Fluid dispensing apparatus for forward sealing and reverse venting pistons

Abstract

The utility model discloses a fluid point gum device of positive sealing reverse exhaust piston, including needle cylinder, the end cover of screw thread connection in the top of needle cylinder and set up in the piston of needle cylinder, the piston includes main part, sets up the knife edge of main part outer wall for making outside gas layer by layer decompression, the outer wall of knife edge and needle cylinder inner wall are pasted together, and the conical body for reducing fluid disturbance is located main part bottom, the opening direction of knife edge is towards the direction of main part away from conical body, the outer wall of knife edge is relatively needle cylinder inner wall and is inclined setting, the utility model discloses through setting multilayer reverse knife edge layer by layer decompression, promotes the point gum direction, and at least three layers annular evenly distributed knife edge and needle cylinder inner wall closely paste together, form multiple sealed surface, and the outer wall is relatively needle cylinder inner wall and is inclined, and provide smooth discharge channel for fluid side retention gas, when the piston does not move, can reduce the infiltration of outside gas into fluid layer, improve sealing effect.

Description

Technical Field

[0001] This utility model relates to the field of dispensing equipment technology, specifically to a fluid dispensing device with a forward-sealing and reverse-exhausting piston. Background Technology

[0002] In the current dispensing field, dispensing devices are part of a complete integrated system, typically consisting of a syringe, piston, adapter, syringe end cap, and head plug. The syringe usually adopts a zero-taper design with a uniform inner diameter; the piston includes a blade and tail support, and has channels to prevent air retention while providing a smoother profile radius; the adapter connects the syringe to the output of the fluid dispenser unit; the end cap and bottom head plug provide an airtight seal.

[0003] In the existing technology, pistons have various structural forms and different fit tightness, suitable for various fluid applications. Among them, a loosely fitted piston is suitable for liquids containing air retention, but it will lead to an increase in the amount of residue in the syringe, which will not only waste fluid, but also hinder detection applications that rely on piston position for judgment. For a tightly fitted piston, gas is easily generated during dispensing due to the tight fit, and it is difficult to expel. During the dispensing stage, when the piston is driven by air pressure, the residual gas on the fluid side cannot be discharged, which will push the piston back in the opposite direction.

[0004] In practical applications, pistons have different blade structures, with two or more layers of blades. The blades in contact with the fluid, due to their unique shape, can reduce fluid residue on the syringe wall. However, if the blade direction is the same as the piston's movement direction, it directly affects the discharge of gas from the fluid side. When the blade direction is opposite to the piston's movement, residual gas is easier to discharge, but a lack of blades can make the seal unreliable. Simultaneously, for tubing of different inner diameters, gas trapped on the fluid side will affect the piston's balance within the tubing to varying degrees. When gas cannot be discharged, the piston will deviate relative to the syringe, affecting the piston's adhesion to the tubing during dispensing and causing piston rebound. Utility Model Content

[0005] The purpose of this invention is to provide a fluid dispensing device with a forward-sealing and reverse-venting piston, which solves the problems in the prior art where a loosely fitted piston has a large gap with the syringe, resulting in more residue and affecting the piston position judgment, while a tightly fitted piston is prone to piston rebound and sinking because gas cannot be discharged, thereby improving the stability and accuracy of the dispensing operation.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a fluid dispensing device with a forward-sealing and reverse-exhausting piston, comprising a syringe, an end cap threaded to the top of the syringe, and a piston disposed inside the syringe;

[0007] The piston includes a main body, a blade disposed on the outer wall of the main body for depressurizing the external gas layer by layer, the outer wall of the blade being in contact with the inner wall of the syringe, and a cone located at the bottom of the main body for reducing fluid disturbance. The blade is opened in the direction away from the cone and the outer wall of the blade is inclined relative to the inner wall of the syringe.

[0008] Preferably, the cutting edge is configured with at least three layers, the cutting edge is arranged in a ring and is evenly distributed along the axis of the main body, and the cutting edge located away from the conical body is provided with an integrally formed trumpet-shaped rim.

[0009] Preferably, the outer wall of the cone is provided with a ring-shaped array of guide grooves, which are streamlined.

[0010] Preferably, the end of the syringe away from the end cap is provided with a connector that can be connected to the needle, and a bottom plug is inserted inside the connector when the needle is not connected.

[0011] Compared with the prior art, the beneficial effects of this utility model are:

[0012] 1. This utility model uses multiple layers of reverse blades to reduce pressure layer by layer. When the dispensing direction is advanced, at least three layers of annularly distributed blades are tightly fitted with the inner wall of the syringe, forming multiple sealing surfaces. The outer wall is inclined relative to the inner wall of the syringe, providing a smooth discharge channel for gas trapped on the fluid side and avoiding piston rebound caused by gas accumulation. When the piston is not moving, since the blade opening direction is opposite to the piston movement direction, and the trumpet-shaped edge of the outermost blade increases the contact area and extends the reverse gas permeation path, it can reduce the infiltration of external gas into the fluid layer and improve the sealing effect.

[0013] 2. By setting the bottom end of the piston to a cone shape, this utility model can reduce fluid adhesion resistance and allow the fluid to flow smoothly along the cone surface. The streamlined guide groove on the outer wall of the cone provides a directional flow channel for the fluid, avoiding local congestion, reducing fluid residue at the piston head, reducing material waste, and preventing residual fluid from obstructing the piston, which is beneficial to improving the accuracy of piston position detection. Attached Figure Description

[0014] Figure 1 This is an exploded view of this utility model;

[0015] Figure 2 This is a cross-sectional schematic diagram of the present invention;

[0016] Figure 3 This is a schematic diagram of the piston structure of this utility model;

[0017] Figure 4 This is a cross-sectional view of the piston of this utility model.

[0018] In the diagram: 1. Syringe; 2. End cap; 3. Piston;

[0019] 301. Main body; 302. Blade edge; 303. Conical body; 304. Trumpet-shaped rim; 305. Flow guide groove; 4. Connector; 5. Bottom plug. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] Please see Figure 1-4 This utility model provides a technical solution: a fluid dispensing device with a forward-sealing and reverse-exhausting piston, including a syringe 1, an end cap 2 threadedly connected to the top of the syringe 1, and a piston 3 disposed inside the syringe 1; the syringe 1 serves as a carrier for fluid storage and dispensing channels, providing a closed space for the movement of the piston 3 and fluid flow; the end cap 2 is detachably fixed to the syringe 1 through a threaded connection.

[0022] The piston 3 includes a main body 301, a blade 302 disposed on the outer wall of the main body 301 for gradually reducing the pressure of external gas, the outer wall of the blade 302 being in contact with the inner wall of the syringe 1, and a conical body 303 located at the bottom of the main body 301 for reducing fluid disturbance. The blade 302 is oriented towards the main body 301 away from the conical body 303, and the outer wall of the blade 302 is inclined relative to the inner wall of the syringe 1. The conical body 303 is the head of the piston 3, and is designed with a conical surface. The streamlined conical design reduces the sharp edges of the piston 3 surface, reduces the frictional resistance when the piston 3 head contacts the fluid, avoids fluid vortices at the sharp edges, and allows the fluid to flow smoothly along the surface of the conical body 303, reducing flow velocity fluctuations. At the same time, the smooth surface reduces fluid adhesion and residue on the piston 3 head, reducing waste, and avoids large-area obstruction of the piston 3, which would affect the reading of the piston 3 position.

[0023] By adjusting the direction of the cutting edge 302, such as Figure 4 As shown, the blade 302 is inclined towards the tail end of the syringe 1 relative to the inner wall of the syringe 1. When the piston 3 and the syringe 1 move relative to each other, the gas on the fluid side is more easily discharged.

[0024] The blade 302 is configured with at least three layers, and the blades 302 are arranged in a ring and evenly distributed along the axial direction of the main body 301. The blades 302 located away from the conical body 303 are provided with an integrally formed trumpet-shaped rim 304. The outer wall of the part of the blade 302 that connects to the main body 301, i.e., the part that fits against the inner wall of the syringe 1, is arc-shaped to facilitate gas discharge at that location. Figure 4 As shown, the flared edge 304 can increase the contact area between the blade 302 at the tail end and the inner wall of the syringe 1, making the fit tighter and improving the positive sealing performance.

[0025] The blade 302 is set to at least three layers, which can increase the sealing surface between the piston 3 and the syringe 1. When the air pressure stops, that is, when the piston 3 does not move relative to the syringe 1, the increased sealing surface can more effectively ensure the real-time seal between the two and prevent external gas from entering the fluid layer. When the plastic undergoes unavoidable irregular deformation, the deformation of the piston 3 and the syringe 1 will be as close as possible under the action of the multi-layer blade 302. Even if a slight leakage occurs, the gas entering the fluid layer will be greatly reduced through the layer-by-layer pressure reduction of the multi-layer blade 302.

[0026] The outer wall of the cone 303 is provided with a ring-shaped array of guide grooves 305, which are streamlined. The ring-shaped array of guide grooves 305 provides a directional flow channel for the fluid, so that the fluid is evenly distributed and flows smoothly along the guide grooves 305, avoiding local congestion of the fluid around the cone 303 and reducing fluid disturbance.

[0027] The syringe 1 is provided with a connector 4 at the end away from the end cap 2, which can be connected to the needle. When the needle is not connected, a bottom plug 5 is inserted inside the connector 4.

[0028] During use, the bottom cap 5 is replaced with a needle, the end cap 2 is unscrewed from the top of the syringe 1, and the air source device is connected through the adapter. Under the pressure of the air source, the piston 3 is pushed, thereby pushing the fluid in the syringe 1 to flow.

[0029] In this embodiment, taking the blade 302 as a three-layer example, the blade 302 is arranged as layer A, layer B and layer C from bottom to top. In the static state, the three layers of blade 302, layer A, layer B and layer C, are tightly attached to the syringe 1 to prevent air from the external environment from entering the fluid side.

[0030] During use, the three-layer blade 302 jointly support the piston 3 in the movement of the syringe 1. The increase in sealing surface can improve the reliability of sealing. When the piston 3 moves, the three-layer blade 302 keep in contact with the inner wall of the syringe 1, forming multi-point support, making the movement trajectory of the piston 3 more stable and avoiding the piston 3 from deviating. At the same time, the increased sealing surface extends the gas permeation path, further blocking the entry of external gas and improving the overall reliability of sealing.

[0031] During dispensing, the external adapter at the top of the syringe 1 inputs air pressure, which drives the piston 3 to move. Since the directions of layers A, B, and C of the blade 302 are opposite to the direction of piston 3 movement, the gas trapped on the fluid side can be discharged along the gap between the outer wall of the blade 302 and the inner wall of the syringe 1, preventing gas from accumulating on the fluid side. The sealing design of the multi-layer blade 302 ensures that when layer C is subjected to air pressure, the tight fit prevents gas from entering, thus keeping the air pressure in the gap between layer C and layer B blade 302 relatively low. Similarly, the protective function of layer B blade 302 keeps the air pressure in the gap between layer B blade 302 and layer A blade 302 even lower. Under the combined action of the multi-layer blade 302, the pressure is reduced layer by layer, reducing the gas entering the fluid side and preventing the piston 3 from rebounding due to excessive air pressure on the fluid side.

[0032] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A fluid dispensing device with a forward-sealing and reverse-venting piston, characterized in that: It includes a syringe (1), an end cap (2) threaded to the top of the syringe (1), and a piston (3) disposed inside the syringe (1); The piston (3) includes a main body (301) and a blade (302) disposed on the outer wall of the main body (301) for reducing the pressure of external gas layer by layer; The outer wall of the blade (302) is in contact with the inner wall of the syringe (1), and a cone (303) is located at the bottom of the main body (301) to reduce fluid disturbance. The blade (302) is opened in the direction away from the cone (303) from the main body (301), and the outer wall of the blade (302) is inclined relative to the inner wall of the syringe (1).

2. The fluid dispensing device with a forward-sealing and reverse-exhausting piston according to claim 1, characterized in that: The cutting edge (302) is configured with at least three layers. The cutting edge (302) is arranged in a ring and is evenly distributed along the axis of the main body (301). The cutting edge (302) located away from the cone (303) is provided with an integrally formed trumpet-shaped rim (304).

3. The fluid dispensing device with a forward-sealing and reverse-exhausting piston according to claim 1, characterized in that: The outer wall of the cone (303) is provided with a ring-shaped array of guide grooves (305), which are streamlined.

4. The fluid dispensing device with a forward-sealing and reverse-exhausting piston according to claim 1, characterized in that: The syringe (1) is provided with a connector (4) at the end away from the end cap (2) that can be connected to the needle. When the needle is not connected, a bottom plug (5) is inserted inside the connector (4).

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