CN109621096B

CN109621096B - Medical needleless injector

Info

Publication number: CN109621096B
Application number: CN201910089732.5A
Authority: CN
Inventors: 胡晓华; 杨伟伟; 陈越; 王才丰
Original assignee: Individual
Current assignee: Hu Xiaohua
Priority date: 2016-11-05
Filing date: 2016-11-05
Publication date: 2020-05-12
Anticipated expiration: 2036-11-05
Also published as: CN109568726A; CN106334240B; CN109621096A; CN109568727A; CN109568730A; CN109568729A; CN109568728A; CN106334240A

Abstract

The invention discloses a medical needleless injector, which consists of a gun body, a ram component, a circulating dragging component, a trigger component and a terminal injection component; the gun body consists of a gun frame and a gun barrel and is used for providing a supporting and operating space for other components; the hammer component consists of a hammer body, an elastic rope and a pressing type alarm, and provides impact force for the terminal injection component through the axial movement of the hammer body in the gun barrel; the circular dragging assembly is positioned in the driving cavity and used for driving the hammer assembly to reach a loading state and controlling the hammer body to be excited; the trigger assembly is used for driving the circulating dragging assembly to operate; the terminal injection assembly is composed of a medicine storage cylinder, a piston and a push rod, and the hammer assembly provides power to realize needleless injection. The medical needleless injector has the advantages of scientific and reasonable structure, convenient holding and convenient operation, can quickly carry out multiple continuous injections to realize the injection of large-dose medicines, and expands the application range of the medical needleless injector in the field of clinical injection.

Description

Medical needleless injector

The invention is a divisional application of an invention patent application with application number 201610967779.3 filed on 2016, 11, 05.

Technical Field

The invention relates to a medical apparatus, in particular to a medical needleless injector which can realize large-dose injection of medicines by continuous multiple injections.

Background

The needleless injection is a novel technology which is characterized in that a liquid medicine directly enters organism tissues in a mode of superfine, high-speed and straight-line ejection of high-pressure jet flow without needle puncture by depending on a needleless injector. Compared with the traditional injection technology, the needleless injection does not need a needle to puncture a body, reduces pain and fear of medicine injection, reduces the risk of bacterial infection, avoids accidents such as scratching and breaking of the needle and the like, and improves the convenience and safety of medicine injection operation; meanwhile, when the needleless injection is adopted, the medicine enters the subcutaneous part in a dispersion manner, is uniformly dispersed, is easily and quickly absorbed by organism tissues, is not easy to block tiny lymphatic vessels, and does not cause induration after being used for a long time, so that the medicine injection effect is improved, and the medicine effect taking speed is increased. Therefore, the needleless injection technology can be called a revolution of medical injection technology, and has wide application prospect in future clinical medical treatment.

The needleless injector is a core instrument for implementing needleless injection, and although the conventional needleless injector has a compact structure and a small volume and has certain advantages in operation convenience, the needleless injector has certain disadvantages in clinical application. Such as:

(1) when the needleless injector works, enough pressure needs to be provided for liquid medicine to form high-pressure jet flow, so that the needleless injector needs to be operated in advance in a necessary manner before injection every time, the needleless injector reaches an energy storage state, some needleless injectors need to be held by hands to be operated in advance, the operation is complex, time and labor are wasted, some needleless injectors are operated in advance by means of special tools, and the needleless injector cannot be used flexibly, conveniently and independently.

(2) The prior operation based on the fact that the existing needleless injector reaches an energy storage state is not convenient enough, continuous injection cannot be carried out quickly, the single injection dosage of the needleless injector is small, the injection dosage becomes a short plate of the existing needleless injector, the needle-free injector can only be used for clinical injection of small-dosage medicines such as insulin and the like, but cannot be used for clinical injection of medicines such as antibiotics, interferons and the like with slightly large dosage, and the existing needleless injector is limited by the key factors and cannot be widely applied to the field of clinical injection.

(3) The existing needleless injector has a compact structure, but has more components, and needs a reasonable design and a precise process to realize mechanical performance, so that the existing needleless injector has high manufacturing cost and high manufacturing difficulty, is usually an imported product, has high acquisition cost, is difficult to bear by mass consumers, and is an important factor for limiting the universal application of the needleless injector.

Disclosure of Invention

The invention aims to provide a medical needleless injector which has a scientific structure and convenient operation and can realize large-dose medicine injection by rapid and continuous injection, and aims to solve the defects of the conventional needleless injector that the operation is not convenient enough, the application range is limited by the injection dose, the manufacturing cost is low, and the like.

In order to achieve the technical purpose, the invention adopts the following technical scheme:

a medical needle-free injector, comprising:

the gun body consists of a gun frame and a gun barrel which are fixedly connected; a cylindrical bore is arranged in the barrel, two sides of the bore are respectively provided with a side cavity communicated with the bore, the front end of the barrel is fixed with a threaded head through a neck tube, the side wall of the neck tube is provided with an observation window with scales, the inner cavity of the neck tube, the inner cavity of the threaded head and the bore are coaxial, and the inner diameter of the neck tube is smaller than that of the bore; the tail end of the gun rack is provided with a downward extending handle, and a driving cavity which is positioned at the lower side of the gun chamber and communicated with the gun chamber is arranged in the gun rack;

the hammer component consists of a hammer body, an elastic rope and a pressing type alarm; the hammer body is positioned in the gun chamber and can only axially move, and a towing mechanism is arranged at the lower side of the hammer body; two elastic ropes are respectively positioned in the cavities at the two sides, one end of each elastic rope is connected with the hammer body, and the other end of each elastic rope is connected with the gun body; the push type alarm comprises a trigger switch for controlling the work of the push type alarm, and the trigger switch is arranged on the rear side of the gun chamber; when the rear end of the hammer body abuts against the trigger switch, the pressing type alarm gives out an alarm, the two elastic ropes are in a stretching state, and the hammer assembly is in a loading state; after the hammer body is excited, the hammer body rapidly moves forwards to generate impact force on the front side part;

the circulating dragging assembly comprises a transmission belt, the transmission belt is supported by a driven wheel and a driving wheel which are arranged in front and at back and is positioned in the driving cavity, and the upper side of the transmission belt is parallel to the axis of the hammer body; the driving wheel is matched with a reverse non-return mechanism and can only rotate in the forward direction, so that the upper side of the conveying belt can only be conveyed from the forward direction to the backward direction; the transmission belt is provided with two spaced dragging fin blocks, when the dragging fin blocks move from front to back along with the transmission belt, the dragging fin blocks are matched with the dragging mechanism to drive the hammer body to move backwards, when the dragging fin blocks move right above the driving wheel, the hammer component reaches a loading state, and when the dragging fin blocks move downwards at the driving wheel, the dragging fin blocks are separated from the dragging mechanism to excite the hammer body;

the trigger assembly comprises a trigger and a one-way transmission mechanism, the trigger is positioned on the front side of the handle and swings back and forth along the main shaft, and the lower end of the trigger is driven by the reset mechanism to automatically reset forwards; the one-way transmission mechanism is arranged between the trigger and the driving wheel, and the driving wheel is driven to rotate positively through the one-way transmission mechanism when the trigger swings backwards;

the terminal injection assembly comprises a medicine storage cylinder and a piston which are in sliding seal fit, an injection hole is formed in the front end of the medicine storage cylinder, a threaded sleeve matched with the threaded head is arranged at the rear end of the medicine storage cylinder, a push rod is connected to the rear side of the piston, and a position mark is arranged on the push rod; after the threaded sleeve and the threaded head are combined, the rear end of the push rod penetrates through the threaded head and the neck tube to enter the gun bore and can be impacted by the hammer body, the length of the push rod extending into the gun bore can be adjusted by rotating the threaded sleeve, and the length value of the push rod extending into the gun bore can be judged through scales and position marks on the observation window, so that the injection dosage is definite.

The medical needleless injector has the working principle that:

when the dragging fin block moves to the position right above the driving wheel along with the transmission belt, the hammer body is driven to move backwards by overcoming the pulling force of the two elastic ropes, the hammer body is positioned at the rear part of the gun chamber, a press type alarm gives out a warning, and an operator can clearly determine that the hammer assembly reaches the loading state; the threaded sleeve and the threaded head are combined, so that the terminal injection assembly stored with liquid medicine is fixed at the front end of the gun body, the length value of the tail end of the push rod extending into the gun bore is observed through the scale on the observation window and the position mark on the push rod, and the length of the push rod extending into the gun bore is adjusted by rotating the threaded sleeve, so that the adjustment of injection dosage is realized, and therefore, all preparation work before injection is completed; the surface of the injection part of the human body is disinfected, the end of the injection hole of the drug storage cylinder is pressed against the injection part, the trigger is pulled continuously, the dragging fin block matched with the dragging mechanism moves backwards and downwards along the driving wheel to be separated from the dragging mechanism, the hammer body in the loading state loses the resistance provided by the dragging fin block and is driven by the pulling force of the two elastic ropes to move forwards rapidly, and the hammer body impacts the tail end of the push rod to enable the piston to move forwards instantly, so that one-time micro-injection is completed; the injection hole end of the medicine storage cylinder is continuously pressed against the injection position, the trigger is continuously pulled, the other dragging fin block is matched with the dragging mechanism, the ram component repeats the actions, therefore, the continuous pulling of the trigger can lead the medical needleless injector to rapidly carry out multiple micro-injections until the rear end of the push rod is completely ejected out of the bore, and at the moment, the hammer body can not continuously impact the tail end of the push rod, thus finishing the medicine injection with the preset dosage.

Furthermore, in the medical needleless injector, the upper side wall of the gun chamber is provided with an axially extending guide groove, the upper side of the hammer body is provided with a guide rib in sliding fit with the slide groove, and the hammer body can only axially move in the gun chamber and cannot relatively rotate through the cooperation of the guide groove and the guide rib.

Further, in the medical needleless injector, the gun frame is made of a composite material, the gun barrel, the neck tube and the screw head are integrally molded and made of a metal material, and the lower side of the gun barrel is perforated so that the gun chamber is communicated with the driving cavity on the lower side.

Furthermore, in the medical needleless injector, the front end of the hammer body and the tail end of the push rod are respectively provided with an impact part, and the impact parts are made of high-strength and high-hardness materials.

Furthermore, in the medical needleless injector, the push type alarm adopts a split design, namely the push type alarm consists of a trigger switch and an alarm main body which are connected through a lead, the trigger switch is fixed at the rear side of the gun bore, and the alarm main body is arranged inside the handle of the gun body.

Further, in the medical needleless injector, the reverse check mechanism is composed of a ratchet wheel and a pawl; the ratchet wheel is positioned on one side of the driving wheel, the ratchet wheel and the driving wheel are coaxial and relatively fixed, and the ratchet wheel and the driving wheel are designed integrally; the pawl is supported by a rotating shaft fixed relative to the gun body; the ratchet wheel can only rotate in the positive direction under the matching of the pawl, so that the driving wheel fixed relative to the ratchet wheel can only rotate in the positive direction.

Furthermore, in the medical needleless injector, the driving cavity is internally provided with a guide frame which is relatively fixed with the gun rack, the guide frame is positioned between the driving wheel and the driven wheel, and the upper end surface of the guide frame is respectively parallel to and closely attached to the inner wall of the upper side of the transmission belt.

Furthermore, the one-way transmission mechanism consists of a ratchet mechanism and a set of planetary reduction mechanism; the ratchet mechanism is arranged between the main shaft and the trigger, so that the main shaft is driven to rotate when the trigger swings backwards only; the planetary reduction mechanism is composed of an inner gear ring, three planet gears, a central gear and a planet carrier, the inner gear ring is arranged on one side of a driving wheel, the driving wheel is supported by a main shaft and can rotate relatively, the central gear is fixed on the main shaft, and the planet carrier and a gun body are relatively fixed to enable gear shafts of the three planet gears to be constant in position; the main shaft, the driving wheel, the inner gear ring and the central gear are coaxial.

Further, in the medical needleless injector, the transmission belt adopts a synchronous gear belt, and the driving wheel and the driven wheel adopt corresponding gears;

or the transmission belt adopts a chain, and the driving wheel and the driven wheel adopt corresponding chain wheels;

or the transmission belt adopts a triangular belt, and the driving wheel and the driven wheel adopt corresponding groove-shaped belt wheels.

Furthermore, in the medical needleless injector, the dragging fin block is composed of an integrally formed fin seat and a fin part, the fin seat and the fin part are perpendicular to each other, the fin part is positioned on one side of the fin seat, and the fin seat is fixed on the transmission belt and can provide support for the fin part.

Furthermore, in the medical needleless injector, the diameter of the driving wheel is larger than that of the driven wheel, so that the track of the transmission belt tends to be triangular, and the front part is smaller and the rear part is larger.

Compared with the prior art, the invention has the following beneficial effects: the medical needleless injector adopts reasonable and scientific structural design, is convenient to hold and beneficial to the force application of hands, so that the medical needleless injector can achieve the work of an energy storage state, namely a loading state, and is particularly easy and labor-saving, the operation can be finished by one hand without an additional device, and the operation is flexible and convenient; the medical needleless injector can be operated very conveniently to achieve the energy storage state, and the circular dragging component which is used for providing power for achieving the loading state can work circularly, so that the medical needleless injector can be used for carrying out continuous injection for many times quickly, the preset large-dose medicine injection can be realized conveniently and quickly through the accumulation of multiple micro-injections, the defect that the conventional needleless injector can only be used for small-dose medicine injection is overcome, and the application range of the needleless injector in the field of clinical injection is expanded. The structure is reasonable, the implementation is easy, the manufacturing cost is low, and the popularization of the medical needleless injector is facilitated.

Drawings

Fig. 1 is an external view of the medical needleless injector.

Fig. 2 is a second external view of the medical needleless injector.

Fig. 3 is a schematic view of the internal structure of the medical needleless injector.

Fig. 4 is an exploded view of a medical needle-free injector.

Fig. 5 is a schematic structural view of a gun rest.

Fig. 6 is a schematic structural view of a barrel.

Fig. 7 is a schematic structural view of the hammer body and the elastic rope.

FIG. 8 is a schematic view of the hammer and barrel assembly.

Fig. 9 is a second schematic view of the hammer and the barrel.

FIG. 10 is a schematic view of the cyclical drag assembly and trigger assembly.

FIG. 11 is a second schematic view of the structure of the cyclical drawing assembly and the trigger assembly.

FIG. 12 is a schematic view of the combination of the hammer block and the endless drag assembly.

Fig. 13 is a second schematic view of the combination of the hammer and the endless drag assembly.

Fig. 14 is a schematic view of the combination of the final injection assembly and the gun body.

FIG. 15 is a diagram of the end injection assembly engaged with the ram at a nominal maximum drug storage capacity.

FIG. 16 is a view showing the engagement of the hammer with the end injection assembly after completion of the injection of the medication.

FIG. 17 is a view of the engagement of the final injection assembly with the ram with the shot dose set to the maximum rating.

Fig. 18 is a schematic structural view of the medical needleless injector after a second trigger switch is added.

Fig. 19 is a schematic structural view of a hammer body after further modification.

FIG. 20 is a schematic view of the trigger assembly engaging the drive wheel.

FIG. 21 is an exploded view of the trigger assembly and the driving wheel.

FIG. 22 is a second exploded view of the trigger assembly and the driver.

FIG. 23 is a schematic view of the structure of the trigger and the main shaft driven by the ratchet mechanism.

Fig. 24 is a schematic view of a further modified end injection assembly.

In the figure, 1, a medicine storage cylinder, 2, a thread sleeve, 3, a position mark, 4, a viewing window, 5, a gun barrel, 6, a handle, 7, a trigger, 8, a gun rack, 9, a neck tube, 10, a scale, 11, a thread head, 12, an injection hole, 13, a driving cavity, 14, a gun bore, 15, a side cavity, 16, a hammer body, 17, an elastic rope, 18, a dragging fin block, 19, a driving wheel, 20, a trigger switch, 21, a one-way transmission mechanism, 22, a pressing alarm, 23, a main shaft, 24, a transmission belt, 25, a driven wheel, 26, a shaft seat, 27, a push rod, 28, a reset mechanism, 29, a guide rib, 30, a dragging mechanism, 31, a guide groove, 32, a guide frame, 33, a pawl, 34, a fin part, 35, a fin seat, 36, a ratchet wheel, 37, a piston, 38, a guide bolt, 39, a striking part, 40, a second trigger switch, 41, a spring, 42, a pin seat, 43, a top pin, sun gear, 45, planet carrier, 46, planet wheel, 47, internal gear, 48, ratchet mechanism, 49, ratchet, 50, pawl, 51, dose scale.

Detailed Description

Referring to fig. 1-4, the invention discloses a medical needleless injector, which mainly comprises a gun body, a ram assembly, a circulating dragging assembly, a trigger assembly and a terminal injection assembly.

As shown in fig. 1-6 and 9, the gun body is composed of a gun frame 8 and a gun barrel 5 which are fixedly connected; a cylindrical bore 14 is arranged in the barrel 5, two sides of the bore 14 are respectively provided with a side cavity 15 communicated with the bore, the front end of the barrel 5 is fixed with a threaded head 11 through a neck tube 9, the side wall of the neck tube 9 is provided with an observation window 4 with scales 10, the inner cavity of the neck tube 9, the inner cavity of the threaded head 11 and the bore 14 are coaxial, and the inner diameter of the neck tube 9 is smaller than that of the bore 14; the tail end of the gun rack 8 is provided with a downward extending handle 6, and the gun rack 8 is internally provided with a driving cavity 13 which is positioned at the lower side of the gun chamber 14 and communicated with the gun chamber 14; the gun body is used as a framework of the medical needleless injector and is used for providing working operation space and necessary support for other components.

Referring to fig. 3, 4, 7, 8 and 9, the ram assembly comprises a ram 16, an elastic rope 17 and a pressing alarm 22; the hammer body 16 is positioned in the gun chamber 14 and can only move axially, because the inner diameter of the neck tube 9 is smaller than that of the gun chamber 14, the front end of the hammer body 16 cannot enter the neck tube 9, and the lower side of the hammer body 16 is provided with a towing mechanism 30; two elastic ropes 17 are arranged and are respectively positioned in the cavities 15 at the two sides, one end of each elastic rope 17 is connected with the hammer body 16, and the other end of each elastic rope 17 is connected with the gun body; the push type alarm 22 comprises a trigger switch 20 for controlling the operation thereof, and the trigger switch 20 is arranged at the rear side of the gun chamber 14; when the rear end of the hammer body 16 abuts against the trigger switch 20, the pressing type alarm 22 gives out a warning, the two elastic ropes 17 are in a stretching state, and the hammer assembly is in a loading state; after being excited, the hammer body 16 rapidly moves forwards to generate impact force on the front side part; the ram assembly is used to absorb external forces to achieve a "charged state" for the medical needleless injector so as to provide the end injection assembly with the pressure required for injection. When the medical needleless injector works, the hammer body 16 generates larger impact force to the front part, so the hammer body 16 is made of a material with higher density to improve the kinetic energy after the hammer body is excited; the two elastic ropes 17 are used for providing forward moving power for the hammer body 16, so that the hammer body has good tensile property and is made of high-elasticity high-quality rubber. The push type alarm 22 is a conventional device, which is generally provided with a trigger switch 20, when the trigger switch 20 is pressed by external pressure, the push type alarm 22 is triggered, and the alarm form of the push type alarm 22 can be sound alarm, light alarm or acousto-optic alarm, which aims to make a user clearly understand that the hammer assembly reaches a loading state at the moment, and injection can be performed by subsequent operation, so that the operation is cautious and injection errors are avoided; the two elastic ropes 17 are positioned in the two side cavities 15, aiming to make the bore 14 as an exclusive space for the movement of the hammer body 16, and the two elastic ropes 17 are mainly stretched in the respective spaces, thereby avoiding the interference of the elastic ropes 17 on the forward movement of the hammer body 16.

As shown in fig. 3, 4 and 10-13, the endless dragging assembly includes a transmission belt 24, the transmission belt 24 is supported by the driving wheel 19 and the driven wheel 25 arranged in front and behind and is located in the driving chamber 13, and the upper side of the transmission belt 24 is parallel to the axis of the hammer 16; the driving wheel 19 is matched with a reverse non-return mechanism and can only rotate in the forward direction, so that the upper side of the conveying belt 24 can only be conveyed from the forward direction to the backward direction but not in the reverse direction; two spaced dragging fin blocks 18 are mounted on the conveyor belt 24, when the dragging fin blocks 18 move from front to back along with the conveyor belt 24, the dragging fin blocks 18 are matched with the dragging mechanism 30 to drive the hammer body 16 to move backwards, when the dragging fin blocks 18 move right above the driving wheel 19, the hammer assembly reaches a loading state, and when the dragging fin blocks 18 move downwards at the driving wheel 19, the dragging fin blocks 18 are separated from the dragging mechanism 30 to enable the hammer body 16 to be excited. Therefore, the circulating dragging assembly can be sequentially and circularly matched with the two dragging fin blocks 18 and the towing mechanism 30 through the circulating transmission in the single direction of the transmission belt 24, the hammer body 16 is dragged to move backwards to the upper chamber state, then the dragging fin blocks 18 are separated from the towing mechanism 30, the hammer body 16 is excited, namely the transmission belt 24 runs for one circle, and the hammer assembly completes the loading and excitation actions twice in succession. The circulating dragging component is used for providing power required for realizing a charging state for the hammer component on one hand, and is used as a control switch for exciting the hammer component on the other hand. In the operation of the circulating dragging component, the power for the operation of the transmission belt 24 is provided by the driving wheel 19, the rotation reverse direction of the driving wheel 19 is defined as the forward direction when the transmission belt 24 is transmitted backwards from the upper side, and when the driving wheel 19 is driven by external force to rotate forward, the reverse check mechanism can not prevent the driving wheel 19 from rotating; when the external force driving the driving wheel 19 to rotate in the forward direction disappears, if the two elastic ropes 17 are in a stretching state, the tensile force of the elastic ropes 17 indirectly acts on the driving wheel 19, so that the driving wheel 19 generates a reverse trend, and at the moment, the reverse check mechanism prevents the driving wheel 19 from rotating in the reverse direction, so that the circular dragging assembly is locked to maintain the existing state.

Referring to fig. 3, 4 and 10-13, the trigger assembly comprises a trigger 7 and a one-way transmission mechanism 21, wherein the trigger 7 is positioned at the front side of the handle 6 and can swing back and forth along a main shaft 23, two ends of the main shaft 23 are limited by two shaft seats 26 fixed in the gun body, and the lower end of the trigger 7 driven by a reset mechanism 28 can be automatically reset forwards; the one-way transmission mechanism 21 is arranged between the trigger 7 and the driving wheel 19, when the trigger 7 swings backwards, the driving wheel 19 is driven to rotate forwards through the one-way transmission mechanism 21, and on the contrary, when the trigger 7 automatically resets and swings forwards, the driving wheel 19 cannot be indirectly driven. It can be seen that the reciprocating swing of the trigger 7 drives the driving wheel 19 to rotate forward intermittently through the one-way transmission mechanism 21, so as to realize the unidirectional circulation transmission of the transmission belt 24. The aforesaid trigger 7 is driven by canceling release mechanical system 28 and can reset forward automatically, and this canceling release mechanical system 28 is more common, for prior art, for example adopt the V-arrangement shell fragment, as shown in fig. 10, 12, the one end and the trigger 7 fixed connection of V-arrangement shell fragment, and the other end is then fixed with the rifle body, and the technical purpose that the lower extreme of trigger 7 can reset forward automatically can be realized through the elasticity of self to the V-arrangement shell fragment.

Referring to fig. 1, 3 and 14, the terminal injection assembly includes a drug storage cartridge 1 and a piston 37 which are in sliding seal fit, an injection hole 12 is formed in the front end of the drug storage cartridge 1, a thread sleeve 2 which is matched with a thread head 11 is formed in the rear end of the drug storage cartridge 1, a cavity in the front side of the piston 37 in the drug storage cartridge 1 is used for prestoring a liquid medicine, a push rod 27 is connected to the rear side of the piston 37, and a position mark 3 is formed on the push rod 27; after the threaded sleeve 2 and the threaded head 11 are combined, the rear end of the push rod 27 penetrates through the threaded head 11 and the neck tube 9 to enter the gun bore 14 and can be impacted by the front end of the hammer body 16, the length of the push rod 27 extending into the gun bore 14 can be adjusted by rotating the threaded sleeve 2, and the length value of the push rod 27 extending into the gun bore 14 can be judged through the observation window 4 and the position mark 3, namely the injection dosage is determined; the injection of the predetermined dose of medication is completed when the ram 16 fully exits the bore 14 by one or more impacts against the rear end of the ram 27.

Referring to fig. 1, 3, 4, 12, 13 and 14, the operating principle of the medical needleless injector is as follows: when the dragging fin block 18 moves along with the transmission belt 24 above the driven wheel 25 and the driving wheel 19 and moves backwards from front to back, the dragging fin block 18 is gradually abutted and matched with the dragging mechanism 30 to drive the hammer body 16 to move backwards by overcoming the pulling force of the two elastic ropes 17, when the dragging fin block 18 moves to the position right above the driving wheel 19, the hammer body 16 is already positioned at the rear part of the gun bore 14, the pressing type alarm 22 gives a warning, and an operator can clearly know that the hammer assembly reaches the loading state; the threaded sleeve 2 is combined with the threaded head 11, so that a terminal injection assembly pre-stored with liquid medicine is combined with a gun body, the length of the tail end of the push rod 27 extending into the gun bore 14 is judged through the scales 10 on the observation window 4 and the position marks 3 on the push rod 27, the length value of the push rod 27 extending into the gun bore 14 is adjusted by rotating the threaded sleeve 2, and then the adjustment of injection dosage is realized, so that all preparation work before injection is completed; the surface sterilization treatment is carried out on the injection part of the human body, the end of the injection hole 12 of the medicine storage cylinder 1 is pushed to the injection part, the trigger 7 is continuously pulled, the dragging fin block 18 matched with the dragging mechanism 30 moves backwards and downwards along the driving wheel 19 to be separated from the dragging mechanism 30, the hammer body 16 in the loading state loses the resistance provided by the dragging fin block 18 and then is driven by the pulling force of the two elastic ropes 17 to move forwards rapidly, the front end of the hammer body 16 impacts the rear end of the push rod 27 to enable the piston 37 to move forwards instantly, and thus, the micro-injection is completed; the end of the injection hole 12 of the drug storage cylinder 1 is continuously pressed against the injection position, the trigger 7 is continuously pulled, the other dragging fin block 18 is matched with the dragging mechanism 30, the hammer component repeats the actions, therefore, the medical needleless injector can rapidly carry out multiple micro injections by continuously pulling the trigger 7 until the rear end of the push rod 27 is completely ejected out of the gun bore 14, at the moment, the hammer body 16 cannot continuously impact the tail end of the push rod 27, and the injection of the drug with the preset dosage is finished.

Compared with the prior needleless injector, the structure design adopted by the invention is more scientific and reasonable, the invention is not only convenient to hold, but also is beneficial to the force application of hands, so that the medical needleless injector can achieve the work of an energy storage state, namely a loading state, and is particularly easy and labor-saving, the operation can be completed by one hand without the help of an additional device, and the operation is flexible and convenient; the circulating dragging assembly which provides power for the hammer assembly to achieve the loading state can work circularly, and meanwhile, the circulating dragging assembly has the function of controlling the hammer assembly to be excited, so that the medical needle-free injector can achieve the energy storage state and control the excitation to be very convenient and fast, multiple times of continuous injection can be rapidly carried out, the preset large-dose medicine injection can be conveniently and rapidly realized through multiple times of micro-injection accumulation, the defect that the conventional needle-free injector can only be used for small-dose medicine injection is overcome, and the application range of the needle-free injector in the field of clinical injection is expanded. In addition, the structure is simple, the implementation is easy, the utilization rate of parts is high, the manufacturing cost is low, and the device has great significance for popularization of the medical needleless injector.

In clinical application, the medical needleless injector can prepare the terminal injection assembly for disposable use or repeated recycling use according to the requirement. When the terminal injection assembly is disposable, the liquid medicine can be directly pre-stored in the terminal injection assembly, the injection hole 12 is plugged, and the terminal injection assembly is wholly circulated in the market as the package of the liquid medicine; if the terminal injection assembly is used repeatedly, the injection hole 12 is connected to an external conduit in consideration of the medicine taking operation of the terminal injection assembly, and the medicine taking operation can be realized by pulling the push rod 27 backwards to drive the piston 37 to move backwards.

Referring to fig. 7, 8 and 9, in the medical needleless injector, the hammer 16 is easily positioned in the bore 14 and can only move axially, an axially extending guide slot 31 is formed in the upper side wall of the bore 14, and the upper side of the hammer 16 is provided with a guide rib 29 in sliding fit with the slide slot, so that the hammer 16 can only move axially in the bore 14 without relative rotation through the cooperation of the guide slot 31 and the guide rib 29.

Referring to fig. 3, 4, 5 and 6, in the medical needleless injector, considering that the neck 9, the threaded head 11 and the bore 14 are subjected to a large force during the operation of the medical needleless injector, the barrel 5 needs to have a large strength, and the frame 8 needs to be subjected to a small force relatively, and it is unreasonable to form the frame from the same material, and therefore, in the present invention, the frame 8 is made of a composite material, the barrel 5, the neck 9 and the threaded head 11 are integrally formed and made of a metal material, and the lower side of the barrel 5 is perforated to communicate the bore 14 with the lower driving chamber 13, so that the circulating drag assembly can drive the hammer 16 to move backward in the bore 14. Therefore, the medical needleless injector is guaranteed to have enough strength and can work stably for a long time, and the weight of the medical needleless injector is reduced to the maximum extent, so that the medical needleless injector is light, convenient and fast; meanwhile, the gun body adopts a split structure of the gun barrel 5 and the gun frame 8, which is beneficial to production and manufacture and reduces material cost.

Referring to fig. 17, 19 and 24, in the clinical application of the medical needle-free injector, the end injection assembly needs to provide a large pressure for the liquid medicine to achieve the purpose of needle-free injection, that is, the front end of the hammer 16 and the rear end of the push rod 27 are required to have a violent impact, in order to ensure that the front end of the hammer 16 and the rear end of the push rod 27 can stably maintain a good impact effect for a long time, the front end of the hammer 16 and the rear end of the push rod 27 are respectively provided with an impact portion 39, the impact portion 39 has a high hardness to ensure that the impact is instantly completed, the influence of the elasticity of the material on energy transmission during the impact process is reduced, and the impact portion 39 has a high strength to improve the impact resistance and prolong the service life, so that the impact portion 39 is made of a high-strength and high-hardness material.

Referring to fig. 3 and 4, in the medical needleless injector, the pressing type alarm 22 warns an operator when the hammer assembly reaches the loading state, which is triggered by the position of the rear end of the hammer 16, such pressing type alarm 22 is common in the prior art, for example, the pressing type alarm 22 is controlled by a trigger switch 20 to operate, when the hammer 16 moves backwards in the barrel 14 until the rear end of the hammer 16 abuts against the trigger switch 20, the pressing type alarm 22 warns, and when the hammer 16 is activated to move forwards, the trigger switch 20 automatically resets to stop the pressing type alarm 22 from warning. However, in order to make the internal structure of the medical needleless injector more compact and the external shape thereof smaller, the push type alarm 22 is preferably designed in a split type, that is, the push type alarm 22 is composed of a trigger switch 20 and an alarm main body which are connected by a lead, the trigger switch 20 is fixed at the rear side of the bore 14, and the alarm main body is arranged inside the grip 6 of the gun body.

Referring to fig. 3, 12 and 13, in the medical needleless injector, the driving wheel 19 is engaged with a reverse check mechanism to rotate only in the forward direction, so that the upper side of the transmission belt 24 can be transmitted only in the forward and backward directions and can not be transmitted in the reverse direction, which is explained in detail in the foregoing description, and the technical purpose can be easily achieved in the prior art, for example, the following design can be adopted:

referring to fig. 11 and 12, the reverse check mechanism is composed of a ratchet wheel 36 and a pawl 33; the ratchet wheel 36 is positioned on one side of the driving wheel 19, the ratchet wheel 36 and the driving wheel 19 are coaxial and relatively fixed, and in order to ensure the strength and reduce the manufacturing cost, the ratchet wheel 36 and the driving wheel 19 are integrally designed; the pawl 33 is supported by a rotating shaft fixed relative to the gun body; the ratchet wheel 36 can only rotate in the positive direction under the coordination of the pawl 33, so that the driving wheel 19 fixed relative to the ratchet wheel 36 can only rotate in the positive direction, and the technical purpose that the upper side of the transmission belt 24 can only be transmitted from the front to the back is realized.

Further, in the medical needle-less injector, in order to ensure stable and safe operation of the medical needle-less injector, the gun body, the ram assembly and the terminal injection assembly should have the following relationships:

① As shown in fig. 15, when the medicine in the terminal injection assembly is in the rated maximum storage capacity, the thread bush 2 and the thread head 11 can be combined and connected without the tail end of the push rod 27 extending into the bore 14, and the terminal injection assembly and the gun body can be firmly combined, thereby ensuring that the terminal injection assembly can be combined with the gun body in the rated maximum storage capacity, and can arbitrarily adjust the injection dosage, and simultaneously, the terminal injection assembly can be combined with the gun body when the ram assembly is not in the loading state, and the portability of the medical needleless injector is improved.

② As shown in fig. 16, when the thread sleeve 2 is rotated to the nearest distance from the thread head 11 and the piston 37 is located at the foremost end of the medicine storage tube 1, the tail end of the push rod 27 is located at the very critical position of the bore 14 and the inner cavity of the neck tube 9, even if the hammer assembly continues to work, the hammer 16 cannot impact the tail end of the push rod 27, thereby ensuring that the medicine in the medicine storage tube 1 can be completely injected when the medical needle-free injector works, and ensuring that the impact force generated by the hammer assembly does not hurt the terminal injection assembly even if the hammer assembly continues to work after the medicine in the medicine storage tube 1 is completely injected.

③ As shown in FIG. 17, when the front end of the hammer 16 abuts against the front end of the barrel 14, the two elastic cords 17 are in a non-stretching state, so as to ensure that the elastic cords 17 will not generate a pulling force to prevent the hammer 16 from moving forward after each time the hammer 16 is excited, thereby increasing the kinetic energy of the hammer 16 before the collision to the maximum, and when the injection module at the adjusting terminal sets the injection dose to the maximum rated value, i.e. the length of the tail end of the push rod 27 extending into the barrel 14 reaches the maximum, if the front end of the hammer 16 contacts the tail end of the push rod 27, the two elastic cords 17 are in a non-stretching state, thereby ensuring that the push rod 27 will not generate a thrust after each time the hammer 16 is excited to collide with the push rod 27, ensuring that the collision between the hammer 16 and the push rod 27 is instantly completed, and preventing the liquid medicine from leaking from the injection hole 12 after the collision is completed.

Further, referring to fig. 1 and 16, when the medical needleless injector is used in clinical practice, during the injection process, when the sum of the multiple micro injections reaches the preset injection dosage, the tail end of the push rod 27 has completely exited from the bore 14, even if the trigger 7 is continuously pulled to continue the operation of the hammer assembly, the medicine injection cannot be performed any more, the operation is safer, and the injection dosage is more accurate. However, in practical operation, it is only necessary to observe the corresponding relationship between the position mark 3 and the scale 10 at the observation window 4 to determine whether the tail end of the push rod 27 completely exits the bore 14, if the observation is not timely, redundant operation is still performed after the injection of the medicine reaches the preset injection dose, which is useless, and is not beneficial for the patient by the operator, and whether the injection of the medicine reaches the preset injection dose is determined by visual observation, which may cause a certain error and affect the accuracy of the injection dose, therefore, the invention has the following improvements:

as shown in fig. 18, the pressing type alarm 22 is connected with a second trigger switch 40 through a lead, the second trigger switch 40 is installed at the front side of the bore 14, when the front end of the hammer 16 abuts against the front end surface of the bore 14, the second trigger switch 40 is pressed by the front end of the hammer 16 to prompt the pressing type alarm 22 to send out an alarm, therefore, when the medical needle-free injector works, after the front end of the hammer 16 abuts against the front end surface of the bore 14, the rear end of the push rod 27 is completely pushed out of the bore 14, that is, the injection of the preset dosage of the medicine is completed, at this time, the pressing type alarm 22 sends out an alarm to prompt the operator that unnecessary operations are not needed, when the operator definitely finishes the injection, the operator only needs to pull the trigger 7 again to slightly move the hammer 16 backwards to be separated from the second trigger switch 40, and the pressing type alarm 22 stops working.

Further, referring to fig. 3, 12 and 13, in the medical needle-less injector, a pulling mechanism 30 is provided on the lower side of the hammer 16, the hitch mechanism 30 is adapted to cooperate with the skeg 18 to move rearwardly with the skeg 18. for this purpose, the hitch mechanism 30 may be a projection extending downwardly from the underside of the hammer block 16, however, this design has certain disadvantages, such as, on the one hand, if the projection extends downward shorter, the stability of the trailing fin block 18 in cooperation therewith is poor and the hammer block 16 is prone to "misfire", on the other hand if the lug is extended downwardly longer, it is imperative that the hammer block 16 be spaced a greater distance from the upper side of the conveyor 24, increasing the shear force of the drag fin block 18 against the conveyor 24, meanwhile, the overall size of the medical needleless injector is not reduced, so that the following design can be adopted for the towing mechanism 30 in the invention:

as shown in fig. 7 and 8, the towing mechanism 30 is a towing groove, the towing groove is formed on the lower side surface of the hammer body 16, the front end of the towing groove extends to the front end surface of the hammer body 16, and the rear end of the towing groove does not extend to the rear end of the hammer body 16, so that the towing groove has a vertical rear end surface; the dragging fin block 18 can move backwards along the groove cavity of the dragging groove, and the dragging fin block 18 can drive the hammer body 16 to move along with the dragging groove after moving backwards and abutting against the rear end face of the dragging groove.

Further, referring to fig. 10-13, in the medical needleless injector, the stable transmission of the transmission belt 24 is a necessary factor for ensuring the stable operation of the medical needleless injector, the transmission belt 24 is stressed greatly in the process of driving the hammer assembly to achieve the loading state, the stable transmission can be achieved by increasing the strength of the transmission belt 24 and improving the supporting force provided by the driving wheel 19 and the driven wheel 25, but the implementation difficulty is high, and the transmission belt 24 is easy to be stressed excessively to be separated from the expected operation track, therefore, the invention has the following improvements:

namely, the driving cavity 13 is internally provided with a guide frame 32 which is fixed relative to the gun rack 8, the guide frame 32 is positioned between the driving wheel 19 and the driven wheel 25, and the upper end surface of the guide frame is respectively parallel to and closely attached to the inner wall of the upper side of the conveying belt 24, so that the upper side of the conveying belt 24 can still keep the backward conveying in the preset direction after being subjected to the resistance exerted by the dragging fin block 18, and meanwhile, the guide frame 32 is arranged in the driving cavity 13, so that the strength of the gun rack 8 is greatly improved; the guide frame 32 may be integrally formed with the gun rack 8, or may be separately formed and then fixedly connected to the gun rack 8 by means of screws or adhesion.

Further, referring to fig. 3, 10 and 13, in the medical needleless injector, when the dragging fin block 18 moves to a position right above the driving wheel 19, the ram assembly just reaches the loading state, and at this time, the dragging fin block 18 and the dragging mechanism 30 can be ensured to keep a stable abutting state, so that the ram assembly can stably maintain the loading state; when the trigger 7 is pulled continuously to continue the transmission of the transmission belt 24, the dragging fin block 18 engaged with the dragging mechanism 30 moves along the rear profile of the driving wheel 19 along with the transmission belt 24, and gradually disengages from the dragging mechanism 30, so that the hammer body 16 is excited. In the above process, it can be found that, during the process of disengaging the dragging fin block 18 from the dragging mechanism 30, the dragging fin block 18 has a horizontal backward displacement component to drive the hammer body 16 to move backward, generally speaking, the trigger 20 of the conventional pressing type alarm 22 has a certain amount of expansion and contraction, but the amount of expansion and contraction is small, which is difficult to satisfy the stroke of backward movement of the hammer body 16 during the activation process, if a specially-made pressing type alarm 22 is required, the manufacturing cost of the medical needleless injector is obviously increased, and therefore, the invention has the following improvements to the hammer body 16:

as shown in fig. 19, a pin seat 42 is provided at the rear end of the hammer 16, a knock pin 43 extending backwards is provided in the pin seat 42, a spring 41 is provided at the front side of the knock pin 43 to make the hammer 16 and the knock pin 43 elastic and telescopic as a whole, and the hammer 16 and the knock pin 43 are coaxial; the push switch of the push type alarm 22 is positioned right behind the ejector pin 43; when the ram assembly is loaded, the rear end of the knock pin 43 just abuts against the push switch to alert the push type alarm 22, and the spring 41 is always in an incompletely compressed state before the drag fin block 18 is disengaged from the drag mechanism 30.

Further, when the medical needleless injector is used in clinical practice, in the process of implementing the loading state of the hammer assembly, the hammer body 16 moves backwards to overcome the pulling force of the two elastic ropes 17, which makes the circulating dragging assembly provide larger driving force, and especially, the stable and unidirectional transmission of the transmission belt 24 is the fundamental key, so the circulating dragging assembly further has the following technical characteristics:

the transmission belt 24 adopts a synchronous gear belt, and the driving wheel 19 and the driven wheel adopt corresponding gears;

or the transmission belt 24 adopts a chain, and the driving wheel 19 and the driven wheel adopt corresponding chain wheels;

or the transmission belt 24 adopts a triangular belt, and the driving wheel 19 and the driven wheel adopt corresponding groove-shaped belt wheels;

as shown in fig. 10 and 11, the towing fin block 18 is composed of a fin base 35 and a fin portion 34, which are integrally formed, and the fin base 35 and the fin portion 34 are perpendicular to each other, and the fin portion 34 is located on one side of the fin base 35, and the fin base 35 is fixed on the conveyor belt 24 and can provide support for the fin portion 34; since the fin block 18 is required to move along with the belt 24 when the drag assembly is in operation, and the belt 24 is required to be bent during operation, the length of the fin base 35 in the transmission direction of the belt 24 is designed according to the diameters of the driving wheel 19 and the driven wheel, so as to ensure that the fin block 18 can still stably and safely move along with the belt 24 when passing through the driving wheel 19 and the driven wheel.

Further, as shown in fig. 3 and 4, the medical needleless injector needs to be held by hand for a series of operations in clinical use, which is significant for the characteristic of convenient holding, the gun body and the trigger assembly adopt a gun-shaped structure, and in order to enable the circular dragging assembly to be matched with the gun-shaped structure, the driving wheel 19 has a larger diameter than the driven wheel 25, so that the track of the transmission belt 24 tends to be triangular, the front part is smaller, the rear part is larger, and the medical needleless injector is more convenient for being held by hand.

Further, referring to fig. 3 and 10-13, in the medical needleless injector, the one-way transmission mechanism 21 is disposed between the trigger 7 and the driving wheel 19, when the trigger 7 swings backwards, the driving wheel 19 is driven to rotate forward through the one-way transmission mechanism 21, it can be seen that the one-way transmission mechanism 21, on one hand, converts the forward and backward swinging of the trigger 7 into a single-direction rotation, and, on the other hand, performs a shoulder power transmission function to finally drive the driving wheel 19 to rotate forward, based on the above technical objects, the one-way transmission mechanism 21 can be realized by using a conventional ratchet mechanism and a transmission member, the ratchet mechanism only absorbs a driving force generated when the trigger 7 swings backwards, so that the ratchet only rotates when the trigger 7 swings backwards, and then the ratchet indirectly drives the driving wheel 19 to rotate forward after the transmission member performs transmission and torque direction adjustment, the driving part can adopt a chain mechanism, the working principle of the chain mechanism is similar to that of a bicycle driving mode, and meanwhile, the driving part can also adopt a gear mechanism commonly used in the mechanical field. However, considering that the above-mentioned structure of the one-way transmission mechanism 21 may make the internal structure of the medical needleless injector not compact enough and the volume thereof not small enough, the present invention provides the following improvements to the one-way transmission mechanism 21:

as shown in fig. 20-23, the one-way transmission mechanism 21 is composed of a ratchet mechanism 48 and a set of planetary reduction gears; the ratchet mechanism 48 is arranged between the main shaft 23 and the trigger 7, as shown in fig. 23, a ratchet 49 is arranged on the side wall of the main shaft 23, a pawl 50 is arranged at the shaft hole of the trigger 7, and the pawl 50 is matched with the ratchet 49, so that the main shaft 23 is driven to rotate when the trigger 7 swings backwards only; the planetary reduction mechanism is composed of an inner gear ring 47, three planet gears 46, a central gear 44 and a planet carrier 45, the inner gear ring 47 is fixed on one side of the driving wheel 19, the driving wheel 19 is supported by the main shaft 23 and can rotate relatively, the central gear 44 is fixed on the main shaft 23, and the planet carrier 45 is fixed relatively to the gun body so that the positions of gear shafts of the three planet gears 46 are constant; the main shaft 23, the driving wheel 19, the inner gear ring 47 and the central gear 44 are coaxial. Therefore, when the trigger 7 swings backwards, the central gear 44 is driven to rotate, the central gear 44 drives the inner gear ring 47 to rotate through the planet wheel 46, and finally the driving wheel 19 rotates forwards.

Further, referring to fig. 3 and 4, in the medical needleless injector, the front end of the push rod 27 is fixedly connected with the piston 37, and the rear end of the push rod 27 extends into the bore 14 to different degrees according to the requirement of the injection dosage, so that the push rod 27 needs to have a longer length, because the length of the push rod 27 is longer and the force is larger in the working process of the medical needleless injector, in order to avoid the influence on the accuracy of the injection dosage caused by the bending of the push rod 27, the push rod 27 can be considered to be made of a high-strength material, but the requirement of the push rod 27 on the manufacturing material is increased, and the manufacturing cost of the medical needleless injector is increased, so that the medical needleless injector has further improvements on the push rod 27:

as shown in fig. 14 and 24, the push rod 27 is provided with a guide bolt 38 integrated therewith, the two are coaxial, and the guide bolt 38 has a larger diameter than the push rod 27, when the final injection assembly is combined with the gun body, the guide bolt 38 is located in the neck tube 9, and the guide bolt 38 cooperates with the inner cavity of the neck tube 9 to provide a guide for the axial movement of the push rod 27; meanwhile, the position mark 3 is arranged on the outer wall of the guide bolt 38, so that the corresponding relation between the position mark 3 and the scale 10 at the observation window 4 can be more conveniently observed, and convenience is provided for presetting the injection dosage.

Further, referring to fig. 24, in the above-mentioned medical needleless injector, the drug cartridge 1 is made of transparent material, the outer wall is marked with the dosage scale 51, and the total amount of the drug in the drug cartridge 1 can be determined by observing the relative position of the piston 37 and the dosage scale 51.

Claims

1. A medical needleless injector comprises a terminal injection assembly, wherein the terminal injection assembly comprises a medicine storage cylinder and a piston which are in sliding seal fit, an injection hole is formed in the front end of the medicine storage cylinder, and a push rod is connected to the rear side of the piston; it is characterized by also comprising:

the trigger assembly comprises a trigger and a one-way transmission mechanism, the trigger is positioned on the front side of the grip and swings back and forth along the main shaft, two ends of the main shaft are limited by two shaft seats fixed in the gun body, and the lower end of the trigger can be automatically reset forwards under the driving of the reset mechanism; the one-way transmission mechanism is arranged between the trigger and the driving wheel, and the driving wheel is driven to rotate positively through the one-way transmission mechanism when the trigger swings backwards;

in the terminal injection assembly, the rear end of the medicine storage cylinder is provided with a thread sleeve matched with the thread head, and the push rod is provided with a position mark; after the threaded sleeve and the threaded head are combined, the rear end of the push rod penetrates through the threaded head and the neck tube to enter the gun bore and can be impacted by the hammer body, the length of the push rod extending into the gun bore can be adjusted by rotating the threaded sleeve, and the length value of the push rod extending into the gun bore can be judged through scales and position marks on the observation window, namely the injection dosage is determined;

the one-way transmission mechanism consists of a ratchet mechanism and a set of planetary reduction mechanism; the ratchet mechanism is arranged between the main shaft and the trigger, so that the main shaft is driven to rotate when the trigger swings backwards only; the planetary reduction mechanism is composed of an inner gear ring, three planet gears, a central gear and a planet carrier, the inner gear ring is arranged on one side of a driving wheel, the driving wheel is supported by a main shaft and can rotate relatively, the central gear is fixed on the main shaft, and the planet carrier and a gun body are relatively fixed to enable gear shafts of the three planet gears to be constant in position; the main shaft, the driving wheel, the inner gear ring and the central gear are coaxial.

2. The medical needle-free injector according to claim 1, wherein:

the transmission belt adopts a synchronous gear belt, and the driving wheel and the driven wheel adopt corresponding gears;

3. The medical needle-free injector according to claim 1, wherein: the dragging fin block is composed of a fin seat and a fin part which are integrally formed, the fin seat and the fin part are vertical, the fin part is positioned on one side of the fin seat, and the fin seat is fixed on the transmission belt and can provide support for the fin part; the push type alarm adopts a split type design, namely the push type alarm consists of a trigger switch and an alarm main body which are connected through a lead, the trigger switch is fixed at the rear side of the gun bore, and the alarm main body is arranged inside a handle of the gun body.

4. The medical needle-free injector according to claim 1, wherein: the upper side wall of the gun chamber is provided with an axially extending guide groove, the upper side of the hammer body is provided with a guide rib in sliding fit with the slide groove, and the hammer body can only axially move in the gun chamber and cannot relatively rotate through the matching of the guide groove and the guide rib.

5. The medical needle-free injector according to claim 1, wherein: the gun rack is made of composite materials, the gun barrel, the neck tube and the threaded head are integrally molded and made of metal materials, and the lower side of the gun barrel is processed through a hole to enable the gun chamber to be communicated with the driving cavity of the lower side.

6. The medical needle-free injector according to claim 1, wherein: the front end of the hammer body and the tail end of the push rod are respectively provided with an impact part, and the impact parts are made of high-strength and high-hardness materials.

7. The medical needle-free injector according to claim 1, wherein: the reverse non-return mechanism consists of a ratchet wheel and a pawl; the ratchet wheel is positioned on one side of the driving wheel, the ratchet wheel and the driving wheel are coaxial and relatively fixed, and the ratchet wheel and the driving wheel are designed integrally; the pawl is supported by a rotating shaft fixed relative to the gun body; the ratchet wheel can only rotate in the positive direction under the matching of the pawl, so that the driving wheel fixed relative to the ratchet wheel can only rotate in the positive direction.

8. The medical needle-free injector according to claim 1, wherein: the driving cavity is internally provided with a guide frame which is relatively fixed with the gun rack, the guide frame is positioned between the driving wheel and the driven wheel, and the upper end surface of the guide frame is respectively parallel to and closely attached to the inner wall of the upper side of the transmission belt.