Pipettor capable of adjusting pipetting amount

Abstract

The utility model relates to a pipettor (10) capable of adjusting the pipetting amount, which comprises a shell (20) used for accommodating a displacement mechanism, and the displacement mechanism comprises a displacement cavity and a movable limiting piece used for limiting the pipetting stroke of the pipettor (10). The pipettor (10) further comprises: an operating element (12) for setting a pipetting amount of the pipettor (10) by moving the stop element (26) in the housing (20) and for performing a pipetting process, the operating element (12) being operatively connected to a movable piston in a displacement chamber of the displacement mechanism via a stroke rod (22); and the counting piece (30) is used for displaying the set pipetting amount. Components (70) are arranged within the housing (20) of the pipettor (10), which have a normal stroke function of the pipettor (10), an over-stroke function of the pipettor (10), and a user adjustment function.

Description

TECHNICAL FIELD

[0001] The utility model relates to the pipette of adjustable pipetting volume and the stroke system of adjustable degree of setting according to the preface part of claim 1. BACKGROUND

[0002] Pipettes are used in particular in laboratories for controlled liquid uptake and discharge. For this purpose, the pipette tip is clamped with its upper opening to the pipette base. The base is preferably shaped as a conical or cylindrical protrusion on the pipette housing. The pipette tip can be filled with liquid and discharged through the lower opening. Air displacement pipettes comprise an air displacement mechanism which communicates through a bore in the base to the pipette tip. By means of the air displacement mechanism, an air cushion is displaced, whereby the pipette tip is filled with liquid and discharged therefrom. For this purpose, the air displacement mechanism has a displacement chamber with a movable stopper. The air displacement mechanism is usually a cylinder with a piston which is movable therein.

[0003] After use, the pipette tip is detached from the base and replaced by a new pipette tip. This avoids contamination during subsequent dosing. The pipette tip usually comprises an ejection mechanism for ejecting the pipette tip, so that the pipette tip can be ejected by pressing a button without having to touch the pipette tip. Disposable pipette tips are made of plastic and are inexpensive.

[0004] The movable stopper is coupled to a drive mechanism for moving the piston in the cylinder. The drive mechanism comprises a stroke lever which is movable with a stop between an upper stop and a lower stop. When the air displacement chamber is initially filled with air, the stop is at the lower stop. When the cylinder is initially discharged, the stop is at the upper stop. The volume of liquid taken up or discharged depends on the stroke of the movable stopper and thus on the stroke of the stroke lever.

[0005] In principle, in addition to the volume adjustment by means of the operating button, it is possible in the known pipettes to implement a user-specific volume adjustment, in particular to adapt the volume adjustment to liquids of different density and / or different viscosity. In addition, the user-specific adjustment can also be used to adapt the pipette to hot or cold liquids.

[0006] The patent document EP 2 659 978 A1 discloses an air displacement pipette whose pipetting volume is adjustable and comprises a locking element for locking the set pipetting volume. The pipette comprises a rod-shaped housing, a base for releasable holding of the pipette tip at the lower end of the housing, and an air displacement mechanism having a displacement chamber and a movable stopper therein. The pipette further comprises a drive mechanism for moving the movable stopper of the air displacement mechanism and a locking body which can be used to lock the drive mechanism against unintentional adjustment of the set pipetting volume.

[0007] Patent documents EP 2 578 317 B1 and US 9,180,446 describe a manually dosing device whose support structure has detachable holding means for an injection gun or pipette tip at the lower end, wherein a piston drive mechanism for moving fluid in the injection gun or pipette tip is attached to the support structure above the detachable holding means. The support structure is formed by longitudinally parallel spaced apart elongated frames, so that the forces occurring when the drive mechanism is activated are introduced into the frames. A housing surrounds the drive mechanism and the frames, which is preferably mounted to the frames at only a few points in order to reduce the load on the housing. The longitudinal struts of the frame sections have interlocking connection structures, and there are also fastening means which connect these connection structures to one another. Embodiments of the dispenser are described in detail below. This is a positive displacement system which is used in conjunction with a syringe, in which the barrel of the syringe is fixed in place and the piston is pulled slightly out of the barrel by means of a pull rod in order to take up liquid. In order to expel the taken-up liquid, the piston is pushed deep into the barrel by means of a toothed rack and ratchet mechanism which can be set in steps. The volume of the syringe is usually much larger than that of the pipette tip (whether integrated with a piston or not). A pipette is also described in which the elongated frame has longitudinally parallel spaced apart longitudinal struts and at the lower end thereof there is arranged a detachable holding means for a pipette tip, above which there is attached a barrel and a movable piston therein and a piston drive mechanism.

[0008] Patent document EP 1 015 110 B1 describes a pipette whose frame is made of hard plastic and is embedded in a pad film which fits to the user's hand. The frame is tubular and in the frame there are arranged in succession components which are partly interlocking, namely a drive mechanism, a counting piece and a gear wheel for transmitting the setting of a liquid volume adjustment ring to the counting piece. The liquid volume adjustment ring is arranged between a lower part of the pipette in which there is arranged a barrel and a movable piston therein and an upper part of the pipette which comprises the film and the frame embedded therein. The assembly of the pipette is very complex.

[0009] However, the disadvantage of this technical solution is that the required mechanical structure requires a relatively large installation space, so that the pipette cannot be made small and compact. If the handle of the pipette is thick, small-handed people will also find it particularly uncomfortable. Utility model content

[0010] The object of the utility model is to propose a pipette which achieves the required functions in a very compact installation space, so that it is possible to shorten the diameter of the "elongated" housing of the pipette.

[0011] To achieve the above object, the utility model provides a pipette, it includes the casing for containing the displacement mechanism, wherein the displacement mechanism includes the displacement cavity and the movable limit piece for limiting the pipetting stroke of the pipette. The pipette includes: operating piece, for setting the pipetting volume of the pipette by making the limit piece move in the casing and for executing the pipetting process, wherein the operating piece is connected with the movable piston in the displacement cavity of the displacement mechanism through the stroke lever;And the counting piece for showing the set pipetting volume.

[0012] According to the utility model, the casing of the pipette is arranged with the assembly, which has the normal stroke function of the pipette, the overstroke function of the pipette and the user adjustment function.

[0013] The pipette generally has an operating knob, which can realize the pipetting volume adjustment function and liquid taking and discharging function. In addition, another operating knob is provided to enable the pipette tip to pop out after the pipetting process. Many users think that this pipette is easy to operate and extremely easy to use. The operating piece can be pressed into the pipette casing in the axial direction to take liquid and discharge liquid. The operating piece has two actuating zones when actuated and fitted in the axial direction. The first actuating zone is used for taking liquid and discharging liquid. The operating piece starts from the empty initial position and is pressed into the pipette casing in the axial direction, for example, 2mm to 16mm according to the set pipetting volume.

[0014] The second actuating zone, also known as overstroke, is used to blow out the liquid remaining in the pipette tip still plugged into the interface of the pipette casing after discharging the liquid. This so-called overstroke is achieved by the additional displacement of the operating piece in the axial direction beyond the end point during liquid taking, for example, 4mm to 6mm of additional displacement.

[0015] Preferably, the actuating zones are mutually delimited by stops and the associated force changes, in order to provide the user with a sensitive feedback on the current activity being carried out.

[0016] In addition, the user can also be provided with additional adjustment options on the pipette, also known as user adjustment, to adapt the pipetting volume to deviations caused by different viscosities, densities and / or temperatures of the liquid and to correct the calibrated pipetting volume based on the new fluid.

[0017] The pipette according to the utility model can shorten the diameter of the handle part of the pipette, so that it is more comfortable to use, especially suitable for operators with small hands.

[0018] The additional features listed in the dependent claims can advantageously improve and further develop the pipette referred to in the independent claim.

[0019] In an advantageous embodiment of the pipette, the assembly comprises a first sub-assembly and a second sub-assembly, wherein the first sub-assembly and the second sub-assembly are displaceable relative to each other in the housing of the pipette. This means that the "stroke" function, the "overstroke" function and the user adjustment function can be constructed in a compact assembly and can be integrated into a thinner pipette housing. The technical solution presented in the utility model makes it possible to reduce the diameter without having to increase other dimensions, in particular the length of the pipette, to compensate for this. This makes it possible to hold the pipette comfortably in the hand, in particular for small-handed operators.

[0020] According to an advantageous embodiment of the pipette, the first sub-assembly is arranged in the housing in a radially fixed and axially movable manner, and the second sub-assembly is arranged in the housing in a radially movable and axially fixed manner. This makes it possible to realize the relative displacement of the first sub-assembly relative to the second sub-assembly along the longitudinal axis of the pipette in a simple design, which in particular allows the user adjustment function to be integrated into the assembly.

[0021] In an advantageous embodiment of the pipette, the first sub-assembly comprises a stroke body with a spindle. In this way, the diameter of the first sub-assembly can be made narrower, wherein the stop for the stroke rod can be adjusted by means of the spindle, which in turn makes it possible to adjust the volume of the pipette.

[0022] In a further advantageous embodiment of the pipette, the second sub-assembly has the overstroke function and the user adjustment function. By transferring the overstroke and the user adjustment to the second sub-assembly, it is possible to separate from the pipetting stroke function, which reduces the complexity of each sub-assembly itself. In particular, a concentric arrangement can be dispensed with, which would otherwise result in an increased diameter and thus less comfort for small-handed operators when operating the pipette.

[0023] According to an advantageous embodiment of the pipette, the first sub-assembly is connected to the second sub-assembly via a first thread.

[0024] In this way, the first sub-assembly can be displaced relative to the second sub-assembly, which is particularly advantageous for the user adjustment function.

[0025] In an advantageous embodiment of the pipette, the stroke rod is connected to the spindle, wherein the spindle is connected to the first sub-assembly via a second thread. In this way, it is possible to axially displace the stop for the stroke rod in a simple manner when adjusting the user.

[0026] According to an advantageous embodiment of the pipette, a setting cone is provided on the second sub-assembly, which can reversibly adjust the stop for the stroke rod. In particular, the setting cone engages with a toothing on an indicator ring of the second sub-assembly, so that by turning the setting cone the distance between the upper edge of the movable stop for the stroke rod and the lower edge of the spindle is changed, which in turn allows the volume to be adapted when adjusting the user.

[0027] In an advantageous embodiment of the pipette, a stop for the overtravel spring is configured in the second subassembly. In this way, the overtravel function can be transferred to the second subassembly in a simple manner, so that the stroke function and the overtravel function can be functionally separated from one another.

[0028] In another advantageous embodiment of the pipette, the first subassembly and the second subassembly are arranged coaxially along the longitudinal axis of the assembly. In this way, a relative displacement between the first subassembly and the second subassembly can be effected in a particularly simple and easily reversible manner, so that a user-specific stroke lever stop displacement can be achieved.

[0029] In a preferred embodiment of the pipette, an observation window is configured on the housing, and a scale for displaying the user adjustment is configured on the second subassembly, wherein the scale is visible through the observation window. In the simplest embodiment, the observation window is a recess in the housing. In this way, the user can easily see whether the pipette is in the calibrated initial position or in a user-specific position that deviates from the initial position, and by how much the pipetting volume deviates from the calibrated initial value.

[0030] The various embodiments of the application mentioned in the present application can advantageously be combined with one another, unless stated otherwise in individual cases. BRIEF DESCRIPTION OF DRAWINGS

[0031] The application will be described in more detail below with reference to the embodiments illustrated in the drawings. Identical parts or parts having the same function are marked with the same reference numerals in the different figures. In the figures:

[0032] Figure 1 A cross-sectional view of a pipette according to the application is shown, which has an adjustable pipetting volume and a user adjustment function;

[0033] Figure 2 A three-dimensional schematic view of a pipette assembly according to the application is shown, which combines a normal stroke function, an overtravel function and a user adjustment function;

[0034] Figure 3 A cross-sectional view of a pipette assembly according to the application is shown, which combines a normal stroke function, an overtravel function and a user adjustment function.

[0035] wherein 10 pipette

[0036] 12 operating element

[0037] 13 finger hook

[0038] 14 operating knob

[0039] 16 ejection element

[0040] 18 upper part

[0041] 19 ejection lever

[0042] 20 housing

[0043] 22-stroke lever

[0044] 26 movable limit components

[0045] 30 count pieces

[0046] 31 Display Window

[0047] 32 mandrels

[0048] 34 strokes

[0049] 36 indicator rings

[0050] 38-stroke rod stop

[0051] 40 Overtravel Spring

[0052] 42 Adjustment Mechanism

[0053] 44 Adjusting Cone

[0054] 46 shoulder

[0055] 48 stops

[0056] 50 First child component

[0057] 52 First Thread

[0058] 54 Longitudinal axis

[0059] 56 Second Thread

[0060] 60 Second Sub-component

[0061] 62 stops

[0062] 64 scale

[0063] 66 Observation Window

[0064] 70 components Detailed Implementation

[0065] Figure 1 A cross-sectional view of a pipette 10 according to the present invention is shown. The pipette 10 has an upper pipette portion 18 and a lower pipette portion ( Figure 1The lower part of the pipette can be coupled to the upper part 18 of the pipette (not shown in detail). The upper part 18 of the pipette comprises a housing 20, wherein the operating element 12, preferably an operating knob 14, projects from an end face of the housing 20 facing away from the lower part of the pipette through an opening in the housing 20. The operating element 12 has two functions: Firstly, the operating element 12 is used to set the pipetting volume, i.e. the amount of liquid which the pipette 10 is to take up and then expel during a pipetting process. The pipetting volume is set by rotating the operating element 12, wherein the set pipetting volume is increased by rotating the operating element 12 in a first direction of rotation and is decreased by rotating the operating element 12 in the opposite direction of rotation. Depending on the design, the settable pipetting volume is between a minimum pipetting volume and a maximum pipetting volume. Secondly, the operating element 12 is used to take up liquid and then expel liquid during a pipetting process, wherein the operating knob 14 of the operating element 12 is moved axially along the longitudinal axis 54 of the pipette 10. Furthermore, a finger hook 13 is configured on the housing 20 in order to easily hold the pipette 10. Furthermore, an ejector 16 is arranged on the housing 20, preferably on the side opposite the finger hook 13, in order to eject the used pipette tip from the interface of the lower part of the pipette after a pipetting process. For this purpose, the ejector 16 is in operative connection with an ejector lever 19 which bears against the end face of the pipette tip and thereby activates the ejection of the pipette tip. In particular, the functions of liquid volume adjustment, taking and expelling of liquid and / or ejection of the pipette tip can also be combined in the operating knob 14, so that only one operating knob 14 is required for easy and convenient operation. Alternatively, the functions can also be distributed between several components of the operating element 12, in particular in addition to the operating knob 14, the ejector 16 can be provided for ejecting the used pipette tip. Furthermore, the operating element 12 can have an operating knob 14 for taking and expelling liquid and a pipetting volume setting element, in particular a pipetting volume setting wheel, which is moved by the operating knob 14.

[0066] The housing 20 has a displacement mechanism comprising a displacement chamber and a movable stop 26 for limiting the pipetting stroke. The operating element 12 is configured to set the pipetting volume of the pipette 10 and to carry out a pipetting process by moving the stop 26 in the housing 20. The operating element 12 is in operative connection with the movable piston (not shown in detail) in the displacement chamber of the displacement mechanism via a stroke lever 22. The stroke lever 22 is in operative connection with the operating element 12 via a pivotable lever arm 24. Figure 1 The pipette 10 further comprises a counting element 30 for displaying the set pipetting volume and a locking mechanism 40 for locking and / or unlocking the volume setting of the operating element 12.

[0067] A transparent display window 31 is embedded in the housing 20 in order to be able to see the counting element 30 from the outside and to be able to read the set pipetting volume. The housing 20 is provided with a movable stop 26 for the stroke lever 22, wherein a shoulder on the stroke lever 22 bears against the movable stop 26, thereby limiting the piston stroke. The pipetting volume is set by moving the stop 26.

[0068] The lower part of the pipette comprises a displacement chamber into which a piston, which can be actuated via the operating element 12 and is connected to the stroke rod 22, dips. The lower part of the pipette also has a clamping region for receiving the pipette tip, wherein, by actuating the operating element 12 via the ejection rod 19, the pipette tip can be released from the clamping region and ejected.

[0069] The pipette 10 has a first actuation region for taking up and expelling liquid with the pipette, referred to as stroke H. The operating element 12 is pressed axially into the housing 20 of the pipette 10 along the stroke path from the unloaded initial position, for example by 2 mm to 16 mm depending on the set pipetting volume.

[0070] The first actuation region is followed by a second actuation region, also referred to as overstroke, in particular for blowing residual liquid out of the pipette 10 after expelling the liquid, which is still inserted into the pipette tip on the interface of the housing 20 of the pipette 10. This so-called overstroke is achieved by an additional displacement of the operating element 12 axially beyond the end of the stroke H during the taking up of liquid, for example by 4 mm to 6 mm.

[0071] Preferably, the actuation regions are delimited from one another by stops and the associated change in force, in order to provide the user with sensitive feedback about the activity currently being carried out.

[0072] Figure 2 An assembly 70 of the pipette 10 according to the application is shown, which comprises a first sub-assembly 50 and a second sub-assembly 60 arranged coaxially along the longitudinal axis 54 of the pipette 10. The first sub-assembly 50 comprises the stroke rod 22 and the mandrel 32 arranged concentrically with the stroke rod 22, which is held in operative connection with the stroke rod 22. The first sub-assembly 50 also comprises the stroke body 34, on which the movable stop 26 for the stroke rod 22 is configured, which forms the stop 48 for the stroke rod 22. The second sub-assembly 60 comprises the adjustment mechanism 42 with a setting cone, with which the user can reversibly adjust the pipetting volume, for example to adapt the pipette 10 to different viscosities of different liquids. To this end, the second sub-assembly 60 is formed with a scale 64 for indicating the deviation of the pipetting volume.

[0073] Figure 3A sectional view of an assembly 70 according to the utility model is shown. The assembly 70 comprises a first sub-assembly 50 and a second sub-assembly 60 coaxially arranged along a longitudinal axis 54 of the pipette 10. The first sub-assembly 50 comprises a stroke rod 22 and a spindle 32 concentrically arranged with the stroke rod 22, the spindle 32 being in operative connection with the stroke rod 22. The first sub-assembly 50 further comprises a stroke body 34, on which a movable stop 26 for the stroke rod 22 is configured. The second sub-assembly 60 comprises an adjustment mechanism 42 with a setting cone, by means of which a user can reversibly adjust the pipetting volume, for example to adapt the pipette 10 to different viscosities of different liquids. To this end, the second sub-assembly 60 comprises an indicator ring 36 with a scale 64 for indicating a pipetting volume deviation. The toothing on the lower edge of the indicator ring 36 engages with the toothing on the setting cone 44 of the adjustment mechanism 42. In addition, the first thread 52 on the upper end of the indicator ring 36 engages with the thread on the stroke body 34, so that the stop 26 for the stroke rod 22 can be moved. The second sub-assembly 60 also comprises an overstroke function. To this end, a stop 62 for an overstroke spring 40 is configured in or on the second sub-assembly 60, which is accommodated in the indicator ring 36.

[0074] By means of the scale 64, the user can see whether the pipette 10 is in the calibrated normal position or in a user-specific adjustment position, in which the stroke of the pipette is adjusted by moving the stop 26. In this regard, the stroke of the pipette 10 is defined by the distance between the upper edge of the stop 26 of the stroke rod 22 and the lower edge of the spindle 32. The housing 20 is provided with a support surface and a guide groove, so that the first sub-assembly 50 is radially fixed and axially loose in the housing 20, and the second sub-assembly 60 is axially fixed and radially loose in the housing 20. If the setting cone 44 of the adjustment mechanism 42 on the second sub-assembly 60 is adjusted, the second sub-assembly 60 moves relative to the first sub-assembly 50, whereby the stroke of the pipette 10 changes, which the user can adjust accordingly.

[0075] The spindle 32 is screwed into the stroke body 34 via the second thread 56, so that the spindle 32 can be adjusted relative to the stroke body 34 by operating the knob 14 when adjusting the volume.

Claims

1. A pipette (10) with adjustable pipetting volume, comprising: - a housing (20) for accommodating a displacement mechanism, wherein the displacement mechanism comprises a displacement chamber and a movable stopper (26) for limiting the pipetting stroke of the pipette (10); - an operating element (12) for setting the pipetting volume of the pipette (10) by moving the movable stopper (26) in the housing (20) and for performing a pipetting process, wherein the operating element (12) is in action connection with a movable piston in the displacement chamber of the displacement mechanism via a stroke rod (22); - a counting element (30) for displaying the set pipetting volume, characterized in that - a module (70) is arranged in the housing (20), which module (70) has a normal stroke function of the pipette (10), an overstroke function of the pipette (10) and a user adjustment function; - the module (70) comprises a first sub-module (50) and a second sub-module (60), wherein the first sub-module (50) and the second sub-module (60) are displaceable relative to each other in the housing (20) of the pipette (10); - the second sub-module (60) is provided with a setting cone (44), which setting cone (44) can be reversibly adjusted for a stop (48) for the stroke rod (22); - a stop (62) for an overstroke spring (40) is configured in the second sub-module (60). - the first sub-module (50) is arranged in the housing (20) in a radially fixed and axially movable manner, and the second sub-module (60) is arranged in the housing (20) in a radially movable and axially fixed manner. - the first sub-module (50) comprises a stroke body (34) with a spindle (32). - the second sub-module (60) has an overstroke function and a user adjustment function. - the first sub-module (50) is connected to the second sub-module (60) via a first thread (52). - the stroke rod (22) is connected to the spindle (32), wherein the spindle (32) is connected to the first sub-module (50) via a second thread (56). - the first sub-module (50) and the second sub-module (60) are arranged coaxially along a longitudinal axis (54) of the module (70). - the housing (20) is configured with a viewing window (66), and the second sub-module (60) is configured with a scale (64) for displaying the user adjustment, wherein the scale (64) is visible through the viewing window (66).

2. A pipettor (10) with adjustable pipetting volume according to claim 1, characterized in that ​ 3. Pipettor (10) with adjustable pipetting volume according to claim 1 or 2, characterized in that ​ 4. Pipettor (10) with adjustable pipetting volume according to claim 1 or 2, characterized in that ​ 5. A pipettor (10) of adjustable pipetting volume according to claim 1 or 2, characterized in that ​ 6. The adjustable pipetting volume pipettor (10) according to claim 3, characterized in that ​ 7. A pipettor (10) with adjustable pipetting volume according to claim 1 or 2, characterized in that ​ 8. A pipettor (10) with adjustable pipetting volume according to claim 1 or 2, characterized in that ​

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