CN221013918U - Double-cavity medicine dispenser with airtight adaptive piston - Google Patents

Abstract

The utility model discloses a double-cavity type medicine dispenser with a closed adaptive piston, which is provided with a first injection cavity, a first injection rod, a first needle tube, a second injection cavity, a second injection rod and a second needle tube, wherein when the double-cavity type medicine dispenser is used, the first needle tube and the second needle tube penetrate into a medicine bottle together, the sliding of the first injection rod can be used for drawing and injecting medicine liquid, the sliding of the second injection rod can be used for balancing air pressure, the air pressure balance of the medicine bottle in the medicine dispensing process is realized, meanwhile, the first injection rod and the second injection rod are both composed of a push rod and a piston, the piston is not only provided with a clamping cavity sleeved on a push rod clamping joint and forms a conical cavity, but also provided with a first annular flange and a second annular flange, so that the tightness is better when the first injection rod slides, and the sliding performance of the second injection rod automatically slides easily without manipulation, thereby the purposes of reducing the operation complexity and the labor intensity of medical staff on the basis of balancing the air pressure during medicine dispensing are realized.

Description

Double-cavity medicine dispenser with airtight adaptive piston

Technical Field

The utility model relates to the field of medical instruments, in particular to a double-cavity medicine dispenser with a closed adaptive piston.

Background

Currently, dispensers are still syringe-based. The device consists of an injection rod, an injection tube, a needle seat, a needle tube and the like. When the medicine dispensing device dispenses medicine, the injector and the medicine liquid bottle form a closed space, and air pressure for impedance operation is formed in the process of extracting or injecting medicine liquid, so that the problem of increasing the operation strength of medical staff is generated.

In order to balance the air pressure resistance generated during pumping and injecting, a pumping and injecting part aiming at air can be added on the basis of a syringe for pumping and injecting liquid medicine. When dispensing, the liquid medicine pumping and injecting part and the air pumping and injecting part of the injector are both penetrated into the liquid medicine bottle, when the liquid medicine pumping and injecting part pumps liquid medicine, the air pumping and injecting part provides air for the liquid medicine bottle to relieve negative pressure in the bottle, and when the liquid medicine pumping and injecting part injects liquid medicine, the air pumping and injecting part pumps air in the liquid medicine bottle to relieve high pressure in the bottle.

However, taking the liquid medicine as an example, when the injection rod of the liquid medicine pumping and injecting part is pulled, the air pumping and injecting part is pushed to supplement the liquid medicine bottle at the same time. This will, while better balancing the air pressure, also lead to increased complexity in the operation of the healthcare worker. If only the liquid medicine pumping and injecting part is pulled, but the air pumping and injecting part is not operated, the piston resistance with higher tightness in the traditional method is also higher, and the negative pressure generated in the air pumping and injecting part is insufficient to push the piston of the air pumping and injecting part. If a piston with lower tightness is adopted, the air pumping and injecting part can be pushed, and the tightness can not meet the requirement of dispensing.

Disclosure of utility model

In view of the above, the present utility model aims to provide a dual-chamber dispenser with a piston having a closed adaptability, which can automatically slide in response to pressure changes during air pressure balancing while ensuring that the tightness of the piston is satisfied during drug infusion.

In order to achieve the above purpose, the present invention adopts the following technical scheme: a dual-chamber dispensing device having a closed compliant piston, comprising:

The injection tube is internally provided with a first injection cavity and a second injection cavity which extend forwards and backwards and are mutually parallel;

A first injection rod slidably mounted within the first injection cavity from the rear end of the syringe barrel;

the second injection rod is slidably arranged in the second injection cavity from the rear end of the injection cylinder;

A needle seat arranged at the front end of the injection tube,

The first needle tube is arranged at the front end of the needle seat in a front-back extending way and is communicated with the first injection cavity through the needle seat; and

The second needle tube is arranged at the front end of the needle seat in a front-back extending way and is communicated with the second injection cavity through the needle seat; wherein,

The first injection rod and the second injection rod respectively consist of a push rod and a piston, the front end of the push rod is provided with a clamping joint, and a clamping cavity with a backward opening is arranged in the piston; the inner side wall of the clamping cavity is provided with a clamping protrusion from the outer side to the center, and the rear end of the clamping connector is abutted with the front end of the clamping protrusion so as to fix the piston to the clamping connector;

The outer side wall of the piston is provided with a first annular flange, the top of the clamping cavity is a conical surface, a cavity is formed between the top of the clamping cavity and the front end of the clamping connector, and the first annular flange is axially positioned at the front side of the clamping connector;

The outer side wall of the piston is also provided with a second annular flange which is positioned at the radial rear part of the clamping protrusion in the axial direction.

Preferably, the front end edge of the clamping cavity is provided with a slope opposite to the conical surface of the front end of the clamping cavity, the gradient of the slope increases gradually from the center to the outer side, and the front end edge of the clamping connector is abutted to the outermost side of the slope.

Further, the slope has a circular arc-shaped cross section and increases in inclination from the center to the outside.

Further, the front end edge of the clamping connector is provided with a chamfer, and the inclination of the outermost edge of the slope is the same as the inclination of the chamfer.

Preferably, the diameter of the first annular flange is greater than the diameter of the second annular flange, and the tolerance of the second annular flange to the first injection cavity or the second injection cavity is equal to or less than zero.

Further, the piston is further provided with a third annular flange located axially rearward of the bayonet, the third annular flange having a diameter smaller than the diameter of the second annular flange.

Further, the cross-sectional shapes of the first annular flange and the second annular flange are circular arcs, and the cross-sectional shape of the third annular flange is rectangular.

Preferably, the front end of the piston is a conical surface, and the taper of the conical surface at the front end of the piston is equal to the taper of the conical surface at the front end of the clamping cavity.

Preferably, the front end of push rod is provided with the fixing base, the joint is equipped with the front end middle part of fixing base, the rear end of piston and the front end butt cooperation of fixing base.

Preferably, the first needle tube and the second needle tube are arranged at the front end of the needle seat in parallel; or the pipe diameter of the second needle tube is larger than that of the first needle tube, the second needle tube is sleeved outside the first needle tube, the front end of the first needle tube extends out of the front end of the second needle tube, the rear end of the first needle tube extends out of the rear end of the second needle tube backwards and is communicated with the first injection cavity, and the rear end of the second needle tube is communicated with the second injection cavity.

Compared with the prior art, the utility model has the following beneficial effects:

(1) The double-cavity type medicine dispenser is provided with the first injection cavity, the first injection rod, the first needle tube, the second injection cavity, the second injection rod and the second needle tube, when the double-cavity type medicine dispenser is used, the first needle tube and the second needle tube penetrate into a medicine bottle together, sliding of the first injection rod can be used for sucking and injecting medicine liquid, sliding of the second injection rod can be used for balancing air pressure, air pressure balancing of the medicine bottle in a medicine dispensing process is achieved, meanwhile, the first injection rod and the second injection rod are both composed of the push rod and the piston, the piston is not only provided with the clamping cavity sleeved on the push rod clamping connector and forms a conical cavity, but also provided with the first annular flange and the second annular flange, so that tightness is better when the first injection rod slides, sliding performance of the second injection rod is better and the second injection rod can slide automatically and easily, and non-manipulation, and therefore operation complexity of medical staff and labor intensity of work are reduced on the basis of balancing air pressure in the medicine dispensing process.

(2) According to the utility model, the slope is arranged in the clamping cavity in the piston, so that when the first injection rod is driven forward, the clamping joint presses the slope in the piston, the radial outward deformation of the first annular flange is larger, and the airtight waterproof capacity of the first injection rod is better; when the second injection rod is passively advanced, the plunger pulls the catch, and the catch does not press the ramp, so that the radially outward deformation of the first annular flange is smaller, and the second injection rod is easier to automatically slide without manipulation.

(3) Furthermore, the injection rod for liquid medicine has good tightness due to different acting forces generated between the liquid medicine pumping and the balancing air, and the injection rod for air pressure balancing has less resistance.

Drawings

FIG. 1 is a schematic cross-sectional view of a dual-chamber dispenser according to a first embodiment of the utility model;

FIG. 2 is a schematic view of a first partially enlarged cross-sectional structure of a dual-chamber dispenser according to a first embodiment of the utility model;

FIG. 3 is a schematic view of a second partially enlarged cross-sectional structure of a dual-chamber dispenser according to a first embodiment of the utility model;

FIG. 4 is a schematic view showing a partially enlarged sectional structure of a dual-chamber dispenser according to a first embodiment of the present utility model when drawing a medicinal solution;

fig. 5 is a schematic view showing a partially enlarged sectional structure of a dual-chamber dispenser according to a first embodiment of the present utility model when a drug solution is injected.

Fig. 6 is a partially enlarged schematic cross-sectional view of a dual-chamber dispenser according to a second embodiment of the present utility model.

The drawings are marked: 10. a syringe; 11. a first injection cavity; 111. a first joint; 12. a second injection cavity; 121. a second joint; 20. a first injection rod; 30. a second injection rod; 40. a needle stand; 41. a first connection hole; 42. a first inner passage; 43. a second connection hole; 44. a second inner passage; 50. a first needle tube; 60. a second needle tube; 70. a push rod; 71. a clamping joint; 72. a fixing seat; 80. a piston; 81. a clamping cavity; 82. a first annular flange; 83. a second annular flange; 84. a third annular flange; 85. a ramp; 86. and the clamping position is convex.

Detailed Description

For a better illustration of the objects, technical solutions and advantages of the present utility model, the following detailed description of the present utility model will be given with reference to the accompanying drawings and examples. The following examples are illustrative of the utility model and are not intended to limit the scope of the utility model.

First embodiment

As shown in fig. 1 to 5, a dual chamber dispenser with a closed compliant piston according to a first embodiment of the present utility model is provided.

Referring to fig. 1, the dispenser includes an injection cartridge 10, a first injection rod 20, a second injection rod 30, a needle hub 40, a first needle cannula 50, and a second needle cannula 60. Wherein a first injection cavity 11 and a second injection cavity 12 are provided inside the syringe 10. The first injection chamber 11 and the second injection chamber 12 each extend in the front-rear direction and are juxtaposed with each other. Conventionally, the first injection cavity 11 and the second injection cavity 12 are cylindrical. Optionally, the diameters and depths of the first injection cavity 11 and the second injection cavity 12 are also approximately equal. The first injection rod 20 is slidably mounted to the first injection chamber 11 of the syringe 10, while the second injection rod 30 is slidably mounted to the second injection chamber 12 of the syringe 10. The rear end of the needle mount 40 is fixedly coupled to the front end of the syringe 10. The front end of the needle holder 40 is fixedly connected with a first needle tube 50 and a second needle tube 60, the first needle tube 50 and the second needle tube 60 extend along the front-rear direction, and the first needle tube 50 and the second needle tube 60 are arranged at the front end of the needle holder 40 in parallel with each other. The first needle cannula 50 communicates through the needle hub 40 to the first injection cavity 11 and the second needle cannula 60 communicates through the needle hub 40 to the second injection cavity 12.

In the description of the present utility model, the front and front ends refer to the end of the dispenser to which the needle tip is directed, and the rear and rear ends refer to the opposite end.

In the description of the present utility model, the first injection chamber 11 is used to draw or inject a medicine into a medicine bottle, and the second injection chamber 12 may be used to supplement or discharge air from the medicine bottle.

In use, the dispenser of the present embodiment holds the syringe 10 of the dispenser with the front ends of the first and second syringes 50, 60 aligned with the mouth of a vial, and manipulates the syringe 10 such that the first and second syringes 50, 60 penetrate into the vial. Thus, the front needles of the first needle cannula 50 and the second needle cannula 60 are both located within the medicament vial.

If withdrawal of the medical fluid is desired, the first injection rod 20 is driven to slide rearward. At this time, a negative high pressure is generated in the first injection chamber 11, and the drug solution is drawn from the drug vial through the first needle tube 50 into the first injection chamber 11. In turn, the vial will develop a negative high pressure as the medical fluid is withdrawn and the negative high pressure will act on the second injection chamber 12. At this time, if the second injection rod 30 is driven to slide forward, air is replenished into the medicine bottle to reach the air pressure balance of the medicine bottle.

If the injection of the medical fluid is required, the first injection rod 20 is driven to slide forward. At this time, a positive high pressure is generated in the second injection chamber 12, and the drug solution in the first injection chamber 11 is injected into the drug vial through the first needle tube 50. In turn, the vial will develop a positive high pressure as a result of the infusion of the medical fluid and the positive high pressure will act on the second injection chamber 12. At this time, if the second injection rod 30 is driven to slide backward, air is discharged into the second injection chamber 12 to reach the air pressure balance in the medicine bottle.

As shown in fig. 2 to 5, in order to ensure tightness and reduce operations, in the dual chamber dispenser of the first embodiment, the first injection rod 20 and the second injection rod 30 are composed of a push rod 70 and a piston 80, respectively. Specifically, the front end of the push rod 70 is provided with a clamping joint 71, a clamping cavity 81 which is opened backwards is arranged in the piston 80, a clamping protrusion 86 which is arranged on the inner side wall of the clamping cavity 81 and faces the center from the outer side, the rear end of the clamping joint 71 is abutted against the front end of the clamping protrusion 86, and the piston 80 is fixed in the clamping joint 71 of the push rod 70 in a matched manner through the clamping cavity 81. The piston 80 of the first injection rod 20 is hermetically fitted to the inner wall of the first injection chamber 11, and the piston 80 of the second injection rod 30 is hermetically fitted to the inner wall of the second injection chamber 12.

For this purpose, the top of the clamping cavity 81 is conical and forms a cavity with the front end of the clamping head 71, and the outer side wall of the piston 80 is provided with a first annular flange 82, and the first annular flange 82 is located at the front side of the clamping head 71 in the axial direction.

Referring to fig. 4, the first injection rod 20 is actively pushed to slide backward during drawing of the medical fluid. For the first injection rod 20 and the first injection cavity 11, the piston 80 is acted by the action force of extracting the liquid medicine, the cavity of the piston 80 is greatly deformed forward, the contact area between the first annular flange 82 and the first injection cavity 11 is correspondingly reduced more, the tightness is reduced, and the sliding performance is increased; at the same time, the snap-in tab 71 being pulled back will act on the snap-in projection 86 of the plunger 80 and evert, and the contact of the second annular flange 83 with the first injection cavity 11 will correspondingly increase more, thereby satisfying the overall tightness of the first injection rod 20. For the second injection rod 30 and the second injection chamber 12, the piston 80 is forced by the negative air pressure of the medicament bottle, the cavity of the piston 80 is deformed forward, and the contact area between the second annular flange 83 and the second injection chamber 12 is reduced. However, compared to the case where the first injection rod 20 is subjected to the liquid medicine, the second injection rod 30 is subjected to a lower negative air pressure, and the deformation amounts of the first annular flange 82 and the second annular flange 83 are smaller, so that the piston 80 of the second injection rod 30 still has a better sliding performance. As the first injection rod 20 is pushed to slide backward, the second injection rod 30 will automatically slide forward under the negative air pressure of the medicament bottle.

Referring to fig. 5, the first injection rod 20 is actively pushed to slide forward during injection of the medical fluid. For the first injection rod 20 and the first injection chamber 11, the piston 80 is subjected to the force of injecting the liquid medicine, the cavity of the piston 80 is greatly deformed backward, the contact area between the first annular flange 82 and the first injection chamber 11 is greatly increased correspondingly, the tightness is increased, and the sliding performance is reduced. For the second injection rod 30 and the second injection chamber 12, the piston 80 is subjected to the positive air pressure of the medicine bottle, the piston 80 is deformed forward and backward, and the contact area between the second annular flange 83 and the second injection chamber 12 increases. However, the second injection rod 30 is subjected to a lower negative pressure than the first injection rod 20, and the first annular flange 82 is less deformed, so that the piston 80 of the second injection rod 30 still has a better sliding performance. As the first injection rod 20 is pushed to slide forward, the second injection rod 30 will automatically slide backward under the positive air pressure of the medicament vial.

As can be seen, in the piston 80 of the first injection rod 20, the first annular flange 82 is contracted and the second annular flange 83 is expanded, and the overall sealing performance is increased when the liquid medicine is extracted; in the piston 80 of the second injection rod 30, the first annular flange 82 is slightly contracted under the action of the cavity, so that the second injection rod 30 automatically slides. When the drug solution is injected, the first annular flange 82 expands in the piston 80 of the first injection rod 20, and the overall sealing performance increases; in the piston 80 of the second injection rod 30, the first annular flange 82 is not much reduced under the action of the cavity, and the sliding performance is better. In whole, this embodiment can realize on the basis of balancing the medicament bottle atmospheric pressure when dispensing, medical personnel advance and draw into the liquid medicine through controlling first injection pole 20, and second injection pole 30 can be unmanned automatic sliding to reduce medical personnel's complexity of operation, the purpose of work intensity of labour.

As shown in fig. 3, in this embodiment, specifically, a slope 85 opposite to the conical surface of the front end of the clamping cavity 81 is provided at the front end edge of the clamping cavity 81, the slope of the slope 85 increases gradually from the center to the outside, and the front end edge of the clamping head 71 abuts against the outermost side of the slope 85. It will be appreciated that in this embodiment, the front edge of the clamping head 71 is provided with a chamfer, and the inclination of the outermost edge of the slope 85 is the same as that of the chamfer, so that the outer edge of the clamping head 71 is in abutting engagement with the outer edge of the bottom cavity of the clamping cavity 81 of the piston 80, so that the chamfer of the clamping head 71 slides along the slope 85. In other embodiments, the front edge of the bayonet 71 may also be at right angles. It will be appreciated that in this embodiment, the cross section of the slope is arc-shaped and the inclination increases from the center to the outside, so that the outer side wall of the locking joint 71 slides forward better, presses the cavity of the piston 80 and pushes the first annular flange 82 to deform outwards, and the slope 85 will prevent the locking joint 71 from sliding further relative to the locking cavity 81 when the locking joint 71 slides to the inside of the slope 85.

Referring to fig. 4, in the first injection chamber 11, when the bayonet joint 71 moves forward to draw out the medicine liquid, the front end edge of the bayonet joint 71 applies pressure to the slope 85, so that the cavity edge of the conical surface expands outwards, the contact area between the first annular flange 82 and the first injection chamber 11 increases, and the sealing property is improved. Similarly, in the second injection chamber 12, the ramp 85 applies pressure to the bayonet 71 under the positive air pressure of the vial. The cavity edge of the conical surface also expands outwardly under the reaction force, increasing the contact area between the first annular flange 82 and the second injection cavity 12. But the piston 80 in the first injection chamber 11 still has a better sliding performance due to the smaller force of the air pressure. It can be seen that, by the slope 85, the dual-cavity dispenser of the present embodiment has better tightness at the first injection rod 20 for injecting the liquid medicine, and better sliding performance at the second injection rod 30 for exhausting air.

As shown in fig. 3, in this embodiment, specifically, the cross-sectional shapes of the first annular flange 82 and the second annular flange 83 are circular arcs, so that the first annular flange 82 and the second annular flange 83 can both be kept in contact during deformation of the piston 80. The diameter of the first annular flange 82 is larger than the diameter of the second annular flange 83, thereby increasing the influence of the first annular flange 82 on the sealing property and decreasing the influence of the second annular flange 83 on the sliding property. At the same time, in the first injection rod 20, the second annular flange 83 of the piston 80 is in tolerance with the first injection chamber 11 equal to zero. In the second injection rod 30, the second annular flange 83 of the piston 80 is in tolerance with the first injection chamber 11 equal to zero. It will be appreciated that in this embodiment, the piston 80 is further provided with a third annular flange 84, the cross-sectional shape of the third annular flange 84 being rectangular, the third annular flange 84 being located axially rearward of the bayonet 71, the diameter of the third annular flange 84 being smaller than the diameter of the second annular flange 83. The third annular flange 84 is provided so as to ensure the sealing performance of the piston 80 at the time of extreme drawing of the medical fluid pressure.

Illustratively, and not by way of limitation, in this embodiment, the diameters of the first and second injection chambers 11, 12 are configured to be 20mm. The first and second injection chambers 11, 12 have pistons 80 of a size. The first annular flange 82 has a diameter of 20+0.15mm, the second annular flange 83 has a diameter of 20mm, and the third annular flange 84 has a diameter of 19mm. In other words, the first annular flange 82 has a larger diameter than the second annular flange 83. Meanwhile, since the sealing performance of the piston 80 in this embodiment is improved along with the deformation of the cavity, compared with the conventional syringe which needs to be provided with an interference of +0.20mm to +0.25mm, the first injection cavity 11 of this embodiment can meet the sealing performance requirement, and the second injection cavity 12 can obtain better sliding performance. In other words, the dimensional tolerance of the second annular flange 83 with the first injection chamber 11 and the second injection chamber 12, respectively, is zero, so that the sliding performance of the piston 80 can be improved during injection, and the sealing performance can be improved during extraction. In other embodiments according to the utility model, the dimensional tolerance of the second annular flange 83 with the first injection cavity 11 or the second injection cavity 12 may also be configured to be slightly less than zero.

Referring to fig. 5, when the medical fluid is injected, the second annular flange 83 of the piston 80 of either the first injection rod 20 or the second injection rod 30 does not generate resistance, but is sealed depending on the first annular flange 82. When the liquid medicine is extracted, the clamping joint 71 of the first injection rod 20 drives the clamping protrusion 86 to deform, and the second annular flange 83 of the clamping protrusion abuts against the first injection cavity 11; the piston 80 of the second injection rod 30 slides along the locking joint 71, and the second annular flange 83 of the piston will also abut against the second injection cavity 12. It follows that the first annular flange 82 and the second annular flange 83 together provide a seal adapted to the medical fluid and actuation upon withdrawal of the medical fluid and meet the sliding performance requirements. When the liquid medicine is injected, the first annular flange 82 is adapted to the liquid medicine and the activated tightness, while the second annular flange 83 is not in contact, so that the sliding performance is improved.

As shown in fig. 3, in this embodiment, specifically, the front end of the piston 80 is a conical surface, and the taper of the conical surface of the front end of the piston 80 is equal to the taper of the conical surface of the front end of the locking cavity 81. In other words, the front end of the piston 80 has a thin-walled structure with a uniform thickness, so that the piston 80 can be more uniformly subjected to the force of the liquid medicine or air.

As shown in fig. 3, in this embodiment, specifically, a fixing seat 72 is provided at the front end of the push rod 70, and the front end of the snap-in connector 71 has a large diameter and the rear shield has a small diameter so as to be snapped into the snap-in protrusion 86 of the piston 80. The front end diameter of the clamping joint 71 is matched with the diameter of the cavity in the piston 80, and the small outer diameter of the rear part of the clamping joint 71 is smaller than the inner diameter of the clamping protrusion 86 and is connected with the middle part of the fixing seat 72. The rear end of the piston 80 may be in abutting engagement with the front end of the anchor block 72. In the initial state, the fixed seat 72 of the push rod 70 and the rear end of the piston 80 form a certain gap, so that the deformation of the second annular flange 83 in the piston 80 is facilitated. In the state of injecting the liquid medicine, the fixing seat 72 of the push rod 70 is abutted against the rear end of the piston 80 so that the deformation direction of the piston 80 is forward.

Second embodiment

As shown in fig. 6, a dual chamber dispenser with a closed compliant piston according to a second embodiment of the present utility model is shown. The dispenser includes an injection cartridge 10, a first injection rod 20, a second injection rod 30, a needle mount 40, a first needle cannula 50, and a second needle cannula 60. Wherein a first injection cavity 11 and a second injection cavity 12 are provided inside the syringe 10. The first injection chamber 11 and the second injection chamber 12 each extend in the front-rear direction and are juxtaposed with each other. Compared with the first embodiment, the second embodiment is particularly characterized in that the pipe diameter of the second needle tube 60 is larger than that of the first needle tube 50, and the second needle tube 60 is sleeved outside the first needle tube 50. The front end of the first needle cannula 50 extends beyond the front end of the second needle cannula 60 and is provided with a needle opening. The front end of the second needle tube 60 is also provided with a needle opening. The rearward end of the first needle cannula 50 extends rearwardly beyond the rearward end of the second needle cannula 60 and communicates with the second injection cavity 12 through the needle hub 40. The rearward end of the second needle cannula 60 communicates with the second injection cavity 12 through the needle hub 40.

When in use, the first needle tube 50 and the second needle tube 60 can simultaneously pierce the bottle mouth of the medicament bottle, ensure the tightness of the pierced mouth and can pierce medicament bottles with different bottle mouth sizes. As can be seen, according to the embodiments of the present utility model, the first needle cannula 50 and the second needle cannula 60 can extend in the same direction, and it is sufficient to ensure that the first needle cannula 50 and the second needle cannula 60 penetrate the medicine bottle together.

Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" and "a second" may explicitly or implicitly include at least one such feature. In the description of the present utility model, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

The foregoing embodiments have described primarily the basic principles, principal features and advantages of the utility model. It will be understood by those skilled in the art that the present utility model is not limited to the embodiments described above, and that the above embodiments and descriptions are merely illustrative of the principles of the present utility model, and various changes and modifications may be made without departing from the spirit and scope of the utility model, which is defined in the appended claims.

Claims (10)

1. A dual-chamber dispenser having a closed compliant piston, comprising:

A syringe (10) having a first injection chamber (11) and a second injection chamber (12) extending in a front-rear direction and arranged in parallel with each other;

A first injection rod (20) slidably mounted within the first injection cavity (11) from the rear end of the injection cylinder (10);

A second injection rod (30) slidably mounted within the second injection chamber (12) from the rear end of the syringe (10);

a needle seat (40) arranged at the front end of the injection tube (10),

The first needle tube (50) is arranged at the front end of the needle seat (40) in a manner of extending forwards and backwards and is communicated with the first injection cavity (11) through the needle seat (40); and

The second needle tube (60) is arranged at the front end of the needle seat (40) in a manner of extending forwards and backwards and is communicated with the second injection cavity (12) through the needle seat (40); wherein,

The first injection rod (20) and the second injection rod (30) are respectively composed of a push rod (70) and a piston (80), a clamping joint (71) is arranged at the front end of the push rod (70), and a clamping cavity (81) which is opened backwards is arranged in the piston (80); the inner side wall of the clamping cavity (81) is provided with a clamping protrusion (86) from the outer side to the center, and the rear end of the clamping connector (71) is abutted with the front end of the clamping protrusion (86) so as to fix the piston (80) to the clamping connector (71);

The outer side wall of the piston (80) is provided with a first annular flange (82), the top of the clamping cavity (81) is a conical surface, a cavity is formed between the top of the clamping cavity and the front end of the clamping joint (71), and the first annular flange (82) is axially positioned at the front side of the clamping joint (71);

The outer side wall of the piston (80) is further provided with a second annular flange (83), and the second annular flange (83) is located at the rear part of the clamping protrusion (86) in the radial direction in the axial direction.

2. A dual-chamber dispenser with a closed adaptive piston according to claim 1, wherein the front edge of the clamping chamber (81) is provided with a slope (85) opposite to the conical surface of the front end of the clamping chamber (81), the slope of the slope (85) increases from the center to the outside, and the front edge of the clamping joint (71) is abutted against the outermost side of the slope (85).

3. A dual chamber dispenser with a closed compliant piston according to claim 2, wherein the ramp (85) is circular arc shaped in cross section and increases in inclination from the centre towards the outside.

4. A dual chamber dispenser with a closed compliant piston according to claim 3, characterized in that the front edge of the bayonet (71) is provided with a chamfer, the inclination of the outermost edge of the ramp (85) being the same as the inclination of the chamfer.

5. A dual chamber medicament dispenser with a closed compliant piston according to claim 1, characterized in that the diameter of the first annular flange (82) is larger than the diameter of the second annular flange (83), the tolerance of the second annular flange (83) to the first injection chamber (11) or the second injection chamber (12) being equal to or smaller than zero.

6. A dual chamber dispensing device with a closed compliance piston according to claim 5, characterized in that the piston (80) is further provided with a third annular flange (84), which third annular flange (84) is axially located at the rear side of the bayonet (71), the diameter of the third annular flange (84) being smaller than the diameter of the second annular flange (83).

7. A dual chamber dispensing device with a closed compliance piston according to claim 6, characterized in that the cross-sectional shape of the first (82) and second (83) annular flange is circular arc shaped and the cross-sectional shape of the third annular flange (84) is rectangular.

8. The dual-chamber dispensing device with a closed adaptive piston according to claim 1, wherein the front end of the piston (80) is a conical surface, and the taper of the conical surface of the front end of the piston (80) is equal to the taper of the conical surface of the front end of the clamping chamber (81).

9. The dual-chamber dispensing device with the airtight adaptive piston according to claim 1, wherein a fixed seat (72) is arranged at the front end of the push rod (70), the clamping connector (71) is provided with a middle part of the front end of the fixed seat (72), and the rear end of the piston (80) can be in butt fit with the front end of the fixed seat (72).

10. The dual chamber dispensing device with a closed compliant piston according to claim 1, wherein the first needle cannula (50) and the second needle cannula (60) are arranged in parallel with each other at the front end of the needle hub (40); or the pipe diameter of the second needle tube (60) is larger than that of the first needle tube (50), the second needle tube (60) is sleeved outside the first needle tube (50), the front end of the first needle tube (50) extends out of the front end of the second needle tube (60), the rear end of the first needle tube (50) extends out of the rear end of the second needle tube (60) backwards and is communicated with the first injection cavity (11), and the rear end of the second needle tube (60) is communicated with the second injection cavity (12).