A drip-proof foam pump

Abstract

The utility model discloses a kind of drip-proof foam pumps, it is related to foam pump technical field, to solve the problem of traditional foam pump inversion, horizontal use liquid leakage, leading to product waste, equipment corrosion and security risk.It includes the pump body of the pump cavity being arranged inside, hollow piston rod, annular liquid piston and duckbill valve;Piston rod is arranged in pump cavity, and liquid delivery channel is formed inside, lower end outer periphery is equipped with liquid inlet, upper end portion is equipped with liquid outlet, three are sequentially conducted;Liquid piston is sleeved in the lower end of piston rod, and the inner wall of pump cavity is sealed to separate liquid chamber and air chamber, when not liquid, liquid inlet is blocked, when liquid, liquid inlet is vertically misaligned and conducted;Duckbill valve is arranged in the middle part of piston rod channel, one-way conduction and need to be opened only when negative pressure higher than the gravity pressure of liquid column in channel is generated.The utility model has good leak-proof effect, compact structure, is suitable for hospital and other scenes and inverted container, and the transformation cost is low.

Description

Technical Field

[0001] This utility model relates to the field of liquid pump technology, specifically to a drip-proof foam pump for containers of hand sanitizer, disinfectant and other products, which is particularly suitable for inverted or horizontal use scenarios. Background Technology

[0002] Foam pumps, as a core component of containers for everyday chemical products (such as hand sanitizer and disinfectant), work by creating negative pressure through pressing the pump head, causing the liquid to mix with air to form foam. Currently, traditional foam pumps can generally meet the needs when used upright, but in inverted or horizontal operation scenarios (such as hanging disinfection bottles in hospitals and horizontal reagent bottles in laboratories), liquid leakage is a common problem.

[0003] For foam pumps used in inverted environments, when the container is inverted and the pump head is pressed, liquid flows into the pump chamber prematurely due to gravity. When the pump head has traveled halfway down its stroke, the liquid leaks through the not-fully-closed valve gap, resulting in liquid being sprayed instead of foam. This problem not only wastes product but also corrodes equipment (such as precision laboratory instruments) and floors. In special environments such as hospital operating rooms, leaked disinfectant can easily make the floor slippery, causing slips and falls, and also contaminates the sterile working environment, posing a significant safety hazard. Summary of the Invention

[0004] The technical problem to be solved by this utility model is to provide a leak-proof foam pump that, by improving its own structure, can solve the problem of leakage that would occur when used upside down in the past.

[0005] To address the aforementioned technical problems, this utility model discloses an anti-drip foam pump, comprising a pump body with an internal pump chamber, a hollow piston rod, a liquid piston, and a duckbill valve. The piston rod passes through the pump chamber of the pump body, forming a liquid delivery channel inside. The piston rod has an inlet located on its lower outer circumferential side and an outlet located on its upper end, with the inlet, liquid delivery channel, and outlet sequentially connected. The liquid piston is disposed within the pump chamber of the pump body, forming a sliding seal with the inner wall of the pump chamber to divide the pump chamber into a liquid chamber below the liquid piston and an air chamber above the liquid piston. The liquid piston has a ring structure and is coaxially sleeved on the lower outer circumference of the piston rod. The inner ring of the liquid piston fits tightly against the outer circumference of the piston rod. In the non-discharge state, the liquid piston blocks the inlet. In the discharge state, the liquid piston and the inlet are vertically offset, allowing the liquid chamber to be connected to the liquid delivery channel of the piston rod through the inlet. The duckbill valve is located in the liquid delivery channel of the piston rod and in the middle of the piston rod. The duckbill valve has a one-way conduction structure. Its opening requires the generation of a negative pressure higher than the gravity pressure of the liquid column in the liquid delivery channel of the piston rod, so as to allow the liquid in the liquid chamber to flow to the outlet through the inlet, the liquid delivery channel, and the duckbill valve.

[0006] The piston rod consists of two parts: a pull rod and a liquid push rod. The lower end of the pull rod is fixedly connected to the upper end of the liquid push rod through a plug-in structure. The duckbill valve is assembled inside the pull rod, and the two ends of the duckbill valve are respectively connected to the liquid delivery channel of the pull rod and the liquid delivery channel of the liquid push rod.

[0007] The bottom circumference of the liquid push rod extends outward to form an annular boss. The outer diameter of the annular boss is larger than the inner diameter of the inner ring of the liquid piston. In the non-discharge state, the lower end face of the liquid piston is in contact with the upper end face of the annular boss to prevent the liquid piston from sliding downward along the liquid push rod axis and dislodging. When the liquid push rod moves upward, the upper end face of the annular boss abuts against the liquid piston and drives it to move upward synchronously, ensuring the coordination of the movement of the liquid piston and the liquid push rod.

[0008] The inner wall of the liquid delivery channel of the liquid push rod extends obliquely inward toward the liquid inlet to form a convex ring. The convex ring has a bucket-shaped structure facing the opening of the liquid inlet. The inner side of the convex ring is provided with multiple claws arranged circumferentially. The multiple claws hold a ball valve. The outer diameter of the ball valve is larger than the minimum inner diameter of the convex ring and smaller than the maximum inner diameter of the convex ring. In the non-discharge state, the ball valve is in contact with the liquid inlet under the action of liquid chamber pressure. In the discharge state, the liquid chamber generates negative pressure to separate the ball valve from the liquid inlet. The liquid can enter the liquid delivery channel of the liquid push rod through the liquid inlet and the internal space of the convex ring.

[0009] An air piston is inserted into the outer periphery of the top of the piston rod. The air piston has a ring structure. The inner ring of the air piston extends downward to form a first bushing that fits the outer periphery of the piston rod. The inner wall of the first bushing has multiple L-shaped protrusions arranged at intervals along its circumference. An air intake groove is formed between two adjacent L-shaped protrusions. The inner ring of the air piston extends upward to form a second bushing. A tubular channel is provided in the middle of the second bushing and runs through it along its axial direction. One end of the air intake groove is connected to the air chamber, and the other end is connected to the tubular channel. Air in the air chamber can flow into the tubular channel through the air intake groove.

[0010] The air piston has an air inlet hole that runs through its upper and lower end faces, which is used to connect external air with the air chamber. A limiting flange extends outward from the middle of the piston rod, and an air inlet gap is formed between the limiting flange and the air piston. The air inlet gap and the air inlet groove are parallel and both connect the air chamber and the tubular channel. A one-way valve is fixed in the air piston inside the air chamber. The one-way valve extends outward to a first valve plate that is close to the lower end face of the air piston and can cover the air inlet hole. Only external air is allowed to enter the air chamber by pushing open the first valve plate from the lower opening of the air inlet hole. When the air in the air chamber is pressurized, the first valve plate tightly covers the air inlet hole. A one-way valve extends inward to insert a second valve plate into the air inlet gap. In the non-liquid discharge state, the piston rod moves upward to reset, increasing the volume of the air chamber and generating negative pressure. Under the action of negative pressure, the second valve plate is tightly attached to the limiting flange, and the air inlet gap and air inlet groove are blocked to prevent liquid from entering the air chamber. External air enters the air chamber through the air inlet hole. In the liquid discharge state, the piston rod moves downward, decreasing the volume of the air chamber and increasing the pressure. Under the action of high pressure, the second valve plate separates from the limiting flange, and the air inlet gap and air inlet groove are connected. The air in the air chamber flows directionally to the tubular channel through the air inlet gap and air inlet groove, ensuring the stable gas pressure required for gas-liquid mixing.

[0011] It also includes an elastic reset mechanism, which is a spring. The spring is sleeved on the outside of the piston rod and located in the liquid chamber. One end of the spring abuts against the bottom of the gas chamber, and the other end abuts against the lower end face of the limiting flange. In the non-liquid state, the spring is in a naturally extended state, providing an upward reset force for the liquid piston, so that the liquid piston stably seals the liquid inlet.

[0012] The bottom of the air chamber is provided with a positioning groove, and a spring seat is fixedly installed in the positioning groove. The end of the spring near the bottom of the air chamber abuts against the spring seat to position the spring and prevent it from shifting radially along the bottom of the air chamber during the extension and contraction process, thus ensuring the stability of the spring's reset force on the limiting flange.

[0013] The tubular channel of the second bushing is provided with a foam generator at the end away from the first bushing, and the foam generator is fixed to the second bushing by threaded connection or snap-fit ​​connection.

[0014] The outer circumferential side of the pump body is fitted with a sealing ring.

[0015] Compared with the prior art, the embodiments of this utility model have the following beneficial effects: (1) By directly integrating the duckbill valve into the liquid delivery channel of the piston rod and making its opening direction perpendicular to the direction of gravity, when the container is inverted, the gravity of the liquid column cannot directly act on the opening direction of the duckbill valve, thus physically blocking the path of liquid to seep into the upper part of the pump chamber by gravity in the non-working state, solving the previous dripping problem.

[0016] (2) The duckbill valve is built into the piston rod as part of the fluid channel. It does not require additional space outside the pump body, making the entire pump body structure very compact. It does not change the external size and installation method of the traditional foam pump, has strong compatibility, and features a compact structure and high integration.

[0017] (3) The opening of the duckbill valve requires the piston movement to generate a specific negative pressure higher than the gravity pressure of the liquid column. This means that liquid will only be drawn in when there is sufficient negative pressure in the pump chamber to generate foam in the latter half of the pressing stroke. This design ensures that foam, not liquid, is output under any circumstances, which significantly improves user experience and product reliability.

[0018] (4) It effectively prevents corrosive or high-viscosity liquids from seeping into the air chamber and moving parts (such as springs, pistons, etc.) in the upper part of the pump body when not in use, thus avoiding the problems of component corrosion, lubrication failure and jamming caused by this, thereby greatly extending the overall service life of the foam pump.

[0019] (5) It is particularly suitable for use scenarios that require inversion, tilting or violent movement (such as medical mobile disinfection devices and hanging hand sanitizer bottles), effectively preventing product waste, environmental pollution and safety accidents caused by slippery ground caused by liquid leakage, especially meeting the needs of hospitals, laboratories and other places with extremely high safety and hygiene requirements.

[0020] (6) By simply adding a low-cost standard component (duckbill valve) to the internal channel on the basis of the existing mature piston pump structure, the excellent anti-leakage function is achieved. The modification cost is extremely low, it is easy to mass-produce and assemble, and it has extremely high market promotion value. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments 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 these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the anti-drip foam pump in this utility model; Figure 2 This is an exploded view of the anti-drip foam pump of this utility model; Figure 3 This is a cross-sectional view of the anti-drip foam pump in this utility model; Figure 4 This is an exploded view of the piston rod in this utility model; Figure 5 This is a schematic diagram of the air piston structure in this utility model; Figure 6 This is a cross-sectional view of the air piston in this utility model; Figure 7 This is a schematic diagram of the one-way valve in this utility model. Detailed Implementation

[0023] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention 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 invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, apparatus, product, or server that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or servers.

[0025] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the present invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0026] This utility model discloses a specific embodiment of an anti-drip foam pump, please see... Figures 1 to 7 As shown, the anti-drip foam pump includes a pump body 1 with an internal pump chamber, and a sealing ring 10 is fitted on the outer peripheral side of the pump body 1. The sealing ring 10 can enhance the sealing performance of the connection between the pump body 1 and the external container, prevent liquid from leaking from the gap between the pump body 1 and the container, and improve the overall sealing reliability.

[0027] As an improvement, combining Figures 1 to 3The anti-drip foam pump includes a hollow piston rod 2, an annular liquid piston 3, and a duckbill valve 7. The piston rod 2 passes through the pump cavity of the pump body 1, forming a liquid delivery channel 20 inside. The piston rod 2 has an inlet 202 located on the lower outer circumferential side and an outlet 201 located on the upper end. The inlet 202, the liquid delivery channel 20, and the outlet 201 are sequentially connected to ensure directional liquid flow. The piston rod 2 consists of two parts: a pull rod 21 and a liquid push rod 22. The lower end of the pull rod 21 is fixedly connected to the upper end of the liquid push rod 22 through a plug-in structure. The duckbill valve 7 is assembled inside the pull rod 21, and the two ends of the duckbill valve 7 are respectively connected to the liquid delivery channel 20 of the pull rod 21 and the liquid delivery channel 20 of the liquid push rod 22. This structural design facilitates the disassembly and maintenance of the duckbill valve 7. The duckbill valve 7 can be replaced or repaired without disassembling the entire piston rod 2, reducing maintenance costs. At the same time, the duckbill valve 7 is a one-way conduction structure. Its opening requires the generation of a negative pressure higher than the gravity pressure of the liquid column in the liquid delivery channel 20 of the piston rod 2, which can fundamentally block the path of liquid leakage due to gravity. To prevent the duckbill valve 7 from sliding out of the liquid delivery channel 20, a positioning protrusion 212 extends inward from the inner wall of the liquid delivery channel 20 (the inner wall of the pull rod 21). The inner diameter of the positioning protrusion 212 is smaller than the outer diameter of the duckbill valve 7. The duckbill valve 7 is located at the lower end of the positioning protrusion 212, thereby preventing the duckbill valve 7 from coming off the liquid delivery channel 20 upward during the liquid delivery process.

[0028] In this embodiment, please see Figure 3The liquid piston 3 is coaxially sleeved on the lower outer circumference of the piston rod 2. The inner ring of the liquid piston 3 is tightly fitted with the outer circumference of the piston rod 2, and the liquid piston 3 forms a sliding seal with the inner wall of the pump chamber of the pump body 1, thereby dividing the pump chamber into a liquid chamber 11 located below the liquid piston 3 and a gas chamber 12 located above the liquid piston 3. In the non-discharge state, the liquid piston 3 blocks the liquid inlet 202 of the piston rod 2. In the discharge state, the liquid piston 3 and the liquid inlet 202 are vertically offset, so that the liquid chamber 11 is connected to the liquid delivery channel 20 of the piston rod 2 through the liquid inlet 202. The bottom outer circumference of the liquid push rod 22 extends outward to form an annular boss. The outer diameter of the annular boss is larger than the inner diameter of the inner ring of the liquid piston 3. In the non-discharge state, the lower end face of the liquid piston 3 is in contact with the upper end face of the annular boss, which can effectively prevent the liquid piston 3 from sliding downward along the axial direction of the liquid push rod 22 and ensuring structural stability. When the liquid push rod 22 moves upward, the upper end face of the annular boss abuts against the liquid piston 3 and drives it to move upward synchronously, ensuring the coordination of the movement of the liquid piston 3 and the liquid push rod 22, and avoiding the failure of liquid inlet control due to asynchronous movement of the two. The inner wall of the liquid delivery channel 20 of the liquid push rod 22 extends obliquely inward toward the liquid inlet 202 to form a convex ring 51. The convex ring 51 has a funnel-shaped structure that opens toward the liquid inlet 202. The inner side of the convex ring 51 is provided with multiple claws 52 arranged circumferentially. The multiple claws 52 arranged circumferentially hold the ball valve 5. The outer diameter of the ball valve 5 is larger than the minimum inner diameter of the convex ring 51 and smaller than the maximum inner diameter of the convex ring 51. In the non-discharge state, the ball valve 5 is in contact with the liquid inlet 202 under the pressure of the liquid chamber 11, which further enhances the sealing effect of the liquid inlet 202 and prevents the liquid in the liquid chamber 11 from accidentally leaking out. In the discharge state, the liquid chamber 11 generates negative pressure to separate the ball valve 5 from the liquid inlet 202. The liquid can smoothly enter the liquid delivery channel 20 through the liquid inlet 202 and the internal space of the convex ring 51. The funnel-shaped convex ring 51 can also guide the liquid, reduce the liquid flow resistance, and improve the liquid inlet efficiency.

[0029] In this embodiment, combined with Figures 3 to 6An air piston 4 is inserted into the outer periphery of the top of the piston rod 2. The air piston 4 has a ring structure, with its inner ring extending downward to form a first bushing 41 that fits the outer periphery of the piston rod 2. The inner wall of the first bushing 41 is provided with a plurality of L-shaped protrusions 44 arranged at intervals along its circumference. An air inlet groove 45 is formed between two adjacent L-shaped protrusions 44. The inner ring of the air piston 4 extends upward to form a second bushing 42. The middle part of the second bushing 42 is provided with a tubular channel 40 that runs through its axial direction. One end of the air inlet groove 45 is connected to the air chamber 12, and the other end is connected to the tubular channel 40. The air in the air chamber 12 can flow into the tubular channel 40 through the air inlet groove 45, providing a stable gas delivery path for gas-liquid mixing. An air inlet 43 is provided on the air piston 4, which passes through its upper and lower end faces. The air inlet 43 is used to communicate with the external air and the air chamber 12. A limiting flange 211 extends outward from the middle of the piston rod 2. An air inlet gap 80 is formed between the limiting flange 211 and the air piston 4. The air inlet gap 80 is parallel to the air inlet groove 45 and both are connected to the air chamber 12 and the tubular channel 40.

[0030] Combination Figure 3 and Figure 7 The air chamber 12 is equipped with a one-way valve 8 fixed in the air piston 4. The one-way valve 8 extends outward to a first valve plate 81 that abuts against the lower end face of the air piston 4 and can cover the air inlet 43. It only allows external air to enter the air chamber 12 by pushing open the first valve plate 81 from the lower opening of the air inlet 43. When the air in the air chamber 12 is pressurized, the first valve plate 81 tightly covers the air inlet 43 to prevent air leakage in the reverse direction. The one-way valve 8 extends inward to a second valve plate 82 that is inserted into the air inlet gap 80. In the non-liquid discharge state (piston rod 2 moves upward to reset), the volume of the air chamber 12 increases and generates negative pressure. Under the action of negative pressure, the second valve plate 82 closes with the limit. The limiting flange 211 is tightly attached, and the air inlet gap 80 and the air inlet groove 45 are blocked to prevent liquid from entering the air chamber 12. External air enters the air chamber 12 through the air inlet hole 43 to ensure normal air replenishment in the air chamber 12. In the liquid discharge state (piston rod 2 moves downward), the volume of the air chamber 12 decreases and the pressure increases. Under high pressure, the second valve plate 82 separates from the limiting flange 211, and the air inlet gap 80 and the air inlet groove 45 are connected. The air in the air chamber 12 flows through the air inlet gap 80 and then through the air inlet groove 45 to the tubular channel 40, ensuring that the gas pressure required for gas-liquid mixing is stable, avoiding the dispersion and loss of high-pressure air, and improving the quality of foam generation.

[0031] The anti-drip foam pump also includes an elastic reset mechanism, which is a spring 61. The spring 61 is sleeved on the outside of the piston rod 2 and located inside the liquid chamber 11. One end of the spring 61 abuts against the bottom of the air chamber 12, and the other end abuts against the lower end face of the limiting flange 211. In the non-discharge state, the spring 61 is in a naturally extended state, providing an upward reset force for the liquid piston 3, so that the liquid piston 3 stably seals the liquid inlet 202, ensuring the sealing reliability of the liquid inlet 202 in the non-use state and preventing liquid leakage. The bottom of the air chamber 12 is provided with a positioning groove, and a spring seat 62 is fixedly installed in the positioning groove. The end of the spring 61 near the bottom of the air chamber 12 abuts against the spring seat 62. The spring seat 62 can position the spring 61, preventing the spring 61 from shifting radially along the bottom of the air chamber 12 during the extension and contraction process, ensuring the stability of the reset force of the spring 61 on the limiting flange 211, and avoiding inaccurate reset of the liquid piston 3 due to the spring 61 shifting, which would affect the on / off control of the liquid inlet 202. The tubular channel 40 of the second bushing 42 is provided with a foam generator 9 at the end away from the first bushing 41. The foam generator 9 is fixed to the second bushing 42 by a threaded connection or a snap-fit ​​connection. Both the threaded connection and the snap-fit ​​connection methods facilitate the disassembly and assembly of the foam generator 9. When the foam generator 9 is blocked or damaged, the user can quickly replace it, improving the convenience of use. The foam generator 9 can convert the gas-liquid mixture into uniform foam to meet the user's foam output requirements.

[0032] This anti-drip foam pump integrates the duckbill valve 7 inside the piston rod 2. Utilizing its opening characteristic perpendicular to gravity and negative pressure opening condition, it completely solves the problem of easy liquid leakage when traditional foam pumps are used upside down or horizontally. This avoids product waste, equipment corrosion, and safety accidents caused by slippery floors. It is especially suitable for scenarios with high safety and hygiene requirements, such as hospitals and laboratories, and can also meet the needs of inverted and suspended containers. The overall structure only adds one key component, the duckbill valve 7, to the traditional foam pump, resulting in extremely low modification costs. It does not change the external dimensions and installation method of the traditional foam pump, has strong compatibility, and is easy to integrate with existing production processes. Users do not need to change their operating habits. The double seal between the liquid piston 3 and the pump chamber inner wall, combined with the elastic seal of the duckbill valve 7, effectively prevents liquid from seeping into the pump body 1, avoiding component corrosion, lubrication failure, and jamming problems. This significantly extends the product's service life and reduces the user's replacement and maintenance costs.

[0033] In the non-discharge state, the spring 61 is in a naturally extended state, pushing the limiting flange 211 upward, which in turn drives the piston rod 2 and the liquid piston 3 upward. At this time, the liquid piston 3 blocks the liquid inlet 202 of the piston rod 2, and the ball valve 5 is in contact with the liquid inlet 202 under the pressure of the liquid chamber 11. The first valve plate 81 of the one-way valve 8 covers the air inlet 43, the second valve plate 82 is in close contact with the limiting flange 211, and the air inlet gap 80 is blocked from the air inlet groove 45. The entire pump body 1 is in a good sealing state, effectively preventing liquid leakage. When liquid needs to be dispensed, press down on the top of the piston rod 2. The piston rod 2 drives the liquid piston 3 downward, and the volume of the liquid chamber 11 decreases accordingly, while the internal pressure increases. Under the pressure, the ball valve 5 further closes to the liquid inlet 202. At the same time, the volume of the air chamber 12 decreases and the pressure increases. The first valve plate 81 of the one-way valve 8 tightly covers the air inlet 43, and the second valve plate 82 separates from the limiting flange 211 under high pressure. The air inlet gap 80 and the air inlet groove 45 are connected. The air in the air chamber 12 flows into the tubular channel 40 of the second bushing 42 through the air inlet gap 80 and the air inlet groove 45. As the piston rod 2 continues to descend, the liquid piston 3 and the inlet 202 are vertically offset. The liquid chamber 11 is connected to the liquid delivery channel 20 of the piston rod 2 through the inlet 202. At this time, a negative pressure higher than the gravity pressure of the liquid column is generated in the liquid delivery channel 20 of the piston rod 2. The duckbill valve 7 is opened, and the liquid in the liquid chamber 11 flows through the inlet 202, the liquid delivery channel 20, and the duckbill valve 7 to the outlet 201 at the upper end of the piston rod 2. It mixes with the air flowing in from the tubular channel 40 to form a gas-liquid mixture. After the gas-liquid mixture enters the foam generator 9, it is cut into uniform foam and sprayed out from the outlet of the foam generator 9. After pressing, the spring 61 pushes the limiting flange 211 upward, driving the piston rod 2 and the liquid piston 3 to move upward and reset. The liquid piston 3 re-seals the liquid inlet 202, the ball valve 5 resets, the second valve plate 82 of the one-way valve 8 is tightly attached to the limiting flange 211, and the first valve plate 81 is pushed open under the negative pressure of the air chamber 12. External air enters the air chamber 12 through the air inlet 43 to replenish it, preparing for the next liquid discharge. The whole working process is smooth and stable, and can continuously output uniform foam and always maintain a good leak-proof effect.

[0034] In the specific implementation, a description of the overall structure is included. The anti-drip foam pump disclosed in this embodiment has a columnar structure, with the pump body 1 as the base to support all core components. A cylindrical pump cavity is formed through the pump body 1, and a sealing ring 10 fitted on the outer circumference fits tightly with the port of the external container to form an initial seal. A hollow piston rod 2 is axially inserted inside the pump cavity, with its lower end extending to near the bottom of the pump body 1 and its upper end extending out of the pump body 1 and connecting to the foam output structure, forming the main shaft for the delivery of liquid and gas.

[0035] The piston rod 2 extends radially outward from the middle section to form a limiting flange 211, dividing the pump chamber into two functional areas: below the limiting flange 211 is the liquid chamber 11, which houses an annular liquid piston 3 fitted inside the piston rod 2. The outer ring of the liquid piston 3 slides and seals against the inner wall of the pump chamber, while the inner ring fits tightly against the outer periphery of the piston rod 2. This achieves both physical separation between the liquid chamber 11 and the upper air chamber 12, and also controls the opening and closing of the liquid inlet 202 as the piston rod 2 moves axially. Above the limiting flange 211 is the air chamber 12, where an annular air piston 4 is inserted into the outer periphery of the top of the piston rod 2. The air piston 4 is adapted to the outer periphery of the piston rod 2 through a first bushing 41, and extends upward through a second bushing 42 to form a tubular channel 40, which together with the liquid delivery channel 20 of the piston rod 2 constitutes the terminal path for gas-liquid mixing.

[0036] The elastic reset mechanism uses a spring 61, which is vertically sleeved on the outside of the piston rod 2 and located inside the liquid chamber 11. The lower end abuts against the spring seat 62 at the bottom of the air chamber 12 (the spring seat 62 is fixed in the positioning groove at the bottom of the air chamber 12), and the upper end abuts against the lower end face of the limiting flange 211. It drives the piston rod 2 to reset through its own elastic deformation, providing the power basis for the reciprocating motion of the entire pump body 1. Inside the liquid delivery channel 20, a duckbill valve 7 and a ball valve 5 are connected in series, forming dual one-way control at the middle and lower ends, respectively. The one-way valve 8 in the air chamber 12, through the first valve plate 81 and the second valve plate 82, realizes the control of external air supply and internal airflow directional delivery, respectively. The components are arranged sequentially along the axial direction, forming a complete anti-drip and foam generation system through mechanical cooperation.

[0037] This integrated structural design combines functions such as liquid delivery, gas control, leak-proof sealing, and elastic reset on the same axis. The radial dimensions of each component are adapted to the pump cavity, and the axial layout is compact. It retains the operational convenience of traditional foam pumps while achieving leak-proof functionality through the nested design of key components. No additional external dimensions are required, and it is compatible with existing container installation standards.

[0038] The liquid piston 3, pump body 1, and piston rod 2 form a double-sealed combination, which, together with the duckbill valve 7 and ball valve 5, provides one-way control, creating a multi-level leak-proof barrier. The coordinated design of the air piston 4 and one-way valve 8 ensures directional gas flow and precise mixing with the liquid. The cooperation between the spring seat 62 and the positioning groove ensures stable transmission of elastic restoring force. Each structural unit independently performs a specific function and forms an organic whole through mechanical linkage, jointly improving the leak-proof performance, operational stability, and service life of the foam pump.

[0039] In the non-discharge state, spring 61 naturally extends, pushing the limiting flange 211 upward, causing piston rod 2 and liquid piston 3 to move upward synchronously. Liquid piston 3 blocks inlet 202, ball valve 5 is in contact with inlet 202, and the first valve plate 81 of check valve 8 covers air inlet 43, while the second valve plate 82 is in close contact with limiting flange 211. The entire pump body 1 is in a fully sealed state, and the liquid is completely confined within liquid chamber 11. During discharge, pressing piston rod 2 downward compresses spring 61, causing liquid piston 3 to be misaligned with inlet 202. The pressure in liquid chamber 11 forces liquid to push open ball valve 5 and enter the delivery channel. Simultaneously, air chamber 12 is compressed, causing second valve plate 82 to separate. Air enters tubular channel 40 through air inlet gap 80 and groove. When the negative pressure in the channel reaches the threshold, duckbill valve 7 opens, and liquid and air merge in tubular channel 40 before entering foam generator 9. After being cut by mesh plates, foam is sprayed out. After pressing, spring 61 resets and drives all components back to their initial state. Air chamber 12 draws in external air under negative pressure to store gas for the next operation. The entire process achieves precise control of leakage prevention, delivery, and mixing through structural linkage.

[0040] Finally, it should be noted that the anti-drip foam pump disclosed in this utility model embodiment is only a preferred embodiment of this utility model and is only used to illustrate the technical solution of this utility model, not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of this utility model.

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