Pipette tip and method for manufacturing the pipette tip

Abstract

The pipette tip comprises a wall (W) defining an internal space (S), a first upper opening (O1) and a second lower opening (O2) disposed at the upper and lower ends of the internal space, respectively, a first compartment (1) adjacent to the upper opening (O1), a second compartment (2) adjacent to the first compartment, a third compartment (3) adjacent to the second compartment (2), a fourth compartment (4) adjacent to the third compartment, a fifth compartment (5) adjacent to the fourth compartment (4) and opening into the lower opening, and a first transition region ( The upper opening (O1) has a diameter (D1) greater than the diameter (D8) of the lower opening (O2), the internal space (S) has at least one section and / or transition region that is at least partially cylindrical and / or tapered from top to bottom, and the internal space (S) has at least one section and / or transition region that widens from top to bottom such that an undercut is formed.

Description

[Technical field]

[0001] The present application relates to disposable pipette tips, particularly plastic pipette tips, and to methods of manufacturing pipette tips. [Background technology]

[0002] Automated pipette machines are used to transfer liquids for various analytical applications. Disposable pipette tips are used in these machines. Disposable pipette tips are usually cone-shaped from top to bottom and may have specially shaped sections for gripping and sealing.

[0003] It may be desirable to grip the outside or inside of the wall of the pipette tip securely. For this purpose, a lockable or expandable gripping device may be used. The pipette tip may have a corresponding gripping surface shape on the outside or inside, designed to complement the contact cross-sectional shape of the gripping device and prevent the pipette tip from slipping off or being pulled away from the closed gripping device. For example, grooves or ridges may be provided in the upper region on the inside or outside of the wall of the pipette tip. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] US Patent Publication No. 2002094302 [Patent Document 2] U.S. Pat. No. 4,748,859 [Patent Document 3] German Patent No. 19917375 [Patent Document 4] European Patent Application Publication No. 3115110 Summary of the Invention [Problem to be solved by the invention]

[0005] The mandrel of the automated pipette tip, which penetrates into the internal space of the pipette tip, may be sealed, for example, by an O-ring, which may rest on a step formed inside the pipette tip, causing the internal space to taper.

[0006] Typically, the inner contour of a conventional pipette tip is cylindrical, conical, or tapered in cross section to facilitate easy manufacture in an injection molding process so that the pipette tip can be easily removed from the inner core of the injection mold. [Means for solving the problem]

[0007] Based on the above, it is an object of the present invention to provide a pipette tip and a method for manufacturing the same that ensures a secure grip on an automated pipette machine while at the same time providing a secure seal between the pipette tip and the mandrel of the automated pipette machine.

[0008] The above mentioned problem is solved by a pipette tip according to claim 1 and a method according to claim 18. The features of the dependent claims refer to preferred embodiments of the invention.

[0009] The object of the present invention is a (disposable) pipette tip comprising a wall defining an internal space, a first upper opening and a second lower opening respectively located at the upper and lower ends of the internal space, a first compartment adjacent to the upper opening, a second compartment adjacent to the first compartment, a third compartment adjacent to the second compartment, a fourth compartment adjacent to the third compartment, a fifth compartment adjacent to the fourth compartment and terminating in a lower opening, a first transition area between the first and second compartments, a second transition area between the second and third compartments, and a third transition area between the third and fourth compartments, these compartments and transition areas having an internal contour or internal shape or form according to the following description of the invention.

[0010] The term "top" ("upper") refers to the area of ​​the wall or interior space of the pipette tip closer to the first, upper opening through which the retaining / sealing mandrel of an automated pipette machine penetrates, intended to retain and seal the pipette tip. The term "bottom" ("lower") refers to the area of ​​the wall or interior space of the pipette tip closer to the second, lower opening, intended to aspirate or dispense dispensed fluid during operation. The upper opening is usually larger than the lower opening.

[0011] The direction "from top to bottom" means in the axial direction from the top opening to the bottom opening. "Axial" is a direction perpendicular to the plane defined by the top and / or bottom ends of the pipette tip. "Radial" means a direction parallel to the plane defined by the top and / or bottom ends of the pipette tip, i.e. perpendicular to the "axial" direction. A tapering or narrowing cross section from top to bottom means that the cross section closer to the first opening is larger than the cross section closer to the second opening. A widening or increase in cross section occurs when the cross section closer to the first opening is smaller than the cross section closer to the second opening. This applies to both the cross section of the pipette tip and the transition region.

[0012] The walls or sections of the interior space of the pipette tip extend axially and, optionally, radially as well. In some embodiments, the transition areas of the walls or interior spaces of the pipette tip may extend axially and / or radially. However, in other embodiments, they may be formed as a continuous transition that does not extend axially / radially, e.g., as an edge.

[0013] An undercut or flared section exists when there is a widening or increase in cross section (when looking at the interior space through the upper opening towards the lower opening), as described above. The undercut may be a continuous transition that may or may not extend axially. The pipette tip according to the invention comprises a wall defining an internal space, a first upper opening and a second lower opening respectively located at the upper and lower ends of the internal space, a first section adjacent to the upper opening, a second section adjacent to the first section, a third section adjacent to the second section, a fourth section adjacent to the third section, a fifth section adjacent to the fourth section and terminating in the lower opening, a first transition region between the first and second sections, a second transition region between the second and third sections, and a third transition region between the third and fourth sections, wherein the diameter of the upper opening is larger than the diameter of the lower opening, and the internal space has cylindrical sections and / or sections and / or transition regions tapering from top to bottom in at least some of the sections, and the internal space has at least one section and / or one transition region widening from top to bottom such that an undercut is formed.

[0014] In a preferred embodiment, the first section includes an upper diameter D1 corresponding to the diameter of the upper opening and an inwardly extending, bulging lower region having a diameter smaller than D1, the lower region of the first section transitioning into a first transition region having a diameter D2 larger than the diameter of the lower region of the first section such that the first transition region forms a first undercut.

[0015] In particular, the second section adjacent to the first transition region has a cylindrical and / or conical inner contour tapering from top to bottom, the inner space of the second section therefore being cylindrical or funnel-shaped.

[0016] A second transition region adjacent to the second section may have a conically tapered and / or radially inwardly extending step (having a radial surface), and a third section below and adjacent the second transition region.

[0017] In particular, the diameter D3 of the second section immediately above the second transition region is greater than the diameter D4 of the third section immediately below the second transition region.

[0018] The second transition region has, on a radial surface or a surface having a radially extending component, one or more axially or obliquely upwardly extending projections or teeth (having an axial component), which projections or teeth may extend circumferentially or be spaced apart from one another circumferentially.

[0019] The protrusions may have any shape. They may be manufactured as edge fillets, rounded hemispheres, square pyramids, etc. They may be provided as damping elements for the second transition region, for example if the second transition region is provided as a stop or seal. They may define, together with the wall of the pipette tip, an annular groove into which a sealing or damping element, for example an O-ring, can be inserted.

[0020] In a preferred embodiment, the third section has a cylindrical and / or conical inner contour extending from top to bottom.

[0021] The fourth section may have a cylindrical and / or conical inner contour that widens from top to bottom. If the contour widens, a second undercut is formed in the third transition region.

[0022] A third transition region between the third and fourth sections may have at least one inwardly extending protrusion such that a minimum diameter of the third transition region is smaller than a diameter D5 of the third section immediately above the third transition region and smaller than a diameter D6 of the fourth section immediately below the third transition region. The third transition region thus forms (possibly together with the fourth transition region) a second undercut.

[0023] In particular, a diameter D5 of the third section immediately above the third transition region is smaller than a diameter D6 of the fourth section immediately below the third transition region.

[0024] Alternatively, the diameter D5 of the third section directly above the third transition region may be larger than the diameter D6 of the fourth section directly below the third transition region. However, the minimum diameter of the third transition region may be smaller than the diameter D6 of the fourth section directly below the third transition region and / or smaller than the diameter D5 of the third section directly above the third transition region.

[0025] In particular, in a preferred embodiment of the present invention, the third section has an inner contour having at least one region that extends from top to bottom to form a third undercut.

[0026] The second section may have an inner contour having at least one region that extends from top to bottom.

[0027] The third transition region may have one or more protrusions, and the protrusions include a first side surface having a first radius (R1), a tip that protrudes radially toward the central axis of an internal space (S) having a second radius (R2), and a second side surface having a third radius (R3). The radii R1, R2, and R3 satisfy the following conditions: i.e., R1 = R2 = R3, or R1 = R2 < R3, or R1 = R3 > R2, or R2 = R3 > R1, or R1 < R2 < R3, or R1 > R2 < R3. When there are a plurality of protrusions, these radii may be different and satisfy different ones of the above conditions. The radii determine the steepness of the rise of the side surface of the protrusion, the shape of the peak protruding inward, and the steepness of the drop of the side surface. In short, the number and shape of the protrusion(s) determine the number and shape of the undercuts, and thus determine the force with which the pipette tip adheres to the molding core when the outer mold is removed, or the force required to pull the pipette tip out of the inner core. In the context of the present invention, it is preferable that a plurality of undercuts are provided in the inner region of the pipette tip, so that when the pipette tip is removed from the inner core, the pipette tip can be reliably adhered to the core without damaging the inner contour by forced demolding.

[0028] In particular, the pipette tip is preferably manufactured as a disposable product, integrally formed or as a single unit, preferably made of plastic.

[0029] The interior space may be cylindrically and / or conically tapered in the third section and conically tapered in the fourth section, so that the cross-sectional reduction in the fourth section is greater than the cross-sectional reduction in the third section, and therefore the third transition region is designed with an angular cross-section.

[0030] In particular, the third transition region may be continuous in the form of an edge or a curvature. The fourth section may serve as a contact surface for a sealing element of an automated dispenser.

[0031] The injection molding process according to the present invention for manufacturing a pipette tip as described above includes the steps of providing an injection molding cavity formed by an inner core and an outer sleeve and corresponding to the wall contour of the pipette tip, introducing liquid plastic into the cavity, solidifying the plastic, detaching the outer sleeve from the outer contour of the pipette tip while the pipette tip remains on the core, and withdrawing the pipette tip axially from the core.

[0032] In particular, the removal of the outer sleeve may involve a radial or radial component movement of the sleeve or a part of the sleeve, the solidified pipette tip according to the invention undergoing this step is reliably attached to the inner core of the injection molding tool due to the special inner contour of the wall, in particular due to the formation of one or more undercuts. [Brief description of the drawings]

[0033] Further features and advantages of the present invention will become apparent from the following description taken in conjunction with the drawings.

[0034] [Figure 1] 1 is a cross-sectional view of the basic structure of a pipette tip according to the present invention; [Diagram 2] FIG. 1 shows a first particular embodiment of the present invention. [Diagram 3] FIG. 2 shows a second particular embodiment of the present invention. [Figure 4]FIG. 3 shows a third specific embodiment of the present invention. [Diagram 5] FIG. 4 illustrates a fourth particular embodiment of the present invention. [Figure 6] FIG. 5 illustrates a fifth particular embodiment of the present invention. [Figure 7] FIG. 6 illustrates a sixth particular embodiment of the present invention. [Figure 8] FIG. 13 illustrates a seventh particular embodiment of the present invention. [Figure 9] FIG. 13 illustrates an eighth particular embodiment of the present invention. [Figure 10] FIG. 13 illustrates an eighth particular embodiment of the present invention. [Figure 11] FIG. 13 illustrates an eighth particular embodiment of the present invention. [Figure 12] FIG. 13 illustrates a ninth particular embodiment of the present invention. [Figure 13] FIG. 17 illustrates a tenth particular embodiment of the present invention. [Figure 14] FIG. 11 illustrates an eleventh particular embodiment of the present invention. [Figure 15] FIG. 12 illustrates a twelfth particular embodiment of the present invention. [Figure 16] FIG. 13 illustrates a thirteenth particular embodiment of the present invention. [Figure 17] FIG. 14 illustrates a fourteenth particular embodiment of the present invention. [Figure 18] FIG. 15 illustrates a fifteenth particular embodiment of the present invention. [Figure 19] FIG. 16 illustrates a sixteenth particular embodiment of the present invention. [Figure 20] FIG. 17 illustrates a seventeenth particular embodiment of the present invention. [Figure 21] FIG. 18 illustrates an eighteenth specific embodiment of the present invention. [Figure 22] FIG. 19 illustrates a nineteenth specific embodiment of the present invention. [Figure 23] FIG. 20 illustrates a twentieth specific embodiment of the present invention. [Figure 24] FIG. 21 illustrates a twenty-first particular embodiment of the present invention. [Diagram 25] FIG. 22 illustrates a twenty-second specific embodiment of the present invention. [Figure 26] FIG. 13 shows variations of the details of the twentieth and twenty-first embodiments of the present invention. [Figure 27] FIG. 13 shows further variations of details of the twentieth and twenty-first embodiments of the present invention. [Figure 28] FIG. 13 shows further variations of details of the twentieth and twenty-first embodiments of the present invention. [Figure 29] FIG. 23 illustrates a twenty-third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] FIG. 1 shows a cross-sectional view of the basic structure of a pipette tip P according to the present invention.

[0036] The pipette tip P has a first, upper (or proximal) opening O1 and a second, lower (or distal) opening O2. A wall W encloses an interior space S between the openings O1 and O2.

[0037] The upper opening O1 has a first diameter D1. Adjacent to the upper opening O1 is a first section 1 having a first inner contour. The upper end of the first section 1 corresponds to the diameter of the upper opening O1. The lower end of the first section 1 has a diameter D2.

[0038] The first section 1 is connected to a second section 2 having a second inner contour. The upper end of the second section 2 has a diameter D2. The lower end of the second section 2 has a diameter D3.

[0039] The second section 2 is connected to a third section 3 having a third inner contour. The upper end of the third section 3 has a diameter D4. The lower end of the third section 3 has a diameter D5.

[0040] The third section 3 is joined to a fourth section 4 having a fourth inner contour. The upper end of the fourth section 4 has a diameter D6. The lower end of the fourth section 4 has a diameter D7.

[0041] The fourth section 4 is connected to a fifth section 5 having a fifth inner contour. The upper end of the fifth section 5 has a diameter D7. The lower end of the fifth section 5 terminates in a second lower (distal) opening O2, the diameter of the lower end of the fifth section 5 corresponding to the diameter D8 of the lower opening O2.

[0042] The different sections may be directly adjacent to one another. This is particularly the case when the diameter of the lower end of a section corresponds to the diameter of the upper end of the following or adjacent section. Between each adjacent section a transition area U1, U2, U3 or U4 is formed. The transition area may not extend, i.e. it may be formed as a continuous transition between the respective sections 1 to 5. The transition area may have a steep slope or be formed as an edge. However, the transition area, i.e. its inner contour, may also extend in the axial and / or radial direction. This means that the inner contour of the transition area may be designed as a cylinder, a slope, a step, a taper (reduced cross-section of the inner contour) and / or a widening of the inner contour. However, the inner contour of the transition area may also have several steps or a combination of the above-mentioned inner contours.

[0043] Within the scope of the present disclosure, it is possible to combine all features of the embodiments described below, which in particular means that the above-mentioned transition areas or stops between the sections of the pipette tip are included within the scope of any combination of the present disclosure.

[0044] Particular examples of inner contours and transition regions are described with respect to the following specific embodiments. In each case, only the upper section of the pipette tip is shown. The fourth section 4 may have a generally cylindrical or frustoconical (i.e. tapered) shape, or a combination thereof. The fifth section 5 is frustoconical (i.e. tapered) and reaches the second opening O2.

[0045] FIG. 2 shows a first particular embodiment of the invention.

[0046] The first section 1 is designed as a bead projecting radially inwards. The second section 2 is designed (essentially) as a downwardly tapering frustoconical section. The transition area U1 (detail x) is a continuous transition area. The diameter D1 is larger than the diameter D2 in the transition area U1. The diameter D3 is smaller than the diameter D2.

[0047] The transition area U2 (detail y) is essentially a continuous transition area extending in the radial direction. In essence, the transition area U2 is designed as a step extending radially inwards, which step forms a stop. The step U2 has a continuous or intermittent protrusion A2 extending circumferentially inside the step, so that a groove N2 is formed between the lower end of the second section 2 and the protrusion A2. However, the transition area U2 may also be formed as an approximately flat step without a protrusion or protrusions A2.

[0048] The third section 3 has an inner contour in the shape of a downwardly flaring frustoconical section. The diameter D2 is greater than the diameter D3. The diameter D3 is greater than the diameter D4. The diameter D4 is smaller than the diameter D5.

[0049] The transition area U3 (detail z) is essentially a continuous transition area extending in the radial direction. Essentially, the transition area U3 is formed as a step extending radially inwards, the transition area to the lower end of the third section 3 being rounded and the transition area to the upper end of the fourth section 4 forming an edge.

[0050] The fourth section 4 has an inner contour in the shape of a cylindrical or slightly downwardly tapered frustoconical section. The diameter D5 is greater than the diameter D6. The diameter D6 is greater than or equal to the diameter D7. The diameter D7 is greater than the diameter D8 of the lower (second) opening O2.

[0051] In the following description of the variants, only the differences of each variant from the first specific embodiment or multiple specific embodiments described above will be described.

[0052] A second specific embodiment of the invention is shown in figure 3. In contrast to the first specific embodiment, the transition area U1 (detail x) extends in the axial direction. The transition area U1 is designed as a radial groove N1 extending in the circumferential direction.

[0053] Also, the transition area U3 (detail z) is designed differently: following the third section 3, it has a tapered inner contour in the form of a downwardly tapering frustoconical section. In the transition area to the fourth section 4, the transition area U3 has a radial groove N3 extending in the circumferential direction.

[0054] In this embodiment, the third section 3 is essentially cylindrical. The diameter D4 corresponds to the diameter D5.

[0055] 4 shows a third specific embodiment of the present invention. In contrast to the second specific embodiment, the transition region U3 (detail z) is formed in a stepped manner as a step extending radially inwards. The step U3 has a continuous or intermittent ridge A3 extending circumferentially on the inside of the step, so that a groove N3 extending circumferentially is formed between the lower end of the third section 3 and the ridge A3.

[0056] A fourth particular embodiment of the invention is shown in figure 5. The transition area U1 between the first section 1 and the second section 2 forms an undercut behind the bead of the first section 1, which transitions smoothly with the same diameter D2 as the second section 2. No groove is provided.

[0057] In contrast to the first particular embodiment, the third section 3 is connected to a transition area U3 (detail z) which has a tapered inner contour in the form of a downwardly tapering frustoconical section K3. In the transition area to the fourth section 4, the transition area U3 has a cylindrical section Z3 and a step S3 which extends inwards towards the fourth section 4.

[0058] Compartment 3 is essentially cylindrical.

[0059] A fifth specific embodiment of the invention is shown in Figure 6. Sections 1, 2 and transition areas U1, U2 correspond to the first and fourth embodiments, respectively. Section 3 is essentially cylindrical, but slightly concavely curved towards the outside. D4 is approximately the same size as D5 (detail z).

[0060] The transition area U3 (detail z) is designed as an inwardly tapered surface in the form of a frustoconical section. Section 4 is tapered conically.

[0061] A sixth particular embodiment of the invention is shown in Fig. 7. The sections 1, 2 and the transition areas U1, U2 correspond to the first embodiment. Section 3 is shorter than the previously described embodiments. Section 3 has the shape of a downwardly tapered frustoconical section. The transition area U3 has a projection A3 extending along the circumferential direction with an inner diameter DA3 smaller than the diameters D5 and D6. The fourth section 4 has, at least in its upper region, the shape of a tapered frustoconical section, the slope of which corresponds to that of the tapered frustoconical section of section 3. The relationship of the diameters D3 to D8 is D3>D4>D5>D6>D7>D8.

[0062] A seventh particular embodiment of the invention is shown in figure 8. The transition area U1 is designed similarly to the transition area U1 of the second embodiment, with the difference that the radius D2 of the adjacent second section 2 approximately corresponds to the radius D11 of the innermost point of the bead 1, and the second section 2 is essentially cylindrical (D2=D3).

[0063] The transition region U2 is in the form of two successive radial steps S21 and S22. The transition between steps 21 and 22 is an arc extending over approximately 90°. Section 3 is cylindrical (D3>D4=D5>D6).

[0064] The transition region U3 has a recess R3 (hidden when viewed from above) and a conical annular surface K3 immediately adjacent thereto, which extends obliquely inwards (as viewed from above) to the section 4. The diameter D6 is smaller than the diameter D5.

[0065] 9-11 show an eighth particular embodiment of the present invention.

[0066] In Fig. 11 the upper section of the pipette tip is shown. Section 1 and section 2 are cylindrical with the same diameter D2. The first transition region U1 is formed as an outwardly extending recessed groove. However, unlike the above-mentioned embodiment, the groove U1 is not formed continuously along the circumference with the same (axial) width B, as can be seen in Figs. 8 and 9, but the width varies periodically along the circumference between a minimum width (up to zero) and a maximum width B. The pipette tip has a similar structure with a discontinuous diameter along the circumference in the upper opening region O1 and in section 3.

[0067] The transition region U2 is designed as a radial step.

[0068] Section 3 has (when viewed from the top down) a conically inwardly extending region 31 and a cylindrical (or conically outwardly extending) region 32. The diameter of these regions, and in particular region 31, may vary along the circumferential direction by providing periodically arranged inwardly extending bulges or protrusions.

[0069] The transition region U3 has an inwardly tapering intra-conical contour (seen from above and below).

[0070] A ninth particular embodiment of the invention is shown in figure 12. The sections / transition regions 1, U1, 2, U2 correspond to the first embodiment. However, in the ninth embodiment, the third section 3 is cylindrical (D4=D5). It has radially inwardly projecting, axially spaced lips or circumferentially extending projections 30, 31, 32.

[0071] The transition region U3 is designed as a step that projects radially inwards.

[0072] A tenth particular embodiment of the invention is shown in figure 13. Regions 1 and U1 correspond approximately to the first embodiment. Section 2 is cylindrical, curved with an inwardly rounded bulge approximately in the middle. Transition region U2 is an inwardly projecting step with a rounded transition region to section 3. Section 3 is also cylindrical, curved with an inwardly rounded bulge approximately in the middle. Section 3 is rounded and transitions into transition region U3, which extends inwards and transitions via an edge into cylindrical section 4. The relationship D4=D5>D6 holds true.

[0073] An eleventh particular embodiment of the invention is shown in figure 14. Areas 1, U1 and 2 (detail x) correspond to the tenth embodiment.

[0074] The transition area U2 (detail y) is essentially designed as a step with a rounded transition area to the sections 2, 3. A projection A2 is formed in the middle of the radially inwardly projecting step surface, which projection A2 projects axially upwards and has a platform surface between its two lateral faces. A groove N2 is formed between the outer lateral face and the section 2. An annular step surface F2 is formed between the inner lateral face of the projection A2 and the section 3.

[0075] Section 3 and transition region U3 are curved. The inner contour of section 3 has (when viewed from top to bottom) a first curved line extending outwards and a second curved line extending inwards that transitions into section 4.

[0076] A twelfth particular embodiment of the invention is shown in Figure 15. This embodiment differs from the tenth embodiment in that a groove N2 is formed in the transition region U2, the groove N2 extends in the circumferential direction and is bounded on the inside by an annular axial projection A2 having a radially extending annular pedestal portion A2P.

[0077] The transition area U3 is designed as a step with a rounded transition area between section 3 and U3 and an edge between U3 and section 4.

[0078] A thirteenth particular embodiment of the invention is shown in figure 16. This embodiment corresponds substantially to the eleventh embodiment (figure 14) in the areas 1, U1 and 2 (detail x).

[0079] The transition area U2 (detail y) has a step S2 extending radially inwards from section 2. In the (radially) inner area of ​​the step S2, a quadrantal recess R2 is formed in cross section, inside which a sealing ring (O-ring OR) is located.

[0080] Section 3 has an inwardly extending bulge that transitions into transition region U3. The curvature of the bulge increases towards transition region U3. Transition region U3 (detail z) has an inwardly (possibly radially) projecting projection V3 and an adjacent annular groove N3. Transition region U3 transitions into section 4.

[0081] A fourteenth particular embodiment of the invention is shown in figure 17. This embodiment differs from the preceding embodiments mainly in that the transition area U2 is formed as a step and the transition area U3 (detail z) is formed as a series of smaller steps.

[0082] FIG. 18 illustrates a fifteenth particular embodiment of the present invention.

[0083] Sections 1, 2 and the transition region U1 can be designed as explained with reference to the above embodiments, for example section 1 can be designed as a bead and section 2 as a slightly downwardly tapered section.

[0084] The transition area U2 between compartments 2 and 3 is a special feature of this embodiment. In principle, the transition area is designed as a step S2. However, on the inner edge of the step, ridges K2 are arranged in a circumferentially continuous or discontinuous distribution, which ridges K2 extend axially upwards towards the first opening O1. The ridges K2 are arranged at a distance from one another. For example, they may be in the form of small pins or pyramids, be (hemi)spherical, e.g. Gaussian. The ridges K2 may, for example, perform a damping function when contacted by a plunger or mandrel (not shown) of an automatic dispenser, or may have a certain degree of elasticity so that an elastic reaction force acts on the plunger pressing against them.

[0085] Section 3 has an inwardly extending, rounded central region B3.

[0086] The transition region U3 is slightly tapered (reduced cross section). Alternatively, the regions 3, 4 may be formed without a reduction in cross section so that they are both cylindrical with the same diameter (D5=D6).

[0087] FIG. 19 shows a sixteenth particular embodiment of the present invention.

[0088] The sections 1, 2 and transition regions U1, U2 may be formed similarly to any one of the embodiments described above, however the configuration of these sections and regions may vary within the scope of the features described in connection with the present invention.

[0089] In this embodiment, the transition region U3 has annular projections or bulges V31, V32, V33 located between the sections 3 and 4 (which have the same diameter (D5=D6)) and extending inwards (radially or obliquely). The projections V31, V32, V33 are three projections in this embodiment, extending around the entire inner circumference, but with different cross sections. The size of the bulges increases towards the bottom (towards the opening O2). The upper bulge V31 is shorter in height (and therefore extends less inwards) and has a shorter axial length than the central bulge V32 below it. The central bulge V32 is shorter in height (and therefore extends less inwards) and has a shorter axial length than the lower bulge V33 below it. Thus, the height and axial length increase as one bulge is traced downwards.

[0090] The (inwardly protruding) projections V31, V32, V33 are shaped as (radial) ridges with an axially extending portion forming a steep front side, a flat or plateau-like portion having an axially aligned upper side, and an axially extending portion forming a flatter rear side.

[0091] A radially inwardly extending and rearwardly axially downwardly sloping bulge (e.g., in the form of a lip or rib) facilitates pulling of a seal on, for example, an automated pipetting machine mandrel that is in contact with the bulge, i.e., ensures ejection of the pipette tip by preventing the seal from binding.

[0092] In this embodiment, sections 3, 4 are cylindrical. The transition region U3 is also essentially cylindrical with three inwardly extending ring-shaped bulges V31, V32, V33.

[0093] FIG. 20 illustrates a seventeenth particular embodiment of the present invention.

[0094] The sections 1, 2 and the transition area U1 are designed similarly to the embodiment described above, however the configuration of these sections and areas may vary within the scope of the features described in connection with the present invention.

[0095] The transition region U2 between section 2 and section 3 is basically designed as a step S2 having a rounded transition region between S2 and section 3. On the step S2, a group of protrusions K21, K22, K23 are arranged continuously or discontinuously in the circumferential direction and extend axially upward / backward. The group of protrusions K21, K22, K23 are each arranged circularly in the circumferential direction of the step S2. Since the protrusion K21 is arranged on an annular line with a diameter DK21, the protrusion K22 is arranged on an annular line with a diameter DK22, and the protrusion K23 is arranged on an annular line with a diameter DK23, D3>DK21>DK22>DK23<D4. On the other hand, the axial extension (height with respect to the step surface) of the innermost protrusion K23 is larger than the axial extensions of the two outer protrusions K22, K21, which have approximately the same height but may have different heights. Alternatively, the protrusions K21, K22, and K23 may all have the same height. The number of the group of protrusions K21, K22, K23 may be more or less than 3.

[0096] The protrusions K21, K22, K23 belonging to the group are each arranged at intervals in the circumferential direction. The cross-sectional shape may be a small pin or pyramid shape and (semi) spherical shape such as a Gaussian curve. The protrusions K21, K22, K23 may, for example, provide a damping function or have a certain degree of elasticity so that a punch pressing them receives an elastic reaction force.

[0097] The transition region U3 is formed substantially in the same manner as in the above-described embodiment. The transition region U3 has annular protrusions or bulges V31, V32, V33 that extend inward (radially or obliquely) between section 3 and section 4, and these protrusions have the same diameter (D5 = D6). The protrusions V31, V32, V33 are, in this case, three protrusions that extend along the entire inner circumference. These cross-sections are essentially the same, that is, they have approximately the same size and shape. However, the number, size, and shape may be different.

[0098] The shape of the protrusions V31, V32, V33 (bulging inward) is a curved ridge having a front surface and a rear surface.

[0099] In this embodiment, sections 3 and 4 are cylindrical. The transition region U3 carrying three inwardly extending ring-shaped bulges V31, V32, V33 is also essentially cylindrical. A diameter D5 at the upper end of the transition region U3 may be smaller than or equal to a diameter D6 at the lower end of the transition region U3.

[0100] 21-23 show further embodiments of the present invention, some of which combine features of the above-mentioned embodiments and some of which introduce new features, any combination of the details specifically discussed is also intended to fall within the scope of the present disclosure.

[0101] Detail Y in Fig. 21 corresponds approximately to detail Y in Fig. 19. Section 3 is formed with an inwardly rounded bead B3 which transitions continuously at its lower end into section 4 via a transition region U3. Section 4 may be a (tapering) cone or cylinder. Therefore "D5 is less than or equal to D6" holds true.

[0102] Detail Z of Figure 22 is substantially similar to the corresponding detail of the embodiment shown in Figure 20, except for the fact that in the embodiment shown in Figure 22 the radial heights of the protrusions V31, V32, V33 are different. Further properties of detail Y will be described in relation to Figure 20. It is particularly noted that the number of protrusions may be reduced to one or further protrusions may be added.

[0103] The embodiment of Fig. 23 corresponds to the embodiment of Fig. 22 except in the area of ​​detail Z. In Fig. 23, only one radial projection V31 is provided and is located between the cylindrical section 3 and the conical section 4, so that the diameters of the area located directly at the upper end of the projection V31 and the area located at the lower end of the projection V31 are approximately equal, or the diameter D6 of the lower end of the projection V31 of section 4 is larger than the diameter D5 of the upper end of the projection V31 of section 3.

[0104] Figure 24 shows the 21st specific embodiment of the present invention. Here, a conical section 2 (D2 < D3) that expands downward (towards the second opening O2), a stepped transition region U2 having a flat step surface, and a cylindrical or downward-expanding conical section 3 are provided (D3 > D4, D4 = D5 or D4 < D5). Section 4 is also a cylindrical or downward-expanding conical section (D6 = D7 or D6 < D7).

[0105] The transition region U3 has a low, inwardly extending protrusion that is continuous in the circumferential direction. The diameter DV is smaller than D5 and D6. It is possible that D5 < D6 holds.

[0106] In the example of this embodiment, the transition region U4 between the fourth section 4 and the fifth section 5 is specially designed. The transition region U4 has a radially extending step that extends inward and a conical section that transitions to the fifth section 5 adjacent to the inner edge of the step. This embodiment is useful for pipette tips with a small filling volume.

[0107] Figure 25 shows the 22nd specific embodiment of the present invention. This embodiment has a first section 1 and a second section 2 (D2 < D3) that expand conically (in the direction of the second opening O2). The transition region U2 corresponds to that in Figure 24. In the transition region U3, a third section 3 that is cylindrical (D4 = D5) in this embodiment is adjacent. The transition region U3 between the third section 3 and the fourth section 4 is continuous. The transition region U3 is an edge. The fourth section 4 is designed as a tapered cone and is directly adjacent to the third section 3. A similarly conical tapered section 5 is directly and continuously connected to the lower end of the third section, that is, the transition region U4 between the fourth section 4 and the fifth section 5. The cone of the fifth section is flatter than that of the fifth section.

[0108] Figure 26 shows different deformation examples of the radii R1, R2, and R3 of the protrusion V31 as shown in, for example, Figures 22 and 23. In Figures 26 a. to f., since the third section 3 and the fourth section 4 are each cylindrical, D5 = D6 or D5 < D6 holds for the diameters D5 and D6 at the upper end (third section) and the lower end (fourth section) of the protrusion V31.

[0109] Figures 27 and 28 show a variant similar to Figure 26, with the difference that in Figure 27 the fourth section 4 is conically tapered at the lower end of the projection V31. However, it may also be designed to be conically widened. In Figure 28 the third section 3 is tapered at the upper end of the projection V31. However, it may also be designed to be conically widened. The combination of conical and cylindrical sections 3, 4 and the conditions of the radii R1, R2, R3 of the projection V31 may be combined in any desired way.

[0110] FIG. 29 shows a further embodiment of the invention, which corresponds closely to the first embodiment and will not be described in detail again.

[0111] Unlike the first embodiment, the pipette tip P has a third transition region U3, the cross section of which may correspond to the embodiment shown in Figures 26 to 28. In particular, the diameter D6 directly below the third transition region U3 is larger than the diameter D5 directly above the third transition region U3.

[0112] The second section 2 is conically flared from top to bottom, with D2 being smaller than D3, and the third section 3 is essentially cylindrical with a diameter D5.

Claims

1. A wall (W) defining an interior space (S); a first upper opening (O1) and a second lower opening (O2) respectively disposed at the upper and lower ends of the internal space; a first compartment (1) adjacent to said upper opening (O1); a second compartment (2) adjacent to the first compartment; a third compartment (3) adjacent to the second compartment (2); a fourth compartment (4) adjacent to the third compartment; a fifth compartment (5) adjacent to the fourth compartment (4) and terminating at the lower opening; a first transition area (U1) between the first section (1) and the second section (2); a second transition region (U2) between the second section (2) and the third section (3); a third transition region (U3) between the third section (3) and the fourth section (4); Including, The diameter (D1) of the upper opening (O1) is larger than the diameter (D8) of the lower opening (O2), The internal space (S) has at least a cylindrical section and / or a section tapering from top to bottom and / or a transition area, The internal space (S) has at least one compartment and / or transition area extending from top to bottom so that an undercut is formed, Pipette tips.

2. 2. The pipette tip of claim 1, wherein the first section (1) has an upper diameter D1 corresponding to the diameter of the upper opening (O1) and a rounded, inwardly extending lower region having a diameter smaller than D1, and wherein the lower region of the first section (1) transitions into the first transition region (U1) having a diameter D2 larger than the diameter of the lower region of the first section (1), thereby forming a first undercut.

3. 2. The pipette tip according to claim 1, wherein the second section (2) adjacent to the first transition region (U1) has a cylindrical and / or conical inner contour tapering from top to bottom.

4. 2. The pipette tip according to claim 1, wherein the second transition region (U2) adjacent to the second section (2) is conically tapered and / or has a step extending radially inward.

5. 2. The pipette tip of claim 1, wherein a diameter D3 of the second section (2) immediately above the second transition area is greater than a diameter D4 of the third section (U2) immediately below the second transition area.

6. 2. The pipette tip of claim 1, wherein the second transition region (U2) has one or more protrusions or teeth that extend axially upward or have an axially extending component, and the protrusions or teeth extend circumferentially or are spaced apart from one another circumferentially.

7. 2. The pipette tip according to claim 1, wherein the third section (3) has an inner contour that is cylindrical and / or conically widening from top to bottom.

8. 2. The pipette tip according to claim 1, wherein the fourth section (4) has an inner contour that is cylindrical and / or conically widening from top to bottom.

9. 2. The pipette tip of claim 1, wherein the third transition region (U3) between the third section (3) and the fourth section (U4) has at least one inwardly extending protrusion, and the minimum diameter of the third transition region (U3) is smaller than the diameter D5 of the third section (3) immediately above the third transition region (U3) and smaller than the diameter D6 of the fourth section (4) immediately below the third transition region (U3).

10. 2. The pipette tip of claim 1, wherein a diameter D5 of the third section (3) immediately above the third transition region (U3) is smaller than a diameter D6 of the fourth section (4) immediately below the third transition region (U3).

11. 2. The pipette tip of claim 1, wherein a diameter D5 of the third section (3) immediately above the third transition region (U3) is greater than a diameter D6 of the fourth section (4) immediately below the third transition region (U3).

12. 2. The pipette tip of claim 1, wherein the third section (3) has an inner contour with at least one area that extends from top to bottom and forms a third undercut.

13. 2. The pipette tip of claim 1, wherein the second section (2) has an inner contour with at least one region extending from top to bottom.

14. 2. The pipette tip of claim 1, wherein the third transition region includes one or more protrusions (V31, V32, V33), each of the protrusions having a first side surface with a first radius (R1), a tip surface protruding radially toward the central axis of the internal space (S) with a second radius (R2), and a second side surface with a third radius (R3), and the radii R1, R2, R3 satisfy the conditions R1 = R2 = R3, or R1 = R2 < R3, or R1 = R3 > R2, or R2 = R3 > R1, or R1 < R2 < R3, or R1 > R2 < R3.

15. The pipette tip of claim 1 , wherein the pipette tip is integrally manufactured from plastic.

16. 2. The pipette tip of claim 1, wherein the internal space (S) is cylindrical and / or conically tapered in the third section (3) and conically tapered in the fourth section (4), the cross-sectional reduction of the fourth section (4) being greater than the cross-sectional reduction of the third section (3), and the third transition region (U3) being formed as a corner.

17. 17. The pipette tip according to claim 16, wherein the third transition area (U3) is formed continuously in the form of an edge or a curve.

18. 2. An injection molding process for manufacturing a pipette tip according to claim 1, comprising the steps of: providing an injection molding cavity formed by an inner core and an outer sleeve and corresponding to the wall contour of the pipette tip; introducing liquid plastic into the cavity; solidifying the plastic; removing the outer sleeve from the outer contour of the pipette tip while the pipette tip remains on the inner core; and removing the pipette tip axially from the inner core.

19. 20. The injection molding process of claim 18, wherein removing the outer sleeve comprises moving the outer sleeve or a part of the outer sleeve radially or in a direction having a radial component.

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