阅读说明：本技术 一种可调针头伸出长度的显微针 (Microneedle with adjustable extending length of needle head ) 是由 廖俊 于 2021-06-25 设计创作，主要内容包括：本发明涉及一种可调针头伸出长度的显微针,包括壳体,壳体的侧壁上设有真空负压接口,壳体内设有负压腔、滑设有处于负压腔上方的针套、固定设置在针套上的多个空心针体、处于针套上方的并与针套固定连接的旋转杆；旋转杆上设有与空心针体相导通的输入通道,旋转杆上套设有能相对其转动的并套设在壳体上端的旋转环,在旋转环和壳体之间还设有在周向上能抵接并相对滑动的限位机构；旋转环内壁绕周向并沿径向向内延伸有依次相连的多个凸台,多个凸台在旋转环轴向上的高度不相同,旋转杆的侧壁延伸有抵接在凸台上的延伸臂。该发明能根据人的皮肤很方便的调节针插入的深度,实现更好的效果,调节结构简单实用。(The invention relates to a microneedle with an adjustable extending length of a needle head, which comprises a shell, wherein the side wall of the shell is provided with a vacuum negative pressure interface, a negative pressure cavity is arranged in the shell, a needle sleeve positioned above the negative pressure cavity is arranged in a sliding manner, a plurality of hollow needle bodies fixedly arranged on the needle sleeve, and a rotating rod positioned above the needle sleeve and fixedly connected with the needle sleeve; the rotating rod is provided with an input channel communicated with the hollow needle body, the rotating rod is sleeved with a rotating ring which can rotate relative to the rotating rod and is sleeved at the upper end of the shell, and a limiting mechanism which can be abutted and relatively slide in the circumferential direction is also arranged between the rotating ring and the shell; the inner wall of the rotating ring is circumferentially and radially and inwardly extended with a plurality of bosses which are sequentially connected, the heights of the plurality of bosses in the axial direction of the rotating ring are different, and the side wall of the rotating rod is extended with an extension arm which is abutted against the bosses. The invention can conveniently adjust the insertion depth of the needle according to the skin of a person, realizes better effect and has simple and practical adjusting structure.)

1. A microneedle with adjustable needle extension length, comprising: the needle sleeve comprises a shell, wherein a vacuum negative pressure interface is arranged on the side wall of the shell, a negative pressure cavity communicated with the vacuum negative pressure interface is arranged in the shell, a needle sleeve which is positioned above the negative pressure cavity and can slide up and down, a plurality of hollow needle bodies which are fixedly arranged on the needle sleeve and can movably extend into the negative pressure cavity, and a rotating rod which is positioned above the needle sleeve and is fixedly connected with the needle sleeve are also arranged in the shell; the rotating rod is provided with an input channel communicated with the hollow needle body, the rotating rod is sleeved with a rotating ring which can rotate relative to the rotating rod and is sleeved at the upper end of the shell, the rotating ring rotates relative to the shell, and a limiting mechanism which can be abutted and relatively slide in the circumferential direction is further arranged between the rotating ring and the shell; the inner wall of the rotating ring extends inwards in the radial direction around the circumferential direction to form a plurality of bosses which are connected in sequence, the heights of the plurality of bosses in the axial direction of the rotating ring are different, and the side wall of the rotating rod extends to form an extension arm which is abutted against the bosses.

2. The microneedle with the adjustable extending length of the needle head as claimed in claim 1, wherein the inner wall of the rotating ring is provided with two boss groups with two ends spaced by the slot and taking the center of the rotating ring as the symmetric center, each boss group is provided with a plurality of identical bosses which are sequentially connected, the bosses in the two boss groups are symmetrically distributed, and the extending arm on the rotating rod is also provided with two corresponding bosses.

3. A microneedle with adjustable needle extension length according to claim 2, wherein the end of the lowest and/or highest boss in each boss group is provided with a stopper.

4. A microneedle with an adjustable protruding length according to claim 1, wherein a plurality of positioning grooves are circumferentially arranged on the outer wall of the upper end of the housing at intervals, positioning blocks capable of being clamped into the positioning grooves along with the rotation of the rotating ring are arranged on the inner wall of the rotating ring below the end boss, and the positioning grooves correspond to the boss.

5. A microneedle with an adjustable protruding length according to claim 1, wherein the limiting mechanism comprises a plurality of sliders circumferentially spaced at intervals on the lower portion of the inner wall of the rotating ring, and a housing step circumferentially disposed on the outer wall of the housing, the sliders being abutted against the lower end of the housing step and being rotatable along the housing step.

6. The microneedle with the adjustable protruding length of the needle head as claimed in claim 1, wherein a shunting part having a plurality of shunting channels is disposed at the bottom of the rotating rod, the shunting channels are communicated with the input channel, and the shunting channels are communicated with the hollow needle body in a one-to-one correspondence manner.

7. The microneedle with the adjustable extending length of the needle head according to claim 1, wherein an elastic gasket is arranged between the needle sleeve and the negative pressure cavity wall, the hollow needle body penetrates through the elastic gasket, a first needle seat is arranged at the bottom of the needle sleeve, a needle seat through hole matched with the first needle seat penetrates through the gasket is arranged at the top of the gasket, a gasket bulge protruding out of the upper surface of the gasket is arranged between the needle seat through holes, a second needle seat sleeved outside the first needle seat in a matched manner is arranged at the bottom end of the needle seat through hole, and the hollow needle body sequentially penetrates out of the needle sleeve, the first needle seat and the second needle seat.

8. The microneedle with the adjustable extending length of the needle head as claimed in claim 1, wherein the needle sheath comprises a first needle sheath fixedly connected with the hollow needle body and the rotary rod, and a second needle sheath sleeved outside the first needle sheath and fixedly connected in the housing, the first needle sheath slides relative to the second needle sheath, a limiting step for limiting the sliding of the first needle sheath is arranged in the second needle sheath, the lower end of the hollow needle body sequentially penetrates through the first needle sheath and the second needle sheath to be inserted into the negative pressure cavity, and the upper end of the hollow needle sheath is communicated with the input channel.

9. The microneedle with the adjustable extending length of the needle head as claimed in claim 1, wherein the bottom surface of the housing is provided with a square groove, the bottom of the square groove is provided with a cone corresponding to the hollow needle body, the cone and the housing are integrally formed, a negative pressure cavity is formed between the cone and the wall of the square groove, and the hollow needle body is movably arranged on the cone in a penetrating manner.

10. A microneedle with an adjustable needle extension length according to claim 1, wherein the height of said projections is gradually reduced or gradually increased.

Technical Field

The invention relates to medical beauty equipment, in particular to a micro-needle with an adjustable needle head extending length.

Background

As for beauty, a microneedle is a medical device for skin beauty, which injects a beauty fluid into the dermis through a tip of a needle inserted into the skin at a front end thereof, and the length of the tip of the needle extended determines the depth of insertion into the dermis, however, since individuals, and the skin of different body parts of the same person have difference, the thickness from the outside of the epidermis to the dermis has difference, the depth of the needle inserted into the skin is shallower, the less the damage to the human skin, but the less absorbent, the too deep the needle into the dermis of the skin, leaving a needle hole in the skin, and causing redness and swelling of the skin, the length of the extended needle of the existing micro-needle is fixed, and the corresponding depth of the micro-needle entering the skin is also fixed, so that the micro-needle cannot be regulated and controlled and cannot be regulated aiming at different skins, and further the treatment effect is uneven.

Disclosure of Invention

Aiming at the existing defects, the invention provides a microneedle with an adjustable extending length of a needle head.

The technical scheme adopted by the invention for solving the technical problems is as follows: a microneedle with an adjustable extending length of a needle head comprises a shell, wherein a vacuum negative pressure interface is arranged on the side wall of the shell, a negative pressure cavity communicated with the vacuum negative pressure interface is arranged in the shell, a needle sleeve which is positioned above the negative pressure cavity and can slide up and down, a plurality of hollow needle bodies which are fixedly arranged on the needle sleeve and can movably extend into the negative pressure cavity, and a rotary rod which is positioned above the needle sleeve and is fixedly connected with the needle sleeve are also arranged in the shell; the rotating rod is provided with an input channel communicated with the hollow needle body, the rotating rod is sleeved with a rotating ring which can rotate relative to the rotating rod and is sleeved at the upper end of the shell, the rotating ring rotates relative to the shell, and a limiting mechanism which can slide relative to the rotating ring in the circumferential direction is arranged between the rotating ring and the shell; the inner wall of the rotating ring extends inwards in the radial direction around the circumferential direction to form a plurality of bosses which are connected in sequence, the heights of the plurality of bosses in the axial direction of the rotating ring are different, and the side wall of the rotating rod extends to form an extension arm which is abutted against the bosses.

Preferably, the inner wall of the rotating ring is provided with two boss groups which are symmetrical about the center of the rotating ring and have two ends spaced by the clamping groove, each boss group is provided with a plurality of identical bosses which are connected in sequence, the bosses in the two boss groups are distributed symmetrically, and the extension arm on the rotating rod is also provided with two bosses corresponding to the two boss groups.

Preferably, the end of the lowest and/or highest boss in each boss group is provided with a stop.

Preferably, a plurality of positioning grooves are formed in the outer wall of the upper end of the shell at intervals in the circumferential direction, positioning blocks capable of being clamped into the positioning grooves along with rotation of the rotating ring are arranged on the inner wall of the rotating ring below the end boss, and the positioning grooves correspond to the bosses in position.

Preferably, the stopper mechanism includes a plurality of sliders provided at circumferentially spaced intervals on a lower portion of an inner wall of the rotating ring, and a housing step provided circumferentially around an outer wall of the housing, and the sliders are in contact with a lower end of the housing step and are rotatable along the housing step.

Preferably, the bottom of rotary rod is provided with the reposition of redundant personnel portion that has a plurality of reposition of redundant personnel passageways, reposition of redundant personnel passageway all switches on with input channel mutually, and reposition of redundant personnel passageway and hollow needle body one-to-one switch on.

Preferably, an elastic gasket is arranged between the needle sleeve and the negative pressure cavity wall, the elastic gasket is penetrated by the hollow needle body, a first needle seat penetrated by the hollow needle body is arranged at the bottom of the needle sleeve, a needle seat through hole matched with the first needle seat is formed in the top of the gasket, a gasket bulge protruding out of the upper surface of the gasket is arranged between the needle seat through holes, a second needle seat matched with the first needle seat and sleeved outside the first needle seat is arranged at the bottom of the needle seat through hole, and the hollow needle body penetrates out of the needle sleeve, the first needle seat and the second needle seat in sequence.

Preferably, the needle sleeve comprises a first needle sleeve fixedly connected with the hollow needle body and the rotary rod, and a second needle sleeve sleeved outside the first needle sleeve and fixedly connected in the shell, the first needle sleeve slides relative to the second needle sleeve, a limiting step for limiting the sliding of the first needle sleeve is arranged in the second needle sleeve, the lower end of the hollow needle body sequentially penetrates through the first needle sleeve and the second needle sleeve to be inserted into the negative pressure cavity, and the upper end of the hollow needle sleeve is communicated with the input channel.

Preferably, the bottom surface of casing is equipped with square groove, square groove's tank bottom is provided with the cone corresponding with hollow needle body, cone and casing integrated into one piece, form the negative pressure chamber between cone and the square groove cell wall, hollow needle body activity is worn to establish on the cone.

Preferably, the height of the plurality of bosses is gradually reduced or gradually increased.

The invention has the beneficial effects that: according to the invention, the rotating ring rotates relative to the rotating rod, so that the extension arm is abutted against the bosses with different heights, the rotating rod drives the needle sleeve to slide in the shell, the needle sleeve slides to drive the hollow needle body to slide, the extending length of the needle head of the hollow needle body is further adjusted, namely the length of the needle head extending into the negative pressure cavity and inserted into the skin is adjusted, the number of the bosses can be set according to requirements, a plurality of bosses form a plurality of adjusting gears, the adjustment can be carried out only by rotating the rotating ring, the structure is simple, the use is convenient, the corresponding skin inserting depth can be adjusted according to different skins, and the skin can not be damaged while the treatment effect is ensured.

Drawings

FIG. 1 is a schematic cross-sectional structural view of an embodiment of the present invention;

FIG. 2 is an exploded view of an embodiment of the present invention;

FIG. 3 is a schematic front view of a rotating ring according to an embodiment of the present invention;

FIG. 4 is a schematic view showing the configuration of the bottom surface of the rotating ring according to the embodiment of the present invention;

FIG. 5 is a schematic view of a rotary lever according to an embodiment of the present invention;

FIG. 6 is a schematic structural view of a housing according to an embodiment of the present invention;

FIG. 7 is a schematic diagram of a front side of a gasket according to an embodiment of the invention;

FIG. 8 is a schematic view of a bottom structure of a gasket according to an embodiment of the invention;

FIG. 9 is a schematic view of a first needle hub arrangement according to an embodiment of the present invention;

fig. 10 is a front view of a second sleeve according to an embodiment of the present invention;

fig. 11 is a schematic view of the bottom structure of a second sleeve according to an embodiment of the present invention;

part names and serial numbers in the figure: 1-shell 10-vacuum negative pressure interface 11-negative pressure cavity 12-positioning groove 13-shell step 14-cone 2-needle sleeve 20-first needle seat 21-first needle sleeve 22-second needle sleeve 220-limit step 3-hollow needle body 4-rotary rod 40-input channel 41-extension arm 42-shunt part 420-shunt channel 5-rotary ring 50-boss 51-clamping groove 52-stop block 53-positioning block 6-limit mechanism 60-sliding block 7-gasket 70-needle seat through hole 71-gasket projection 700-second needle seat.

Detailed Description

To more clearly illustrate the objects, technical solutions and advantages of the embodiments of the present invention, the present invention will be further described in detail with reference to the accompanying drawings and embodiments, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without inventive step, are within the scope of the present invention. In addition, directional terms used in the present invention, such as "upper", "lower", "front", "rear", "left", "right", "inner", "outer", etc., refer to directions only as shown in the attached drawings, and are used for better and clearer explanation and understanding of the present invention, and do not indicate or imply orientation which the present invention must have, and thus, should not be construed as limiting the present invention.

Embodiment of the invention as shown in fig. 1 to 11, a microneedle with adjustable needle extension length comprises a housing 1, a vacuum negative pressure port 10 is arranged on the side wall of the housing 1, a negative pressure cavity 11 communicated with the vacuum negative pressure port 10 is arranged in the housing 1, the cavity wall at the top of the negative pressure cavity 11 divides the interior of the housing 1 into two parts, the negative pressure cavity 11 is arranged at the lower part of the housing 1, the vacuum negative pressure port 10 can be arranged at any position of the side wall of the housing 1 according to different conditions, and then is communicated with the negative pressure cavity 11, meanwhile, the vacuum negative pressure port 10 is used for connecting a negative pressure device generating negative pressure, when in use, a negative pressure environment is formed in the negative pressure cavity 11 through the negative pressure device, so that the needle housing 1 can suck the skin conveniently, and liquid can be injected conveniently, and a needle sleeve 2 capable of sliding up and down is further arranged in the housing 1 and positioned above the negative pressure cavity 11 and can slide up and down, A plurality of hollow needle bodies 3 which are fixedly arranged on the needle sleeve 2 and can movably extend into the negative pressure cavity 11, and a rotary rod 4 which is arranged above the needle sleeve 2 and is fixedly connected with the needle sleeve 2, at the moment, the needle sleeve 2 and the rotary rod 4 are both arranged on the upper part of the shell 1 and slide up and down in the shell, preferably, a square cavity is arranged in the shell, the needle sleeve 2 is prevented from rotating in the square cavity, at the moment, the square cavity is realized by arranging a groove on the upper part of the shell 1, the needle sleeve 2, the rotary rod 4 and the hollow needle bodies 3 are fixedly connected, the hollow needle bodies 3 penetrate through the needle sleeve 2, when the needle sleeve 2 slides up and down in the shell 1, the hollow needle bodies 3, the rotary rod 4 are enabled to synchronously move with the hollow needle bodies 3, the needle heads of the hollow needle bodies 3 extend into the negative pressure cavity 11 with different lengths along with the sliding of the hollow needle bodies, namely, the extending lengths of the hollow needles 3 are set into 4 hollow needle bodies according to use requirements at the moment, 9 micro needles with 4 needles or 9 needles are formed in equal and different numbers, the 4 needles are distributed in a row-column structure of 2X2 and form an X-shaped structure by taking the input channel as the center, and the 9 needles are distributed in a row-column structure of 3X3 and form a meter-shaped structure by taking the input channel as the center; the rotating rod 4 is provided with an input channel 40 communicated with the hollow needle body 3, liquid can be conveniently injected through the input channel 40, and then the liquid is injected into skin through the hollow needle body 3, the input channel 40 is communicated with external equipment, the outer wall of the rotating rod 4 is correspondingly provided with a connecting bulge or a connecting mechanism for connecting liquid supply equipment or supply appliances, the rotating rod 4 is sleeved with a rotating ring 5 which can rotate relative to the rotating rod 4 and is sleeved at the upper end of the shell 1, the rotating ring 5 rotates relative to the shell 1, a limiting mechanism 6 which can slide relative to the circumferential direction is also arranged between the rotating ring 5 and the shell 1, namely, the rotating ring 5 is sleeved outside the rotating rod 4 and the shell 1 at the same time and can rotate relative to the rotating rod 4 and the shell 1 at the same time, the rotating ring 5 adopts a structure similar to a bottle cap, and is sleeved on the rotating rod 4 through a through hole in the middle, the edge is sleeved on the shell 1 through the side wall, the rotating ring 5 is combined with the shell 1, and the limiting mechanism 6 between the rotating ring 5 and the shell 1 enables the rotating ring 5 to be sleeved on the shell 1 and then not to fall off from the shell 1, and the rotation of the rotating ring 5 is not influenced; the inner wall of the rotating ring 5 extends inwards along the radial direction and is provided with a plurality of bosses 50 which are connected in sequence, the plurality of bosses 50 are different in height in the axial direction of the rotating ring 5, namely, the bosses 50 are arranged along the circumferential direction of the rotating ring 5, the bosses 50 are formed by extending inwards along the radial direction from the inner wall of the rotating ring 5, the inner diameter of the rotating ring 5 is reduced by the bosses 50, meanwhile, the plurality of bosses 50 are connected in sequence, namely, the first boss is connected with the second boss, the second boss is connected with the third boss, the third boss is connected with the fourth boss, and so on until the last boss, for the plurality of bosses 50, the relative heights are different, at the moment, the bosses can be arranged in a mode of gradually reducing or gradually increasing, the adjustment is convenient by sequentially increasing or decreasing, and the adjustment can be carried out from deep to shallow or from shallow to deep in use, forming a progressive process, the side wall of the rotary bar 4 is extended with the extension arm 41 abutting on the boss 50, which means that the extension arm 41 and the rotary bar 4 are integral. Thus, in the structure of the whole micro-needle, the rotary rod 4 is fixedly connected with the needle sleeve 2, the needle sleeve 2 is fixedly connected with the hollow needle body 3, the needle sleeve 2 slides up and down in the shell 1 to drive the hollow needle body 3 to slide up and down, meanwhile, the rotary ring 5 rotates around the shell 1 and the rotary rod 4 simultaneously, the rotary rod 4 can not rotate relative to the shell 1, the extending length of the needle head of the hollow needle body 3 is also adjusted, namely the extending length of the needle head of the hollow needle body 3 extends into the negative pressure cavity 11 to be inserted into the skin, only the rotary ring 5 needs to be rotated in use, the extension arm 41 is abutted on bosses 50 with different heights, the rotary rod 4 slides up and down with the needle sleeve 2 in the shell 1, the needle sleeve 2 slides to drive the hollow needle body 3 to slide, when the abutment is on the highest boss 50, the extending length of the needle head of the hollow needle body 3 is shortest, when the abutment is on the lowest boss 50, the extending length of the needle head of the hollow needle body 3 is longest, the quantity of boss 50 just can set up according to the demand, there are several bosses 50 just to form several regulation gears, only need just can adjust through rotatory ring 5, moreover, the steam generator is simple in structure, high durability and convenient use, both can adjust its corresponding degree of depth of inserting skin to different skin, still can not cause the damage to skin when having ensured treatment, simultaneously in order to can understand the gear of adjusting hollow needle body 3 directly perceivedly, just be provided with the corresponding sign that indicates different boss 50 heights at the upper surface of rotatory ring 5.

A further improvement, as shown in fig. 1 to 5, the inner wall of the rotating ring 5 is provided with two boss groups having two ends spaced by a slot 51 and taking the center of the rotating ring 5 as a symmetric center, each boss group is provided with a plurality of identical bosses 50 connected in sequence, the bosses 50 in the two boss groups are distributed symmetrically, the extension arm 41 on the rotating rod 4 is also provided with two corresponding to the two boss groups, the bosses 50 are divided into two groups in the rotating ring 5, the number of the bosses 50 in each group and the height of the corresponding bosses 50 are the same, the two groups of symmetrical distribution in the rotating ring 5, the two extension arms 41 correspond to the two boss groups, the slot 51 between the two groups facilitates the installation of the rotating rod 4 during the production and assembly, so that the extension arm 41 on the rotating rod 4 is aligned with the slot 51, when the rotating rod is installed, the extension arm 41 abuts against one boss group, the other extension arm 41 abuts against the other boss group to form a symmetrical structure, so that the rotating ring 5 can move stably during rotation, the stop blocks 52 are arranged at the ends of the bosses 50 which are at the lowest position and/or the highest position in each boss group, the rotation of the rotating ring 5 is limited, the rotating ring can not rotate when rotating to the lowest position or the highest position, and the extension arm 41 on the rotating ring 4 is prevented from falling into the clamping groove 51 to influence use.

In a further improvement, as shown in fig. 6, a plurality of positioning grooves 12 are circumferentially arranged on the outer wall of the upper end of the housing 1 at intervals, as shown in fig. 4, the inner wall of the rotating ring 5 is provided with positioning blocks 53 capable of being clamped into the positioning grooves 12 along with the rotation of the rotating ring 5 below the bosses 50 at the end, the positioning grooves 12 correspond to the bosses 50, that is, corresponding to the bosses 50 at each height, one positioning groove 12 corresponding to the positioning groove is arranged on the housing 1, the positioning block 53 is arranged on the inner wall of the rotating ring 5 and is also positioned below the boss 50, the boss 50 is the boss 50 at the head end or the tail end, the rotating ring 5 rotates to adjust to the boss 50 at one height, the positioning block 53 is clamped in the positioning groove 12 corresponding to the boss 50 at the height, and the adjusted height, that is, the needle head extension length of the hollow needle body 3 is fixed, ensuring stability in use.

In a further improvement, as shown in fig. 1, 4 and 6, the limiting mechanism 6 includes a plurality of sliders 60 circumferentially spaced at intervals at the lower portion of the inner wall of the rotating ring 5, and a plurality of housing steps 13 circumferentially spaced at intervals at the outer wall of the housing 1, the sliders 60 abut against the lower end of the housing steps 13 and can rotate along the housing steps 13, the housing steps 13 circumferentially surround the outer wall of the housing 1, the sliders 60 are circumferentially spaced at intervals at the rotating ring 5, after the rotating ring 5 is sleeved on the upper end of the housing 1, the sliders 60 are oppositely located at the lower end surface of the housing steps 13, when the rotating ring 5 is pulled upwards, the sliders 60 abut against the housing steps 13, so that the two cannot fall off, and during the rotation of the rotating ring 5, the sliders 60 move synchronously therewith.

In a further improvement, as shown in fig. 5, the bottom of the rotating rod 4 is provided with a shunting portion 42 having a plurality of shunting channels 420, the shunting channels 420 are communicated with the input channel 40, and the shunting channels 420 are communicated with the hollow needle bodies 3 in a one-to-one correspondence manner, that is, how many hollow needle bodies 3 are arranged, how many shunting channels 420 are correspondingly arranged, and one shunting channel 420 corresponds to one hollow needle body 3, so that the liquid can uniformly enter each hollow needle body 3.

A further improvement, as shown in fig. 1, 2, 7 and 8, an elastic gasket 7 through which the hollow needle body 3 passes is arranged between the needle sleeve 2 and the cavity wall of the negative pressure cavity 11, that is, the gasket 7 is arranged on the top of the outer wall of the negative pressure cavity 11, so as to play a role of buffering the sliding of the needle sleeve 2 in the housing 1, and prevent the needle sleeve 2 from impacting the cavity wall of the negative pressure cavity 11 in the sliding process and causing damage to the cavity wall, a first needle seat 20 through which the hollow needle body 3 passes is arranged at the bottom of the needle sleeve 2, a needle seat through hole 70 through which the first needle seat 20 passes is arranged at the top of the gasket 7, a gasket protrusion 71 protruding out of the upper surface of the gasket 7 is arranged between the needle seat through holes 70, a second needle seat 700 sleeved outside the first needle seat 20 is arranged at the bottom end of the needle seat through hole 70, the hollow needle body 3 sequentially penetrates from the needle sleeve 2, the first needle seat 20 and the second needle seat 700, thus, the gasket 7 and the needle sleeve 2 are connected into a whole, and the protection of the hollow needle body 3 is enhanced by each needle seat.

In a further improvement, as shown in fig. 1, 2, 9 to 11, the needle sheath 2 includes a first needle sheath 21 fixedly connected to the hollow needle body 3 and the rotary rod 4, and a second needle sheath 22 sleeved outside the first needle sheath 21 and fixedly connected to the inside of the housing 1, the first needle sheath 21 slides relative to the second needle sheath 22, and a limit step 220 for limiting the sliding of the first needle sheath 21 is provided in the second needle sheath 22, the two needle sheaths 2 are provided, the second needle sheath 22 is fixed in the housing 1, the housing 1 and the negative pressure cavity 11 provided on the housing 1 are protected, the strength and durability of the structure are ensured, the first needle sheath 21 is fixedly connected to the hollow needle body 3 and the rotary rod 4, and slides in the second needle sheath 22 to adjust the extending length of the needle head of the hollow needle body 3, the limit step 220 provided in the second needle sheath 22 forms a cavity in the second needle sheath 22, when first needle cover 21 gliding butt on spacing step 220, the length that the hollow needle body 3 syringe needle stretches out is the longest, and first needle cover 21, second needle cover 22, negative pressure cavity 11 chamber wall etc. just form the multiple spot protection to hollow needle body 3, ensure its normal use, the lower extreme of hollow needle body 3 passes first needle cover 21, second needle cover 22 in proper order and inserts negative pressure cavity 11, and the upper end switches on with input channel 40 mutually.

In a further development, as shown in fig. 1, for the underpressure chamber 11 of the housing 1, the bottom surface of the housing 1 is provided with a square recess, the bottom of the square groove is provided with a cone 14 corresponding to the hollow needle body 3, the cone 14 and the shell 1 are integrally formed, namely, the cone 14 is arranged at the bottom of the square groove and extends into the square groove, the position of the cone is corresponding to the hollow needle bodies 3, one hollow needle body 3 is corresponding to one cone 14, a negative pressure cavity 11 which generates negative pressure in use is formed between the cone 14 and the wall of the square groove, the hollow needle body 3 is movably arranged on the cone 14 in a penetrating way, namely the cone 14 is provided with a through hole through which the hollow needle body 3 passes, when the hollow needle body 3 moves up and down along with the needle sleeve 2, the hollow needle body moves up and down on the cone 14, and the needle head extending out of the cone 14 is inserted into the skin.

It will be understood that modifications and variations can be made by persons skilled in the art in light of the above teachings and all such modifications and variations are intended to be included within the scope of the invention as defined in the appended claims.