EP2243553A1 - Handheld pipette - Google Patents

Abstract

The handheld pipetting device (11) has a valve system that is partially electrically controllable and which is arranged within the air line. An aspirating button (17) is coupled to the housing (13). A light source (37) is coupled to the housing at a relatively short distance to a longitudinal axis (31) of the pipette receptacle (23). An optical system is coupled to the light source which generates a light cone (38) from light emanating from the light source.

Description

Field of the invention

The invention relates to a hand pipetting device according to the preamble of patent claim 1.

State of the art

The precise measurement of liquid volumes and the transfer of a precisely measured volume of liquid from a first container into a second container are among the most frequent steps in the chemical and physical laboratories worldwide. As pipetting aids, so-called Peleus balls are used as standard in the laboratories. After the Peleus ball is placed on a commercial measuring pipette, the air in the ball must be expressed via a ball valve opposite the pipette. By actuating two further ball valves, the liquid level in the pipette can be raised or lowered. One disadvantage of a Peleusballes is on the one hand in the possibility that liquid is inadvertently sucked into the ball and thereby contaminated. Another disadvantage is that to operate the ball valves of the thumb and another finger of a hand are needed and the operation of the ball valves requires motor skills.

In laboratories, other constructions for the safe metering of liquids are used. Ergonomic and safe pipetting aids are hand pipetting devices into which the serological pipettes are inserted. The pipetting speed can be infinitely adjusted with a knurled screw. By pressing on an upper dosing button, liquid is suctioned in a controlled manner. A lower dosing button is used to precisely dispense the liquid, which is also possible drop by drop. A sterile filter in the pipetting head prevents contamination. These pipetting aids are operated with electric current, in particular with rechargeable batteries. The operating life of such hand pipetting equipment is limited by the relatively high power consumption of the aspirator.

The removal of liquid from containers requires high concentration, especially if there is a visual impairment, because z. B. the containers are made of stained glass or completely opaque. On the one hand, it is difficult to determine whether the pipette tip actually immersed in the liquid, on the other hand, the scale on the pipette is difficult to read. In particular, in deep containers, in which the liquid level is low, the removal of accurate liquid removal shows to be complicated and exhausting. These disadvantages also apply to the emptying of liquids from the pipette in containers described above, where, for example, a contact between a container and the pipette tip to be avoided.

From the US 5,919,706 a pipetting device is known, which is equipped with a device for measuring the height of a liquid level. The device comprises a light source and a light-conducting fiber adjoining the light source, on which the light emerges focused in the form of a thin measuring beam. The light-conducting fiber is in the lower region of a neck tube, on which an interchangeable pipette tip is plugged arranged.

The quality of the measurement requires a clear and precisely focused light signal. The focusing of the measuring beam serves the lower end of the light-emitting body in the form of a converging lens. The emerging light is reflected at a liquid level and partially absorbed depending on the height of the liquid level and the nature of the liquid. The reflected light, in contrast to the exiting light of attenuated intensity. The intensity difference of the incoming and outgoing light beam is used to generate an electrical measurement signal.

The emerging light beam acts as a non-contact measuring beam and is specifically adapted to this task. The light used is therefore completely unsuitable for other tasks, such as the illumination of the environment of the pipette or the pipette scale to take over. The advantage of the described pipetting device is that the user is informed of the height of the liquid level. The disadvantage, however, is that the pipetting device is relatively expensive to manufacture by the additional measuring device.

Object of the invention

Object of the present invention is therefore to avoid the disadvantages described. It should be created a hand-held pipetting device whose handling requires less concentration, so z. B. an unwanted suction of air, eg. B. because the pipette is not visible, can be avoided. The Handpippetirergerät should be particularly simple and inexpensive. Also, the reading of the measuring scale on the pipette should be simplified. Another goal is that the power consumption of the proposed hand-held pipetting device is minimized.

description

According to the invention, the mentioned object is achieved in a hand pipetting device according to the preamble of claim 1, characterized in that the light source is provided at a short distance to the longitudinal axis of the pipette holder on the housing and at the light source, an optical device is provided, which emits a cone of light emerging from the light source Light rays generated.

The handheld pipetting apparatus according to the invention has the advantage that the pipette tip and its close surroundings are illuminated by the light cone during aspiration or dispensing. The fact that the light source is located on the housing at a short distance from the pipette holder, the light cone can unhindered illuminate the area around the pipette tip. The light source can be fully integrated into the housing. The light source therefore has no protrusions or heels that could become dirty or break while working with the hand pipetting device.

An unwanted suction of air, which is due to the fact that the pipette tip is located during the suction above the liquid level of the liquid to be aspirated, is easily avoided by the very good illumination conditions. Another advantage of the light source is that the scaling of the pipette used is well lit and readable. The precision of a pipetting process can therefore be improved in a simple and cost-effective manner by the hand-held pipetting device according to the invention. For forming the light cone, a diverging lens is preferably provided. However, other optical devices which produce a light cone are also conceivable.

Since the space requirement of the light source is low, the manual pipetting apparatus according to the invention, despite the existing light source, has a handy size which does not differ from manual pipetting devices without a light source. The course of the pipetting process also remains unchanged in comparison to a hand pipetting device without a light source. There are no additional handles necessary to operate the handheld pipetting device according to the invention.

In a preferred embodiment, the light source is an LED which emits light substantially in the visible light spectrum. LED's are known to have a good light output with comparatively low power consumption and a very long life. The LED ensures that the duration of the operating time of the hand pipetting device is affected as little as possible by the provision of the light source. It is also conceivable the use of other light sources that meet the above requirements. LED's usually have optics integrated in their housing, so that the light emerging from the LED has the shape of a cone

Expediently, the light beams at a distance of 300 mm from the light source emit a circle diameter between 1.5 cm and 5 cm, more preferably between 2 cm and 4 cm, and most preferably between 2.5 and 3.5 cm. Since standard pipettes have a length of 290 mm, the circle diameter with the above dimensions is substantially at the level of the recorded pipette tip. The dimensions of the circle diameter at the level of the pipette tip can only be achieved if the light rays are present in the form of a light cone. The circular illumination causes the liquid level, in which the pipette dives, in low light conditions, such as prevail, for example, in an opaque container recognizable. The working area is also better lit than the surroundings. Shadow cast by the user or the hand-held pipetting device, which inevitably results in conventional ceiling lighting, is reliably compensated by the additional light source on the hand-held pipetting device. At any time, it is possible for the user to avoid unintended loss of contact between the pipette tip and the liquid.

The fact that the angle between the longitudinal axis of the pipette holder and the longitudinal axis of the light source is 0-5 degrees, preferably 1-4 degrees and very particularly preferably 2-3 degrees, ensures that the pipette tip and its close surroundings are optimally illuminated.

Advantageously, the circuit of the light source can be closed and interrupted by the aspiration button and / or the dispensing button. The light source is therefore only switched on when the aspiration button or the dispensing button is actuated. On additional switches and operations for turning on and off the light source can be waived. The light source is automatically turned on only when the illumination of the environment of the pipette tip is also needed during pipetting. The power consumption of the light source is reduced by this electrical circuit to the minimum.

In a preferred embodiment, a delay circuit is provided in the circuit of the light source which switches off the light source after actuation of the aspiration button or the dispensing button after 1 to 30 seconds, preferably after 3 to 20 seconds and more preferably after 5 to 6 seconds. The delay circuit causes a turn-off delay. The switched-on light source therefore also illuminates the region of the pipette tip when the pipetting process has been completed. When the aspirated liquid is transferred to another vessel, it is illuminated without the dispensing button having to be actuated. Also, the unwanted contact of the pipette tip with the liquid, which can occur due to poor lighting conditions, is easily avoided by the delay circuit after the aspirator or dispensing process has been carried out.

In one embodiment, the light source can be activated with a separate switch. The light source can therefore be used individually according to the needs of the user.

Advantageously, the light source is arranged on a separate component, which is detachably connectable to the housing of the hand pipetting device. Subsequent equipment of a hand pipetting device with the light source is made possible by this design feature.

According to a particularly preferred embodiment variant, the light source is attached to a lighting support. Since the illumination carrier is a separate component, the light source is particularly easy to integrate.

Because the illumination carrier is advantageously pivotable from a first position to a second position, the light source in the second position is always optimally positioned to illuminate the pipette tip, a container and the liquid level in the container.

On the outside of the housing, electrical contacts which can be tapped off from outside are advantageously arranged, which interact with electrical contacts arranged on the lighting support. The electrical contacts have the effect of that Circuit between the light source and a voltage source is closed only in the second position of the illumination carrier. An unwanted switching on of the light source can be reliably avoided.

Conveniently, the light source and the pressure or vacuum source are powered by a battery with power. The operation of the inventive hand-pipetting device is therefore independent of an external power source and not limited by power supply cable. Only the low power consumption of the light source allows the use of a battery.

Figur 1

eine Seitenansicht eines Handpipettiergeräts mit Beleuchtungsträger, einer in den Beleuchtungsträger integrierten Lichtquelle und einer in dem Handpipettiergerät aufgenommenen Pipette;

Figur 2

eine perspektivische Ansicht des Handpipettiergeräts;

Figur 3

eine Detailansicht des Beleuchtungsträgers;

Figur 4

eine Detailansicht des Handpipettiergeräts;

Figur 5

eine Seitenansicht einer zweiten Ausführungsvariante des Handpipettier- geräts mit einer im Gehäuse integrierten Lichtquelle und

Figur 6

eine Seitenansicht einer dritten Ausführungsvariante, bei der die Licht- quelle in einem separaten Anbau integriert ist.

In the following, the invention will be described in more detail in a schematic representation with reference to the figures. It shows:

FIG. 1

a side view of a hand pipetting device with illumination carrier, a light source integrated in the light source and a recorded in the hand pipetting pipette;

FIG. 2

a perspective view of the hand pipetting device;

FIG. 3

a detailed view of the illumination carrier;

FIG. 4

a detailed view of the hand pipetting device;

FIG. 5

a side view of a second embodiment of the hand pipetting device with a light source integrated in the housing and

FIG. 6

a side view of a third embodiment in which the light source is integrated in a separate extension.

FIG. 1 and 2 show a Handpipettiergerät 11 with an L-shaped housing 13 with two legs (15,21). The first leg of the L-shaped housing 13 serves as a handle 15. In the handle 15, an aspiration button 17 and a dispensing button 19 are accommodated. The aspiration button 17 is operated by the index finger, the dispensing button 19 by the middle finger of a user. On the handle 15 remote from the end of the second leg 21 of the L-shaped housing 13 is approximately parallel to the handle 15, a pipette holder 23. The pipette holder 23 has a circular opening 25 in a commercial pipette 24 is inserted with a first end. A second open end of the pipette 24 is formed as a tip 26.

Between the pipette holder 25 and the second leg 21, a lighting support 27 is pivotally received on the second leg 21. The illumination carrier 27 is pivotable between a first position and a second position. The axis of rotation 29 of the illumination carrier 27 corresponds in this embodiment, the longitudinal axis 31 of the pipette holder. It is also conceivable that the illumination carrier is firmly connected to the second leg 21 and is permanently in the first or the second position.

The Figures 3 and 4 show the illumination support 27 in more detail. The illumination carrier 27 has a housing 28, a first extension 33 and a second extension 35, which extensions are opposite each other. In the housing 28, an intermediate plate 36 is received positively.

In the first extension 33, a light source 37 is positioned so that the light source 37 radiates in the direction of the tip 26 of a recorded pipette 24. The light source 37 is preferably a light-emitting diode, but it can also be any other suitable bulbs are used when the power consumption is low and for the present application, a sufficient light output can be achieved. An optical device (not shown in the figures), preferably a diverging lens, serves to ensure that the exiting light has the shape of a light cone 38. By the light cone 38 ensures that not only the pipette tip 26, but also their environment is illuminated in the range of a diameter of about 3 cm.

In the second extension 35 is a first and second electrical contact 39,41. The electrical contacts 39,41 are mounted on the intermediate plate 36. FIG. 3 and 4 let recognize that the first and second electrical contact 39,41 resp. 43,45 different distances from the axis of rotation 29 and are located on a straight line which passes through the axis of rotation 29. It would also be conceivable for the electrical contacts 39, 41 to be located on a circular arc with respect to the axis of rotation 29.

Out FIG. 3 It can be seen that two further electrical contacts 43,45 are attached to the second leg 21 at a short distance from the pipette holder such that these can be brought to coincide with the electrical contacts 39,41 of the illumination support 27.

The power supply is effected by the central voltage source of the hand pipetting device 11, wherein the voltage source is an accumulator in the exemplary embodiment. It would also be conceivable that the light source 37 is supplied by a separate voltage source and the circuit of the light source 37 can be closed and interrupted by a separate switch 46. The optional switch 46 is only in FIG. 6 shown. In the illumination support electronics not shown is integrated, which adapts the existing voltage to the required voltage of the light source 37, if the supplied electrical voltage does not match the required electrical voltage of the light source 37. A further object of the mentioned electronics is that, when the dispensing button 19 is actuated, the voltage supply of the light source is not momentarily interrupted, but the light source 37 continues to be illuminated for about 5 to 30 seconds.

The inventive Handpipettiergerät 11 operates as follows: After a commercially available pipette was introduced into the pipette 24 receptacle 23, the illumination beam 27 is pivoted from the first position to the second position. In the second position, the electrical contacts 39,41 of the illumination carrier with the electrical contacts 43,44 of the second leg 21 are made to coincide. Then, the pipette tip 26 is immersed in a liquid to be aspirated in a container. In order to avoid unwanted emptying a central power supply, which is located in the handle 15, the circuit between the power supply and light source 37 is closed only by pressing the Aspieriertaste 17. The light source 37 is active during the aspiration process and illuminates the pipette tip 26 and the liquid level about 3 cm around the pipette tip 26. Thus, the user of the hand-held pipetting device 11 can see through the entire aspiration process whether the pipette tip 26 dips into the liquid. An empty air intake is easily avoidable for the user.

After the dispensing button 19 has been actuated to empty the pipette 24, the light source will remain lit for about 5 to 30 seconds. The pipette tip 26 and the liquid jet emerging from the pipette 24 are illuminated. The user can easily hold the jet of liquid in the desired path. Also is for that Eye of the user easily recognizable whether the pipette tip 26 is immersed in the liquid or not. The afterglow of the light source 37 causes the user can easily determine by optical control, whether the pipette tip 26 is not unintentionally re-immersed in the liquid after dispensing the liquid. The light source 37 thus allows fatigue-free working, which demands less concentration from the user of the hand-held pipetting device.

If the user wishes to drop the hand-held pipetting device 11 briefly, for example on a laboratory bench, then he pivots the lighting support 27 from the second to the first position. The circuit between the voltage source and the light source 37 is interrupted and the hand pipetting device 11 can be stored without the pipette tip 26 touching the deposition surface and thereby becoming contaminated.

The FIG. 5 shows a variant of the hand pipetting device 11, in which the light source 37 is arranged in the housing at a short distance from the pipette holder 23. This variant has the advantage that no additional handles are necessary to operate the hand-held pipetting device 11. The light source 37 is fully integrated into the housing at the bottom of the leg 21. The light source 37 is therefore located within the housing 13 and the light rays leave the housing through a correspondingly sized passage opening (in FIG. 5 not visible). The housing is formed from two half-shells 13a, 13b, wherein half of the passage opening is provided on each half-shell 13a, 13b. As a result, the half-shells are easy to remove from the molds during production. By the light source 37, no protrusions or extensions are formed, which could be dirty or the user in the operation of the hand-held pipetting device 11 could be a hindrance. Since the light source 37 has a very small footprint, the dimensions of the housing remain unchanged compared to a hand pipetting without light source.

As FIG. 6 can recognize an embodiment is also conceivable, in which the light source 37 is integrated in a separate housing extension 47. The installation of the light source 37 in the housing extension 47 can be carried out easily because there is sufficient space in the housing extension 47. The extension may be arranged on the second leg 21 at a short distance from the pipette holder 23. With this arrangement of the light source 37, it is avoided that the user's fingers holding the aspirating and Dispensiertaste 17,19 operate, are within the light rays of the light source 37 and therefore throw a shadow.

• Ein Handpipettiergerät 11 ist zusätzlich mit einer Lichtquelle 37 ausgerüstet. Die Lichtquelle 37 dient der Beleuchtung der Spitze 26 einer handelsüblichen Pipette 24, welche in einer Pipettenaufnahme 23 aufgenommen ist. Die Lichtquelle 37 ist direkt in dem Gehäuse 13 des Handpipettiergeräts 11 integriert und befindet sich in kurzem Abstand und parallel zur Längsachse 31 der Pipettenaufnahme 23. Über eine Aspiriertaste 17 wird die Lichtquelle 37 eingeschaltet. Bei Betätigung einer Dispensiertaste 19 leuchtet die Lichtquelle 37 eine gewisse Zeit nach, bevor sie erlischt.

In summary, the following can be stated:

• A hand pipetting device 11 is additionally equipped with a light source 37. The light source 37 serves to illuminate the tip 26 of a commercially available pipette 24, which is received in a pipette holder 23. The light source 37 is integrated directly into the housing 13 of the hand-held pipetting device 11 and is located at a short distance and parallel to the longitudinal axis 31 of the pipette receiver 23. The light source 37 is switched on via an aspiration button 17. Upon actuation of a dispensing button 19, the light source 37 lights up for a while before it goes out.

The light source 23 may also be integrated in a lighting support 27. At least two electrical contacts 39,41,43,45 are attached to the illumination support 27 and the housing 13. If the illumination carrier 27 is rotated to the side in a first position, the electrical contacts of the housing 43,45 and the electrical contacts of the illumination carrier 39,41 are separated from each other. If the illumination carrier 27 is in a second position, the circuit between the voltage source in the manual pipetting device 11 and the light source 23 is closed, the contacts 39, 41 are connected to the contacts 43, 55. The illumination support 27 is removable and can be re-attached to the hand-held pipetting device 11.

Another possibility of fixing the light source 37 is that the light source 37 is accommodated in a housing extension 47.

Legend:

11

Handpipettiergerät

13

casing

13a, 13b

Half shells of the housing

15

Handle (first leg)

17

Aspiriertaste

19

Dispensiertaste

21

Second thigh

23

pipette recording

24

pipette

25

opening

26

pipette tip

27

lighting carrier

28

Housing of the illumination carrier

29

Rotary axis of the illumination carrier

31

Longitudinal axis of the pipette holder

33

First extension

35

Second extension

36

intermediate plate

37

light source

38

light cone

39

First electrical contact on the lighting support

41

Second electrical contact on the lighting support

43

First electrical contact on the housing

45

Second electrical contact on the housing

46

Separate switch

47

Housing extension

Claims (13)

Hand pipetting device (11) with a housing (13), - a pipette receptacle (23) on the housing (13) for a replaceable pipette (24), which pipette (24) is received with a first end in the pipette receptacle (23) and having a tip (26) as a second end, a vacuum source for aspirating a liquid, an overpressure source for dispensing an aspirated fluid, - An air line which connects the vacuum and the pressure source with the pipette holder an at least partially electrically controllable valve device which is arranged in the air line, - An aspiration button provided on the housing (17), as well - a dispensing button (19) and a light source (37)
characterized,
in that the light source (37) is provided at a short distance from the longitudinal axis (31) of the pipette receptacle (23) on the housing (13) and an optical device is provided at the light source which generates a light cone (38) of the light rays emerging from the light source , Handpipettiergerät (11) according to claim 1, characterized in that the light source is an LED, which emits light substantially in the visible light spectrum. Handpipettiergerät (11) according to one of claims 1 to 2, characterized in that the light beams at a distance of 300 mm from the light source (37) has a circle diameter between 1.5 cm and 5 cm, more preferably between 2 cm and 4 cm and completely more preferably between 2.5 and 3.5 cm illuminate. Handpipettiergerät (11) according to one of claims 1 to 3, characterized in that the angle between the longitudinal axis (31) of the pipette receiver (23) and the longitudinal axis of the light source (37) 0 - 5 degrees, preferably 1 - 4 degrees and most preferably 2 to 3 degrees. Handpipettiergerät (11) according to one of claims 1 to 4, characterized in that the circuit of the light source (37) by the Aspiriertaste (17) and / or the Dispensiertaste (19) is closable and interruptible. Handpipettiergerät (11) according to one of claims 1 to 5, characterized in that in the circuit of the light source (37) is provided a delay circuit which the light source (37) after actuation of the Aspiriertaste (17) or the Dispensiertaste (19) according to 1 to 30 seconds, preferably after 3 to 20 seconds and more preferably after 5 to 6 seconds off. Handpipettiergerät (11) according to one of claims 1 to 5, characterized in that the light source (37) with a separate switch (46) can be activated. Handpipettiergerät (11) according to any one of claims 1 to 7, characterized in that the light source (37) is arranged on a separate component which is detachably connectable to the housing (13) of the hand pipetting device (11). Handpipettiergerät (11) according to claim 8, characterized in that the light source (37) on a lighting support (27) is mounted. Handpipettiergerät (11) according to claim 9, characterized in that the illumination support (27) from a first position, can be pivoted into a second position. Handpipettiergerät (11) according to one of claims 9 to 10, characterized in that on the outside of the housing from the outside tangible electrical contacts (43,44) are arranged, which cooperate with the illumination carrier (27) arranged electrical contacts (39,41) , Handpipettiergerät (11) according to claim 11, characterized in that the connection between the electrical contacts (43,44) on the housing and the electrical contacts (39,41) of the illumination carrier (27) are interrupted when the illumination carrier (27) in the first position and that the contacts (43,45) on the housing with the contacts (39,41) on the illumination support are connected when the illumination carrier (24) is in the second position. Handpipettiergerät (11) according to one of claims 1 to 12, characterized in that the light source (37) and the pressure or vacuum source are powered by a battery with power.

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