Pipette assembly

Abstract

The invention relates to a pipette assembly (1) comprising a pipetting unit (2) having a pipette housing (3) with a cylinder chamber (4) and a pipetting opening (5), as well as a piston (6) that is moveably mounted in a cylinder chamber (4), and a drive unit (7) having a drive motor (8) acting on the piston (6) and moving the piston, an actuation element (9) for specifying a movement of the piston (6), and a sensor assembly (10) for detecting the movement of the actuation element (9) and for providing a signal corresponding to the movement to the drive motor (8) in such a way that the drive motor (8) is controlled based on the signal (S) and acts correspondingly on the piston (6), wherein the drive unit (7) also has a mode switch (11) that can be shifted from a manual mode position into a stepwise mode position in such a way that, when the mode switch (11) is in the manual mode position, the actuation element (9) can be actuated in a manual actuation mode, in such a way that a pipetting volume can be output that is proportional to the movement of the actuation element (9), and when the mode switch (11) is in the stepwise mode position, the actuation element (9) can be actuated in a stepwise actuation mode in such a way that a determined pipetting volume is output for each actuation of the actuation element (9).

Description

[0001] TITLE

[0002] PIPETTE ARRANGEMENT

[0003] TECHNICAL FIELD

[0004] The present invention relates to a pipette arrangement according to the independent claims.

[0005] STATE OF THE ART

[0006] Pipettes for dosing liquids are known from the prior art. These pipettes comprise a cylinder and a movable piston within it, which can be used to draw up the liquid and dispense it in a measured amount.

[0007] EP 0 576 967 discloses a pipette with a mechanical actuating element that is moved by the user. The movement is then detected by sensors, and the piston is moved by a piston drive based on the recorded sensor values. The piston can be actuated continuously to dispense liquid in relation to the movement of the actuating element, or stepwise to dispense a predetermined volume per actuation.

[0008] PRESENTATION OF THE INVENTION

[0009] Based on this prior art, the invention is based on the object of providing a pipetting arrangement that can be operated ergonomically. This object is achieved by the subject matter of claims 1 and 16.

[0010] A pipette assembly according to claim 1 comprises a pipetting unit and a drive unit. The pipetting unit has a pipette housing with a cylinder chamber and a pipetting opening, as well as a piston movably mounted in the cylinder chamber. The drive unit comprises a drive motor acting on and moving the piston, an actuating element for specifying a movement of the piston, and a sensor arrangement for detecting the movement of the actuating element and for providing a signal corresponding to the movement to the drive motor, such that the drive motor is controlled based on the signal and acts accordingly on the piston.The drive unit further comprises a mode switch which can be moved from a manual mode position to a stepwise mode position such that when the mode switch is in the manual mode position, the actuating element can be actuated in a manual actuation mode such that a pipetting volume can be dispensed which is proportional to the movement of the actuating element or which is proportional to the actuation path of the actuating element and that when the mode switch is in the stepwise mode position, the actuating element can be actuated in a stepwise actuation mode such that a determined or identical pipetting volume is dispensed per actuation.

[0011] This type of pipetting system provides laboratory personnel with a flexible pipetting system. The switchable design allows the same actuating element to be used for both actuation modes, offering the ergonomic advantage of allowing the same actuation direction to be used.

[0012] Preferably, the mode switch limits the movement of the actuating element in the step-by-step mode position. Limiting the movement of the actuating element for the step-by-step actuation mode has the advantage of allowing a determined movement of the actuating element, which increases the ergonomics of the pipetting assembly. Preferably, the movement limitation in the step-by-step actuation mode is such that the user perceives the actuation as pressing a push button.

[0013] In manual actuation mode, the pipetting volume is proportional to the movement of the actuating element. This means that a volume corresponding to the actuating element's movement is dispensed for each actuation increment. The movement of the piston can correspond to the movement of the actuating element, or the movement of the piston can be geared or stepped down relative to the movement of the actuating element.

[0014] Preferably, the travel of the actuating element in step-by-step mode is very small, so that actuation does not require a large movement of the finger that activates the actuating element. The travel of the actuating element in step-by-step mode is preferably between 0.5 millimeters and 5 millimeters, in particular between 0.5 millimeters and 3 millimeters.

[0015] The mode switch can be moved from the step-by-step mode position to the manual mode position when returning from the step-by-step mode.

[0016] The mode switch can be moved from the manual mode position to the step mode position and back through user interaction.

[0017] As mentioned, the piston is driven by the drive motor. The drive motor moves the piston proportionally to the movement of the actuating element. The movement of the actuating element can, as mentioned, be transmitted in a geared or stepped-down manner, or directly to the piston. When the piston moves away from the pipette opening, a liquid can be drawn into the cylinder chamber through the pipette opening, and when the piston moves toward the pipette opening, a liquid can be dispensed from the cylinder chamber through the pipette opening.

[0018] Preferably, the actuating element is movable from a first starting position to a first end position in the manual actuation mode and the actuating element is movable from a second starting position to a second end position in the step-by-step actuation mode.

[0019] In a first variant, the position of the first starting position is equal to the position of the second starting position, and the position of the first end position is at a greater distance from the starting position than the position of the second end position.

[0020] In a second variant, the position of the first end position is equal to the position of the second end position, and the position of the first starting position is at a greater distance from the end position than the position of the second starting position.

[0021] In a third variant, the position of the first starting position is different from the position of the second starting position and the position of the first end position is different from the position of the first starting position, wherein the position of the second starting position and the position of the second end position lie between the position of the first starting position and the first end position. Preferably, the actuating path of the actuating element in manual actuation mode is greater than the movement path of the actuating element in step-by-step actuation mode, preferably with the proviso that the movement path of the actuating element in step-by-step actuation mode is greater than 0.5 millimeters. Particularly preferably, the actuating path of the actuating element in manual actuation mode is a factor of 3 to 6 greater than the movement path of the actuating element in step-by-step actuation mode.

[0022] Consequently, the actuation movement of a user's finger is smaller in step-by-step actuation mode than in manual actuation mode. This has the advantage of making the actuation more ergonomic.

[0023] Preferably, the actuating element is movable along a respective movement path in both manual actuation mode and step-by-step actuation mode. Particularly preferably, the movement path in manual actuation mode and step-by-step actuation mode runs in the same direction. Particularly preferably, the movement path in manual actuation mode and step-by-step actuation mode runs along a linearly oriented axis.

[0024] Moving the actuator in both manual and step-by-step actuation modes is advantageous because it improves user ergonomics. In both cases, the user experiences haptic feedback from the movement of the actuator. Furthermore, the user can move their finger in both actuation modes and preferably apply approximately the same force in both actuation modes.

[0025] The movement of the actuator in both manual and step-by-step actuation modes is advantageous because the movement provides the user with haptic feedback with each dispensing. This haptic feedback indicates to the user that the dispensing was successful. The user can therefore continue dispensing without being distracted by looking at a screen or other display device.

[0026] Preferably, in the step-by-step actuation mode, when the actuating element is actuated upon detection of a movement of the actuating element by the sensor arrangement, a predefined control signal is output to the drive motor instead of the signal, such that a predefined pipetting volume, which is independent of the actuating path of the actuating element, can be output.

[0027] Preferably, the predefined pipetting volume is set via an input element. For example, via a mechanically actuated input element, such as a rotary ring or a slider, or via an electronic input element, such as a switch or a touchscreen.

[0028] In manual actuation mode, a pipetting volume is dispensed which correlates with the movement path of the actuating element or which is proportional to the movement path of the actuating element.

[0029] The mode switch preferably has a stop surface on the mode switch side. The actuating element preferably has a stop surface on the actuating element side. When the mode switch is in the step-by-step mode position, the stop surface on the mode switch side is positioned such that the actuating element side stop surface abuts the stop surface on the mode switch side. When the mode switch is in the manual mode position, the stop surface on the mode switch side, in a first variant, is positioned such that the actuating element side stop surface can be freely moved past the mode switch side stop surface or can be moved without interaction with the actuating element side stop surface.When the mode switch is in the manual mode position, in a second variant, the stop surface on the mode switch side is positioned such that the stop surface on the actuating element side only strikes the stop surface on the mode switch side in an upper end position of the actuating element.

[0030] In other words, the mode switch provides a mechanical stop against which the actuating element can strike when the mode switch is in the step-by-step actuation position.

[0031] Preferably, the actuating element has an actuating surface on the actuating element side, and the mode switch has a mode switch-side actuating surface. When the actuating element is not actuated and the mode switch is preferably in the manual mode position, the mode switch-side actuating surface is located at a maximum distance of 80 millimeters from the actuating element-side actuating surface, viewed in the direction of the actuating movement of the actuating element. Particularly preferably, the distance is between 40 and 70 millimeters. The distance is to be understood in the direction of the movement axis of the actuating element. The distance is advantageous because a user can operate the pipette arrangement with one hand and can switch back and forth between the two modes with one hand.

[0032] The pipette assembly preferably comprises a further sensor assembly. The further sensor assembly has a sensor, wherein the sensor is configured and arranged such that the position of the mode switch can be detected and that a control signal corresponding to the position can be provided to the drive motor. The control signal can be processed by the drive motor, for example, such that it processes the signal from the sensor assembly differently between the two actuation modes to detect the movement of the actuating element.

[0033] Particularly preferably, the sensor of the further sensor arrangement is an electrical switch that is mechanically actuated by the mode switch. Other sensors, such as inductive sensors, capacitive sensors, optoelectronic sensors, or magnetic field sensors, can also be used.

[0034] Preferably, the pipette arrangement further comprises at least one circuit board which is arranged laterally adjacent to the drive motor.

[0035] Preferably, said sensor arrangement for detecting the movement of the actuating element comprises an active sensor element and a passive sensor element, wherein the active sensor element is arranged on the circuit board and the passive sensor element is arranged on the actuating element. Upon actuation of the actuating element, a relative displacement occurs between the two sensor parts, which can be detected by the active sensor part. The active sensor element is preferably an inductive sensor, and the passive sensor element is preferably made of metal, wherein said relative displacement results in a magnetic field change that can be detected by the active sensor part. Alternatively, an optoelectronic sensor could also be used for position measurement.

[0036] Preferably, the sensor of the further sensor arrangement is also arranged on said circuit board. In a first embodiment, the mode switch can be moved from the manual mode position to the step-by-step mode position in a direction nearly parallel or parallel to the actuation direction of the actuating element. This embodiment has the advantage that a user can operate the pipette arrangement with one hand.

[0037] The expression "almost parallel" also includes a direction that occurs with a small angular offset to the direction of actuation of the actuating element.

[0038] Preferably, the mode switch-side stop surface is displaceable in said direction, and the mode switch-side stop surface provides a stop for the actuating element both in the first starting position for the manual actuation mode and in the second starting position for the step-by-step actuation mode.

[0039] Preferably, upon actuation of the mode switch, the stop surface on the mode switch side can be brought into contact with the stop surface on the actuating element side. This contact allows the actuating element to be moved from a starting position for the manual actuation mode to a starting position for the step-by-step actuation mode. In other words, the movement of the mode switch moves the actuating element from the aforementioned first starting position for the manual actuation mode to the aforementioned second starting position for the step-by-step actuation mode. This allows for simple and ergonomic switching. In particular, switching can be performed with one hand.

[0040] In a second embodiment, the mode switch is displaceable in a direction substantially transverse or transverse to the direction of actuation of the actuating element from the manual mode position to the step-by-step mode position.

[0041] The expression "almost transverse" also includes a direction that occurs with a small angular offset transverse to the direction of actuation of the actuating element.

[0042] Preferably, the mode switch has a rod-shaped portion that engages a corresponding opening on the actuating element, wherein the corresponding opening has an extension in the direction of actuation of the actuating element that is larger than the cross-section of the rod-shaped portion. In another embodiment, the mode switch is displaceable from the manual mode position to the step-by-step mode position in a direction inclined at an angle to the actuation direction of the actuating element.

[0043] In a third embodiment, the mode switch is a rotary disk. The rotary disk has a first groove and a second groove. The second groove extends at an angle to the first groove. Furthermore, the actuating element has a pin that projects into the grooves. The grooves have different lengths, such that the aforementioned movement limitation can be provided.

[0044] The turntable can be pivoted about an axis of rotation which runs transversely to the direction of actuation of the actuating element.

[0045] The angle between the two grooves determines the pivot angle of the turntable, such that the grooves run parallel to the direction of actuation of the actuator in the respective mode position. The grooves intersect at the center of rotation of the turntable, and when the pin is at the intersection point, the turntable can be moved from the manual mode position to the step-by-step mode position.

[0046] In a fourth embodiment, the mode switch has a rigid shaft which engages in a receptacle arranged on the actuating element, wherein the receptacle has a region for the manual actuation mode and a region for the step-by-step actuation mode, wherein the two regions can be brought into a cooperating position with the shaft by pivoting the actuating element about the axis along which the actuating element is actuated.

[0047] In the following, further optional features of the pipette arrangement are described, which can be used optionally for all variants.

[0048] Preferably, the mode switch can be locked in the manual mode position via a locking element with respect to the drive unit. Preferably, the mode switch can be locked in the step-by-step mode position via a locking element with respect to the drive unit and / or with respect to the actuating element.

[0049] Preferably, the drive unit further comprises a spring-loaded return element. The return element acts on the actuating element and is compressed during the actuating movement of the actuating element. When the actuating force is removed, the return element relaxes and returns the actuating element to its original position. The spring return provides the user with haptic feedback after the actuation.

[0050] Preferably, the drive unit further comprises a battery which supplies the drive motor with electrical energy.

[0051] The drive motor is preferably a linear motor or a rotary spindle motor. The drive motor preferably acts on the piston via a linearly displaceable actuator, displacing the piston accordingly. Preferably, at least one Hall sensor is provided to detect the position of the actuator. The at least one Hall sensor or parts thereof can be arranged on the aforementioned circuit board. The use of a linear motor is particularly advantageous because the drive movement occurs without a transmission or gear, which improves the motor dynamics.

[0052] In one variant, the drive unit is designed separately from the pipetting unit. The pipetting unit can then be operatively connected to the drive unit, so that the movement of the drive motor acts on the piston. The drive unit and the pipetting unit can be separated, allowing a used pipetting unit to be replaced with an unused one.

[0053] In another variant, the drive unit is integrally formed with the pipetting unit. This means that the drive unit and the pipetting unit cannot be separated.

[0054] Preferably, the drive unit includes a control module. The sensor signal is transmitted to the control module. The signal is processed in the control module and then transmitted to the drive motor as a processed signal.

[0055] In another embodiment, the mode switch does not limit the movement of the actuating element in the step-by-step mode position. This means that the actuating element can be actuated over a portion of the maximum actuation travel or over the maximum actuation travel in step-by-step actuation mode.

[0056] A pipette assembly according to claim 22 comprises a pipetting unit and a drive unit. The pipetting unit has a pipette housing with a cylinder chamber and a pipetting opening, as well as a piston movably mounted in the cylinder chamber. The drive unit comprises a drive motor acting on and moving the piston, an actuating element for specifying a movement of the piston, and a sensor arrangement for detecting the movement of the actuating element and for providing a signal corresponding to the movement to the drive motor such that the drive motor is controlled based on the signal and acts accordingly on the piston. The actuating element can be actuated in a manual actuation mode such that a pipetting volume can be dispensed that is proportional to the movement of the actuating element or that is proportional to the actuating travel of the actuating element.For a step-by-step actuation mode, a pressure switch is arranged separately from the actuating element, wherein the pressure switch provides a control signal to the drive motor such that a determined or identical pipetting volume is dispensed per actuation of the pressure switch.

[0057] This type of pipetting system provides laboratory personnel with a flexible, user-friendly pipetting system. The positioning of the push button for step-by-step actuation offers the advantage of allowing a pre-determined movement of the push button, which enhances the ergonomics of the pipetting system.

[0058] Further preferred embodiments of the pipetting arrangement according to claim 22 are described below:

[0059] Preferably, the pressure switch is arranged next to the actuating element, with the pressure switch and the actuating element each having an actuating surface. The actuating surfaces are preferably arranged adjacent to one another.

[0060] The pressure switch can be designed in various ways. For example, the pressure switch can be an electromechanical pressure switch, it can be provided by an actuation pad in a touchscreen, or it can be provided by an inductive or capacitive detection sensor.

[0061] In manual actuation mode, the pipetting volume is proportional to the movement of the actuating element. This means that for each actuation increment, a volume corresponding to the actuation increment is dispensed. The movement of the piston can correspond to the movement of the actuating element, or the movement of the piston can be stepped down or stepped up relative to the movement of the actuating element. When the piston moves away from the pipetting orifice, liquid can be drawn into the cylinder chamber through the pipetting orifice, and when the piston moves toward the pipetting orifice, liquid can be dispensed from the cylinder chamber through the pipetting orifice.

[0062] As mentioned, the piston is driven by the drive motor. The drive motor moves the piston proportionally to the movement of the actuating element. The movement of the actuating element can be stepped up, reduced, or directly transmitted to the piston.

[0063] Preferably, the actuating element is movable from a first starting position to a first end position in the manual actuation mode and the actuating element is movable from a second starting position to a second end position in the step-by-step actuation mode.

[0064] Preferably, the actuation travel of the actuating element in manual actuation mode is greater than the travel of the push button in step-by-step actuation mode. Consequently, the actuation movement of a user's finger is smaller in step-by-step actuation mode than in manual actuation mode. This has the advantage of making the actuation more ergonomic.

[0065] Preferably, in the step-by-step actuation mode, when the pressure switch is actuated upon detection of actuation of the pressure switch, a predefined control signal is sent to the drive motor instead of the signal, such that a predefined pipetting volume, which is independent of the actuation path of the actuating element, can be delivered.

[0066] Preferably, the predefined pipetting volume is set via an input element. For example, via a mechanically actuated input element, such as a rotary ring or a slider, or via an electronic input element, such as a switch or a touchscreen.

[0067] In manual actuation mode, a pipetting volume is dispensed that correlates with the movement of the actuating element or is proportional to the movement of the actuating element. Further embodiments are specified in the dependent claims.

[0068] BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Preferred embodiments of the invention are described below with reference to the drawings, which are for illustrative purposes only and are not to be construed as limiting. In the drawings:

[0070] Fig. 1 is a schematic view of a pipette assembly according to an embodiment of the present invention;

[0071] Fig. 2a is a schematic view of parts of a drive unit for the pipette arrangement according to Fig. 1 in a manual actuation mode according to a first embodiment;

[0072] Fig. 2b shows the embodiment according to Fig. 2a in a step-by-step actuation mode;

[0073] Fig. 2c shows a further schematic view of parts of the drive unit according to a further development of the first embodiment of Figs. 2a and 2c in manual actuation mode;

[0074] Fig. 2d shows the embodiment according to Fig. 2c in a step-by-step actuation mode;

[0075] Fig. 2e shows a locking mechanism for a mode switch for use in Figures 2a to 2d in manual operation mode;

[0076] Fig. 2f shows a locking mechanism for a mode switch for use in Figures 2a to 2e in the step-by-step actuation mode;

[0077] Fig. 3a is a schematic view of parts of a drive unit for the pipette arrangement of Fig. 1 in a manual actuation mode according to a second embodiment;

[0078] Fig. 3b shows the embodiment according to Fig. 3a in a step-by-step actuation mode;

[0079] Fig. 4a is a schematic view of parts of a drive unit for the pipette arrangement of Fig. 1 in a manual actuation mode according to a third embodiment;

[0080] Fig. 4b shows the embodiment according to Fig. 4a in a step-by-step actuation mode;

[0081] Fig. 5a is a schematic view of parts of a drive unit for the pipette arrangement of Fig. 1 in a manual actuation mode according to a fourth embodiment;

[0082] Fig. 5b shows the embodiment according to Fig. 4a in a step-by-step actuation mode;

[0083] Fig. 6a shows a further variant of a drive unit for the pipette arrangement according to Fig. 1 in a manual actuation mode; and Fig. 6b shows the embodiment according to Fig. 6a in a step-by-step actuation mode.

[0084] DESCRIPTION OF PREFERRED EMBODIMENTS

[0085] Figure 1 shows a pipette assembly 1. The pipette assembly 1 comprises a pipetting unit 2 and a drive unit 7. In the embodiment shown, the pipetting unit 2 and the drive unit 7 are formed separately from one another and can be connected to one another. In other embodiments, it is also conceivable for the pipetting unit 2 and the drive unit 7 to be integrally connected to one another.

[0086] The pipetting unit 2 comprises a pipette housing 3 with a cylinder chamber 4 and a pipetting opening 5, as well as a piston 6 movably mounted in the cylinder chamber 4. The piston 6 is movable by the drive unit 7. When the piston 6 moves away from the pipetting opening 5, a liquid can be drawn into the cylinder chamber 4. When the piston 6 moves toward the pipetting opening 5, a liquid can be dispensed from the cylinder chamber 4.

[0087] The drive unit 7 has a drive motor 8, an actuating element 9 and a sensor arrangement 10. The drive motor 8 acts on the piston 6 and thus the piston 6 can be moved in the cylinder chamber 4. The drive motor 8 provides a linear movement to the piston 6. A movement of the piston 6 can be specified using the actuating element 9. The specified movement of the actuating element 9 is detected by the sensor arrangement 10. The sensor arrangement 10 provides a signal which corresponds to the movement of the actuating element 9. The signal is forwarded to the drive motor 8 and the drive motor 8 is controlled based on the signal. The drive motor 8 acts on the piston 6 in accordance with the signal and the piston 6 is moved in accordance with the specified movement of the actuating element 9.

[0088] The drive motor 8 is preferably a linear motor and the sensor arrangement comprises a sensor for detecting the movement of the actuating element 9, such as an induction-based sensor, an incremental sensor or an analog sensor.

[0089] Preferably, the drive unit further comprises a battery which

[0090] The drive motor and the sensor arrangement 10 are also supplied with electrical energy. The drive motor 8 can further comprise a position detection system that checks the position specified by the sensor arrangement.

[0091] The drive unit 7 further comprises a mode switch 11, which can be moved from a manual mode position to a stepwise mode position. When the mode switch 11 is in the manual mode position, the actuating element 9 can be actuated in a manual actuation mode such that a pipetting volume can be dispensed that correlates with the movement of the actuating element 9. When the mode switch 11 is in the stepwise mode position, the actuating element 9 can be actuated in a stepwise actuation mode such that a determined pipetting volume is dispensed per actuation of the actuating element 9. The mode switch 11 is designed such that it limits the movement of the actuating element 9 in the stepwise mode position. This limitation is a mechanical limitation such that the actuating element 9 can only be moved over a limited actuation travel.Various embodiments are described below with reference to Figures 2a to 5b.

[0092] Figures 2a to 5b show various embodiments of a drive unit 7.

[0093] Figures 2a, 2c, 3a, 4a, 5a show the manual actuation mode. In manual actuation mode, the actuating element 9 is moved from a first starting position, shown on the left in each case, towards a first end position, shown on the right in each case. When the actuating element 9 travels the full distance between the first starting position and the end position, the piston 6 is also actuated over its maximum travel. During the movement from the first starting position to the first end position, the piston 6 is moved towards the pipetting opening 5. The liquid is dispensed from the cylinder chamber 4. During the movement from the first end position to the first starting position, the piston 6 is moved away from the pipetting opening 5 and the liquid is drawn into the cylinder chamber 4.

[0094] Figures 2b, 2d, 3b, 4b, and 5b show the step-by-step actuation mode. The mode switch 11 is positioned such that the actuating element 9 can be moved from a second starting position, shown on the left in each case, to a second end position, shown on the right in each case. The actuation path between the second starting position and the second end position is preferably selected such that the movement feels as if the user were tapping a button.

[0095] In all embodiments of Figures 2a to 5b, the mode switch 11 has a mode switch-side stop surface 12. The actuating element 9 has an actuating element-side stop surface 13. When the mode switch 11 is in the step-by-step mode position, the mode switch-side stop surface 12 is positioned such that the actuating element-side stop surface 13 abuts the mode switch-side stop surface 11. When the mode switch 11 is in the manual mode position, the mode switch-side stop surface 12 is positioned such that the actuating element-side stop surface 13 can be freely moved past the mode switch-side stop surface 12 or can be moved without interaction with the actuating element-side stop surface 13.

[0096] In all embodiments of Figures 2a to 5b, the maximum actuating travel B in manual actuation mode and the maximum actuating travel B' in step-by-step actuation mode are also shown. The maximum actuating travel B in manual actuation mode is greater than the maximum actuating travel B' in step-by-step actuation mode. This is preferably subject to the proviso that the movement path of the actuating element 9 in step-by-step actuation mode is greater than 0.5 millimeters. This means that the actuating element is moved accordingly in both modes.

[0097] In all embodiments, the mode switch 11 can preferably be locked in the manual mode position via a locking element with respect to the drive unit 7. Preferably, the mode switch 11 can be locked in the step-by-step mode position via a locking element with respect to the drive unit 7 and / or with respect to the actuating element 11.

[0098] In all embodiments, the drive unit preferably has a spring-elastic return element 24, which acts on the actuating element 9. The spring-elastic return element 24 ensures that the actuating element is returned to the first or second starting position when an actuating force is removed.

[0099] Preferably, the actuating element 9 is moved along a respective movement path in both the manual actuation mode and the stepwise actuation mode. The movement path runs in the same direction in the manual actuation mode and the stepwise actuation mode. In particular, the movement path of the actuating element 9 runs along a rectilinear axis A in the manual actuation mode and the stepwise actuation mode. The axis A is preferably collinear with the movement of the piston 6.

[0100] Preferably, the actuating element 7 and the mode switch 11 are arranged relative to one another in such a way that a user can operate both the actuating element 7 and the mode switch 11 with the same finger, typically the thumb. Preferably, the actuating element 7 has an actuating surface 27 on the actuating element side, and the mode switch 11 has a mode switch-side actuating surface 28. When the actuating element 9 is not actuated and the mode switch 11 is preferably in the manual mode position, the mode switch-side actuating surface 28 is at a distance Z of a maximum of 80 millimeters from the actuating element-side actuating surface 27, viewed in the direction of the actuating movement of the actuating element 9. The distance Z is shown in Figure 2a. The distance Z can be provided in all embodiments described herein according to Figures 1 to 5b.

[0101] In the first embodiment according to Figures 2a and 2b, the position of the first end position is equal to the position of the second end position. The position of the first starting position is a greater distance from the first or second end position than the position of the second starting position. The mode switch 11 is moved such that the position of the first starting position and the position of the second starting position are different from each other.

[0102] The mode switch 11 is moved in a direction parallel or nearly parallel to the actuation direction of the actuating element 9 from the manual mode position to the step-by-step mode position. In the step-by-step mode position, the stop surface 12 on the mode switch side limits the movement of the actuating element 9. Preferably, the stop surface 12 on the mode switch side provides a stop for the actuating element 9 both in the first starting position for the manual actuation mode and in the second starting position for the step-by-step actuation mode. When the mode switch 11 is actuated, the stop surface 12 on the mode switch side can be brought into contact with the stop surface 13 on the actuating element side. Through this contact, the actuating element 9 can be moved from the first starting position for the manual actuation mode to the second starting position for the step-by-step actuation mode.Looking at Figures 2a to 2d, it can be seen that the mode switch 11 moves the actuating element 9 downwards when actuated.

[0103] In the embodiment shown, the movement of the mode switch 11 is limited by stops 26.

[0104] Figures 2c and 2d show that the pipette assembly 1 comprises a further sensor assembly 29. The further sensor assembly 29 comprises a sensor 30, which is configured and arranged such that the position of the mode switch 11 can be detected and that a control signal corresponding to the position can be provided to the drive motor 8. In the embodiment shown, the sensor 30 is an electrical switch, which is actuated by a contact edge 34 on the mode switch 11. The further sensor assembly 29 can also be arranged in all other embodiments.

[0105] Figures 2c and 2d further show that the pipette assembly 1 further comprises a circuit board 31. Here, the circuit board 31 is arranged laterally adjacent to the drive motor 8. The said sensor assembly 10 for detecting the movement of the actuating element 9 comprises an active sensor element 32 and a passive sensor element 33. The active sensor element 32 is arranged on the circuit board 31, and the passive sensor element 33 is arranged on the actuating element 9. Particularly preferably, the sensor 30, here the switch, of the further sensor assembly 29 is also arranged on the said circuit board 31. The circuit board 31 can also be arranged in all other embodiments.

[0106] Figures 2e and 2f show a preferred locking mechanism for the mode switch 11. Two spring clips 35 are arranged here, through which the mode switch 11 is moved by a locking cam 36. The spring clips have a gap 37 with a smaller cross-section than the diameter of the locking cam 36. When the mode switch 11 is moved, the locking cam 36 slides through the gap, whereby a force must be exerted on the mode switch 11 such that the two spring clips move away from each other, allowing the locking cam to pass through the gap 37.

[0107] In the second embodiment according to Figures 3a and 3b, the position of the first starting position is equal to the position of the second starting position. The position of the first end position is at a greater distance from the first or second starting position than the position of the second end position. The mode switch 11 is moved such that the position of the first end position and the position of the second end position are different from each other.

[0108] In the second embodiment, the mode switch 11 is displaceable in a direction transverse or nearly transverse to the actuating direction of the actuating element 9 from the manual mode position to the step-by-step mode position.

[0109] In the preferred embodiment shown, the mode switch 11 has a rod-shaped section 14, which engages in a corresponding opening 15 on the actuating element 9. The corresponding opening 15 has an extension in the direction of actuation of the actuating element 9 that is larger than the cross-section of the rod-shaped section. The opening 15 provides the stop surface 13 on the actuating element side, and the rod-shaped section has the stop surface 12 on the mode switch side.

[0110] In the embodiment shown, the opening 15 provides a further stop surface 25, which is spaced apart from the stop surface 13 on the actuating element side. The further stop surface 25 can also be brought into contact with the rod-shaped section 14. The distance between the two stop surfaces 13, 25 determines the maximum actuation travel B'.

[0111] In the third embodiment according to Figures 4a and 4b, the position of the first starting position is equal to the position of the second starting position. The position of the first end position is at a greater distance from the first or second starting position than the position of the second end position. The mode switch 11 is moved such that the position of the first end position and the position of the second end position are different from each other.

[0112] The mode switch 11 is a rotary disk 16. The rotary disk 16 has a first groove 17 and a second groove 18. The two grooves 17, 18 run at an angle to each other. Here, the angle is 90°. However, the angle can also be larger or smaller. The actuating element 9 has a pin 19 which projects into the grooves 17, 18. The grooves 17, 18 have different lengths such that the said movement limitation can be provided. The groove 18 provides the said stop surface 12 on the mode switch side. The angle between the two grooves 17, 18 specifies a pivot angle for the rotary disk such that the grooves 17, 18 run parallel to the direction of actuation of the actuating element in the respective mode position. The grooves 17, 18 intersect at the rotation center 23 of the turntable 16 and when the pin 19 is at the intersection point orin the rotation center 23, the turntable 16 can be moved from the manual mode position to the step mode position.

[0113] In the fourth embodiment according to Figures 5a and 5b, the position of the first end position is equal to the position of the second end position. The position of the first starting position is a greater distance from the first or second end position than the position of the second starting position. The mode switch 11 is moved such that the position of the first starting position and the position of the second starting position are different from each other.

[0114] In the fourth embodiment, the mode switch 11 has a rigid shaft 20. The rigid shaft 20 engages in a receptacle 21 arranged on the actuating element 9, wherein the receptacle 21 has a region for the manual actuation mode and a region for the step-by-step actuation mode. The two regions can be brought into a cooperating position with the shaft 20 by pivoting the actuating element 9 about the axis along which the actuating element 9 is actuated. The receptacle provides the mode switch-side stop surface 12 at one end of the respective regions. The other ends of the respective regions also act as stop surfaces. These stop surfaces are designated by the reference numeral 22.

[0115] Figures 6a and 6b show another pipette assembly 1. This pipette assembly differs essentially from the pipette assembly according to the preceding figures in that, instead of the mode switch, a pressure switch 100 for the step-by-step actuation mode is provided. The pipette assembly 1 comprises a pipetting unit 2 and a drive unit 7. In the embodiment shown, the pipetting unit 2 and the drive unit 7 are formed separately from one another and can be connected to one another. In other embodiments, it is also conceivable for the pipetting unit 2 and the drive unit 7 to be integrally connected to one another.

[0116] The pipetting unit 2 comprises a pipette housing 3 with a cylinder chamber 4 and a pipetting opening 5, as well as a piston 6 movably mounted in the cylinder chamber 4. The piston 6 is movable by the drive unit 7. When the piston 6 moves away from the pipetting opening 5, a liquid can be drawn into the cylinder chamber 4. When the piston 6 moves toward the pipetting opening 5, a liquid can be dispensed from the cylinder chamber 4.

[0117] The drive unit 7 has a drive motor 8, an actuating element 9 and a sensor arrangement 10. The drive motor 8 acts on the piston 6 and thus the piston 6 can be moved in the cylinder chamber 4. The drive motor 8 provides a linear movement to the piston 6. A movement of the piston 6 can be specified using the actuating element 9. The specified movement of the actuating element 9 is detected by the sensor arrangement 10. The sensor arrangement 10 provides a signal which corresponds to the movement of the actuating element 9. The signal is forwarded to the drive motor 8 and the drive motor 8 is controlled based on the signal. The drive motor 8 acts on the piston 6 in accordance with the signal and the piston 6 is moved in accordance with the specified movement of the actuating element 9.Furthermore, the drive unit 7 for the step-by-step actuation mode has a pressure switch 100 arranged separately from the actuation element 9. The pressure switch provides a control signal to the drive motor such that a predetermined pipetting volume is delivered each time the pressure switch 100 is actuated. LIST OF REFERENCE SYMBOLS.

[0118] Pipette arrangement 33 passive sensor element pipetting unit 34 contact edge pipette housing 35 spring clip cylinder chamber 36 locking cam pipetting opening 100 push button piston A axis drive unit B actuation path drive motor B' actuation path actuation element S signal sensor arrangement Z distance mode switch stop surface on mode switch side stop surface on actuation element side rod-shaped section opening rotary disc first groove second groove pin stop receptacle stop surfaces center of rotation reset element further stop surface stop actuation surface of 7 actuation surface of 11 further sensor arrangement sensor circuit board active sensor element

Claims

PATENT CLAIMS 1. A pipette assembly (1) comprising a pipetting unit (2) having a pipette housing (3) with a cylinder chamber (4) and a pipetting opening (5) as well as a piston (6) movably mounted in a cylinder chamber (4), and a drive unit (7) having a drive motor (8) acting on the piston (6) and moving the piston, an actuating element (9) for specifying a movement of the piston (6), and a sensor arrangement (10) for detecting the movement of the actuating element (9) and for providing a signal corresponding to the movement to the drive motor (8), such that the drive motor (8) is controlled based on the signal (S) and acts accordingly on the piston (6), wherein the drive unit (7) further comprises a mode switch (11) which can be moved from a manual mode position to a step-by-step mode position, such that when the mode switch (11) is in the manual mode position,the actuating element (9) is operable in a manual actuation mode such that a pipetting volume can be dispensed which is proportional to the movement of the actuating element (9), and that when the mode switch (11) is in the step-by-step mode position, the actuating element (9) is operable in a step-by-step actuation mode such that a determined pipetting volume is dispensed per actuation of the actuating element (9).

2. Pipette arrangement (1) according to claim 1, characterized in that the mode switch (11) limits the movement of the actuating element (9) in the step-by-step mode position.

3. Pipette arrangement (1) according to claim 1 or 2, characterized in that the actuating element (9) is movable in the manual actuation mode from a first starting position to a first end position; and in the stepwise actuation mode the actuating element (9) is movable from a second starting position to a second End position is movable.

4. Pipette arrangement (1) according to claim 3, characterized in that the position of the first starting position is equal to the position of the second starting position, and the position of the first end position is at a greater distance from the starting position than the position of the second end position; or that the position of the first end position is equal to the position of the second end position, and the position of the first starting position is at a greater distance from the end position than the position of the second starting position; or that the position of the first starting position is different from the position of the second starting position and the position of the first end position is different from the position of the first starting position, wherein the position of the second starting position and the position of the second end position lie between the position of the first starting position and the first end position.

5. Pipette arrangement (1) according to one of the preceding claims, characterized in that the actuating path of the actuating element (9) in the manual actuating mode is greater than the movement path of the actuating element in the step-by-step actuating mode, preferably with the proviso that the movement path of the actuating element (9) in the step-by-step actuating mode is greater than 0.5 millimeters.

6. Pipette arrangement (1) according to one of the preceding claims, characterized in that the actuating element (9) is movable or is moved along a respective movement path both in the manual actuation mode and in the stepwise actuation mode, wherein the movement path runs in the same direction in the manual actuation mode and in the stepwise actuation mode; and / or wherein the movement path of the actuating element (9) in the manual actuation mode and in the stepwise actuation mode occurs along a rectilinearly oriented axis.

7. Pipette arrangement (1) according to one of the preceding claims, characterized in that in the step-by-step actuation mode upon actuation of the actuating element (9) upon detection of a movement of the actuating element by the sensor arrangement (10), a predefined control signal is sent to the drive motor (8) is delivered in such a way that a predefined pipetting volume, which is independent of the actuating path of the actuating element (9), can be delivered.

8. Pipette arrangement (1) according to one of the preceding claims, characterized in that the mode switch (11) has a mode switch-side stop surface (12) and the actuating element (9) have an actuating element-side stop surface (13), wherein when the mode switch (11) is in the step-by-step mode position, the mode switch-side stop surface (12) is positioned such that the actuating element-side stop surface (13) abuts the mode switch-side stop surface (11), and wherein when the mode switch (11) is in the manual mode position, the mode switch-side stop surface (12) is positioned such that the actuating element-side stop surface (13) is freely movable past the mode switch-side stop surface (12) or without interaction with the actuating element-side stop surface (13) is movable; or wherein, when the mode switch (11) is in the manual mode position, the mode switch-side stop surface (12) is positioned such that the actuating element-side stop surface (13) abuts the mode switch-side stop surface (12) exclusively in an upper end position of the actuating element (9).

9. Pipette arrangement (1) according to one of the preceding claims, characterized in that the actuating element (7) has an actuating surface (27) on the actuating element side, that the mode switch (11) has a mode switch-side actuating surface (28), and that when the actuating element (9) is not actuated and the mode switch (11) is preferably in the manual mode position, the mode switch-side actuating surface (28), seen in the direction of the actuating movement of the actuating element (9), is at a distance (Z) of a maximum of 80 millimeters from the actuating surface (27) on the actuating element side.

10. Pipette arrangement (1) according to one of the preceding claims, characterized in that the pipette arrangement (1) comprises a further sensor arrangement (29), wherein the further sensor arrangement (29) has a sensor (30), wherein the sensor (30) is configured and arranged such that the position of the mode switch (11) can be detected and that a control signal corresponding to the position can be provided to the drive motor (8).

11. Pipette arrangement (1) according to one of the preceding claims, characterized in that the pipette arrangement (1) further comprises a printed circuit board (31) which is arranged laterally adjacent to the drive motor (8), wherein said sensor arrangement (10) for detecting the movement of the actuating element (9) comprises an active sensor element (32) and a passive sensor element (33), wherein the active sensor element (32) is arranged on the printed circuit board (31) and the passive sensor element (33) is arranged on the actuating element (9).

12. Pipette arrangement (1) according to claim 10 and 11, characterized in that the sensor (30) of the further sensor arrangement (29) is arranged on the said circuit board (31).

13. Pipette arrangement (1) according to one of the preceding claims 1 to 12, characterized in that the mode switch (11) can be moved in a direction almost parallel or parallel to the actuating direction of the actuating element (9) from the manual mode position to the step-by-step mode position.

14. Pipette arrangement (1) according to claim 13, characterized in that the mode switch-side stop surface (12) is displaceable in said direction, and in that the mode switch-side stop surface (12) provides a stop for the actuating element (9) both in the first starting position for the manual actuation mode and in the second starting position for the step-by-step actuation mode.

15. Pipette arrangement according to one of claims 13 to 14, characterized in that when the mode switch (11) is actuated, the stop surface (12) on the mode switch side can be brought into contact with the stop surface (13) on the actuating element side, and that by this contact the actuating element (9) can be moved from a starting position for the manual actuation mode into a starting position for the step-by-step actuation mode.

16. Pipette arrangement (1) according to one of the preceding claims 1 to 12, characterized in that the mode switch (11) is arranged in a direction almost transversely or can be moved transversely to the actuating direction of the actuating element (9) from the manual mode position to the step-by-step mode position.

17. Pipette arrangement (1) according to one of the preceding claims 1 to 12, characterized in that the mode switch (11) can be moved in a direction inclined at an angle to the actuating direction of the actuating element (9) from the manual mode position to the step-by-step mode position.

18. Pipette arrangement (1) according to one of the preceding claims 1 to 12, characterized in that the mode switch (11) is a rotary disk (16), which rotary disk (16) has a first groove (17) and a second groove (18) which runs at an angle to the first groove (17), wherein the actuating element (9) has a pin (19) which projects into the grooves (17, 18), and wherein the grooves (17, 18) have a different length such that the said movement limitation can be provided.

19. Pipette arrangement (1) according to one of the preceding claims 1 to 12, characterized in that the mode switch (11) has a rigid shaft (20) which engages in a receptacle (21) arranged on the actuating element (9), wherein the receptacle (21) has a region for the manual actuation mode and a region for the step-by-step actuation mode, wherein the two regions can be brought into a cooperating position with the shaft (20) by pivoting the actuating element (9) about the axis along which the actuating element (9) is actuated.

20. Pipette arrangement (1) according to one of the preceding claims, characterized in that the mode switch (11) can be locked in the manual mode position via a locking element with respect to the drive unit (7); and / or the mode switch (11) can be locked in the step-by-step mode position via a locking element with respect to the drive unit (7) and / or with respect to the actuating element.

21. Pipette arrangement (1) according to claim 1 or according to claim 1 and one of claims 3 to 7 or 10 to 12 or 20, characterized in that the mode switch (11) in the stepwise mode position does not limit the movement of the actuating element (9), such that the actuating element (9) can be actuated over a partial distance of the maximum actuating travel or over the maximum actuating travel in the stepwise actuating mode.

22. A pipette assembly (1) comprising a pipetting unit (2) having a pipette housing (3) with a cylinder chamber (4) and a pipetting opening (5), as well as a piston (6) movably mounted in the cylinder chamber (4), and a drive unit (7) having a drive motor (8) acting on the piston (6), an actuating element (9) for specifying a movement of the piston (6), and a sensor arrangement (10) for detecting the movement of the actuating element (9) and for providing a signal corresponding to the movement to the drive motor (8), such that the drive motor (8) is controlled based on the signal, wherein the actuating element (9) is operable in a manual actuation mode such that a pipetting volume can be delivered that is proportional to the movement of the actuating element (9), and wherein a pressure switch (100) arranged separately from the actuating element (9) is arranged for a step-by-step actuation mode,wherein the pressure switch provides a control signal to the drive motor such that a determined pipetting volume is delivered per actuation of the pressure switch (100).

23. Pipette arrangement according to claim 22, characterized in that the pressure switch (100) is arranged next to the actuating element (9), wherein the pressure switch (100) and the actuating element (9) each have an actuating surface, which actuating surfaces are preferably arranged adjacent to one another.

24. A method for operating a pipette assembly (1) according to any one of the preceding claims 1 to 21, wherein in a step of activating the stepwise operating mode, the mode switch is moved to a stepwise mode position; and wherein in a step of activating the manual operating mode, the mode switch is moved to a manual mode position.

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