EP3560596A1 - Pipette for use with a pipette tip and pipette family comprising multiple pipettes with different nominal volumes - Google Patents

Abstract

A pipette tip for use with a pipette tip comprising • a stem-shaped pipette housing, • a pin at the lower end of the pipette housing for clamping a pipette tip with a collar having a plug-in opening at its upper end, • a drive device comprising a drive element for displacing a displacement element for sucking in liquid Samples in the pipette tip and ejecting the samples from the pipette tip and a protruding from the pipette housing, relative to the pipette housing displaceable operating element, • a scanning arranged with a next to the pin, when clamping a pipette tip on the pin from the collar in the longitudinal direction of the pin relative to the pipette housing displaceable Scanning element and • a mechanical display device coupled to the scanning device, wherein the scanning device is designed so that they are different when clamping pipette tips on the pins type and whose collar has a height indicative of the type of pipette tip, sets a display of the display device that depends on the type of pipette tip.

Description

The invention relates to a pipette for use with a pipette tip. Furthermore, the invention relates to a pipette tip family comprising a plurality of pipette tips with different nominal volumes.

Pipettes are used in particular in scientific and industrial laboratories with medical, molecular biological and pharmaceutical applications for dosing selected volumes of liquids. The liquids may in particular be homogeneous (single-phase) liquids, consisting of a single liquid component or of a homogeneous mixture of several liquid components (solutions). Furthermore, the liquids may be heterogeneous (multiphase) mixtures of a liquid with another liquid (emulsions) or a solid (suspensions).

Pipettes have a stem-shaped pipette housing with a pin (neck) at the bottom for clamping a pipette tip. The pin is often a conical, cylindrical or partially conical and cylindrical projection and is also referred to as a "working cone". A pipette tip is a hollow tube with a tip opening at the lower end and a plug-in opening at the upper end, with which the pipette tip can be clamped onto the journal. The liquid is taken up in and out of the pipette tip. The intake and delivery of the liquid is controlled by means of the pipette. Fixed volume pipettes are used for pipetting constant volumes. With variable pipettes, the volume to be dispensed is adjustable. A mechanical counter is used to display the set volume. To adjust the volume of the stroke of the drive means is adjustable by means of an adjustment, which is coupled to the counter. The pipette tip is released from the neck after use and can be placed against a fresh pipette tip be replaced. As a result, contamination can be avoided in subsequent pipetting.

Bubble pipettes have in the pipette housing on a piston-cylinder system, which is connected via a channel with a hole in the pin. Pipette tips for air bubble pipettes (bubble cushion pipette tips) have no integrated piston. By moving the piston in the cylinder, an air cushion is moved to suck liquid into a clamped on the pin pipette tip and expel from this. A disadvantage of air cushion pipettes dosing errors due to the change in the length of the air cushion by the weight of the sucked liquid and the effects of temperature, air pressure and humidity. A problem may also be a contamination of the pipette by aerosols.

Direct displacement pipettes are used with pipette tips with integrated piston (direct displacement pipette tips). This type of pipette has a spigot for attaching the pipette tip and a drive means for moving the spool which can be coupled to the integrated piston. The piston comes into direct contact with the fluid, eliminating the effects of an air cushion. In particular, direct displacement pipettes are useful for metering high vapor pressure, high viscosity, or high density liquids and applications in molecular biology that require no aerosol to avoid contamination.

Single-use or reusable air-cushion or direct-displacement pipette tips are made of plastic or glass.

Pipettes are available in different sizes, each with a matching pipette tip type or several matching pipette tip types with closely spaced nominal volumes. For different applications, the user must hold pipettes and pipette tips of different sizes, which causes corresponding costs for purchase, maintenance and storage. The identification of pipettes and pipette tips by a color code is known in order to facilitate the correct assignment. There is a risk of misinterpretation by the user.

The EP 2 574 402 B1 describes a syringe for use with a metering device having a syringe-dependent coding at the top of the syringe barrel. In addition, a metering device for use with a syringe is described which has a scanning device with a ring sensor for sensing the coding, which is connected to an evaluation device which controls the metering device in the case of an error-free scanning in an encoding-dependent operating state. This includes, for example, the display of the set dosing volume.

The DE 199 48 818 A1 describes a syringe with a coding at the top of the syringe plunger and a pipette ("syringe holder") with an information reader for reading the coding. Upon detection of a particular syringe of a particular type, eg, a 50ml syringe, this value may be output by optical display elements (eg, LEDs or LCDs).

The US 6,749,812 B2 describes an air cushion pipette with an automatic tip ejector having a lug attachment approach and a spring loaded ejector sleeve thereon. There is also a tip detection of pipette tips where different tip types have a different base configuration. In this tip detection different types of pipette tip are detected by a different displacement of the approach with respect to the ejector, which is detected by an electronic sensor.

The known pipettes have the disadvantage that the detection of the pipette tips or syringes by means of electronic sensors. The electronic sensors can be subjected to heavy loads by forces, vapors, etc. and are at risk of failure. The electronics increase the structural complexity and equipment costs. In addition, the electronics limits the possibilities to sterilize the pipettes.

Based on this, the object of the invention is to create a less risk of failure pipette that can be used with pipette tips of different types. Furthermore, a pipette tip family comprising several pipette tips of different types is to be created, which can be used with the same, less risk of failure pipette.

The object is achieved by a pipette having the features of claim 1. Advantageous embodiments of the invention are specified in subclaims.

• ein stielförmiges Pipettengehäuse,
• einen Zapfen am unteren Ende des Pipettengehäuses zum Aufklemmen einer Pipettenspitze mit einem eine Aufstecköffnung aufweisenden Kragen an ihrem oberen Ende,
• eine Antriebseinrichtung umfassend ein Antriebselement zum Verlagern einesVerdrängungselementes zum Einsaugen von flüssigen Proben in die Pipettenspitze und Ausstoßen der Proben aus der Pipettenspitze und ein vom Pipettengehäuse vorstehendes, relativ zum Pipettengehäuse verlagerbares Bedienelement,
• eine Abtasteinrichtung mit einem neben dem Zapfen angeordneten, beim Aufklemmen einer Pipettenspitze auf den Zapfen vom Kragen in Längsrichtung des Zapfens relativ zum Pipettengehäuse verlagerbaren Abtastelement und
• eine mit der Abtasteinrichtung gekoppelte mechanische Anzeigeeinrichtung, wobei die Abtasteinrichtung so ausgebildet ist, dass sie beim Aufklemmen von Pipettenspitzen auf den Zapfen, die unterschiedlichen Typs sind und deren Kragen eine den Typ der Pipettenspitze kennzeichnende Höhe aufweist, eine Anzeige der Anzeigeeinrichtung einstellt, die vom Typ der Pipettenspitze abhängt.

The pipette according to the invention for use with a pipette tip comprises:

• a stick-shaped pipette housing,
• a pin at the lower end of the pipette housing for clamping a pipette tip with a collar having a plug-in opening at its upper end,
• a drive device comprising a drive element for displacing a displacement element for sucking liquid samples into the pipette tip and ejecting the samples from the pipette tip and a control element projecting from the pipette housing and displaceable relative to the pipette housing,
• a scanning device with a arranged next to the pin, when clamping a pipette tip on the pin from the collar in Longitudinal direction of the pin relative to the pipette housing displaceable sensing element and
• a mechanical indicator coupled to the scanner, the scanner being adapted to adjust a display of the type of display device as the pipette tips are clamped onto the pins, of different types and the collar has a height indicative of the type of pipette tip depends on the pipette tip.

On the pins of the same pipette pipette tips of different types can be clamped. Specifically, pipette tips of different types differ in one or more of the following features: nominal volume, shape, dimensions, material (eg, PP and / or PE), with or without coating, without or with surface treatment (eg, Perl-effect technology treatment for a better drainage of detergents containing liquids), tubes with or without inserted filter (filter tip), electrically insulating or electrically conductive, degree of purity (eg standard, sterile, protein-free, PCR-pure, biologically pure). Pipette tips of different types have different heights collar. Pipette tips of the same type have collars of the same height. The height of the collar is indicative of the type of pipette tip. The collar is the area at the top of the pipette tip that lifts this pipette tip up onto the spigot or into which the spike dips when the pipette tip is clamped onto the spigot. For clamping on the pin, the pipette tip on the inner circumference of the collar on a seating area. The sensing element is disposed adjacent the pin so that it is displaceable by the collar of a pipette tip when it is clamped onto the pin. In this case, the sensing element can be displaced by different height collar to varying degrees. But it can also be displaced by a collar of low height and displaceable by one (or more different high) collar of greater height. Depending on the Sensing element detected height of the collar, the scanning device, the display of the display device. The display includes, for example, a volume indication or an indication of another feature of the pipette tip. The user can use pipette tips of different types and directly read a display dependent on the type used. The display is automatically adjusted to the type of pipette tip used. The mechanical display device is a display device in which the different displays are mechanically adjusted. For setting the display, the display device is coupled to the scanner. By shifting the sensing element, the display is adjusted. Since the pipette does not require an electrical sensor to detect the pipette tip type, the risk of failure is reduced. It is also advantageous that the pipette can be executed purely mechanically without electronic components, so that the replacement of batteries or the recharging of batteries is eliminated and the possibilities for sterilization are extended.

According to one embodiment of the invention, the or the type dependent on the type of pipette tip display comprises a volume display. In this embodiment, the pipette tips of different types are pipette tips of different nominal volumes. The nominal volume is the volume of the pipette tip that can be used for pipetting. It is determined by the manufacturer and used to specify the measuring range. According to another embodiment, the height of the collar increases with the nominal volume of the pipette tip. According to another embodiment, the height of the collar falls with the nominal volume of the pipette tip. The volume display comprises at least one volume displayed by the display device. In the case of a variable pipette, this is the volume which can be metered with a plugged-on pipette tip having a specific nominal volume for a specific setting of the setting device and / or the nominal volume of the clamped-on pipette tip in the case of a variable pipette or fixed-volume pipette. As the nominal volume of the pipette tip increases, the volume indicator shifts to higher levels.

This automatically adjusts the volume display to the pipette tip used. The user can use pipette tips with different nominal volumes and read off the set pipetting volume and / or the nominal volume directly on the display device without any interpretation effort.

According to a further embodiment of the invention, the mechanical indicator displays a display dependent on a particular type of pipette tip when the sensing element is not displaced by the collar of a pipette tip attached to the pin. This is the case if no pipette tip is attached to the pin, or if a pipette tip with a short collar is attached to the pin which is not high enough to displace the sensing element. In either case, the indicator is set to display a display dependent on the type of pipette tip with the short collar. In this case, the sensing element can be held by a stop device in a starting position, from which it is not displaced when a pipette tip is clamped with the short collar on the pin. When a pipette tip with a long collar is pinched on the pin and high enough to displace the sensing element, the scanner sets a display that depends on the type of pipette tip attached to the long collar. In another embodiment, the display of the display device is always set when a pipette tip is fitted with a collar on the pin.

According to a further embodiment, the operating element is coupled to the drive element. According to a further embodiment, the operating element is firmly connected to the drive element or coupled via a transmission with this.

According to one embodiment of the invention, the pipette is an air cushion pipette for use with an air-cushion pipette tip. According to a further embodiment, a displacement device is arranged in the pipette housing, which is connected via a channel with a hole at the lower end of the pin. According to a further embodiment, the displacement device is a displacement chamber with a displaceable therein displaceable element. According to a further embodiment, the displacement device is a cylinder with a displaceably guided displaceable piston. According to a further embodiment, the drive element is a vertically displaceable in the pipette housing lifting rod, which is coupled at the lower end with the displacement element and at the upper end with the operating element. According to a further embodiment, the operating element is a control knob, which protrudes from the upper end of the pipette housing and is at least partially hineindrückbar in this.

In another embodiment, the pipette is a direct displacement pipette for use with a direct displacement pipette tip. According to a further embodiment, the drive element is a lifting rod guided in a vertical through-channel of the pin with a vertical bore at the lower end for clamping a piston rod projecting above from the integrated piston of a pipette tip. According to a further embodiment, the upper end of the lifting rod is coupled to the operating element. According to a further embodiment, the operating element is a control knob, which protrudes from the upper end of the pipette housing and at least partially hineinindrückbar in the pipette housing.

In another embodiment, the pipette is a fixed volume pipette. In the case of the fixed-volume pipette, the drive element can be moved back and forth by a defined measuring stroke. When used as a direct displacement pipette, the pipette can be used with direct displacement pipette tips, the different diameter of the tube and respective piston diameter adapted thereto have to pipette different volumes with the same measuring stroke. According to a further embodiment, the fixed-volume pipette has a display device which displays the nominal volume of a pipette tip clamped onto the projection.

According to another embodiment, the pipette is a variable pipette. This has an adjustable volume. According to another embodiment, the measuring stroke of the pipette is adjustable. According to a further embodiment, the pipette has a display device which displays the set measuring stroke. According to a further embodiment, the display device comprises a counter. According to a further embodiment, the variable pipette comprises a first adjusting element for adjusting the volume, which is arranged at the upper end of the pipette housing. According to a further embodiment, the first adjusting element is at the same time the operating element or an additional component. When designed as an additional component, the first adjusting element, for example, a rotatably mounted at the upper end of the pipette housing, sleeve-shaped adjustment knob, which surrounds a control knob, the control knob is at least partially hineindrückbar in the adjustment. According to a further embodiment, the variable pipette has a display device which displays the nominal volume of a pipette tip clamped on the projection. According to a further embodiment, the display device displays the nominal volume in addition to the set volume.

According to a further embodiment, the pipette has a piston spring which, after relieving the operating element, displaces the drive element upwards until it becomes effective (striking) of a first stop device. By operating the control element is against the action of the piston spring, the lifting rod down to the effective (beating) a second stop means displaced. According to another embodiment, the operating element is coupled via a gear with the drive element, which it allows to drive the drive element in different directions. According to a further embodiment, the drive device comprises a switching device, so that upon actuation of the control element first the drive element is displaced down to the effective of the second stop means down and further switching of the operating element, the switching device controls the displacement of the drive element in the opposite direction until the first stop means ,

According to another embodiment, the nominal volumes of the pipette tips or other type-characterizing features of the pipette tips that can be used with the pipette are indicated on the pipette and / or the pipette is provided with one or more markings on the nominal volume or other type indicate characteristics of the pipette tips that can be used with the pipette. According to another embodiment, the nominal volumes or other features characterizing the type are indicated on the pipette tips and / or the pipette tips are provided with one or more markings indicating the nominal volumes or other features characterizing the type.

According to a further embodiment, the scanning device comprises a slider which is displaceably guided on the pipette housing in the vertical direction and which has the scanning element at the lower slider end and whose upper slider end is coupled to the indicator device. In this embodiment, by clamping pipette tips with different heights collar on the pin, the lower slider end and thus the slider different far upward displaced. During the displacement, the upper slider end acts on the indicator and adjusts the volume indicator or other indicator dependent on the type of pipette tip.

According to a further embodiment, the slider carries on an outer side in the vertical direction one above the other different nominal volumes or various other the type of pipette tip characterizing information and has the pipette housing in the displacement range of the nominal volume or the other information of the slider on a window through which only from outside a full nominal volume or a complete other indication is visible on the slider. The nominal volume or other indication and the window are arranged so that for each plugged on the pin pipette the associated nominal volume or other information through the window is visible from the outside. This is controlled by the height of the collar of the pipette tip. This makes it easy for the user to know which type of pipette tip is attached.

According to a further embodiment, the pipette comprises a first stop device with a first stop element on the drive device and a second stop element on the pipette housing, which can be brought into abutment by displacement of the drive element in a first direction and a second stop means with a third stop element on the drive means and a fourth abutment element on the pipette housing which can be brought into contact with each other by displacing the drive element in a second direction, which is opposite to the first direction, in order to define a measuring stroke of the drive device together with the first stop device.

According to a further embodiment, the pipette comprises an adjusting device with a first adjusting element mounted on the pipette housing and a second adjusting element on the first or second stop device for adjusting the measuring stroke by adjusting the first adjusting element and a mechanical counter coupled to the setting device for indicating the setting of the adjusting device, wherein the scanning device with a mechanical range setting is coupled to the counter, whereby the clamping area of the counter adjusts the counting range of the counter when clamping pipette tips with different heights collar at the upper end on the pin, the area setting depending on the height of the collar.

According to a further embodiment, the range setting means comprises a mark arranged on the outside of the counter at the upper end of the slide, whereby when clamping pipette tips with different heights collar on the pins of the slider is different far upward displaced to the marker for displaying different counting areas laterally next to or between different positions of the counter. In this embodiment, the collar is positioned laterally adjacent to or between various locations of the counter by means of different height collars, i. laterally next to or behind the first digit before and / or laterally next to or before the first decimal place. Depending on the height of the collar, the marker can be set so that the counter directly displays the volume that can be pipetted with the pipette tip inserted at the given setting of the measuring stroke. As a result, the counting range of the counter can be shifted by one or more orders of magnitude. This allows the use of pipette tips whose nominal volumes differ one or more orders of magnitude from each other with the same pipette.

According to another embodiment, the range setting device comprises a switchable transmission, via which the counter is coupled to the setting device. By switching the shiftable transmission different gear ratios of the transmission can be selected. Depending on the height of the collar, the gear can be switched so that the counter displays the volume that can be pipetted at the given setting of the measuring stroke with the attached pipette tip.

According to a further embodiment, the sensing element is formed at the lower slide end of a slide sleeve, which is displaceable in the vertical direction along a housing shaft of the pipette housing, which has the pin at the lower end. The slide sleeve is guided particularly simple and precise on the housing shaft.

According to a further embodiment, the marking is a boundary of an aperture connected to the upper slider end. Through the aperture and a window of the pipette housing numbers from the counter are read from the outside. According to a further embodiment, the aperture is adjusted by the slider so that only the numbers are readable and / or framed by the aperture that indicate the set pipetting volume for the attached pipette tip, and / or the marker the first digit before and / or the highest Indicates decimal place. According to another embodiment, the positions of the counter or the counter rollers are arranged one above the other. According to another embodiment, the positions of the counter or the counter rollers are arranged side by side in the horizontal direction. In this embodiment, the marker is connected via a translation to the upper slider end, which converts a vertical displacement of the upper slider end into a horizontal displacement of the marker. According to a further embodiment, the marking is a ridge-like graduation in a blender frame of the diaphragm, which can be positioned behind the smallest digit of the counter and / or before the highest fractional part of the counter, which applies to a clamped pipette tip.

According to a further embodiment, the pipette comprises a first spring means with a first point of attack on the pipette housing and a second point of attack on the drive means to relocate at unloaded control element, the drive element in the first direction to the abutment of the first stop element on the second stop element.

According to a further embodiment, the first spring device is a first helical spring, which is supported at the lower end on a first spring bearing on the housing and at the upper end on a second spring bearing on the lifting rod. According to a further embodiment, the lifting rod is passed through the first coil spring.

According to a further embodiment, the operating element is at the same time the first adjusting element, wherein the operating element is rotatably mounted in the housing and is coupled via a first gear with the second adjusting element. According to a further embodiment, the first gear comprises a spindle nut, a threaded spindle with the spindle, vertically aligned, rotatably coupled to the control element threaded spindle with a longitudinal bore through which the lifting rod is passed, and a vertically aligned in the pipette housing linear guide on which the Spindle nut is guided. Here, the spindle nut is the second adjusting element, the lower end face of the spindle nut, the first stop element and a below the spindle nut radially projecting from the lifting rod bead the second stop element.

According to a further embodiment, the mechanical counter is coupled via a second gear with the rotatably mounted in the housing knob or control knob.

A further embodiment has a third stop means with a fifth stop element on the slide and a sixth stop element on the pipette housing and a second spring device with a third point of attack on the pipette housing and a fourth point of attack on the slider to load the slider down and the fifth stop element to the Apply sixth stop element if no pipette tip is attached to the pin. As a result, the slider is before attaching a pipette tip in one defined lower stop position held out of the slide out by attaching the pipette tip on the pin is displaced upwards.

According to a further embodiment, the second spring means is a second coil spring, which is held at the lower end to a third spring bearing on the slide and at the upper end to a fourth spring bearing on the housing. This embodiment is structurally simple and space-saving.

To clamp the piston rod in the bore of the lifting rod after lifting the pipette tip, the lifting rod by pushing the control knob until the effectiveness of the second stop means is displaced downwards. This can be done just prior to picking up the liquid in the pipette tip. To record, the user only has to release the control knob, since the first spring means displaces the lifting rod upwards. By re-pressing the control knob, the liquid is dispensed at the pipette tip.

The pipette tip can be detached manually from the pipette. According to another embodiment of the Direktverdrängerpipette ejection of the pipette tip with integrated piston by the operating element is made possible by the lifting rod having a lower Hubstangenteil, the vertical bore extends to the upper end of the lower Hubstangenteils, an upper Hubstangenteil engages in the vertical bore and in the upper Hubstangenteil a third spring means is integrated, which is designed so that by pressing the operating element down first, the upper Hubstangenteil concurrently with the lower Hubstangenteil downwardly displaced until the third stop member abuts the fourth stop member and when applying an increased pressure force on the control knob springs in the third spring means, so that the upper Hubstangenteil penetrates deeper into the lower Hubstangenteil, whereby the piston rod pushed out of the vertical bore and the pipette tip from the journal wreaths was pressed.

According to a further embodiment, the air cushion pipette on an ejector, which allows a release of the pipette tip by pressing the control element and / or an additional ejector button.

According to a further embodiment, the slide is connected at the top with a discharge button projecting from the upper end of the pipette housing, by the actuation of which the slide can be displaced downwards in order to strip a pipette tip from the pin with the lower slide end. In this way, by means of the slider, an ejector is realized with the pipette tips are detachable from the pin without touching it by hand.

To disengage the integrated piston from the lift rod, the withdrawal of the piston from the pipette tip may be limited by a stop so that the piston is separated from the lift rod by stripping off the pipette tips.

Another embodiment has a fourth stop device with a seventh stop element on the ejection button and an eighth stop element on the housing, which are designed to limit the displacement of the ejection button up and a transmission device between the ejection button and slide, which is formed at a displacement of the slider upwards, do not shift the ejection button upwards and, if the ejection button is displaced downwards, move the slide downwards. As a result, the starting position of the non-actuated ejection button is not changed by displacement of the slider upwards. As a result, the ejection button when attaching pipette tips with different heights collar does not take a different starting positions. Furthermore, the path of the ejection button for stripping a pipette tip from the pin can be kept constant independently of the used pipette tip. Compared to embodiments in which Release button and slide are rigidly interconnected, the ease of use and visual appearance is improved.

According to a further embodiment (i.) The transmission device is a fourth spring device which has a fifth point of attack on the ejection button and a sixth point of attack on the slider, whereby the fourth spring means is compressed at a displacement of the slider upwards and at displacement of the ejection button down first the fourth spring means is compressed and then the ejection button entrains the slide, or (ii.) The transmission means is a locking device disposed between the ejection button and slide locking device which allows a displacement of the slide relative to the ejection button upwards and a displacement of the push button relative to the slider down prevented. According to a preferred embodiment, the locking device is a Richtgesperre.

In both variants (i.) And (ii.), The displacement of the ejection button upwards is limited by the fourth stop device. Thus, this assumes a defined upper stop position, from which he is displaced downwards.

In the variant (i.) Abwurfknopf and discharge bar are not rigidly coupled together, but via a fourth spring means. The fourth spring device may in particular be a (screw) spring or a flexible element (eg an element of rubber, silicone or a thermoplastic elastomer). Release button and slide have only a small distance from each other, so that upon actuation of the ejection button first, the fourth spring means is compressed and this is applied to the slide of the ejection button on this slide down. On the other hand, an upward movement of the slide when attaching a pipette tip does not lead to a movement of the ejection button upwards, as the fourth stop means prevents this and only the fourth spring means is compressed.

In the variant (ii.) The ejection button and the slider are connected to each other via a locking device. The locking device has the function of preventing the movement of a component in a certain direction, while a movement in the opposite direction remains possible. The locking device comprises, for example, a gear mounted on the ejection button, which has a freewheel. The slider is provided on one side like a rack with a toothing. When attaching a pipette tip, the ejector is moved up and the gear rotates freely with. On actuation of the ejection button, however, the free rotation of the gear is stopped and the slider moves down so that the lower end of the slider strips the pipette tip from the pin.

Another embodiment, in addition to the slide on a guided vertically on the pipette housing discharge slide, which is connected at the upper end with the ejection button and the lower end is arranged radially offset to the lower end of the slide next to the pin, wherein (i.) The lower Ends of slide and discharge slide are arranged at the same height, so that by clamping a pipette tip with two circumferential steps at the top of the pin through the inner stage of the slide is displaced and the discharge slide is not displaced by the outer stage and by pressing the ejection button the (ii) the lower end of the slider is located lower than the lower end of the ejector slide, so that by clamping a pipette tip with a flat upper edge on the bottom of the ejector slide can be pressed against the outer stage of the pipette tip Tap the slide to the top n is displaced and the discharge slide is not displaced upward and pressed by pressing the ejection button of the discharge slide against the upper end of the pipette tip and the pipette tip from the pin is strippable.

In this embodiment, the range setting and the ejection of the pipette tip are achieved by a slide valve and a separate ejector slide. This may be, for example, an outer and an inner slide sleeve, wherein the inner slide sleeve is guided on a shaft of the pipette and the outer slide sleeve on the inner slide sleeve. While one pusher sleeve is displaced upwards when the pipette tip is attached and the range setting is shifted, the other pusher sleeve is not displaced. This sliding sleeve is used only when pressing the ejection button. This is achieved in variant (i.) By the fact that the pipette tip has two concentric circumferential steps at the top, with the further upwardly projecting stage actuates the range setting and hits the lower end of the ejection slide on the less far upstanding stage. In variant (ii.) This is achieved in that in the non-actuated state, the slide further down than the discharge slide, so that is displaced by attaching a pipette tip with a flat upper edge of the slide and not the discharge slide.

According to a further embodiment, the approach at a distance from its lower end on the outer circumference on a circumferential shoulder, so that a pipette tip with an upper edge of the collar or on the inner circumference of the collar radially inwardly projecting, circumferential inner stage until the inner stage of the Shoulder is clamped on the neck. This ensures that the approach always engages equally deep into the clamped pipette tip of the respective type. If the collar of the pipette tip above the inner stage has an extended portion and the approach above the shoulder is not extended according to the collar, the pipette tip can only be clamped with a seating area below the inner stage on the neck. Even if the pipette tip can be pushed onto the shoulder until the upper edge of the collar rests on the shoulder, it can only be clamped on the projection with a seating area below the upper edge of the collar. This will ensures that pipette tips of different types, which have different heights collar, are clamped equally tight on the approach. This is advantageous for the secure clamping of pipette tips on the approach and the release of the pipette tips from the approach without excessive force. In embodiments of the pipette tip family discussed below, in which the pipette tips are slidable onto the shoulder until the upper edge of the collar or an inner shoulder of the collar engages the shoulder, the upper edge of the collar or the inner step is referred to as the "ninth stop element".

According to another embodiment, the pipette is a single-channel pipette. A single-channel pipette has only a single approach at the bottom of the housing for clamping a pipette tip. According to another embodiment, the pipette is a multi-channel pipette. A multichannel pipette is a pipette having a plurality of parallel lugs at the bottom of the pipette housing for simultaneously clamping a plurality of pipette tips. In this embodiment, the scanning device may in particular comprise a scanning element, which is arranged next to only one or more pins.

Furthermore, the object is achieved by a pipette tip family having the features of claim 17. Advantageous embodiments of the pipette tip family are specified in subclaims.

The pipette tip family according to the invention comprises at least two pipette tips of different types, each pipette tip having a tip opening at the lower end, a plug-in collar having a pipette tip height at the upper end, and at the inner periphery of the collar a seating area for clamping to a pin having a certain contour of a pipette, wherein pipette tips of different types are clamped with its seating on the same pin so that they stand up with their collar at different levels on the pin.

The collar is the area at the top of the pipette tip that lifts this pipette tip up onto the spigot or into which the spike dips when the pipette tip is clamped onto the spigot. In this pipette tip family, differently sized collar pipette tips control a sensing element of a pipette scanner such that the scanner adjusts a pipette tip-type display of a pipette indicator. As a result, when clamping pipette tips of different types onto the hub, the display is set to indicate the type of pipette tip attached. The pipette tips of the pipette tip family may be air-bubble pipette tips or direct-displacement pipette tips. Direktverdränger pipette tips have inside a cylindrical piston raceway between the tip opening and Aufstecköffnung and an integrated piston, which is displaceable along the piston barrel.

Specifically, pipette tips of different types differ in one or more of the following features: nominal volume, shape, dimensions, material (eg, PP and / or PE), with or without coating, without or with surface treatment (eg, Perl-effect technology treatment for a better drainage of liquids containing detergents), tubes without inserted filter or with inserted filter (filter tip), electrically insulating or electrically conductive, degree of purity (eg standard, sterile, protein-free, PCR-pure, biologically pure).

According to another embodiment, the pipette tip family comprises at least two pipette tips with different nominal volume, wherein the pipette tips with different nominal volume can be clamped with its seating area on the same pin, so that they stand up with their collar different height on the pin. In this pipette tip family, pipette tips with differently high collar control one sensing element of a Scanning the pipette so that the scanning device sets or maintains the volume display of a display device of the pipette depending on the height of the collar. As a result, when clamping pipette tips of different nominal volumes onto the shoulder, the appropriate volume indicator will always be displayed.

According to one embodiment, the pipette tip family includes pipette tips whose nominal volumes differ by one or more orders of magnitude. These pipette tips can be used with a pipette with a mechanical counter to set a mark on the scanner adjacent one of the meter rollers. In this pipette tip family, the heights of the collars differ by a simple or integer multiple of the height of a counter roller.

According to another embodiment, the difference in height of the collars is the simple or integer multiple of the height of a register roller, which is in the range of 1 to 7 mm, in particular in the range of 3 to 5 mm, which is preferably 4.5 mm. In the areas mentioned, the numbers of the register wheels are easily visually detectable with a small volume of construction.

The pipette tips of the pipette tip family according to the invention have, in addition to the push-on opening on the inner circumference, a seating area with which they can be clamped onto the journal of a pipette. The seating area is adapted to the contour of at least part of the pin. For this purpose, the seating area can either have a contour that is complementary to the contour (eg a cylindrical or conical contour) of at least one part of the pin or have sealing and / or guide structures (eg sealing and / or guide beads) projecting on its inner circumference, which are adapted to the contour (eg a cylindrical or conical contour) of at least a part of the pin. The pipette tips with different nominal volumes are with their seating on the same pin clamped so that they stand up with their collar different height on the pin.

According to a further embodiment, the clamping on the approach of a pipette is determined by a ninth stop element, which limits the sliding of the pipette tip onto the pin of a pipette by abutment with the pipette. The ninth stop element is e.g. a radially inwardly projecting inner end of the pipette tip on the inner circumference of the pipette tip, which comes to rest on the lower end of the pin, or a downwardly tapered conical braking region of the pipette tip, which comes to rest at the lower end of the pin. In the foregoing manner, the ninth stop member may be formed on both an air cushion and a direct displacement pipette tip. In a Direktverdränger pipette tip according to another embodiment, the ninth stop element is an upper side or a circumferential, radially outwardly projecting shoulder of the piston or the piston rod, which comes to rest on the lifting rod of the pipette.

According to a further embodiment, the ninth stop element is an upper edge of the collar or a circumferential inside of the collar radially inwardly projecting circumferential inner level of the pipette tip, above which the collar has an extended portion, so that the pipette tip to the plant the upper edge of the collar or the inner stage with a arranged below the upper edge of the collar or the inner seating area is clamped onto a neck of a pipette until the upper edge of the collar or the inner stage rests against a shoulder of the approach. In this embodiment, it is ensured that pipette tips of a certain type can be pushed onto an extension at the same height. The upper edge of the collar can control the sensing element of a scanning device, regardless of whether the upper edge of the collar or the inner stage rests against the shoulder. According to a further embodiment, the pipette tips are formed so that the pipette tips with only one Sitting below the upper edge of the collar or below the inner stage on the approach are clamped and with the extended portion of the collar above the inner stage are not clamped on the approach. According to a further embodiment, the pipette tips are designed so that they can be clamped with their seating on a cylindrical or conical portion of a lug below a shoulder of the neck. According to a further embodiment, the pipette tips are designed such that they can not be clamped onto a cylindrical or conical section of the projection above the shoulder with an enlarged section of the collar above the inner step. According to another embodiment, the extended portion of the collar above the inner stage is formed so that there is a gap between the extended portion of the collar and an enlarged portion of the collar above the shoulder when the pipette tip is clamped onto the hub. In this way it can be achieved that pipette tips of different types can be firmly clamped onto the same attachment. As a result, a secure clamping and easy release of the pipette tip are promoted by the approach without excessive forces.

According to a further embodiment, the seating area extends to the upper edge of the collar with which the pipette tip can be clamped onto the projection until it rests against the shoulder. According to a further embodiment, the seating area extends to the inner level with which the pipette tip can be clamped onto the projection until it rests against the shoulder.

According to a further embodiment, the pipette tip family comprises a pipette tip which is designed to be pushed onto the shoulder on a shoulder until the upper edge of the collar abuts, and at least one pipette tip of different type which is formed until the inner stage abuts one another Shoulder on the approach to be postponed. According to another embodiment, the pipette tip family comprises at least two Pipette tips of different types, which are designed to be pushed onto an approach of a pipette until an internal stage on one shoulder.

In another embodiment, each pipette tip has two concentric circumferential steps at the top, one step further protruding with respect to the bottom syringe opening than the other step. These pipette tips are advantageously used for pipettes in which the ejection button, regardless of the height of the collar of the attached pipette tip maintains the same position when it is not operated.

According to another embodiment, the pipette tip family comprises pipette tips having at least two of the following nominal volumes: 10 μl, 25 μl, 100 μl, 250 μl or 1000 μl.

According to a further embodiment, the pipette tip family comprises pipette tips having the nominal volume of 10 μl, 100 μl and optionally 1,000 μl or 25 μl and 250 μl. In these embodiments, it is particularly advantageous that the mechanical display device can change the volume display for pipette tips with different nominal volumes by adjusting the marking to different decimal places.

Furthermore, the invention relates to a pipette system comprising a pipette according to one of claims 1 to 16 and at least one pipette tip from the pipette tip family according to one of claims 17 to 23. The pipette system has the advantages of the pipette according to one of claims 1 to 16 and the pipette tips of the pipette tip family according to any one of claims 17 to 23.

Fig. 1

eine Direktverdrängerpipette in nicht betätigtem Zustand in einem Vertikalschnitt;

Fig. 2

dieselbe Direktverdrängerpipette mit aufgeklemmter und mit der Antriebseinrichtung gekoppelter Pipettenspitze in einem Vertikalschnitt;

Fig. 3

dieselbe Direktverdrängerpipette beim Abwerfen einer Pipettenspitze in einem Vertikalschnitt;

Fig. 4

dieselbe Direktverdrängerpipette mit einer aufgesteckten 10 µl-Pipettenspitze ohne Gehäuse (Fig. 4a) und mit Gehäuse (Fig. 4b) jeweils in einer perspektivischen Seitenansicht und vergrößertes Detail von Fig. 4a (Fig. 4c);

Fig. 5

dieselbe Direktverdrängerpipette mit einer aufgesteckten 100 µl-Pipettenspitze ohne Gehäuse (Fig. 5a) und mit Gehäuse (Fig. 5b) jeweils in einer perspektivischen Seitenansicht und vergrößertes Detail von Fig. 3a (Fig. 5c);

Fig. 6-8

dieselbe Direktverdrängerpipette mit aufgesteckter Pipettenspitze mit einem Nennvolumen von 10 µl (Fig. 6), 100 µl (Fig. 7) und ohne aufgesteckte Pipettenspitze (Fig. 8), jeweils in einer Vorderansicht;

Fig. 9-10

Schaft derselben Direktverdrängerpipette mit aufgesteckter Pipettenspitze mit einem Nennvolumen von 10 µl (Fig. 9) und 100 µl (Fig. 10) in einem Vertikalschnitt;

Fig. 11

Übertragungseinrichtung mit Feder zwischen Abwurfknopf und Abwurfschieber einer Luftpolsterpipette in grobschematischer Darstellung;

Fig. 12

Übertragungseinrichtung mit Sperrvorrichtung zwischen Abwurfknopf und Schieber einer Luftpolsterpipette in grobschematischer Darstellung;

Fig. 13

vergrößertes Detail von Fig. 12;

Fig. 14

eine Luftpolsterpipette mit getrennter Abtasteinrichtung und Abwurfeinrichtung und Pipettenspitze mit Stufen am oberen Ende in einer grobschematischen Seitenansicht;

Fig. 15-17

eine Direktverdrängerpipette mit Bedienhebel und Umschalteinrichtung zum Verlagern des Kolbens in beiderlei Richtungen in Vorderansicht (Fig. 15), Seitenansicht (Fig. 16) und Perspektivansicht von vorn und von der Seite (Fig. 17).

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

Fig. 1

a Direktverdrängerpipette in the non-actuated state in a vertical section;

Fig. 2

the same Direktverdrängerpipette with clamped and coupled to the drive means pipette tip in a vertical section;

Fig. 3

the same Direktverdrängerpipette when ejecting a pipette tip in a vertical section;

Fig. 4

the same direct displacement pipette with an attached 10 μl pipette tip without housing ( Fig. 4a ) and with housing ( Fig. 4b ) each in a perspective side view and enlarged detail of Fig. 4a (Fig. 4c );

Fig. 5

the same direct displacement pipette with a plugged 100 μl pipette tip without housing ( Fig. 5a ) and with housing ( Fig. 5b ) each in a perspective side view and enlarged detail of Fig. 3a ( Fig. 5c );

Fig. 6-8

the same direct displacement pipette with attached pipette tip with a nominal volume of 10 μl ( Fig. 6 ), 100 μl ( Fig. 7 ) and without attached pipette tip ( Fig. 8 ), each in a front view;

Fig. 9-10

Shaft of the same direct displacement pipette with attached pipette tip with a nominal volume of 10 μl ( Fig. 9 ) and 100 μl ( Fig. 10 ) in a vertical section;

Fig. 11

Transmission device with spring between ejection button and discharge slide an air cushion pipette in a rough schematic representation;

Fig. 12

Transmission device with locking device between the ejection button and slide an air cushion pipette in a rough schematic representation;

Fig. 13

enlarged detail of Fig. 12 ;

Fig. 14

an air cushion pipette with separate scanning and ejector and pipette tip with steps at the top in a rough schematic side view;

Fig. 15-17

a Direktverdrängerpipette with control lever and switching device for moving the piston in both directions in front view ( Fig. 15 ), Side view ( Fig. 16 ) and perspective view from the front and from the side ( Fig. 17 ).

In the present application, the terms "top" and "bottom" and "vertical" and "horizontal" and related terms such as e.g. "Above" and "below" and "above each other" on a direct displacement pipette assembly where the pin is vertically aligned and located at the downwardly facing end of the pipette housing. With regard to the pipette tip, this information refers to a vertical alignment of the central axis of the pipette tip, wherein the tip opening is arranged at the bottom and the attachment opening at the top.

According to Fig. 1 For example, a pipette 1 embodied as a direct displacement pipette has a substantially stem-shaped pipette housing 2, the upper part of which is formed as a handle 3 and its lower part as a shaft 4. From the lower end of the shaft 4 is a downwardly tapered in stages pin 5. On the outer circumference of the pin runs a first shoulder 6 and about a second shoulder 7 to. From the lower end of the pin 5 extends vertically into the pipette housing 2 in a passage 8th

From the upper end of the pipette housing 2 is an operating element 9 in the form of a sleeve-shaped, closed at the top and open at the bottom control knob. Below the operating element 9, a first adjusting element 10 in the form of a sleeve-shaped adjusting knob of an adjusting device 11 for adjusting the Measuring strokes arranged at the upper end of the pipette housing 2. The operating element 9 can be moved almost completely vertically into the first adjusting element 10.

In the passage 8 of the pin 5 engages from above the lower end of a lifting rod 12 a. This extends in the pipette housing 2 upwards and is connected to the underside of the control element 9.

The lift rod 12 includes an upper lift rod member 13 and a lower lift rod member 14. The upper lift rod member 13 is inserted from above into a vertical first bore 15 which extends longitudinally through the entire lower lift rod member 14 so that the upper lift rod member 13 in the lower Hubstangenteil 14 is displaced.

A lower portion of a tubular cage 16 is fixed in an upper portion of a connecting member 17 in the form of a reducing sleeve (e.g., by screwing in). The lower end of the cage 16 rests against a first projection 18 of the connecting element 17 which revolves on the inner circumference. In the lower portion of the connecting member 17, the lower lifting rod member 14 is fixed (e.g., by press-fitting). The upper portion of the connecting element 17 has larger inner and outer diameter than the lower portion and in between, the connecting element 17 on the outer periphery of a third shoulder 19.

The cage 16 is bounded above by a radially inwardly projecting, circumferential second projection 20. The upper Hubstangenteil 13 is passed through the cage 16 and the connecting element 17. The upper Hubstangenteil 13 has a circumferential bead 21 which is arranged in the cage 16. Between the bead 21 and the first projection 18 sits a prestressed first coil spring 22 on the upper Hubstangenteil 13. This presses the bead 21 against the second projection 20th

The top of the cage 16 is a first stop element 23. In addition, a spindle nut 24 fixed in the pipette housing 2 is arranged. In the spindle nut 24 engages a threaded spindle 25 having a second bore 26 through which the upper Hubstangenteil 13 is passed. The lower end face of the threaded spindle 25 forms a second stop element 27. The spindle nut 24 and the threaded spindle 25 are part of a first gear for adjusting the vertical position of the second stop element 27th

The first adjusting element 10 is fixedly connected to an adjusting sleeve 28. This is rotatably coupled via a driving device 29 with axially extending grooves 30 on the inside of the adjusting sleeve 28 and in this, radially outwardly projecting wings 31 on the threaded spindle 25 and in the vertical direction relative to each other displaceable with the threaded spindle 25. As a result, by rotating the first adjusting element 10, the axial position of the second stop element 27 in the pipette housing 2 is adjustable, without displacing the first adjusting element 10 axially.

The first stop element 23 and the second stop element 27 together form a first stop device 32, which limits the displacement of the lifting rod 12 upwards.

The upper Hubstangenteil 13 is passed through the spindle nut 24 and fixedly connected to the operating element 9, that it is displaced vertically by pressing the operating element 9 down.

The adjusting sleeve 28 is coupled at its lower end via a pinion 33 with a mechanical display device in the form of a mechanical counter. Counting rollers 35 of the counter 34, which are arranged one above the other on a vertical axis of rotation, are visible from outside through a first window 36.1 in a vertical side surface of the pipette housing 2.

The lower end face of the connecting element 17 is a third stop element 37.

In the pipette housing 2, a pot-shaped fourth stop element 38 is held below the connecting element 17, which has a central through-hole 39 in its bottom 40, through which the lower Hubstangenteil 14 extends therethrough. The fourth stop element 38 is held by an engaging at its upper edge and supported in the pipette housing 2 compensating spring 41 via a circumferential on its outer circumference collar 42 to a fourth shoulder 43 in the pipette housing 2. The third stop element 37 and the fourth stop element 38 together form a second stop 44, which limits the displacement of the lower Hubstangenteils 14 down.

A first spring device 45 in the form of a conical spring has at the top of the bottom 40 a first point of attack in the pipette housing 2 and on the third shoulder 19 of the connecting element 17, a second point of attack to the unloaded control button 9 the cage 16 to stop the first stop means 32 after to shift up.

The lifting rod 12 and the control knob 9 are part of a drive means 46 for a piston.

According to Fig. 4 and 5 a scanning device 47 is mounted on the pipette housing 2. This has a sensing element 48, which is formed by the lower end of a slider 49. The slide 49 has at the bottom a guided on the shaft 4 slide sleeve 50 and above a shutter 51. The slide sleeve 50 and the aperture 51 are connected to each other via a rod 52. The rod 52 is fixed at the bottom in a laterally projecting from the sliding sleeve 50 projection 53. A bar-like division 54 the aperture 51 forms a marking 55, which is adjustable behind the lowest digit before and / or before the highest decimal place of the counter 34.

The aperture 51 is arranged on the inside of the pipette housing 2 outside the counter 34 so that the graduated line 54 is visible through the first window 36.1 of the pipette housing 2 from the outside, which is covered by a transparent disc.

At the upper end of the aperture 51 is a flag 56, on which several different nominal volume data 57, 58 are arranged one above the other. A nominal volume indication 57, 58 is visible from the outside through a second window 36. 2 of the pipetting housing 2, which is covered by a transparent pane.

The rod 52 of the slider 49 carries a radially projecting disk 59, which forms a fifth stop element 60.

The projection 53 is arranged through a shaft opening 61 with a shaft 62 arranged at the lower end of a laterally arranged on the pipette housing 2. Within the duct 62, the rod 52 is passed through a hole in a horizontal partition wall 63 of the pipette housing 2. The top of the partition 63 (in Fig. 4 additionally registered) is a sixth stop element 64 which limits the displacement of the slide 49 down by abutment of the fifth stop element 60. Fifth stop element 60 and sixth stop element 64 together form a third stop device 65.

A second spring means 66 in the form of a second helical spring 67 is supported at the top at a third point of attack on a holder 68 of the pipette housing 2 for the counter 34 and at the bottom at a fourth point of attack on a horizontal frame part 69 of the shutter 51. The second coil spring 67 is under Bias to hold the fifth stop member 60 in abutment with the sixth stop member 64.

A pipette tip 70 is shown in FIG Fig. 2 and 3 a cylindrical piston running area 71. At the lower end of the cylindrical Kolbenlaufbereiches 71 a conical initial section 72 is present. At the lower end of the initial portion 72, the tip opening 73 is centrally located.

The piston running region 71 is connected at the top to a conical transition region 74, which is adjoined by a cylindrical connection region 75. The cylindrical connection region 75 is connected to a collar 77 via an inner step 76. The collar 77 has an upwardly flared, slightly conical shape. On the inner circumference, it has a circumferential bead 78.

In the pipette tip 70, a piston 79 is arranged. This has a conical piston section 80 which can be inserted into the cylindrical piston running region 71. At the upper end, the piston section 80 is sealed off from the piston running region 71 via a sealing edge 81. At the bottom, the piston section 80 can be inserted into the conical initial section 72 of the pipette tip 70.

At the top, the piston portion 80 is connected to a conical connecting portion 82 which is insertable into the transition region 74. From the transition region 74, a short piston rod 83 projects upwards.

Pipette tips 70 of different nominal volumes have cylindrical piston running regions 71 and corresponding conical piston sections 80 with different cross sections. In addition, they differ in that the collar 77 has a different height with respect to the inner step 76.

At the upper end of the collar 77 is the insertion opening 84 of the pipette tip 70th

According to Fig. 2 and 4 to 7 a pipette 1 with the pin 5 is inserted into the insertion opening 84 of a pipette tip 70 with integrated piston 79. When attaching the pipette tip 70 on the pin 5 an inner stage 76 meets within the collar 77 (see. Fig. 9 ) or the upper edge of the collar 77 (see. Fig. 10 ) In both embodiments, the bead 78 under the first shoulder 6 under bias equally on the pin 5, so that the pipette tip 70 is securely clamped on the pin 5.

When the upper edge of the collar 77 hits the second shoulder 7, the slider 49 is not displaced and the display of the mechanical counter 34 remains unchanged. This is the case when plugging the 100 μl pipette tip into the Figures 2 . 5 . 7 and 10 is shown. The display is the same as in Fig. 8 showing the pipette without a pipette tip 70 attached. The graduation 54 indicates to the user the lowest decimal place or the highest decimal place.

When the inner step 76 strikes the second shoulder 7, the upper edge of the collar 77 protruding beyond the inner step 76 strikes the lower end of the slide 49 and displaces it upward against the action of the second helical spring 67. In this case, the aperture 51 is displaced, so that the graduated line 54 is pushed into a different position between two counter rollers 35 of the counter 34. This is the case when attaching the 10 .mu.l pipette tip 1, the in Fig. 4 . 6 and 9 is shown. The displacement of the scale 54 depends on the height of the collar 77. Depending on the nominal volume of the pipette tip 70, the graduated line 54 is thus set next to a specific point of the counter 34.

In addition, the user is the respective nominal volume indication 57, 58 is displayed to the attached pipette tip 70 in the second window 36.2.

Hereinafter, the pipetting with the pipette 1 will be explained.

The piston rod 83 is connected to the lifting rod 12 by pressing in the operating element 9 until the second stop device 44 is struck. Here, the piston rod 83 is clamped in the first bore 15 of the lifting rod 12. This is in Fig. 2 shown.

Thereafter, with the operating element 9 pressed in, the lower end of the pipette tip 70 can be immersed in a liquid in a vessel. When the operating element 9 is released, the lifting rod 12, and thus the piston 79, is displaced upward by the first spring device 45 until the first stop device 32 stops, and liquid is drawn into the pipette tip 70.

For the delivery of the recorded liquid volume, the lower end of the pipette tip 70 is inserted into a further vessel and the liquid is discharged by pressing the operating element 9 until it stops the second stop 44. In this case, the piston 79 is moved to its lowest position in the pipette tip 70 and displaces the liquid volume through the tip opening 73 into the vessel.

According to Fig. 3 For releasing the pipette tip 70, the operating element 9 is further pressed in, so that the first coil spring 22 springs in and the upper lifting rod part 13 pushes the piston rod 83 out of the first bore 15.

In a pipette 1 designed as an air cushion pipette, the lifting rod 12 is coupled to a piston which can be displaced by actuating the operating element 9 in a cylinder arranged in the pipette housing 2. The cylinder is connected via a channel with a hole in the lower end of the pin 5.

As in the case of the direct displacement pipette, the scanning device 47 can be designed such that it has a sensing element 48 at the lower end of a slide 49 which has a slide sleeve 50 guided on the shaft 4. The slider 49 is coupled at the top with a marker 55 for adjustment laterally adjacent to a register roller 35 of a counter 34 and optionally with a flag 56 for displaying various nominal volume data 57, 58 in a window.

The slider 49 can also be used to eject the pipette tip 70. For this purpose, the slider 49 according to Fig. 9 coupled with a discharge button 85 which protrudes outwardly from the pipette housing 2. In principle, the ejection button 85 may be rigidly connected to the slider 49. However, this has the consequence that the position of the ejection button 85 depends on the height of the collar 77 of the respectively attached pipette tip 70.

In the embodiments of Fig. 11 to 13 This is avoided in that a fourth stop device 86 is provided with a seventh stop element 87 on the ejection button 85 and an eighth stop element 88 on the pipette housing 2, which limit a displacement of the ejection button 85 upwards. In addition, between Abwurfknopf 85 and slide 49, a transmission device 89 is present, the ejection button 85 is not displaced upward upon displacement of the slide 49 upwards and relocated at a displacement of the ejection button 85 down the slide 49 with downward.

According to Fig. 11 The transmission device 89 comprises a fourth spring device 90 between the discharge button 85 and the rod 52 of the slide 49, which is designed as a third helical spring 91.

The fourth spring device 90 is under pretension, so that when the ejection button 85 is not pushed in, the fourth stop device 86 is active. When attaching a pipette tip 70, the slider 49 is displaced upward and compresses the fourth spring means 90. The ejection button 85 remains in its upper stop position. Upon actuation of the ejection button 85, the fourth spring device 90 is first compressed further. Thereafter, the ejection button 85 presses on the rod 52 of the slider 49, causing it the tape tip 70 from the pin 5 strips.

According to Fig. 12 and 13 the transmission device 89 comprises a blocking device 92 arranged between the ejection button 85 and the slide 49. This is a toothed wheel 93 which is rotatably mounted on the ejection button 85 and has a freewheel 94. The rod 52 has on one side a rack 95, which is in engagement with the gear 93.

When not actuated ejection button 85, the fourth stop means 86 is effective due to acting on this fifth spring means 96. When attaching a pipette tip 70, the slider 49 is displaced upward, wherein the gear 93 rotates freely. Only upon actuation of the ejection button 85, the free rotation of the gear 93 is stopped and the rod 52 moves down with. As a result, the slider 49 pushes the pipette tip 70 from the pin 5.

According to Fig. 14 a displacement of the ejection button 85 when attaching the pipette tip 70 is prevented by the fact that in addition to the slide 49, a discharge slide 97 is present. The slide 49 has at the lower end guided on the shaft inner slide sleeve 98 and the discharge slide 97 has at the lower end guided on the inner slide sleeve 98 outer slide sleeve 99th

The pipette tip 70 has at the upper edge two concentric circumferential steps 100, 101, wherein the inner step 100 protrudes further upward in the vertical direction than the outer step 101.

When attaching the pipette tip 70, the inner stage 100 actuates the slider 49, whereby the graduation 54 is set on the mechanical counter 34. The discharge slide 97 is not actuated by the outer stage 101. When pressing the ejection button 85, the lower end of the discharge slide 97 strikes the outer stage 101 and pushes the pipette tip 70 from the pin 5.

According to 15 to 17 has a pipette 1 designed as Direktverdrängerpipette a pipette housing 2 with a designed as a vertically swinging up and down lever 102 control element 9 on a vertical side surface and designed as a knob 103 first adjusting member 10 for adjusting a volume at the top. Below is on the pin 5 a Direktverdränger pipette tip 70 clamped.

By pressing one or more times the operating lever 102 down a set volume in the pipette tip 70 can be pulled up. In the pipette housing 2, a spring is arranged, which is stretched by pressing the operating lever 102 down and the operating lever 102 pivots after discharge upwards. The length of the movement of the operating lever 102 and / or the number of its operations depends on the set volume. Further, by single or multiple pivoting of the operating lever 102 down the liquid collected from the pipette tip 70 can be issued. The actuation or the number of actuations in turn depends on the set volume.

To control by pivoting the operating lever 102 down both the suction of the liquid in the pipette tip 70 and the ejection of the liquid from the pipette tip 70, the drive means of the pipette 1 has a switching device which the direction of displacement of the piston 79 by pressing of the operating lever 102 after sucking the set volume in the pipette tip 70 reverses. As a result, will be through more Operation of the operating lever 102 causes the ejection of the liquid absorbed from the pipette tip 70.

LIST OF REFERENCE NUMBERS

1

pipette

2

pipette housing

3

handle

4

shaft

5

spigot

6

first shoulder

7

second shoulder

8th

Through channel

9

operating element

10

first adjustment

11

adjustment

12

lifting rod

13

Upper lifting rod part

14

lower lifting rod part

15

first hole

16

Cage

17

connecting element

18

first advantage

19

third shoulder

20

second lead

21

bead

22

first coil spring

23

first stop element

24

spindle nut

25

screw

26

second hole

27

second stop element

28

adjusting

29

driving device

30

groove

31

wing

32

first stop device

33

pinion

34

mechanical counter

35

Zählwerkrolle

36.1

first window

36.2

second window

37

third stop element

38

fourth stop element

39

Through Hole

40

ground

41

balancing spring

42

Federation

43

fourth shoulder

44

second stop device

45

first spring device

46

driving means

47

scanning

48

scanning

49

pusher

50

sliding sleeve

51

cover

52

pole

53

projection

54

tick

55

mark

56

Banner, flag

57

Nominal flow statement

58

Nominal flow statement

59

disc

60

fifth stop element

61

shaft opening

62

shaft

63

partition wall

64

sixth stop element

65

third stop device

66

second spring device

67

second coil spring

68

bracket

69

frame part

70

pipette tip

71

Piston movement area

72

conical beginning section

73

tip opening

74

conical transition area

75

cylindrical connection area

76

indoor stage

77

collar

78

bead

79

piston

80

conical piston section

81

sealing edge

82

conical connecting section

83

piston rod

84

attachment opening

85

ejector button

86

fourth stop device

87

seventh stop element

88

eighth stop element

89

Übertragungsrinrichtung

90

fourth spring device

91

third coil spring

92

locking device

93

gear

94

freewheel

95

rack

96

fifth spring device

97

ejection slide

98

inner slide sleeve

99

outer sliding sleeve

100

inner stage

101

outer stage

102

operating lever

103

knob

Claims (24)

Includes pipette for use with a pipette tip A stalk-shaped pipette housing (2), A pin (5) at the lower end of the pipette housing (2) for clamping a pipette tip (70) with a collar (77) having a plug-in opening (84) at its upper end, A drive means (46) comprising a drive member (12) for displacing a displacing member (79) for sucking liquid samples into the pipette tip (70) and expelling the samples from the pipette tip (70) and protruding from the pipette housing (2) to the pipette housing displaceable operating element (9), • A scanning device (47) with a next to the pin (5) arranged when clamping a pipette tip (70) on the pin (5) from the collar (77) in the longitudinal direction of the pin (5) relative to the pipette housing displaceable sensing element (48) and A mechanical display device (34) coupled to the scanning device (47), wherein the scanning device (47) is designed such that when clamping pipette tips (70) on the journal (5) they are of different types and their collars (77 ) has a height indicative of the type of pipette tip (70) sets a display of the indicator (34) that depends on the type of pipette tip (70). A pipette according to claim 1, wherein the display dependent on the type of pipette tip (70) comprises or is a volume indicator. A pipette according to claim 1 or 2, wherein the scanning device (47) has a slide (49) displaceably guided in the vertical direction on the pipette housing (2), which has the scanning element (48) at the lower slide end and whose upper slide end is connected to the display device (34 ) is coupled. A pipette according to claim 2 or 3, wherein the slider (49) bears on a vertical outside of each other different nominal volumes (57, 58) or various other the type of pipette tip (70) characterizing statements and the pipette housing (2) in the displacement region of Nominal volume information or the other information of the slide (49) has a window (36) through which only a full nominal volume (57, 58) or a complete other indication on the slide (49) is visible from the outside. A pipette according to any one of claims 1 to 4, comprising A first stop device (32) with a first stop element (23) on the drive device (46) and a second stop element (27) on the pipette housing (2), which can be brought into abutment by displacement of the drive element (12) in a first direction , and A second stop means (44) having a third stop member (37) on the drive means and a fourth stop member on the pipette housing (2) which abut each other by displacing the drive member (12) in a second direction opposite to the first direction can be brought to define together with the first stop means (32) a measuring stroke of the drive means (46). A pipette according to claim 5, comprising An adjusting device (11) with a first adjusting element (10) mounted on the pipette housing (2) and a second adjusting element on the first or second stop device (32, 44) for adjusting the measuring stroke by adjusting the first adjusting element (10), and A mechanical counter (34) coupled to the setting device (11) for indicating the setting of the setting device (11), Wherein the scanning device (47) is coupled to a mechanical range setting device on the counter (34), whereby when clamping pipette tips (70) with different height collar (77) at the upper end on the pin (5), the area setting depending on the height of the collar (77) sets the counting range of the counter (34). A pipette according to claim 6, wherein the range setting means comprises a marker (55) located at the top of the slider at the outside of the counter (34), whereby when clamping pipette tips (70) with different heights (77) on the pins (5) the slides (49) is displaceable up to the top to position the marker (55) to indicate different counting areas laterally adjacent to or between different register rollers (35) of the counter (34). A pipette according to any one of claims 1 to 7, wherein the sensing element (48) is formed at the lower slide end of a slide sleeve (50) displaceable in the vertical direction along a shaft (4) of the pipette housing (2) Having pin (5). A pipette according to claim 7 or 8, wherein the mark is a ridge-like graduation (54) of an aperture (51) connected to the upper pusher end. A pipette according to any one of claims 1 to 9, comprising a first spring device (45) with a first point of attack on the pipette housing (2) and a second point of attack on the drive means (46) to the drive element (12) in unloaded operating element (9) first direction to the abutment of the first stop element (23) on the second stop element (27) to relocate. A pipette according to any one of claims 1 to 10, including a third stop means (65) having a fifth stop member (60) on the slider (49) and a sixth stop member (64) on the pipette body (2) and a second spring means (66) having a third one Engagement point on the pipette housing (2) and a fourth point of attack on the slide (49) to load the slider (49) down and apply the fifth stop element (60) to the sixth stop element (64), if no pipette tip (70) on the pin (5) is attached. Pipette according to one of Claims 1 to 11, in which the slide (49) is connected at the top to a discharge button (85) projecting from the upper end of the pipette housing (2), by the actuation of which the slide (49) is displaceable downwards a pipette tip (70) from the pin (5) strip the lower slide end. A pipette according to claim 12 including a fourth stop means (86) having a seventh stop member (87) on the ejection button (85) and an eighth tee (88) on the pipette housing (2) adapted to relocate the ejection button (85) above, and which comprises a transfer device (89) between Abwurfknopf (85) and slide (49) which is adapted to displace the ejection button (85) upwards in a displacement of the slide (49) and at a Shifting the ejection button (85) down the slide (49) with downward shift. The pipette of claim 13, (i) wherein the transfer means (89) is a fourth spring means (90) having a fifth engagement point on the ejection button (85) and a sixth point of engagement on the slider (49), whereby upon displacement of the slider (49) is compressed to the top of the fourth spring means (90) and upon displacement of the ejection button (85) down first the fourth spring means (90) is compressed and then the ejection button (85) takes the slide (49), or (ii. ) in which the transfer device (89) between a discharge button (85) and slide (49) arranged locking device (92) which allows a displacement of the slider (49) relative to the ejection button (85) upwards and a displacement of the ejection button (85 ) is prevented relative to the slider (49) down. Pipette according to one of claims 1 to 11, which in addition to the slide (49) in the vertical direction on the pipette housing (2) guided discharge slide (97) which is connected at the upper end with the ejection button (85) and the lower end radially to offset lower end of the slide (49) is arranged adjacent to the pin, (i.) The lower ends of slide (49) and discharge slide (97) are arranged at the same height, so when clamping a pipette tip (70) with two circumferential steps (100, 101) at the upper end on the pin (5) through the inner stage (100) of the slide (49) is displaceable and the discharge slide (97) by the outer stage (101) is not displaced and by pressing the ejection button ( 85), the lower end of the discharge slide (97) is pressed against the outer step (101) of the pipette tip (70) to strip it from the pin (5), or (ii.) The lower end of the slide (49) deeper than that lower end of the discharge slide (9 7) is arranged so that when clamping a pipette tip (70) with a flat upper edge on the pin (5) of the slide (49) is displaced upward and the discharge slide (97) is not displaced upward and by pressing the ejection button ( 85) of the discharge slide (97) against the upper end of the pipette tip (70) pressed and the pipette tip (70) from the approach (5) is strippable. Pipette according to one of claims 1 to 15, whose projection (5) at a distance from the lower end on the outer circumference has a circumferential shoulder (7), so that a pipette tip (70) with a on the inner circumference of the collar (77) radially inwardly projecting, circulating inner stage (76) until the installation of the inner stage (76) on the shoulder (7) can be pushed. A pipette tip family comprising at least two pipette tips (70) of different types, each pipette tip (70) having a top opening (73) at the bottom, a collar (77) having an attachment opening (84) with a height indicative of the type of pipette tip (70) upper end and on the inner circumference of the collar (77) has a seating area for clamping on a pin (5) with a certain contour of a pipette (1), wherein pipette tips (70) of different types with its seating on the same pin (5) can be clamped , so that they stand with their collar (77) at different heights on the pin (5). A pipette tip family comprising at least two pipette tips (70) having one or more of the following characteristics: nominal volume, shape, dimensions, material, with or without coating, with or without surface treatment, tubes with or without filters, electrically insulating or electrically conductive, degree of purity. A pipette tip family according to claim 17 or 18, wherein the height difference of the height at which the collar (77) of different nominal volume pipette tips (70) on the same pin (5) is high, is one or even a multiple of the height of a meter roller (35). of a mechanical counter (34). Pipette tip family according to one of claims 17 to 19, wherein the height difference is the single or integer multiple of 1 to 7 mm, preferably 3 to 5 mm, preferably 4.5 mm. A pipette tip family according to any one of claims 17 to 20, wherein the collar (77) above the seating area has an upper edge or peripheral inner step (76) projecting radially inwardly on the inner circumference, and the collar (77) above the inner step (76) extended section, so that the pipette tip (70) to the abutment of the upper edge or the inner stage (76) on a shoulder (7) of a lug (5) can be pushed onto this. The pipette tip family of any one of claims 17 to 21, wherein each pipette tip (70) has two concentric circumferential steps (100, 101) at the top, one step (100) projecting further upwardly of the bottom tip opening (73) than the other Stage (101). A pipette tip family according to any one of claims 17 to 22, including a cylindrical piston barrel portion (71) between tip aperture (73) and plug hole (84) and a piston (79) having a top end piston rod (83) for clamping into a hole of a lift rod (12 ) has a designed as direct displacement pipette pipette (1). A pipette system comprising a pipette according to one of claims 1 to 16 and at least one pipette tip (70) from the pipette tip family according to one of claims 17 to 23.

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