FR3132035A3 - LIQUID SUCTION DEVICE - Google Patents

Abstract

The present invention relates to a device for the suction of liquids, in particular waste, comprising: - a suction pump for transferring liquids (2), adapted to be coupled to an opening of a container intended to receive said liquids aspirated, - a suction tube (3) having a proximal end connected to said pump (2), and a distal end provided with a manipulation tool (4) of said tube (3) associated with a pipette (5) d suction, and - a device (I) with on/off positions configured to start up said pump (2), respectively stop it, characterized in that said device (I) for starting and stopping the pump comprises an actuator (I1) carried by said handling tool (4) and a switch (I2) separate from the actuator, the actuator (I1) cooperating with the switch (I2) such that said device ( I) for starting and stopping the pump is in the off position when the actuator and the switch are in a position of mutual coupling, while it is in the on position when the actuator and the switch are not are not in said mutual coupling position. Figure for abstract: Fig 2

Description

LIQUID SUCTION DEVICE

The present invention relates to a device for suction of liquids, in particular waste.

It is particularly suitable for use in laboratories to collect liquids.

State of the art

In many manipulations carried out in laboratories, "clean" liquids are used, then are contaminated during handling and finally recovered to be stored in the form of waste.

In this context, storage tanks for such waste have already been proposed, which are coupled to a suction pump.

A tube is on the one hand connected to the reservoir and on the other hand to a suction nozzle, the reservoir being placed under negative pressure by the pump.

So, for example, to suck up a dirty liquid contained in a Petri dish, you turn on the pump and bring the nozzle closer to the liquid to suck it up until it is completely stored in the tank.

Such devices are generally satisfactory. However, they can be improved in terms of ergonomics in particular.

Thus, to start and stop the pump, it is necessary to activate a switch in advance and wait until the depression is sufficient. When carrying out a high number of aspirations during the same day, this can be tedious.

In practice, the pump is generally activated throughout the working period and therefore even outside of suction times.

Some existing devices, among the most recent and most sophisticated and therefore the most expensive, have a depression control in the tank. This means that when the vacuum is sufficient, a pressure sensor gives the order to the pump to stop. These devices, on the other hand, require to be equipped with a sort of shutter valve placed at the level of the pipette. Without this valve, the system would be constantly open, forcing the pump to operate constantly, which makes the vacuum self-control system lose its interest. This valve must be opened manually at the precise moment when you want to vacuum. Here, it is not a switch that we manipulate each time, but a flap.

Furthermore, the fact that the tank is in depression means, to empty it or replace it with another, you have to wait until the internal pressure has returned to atmospheric pressure.

Another disadvantage arises from the presence of the tube and more particularly its length. This must be sufficient so as not to have to move the tank to carry out each aspiration. On the other hand, when the device is not used, the presence of this tube can be annoying, since it clutters the work surface.

Brief description of the invention

The present invention aims precisely to solve the first problem detailed above, or also that presented just after.

Thus, the present invention essentially relates to a device for suction of liquids, in particular waste, comprising:

- a suction pump for transferring liquids, adapted to be coupled to an opening of a container intended to receive said sucked liquids,

- a suction tube having a proximal end connected to said pump, and a distal end provided with a tool for manipulating said tube associated with a suction pipette, and

- a device with on/off positions configured to start said pump, respectively stop it,

characterized by the fact that said device for starting and stopping the pump comprises an actuator carried by said handling tool and a switch separate from the actuator, the actuator cooperating with the switch such that said device on and off position of the pump is in the off position when the actuator and the switch are in a mutually coupled position, while it is in the on position when the actuator and the switch are not in said mutual coupling position.

Furthermore, according to other non-limiting and advantageous characteristics of the invention:

- the coupling between the actuator and the switch of the pump starting and stopping device is of the magnetic type,

- the switch is integral with said pump,

- said tube is spiraled,

- said pump is associated with a projecting cylindrical element around which said tube winds,

- the switch is integral with said cylindrical element,

- the actuator comprises at least one permanent magnet,

- the switch is made up of a magnetic proximity detector,

- the coupling between the actuator and the switch is of the mechanical type, the actuator comprising a finger made of insulating material, while the switch comprises two electrically conductive blades, capable of being spaced apart from each other by insertion point between them.

Brief description of the figures

Other characteristics and advantages of the invention will appear on reading the following description of a preferred embodiment of the invention. This description is made with reference to the appended drawings in which:

is a side view of the device according to the invention;

is an overview of the suction device and the reservoir, covered with a protective cover, according to a first embodiment of the invention;

is a view of the whole represented at , when used to suck liquids into a Petri dish;

illustrates the suction device and the tank before assembling the tank on the cover containing the suction device, according to said first embodiment of the invention,

illustrates the installation of the tank in the hood, according to said first embodiment of the invention;

illustrates the tank after its installation in the hood, according to said first embodiment of the invention;

is an overview of the suction device and the reservoir, covered with a protective cover, according to a second embodiment of the invention;

is a view analogous to the , without the protective cover;

is a view of the suction device arranged in a hood according to a third embodiment of the invention, the tank being arranged outside the hood.

Detailed description of embodiments

The objective of the device according to the invention is to delicately collect liquids and collect them in a reservoir. The operation must be carried out in complete safety, without risk of contamination for the operator and those around him. When it comes to waste, several separate tanks can be provided, which allows only chemically compatible effluents to be mixed, in order to treat them separately and subsequently, before eliminating them.

The main field of use of the suction device according to the invention is that of cell culture, but its use can be multiple in the biology or chemistry laboratory. It is particularly useful when implementing “western blot” techniques (in French “protein transfer”), immunofluorescence on slide and/or as part of the ELISA test (acronym for Enzyme Linked ImmunoSorbent Assay), or in any other circumstance.

The device according to the invention essentially comprises a pump 2 for transferring liquids, adapted to be coupled to an opening of a reservoir 1 (cf. et seq.), and a suction tube 3 fitted with a tube handling tool 4 and a pipette 5.

The pump 2 which is advantageously used is for example an electromagnetic piston pump with PTFE (polytetrafluoroethylene) valves and a GOTEC brand chrome steel piston and piston liner. It operates at a voltage of 24V/50Hz at a maximum flow rate of 500 ml/min or an intermediate flow rate of 80 ml/min, this at a maximum pressure of 0.8bar.

The pump 2 for transferring liquids can also be of the diaphragm type, membrane or centrifugal type.

This pump 2 has two nozzles 22 and 23 which correspond respectively to a liquid inlet and outlet. The inlet 22 is connected to the suction tube 3, while the outlet 23 is adapted to be connected to the tank 1. An extension tube can advantageously be placed between the outlet nozzle 23 and the interior of the tank 1.

The pump is directly controlled by an electronic card 20. It is powered by a current generator, its activation being dependent on both a general switch (referenced 70 in Figures 2, 3, 5 and 7) of the device suction and a second switch which will be discussed later in the description.

The electronic card 20 provides several functions: management of powering on and stopping the device by the general switch 70; generation of an alternating current having a square wave and a frequency compatible with pump 2 from the initial 24V, 1A direct current; management of the choice of pump flow rate by the general switch 70; management of the second aforementioned switch; management of the effluent level controller in the tank; autonomous battery charge and flow management.

The general switch 70 has a push button allowing, with a long press, to turn the device on, a second long press conversely turning it off. It also and advantageously allows, by a short press, to preselect an intermediate flow rate and by a second short press, to preselect a maximum flow rate. A light-emitting diode placed for example in the push button can indicate power on (green), intermediate flow (yellow) or maximum (orange).

Opposite the electronic card 20 extends, integral with the pump, a projecting cylindrical element 21 also called cylindrical core. At its free end there is a support comprising a metal plate 211 of, for example, circular shape.

Advantageously, the tube 3 is arranged in a spiral, so that the core 21 serves as a winder for it. Its role is to guide the winding of the tube, in order to facilitate its spontaneous return in good order at the moment when the device is in the waiting position for the . To further facilitate the return of the connecting tube, an angle of approximately 10° can be established between the longitudinal axis of element 21 and the work surface.

Preferably, the tube 3 is made of flexible, elastic and transparent polymer such as, for example, high-density polyethylene (HDPE). Its flexibility and its spiral shape allow it to be stretched to its maximum length, for example around one meter, which gives a sufficient radius of use to the collection device.

Conversely, outside the period of use, the elasticity of the connecting tube 3 allows it to quickly and spontaneously return to its contiguous spiral shape. By shape memory effect, the tube 3 spontaneously regains a small footprint by wrapping around the core 21. This effect frees up the user's working surface. The transparency of the tube allows you to visualize the correct evacuation of the liquid.

At the distal end of the tube 3 is provided a manipulation tool 4 of the tube 3. It is also called a sleeve. The latter includes an elastomer cone which allows a tight connection between a suction pipette 5 and the tube 3. This tool is also used to hold the pipette 5 in the hand.

In addition, the sleeve 4 includes in its thickness, at least one permanent magnet I1 constituting an actuator of a device I for starting and stopping the pump, the function of which will be explained later. In the embodiment illustrated on the , the sleeve comprises two magnets I1 whose magnetization directions are parallel and whose north and south poles are oriented in the same direction.

The suction pipette 5 is preferably made of plastic and is single-use.

It is preferable to add a sterile tip 6 also for single use. This tip or cone allows precision work to be carried out in sterile conditions. Tip 6 reduces the liquid collection flow due to its small opening diameter and therefore increases the precision of the work. This avoids, for example, the resuspension of dissociated and sedimented cells by centrifugation.

Replacing it after each use with a new tip helps avoid contamination, for example from one cell type to another when operating in different reservoirs. Replacing the tip therefore avoids having to change the pipette after each use.

As indicated above, the tool or sleeve 4 comprises at least one permanent magnet I1 constituting an actuator of the device I for starting and stopping the pump.

Furthermore, said device I comprises a magnetic switch I2 comprising for example a Hall effect electronic component which is located on the reverse (internal side) of the metal plate 211 of the element 21. This component is able to detect at through the metal plate 211, the presence of the magnet(s) I1 and therefore of the tool 4. Optionally, the plate 211 can be covered with a protective layer, for example made of plastic, the thickness of which is sufficiently weak to allow magnetic coupling between the magnet(s) I1 and the switch I2. This device I, connected by a double electrical cable to the electronic card 20, systematically cuts the power supply to the pump 2 each time the pipette 5 is placed on hold against the element 21. Conversely, it controls the powering up the pump when the magnet(s) of the sleeve 4 is (are) in the position away from the magnetic switch I2, that is to say when the pipette 5 is in use.

The permanent magnet I1 included in the sleeve 4 allows on the one hand to maintain the pipette 5 in the waiting position on its support, outside periods of use. The two-magnet configuration is preferred because it allows the pipette to be oriented in the desired direction, parallel to an axis connecting the two magnets. By activating the magnetic switch I2, the permanent magnet I1 also allows the pump 2 to be stopped and started. The two-magnet configuration is also preferred to fulfill this function, because it allows more activation. effective magnetic switch.

Figures 2 to 4C illustrate a first embodiment of the invention.

To the , the suction device is represented with the outline of a cover 7, for example in injected polymer, which joins the different elements of the device, protects and covers the whole.

Preferably, the top of the cover 7 carries the general switch 70 of the device.

This cover advantageously includes a base 71 which serves as ballast for the assembly and prevents the device from overturning, mainly when tank 1 is empty.

According to an advantageous embodiment, an autonomous battery 8 equips the device. This allows the device to be used without it being permanently connected to a mains electricity source. In addition, this battery helps to weight the device. Said battery can be arranged in the lower part of the cover 7 and electrically connected to the electronic card 20.

Preferably, the device is powered by a low voltage direct current generator 80 of 24 Volts and 18 Watts connected to a mains electrical outlet.

Referring more particularly to the , we visualize the tank 1 which for example here has a capacity of 1 liter, is of cylindrical format, and is made of a transparent or semi-transparent polymer (for example HDPE (high density polyethylene)). It serves as a receptacle for liquid effluents or preferably made of polypropylene (PP) which can be autoclaved for 20 minutes at 120°C in humid heat in order to definitively destroy any germs present in the liquid effluent.

Other capacities, shapes and materials can of course be considered. The tanks are preferably of standard format (for example, those marketed under the NALGENE brand are perfectly suitable). They are made of different materials, adapted to chemical and thermal (sterilization) requirements.

The reservoir 1 is arranged in the cover 7 without a cap being fixed on its neck: the connection with the pump is made via a cap 24 secured to the cover and pierced with a passage (shown in dotted lines ) for aspirated liquids. The cap 24 has a curved shape and includes an elastically deformable cushion 25 for placing and removing the reservoir.

As seen in Figures 4A to 4C, the installation of the tank 1 in the cover 7 is done by tilting the tank and bringing its neck into contact with the cap 24 ( ). The tank 1 is then rotated by sliding the neck on the curved surface of the cap 24, so as to bring the tank into a vertical position, the bottom of the tank resting on the base 71. This movement is accompanied by compression of the part of the cushion 25 which extends between the neck of the tank and the pump. Thus, the cushion exerts a compressive force aimed at trapping the tank in the cover in the closed position, without sealing being sought.

The tank is therefore easily removable, which facilitates its emptying or replacement with another identical empty tank. As we will see later, due to the fact that this tank is not depressurized by a pump (unlike existing systems), its extraction (i.e. its dismantling) is rapid.

This ease of disassembly means that a low capacity tank is suitable, which ultimately gives the device a small footprint. In addition, the use of several tanks, for example of one liter each, placed on standby, avoids mixing the effluents which will have to be treated separately.

There is similar to the and represents the suction device in operation during the suction of liquids in a Petri dish B. We observe the tube 3 in the deployed position and the magnets I1 distant from the switch I2, which makes it possible to start the pump 2.

Figures 5 and 6 illustrate a second embodiment of the invention.

Compared to the previous embodiment, the cover does not include a base and the tank is screwed into the cover from below.

The reservoir 1, which here has the shape of a bottle, is secured to the entire device by a cap 11 which covers its opening. This cap has a non-visible through channel which allows the passage of liquid, from the outside to the inside of the tank 1. The latter preferably having a transparent wall, the filling level is visible from the outside.

A liquid level sensor 10 can be immersed in the tank 1 or be present only on certain versions of the device. This sensor located in the tank makes it possible to signal an excessive filling level by rapid flashing of a light-emitting diode. If this upper limit is exceeded, a sensor gives a stop order to pump 2 described below, to avoid liquid overflow.

Note that the cap 11 which closes the reservoir also serves as a mechanical connection and therefore as a support for a sleeve assembly (handling tool) 4 + tube 3 + pump 2 + electronic card 20.

There illustrates a third embodiment of the invention.

Unlike the two previous embodiments, where the suction device is integrated into a cover also enclosing the reservoir, and is therefore generally adapted to be placed on a work table, this third embodiment dissociates the location of the suction device and the tank.

Thus, the suction device is arranged inside a sterile hood 26, while the reservoir 1 is arranged outside said hood 26 and is connected to the pump by a tube 260 passing through an opening 261 provided in a wall of the hood 26.

The suction device is identical to that shown on the and will therefore not be described again.

The electronic card 20, the pump 2 and the core 21 are housed in a cover 7 secured to a wall of the hood 26 by a fixing means, this means being able to use for example a magnet, a screw, glue , a suction cup (non-limiting list).

An advantage of this third embodiment is that replacing the tank does not affect the sterility of the interior of the hood 26.

Compared to competing systems known to the inventors, existing on the market and traditionally used in laboratories, the device described above has the following advantages:

1- Due to the fact that tank 1 is not depressurized (said tank in fact remains at atmospheric pressure), it is very easy to remove it at any time to empty it or to replace it with another. This makes it possible to keep several tanks on standby, each dedicated (for example by labeling) to a different type of liquid waste.

2- The device meets the strictest user safety standards, in particular those known under the name “Biosafety in Microbiological and Biomedical Laboratories”. Unlike competing products, this device does not use air flow, so it does not generate the formation of aerosols likely to carry pathogenic germs. It also does not require the use of expensive filters, which are likely to retain proliferating contaminants, become clogged and need to be replaced. This advantage is decisive for avoiding the dissemination of bacterial, parasitic or viral germs in the laboratory environment.

3- Unlike competing devices existing on the market, the connection is direct between pump 2 and tank 1. There is therefore no need for expensive connections (CPC quick connector type), which are fragile and sources of accumulation of residues and therefore contamination. These connections are also a source of dirt (drops) when disconnecting.

4- The device uses a minimalist hydraulic circuit, as short as possible from the sampling location to tank 1. This circuit is therefore very easily and completely decontaminated by circulating a disinfectant liquid through it by suction (bleach or alcoholic solution For example).

5- The use of standard sterile tips (automatic pipette cones from 100µl to 1,000µl) allows simple use in cell culture (renewal of culture medium) without risk of cross-contamination from culture to culture (for example in the case cultures on multi-well plates). These tips allow you to carry out precision work (for example sucking up liquids on a microscopy slide). They do not generate additional costs for the supply of consumable plastic.

6- The use of a standard single-use plastic pipette avoids the use of glass Pasteur pipettes (source of risk of injury and complications: autoclaving and storage). Each pipette can be reused a large number of times if the sterile tip at the end is renewed.

7- The spiral connection tube 3 allows suction work to be carried out within an extended radius of action (approximately 1 meter, for example the entire surface of a cultivation hood) without being hindered or encumbered. It can be easily replaced with a new tube if necessary.

8- The core 21 allows the pipette 5 to always be available in the same place after each use. It does not rest on the work surface, does not become contaminated, does not cause dirt by flowing, is picked up quickly, at the right height and in the right orientation. After use, the pipette is spontaneously returned to the correct place, guided by the winding of the tube. This ease of use allows the operator to keep his attention on his work.

9- Outside the period of use of the device, the pump is stopped, the device is therefore silent and does not consume energy. By removing the pipette 5 from its support, the pump 2 is activated and conversely, it stops when the pipette is put back in place. It is an “all or nothing” system which is only possible with this device. In fact, it works with a non-depressurized tank (unlike competing systems), and therefore does not require the pump to run constantly to create a vacuum.

10- The electromagnetic pump 2 for liquid transfer is robust, capable of self-priming with even viscous solutions such as printing inks. It can generate strong depressions (0.8 bar), compared to the modest requirement (column height of 25 to 30 cm maximum). It requires little maintenance because it has no rotating parts and the materials in contact with liquids are stainless steel and Teflon (PTFE). These characteristics mean that it does not risk getting stuck by leftover solutions.

11- The integration of the entire suction device in a small volume assembly, without visible tubing or pump, makes it available anywhere at any time and protected from dust.

12- Unlike competing devices, the device has no external flexible tubing likely to bend or get pinched between cell culture furniture.

13- Unlike competing devices, the device does not require the use of filters to clean the air leaving the laboratory atmosphere, since there is no air flow, the pump being designed for transfer of liquids. It should be noted that the hydrophobic filters used are specific, they are not intended to stop dry dust but to stop micro-droplets of liquid as a surgical mask does. These droplets ultimately form a liquid film on the surface of the filter. Which film is forced to pass through the filter membrane by progressive increase in pressure by clogging effect. This phenomenon can be the cause of forced nebulization or aerosolization of the liquid which may contain pathogenic germs which are precisely cultured for study purposes. These filters are clogged and therefore rendered ineffective as soon as they are humidified, they must then be replaced which generates a substantial expense.

The different elements making up the laboratory device are interdependent but constitute an inseparable whole which cannot function if an element is missing (with the exception, of course, of optional elements such as the level gauge, the battery and possibly the power selector). suction speed).

The coherence of the system is due in particular to the multiple role played by each element, namely:

The sleeve 4 which is used to connect the pipette 5 to the tube 3 also serves to hold the pipette ready for use on the core 21 and is also used to hold the assembly.

The tube 3 which serves as a connection between the pipette 5 and the pump 2 also serves as a spring to ensure its instant storage.

The cylindrical element 21 which serves to guide the winding of the connecting tube 3, also serves as a support for the sleeve 4.

The permanent magnet I1 of the sleeve 4 which is used to hold the pipette 5 in place on the core 21, is also used to start the pump 2 by activating the magnetic switch I2.

The core 21 which allows the winding of the connecting tube 3, also serves to contain inside the magnetic switch I2 of the pump.

Furthermore, cover 7 also serves as a support for the entire device. In particular, it makes it possible to place the tool 4 pipette support 5 at a sufficient height from the work table (i.e. approximately 25 cm).

In the embodiment of Figures 5 and 6, the cap 11 which closes the reservoir 1 also serves as a mechanical connection and therefore as a support for the one-piece pipette assembly 5 + sleeve 4 + tube 3 + pump 2 + electronic card 20.

Battery 8 positioned in the lower part serves as a source of energy, but it also serves to ballast the device.

The general switch 70 is also used to select the desired flow rate, and forms a power-on indicator (LED).

In an embodiment not shown, the device I for starting and stopping the pump could be of another type, non-magnetic. Thus, the actuator I1 could include a finger made of electrically insulating material, while the switch I2 would include two electrically conductive blades housed in a cavity. In this hypothesis the blades are preferentially elastic and form a V when they touch. Inserting the finger into the cavity not only ensures a mechanical connection between the actuator and the switch, but also separates the two blades from each other, thus forming an interruption in the flow of current. .

Claims (10)

Device for suction of liquids, in particular waste, comprising:
- a suction pump for transferring liquids (2), adapted to be coupled to an opening of a container intended to receive said sucked liquids,
- a suction tube (3) having a proximal end connected to said pump (2), and a distal end provided with a manipulation tool (4) of said tube (3) associated with a suction pipette (5) , And
- a device (I) with on/off positions configured to start said pump (2), respectively stop it,
characterized by the fact that said device (I) for starting and stopping the pump comprises an actuator (I1) carried by said handling tool (4) and a switch (I2) distinct from the actuator, the actuator (I1) cooperating with the switch (I2) such that said device (I) for starting and stopping the pump is in the off position when the actuator and the switch are in a coupling position mutual, while it is in the on position when the actuator and the switch are not in said mutual coupling position. Device according to claim 1, characterized in that the coupling between the actuator (I1) and the switch (I2) of the device for starting and stopping the pump is of the magnetic type. Device according to one of claims 1 or 2, characterized in that the switch (I2) is integral with said pump (2). Device according to one of the preceding claims, characterized in that said tube (3) is spiraled. Device according to claim 4, characterized in that said pump (2) is associated with a projecting cylindrical element (21) around which said tube (3) winds. Device according to claim 5, in which the spiral tube (3) and the protruding cylindrical element (21) cooperate to guide and maintain the pipette (5) in a single position on the protruding cylindrical element (21) when the device ( I) starting and stopping the pump is in the off position. Device according to one of claims 5 or 6, taken in combination with one of claims 1 to 4, characterized in that the switch (I2) is integral with said cylindrical element (21). Device according to one of the preceding claims, characterized in that the actuator (I1) comprises at least one permanent magnet. Device according to one of the preceding claims, characterized in that the switch (I2) consists of a magnetic switch. Device according to one of claims 1 to 9, in which the pump is arranged to be connected directly to the container.