A liquid dispenser having a one-way dispensing function

Abstract

The application relates to the field of liquid dispensers, in particular to a liquid dispenser with one-way dispensing function, which comprises an elastic valve body, a center seat, a drip head and a flexible container which can be manually deformed to a rigid neck to gradually reduce the internal volume, the elastic valve body is sleeved in the drip head, cooperates with the center seat to form a liquid flow channel, one-way delivers the liquid in the flexible container under pressure to the drip head, makes at least part of the liquid drip from the drip head, thereby realizes one-way flow to complete drip infusion, prevents the liquid dispenser from back gas, avoids the sterile environment in the liquid dispenser from being destroyed and causes the risk of drug oxidation.

Description

Technical Field

[0001] This application relates to the field of liquid dispensers, and more specifically, to a liquid dispenser with a unidirectional dispensing function for applying drugs or other substances to the eye. Background Technology

[0002] Various known devices exist for applying medications to the eyes. Traditional eye drop containers use flexible containers to hold the liquid, which is then applied to the eye through a dropper by squeezing the flexible container. After dispensing, air needs to be evacuated from the flexible container to restore its original shape and maintain pressure balance inside and outside the container. During the air aspiration process, residual liquid from the dropper exposed to air is re-pressurized into the liquid flow channel and the flexible container by the aspirated air, thus disrupting the sterile environment inside the flexible container.

[0003] To address the technical challenge of easily disrupting the sterile environment within traditional eye drop containers, existing technologies such as the liquid dispenser disclosed in EP1466668A1, CN104114456B, and CN200980130622.3 introduce antibacterial substances into the liquid flow channel. However, during long-term use, the antibacterial substances may detach from the flow channel or migrate into the liquid. If this liquid enters the eye tissues or the human body, it may damage extremely sensitive eye tissues such as the cornea, conjunctiva, and tear film.

[0004] Although the dispenser disclosed in the prior art CN201680019231.4 uses a bifunctional polyethersulfone membrane with hydrophilic and hydrophobic parts to filter air and antibacterial components in residual liquid, it has been found in practice that the filter membrane material used in this technical solution is prone to clogging. During the press-to-drip process, not only are air bubbles easily formed in the nozzle or flow channel, affecting the accuracy of the dosage, but air can still enter the bottle through the filter membrane and come into contact with the liquid, which can easily lead to the risk of drug oxidation and reduced liquid stability. Summary of the Invention

[0005] The purpose of this application is to provide a liquid dispenser with a unidirectional dispensing function, which can deliver liquid to the ocular tissue in a unidirectional manner, and prevent the liquid dispenser from refluxing, thus avoiding damage to the sterile environment inside the liquid dispenser and the risk of drug oxidation.

[0006] To achieve the above objectives, the technical solution adopted in this application is as follows: a liquid dispenser with a unidirectional dispensing function, comprising an elastic valve body, a central seat, a dripper, and a flexible container that can be manually deformed toward a rigid neck to gradually reduce its internal volume, wherein the elastic valve body is fitted inside the dripper and cooperates with the central seat to form a liquid flow channel, thereby delivering the pressurized liquid in the flexible container unidirectionally to the dripper, so that at least a portion of the liquid drips out from the dripper.

[0007] In some embodiments of this application, the center seat includes a base and a guide post extending from the center of the base toward the nozzle of the dropper, wherein the guide post is fitted with an elastic valve body, the base of the center seat is covered by the elastic valve body and is sealed to the skirt of the elastic valve body, so that air or liquid cannot pass through the connection between the base of the center seat and the skirt of the elastic valve body.

[0008] When the flexible container is squeezed, the liquid inside the flexible container is pressurized and enters the gap between the bottom of the elastic valve body and the base of the center seat. The elastic valve body is squeezed and deformed, detaching from the guide post of the center seat and moving towards the drip tip to abut against the drip tip. A liquid flow channel is formed between the center seat and the elastic valve body, which connects the liquid of the flexible container to the drip tip, so that at least a portion of the liquid in the flexible container is transported to the drip tip through the liquid flow channel, thereby completing the liquid dripping.

[0009] When the flexible container is released, the liquid inside the flexible container loses pressure, the elastic valve body elastically recovers, moves towards the guide post of the central seat and fits against each other, thereby closing the liquid flow channel and cutting off the liquid flow between the liquid flow channel and the dropper nozzle, and back-pressuring the liquid in the liquid flow channel to the flexible container, avoiding the risk of liquid residue in the liquid flow channel increasing the risk of contamination.

[0010] When the flexible container delivers liquid to the dropper, its volume is automatically compressed by atmospheric pressure as the liquid drips out, and its internal interconnections allow all the liquid to flow to the rigid neck. When the flexible container is released, there is no need to add air to balance the internal and external pressures, thus preventing air from entering the flexible container and causing oxidative degradation of the drug components inside.

[0011] The flexible container maintains the fixed shape of a regular container whether empty or filled with liquid. However, during liquid dispensing (i.e., when liquid flows from the nozzle), its volume can be compressed by atmospheric pressure. Whether empty or filled with liquid, the flexible container can stand upright like a regular bottle, maintaining a relatively fixed shape, facilitating liquid filling, transportation, storage, and dispensing. During dispensing, the flexible bottle contracts inward as the liquid flows out, reducing its volume and ensuring the internal space remains a fully flowing volume. The internal space is not blocked into two or more chambers due to the inward contraction of the container walls.

[0012] In some embodiments of this application, the liquid dispenser has a sterilization filter membrane between the bottom of the central seat and the flexible container to filter bacteria brought by liquid or gas that is abnormally poured into the flexible container through the liquid flow channel, so as to better ensure the sterile environment inside the flexible container.

[0013] In some embodiments of this application, the liquid dispenser has a drainage cover at the nozzle of the dropper, causing the liquid discharged from the nozzle to flow back within the drainage cover and collect into droplets on the outer end face of the drainage cover. The top of the drainage cover has a blocking area that prevents the liquid discharged from the nozzle from forming a jet, thus avoiding damage to the conjunctiva, cornea, and other ocular surface tissues by the jetting liquid flow. Drainage holes are arranged around the periphery of the blocking area at the top of the drainage cover, allowing the liquid flowing back within the drainage cover to collect into droplets on the outer surface of the top of the drainage cover under its own gravity, thus completing the liquid infusion.

[0014] In some embodiments of this application, a flow path is provided on the outer end face of the dropper, which is arranged around the nozzle of the dropper. The flow path is connected to a guide port provided at the connection between the flange of the nozzle and the flow guide cover. The residual liquid on the nozzle of the dropper is drawn and adsorbed by the siphon effect, so that it can quickly diffuse in the flow path and come into full contact with the air to dry quickly.

[0015] In a preferred embodiment of this application, the tip of the nozzle's flange extends into the flow guide shroud, guiding residual liquid adhering to the nozzle into the flow path through the guide port.

[0016] In a specific embodiment of this application, the flow route consists of radial grooves and annular grooves between the radial grooves, wherein the radial grooves are connected to the guide port of the drainage hood, allowing residual liquid to diffuse rapidly through the radial grooves and annular grooves.

[0017] In a specific embodiment of this application, a flow guide layer made of liquid moisture-wicking material is provided on the outer end face of the dripper, and a flow path connected to the guide port is arranged on the flow guide layer according to the fiber orientation of the liquid moisture-wicking material, so that the residual liquid gradually changes its surface energy along the flow path to achieve pump-free self-driven flow.

[0018] In some embodiments of this application, the liquid dispenser has an air guide hole on the drip head to allow air to flow through the cavity inside the drip head. This prevents the air pressure inside the drip head from being unable to release, which would cause the elastic valve body to expand outward due to the pressure difference between the inside and outside and fail to block the passage between the air and the flexible container. This would allow air to abnormally enter the flexible container and disrupt the sterile environment inside the flexible container.

[0019] In some embodiments of this application, the flexible container is a foldable container, a stand-up pouch container, or a flexible bladder container.

[0020] The folding bottle is a corrugated tube structure that can deform longitudinally, and the end away from the dripper is a rigid bottom in the lateral direction. By pressing the rigid bottom, the folding bottle is compressed and folded, and at least a part of the liquid in the folding bottle is unidirectionally delivered to the dripper in conjunction with the dripper to complete the dripping.

[0021] The stand-up pouch container is a bag-shaped structure with a round bottom made of soft or elastic material. The end away from the dripper is a support structure formed by heat sealing to create a flat or folded surface. By squeezing the sidewalls, the stand-up pouch container is compressed and deformed, and at least a portion of the liquid in the stand-up pouch container is unidirectionally transported to the dripper with the help of the dripper to complete the dripping.

[0022] The flexible capsule-shaped container is made of rubber, polymer, or composite material. Its deformation compensates for changes in the volume of the contents, maintaining stable system pressure. By compressing the sidewalls, the flexible capsule-shaped container is deformed, allowing at least a portion of the liquid inside to be unidirectionally delivered to the drip tip in conjunction with the dropper, thus completing the dripping process.

[0023] The stand-up pouch container described in this application can be formed with an inwardly folded bottom strip or a horizontal support surface through a hot-pressing process. After filling, it automatically expands to provide stability, and can stand upright in both empty and full states.

[0024] The flexible bladder-type container described in this application uses a multi-layer rubber-based composite material (such as corrosion-resistant synthetic rubber), and the bladder body is permanently bonded to the rigid neck through a vulcanization process. The wall thickness is precisely controlled between 0.5-1.2 mm to ensure no leakage under a working pressure of 200 kPa.

[0025] In some embodiments of this application, the liquid dispenser is further fitted with an outer shell over the flexible container, and a protective interlayer is provided between the outer shell and the flexible container. By filling the protective interlayer with protective gas, not only can oxygen be effectively reduced from seeping in through the wall of the flexible container and causing the liquid to oxidize and decompose, but moisture loss of the liquid inside the flexible container can also be effectively prevented.

[0026] In a preferred embodiment of this application, the outer shell is an elastic structural component, and the bottom of the outer shell is connected to the bottom of the flexible container. This arrangement not only forces the liquid inside the flexible container to flow unidirectionally towards the dropper by squeezing the outer shell, but also avoids longitudinal deformation of the flexible container under negative pressure, which would lead to difficulties in subsequent squeezing and use, resulting in a large amount of unusable liquid remaining in the flexible container. The outer shell is subjected to force, causing its wall to press against and squeeze the flexible container. The outer shell and the flexible container are configured together.

[0027] (1) When the user squeezes the inner deformation of the outer shell side wall, the liquid in the flexible container generates enough pressure to make the elastic valve body disengage from the center seat and move towards the dropper nozzle to abut against the dropper nozzle, forming a liquid flow channel between the center seat and the dropper nozzle, connecting the liquid with the dropper nozzle, so that at least a part of the liquid in the flexible container is transported to the dropper nozzle through the liquid flow channel, thereby completing the liquid dripping.

[0028] (2) When the force applied to the outer shell is removed, the liquid in the flexible container loses pressure, the elastic valve body elastically recovers, moves towards the central seat guide post and fits together to seal the liquid flow channel, thereby cutting off the liquid flow between the liquid flow channel and the dropper nozzle, and back-pressing the liquid in the liquid flow channel to the flexible container, avoiding the risk of liquid remaining in the liquid flow channel and increasing the risk of external contamination.

[0029] (3) When the liquid loses pressure, the flexible container is affected by the negative pressure inside and shrinks laterally within the space defined by the outer shell, shortening the liquid height during the dripping process of the flexible container, thus avoiding the impact on the pressure of the elastic valve body, thereby ensuring that the flexible container can be used when the same force is applied to the outer shell in the future.

[0030] In a specific embodiment of this application, the outer shell is further provided with an air exchange hole, and a removable sealing film is attached to the air exchange hole. The air exchange hole can protect the filling of the interlayer with inert gas, thereby effectively reducing the loss of moisture or the infiltration of oxygen into the flexible container during long-term storage or transportation of the liquid dispenser.

[0031] After the protective gas has filled the protective interlayer, a sealing diaphragm is attached to the air exchange hole to prevent leakage of the protective gas. This avoids increasing the moisture loss and oxygen permeability within the flexible container during long-term storage or transportation. When liquid needs to be dispensed, first pull open and tear off the sealing diaphragm, then press the outer shell. At least some of the protective gas will escape through the air exchange hole, reducing the resistance of the flexible container when compressing the liquid and making the liquid dripping smoother. When the outer shell is released, the protective interlayer draws air through the air exchange hole, restoring the outer shell to its initial state, ensuring that the subsequent use of the liquid dispenser is not affected.

[0032] In a specific embodiment of this application, a one-way inflation valve is provided on the air exchange hole. When the pressure of the protective gas source is higher than the internal pressure of the protective jacket, the pressure of the protective gas source overcomes the preload force of the valve core spring and the friction force, pushing the valve core (such as a conical valve core, ball valve, or diaphragm) away from the sealing seat, allowing the protective gas to enter the protective jacket through the open flow channel. When the internal pressure of the protective jacket is higher than the external pressure or the gas source for filling the protective gas is disconnected, the spring force pushes the valve core to reset, pressing the sealing seat tightly, thus physically blocking the path of the protective gas leaking from the protective jacket through the air exchange hole.

[0033] In a preferred embodiment of this application, the outer shell is a rigid cylinder, and a reset actuator is provided at the bottom end of the outer shell. The reset actuator is installed inside the outer shell and is configured such that the proximal end is subjected to force and the distal end abuts against the bottom of the flexible container. With the cooperation of the inner wall of the outer shell, the flexible container is pushed to move unidirectionally towards the dripper by the spring action of the reset actuator.

[0034] The reset actuator is configured together with the outer shell and the flexible container as follows:

[0035] (1) When the resetting actuator is subjected to force on the proximal part, the distal part of the resetting actuator abuts against the flexible container, so that the liquid in the flexible container is pressurized and enters the gap between the bottom of the elastic valve body and the base of the center seat, and generates sufficient pressure to make the elastic valve body disengage from the guide post of the center seat and move towards the drip tip to abut against the drip tip, thereby forming a liquid flow channel between the center seat and the elastic valve body, connecting the liquid between the flexible container and the drip tip, so that at least a portion of the liquid in the flexible container is transported to the drip tip through the liquid flow channel, thereby completing the liquid dripping;

[0036] (2) When the force applied to the proximal portion of the reset actuator is removed, the proximal portion of the reset actuator rebounds, causing the liquid in the flexible container to lose pressure. The elastic valve body elastically recovers, moves towards the guide post of the center seat and fits against the guide post, thereby closing the liquid flow channel and cutting off the liquid flow between the liquid flow channel and the drip tip. The liquid in the liquid flow channel is back-pressed into the flexible container to avoid the risk of liquid remaining in the liquid flow channel and increasing the risk of air contamination.

[0037] (3) The distal end of the reset actuator restricts the movement of the flexible container toward the bottom of the outer shell under the cooperation of the inner wall of the outer shell, thereby effectively restricting the elastic recovery of the flexible container and the suction of air.

[0038] In a specific embodiment of this application, the inner wall of the housing may be provided with a stop, and the distal end of the reset actuator has a wedge-shaped groove that moves toward the bottom of the housing. The wedge-shaped groove can engage with the outer edge of the distal end of the reset actuator. When a force is applied to the proximal portion of the reset actuator, the outer edge of the distal end can easily slide out of the wedge-shaped groove when moving toward the drip head. When the force applied to the proximal portion of the reset actuator is removed, the outer edge of the distal end of the reset actuator slides toward the bottom of the housing.

[0039] This application has found through research that when the critical angle of the wedge groove is 5°-30°, it is more effective in preventing the distal end of the reset actuator from retracting.

[0040] The inner wall of the housing described in this application may also be provided with other components to prevent the distal end of the reset actuator from moving toward the bottom of the housing.

[0041] The outer edge of the near end of the reset actuator moves against the flange provided at the bottom end of the housing. When the reset actuator moves towards the bottom end of the housing by the return force, the flange can restrict the near end of the reset actuator to always be within the inner cavity of the housing, ensuring the full recovery of the spring of the reset actuator, providing sufficient squeezing force for subsequent pressing into the liquid in the flexible container, thereby making the liquid dripping smoother.

[0042] In a specific embodiment of this application, the reset actuator is further provided with a support portion that cooperates with the flexible container. The bottom of the support portion is connected to the spring of the reset actuator. When the support portion moves toward the dripper, the reset actuator moves relative to the dripper, so that the spring of the reset actuator will not be in a stretched state during long-term use, causing the spring to undergo plastic deformation, which would lead to elasticity attenuation and affect the provision of sufficient squeezing force to the liquid in the flexible container during subsequent use.

[0043] The top surface of the support is concave, which allows it to fully contact the bottom of the flexible container to provide adequate support and prevent irregular deformation of the bottom of the flexible container under the influence of internal negative pressure, thus ensuring smoother subsequent liquid dripping.

[0044] In some embodiments of this application, the liquid dispenser is provided with a cover, and a retaining ring is provided at the bottom of the inner wall of the cover, which cooperates with a retaining ring provided on the rigid neck of the flexible container, so that the cover is locked and fixed on the flexible container. When the cover is placed on the drip tip of the liquid dispenser, the cover is adapted to pressurize the air in the drip tip through the air guide hole on the drip tip, compressing the elastic valve body so that the elastic valve body and the center seat can fit more tightly, thereby further improving the airtightness between the elastic valve body and the center seat and preventing abnormal air infiltration into the flexible container.

[0045] Compared with the prior art, this application has the following beneficial effects:

[0046] 1. The liquid dispenser provided in this application, with the cooperation of the elastic valve body and the center seat, enables one-way communication between the dropper and the flexible container. This not only effectively delivers the liquid to the eye tissue through the dropper in one direction, but also prevents the flexible container from drawing back outside air or residual liquid, thus preventing damage to the sterile environment inside the flexible container and reducing the risk of oxidation of the active pharmaceutical ingredients in the liquid solution.

[0047] 2. The liquid dispenser provided in this application uses an air guide hole to allow air to flow through the cavity inside the dripper, preventing the pressure in the dripper from failing to release. This would cause the elastic valve body to expand outward due to the internal and external pressure difference, thus failing to block the passage between the air and the flexible container. Consequently, air would be abnormally injected into the flexible container, disrupting the sterile environment inside the flexible container.

[0048] 3. The liquid dispenser provided in this application is further equipped with a drainage cover through the dropper nozzle, so that the pressurized liquid flows back and gathers into droplets in the drainage cover, thereby avoiding excessive pressure of the pressurized liquid in the liquid channel, which would cause liquid spray and damage to the ocular surface tissue.

[0049] 4. The liquid dispenser provided in this application has a flow path arranged around the dropper tip on the outer end face of the dropper tip. The flow path is connected to the guide port of the dropper tip guide portion. It uses siphon effect to draw and adsorb the residual liquid on the dropper tip, so that it can quickly diffuse in the flow path and come into full contact with the air to dry quickly.

[0050] 5. The liquid dispenser provided in this application has a protective interlayer between the outer shell and the flexible container. By filling the protective interlayer with protective gas, it can not only effectively reduce the oxygen from seeping into the flexible container through the wall of the flexible container, causing the liquid to oxidize and decompose, but also effectively prevent the loss of moisture from the liquid in the flexible container.

[0051] 6. The liquid dispenser provided in this application, by arranging the reset actuator inside the housing and cooperating with the support portion that matches the bottom of the flexible container, not only makes the flexible container uniformly stressed along the proximal portion of the reset actuator, thus making the elastic deformation of the flexible container more uniform, but also effectively reduces liquid residue in the flexible container and improves liquid utilization.

[0052] 7. The liquid dispenser provided in this application has a cover that cooperates with the chamber of the dropper through an air guide hole on the dropper. When the cover is placed on the liquid dispenser, it can quickly pressurize the air in the nozzle, squeeze the elastic valve body, and make the elastic valve body fit more tightly with the center seat, thereby further improving the airtightness between the elastic valve body and the center seat and preventing abnormal air from seeping into the flexible container. Attached Figure Description

[0053] Figure 1 This is a schematic diagram of the flexible container, a stand-up pouch-type liquid dispenser, as described in Example 1.

[0054] Figure 2 A schematic diagram illustrating the liquid dispenser described in Example 1, used to complete the droplet injection.

[0055] Figure 3To release the liquid dispenser described in Example 1, the elastic valve body closes the liquid flow channel, and the flexible container is compressed (illustration).

[0056] Figure 4 This is a schematic diagram illustrating the effect of the liquid dispenser described in Example 1 failing to drip liquid.

[0057] Figure 5 This is a schematic diagram of the liquid dispenser structure of Example 1, where the flexible container is a foldable container.

[0058] Figure 6 This is a schematic diagram of the liquid dispenser structure of Example 1, where the flexible container is a flexible bladder-type container.

[0059] Figure 7 This is a schematic diagram of the structure of the liquid dispenser with a flow guide cover in Example 2.

[0060] Figure 8 This is a schematic diagram of the liquid distributor having a flow path in Example 3.

[0061] Figure 9 This is a top view of the flow path provided on the liquid distributor in Embodiment 3.

[0062] Figure 10 This is a schematic diagram of the structure of the liquid dispenser with a flow guiding layer on the nozzle as described in Embodiment 3.

[0063] Figure 11 is a schematic diagram of the flexible container of the liquid dispenser described in Embodiment 4 with an outer shell. Figure 11(a) is a schematic diagram of a removable sealing film attached to the air exchange hole of the outer shell, and Figure 11(b) is a schematic diagram of a one-way air inlet valve provided on the air exchange hole.

[0064] Figure 12 A schematic diagram illustrating the liquid dispenser described in Example 4, used to complete the droplet injection.

[0065] Figure 13 To release the liquid dispenser described in Example 4, the elastic valve body closes the liquid flow channel, and the flexible container is compressed (illustration).

[0066] Figure 14 This is a schematic diagram of the liquid dispenser described in Example 5.

[0067] Figure 15 A schematic diagram illustrating the liquid dispenser described in Example 5, used to complete the droplet injection.

[0068] Figure 16 To release the liquid dispenser described in Example 5, the elastic valve body closes the liquid flow channel, and a schematic diagram of the flexible container being compressed.

[0069] Figure 17 This is a schematic diagram of the final use of the liquid dispenser described in Example 5.

[0070] Figure 18 shows the liquid dispenser of Embodiment 5 with a support portion. The flexible container in Figure 18(a) is a foldable container, the flexible container in Figure 18(b) is a stand-up pouch container, and the flexible container in Figure 18(c) is a flexible bladder container.

[0071] Figure 19 This is a schematic diagram of the liquid dispenser with a cover as described in Example 6.

[0072] Explanation of reference numerals in the attached figures:

[0073] 1-Elastic valve body, 11-Skirt

[0074] 2. Center seat, 21-base, 22-guide post

[0075] 3. Dropper, 31-Drip tip, 32-Drainage hood, 321-Blocking area, 322-Drainage hole, 323-Guide port, 33-Flow path, 331-Radial groove, 332-Annular groove, 34-Guide layer, 35-Gas guide hole

[0076] 4. Flexible containers

[0077] 5. Liquid flow channel

[0078] 6. Sterilizing filter membrane

[0079] 7. Housing, 71-Air exchange port, 72-Sealing diaphragm, 73-One-way inflation valve, 74-Reset actuator, 741-Spring, 742-Distal outer edge, 743-Proximal outer edge, 744-Support, 75-Wedge groove, 76-Flange

[0080] 8. Protective interlayer

[0081] 9. Cover Detailed Implementation

[0082] The technical solutions in the embodiments described in this application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments created in this application, and not all of the embodiments. Based on the embodiments created in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0083] The "pressurized liquid" mentioned in this article refers to the liquid inside the flexible container that enters the gap between the bottom of the elastic valve body and the center seat base by applying force to the flexible container, and can generate a force that causes the elastic valve body to detach from the center seat.

[0084] The "depressurized liquid" refers to the liquid in the gap between the bottom of the elastic valve body and the center seat base after the force applied to the flexible container is removed, which is insufficient to overcome the elastic restoring force of the elastic valve body, causing the elastic valve body to move towards the center seat and fit against the center seat.

[0085] Example 1

[0086] This embodiment provides a liquid dispenser with unidirectional dispensing function, such as Figure 1-4 As shown, it includes an elastic valve body 1, a center seat 2, a dripper 3, and a flexible container 4 that can be manually deformed toward a rigid neck to gradually reduce its internal volume. The elastic valve body 1 is fitted inside the dripper 3, and a liquid flow channel 5 is formed by the cooperation of the center seat 2 and the elastic valve body 1, which can deliver the pressurized liquid in the flexible container 4 to the dripper 3 in one direction, so that at least a portion of the liquid is discharged from the dripper 3.

[0087] The center seat 2 consists of a base 21 and a guide post 22 extending from the center of the base 21 toward the drip head 3. The guide post 22 is attached to the elastic valve body 1. The base 21 of the center seat 2 is covered by the elastic valve body 1 and is sealed to the bottom skirt 11 of the elastic valve body 1, so that air or liquid cannot pass through the connection between the base 21 of the center seat 2 and the skirt 11 of the elastic valve body 1.

[0088] The basic working principle of the liquid dispenser with unidirectional dispensing function described in this embodiment is as follows:

[0089] When the user squeezes the flexible container 4, the liquid inside the flexible container 4 is forced into the gap between the bottom of the elastic valve body 1 and the base 21 of the center seat 2. The squeezed elastic valve body 1 causes it to elastically deform and detach from the center seat 2, and moves towards the dripper 3 nozzle 31 and abuts against the dripper 3 nozzle 31. A liquid flow channel 5 is formed between the center seat 2 and the elastic valve body 1, which conducts the liquid connection with the dripper 3 nozzle 31, so that at least a part of the liquid in the flexible container 4 is transported to the dripper 3 nozzle 31 through the liquid flow channel 5, thereby completing the liquid dripping.

[0090] When the user releases the flexible container 4, the liquid inside the flexible container 4 loses pressure. The liquid in the gap between the bottom of the elastic valve body 1 and the base of the center seat 2 is insufficient to overcome the elastic restoring force of the elastic valve body 2, causing the elastic valve body 2 to move towards the guide post 22 of the center seat 2 and close together to shut off the liquid flow channel 5. This cuts off the liquid flow between the liquid flow channel 5 and the drip tip 31 of the dropper 3, and back-presses the liquid in the liquid flow channel 5 into the flexible container 4, preventing the liquid from remaining in the liquid flow channel 5 and increasing the risk of exposure to air. The flexible container 4 does not require air replenishment to balance the internal and external pressure when the user releases it; it automatically adjusts its shape according to the amount of liquid inside the container to balance the internal and external pressure, thereby preventing air from entering the flexible container 4 and ensuring the stability of easily oxidized and degradable substances in the liquid inside.

[0091] The flexible container 4 is a self-contracting container that does not generate negative pressure during liquid dripping. Its volume is automatically compressed by atmospheric pressure as the liquid drips, while the internal space remains completely interconnected, allowing all the liquid to flow to the rigid neck of the container. When the flexible container 4 is released, there is no need to replenish air to balance the internal and external pressures, thus preventing air from entering the flexible container 4 and causing oxidative degradation of the drug components inside.

[0092] The flexible container 4 maintains the fixed shape of a conventional container whether empty or filled with liquid. However, when liquid is being dispensed (i.e., flowing from the nozzle 31), it is compressed by atmospheric pressure. Whether in an empty bottle or filled with liquid, the flexible container 4 can stand upright like a regular bottle, maintaining a relatively fixed shape, facilitating liquid filling, transportation, storage, and pre-dispensing operations. During dispensing, the flexible container 4 contracts inward as the liquid flows out, reducing its volume and ensuring the internal space remains a fully circulating volume. The internal space is not blocked into two or more chambers due to the inward contraction of the container walls.

[0093] The flexible container 4 described in this embodiment is preferably a foldable container, a stand-up pouch container, or a flexible bladder container.

[0094] Among them, such as Figure 5 As shown, the folding container is a corrugated tube structure that can deform longitudinally, and the end away from the dripper is a horizontally rigid bottom. By pressing the rigid bottom, the folding container is compressed and folded, and at least a portion of the liquid in the folding container is unidirectionally transported to the dripper nozzle 31 of the dripper 3 in conjunction with the dripper 3 to complete the dripping.

[0095] like Figure 1As shown, the stand-up pouch container is a bag-shaped structure made of soft or elastic material. The end away from the dripper is a support structure formed by heat sealing to form a flat or folded shape. By squeezing the side wall, the stand-up pouch container is compressed and deformed, and at least a portion of the liquid in the stand-up pouch container is unidirectionally transported to the dripper nozzle 31 of the dripper 3 in conjunction with the dripper 3 to complete the dripping.

[0096] like Figure 6 As shown, the flexible capsule-shaped container is made of rubber, polymer, or composite material. Its deformation compensates for changes in the volume of the contents, maintaining stable system pressure. By squeezing the sidewalls, the flexible capsule-shaped container is compressed and deformed, allowing at least a portion of the liquid inside to be unidirectionally delivered from the dropper 3 to the nozzle 31, thus completing the dripping process.

[0097] The stand-up pouch container described in this embodiment can be formed with an inwardly folded bottom strip or a horizontal support surface through a hot-pressing process. After filling, it automatically expands to provide stability, and can stand upright in both empty and full states.

[0098] The flexible bladder container described in this embodiment uses a multi-layer rubber-based composite material (such as corrosion-resistant synthetic rubber). The bladder body is permanently bonded to the rigid neck through a vulcanization process. The wall thickness is precisely controlled within the range of 0.5-1.2 mm to ensure no leakage under a working pressure of 1.25 MPa.

[0099] In this embodiment, the outer end face of the dropper 3 is also provided with an air guide hole 35, which allows the cavity inside the dropper 3 to be connected with air. This prevents the air pressure inside the dropper 3 from being unable to be released, causing the elastic valve body 1 to expand outward due to the internal and external pressure difference. This would prevent the passage between the air and the flexible container 4 from being blocked, allowing air to be abnormally injected into the flexible container 4, thereby damaging the sterile environment inside the flexible container 4 and posing a risk of oxidation to the active pharmaceutical ingredients in the liquid solution.

[0100] The liquid dispenser described in this embodiment may also be provided with a sterilization filter membrane 6 between the bottom 21 of the central seat 2 and the flexible container 4 to filter bacteria brought by liquid or gas abnormally poured into the flexible container 4 through the liquid flow channel 5.

[0101] The sterilization filter membrane 6 described in this embodiment is uniformly distributed with micropores of ≤0.22 micrometers. The sterilization filter membrane 6 can be made of one or more materials selected from polyethersulfone (PES), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE) or nylon.

[0102] The sterilization filter membrane 6 described in this embodiment can also be selected from commercially available sterilization filter membranes such as Jinchun PTFE industrial filter membrane, Lechun Bio Extreme™ PVDF membrane, SteriPure series filter cartridges, or Millipore sterile single-piece filter membrane.

[0103] Example 2

[0104] This embodiment is based on embodiment 1, such as... Figure 7 As shown, the dropper 3 has a flow guide 32 on the dropper 3 nozzle 31, so that the liquid discharged by the dropper 3 forms a backflow in the flow guide 32 and gathers into droplets on the outer end face of the flow guide 32.

[0105] The drainage hood 32 has a blocking area 321 at its top, which prevents the liquid discharged from the nozzle 31 from forming a jet, thus avoiding damage to the conjunctiva, cornea, and other ocular surface tissues by the jetting liquid flow. Drainage holes 322 are arranged around the periphery of the blocking area 321 at the top of the drainage hood 32, allowing the liquid flowing back into the drainage hood 32 to collect as droplets on the outer surface of the top of the drainage hood 32 under its own gravity, completing the liquid dripping process.

[0106] Example 3

[0107] This embodiment is based on embodiment 2, such as Figure 8-10 As shown, a flow path 33 is provided on the outer end face of the dropper 3, surrounding the dropper tip 31. The flow path 33 is connected to the guide port 323 located at the connection between the flange of the dropper tip 31 and the flow guide 32. The residual liquid on the dropper tip 31 is drawn and adsorbed by the siphon effect, so that it diffuses rapidly in the flow path 33 and dries quickly by fully contacting the air.

[0108] In this embodiment, the flange tip of the dropper 3 nozzle 31 extends into the drainage cover 32, guiding the residual liquid attached to the dropper 3 nozzle 31 to quickly enter the flow path 33 through the guide port 323.

[0109] In this embodiment, the flow path 33 is composed of radial grooves 331 that radiate radially around the guide port 323 of the drip tip 31 and annular grooves 332 between each radial groove 331, so that residual liquid can be rapidly diffused in the flow path 33 through the radial grooves 331 and the annular grooves 332.

[0110] Among them, such as Figure 10 As shown, a flow guide layer 34 made of liquid moisture-wicking material is provided on the outer end face of the dripper 3, and a flow path 33 connected to the guide port 323 of the dripper nozzle 31 flow guide cover 32 is arranged on the flow guide layer 34 according to the fiber orientation of the liquid moisture-wicking material, so that the residual liquid gradually changes its surface energy along the flow path 33 to achieve pump-free self-driven flow.

[0111] Example 4

[0112] Based on Embodiment 1, as shown in Figures 11(a) and 11(b), the liquid dispenser further includes an outer shell 7 fitted over the flexible container 4. A protective interlayer 8 is provided between the outer shell 7 and the flexible container 4. By filling the protective interlayer 8 with a protective gas, not only can oxygen be effectively reduced from seeping through the wall of the flexible container 4, thus preventing the liquid from oxidizing and decomposing, but it can also effectively prevent water loss from the liquid inside the flexible container 4. This would prevent discomfort such as burning pain, foreign body sensation, and congestion in the eyes caused by an increase in drug concentration or pH change in the solution, and in severe cases, damage to the corneal epithelium. The protective gas in this embodiment can be selected from nitrogen, argon, or carbon dioxide.

[0113] As shown in Figure 11(a), the outer shell 7 is also provided with an air exchange hole 71, and a removable sealing film 72 is attached to the air exchange hole 71. Protective gas can be injected into the protective interlayer 8 through the air exchange hole 71, thereby effectively reducing the loss of moisture or oxygen infiltration into the flexible container 4 during long-term storage or transportation of the liquid distributor.

[0114] After the protective gas has filled the protective interlayer 8, a sealing diaphragm 72 is affixed to the air exchange hole 71 to seal it and prevent leakage of the protective gas. This effectively reduces moisture loss or oxygen infiltration into the flexible container during long-term storage or transportation. When liquid needs to be dispensed, first pull off the sealing diaphragm 72 and press the outer shell 7. At least some of the protective gas will escape through the air exchange hole 71, reducing the resistance of the flexible container 4 to the liquid and making the liquid dispensing smoother. When the outer shell 7 is released, the protective interlayer 8 draws air through the air exchange hole 71 to restore the outer shell to its initial state, ensuring that the subsequent use of the liquid dispenser is not affected.

[0115] As shown in Figure 11(b), the liquid distributor in this embodiment may also be provided with a one-way inflation valve 73 on the air exchange hole 71. When the pressure of the protective gas source is higher than the internal pressure of the protective jacket 8, the pressure of the protective gas source overcomes the preload force and friction of the valve core spring of the one-way inflation valve 73, pushing the valve core (such as a conical valve core, ball valve or diaphragm) away from the sealing seat, thereby opening the one-way inflation valve 73 and allowing the protective gas to enter the protective jacket 8 through the air exchange hole 7. When the internal pressure of the protective jacket 8 is higher than the external pressure or when the protective gas is filled, the gas source is disconnected, and the spring force of the one-way inflation valve 73 pushes the valve core to reset, pressing the sealing seat tightly, thereby closing the inflation valve 73 and physically blocking the path of the protective gas leaking from the protective jacket 8 through the air exchange hole 71.

[0116] In this embodiment, the outer shell 7 is an elastic structural component, as shown in Figures 11(a) and 11(b). The bottom center of the outer shell 7 is connected to the bottom center of the flexible container 4. This design allows the liquid in the flexible container 4 to flow unidirectionally towards the drip nozzle 31 under pressure by squeezing the outer shell 7, while also preventing the flexible container 4 from deforming longitudinally under negative pressure, which would make subsequent squeezing difficult and cause it to become unusable, resulting in a large amount of liquid remaining in the flexible container 4 and rendering it unusable.

[0117] The specific principle is as follows: Force is applied to the outer shell 7, causing its wall to deform and press against and compress the flexible container 4. Under the combined configuration of the outer shell 7 and the flexible container 4:

[0118] (1) When the inner wall of the outer shell 7 deforms, such as Figure 12 As shown, the liquid in the flexible container 4 is pressurized and enters the gap between the bottom of the elastic valve body 1 and the base 21 of the center seat 2, generating sufficient pressure to make the elastic valve body 1 disengage from the guide post 22 of the center seat 2 and move towards the dripper 3 nozzle 31 to abut against the dripper 3 nozzle 31, thereby forming a liquid flow channel 5 between the center seat 2 and the elastic valve body 1, connecting the liquid to the dripper 3 nozzle 31, so that at least a portion of the liquid in the flexible container 4 is transported to the dripper 3 nozzle 31 through the liquid flow channel 5, thereby completing the liquid dripping;

[0119] (2) When the force applied to the outer casing 7 is removed, such as Figure 13 As shown, when the liquid in the flexible container 4 loses pressure, the elastic valve body 1 elastically recovers, moves towards the guide column of the center seat 2 and fits together, closing the liquid flow channel 5, thereby cutting off the liquid flow between the liquid flow channel 5 and the drip tip 31 of the dripper 3, and back-pressing the liquid in the liquid flow channel 5 to the flexible container 4, avoiding the risk of liquid remaining in the liquid flow channel 5 and increasing the risk of air contamination.

[0120] (3) When the liquid loses pressure, the flexible container 4, as Figure 13 As shown, the liquid height of the flexible container 4 during the dripping process is shortened by the lateral contraction and deformation within the outer shell 7 due to the internal negative pressure, thus avoiding the impact on the pressure of the elastic valve body 1 and ensuring that the flexible container 4 can be used even when the same force is applied to the outer shell 7 in the future. This also avoids the problem of a large amount of liquid remaining in the flexible container 4, making it unusable.

[0121] The one-way inflation valve 73 described in this embodiment can also be selected from gravity type, diaphragm type or swing type one-way inflation valve, wherein the one-way inflation valve 73 can be injection molded into the outer shell 7 as an integral component by a melt process.

[0122] Example 5

[0123] The difference between this embodiment and embodiment 4 is that, Figure 14As shown, the outer shell 7 is a rigid cylinder. A reset actuator 74 is provided at the bottom end of the outer shell 7. The reset actuator 74 is configured to be placed inside the outer shell 7. The reset actuator 74 is configured to be subjected to force at its proximal end and to abut against the bottom of the flexible container 4 at its distal end. With the cooperation of the inner wall of the outer shell 7, the flexible container 4 is pushed to move unidirectionally toward the dripper 3 by the action of the spring 741 located inside the reset actuator 74.

[0124] The reset actuator 74 is configured together with the outer shell 7 and the flexible container 4 as follows:

[0125] (1) When a force is applied to the proximal portion of the reset actuator 74, such as Figure 15 As shown, the distal end of the reset actuator 74 abuts against the flexible container 4, causing the liquid in the flexible container 4 to be pressurized and enter the gap between the bottom of the elastic valve body 1 and the base 21 of the center seat 2, and generating sufficient pressure to make the elastic valve body 1 disengage from the guide post 22 of the center seat 2 and move towards the dripper 3 nozzle 31 to abut against the dripper 3 nozzle 31, thereby forming a liquid flow channel 5 between the center seat 2 and the elastic valve body 1, connecting the liquid to the dripper 3 nozzle 31, so that at least a portion of the liquid in the flexible container 4 is transported to the dripper 3 nozzle 31 through the liquid flow channel 5, thereby completing the liquid dripping;

[0126] (2) When the force applied to the proximal portion of the reset actuator 74 is removed, such as Figure 16 As shown, the proximal portion of the reset actuator 74 rebounds, causing the liquid in the flexible container 4 to lose pressure. The elastic valve body 1 elastically recovers and moves towards the guide post of the center seat 2 and fits against each other, thereby cutting off the liquid flow between the liquid channel 5 and the drip tip 31 of the dropper 3, and closing the liquid channel 5 to back-press the liquid in the liquid channel 5 to the flexible container 4, avoiding the risk of liquid remaining in the liquid channel 5 and increasing the risk of air contamination.

[0127] (3) The distal end of the reset actuator 74 restricts the flexible container 4 from moving toward the bottom of the outer shell 7 under the cooperation of the inner wall of the outer shell 7, thereby restricting the flexible container 4 from elastically recovering and sucking air.

[0128] In this embodiment, the inner wall of the outer casing 7 may be provided with a wedge-shaped groove 75 to prevent the distal end of the reset actuator 74 from moving toward the bottom of the outer casing 7. The wedge-shaped groove 75 engages with the outer edge 742 of the distal end of the reset actuator 74. When force is applied to the proximal portion of the reset actuator 74, the outer edge 742 of the distal end can easily slide out of the wedge-shaped groove 75 when moving toward the drip head. When the force applied to the proximal portion of the reset actuator 74 is removed, the outer edge 742 of the distal end of the reset actuator 74 slides toward the bottom of the outer casing 7.

[0129] This application has found through research that when the critical angle of the wedge-shaped groove 75 is between 5° and 30°, its effect in preventing the distal end of the reset actuator 74 from retracting is even better. In this embodiment, the inner wall of the housing 7 may also be configured with other components to prevent the distal end of the reset actuator 74 from moving towards the bottom of the housing 7.

[0130] Among them, such as Figure 15-17 As shown, the proximal outer edge 743 of the reset actuator 74 movably abuts against the flange 76 provided at the bottom end of the housing 7. When the reset actuator 74 moves toward the bottom end of the housing 7 by the return force generated by the spring 741 located inside the reset actuator 74, the flange 76 can always restrict the proximal end of the reset actuator 74 within the inner cavity of the housing 7, ensuring that the spring 741 of the reset actuator 74 can be fully restored, providing sufficient squeezing force to the liquid in the flexible container 3 during subsequent use, thereby making the liquid dripping smoother.

[0131] The reset actuator 74 described in this embodiment is also provided with a support portion 744 that cooperates with the flexible container 4, as shown in FIG18. The bottom of the support portion 744 is connected to the spring 741 of the reset actuator 74. When the support portion 744 moves toward the dripper 3, the reset actuator 74 moves relative to the dripper 3, so that the spring 741 of the reset actuator 74 will not be in a stretched state during long-term use, causing the spring 741 to undergo plastic deformation, which would lead to the loss of elasticity and affect the supply of sufficient squeezing force to the liquid in the flexible container 3 during subsequent use.

[0132] The top surface of the support 744 is concave, which allows the top surface of the support 744 to fully contact the bottom of the flexible container 4, so as to fully support the flexible container 4 and prevent the flexible container 4 from undergoing irregular deformation during filling, storage, transportation and use, thereby ensuring smoother liquid dripping.

[0133] In this embodiment, the reset actuator 74 can achieve reset not only through a spring, but also through its own elasticity or other means.

[0134] Example 6

[0135] This embodiment is based on any of the embodiments 1-5, such as Figure 19 As shown, the liquid dispenser is provided with a cover 9, and a retaining ring is provided at the bottom of the inner wall of the cover 9, which cooperates with the retaining ring provided on the rigid neck of the flexible container 4, so that the cover 9 is locked and fixed on the flexible container 4.

[0136] When the cover 9 is placed on the dripper 3, the cover 9 pressurizes the air inside the dripper 3 through the air guide hole 35, squeezing the elastic valve body 1, thereby further improving the airtightness between the elastic valve body 1 and the center seat 2, and preventing abnormal air infiltration into the flexible container 4.

[0137] The elastic valve body described in this application is made of a material that can return to its original shape after the external force is removed. This material can be selected from any one or more of rubber, silicone, elastic alloys, sponge, latex, styrene-based block copolymers, polyurethane, polyolefins, and polyamides. The elastic valve body described in this application can also be made of a shape memory material, which can be selected from any one or more of shape memory alloys, shape memory ceramics, and shape memory polymers.

[0138] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the method and its core ideas. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A liquid dispenser with unidirectional dispensing function, comprising a resilient valve body, a central seat, a dripper, and a flexible container that can be manually deformed toward a rigid neck to progressively reduce its internal volume, characterized in that, The elastic valve body is fitted inside the dripper and cooperates with the center seat to form a liquid flow channel, delivering the pressurized liquid in the flexible container unidirectionally to the dripper, so that at least a portion of the liquid drips out from the dripper.

2. The liquid dispenser with unidirectional dispensing function according to claim 1, characterized in that, The center seat includes a base and a guide post located at the center of the base and extending toward the drip tip, wherein the guide post is in contact with the elastic valve body; The base of the central seat is covered by the elastic valve body and is sealed to the skirt of the elastic valve body, so that air or liquid cannot pass through the connection between the base of the central seat and the skirt of the elastic valve body.

3. The liquid dispenser with unidirectional dispensing function according to claim 1, characterized in that, When the flexible container delivers liquid to the dropper, the volume inside the flexible container is automatically compressed by atmospheric pressure as the liquid drips out, and the internal space is a fully unobstructed volume space, so that all the liquid can flow to the rigid neck.

4. The liquid dispenser with unidirectional dispensing function according to claim 1, characterized in that, The flexible container has a fixed shape when it is empty and when it is filled with liquid medicine.

5. The liquid dispenser with unidirectional dispensing function according to claim 1, characterized in that, The flexible container is a foldable container, a stand-up pouch container, or a flexible bladder container.

6. The liquid dispenser with unidirectional dispensing function according to claim 1, characterized in that, A sterilization filter membrane is provided between the bottom of the central seat and the flexible container.

7. The liquid dispenser with unidirectional dispensing function according to claim 2, characterized in that, The dropper head is equipped with a flow guide, which causes the liquid discharged from the nozzle to flow back within the flow guide and to collect into droplets on the outer end face of the flow guide.

8. The liquid dispenser with unidirectional dispensing function according to claim 7, characterized in that, The top of the drainage hood is provided with a blocking area, which can block the liquid discharged from the nozzle from forming a jet; drainage holes are arranged around the periphery of the blocking area on the top of the drainage hood, so that the liquid flowing back in the drainage hood can be collected into droplets on the outer surface of the top of the drainage hood under its own gravity and complete the liquid dripping.

9. The liquid dispenser with unidirectional dispensing function according to claim 8, characterized in that, The outer end face of the dropper is provided with a flow path arranged around the dropper tip. The flow path is connected to the guide port located at the connection between the flange of the dropper tip and the flow guide cover. The flow path draws in and absorbs the residual liquid in the dropper tip, allowing it to quickly diffuse within the flow path and come into full contact with the air for rapid drying.

10. The liquid dispenser with unidirectional dispensing function according to claim 9, characterized in that, The tip of the nozzle's flange extends into the drainage hood, guiding residual liquid adhering to the nozzle into the flow path through the guide port.

11. The liquid dispenser with unidirectional dispensing function according to claim 9, characterized in that, The flow path consists of radial grooves and annular grooves between each radial groove, wherein the radial grooves are connected to the guide port of the drainage hood, allowing residual liquid to diffuse rapidly through the radial grooves and annular grooves.

12. The liquid dispenser with unidirectional dispensing function according to claim 9, characterized in that, A flow guide layer made of liquid moisture-wicking material is provided on the outer end face of the dripper, and flow paths connected to the guide port are arranged on the flow guide layer according to the fiber orientation of the liquid moisture-wicking material, so that the residual liquid gradually changes its surface energy along the flow path and drives the flow.

13. The liquid dispenser with unidirectional dispensing function according to claim 1, characterized in that, The liquid dispenser has an air guide hole on the dropper head, which allows the cavity inside the dropper head to be connected with air.

14. A liquid dispenser with unidirectional dispensing function according to any one of claims 1-13, characterized in that, An outer shell is fitted over the flexible container.

15. The liquid dispenser with unidirectional dispensing function according to claim 14, characterized in that, The outer shell is an elastic structural component, and the bottom of the outer shell is connected to the bottom of the flexible container.

16. The liquid dispenser with unidirectional dispensing function according to claim 15, characterized in that, A protective interlayer is provided between the outer shell and the flexible container.

17. The liquid dispenser with unidirectional dispensing function according to claim 16, characterized in that, The outer casing is provided with an air exchange vent, which is configured to inject inert gas into the protective interlayer.

18. The liquid dispenser with unidirectional dispensing function according to claim 17, characterized in that, A removable sealing diaphragm or a one-way inflation valve is provided on the air exchange port.

19. The liquid dispenser with unidirectional dispensing function according to claim 14, characterized in that, The outer shell is a rigid cylinder, and a reset actuator is provided at the bottom end of the outer shell. The reset actuator, in cooperation with the inner wall of the outer shell, pushes the flexible container to move unidirectionally towards the dripper.

20. The liquid dispenser with unidirectional dispensing function according to claim 19, characterized in that, The inner wall of the housing may be provided with a wedge-shaped groove to stop the distal end of the reset actuator from moving toward the bottom of the housing; The wedge-shaped groove can engage with the distal outer edge of the reset actuator. When force is applied to the proximal portion of the reset actuator, the distal outer edge can easily slide out of the wedge-shaped groove when moving towards the dropper. When the force applied to the proximal portion of the reset actuator is removed, the distal outer edge of the reset actuator slides out towards the bottom of the housing.

21. The liquid dispenser with unidirectional dispensing function according to claim 20, characterized in that, The outer edge of the near end of the reset actuator moves against the flange provided at the bottom end of the housing. When the reset actuator moves toward the bottom end of the housing by the return force, the flange can restrict the near end of the reset actuator to always be within the inner cavity of the housing.

22. The liquid dispenser with unidirectional dispensing function according to claim 21, characterized in that, The reset actuator is provided with a support portion that cooperates with the flexible container. The bottom of the support portion is connected to the spring of the reset actuator. When the support portion moves toward the dripper, the reset actuator moves relative to the dripper.

23. The liquid dispenser with unidirectional dispensing function according to claim 22, characterized in that, The top surface of the support is concave, making full contact with the bottom of the flexible container to support the flexible container.

24. The liquid dispenser with unidirectional dispensing function according to any one of claims 14-23, characterized in that, The liquid dispenser is provided with a cover, and a retaining ring is provided at the bottom of the inner wall of the cover, which cooperates with a retaining ring provided on the rigid neck of the flexible container to lock and fix the cover to the flexible container.

25. The liquid dispenser with unidirectional dispensing function according to claim 24, characterized in that, When the cap is placed over the drip tip of the liquid dispenser, the cap is adapted to pressurize the air inside the drip tip through an air vent on the drip tip.

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