CN216322019U - Suck-back prevention pipettor - Google Patents

Abstract

The utility model relates to a pipette, in particular to a suck-back prevention pipette. Including pipettor upper portion, pipettor lower part and suck-back prevention adapter, suck-back prevention adapter upper end is connected with pipettor upper portion lower extreme, and suck-back prevention adapter lower extreme is connected with pipettor lower part upper end, has well cavity in the suck-back prevention adapter, goes up cavity, lower cavity and well cavity intercommunication each other, is provided with two piece at least and possesses elastic lamella form films in the well cavity. If press the pipettor piston rod and if the speed is too fast when absorbing liquid, the inside gas velocity of flow of pipettor is great, because bernoulli's principle, the inboard pressure intensity of film reduces, and two films receive power in opposite directions, take place deformation and closure, prevent the rapid flow of gas, and then prevent that liquid from splashing and get into pipettor inside. At this time, the piston rod of the liquid transfer device is slightly pressed, and the thin film can restore to the original shape.

Description

Suck-back prevention pipettor

Technical Field

The utility model relates to a pipette, in particular to a suck-back prevention pipette.

Background

In the process of taking liquid from the liquid-transferring gun, when liquid is sucked into the suction head, the liquid is sucked back onto the trunk due to the fact that the spring on the trunk of the piston is recovered to deform too fast, the surface of the trunk is corroded, the trunk and the sealing ring cannot be completely sealed, and air leakage is caused. If the liquid is sucked to the upper part of the trunk, the liquid further corrodes the sealing ring and the piston along with the upward movement of the trunk, so that air leakage is caused. In the use of liquid-transfering gun, or because of getting liquid process spring and recovering deformation too fast, or put liquid-transfering gun slope, all can produce liquid refluence phenomenon, make trunk, sealing washer and piston receive the pollution, lead to liquid-transfering gun's precision and degree of accuracy decline. The filter element in the disposable pipette tip with the filter element on the market is generally made of ultra-high molecular polyethylene material, so that the disposable pipette tip with the filter element cannot be repeatedly used, is extremely waste and is easy to cause environmental pollution.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the problem that liquid is easy to splash to a piston main stem during the use process of a liquid-moving gun in the prior art.

The utility model provides a liquid transfer device with an adapter, which can temporarily block suction action when a spring is deformed too fast and air flow is fast, so as to prevent liquid from splashing.

In order to achieve the purpose, the utility model adopts the following technical scheme:

the utility model provides a suck-back-preventing liquid transfer device which comprises an upper liquid transfer device body, a lower liquid transfer device body and a suck-back-preventing adapter, wherein an upper cavity is arranged in the upper liquid transfer device body, a spring, a piston and a piston rod are arranged on the upper end of the upper cavity in a separating mode, one end of the piston rod is arranged at the upper end of the piston, the other end of the spring is connected with the upper end of the upper liquid transfer device body, a lower cavity is arranged in the lower liquid transfer device body, the upper end of the suck-back-preventing adapter is connected with the lower end of the upper liquid transfer device body, the lower end of the suck-back-preventing adapter is connected with the upper end of the lower liquid transfer device body, a middle cavity is arranged in the suck-back-preventing adapter, the upper cavity, the lower cavity and the middle cavity are mutually communicated, at least two elastic petal-shaped films are arranged in the middle cavity, the middle cavity is separated into the upper cavity and the middle cavity, and the lower cavity are arranged between the petal-shaped films. When the liquid transfer device is used, if liquid is slowly pressed or sucked, the gas flowing speed in the liquid transfer device is low, the two films are not deformed, and the gas normally flows; however, if the speed is too fast when the piston rod of the liquid transfer device is pressed and liquid is sucked, the gas flow speed in the liquid transfer device is large, the pressure intensity inside the thin films is reduced due to the Bernoulli principle, the two thin films are deformed and closed by opposite forces, the gas is prevented from flowing fast, and then the liquid is prevented from splashing to enter the liquid transfer device. At this time, the piston rod of the liquid transfer device is slightly pressed, and the thin film can restore to the original shape.

Optionally, a partition plate is arranged in the middle cavity, a rectangular opening is formed in the partition plate, and the petal-shaped film is arranged on the rectangular cavity.

Optionally, the petal-shaped film is arranged in an inverted splayed shape. The film material can be made of various high polymer materials such as polyethylene, polyethylene terephthalate, organic silica gel and the like. The inverted V-shaped arrangement can ensure that the closed box is not easy to overturn to the upper part due to air pressure difference to generate a space for air to pass through again.

Optionally, the thickness of the petal-shaped film is between 0.05mm and 0.5 mm.

Optionally, the ratio of the upper side interval to the lower side interval of the petal-shaped film is greater than or equal to 8: 1.

optionally, the ratio of the upper side interval to the lower side interval of the petal-shaped film is less than or equal to 4: 1.

optionally, the lower end of the upper cavity is further provided with a dustproof diaphragm, and the lower end of the piston is provided with a bulge for puncturing the dustproof diaphragm. The dust barrier may prevent dust accumulation on the upper portion of the pipette prior to use.

Optionally, the dust diaphragm is provided with a pre-fabricated crack. The prefabricated crack can effectively prevent the dust-proof diaphragm from generating chips when being broken and falling into the middle cavity and the lower cavity to cause pollution.

The flap-shaped film can be automatically closed when liquid is sucked too fast, so that the liquid splashing condition caused by too fast air flow speed is prevented. And the structure is simple, the manufacturing cost is low, the normal use habit of the pipettor is not influenced, and the pipettor can be reused. Compared with a disposable filter element, the filter element does not need to be frequently replaced, is environment-friendly and energy-saving, and is convenient to use.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic top view of the suck back prevention adapter of the present invention;

fig. 3 is a schematic view of the structure of the upper lower end of the pipette of the present invention.

In the figure: 1-upper part of a liquid transfer device, 2-lower part of the liquid transfer device, 3-anti-suck-back adapter, 4-upper cavity, 5-spring, 6-piston rod, 7-piston, 8-lower cavity, 9-middle upper cavity, 10-middle lower cavity, 11-clapboard, 12-petal-shaped film, 13-dustproof diaphragm, 14-prefabricated crack and 15-bulge.

Detailed Description

The utility model will be further described with reference to the accompanying drawings, which will serve to assist the public in understanding the utility model, and the following description of the embodiments is not intended to limit the utility model to the specific embodiments given by the applicant, and any changes in the definition of parts or features, or in the form of an overall structure, rather than essential changes, may be made to the utility model as defined in the claims.

Example 1

As shown in fig. 1, 2 and 3, a preferred embodiment of the present invention provides a suck back prevention pipette, which includes a pipette upper portion 1, a pipette lower portion 2 and a suck back prevention adapter 3.

The upper portion 1 of the liquid transferring device is in a cylindrical tubular shape, an upper cavity 4 is arranged in the upper cavity, the upper cavity 4 is provided with a spring 5, a piston 7 and a piston rod 6, the piston 7 and the piston rod are used for separating the upper cavity from the lower cavity 4, the piston rod 6 is arranged at the upper end of the piston 7, and the spring 5 is sleeved on the piston rod 6. One end of the spring 5 is connected with the piston 7, the other end of the spring 5 is connected with the upper end of the upper part 1 of the liquid transferring device, and the lower cavity 8 is arranged in the lower part 2 of the liquid transferring device.

The anti-suck-back adapter 3 is in a cylindrical tubular shape, the upper end of the anti-suck-back adapter is in threaded connection with the lower end of the upper portion 1 of the liquid transferring device, and a step with a sealing ring is arranged at the threaded connection position. The lower end of the liquid transferring device is in threaded connection with the upper end of the lower liquid transferring device 2, and a step with a sealing ring is arranged at the threaded connection position. Have cylindrical well cavity in the anti-suck-back adapter 3, go up cavity 4, lower cavity 8 and well cavity intercommunication each other, be provided with baffle 11 in the well cavity, be provided with the rectangle opening on the baffle 11, rectangle opening both edges are provided with two lamella form films 12 that possess elasticity. The film material can be made of various high polymer materials such as polyethylene, polyethylene terephthalate, organic silica gel and the like. The two petal-shaped films 12 divide the middle cavity into an upper middle cavity 94 and a lower middle cavity 108, and a gap for communicating the upper middle cavity 94 and the lower middle cavity 108 is arranged between the petal-shaped films 12. The two petal-shaped films 12 are arranged in an inverted splayed shape. The inverted splayed flap-shaped film 12 is designed to ensure that the closed flap-shaped film is not easy to overturn to the upper side due to air pressure difference to generate a space for air to pass through. The thickness of the flap film 12 is 0.3 mm. The ratio of the upper side interval to the lower side interval of the petal-shaped thin film 12 is more than or equal to 8: 1. the lower end of the upper cavity 4 is also provided with a dustproof diaphragm 13, and the lower end of the piston 7 is provided with a bulge 15 for puncturing the dustproof diaphragm 13. The dust barrier 13 may prevent dust accumulation in the pipette upper part 1 prior to use. The dust diaphragm 13 is provided with a pre-manufactured crack 14. The pre-crack 14 can effectively prevent the dust-proof diaphragm 13 from falling into the middle cavity and the lower cavity 8 to cause pollution when being broken.

When installing the pipettor, at first slightly press piston rod 6, observe dustproof diaphragm and whether have the gas leakage phenomenon. Then, the anti-suck-back adapter 3 is rotatably connected to the lower end of the upper part 1 of the liquid transfer device, and the lower part 2 of the liquid transfer device is rotatably connected to the anti-suck-back adapter 3 to complete installation. Before use, the piston rod 6 is pressed, so that the bulge 15 on the piston rod 6 punctures the dustproof diaphragm 13, and the preparation before use can be completed. When the liquid transfer device is used, if liquid is slowly pressed or sucked, the gas flowing speed in the liquid transfer device is slow, the two petal-shaped films 12 are not deformed, and the gas normally flows; however, if the speed is too fast when the piston rod 6 of the pipette is pressed and liquid is sucked, the flow rate of gas in the pipette is large, and due to the bernoulli principle, the pressure inside the flap films 12 is reduced, and the two flap films 12 are deformed and closed by opposite forces, so that the gas is prevented from flowing fast, and further, the liquid is prevented from splashing into the upper portion 1 of the pipette or from splashing into the lower end of the piston 7. At this time, the pipette piston rod 6 is slightly pressed, and the flap-shaped film 12 is restored to its original shape.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore intended that all such changes and modifications as fall within the true spirit and scope of the utility model be considered as within the following claims.

Claims (6)

1. A suck-back prevention pipettor is characterized by comprising an upper pipettor part, a lower pipettor part and a suck-back prevention adapter, wherein an upper cavity is arranged in the upper pipettor part, the upper cavity is provided with a spring, a piston and a piston rod for separating the upper pipettor part from the lower pipettor part, the piston rod is arranged at the upper end of the piston, one end of the spring is connected with the piston, the other end of the spring is connected with the upper end of the upper pipettor part, a lower cavity is arranged in the lower pipettor part, the upper end of the suck-back prevention adapter is connected with the lower end of the upper pipettor part, the lower end of the suck-back prevention adapter is connected with the upper end of the lower pipettor part, a middle cavity is arranged in the suck-back prevention adapter, the upper cavity, the lower cavity and the middle cavity are mutually communicated, at least two elastic petal-shaped films are arranged in the middle cavity and divide the middle cavity into the upper cavity and the middle cavity, gaps for communicating the upper cavity with the lower cavity are arranged between the petal-shaped films.

2. The pipette of claim 1, wherein a partition is disposed in the middle chamber, the partition has a rectangular opening, and the flap is disposed on the rectangular opening.

3. The pipette of claim 2, wherein the flap is in the shape of an inverted "eight".

4. A pipette as defined in claim 3 wherein the film has a thickness of between 0.05mm and 0.5 mm.

5. A pipette as defined in claim 3 wherein the ratio of the upper to lower spacing of the membrane is greater than or equal to 8: 1.

6. the pipette of claim 5, wherein the ratio of the upper side interval to the lower side interval of the membrane is not more than 4: 1.

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