CN211935059U

CN211935059U - Automatic injection device

Info

Publication number: CN211935059U
Application number: CN202020123434.1U
Authority: CN
Inventors: 桑会庆; 吴亚金; 朱涛
Original assignee: Shanghai Umitai Medical Technology Co ltd
Current assignee: Shanghai Umitai Medical Technology Co ltd
Priority date: 2020-01-19
Filing date: 2020-01-19
Publication date: 2020-11-17
Anticipated expiration: 2030-01-19

Abstract

The utility model provides an automatic injection device, which comprises a shell, a push rod driving component and a spring force application component; the shell comprises an accommodating shell, a supporting shell and a pressing cover, the injector is arranged in the accommodating shell, the supporting shell is connected with the accommodating shell, and the pressing cover is positioned on the supporting shell; the working end of the push rod is arranged in the accommodating shell in a manner of extending into the accommodating shell, and the driving end of the push rod is arranged in the supporting shell and is driven by applying force through the pressing cover; the push rod driving component comprises a revolving body, a spiral guide cylinder, an inner revolving cylinder and an outer revolving cylinder; the spring force application assembly comprises a force application spring and a return spring and is used for providing driving acting force. The utility model discloses a change the position relation between outer rotary drum and the solid of revolution and realize stretching into of this effort drive catch bar, finally realize the ration injection of medicament, whole injection process is accomplished by a key for the injection process is lighter, and whole injection process stability is good, the degree of accuracy of injection dosage is high.

Description

Automatic injection device

Technical Field

The utility model belongs to the technical field of medical instrument, concretely relates to automatic injection device.

Background

The known injection device has the following disadvantages in use: firstly, a dose setting assembly of a known injection device is formed by manually rotating a dose display barrel, the dose display barrel is connected with a housing of the injection device through a large-pitch thread, scales are uniformly arranged on a spiral line and are used as reference when setting accurate injection dose, the dose display barrel needs to be rotated clockwise when setting the injection dose, the dose display barrel is exposed outside the injection device due to the spiral motion, a release button exposed on the dose display barrel needs to be continuously pressed to return the dose display barrel to the inside of the injector and apply force to a driving assembly for injecting the set dose during injection, the injection mode needs to continuously press the thumb of a patient to exert force during injection, the injection device is easy to shake in the injection direction due to uneven force, so that the pain of the patient during injection is increased, and the attention of the patient during injection is also shared, the injection experience is not good. The traditional injection device has no residual dose memory function, when the medicament in the container is injected for the last time, the set injection dose is larger than the residual injectable dose in the container, and a patient subjectively considers that the injection dose reaches the requirement when the injection dose reaches the requirement, but does not inject the set dose actually, so that the effect of injecting the medicament cannot be achieved, more serious insulin injection such as insulin injection is caused, the blood sugar of the patient is increased due to the reduction of the dose, and the life safety of the patient is influenced.

SUMMERY OF THE UTILITY MODEL

To prior art's defect, the utility model provides an automatic injection device can realize the automation mechanized operation of injection process, convenient to use.

In order to achieve the purpose, the utility model provides an automatic injection device, which comprises a shell, a push rod acting on an injector, a push rod driving component and a spring force application component;

the injector is arranged in the accommodating shell, the supporting shell is connected with the accommodating shell, and the pressing cover is positioned on the supporting shell;

the working end of the push rod can be arranged in the accommodating shell in a stretching mode, and the driving end of the push rod is arranged in the supporting shell and is driven by force application through the pressing cover;

wherein the push rod driving component comprises a revolving body, a spiral guide cylinder, an inner revolving cylinder and an outer revolving cylinder;

the spiral guide cylinder is arranged in the support shell, and the inner rotary cylinder is sleeved on the spiral guide cylinder and can slide on the spiral guide cylinder to change the position;

the outer rotary drum is sleeved on the inner rotary drum and can perform relative sliding in the process of synchronous rotation with the inner rotary drum;

the revolving body is arranged in the supporting shell and can be coupled with the outer revolving drum, the revolving body is rotatably connected with the push rod, and the autorotation of the revolving body is converted into the extension of the push rod;

the spring force application assembly comprises a force application spring and a return spring;

the force application spring is sleeved on the spiral guide cylinder, and the extruded force application spring drives the inner rotary cylinder to rotate on the spiral guide cylinder;

the return spring is arranged between the outer rotary drum and the pressing cover, and the pressing brake pressing cover can compress the return spring so that the outer rotary drum is axially separated from the support shell and slides to be coupled with the rotary body.

The above technical scheme of the utility model, the catch bar direct action carries out the drive of catch bar through catch bar drive assembly in the movable plug of syringe for the catch bar stretches into to the assigned position forward, and then injects the medicament of assigned dose.

Furthermore, the push rod driving assembly is of a plurality of nested tubular structures, wherein the inner rotary cylinder and the outer rotary cylinder can slide relatively in the synchronous rotating process, so that the matching relation between the outer rotary cylinder and the rotary body is changed, and finally the matching connection between the outer rotary cylinder and the rotary body is realized, so that the push rod is driven to extend through the rotary body to perform the injection administration process.

Specifically, the utility model discloses a spring structure, cooperation catch bar drive assembly changes the rotation of the relative spiral guide cylinder of interior rotary drum into with the straight line effort of spring, through interior rotary drum and the cooperation between the outer rotary drum, the cooperation between outer rotary drum and the solid of revolution, turns into the straight line feed of catch bar with rotating once more to obtain quantitative injection and dose.

According to the utility model discloses a another kind of embodiment further includes one-way jump ring, and the drive end of catch bar is located the spiral guide cylinder, and wherein one-way jump ring setting is served and can carry out one-way the sliding in the spiral guide cylinder on the drive of catch bar.

According to the utility model discloses a another kind of embodiment, the spiral guide cylinder be equipped with one-way jump ring matched with notch, as the biggest form position that stretches into of restriction catch bar, after one-way jump ring slided to notch department, one-way jump ring was spacing and can't continue to slide, and this position is the biggest position of stretching into of catch bar promptly.

According to the utility model discloses a another kind of embodiment is equipped with the gib block along its length direction in the spiral guide cylinder, be equipped with on the catch bar with gib block complex guide way to restriction spiral guide cylinder does not rotate, so that the structure is more stable.

According to the utility model discloses a another kind of embodiment, set up with following structure between interior rotary drum and the outer rotary drum to relative slip is carried out at synchronous pivoted in-process:

a plurality of symmetrically distributed sliding blocks which are staggered in the axial direction are arranged on the periphery of the inner rotary drum;

the outer rotary cylinder is internally provided with sliding chutes which are matched with the sliding blocks one by one.

According to another embodiment of the present invention, the device further comprises a screw rod orientation ring fixed on the housing, the screw rod orientation ring is provided with a guide projection, the push rod is provided with an open slot matched with the guide projection,

according to another embodiment of the present invention, the revolving body and the outer revolving drum are connected by engaging teeth.

According to another embodiment of the present invention, the dose control device further comprises a dose control assembly including a dose knob and a one-way ratchet fixed to the support housing, the dose knob being rotatably disposed on the one-way ratchet;

wherein, the one-way ratchet wheel is in a cylinder shape, and one end of the outer cylinder passes through the one-way ratchet wheel and is clamped with the dosage knob;

the rotation of the dose knob drives the outer rotary cylinder to synchronously rotate, and drives the inner rotary cylinder to rotate around the spiral guide cylinder so as to compress the force application spring and further obtain the specified injection dose.

According to the utility model discloses a another kind of embodiment, dose control subassembly is still including the memory ring that is used for injecing the dose knob and rotates the number of turns, and the memory ring rotates and sets up on one-way ratchet, and the dose knob is equipped with the block recess, is equipped with on the memory ring with block recess matched with block lug.

According to the utility model discloses a another kind of embodiment, interior rotary drum is provided with and is spiral dose scale, is equipped with the window that shows dose scale on the support housing, wherein, outer rotary drum be equipped with window assorted transparent construction or hollow out construction.

According to another embodiment of the utility model, the helical pitch of the dose scale is consistent with the helical pitch of the helical guide cylinder,

according to another specific embodiment of the utility model, the utility model also comprises a hidden needle assembly which comprises a hidden needle cap, a return spring and a hidden needle sleeve;

the needle hiding sleeve is detachably connected to the accommodating shell and is provided with a directional chute along the length direction of the needle head;

the needle hiding cap is provided with a directional sliding block which is connected to the needle hiding sleeve through the directional sliding block;

the reset spring is arranged in the needle hiding sleeve and is respectively abutted against the needle hiding sleeve and the needle hiding cap;

the working end face of the needle hiding cap is provided with a gasket which can be in direct contact with the skin, and the gasket can be made of skin-friendly materials such as silica gel and the like so as to be convenient to use.

The utility model discloses possess following beneficial effect:

the utility model discloses an automatic injection device adopts the conversion that can synchronous pivoted interior rotary drum, go out the rotary drum and realize the effort to through changing the position relation between the outer rotary drum of turning round and the solid of revolution and realizing stretching into of this effort drive catch bar, finally realize the ration injection of medicament, whole injection process key (press the gland) is accomplished, makes the injection process lighter, and whole injection process stability is good, the degree of accuracy of injection dosage is high.

Furthermore, the utility model discloses when the non-use form, contactless between outer revolving drum and the solid of revolution, through applying the effort to the press cover this moment, will turn into the use form, establish the lotus root between outer revolving drum and the solid of revolution this moment and close and be connected, under force application spring's effect, the synchronous rotation of revolving drum, outer revolving drum in the drive, and then make the solid of revolution rotate, realize the purpose that the drive catch bar stretched into forward.

Furthermore, the utility model discloses set up one-way jump ring, stretch into forward of catch bar and restrict, make it only can carry out one-way sliding, and then stabilize the process of sliding of catch bar.

Furthermore, the utility model discloses still be equipped with dosage control subassembly, be used as the dose that accurate control single injection was dosed, can remember remaining medicament simultaneously to the injection that can control the settlement dose of dosing is not more than the remaining actual dose in the syringe, with the medicine effect of guaranteeing the patient and use medicine safety.

Furthermore, the utility model discloses still be provided with hidden needle subassembly to hide the syringe needle, on the one hand make things convenient for the injection process, with hidden needle cap's work terminal surface paste at patient injection position can, on the other hand makes the syringe needle that makes the people produce the fear among the injection process easiest invisible, reduces patient's fear, makes injection experience better.

The present invention will be described in further detail with reference to the accompanying drawings.

Drawings

Fig. 1 is a schematic view of the entire structure of the automatic injection device of the present invention;

FIG. 2 is a schematic sectional view taken along line A-A of FIG. 1;

fig. 3 is an exploded schematic view of the automatic injection device of the present invention;

FIG. 4 is a schematic structural view of the front cap of the present invention;

FIG. 5 is a schematic view of the hidden needle assembly of the present invention;

FIG. 6 is an exploded view of FIG. 5;

FIG. 7 is a schematic view of the construction of the needle covering of FIG. 5;

fig. 8 is a schematic structural view of the accommodating case of the present invention;

FIG. 9 is a schematic structural view of the push rod of the present invention;

fig. 10 is a schematic structural view of the one-way circlip of the present invention;

FIG. 11 is a schematic structural view of the revolving body and the screw orientation ring of the present invention;

FIG. 12 is a schematic view showing the combination of the revolving body, the pushing rod and the screw rod orientation ring of the present invention;

fig. 13 is a schematic structural view of the spiral guide cylinder of the present invention;

FIG. 14 is a schematic view of the structure of FIG. 13 from another perspective;

FIG. 15 is a schematic structural view of the inner drum of the present invention;

FIG. 16 is a schematic view of the structure of FIG. 15 from another perspective;

FIG. 17 is a schematic view showing the combination of the inner rotary drum, the spiral guide cylinder and the urging spring according to the present invention;

fig. 18 is a schematic structural view of the outer rotary drum of the present invention;

FIG. 19 is a cross-sectional schematic view of FIG. 18;

fig. 20 is a schematic structural view of the support housing of the present invention;

FIG. 21 is a schematic view of the dose control assembly of the present invention;

FIG. 22 is a structural schematic view of the one-way ratchet of FIG. 21;

figure 23 is a schematic view of the dose knob of figure 21.

Detailed Description

An automatic injection device for administering an injection of a medicament, as shown in fig. 1-23, comprises a housing 100, an injector portion 200, a pusher arm 300, a pusher arm drive assembly 400, a spring bias assembly 500, a dose control assembly 600, and a concealed needle assembly 700.

Referring to fig. 1 and 2, the automatic injection device of the present example is constructed in an overall pen type structure, i.e., an injection pen, and the housing 100 includes a receiving housing 110 at a front end, a front cap 120 detachable from the receiving housing 110, a support housing 130 at a rear end, and a pressing cap 140 for an injection operation by a user.

The syringe part 200 is disposed in the accommodating housing 110, and referring to fig. 3, the syringe part 200 in this example includes a needle 210, a cartridge 220, and a movable plug 230, wherein the cartridge 220 is disposed in the accommodating housing 110, the movable plug 230 is disposed at the rear end of the cartridge 220, and the injection of the liquid medicine in the cartridge 220 can be performed by pushing the movable plug 230.

The middle of the accommodating case 110 in this example is a hollow design, and is used as the observation port 111 for observing the remaining medicine in the cartridge 220.

The front end of the accommodating shell 110 in this example is provided with a threaded part 112 for connecting with the needle 210, and the needle 210 is in fit connection with the threaded part 112, so as to facilitate the detachment of the needle and the assembly of a new needle, wherein the needle 210 is provided with a small needle cap 240, and the small needle cap 240 does not need to be removed during the assembly, thereby preventing the patient from being accidentally injured when the needle 210 is installed.

The working end of the push rod 300 is planar, and it can be inserted into the housing 110 for directly acting on the movable rubber plug 230 to perform the injection operation, and it is driven by the push rod driving assembly 400 and the spring force application assembly 500.

Referring to fig. 3, 10-19, the push rod driving assembly 400 includes a rotation body 410, a spiral guide cylinder 420, an inner rotation cylinder 430, and an outer rotation cylinder 440;

the spiral guide cylinder 420 is installed in the support housing 130, and the inner rotary cylinder 430 is sleeved on the spiral guide cylinder 420 and can slide (rotate in a spiral manner) on the spiral guide cylinder 420 to change the position;

the outer rotary cylinder 440 is sleeved on the inner rotary cylinder 430, and can perform relative sliding in the process of synchronously rotating with the inner rotary cylinder 430, and the connection mode between the two is preferably as follows:

a plurality of symmetrically distributed and axially staggered sliding blocks 431 are arranged on the periphery of the inner rotating cylinder 430, for example, four sliding blocks 431 are arranged, and sliding grooves 441 which are matched with the sliding blocks 431 one by one are arranged in the outer rotating cylinder 440, wherein the sliding grooves 441 have enough length to meet the relative sliding distance between the inner rotating cylinder 430 and the outer rotating cylinder 440.

Specifically, the outer rotary drum 440 and the inner rotary drum 430 can rotate synchronously but can slide freely in the axial direction, and either one of the two can rotate synchronously, that is, the inner rotary drum 430 performs a spiral motion on the spiral guide drum 420.

The revolving body 410 is arranged in the supporting shell 130, can be coupled with the outer revolving drum 440, is rotatably connected with the push rod 300, and converts the rotation of the revolving body 410 into the extension of the push rod 300;

the front end of the spiral guide cylinder 420 is in direct contact with the revolving body 410, the spiral guide cylinder 420 does not rotate, in order to reduce the rotating friction generated between the spiral guide cylinder 420 and the revolving body 410, a conical abutting boss 421 is arranged at the front end of the spiral guide cylinder 420, the abutting boss 421 has a small contact area, and the friction force generated by relative rotation between the two can be reduced.

Further, a circular connecting cylinder 411 capable of extending into the spiral guide cylinder 420 is further provided on the rotation body 410 to improve the relative rotation capability between the rotation body and the spiral guide cylinder 420.

Specifically, the circular connecting cylinder 411 is provided with a circular/semicircular annular flange 412, and a semicircular groove 422 is provided on the inner circumferential surface of the front end of the spiral guide cylinder 420 for loosely engaging with the flange 412 so that they can rotate relatively to each other without being separated in the axial direction.

A sleeve structure 450 may be further disposed at a position where the inner drum 430 contacts the rotator 410, so that the relative rotation process between the two is more stable.

The spring force application assembly 500 includes a force application spring 510 and a return spring 520, the force application spring 510 is sleeved on the spiral guide cylinder 420, the extruded force application spring 510 drives the inner drum 430 to rotate on the spiral guide cylinder 420, wherein the extrusion acting force of the force application spring 510 comes from the rotational extrusion of the inner drum 430.

Specifically, one end of the biasing spring 510 abuts against the inner drum 430, and the other end of the biasing spring 510 abuts against the spiral guide cylinder 420, as shown in fig. 17, preferably, a circular truncated cone 423 is disposed at the rear end of the spiral guide cylinder 420, a first rotating disc 460 for abutment is sleeved on the spiral guide cylinder 420, one end of the biasing spring 510 abuts against the inner drum 430 through the first rotating disc 460, wherein a conical abutment boss is also disposed at a position of the first rotating disc 460, which is in contact with the inner drum 430, so as to reduce a friction force generated by relative rotation between the first rotating disc and the inner drum 430.

The return spring 520 is disposed between the outer drum 440 and the pressing cap 140, and the pressing brake of the pressing cap 140 can compress the return spring 520, and the compressed return spring 520 provides sufficient force to axially disengage the outer drum 440 from the support housing 130 and slide into coupling with the rotator 410.

When the outer rotary cylinder 440 is disengaged from the support housing 130, the rotation restriction thereof is lost, and at this time, the outer rotary cylinder 440 and the inner rotary cylinder 430 form the rotation of the inner rotary cylinder 430 relative to the spiral guide cylinder 420 under the action of the force application spring 510, so as to drive the outer rotary cylinder 440 to rotate synchronously;

under the action of the return spring 520, the outer cylinder 440 slides to be coupled with the revolving body 410, and particularly, the coupling connection between the outer cylinder 440 and the revolving body 410 preferably adopts a meshing tooth 470 connection structure to realize a normal meshing process at a plurality of rotation positions, at this time, the revolving motion of the outer cylinder 440 is transmitted to the revolving body 410 to drive the revolving body 410 to rotate, and further, the pushing rod 300 rotationally connected (specifically, for example, threaded or screwed) with the revolving body 410 is driven to extend forwards to complete the injection.

When the force of the force application spring 510 is removed, the push rod 300 will not extend forward, and the single injection administration process is finished.

In this example, in order to stabilize the injection process of the pushing rod 300 extending forward, a screw rod orientation ring 480 is provided, the screw rod orientation ring 480 is fixedly installed on the housing 100, specifically, for example, is clamped at the end position of the accommodating housing 110 by a positioning bump 481, wherein an inner circular boss 482 is provided at the inner ring of the screw rod orientation ring 480, and a rectangular groove 310 matched with the inner circular boss 482 is provided at the pushing rod 300 to prevent the pushing rod 300 from rotating during the pushing process.

A compression spring 483 can also be arranged between the screw positioning ring 480 and the revolving body 410.

Further, the inner wall of the spiral guide cylinder 420 is also provided with a guide strip 424 along the length direction of the spiral guide cylinder, and the push rod 300 is provided with a guide groove matched with the guide strip 424, so that the spiral guide cylinder 420 is limited not to rotate, and the structure is more stable.

The guide groove may also be a rectangular groove 310, so as to simplify the structure.

In this example, in order to ensure the one-way sliding effect of the pushing rod 300, a one-way snap spring 490 is further provided, and a preferred structure of the one-way snap spring 490 is shown in fig. 10, and two square grooves 491 are provided in the middle of the one-way snap spring 490 for being clamped with two symmetrical bosses 320 provided at the driving end (rear end) of the pushing rod 300 to define the position of the one-way snap spring 490.

Specifically, the front end of the one-way snap spring 490 is provided with a bending portion 492, the bending portion 492 forms a bending angle towards the rear end to enable the bending portion 492 to have elastic deformation capability in the radial direction, so as to achieve the capability of moving forwards in one direction, wherein the bending portion 492 limits the possibility of moving towards the rear end.

Preferably, the end of the bending portion 492 is formed in a circular arc shape, so that the sliding resistance in the spiral guide cylinder 420 is greatly reduced.

Further, the spiral guide cylinder 420 is provided with a notch 425 matched with the one-way clamp spring 490, and the notch 425 is used for limiting the maximum extending form position of the push rod 300, after the one-way clamp spring 490 slides to the notch 425, a bent part 492 on the one-way clamp spring 490 extends out of the notch 425 to be limited and cannot slide continuously, meanwhile, a clamping groove 433 is arranged on the inner wall of the inner rotary cylinder 430, and the bent part 492 extending out of the notch 425 is clamped in the clamping groove 433.

This position is the maximum extension position of the pushing rod 300, and the pushing rod 300 cannot move further to inform the patient that the injection is completed.

Referring to fig. 3, 20-23, a dose control assembly 600 is used to set a single shot dose, wherein the set dose is adjustable and never greater than the actual dose of the drug remaining in the cartridge, a preferred dose control assembly 600 includes a dose knob 610, a one-way ratchet 620, and a memory ring 630.

The one-way ratchet 620 is a cylinder, and is installed at the rear end of the support housing 130, for example, by a snap-fit manner, the dose knob 610 is rotatably installed on the one-way ratchet 620, wherein the rear end of the outer cylinder 440 passes through the one-way ratchet 620 and then is in a snap-fit/insertion fit with the dose knob 610, and the press cap 140 is connected with the outer cylinder 440 in a snap-fit manner, wherein the press cap 140 and the outer cylinder are capable of not only sliding back and forth synchronously but also rotating relatively.

Wherein a return spring 520 is provided between the dose knob 610 and the press cap 140 to achieve axial separation of the press cap 140 from the outer barrel 440.

In this example, a second rotating disc 640 may be further disposed between the pressing cover 140 and the outer rotating cylinder 440, and the second rotating disc 640 is preferably made of a self-lubricating POM material and keeps the two smooth, so that the pressing cover 140 and the outer rotating cylinder 440 can freely rotate in the radial direction.

The snap fit between the dose knob 610 and the outer barrel 440 is preferably:

the outer rotor 440 is in a stepped cylindrical shape, the outer circumference of the rear end of the outer rotor 440 is provided with a plug-in tooth 442 arranged along the axial direction thereof, the inner circumferential wall of the dose knob 610 is provided with a plug-in groove 611, and the plug-in tooth 442 arranged in the plug-in groove 611 can drive the outer rotor 440 and the dose knob 610 to synchronously rotate.

The rotation of the dose knob 610 drives the outer rotary cylinder 440 to rotate synchronously, and drives the inner rotary cylinder 430 to rotate around the spiral guide cylinder 420 to compress the force application spring 510, so that the force application spring 510 obtains a determined compression stroke, and thus obtains a specified injection dose.

The memory ring 630 is used to limit the number of turns of the dose knob 610, which is threaded onto the one-way ratchet 620, wherein the dose knob 610 is provided with a snap groove 612, and the memory ring 630 is provided with a snap projection 631 cooperating with the snap groove 612, which on one hand rotates synchronously with the dose knob 610 and on the other hand limits the maximum number of turns of the dose knob 610 to ensure that the set dose is always no greater than the actual dose of the remaining drug in the cartridge.

In particular, the dose knob 610 in this example does not itself experience a rotational advancement phenomenon, which changes the position of the memory ring 630 on the one-way ratchet 620 by way of a sliding fit relationship with the memory ring 630 to achieve its effect of limiting the maximum number of turns of the dose knob 610.

The set injection dose can be directly displayed in an intuitive mode in the example, and the specific structure is as follows:

the inner rotating cylinder 430 is provided with a spiral dose scale 432, the support housing 130 is provided with a window 131 for displaying the dose scale 432, wherein the outer rotating cylinder 440 is provided with a transparent structure matched with the window or is made of a transparent material as a whole.

Further, the helical pitch of the dose scale 432 is matched to the helical pitch of the helical guide 420, so that the inner drum 430 is always accurately displayed on the window 131 by the corresponding scale when the outer drum 440 rotates relatively.

In this example, the one-way ratchet 620 can simultaneously hold the dose scale 432, wherein the inner circumferential surface of the dose knob 610 is provided with ratchet teeth 613, the rear end of the one-way ratchet 620 is provided with a pawl 621, which can perform one-way intermittent motion after being matched with the one-way ratchet 620, and has a self-locking characteristic, and simultaneously transmit the intermittent and locking characteristics to the outer rotary cylinder 440 and the inner rotary cylinder 430, so that the inner rotary cylinder 430 also has the functions of clearance motion and locking, and then the functions of intermittent jumping and locking holding of the dose scale 432 are realized.

Referring to fig. 3, 5-8, the concealed needle assembly 700, which serves to provide a needle concealing function, includes a concealed needle cap 710, a return spring 720 and a concealed needle sleeve 730.

The hidden needle sleeve 730 is detachably connected to the accommodating shell 110, four directional sliding grooves 732 are arranged on the hidden needle sleeve 730 along the length direction of the needle, the hidden needle cap 710 is provided with directional sliding blocks 712 which correspond to the directional sliding grooves 732 in a one-to-one mode, the hidden needle cap 712 is connected to the hidden needle sleeve 730 through the directional sliding blocks 712, and the hidden needle cap 710 can slide along the length direction of the needle, wherein the four directional sliding grooves 732 are distributed at intervals;

the return spring 720 is arranged in the needle covering sleeve 730 and is respectively abutted against the needle covering sleeve 730 and the needle covering cap 710;

one preferred connection between the needle covering sleeve 730 and the accommodating housing 110 is:

two connecting bosses 731 which are centrosymmetric are arranged on the inner circular surface of the needle covering sleeve 730, two L-shaped opening grooves 113 are arranged on the accommodating shell 110, the connecting bosses 731 can slide along the track of the L-shaped opening grooves 113 in the axial direction, then are converted into radial rotary motion at the corner position, and finally rotate to the tail end position of the L-shaped opening grooves 113 to complete connection.

Further, in the radial rotation process of the corner position, a matching boss 114 can be arranged in the L-shaped opening groove 113 to form slight interference with the connecting boss 731, so as to form slight pause and drag, and remind the patient that the needle covering sleeve 730 is installed in place.

In this example, a gasket 711 capable of directly contacting with the skin is disposed on the working end surface of the needle hiding cap 710, and the gasket 711 may be made of a skin-friendly material such as silica gel for convenient use.

In this example, before injection, under the action of the return spring 720, the needle hiding cap 710 extends out of the needle hiding sleeve 730 to shade the needle for hiding the needle, the gasket 711 on the working end face of the needle hiding cap 710 is attached to the injection site of the patient during injection, the shell 100 (the supporting shell 130 or the accommodating shell 110) is pressed to enable the return spring 720 to contract, the needle is punctured into the skin, and the needle is not visible during puncturing. After the injection is finished, the patient pulls out the needle head, and the hidden needle cap 710 is popped out under the action of the return spring 720, so that the needle head is not visible in the process of pulling out the needle.

As shown in FIG. 4, the front cap 120 in this embodiment is a cylindrical cap-shaped thin-walled component for protecting the fluid container from being exposed to the outside and avoiding contamination, and the outer circumferential surface of the front cap 120 is provided with pen clip bosses 121, so that the local clamping force is larger for carrying.

The receiving housing 110 and the supporting housing 130 in this example can be connected by snap-fit structure to facilitate the manufacturing process.

Although the present invention has been described with reference to the preferred embodiments, it is not intended to limit the scope of the invention. Any person skilled in the art can make some modifications without departing from the scope of the invention, i.e. all equivalent modifications made according to the invention shall be covered by the scope of the invention.

Claims

1. An automatic injection device is characterized by comprising a shell, a push rod acting on an injector, a push rod driving assembly and a spring force application assembly;

the working end of the push rod is arranged in the accommodating shell in a stretching mode, and the driving end of the push rod is arranged in the supporting shell and is driven by the pressing cover in a force application mode;

the push rod driving component comprises a revolving body, a spiral guide cylinder, an inner rotary cylinder and an outer rotary cylinder;

the revolving body is arranged in the supporting shell and can be coupled and connected with the outer revolving drum, the revolving body is rotatably connected with the push rod, and the revolving body converts the autorotation of the revolving body into the extension of the push rod;

the return spring is arranged between the outer rotary drum and the pressing cover, and the return spring can be compressed by pressing and braking the pressing cover, so that the outer rotary drum is axially separated from the supporting shell and slides to be coupled with the rotary body.

2. The automatic injection device of claim 1, further comprising a one-way snap spring, the drive end of the pusher rod being located within the screw guide, wherein the one-way snap spring is disposed on the drive end of the pusher rod and is capable of one-way sliding within the screw guide.

3. The automatic injection device of claim 2, wherein said helical guide cylinder is provided with a notch for cooperating with said one-way circlip for limiting the maximum reach configuration position of said pusher rod.

4. The automatic injection device according to claim 1, wherein a guide strip is provided in the spiral guide cylinder along a length direction thereof, and the push rod is provided with a guide groove engaged with the guide strip.

5. The automatic injection device of claim 1, wherein the inner and outer barrels are arranged for relative sliding movement during synchronous rotation as follows:

and sliding grooves matched with the sliding blocks one by one are arranged in the outer rotating cylinder.

6. The automatic injection device of claim 1, further comprising a screw orientation ring secured to said housing, said screw orientation ring having a guide projection, said pusher arm having an open slot for engaging said guide projection.

7. The automatic injection device of claim 1, further comprising a dose control assembly including a dose knob and a one-way ratchet fixed to the support housing, the dose knob rotatably disposed on the one-way ratchet;

the one-way ratchet wheel is cylindrical, and one end of the outer cylinder penetrates through the one-way ratchet wheel and is clamped with the dose knob;

8. The automatic injection device of claim 7, wherein said dose control assembly further comprises a memory ring for limiting the number of revolutions of said dose knob, said memory ring being rotatably disposed on said one-way ratchet, said dose knob being provided with a snap groove, said memory ring being provided with a snap projection cooperating with said snap groove.

9. The automatic injection device of claim 7, wherein said inner drum is provided with a helical dose scale and said support housing is provided with a window displaying said dose scale, and wherein said outer drum is provided with a transparent or hollowed-out structure matching said window.

10. The automatic injection device of claim 1, further comprising a needle hider assembly comprising a needle hider cap, a return spring, a needle hider sleeve;

the needle hiding sleeve is detachably connected to the accommodating shell and is provided with a directional sliding groove along the length direction of the needle head;

the working end face of the needle hiding cap is provided with a gasket which can be in direct contact with the skin.