Spacer and assembly

Abstract

The utility model discloses a spacer, application thereof and an assembly. A frame-shaped rectangular (34) spacer is used for a pipette tip carrier (1), the rectangular spacer being configured to be stacked on top of another spacer, thereby providing a vertical space (58) between the spacers for the carrier. The spacer (34) comprises a horizontal base surface (35); a peripheral side wall (36) standing substantially perpendicular to the base surface (35) and providing two longitudinal sides (37) and two lateral sides (38) connected to the base surface. The peripheral side wall (36) includes an upper surface (39) on an upper edge (40) of the side wall (36) and a lower surface (41) on a lower edge (42) of the side wall, and the upper surface of the peripheral side wall is configured to support a pipette tip carrier (1). The spacers include a load transfer element (43) configured to transfer a vertical load directly from one spacer to the underlying spacer.

Description

TECHNICAL FIELD

[0001] The invention relates to a frame-shaped substantially rectangular spacer for a rectangular pipette tip carrier, the spacer being configured to be stacked on top of another spacer, thereby providing vertical space between the spacers for pipette tip carriers. An assembly comprising a stack of at least two spacers, wherein a pipette tip carrier is positioned between two spacers, and the use of a spacer for creating an alternating stack of spacers and pipette tip carriers. BACKGROUND

[0002] In analytical, biological or pharmaceutical laboratories, pipettes are commonly used to receive and dispense small volumes of liquids. Automated liquid handling platforms are often used for this purpose, which are capable of aspirating and / or dispensing liquid volumes with high precision for liquids and samples and still high throughput rates. Such liquid handling platforms usually comprise a pipetting robot, which is equipped with disposable or single-use pipette tips to avoid contamination between handling liquids or sample liquids. Liquid handling platforms are often equipped with such disposable pipette tips, i.e. a carrier plate or carrier disk or even a stack of such carrier plates equipped with pipette tips is provided. Such carrier plates usually comprise an array of pipette tips arranged in a standardized matrix, so that the pipetting head of the pipetting robot can collect one or more of these pipette tips from a known position. The multi-channel pipetting head of the pipetting robot can collect one or more rows of pipettes or pipette arrays from the carrier plate by coupling each pipetting head to a pipette in the carrier. Pushing the pipetting head onto the pipette tips thereby exerts a vertical load onto the pipette carrier for elastically deforming the collar of the pipette tip or for elastically deforming a rubber seal on the pipetting head. The frictional fit engagement between the pipetting head and the collar of the pipette facilitates the pick-up of the pipette. The pipettes used by the robot to aspirate and dispense liquids are discarded after use, which leads to an increased need for disposable pipette tips that need to be stored within the pipetting robot. Space-saving solutions for storing disposable tips have been developed, for example by stacking multiple pipette tip carriers using spacers.

[0003] Carrying plates for disposable pipette tips and stacks of such carrying plates with inserted pipette tips for storing the tips are known from the prior art. EP 2210668 A2 discloses a storage system comprising a frame-shaped rectangular box and a rectangular pipette carrying plate having a plurality of holes for insertion of pipette tips arranged as a matrix. The pipette carrying plate can be placed on top of the rectangular box so that the space in the box can be used for pipette tips extending through the holes of the carrying plate. Spacers for providing an alternating stack comprising a plurality of pipette carrying plates each separated by a spacer are disclosed. The spacer comprises a rectangular frame surrounding a plate having channels arranged according to the same pattern as the holes in the pipette carrying plates so that pipette tips inserted into the carrier are guided through the channels of the spacer. The end of the pipette tip engaging the carrier fits into an opening of a pipette provided on the underlying carrier separated by the spacer. Using a plurality of carrying plates and a plurality of spacers results in a space-saving nesting of pipette tips whereby, for example, during collection of the pipette tips by a pipetting robot, the vertical load is repeatedly transferred from the carrier to the spacer and finally via the rectangular box to the worktable of the pipetting robot. The spacer and the carrier need a certain wall thickness and mechanical strength to absorb the vertical load.

[0004] EP 2848308 B1 discloses a rectangular spacer for stacking rectangular pipette tip carriers on top of each other. The spacer is clamped between two carriers and the vertical load is transferred from the carriers to the spacer in an alternating manner, for example, during picking up of the pipettes by a robot. Each spacer comprises two elastic elements near each corner which can be deflected by guiding surfaces of the underlying pipette carrier when the spacer is placed on the underlying carrier. The elastic elements are intended to reduce the horizontal play within the stack of a plurality of carriers and spacers. During picking up of the pipettes, the vertical load is transferred from the edges of the carriers to the spacers which requires a rigid construction of the carriers and the spacers.

[0005] EP 4190452 A1 discloses a rectangular spacer for releasably stacking rectangular pipette tip carriers. The spacer is clamped between two carriers and the vertical load is transferred from the carriers to the spacer in an alternating manner. Each spacer comprises an elastic element near each corner for reducing the horizontal play within the stack of a plurality of carriers and spacers. SUMMARY

[0006] The alternating load transfer from the pipette carriers to the spacers requires that both the spacers and the pipette carriers need to be manufactured with low dimensional tolerances to reduce the superposition of a plurality of tolerances which can affect the effective transfer of the vertical load. Furthermore, the vertical load is transferred to the spacers only via the edges of the carriers so that the carriers need to have a rigid and material demanding construction.

[0007] It is an object of the present invention to overcome the drawbacks of the prior art and to provide a spacer for a pipette tip carrier stacked on top of each other, which provides improved stability of the carrier stack avoiding the superposition of multiple dimensional tolerances. It is a further object to provide an assembly of pipette tip carriers and spacers with efficient spacer-to-spacer load transfer, which requires less material or reduces the carbon footprint of the assembly.

[0008] These objects are solved by a spacer for rectangular pipette tip carriers and being frame-shaped substantially rectangular and configured to be stacked on top of each other, thereby providing vertical space for the pipette tip carriers between the spacers, wherein the spacer comprises:

[0009] a horizontal base surface,

[0010] a peripheral sidewall standing substantially perpendicular to the base surface, the peripheral sidewall providing two longitudinal sides and two lateral sides, wherein each longitudinal side and lateral side comprises an inner side connected to the base surface,

[0011] the peripheral sidewall comprises an upper surface arranged at an upper rim of the peripheral sidewall and a lower surface arranged at a lower rim of the peripheral sidewall, wherein the upper surface and the lower surface extend substantially horizontally and the upper surface of the peripheral sidewall is configured to support the pipette tip carrier,

[0012] wherein the spacer comprises a load transfer element configured to directly transfer a vertical load from one spacer to an underlying spacer.

[0013] The first aspect relates to a frame-shaped substantially rectangular spacer for a rectangular pipette tip carrier, the spacer being configured to be stacked on top of another spacer, thereby providing vertical space for pipette tip carriers between the spacers. Alternatively, the spacer can be stacked on top of a pipette tip box to be placed on a worktable of a pipetting robot. The spacer comprises a horizontal base surface connected to a peripheral sidewall which stands substantially perpendicular to the base surface and provides two longitudinal sides and two lateral sides. Each longitudinal side and each lateral side comprises an inner side or inner surface connected to the base surface. The peripheral sidewall comprises an upper surface arranged on an upper edge of the peripheral sidewall and a lower surface arranged on a lower edge of the peripheral sidewall. The upper surface and the lower surface or the upper edge and the lower edge extend substantially horizontally and are preferably arranged parallel to each other. At least a portion of the upper surface or the upper edge of the peripheral sidewall is configured to support a pipette tip carrier. The spacer comprises a load transfer element configured to transfer a vertical load from one spacer directly to an underlying spacer. The vertical load can be applied to a pipette tip carrier positioned on the upper edge of a top spacer. The vertical load in a stack of alternating spacers and pipette tip carriers is then transferred from spacer to spacer without having to transfer the vertical load to one of the pipette tip carriers positioned between the spacers. Transferring the load from spacer to spacer via the load transfer element without vertical force being transferred to the pipette tip carriers means that the accumulation of dimensional tolerances in a stack of multiple spacers and carriers is governed by the manufacturing tolerances of the spacers, as the pipette tip carriers are not vertically loaded. Therefore, the manufacturing tolerances of the spacers need to be tighter or, in other words, the dimensional accuracy of the pipette tip carriers can be less demanding compared to a stack of alternating spacers and carriers with spacer-to-carrier loading. The mechanical strength of the pipette tip carriers can also be adjusted according to the spacer-to-spacer loading principle, such that the wall thickness can be reduced, such that the use of e.g. polymeric materials is reduced, thereby reducing the carbon footprint of the carriers and, thus, the stack of carriers and spacers.

[0014] The load transfer element on each spacer can comprise a protrusion extending vertically from the upper surface of the spacer, for example extending vertically from each corner of the spacer. The spacer can comprise at least one protrusion extending vertically from the top surface, preferably two protrusions, more preferably three protrusions, and most preferably four protrusions. The protrusions can be located near or at the corners of a rectangular spacer. The protrusions can be oriented perpendicular to the horizontal base surface, or can be angled relative to the horizontal base surface. The protrusions can all be oriented parallel to one another, or one or more of the protrusions can be positioned at a different angle relative to the horizontal base surface compared to the other protrusions. Each protrusion can have a hemispherical end face, a beveled end face, a tapered end face, or a surface that is substantially parallel to the horizontal base surface. Each protrusion can comprise a facet around the end face. The cross-section of the protrusion can be circular for a cylindrical protrusion, or can be rectangular, triangular, or elliptical. The end face of the protrusion is adapted to engage with a stop surface on an overlying spacer.

[0015] The stop surface can be recessed from the lower surface or lower rim of the spacer, and can be positioned on or near one or each corner of the spacer. The stop surface can be complementary to the end face of the protrusion of the underlying spacer, and can be flat, beveled, or hemispherical.

[0016] The stop surface on each corner and the end face on each protrusion of the spacer define virtual planes, and the planes connecting the end faces on the protrusions and the planes connecting the stop surfaces are preferably oriented parallel to one another, and preferably parallel to the horizontal base surface.

[0017] The vertical load can ultimately be transferred to the workbench via a pipette tip. The last spacer can therefore abut the upper rim of the pipette tip.

[0018] In embodiments, the protrusion extending vertically from the upper surface and the stop surface recessed from the lower surface can be substantially vertically aligned relative to one another. Alternatively, the protrusion and the stop surface are horizontally displaced relative to one another. The centers of the protrusion and the stop surface can define an axis, and the axis can be inclined or perpendicular relative to the base surface of the spacer. The alignment of the protrusion, as well as the alignment of the top surface of the protrusion and the stop surface, ensures efficient vertical load transfer from spacer to spacer by the load transfer elements.

[0019] The load transfer elements of the spacer engage the load transfer elements of the underlying and / or overlying spacers in the stack of spacers. The stop surface recessed from the lower surface of each spacer is configured for abutting the end of the protrusion extending from the underlying spacer. Each end of the protrusion extending from the upper surface of each spacer is configured to abut the stop surface of the overlying spacer.

[0020] The stop surface on the spacer can be part of a protrusion that extends vertically from the horizontal base surface toward the lower rim. The protrusion, or at least the stop surface on the protrusion, is recessed relative to the lower rim. The stop surface can be part of the peripheral sidewall, for example part of a horizontal flange on the inside of a corner of the peripheral wall that connects a longitudinal side to a transverse side. Alternatively, the stop surface is at the end of a rib that protrudes inwardly from at least one corner, for example diagonally inwardly.

[0021] The vertical distance between the upper rim and the lower rim of the peripheral sidewall is preferably lower than the length of the load transfer element defined by the vertical distance between the end of the protrusion extending vertically from the upper surface and the stop surface recessed from the lower surface. When the pipette tip carriers are stacked between two spacers, a vertical gap will be available for the pipette tip carriers, preventing vertical loading of the pipette tip carriers from one spacer to the spacer below, as long as the vertical dimension of the pipette tip carriers at the location of the peripheral sidewall is lower than the vertical dimension of the gap.

[0022] The upper rim of the peripheral sidewall can comprise a ledge for holding and supporting a pipette tip carrier. The ledge can protrude upwardly from the upper rim of the sidewall. The ledge can engage a complementary recessed section in the bottom surface.

[0023] The load transfer element on each spacer can further comprise a protrusion extending vertically downwardly from the lower rim of the peripheral sidewall, and the downward protrusion is configured to pass through a complementary opening in a pipette tip carrier clamped between two spacers. An end face of the downward protrusion is configured to abut an upper surface of the peripheral sidewall of the spacer below. A horizontal play between the protrusion extending vertically from the lower rim and the complementary opening in the carrier prevents vertical load transfer between the spacer and the carrier, and ensures that the spacer can be removed from the stack independently of the pipette tip carrier.

[0024] The horizontal base surface of the spacer can comprise a protrusion at the center of the rectangular spacer that protrudes vertically toward the upper rim of the peripheral sidewall and toward the lower rim of the peripheral sidewall, and a top surface of the protrusion is configured to abut a pipette tip carrier positioned on top of the spacer, and a bottom surface of the protrusion is configured to abut a pipette tip carrier positioned below the spacer during vertical loading. The protrusion is preferably coupled to the horizontal base surface and is integrally formed with the rectangular spacer during, for example, injection molding. The protrusion can protrude vertically upwardly and downwardly from the horizontal base surface. Alternatively, the protrusion is a separate part, and one part of the protrusion snaps onto the center of the top surface of the base surface, while another part of the protrusion snaps onto the center of the bottom surface of the base surface.

[0025] In a stack of alternating spacers and pipette tip carriers, the central protrusion can support the transfer of a vertical load from spacer to spacer via the center of a pipette tip carrier placed between two spacers. During pipette picking, the pipette head can apply a vertical load to the center of the pipette carrier, and this central load is transferred via the edges of the pipette tip carrier to the underlying spacer. The pipette tip carrier can bend towards the underlying spacer, and the central protrusion of that spacer can support the bottom surface of the pipette carrier. The central protrusion is preferably designed such that the protrusion towards the upper rim and the protrusion towards the lower rim do not touch the pipette tray in the rest position when no load is applied. Preferably, the end face of the central protrusion does not extend beyond the upper rim and the lower rim of the peripheral sidewall. The protrusion can have a circular cross section, a rectangular cross section, or can have an outer shape that is adapted to the inner shape of the gripper of the pipetting robot in order to facilitate gripping of the spacer. The protrusion that protrudes upwards from the center of the spacer can be configured to receive the protrusion that protrudes downwards from the center of the spacer placed on top of the spacer when no pipette tip carrier is placed between the spacers. The engagement of the central protrusions of the spacers can facilitate the stacking of the spacers for transport or handling purposes within the pipetting robot.

[0026] Alternatively, the protrusion of the center is on the pipette tip carrier disk, which is configured to engage the opening of the center of the spacer. The protrusion that protrudes from the top of the carrier can abut or engage the protrusion that protrudes from the bottom of the upper carrier, while the protrusion that protrudes from the bottom of the carrier can engage the protrusion that protrudes from the top surface of the carrier. The top and bottom of the engagement of the central protrusions pass through the central opening of the spacer placed between the carriers.

[0027] The horizontal base surface of the spacer can comprise a plurality of openings oriented according to a pattern complementary to the pattern of the pipette holes in the pipette tip carrier. The plurality of openings are preferably circular openings that intersect each other, thereby providing a shamrock-shaped opening. The openings provide space for the pipettes that engage the upper pipette carrier, and the rim of the openings axially fix the pipettes that engage the underlying spacer, for example during transport.

[0028] The horizontal base can further comprise ribs protruding from the top and / or bottom surface of the horizontal base for mechanically reinforcing the horizontal base surface of the spacer. The ribs can be placed between the plurality of openings and can be connected to the central protrusion described above. As an alternative, a corrugated structure is included in the horizontal base surface or base layer.

[0029] In embodiments, the spacer can comprise a centering spring element at each corner, and the centering spring element is configured to act on a protrusion on each corner of an underlying spacer, which is positioned on the underlying spacer with horizontal and / or vertical play, thereby acting as a centering aid or as a twist barrier in the stack of spacers and underlying spacers. The centering aid corrects for misalignment in the horizontal plane. The twist barrier realigns a stack of spacers that have been twisted or twisted around the vertical axis of the stack.

[0030] The spring element of the spacer acts directly on the underlying spacer, without acting on a pipette tip carrier positioned between the spacer and the underlying spacer. The centering aid provided by the spring element or twist barrier acts between the spacers without involving the pipette tip carrier, so that the dimensional manufacturing tolerances of the carrier can be less stringent. The spring element is preferably positioned opposite the protrusion extending vertically from the top surface and facing the lower edge.

[0031] The centering spring element at each corner of the spacer can at least partially surround a stop surface. The centering spring element can surround a rib protruding inward from the corner or a horizontal flange located inside the corner.

[0032] The spring element can be configured to at least partially surround a protrusion on each corner of an underlying placed spacer. The spring element can extend vertically, with one end of the spring element being attached or attachable to the bottom of a horizontal base surface and the other end being configured to flex along a diagonal of the rectangular spacer or towards the center of the spacer. The spring element can be further mechanically supported by a fin extending from the bottom of the horizontal base surface, and the fin can be coupled or adjacent to the spring element to reduce or adjust the degree of flexing of the spring element.

[0033] The spring element can be shaped as a half-shell, or at least the cross-section of the spring element can be shaped as a half-shell with a radius adapted to engage the outer radius of a cylindrical protrusion of an underlying spacer when the spacer is positioned on the top of the underlying spacer. The spring element can elastically deform when engaging the protrusion of the underlying spacer during placement. The half-shell can be positioned in the corner with the outer surface of the half-shell facing the inner surface of the peripheral wall in the corner, or the inner surface of the half-shell facing the peripheral wall in the corner.

[0034] A second aspect relates to an assembly comprising a stack of at least two spacers and a rectangular pipette tip carrier positioned between two spacers, wherein the pipette tip carrier comprises a plate comprising:

[0035] - a lower surface for engaging an upper surface of an underlying spacer,

[0036] - a plurality of pipette holes for detachably holding a pipette tip,

[0037] - a corner hole on each corner of the plate, fitting onto a protrusion of the lower spacer,

[0038] - an opening, providing access to a protrusion extending vertically from a lower edge of a peripheral side wall of the upper spacer, the end of the protrusion extending vertically from the lower edge being configured to abut an upper edge of the peripheral side wall of the lower spacer.

[0039] The lower surface of the plate, or at least the lower surface of the rim section of the plate, can engage the upper surface of the lower spacer, or can engage a ledge protruding from the upper surface of the lower spacer. The opening in the plate, or preferably the opening in the rim section of the plate, can be a closed opening, or can be provided as a cut-out in the rim of the plate.

[0040] A third aspect relates to the use of at least one spacer according to the invention, wherein a stack of pipette tip carriers provided with pipette tips is produced, the pipette tip carriers being spaced apart by the spacers. The stack is an alternating stack of pipette tip carriers and spacers.

[0041] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0042] Embodiments of the invention will be described in more detail with reference to the drawings, in which:

[0043] Figure 1 : perspective view from the top of a pipette tip carrier according to the invention,

[0044] Figure 2 : perspective view from the bottom of a pipette tip carrier according to the invention,

[0045] Figure 2a : bottom view of a pipette tip carrier according to another embodiment,

[0046] Figure 3 : detail of a corner section of a pipette tip carrier holding a pipette and a gripper of a pipette robot,

[0047] Figure 4a : detail of a thin rectangular skirt section of a pipette carrier allowing picking up a first row of pipette tips using a pipette robot,

[0048] Figure 4b : detail of a medium thickness rectangular skirt section of a pipette carrier allowing picking up a first row of pipette tips using a pipette robot,

[0049] Figure 4c : detail of a high thickness rectangular skirt section of a pipette carrier preventing picking up a first row of pipette tips using a pipette robot due to collision of a collar adapter of a pipette head with the skirt before picking up the pipette tip,

[0050] Figure 4d Detail of thin rectangular skirt section of pipette carrier allowing detection of missing tip in allowed carriers,

[0051] Figure 4e Detail of rectangular skirt section of pipette carrier not allowing detection of missing tip due to hard stop of collar adapter on skirt of carrier,

[0052] Figure 5 Packaging for pipette tip carriers, Figure 1 and Figure 2 Packaging for pipette tip carriers in unfolded configuration,

[0053] Figure 6 Folded packaging for pipette tip carriers, Figure 1 and Figure 2

[0054] Figure 7 Packaging holding two pipette tip carriers,

[0055] Figure 8 Longitudinal section of packaging showing, Figure 7

[0056] Perspective top view of spacer for pipette tip carriers, Figure 9 Figure 1 Figure 2 Perspective bottom view of spacer for pipette tip carriers,

[0057] Figure 10 Exploded view of two spacers with three pipette tip carriers positioned therebetween,

[0058] Figure 11 Stack of pipette tip carriers and spacers,

[0059] Figure 12 Longitudinal section of stack showing,

[0060] Figure 13 Detail of corner section of stack, Figure 12

[0061] Detail of corner section, cross-sectional view. Figure 14

[0062] Detail of spacer to spacer stacking via spacer protrusions and openings in longitudinal skirt sections of pipette tip carriers, Figure 15

[0063] Detail of corner section, cross-sectional view. Figure 16

[0064] List of reference signs ​​​​

[0065] DETAILED DESCRIPTION

[0066] Definitions: The distal or distal direction is defined by the flow direction of the liquid, thus the distal tip of the pipette is defined by the outlet of the pipette tip, and the proximal end is opposite to the distal end. The term "below" means lower or underneath; the term "above" means located on top or on top of. The word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. For example, "an opening" does not exclude that there are two or more openings, which can be functionally or structurally implemented to fulfill the purpose of the "opening".

[0067] Perspective top and perspective bottom views of a pipette tip carrier 1 according to an embodiment of the application are shown in Figure 1 and Figure 2 respectively. The pipette tip carrier 1 has a rectangular outer shape, wherein a rectangular top plate 3 is surrounded by a peripheral wall 4 connecting the top plate 3 to a rectangular skirt 5. The top plate 3 defines a horizontal plane, and the rectangular skirt 5 is also horizontally oriented. The top plate 3 comprises a plurality of circular openings 7, which are organized in a matrix of rows and columns according to ANSI / SLAS microplate standards, for example according to the 96-well plate standard (ANSI SLAS 4-2004 (R2012): Well Positions). Hollow cylinders 6 overhang or start at the circular openings 7, thereby providing a matrix of passages 8 through the pipette tip carrier 1. The pipette tip carrier can releasably hold disposable pipette tips 2 using the passages 8 (see Figure 3). The perimeter wall 4 can comprise a marking segment 58 for printing information, for example a trademark name or a two- or three-dimensional barcode for identification or logistical purposes. The perimeter wall 4 can also comprise notches 59. The rectangular skirt 5 comprises longitudinal sides 12 and transverse sides 13 and is relatively thin to obtain a material saving product. The thickness of the skirt is lower than 3 mm, preferably lower than 2 mm, more preferably lower than 1.5 mm. The relatively thin rectangular skirt 5 is reinforced by a plurality of rim ribs 10 connecting the top surface of the rectangular skirt 5 to the perimeter wall 4. The rim ribs 10 also provide guidance and limit the horizontal play for a lid that can be placed on top of the pipette tip carrier 1. The top surface of the rim ribs 10 can be used to mechanically detect the presence of the pipette tip carrier by a gripper of a pipetting robot. The space between two rim ribs 10 on the perimeter wall or on the top surface of the skirt 5 can provide a marking segment 58. The rectangular skirt 5 comprises an opening 14 at each corner of the pipette tip carrier, which opening is adapted to engage a complementary protrusion of a spacer that will be placed below the pipette tip carrier, as will be further discussed below. Alternatively, the opening 14 engages a protrusion of a pipette box that is fixed on a worktable of a pipetting robot. A circular rim can surround each opening 14, providing an entry segment, for example a faceted rim, for guiding the protrusion during the stacking of the spacer and the pipette tip carrier. The circular rim can further locally reinforce the rectangular skirt 5 in the corner segment. The opening 14 can be dimensioned such that there is a horizontal play between the opening 14 and the protrusion of the spacer, or there can be a friction fit engagement between the outer surface of the protrusion and the inner surface of the opening 14. The form fit engagement can enable the assembly of the spacer and the carrier to be temporarily transported by gripping only the carrier. Preferably, only the spacer is gripped by the pipetting robot in form fit or friction fit engagement.

[0068] The corner rib 15 can connect the opening 14 or the circular rim surrounding the opening 14 to the perimeter wall 4, preferably to the corner 16 of the perimeter wall. The rectangular skirt 5 can also comprise at least one opening 11, preferably two openings 11 that penetrate both longitudinal sides 12 or both transverse sides 13 of the skirt. The opening 11 can have a rectangular, circular or triangular shape and provides a passage for a complementary protrusion of an upper spacer. The corners of the opening can be rounded and the edges of the opening can comprise facets. The opening 11 can be surrounded by a rim for mechanically supporting the rectangular skirt 5 surrounding the opening 11. The rectangular skirt 5 can comprise a cut-out 55 that provides a passage for a protrusion of an upper spacer.

[0069] The pipette tip carrier 1 can comprise a bottom wall 18 extending vertically from the bottom surface 17 of the rectangular skirt 5. The bottom wall 18 surrounds the matrix of channels 8 and provides an end of the cylinder 6 of the channels 8 that is preferably flush or level with the bottom surface 17 of the rectangular skirt 5. Alternatively, the cylinder penetrates and exceeds the bottom surface 17, but further extension of the cylinder beyond the bottom surface 17 can result in unnecessary material usage. The further extension of the cylinder can mechanically strengthen the pipette tip carrier. The cylinder 6 can be directly connected to adjacent cylinders by connecting ribs 9 to mechanically strengthen the pipette tip carrier. The cylinder 6 can also intersect with adjacent cylinders without using connecting ribs 9 and the cylinder 6 can be connected to the inner surface of the peripheral wall 4 by connecting ribs or, as shown in Figure 2 The thickness of the ribs can vary depending on the location within the pipette tip carrier according to the local need defined by the mechanical stresses in the carrier upon vertical loading. The ribs 9 can be thicker in the center of the carrier compared to the ribs in the outer region towards the skirt 5.

[0070] The notch 59 on the bottom wall 18 of the carrier can comprise a horizontal ridge 60 that can serve as a vertical position holder for stacking multiple carriers or the notch can provide a snap-on connector between two carriers or between a carrier and a pipette box. The guide member 19 on the bottom wall 18 can serve self-alignment purposes or clamping purposes. The notch 59 and / or the guide member 19 can locally strengthen the bottom wall 18.

[0071] Figure 2a An alternative embodiment of a pipette tip carrier is shown in. The view on the bottom surface 17 shows two openings 11 in the skirt of the carrier and a bottom wall 18 that penetrates from the bottom surface 17. The multiple channels 8 for pipette tips are surrounded by cylinders that are connected to each other by connecting ribs 9. Figure 2a The embodiment shown is additionally mechanically supported by a strengthening rib 71 that connects the two connecting ribs 9 to each other providing a vertically oriented strengthening rib. The strengthening rib 71 is oriented vertically in Figure 2a Alternatively, the strengthening rib is oriented horizontally parallel to the longitudinal side of the pipette tip carrier. In yet another embodiment, there are both horizontally and vertically oriented strengthening ribs 71.

[0072] Figure 3 A detail of a corner section of a pipette tip carrier 1 holding a pipette 2 is shown. The pipette 2 comprises a collar 32 that engages the top plate 3 of the carrier and a pipette shaft 33 that extends from the collar 32 through the channels. A gripper 61 of a pipette robot abuts the top surface of the rim rib 10, for example to mechanically detect whether a tray is present. The pipette robot can comprise a pipette head 62 for collecting pipette tips 2, see Figures 4a to 4eThe thickness and position of the rectangular skirt 5 defines the height of the perimeter wall 4, which can affect the accessibility of a single row of pipette tips from the matrix of pipette tips in the carrier (see Figures 4a to 4c ) or the detection of a missing row of pipette tips (see Figure 4d and Figure 4e ). The pipetting head 62 comprises a plurality of collar adapters 70, which are lowered by the pipetting robot towards the collars 32 of the pipettes 2 for picking up the pipettes. When the collar adapters 70 of the pipetting head abut against a mechanical stop, such as the rectangular skirt 5 of the carrier 1, the lowering process stops, and a thin rectangular skirt 5 (see Figure 4a and Figure 4b ) can provide sufficient accessibility to the pipettes in the carrier for picking up a single row of pipettes, while the adjacent collar adapters 70 do not touch the skirt 5 around the carrier. If the pipetting robot detects a hard stop before effectively picking up the pipettes from the carrier, the picking up of the tips can be compromised, or the picking up of the rows can damage the hardware of the pipetting robot, see Figure 4c , where the thickness of the skirt 5 affects the collar adapters 70 abutting against the skirt 5 before the adjacent collar adapters 70 can capture the pipette tips 2 from the first row. The thickness of the rectangular skirt 5 can also affect the detection of a missing row of pipettes in the pipette tip carrier. Figure 4d A pipette tip carrier 1 is shown with a missing first row of pipettes 2, and the firmware of the pipetting robot can detect the missing row, because the vertical position of the pipetting head 62 with the collar adapters 70 will typically detect an increase in the vertical force required to pick up the pipettes, since the collar adapters 70 can need to elastically deform the rim of the pipette collar 32. The collar adapters adjacent to the collar adapters entering the channels 8 of the pipette carrier 1 do not abut against the thin wall rectangular skirt 5. A circumferential skirt 5 with a larger thickness as shown in Figure 4e will result in a hard stop for the collar adapters 70 adjacent to the collar adapters entering the channels 8 of the first row, and the hard stop on the skirt will be detected before the firmware of the pipetting robot can detect the missing row. Thus, the thin wall circumferential skirt 5 can provide a universal solution when used in the pipetting robot.

[0073] An example of a package 20 for a pipette tip carrier is shown in Figures 5 to 8 . The package 20 is based on a foldable sheet 66, which is punched out of a sheet of material such as paperboard, coated paperboard, plastic or composite material. The foldable sheet 66 comprises two longitudinal sides 22 connected by a transverse side 23. Each longitudinal side 22 comprises two protrusions or flaps, a flap or protrusion 27 and a flap or protrusion 28, which extend from the top edge 25 and the bottom edge 26 of the package 20 after the sheet 66 is folded into a rectangular box 24 (see Figure 6). The top cover 29 and the bottom cover 30 are attached to one of the two lateral sides 23 and a closure flap or closure tab extends from the top cover and the bottom cover, respectively. A closure slit 63 is included in the other of the two lateral sides 23 which is configured for engaging the closure flap 31. A closure tab 64 is attached to one of the lateral sides 23 for closing the rectangular box 24. Folding lines or pre-determined creases are integrated in the foldable sheet 66, for example perforation lines or cut lines 65 can be integrated in the foldable sheet 66. The two protrusions or tabs 27 or 28 can comprise barbs for releasably securing the pipette tip carriers to the package.

[0074] The sheet 66 can be folded into a rectangular box 24 as shown in Figure 6 The top rim 25 and the bottom rim 26 extend from the upper and lower surfaces of the longitudinal sides 22 and the lateral sides 23, thereby providing a top opening and a bottom opening which are accessible for the insertion of the two pipette tip carriers 1. The top opening and the bottom opening are surrounded by the top rim and the bottom rim, respectively. The protrusions or tabs 27, 28 extend from the top rim 25 and the bottom rim 26, respectively. The top cover 29 and the bottom cover 30 are bendable from the vertical direction, thereby allowing access to the carriers towards the top rim and the bottom rim for closing the package.

[0075] Figure 7 An assembly comprising the package 20 and the two pipette tip carriers 1 is shown. The two carriers 1 are each inserted with their respective bottom surfaces 17 of the skirt 5 facing the top rim 25 and the bottom rim 26 of the package 20. The pipette shafts 33 releasably connected to the two pipette tip carriers are enclosed within the rectangular box 24 and the two tabs 27 extending from the top rim 25 engage the opening 11 of one of the two pipette tip carriers. The two tabs 28 extending from the bottom rim 26 engage the two openings 11 of the other of the two pipette tip carriers. Optional barbs on the tabs can provide a temporary fixation of the carriers to the package. The bottom surfaces 17 on the rectangular skirt 5 of each pipette tip carrier are supported by the top rim 25 and the bottom rim 26 of the rectangular box 24 and the engagement between the protrusions 27, 28 and the openings 11 can prevent dislodgement between the rectangular skirt 5 of the carriers and the rectangular box 24. The package 20 is closed by folding the top cover 29 and the bottom cover 30 such that the covers are aligned with the horizontal plane of the pipette tip carriers. The closure flap 31 is attached to the lateral side 23 of the package using the slit 63 (see Figure 5 ). Figure 8 A longitudinal cross-section of a package filled with two pipette tip carriers holding pipette tips is shown. The pipette shafts 33 of each carrier are engaged with each other to save space for the arrangement of the pipette tips 2. After opening the closure flap 31 and tilting the top cover 29 and the bottom cover 30 towards the vertical position, the two pipette tip carriers 1 can be removed from each side of the box.

[0076] Figure 9and Figure 10 A rectangular spacer 34 for stacking pipette tip carriers is shown in FIG. 12. The spacer 34 includes a horizontal base surface 35 surrounded by a perimeter sidewall 36 that is oriented substantially vertically with respect to the base surface 35. The base surface 35 includes semicircular openings 53 that are centered to have the same pattern as the channels 8 in the pipette tip carriers. The semicircular openings can intersect, resulting in a plurality of shamrock-shaped openings. The openings provide passageways for the pipette shafts 33 of the pipette tips 2 that engage the pipette tip carriers positioned on top of the spacer 34, and prevent the collars 33 from being misaligned from the pipette tip carriers positioned below the spacer 34. The horizontal base surface 35 is reinforced by a corrugated structure 67, such that material is added to the base surface where mechanical reinforcement is needed. The perimeter sidewall 36 includes two longitudinal sides 37 and two lateral sides 38, providing an upper rim 40 and a lower rim 42 that are oriented parallel to each other. A ledge 50 protrudes upward from the upper surface 39 of the upper rim, and a protrusion 51 protrudes downward from the lower surface 41 of the lower rim 42. A corner protrusion 44 protrudes upward from the upper surface 39 in each corner of the rectangular spacer 34. A protrusion 52 protrudes from the center of the rectangular spacer 34 toward the upper rim 40 ( Figure 9 ), and also from the center toward the lower rim 42 ( Figure 10 ). A load transfer element 43 is located on each corner of the rectangular spacer 34, which includes the corner protrusion 44 and a stop surface 45. Optionally, there are additional load transfer elements between the corners of the spacer. Figure 14 and Figure 15 Further details of the load transfer elements will be illustrated in FIG. 13. Figure 10 The perspective bottom view in FIG. 13 further shows a spring element 54 that surrounds the stop surface 45 in each corner, and the spring element 54 is connected to the bottom surface of the horizontal base surface 35, and the free end of the spring element 54 can flex toward the center or corners of the rectangular spacer 34. The spring element 54 can be mechanically supported by a support rib 56 that protrudes from the bottom surface of the base 35. The load transfer element 43 provides transfer of vertical load from the spacer to the spacer below, while the spring element 54 provides correct alignment of the spacer to spacer in the spacer stack.

[0077] Figure 11An exploded view of the stack of alternating spacers 34 and pipette tip carriers 1 is depicted. Each pipette tip carrier 1 is positioned such that an opening 14 at each corner is located on a corner protrusion 44 at each corner of the spacer below. A protrusion 51 projecting from the lower edge 42 of each spacer 34 aligns with a cutout 55 and an opening 11 in the rectangular skirt 5 of each pipette tip carrier 1, such that the opening 11 provides a channel for the protrusion, preferably not contacting or adjacent to the protrusion 51, thereby avoiding vertical load transfer from the spacer 34 to the pipette tip carrier 1 positioned below the spacer. The clearance between the protrusion 51 on the spacer and the cutout 55 or opening 11 on the carrier in the horizontal plane is sufficient to avoid direct contact.

[0078] The stack of spacer 34 and carrier 1 in the stack 69 Figure 12 As shown in the diagram. The stack is placed on top of a pipette cassette 68 that releasably holds the stack, such that the stack or a portion thereof can be removed by the gripper of a pipetting robot. The pipette cassette 68 can be secured to the worktable of the pipetting robot. Each pipette tip carrier 1 is placed on the upper surface 39 of the upper edge 40 of the lower spacer. Optionally, the carrier is supported by a ledge 50. A protrusion 51 projecting downward from the lower edge of each spacer abuts the upper surface 39 of the lower spacer via a cutout 55 or via an opening 11 in the rectangular skirt 5 of each pipette tip carrier 1. The vertical load of the pipette tip carrier 1 within the vertical space or gap between the two spacers 34 and applied to the top of the stack is transferred via the rectangular skirt 5 to the upper edge 40 of the first spacer 34, and the vertical load is then transferred to the second spacer 34 via load transfer elements 43 at each corner of the first spacer and / or via a protrusion 51 extending from the lower edge of the first spacer. The vertical load is ultimately transferred to the stage of the pipetting robot via the pipetting cartridge 68. Details of the load transfer via the load transfer element 43 are as follows: Figure 14 The details of load transfer via protrusion 51 are shown in [the diagram]. Figure 15 As shown in the image.

[0079] Figure 13 The longitudinal section of the stack is depicted. The vertical load from the pipetting tip carrier 1 on top is transferred to the upper edge 40 of the first spacer 34 via the rectangular skirt 5. The first spacer 34 includes a base surface 35 surrounded by peripheral sidewalls 36, and the base surface 35 is reinforced by a corrugated structure 67 (see also...). Figure 9 In the event that the pipette carrier 34 on top flexes or bends due to a vertical load, the protrusion 52, which does not contact the pipette tip carrier below or above in the resting position, can additionally absorb the vertical load, thereby transferring a small portion of the load from the pipette tip carrier on top to the first spacer, and ultimately from the first spacer to the next pipette tip carrier.

[0080] Figure 14 Details of the load transfer elements are shown in FIG. 5. Starting from the bottom of the illustration: the spacer below the pipette tip carrier provides a corner protrusion 44 through the corner opening 14 of the pipette tip carrier 1, and the top surface 46 of the corner protrusion 44 abuts a stop surface 45 of the spacer positioned above the pipette tip carrier 1. There is a gap 57 (see FIG. 6) between the two spacers, which can be used by the pipette tip carrier to prevent load transfer to the carrier. The vertical height of the perimeter wall 36 is defined by the distance 48 between the upper rim 40 and the lower rim 42, while the height of the load transfer element 43 is defined by the vertical distance 49 between the end of the protrusion 46 and the stop surface 45. The vertical distance 49 exceeds the height 48 of the perimeter wall 36, leaving a gap below the lower rim 42 of each spacer that can be used by the pipette tip carrier. Each pipette tip carrier can be placed on the upper rim 40 of the first spacer 34, the second spacer 10 can be placed on top of the first spacer, and the lower rim 42 of the second spacer will not contact the rectangular skirt 5 around the pipette tip carrier. Figure 15

[0081] Figure 15 Further details of the protrusion 51 of a spacer engaging the top surface of an underlying spacer are shown in FIG. 6. The protrusion 51 projecting downward from the longitudinal side of the lower surface 41 of the upper spacer 34 abuts the upper surface 39 of the underlying spacer 34 via the opening 11 in the pipette tip carrier 1. The abutment of the protrusion 51 projecting downward from the lateral side provides a comparable cross-sectional view, with the only difference being that the opening 11 is replaced by the cutout 55.

[0082] Thus, in the stack of spacers and carriers, a vertical load applied to the pipette tip carrier can be transferred via the load transfer elements 43 on each corner, and / or via the protrusions 51 on the longitudinal sides of the spacers, and / or via the protrusions 51 on the lateral sides of the spacers, for direct spacer-to-spacer load transfer. Optionally, a portion of the vertical load is transferred via the central protrusion 52, for spacer-to-carrier loading.

[0083] As Figure 10 , Figure 15 and Figure 16 ​As shown, spacer 34 includes a spring element 54 at each corner. When spacer 34 is placed on top of another spacer carrying a pipette tip carrier, this placement may be accompanied by a horizontal displacement of one spacer relative to the other. The spring element 54 at each corner is used to compensate for or eliminate play in the horizontal plane. The spring element 54 protrudes from the bottom surface of the horizontal base 35 toward the lower edge 42 and may flex along the diagonal of the rectangular spacer toward the center or toward the corner of the peripheral wall 36. The spring element 54 of the spacer may have a semi-circular shape for at least partially surrounding a corner protrusion 44 projecting upward from the lower spacer. When the corner protrusion 44 of the lower spacer is engaged, the spring element of the top spacer at each corner may flex, thereby self-centering the spacer relative to the lower spacer and compensating for horizontal misalignment or providing a barrier against twisting the stack of spacers. The twisting barrier provides a resilient realignment force when the top of the stack is twisted relative to the bottom of the stack. Reliable pickup of the pipette from the carrier depends on the accuracy of the pipetting robot's movements and the dimensional tolerances of the stacking of the spacer and pipetting tip carrier. Therefore, a self-centering spring element can reduce the cumulative tolerances caused by the placement and handling of the spacer and carrier. The flexibility or elasticity of the spring element can be adjusted by the material used for spring element 54 and / or the wall thickness of the spring element and / or by using support ribs 56 projecting along the rear surface of spring element 54 toward the end of the spring element. Spring element 54 can surround a stop surface 45 at each corner, thus serving as a guide element during spacer placement to guide the post 44 of the lower spacer toward the stop surface of the upper spacer, see [link to relevant documentation]. Figure 16 .

[0084] Figure 15 A gap 57 between the two spacers 34 is also shown, which can be used to place the pipetting tip carrier 1 between the two spacers. The height of the gap 57 is determined by the length 49 of the transfer element and... Figure 14 The difference between the vertical distance 48 between the upper and lower edges of the spacer shown is defined. Figure 14 A spring element 54, engaging with the corner protrusion 44 of the lower spacer, is also shown in the longitudinal cross-section. The spring element 54, for guiding and aligning the spacer, functions during the stacking or pile-up of the spacer and pipette tip carrier. This step in laboratory automation procedures is accomplished by picking up the stack before initiating the liquid handling process, thereby achieving vertical loading of the stack. Therefore, the combination of spacer and tray shown above allows for proper alignment during stacking and efficient transfer of vertical load during liquid handling, and this, combined with the spacer and pipette tip carrier, requires less material and has a lower carbon footprint during manufacturing.

[0085] The fact that certain elements or steps are recited only in different portions of the specification should not be taken as exclusion of further meaningful combinations of those elements or steps.

Claims

1. A spacer (34) for a rectangular pipette tip carrier (1), the spacer being frame-shaped and rectangular and configured to be stacked on top of another spacer, providing vertical space (58) for the pipette tip carrier between the spacers, wherein, The spacer (34) comprises: - a horizontal base surface (35), - a peripheral sidewall (36) standing perpendicular to the base surface (35), the peripheral sidewall providing two longitudinal sides (37) and two lateral sides (38), wherein each longitudinal and lateral side comprises an inner side connected to the base surface, - the peripheral sidewall (36) comprises an upper surface (39) and a lower surface (41), the upper surface (39) being arranged at an upper rim (40) of the peripheral sidewall (36) and the lower surface (41) being arranged at a lower rim (42) of the peripheral sidewall, wherein the upper surface (39) and the lower surface (41) extend horizontally and the upper surface of the peripheral sidewall is configured to support the pipette tip carrier (1), characterized in that the spacer comprises a load transfer element (43) configured to directly transfer a vertical load from one spacer to an underlying spacer.

2. The spacer of claim 1, wherein, The load transfer element (43) on each spacer (34) comprises a corner protrusion (44) vertically extending from the upper surface (39) on each corner of the spacer and a stop surface (45) recessed from the lower surface on each corner of the spacer.

3. The spacer of claim 2, wherein, The corner protrusion (44) and the stop surface (45) on each corner of each spacer are vertically aligned relative to each other.

4. The spacer of claim 3, wherein, The stop surface (45) of the spacer is configured for abutting an end of a protrusion of an underlying spacer and wherein an end (46) of the corner protrusion (44) of the spacer is configured for abutting a stop surface (45) of an overlying spacer.

5. The spacer of any one of claims 2-4, wherein, The stop surface (45) vertically protrudes from the horizontal base surface (35).

6. The spacer of claim 5, wherein, The stop surface (45) is located at an end of a rib (47) protruding diagonally inward from each corner.

7. The spacer of any one of claims 2-4, wherein, A vertical distance (48) between the upper rim (40) and the lower rim (42) of the peripheral sidewall (36) is lower than a height (49) of the load transfer element (43), the height being defined by a vertical distance between the end (46) of the corner protrusion (44) vertically extending from the upper surface (39) and the stop surface (45) on each corner.

8. The spacer of any one of claims 1 to 4, wherein, The upper rim (40) of the peripheral sidewall (36) comprises a ledge (50) for holding and supporting the pipette tip carrier.

9. The spacer of any one of claims 1-4, wherein, The load transfer element (43) on each spacer further comprises a protrusion (51) vertically extending from the lower rim (42) of the peripheral sidewall (36), the protrusion being configured to pass through a complementary opening (11) in the pipette tip carrier, an end of the protrusion being configured to abut an upper surface (39) of a peripheral sidewall of an underlying spacer (34).

10. The spacer of any one of claims 1-4, wherein, The horizontal base surface comprises a protrusion (52) at the center of the rectangular spacer, which protrudes vertically towards the upper rim (40) of the peripheral sidewall (36) and which protrudes vertically towards the lower rim (42) of the peripheral sidewall, and the top surface of the protrusion (52) is configured to abut a pipette tip carrier positioned on top of the spacer, and the bottom surface of the protrusion is configured to abut a pipette tip carrier positioned below the spacer.

11. The spacer of any one of claims 1-4, wherein, The horizontal base surface comprises a plurality of openings (53) oriented according to a pattern complementary to the pattern of pipette holes for holding pipette tips in the pipette tip carrier.

12. The spacer of any one of claims 2-4, wherein, Further comprising a centering spring element (54) at each corner, and wherein the centering spring element (54) is configured to act on a protrusion on each corner of a lower spacer positioned on top of the spacer with horizontal and / or vertical play, thereby acting as a centering aid or as a twist barrier in the stack of the spacer and the lower spacer.

13. The spacer of claim 12, wherein, The centering spring element (54) at each corner at least partially surrounds the stop surface.

14. The spacer of claim 12, wherein, The spring element is configured to at least partially surround a corner protrusion (44) on each corner of a lower placed spacer.

15. The spacer of claim 12, wherein, The spring element extends vertically, wherein one end of the spring element is attached or attachable to the bottom of the horizontal base surface (35) and the other end is configured to flex along a diagonal of the rectangular spacer.

16. The spacer of claim 14 or 15, wherein, The spring element (54) is shaped as a half shell with a radius adapted to engage the outer radius of a cylindrical protrusion of a lower spacer when the spacer is positioned on top of the lower spacer, thereby elastically deforming the spring element.

17. An assembly comprising a stack of at least two spacers (34) according to any one of claims 2 to 16 and a rectangular pipette tip carrier positioned between two spacers, wherein, The pipette tip carrier comprises a plate comprising: - a lower surface for engaging an upper surface (39) of a lower spacer, - a plurality of pipette holes for holding pipette tips (2), - a corner opening (14) on each corner of the plate, fitting onto a corner protrusion (44) of the lower spacer, - an opening (11) providing access for a protrusion (51) extending vertically from a lower rim (42) of a peripheral sidewall (36) of an upper spacer, the end of the protrusion (51) extending vertically from the lower rim is configured to abut an upper rim (40) of the peripheral sidewall (36) of the lower spacer.

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