Small-dose automatic injection pen

Abstract

The small-dose automatic injection pen comprises a lower pen holder and an upper pen holder which are of hollow structures, the ends, away from each other, of the lower pen holder and the upper pen holder are detachably connected with a pen cap and an end cover respectively, and an excitation push rod, a medicine frame and an injection push rod are sequentially arranged in a pen holder cavity formed by the lower pen holder and the upper pen holder from the pen cap end to the end cover end; according to the scheme, the injection push rod is matched with the upper penholder, so that the injection push rod can be locked in an initial state, and the injection needle is prevented from popping out; by arranging the excitation push rod, the injection push rod can be pushed to rotate and unlock during pressing, then the injection action is completed, use is convenient, and operation is convenient; by arranging the opening groove and the clamping hook at the end of the medicine frame and the clamping hole matched with the clamping hook in the excitation push rod, locking can be achieved after injection is completed, and the injection needle is protected.

Description

Technical Field

[0001] The utility model relates to an injection device, in particular to a small-dose automatic injection pen. Background Art

[0002] With the rapid development of modern medical technology, many types of diseases have been treated. However, there are some diseases that require long-term multiple or complex repeated dosing regimens for continuous treatment or control of symptoms. For example, diabetic patients need to use insulin for a long time, and moderate to severe chronic pain patients need to use fentanyl for a long time; currently, the treatment of such diseases must be through subcutaneous injection to exert the efficacy of the drug. The current drug syringes are relatively large in size and inconvenient to carry and operate during use. Therefore, it is an urgent problem for technicians in the related field to design a small-dose automatic injection pen. Content of the Utility Model

[0003] To solve the above technical problems, the technical solution provided by the utility model is: a small-dose automatic injection pen, including a lower pen barrel and an upper pen barrel with a hollow structure. The ends of the lower pen barrel and the upper pen barrel away from each other are respectively detachably connected with a pen cap and an end cap. Inside the pen barrel cavity formed by the lower pen barrel and the upper pen barrel, a firing push rod, a medicine rack and an injection push rod are sequentially arranged from the pen cap end to the end cap end; one end of the medicine rack is clamped on the inner wall of the lower pen barrel, and the other end extends into the firing push rod; one end of the injection push rod is detachably inserted into the end of the upper pen barrel through an injection spring, and the other end is inserted into the medicine rack. The firing push rod is arranged outside the medicine rack, one end of which contacts the injection push rod, and the other end extends out of the lower pen barrel. An injection firing structure is formed among the firing push rod, the injection push rod and the upper pen barrel. When the firing push rod pushes the injection push rod, the injection push rod is detached from the end of the upper pen barrel, and under the action of the injection spring, the injection needle in the medicine rack is pushed out; one end of the medicine rack away from the injection push rod is connected with the inner end of the firing push rod through a push rod spring to form a needle protection structure. After the firing push rod returns to the starting position, the medicine rack is locked with the firing push rod.

[0004] Further, the injection push rod includes a lower push rod extending into the medicine rack. One end of the lower push rod extending out of the medicine rack is provided with a push block and an upper push rod. A pushing structure cooperating with the firing push rod is arranged on the side wall of the push block, so that the injection push rod rotates. Lock blocks are respectively arranged on the upper side of the upper push rod. A lock hole corresponding to the lock block and its rotation angle is arranged at the end of the upper pen barrel. A locking platform is arranged at the bottom of one side of the lock hole away from the rotation direction of the lock block. The injection spring is arranged between the push block and the inner end face of the upper pen barrel. When the injection push rod is locked with the upper push rod, the bottom of the lock block is located above the locking platform. When the firing push rod pushes the injection push rod to rotate, the lock block is detached from the end of the upper pen barrel from the part of the lock hole without the locking platform.

[0005] Further, an included angle is provided between the side wall of the keyhole and the side wall of the lock block, and the included angle is 5°.

[0006] Further, the pushing structure includes pushing grooves arranged on both sides of the pushing block. The pushing grooves are on the side close to the rotation direction of the injection push rod, and a pushing end block is arranged at the end away from the lower push rod. A first pushing inclined surface is arranged at the end of the pushing end block. The excitation push rod includes an excitation sleeve arranged outside the medicine rack. Side push rods extending into the pushing grooves are arranged on both sides of the excitation sleeve. The end of the side push rod is matched with the first pushing inclined surface through a second pushing inclined surface. When the side push rod moves towards the first pushing inclined surface, the injection push rod is pushed to rotate.

[0007] Further, at one end of the medicine rack extending into the excitation push rod, first opening grooves are respectively arranged on both sides, dividing the medicine rack into a first medicine rack flap and a second medicine rack flap. Hook strips are also arranged in the middle of the first medicine rack flap and the second medicine rack flap. The two sides of the hook strip are respectively movably arranged with the first medicine rack flap and the second medicine rack flap through second opening grooves. Hooks are arranged on the outer sides of the ends of the hook strips; a wedge block that can be inserted into the first opening groove is arranged on the inner wall of the excitation sleeve, and a card hole corresponding to the hook is also arranged on the side wall of the excitation sleeve. When the excitation sleeve returns to the initial position, the hook is clamped with the card hole.

[0008] Further, the end of the first opening groove away from its opening is a triangular tightening end, so that when the wedge block in the excitation push rod is inserted into the first opening groove, the first medicine rack flap and the second medicine rack flap are pushed outwards.

[0009] Further, step end faces are arranged on the inner walls at the openings of the first medicine rack flap and the second medicine rack flap, and an annular end face is arranged at the outlet at the end of the excitation push rod away from the side push rod. A push rod spring is clamped between the annular end face and the step end face.

[0010] Further, a visual window for exposing the pushing end of the injection push rod is arranged on the lower pen rod.

[0011] The advantages of the present utility model compared with the prior art are as follows: Through the cooperation of the injection push rod and the upper pen rod in this solution, the injection push rod can be locked in the initial state to prevent the injection needle from popping out; by arranging the excitation push rod, the injection push rod can be pushed to rotate and unlock when pressed, thereby completing the injection action, which is convenient to use and operate; by arranging the opening grooves, hooks at the end of the medicine rack, and the card holes on the excitation push rod that cooperate with the hooks, the injection can be locked after completion to protect the injection needle. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a schematic structural diagram of a small-dose automatic injection pen of the present utility model.

[0013] Figure 2 is a schematic cross-sectional structural diagram of a small-dose automatic injection pen of the present utility model.

[0014] Figure 3 It is a schematic diagram of the internal structure of a small-dose automatic injection pen of the present utility model.

[0015] Figure 4 It is a schematic diagram of the structure of the injection push rod in a small-dose automatic injection pen of the present utility model.

[0016] Figure 5 It is a schematic diagram of the connection structure between the injection push rod and the upper pen rod in a small-dose automatic injection pen of the present utility model.

[0017] Figure 6 It is a schematic diagram of the structure of the end of the upper pen rod in a small-dose automatic injection pen of the present utility model.

[0018] Figure 7 It is a schematic diagram of the connection structure between the activation push rod and the injection push rod in a small-dose automatic injection pen of the present utility model.

[0019] Figure 8 It is a schematic diagram of the bottom structure of the medicine rack in a small-dose automatic injection pen of the present utility model.

[0020] Figure 9 It is a schematic diagram of the internal structure between the lower pen rod and the medicine rack in a small-dose automatic injection pen of the present utility model.

[0021] Figure 10 It is a schematic diagram of the external structure of the medicine rack in a small-dose automatic injection pen of the present utility model.

[0022] Figure 11 It is a schematic diagram of the bottom structure of the lower pen rod in a small-dose automatic injection pen of the present utility model. Detailed implementation manners

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. Usually, the components of the embodiments of the present utility model described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0024] In the description of the embodiments of the present utility model, it should be noted that if terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the utility model product is usually placed during use, it is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation on the present utility model. In addition, terms such as "first", "second", "third", etc. are only used for distinguishing descriptions and cannot be construed as indicating or implying relative importance.

[0025] In addition, if terms such as "horizontal", "vertical", "hanging" and other terms do not mean that the components are required to be absolutely horizontal or hanging, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0026] In the description of the embodiments of the present utility model, "a plurality of" represents at least two.

[0027] In the description of the embodiments of the present utility model, it should also be noted that unless otherwise clearly specified and defined, if terms such as "set", "installed", "connected", "connected" are understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0028] Embodiment:

[0029] Combined with the attached Figures 1-11, a small-dose auto-injector pen in this embodiment includes a lower pen barrel 1 with a hollow structure and an upper pen barrel 2. At the ends of the lower pen barrel 1 and the upper pen barrel 2 away from each other, a pen cap 3 and an end cap 4 are detachably connected respectively. In the pen barrel cavity formed by the lower pen barrel 1 and the upper pen barrel 2, an activation push rod 5, a medicine rack 6, and an injection push rod 7 are sequentially arranged from the pen cap 3 end to the end cap 4 end; one end of the medicine rack 6 is clamped on the inner wall of the lower pen barrel 1, and the other end extends into the activation push rod 5; one end of the injection push rod 7 is detachably inserted into the end of the upper pen barrel 2 through an injection spring 8, and the other end is inserted into the medicine rack 6. The activation push rod 5 is arranged outside the medicine rack 6, one end contacts the injection push rod 7, and the other end extends out of the lower pen barrel 1. An injection activation structure is formed among the activation push rod 5, the injection push rod 7, and the upper pen barrel 2. When the activation push rod 5 pushes the injection push rod 7, the injection push rod 7 is disengaged from the end of the upper pen barrel 2, and under the action of the injection spring 8, the injection needle in the medicine rack 6 is pushed out; one end of the medicine rack 6 away from the injection push rod 7 is connected to the inner end of the activation push rod 5 through a push rod spring 9 to form a needle protection structure. After the activation push rod 5 returns to the starting position, the medicine rack 6 is locked with the activation push rod 5; a visual window 10 for exposing the pushing end of the injection push rod 7 is arranged on the lower pen barrel 1.

[0030] The injection push rod 7 includes a lower push rod 701 extending into the medicine rack 6. At the end of the lower push rod extending out of the medicine rack 6, a pushing block 702 and an upper push rod 703 are arranged. A pushing structure cooperating with the activation push rod 5 is arranged on the side wall of the pushing block 702, so that the injection push rod 7 rotates. Locking blocks 704 are respectively arranged on the upper side of the upper push rod 703. Locking holes 201 corresponding to the locking blocks 704 and their rotation angles are arranged at the end of the upper pen barrel 2. A locking platform 202 is arranged at the bottom of one side of the locking hole 201 away from the rotation direction of the locking block 704. An included angle is arranged between the side wall of the locking hole 201 and the side wall of the locking block 704, and the included angle is 5°. The 5° included angle makes the injection push rod tightly locked with the locking platform under the pressure of the spring to prevent the injection push rod from being accidentally activated; the injection spring 8 is arranged between the pushing block 702 and the inner end face of the upper pen barrel 2. When the injection push rod 7 is locked with the upper push rod 703, the bottom of the locking block 704 is located above the locking platform 202. When the activation push rod 5 pushes the injection push rod 7 to rotate, the locking block 704 disengages from the end of the upper pen barrel 2 at the part of the locking hole 201 where the locking platform 202 is not arranged.

[0031] The pushing structure includes pushing grooves 705 arranged on both sides of the pushing block 702. On the side of the pushing groove 705 close to the rotation direction of the injection push rod 7 and at the end away from the lower push rod 701, a pushing end block 706 is arranged. A first pushing inclined surface 707 is arranged at the end of the pushing end block 706. The activation push rod 5 includes an activation sleeve 301 arranged outside the medicine rack 6. Side push rods 302 extending into the pushing grooves 705 are arranged on both sides of the activation sleeve 301. The end of the side push rod 302 cooperates with the first pushing inclined surface 707 through a second pushing inclined surface 303. When the side push rod 302 moves towards the first pushing inclined surface 707, the injection push rod 7 is pushed to rotate.

[0032] The medicine rack 6 extends into one end of the excitation push rod 5. On both sides of the medicine rack 6, there are respectively arranged first opening grooves 601, which divide the medicine rack 6 into a first medicine rack flap 602 and a second medicine rack flap 603. In the middle of the first medicine rack flap 602 and the second medicine rack flap 603, there is also arranged a hook strip 604. The two sides of the hook strip 604 are respectively movably arranged with the first medicine rack flap 602 and the second medicine rack flap 603 through second opening grooves 605. On the outer side of the end of the hook strip 604, there is arranged a hook 606; on the inner wall of the excitation sleeve 301, there is arranged a wedge block 304 that can be inserted into the first opening groove 601, and on the side wall of the excitation sleeve 301, there is also arranged a card hole 305 corresponding to the hook 606. When the excitation sleeve 301 returns to the initial position, the hook 606 is clamped with the card hole 305.

[0033] One end of the first opening groove 601 far from its opening is a triangular tightening end 607, so that when the wedge block 304 in the excitation push rod 5 is inserted into the first opening groove 601, the first medicine rack flap 602 and the second medicine rack flap 603 are pushed outwards.

[0034] On the inner wall at the opening of the first medicine rack flap 602 and the second medicine rack flap 603, there is arranged a stepped end face 608. At the outlet of one end of the excitation push rod 5 far from the side push rod 302, there is arranged an annular end face 306. A push rod spring 9 is clamped between the annular end face 306 and the stepped end face 608.

[0035] In the initial state, the lock block at the end of the injection push rod contacts the locking platform at the end of the upper pen rod, so that the injection push rod is locked with the upper pen rod. Remove the pen cap to expose the part of the excitation push rod extending out of the lower pen rod, and press this part at the position where injection is required. At this time, the excitation push rod moves into the lower pen rod. The side push rods on both sides of the excitation push rod move along the push groove in the injection push rod towards the push end block. Through the contact and push of the second push slope and the first push slope, the injection push rod rotates. At this time, the lock block at the end of the injection push rod rotates in the lock hole at the end of the upper pen rod and disengages from the stepped end face, so that the injection push rod is disengaged from the upper pen rod, and driven by the injection spring, the injection push rod drives the injection needle arranged at its other end to extend out from the outlet of the excitation push rod for injection; in the initial state, the card hole of the excitation push rod and the hook on the medicine rack are in different planes and there is no contact between them. When the excitation push rod moves into the lower pen rod, the wedge block on the inner wall of the excitation push rod is inserted into the first opening groove of the medicine rack, so that the first medicine rack flap and the second medicine rack flap of the medicine rack open outwards. At this time, the push rod spring enters the medicine rack. When the injection is completed and the excitation push rod retracts to the starting position, at this time, the hook on the medicine rack has protruded under the action of the push rod spring, retracted and locked into the card hole on the excitation push rod, so that the internal injection needle is completely protected from being exposed again.

[0036] The above description is about the present utility model and its implementation manners. Such description is not restrictive. What is shown in the drawings is only one of the implementation manners of the present utility model, and the actual structure is not limited thereto. Generally speaking, if those of ordinary skill in the art are inspired by it and, without departing from the gist of the creation of the present utility model, design similar structural manners and embodiments to this technical solution without creative efforts, they shall fall within the protection scope of the present utility model.

Claims

1. A small-dose automatic injection pen, characterized in that: The invention comprises a lower pen rod and an upper pen rod of a hollow structure, wherein the ends of the lower pen rod and the upper pen rod away from each other are detachably connected with a pen cap and an end cover, and an excitation push rod, a medicine rack and an injection push rod are sequentially arranged in the pen rod cavity formed by the lower pen rod and the upper pen rod from the pen cap end to the end cover end; one end of the medicine rack is clamped on the inner wall of the lower pen rod, and the other end extends into the excitation push rod; one end of the injection push rod can be detachably plugged into the end of the upper pen rod through an injection spring, and the other end is plugged into the medicine rack; the excitation push rod is arranged at the medicine rack end; The medicine rack is outside the medicine rack, and one end of the medicine rack is in contact with the injection push rod, and the other end extends out of the lower pen rod. An injection excitation structure is formed among the excitation push rod, the injection push rod and the upper pen rod. When the excitation push rod pushes the injection push rod, the injection push rod is separated from the end of the upper pen rod, and the injection needle in the medicine rack is pushed out under the action of the injection spring; one end of the medicine rack away from the injection push rod is connected to the inner end of the excitation push rod through the push rod spring to form a needle protection structure. When the excitation push rod returns to the starting position, the medicine rack and the excitation push rod are locked.

2. A low-dose automatic injection pen according to claim 1, characterized in that: The injection push rod includes a lower push rod extending into the medicine rack, and a push block and an upper push rod are arranged at one end of the lower push rod extending out of the medicine rack. A push structure cooperating with the excitation push rod is arranged on the side wall of the push block, so that the injection push rod rotates. Locking blocks are respectively arranged on the upper side of the upper push rod, and a locking hole corresponding to the locking block and its rotation angle is arranged at the end of the upper pen rod. A locking platform is arranged at the bottom of the locking hole on the side away from the rotation direction of the locking block. The injection spring is arranged between the push block and the inner end surface of the upper pen rod. When the injection push rod is locked with the upper push rod, the bottom of the locking block is located at the upper part of the locking platform. When the excitation push rod pushes the injection push rod to rotate, the locking block is separated from the end of the upper pen rod by the part of the locking hole where the locking platform is not arranged.

3. A low-dose automatic injection pen according to claim 2, characterized in that: An angle is set between the side wall of the lock hole and the side wall of the lock block, and the angle is 5°.

4. A low-dose automatic injection pen according to claim 2, characterized in that: The pushing structure includes pushing grooves arranged on both sides of the pushing block, the pushing groove is close to the side of the rotation direction of the injection push rod, and a pushing end block is arranged at the end away from the lower push rod, and a pushing inclined surface 1 is arranged at the end of the pushing end block, and the excitation push rod includes an excitation sleeve arranged outside the medicine rack, and side push rods extending into the pushing grooves are arranged on both sides of the excitation sleeve, and the ends of the side push rods cooperate with the pushing inclined surface 1 through the pushing inclined surface 2. When the side push rod moves toward the pushing inclined surface 1, the injection push rod is pushed to rotate.

5. A low-dose automatic injection pen according to claim 4, characterized in that: The medicine rack extends into one end of the excitation push rod, and has an opening groove 1 on both sides thereof, dividing the medicine rack into medicine rack petal 1 and medicine rack petal 2. A hook strip is also provided in the middle of the medicine rack petal 1 and medicine rack petal 2. The two sides of the hook strip are movably arranged with the medicine rack petal 1 and medicine rack petal 2 through the opening groove 2, and a hook is provided on the outer side of the end of the hook strip; a wedge block that can be inserted into the opening groove 1 is provided on the inner wall of the excitation sleeve, and a clamping hole corresponding to the clamping hook is also provided on the side wall of the excitation sleeve. When the excitation sleeve returns to its initial position, the clamping hook is clamped with the clamping hole.

6. A low-dose automatic injection pen according to claim 5, characterized in that: The end of the opening slot 1 away from its opening is a triangular tightening end, so that when the wedge block in the excitation push rod is inserted into the opening slot 1, the medicine rack petal 1 and the medicine rack petal 2 are pushed outward.

7. A low-dose automatic injection pen according to claim 6, characterized in that: The inner walls of the openings of the medicine rack flap 1 and the medicine rack flap 2 are provided with step end surfaces, and the outlet of the end of the excitation push rod away from the side push rod is provided with an annular end surface, and a push rod spring is clamped between the annular end surface and the step end surface.

8. A low-dose automatic injection pen according to claim 1, characterized in that: The lower pen rod is provided with a visual window for revealing the pushing end of the injection push rod.

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