Syringe and self-venting syringe

Abstract

The utility model discloses a syringe and self -bleeding syringe relates to medical instrument technical field, and self -bleeding syringe includes piston push rod and float valve, is equipped with air channel in piston push rod, and air channel lower extreme extends to piston push rod lower end portion, and float valve is swingedly connected in piston push rod lower end portion along up and down direction, syringe includes cylinder and stop mouth structure, cylinder lower end portion is equipped with the injection port of intercommunication its inner chamber, piston push rod slides along cylinder inner chamber up and down, and the part of between piston push rod lower end portion and injection port in cylinder inner chamber is liquid storage chamber, and float valve moves up and blocks air channel under the buoyancy of liquid in liquid storage chamber, and stop mouth structure is established at cylinder upper end opening, when stop mouth structure abuts piston push rod and prevents its relative cylinder and moves down, and float valve has preset interval between with liquid storage chamber bottom surface, the scheme can position to the down -pressing action of piston push rod, avoids the collision damage to float valve, can prevent because float valve parameter changes and reduces the action accuracy of float valve in the exhaust process.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, and in particular to an injection cylinder and a self-venting syringe. Background Technology

[0002] In medical practice, syringes are commonly used for drug administration, vaccination, blood drawing, and contrast agent injection. Before performing an injection, it is often necessary to manually remove any gas mixed in with the syringe to prevent air bubbles from entering the patient's body with the injection fluid, causing discomfort or even serious complications.

[0003] During manual venting, in order to ensure that the gas inside the syringe is completely expelled, the operator often squeezes out a portion of the injection fluid from the injection port. This results in waste of the injection fluid and makes it unsuitable for occasions where the injection dosage is strictly required. In addition, the expelled injection fluid may also pollute the environment.

[0004] To address these issues, researchers attempted to incorporate an air passage and a float valve into the syringe piston rod. The float valve, buoyed by the injectable liquid, moves relative to the piston rod, adaptively controlling the opening and closing of the air passage. This allows for venting through the air passage without passing through the injection port, and the float valve automatically seals the air passage during gas venting to prevent the injected liquid from being expelled along with it. However, after a period of use, this solution re-emerges with the problem of difficulty in venting gas or the injection liquid being expelled along with it. Utility Model Content

[0005] The main purpose of this invention is to provide an injection cylinder that solves the technical problem that, after a period of use, the gas in a syringe that achieves venting through the cooperation of a float valve and an air passage is difficult to vent or the injection liquid is expelled along with the syringe.

[0006] To achieve the above objectives, the present invention provides an injection cylinder for use in a self-venting injector. The self-venting injector includes a piston rod and a float valve. The piston rod has an air passage, the lower end of which extends to the lower end of the piston rod. The float valve is movably connected to the lower end of the piston rod in a vertical direction. The injection cylinder includes:

[0007] The cylinder has an injection port at its lower end, which communicates with the inner cavity of the cylinder. A piston rod is slidably fitted into the inner cavity of the cylinder in a vertical direction. The portion of the inner cavity of the cylinder between the lower end of the piston rod and the injection port forms a liquid storage chamber. A float valve moves upward under the buoyancy of the liquid in the liquid storage chamber to block the lower end of the air passage.

[0008] A stop structure is provided at the upper opening of the cylinder; when the stop structure abuts against the piston rod and prevents the piston rod from moving downward relative to the cylinder, there is a preset distance between the float valve and the bottom surface of the liquid storage chamber.

[0009] In one embodiment, the upper opening edge of the cylinder is provided with an annular flange; the stop structure has a limiting part and a mounting part, the limiting part is arranged in an annular shape, the limiting part is mounted on the upper end of the annular flange, the upper end of the mounting part is connected to the limiting part, and the lower end of the mounting part is detachably engaged with the lower end of the annular flange;

[0010] The limiting part is used to abut against the piston rod to prevent the piston rod from moving downward relative to the cylinder.

[0011] In one embodiment, the upper end of the piston rod is provided with a first limiting flange extending radially outward; the upper end face of the limiting portion is used to abut against the first limiting flange to prevent the piston rod from moving downward relative to the cylinder.

[0012] In one embodiment, the piston push rod has a second limiting flange extending radially outward at its middle portion, and the second limiting flange slides in the inner cavity of the cylinder in the vertical direction; the lower end face of the limiting portion is used to abut against the second limiting flange to prevent the piston push rod from moving upward relative to the cylinder.

[0013] In one embodiment, the stop structure is made of an elastic material.

[0014] In one embodiment, the cylinder is made of a transparent material, and a background strip is provided on the surface of the cylinder to indicate the total amount of liquid in the storage chamber.

[0015] In one embodiment, the background bar includes scale lines arranged along the axial direction of the cylinder.

[0016] In one embodiment, the background strip includes a plurality of color-differentiated marker blocks, which are arranged along the axial direction of the cylinder.

[0017] In one embodiment, a ring structure is provided on the outer wall of the cylinder.

[0018] In one embodiment, two finger ring structures are provided on the outer wall of the cylinder, and the two finger ring structures are arranged at intervals along the circumference of the cylinder.

[0019] In one embodiment, a reinforcing rib is provided in the spacer area between the ring structure and the outer wall of the cylinder.

[0020] In one embodiment, the cross-sectional area of ​​the bottom of the reservoir gradually decreases along the direction close to the injection port.

[0021] This utility model also proposes a self-venting injector, which includes a piston rod, a float valve, and an injection cylinder as described above;

[0022] The piston push rod has an air passage inside, the lower end of which extends to the lower end of the piston push rod. The float valve is movably connected to the lower end of the piston push rod in the vertical direction. The piston push rod slides in the vertical direction within the inner cavity of the cylinder. The portion of the inner cavity of the cylinder between the lower end of the piston push rod and the injection port forms a liquid storage chamber. The float valve is used to move upward under the buoyancy of the liquid in the liquid storage chamber to block the lower end of the air passage.

[0023] When the stop structure abuts against the piston rod and prevents the piston rod from moving downward relative to the cylinder, there is a preset distance between the float valve and the bottom surface of the liquid storage chamber.

[0024] In the technical solution of this utility model, a float valve is installed between the liquid storage chamber of the cylinder and the air passage of the piston push rod. During the venting process after liquid extraction, the movement of the float valve relative to the piston push rod adaptively changes the communication state between the liquid storage chamber and the air passage. When the float valve is at the first height position relative to the piston push rod, the air passage is connected to the liquid storage chamber, and the gas in the liquid storage chamber can be discharged outward through the air passage. After the gas in the liquid storage chamber is emptied, the float valve moves relative to the piston push rod to the second height position under the buoyancy of the liquid in the liquid storage chamber. At this time, the float valve forms a sealing effect between the air passage and the liquid storage chamber, which can prevent the liquid in the liquid storage chamber from leaking along the air passage. Based on this embodiment, the gas mixed in the liquid storage chamber can be emptied without adjusting the placement of the self-venting syringe and without avoiding the liquid in the liquid storage chamber being discharged together, thereby reducing the injection volume. This design minimizes waste and is suitable for applications with strict dosage requirements, preventing environmental pollution caused by accidental discharge of the injection solution. Furthermore, by incorporating a stop structure at the upper opening of the cylinder, the downward pressure of the piston rod relative to the cylinder during subsequent injection is limited, ensuring a safe capacity at the bottom of the cylinder's inner cavity. This prevents the operator from excessively pressing the piston rod, which could cause the float valve to collide directly with the bottom of the cylinder's inner cavity, thus protecting the float valve. This design also helps prevent damage from collisions or parameter changes that could reduce the float valve's accuracy during venting, ensuring that the float valve can seal the gas passage at a preset time under buoyancy. This reduces the probability of problems such as difficulty in venting gas or the injection solution being discharged during venting. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0026] Figure 1 A three-dimensional structural schematic diagram of an embodiment of the injection cylinder provided by this utility model;

[0027] Figure 2 A schematic diagram of the overall front view of an embodiment of the self-venting injector provided by this utility model in its initial state;

[0028] Figure 3 A schematic cross-sectional view of the self-venting injector provided by this utility model in its initial state.

[0029] Figure 4 A schematic diagram of the overall front view of an embodiment of the self-venting injector provided by this utility model when it is in the suction state;

[0030] Figure 5 A partial cross-sectional view of the float valve relative to the piston rod in a first height position in one embodiment of the self-venting injector provided by this utility model;

[0031] Figure 6 This is a partial cross-sectional view of a self-venting injector provided by the present invention, showing the float valve at the second height position relative to the piston rod.

[0032] Explanation of icon numbers:

[0033] 1. Injector; 11. Bottle body; 12. Stop structure; 13. Background strip; 111. Injection port; 112. Liquid reservoir; 113. Annular flange; 114. Finger ring structure; 115. Reinforcing rib; 121. Limiting part; 122. Mounting part; 131. Scale line;

[0034] 2. Piston push rod; 21. Air passage; 22. First limiting flange; 23. Second limiting flange; 24. First ring;

[0035] 3. Float valve.

[0036] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0037] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0038] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0039] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0040] In medical practice, syringes are commonly used for drug administration, vaccination, blood drawing, and contrast agent injection. Before performing an injection, it is often necessary to manually remove any gas mixed in with the syringe to prevent air bubbles from entering the patient's body with the injection fluid, causing discomfort or even serious complications.

[0041] During manual venting, in order to ensure that the gas inside the syringe is completely expelled, the operator often squeezes out a portion of the injection fluid from the injection port. This results in waste of the injection fluid and makes it unsuitable for occasions where the injection dosage is strictly required. In addition, the expelled injection fluid may also pollute the environment.

[0042] To address these issues, researchers attempted to incorporate an air passage and a float valve into the syringe piston rod. The float valve, buoyed by the injectable liquid, moves relative to the piston rod, adaptively controlling the opening and closing of the air passage. This allows for venting through the air passage without passing through the injection port, and the float valve automatically seals the air passage during gas venting to prevent the injected liquid from being expelled along with it. However, after a period of use, this solution re-emerges with the problem of difficulty in venting gas or the injection liquid being expelled along with it.

[0043] After studying and analyzing the improved syringe, the researchers found that the proposed solution has relatively strict requirements on the parameters of the float valve. By controlling the size, mass, and contact area with the injection liquid of the float valve, it ensures that the float valve gradually rises at a preset rate under the buoyancy of the injection liquid during the venting process, accurately sealing the air passage at the point of gas venting to prevent the injection liquid from being discharged along with the air passage. During subsequent injection, the operator discharges the injection liquid from the injection port by pressing down the piston rod. Since the operator often presses the piston rod all the way down, the float valve connected to the lower end of the piston rod collides with the bottom of the syringe barrel. After repeated injection operations, the float valve may suffer impact damage due to continuous collisions, causing changes in its size and other parameters. This affects the accuracy of the float valve's coordination with the injection liquid and air passage during the venting process. The float valve may block the air passage before the gas is vented, or it may fail to block the air passage in time after the gas is vented, resulting in the injection liquid being discharged along with the air passage.

[0044] Based on the above problems and findings, this utility model provides an injection cylinder designed to limit the downward pressing action of the piston push rod, preventing the piston push rod from being pressed directly to the bottom and causing collision damage to the float valve, thereby avoiding to some extent the reduction in the accuracy of the float valve's action during the exhaust process due to changes in the float valve parameters.

[0045] Please see Figures 1 to 6 The syringe 1 provided by this utility model is applied to a self-venting syringe. The self-venting syringe includes a piston rod 2 and a float valve 3. The piston rod 2 has an air passage 21, the lower end of which extends to the lower end of the piston rod 2. The float valve 3 is movably connected to the lower end of the piston rod 2 in the vertical direction. The syringe 1 includes:

[0046] The cylinder 11 has an injection port 111 at its lower end, which connects to the inner cavity of the cylinder 11. The piston rod 2 is slidably fitted into the inner cavity of the cylinder 11 in the vertical direction. The portion of the inner cavity of the cylinder 11 between the lower end of the piston rod 2 and the injection port 111 forms a liquid storage chamber 112. The float valve 3 moves upward under the buoyancy of the liquid in the liquid storage chamber 112 to block the lower end of the air passage 21.

[0047] The stop structure 12 is located at the upper opening of the cylinder 11. When the stop structure 12 abuts against the piston rod 2 and prevents the piston rod 2 from moving downward relative to the cylinder 11, there is a preset distance between the float valve 3 and the bottom surface of the liquid storage chamber 112.

[0048] In this embodiment, the upper end of the piston rod 2 is located outside the cylinder 11. The operator can drive the piston rod 2 to move up and down relative to the cylinder 11 by holding the upper end of the piston rod 2. The circumferential sidewall of the lower end of the piston rod 2 can be sealed with the inner wall of the cylinder 11 in the circumferential direction. When the operator drives the piston rod 2 to move upward relative to the cylinder 11, the liquid at the injection port 111 can be drawn into the reservoir 112 based on the negative pressure. When the operator drives the piston rod 2 to move downward relative to the cylinder 11, the liquid in the reservoir 112 can be discharged outward through the injection port 111 based on the positive pressure, thereby completing the injection operation. The liquid drawn into the reservoir 112 and used for injection includes, but is not limited to, drugs, saline, blood, contrast agents, etc. The injection port 111 can be used to connect puncture devices such as needles, so that the above-mentioned liquid can be injected into the human body after puncturing the skin with puncture devices.

[0049] The float valve 3 can be movably connected to the lower end of the piston rod 2 using structures such as snaps, barbs, and pins. This ensures that the float valve 3 has a certain degree of freedom of movement relative to the piston rod 2 in the vertical direction while preventing complete separation of the float valve 3 from the piston rod 2. The float valve 3 needs to be positioned directly opposite the lower opening of the air passage 21. When the float valve 3 is in the low position (i.e., the float valve 3 is positioned relative to the piston rod 2 as shown in the image), it is in the lower position. Figure 5 When the float valve 3 is in the first height position shown, there is a certain gap between a portion of the float valve 3 and the lower end of the piston rod 2. That is, at this time, the float valve 3 does not block the lower opening of the air passage 21, and the gas in the liquid storage chamber 112 can enter the air passage 21 through the gap between the float valve 3 and the lower end of the piston rod 2. When the float valve 3 is in the high position (i.e., the float valve 3 is positioned relative to the piston rod 2 as shown in the figure), Figure 6 When the second height position is shown, the lower end of the float valve 3 and the piston push rod 2 are completely attached and block the lower opening of the air passage 21. At this time, neither the gas nor the liquid in the liquid storage chamber 112 can enter the air passage 21.

[0050] It is understandable that the aforementioned first height position can refer to a height range. When the float valve 3 is in different positions relative to the piston push rod 2 within this height range, there is a gap between a part of the float valve 3 and the lower end of the piston push rod 2 that allows gas to pass through, only the specific size of the gap is different.

[0051] Based on the above settings, in actual operation, the self-venting injector is in the following state when no aspiration operation is performed: Figure 2 and Figure 3 In the initial state shown, the operator can first immerse the injection port 111 into the liquid to be injected, and then proceed as follows: Figure 4 and Figure 5 As shown, the piston rod 2 is pulled upwards to draw liquid through the injection port 111 into the reservoir 112. The float valve 3 will also move upwards synchronously under the action of the piston rod 2. When the liquid in the reservoir 112 reaches a preset value, the upward pulling of the piston rod 2 stops. At this time, the gas mixed in the liquid, due to its lower density, will float above the liquid in the reservoir 112 and contact the float valve 3, provided the self-venting injector remains in its original position. Due to the presence of this gas, the float valve 3 is not yet fully in contact with the liquid in the reservoir 112. Under its own weight, the float valve 3 is at a low position relative to the piston rod 2 (i.e., in a position similar to...). Figure 5 At the first height position shown, the float valve 3 does not block the lower opening of the air passage 21; the operator can then block the injection port 111 to prevent liquid from escaping from the injection port 111, and then push the piston rod 2 downward. Under the pressure of the lower end of the piston rod 2, the gas in the liquid storage chamber 112 will be squeezed and enter the air passage 21 through the gap between the float valve 3 and the lower end of the piston rod 2; as the piston rod 2 continues to be pressed down, the gas in the liquid storage chamber 112 will continuously enter the air passage 21. The gas is discharged from the upper end of the air passage 21. During this process, as the gas is continuously discharged, the contact area between the float valve 3 and the liquid in the storage chamber 112 will gradually increase, and the buoyancy of the liquid on the float valve 3 will also gradually increase. Under the action of this gradually increasing buoyancy, the float valve 3 will overcome its own weight and gradually move upward relative to the piston rod 2. The gap between the float valve 3 and the lower end of the piston rod 2 will also gradually decrease as the float valve 3 moves upward. When the float valve 3 moves upward relative to the piston rod 2 to a high position (i.e., in the position shown in the image), the buoyancy of the float valve 3 will gradually increase. Figure 6 At the second height position shown, the gas in the reservoir 112 has been completely emptied through the air passage 21. At this time, the float valve 3 and the lower end of the piston rod 2 are completely abutted and block the lower opening of the air passage 21. The liquid in the reservoir 112 will not be able to enter the air passage 21. This avoids leakage of some liquid in the reservoir 112 through the air passage 21 due to excessive downward pressure of the piston rod 2. Based on the above operation, the venting operation can be completed without adjusting the placement of the self-venting syringe and without preventing the liquid in the reservoir 112 from being vented. Subsequently, the seal on the injection port 111 can be released, and the liquid in the reservoir 112 can be pushed out of the injection port 111 by the piston rod 2 for injection operation.

[0052] The stop structure 12 can be a boss or flange integrally formed at the upper opening of the cylinder 11. Alternatively, the stop structure 12 can be a flange structure detachably connected to the upper opening of the cylinder 11 via snap-fit, threaded connection, pin connection, or adhesive bonding. In practical applications, it is only necessary to ensure that the corresponding part of the stop structure 12 can block the downward-moving piston rod 2 at a preset position; the specific structural form of the stop structure 12 is not limited here.

[0053] By setting the stop structure 12, the sliding of the piston rod 2 in the inner cavity of the cylinder 11 can be limited during the injection process. This allows the bottom surface of the inner cavity of the cylinder 11 (i.e., the bottom surface of the liquid storage chamber 112) to retain a certain safe capacity, preventing the operator from pressing the piston rod 2 down excessively, which could cause the float valve 3 to collide directly with the bottom surface of the inner cavity of the cylinder 11. This can protect the float valve 3 and, to a certain extent, prevent the float valve 3 from being damaged by collision or its parameters from being changed, thus reducing the accuracy of the float valve 3's action during the venting process. This ensures that the float valve 3 can complete the sealing of the air passage 21 at the preset time node under the action of buoyancy, thereby reducing the probability of problems such as difficulty in venting gas and the injection liquid being discharged together during the venting process.

[0054] It should be noted that the space corresponding to the preset distance between the float valve 3 and the bottom surface of the inner cavity of the cylinder 11 contains a portion of gas. This portion of gas does not affect the liquid suction operation, and this portion of gas can be discharged outward during the exhaust operation.

[0055] Therefore, the syringe 1 provided in this embodiment has a float valve 3 installed between the liquid storage chamber 112 of the syringe body 11 and the air passage 21 of the piston push rod 2. During the venting process after liquid extraction, the movement of the float valve 3 relative to the piston push rod 2 adaptively changes the communication state between the liquid storage chamber 112 and the air passage 21. When the float valve 3 is at the first height position relative to the piston push rod 2, the air passage 21 is connected to the liquid storage chamber 112, and the gas in the liquid storage chamber 112 can be discharged outward through the air passage 21. After the gas in the liquid storage chamber 112 is emptied, the float valve 3 moves relative to the piston push rod 2 to the second height position under the buoyancy of the liquid in the liquid storage chamber 112. At this time, the float valve 3 forms a sealing effect between the air passage 21 and the liquid storage chamber 112, which can prevent the liquid in the liquid storage chamber 112 from leaking along the air passage 21. Based on the solution of this embodiment, the liquid storage chamber 112 can be vented without adjusting the placement of the self-venting syringe and without the liquid in the liquid storage chamber 112 being discharged together. The gas mixed in 12 is vented, thereby reducing the waste of injection solution. This is suitable for occasions with strict requirements on injection dosage and avoids environmental pollution caused by accidental discharge of injection solution. On this basis, by setting a stop structure 12 at the upper opening of the cylinder 11, the downward pressing action of the piston rod 2 relative to the cylinder 11 can be limited during subsequent injection. This ensures that the bottom surface of the inner cavity of the cylinder 11 retains a certain safety capacity, preventing the operator from pressing the piston rod 2 down excessively, which could cause the float valve 3 to collide directly with the bottom surface of the inner cavity of the cylinder 11. This protects the float valve 3 and can, to a certain extent, prevent the float valve 3 from being damaged by collision or its parameters from changing, thus reducing the accuracy of the float valve 3's action during the venting process. This ensures that the float valve 3 can complete the sealing of the gas passage 21 at the preset time node under the action of buoyancy, thereby reducing the probability of problems such as difficulty in venting gas and injection solution being discharged together during the venting process.

[0056] In one embodiment, refer to Figures 1 to 6 The upper opening edge of the cylinder 11 is provided with an annular flange 113; the stop structure 12 has a limiting part 121 and a mounting part 122. The limiting part 121 is arranged in an annular shape and is mounted on the upper end of the annular flange 113. The upper end of the mounting part 122 is connected to the limiting part 121, and the lower end of the mounting part 122 is detachably engaged with the lower end of the annular flange 113.

[0057] The limiting part 121 is used to abut against the piston rod 2 to prevent the piston rod 2 from moving downward relative to the cylinder 11.

[0058] In this embodiment, the annular flange 113 can be integrally formed on the upper opening edge of the cylinder 11, or it can be connected to the upper opening edge of the cylinder 11 by means of bonding, snap-fit ​​connection, locking, etc., which is not limited here. Illustrationly, the inner ring of the annular flange 113 can be flush with the inner cavity wall of the cylinder 11, and the outer peripheral side of the annular flange 113 can protrude radially from the outer cylinder wall of the cylinder 11 to provide a basis for snap-fit ​​engagement with the lower end of the mounting part 122.

[0059] The limiting part 121 and the mounting part 122 can be as follows Figure 3 , Figure 5 and Figure 6 The structure shown is an integrally formed structure. The inner part of the lower end face of the limiting part 121 is attached to the upper end face of the annular flange 113. The upper end of the mounting part 122 is connected to the outer part of the lower end face of the limiting part 121. The lower end of the mounting part 122 extends downward to form an inwardly bent hook structure. This hook structure can be fastened to the lower end face of the annular flange 113. In this way, the mounting fit between the stop structure 12 and the cylinder 11 is realized. Subsequently, the stop structure 12 and the cylinder 11 can be easily separated and disassembled by releasing the fastening fit between the hook structure and the annular flange 113.

[0060] The piston rod 2 passes through the inner ring of the limiting part 121 and the inner ring of the annular flange 113 and slides in the inner cavity of the cylinder 11. When the piston rod 2 is pressed down relative to the cylinder 11 to a preset height position (that is, when the float valve 3 and the bottom surface of the liquid storage chamber 112 reach a preset distance), the corresponding part on the piston rod 2 abuts against the upper end face of the limiting part 121, thereby preventing the piston rod 2 from continuing to move downward relative to the cylinder 11 and avoiding collision between the float valve 3 and the bottom surface of the liquid storage chamber 112.

[0061] In one embodiment, refer to Figures 1 to 6 The upper end of the piston rod 2 is provided with a first limiting flange 22 extending radially outward; the upper end face of the limiting part 121 is used to abut against the first limiting flange 22 to prevent the piston rod 2 from moving downward relative to the cylinder 11.

[0062] In one embodiment, refer to Figures 1 to 6 The piston push rod 2 is provided with a second limiting flange 23 extending radially outward in the middle part. The second limiting flange 23 is slidably fitted in the inner cavity of the cylinder 11 in the vertical direction. The lower end face of the limiting part 121 is used to abut against the second limiting flange 23 to prevent the piston push rod 2 from moving upward relative to the cylinder 11.

[0063] Illustration: The diameter of the main body of the piston rod 2 is smaller than the inner diameter of the cylinder 11. The outer diameter of the second limiting flange 23 matches the inner diameter of the cylinder 11. The inner diameter of the limiting part 121 is between the diameter of the main body of the piston rod 2 and the outer diameter of the second limiting flange 23. The outer diameter of the first limiting flange 22 is larger than the inner diameter of the limiting part 121. When the piston rod 2 moves downward relative to the cylinder 11 to a preset position, the lower end face of the first limiting flange 22 abuts against the upper end face of the limiting part 121, thereby preventing the piston rod 2 from moving further downward relative to the cylinder 11. Similarly, when the piston rod 2 moves upward relative to the cylinder 11 to a preset position, the upper end face of the second limiting flange 23 abuts against the lower end face of the limiting part 121, thereby preventing the piston rod 2 from moving further upward relative to the cylinder 11.

[0064] Based on the abutting fit between the limiting part 121 and the first limiting flange 22 and the second limiting flange 23, the sliding of the piston rod 2 in the inner cavity of the cylinder 11 can be limited, which can prevent the piston rod 2 from being pulled out of the cylinder 11 due to excessive upward pulling by the operator during the liquid aspiration process. At the same time, it can prevent the float valve 3 from colliding with the bottom of the inner cavity of the cylinder 11 due to excessive downward pressure by the operator during the injection process.

[0065] In addition, a sealing structure is provided between the outer wall of the piston rod 2 and the inner wall of the cylinder 11 to prevent liquid in the storage chamber 112 from leaking outward through the gap between the piston rod 2 and the cylinder 11, and to prevent external gas from entering the storage chamber 112 through the gap between the piston rod 2 and the cylinder 11; the second limiting flange 23 can be as follows Figure 3 , Figure 5 and Figure 6 The spacing shown is set above the sealing structure. The second limiting flange 23 can cooperate with the sealing structure to limit the piston rod 2 in the radial direction, so as to prevent the piston rod 2 from shaking excessively relative to the cylinder 11.

[0066] In one embodiment, refer to Figures 1 to 6 The stop structure 12 is made of elastic material.

[0067] Specifically, the stop structure 12 can be made of elastic materials such as rubber or polyurethane. This allows the mounting portion 122 of the stop structure 12 to have a certain elastic deformation capability, making it easier to snap the mounting portion 122 and the annular flange 113 together and disassemble them; at the same time, it allows the limiting portion 121 of the stop structure 12 to have a certain flexible buffering capability, which can reduce the impact when the limiting portion 121 abuts against the first limiting flange 22 and the second limiting flange 23.

[0068] In one embodiment, refer to Figures 1 to 6The cylinder 11 is made of transparent material, and a background strip 13 is provided on the surface of the cylinder 11. The background strip 13 is used to indicate the total amount of liquid in the liquid storage chamber 112.

[0069] When the cylinder 11 is made of a transparent material, it is easier for the operator to observe the liquid status in the storage chamber 112. The background strip 13 can be set on the surface of the cylinder 11 by means of attachment, etching, etc. The background strip 13 can use scale lines 131, color blocks, patterns, etc. to indicate the total amount of liquid in the storage chamber 112, so as to help the operator to know the current total amount of liquid in real time and intuitively according to the marking of the background strip 13, and to accurately determine whether the current total amount of liquid in the storage chamber 112 meets the preset requirements.

[0070] For example, the background bar 13 includes scale lines 131, which are arranged along the axis of the cylinder 11. The operator can accurately read the current total liquid volume by observing the scale lines 131 corresponding to the liquid level in the storage chamber 112. Alternatively, the background bar 13 may include multiple color-coded markers with different colors. These markers can be arranged along the axis of the cylinder 11, and each marker can correspond to a specific liquid volume range. When it is inconvenient to read the numbers on the scale lines 131, the operator can quickly and intuitively determine the current liquid volume range by observing the markers corresponding to the liquid level in the storage chamber 112.

[0071] In one embodiment, refer to Figures 1 to 6 A ring structure 114 is provided on the outer wall of the cylinder 11.

[0072] In practical applications, the operator can insert their fingers into the finger ring structure 114 to hold and fix the cylinder 11, thereby driving the piston rod 2 to move up and down relative to the cylinder 11 more stably, and thus completing the liquid suction, degassing and injection operations more stably and accurately.

[0073] In one embodiment, refer to Figures 1 to 6 Two finger ring structures 114 are provided on the outer wall of the cylinder 11, and the two finger ring structures 114 are arranged at intervals along the circumference of the cylinder 11.

[0074] When two finger ring structures 114 are spaced apart circumferentially on the cylinder 11, the operator can insert two fingers into one finger ring structure 114, thereby further improving the grip stability of the cylinder 11. In an exemplary embodiment, such as Figures 2 to 6As shown, the upper end of the piston rod 2 is provided with a first finger ring 24, and the two finger ring structures 114 set on the outer wall of the cylinder 11 are respectively called the second finger ring and the third finger ring. In actual operation, the operator can insert the index finger and middle finger into the second finger ring and the third finger ring respectively, and insert the thumb into the first finger ring 24. In this way, the piston rod 2 can be driven up and down relative to the cylinder 11 with less effort and convenience, thereby solving the problem of poor grip of traditional syringes and being more in line with the force application characteristics of the human body.

[0075] In one embodiment, refer to Figures 1 to 6 A reinforcing rib 115 is provided in the space between the ring structure 114 and the outer wall of the cylinder 11. The reinforcing rib 115 enhances the structural strength of the ring structure 114 and improves the connection stability between the ring structure 114 and the outer wall of the cylinder 11.

[0076] In one embodiment, refer to Figures 1 to 6 The cross-sectional area of ​​the bottom of the reservoir 112 gradually decreases along the direction close to the injection port 111.

[0077] In practical applications, when the float valve 3 is made of an elastic material, the bottom of the float valve 3 is usually designed to extend downwards along a direction close to the central axis X, to form a shape like... Figure 3 , Figure 5 and Figure 6 The shape shown is low at the center and high at the periphery. This increases the contact area between the bottom of the float valve 3 and the liquid in the storage chamber 112, thereby increasing buoyancy. On the other hand, the buoyancy of the liquid causes the downward protruding part of the bottom of the float valve 3 to undergo a certain degree of elastic deformation upward. This deformation is equivalent to squeezing the central area of ​​the bottom of the float valve 3 upward. This causes the periphery of the float valve 3 to undergo elastic deformation radially outward, thereby improving the tightness of the fit between the float valve 3 and the lower end of the piston push rod 2, and thus improving the sealing effect of the float valve 3 on the air passage 21.

[0078] Based on the above-described structure of the float valve 3, in this embodiment, the bottom of the liquid storage chamber 112 is configured to have a lower center and higher periphery, which is compatible with the bottom of the float valve 3. During the injection process, when the piston rod 2 is pressed down to the lowest position relative to the cylinder 11 (that is, when the stop structure 12 abuts against the piston rod 2 and prevents the piston rod 2 from moving further downward), the above-described configuration can reduce unnecessary reserved space between the bottom of the float valve 3 and the bottom of the liquid storage chamber 112, thereby avoiding interference with subsequent liquid suction operations due to excessive gas retention between the bottom of the float valve 3 and the bottom of the liquid storage chamber 112.

[0079] This utility model embodiment also provides a self-venting injector; please refer to [link / reference]. Figures 1 to 6The self-venting injector includes a piston rod 2, a float valve 3, and an injection cylinder 1 as described in any of the above embodiments;

[0080] The piston rod 2 is provided with an air passage 21, the lower end of which extends to the lower end of the piston rod 2. The float valve 3 is movably connected to the lower end of the piston rod 2 in the vertical direction. The piston rod 2 is slidably fitted in the inner cavity of the cylinder 11 in the vertical direction. The part of the inner cavity of the cylinder 11 between the lower end of the piston rod 2 and the injection port 111 forms a liquid storage chamber 112. The float valve 3 is used to move upward under the buoyancy of the liquid in the liquid storage chamber 112 to block the lower end of the air passage 21.

[0081] When the stop structure 12 abuts against the piston push rod 2 and prevents the piston push rod 2 from moving downward relative to the cylinder 11, there is a preset distance between the float valve 3 and the bottom surface of the liquid storage chamber 112.

[0082] The self-venting injector provided in this embodiment has a float valve 3 installed between the liquid storage chamber 112 of the cylinder 11 and the air passage 21 of the piston push rod 2. During the venting process after liquid extraction, the movement of the float valve 3 relative to the piston push rod 2 adaptively changes the communication state between the liquid storage chamber 112 and the air passage 21. When the float valve 3 is at the first height position relative to the piston push rod 2, the air passage 21 is connected to the liquid storage chamber 112, and the gas in the liquid storage chamber 112 can be discharged outward through the air passage 21. After the gas in the liquid storage chamber 112 is emptied, the float valve 3 moves relative to the piston push rod 2 to the second height position under the buoyancy of the injected liquid in the liquid storage chamber 112. At this time, the float valve 3 forms a sealing effect between the air passage 21 and the liquid storage chamber 112, which can prevent the injected liquid in the liquid storage chamber 112 from leaking along the air passage 21. Based on the scheme of this embodiment, the liquid storage chamber 112 can be vented without adjusting the placement of the self-venting injector and without avoiding the injected liquid in the liquid storage chamber 112 being discharged together. The gas mixed in 12 is vented, thereby reducing the waste of injection solution. This is suitable for occasions with strict requirements on injection dosage and avoids environmental pollution caused by accidental discharge of injection solution. On this basis, by setting a stop structure 12 at the upper opening of the cylinder 11, the downward pressing action of the piston rod 2 relative to the cylinder 11 can be limited during subsequent injection. This ensures that the bottom surface of the inner cavity of the cylinder 11 retains a certain safety capacity, preventing the operator from pressing the piston rod 2 down excessively, which could cause the float valve 3 to collide directly with the bottom surface of the inner cavity of the cylinder 11. This protects the float valve 3 and can, to a certain extent, prevent the float valve 3 from being damaged by collision or its parameters from changing, thus reducing the accuracy of the float valve 3's action during the venting process. This ensures that the float valve 3 can complete the sealing of the gas passage 21 at the preset time node under the action of buoyancy, thereby reducing the probability of problems such as difficulty in venting gas and injection solution being discharged together during the venting process.

[0083] The specific structure of the syringe 1 can be referred to the above embodiments. Since this self-venting syringe adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, and will not be described in detail here.

[0084] The above description is merely an exemplary embodiment of the present utility model and does not limit the patent scope of the present utility model. Any equivalent structural transformations made based on the technical concept of the present utility model and the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A syringe, characterized in that, An instrument for use in self-venting injectors includes a piston rod and a float valve. The piston rod has an air passage extending from its lower end to the lower end of the piston rod. The float valve is movably connected to the lower end of the piston rod in a vertical direction. The syringe includes: The cylinder has an injection port at its lower end, which communicates with the inner cavity of the cylinder. A piston rod is slidably fitted into the inner cavity of the cylinder in a vertical direction. The portion of the inner cavity of the cylinder between the lower end of the piston rod and the injection port forms a liquid storage chamber. A float valve moves upward under the buoyancy of the liquid in the liquid storage chamber to block the lower end of the air passage. A stop structure is provided at the upper opening of the cylinder; when the stop structure abuts against the piston rod and prevents the piston rod from moving downward relative to the cylinder, there is a preset distance between the float valve and the bottom surface of the liquid storage chamber.

2. The syringe as described in claim 1, characterized in that, The upper opening edge of the cylinder is provided with an annular flange; the stop structure has a limiting part and a mounting part. The limiting part is arranged in an annular shape and is mounted on the upper end of the annular flange. The upper end of the mounting part is connected to the limiting part, and the lower end of the mounting part is detachably snapped into the lower end of the annular flange. The limiting part is used to abut against the piston rod to prevent the piston rod from moving downward relative to the cylinder.

3. The injection cartridge as described in claim 2, characterized in that, The upper end of the piston rod is provided with a first limiting flange extending radially outward; the upper end face of the limiting part is used to abut against the first limiting flange to prevent the piston rod from moving downward relative to the cylinder. And / or, the piston push rod is provided with a second limiting flange extending radially outward at its middle part, and the second limiting flange is slidably fitted in the inner cavity of the cylinder in the vertical direction; the lower end face of the limiting part is used to abut against the second limiting flange to prevent the piston push rod from moving upward relative to the cylinder.

4. The syringe as described in claim 2, characterized in that, The stop structure is made of an elastic material.

5. The syringe as described in claim 1, characterized in that, The cylinder is made of transparent material, and a background strip is provided on the surface of the cylinder. The background strip is used to indicate the total amount of liquid in the storage chamber.

6. The syringe as described in claim 5, characterized in that, The background strip includes scale lines, which are arranged along the axial direction of the cylinder. And / or, the background strip includes multiple color blocks with color differences, and the multiple color blocks are arranged along the axial direction of the cylinder.

7. The syringe as described in claim 1, characterized in that, A ring structure is provided on the outer wall of the cylinder.

8. The syringe as described in claim 7, characterized in that, Two finger ring structures are provided on the outer wall of the cylinder, and the two finger ring structures are arranged at intervals along the circumference of the cylinder; And / or, a reinforcing rib is provided in the space between the ring structure and the outer wall of the cylinder.

9. The syringe as described in claim 1, characterized in that, The cross-sectional area of ​​the bottom of the reservoir gradually decreases along the direction close to the injection port.

10. A self-venting injector, characterized in that, The self-venting injector includes a piston rod, a float valve, and an injection cylinder as described in any one of claims 1 to 9; The piston push rod has an air passage inside, the lower end of which extends to the lower end of the piston push rod. The float valve is movably connected to the lower end of the piston push rod in the vertical direction. The piston push rod slides in the vertical direction within the inner cavity of the cylinder. The portion of the inner cavity of the cylinder between the lower end of the piston push rod and the injection port forms a liquid storage chamber. The float valve is used to move upward under the buoyancy of the liquid in the liquid storage chamber to block the lower end of the air passage. When the stop structure abuts against the piston rod and prevents the piston rod from moving downward relative to the cylinder, there is a preset distance between the float valve and the bottom surface of the liquid storage chamber.

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