25 rotates with the spiral inclined part 102 and is inserted into the axial limiting groove 101. At this time, the limiting slider 2111 is inserted into the release slide rail 242, and the rear end of the needle tip protective sleeve 4 extends into the pen body 1 and can push the release member 21 to move axially backward on the sound-generating base 25. After the release member 2 moves, it can release the push rod assembly and the injection spring 23, so that the injection spring 23 drives the push rod assembly to push the syringe 3.In other embodiments, the spiral tilting part can be omitted. When the anti-accidental injection component 2 is installed onto the pen body 1, the assembler only needs to manually rotate the release component 21 and the sound-generating base 25 by a certain angle to install the front limiting rib 2101 and the rear limiting rib 2102 into the axial limiting groove 101. Alternatively, the spiral tilting part 102 can be configured to drive the release component 21 to rotate. The front limiting rib 2101, the rear limiting rib 2102, the axial limiting groove 101, and the spiral tilting part 102 can be adjusted to appropriate angles.

[0046] Furthermore, the rear part of the base 251 is provided with a rear spring piece 2512 at the position of the third shaft part 25103 to block the sound-emitting element 24. The bottom end of the rear spring piece 2512 is connected to the collision step part. The top outer wall of the rear spring piece 2512 is provided with a protruding rear spring block 25121. The rear spring block 25121 gradually thickens from front to back, forming a slope shape. The push rod 261, push rod linkage 262, and injection spring 23 are installed in the inner cavity of the base 251. The inner cavity of the base 251 is provided with a first sliding groove. The push rod linkage 262 has a flange 622 on its side. The push rod linkage 262 is slidably installed on the first sliding groove through the flange 622 and can abut against the inner side of the rear spring 2512. The rear spring block 25121 blocks the sound-emitting element 24, so that a collision gap is formed between the rear end of the sound-emitting element 24 and the collision step portion. The push rod linkage 262 is provided with a second sliding groove 620. The top end of the push rod extends out of the rear end of the push rod linkage 262 and extends out of the base 251. The push rod assembly at the top has an opening, and the bottom end of the push rod 261 is provided with a push rod slider 610. The push rod slider 610 is slidably installed in the second slide groove 620. The first slide groove and the second slide groove 620 can ensure that the push rod linkage 262 and the push rod 261 have radial constraints in the inner cavity of the base 251, preventing them from rotating and ensuring their sliding stability. For the stability of the mechanism, axial limiting ribs and limiting grooves can be provided between the push rod 261 and the push rod linkage 262, and / or between the push rod linkage 262 and the base 251, and / or between the base 251 and the sound-generating component 24, to ensure that the sliding components do not rotate and cause misalignment. The top of the front end of the second slide groove is provided with a limit position, and the two ends of the injection spring 23 respectively abut against and connect the push rod 261 and the base 251. Figure 2aAs shown, in the initial state, the push rod linkage 262 abuts against the inner side of the first spring piece 512. Thus, when the release spring 2 pushes the sound-generating component 24 from front to back against the rear spring block 25121, it will impart inward and backward force to the rear spring block 25121. However, because the push rod linkage 262 abuts against the rear spring piece 2512 inside the base 251, it cannot retract inward, thereby the rear spring block 25121 will restrict the rearward movement of the sound-generating component 24. When the injection spring 23 pushes the push rod 261 forward a certain distance (approximately 21.5 mm), the push rod slider 610 on the push rod 261 reaches the limit position of the second slide groove, and the injection spring 23 will push... The push rod 261 and the push rod linkage 262 slide forward synchronously. When the push rod linkage 262 slides forward a certain distance (approximately 14mm), the injection is complete, and the push rod linkage 262 moves away from the inner side of the rear spring 2512. The rear spring block 25121 can retract inward and lose its blocking function. The release spring 22 will push the sound-emitting element 24 to collide with the collision step portion. The collision gap between the sound-emitting element 24 and the collision step portion disappears, emitting a "click" sound. To increase the volume, several protruding ribs can be spaced out on the collision step portion so that the air between the sound-emitting element 24 and the base 251 is not completely compressed and expelled. Figure 9 As shown, at this time, the push rod 261 will push forward to its highest position, and the sound-emitting element 24 will contact the base 251. This design forms a telescopic structure with the push rod and the push rod linkage. In this way, the push rod linkage 262 can delay the injection stroke designed for the automatic injector until the injection is completed. The push rod linkage 262 just slides away from the inner side of the first elastic part and then emits a "click" sound to remind the user that the injection is complete, making the prompt sound more accurate. Moreover, the telescopic structure can also save the length of the push rod assembly and the entire structure, making the product more compact and durable. In this embodiment, the push rod 261 moves a certain distance and then drives the push rod linkage 262 to move through the push rod sliders on both sides. At the beginning, these two parts cannot move at the same time. Only when the push rod sliders reach the limit position of the second slide groove can the two parts connect in the forward direction, so that the push rod drives the push rod linkage to slide forward.

[0047] Furthermore, the release member is sleeved on the second shaft portion 25102, and the second shaft portion 25102 is provided with an irregularly shaped recess 2514 corresponding to the position of the release spring 211. The irregularly shaped recess 2514 provides deformation space for the release spring 211, which facilitates the rotation of the release member 21 or the sound-generating member 24.

[0048] Furthermore, the outer diameter of the second shaft portion 25102 matches the inner diameter of the rear sleeve of the release member, and the outer diameter of the third shaft portion 25103 matches the rear inner diameter of the sound-generating member 24 (i.e., outer diameter - inner diameter < 4mm), making the installation fit between the sound-generating base 25, the sound-generating member 24 and the release member 21 tighter and more stable. The first step portion and the second step portion can respectively serve as blocking portions that limit the maximum stroke of the release member 21 and the sound-generating member 24 to move backward.

[0049] Furthermore, the limiting slider 2111 gradually thickens from front to back, forming a slope. This allows the rear end of the limiting slider 2111 to effectively engage with the front end of the sound-generating element 24. When the limiting slider 2111 engages with the release slide rail 242, the force of the release spring 2 can also pull the limiting slider 2111 out of the release slide rail 242, causing the release element 21 and the sound-generating element 24 to separate and reset. As a result, after the limiting slider 2111 disengages from the release slide rail 242, the limiting slider 2111 will abut against the front end face of the sound-generating element 24.

[0050] Furthermore, the front of the base 251 is provided with a limiting block 2511 that blocks the release member 21. The limiting block 2511 is located on the front side of the front spring piece 2513. The front of the limiting block 2511 is gradually thickened from front to back, and the bottom of the limiting block 2511 is flat. The design of the gradually thickened upper part of the limiting block 2511 makes it convenient to put the release member into the base 251 during installation, while the design of the flat bottom of the limiting block 2511 restricts the release member from moving upward and prevents the release member 21 from detaching from the base 251.

[0051] Furthermore, to ensure the stability of the push rod linkage 262 during installation, the push rod linkage 262 is also provided with a linkage spring 2621. One end of the linkage spring 2621 is connected to the push rod linkage 262, and the outer wall of the other end is provided with a linkage elastic block 26211. The linkage elastic block 26211 is gradually thickened from front to back. The base 251 is provided with a locking hole that matches the linkage elastic block 26211. Because the linkage elastic block 26211 is gradually thickened from front to back, the injection spring pushes the push rod linkage 26221... When the rod and the push rod linkage slide forward synchronously, the linkage elastic block 26211 can disengage from the locking hole under force. The cooperation between the linkage elastic block 26211 and the locking hole is mainly to provide a simple positioning and fixation for the connection between the push rod linkage 262 and the base 251, ensuring that the push rod linkage will not be displaced along the first slide groove due to shaking during installation and transportation. However, when subjected to a sufficiently large driving force from the injection spring, the linkage elastic block 26211 and the locking hole will fail, allowing the push rod 261 and the push rod linkage 262 to slide forward synchronously.

[0052] Furthermore, the base 251 and the cap 252 are provided with mutually cooperating positioning buckles, and the base 251 and the cap 252 are connected by detachable buckles to facilitate product assembly. The outer side of the cap 252 is also provided with several external fasteners for cooperating and fixing with the rear end of the pen body 1.

[0053] Furthermore, the push rod assembly also includes a spring bracket 263. The push rod 261 has an inner cavity, and the injection spring 23 and spring bracket 263 are disposed within this cavity. The injection spring 23 is fitted onto the spring bracket 263, with one end of the injection spring 23 abutting against the push rod 261 and the other end abutting against the spring bracket 263. The bottom end of the spring bracket 263 is connected to the cap 252. Under the dual constraint of the inner wall of the push rod 261 and the outer and inner surfaces of the spring bracket 263, the injection spring 23 is less prone to bending and deformation, thus affecting its use.

[0054] Furthermore, the automatic injector of this design also includes a refill holder 6 installed inside the pen body 1. The pen body 1 is provided with a hollow or transparent viewing window 100, and the refill holder 6 is installed at the viewing window 100, such as... Figure 11 As shown, a pen refill holder 6 and a pen body 1 are provided with a pen refill holder buckle 61 that cooperates and fixes each other. The pen refill holder 6 is provided with a medicine chamber for installing the syringe 3. The inner wall of the pen body 1 is provided with a protective sleeve groove 105. The front end of the needle tip protective sleeve 4 extends out of the pen body 1, and the rear end of the needle tip protective sleeve 4 extends into the pen body 1. The rear end of the needle tip protective sleeve 4 is provided with a protective sleeve spring. The outer side of the protective sleeve spring is provided with a protective sleeve block 41 that can be inserted into the protective sleeve groove 105. The protective sleeve block 41 is gradually thickened from back to front to facilitate the insertion of the needle tip protective sleeve 4 into the pen body 1. The outer end of the pen refill holder 6 is provided with a stop block 62 that presses against the inner side of the protective sleeve spring. The stop block 62 can make the protective sleeve block 41 fit tightly in the protective sleeve groove 105. Even if the needle tip protective sleeve 4 is subjected to external force, the protective sleeve spring will not deform, which can prevent the assembled needle tip protective sleeve 4 from being pulled out of the pen body. The needle tip protective sleeve 4 is provided with a limiting hole 42 at its rear end. The pen refill holder 6 is provided with a pen refill holder spring piece. The pen refill holder spring piece is provided with a pen refill holder elastic positioning block 63 that is engaged with the limiting hole 42. The pen refill holder elastic positioning block 63 can be disengaged from the limiting hole 42 under external force. The function of this elastic buckle is to prevent the needle tip protective sleeve from shaking back and forth during transportation. However, the pen refill holder elastic positioning block has sufficient deformation capacity and will not hinder the user's squeezing of the needle tip protective sleeve during use.

[0055] Furthermore, the automatic injector of this design also includes a pen cap 5. The needle end of the injector 3 is provided with a safety cap. The pen cap 5 is provided at the front end of the pen body 1 and covers the front end of the needle tip protective sleeve 4. The pen cap 5 and the pen body 5 are provided with a pen cap elastic buckle that cooperates and fixes each other. The pen cap 2 is provided with a cylindrical buckle that extends into the pen body 1 and fastens the safety cap. In this way, when the pen cap is pulled out, the safety cap of the injector is also pulled out at the same time, which greatly facilitates the use.

[0056] The assembly steps of one type of automatic injector according to this solution are as follows:

[0057] S1. As Figure 10a As shown, the needle tip protective sleeve 4 is inserted into the pen body 1, and the protective sleeve on the needle tip protective sleeve;

[0058] S2. For example Figure 10b As shown, insert the pen refill holder 6 into the pen body 1;

[0059] S3. For example Figure 10c As shown, insert the pen cap 5 and syringe 3 into the pen body;

[0060] S4. For example Figure 10d As shown, the anti-accidental injection component 2 is installed into the pen body; the final product is shown in Figure 1.

[0061] The operating principle of one type of automatic injector in this solution is as follows:

[0062] P1. Remove the pen cap: as in Figure 12a As shown, the pen cap 5 is fixed to the front end of the pen body 1 by a buckle. Inside the pen cap 5, there is a cylindrical buckle 51 that holds the safety cap of the syringe 3. When the pen cap 5 is pulled out, the safety cap of the syringe 3 is also pulled out at the same time. At this time, although the safety cap of the syringe 3 is pulled out, the front end of the needle tip protective sleeve 4 will cover the needle of the syringe 3, reducing the user's fear.

[0063] P2. Injection: Hold the pen body 1 against the injection site and press down. The needle tip protective sleeve 4 will retract relative to the pen body 1, exposing the needle of the syringe 3, which will then pierce the body. When the needle tip protective sleeve 4 moves backward and the needle tip is exposed, as... Figure 12b As shown, the release element 21 will be squeezed away from the position of the front spring 2513 by the needle tip protective sleeve 4, the buckle of the push rod 261 will no longer be restrained, the injection spring 23 will drive the push rod 261 forward, push the syringe 3 to start injection, and inject the medicine into the body.

[0064] P3. Reset: (e.g., ...) Figure 12cAs shown, when the injection spring 23 drives the push rod 261, causing the push rod linkage 262 to move away from the inner side of the rear spring 2512, the release spring 22 will push the sound-emitting element 24 to collide with the collision step. The patient hears a "click" sound or can confirm the injection is complete through the viewing window, holds the injection for ten seconds, and then removes the syringe from the body. At this time, the release element 21 will be returned to its initial position by the force of the injection spring 22 (the positions of the sound-emitting element 24, push rod 261, and push rod linkage 262 do not change), and the needle tip protective sleeve 4 will also be pushed back to its original position by the release element 21 to protect the needle tip. After resetting, as... Figure 12d As shown, due to the backward movement of the sound-emitting component 24, the limiting slider 2111 will collide with the sound-emitting component 24 and deform. After the reset is completed, the limiting slider 2111 will pop out of the release slide rail 242, and the limiting slider 242 will abut against the front end of the sound-emitting component 24. The release component 21 and the sound-emitting component 24 can no longer move relative to each other, and the user will not be able to squeeze the needle tip protective sleeve 4 inward again. Therefore, the release component 21 is stuck and cannot be injected a second time, thus protecting the syringe needle tip and preventing secondary injury to the user.

[0065] Example 2

[0066] An automatic injector includes a needle tip protective sleeve 4, a pen body 1, and an anti-accidental injection component 2 and a syringe 3 installed in the pen body. Its structure is similar to that of the embodiment, except that in this embodiment 2, the pen body 1 adopts a two-section design with snap-fit ​​installation for easy installation, but it is not limited to two sections in actual application.

[0067] The above description is merely a preferred embodiment of the present invention and should not be construed as limiting the scope of the present invention. Any simple equivalent changes and modifications made in accordance with the scope of the patent application and the description of the invention shall still fall within the scope of the patent of the present invention.

Claims

1. An automatic injector, characterized in that, The device includes a needle tip protective sleeve, a pen body, and an anti-accidental injection assembly and syringe installed inside the pen body. The rear end of the needle tip protective sleeve extends into the pen body. The anti-accidental injection assembly includes a sound-generating base and a release element, a release spring, an injection spring, and a push rod assembly installed on the sound-generating base. The release element is provided with a limiting slider, and the sound-generating base is provided with a release slide rail that cooperates with the limiting slider. The outer sides of the release element and the sound-generating base are respectively provided with a front limiting rib and a rear limiting rib. The inner wall of the pen body is provided with an axial limiting groove that matches the front limiting rib and the rear limiting rib.

2. An automatic injector according to claim 1, characterized in that, The anti-accidental touch injection component has two states: initial and after installation. In the initial state, the anti-accidental touch injection component is not installed in the pen body, and the limiting slider is not engaged in the release rail. After installation, the anti-accidental touch injection component is installed in the pen body, and the limiting slider is engaged in the release rail.

3. An automatic injector according to claim 1 or 2, characterized in that, The sound-generating base is also equipped with a sound-generating component. The sound-generating component and the sound-generating base are provided with mutually cooperating axial limiting grooves and axial limiting strips. The release component, the sound-generating component, and the release spring are movably sleeved on the outer surface of the sound-generating base. The push rod assembly and the injection spring are installed in the inner cavity of the sound-generating base. The two ends of the release spring respectively abut against and connect the release component and the sound-generating component. The release component is provided with a release spring piece. The end of the release spring piece is provided with the limiting slider. The front end of the sound-generating component is provided with a groove that cooperates with the limiting slider. The inner wall of the sound-generating component is provided with the release slide rail.

4. An automatic injector according to claim 3, characterized in that, The front end of the sound-generating base is also provided with a front spring plate. One end of the front spring plate is connected to the sound-generating base, and the inner side and outer side of the other end are respectively provided with an inner locking block and an outer protrusion.

5. An automatic injector according to claim 4, characterized in that, The rear end of the sound-generating base is also provided with a collision step and a rear spring. The rear spring is placed on the front side of the collision step. One end of the rear spring is connected to the sound-generating base, and the outer side of the other end is provided with a protruding rear spring block. The push rod assembly abuts against the inner side of the rear spring, and the rear spring block blocks the sound-generating component.

6. An automatic injector according to claim 4, characterized in that, The push rod assembly includes a push rod, a push rod linkage, and a spring bracket. The push rod has a locking hole that engages with the inner locking block. The inner cavity of the sound-generating base has a first sliding groove. The push rod linkage is slidably mounted on the first sliding groove and abuts against the inner side of the rear spring. The push rod linkage has a second sliding groove. The top end of the push rod extends out of the front end of the push rod linkage, and the bottom end of the push rod is slidably mounted in the second sliding groove. The top of the front end of the second sliding groove has a limit position. The two ends of the injection spring abut against the push rod and the sound-generating base, respectively. The push rod has an inner cavity. The injection spring and the spring bracket are located in the inner cavity of the push rod, and the injection spring is sleeved on the spring bracket. One end of the injection spring abuts against the push rod, and the other end abuts against the spring bracket.

7. An automatic injector according to claim 6, characterized in that, The push rod linkage is also provided with a linkage spring piece. One end of the linkage spring piece is connected to the push rod linkage, and the outer wall of the other end is provided with a linkage elastic block. The sound-generating base is provided with a locking hole that cooperates with the linkage elastic block.

8. An automatic injector according to claim 1, characterized in that, It also includes a refill holder installed inside the pen body. The pen body has a hollow or transparent window. The refill holder is installed in the window. The refill holder and the pen body are provided with a refill holder buckle that cooperates and fixes each other. The refill holder has a medicine chamber for installing the syringe inside.

9. An automatic injector according to claim 8, characterized in that, The inner wall of the pen body is provided with a protective sleeve groove. The front end of the needle tip protective sleeve extends out of the pen body. The rear end of the needle tip protective sleeve is provided with a protective sleeve spring. The outer side of the protective sleeve spring is provided with a protective sleeve locking block that engages with the protective sleeve groove. The outer end of the pen refill holder is provided with a stop block that engages with the inner side of the protective sleeve spring. The rear end of the needle tip protective sleeve is also provided with a limiting hole. The pen refill holder is provided with a pen refill holder spring. The pen refill holder spring is provided with a pen refill holder elastic positioning block that engages with the limiting hole.

10. An automatic injector according to claim 1, characterized in that, It also includes a pen cap, the needle end of the syringe is provided with a safety cap, the pen cap is sleeved on the front end of the pen body, the pen cap and the pen body are provided with a pen cap elastic buckle that cooperates and fixes each other, the pen cap is provided with a cylindrical buckle that extends into the pen body and fastens the safety cap, and the end of the axial limiting groove is provided with a spiral inclined part that makes the release member or the sound-generating base rotate.

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