CN109966591B - Large-dose needleless injector capable of automatically taking medicine - Google Patents

Abstract

The invention relates to medical equipment, and discloses a large-dose needleless injector capable of automatically taking medicine, which consists of a gun body, a ram component, a circulating dragging component, a trigger component, a terminal injection component, a medicine taking locking component, a medicine taking amount setting component and a catheter component, wherein the gun body is provided with a plurality of nozzles; the purpose of large-dose injection of the medicine can be realized through the accumulation of multiple times of micro-injections, and the defect that the conventional needleless injector can only be used for small-dose injection of the medicine is overcome; the automatic medicine taking device is integrated with an automatic medicine taking function, medicine taking can be easily realized by virtue of the medicine taking locking assembly, the medicine taking quantity setting assembly and the catheter assembly, the medicine taking quantity can be flexibly preset, the operation is simple and easy, the trouble and labor are saved, and the efficiency is higher; the device reduces the purchase cost of a user, is favorable for improving the portability of the needleless injector, and provides great convenience for the user.

Description

Large-dose needleless injector capable of automatically taking medicine

The invention is a divisional application of an invention patent application with application number 201710064022.8, which is filed on 04.02.2017.

Technical Field

The invention relates to a medical instrument, in particular to a large-dose needleless injector which is used for injecting large doses of medicines and can take the medicines automatically.

Background

Needleless injection is a novel injection technology which can achieve the purpose of medicine injection without needle puncture, has the advantages of reducing pain and fear of medicine injection, reducing the risk of bacterial infection, avoiding accidents such as needle scratch and breakage, being fast in medicine absorption, being not hardened under the skin after long-term use, being high in injection efficiency and the like, and further has wide application prospect in future clinical medical treatment. However, the pre-preparation operation before each injection of the conventional needleless injector is complicated, time-consuming and labor-consuming, and continuous injection cannot be performed quickly, so that the injection dosage becomes a short plate of the conventional needleless injector, and the conventional needleless injector can only be used for clinical injection of small dosage of 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 reason hinders the wide-range application of the needleless injector in the field of clinical injection. The invention patent with application number 2016109677793 discloses a needle-free injector, which comprises a gun body, a ram component, a circular dragging component, a trigger component and a terminal injection component, wherein the circular dragging component can be driven to circularly run by the trigger component, and the ram component can be driven to rapidly and repeatedly complete the 'loading' and 'excitation' actions in the circular running process of the circular dragging component, so that the terminal injection component can rapidly realize multiple microinjection, and the large-dose injection of medicines can be realized by the accumulation of multiple microinjection.

In the needleless injector disclosed in the patent application No. 2016109677793, the terminal injection assembly for storing and releasing the medicine is an important component of the needleless injector, and it is necessary to take the medicine from the terminal injection assembly before the use of the needleless injector; seen from the structure of the terminal injection assembly, the medicine taking mode of the traditional needleless injector is adopted, namely after the terminal injection assembly is taken down, the push rod is pulled backwards manually to drive the piston to move backwards, so that negative pressure is generated at the injection hole, and the medicine taking is realized without difficulty in theory. Generally speaking, in order to achieve a better injection effect, the injection holes of the existing terminal injection assembly are mostly designed in a micro-hole mode (micron order), the medicine flows into the medicine storage cylinder slowly, negative pressure required by medicine taking is large, and when the medicine is taken in a traditional manual mode, operation is time-consuming and labor-consuming, efficiency is low, and great inconvenience is caused; in the process of taking medicine, the push rod is often pulled backwards by violent force in order to improve the medicine taking efficiency, so that the connection between the push rod and the piston and the sealing performance between the piston and the medicine storage cylinder are easily damaged, and the working stability and the service life of the terminal injection assembly are reduced; in addition, since the needle-free injector disclosed in the above patent is characterized by large-dose injection of medicine, the capacity of the medicine storage cartridge and the pre-stored amount of medicine are both larger than before, and the inconvenience in the manual medicine taking process is more prominent. In summary, the needleless injector cannot autonomously complete the medicine taking operation, and there is a great inconvenience in manually taking the medicine from the terminal injection assembly, and in order to achieve efficient and rapid medicine taking while ensuring the structural stability of the terminal injection assembly, a matched medicine taking auxiliary device is required, and the medicine taking auxiliary device which can better achieve the above effects in cooperation with the matched medicine taking auxiliary device does not appear in the prior art.

Further, even if a medication dispensing aid capable of cooperating with a terminal injection assembly is available and overcomes the aforementioned deficiencies in manual medication dispensing operations, there are still a number of drawbacks in clinical applications: on one hand, in the medicine taking operation, the terminal injection assembly needs to be taken down from the needle-free injector body and then assembled on the medicine taking auxiliary device, so that the flow is complicated, the operation is inconvenient, and the medicine taking efficiency is influenced; on the other hand, when the needleless injector is purchased, a medicine taking auxiliary device matched with the needleless injector needs to be purchased additionally, so that the purchase cost is increased, and a certain economic burden is brought to a user; in addition, for example, a patient with diabetes and the like is often required to carry with a needleless injector after being equipped with the needleless injector, so that the needleless injector has great significance in portability, and if the needleless injector can be normally used only by being equipped with an additional medicine taking auxiliary tool, the portability is greatly reduced.

Disclosure of Invention

The invention aims to provide a needleless injector which is simple, convenient and quick to operate, can inject large-dose medicines, and can quickly, conveniently and quickly finish the medicine taking operation without other medicine taking auxiliary devices.

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

an autonomously deliverable bolus needleless 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, a threaded head is fixed at the front end of the barrel through a neck tube, an observation window marked with injection dosage scales is arranged on the side wall of the neck tube, and the bore, the neck tube and the threaded head are coaxial;

the hammer component consists of a hammer body, an elastic rope and a pressing type alarm; the hammer body is limited in the gun bore and can only axially move, the front end of the hammer body is provided with a hammer head with a smaller diameter than the hammer head, the front end of the hammer head is provided with a blind hole-shaped impact seat, the side wall of the front end of the impact seat is provided with a locking hole, and the lower side of the hammer body is provided with a towing mechanism; the hammer body, the hammer head and the impact seat are coaxial with the gun bore; the two elastic ropes and the press type alarm are arranged in the gun body, when the hammer body moves backwards to the loading state, the press type alarm gives an alarm, and the two elastic ropes are in a stretching state; after the hammer body is excited, the hammer body is driven by the two elastic ropes to move forwards quickly, and the impact seat impacts the front part;

the circulating dragging assembly is arranged in the gun body and can only circularly operate in a single direction, and in the circulating operation process, the circulating dragging assembly can drive the ram assembly to reciprocate to reach a loading state and then be excited, so that the ram assembly is circulated to sequentially impact the front side part;

the trigger assembly is supported by the gun body, takes artificial external force as input and can drive the circulating dragging assembly to circularly operate in a single direction;

a terminal injection assembly including a drive rod and a cartridge and piston in sliding sealing engagement; the front end of the medicine storage cylinder is provided with an injection hole, and the rear end is provided with a threaded sleeve; the driving rod can be stretched and can automatically retract to the shortest initial length, the front end of the driving rod is fixedly connected with the piston, the rear end of the driving rod is provided with a striking part with a diameter larger than that of the driving rod, and the retraction force of the driving rod in the stretching state is enough to drive the piston to move backwards in the medicine storage cylinder; a limiting bolt which has a constant distance with the piston and is larger than the outer diameter of the hammer head is arranged on the driving rod, and a position mark is arranged on the outer wall of the limiting bolt; when the terminal injection assembly is combined with the gun body, the driving rod, the impact part and the limiting bolt are all coaxial with the impact seat, and the limiting bolt and the impact part extend backwards through the neck tube; the impact part can extend into the impact seat and be impacted by the bottom of the impact seat, and then the piston is driven to move forward to realize injection; the corresponding relation between the position mark and the injection dose scale can reflect the axial position of the impact part, so that the preset injection dose is determined;

the medicine taking locking assembly comprises a first sliding groove formed in the barrel in the axial direction, a guide rail fixed outside the barrel and parallel to the first sliding groove, and a sliding block limited by the first sliding groove and the guide rail and only capable of moving back and forth, wherein a locking pin with an adjustable axial position is fixed on the sliding block; the inner end of the locking pin can extend into the impact seat through the locking hole to lock the impact part in the impact seat, so that the sliding block and the impact part can move backwards along with the hammer head; after the inner end of the locking pin is moved out of the gun bore, the locking pin does not form an obstacle to the operation of the ram assembly and the terminal injection assembly;

the medicine taking quantity setting assembly comprises a second sliding chute arranged on the gun barrel along the axial direction, a screw rod fixed outside the gun barrel and parallel to the second sliding chute, an adjusting nut matched with the screw rod, and a sliding arm which is driven by the adjusting nut and can only move back and forth along the second sliding chute; the inner end of the sliding arm is fixedly connected with an arc-shaped stop block positioned in the gun bore, and the arc-shaped stop block is coaxial with the hammer head; the inner diameter of the arc-shaped stop block is larger than the outer diameter of the hammer head, and the side wall of the hammer body is provided with a yielding groove for preventing the arc-shaped stop block from moving back and forth, so that the arc-shaped stop block and the hammer component cannot form a running obstacle; the inner diameter of the arc-shaped stop block is smaller than the outer diameter of the limiting bolt, and the limiting bolt cannot move backwards continuously after being abutted against the limiting bolt; one side of the second sliding chute is provided with a dosage scale, and the corresponding relation between the adjusting nut and the dosage scale can reflect the axial position of the arc-shaped stop block;

the catheter component comprises a rubber cap, the bottom of the rubber cap is connected with the needle through a catheter, and the rubber cap can be sleeved at the front end of the drug storage cylinder in a sealing mode so that the injection hole is only communicated with the needle.

The working principle of the self-taking large-dose needleless injector during injection is as follows:

combining a terminal injection assembly stored with a medicament on a gun body, observing a numerical value corresponding to the position mark and the injection dose scale through an observation window, and adjusting in a mode of rotating the terminal injection assembly, thereby finishing presetting of the injection dose; the front end of the terminal injection assembly is abutted against the body surface of a patient, the trigger assembly is used for driving the circular dragging assembly to circularly run, the circular dragging assembly firstly drags the hammer body to move backwards, when the hammer assembly reaches a loading state, the pressing type alarm gives an alarm, an operator can clearly see that the hammer assembly is excited when the circular dragging assembly continuously runs, after the hammer assembly is excited, the hammer body is driven by the two elastic ropes to rapidly move forwards, finally, the bottom of the impact seat impacts the impact part, the piston is pushed to move forwards to enable the terminal injection assembly to complete one-time microinjection, the circular dragging assembly circularly works, the terminal injection assembly is enabled to rapidly carry out multiple-time microinjection, and the piston cannot be continuously driven to move forwards by the hammer assembly, so that the medicine injection with preset dosage is completed.

The working principle of the large-dose needleless injector capable of automatically taking medicine during taking medicine is as follows:

the terminal injection assembly is combined on the gun body, the position of the terminal injection assembly is adjusted by rotating the terminal injection assembly, the impact part at the tail end of the driving rod is ensured to extend into the impact seat and abut against the bottom of the impact seat, the position of the locking pin is adjusted, the inner end of the locking pin extends into the gun bore and is inserted into the locking hole to lock the impact part in the impact seat, and the impact part is fixedly connected with the impact seat; rotating the adjusting nut to adjust the corresponding relation between the adjusting nut and the dosage scale, namely presetting the dosage; the rubber cap in the conduit assembly is buckled at the front end of the medicament storage cylinder, the needle head is placed in a medicament container filled with medicament liquid, a medicament liquid conveying channel is established between the terminal injection assembly and the medicament container by the conduit assembly, the circulating dragging assembly is driven by the trigger assembly to run, the hammer body is dragged to move backwards by the circulating dragging assembly, simultaneously, the impact part and the slide block synchronously move backwards along with the hammer head, negative pressure is generated in the medicament storage cylinder at the moment, the medicament liquid in the medicament container enters the medicament storage cylinder through the conduit assembly, but because the negative pressure in the medicament storage cylinder can not be timely removed, the driving rod is stretched along with the backward movement of the impact part, the operation of the trigger assembly is stopped after the impact hammer assembly reaches a loading state, the impact part is locked at a constant position along with the hammer head at the moment, the driving rod applies stable and continuous traction force to the piston by the retraction force of the driving rod, and the medicament liquid in the medicament container smoothly, after the limiting bolt moves backwards to abut against the arc-shaped stop block, the piston cannot move backwards continuously, and the liquid medicine in the terminal injection assembly reaches the preset medicine taking amount at the moment; the locking pin is pulled outwards to release the locking between the impact part and the impact seat, the driving rod retracts to the initial length, the catheter component is detached, and the whole medicine taking operation is completed.

Further, the lateral wall of going up of bore opens and has an axial extension's guide way, and the upside of hammer block be equipped with spout sliding fit's direction muscle, on the one hand guide way and direction muscle cooperation, but make hammer block axial displacement and can not take place relative rotation in the bore, on the other hand, guide way and direction muscle cooperation are injectd the hammer block in the stroke of predetermineeing.

Further, the gun body, ram assembly and terminal injection assembly should have the following relationships:

when the medicine in the terminal injection assembly is in the rated maximum reserve volume and the hammer body is at the foremost end of the stroke, the thread sleeve and the thread head can be combined and connected under the condition that the impact part does not abut against the bottom of the impact seat, and the terminal injection assembly and the gun body are firmly combined;

and secondly, when the threaded sleeve rotates to reach the closest distance with the threaded head, the liquid medicine in the medicine storage cylinder is completely emptied, and the hammer body is positioned at the forefront end of the stroke, the impact part just abuts against the bottom of the impact seat.

Further, the ram assembly, the terminal injection assembly, the dose lock assembly, and the dose setting assembly should have the following relationships:

firstly, when the hammer body and the slide block in the medicine taking locking assembly are positioned at the foremost end of respective stroke, the central axes of the locking pin and the locking hole are superposed; if the locking pin is inserted into the locking hole, the slide block can move along with the hammer head until the hammer body reaches the rearmost stroke end;

secondly, when the hammer body and the adjusting nut are positioned at the foremost end of respective stroke and the impact part is locked in the impact seat, if the driving rod is at the initial length, the limiting bolt is abutted against the arc-shaped stop block; when the adjusting nut is positioned at the rearmost end of the travel, if the limiting bolt is abutted against the arc-shaped stop block, the amount of the medicament in the medicament storage barrel reaches the rated maximum storage amount;

and thirdly, when the impact part moves to the hammer assembly along with the hammer head to reach the loading state, the driving rod is always in a stretching state and is not in a fully stretching state.

Furthermore, the slider on open and to have a shaft hole, the shaft hole is crossing perpendicularly with striking seat center pin between them, the shaft hole is parallel with the center pin of locking hole two, but the fitting pin is supported and axial displacement by the shaft hole, the diameter of fitting pin is less than the internal diameter of locking hole, the outer end of fitting pin is equipped with the stalk portion.

Furthermore, a damping rubber ring A for applying resistance to the locking pin is fixed in the shaft hole, and the locking pin is matched with the damping rubber ring A and cannot automatically move axially.

Furthermore, the driving rod is composed of a front rod, a rear rod and an elastic piece, and the outer diameters of the front rod and the rear rod are equal; the front end of the front rod is fixedly connected with the piston, the rear end of the front rod is provided with a blind hole-shaped plugging cavity, and the middle rear part of the front rod is fixedly provided with a limit bolt which is superposed with the central shaft of the front rod and has a larger diameter than the central shaft; the rear end of the rear rod is connected with an impact part which is superposed with the central shaft of the rear rod and has a larger diameter than the central shaft of the rear rod, the front end of the rear rod is fixed with a core rod which is superposed with the central shaft of the rear rod, the core rod is inserted into the insertion cavity of the front rod and is in axial sliding fit with the insertion cavity of the front rod, and the front end of the core rod is backwards provided with a blind hole; the elastic piece adopts rubber rope or extension spring, and its front end and grafting chamber bottom fixed connection, rear end and accomodate chamber bottom fixed connection, and when the actuating lever was in initial length, when front-end lever and back pole supported, the elastic piece still was in tensile state.

Furthermore, the front end of the adjusting nut is fixed with a shaft seat coinciding with the central axis of the adjusting nut, the outer end of the sliding arm is provided with a shaft sleeve sleeved on the shaft seat, and the shaft sleeve and the shaft seat can rotate relatively but cannot move relatively in the axial direction.

Furthermore, the outer wall of the front end of the adjusting nut is provided with secondary scales distributed along the outer circle of the adjusting nut, the medicine taking quantity setting assembly is provided with a pointer which is fixed in position and matched with the secondary scales, the adjusting nut rotates for a circle along the screw rod, and the generated axial displacement is a scale unit of the medicine taking quantity scales.

Compared with the prior art, the invention has the following beneficial effects: the trigger assembly can drive the circulating dragging assembly to work in a one-way circulating mode, so that the ram assembly is driven to reciprocate to reach the loading state and then is excited, the terminal injection assembly can carry out multiple times of microinjection rapidly, the purpose of large-dose injection of medicines is realized through accumulation of multiple times of microinjection, the defect that the conventional needle-free injector can only be used for small-dose injection of medicines is overcome, the application range of the needle-free injector in the field of clinical injection is expanded, and the operation is convenient and rapid; the large-dose needleless injector capable of automatically taking the medicine integrates an automatic medicine taking function, the medicine can be taken after simple operation and setting, the medicine taking amount can be flexibly preset, the terminal injection assembly does not need to be taken down in the medicine taking process, manual interference is not needed in the process that the liquid medicine enters the terminal injection assembly and slowly flows into the terminal injection assembly, the operation is simple and easy, the trouble and the labor are saved, and the efficiency is higher; in the process of injection and medicine taking, the trigger assembly, the circular dragging assembly and the ram assembly provide power, so that the injection and medicine taking device is simple in structure, high in part utilization rate, low in overall cost and capable of reducing operation difficulty; because the piston is driven to move backwards mainly by the retraction force of the driving rod in the medicine taking process, the traction force applied to the piston is continuous, stable and gentle, and the structure and the performance of the terminal injection assembly cannot be damaged; because the large-dose needleless injector capable of automatically taking the medicine does not need to take the medicine by means of the auxiliary medicine taking device, the purchase cost of a user is reduced, the portability of the needleless injector is improved, and great convenience is provided for the user.

Drawings

Fig. 1 is a schematic view of the whole structure of the self-administration large-dose needleless injector.

Fig. 2 is a second schematic view of the whole structure of the self-administration large-dose needleless injector.

Fig. 3 is a partially broken-away schematic view of the self-administered high-dose needleless injector.

Fig. 4 is an exploded view of the barrel, ram assembly, terminal injection assembly, dispensing lock assembly and dispensing quantity setting assembly.

Fig. 5 is a schematic view of a barrel and a connecting member fixed thereto.

Fig. 6 is a second schematic view of the structure of the gun barrel and the connecting member fixed thereto.

FIG. 7 is a schematic view of the ram assembly.

Fig. 8 is a schematic view of the end injection assembly.

Fig. 9 is a schematic structural view of a slide block and a locking pin in the medicine taking locking assembly.

Fig. 10 is a schematic view of the screw, adjusting nut, sliding arm and arc-shaped stopper of the dose setting assembly.

FIG. 11 is a schematic view of a barrel, ram assembly, end injection assembly, dispensing lock assembly and dispensing quantity setting assembly in combination.

Fig. 12 is a second view of the barrel, ram assembly, end injection assembly, dispensing lock assembly and dispensing quantity setting assembly in combination.

Fig. 13 is a schematic structural diagram of the large-dose needleless injector capable of self-administration at the initial stage of administration.

Fig. 14 is a second schematic structural view of the self-administered large-dose needleless injector at the initial stage of drug delivery.

FIG. 15 is a schematic diagram of the engagement of the dispensing lock assembly, the terminal injection assembly and the ram assembly during dispensing.

Fig. 16 is a schematic structural view of the present self-administered high-dose needleless injector reaching a predetermined dose.

Fig. 17 is a schematic view of the structure of the drive rod.

Fig. 18 is a schematic structural diagram of the adjusting nut after secondary scales are added.

FIG. 19 is a further improved view of the drive rod

In the figures, 1, a gun barrel, 2, a medicine taking amount setting assembly, 3, a medicine taking locking assembly, 4, a neck tube, 5, a screw head, 6, a thread bushing, 7, a medicine storage barrel, 8, a rubber cap, 9, a conduit, 10, a needle head, 11, a gun rack, 12, a trigger assembly, 13, a viewing window, 14, an injection dose scale, 15, a pressing alarm, 16, a circulating dragging assembly, 17, a driving rod, 18, a striking part, 19, a sliding block, 20, a locking pin, 21, a first sliding chute, 22, a guide rail, 23, an elastic rope, 24, a striking seat, 25, a locking hole, 26, a hammer head, 27, a hammer body, 28, a yielding groove, 29, a guide rib, 30, a screw rod, 31, a second sliding chute, 32, an adjusting nut, 33, a sliding arm, 34, an arc-shaped stop, 35, a medicine taking amount scale, 36, a position mark, 37, a limit bolt, 38, a gun bore, 39, a piston, 40, a handle part, 41, a damping rubber ring A, 42. the device comprises a dragging mechanism, 43, a shaft seat, 44, a shaft sleeve, 45, a guide groove, 46, an inserting cavity, 47, a containing cavity, 48, a front rod, 49, an elastic piece, 50, a rear rod, 51, a core rod, 52, secondary scales, 53, a pointer, 54 and a damping rubber ring B.

Detailed Description

Referring to fig. 1-3, the present invention discloses an autonomous self-administered high-volume needleless injector, which comprises a gun body, a ram assembly, a cyclic drag assembly 16, a trigger assembly 12, a terminal injection assembly, a drug delivery locking assembly 3, a drug delivery setting assembly 2, and a catheter 9.

Referring to fig. 1, 4, 5 and 6, the gun body is composed of a gun rack 11 and a gun barrel 1 which are fixedly connected; a cylindrical bore 38 is arranged in the barrel 1, a threaded head 5 is fixed at the front end of the barrel 1 through a neck tube 4, an observation window 13 is formed in the side wall of the neck tube 4, an injection dosage scale 14 is marked on one side of the observation window 13, and the central axes of the bore 38, the neck tube 4 and the threaded head 5 are overlapped; the gun body is used for placing or supporting other components and has the characteristic of being convenient to hold by hands.

Referring to fig. 3, 4, 7, 11 and 13, the ram assembly comprises a ram body 27, an elastic rope 23 and a pressing alarm 15; the hammer body 27 is limited in the gun chamber 38 and can only move axially, the front end of the hammer body 27 is fixed with the hammer head 26, the outer diameter of the hammer head 26 is smaller than that of the hammer body 27, the front end of the hammer head 26 is provided with a blind hole-shaped impact seat 24, the front end of the impact seat 24 is provided with a locking hole 25 for penetrating through the side wall, the lower side of the hammer body 27 is provided with a towing mechanism 42, and the towing mechanism 42 is used for being matched with the circulating towing assembly 16; the central axes of the hammer body 27, the hammer head 26, the impact seat 24 and the gun chamber 38 are overlapped; the two elastic ropes 23 are used for providing driving force for the hammer 26 to reset forwards; the elastic ropes 23 and the pressing type alarm 15 are both arranged in the gun body, when the hammer body 27 moves backwards to the loading state, the pressing type alarm 15 gives an alarm, and the two elastic ropes 23 are in a stretching state and have elastic potential energy; when the hammer 27 is activated, it will be driven by the two elastic ropes 23 to move forward rapidly, and the impact seat 24 will impact the front part.

Referring to fig. 3, the circulating drag assembly 16 is disposed in the gun body and can only perform one-way circulation, during which the hammer 27 of the ram assembly is driven to move backwards in the gun bore 38 and then excited to circulate the ram assembly, thereby successively striking the front part and thus providing the final injection assembly with the power required for injection.

Referring to fig. 3, the trigger assembly 12 is supported by the gun body, and the trigger assembly can drive the circulating drag assembly 16 to circulate in one direction by taking an artificial external force as an input.

Referring to fig. 2, 3, 4, 8 and 11, the terminal injection assembly includes a drive rod 17, a cartridge 7 and a piston 39, the piston 39 is located in the cartridge 7 and is in sliding sealing engagement with the cartridge; the front end of the medicine storage barrel 7 is provided with an injection hole, the rear end is provided with a threaded sleeve 6, and the threaded sleeve 6 can be combined with the threaded head 5 to realize the combined connection of the terminal injection assembly and the gun body; the driving rod 17 can be stretched and can automatically retract to the shortest initial length, the driving rod 17 cannot be continuously shortened when in the initial length, the front end of the driving rod 17 is fixedly connected with the piston 39, the rear end of the driving rod 17 is fixedly provided with a striking part 18, the diameter of the striking part 18 is larger than that of the driving rod 17, and the retraction force of the driving rod 17 in the stretching state is enough to drive the piston 39 to move backwards in the medicine storage cylinder 7; a limit bolt 37 with a constant distance from the piston 39 is arranged on the driving rod 17, the limit bolt 37 and the impact part 18 still keep a distance when the driving rod 17 is at the initial length, the outer diameter of the limit bolt 37 is larger than that of the hammer 26, and the outer wall of the limit bolt 37 is provided with a position mark 36; after the terminal injection assembly is combined with the gun body, the central axes of the driving rod 17, the impact part 18, the limit bolt 37 and the impact seat 24 are superposed, and the limit bolt 37 and the impact part 18 extend backwards through the neck tube 4; the striking part 18 can extend into the striking seat 24 and be struck by the bottom of the striking seat 24, which in turn drives the piston 39 forward to perform injection; the correspondence between the position markings 36 and the injected dose scale 14 reflects the axial position of the strike 18 at the initial length of the drive rod 17, thereby specifying the preset injected dose.

Referring to fig. 3, 4, 5, 9, 11, 12, 13 and 15, the dispensing locking assembly 3 includes a first sliding slot 21, a guide rail 22 and a sliding block 19, the first sliding slot 21 extends axially on the barrel 1 and penetrates through a side wall of the barrel 1, the guide rail 22 is fixed outside the barrel 1 and is parallel to the first sliding slot 21, and the sliding block 19 is limited by the first sliding slot 21 and the guide rail 22 and can only move back and forth; a locking pin 20 with an adjustable axial position is fixed on the slide block 19; the inner end of the locking pin 20 can extend into the impact seat 24 through the locking hole 25 to lock the impact part 18 in the impact seat 24, so that the slide block 19 and the impact part 18 can move backwards along with the hammer 26; the locking pin 20 does not obstruct the operation of the ram assembly and the end injection assembly after the inner end thereof is removed from the bore 38.

As shown in fig. 4, 6, 10, 12, 13, and 15, the medicine taking amount setting assembly 2 includes a second sliding chute 31, a screw 30, an adjusting nut 32, and a sliding arm 33, the second sliding chute 31 extends axially on the barrel 1 and penetrates through a side wall of the barrel 1, the screw 30 is fixed outside the barrel 1 and is parallel to the second sliding chute 31, the adjusting nut 32 is in threaded engagement with the screw 30 to generate axial displacement through rotation, and the sliding arm 33 is driven by the adjusting nut 32 and can only move back and forth along the second sliding chute 31; the inner end of the sliding arm 33 passes through the second sliding chute 31 to enter the gun chamber 38 and is fixedly connected with an arc-shaped stop block 34 positioned in the gun chamber 38, and the arc-shaped stop block 34 is superposed with the central axes of the hammer head 26; the inner diameter of the arc-shaped stop block 34 is larger than the outer diameter of the hammer head 26, and the side wall of the hammer body 27 is provided with a yielding groove 28 for preventing the arc-shaped stop block 34 from moving back and forth, so that the arc-shaped stop block 34 and the hammer component cannot form a running obstacle; the inner diameter of the arc-shaped stop block 34 is smaller than the outer diameter of the limit bolt 37, and the limit bolt 37 cannot move backwards continuously after being abutted against the limit bolt, so that the arc-shaped stop block 34 can limit the terminal position of the limit bolt 37; the dosage scale 35 is arranged on one side of the second chute 31, and the corresponding relation between the adjusting nut 32 and the dosage scale 35 can reflect the axial position of the arc-shaped stop block 34, so that the dosage can be preset.

Referring to fig. 1 and 2, the catheter 9 assembly comprises a rubber cap 8, the bottom of the rubber cap 8 is connected with a needle 10 through a catheter 9, and the rubber cap 8 can be hermetically sleeved at the front end of the medicine storage barrel 7 so that an injection hole is only communicated with the needle 10.

As shown in fig. 1, 2 and 3, in the above-mentioned needle-less injector for large dosage capable of taking medicine autonomously, the specific structure of the gun rack 11 and the matching relationship with the gun barrel 1, the matching relationship among the hammer 27, the elastic cord 23 and the pressing type alarm 15, the matching relationship among the elastic cord 23, the pressing type alarm 15 and the gun body, the specific structure of the circulating drag assembly 16 and the trigger assembly 12, and the matching relationship among the circulating drag assembly 16, the trigger assembly 12, the hammer 27 and the gun body are described in detail in the needle-less injector disclosed in the patent application No. 2016109677793, which is regarded as the prior art and thus needs no further description.

Referring to fig. 2, 4, 8 and 11, in the above-mentioned needleless injector for self-administration of large doses, the hammer 27 is confined in the bore 38, so that the foremost position of the stroke of the hammer 27 is fixed, and when the hammer 27 reaches the foremost position of the stroke, it cannot move forward and cannot impact the striker 18, and thus the entire injection is completed, i.e. the end position of the striker 18 is definite and constant after each injection is completed; after the terminal injection assembly is combined with the gun body, before injection, the impact part 18 at the rear end of the driving rod 17 is not subjected to backward traction force, so that the driving rod 17 keeps the initial length, the impact part 18, the limit bolt 37 and the piston 39 keep relatively fixed, and the axial relative position of the impact part 18 and the gun barrel 1 at the initial injection can be reflected through the matching between the position mark 36 on the limit bolt 37 and the injection dosage scale 14 at the observation window 13, namely the initial point position of the impact part 18 before injection is determined; in this way, before injection, the displacement that can be generated by the striking part 18 in the next injection process, i.e. the displacement that can be generated by the piston 39, can be reflected by the matching of the position mark 36 and the injected dose scale 14, and based on the above relationship, the injected dose scale 14 is calculated and quantified, so that the value of the injected dose scale 14 corresponding to the preset position mark 36 is just the injected dose, which is easy to realize.

Referring to fig. 4, 8 and 16, in the above-mentioned self-administered large-dose needleless injector, before the administration operation, the hammer 27 is located at the foremost end of the stroke, and after the final injection assembly is combined with the gun body, the striking part 18 is connected with the striking seat 24 through the administration locking assembly 3, and at this time, the axial position of the striking part 18 is definite, and since the striking seat 24 is not yet pulled backward, the driving rod 17 is at the initial length, the axial position of the stop bolt 37 is also definite, that is, the starting point position of the stop bolt 37 is definite and constant in each administration operation; in the medicine taking amount setting assembly 2, the axial positions of the adjusting nut 32, the sliding arm 33 and the arc-shaped stop block 34 are relatively fixed all the time, the axial position of the arc-shaped stop block 34 can be reflected through the corresponding relation between the adjusting nut 32 and the medicine taking amount scale 35, and because the limiting bolt 37 gradually moves backwards along with the retraction of the driving rod 17 in the process of medicine taking operation, the limiting bolt cannot continuously move backwards after being abutted against the arc-shaped stop block 34, the whole medicine taking operation is completed, namely the end position of the limiting bolt 37 after the medicine taking is completed each time can be reflected through the corresponding relation between the adjusting nut 32 and the medicine taking amount scale 35; therefore, the corresponding relation between the adjusting nut 32 and the dosage scale 35 can reflect the displacement generated by the limit bolt 37 in the following dosage operation process, namely the displacement generated by the piston 39, and based on the relation, the dosage scale 35 is calculated and quantized when designed, so that the dosage obtained by the terminal injection assembly is just the numerical value of the dosage scale 35 corresponding to the adjusting nut 32 in the preset process is easy to realize.

Referring to fig. 4, 13 and 14, in the above-mentioned large-dose needleless injector capable of automatically taking medicine, the outer diameter of the hammer 27 is larger than that of the hammer head 26, which is intended to make the sliding fit between the hammer 27 and the barrel 38 easier to achieve on one hand, and to facilitate increasing the volume of the hammer 27 and indirectly increasing the mass thereof on the other hand, so as to ensure that the hammer 27 and the hammer head 26 are sufficient to drive the large-dose needleless injector capable of automatically taking medicine to complete each micro-injection through inertia.

The working principle of the self-taking large-dose needleless injector during injection is as follows:

referring to fig. 3, 4, 11 and 12, the terminal injection assembly storing the medicament is assembled on the gun body, the numerical value corresponding to the position mark 36 and the injection dose scale 14 is observed through the observation window 13, and is adjusted by rotating the terminal injection assembly, thereby completing the presetting of the injection dose; the front end of the terminal injection assembly is abutted against the body surface of a patient, the trigger assembly 12 is used for driving the circular dragging assembly 16 to circularly operate, the circular dragging assembly 16 firstly drags the hammer body 27 to move backwards, when the hammer assembly reaches a loading state, the press type alarm 15 gives an alarm, an operator is clear, when the circular dragging assembly 16 continuously operates, the hammer assembly is prompted to be excited, after the hammer assembly is prompted to be excited, the hammer body 27 is driven by the two elastic ropes 23 to rapidly move forwards, finally the bottom of the impact seat 24 impacts the impact part 18, the piston 39 is pushed to move forwards so that the terminal injection assembly completes one-time microinjection, the circular dragging assembly 16 circularly operates, the terminal injection assembly further rapidly performs multiple times of microinjection, until the hammer assembly cannot continuously drive the piston 39 to move forwards, and the injection of the medicine with the preset dosage is completed.

The working principle of the large-dose needleless injector capable of automatically taking medicine during taking medicine is as follows:

referring to fig. 2, 3, 11, 13, 14, 15 and 16, the terminal injection assembly is assembled on the gun body, and the position of the terminal injection assembly is adjusted by rotating the terminal injection assembly, so that the striking part 18 at the tail end of the driving rod 17 is ensured to extend into the striking seat 24 and abut against the bottom of the striking seat 24, the position of the locking pin 20 is adjusted, the inner end of the locking pin 20 extends into the gun bore 38 and is inserted into the locking hole 25 to lock the striking part 18 in the striking seat 24, and thus the striking part 18 is fixedly connected with the striking seat 24; rotating the adjusting nut 32 to drive the arc-shaped stop block 34 to axially displace, and finishing the presetting of the dosage by observing the corresponding relation between the adjusting nut 32 and the dosage scale 35; a rubber cap 8 in the conduit 9 assembly is buckled at the front end of the medicine storage cylinder 7, and the needle head 10 is placed in a medicine container filled with medicine liquid, so that the conduit 9 assembly establishes a medicine liquid conveying channel for the terminal injection assembly and the medicine container; the trigger assembly 12 is used for driving the circulating dragging assembly 16 to operate, the circulating dragging assembly 16 drags the hammer body 27 to move backwards, meanwhile, the impact part 18 and the slide block 19 synchronously move backwards along with the hammer head 26, negative pressure can be generated in the medicine storage cylinder 7 at the moment, medicine liquid in a medicine container enters the medicine storage cylinder 7 through the guide pipe 9 assembly, but the negative pressure in the medicine storage cylinder 7 cannot be timely removed, the driving rod 17 is stretched along with the backward movement of the impact part 18, the operation on the trigger assembly 12 is stopped after the hammer assembly reaches a loading state, the impact part 18 is locked at a constant position along with the hammer head 26 at the moment, the driving rod 17 applies stable and continuous traction on the piston 39 by the retracting force of the driving rod 17, the medicine liquid in the medicine container smoothly enters the medicine storage cylinder 7, and after the limit bolt 37 moves backwards to abut against the arc-shaped stop block 34, the piston 39 cannot continuously move backwards, at the moment, the liquid medicine in the terminal injection assembly reaches the preset medicine taking amount, the locking pin 20 is adjusted to unlock the impact part 18, the impact part 18 is separated from the impact seat 24, the driving rod 17 automatically retracts to the initial length, the guide pipe 9 assembly is detached, and the whole medicine taking operation is completed.

In the large-dose needleless injector capable of automatically taking medicine, the trigger assembly 12 can drive the circulating dragging assembly 16 to work in a one-way circulating mode, so that the ram assembly is driven to reciprocate to reach a loading state and then is excited, the terminal injection assembly can rapidly carry out multiple times of microinjection, and the purpose of large-dose injection of the medicine is realized through the accumulation of multiple times of microinjection.

In the large-dose needleless injector capable of automatically taking the medicine, the large-dose needleless injector has the function of automatically taking the medicine by additionally arranging the medicine taking locking component 3 and has the function of presetting the medicine taking quantity by additionally arranging the medicine taking quantity setting component 2, so that the medicine can be taken after being simply operated and set, the medicine taking quantity can be flexibly preset, the operation is convenient and rapid, and the trouble and the labor are saved; in the process of injection and medicine taking, the trigger assembly 12, the circular dragging assembly 16 and the ram assembly provide power, so that the utilization rate of parts is high, and the overall cost is low; in the process of taking medicine, the piston 39 is mainly driven by the retraction force of the driving rod 17, and the traction force applied to the piston 39 is continuous, stable and gentle, so that the structure and the performance of the terminal injection assembly cannot be damaged; because the operation of getting it filled need not to rely on extra auxiliary device of getting it filled, reduced the acquisition cost, improved needleless injector's portability.

Further, referring to fig. 4, 7, 11 and 13, in the present self-administered needleless injector for large doses, the hammer 27 is confined in the bore 38 and is movable only in the axial direction, and the technical feature is that there are various embodiments, such as a guide groove 45 extending in the axial direction is formed on the upper side wall of the bore 38, and a guide rib 29 slidably engaged with the slide groove is formed on the upper side of the hammer 27, on one hand, the guide groove 45 is engaged with the guide rib 29, so that the hammer 27 can move only in the axial direction in the bore 38 without relative rotation, and on the other hand, the guide groove 45 is engaged with the guide rib 29, so that the hammer 27 is confined in a predetermined stroke.

Further, referring to fig. 4, 8, 11 and 12, in order to ensure the safe and stable injection of the self-administered large-dose needleless injector, the gun body, the ram assembly and the final injection assembly should have the following relationships:

firstly, when the medicine in the terminal injection assembly is in the rated maximum storage capacity and the hammer body 27 is at the foremost end of the stroke, the thread sleeve 6 and the thread head 5 can be combined and connected under the condition that the impact part 18 does not abut against the bottom of the impact seat 24, and the terminal injection assembly is firmly combined with the gun body, so that the terminal injection assembly can be combined with the gun body under the rated maximum storage capacity, the injection dosage can be randomly adjusted, meanwhile, the terminal injection assembly can be combined with the gun body under the condition that the hammer assembly is not in the loading state, and the portability of the large-dosage needleless injector capable of automatically taking medicine is improved.

When the threaded sleeve 6 rotates to reach the nearest distance from the threaded head 5, the liquid medicine in the medicine storage cylinder 7 is completely emptied, and the hammer body 27 is positioned at the forefront end of the stroke, the impact part 18 just abuts against the bottom of the impact seat 24; even if the ram assembly continues to operate, the impact socket 24 cannot drive the impact portion 18 forward; therefore, on one hand, the large-dose needleless injector capable of automatically taking medicine can ensure that the medicine in the medicine storage cylinder 7 can be completely injected when the large-dose needleless injector works, and on the other hand, the impact force generated by the hammer assembly cannot injure the terminal injection assembly even if the hammer assembly continues to work after the medicine in the medicine storage cylinder 7 is completely injected.

Further, referring to fig. 4, 13, 14 and 16, in order to ensure efficient and convenient dispensing of the large-dose self-dispensing needleless injector, the ram assembly, the terminal injection assembly, the dispensing lock assembly 3 and the dispensing quantity setting assembly 2 have the following relationships:

firstly, when the hammer body 27 and the slide block 19 in the medicine taking locking assembly 3 are positioned at the foremost end of respective stroke, the central axes of the locking pin 20 and the locking hole 25 are overlapped, so that when medicine is taken, the inner end of the locking pin 20 can be quickly inserted into the locking hole 25, and the impact part 18 is locked in the impact seat 24; if the locking pin 20 is inserted into the locking hole 25, the slide 19 can move with the hammer 26 until the hammer 27 reaches the final end of its stroke.

Secondly, when the hammer body 27 and the adjusting nut 32 are positioned at the foremost end of the respective strokes and the impact part 18 is locked in the impact seat 24, if the driving rod 17 is in the initial length, the limit bolt 37 abuts against the arc-shaped stop block 34; when the adjusting nut 32 is located at the rearmost end of the stroke, if the limiting bolt 37 abuts against the arc-shaped stop block 34, the amount of the medicament in the medicament storage barrel 7 reaches the rated maximum storage amount; therefore, the medicine taking quantity setting assembly 2 can meet the presetting of any medicine taking quantity between zero and the rated maximum storage quantity of the medicine storage barrel 7, and can avoid the situation that the medicine quantity in the medicine storage barrel 7 exceeds the rated maximum storage quantity due to excessive backward movement of the piston 39.

And thirdly, after the impact part 18 moves backwards along with the hammer head 26 to the hammer assembly to reach the loading state, the driving rod 17 is always in a stretching and incomplete stretching state, so that the traction force provided by the driving rod 17 for the piston 39 can meet the power requirement of any dosage.

Further, referring to fig. 9, 13, 14 and 15, in the present needleless injector for bolus injection, the locking pin 20 is supported by the slider 19, the inner end of the locking pin 20 can extend into the striking seat 24 through the locking hole 25 to lock the striking part 18 in the striking seat 24, and the inner end of the locking pin 20 is removed from the bore 38, so that it does not form an obstacle to the operation of the hammer assembly and the terminal injection assembly; based on the technical purpose, the matching form of the locking pin 20 and the sliding block 19 has various structures, for example, a shaft hole can be formed on the sliding block 19, the shaft hole is vertically intersected with the central shafts of the striking seat 24, the shaft hole is parallel to the central shafts of the locking hole 25, the locking pin 20 is supported by the shaft hole and can axially move, the diameter of the locking pin 20 is smaller than the inner diameter of the locking hole 25, and the outer end of the locking pin 20 is provided with a handle portion 40, so that the technical purpose can be achieved.

Meanwhile, as shown in fig. 15, in the process of injecting and taking medicine, the locking pin 20 of the self-contained large-dose needleless injector must be adjusted to and maintained at the corresponding axial position to ensure the smooth operation of injecting and taking medicine, so the locking pin 20 should have a certain locking function, and after the position of the locking pin is manually adjusted, the locking pin can be maintained at the position and cannot automatically move, and therefore, a damping rubber ring a41 for applying resistance to the locking pin 20 is fixed in the shaft hole, and the locking pin 20 is matched with the damping rubber ring a41 and cannot automatically move axially.

Further, referring to fig. 4, 8 and 13, in the present self-administered high-dose needleless injector, the driving rod 17 has a dual function, and is an initial length that cannot be shortened further during the injection process, so that the impact force applied to the striking part 18 can be transmitted to the piston 39 to cause the end injection assembly to perform the injection; in the process of taking medicine, the ram assembly is stretched, the traction force generated by the ram assembly is stored as the potential energy of the ram assembly, and then the piston 39 is stably and smoothly pulled through the retraction force of the ram assembly in the stretching state, so that medicine taking is realized; for this technical purpose, the drive rod 17 is relatively easy to implement using the prior art. Meanwhile, the large-dose needleless injector capable of automatically taking medicine has other technical requirements on the driving rod 17, for example, the initial length of the driving rod 17 is not suitable to be too long, so that the structure of the large-dose needleless injector capable of automatically taking medicine is more compact; in the whole medicine taking process, the impact part 18 needs to move backwards along with the hammer 26 until the hammer component reaches a loading state, the displacement generated by the impact part 18 is large, and the driving rod 17 has a large telescopic range; in order to ensure that the traction force applied to the piston 39 by the driving rod 17 in the stretching state is smooth and stable, the retraction force of the driving rod 17 tends to be balanced; in order to achieve the above technical effects, in the present invention, the driving rod 17 adopts the following structure:

referring to fig. 8, 13, 14 and 17, the driving rod 17 is composed of a front rod 48, a rear rod 50 and an elastic member 49, and the outer diameters of the front rod 48 and the rear rod 50 are equal; the front end of the front rod 48 is fixedly connected with the piston 39, the rear end is provided with a blind hole-shaped inserting cavity 46, and the middle rear part is fixedly provided with a limit bolt 37 which is superposed with the central shaft and has a larger diameter than the central shaft; the rear end of the rear rod 50 is connected with a striking part 18 which is coincident with the central axis and has a larger diameter than the central axis, the front end is fixed with a core rod 51 which is coincident with the central axis, the core rod 51 is inserted into the insertion cavity 46 of the front rod 48 and is in axial sliding fit with the insertion cavity and the insertion cavity, and the front end of the core rod 51 is backwards provided with a blind hole-shaped containing cavity 47; the elastic member 49 is a rubber rope or a tension spring, the front end of the elastic member 49 is fixedly connected with the bottom of the inserting cavity 46, the rear end of the elastic member is fixedly connected with the bottom of the accommodating cavity 47, and when the driving rod 17 is at the initial length, that is, the front rod 48 abuts against the rear rod 50, the elastic member 49 is still in a stretching state. After the driving rod 17 adopts the above structure, the driving rod 17 can be stretched and can automatically retract to the initial length, and the initial length of the driving rod can not be too long, but the driving rod has a larger telescopic range, and meanwhile, because the elastic piece 49 is positioned in the inserting cavity 46 and the accommodating cavity 47, the elastic piece 49 is ensured to have a larger length, and the retraction force of the driving rod 17 in the stretching state is ensured to be balanced and stable.

Further, referring to fig. 10, 13 and 14, in the present needleless injector for large dose capable of self-sustained drug delivery, the adjusting nut 32 is in threaded engagement with the screw 30, and can generate axial displacement by rotating, so as to drive the sliding arm 33 to move back and forth along the second sliding slot 31, thereby indirectly achieving the purpose of adjusting the axial position of the arc-shaped stopper 34, the engagement structure between the adjusting nut 32 and the sliding arm 33 can be achieved by the prior art, for example, a shaft seat 43 coinciding with the central axis of the adjusting nut 32 is fixed at the front end of the adjusting nut 32, a sleeve 44 is provided at the outer end of the sliding arm 33, and the sleeve 44 and the shaft seat 43 can rotate relatively, but cannot move axially relatively.

Further, referring to fig. 13, 14 and 16, in the present autonomous large-dose needleless injector, a dose scale 35 is disposed on one side of the second chute 31, and the corresponding relationship between the adjusting nut 32 and the dose scale 35 can reflect the axial position of the arc-shaped stopper 34, so that the dose can be preset before the dose taking operation, and the mechanism on which this function is realized is discussed in detail in the foregoing. However, since the inner diameter of the drug storage cylinder 7 is larger, the smaller axial displacement of the piston 39 can cause the drug-taking amount to change greatly, so that if the drug-taking amount is preset only by the corresponding relationship between the adjusting nut 32 and the drug-taking scale 35, the precision is lower, and the error is larger, therefore, the invention also has the following improvements:

further, referring to fig. 18, the outer wall of the front end of the adjusting nut 32 is provided with a secondary scale 52 distributed along the outer circumference thereof, the dose setting assembly is provided with a pointer 53 fixed in position and used for matching with the secondary scale 52, for example, the pointer 52 can be marked on the shaft sleeve 44, the adjusting nut 32 rotates one circle along the screw 30, the generated axial displacement is a scale unit of the dose scale 35, therefore, before taking the dose, the dose can be roughly preset through the adjusting nut 32 and the dose scale 35, and then the dose can be finely preset by matching the secondary scale 52 with the pointer 53.

Further, referring to fig. 16, in the process of taking medicine, when the medicine liquid in the final injection assembly reaches the preset medicine taking amount, the position of the locking pin 20 is adjusted to release the locking of the striking part 18, since the driving rod 17 is still in the stretching state, if the rear rod 50 moves forward too fast in the retraction process, a certain impact is certainly generated on the front rod 48 to slightly move forward the piston 39, which may affect the accuracy of the final medicine taking amount of the final injection assembly on the one hand, and on the other hand, easily cause the medicine liquid to seep out from the injection hole to cause medicine waste, and in order to prevent the above situation, the structure of the driving rod 17 of the present invention is further improved as follows:

referring to fig. 19, a damping rubber ring B54 is fixed in the insertion cavity 46 of the front rod 48, and the damping rubber ring B54 can generate resistance to the axial movement of the core rod 51, so as to ensure that the rear rod 50 and the core rod 51 slowly move forward during the retraction of the driving rod 17, thereby reducing the impact on the front rod 48.

Claims (5)

1. A self-contained, high-volume needleless 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, a threaded head is fixed at the front end of the barrel through a neck tube, an observation window marked with injection dosage scales is arranged on the side wall of the neck tube, and the bore, the neck tube and the threaded head are coaxial;

the hammer component consists of a hammer body, an elastic rope and a pressing type alarm; the hammer body is limited in the gun bore and can only axially move, the front end of the hammer body is provided with a hammer head with a smaller diameter than the hammer head, the front end of the hammer head is provided with a blind hole-shaped impact seat, the side wall of the front end of the impact seat is provided with a locking hole, and the lower side of the hammer body is provided with a towing mechanism; the hammer body, the hammer head and the impact seat are coaxial with the gun bore; the two elastic ropes and the press type alarm are arranged in the gun body, when the hammer body moves backwards to the loading state, the press type alarm gives an alarm, and the two elastic ropes are in a stretching state; after the hammer body is excited, the hammer body is driven by the two elastic ropes to move forwards quickly, and the impact seat impacts the front part;

the circulating dragging assembly is arranged in the gun body and can only circularly operate in a single direction, and in the circulating operation process, the circulating dragging assembly can drive the ram assembly to reciprocate to reach a loading state and then be excited, so that the ram assembly is circulated to sequentially impact the front side part;

the trigger assembly is supported by the gun body, takes artificial external force as input and can drive the circulating dragging assembly to circularly operate in a single direction;

a terminal injection assembly including a drive rod and a cartridge and piston in sliding sealing engagement; the front end of the medicine storage cylinder is provided with an injection hole, and the rear end is provided with a threaded sleeve; the driving rod can be stretched and can automatically retract to the shortest initial length, the front end of the driving rod is fixedly connected with the piston, the rear end of the driving rod is provided with a striking part with a diameter larger than that of the driving rod, and the retraction force of the driving rod in the stretching state is enough to drive the piston to move backwards in the medicine storage cylinder; a limiting bolt which has a constant distance with the piston and is larger than the outer diameter of the hammer head is arranged on the driving rod, and a position mark is arranged on the outer wall of the limiting bolt; when the terminal injection assembly is combined with the gun body, the driving rod, the impact part and the limiting bolt are all coaxial with the impact seat, and the limiting bolt and the impact part extend backwards through the neck tube; the impact part can extend into the impact seat and be impacted by the bottom of the impact seat, and then the piston is driven to move forward to realize injection; the corresponding relation between the position mark and the injection dose scale can reflect the axial position of the impact part, so that the preset injection dose is determined;

the medicine taking locking assembly comprises a first sliding groove formed in the barrel in the axial direction, a guide rail fixed outside the barrel and parallel to the first sliding groove, and a sliding block limited by the first sliding groove and the guide rail and only capable of moving back and forth, wherein a locking pin with an adjustable axial position is fixed on the sliding block; the inner end of the locking pin can extend into the impact seat through the locking hole to lock the impact part in the impact seat, so that the sliding block and the impact part can move backwards along with the hammer head; after the inner end of the locking pin is moved out of the gun bore, the locking pin does not form an obstacle to the operation of the ram assembly and the terminal injection assembly;

the medicine taking quantity setting assembly comprises a second sliding chute arranged on the gun barrel along the axial direction, a screw rod fixed outside the gun barrel and parallel to the second sliding chute, an adjusting nut matched with the screw rod, and a sliding arm which is driven by the adjusting nut and can only move back and forth along the second sliding chute; the inner end of the sliding arm is fixedly connected with an arc-shaped stop block positioned in the gun bore, and the arc-shaped stop block is coaxial with the hammer head; the inner diameter of the arc-shaped stop block is larger than the outer diameter of the hammer head, and the side wall of the hammer body is provided with a yielding groove for preventing the arc-shaped stop block from moving back and forth, so that the arc-shaped stop block and the hammer component cannot form a running obstacle; the inner diameter of the arc-shaped stop block is smaller than the outer diameter of the limiting bolt, and the limiting bolt cannot move backwards continuously after being abutted against the limiting bolt; one side of the second sliding chute is provided with a dosage scale, and the corresponding relation between the adjusting nut and the dosage scale can reflect the axial position of the arc-shaped stop block; the outer wall of the front end of the adjusting nut is provided with secondary scales distributed along the outer circle of the adjusting nut, the dosage setting assembly is provided with a pointer which is fixed in position and is used for being matched with the secondary scales, the adjusting nut rotates for a circle along the screw rod, and the generated axial displacement is a scale unit of the dosage scales;

the catheter component comprises a rubber cap, the bottom of the rubber cap is connected with the needle through a catheter, and the rubber cap can be sleeved at the front end of the drug storage cylinder in a sealing mode so that the injection hole is only communicated with the needle.

2. An auto-deliverable bolus needleless injector as claimed in claim 1 wherein: the lateral wall of going up of bore opens the guide way that has an axial extension, and the upside of hammer block be equipped with spout sliding fit's direction muscle, but guide way and direction muscle cooperation on the one hand make the hammer block in the bore only axial displacement and can not take place relative rotation, on the other hand, guide way and direction muscle cooperation are injectd the hammer block in the stroke of predetermineeing.

3. An auto-deliverable bolus needleless injector as claimed in claim 1 wherein: the gun body, ram assembly and terminal injection assembly should have the following relationships:

a. when the medicine in the terminal injection assembly is in the rated maximum reserve and the hammer body is at the foremost end of the stroke of the hammer body, the thread sleeve and the thread head can be combined and connected under the condition that the impact part does not abut against the bottom of the impact seat, and the terminal injection assembly and the gun body are firmly combined;

b. when the thread sleeve rotates to reach the closest distance with the thread head, the liquid medicine in the medicine storage cylinder is completely emptied, and the hammer body is positioned at the foremost end of the stroke, the impact part just abuts against the bottom of the impact seat.

4. An auto-deliverable bolus needleless injector as claimed in claim 1 wherein: the ram assembly, the terminal injection assembly, the medicine taking locking assembly and the medicine taking quantity setting assembly are in the following relations:

a. when the hammer body and the slide block in the medicine taking locking assembly are positioned at the foremost end of respective stroke, the central axes of the locking pin and the locking hole are superposed; if the locking pin is inserted into the locking hole, the slide block can move along with the hammer head until the hammer body reaches the rearmost stroke end;

b. when the hammer body and the adjusting nut are positioned at the foremost end of respective stroke and the impact part is locked in the impact seat, if the driving rod is at the initial length, the limiting bolt is abutted against the arc-shaped stop block; when the adjusting nut is positioned at the rearmost end of the travel, if the limiting bolt is abutted against the arc-shaped stop block, the amount of the medicament in the medicament storage barrel reaches the rated maximum storage amount;

c. when the impact part moves to the hammer assembly along with the hammer head to reach the loading state, the driving rod is always in a stretching state and is not in a complete stretching state.

5. An auto-deliverable bolus needleless injector as claimed in claim 1 wherein: the front end of the adjusting nut is fixed with a shaft seat coincident with the central shaft thereof, the outer end of the sliding arm is provided with a shaft sleeve sleeved on the shaft seat, and the shaft sleeve and the shaft seat can rotate relatively but can not move relatively in the axial direction.

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