CN113209421A

CN113209421A - Automatic injection device

Info

Publication number: CN113209421A
Application number: CN202110552333.5A
Authority: CN
Inventors: 侯士双; 袁霞林; 陈常娇; 胡高扬; 徐祥俊
Original assignee: Ningbo Ruiai Product Design Co ltd
Current assignee: Ningbo Ruiai Product Design Co ltd
Priority date: 2021-05-20
Filing date: 2021-05-20
Publication date: 2021-08-06
Anticipated expiration: 2041-05-20
Also published as: CN113209421B

Abstract

The invention relates to an automatic injection device, comprising a tube body; an injection assembly; a cap body; a movable sleeve; the first elastic piece is arranged in the tube body and acts on the movable sleeve to enable the movable sleeve to always keep the trend of moving downwards; the cap body is provided with a first positioning piece, the tube body is internally provided with a second positioning piece, and the first positioning piece extrudes the second positioning piece to enable the second positioning piece to be abutted against the movable sleeve under the state that the cap body is covered on the tube body, so that the movable sleeve is limited to move upwards; the second positioning piece can release the constraint on the movable sleeve when the cap body is detached from the tube body. When the cap body is covered on the pipe body, the first positioning piece extrudes the second positioning piece to enable the second positioning piece to be abutted against the movable sleeve, so that the movable sleeve is limited to move upwards, and the movable sleeve is prevented from moving upwards under the unnecessary condition; under the state that the cap body is detached from the tube body, the second positioning piece can release the constraint on the movable sleeve, and the movable sleeve can move upwards to enable the injection device to work normally.

Description

Automatic injection device

Technical Field

The invention belongs to the technical field of medical appliances, and particularly relates to an automatic injection device.

Background

The most common way of administering drugs is by injection, e.g. intravenous, subcutaneous or intramuscular injection, where syringes containing the drug are used for injection, which is usually performed by trained medical personnel. In some cases, where it is desirable to inject drugs on a regular basis, it is desirable for a patient or other individual to use a syringe to self-inject or to inject other individuals, and devices for automatic injection have been developed to allow the patient to self-inject.

However, since the patient is usually neither a nurse nor a person educated in the medical device setting, such a device for automatic injection must prove to be simple and safe to use. It is therefore important for the user to be informed that the product has started injection, that the injection has been substantially completed and that the user can pull the device from the injection site.

As shown in "an automatic injection device" disclosed in the chinese patent application with patent No. CN202010409755.2 (publication No. CN111450356A), the device includes a tube body with an open lower end, a fixed sleeve positioned in the tube body, and an injection assembly disposed in the tube body; the sounding piece comprises an annular body which is coaxial and movably arranged in the fixed sleeve and a sounding block arranged on the outer peripheral wall of the annular body, the sounding block radially penetrates through the fixed sleeve, and the sounding block and the fixed sleeve are oppositely positioned through a positioning structure; the fixed sleeve is provided with a sliding groove for the sounding block to move axially and downwards after getting rid of the constraint of the positioning structure, the sounding block can emit sound for indicating the start of injection when impacting on the inner wall of the sliding groove, the sounding piece and the injection assembly are linked through a linkage structure, and the injection assembly starts to inject when the sounding block sounds; the movable sleeve is sleeved on the fixed sleeve, the lower end of the movable sleeve can extend out of the pipe body and can move upwards relative to the fixed sleeve when being pressed by skin, and the movable sleeve is provided with a pushing part which can push the sounding block to move when moving upwards so as to enable the sounding block to release the constraint of the positioning structure; the first elastic piece is arranged in the pipe body and acts on the sounding piece to enable the sounding piece to always keep a downward moving trend; the second elastic piece is arranged in the tube body and acts on the movable sleeve to enable the movable sleeve to always keep the trend of moving downwards.

The movable sleeve of this patent is equivalent to an actuating member which, when an injection is required, eventually triggers the injection assembly by pressing on the movable sleeve, so that the injection assembly performs the injection of the medical fluid. However, if the injection device is dropped onto a hard surface (for example if the user drops the device onto the floor), the holster is likely to move on impact and trigger the injection assembly, causing waste of medication.

If the injection device is disposable and the user has not used it is scrapped and a new injection device must be purchased again, resulting in money and waste of the injection device; if the injection device is reusable, it must also be reloaded to deliver a new dose, resulting in wasted medication.

Disclosure of Invention

The present invention is directed to an automatic injection device having a sound prompt function that can prevent an unnecessary upward movement of a movable cover, in view of the current state of the prior art.

The technical scheme adopted by the invention for solving the technical problems is as follows: an automatic injection device comprising

A pipe body with an open lower end;

the injection assembly is arranged in the tube body;

a cap body detachably covering the lower end of the pipe body;

the movable sleeve can be movably arranged in the tube body, and the lower end of the movable sleeve can extend out of the tube body and upwards move relative to the tube body when being pressed by skin so as to trigger the injection assembly to inject;

the first elastic piece is arranged in the tube body and acts on the movable sleeve to enable the movable sleeve to always keep the trend of moving downwards;

the movable sleeve is characterized in that a first positioning piece is arranged on the cap body, a second positioning piece is arranged in the tube body, and the first positioning piece extrudes the second positioning piece to enable the second positioning piece to be abutted against the movable sleeve under the condition that the cap body is covered on the tube body, so that the movable sleeve is limited to move upwards; the second positioning piece can release the constraint on the movable sleeve when the cap body is detached from the tube body.

The second locating element can be through the constraint of multiple form liberation to the movable sleeve, in order to improve the operational reliability of movable sleeve and second locating element, the cap body certainly under the state of dismantling on the body, the second locating element with the movable sleeve separates from each other, and the second locating element can not produce the interference to the removal of movable sleeve like this, can not influence the normal work of movable sleeve.

First setting element and second setting element can have multiple structural style, simple structure ground, first setting element is vertical extension's support arm, the second setting element includes swing arm and dog, swing arm one end links to each other with the inner wall of body, and the other end links to each other with the dog the cap body lid is established under the state on the body, the dog is located support arm one side and is extruded to offset with the movable sleeve.

In order to enable the stop block to be abutted against the movable sleeve so as to limit the movable sleeve to move upwards, the peripheral wall of the movable sleeve is provided with a positioning hole, and the stop block can be abutted against the bottom wall of the positioning hole.

Preferably, in a state that the cap body covers the tube body, the stopper is located between the support arm and the movable sleeve, and the stopper is pressed into the positioning hole to abut against the bottom wall of the positioning hole.

Preferably, the top end of the support arm is provided with a first inclined plane, the surface of the stop block contacting with the support arm is a second inclined plane, and the first inclined plane and the second inclined plane are matched and both incline from top to bottom in the direction far away from the central line of the pipe body. The cooperation of first inclined plane and second inclined plane can prevent that the support arm from being interfered by the dog, leading to the support arm can not upwards remove to the problem that can not extrude the dog outwards.

In order to enable the stop block to be abutted against the movable sleeve so as to limit the movable sleeve to move upwards, the peripheral wall of the movable sleeve is provided with a blocking rib, and the stop block can be abutted against the upper end face of the blocking rib.

In order to ensure that the movable sleeve can smoothly move upwards after the cap body is removed, the blocking ribs are positioned on the inner peripheral wall of the movable sleeve, the support arms are positioned on the inner sides of the stop blocks under the state that the cap body is covered on the tube body, and the upper end surfaces of the blocking ribs are fifth inclined surfaces which are gradually inclined towards the direction close to the central line of the tube body from top to bottom. Therefore, in the process that the movable sleeve moves upwards, the fifth inclined surface can extrude the stop block to move inwards, and the hard interference between the fifth inclined surface and the stop block is avoided, so that the movable sleeve cannot move upwards.

In order to further remove the cap body, the movable sleeve can smoothly move upwards, the surface of the stop dog, which is contacted with the blocking rib, is a sixth inclined surface or a second arc-shaped surface which is arched downwards, and the sixth inclined surface or the second arc-shaped surface is matched with the fifth inclined surface on the blocking rib.

Compared with the prior art, the invention has the advantages that: according to the invention, the first positioning piece is arranged on the cap body, the second positioning piece is arranged in the tube body, and the first positioning piece extrudes the second positioning piece to enable the second positioning piece to be abutted against the movable sleeve under the state that the cap body is covered on the tube body, so that the movable sleeve is limited to move upwards, and the movable sleeve is prevented from moving upwards under the unnecessary condition (when an injection device does not work), and further an injection assembly is triggered to cause waste of liquid medicine or scrapping of the injection device; under the state that the cap body is detached from the tube body, the second positioning piece can release the constraint on the movable sleeve, and the movable sleeve can move upwards to enable the injection device to work normally.

Drawings

FIG. 1 is a schematic structural view of example 1 of the present invention;

FIG. 2 is a cross-sectional view of FIG. 1;

FIG. 3 is an enlarged view at A of FIG. 2 (the injection is not completed);

FIG. 4 is an enlarged view of FIG. 2 at A (the injection is completed and the sounding body starts moving upward);

FIG. 5 is an enlarged view of FIG. 2 at A (injection completed, sounding body impacting the harness);

fig. 6 is a schematic structural view of the fixing sleeve and the fixing tube in fig. 2;

FIG. 7 is a schematic structural diagram of the sounding body in FIG. 2;

FIG. 8 is a schematic view of the assembly of FIG. 6 with a sounding body;

FIG. 9 is a cross-sectional view of the syringe and holder of FIG. 2;

FIG. 10 is a cross-sectional view in the other direction of FIG. 1 (with the cap mounted on the tube body);

FIG. 11 is a cross-sectional view in the other direction of FIG. 1 (with the cap removed from the body and the boot not pressed upward);

FIG. 12 is a cross-sectional view in the other direction of FIG. 1 (with the cap removed from the body and the boot pressed upward);

FIG. 13 is a schematic structural view of the cap of FIG. 12;

FIG. 14 is a partial sectional view of embodiment 2 (with the cap body mounted on the pipe body);

FIG. 15 is a partial sectional view of example 2 (the cap body is removed from the pipe body and the movable sleeve is pressed upward);

fig. 16 is a schematic structural view of the cap of fig. 14.

Detailed Description

The invention is described in further detail below with reference to the accompanying examples.

Example 1

As shown in fig. 1 to 13, the automatic injection device with sound prompt function of the preferred embodiment includes a tube body 1 with an open lower end, a cap body 2 is detachably covered on the lower end of the tube body 1, and a movable sleeve 3, a fixed sleeve 4, an injection assembly, a sound generator 5, a first elastic member 61, a second elastic member 62, etc. are arranged in the tube body 1. In this embodiment, the end of the pipe body 1 to which the cap 2 can be attached is defined as a lower end, and the other end is defined as an upper end.

As shown in fig. 1, 2, and 10 to 13, the movable sleeve 3 is vertically arranged (i.e., along the central axis of the pipe body 1), and the movable sleeve 3 can move up and down (i.e., along the central axis of the pipe body 1) relative to the pipe body 1. The lower end of the movable sleeve 3 can extend out of the tube body 1 and move upwards relative to the tube body 1 when pressed by skin to trigger the injection assembly to inject (how the upward movement of the movable sleeve 3 triggers the injection assembly is described in CN202010409755.2, and is not described in detail herein), the first elastic member 61 acts on the movable sleeve 3, and the first elastic member 61 accumulates elastic potential energy, so that the movable sleeve 3 always keeps a downward movement tendency.

The cap body 2 is provided with a first positioning piece, the pipe body 1 is internally provided with a second positioning piece, and the first positioning piece extrudes the second positioning piece under the state that the cap body 2 is covered on the pipe body 1, so that the second positioning piece is abutted against the movable sleeve 3, and the movable sleeve 3 is limited from moving upwards; under the state that the cap body 2 is dismantled from the pipe body 1, the second positioning piece can release the constraint on the movable sleeve 3, and the movable sleeve 3 can move upwards relative to the pipe body 1. The first positioning piece and the second positioning piece enable the operation process of a user to be convenient, the cap body 2 can be effectively covered under the condition of the tube body 1, the position of the movable sleeve 3 is locked, and accidental triggering of the injection device is avoided.

In this embodiment, first setting element and second setting element simple structure, concrete structure is as follows: as shown in fig. 13, the first positioning member is a supporting arm 21 formed on the cap body 2 and extending vertically, specifically, the supporting arm 21 extends vertically and upwardly from the inner bottom surface of the cap body 2, and in order to be stressed evenly, so that there are two supporting arms 21, which are distributed symmetrically, but not limited to two, the specific number of the supporting arms 21 can be set as required, and meanwhile, in consideration of the stability of the two supporting arms 21, a first arc-shaped surface 22 connecting the two supporting arms 21 is formed on the inner bottom surface of the cap body 2. The second positioning member comprises a swing arm 71 and a stop block 72, one end of the swing arm 71 is fixedly connected with the inner wall of the pipe body 1, the other end of the swing arm is connected with the stop block 72, the stop block 72 is positioned at the inner side of the movable sleeve 3, and the peripheral wall of the movable sleeve 3 is provided with a positioning hole 31. In the state that the cap body 2 is covered on the tube body 1 (see fig. 10), the arm 21 is located inside the stopper 72 and presses the stopper 72 outwards, the stopper 72 is pressed outwards and located inside the positioning hole 31, and when the movable sleeve 3 is pushed to move upwards, the stopper 72 is pressed against the bottom wall of the positioning hole 31 to limit the upward movement of the movable sleeve 3.

The top end of the support arm 21 is provided with a first inclined surface 211, the surface of the stop block 72, which is contacted with the support arm 21, is a second inclined surface 721, the first inclined surface 211 is matched with the second inclined surface 721, and the first inclined surface 211 and the second inclined surface 721 are both inclined from top to bottom in the direction away from the central line of the pipe body 1, so that the problem that the support arm 21 cannot move upwards due to interference of the stop block 72 and the stop block 72 cannot be extruded outwards can be prevented, the matched structural form of the first inclined surface 211 and the second inclined surface 721 is simple, the arrangement of the first inclined surface 211 and the second inclined surface 721 is relatively compact, the stop block 72 can be effectively locked with the movable sleeve 3, and the locking failure of the stop block 72 can be avoided.

The arm 21 and the stop 72 may of course have other forms of cooperation, such as the cooperation of an inclined surface and a vertical surface: the top end of the support arm 21 is provided with a first inclined surface 211, and the surface of the stop block 72, which is in contact with the support arm 21, is a vertical surface; or one side of the support arm 21 facing the stopper 72 is a vertical surface, and the surface of the stopper 72 contacting the support arm 21 is a second inclined surface 721; the first inclined plane and the second inclined plane incline from top to bottom in the direction far away from or close to the central line of the pipe body.

When the injection device is not used, the cap body 2 is covered on the tube body 1, the support arm 21 is positioned at the inner side of the stop block 72 and extrudes the stop block 72 outwards to be abutted against the bottom wall of the positioning hole 31, and at the moment, the movable sleeve 3 cannot move upwards; when the injection device is used, the cap body 2 is taken down, the support arm 21 on the cap body 2 moves out of the tube body 1, the support arm 21 extrudes the stopper 72 to disappear, the swing arm 71 deflects inwards in the direction away from the movable sleeve 3 at the moment, the stopper 72 is driven to be separated from the positioning hole 31 on the movable sleeve 3, and the lower end of the movable sleeve 3 moves upwards relative to the tube body 1 when being pressed by skin to trigger the injection assembly to inject.

By last, the cooperation of first setting element and second setting element can prevent that injection device when not being in operating condition (when the cap body 2 lid was established on body 1 promptly), and even if the movable sleeve 3 received the impact and had the trend of rebound, can not trigger injection assembly yet, causes the waste of liquid medicine or injection device scrapps.

As shown in fig. 1 to 9, the injection device has the following structure to realize the function of making a sound to prompt a user when injection is completed:

the injection assembly comprises a needle tube 81, a piston tube 82 and a piston 83 (of course, the injection assembly comprises not only these three components, but also a piston rod, a third elastic element and a needle shown in CN202010409755.2, and the piston rod, the third elastic element and the needle are not the main components for realizing the sound when the injection is completed, and are not described in detail herein).

The fixed sleeve 4 is fixedly arranged relative to the pipe body 1, the movable sleeve 3 is sleeved on the fixed sleeve 4, the needle tube 81 is fixedly arranged below the fixed sleeve 4, the piston tube 82 is inserted in the fixed sleeve 4 and can axially move relative to the fixed sleeve 4, the lower end of the piston tube 82 is inserted in the needle tube 81, and the piston 83 is arranged in the needle tube 81 and can be pushed downwards by the piston tube 82.

As shown in fig. 2, 3 and 6, in this embodiment, the fixing sleeve 4 is formed with a fixing tube 41 at a lower end thereof, the fixing tube 41 is sleeved on the piston tube 82, the outer diameter of the fixing tube 41 is smaller than the outer diameter of the fixing sleeve 4, a shoulder 43 is formed therebetween, the shoulder 43 forms a limiting portion for upward movement of the sounding body 5, the fixing tube 41 is provided with a through hole 42 in a peripheral wall thereof, and the through hole 42 is provided with a third positioning element 9, that is, the third positioning element 9 is located outside the piston tube 82. Preferably, the third positioning element 9 can be symmetrically provided with a plurality of positioning elements to realize the stability of the locking process.

The third positioning member 9 includes an extension arm 91 and a positioning portion 92, the extension arm 91 extends vertically, the upper end of the extension arm 91 is connected to the top wall of the through hole 42, the lower end of the extension arm 91 is connected to the positioning portion 92, the back surface (i.e., the inner side surface) of the positioning portion 92 can abut against the outer peripheral wall of the piston tube 82, and the front surface (i.e., the outer side surface) of the positioning portion 92 has a third inclined surface 921 gradually thinned along the downward movement direction of the piston tube 82. The working principle of the third positioning element 9 is as follows: the position change of the positioning portion 92 in the radial direction of the piston tube 82 is changed by the elastic deformation of the extension arm 91 to improve the stability and reliability of the locking effect. Of course, the third positioning element 9 can also have other configurations, as long as it is sufficient to position the piston tube 82 and to deform it radially relative to the piston tube 82.

The sounding body 5 can be disposed outside the piston tube 82 in a vertically movable manner, as shown in fig. 2, 7 and 8, in this embodiment, the sounding body 5 is annular and is sleeved on the fixed tube 41, the inner wall surface of the sounding body 5 is provided with a sliding block 51, the outer wall surface of the fixed tube 41 is provided with a sliding groove 411 extending vertically, the sliding block 51 can move along the sliding groove 411, and the sliding block 51 and the sliding groove 411 together form a guiding structure. Of course, the slider 51 may be provided on the fixed pipe 41 and the slide slot 411 may be provided on the sounding body 5.

The top of the sounding body 5 can abut against the front surface of the positioning portion 92 (of course, a protrusion on the inner wall of the sounding body 5 can abut against the positioning portion 92), and when the sounding body 5 abuts against the positioning portion 92, the sounding body 5 cannot move upward, but the sounding body 5 always tends to move upward under the action of the second elastic member 62. When the piston 83 is pushed to the bottom of the needle tube 81 by the piston tube 82, the extension arm 91 can swing inward (the original position of the piston tube 82) by a certain angle, and the sounding body 5 can get rid of the constraint of the positioning part 92, and move upward under the action of the second elastic element 62 until colliding with the limit part of the fixed sleeve 4, thereby generating the sound indicating the completion of the injection.

As can be seen from the above, in a state where the piston 83 is pushed to the bottom of the needle tube 81 by the piston tube 82, the extension arm 91 can swing inward by a certain angle because the blockage of the piston tube 82 is lost, but in order to prevent the swing angle of the extension arm 91 from being too small, the positioning portion 92 still abuts against the sounding body 5, so that the sounding body 5 cannot move upward, the wall surface of the sounding body 5 abutting against the front surface of the positioning portion 92 is the fourth inclined surface 52 engaged with the third inclined surface 921, and the fourth inclined surface 52 is located at the top end of the inner wall surface of the sounding body 5. Even if the positioning portion 92 still abuts against the sounding body 5, the sounding body 5 will move upward by a certain distance under the action of the second elastic member 62, and in the process, the fourth inclined surface 52 presses the third inclined surface 921 until the positioning portion 92 completely releases the constraint on the sounding body 5.

The specific working process of the generator 5 is as follows:

before the piston 83 moves to the bottom of the needle tube 81, the back surface of the positioning part 92 abuts against the piston tube 82, the front surface of the positioning part 92 abuts against the sounding body 5, and the sounding body 5 cannot move upwards, as shown in fig. 3;

as shown in fig. 4, when the piston 83 moves to the bottom of the needle tube 81, the liquid medicine is completely pushed out, at this time, the piston tube 82 moves downward to be separated from the contact with the positioning portion 92, the positioning portion 92 can move inward (move toward the original position of the piston tube 82), at this time, the positioning portion 92 cannot completely position the sounding body 5, the sounding body 5 moves upward under the action of the second elastic member 62, the fourth inclined surface 52 further presses the third inclined surface 921 during the upward movement of the sounding body 5, so that the positioning portion 92 swings inward (toward the original position of the piston tube 82) further, the limitation on the sounding body 5 is completely lost, the sounding body 5 continues to move upward under the action of the second elastic member 62, until the sounding body 5 collides with the limiting portion of the fixing sleeve 4 to generate a sound indicating the completion of injection, as shown in fig. 5;

as shown in fig. 2 and 9, a fixing frame 01 sleeved on the needle tube 81 is fixedly arranged in the tube body 1, the top end of the needle tube 81 is exposed outside the fixing frame 01, a blocking portion 011 extending towards the needle tube 81 is arranged at the bottom of the fixing frame 01, the needle tube 81 is partially placed on the blocking portion 011, and a positioning frame 02 capable of abutting against the top end of the needle tube 81 is arranged above the fixing frame 01. The second elastic member 62 is a spring, and two ends of the second elastic member respectively abut against the positioning frame 02 and the sounding body 5.

The positioning frame 02 and the stopping portion 011 cooperate to position the needle tube 81, and the positioning frame 02 is pressed against the needle tube 81 due to the second elastic member 62, so as to allow the needle tube 81 to have a certain tolerance during manufacturing. Because the position of the positioning frame 02 has a certain movement allowance in the vertical direction, when the needle tube 81 is manufactured, the length of the needle tube 81 has a certain deviation within an allowable range, and when the positioning frame 02 has a certain movement allowance in the vertical direction, the manufacturing deviation of the needle tube 81 can be allowed, otherwise, when the length of the needle tube 81 is longer, the needle tube 81 interferes with the positioning frame 02, so that the needle tube cannot be assembled, and when the length of the needle tube 81 is shorter, the needle tube 81 cannot contact the positioning frame 02, so that the needle tube 81 becomes loose.

The present embodiment focuses on the structure of sounding when the injection is completed and the structure of how to prevent the movable sleeve 3 from moving upward due to impact, but the injection device of the present embodiment does not only include these structures, and other structures of the automatic injection device of the present embodiment can refer to the chinese patent application with application number CN202010409755.2, publication number CN111450356A, and name "an automatic injection device".

Example 2

As shown in fig. 14 to 16, example 2 differs from example 1 in that: the first positioning piece and the second positioning piece are different in structure.

Be equipped with on the internal perisporium of movable sleeve 3 and keep off muscle 32, under the state that the body of the cap 2 lid was established on body 1, support arm 21 on the body of the cap 2 was located the inboard of dog 72, and support arm 21 extrudees dog 72 to pressing the position on keeping off the up end of muscle 32, limits movable sleeve 3 through dog 72 and upwards removes, and then limits the triggering of injection unit.

In order to smoothly move the movable sleeve 3 upward after the cap body 2 is removed from the tube body 1, the upper end surface of the rib 32 is a fifth inclined surface 321 which is inclined gradually inward from top to bottom (i.e. the direction of the inner surface close to the central line of the tube body 1), the contact surface of the stopper 72 and the rib 32 is a second arc-shaped surface 722 which is arched downward, and the second arc-shaped surface 722 is in inclined surface fit with the fifth inclined surface 321 on the rib 32. The second arc-shaped face 722 can also be a sixth inclined face which can be matched with the fifth inclined face 321 on the stop rib 32.

When the injection device is not used, the cap body 2 covers the tube body 1, the support arm 21 is positioned at the inner side of the stop block 72 and extrudes the stop block 72 outwards to be abutted against the upper end surface of the stop rib 32, and at the moment, the movable sleeve 3 cannot move upwards; when will using injection apparatus, take off the cap body 2, move out in the body thereupon with support arm 21 on the cap body 2, support arm 21 disappears to the extrusion of dog 72, dog 72 has had the space of inward movement, relative body 1 rebound when the lower extreme of movable sleeve 3 received skin to press this moment injects in order to trigger the injection subassembly, and move up the in-process at movable sleeve 3, because the cooperation of the face inclined plane that dog 72 and fender muscle 32 contacted, can extrude dog 72 inward movement, guarantee that movable sleeve 3 can shift up smoothly.

In this embodiment, a tubular body 23 extending vertically is formed inside the cap body 2, and a partial outer peripheral wall surface of the tubular body 23 forms the arm 21.

The injection devices of the above embodiments are all disposable items and therefore do not take into account the problem of resetting the components after completion of the injection.

Claims

1. An automatic injection device comprising

The lower end of the tube body (1) is open;

the injection assembly is arranged in the tube body (1);

a cap body (2) which is detachably covered on the lower end of the tube body (1);

the movable sleeve (3) can be movably arranged in the tube body (1), and the lower end of the movable sleeve (3) can extend out of the tube body (1) and move upwards relative to the tube body (1) when being pressed by skin so as to trigger the injection assembly to inject;

the first elastic piece (61) is arranged in the pipe body (1) and acts on the movable sleeve (3) to enable the movable sleeve (3) to keep a downward moving trend all the time;

the device is characterized in that a first positioning piece is arranged on the cap body (2), a second positioning piece is arranged in the tube body (1), and the first positioning piece extrudes the second positioning piece to enable the second positioning piece to be abutted against the movable sleeve (3) under the state that the cap body (2) is covered on the tube body (1), so that the movable sleeve (3) is limited to move upwards; the second positioning piece can release the constraint on the movable sleeve (3) when the cap body (2) is detached from the tube body (1).

2. The automatic injection device of claim 1, wherein: the cap body (2) is detached from the tube body (1), and the second positioning piece and the movable sleeve are separated from each other.

3. The automatic injection device of claim 2, wherein: first locating part is vertical extension's support arm (21), the second locating part includes swing arm (71) and dog (72), swing arm (71) one end links to each other with the inner wall of body (1), and the other end links to each other with dog (72) the cap body (2) lid is established under the state on body (1), dog (72) are located support arm (21) one side and are extruded to offset with movable sleeve (3).

4. An autoinjector according to claim 3, wherein: the peripheral wall of the movable sleeve (3) is provided with a positioning hole (31), and the stop block (72) can be pressed against the bottom wall of the positioning hole (31).

5. The automatic injection device of claim 4, wherein: under the state that the cap body (2) is covered on the tube body (1), the stop block (72) is positioned between the support arm (21) and the movable sleeve (3), and the stop block (72) is extruded into the positioning hole (31) to abut against the bottom wall of the positioning hole (31).

6. An autoinjector according to claim 3, wherein: the top end of the support arm (21) is provided with a first inclined surface (211), the surface of the stop block (72) contacted with the support arm (21) is a second inclined surface (721), the first inclined surface (211) is matched with the second inclined surface (721), and the first inclined surface and the second inclined surface are inclined from top to bottom towards the direction far away from the central line of the tube body (1).

7. An autoinjector according to claim 3, wherein: the top end of the support arm (21) is provided with a first inclined surface (211), and the surface of the stop block (72) which is in contact with the support arm (21) is a vertical surface; or one side of the support arm (21) facing the stop block (72) is a vertical surface, and the surface of the stop block (72) contacting the support arm (21) is a second inclined surface (721); the first inclined plane and the second inclined plane incline from top to bottom in the direction away from or close to the central line of the pipe body.

8. An autoinjector according to claim 3, wherein: the peripheral wall of the movable sleeve (3) is provided with a blocking rib (32), and the stop block (72) can be pressed against the upper end face of the blocking rib (32).

9. The automatic injection device of claim 8, wherein: the stop rib (32) is positioned on the inner peripheral wall of the movable sleeve (3), the support arm (21) is positioned on the inner side of the stop block (72) in the state that the cap body (2) covers the pipe body (1), and the upper end surface of the stop rib (32) is a fifth inclined surface (321) which is inclined towards the direction close to the central line of the pipe body (1) from top to bottom gradually.

10. The automatic injection device of claim 9, wherein: the surface of the stop block (72) contacting with the stop rib (32) is a sixth inclined surface or a second arc-shaped surface (722) which is arched downwards, and the sixth inclined surface or the second arc-shaped surface (722) is matched with the fifth inclined surface (321) on the stop rib (32) in an inclined surface manner.