Pneumatic needleless injector

Abstract

The application discloses a kind of pneumatic needleless injectors.It includes needle cylinder assembly, gas source assembly, dose adjustment assembly, injection piston assembly, shell assembly, the rear end of injector housing is fixed with the magnet that can be magnetically attracted impact piece, rear end is equipped with the airflow passage that is connected with cylinder inner cavity, the dose of inhaled liquid is adjusted by dose adjustment mechanism, compressed gas is filled into needleless injector energy storage cavity by gas source assembly, when the air pressure in energy storage cavity reaches a certain value, injection piston assembly overcomes the attraction between magnets and impacts forward and completes injection process.The needleless injector of the application has simple structure, low manufacturing process requirement, easy operation, low cost, dose adjustment, wide application range, high injection efficiency and high reliability.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of medical devices, and particularly relates to a pneumatic needleless injector. BACKGROUND

[0002] Liquid needleless injection is a drug delivery method by which a high-speed jet flow of drug is generated by power and enters subcutaneous tissue. A standard needleless injector is usually composed of two parts: a shot chamber (ampoule) for aspirating and temporarily storing the drug, and a power device for generating the thrust. The power device is usually composed of a power source, a trigger, and a dose regulator. The power source is usually a spring, a voice coil motor, or compressed gas.

[0003] Needleless injection for animal epidemic prevention can produce many favorable effects: 1. Increased biological safety. Traditional needle injection is a method of injecting drugs into the subcutaneous tissue through a stainless steel needle. This injection method can easily cause damage, bleeding, swelling, and other conditions to the skin, and produce obvious pain, and even the risk of broken needles. Needleless injection eliminates such hidden dangers. 2. Injection efficiency is improved, injection time is short, and is suitable for large-scale injection; the safety of the operation is increased, and the risk of human infection with the virus is greatly reduced due to the stress reaction of the animal during injection. 3. Reduces medical waste disposal, purifies the environment, and reduces costs. Since the requirements for the injection system for large-scale animal immunization injection are not as strict as for human injection, the animal injector should be used multiple times, respond quickly, and be able to automatically aspirate the drug and continuously inject.

[0004] The existing pneumatic needleless injectors on the market have complex structures, high manufacturing and processing precision requirements, and high prices, which limits the popularization of needleless injectors. SUMMARY

[0005] In order to solve the problems in the background art, the purpose of the present application is to provide a pneumatic needleless injector with simple structure and good manufacturing process.

[0006] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0007] The present application comprises a needle cylinder assembly for introducing and containing medicine liquid, a gas source assembly for providing and delivering high pressure gas, a dose adjusting assembly for adjusting medicine liquid dose, an injection piston assembly for ejecting medicine liquid, a housing assembly for supporting various components, the injection piston assembly is installed inside the housing assembly, the dose adjusting assembly is installed on the side of the housing assembly, the dose adjusting assembly is connected to the injection piston assembly and drives the movement of the injection piston assembly in the housing assembly; the needle cylinder assembly is installed at the front end of the housing assembly, the gas source assembly is installed at the rear end of the housing assembly, the gas introduced by the gas source assembly drives the injection piston assembly to move and ejects the medicine liquid in the needle cylinder assembly.

[0008] The housing assembly comprises a syringe housing, a permanent magnet and an iron block; the injection piston assembly is installed in the piston cavity channel of the syringe housing, the permanent magnet is fixed to the rear end of the syringe housing by screws, and the iron block is fixed to the rear end of the injection piston assembly; the iron block and the permanent magnet are attracted to each other.

[0009] The injection piston assembly comprises an ampoule piston, a power plunger, a power plunger sealing ring, an ampoule piston sealing ring and a spring; the ampoule piston is installed at the front part of the piston cavity channel of the syringe housing of the housing assembly, the power plunger is installed at the rear part of the piston cavity channel of the syringe housing of the housing assembly, and the ampoule piston and the power plunger are connected by the spring; the outer peripheral surface of the front end of the ampoule piston is provided with the ampoule piston sealing ring for sealing with the inner wall of the piston cavity channel of the syringe housing, and the outer peripheral surface of the rear end of the power plunger is provided with the power plunger sealing ring for sealing with the inner wall of the piston cavity channel of the syringe housing.

[0010] The dose adjusting assembly comprises a gun trigger, a gun pull rod, a positioning cap, a positioning cap spring, a positioning sleeve, a pull rope handle block, a pull rope, a telescopic cap spring and a telescopic cap; the outer end of the gun pull rod is provided with the pull rope handle block, the outer end surface of the gun pull rod is provided with a stepped groove matched with the pull rope handle block, one end of the pull rope handle block and the pull rope are fixedly connected, the inner end of the gun pull rod is provided with a threaded hole, the gun pull rod is screwed into the threaded hole, the middle part of the gun pull rod is embedded in and can move along the strip-shaped through slot of the syringe housing, the middle part of the gun pull rod is provided with a through hole, two positioning caps are installed at both ends of the through hole, the positioning caps at both ends of the through hole are connected by the positioning cap spring, the gun pull rod at the through hole is provided with the positioning sleeve, the positioning sleeve is fixedly connected with the gun pull rod by screwing, the positioning sleeves at both ends of the through hole are provided with through holes with a smaller diameter than the positioning caps, so that the positioning caps are limited in the through hole and the end parts protrude from the through holes, and the positioning caps protruding from the through holes of the positioning sleeve are also embedded in the recesses, so that the gun pull rod is limited by the strip-shaped through slot; the other end of the gun pull rod is provided with the telescopic cap, the telescopic cap is connected with the end surface of the gun pull rod by the telescopic cap spring, and the other end of the pull rope passes through the channel in the gun pull rod and the gun trigger, and then passes through the telescopic cap spring and is fixedly connected to the telescopic cap.

[0011] The outer end face of the machine gun handle is provided with a concave counterbore groove, the rope handle block is supported on the step face of the counterbore groove or the outer end face of the machine gun handle, and then the distance between the telescopic cap and the other end of the bolt handle is adjusted by pulling the rope, and the telescopic cap is selectively and movably inserted into the mounting hole of the ampoule piston side.

[0012] The needle cylinder assembly comprises an ampoule nozzle, a rubber fixing ring and a water inlet valve cover; the rear end of the ampoule nozzle is connected to the front end of the syringe shell of the shell assembly, the ampoule nozzle is internally provided with an axial channel, the axial channel of the ampoule nozzle and the front end port of the piston cavity channel of the syringe shell of the shell assembly are coaxially communicated, the front end of the axial channel is provided with a first one-way valve structure allowing only rear-to-front conduction, the rubber fixing ring is installed at the outlet of the first one-way valve structure, the side of the axial channel is provided with an injection channel, the water inlet valve cover is installed at the injection channel, the injection channel is connected with the medicine storage assembly through the water inlet valve cover, and the second one-way valve structure allowing only conduction from the medicine storage assembly to the injection channel is installed in the water inlet valve cover.

[0013] The medicine storage assembly comprises a dosing support, a medicine bottle, a medicine bottle piston and a infusion tube, the medicine bottle is installed on the syringe shell of the shell assembly through the dosing support, the rear end of the medicine bottle is internally provided with the medicine bottle piston, and the outlet of the medicine bottle is communicated with the water inlet valve cover of the needle cylinder assembly through the infusion tube.

[0014] The air source assembly comprises a high-pressure gas cylinder, an air hose, an electromagnetic valve and a quick connector; the high-pressure gas cylinder is communicated with one end of the air hose through the electromagnetic valve, and the other end of the air hose is communicated with the rear end port of the piston cavity channel of the syringe shell of the shell assembly through the quick connector.

[0015] The rear end of the power plunger is provided with a blind hole, and the rear end face of the power plunger is fixedly provided with an iron block.

[0016] The shell assembly further comprises a silica gel buffer block, a limiting plate, a bolt return spring and a bolt return top block; the side of the ampoule piston is provided with a mounting hole for the telescopic cap of the dose adjusting assembly to be inserted; the side wall of the syringe shell outside the piston cavity channel is provided with a strip-shaped through groove; the groove walls on both sides of the strip-shaped through groove are provided with the limiting plates, the inner surfaces of the limiting plates are provided with concave pits for cooperating with the positioning cap of the dose adjusting assembly, each limiting plate is provided with a plurality of concave pits arranged at intervals along the direction of the strip-shaped through groove, and the limiting plates limit the degrees of freedom of the bolt handle and prevent the bolt handle from being separated from the syringe shell. The silica gel buffer block is fixedly installed at one end of the strip-shaped through groove of the syringe shell close to the needle cylinder assembly, the bolt return spring and the bolt return top block are installed at the other end of the strip-shaped through groove of the syringe shell close to the air source assembly, one end of the bolt return top block is crimped to the side of the bolt handle of the dose adjusting assembly, and the other end of the bolt return top block is connected to the groove end wall of the strip-shaped through groove close to the air source assembly through the bolt return spring.

[0017] The syringe housing below the groove has graduations on its outer surface.

[0018] The first one-way valve structure includes an outlet valve core spring, an outlet valve core sealing ring, an outlet valve core, a spray head, and a spray head sealing ring. A tapered hole and a stepped hole structure are sequentially arranged from the inside to the outside at the outlet of the piston chamber channel. The inner diameter of the stepped hole is larger than the inner diameter of the piston chamber channel. The inner diameter of the stepped hole and the inner diameter of the piston chamber channel are connected by the tapered hole. The outlet valve core is installed in the tapered hole, and the spray head is installed in the stepped hole. The spray head and the outlet valve core are connected by an outlet valve core spring. The spray head and the enlarged hole are threaded together, and the spray head and the enlarged hole are sealed together by the spray head sealing ring. A tapered surface is provided at the end where the outlet valve core connects to the tapered hole. An outlet valve core sealing ring is provided on the tapered surface of the outlet valve core, and the tapered surface of the outlet valve core mates with the tapered hole.

[0019] The second one-way valve structure includes an inlet valve core, an inlet valve core spring, an inlet valve core sealing ring, and an inlet valve seat sealing ring. One end of the inlet valve cover is installed at the inlet of the injection channel via a threaded connection to the inlet valve seat, and the other end of the inlet valve cover is connected to the drug storage assembly. The inlet valve cover and the inlet valve seat are sealed together by the inlet valve seat sealing ring. The inlet valve cover has an inner cavity that connects the inlet and outlet of the inlet valve cover. The inlet valve core is installed inside the inner cavity. The end of the inlet valve core and the end face of the inlet valve seat are connected by the inlet valve core spring. The inner wall of the inner cavity of the inlet valve cover near the inlet side is set as an inner conical surface. The inlet valve core has an outer conical surface that mates with the conical surface. The inlet valve core sealing ring is set on the outer conical surface. The outer conical surface of the inlet valve core mates with the inner conical surface of the inner cavity of the inlet valve cover.

[0020] The solenoid valve is equipped with a pressure relief port.

[0021] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0022] 1. Existing pneumatic needleless injectors all have relatively complex structures and employ multiple air path designs. High-precision machining is required at the trigger point and within the energy storage firing chamber, resulting in significant costs. This invention simplifies the device structure, reduces air path design, fully considers manufacturing process requirements, lowers manufacturing difficulty, and reduces costs.

[0023] 2. Existing pneumatic needleless injectors mostly use a lead screw and nut connection for dosage adjustment, which takes a long time and is time-consuming when performing large-scale needleless injections. In this invention, the gun-type mechanism enables rapid dosage control, is simple and reliable, and is convenient to use.

[0024] 3. In this invention, a rubber fixing tube is set up to absorb the injection site using the principle of atmospheric pressure, preventing the syringe nozzle from detaching from the animal's skin due to stress response, thus preventing injection failure. Attached Figure Description

[0025] Figure 1 This is an isometric view of the present invention.

[0026] Figure 2a This is a cross-sectional view of the dosage adjustment assembly in conjunction with the ampoule piston.

[0027] Figure 2b Appearance diagram of part of the dose adjustment component

[0028] Figure 3 This is an isometric view of the dose adjustment assembly and the injection piston assembly.

[0029] Figure 4a This is a cross-sectional view in the state to be triggered.

[0030] Figure 4b This is a cross-sectional view during the triggering process.

[0031] Figure 4c This is a cross-sectional view after the injection is completed.

[0032] Figure 5a This is an appearance diagram of the present invention in the state before it is triggered.

[0033] Figure 5b This is a partial view of the state to be triggered in this invention.

[0034] Figure 6a This is an appearance diagram of the state during the triggering process of this invention.

[0035] Figure 6b This is a partial view of the state during the triggering process of this invention.

[0036] Figure 7a This is an appearance diagram of the completed state of the present invention.

[0037] Figure 7b This is a partial view of the completed state of the invention.

[0038] Figure 8 This is a partial sectional view of the syringe assembly.

[0039] The diagram shows: 1. Syringe assembly: rubber retaining ring 11, ampoule nozzle 12, water inlet valve cover 13, water inlet valve core sealing ring 131, water inlet valve core 132, water inlet valve spring 133, water inlet valve seat sealing ring 134, water inlet valve seat 135, water outlet valve spring 14, water outlet valve core 141, water outlet valve core sealing ring 142, spray head 15, spray head sealing ring 16.

[0040] 2. Dosage adjustment components: bolt handle 21, bolt lever 22, positioning cap 23, positioning cap spring 24, positioning sleeve 25, positioning sleeve 26, pull rope handle block 26, pull rope 27, telescopic cap spring 28, telescopic cap 29.

[0041] 3. Injection piston assembly: ampoule piston 31, ampoule piston spring 32, power plunger 33, power plunger seal ring 34, ampoule piston seal ring 35.

[0042] 4. Housing assembly: syringe housing 41, permanent magnet 42, silicone buffer seat 43, iron block 44, limiting plate 45, bolt return spring 46, bolt return top block 47.

[0043] 5. Drug storage components: infusion tube 51, medicine bottle 52, drug delivery holder 53, medicine bottle piston 54.

[0044] 6. Gas source components: quick connector 61, air hose 62, solenoid valve 63, high-pressure gas cylinder 64. Detailed Implementation

[0045] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0046] The following descriptions of direction are defined according to the direction observed by the operator during the injection procedure, with the injection end being "forward" and the opposite being "backward".

[0047] The syringe of this invention includes a syringe assembly for introducing and containing a drug solution, a gas source assembly for providing and delivering high-pressure gas, a dose adjustment assembly for adjusting the drug solution dosage, an injection piston assembly for injecting the drug solution, and a housing assembly for supporting various components. The injection piston assembly is installed inside the housing assembly, and the dose adjustment assembly is installed on the side of the housing assembly. The dose adjustment assembly is connected to the injection piston assembly and thus drives the injection piston assembly to move within the housing assembly. The syringe assembly is installed at the front end of the housing assembly, and the gas source assembly is installed at the rear end of the housing assembly. The gas introduced by the gas source assembly drives the injection piston assembly to move and inject the drug solution in the syringe assembly.

[0048] The syringe shell has a magnet fixed at the rear end that can magnetically attract the impact component, and an airflow channel connected to the inner cavity of the cylinder at the rear end. The dosage of the inhaled drug is adjusted by the dosage adjustment mechanism. Compressed gas is charged into the energy storage chamber of the needleless syringe through the gas source component. When the gas pressure in the energy storage chamber reaches a certain value, the injection piston assembly overcomes the attraction between the magnets and impacts forward to complete the injection process.

[0049] like Figure 1As shown, the housing assembly includes a syringe housing 41, a permanent magnet 42, and an iron block 44; the injection piston assembly is installed in the piston chamber channel axially opened in the syringe housing 41, the permanent magnet 42 is fixed to the rear end of the syringe housing 41 by screws, and the iron block 44 is fixed to the rear end of the power plunger 33 of the injection piston assembly by screws, and the iron block 44 and the permanent magnet 42 attract each other; the syringe assembly is installed at the front end of the syringe housing 41, the gas source assembly is installed at the rear end of the syringe housing 41, and a strip groove is opened on the side of the inner cavity of the syringe housing 41, in which a dose adjustment assembly is installed.

[0050] The end faces connecting the positioning caps 23 are provided with stepped surfaces, and the two ends of the positioning cap spring 24 are respectively connected to the stepped surfaces of the two positioning caps 23.

[0051] like Figure 3 As shown, the injection piston assembly includes an ampoule piston 31, a power plunger 33, a power plunger sealing ring 34, an ampoule piston sealing ring 35, and a spring 32. The ampoule piston 31 is installed at the front part of the piston chamber channel of the syringe housing 41 in the housing assembly, and the power plunger 33 is installed at the rear part of the piston chamber channel of the syringe housing 41 in the housing assembly. The ampoule piston 31 and the power plunger 33 are connected by the spring 32. An ampoule piston sealing ring 35 for sealing between the front end of the ampoule piston 31 and the inner wall of the piston chamber channel of the syringe housing 41 is installed on the outer peripheral surface of the front end of the ampoule piston 31, and a power plunger sealing ring 34 for sealing between the rear end of the power plunger 33 and the inner wall of the piston chamber channel of the syringe housing 41 is installed on the outer peripheral surface of the rear end of the power plunger 33.

[0052] The power plunger seal ring 34 is fitted into an annular groove on the outer circumferential surface of the power plunger 33. The ampoule piston seal ring 35 is fitted into an annular groove on the outer circumferential surface of the ampoule piston 31. One end of the spring 32 is fitted into a blind hole at the rear end of the ampoule plunger 31, and the other end of the spring 32 is fitted into a blind hole at the front end of the power plunger 33. A piston groove is provided inside the power plunger 33, and the ampoule piston 31 is coaxial with the power plunger 33.

[0053] In a specific implementation, the piston chamber channel of the syringe housing 41 is divided into a front piston chamber and a rear plunger chamber. The piston chamber and the plunger chamber are coaxially connected, and the inner diameter of the piston chamber is smaller than the inner diameter of the plunger chamber. The ampoule piston 31 is located in the piston chamber, and the power plunger 33 is located in the plunger chamber. The power plunger 33 can carry the ampoule piston 31 to move along the axial direction.

[0054] A blind hole is provided at the rear end of the power plunger 33, and an annular iron block 44 is fixedly installed on the rear end face of the power plunger 33.

[0055] like Figure 5a , Figure 5b , Figure 6a , Figure 6b , Figure 7a , Figure 7bAs shown, the housing assembly also includes a silicone buffer block 43, a limiting plate 45, a bolt return spring 46, and a bolt return top block 47; the side of the ampoule piston 31 is provided with a mounting hole for inserting the telescopic cap 29 of the dosage adjustment assembly; a strip-shaped through groove is provided on the side wall of the syringe housing 41 outside the piston cavity channel, and the strip-shaped through groove is parallel to the piston cavity channel.

[0056] Limiting plates 45 are provided on both sides of the groove. Each limiting plate 45 has a recess for engaging with the positioning cap 23 of the dose adjustment component. Each limiting plate 45 has multiple recesses spaced apart along the direction of the groove. The width of the groove matches the outer diameter of the bolt pull rod 22. The limiting plates 45 are used to restrict the movement of the dose adjustment component along the groove.

[0057] A silicone buffer block 43 is fixedly installed on the strip-shaped channel of the syringe housing 41 near the end of the syringe barrel assembly. A gun reset spring 46 and a gun reset top block 47 are installed on the strip-shaped channel of the syringe housing 41 near the end of the gas source assembly. One end of the gun reset top block 47 is pressed against the side of the gun lever 22 of the dose adjustment assembly. The other end of the gun reset top block 47 is connected to the end wall of the strip-shaped channel near the gas source assembly after passing through the gun reset spring 46. The gun reset spring 46 and the gun reset top block 47 can ensure that the dose adjustment device is reset.

[0058] The outer side of the syringe housing 41 below the strip groove is provided with a scale for indicating the movement position of the injection piston assembly.

[0059] like Figure 2a , Figure 2bAs shown, the dosage adjustment assembly includes a bolt handle 21, a bolt lever 22, a positioning cap 23, a positioning cap spring 24, a positioning sleeve 25, a pull rope handle block 26, a pull rope 27, a telescopic cap spring 28, and a telescopic cap 29. A pull rope handle block 26 is installed on the outer end of the bolt lever 21. One end of the pull rope handle block 26 and the pull rope 27 are fixedly connected. A threaded hole is opened on the inner end of the bolt lever 21. One end of the bolt handle 22 is threaded into the threaded hole, so that the bolt lever 21 and the bolt handle 22 are relatively fixed. The bolt lever 21 is located outside the strip groove on the side wall of the syringe housing 41. The middle part of the bolt lever 22 is embedded in the strip groove on the side wall of the syringe housing 41 and can move along the strip groove to complete the drug intake and dosage adjustment process. A through hole is formed in the middle of the bolt handle 22. A positioning cap 23 is installed in each end of the through hole. The positioning caps 23 at both ends of the through hole are connected by a positioning cap spring 24. A positioning sleeve 25 is fixedly installed on the outside of the bolt handle 22 at the through hole. The positioning sleeve 25 at both ends of the through hole has a through hole with a diameter smaller than that of the positioning cap 23, so that the positioning cap 23 is confined in the through hole and its end protrudes out of the through hole. After the positioning cap 23 protrudes out of the through hole of the positioning sleeve 25, it is also embedded. The bolt handle 22 is installed in the recess, so that the bolt lever 22 is limited by the strip groove; the other end of the bolt handle 22 is provided with a telescopic cap 29, which is movably fitted onto the end of the bolt lever 22. The telescopic cap 29 is connected to the end face of the bolt lever 22 via a telescopic cap spring 28. The other end of the pull rope 27 passes through the channel inside the machine gun lever 21 and the bolt handle 22, then passes through the telescopic cap spring 28 and is fixedly tied to the telescopic cap 29. The pull rope 27 passes through the positioning cap spring 24 between the two positioning caps 23.

[0060] Two positioning caps 23 are connected from both sides to the positioning cap spring 24 in the middle of the through hole, and are inserted into the through hole of the machine gun rod 22. The positioning assembly is fixed by the positioning sleeve 25. The positioning caps 23 are installed in the small hole of the positioning sleeve 25 to ensure that the positioning caps 23 will not fall off during rotation.

[0061] The outer end face of the machine gun lever 21 has a recessed countersunk groove. The pull rope handle block 26 is supported on the stepped surface of the countersunk groove or the outer end face of the machine gun lever 21. By adjusting the pull rope 27, the distance between the telescopic cap 29 and the other end of the bolt handle 22 is adjusted under the elastic limit of the telescopic cap spring 28. This allows the telescopic cap 29 to be selectively and movably inserted into the mounting hole on the side of the ampoule piston 31.

[0062] The telescoping cap 29 is fitted onto the bolt handle 22, and the telescoping cap spring 28 is placed between the end face of the bolt handle 22 and the inner end face of the telescoping cap 29. One end of the pull rope 27 is positioned on the inner end face of the telescoping cap 29, and the other end is positioned on the small end face of the pull rope handle block 26. By pulling the pull rope 27 axially through the pull rope handle block 26, the telescoping cap 29 moves closer to or away from the end of the bolt handle 22 under the elastic limit of the telescoping cap spring 28.

[0063] The syringe assembly includes an ampoule nozzle 12, a rubber retaining ring 11, and a water inlet valve cover 13. The rear end of the ampoule nozzle 12 is connected to the front end of the syringe housing 41 of the housing assembly, and can be fixedly inserted into the front end of the syringe housing 41. An axial channel is provided inside the ampoule nozzle 12. The axial channel of the ampoule nozzle 12 and the front port of the piston chamber channel of the syringe housing 41 of the housing assembly are coaxially connected. A first one-way valve structure that only allows flow from back to front is installed at the front end of the axial channel. A rubber retaining ring 11 is installed at the outlet of the first one-way valve structure. An injection channel is opened on the side of the axial channel. A water inlet valve cover 13 is installed at the injection channel. The injection channel is connected to the drug storage assembly through the water inlet valve cover 13. A second one-way valve structure that only allows flow from the drug storage assembly to the injection channel is installed inside the water inlet valve cover 13.

[0064] The rubber retaining ring 11 is placed against the target skin, and a local vacuum is formed inside the rubber ring through elastic deformation, so that the syringe and the injection target are fixed to each other, thus facilitating injection.

[0065] like Figure 8 As shown, the first one-way valve structure includes an outlet valve core spring 14, an outlet valve core sealing ring 142, an outlet valve core 141, a spray head 15, and a spray head sealing ring 16. A tapered hole and an enlarged hole structure are sequentially arranged from the inside to the outside at the outlet of the piston chamber channel. The inner diameter of the enlarged hole is larger than the inner diameter of the piston chamber channel. The inner diameter of the enlarged hole and the inner diameter of the piston chamber channel are connected by the tapered hole. The outlet valve core 141 is installed inside the tapered hole, and the spray head 15 is installed inside the enlarged hole. The spray head 15 and the outlet valve core 141 are connected by the outlet valve core. The spring 14 is connected, and the inner end of the nozzle 15 is connected to the step between the conical hole and the enlarged hole. The nozzle 15 and the enlarged hole are sealed together by the nozzle sealing ring 16. A rubber fixing ring 11 is installed at the front end of the nozzle 15. The end of the outlet valve core 141 connected to the conical hole is set as a conical surface. An outlet valve core sealing ring 142 is set on the conical surface of the outlet valve core 141. The conical surface of the outlet valve core 141 and the conical hole cooperate. When the conical surface of the outlet valve core 141 and the conical hole are in close contact, they are sealed together by the outlet valve core sealing ring 142.

[0066] like Figure 8As shown, the second one-way valve structure includes an inlet valve core 132, an inlet valve core spring 133, an inlet valve core sealing ring 131, and an inlet valve seat sealing ring 134. One end of the inlet valve cover 13 is installed at the entrance of the injection channel via an inlet valve seat 135, and the other end of the inlet valve cover 13 is connected to the drug storage assembly. A central through hole is formed in the center of the inlet valve seat 135, connecting the outlet of the inlet valve cover 13 and the inlet of the injection channel. The inlet valve cover 13 and the inlet valve seat 135 are sealed together by the inlet valve seat sealing ring 134. The inlet valve cover 13 has an inner cavity that connects the inlet of the inlet valve cover 13 to the... The outlet is connected, and the inner cavity is equipped with an inlet valve core 132. The end of the inlet valve core 132 and the end face of the inlet valve seat 135 are connected by an inlet valve core spring 133. The inner wall of the inner cavity of the inlet valve cover 13 is set with an inner conical surface facing the outlet on the side near the inlet. The inlet valve core 132 is provided with an outer conical surface that mates with the conical surface. An inlet valve core sealing ring 131 is provided on the outer conical surface. The outer conical surface of the inlet valve core 132 mates with the inner conical surface of the inner cavity of the inlet valve cover 13. When the outer conical surface of the inlet valve core 132 and the inner conical surface of the inner cavity of the inlet valve cover 13 are in close contact, they are sealed by the inlet valve core sealing ring 131.

[0067] The circular end of the ampoule nozzle 12 is threaded into the syringe housing 41, and the other square end is connected to the injection head 15 and fixed by threads. One end of the water outlet valve core spring 14 rests against the inner end face of the injection head 15, and the other end is connected to the water outlet valve core 141. Under the action of the water outlet valve core spring 14, the water outlet valve core sealing ring 142 is tightly pressed against the inner inclined surface of the ampoule nozzle 12.

[0068] The inlet valve seat 135 is connected to the threaded hole on the side wall of the syringe housing 41 via threads. The inlet valve seat sealing ring 134 is located in the groove between the inlet valve cover 13 and the inlet valve seat 135. The inlet valve core 132 and the inlet valve core spring 133 are located in the cavity between the inlet valve cover 131 and the inlet valve seat 135. One end of the inlet valve core spring 133 is in contact with the inlet valve core 132, and the other end abuts against the inlet valve seat 134. The inlet valve core sealing ring 131 is fitted into the groove on the conical surface of the inlet valve core 132. Under the action of the inlet valve core spring 133, the inlet valve core sealing ring 131 is tightly pressed against the sealing slope of the inlet valve cover 13.

[0069] The drug storage assembly includes a drug delivery holder 53, a drug bottle 52, a drug bottle piston 54, and an infusion tube 51. The drug bottle 52 is mounted on the syringe housing 41 of the housing assembly via the drug delivery holder 53. The drug bottle piston 54 is installed inside the rear end of the drug bottle 52. The outlet of the drug bottle 52 is connected to the inlet of the infusion valve cap 13 of the syringe assembly via the infusion tube 51. The drug bottle 52 is fitted onto the drug delivery holder 53, and one end of the infusion tube 51 is inserted into the mouth of the drug bottle 52, while the other end is connected to the infusion valve cap 13.

[0070] The gas supply assembly includes a high-pressure gas cylinder 64, a ventilation hose 62, a solenoid valve 63, and a quick connector 61. The high-pressure gas cylinder 64 is connected to one end of the ventilation hose 62 via the solenoid valve 63. The other end of the ventilation hose 62 is connected to the rear port of the piston chamber channel of the syringe housing 41 of the housing assembly via the quick connector 61. The high-pressure gas cylinder 64 is connected to the rear end of the syringe housing 41 of the housing assembly via the solenoid valve 63, the ventilation hose 62, and the quick connector 61 in sequence. The quick connector 61 is fixed to the permanent magnet 42 by a threaded connection, and the ventilation hose 62 is inserted into the quick connector 61. The two ends of the solenoid valve 63 are connected to the ventilation hose 62, with one end of the ventilation hose 62 connected to the quick connector 61 and the other end of the ventilation hose 62 connected to the high-pressure gas cylinder 64.

[0071] The solenoid valve 63 in the specific implementation is provided with a pressure relief port, through which air can be released and pressure relieved.

[0072] The needle-free injection process of this invention is as follows:

[0073] The machine gun handle 21 can rotate freely during use to position the dosage adjustment component. The power plunger 33 and the ampoule piston 31 are coaxial.

[0074] During injection, the power plunger 33 impacts forward, compressing the spring 32 and pushing the ampoule piston 31 forward. Because the speed of the power plunger 33 is greater than the speed of the ampoule piston 31 in the early stages of injection, the power plunger 33 will fit onto the ampoule piston 31; when their speeds are equal, the spring is compressed to its limit.

[0075] In the later stages of injection, the energy from the power plunger 33 and the spring 32 is transferred to the ampoule piston 31, which gains maximum kinetic energy and impacts the liquid medication inside the ampoule nozzle 12, completing the liquid medication injection process.

[0076] Combination Figure 2a , Figure 2b :

[0077] When the operator performs the drug suction operation, the pull rope handle block 26 is placed in the internal groove of the bolt handle 21, the telescopic cap spring 28 is released, the telescopic cap 29 extends and is inserted into the small hole of the ampoule piston 31. At this time, pulling the bolt handle 21 backward can move the ampoule piston 31 together to achieve the purpose of drug suction.

[0078] When the release operation is performed, the pull cord handle block 26 is pulled to the outer end face of the bolt handle 21, the pull cord 27 is stretched, the telescopic cap 29 moves towards the bolt handle 21, the telescopic cap spring 28 is compressed, at this time the telescopic cap 29 disengages from the ampoule piston 31, and the bolt handle 21 is rotated to disengage the positioning cap 23 from the positioning groove. Under the combined action of the bolt reset spring 46 and the bolt reset top block 47, the dose adjustment component is reset.

[0079] like Figure 4a , Figure 5a , Figure 5b As shown, in the needle-free injection positioning state: the iron block 44 is relatively fixed to the power plunger 33 by screws. The spring 32 is compressed, pushing the iron block 44 closer to the permanent magnet 42. Due to magnetic attraction, the iron block 44 and the permanent magnet 42 form a sealed cavity at the end of the syringe. At this time, rotating the bolt handle 21 causes the positioning cap 23 to engage in the groove for positioning. Figure 4a This is a cross-sectional view of the bolt assembly and syringe housing 41 in the ready-to-trigger state, for example, when the operator needs to adjust the injection volume to 0.4ml, they move the bolt handle 21 to the groove marked with 4 on the syringe housing 41, and rotate the bolt handle 21 until the positioning cap 23 is locked in the groove. At this time, the high-pressure gas cylinder solenoid valve inlet switch 63 is adjusted to deliver high-pressure gas. The high-pressure gas enters the sealed cavity composed of permanent magnet 42 and iron block 44 through the ventilation hose 62 and quick connector 61. When the driving force of the gas pressure in the sealed cavity on the power plunger 33 exceeds the magnetic force of permanent magnet 42 on iron block 44, the power plunger 33 carries iron block 44 away from permanent magnet 42 and impacts forward. Before the power plunger 33 impacts, the pull rope handle block 26 needs to be pulled to disengage the telescopic cap 29 from the ampoule piston 31.

[0080] like Figure 4b , Figure 6a , Figure 6b As shown, during the impact process of needle-free injection: the power plunger 33 impacts forward. According to multiple papers, the maximum impact pressure is related to the distance between the power plunger and the ampoule piston. Figure 4b This is a cross-sectional view showing the interaction between the bolt assembly and the syringe housing 41 during the triggering process. Before pressing the high-pressure gas cylinder solenoid valve 63, the operator needs to rotate the bolt handle 21 by 90° to ensure that the positioning cap 23 is disengaged from the groove. At this time, pressing the gas inlet switch of the solenoid valve 63 causes the power plunger 33 to be impacted forward by the pressure generated by the high-pressure gas, compressing the spring 32 to its compression limit. The power plunger 33 will be pushed onto the ampoule piston 31 by the thrust, simultaneously pushing the ampoule piston 31 forward and propelling the liquid medication. At this time, the dosage adjustment component is pushed by the bolt reset top block 47 and moves towards the silicone buffer seat 43.

[0081] like Figure 4c ,Figure 7a , Figure 7b As shown, after the needle-free injection impact ends: During the injection of the drug solution, the bolt handle 21 and the ampoule piston 31 move forward respectively. The bolt handle is subjected to the elastic force of the bolt return spring 47. When the bolt lever 22 hits the silicone buffer seat 43, it decelerates until it stops; the ampoule piston 31 is impacted forward by the force of the power plunger 33, completing the drug injection. The operator pulls the bolt handle 21 to the "0" mark on the syringe housing 41 and rotates the bolt handle 21 to make the positioning cap 23 lock into the groove of the syringe housing 41. Figure 4c This is a cross-sectional view of the injection piston assembly and syringe housing 41 after the triggering process has ended. At this time, the ampoule piston 31 is fixed, and the solenoid valve 63 is opened to release pressure. Due to the decrease in internal air pressure, the compressed spring 32 extends, pushing the power plunger 33 backward until the iron block 44 contacts the permanent magnet 42. After the dosage adjustment assembly is reset, the pull cord handle block 26 is moved to the stepped surface of the inner end face of the bolt handle 21, and the telescopic cap 29 pops out, engaging with the ampoule piston 31 in preparation for the next injection.

[0082] Figure 8 This is a cross-sectional view of the syringe injection assembly. The injection head 15 is fixed to the ampoule nozzle 12 by a threaded connection. The spring 14 abuts against the shaft end of the injection head, and the other end abuts against the water outlet valve core 141. The water outlet valve core sealing ring 142 is fitted onto the water outlet valve core 141. Under the elastic force of the water outlet valve spring 14, it abuts against the inclined surface of the ampoule nozzle 12 to seal. The water inlet valve seat 135 is connected to the ampoule nozzle 12 via threads. The water inlet valve seat sealing ring 134 is fitted onto the water inlet valve seat 135 and seals against the water inlet valve cover 13. The water inlet valve cover is connected to the water inlet valve seat via threads. The water inlet valve spring 133 rests against the bottom of the water inlet valve core 132. The water inlet valve sealing ring 131 is placed on the shaft end of the water inlet valve core 132. Under the elastic force of the water inlet valve spring 133, the water inlet valve sealing ring 134 contacts the inclined surface inside the water inlet valve cover 13 for sealing. When the ampoule piston 31 moves backward, a vacuum is generated in the ampoule nozzle 12. Under the action of atmospheric pressure, the spring 133 is compressed, the water inlet valve core 132 moves downward, and the liquid in the medicine bottle 52 flows into the ampoule nozzle 12, forming an injection chamber. At the same time, the medicine bottle piston 52 moves forward under the action of atmospheric pressure, thus completing the drug aspiration process.

[0083] As can be seen from this implementation, the needle-free injector of the present invention has a simple structure, low manufacturing process requirements, convenient operation, low cost, adjustable dosage, wide applicability, high injection efficiency, and strong reliability.

Claims

1. A pneumatic needle-free injector characterized by: The injection device comprises a syringe assembly for introducing and containing medicine, a gas source assembly for providing and delivering high-pressure gas, a dose adjusting assembly for adjusting the dose of medicine, an injection piston assembly for ejecting medicine, and a housing assembly for supporting various components, wherein the injection piston assembly is installed in the housing assembly, the dose adjusting assembly is installed on the side of the housing assembly, the dose adjusting assembly is connected to the injection piston assembly to drive the movement of the injection piston assembly in the housing assembly, the syringe assembly is installed at the front end of the housing assembly, and the gas source assembly is installed at the rear end of the housing assembly, wherein the gas introduced by the gas source assembly drives the injection piston assembly to move and eject the medicine in the syringe assembly. The housing assembly comprises an injector housing (41), a permanent magnet (42) and an iron block (44), wherein the injection piston assembly is installed in the piston cavity channel of the injector housing (41), the permanent magnet (42) is fixed to the rear end of the injector housing (41) by a screw, and the iron block (44) is fixed to the rear end of the injection piston assembly, and the iron block (44) and the permanent magnet (42) are attracted to each other. The dose adjusting assembly comprises a gun trigger (21), a gun trigger rod (22), a positioning cap (23), a positioning cap spring (24), a positioning sleeve (25), a pull rope handle block (26), a pull rope (27), a telescopic cap spring (28) and a telescopic cap (29), wherein the pull rope handle block (26) is installed at the outer end of the gun trigger (21), one end of the pull rope handle block (26) and the pull rope (27) are fixedly connected, the inner end of the gun trigger rod (22) is provided with a threaded hole, one end of the gun trigger rod (22) is installed in the threaded hole by screwing, the middle part of the gun trigger rod (22) is embedded in the strip-shaped through slot of the side wall of the injector housing (41) and can move along the strip-shaped through slot, the middle part of the gun trigger rod (22) is provided with a through hole, two positioning caps (23) are installed in the through hole, the positioning cap spring (24) is connected between the two positioning caps (23) at the two ends of the through hole, the positioning sleeve (25) is installed outside the through hole of the gun trigger rod (22), the through hole of the positioning sleeve (25) at the two ends of the through hole is provided with a hole with a smaller diameter than the positioning cap (23), so that the positioning cap (23) is limited in the through hole and the end part protrudes from the hole, and the positioning cap (23) protruding from the hole of the positioning sleeve (25) is also embedded in the recess, so that the gun trigger rod (22) is limited by the strip-shaped through slot; the telescopic cap (29) is arranged at the other end of the gun trigger rod (22), the telescopic cap (29) is connected to the end surface of the other end of the gun trigger rod (22) through the telescopic cap spring (28), and the other end of the pull rope (27) passes through the channel in the gun trigger rod (22) and the gun trigger (21), and then passes through the telescopic cap spring (28) and is fixedly connected to the telescopic cap (29). The outer side of the injector housing (41) below the strip-shaped through slot is provided with a scale. The injection piston assembly comprises an ampoule piston (31), a power plunger (33), a power plunger sealing ring (34), an ampoule piston sealing ring (35), and a spring (32); the ampoule piston (31) is installed at the front part in the piston cavity channel of the injector shell (41) of the shell assembly, the power plunger (33) is installed at the rear part in the piston cavity channel of the injector shell (41) of the shell assembly, and the ampoule piston (31) and the power plunger (33) are connected by the spring (32); the outer circumferential surface of the front end of the ampoule piston (31) is provided with the ampoule piston sealing ring (35) for sealing with the inner wall of the piston cavity channel of the injector shell (41), and the outer circumferential surface of the rear end of the power plunger (33) is provided with the power plunger sealing ring (34) for sealing with the inner wall of the piston cavity channel of the injector shell (41). The outer end surface of the bolt handle (21) is provided with a concave counterbore groove, the pull rope handle block (26) is supported on the step surface of the counterbore groove or the outer end surface of the bolt handle (21), and then the distance between the pull rope (27) and the other end of the bolt handle (21) is adjusted to adjust the distance between the telescopic cap (29) and the other end of the bolt handle (22) under the elastic limiting of the telescopic cap spring (28), so as to selectively and movably insert the telescopic cap (29) into the mounting hole on the side of the ampoule piston (31). The needle cylinder assembly comprises an ampoule nozzle (12), a rubber fixing ring (11), and a water inlet valve cover (13); the rear end of the ampoule nozzle (12) is connected to the front end of the injector shell (41) of the shell assembly, the ampoule nozzle (12) is provided with an axial channel inside, the axial channel of the ampoule nozzle (12) and the front end port of the piston cavity channel of the injector shell (41) of the shell assembly are coaxially communicated, the front end of the axial channel is provided with a first one-way valve structure allowing only rear-to-front conduction, the rubber fixing ring (11) is installed at the outlet of the first one-way valve structure, a injection channel is formed in the side of the axial channel, the water inlet valve cover (13) is installed at the injection channel, the injection channel is connected with the medicine storage assembly through the water inlet valve cover (13), and the second one-way valve structure allowing only conduction from the medicine storage assembly to the injection channel is installed in the water inlet valve cover (13).

2. The gas-operated needle-free injector of claim 1, wherein: The medicine storage assembly comprises a medicine administration support (53), a medicine bottle (52), a medicine bottle piston (54), and a infusion tube (51); the medicine bottle (52) is installed on the injector shell (41) of the shell assembly through the medicine administration support (53), the medicine bottle piston (54) is installed inside the rear end of the medicine bottle (52), and the outlet of the medicine bottle (52) is communicated with the water inlet valve cover (13) of the needle cylinder assembly through the infusion tube (51).

3. The gas-operated needle-free injector of claim 1, wherein: The air source assembly comprises a high-pressure gas cylinder (64), an air hose (62), an electromagnetic valve (63), and a quick connector (61); the high-pressure gas cylinder (64) is communicated with one end of the air hose (62) through the electromagnetic valve (63), and the other end of the air hose (62) is communicated with the rear end port of the piston cavity channel of the injector shell (41) of the shell assembly through the quick connector (61).

4. The gas-operated needle-free injector of claim 1, wherein: The rear end of the power plunger (33) is provided with a blind hole, and the iron block (44) is fixedly installed on the rear end surface of the power plunger (33).

5. The gas-operated needle-free injector of claim 1, wherein: The shell assembly further comprises a silica gel buffer block (43), a limiting plate (45), a bolt carrier return spring (46) and a bolt carrier return top block (47); a side of the ampoule piston (31) is provided with a mounting hole for inserting the telescopic cap (29) of the dose adjusting assembly; a side wall of the syringe shell (41) outside the piston cavity passage is provided with a strip-shaped through groove; both side groove walls of the strip-shaped through groove are provided with the limiting plate (45), and the limiting plate (45) is provided with a recess for cooperating with the positioning cap (23) of the dose adjusting assembly; each limiting plate (45) is provided with a plurality of recesses arranged at intervals along the direction of the strip-shaped through groove; the strip-shaped through groove of the syringe shell (41) is fixedly provided with the silica gel buffer block (43) at one end close to the push-throw needle cylinder assembly; the strip-shaped through groove of the syringe shell (41) is provided with the bolt carrier return spring (46) and the bolt carrier return top block (47) at one end close to the gas source assembly; one end of the bolt carrier return top block (47) is crimped to the side of the bolt carrier pull rod (22) of the dose adjusting assembly; the other end of the bolt carrier return top block (47) is connected to the groove end wall at one end close to the gas source assembly through the bolt carrier return spring (46).

6. The gas-operated needle-free injector of claim 1, wherein: The first one-way valve structure comprises a water outlet valve core spring (14), a water outlet valve core sealing ring (142), a water outlet valve core (141), a jet head (15) and a jet head sealing ring (16); a taper hole and a stepped hole structure are sequentially arranged from the inside to the outside at the outlet of the piston cavity passage, the inner diameter of the stepped hole is larger than the inner diameter of the piston cavity passage, the inner diameter of the stepped hole and the inner diameter of the piston cavity passage are connected through the taper hole, the water outlet valve core (141) is installed in the taper hole, the jet head (15) is installed in the stepped hole, the jet head (15) and the water outlet valve core (141) are connected through the water outlet valve core spring (14), and the jet head (15) and the enlarged hole are sealed and connected through the jet head sealing ring (16); one end of the water outlet valve core (141) connected with the taper hole is provided with a taper surface, the water outlet valve core sealing ring (142) is arranged on the taper surface of the water outlet valve core (141), and the taper surface of the water outlet valve core (141) is matched with the taper hole; The second one-way valve structure comprises a water inlet valve core (132), a water inlet valve core spring (133), a water inlet valve core sealing ring (131) and a water inlet valve seat sealing ring (134); one end of a water inlet valve cover (13) is threadedly connected and installed at the inlet of the injection channel through a water inlet valve seat (135), the other end of the water inlet valve cover (13) is connected with a medicine storage assembly, the water inlet valve cover (13) and the water inlet valve seat (135) are sealingly connected through the water inlet valve seat sealing ring (134), the water inlet valve cover (13) is internally provided with an inner cavity, the inner cavity communicates the inlet and the outlet of the water inlet valve cover (13), the inner cavity is internally provided with the water inlet valve core (132), the end of the water inlet valve core (132) and the end face of the water inlet valve seat (135) are communicated through the water inlet valve core spring (133), the inner wall of the inner cavity of the water inlet valve cover (13) is provided with an inner conical surface near the inlet, the water inlet valve core (132) is provided with an outer conical surface matched with the conical surface, the outer conical surface is provided with the water inlet valve core sealing ring (131), and the outer conical surface of the water inlet valve core (132) is matched with the inner conical surface of the inner cavity of the water inlet valve cover (13).

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