EP2656916B1 - Method for metering a liquid using a pipette and a syringe and pipette for actuating the syringe to dose the liquid - Google Patents

Description

The invention relates to a method for dosing liquid by means of a pipette and a syringe and to a pipette for actuating a syringe for dosing liquid.

The pipettes used here for actuating a syringe serve to dispense liquid received in the syringe in several steps. They are also referred to as dispensers or repeating pipettes. These pipettes have at the lower end of a rod-shaped housing a receptacle for a flange of a cylinder of the syringe and in the housing a displaceable receiving body with a piston receptacle for the upper end portion of a piston rod of a piston of the syringe. The syringe can be used with the flange and the end portion of the piston rod through axially directed openings of the receptacles. The flange and the end portion are held in the receptacles by means for detachable holding, which are designed, for example, as spring-loaded gripping levers. Furthermore, the pipette comprises means for displacing the receiving body, which allow a partial withdrawal of the piston from the cylinder for the suction of liquid into the syringe and a stepwise depression of the piston into the cylinder for the stepwise discharge of liquid.

The DE 2926691 C2 and the US 4406170 A describe means for displacing the receiving body in the housing. These include an elevator lever connected to the receiving body and projecting out of the housing through a straight-line slot for drawing fluid into the syringe by displacing the receiving body away from the receptacle. In addition, they include a rack-pawl means for gradually advancing the piston by a reciprocating metering lever. At the metering lever is a pivoting pawl stored. The rack is connected to the receiving body and arranged in the pivoting range of the pawl. An adjustable sliding cover covers more or less the row of teeth on the rack in order to limit the engagement of the pawl in the rack when pivoting the metering lever. Further, the rack is designed with a contour through which in the advanced position of the piston, the cover of the rack is displaced away, so that it prevents the pawl from engaging in the uncovered teeth of the rack. This prevents that a residual amount is discharged from the syringe, which is smaller than the dispensed in each dosing step dosage.

Further developments of the means for releasably holding the syringe are in the EP 0656229 B1 and US 5620660 A described. The EP 1724020 B1 and the US 7731908 B2 describe a further development of the holding devices, which allows a detachment of the syringe from the pipette by one-hand operation.

The EP 0657216 B1 and US 5620661 A describe such a pipette with a sensor for sensing protrusions and depressions on the syringe flange and associated syringes. The sensor is used to determine the size of the syringe used. Based on the set increment, electronics determines the amount of fluid dispensed at each dispensing step. This is displayed on a display.

EP 1 524 035 A1 describes a pipette in which the opening and closing of a connection mechanism for connecting the pipette to a syringe is detected electronically. Information about the syringe (especially about its size) is entered via a keyboard.

Further developments of the means for shifting the receiving body are in the DE 4437716 C2 . EP 0679439 B1 and US 5591408 A described. According to EP 0679439 B1 and US 5591408 A a Repetierpipette has a Konstantschrittinrichtung, which sets the width of the first step for moving the receiving body for the operating portion of the syringe plunger for cylinder intake for the syringe barrel to a constant value, which is independent of the setting of the subsequent step sizes. By this constant reversal stroke when moving the receiving body back to the cylinder holder after the liquid is drawn up, a dosing accuracy impairing game between the pipette and syringe is overcome.

The known manually operated repeating pipettes have the disadvantage that the user has to look up the maximum number of dosing steps that are possible with completely filled syringe with the set dosing volume after performing a reverse stroke without refilling the syringe in the manual or experimentally determined. Furthermore, the user must count the dosing steps performed if he wants to know the number of additional dosing steps that are still possible with the remaining liquid in the syringe. This is particularly troublesome and error prone with small dosing increments. In addition, it is disadvantageous that in the known repeating pipettes no play compensation is ensured if, in the case of only partial filling of the syringe by means of the pipette, the delivery of the liquid from the syringe is controlled by the pipette. This will affect the accuracy of the initial dosages.

US 6,254,832 B1 describes a portable, microprocessor-controlled pipette with an electrical power supply. The pipette has a piston in a cylinder driven by an electric stepper motor. The pipette is with tube-shaped pipette tips can be fitted, which are attachable to a shaft at the lower end of the pipette. By means of input keys the dispensing volume is adjustable, as it is displayed on a display. By pressing a further key, the number of dispensing steps that can be performed by the pipette with the dispensing volume set can also be displayed. In dispensing mode, after each dispensing step, the number of dispensing steps still possible with the remaining amount of sample liquid in the pipette tip is displayed

Based on this, the object of the invention is to provide a method for dosing liquid by means of a pipette and a syringe and a pipette for actuating a syringe for dosing liquid with more favorable application properties.

The object is achieved by a method having the features of claim 1.

• 1.1 wird die Spritze lösbar mit der Pipette verbunden,
• 1.2 wird wahlweise die Dosierschrittweite eingestellt oder die zuvor eingestellte Dosierschrittweite beibehalten,
• 1.3 wird das über die Dosierschrittweite eingestellte Dosiervolumen mittels der Anzeigeeinrichtung angezeigt,
• 1.4 wird die mit der eingestellten Dosierschrittweite und vollständig befüllter Spritze ohne Nachbefüllen der Spritze mögliche maximale Anzahl Dosierschritte mittels der Anzeigeeinrichtung angezeigt,
• 1.5 wird Flüssigkeit in die Spritze eingesogen,
• 1.6 wird nach dem Befüllen der Spritze mit Flüssigkeit ein Umkehrhub ausgeführt,
• 1.7 werden Dosierschritte ausgeführt, die ausgeführten Dosierschritte gezählt und/oder die Anzahl der ohne Nachbefüllen der Spritze noch möglichen Dosierschritte ermittelt und mittels der Anzeigeeinrichtung angezeigt und
• 1.8 wird nach Ausführen der maximalen Anzahl Dosierschritte entweder die Spritze von der Pipette gelöst oder werden mittels derselben Spritze die Schritte 1.2 bis 1.8 erneut durchgeführt, wobei in Schritt 1.7 die insgesamt mit der Spritze mit der eingestellten Dosierschrittweite durchgeführte Anzahl Dosierschritte gezählt und/oder die Anzahl der ohne Nachbefüllen der Spritze noch möglichen Dosierschritte ermittelt und mittels der Anzeigeeinrichtung angezeigt werden.

In the method according to the invention for metering liquid by means of a pipette with an adjustable dosing step size and a display device and a syringe which can be actuated by means of the pipette

• 1.1, the syringe is releasably connected to the pipette,
• 1.2, the dosing increment is set or the previously set dosing increment is maintained,
• 1.3, the dosing volume set via the dosing increment is displayed by means of the display device,
• 1.4, the maximum number of dosing steps possible with the set dosing step width and completely filled syringe without refilling the syringe is indicated by means of the display device,
• 1.5, liquid is drawn into the syringe,
• 1.6, after the filling of the syringe with liquid, a reversal stroke is carried out,
• 1.7 metering steps are performed, the numbering steps performed counted and / or determines the number of possible without refilling the syringe still possible metering and displayed by the display device and
• 1.8, after the maximum number of dosing steps, either the syringe is released from the pipette or steps 1.2 to 1.8 are repeated using the same syringe, in step 1.7 counting the total number of dosing steps performed with the syringe with the dosing increment set and / or the number be determined without refilling the syringe still possible dosing and displayed by the display device.

In the method according to the invention, the user is shown the maximum number of metering steps that are possible with completely filled syringe with the set metering volume after performing a reverse stroke without refilling the syringe. Furthermore, the user is shown the number of dosing steps performed and / or the number of dosing steps still possible without refilling the syringe with the set dosing increment. Optionally, after carrying out the maximum number of metering steps in the syringe, a residual amount of liquid remains that is less than the set metering volume. After the maximum number of dosing steps has been performed, the user either has the option of dislodging the used syringe from the pipette and starting the procedure again from the beginning after inserting a new syringe. Alternatively, the user may use the same syringe multiple times. If he repeatedly uses the syringe, the display device displays the total number of dosing steps performed by the same syringe. The user can thus perform the dosing easier and with reduced risk of error.

According to one variant, the number of executed dosing steps is displayed instead of the display of the still possible number of dosing steps. According to another variant, instead of the number of dosing steps carried out, the number of refilling of the syringe still possible dosing steps is displayed. The number of possible dosing steps is the difference between the possible maximum number of dosing steps and the number of executed dosing steps. According to a further variant, at the same time the number of metering steps performed and the number of possible metering steps until the syringe is completely emptied are displayed.

According to one embodiment of the method, one of the two abovementioned numbers is displayed larger than the other one. For example, During dispensing, the sum of the executed number of dosing steps greater than the number of possible dosing steps displayed.

According to a further embodiment, the method is carried out with a hand-driven pipette. In the hand-driven pipette, both the drawing-in of liquid into the syringe and the gradual discharge of liquid through the syringe are performed by means of a mechanical drive which the user drives by muscle power.

In accordance with one embodiment of the method, the pipette detects a coding of the syringe connected to the pipette and indicates the metering volume on the basis of the set metering increment and the detected coding detected and displayed by the display device. This embodiment allows the use of different sized syringes, which always automatically the dosing volume is displayed, which is delivered at the set dosing increment with each syringe used.

According to a further embodiment, prior to the picking up of liquid by means of the syringe detachably connected to the pipette, a display indicative of the picking up of liquid is indicated by means of the display device. The display is according to an embodiment an upward arrow or other obvious symbol. This facilitates the operation of the pipette.

According to a further embodiment, when liquid is picked up by means of the display device, a flashing or otherwise indicative of the current process of receiving liquid into the syringe and performing a reverse stroke is displayed. As a result, the user is instructed to fill the syringe completely with liquid as far as possible and to perform the reversal stroke. As a result, operator errors and dosing errors can be avoided.

According to a further embodiment, after the reversal stroke has been carried out completely by means of the display device, the set metering volume and the number of metering steps have been indicated. During dispensing, the user can obtain information at any time about the set dosing volume and the number of doses taken.

According to a further embodiment, after complete execution of the reversal stroke, a display indicative of the dispensing of liquid is displayed. The display is according to one embodiment, a downward arrow or other obvious symbol. This facilitates the operation of the pipette.

According to a further embodiment, after executing the maximum number of metering steps by means of the display device, a display indicating the optional dispensing of residual liquid from the syringe and detaching the syringe from the pipette or taking up further liquid by means of the same syringe is displayed. According to one embodiment, the display comprises a downward and an upward arrow or other obvious symbols. This facilitates the operation of the pipette.

According to a further embodiment, after dispensing residual liquid from the syringe by means of the display device, an indication of the release of the syringe from the pipette is displayed. According to another embodiment, this display comprises a downwardly directed arrow or another obvious symbol. This facilitates the operation of the pipette.

According to a further embodiment, a display is only displayed by means of the display device when a syringe is detachably connected to the pipette and / or the display goes out when the syringe is disconnected from the pipette. As a result, a battery or other electrical power supply of the pipette is spared.

According to a further embodiment, after releasably connecting the pipette to the syringe and before picking up liquid into the syringe by means of the display device, an indication indicative of the setting of the pipette to a lower end position for receiving liquid is displayed when the pipette is not in the lower end position for picking up liquid located. The display is according to one embodiment, a downwardly directed arrow or other obvious symbol for the setting of the pipette in the lower end position. This facilitates the operation of the pipette.

According to a further embodiment, after performing at least one metering step and before carrying out the possible maximum number of metering steps when changing the setting of Dosierschrittweite by means of the display device, the newly set metering and the possible without refilling the pipette maximum number of additional metering with the newly set metering volume is displayed and the number of further dosing steps carried out is displayed with the newly set dosing volume by means of the display device. As a result, after changing the setting of the dosing increment, the user receives the information about the set dosing volume, the maximum possible number of further dosing steps and the number of further dosing steps performed.

According to a further embodiment, after changing the dosing step size and subsequent resetting of the dosing step size to the previously set value, the maximum number of further dosing steps possible without refilling the syringe with the previously set dosing increment by means of the display device and the dosing steps carried out by means of the dosing step width set after the reset or the total dosing steps performed before and after the reset are counted and displayed by means of the display device. In this way, when returning to the previous metering step size, the user obtains the information as to how many metering steps he can still carry out with this metering volume and how many metering steps he has performed overall with this metering volume with the same syringe.

According to a further embodiment, in the case of carrying out dosing steps after incomplete fluid intake into the syringe by means of the display device indicative of the execution of a Umkehrhubes display is displayed until the Umkehrhub is performed by one or more dosing and the subsequent dosing steps are counted and by means of Display device displayed. This ensures that even after partial fluid intake a Umkehrhub is performed, which overcomes a game between the pipette and syringe and concomitant inaccuracies in dosing. Furthermore, the user is also shown after an incomplete filling of the syringe, the number of dosing steps performed subsequently. As a result, the operation is facilitated overall. This is particularly advantageous when dosing valuable or only in small quantities available liquids that are not sufficient for a complete filling of a syringe.

Furthermore, the object is achieved by a pipette having the features of claim 14.

• ein stangenförmiges Gehäuse,
• eine Aufnahme mit einer Öffnung am unteren Ende des Gehäuses zum Einsetzen einer Spritze mit einem Befestigungsabschnitt am oberen Rand eines Zylinders,
• einen Aufnahmekörper mit einer weiteren Aufnahme und einer weiteren Öffnung am unteren Ende im Gehäuse zum Einsetzen eines weiteren Befestigungsabschnittes eines Kolbens der Spritze,
• Mittel zum lösbaren Halten des Befestigungsabschnittes in der Aufnahme und des weiteren Befestigungsabschnittes in der weiteren Aufnahme,
• Mittel zum Verlagern des Aufnahmekörpers innerhalb des Gehäuses in Längsrichtung des Gehäuses,
• die einen außerhalb des Gehäuses betätigbaren Aufzugshebel zum Aufnehmen von Flüssigkeit in die Spritze,
• einen außerhalb des Gehäuses betätigbaren Bedienknopf zum schrittweisen Abgeben von Flüssigkeit aus der Spritze und
• ein außerhalb des Gehäuses einstellbares Einstellelement zum Einstellen einer Dosierschrittweite aufweisen,
• Mittel zum Erfassen der mittels des Einstellelements eingestellten Dosierschrittweite,
• Mittel zum Erfassen einer in die Pipette eingesetzten Spritze,
• Mittel zum Erfassen eines Umkehrhubes. welche die Betätigung eines Übertragungsgliedes zum Steuern des Umkehrhubes erfassen,
• Mittel zum Erfassen der Durchführung eines Dosierschrittes durch Betätigen des Bedienknopfes,
• eine mit den Mitteln zum Erfassen verbundene elektronische Steuerungseinrichtung und
• eine mit der elektronischen Steuerungseinrichtung verbundene elektronische Anzeigeeinrichtung,
• wobei die Steuerungseinrichtung so beschaffen ist, dass sie bei in der Pipette eingesetzter Spritze anhand der eingestellten Dosierschrittweite das Dosiervolumen und die mit der eingestellten Dosierschrittweite und vollständig befüllter Spritze ohne Nachbefüllen der Spritze mögliche maximale Anzahl Dosierschritte ermittelt und mittels der Anzeigeeinrichtung anzeigt und die Anzahl ausgeführter Dosierschritte ermittelt und die Anzahl ausgeführter Dosierschritte und/oder die Anzahl der ohne Nachbefüllen der Spritze noch möglichen Dosierschritte mittels der Anzeigeeinrichtung anzeigt.

The pipette according to the invention for handling a syringe has

• a rod-shaped housing,
• a receptacle with an opening at the lower end of the housing for inserting a syringe with a mounting portion at the upper edge of a cylinder,
• a receiving body with a further receptacle and a further opening at the lower end in the housing for inserting a further attachment portion of a piston of the syringe,
• Means for releasably holding the attachment portion in the receptacle and the further attachment portion in the further recording,
• Means for displacing the receiving body within the housing in the longitudinal direction of the housing,
• an elevator lever operable outside the housing for receiving liquid into the syringe,
• an operable outside the housing control knob for gradually dispensing liquid from the syringe and
• have an adjustable outside the housing adjustment for setting a Dosierschrittweite,
• Means for detecting the metering increment set by means of the adjustment member,
• Means for detecting a syringe inserted in the pipette,
• Means for detecting a reversing stroke. which detect the operation of a transmission member for controlling the reverse stroke,
• Means for detecting the execution of a dosing step by operating the control knob,
• an electronic control device connected to the means for detecting and
• an electronic display device connected to the electronic control device,
• wherein the control device is designed so that it determines the dose volume and the set with the dosing step size and completely filled syringe without refilling the syringe possible maximum number of dosing with the syringe inserted in the pipette and displayed by means of the display device and the number of executed dosing determined and the number of dosing steps performed and / or the number of without refilling the Syringe still indicates possible dosing by means of the display device.

The means for detecting a syringe detachably connected to the pipette signal to the control means that a syringe is inserted. The control device then determines the possible maximum number of metering steps, which is possible after complete filling of the syringe without refilling the syringe, on the basis of the detected metering step width and data present in the control device about the syringe used. By means of the display device, the control device displays the metering volume determined from the metering step width and the determined maximum number of metering steps. When dosages take place, this is signaled to the control device by the means for detecting the execution of a dosing step. The control device counts the metering steps and displays the respectively performed number of metering steps by means of display device. Thus, the user is informed about the set dosing volume, the maximum possible number of dosing steps and the number of dosing steps performed in each case. According to a variant, the control device is such that the display of the number of dosing steps carried out takes place instead of the display of the number of dosing steps still possible without refilling the syringe. According to a further variant, the control device is designed such that the display of the number of dosing steps still possible without refilling the syringe takes place in place of the display of the number of dosing steps carried out. According to another variant, the control device is such that the number of metering steps performed and at the same time the number of metering steps still possible without refilling the syringe is displayed.

According to a further embodiment, the control device is such that one of the two aforementioned numbers indicates greater than the other.

According to one embodiment, the pipette is a pipette driven by the user's muscular strength. According to a further embodiment, the pipette on mechanical drive means for driving the receiving body, which are driven by the muscle power of the user.

According to one embodiment, the pipette has a sensor for detecting a coding indicating the syringe volume on a syringe detachably connected to the pipette. This makes it possible to use the pipette with syringes having different volumes, wherein the control device always determines the set metering volume based on the set metering step size and the determined syringe volume and displays it via the display device. Preferably, the sensor is a ring sensor. The sensor for detecting a coding is according to a preferred embodiment at the same time the means for detecting a syringe detachably connected to the pipette.

According to a further embodiment, the control device is designed such that, after carrying out the maximum number of metering steps and refilling the same syringe, the total number of metering steps performed with the syringe with the set metering increment is determined and / or the number of metering steps still possible without refilling the syringe is determined and indicated by the display device.

According to a further embodiment, the control device is arranged to display, prior to receiving liquid by means of the syringe detachably connected to the pipette, an indication of the picking up of liquid indicated by the display device. According to one embodiment, the control device controls this display when the means for detecting a syringe signal that a syringe is detachably connected to the pipette before the means for detecting the execution of a dosing step signal a dosing step.

According to a further embodiment, the control device is designed so that it indicates a flashing or otherwise indicative of the current process of receiving liquid in the syringe and performing a reverse stroke when recording liquid until complete execution of a reverse stroke by means of the display. For this purpose, the pipette according to one embodiment comprises means for detecting a displacement of the receiving body in a lower end position for releasable connection with a syringe and means for detecting a displacement of the receiving body in an upper end position for the full filling of a syringe, said means for detecting are connected to the electronic control device. These means for detecting signal to the controller that a syringe has been completely filled. The execution of the reverse stroke can be signaled to the control device by the means for detecting the execution of a dosing step if the reverse stroke is controlled by the control knob.

Further, means for detecting a reverse stroke are provided, which detect the operation of a transfer member for the reverse stroke and are connected to the electronic control device. According to a further embodiment, the transfer member for the reverse stroke is coupled to the receiving body, so that it at the end of the displacement of the receiving body in the upper end position for the complete Filling the syringe taken and taken in reverse stroke in the opposite direction and are the means for detecting the displacement of the receiving body in the upper end position at the same time the means for detecting the Umkehrhubes. These means for detecting are formed according to an embodiment by a single microswitch, which is switched by the transfer member for the reverse stroke in reaching the position for the full filling of the syringe and after execution of the reverse stroke in different switching states.

According to a further embodiment, the control device is designed such that it indicates the set dosing volume and the number of dosing steps taken after complete execution of the reverse stroke by means of the display device. The execution of the reverse stroke is signaled to the control device by the means for detecting the execution of a dosing step or by the means for detecting the execution of a reverse stroke. The execution of a dosing step is signaled to the control device by the means for detecting the execution of a dosing step. The controller counts the dosing steps performed and displays them.

According to a further embodiment, the control device is designed such that it indicates, after complete execution of the reversal stroke by means of the display device indicative of the dispensing of liquid. The execution of the reverse stroke is signaled to the control device by the means for detecting the execution of a dosing step or by the means for detecting the execution of a reverse stroke.

According to a further embodiment, the control device is designed such that, after the maximum number of metering steps have been carried out by the display device, it indicates an indication of the optional dispensing of remaining liquid from the syringe and the detachment of the syringe from the pipette or the taking up of further liquid by means of the same syringe displays. According to another embodiment, the control device is designed such that it determines the execution of the maximum number of metering steps by comparing the number of metering steps performed with the determined maximum number of metering steps for emptying the syringe.

According to a further embodiment, the control device is designed such that, after dispensing residual liquid from the syringe by means of the display device, it indicates an indication of the release of the syringe. The delivery of residual liquid from the syringe is signaled to the controller by the means for detecting the displacement of the receiving body to a lower end position for insertion of the syringe. In the lower end position, the receiving body is displaced as far as possible for receiving the syringe barrel. The control device then brings this information to the display when previously dosing has taken place. This can be signaled to the control device by the means for detecting the execution of a dosing step.

According to a further embodiment, the control device is such that after the detachable connection of the pipette to the syringe and before the liquid is taken up into the syringe by means of the display device, a display indicative of the setting of the pipette into a lower end position for receiving liquid is displayed when the pipette is not in the initial position for picking up liquid. This will be the pipette signaled by the means for detecting the arrangement of the receiving body in the lower end position for the insertion of a syringe.

According to a further embodiment, the control device is such that after performing at least one dosing step and before carrying out the possible maximum number of dosing in a change in the setting of Dosierschrittweite means of the display the newly set dosing and the possible without refilling the syringe maximum number of additional dosing be displayed with the newly set dosing and determined the number of further dosing performed with the newly set dosing and displayed by the display device. The change in the setting of the dosing increment is signaled to the control device by the means for detecting the set dosing increment. The number of further metering steps is determined by the control device on the basis of available data of the syringe volume and the number of metering steps taken with the previously set metering step size.

According to a further embodiment, the control device is such that, after changing the dosing step size and subsequent resetting of the dosing step size to the previously set value, the maximum number of additional dosing steps with the dosing step width set by the display device without refilling the syringe is indicated by means of the display device and by means of the display again metering steps performed after the reset counts and displays by means of the display device or counts before and after the reset total metering steps and displays by means of the display device. According to one embodiment, the control device stores when changing the Dosierschrittweite the previously set value of the metering step and the number of metering steps performed.

According to a further embodiment, the control device is designed so that it indicates in the case of performing dosing steps after incomplete fluid intake into the syringe by means of the display device indicative of the execution of a reverse stroke display until the reversal stroke is performed by one or more dosing steps on it the following dosing counts and indicates by means of the display. The incomplete fluid intake is signaled to the pipette in that the means for detecting dosing steps signal the execution of dosing steps, without the means for detecting a displacement of the receiving body in the upper end position signaling the displacement of the receiving body in the upper end position. The control device can make the number of required metering steps for performing a reverse stroke as a function of the set metering step size, which is signaled to the control device by the means for detecting the metering step. For this purpose, according to one embodiment, the control device accesses a stored table in which the number of metering steps for carrying out a reversal stroke is specified as a function of the setting of the metering step width.

The means for detecting are preferably carried out in one or more of the following manners: microswitch, Hall sensor with magnet, reed contact with magnet, light barrier, pressure sensor (for example foil pressure sensor), capacitive sensor or printed circuit board with a meandering conductor track actuated by a carbon switching pill on a flex foil.

The control device is preferably a microcontroller.

The means for holding the attachment portion in the receptacle and the further attachment portion in the further receptacle are preferably formed as described in the above-mentioned prior art documents. The means for displacing the receiving body within the housing are preferably formed as described in the prior art documents mentioned above. The sensor for detecting a coding of a syringe and the coding of the syringe are preferably designed as described in the prior art documents mentioned above. In this regard, reference is made to the documents mentioned above DE 29 26 691 C2 . US 4,406,170A . DE 44 37 716 C2 . EP 0 679 439 B1 . US 5,591,408A . EP 056 229 B1 . US 5,620,660 A . EP 1 724 020 B1 . US 7,731,908 B2 . EP 0 657,216 B1 . US 5,620,661 A , the contents of which are hereby incorporated into the present application.

Fig. 1

Eine erfindungsgemäße Pipette mit darin gehaltener Spritze in einer Perspektivansicht von der Seite;

Fig. 2

dieselbe Pipette in einem Längsschnitt;

Fig. 3

Aufnahmekörper mit Zahnstange, Verbindungselement, Aufzugshebel und Abdeckband derselben Pipette in einem vergrößerten Teilschnitt in Längsrichtung;

Fig. 4

dieselbe Anordnung in einer perspektivischen Teilansicht von der Seite;

Fig. 5

dieselbe Anordnung in einer Gehäuschälfte der Pipette in einer perspektivischen Teilansicht von einer anderen Seite;

Fig. 6

Aufzugshebelhalterung in einer Perspektivansicht von der Seite;

Fig. 7

Aufzugshebelträger in einer Perspektivansicht von der anderen Seite;

Fig. 8

Aufzugshebelträger mit eingesetztem Abdeckband in einer Perspektivansicht von der Seite;

Fig. 9

Aufzugshebelträger mit eingesetztem Abdeckband in einer weiteren Perspektivansicht;

Fig. 10

Aufnahmekörper mit Mitteln zum Verlagern des Aufnahmekörpers umfassend Aufzugshebel, Bedienknopf, Klinke, Zahnstange, Übertragungsglied für einen Umkehrhub, oberen und unteren Endlagenschalter in der oberen Endposition in einem Längsschnitt;

Fig. 11

dieselbe Anordnung nach einem Umkehrhub in demselben Längsschnitt unter Weglassung des vorderen Schenkels des Dosierhebels;

Fig. 12

dieselbe Anordnung kurz vor Erreichen der unteren Endposition in einem Längsschnitt betrachtet von der gegenüberliegenden Seite;

Fig. 13

dieselbe Anordnung in der unteren Endposition in demselben Längsschnitt;

Fig. 14

dieselbe Anordnung in einem weiteren Längsschnitt durch einen Dosierschrittsensor zum Erfassen von Dosierschritten beim Betätigen dieses Schalters;

Fig. 15

die Endlagenschalter und der Dosierschrittsensor zum Erfassen eines Dosierschrittes mit dem Dosierhebel und einem Übertragungsglied für einen Umkehrhub bei unbetätigtern Dosierschrittsensor in einer perspektivischen Teilansicht;

Fig. 16

dieselbe Anordnung bei betätigtem Dosierschrittsensor in derselben perspektivischen Teilansicht;

Fig. 17

Verfahren zum Dosieren bei vollständiger Befüllung der Spritze und Anzeige des eingestellten Dosiervolumens sowie der Dosierschritte in einem Ablaufplan;

Fig. 18

Verfahren zum Dosieren mit anfänglich nicht in die untere Endposition zurückgeschobenem Aufnahmekörper in einem Ablaufplan;

Fig. 19

Teil eines Verfahrens zum Dosieren bei Änderung der Dosierschrittweite in einem Ablaufplan;

Fig. 20

Teil eines Verfahrens zum Dosieren bei Änderung der Dosierschrittweite und nachträglicher Rückstellung der Dosierschrittweite auf den ursprünglichen Wert in einem Ablaufplan.

Fig. 21

Verfahren zum Dosieren bei Teilbefüllung der Spritze in einem Ablaufplan;

Fig. 22

Tabelle mit der Anzahl Dosierschritte zur Durchführung eines Umkehrhubes bei verschiedenen Einstellungen der Dosierschrittweite.

The invention will be explained in more detail with reference to the accompanying drawings of an embodiment. In the drawings show:

Fig. 1

A pipette according to the invention with syringe held therein in a perspective view from the side;

Fig. 2

the same pipette in a longitudinal section;

Fig. 3

Receiving body with rack, connecting element, elevator lever and cover strip of the same pipette in an enlarged partial section in the longitudinal direction;

Fig. 4

the same arrangement in a partial perspective view from the side;

Fig. 5

the same arrangement in a housing half of the pipette in a partial perspective view from another side;

Fig. 6

Elevator lever holder in a perspective view from the side;

Fig. 7

Elevator lever carrier in a perspective view from the other side;

Fig. 8

Elevator lever carrier with inserted cover strip in a perspective view from the side;

Fig. 9

Elevator lever carrier with inserted cover strip in a further perspective view;

Fig. 10

Receiving body with means for displacing the receiving body comprising elevator lever, control knob, pawl, rack, transfer member for a reverse stroke, upper and lower limit switch in the upper end position in a longitudinal section;

Fig. 11

the same arrangement after a reverse stroke in the same longitudinal section with omission of the front leg of the metering lever;

Fig. 12

the same arrangement shortly before reaching the lower end position in a longitudinal section viewed from the opposite side;

Fig. 13

the same arrangement in the lower end position in the same longitudinal section;

Fig. 14

the same arrangement in a further longitudinal section through a Dosierschrittsensor for detecting dosing steps in operating this switch;

Fig. 15

the limit switches and the Dosierschrittsensor for detecting a metering step with the metering lever and a transfer member for a reverse stroke with unattached Dosierschrittsensor in a partial perspective view;

Fig. 16

the same arrangement with actuated Dosierschrittsensor in the same perspective partial view;

Fig. 17

Method of dosing with complete filling of the syringe and display of the set dosing volume and dosing steps in a flowchart;

Fig. 18

Dosing method with initially not pushed back into the lower end position receiving body in a flowchart;

Fig. 19

Part of a method of dosing when changing the dosing increment in a flowchart;

Fig. 20

Part of a method for dosing when changing the dosing increment and subsequently resetting the Dosierschrittweite to the original value in a flowchart.

Fig. 21

Method for dosing with partial filling of the syringe in a flowchart;

Fig. 22

Table with the number of dosing steps for performing a reversing stroke with different dosing increment settings.

In the present application, the indications "top" and "bottom" refer to the orientation of the pipette, in which the rod-shaped housing is vertically aligned and the receptacle for the syringe is arranged below.

According to Fig. 1 a pipette 1 has a rod-shaped housing 2 in which a syringe 3 is held at the bottom. From a side wall of the housing 2 is above a straight line slot 4, an elevator lever 5 of the housing 2 before. From the same side wall of the housing is about two further slots 6, 7 before a control knob 8 a rack-pawl control. In addition, a display device in the form of an LCD display 9 is embedded in the same side wall of the housing 2. From openings in the adjacent side wall are segments of a dial 10 out.

According to Fig. 2 the syringe 3 has a cylinder 11 and a piston 12 arranged displaceably therein. The cylinder 11 has at the bottom a conical portion 13 with a hole 14 for the passage of liquids and above a cylindrical portion 15 in which the piston 12 is displaceable. Above has the Cylinder 11 a mounting portion 16 with a circumferential flange 17. From the piston 12 is upwardly a piston rod 18 before, which has a further mounting portion 19 with a plurality of circumferential beads (not shown).

The syringe 3 is arranged with the flange 17 in a receptacle 20 at the lower end of the housing 2, which at the lower end of the housing 2 has an axially directed opening 21.1 for insertion and removal of the syringe 3. The syringe 3 presses with its upper side against a pressure-sensitive ring sensor 22, which scans projections on the upper edge of the flange 17. The flange 17 is held in this position by means of gripping levers 23 in the housing 2.

The further attachment portion 19 of the piston 12 is arranged in a further receptacle 24 in a hollow cylindrical receiving body 25. This has for insertion of the attachment portion 19, a further axially directed opening 21.2, the further attachment portion 19 is held by means of further gripping levers 26 which engage between the beads of the further attachment portion 19 or pinch this.

The receiving body 25 is fixedly connected to a rack 27 which extends below the slot 4 in the longitudinal direction of the housing 2.

An elevator lever holder 28 is fixed to the receiving body 25 and to a lower part of the rack 27.

Further, an elevator lever carrier 29 is present, which abuts with a sliding plate 30 at the bottom of the edges of the slot 4. The elevator lever carrier 29 has an upwardly projecting post 31, which passes through the slot 4. On the post outside the housing 2 of the elevator lever 5 is fixed.

In the upper half of the housing 2, a metering lever 34 is pivotally mounted in a swivel bearing 32 in a bulge 33 of the slot 4 opposite side wall of the housing 2. The metering lever 34 has two spaced apart legs 35, 36 which protrude on the opposite side wall of the housing 2 from the two slots 6, 7. There, the control knob 8 is fixed on the protruding ends of the legs 35, 36.

Between the two legs 35, 36 of the metering lever 34, a pawl 37 is pivotally mounted. The pawl 37 is arranged with a ratchet tooth 38 above the toothing 39 of the rack 27. The metering lever 34 is moved by a spring device not shown in the position of Fig. 2 pressed. Contrary to the action of the spring device of the metering lever 34 by pressing the control knob 8 is pivoted downwards. The pawl 37 is pressed by means of a further spring means not shown to the teeth 39 of the rack 27.

Between the pawl 37 and the rack 27, a sliding cover 40 is arranged. The cover 40 is displaceable by turning the laterally projecting out of the housing 2 dial 10 so that it covers the teeth 39 of the rack 27 more or less.

Further, in the upper half of the housing 2, a circuit board 41 is arranged with an electronics. There is also an electrical power supply in the form of batteries or batteries 42.

The dial 10 is associated with a further sensor 43 which detects the rotational position of the dial 10. The measured values determined by the ring sensor 22 and the further sensor 43 are forwarded to the electronics via cables.

The code indicated on the flange 17 designates the size of the respective syringe 3. The electronics determine the respective syringe size from the measuring signals supplied by the ring sensor 22 and the respective step size from the setting of the dial 10. From this, it calculates the set dosing volume and brings it to display 9 for display.

The slots 6, 7 are covered on the inside by a diaphragm 44 connected to the metering lever 34.

To cover the slot 4 is according to Fig. 3 to 5 below the slot 4 in the housing 2, a flexible cover strip 45 is present. The stake strip 45 is made of polypropylene. According to Fig. 8 has the cover strip 45 at the ends of eyes 46, 47, according to Fig. 2 are fixed to pins 48, 49 projecting from the inside of the Scitenwand of the housing 2, which has the slot 4.

According to Fig. 3 to 5 the cover strip 45 extends through a channel 50 between the elevator lever holder 28 and the elevator lever carrier 29. According to 6 and 7 the channel 50 is bounded on opposite sides by a side surface 51 with a radius of the elevator lever holder 28 and by a further side surface 52 with a corresponding radius of the elevator lever carrier 29. The two lateral boundaries of the channel 50 are formed by two strip-shaped side walls 53, 54 of the elevator lever carrier 29. These are connected to each other at a distance from the side surface 52 having the radius by a crossbar 55. Between the radius having another Side surface 52 and the cross member 55, the elevator lever carrier on an opening 56. From one side of the cross member 55 projecting two projections 57, 58, which are insertable into corresponding pockets 59, 60 of the elevator lever holder 28. The two strip-shaped side walls 53, 54 are bridged by a front wall 61 which has the further side surface 52 with the radius at the bottom and protrudes from the top of the post 31.

According to 8 and 9 the elevator lever carrier 29 is preassembled with the cover strip 45 by the cover strip 45 is guided along the other side surface 52 and through the aperture 56 so that it extends on the top of the crossbar 55 between the two strip-shaped side walls 53, 54. In this arrangement, the elevator lever carrier 29 is connectable to the elevator lever holder 28 by the projections 57, 58 are inserted into the pockets 59, 60 and elevator lever carrier 29 and elevator lever holder 28 are glued together or snapped together by means of suitable snap means.

The elevator lever holder 28 and the elevator lever carrier 29 together form a connecting element 62 between the receiving body 25 and the elevator lever 5 (cf. Fig. 2 . 3 . 4 ).

According to 4 and 5 The elevator lever mount 28 has wings 63, 64 projecting from both sides. In the example, the wings 63, 64 have a cylindrical shape. They engage in grooves 65, 66 on two opposite Scitenwänden of the housing 2 a. The grooves 65, 66 are bounded on one side by an edge of a housing half and on the other side by a bar of a chassis in which parts of the drive mechanism of the pipette 1 are mounted.

According to Fig. 2 is the cover strip 45 of the two pins 48, 49 to the eyes 46, 47 according to Fig. 8, 9 held clamped on the inside of the slot 4. According to Fig. 3 it is due to the radii of the side surfaces 51, 52 of the channel 50 on the level in which it is extended on both sides of the channel 50, bulged. As a result, a close contact of the cover strip 45 is achieved at the edges of the slot 4.

According to Fig. 10 and 11 carries the circuit board 41 on the side facing away from the rack 27 side at its lower end designed as a microswitch upper limit switch 67 for detecting the upper end position of the receiving body 25. In the upper end position of the receiving body 25 is a maximum of the receptacle 24 (see. Fig. 2 ) displaced to fill a syringe 3 completely. The upper limit switch 67 is a button with a respect to the circuit board 41 outwardly projecting lever 68th

The upper limit switch 67 also serves to detect a reverse stroke. For this purpose, in addition to the rack 27, a transmission member 69 is arranged for controlling a Umkehrhubes in the housing of the pipette. The transmission member 69 has a strip-shaped transmission section 70, which is guided parallel to the rack 27 in the housing of the pipette and displaced. The strip-shaped transmission section 70 has a lower transmission member end 71, which is located in a displacement of the transmission member 69 down in the displacement region of a side of the rack 27 projecting lower stop 72.

Further, the transmission member 69 has above two control arms 73, 74, in the (zu Fig. 10 and 11 vertical) plane of the circuit board 41 are extended and engage around the lower end of the circuit board 41 on both sides. The transmission element 69 is displaceable such that the control arms 73, 74 with upper control arm ends 75, 76 in the displacement region of bevelled stop edges 77, 78 on the legs 35, reach 36 (cf. Fig. 10 to 13 ).

Further, the transmission member 69 has a switching arm 79 above, which engages over the circuit board 41 on the side at a distance on which the upper limit switch 67 is arranged. The switching arm 79 is designed so that it actuates with its upper Schaltarmende 80 upon displacement of the transmission member 69, the sensing lever 68 of the upper limit switch 67 and releases. In the situation of Fig. 10 the switching arm 79 actuates the upper limit switch 67, wherein the sensing lever 68 is covered by the leg 35 of the metering lever 34. In Fig. 11 It is shown how the switching arm 79 releases the sensing lever 68 of the upper limit switch 67.

The circuit board 41 carries according Fig. 12 and 13 next to its lower end on the side facing the rack 27, designed as a microswitch lower limit switch 81. The lower. End position switch 81 is a push-button with a toothed rod 82 protruding toward the rack 27. The feeler lever 82 is located in the displacement area of an upper stop 83 projecting from the opposite side of the rack 27 FIG. 12 gives the upper stop 83, the sensing lever 82 free and in Fig. 13 he pushes him.

According to Fig. 14 to 16 is arranged on the circuit board 41 next to the upper limit switch 67 a Dosierschrittsensor 84 for detecting dosing steps. The metering step sensor 84 is also a button. The feeler is preferably a sheet metal membrane which is deformable from a stable, outwardly curved initial position into an unstable, inwardly curved position in which it closes a circuit. After relieving the sheet membrane automatically returns from the unstable to the stable position in which the circuit is open.

The metering step sensor 84 is located with the membrane in the pivoting range of a pin 85 made of silicone, which is arranged on a leg 35, 36 of the metering lever 34 connecting and mounted on the pivot bearing 32 Dosierhebelbasis 86 of the metering lever 34.

According to Fig. 2 . 10 and 11 the circuit board 41 carries an electronic control device 87 which is wired to the ring sensor 22, the further sensor 43 for detecting the rotational position of the dial 10, the upper limit switch 67, the lower limit switch 81, the Dosierschrittsensor 84 and the display 9. Furthermore, the control device 87 is connected to the battery 42.

When using the pipette 1 of Fig. 1 to 16 First, a syringe 3 with a syringe size selected by the user is releasably connected to the pipette by being inserted into the receptacle 20 in the attachment section 16 and into the receptacle 24 with the attachment section 19, so that the flange 22 of the gripping levers 23 and the attachment section 19 is gripped by the gripping levers 26.

The ring sensor 22 scans the coding on the flange 17 of the syringe 3. The control device 87 determines from the signals supplied by the ring sensor 22 that a syringe 3 is inserted and switches the display 9 on. Based on the signals supplied by the ring sensor 22 and the signals supplied by the sensor 43, the control device 87 determines the set metering volume and displays it on the display 9. Optionally, the user changes the setting of the metering volume by means of the dial 10 and the changed metering volume is displayed by the display 9.

Furthermore, the control device 87 determines the possible maximum number of metering steps for emptying the syringe 3 after complete filling and displays this. Furthermore, the control device 87 by an upward arrow on the display 9 indicates that liquid can be received in the syringe 3.

To draw liquid through the opening 14 of the syringe 3, the elevator lever 5 is moved out of the position of Fig. 1 . 2 and 13 pushed up. In the lower end position of the receiving body 25, the upper stop 83 operates according to Fig. 13 the sensing lever 82 of the lower limit switch 81. When the receiving body 25 leaves the lower end position, the upper stop 83 releases the lower limit switch 81, as shown in FIG Fig. 12 will be shown. As soon as this signals the lower limit switch 81 of the controller 87, this controls a flashing of the display on the display. 9

At the end of the elevator movement of the lower stop 72 takes the transmission member 69, so that the switching arm 79 presses against the sensing lever 68 of the upper limit switch 67. By this actuation of the upper limit switch 68, the control device 87 is signaled that the syringe 3 has been completely filled.

Before the set dosing volume can be dispensed step by step, a reverse stroke must be carried out. This is done by pressing the control knob 8. Here hit the stop edges 74, 78 on the control arms 73, 74 and move the transmission member 69 down. The transmission member 69 takes over the lower stop 72 with the rack 27. This reverse stroke removes the lots from the system. In addition, in this case the switching arm 79 is released from the sensing lever 68 of the upper limit switch 67, whereby the controller 87 is signaled that the reversal stroke has been executed.

After the reverse stroke, the display 9 stops flashing and indicates that zero dosing steps have been performed. Furthermore, the display 9 indicates by indicating a downward arrow that liquid can be dispensed.

Thereafter, the absorbed liquid amount can be delivered in small steps by the control knob 8 is pressed repeatedly against the action of the spring device down. In this case, the further spring device presses the pawl 37 with the pawl tooth 38 against the cover 40 until the pawl tooth 38 reaches the lower end of the cover 40. Thereafter, the pawl 37 falls with the ratchet tooth 38 in the toothing 39 of the rack 27 and takes the rack 27 during further pivoting of the metering lever 34 down with a piece. In this case, the displacement of the rack 27 depends on each pivoting of the metering lever 34 until reaching a lower stop of a set by means of the dial 10 position of the cover 40 from. After relieving the control knob 8 he is pushed by the spring device up and another dosing step can be performed

In each dosing step, the pin 85 hits the dosing step sensor 84 and actuates it (cf. Fig. 14 ). This signals the control device 87 to carry out a dosing step. The control device 87 adds the dosing steps carried out and displays the respective number of dosing steps carried out on the display 9.

The dispensing without refilling the syringe 3 is possible until the residual amount of liquid remaining in the syringe 3 is smaller than the set metering. A Resthubsperre then ensures that the cover 40 is pivoted against the underside of the pawl 37, so that the ratchet tooth 38 can not occur in the teeth 39.

The control device 87 then indicates on the display 9 that the maximum number of metering steps has taken place. It also indicates by indicating an upward and downward arrow on the display 9 the indication that either liquid can be sucked into the syringe 3 again or empties the residual liquid from the syringe 3 and the syringe 3 separated from the pipette 1 can be. If additional liquid is absorbed into the same syringe 3, the sequence is as described above, wherein the controller 87 determines the sum of the dosing performed with the same dosing and displays on the display 9.

A residual liquid in the syringe 3 can be discharged by displacing the elevator lever 5 down. Here, the lower limit switch 81 is actuated. The control device 87 then displays a downward arrow on the display 9 as an indication that the syringe 3 can be separated from the pipette 1. For this purpose, the user actuates the handle lever 23, 26th

When shifting the elevator lever 5, the cover strip 45 is passed through the channel 50. Always the slot 4 is covered. An unintentional displacement of the receiving body 25, and the connecting element with the elevator lever 5, the friction between the cover strip 45 and the connecting element counteracts.

The procedure described above is in Fig. 17 illustrated. In the boxes of the flow chart, the respective display is indicated in the display and with explanations. The example shows a set dosing volume of 500 ml.

The expiration of Fig. 18 is different from the expiration of Fig. 17 in that the elevator lever 5 is not in the lower end position when releasably connecting the pipette 1 to the syringe 3. This can be detected by the control device 87 that the ring sensor 22 reports the onset of a syringe 3 and the lower limit switch 81 reports that the receiving body 25 is not in the lowest end position. In this situation, the display on the display device 9 by a downward arrow to indicate to shift the elevator lever 5 down. Only when this is done, the set dosing volume, the maximum number of metering steps and the upward arrow is displayed as an indication of the filling of the syringe 3. The further procedure corresponds to that of Fig. 17 ,

The expiration of Fig. 19 is different from the expiration of Fig. 17 in that during dispensing the setting of the dosing volume is changed. For example, after a metering step with a metering volume of 500 ml, the metering volume is adjusted to 250 ml. Then, the newly set dosing volume is displayed by means of the display device 9 and the amount of liquid present with this dosing volume and the amount of liquid still present in the syringe 3 possible maximum number of further dosing steps. In the example, these are 8 further steps. Furthermore, the dosing steps carried out with the newly set dosing volume are counted and displayed.

The expiration of Fig. 20 is different from the expiration of Fig. 19 in that, after the change in the dosing volume, the dosing volume is reset to the original value. In the example, the metering volume is changed after a metering step of 500 ml to a metering volume of 250 ml. After a metering step with a metering volume of 250 ml, the metering volume is reset to the original metering volume of 500 ml. Thereafter, the with the original metering volume and the displayed in the syringe amount of liquid possible maximum number of additional dosing steps. During dispensing, the dosing steps that have taken place after returning to the original dosing quantity to the original value with this dosing quantity are counted and displayed. In one possible alternative, the dosing steps taken in total before and after the reset are counted and displayed when the dosing quantity is reset to the originally set value during dispensing.

The expiration of Fig. 21 is different from the expiration of Fig. 17 in that the syringe 3 is only partially filled. This is determined by the controller 87 based on the signals of the lower limit switch 81 and the upper limit switch 67. Namely, when the lower limit switch 81 reports that the receiving body 25 has left the lower end position and then the Dosierschrittzähler reports performing a dosing without the upper limit switch 67 reports reaching the upper end position, the syringe has been only partially filled. The control device 87 then outputs via the display 9 a flashing display. The flashing display also shows the set dosing volume, the possible maximum number of dosing steps and the arrow pointing upwards. The blinking of the display indicates to the user that a partial fill is in progress so that reaching the maximum number of dosing steps is not ensured.

The controller 87 stops flashing the display only when the user has performed a sufficient number of dosing steps that correspond to a Umkehrhub. This indicates to the user that no precise dosing has taken place and he should discard the dispensed doses. As soon as the reversing stroke has been carried out, the control device 87 outputs via the display device 9 the set metering volume, the number of metering steps that have taken place and an arrow indicating the displacement of the receiving body 25 downwards.

The control device 87 takes the number of required dosing for the realization of a reverse stroke for each set dosing a stored table. An example of such a table is in Fig. 22 specified.

The above processes of Fig. 17 to 21 can in particular by means of the pipette according to Fig. 1 to 16 be performed. The processes of Fig. 1 to 17 can also be carried out by means of other suitable pipettes.

Rezugszeichenliste

1

pipette

2

casing

3

syringe

4

slot

5

winding lever

6

slot

7

slot

8th

control knob

9

display

10

dial

11

cylinder

12

piston

13

section

14

hole

15

section

16

attachment section

17

flange

18

piston rod

19

attachment section

20

admission

21.1

opening

21.2

opening

22

ring sensor

23

gripping levers

24

admission

25

receiving body

26

gripping levers

27

rack

28

Lift lever bracket

29

Lift lever support

30

sliding plate

31

post

32

pivot bearing

33

bulge

34

apportioning

35

leg

36

leg

37

pawl

38

ratchet tooth

39

Perforation

40

cover

41

circuit board

42

battery pack

43

sensor

44

cover

45

flap

46

eye

47

eye

48

spigot

49

spigot

50

channel

51

side surface

52

side surface

53

Side wall

54

Side wall

55

traverse

56

breakthrough

57

head Start

58

head Start

59

bag

60

bag

61

wall

62

connecting element

63

wing

64

wing

65

groove

66

groove

67

Upper limit switch

68

sensing lever

69

transmission member

70

transmission section

71

lower transfer member end

72

bottom stop

73

control arm

74

control arm

75

Upper control arm end

76

Upper control arm end

77

stop edge

78

stop edge

79

shifting

80

upper end of the switcharm

81

lower limit switch

82

sensing lever

83

upper stop

84

Dosierschrittsensor

85

spigot

86

Dosierhebelbasis

87

control device

Claims (17)

1. A method for dosing a liquid using a pipette with adjustable dosing step size and an indicating equipment and a syringe that can be operated using the pipette, wherein

   1.1 the syringe is detachably connected to the pipette,

   1.2 at option, the dosing step size is set, or the dosing step size set before is maintained,

   1.3 the dosing volume adjusted via the dosing step size is indicated by means of the indicating equipment,

   1.4 the maximum number of dosing steps possible without refilling the syringe, with the set dosing step size and completely filled syringe, is indicated by means of the indicating equipment,

   1.5 liquid is aspirated into the syringe,

   1.6 a reverse stroke is performed after the syringe is filled with liquid,

   1.7 dosing steps are performed, the performed dosing steps are counted and the number of performed dosing steps and/or the number of dosing steps still possible without refilling the syringe is determined and indicated by means of the indicating equipment, and

   1.8 after performing the maximum number of dosing steps possible without refilling the syringe, either the syringe is detached from the pipette, or steps 1.2 to 1.8 are performed anew by means of the same syringe, wherein in step 1.7, the overall performed number of dosing steps with the syringe with the set dosing step size is counted, and/or the number of dosing steps still possible without refilling the syringe is determined and indicated by means of the indicating equipment.
2. The method according to claim 1, wherein an encoding specifying a syringe volume of the syringe that is connected to the pipette is detected by the pipette, and the dosing volume is determined on the basis of the set dosing step size and the detected encoding, and is indicated by means of the indicating equipment.
3. A method according to claim 1 or 2, wherein an indication referring to the pick-up of liquid is indicated by means of the indicating equipment before liquid is picked up using the syringe that is detachably connected to the pipette.
4. A method according to any one of claims 1 to 3, wherein when liquid is being picked up, an indication, blinking or in other ways referring to the actual process of picking up liquid into the syringe and to the execution of a reverse stroke, is indicated by means of the indicating equipment for so long until a reverse stroke has been performed completely.
5. A method according to any one of claims 1 to 4, wherein after the complete execution of the reverse stroke, the set dosing volume and the number of performed dosing steps is indicated by means of the indicating equipment.
6. The method according to claim 5, wherein an indication referring to the delivery of liquid is indicated after the complete execution of the reverse stroke.
7. A method according to any one of claims 1 to 6, wherein after performing the maximum possible number of dosing steps, an indication referring to the optional discharge of residual liquid from the syringe and to detaching the syringe from the pipette or to picking up liquid using the same syringe is indicated by means of the indicating equipment.
8. The method according to claim 7, wherein after discharging residual liquid from the syringe, an indication referring to detaching the syringe from the pipette is indicated by means of the indicating equipment.
9. A method according to any one of claims 1 to 8, wherein an indication is indicated by means of the indicating equipment only then when a syringe is being detachably connected to the pipette, and wherein the indication expires when the syringe is being detached from the pipette.
10. A method according to any one of claims 1 to 9, wherein after detachably connecting the pipette to the syringe and before picking up liquid into the syringe, an indication referring to positioning the pipette into a lower end position for picking up liquid is indicated by means of the indicating equipment when the pipette is not in the lower end position for picking up liquid.
11. A method according to any one of claims 1 to 10, wherein after the execution of at least one dosing step and before the execution of the maximum possible number of dosing steps, upon change of the setting of the dosing step size, the newly set dosing volume and the maximum possible number of further dosing steps with the newly set dosing volume without refilling the syringe are indicated by means of the indicating equipment, and the executed number of further dosing steps with the newly set dosing volume is counted and indicated by means of the indicating equipment.
12. The method according to claim 11, wherein after changing the dosing step size and subsequent resetting of the dosing step size to the value set before, the maximum possible number of further dosing steps with the dosing step size set before and without refilling the syringe is indicated by means of the indicating equipment, and the dosing steps executed by means of the newly set dosing step size after the resetting, or the overall performed dosing steps before and after the resetting, are counted and indicated by means of the indicating equipment.
13. A method according to any one of claims 1 to 12, wherein an indication referring to the execution of a reverse stroke is indicated by means of the indicating equipment in case of performing dosing steps after incomplete pick-up of liquid into the syringe, for so long until the reverse stroke is executed by one or several dosing steps, and dosing steps subsequent to this are counted and indicated by means of the indicating equipment.
14. A pipette for handling a syringe, with

    • a bar-shaped housing (2),

    • a fixture (20) with an opening (21.1) at the lower end of the housing (2) for putting in a syringe (3) with a fastening portion (16) on the upper edge of a cylinder (11),

    • a fixture body (25) with a further fixture (24) and a further opening (21.2) on the lower end of the housing (2), for putting in a further fastening portion (19) of a piston (12) of the syringe (3),

    • means for detachably holding (23, 26) the fastening portion (16) in the fixture (20) and the further fastening portion (19) in the further fixture (24),

    • means for relocating (5, 8, 34, 37, 27) the fixture body (25) within the housing (2) in the longitudinal direction of the housing (2),

    • which comprise a draw-up lever (5), activated from the outside of the housing (2) for picking up liquid into the syringe,

    • an actuation button (8), activated from the outside of the housing (2) for stepwise discharging liquid from the syringe (3),

    • an adjusting element (10), adjustable from the outside of the housing (2) for setting a dosing step size,

    • means for detecting (43) the dosing step size set by means of the adjusting element (10),

    • means for detecting (22) a syringe (3) that is detachably connected to the pipette (1),

    • means for detecting (84) the execution of a dosing step by actuating the actuation button (8),

    • an electronic control equipment (87), connected to the means for detecting (22, 43, 84),

    • an electronic indicating equipment (9), connected to the electronic control equipment (87),

    • wherein the control equipment (87) is configured such that upon syringe (3) inserted into the pipette (1), it determines the dosing volume based on the set dosing step size and the maximum possible number of dosing steps with the set dosing step size and completely filled syringe (3) without refilling the syringe (3), and indicates it by means of the indicating equipment, and determines the number of executed dosing steps and indicates the number of performed dosing steps and/or the number of still possible dosing steps without refilling the syringe by means of the indicating equipment (9),

    characterized by means for detecting (67) a reverse stroke, which detect the actuation of a transmission element (69) for triggering the reverse stroke.
15. The pipette according to claim 14, which comprises a sensor (22) for detecting an encoding imposing the syringe volume on a syringe (3) that is detachably connected to the pipette (1).
16. A pipette according to claim 14 or 15, which comprises means for detecting (81) a relocation of the fixture body (25) into a lower end position (67) for detachably connecting the pipette (1) to a syringe (3), and means for detecting (67) a relocation of the fixture body (25) into an upper end position for completely filling a syringe (3), wherein these means for detecting are connected to the electronic control equipment (87).
17. The pipette according to any one of claims 14 to 16, wherein the transmission element (69) is coupled to the fixture body (25), so that it is taken along in the relocation of the fixture body (25) into the upper end position and is taken along in the opposite direction in the reverse stroke, and the means for detecting (67) the relocation of the fixture body (25) into the upper end position are the means for detecting (67) the reverse stroke at the same time.

Images