CN114729294A

CN114729294A - Pipetting device, pipette tip coupler, pipette tip device and method

Info

Publication number: CN114729294A
Application number: CN202080083225.1A
Authority: CN
Inventors: J·E·古斯曼; T·巴雷斯; T·康明斯
Original assignee: Hamilton Co Inc
Current assignee: Hamilton Co Inc
Priority date: 2020-07-31
Filing date: 2020-07-31
Publication date: 2022-07-08
Also published as: EP4034631A4; JP2023509127A; JP7377985B2; WO2022025920A1; EP4034631A1

Abstract

A pipette assembly comprising a pipette device, a pipette tip, and a leaf spring coupling device coupling the tip to the pipette device, the coupling device comprising a plurality of circumferentially disposed elements or segments in the form of flexible leaf springs having stabilizer platforms for holding the pipette tip to the coupler and preventing the pipette tip from rocking on the coupler and distal elastomeric elements (such as O-rings), and the pipette tip comprising dual complementary working surfaces in the pipette tip to provide precise control over an axial coupling position defined as the axial distance from a distally facing axial stop surface of the pipette tip coupler to a liquid contacting end of the pipette tip when the pipette tip coupler and disposable pipette tip are in a coupled configuration.

Description

Pipetting device, pipette tip coupling, pipette tip device and method

Technical Field

The present disclosure relates generally to pipetting devices and, more particularly, to pipette tip couplers, disposable pipette tips, pipette tip and coupler combinations, and methods of coupling and decoupling at least one disposable pipette tip with at least one pipette tip coupler operably carried by a pipette device.

Background

Pipette devices are used in a variety of industries for transferring liquids for experimental analysis. Thus, in order to provide control within the performed experiment, a disposable pipette tip is used and is intended for single use. Disposable pipette tips are employed both with manual pipette devices and with automated pipette devices having a large number of pipette units arranged in rows or in a matrix for simultaneously aspirating samples from a large number of containers and distributing them elsewhere.

Disposable pipette tips have historically been configured to couple with either conical or stepped coupling posts. In the case of a conical coupling post, the disposable pipette tip is constructed in such a way that it must be pre-stressed onto the coupling post to provide an airtight seal. Due to the tolerances of the two docking components, the distance to the end of the pipette tip that is in contact with the liquid is not well controlled. In addition, high compressive forces are required to pre-stress the pipette tip to form a hermetic seal. As a result, micro-cracks may form in the pipette tip, which is a cause of leakage. Furthermore, the high pressing forces during the placement of the pipette tips have the disadvantage that, in order to release the pipette tips, correspondingly high forces have to be applied.

U.S. patent No. 7,033,543 issued by HAMILTON, inc. on 25/4/2006, the assignee of the present application, teaches a stepped coupling post in combination with an O-ring that provides a solution for reducing the high squeezing forces required to form a hermetic seal and provides a well-defined axial location for the end of a pipette tip that is in contact with liquid. When the O-ring is compressed, it provides an axially directed force to not only provide an air tight seal, but also to engage an axial coupling feature on the coupling post to an anti-axial coupling feature on the pipette tip.

However, current systems utilizing stepped coupling posts and separate O-ring configurations are problematic when the O-ring is damaged, as the result compromises the performance of the hermetic seal and pipette device.

Additionally, compression of the O-ring causes the O-ring to deform, which in turn provides an axially directed force and an airtight seal against the pipette tip working surface. In contrast to this operation, when compression of the O-ring is removed, the O-ring must be disengaged from the working surface of the pipette tip to allow the pipette tip to be removed from the coupling post and pipette device for disposal. If the O-ring is not fully decompressed, some residual force will remain, causing the pipette tip to remain engaged to the coupling post, and thus requiring an automated external axial reaction force to remove the pipette tip for disposal.

Furthermore, as the size of the aperture to and/or from which liquid is transferred decreases, the need to precisely position all pipette tips in a controlled manner so as to allow successful targeting increases.

Accordingly, there exists a need to ameliorate or overcome one or more of the significant disadvantages outlined above.

Disclosure of Invention

Accordingly, and in one aspect, embodiments of the present disclosure ameliorate or overcome one or more disadvantages of the known prior art by providing a pipette tip coupler and disposable pipette tip combination, the combination comprising a plurality of circumferentially disposed elements or segments that engage the circumferential inner working surface, the circumferential inner working surface defining a first working surface formed into an inner envelope surface of a pipette tip sidewall in a region above a proximally facing axial stop surface of the pipette tip for providing a resultant pre-stress, the resultant pre-stress axially pre-stresses upward the pipette tip, causing the distal elastomeric element of the coupler to be pre-stressed against the second interior working surface of the pipette tip, thereby forming a sealing arrangement that eliminates the deterioration or failure of known prior art seals.

Additionally, and in one aspect, when the distal elastomeric element is pressed against the second inner working surface, it provides an anti-axial force to the plurality of elements or segments, wherein at least one benefit of the anti-axial force is that the plurality of individual elements or segments apply additional force to the first working surface when the plurality of individual elements or segments are in a radially and axially abutting state to provide a stronger distal seal.

Another benefit of the anti-axial force is that when the plurality of individual elements or segments are disengaged to the radially retracted state, the anti-axial force of the distal elastomeric element defines an anti-axially directed disengagement force that facilitates removal of the pipette tip from the pipette tip coupler for disposal.

In another aspect, embodiments of the present disclosure provide a pipette tip coupler and disposable pipette tip combination, the coupler comprising a plurality of circumferentially disposed elements or segments and a distal elastomeric element in the form of, but not limited to, O-rings, and the pipette tip comprising dual complementary internal working surfaces in the pipette tip to provide a resultant axial force enabled by engagement of the plurality of elements or segments and the distal elastomeric element with the dual complementary working surfaces for pre-stressing the disposable pipette tip into an axial coupling position provided by a distally facing axial stop surface of the pipette tip coupler and a proximally facing complementary counter axial stop surface of the disposable pipette tip such that a vertical reference to a longitudinal axis of a channel of a pipette device carrying the tip coupler and disposable tip combination is established, this provides straightness and controlled concentricity of the pipette tip.

Thus, one benefit of the resultant axial force coupling position over known prior art is that the vertical reference is established which provides straightness and controlled concentricity of the pipette tip. With the angle between the transverse axis and the longitudinal axis perpendicular to the transverse axis (defined herein as "

") increases, the concentricity becomes worse. Controlled concentricity, therefore, becomes especially important for multi-channel systems and for targeting multiple receptacles. Thus, the combination of a pipette tip coupler and a disposable pipette tip provides tighter concentricity, allowing tighter precision of all pipette tips in a controlled manner, allowing for successful targeting of multiple receptacles and/or smaller holes to and/or from which liquid is transferred.

In another aspect, embodiments of the present disclosure provide a pipette tip coupler and disposable pipette tip combination, the coupler comprising a plurality of circumferentially disposed elements or segments and a distal elastomeric element in the form of, but not limited to: the O-rings and pipette tip include dual complementary working surfaces in the pipette tip to provide precise control of an axial coupling position defined as an axial distance from a distally facing axial stop surface of the pipette tip coupler to a liquid contacting end of the pipette tip when the pipette tip coupler and disposable pipette tip are in a coupled configuration. This, in combination with the straightness of the pipette tip, allows a pipette device carrying a combination of a pipette tip coupler and a disposable pipette tip to target smaller holes. In addition, smaller volumes of liquid may be transferred because the known fixed distance of the disposable pipette tip allows the pipette tip/liquid to controllably contact the work surface onto or from which the liquid is to be transferred.

In another aspect, embodiments of the present disclosure provide a pipette tip coupler and disposable pipette tip combination that includes an angled pressing mechanism that guides movement of a plurality of individual elements into contact with a first working surface of a pipette tip. The result is that a greater axial force pre-stresses the pipette tip into the axial coupled position.

In yet another aspect, embodiments of the present disclosure provide a pipette tip coupler and disposable pipette tip combination, the coupler comprising a plurality of circumferentially disposed elements or segments, in the form of a flexible leaf spring with a retaining protrusion for retaining a pipette tip to the coupler, a stabilizer platform for preventing the pipette tip from rocking on the coupler, and a distal elastomeric element in the form of, but not limited to, an O-ring, and the pipette tip includes dual complementary working surfaces in the pipette tip to provide precise control of the axial coupling position, the axial coupling position is defined as when the pipette tip coupler and the disposable pipette tip are in a coupled configuration, an axial distance from a distally facing axial stop surface of the pipette tip coupler to a liquid contacting end of the pipette tip.

Other aspects of the embodiments of the present disclosure will become apparent from the detailed description provided hereinafter when taken in conjunction with the appended drawings and the appended claims. However, it should be understood that various modifications and adaptations may be made without departing from the scope and fair meaning of the claims, which are described in detail below with respect to the preferred embodiments of the present disclosure.

Drawings

The foregoing summary of the disclosure, as well as the following detailed description, will be more fully understood by reference to the following drawings, which are provided for purposes of illustration only and are not intended to limit the scope of the present disclosure. Further, it should be understood that the drawings are not necessarily drawn to scale, as some features may be shown exaggerated or not in scale relative to dimensions in actual implementations in order to more clearly illustrate one or more concepts of the present disclosure. In the drawings:

fig. 1 is a perspective view of an example embodiment of an air displacement pipette device assembly of an automated liquid handling system.

Fig. 2 is a longitudinal cross-sectional side elevation view of an example embodiment of a pipette device assembly.

Fig. 3 is a partial longitudinal section side elevation view of an example embodiment of a pipette device assembly including a pipette device operably coupled to an example embodiment of an expanding mandrel collet coupling device or pipette tip coupler operably coupled to an example embodiment of a disposable pipette tip.

Fig. 4 is a side elevational view of an exemplary embodiment of a pipette device assembly.

Fig. 5 is a partially exploded perspective part view of a pipette device assembly, detailing parts of an example embodiment of an expansion mandrel collet coupling device.

Fig. 6 is a partially exploded part perspective view detailing the parts of an exemplary embodiment of an expanding mandrel collet coupling device sandwiched between a disposable pipette tip and a pipette device.

Figure 7 is a side elevational view of an example embodiment of an expansion mandrel collet coupling.

FIG. 8 is a top and side perspective view of a center coupling body of an example embodiment of an expansion mandrel collet coupling device.

FIG. 9 is a top and side perspective view of an example embodiment of a lower or distal elastomeric element or O-ring of an example embodiment of an expansion mandrel collet coupling device.

Fig. 10 is a top and side perspective view of a distal elastomeric element surrounding the distal stem of the central coupler body and a cylindrical spacer surrounding and mounted on the central body axially above the distal elastomeric element.

FIG. 11 is a top and side perspective view of an example embodiment of an expansion mandrel collet of the expansion mandrel collet coupling.

Figure 12 is a longitudinal cross-sectional side perspective view of an example embodiment of an expansion mandrel collet of the expansion mandrel collet coupling.

FIG. 13 is a top and side perspective view of an example embodiment of an annular wedge of an example embodiment of an expansion mandrel collet coupling device.

FIG. 14 is a side elevational view of an exemplary embodiment of an expansion mandrel collet in an expanded configuration by applying a force from a piston sleeve or a crush sleeve, as shown in the partial view.

Fig. 15 is a partial longitudinal section side elevational view of an example embodiment of an expansion mandrel collet operably coupled to an expansion mandrel collet coupling device of a pipette device.

Fig. 16 is a partial, cross-sectional, side elevational view of an exemplary embodiment of a disposable pipette tip operably coupled to a pipette device through an embodiment of an expanding mandrel collet coupling device.

Fig. 17 is a side elevational view of an exemplary embodiment of a disposable pipette tip in a support position.

Fig. 18 is a partial longitudinal cross-sectional side elevation view of an exemplary embodiment of a disposable pipette tip, showing its interior in detail.

Fig. 19 is a partial longitudinal cross-sectional side elevation view of an upper coupling portion of an exemplary embodiment of a disposable pipette tip illustrating in detail an interior coupled thereto.

FIG. 20 is a diagrammatic block diagram of an example embodiment of an automated pipetting station or system.

Fig. 21 is a partial longitudinal section side elevation view of an example embodiment of a pipette device supporting an example embodiment of an expanding mandrel collet coupling device on a disposable pipette tip.

Fig. 22 is a partial longitudinal cross-sectional side elevation view of an exemplary embodiment of an expanding mandrel collet coupling device positioned on and into a disposable pipette tip defining a coupling stage in which a distal elastomeric element initially contacts a seal seat surface of the pipette tip with a plurality of discrete coupling elements or segments in an uncompressed or radially outward unextended state, the seal seat surface having an acute seal seat surface angle with respect to a central longitudinal axis of the pipette tip.

Fig. 23 is a partial longitudinal cross-sectional side elevation view of an exemplary embodiment of an expanding mandrel collet coupling and a pipette tip, wherein the pipette tip is lifted due to a piston sleeve pushing down on an annular wedge to radially extend a circular portion of a plurality of expanding mandrel collet segments against an upper corner of a recess formed in the pipette tip, thereby creating an axial force that lifts or pulls the pipette tip upward, which begins the process of seating the pipette tip and pressing a distal elastomeric element against a seal seat surface of the pipette tip.

Fig. 24 is a partial longitudinal cross-sectional side elevational detail view of the rounded surface of one of the plurality of expansion mandrel collet segment arms of the expansion mandrel collet of the segmented coupling extending into contact with a corner of the pipette tip recess as shown in fig. 23.

Fig. 25 is a partial longitudinal cross-sectional side elevational view of a distal elastomeric element in an initial compressed state against a seal seat surface of the pipette tip shown in fig. 23.

Fig. 26 is a partial longitudinal cross-sectional side elevation view of an exemplary embodiment of an expanding mandrel collet coupling device further positioned in a pipette tip, wherein the pipette tip is lifted while the piston sleeve further depresses the annular wedge to continue radially extending the circular surfaces of the plurality of expanding mandrel collet segments into the recess of the pipette tip, thereby further pulling the pipette tip upward and further compressing the distal elastomeric element against the seal seat surface of the pipette tip.

Fig. 27 is a partial longitudinal cross-sectional side elevation view of a rounded surface of one of the plurality of expanding mandrel collet segments further extending into a recess of the pipette tip of fig. 26.

Fig. 28 is a partial longitudinal section side elevational detail of a distal elastomeric element further compressed from an initial compressed state against a seal seat surface of the pipette tip shown in fig. 26.

Fig. 29 is a partial longitudinal cross-sectional side elevational view of an exemplary embodiment of an expanding mandrel collet coupling device positioned at a disposable pipette tip, wherein the pipette tip is lifted to its final seated state by moving the annular wedge to its final position, thereby defining a final coupled state in which the distal elastomeric element is in a final compressed seated sealing state against a seal seat surface of the pipette tip.

Figure 30 is a partial longitudinal cross-sectional side elevation view of the circular surface of one of the plurality of expansion mandrel collet segments extending into abutment with the surface defining the groove, as shown in figure 29.

Fig. 31 is a partial longitudinal section side elevational detail view of a distal elastomeric element in a final compressed seated sealing condition against a seal seat surface of the pipette tip shown in fig. 29.

Fig. 32 is a partial longitudinal cross-sectional side elevation view of the beginning of a coupling between an example embodiment of an expanding mandrel collet coupling device and a disposable pipette tip, with a graphical representation of the associated forces.

Fig. 33 is a partial longitudinal cross-sectional side elevation view of one of the plurality of arcuate or circular segment surfaces of one of the plurality of expansion mandrel collet segments beginning with a recess of an example embodiment of a disposable pipette tip and interfacing with a diagram of associated forces.

Fig. 34 is a partial longitudinal cross-sectional side elevational detail view of a fully coupled state between an example embodiment of an expansion mandrel collet coupling device and a disposable pipette tip with a graphical representation of the associated forces.

Fig. 35 is a partial longitudinal cross-sectional side elevation view illustrating a misalignment coupling between an example embodiment of an expanding mandrel collet coupling device and a disposable pipette tip for defining a misalignment parameter.

Fig. 36 is a partial and cut-away longitudinal cross-sectional side elevational view of an embodiment of a pipette device operably coupled to a misalignment coupling between an example embodiment of an expanding mandrel collet coupling device and a disposable pipette tip for defining a misalignment parameter.

Fig. 37 is a partial and cutaway longitudinal cross-sectional side elevational view of an example embodiment of an air displacement pipette device coupled to an expansion mandrel collet coupling device coupled to a disposable pipette tip having a small liquid volume sandwiched between an end of the pipette tip and a working surface, and this view also having dimensional lines illustrated and identified.

Fig. 38 is a partial longitudinal cross-sectional side elevational view detailing the interior of an exemplary embodiment of a disposable pipette tip, and having dimension lines illustrated and identified.

Fig. 39 is a partial longitudinal section side elevational view of an example embodiment of a pipette device operably coupled to an example embodiment of an expansion mandrel collet coupling device, and illustrating and identifying dimension lines relative to dimension lines in fig. 38.

Fig. 40 is a longitudinal side elevation view of a pipette device assembly illustrating a circuit board processing signals from Liquid Level Detection (LLD) circuit contacts connected between the circuit board and a pinch sleeve in contact with the plurality of segments or elements coupled with a pipette tip via an annular wedge, wherein a distal end of the pipette tip is shown in contact with a liquid.

Fig. 41 is a partial longitudinal cross-sectional side elevation view of an example embodiment of an expanding mandrel collet coupling device positioned on an example embodiment of a disposable pipette tip, including an alternative seal seat surface at a substantially 90 degree angle relative to a central longitudinal axis of the pipette tip.

Fig. 42 is a partial longitudinal cross-sectional side elevational view of an exemplary embodiment of an expanding mandrel collet coupling device positioned in a disposable pipette tip, including an alternate seal seat surface angle of substantially 90 degrees, with the pipette tip lifted to its final seated state, and with the annular wedge moved to its final position for defining a final coupled state with the distal elastomeric element in a final compressed and seated sealing state against the alternate seal seat surface angle of substantially 90 degrees.

FIG. 43 is a partial longitudinal cross-sectional side elevational detail of the distal elastomeric member in a final compressed state against the substantially 90 degree alternative seal seat surface angle shown in FIG. 42.

Fig. 44 is a partial longitudinal cross-sectional side elevation view of an exemplary embodiment of a disposable pipette tip illustrating details of an interior on the disposable pipette tip including another alternative seal seat surface in the form of a circumferential radially concave seal seat surface.

Fig. 45 is a partial longitudinal cross-sectional side elevational detail view of an exemplary embodiment of a disposable pipette tip illustrating details of the circumferential radial concave seal seat surface shown in fig. 44.

Fig. 46 is a partial longitudinal cross-sectional side elevation view of an exemplary embodiment of a disposable pipette tip illustrating details of another alternative seal seat surface in the form of a circumferential radially convex seal seat surface.

Fig. 47 is a partial longitudinal cross-sectional side elevation view of an exemplary embodiment of a disposable pipette tip illustrating details of the circumferential radially convex seal seat surface shown in fig. 46.

Fig. 48 is a partial longitudinal cross-sectional side elevational view of an exemplary embodiment of a disposable pipette tip illustrating another alternative seal seat surface in the form of a toothed edge seal seat surface on a circumferential face.

Fig. 49 is a partial longitudinal cross-sectional side elevational view of an exemplary embodiment of a disposable pipette tip illustrating details of a tooth edge seal seat surface on the circumferential face shown in fig. 48.

Fig. 50 is a partial longitudinal section side elevational view of an exemplary embodiment of an expanding mandrel collet coupling device positioned on an exemplary embodiment of a disposable pipette tip that includes an alternative V-shaped groove defined by a V-shaped circumferential inner surface of the disposable pipette tip, the groove being open to the longitudinal axis and having a V-shaped cross-section as shown.

Fig. 51 is a partial longitudinal cross-sectional side elevation view of an example embodiment of an expanding mandrel collet coupling device positioned in a disposable pipette tip, including an alternative V-shaped groove, wherein the pipette tip is elevated to its final state, the circular surfaces of the plurality of expanding mandrel collet segments extending into the V-shaped groove and extending into abutting abutment against the V-shaped circumferential inner surface, wherein the distal elastomeric element is in a final compressed sealing state against a seal seat surface of the pipette tip.

Figure 52 is a partial longitudinal cross-sectional side elevational view of the circular surface of one of the plurality of expansion mandrel collet segments extending into the V-shaped groove and abutting against a V-shaped circumferential inner surface defining the V-shaped groove as shown in figure 51.

Fig. 53 is a partial longitudinal cross-sectional side elevation view of an example embodiment of an expanding mandrel collet coupling positioned on a second example embodiment of a disposable pipette tip.

Fig. 54 is a partial longitudinal cross-sectional side elevation view detailing the interior of a second exemplary embodiment of a disposable pipette tip.

Fig. 55 is a partial longitudinal cross-sectional side elevational view of an exemplary embodiment of an expanding mandrel collet coupling positioned in a second exemplary embodiment of a disposable pipette tip, with a stop disk shoulder surface of the coupling abutting against an axial stop surface of the second exemplary embodiment of the disposable pipette tip, and a circular surface of the plurality of expanding mandrel collet segments extending against an inner surface of a surrounding sidewall of the second exemplary embodiment of the disposable pipette tip, causing the inner surface to deform and the distal elastomeric element to be in a final compressed and seated sealing state against a seal seat surface of the second exemplary embodiment of the disposable pipette tip.

Fig. 56 is a partial longitudinal cross-sectional side elevational view of a circular surface of one of the plurality of expansion mandrel collet segments of an expansion mandrel collet coupling extending against and deforming an inner surface of an enclosing sidewall of the second exemplary embodiment of a disposable pipette tip as shown in fig. 55.

Fig. 57-67 are partial longitudinal cross-sectional side elevation views of an exemplary embodiment of a disposable pipette tip including alternative groove shape embodiments relative to at least the circumferential annular tip groove shown in fig. 19.

Fig. 68 is a top and side perspective view of a second or alternative example embodiment of an expansion mandrel collet of the expansion mandrel collet coupling device.

Figure 69 is a longitudinal cross-sectional side perspective view of a second or alternative example embodiment of an expansion mandrel collet coupling device.

Fig. 70 is a perspective view of an alternative example embodiment of an air displacement pipette device assembly of an automated liquid handling system.

Fig. 71 is a longitudinal-section side elevational view of one side of an alternative example embodiment of a pipette device assembly.

Fig. 72 is a partial longitudinal section side elevation view of another side of an alternative example embodiment of a pipette device assembly.

Fig. 73 is a partially exploded part view of a pipette device assembly illustrating in detail the parts of the pipette device shown in fig. 72.

Fig. 74 is a partially exploded perspective part view of a pipette device assembly illustrating in detail parts of an example embodiment of a nozzle and leaf spring coupling device.

Fig. 75 is a partially exploded, perspective part view detailing the parts of an exemplary embodiment of a nozzle and leaf spring coupling device sandwiched between a disposable pipette tip and a pipette device.

Fig. 76 is a side elevational view of an example embodiment of a leaf spring coupling.

Figure 77 is a top and side perspective view of an example embodiment of a leaf spring coupling device.

Fig. 78 is a top and side perspective view of an example embodiment of a lower or distal elastomeric element or O-ring of an example embodiment of a leaf spring coupling device.

Fig. 79 is a partial longitudinal section side elevation view of an example embodiment of a nozzle and leaf spring coupling device operably coupled to a pipette device.

Fig. 80 is a partial, cross-sectional, side elevational view of an exemplary embodiment of a disposable pipette tip operably coupled to a pipette device through an embodiment of a nozzle and leaf spring coupling device.

Fig. 81 is a partial longitudinal section side elevation view of an example embodiment of a pipette device supporting an example embodiment of a nozzle and leaf spring coupling device on a disposable pipette tip.

Fig. 82 is a partial longitudinal cross-sectional side elevation view of an exemplary embodiment of a nozzle and leaf spring coupling device positioned on and into a disposable pipette tip, defining a coupling stage in which the leaf spring is compressed, the retaining protrusion begins to enter a recess of the pipette tip, and the distal elastomeric element initially contacts a seal seat surface of the pipette tip, the seal seat surface having an acute seal seat surface angle with respect to a central longitudinal axis of the pipette tip.

Fig. 83 is a partial longitudinal cross-sectional side elevational detail view of a rounded surface of one of the plurality of retaining projections of a leaf spring coupling device in contact with a corner of the pipette tip recess shown in fig. 82.

Fig. 84 is a partial longitudinal cross-sectional side elevational view of a distal elastomeric element initially in contact with a seal seat surface of the pipette tip of fig. 82.

Fig. 85 is a partial longitudinal cross-sectional side elevation view of an example embodiment of a nozzle, a leaf spring coupling device, and a pipette tip with a retaining protrusion of a leaf spring snapped into a groove of the pipette tip and a distal elastomeric element compressed and seated against a seal seat surface of the pipette tip.

Fig. 86 is a partial longitudinal cross-sectional side elevation view of one of a plurality of arcuate or circular segment surfaces of a retaining projection of a leaf spring initially coupling with a groove of an example embodiment of a disposable pipette tip with a graphic representation of the associated forces.

Fig. 87 is a partial longitudinal cross-sectional side elevational view of one of the plurality of arcuate or circular segment surfaces of the retaining projection of the leaf spring initially coupling with a groove of an exemplary embodiment of a disposable pipette tip with a graphic representation of the associated forces.

Fig. 88 is a partial longitudinal cross-sectional side elevational view of a completed coupled state between a leaf spring coupling device and an exemplary embodiment of a disposable pipette tip with an illustration of the associated forces.

Fig. 89 is a partial longitudinal cross-sectional side elevation view of an example embodiment of a pipette device operably coupled to an example embodiment of a leaf spring coupling device, illustrating a Z-axis.

Fig. 90 is a partial longitudinal cross-sectional side elevation view of an exemplary embodiment of a leaf spring coupling device positioned in a disposable pipette tip including an alternative seal seat surface angle of substantially 90 degrees, wherein the pipette tip is lifted to its final seated state with the distal elastomeric element in final compressed and seated sealing state against the alternative seal seat surface angle of 90 degrees.

FIG. 91 is a partial longitudinal cross-sectional side elevational view of the distal elastomeric member in a final compressed state against a 90 degree alternative seal seat surface angle as shown in FIG. 90.

Detailed Description

For the purpose of illustrating the disclosure, there is shown in the drawings embodiments which are presently preferred. These example embodiments will now be described more fully with reference to the accompanying drawings, in which like reference numerals are used to refer to like parts or portions throughout the several views of the drawings.

Pipette assembly with expanding mandrel collet coupler and tip

Fig. 1 and 2 illustrate an example embodiment of a pipette device assembly 10, the pipette device assembly 10 including an example embodiment of a pipette device 20, an example embodiment of an expanding mandrel collet coupling device 100 or pipette tip coupler, and an example embodiment of a disposable pipette tip 220 removably coupled to the pipette device 20 by the expanding mandrel collet coupling device 100.

Pipette device 20

Referring to fig. 2, the pipette device 20 includes a body 22 supporting an aspiration and dispense device 24, the aspiration and dispense device 24 including a plunger 26 operably coupled to and driven by a motor 28. The plunger 26 resides within a plunger cylinder 30 extending from a distal or lower end 32 of the body 22 of the pipette device 20.

Pipette device 20 further includes a suction and dispensing cylinder 34 disposed at least partially within plunger cylinder 30 at a location axially aligned with plunger 26 and distally below plunger 26. Aspiration and dispensing cylinder 34 transitions distally to distal mounting flange 36 for attachment with expansion mandrel collet coupling 100, which expansion mandrel collet coupling 100 in turn removably couples with disposable pipette tip 220.

Referring to fig. 1, 3 and 15, the aspiration and dispensing cylinder 34 further includes an interior enclosing sidewall 38, the interior enclosing sidewall 38 defining an open-ended pipette channel 40 extending therethrough. The open-ended pipette channel 40 extends longitudinally along a longitudinal channel axis 80 of the pipette device assembly 10 between the open upper end portion 42 and the open lower end portion 44 of the aspiration and dispensing cylinder 34 for providing open communication between the plunger 26 and an exterior region adjacent the distal mounting flange 36, wherein the distal mounting flange 36 is operably coupled to the central body member 102 of the expansion mandrel collet coupling device 100, and the central body member 102 includes an open-ended central channel 136 extending through the central body member 102 to provide open communication between the tip 220 and the aspiration and dispensing cylinder 34 via the expansion mandrel collet coupling device 100.

Piston or squeeze sleeve 46

Referring to fig. 3 and 4, the pipette device 20 further includes a hollow piston or squeeze sleeve 46 having a proximal or upper end 48 and a distal or lower end 50. The compression sleeve 46 surrounds both the plunger cylinder 30 and the aspiration and dispensing cylinder 34 and is operably coupled to the compression motor 52.

As shown in fig. 4, the squeeze motor 52 of the pipette device assembly 10 is supported on the body 22 of the device 20 and is operatively coupled to and drives a lead screw 54, the lead screw 54 in turn being coupled to an axially translating lead nut 56, the lead nut 56 being operatively coupled to a squeeze link 58. The compression link 58 is operatively coupled to the proximal or upper end 48 of the compression sleeve 46 via the compression link arm 60 such that rotation of the compression motor 52 in a first direction results in linear axial translation of the compression sleeve 46 in a distal or vertically downward direction along the longitudinal channel axis 80 (fig. 3) and such that subsequent rotation of the compression motor 52 in a second or opposite direction results in linear counter-axial translation of the compression sleeve 46 in a proximal or vertically upward direction opposite the downward direction along the longitudinal channel axis 80 (fig. 3).

Ejector sleeve 62

Referring to fig. 4, the pipette device 20 further includes an ejector sleeve 62 for ejecting a disposable pipette tip 220 from the pipette device 20, wherein the ejector sleeve 62 is axially movable relative to the aspiration and dispensing cylinder 34 (fig. 2) and includes a proximal or upper end 64, a distal or lower end 66, and an ejector sleeve arm 68 attached to the ejector sleeve 62 at a first end adjacent the upper end 64, and having an opposite second end attached to the first end of the plunger device 70.

As shown in fig. 5, the plunger device 70 includes an opposing end surface 72 abutting one end of an ejection sleeve spring 74, the ejection sleeve spring 74 having an opposing spring end abutting against an upper surface portion 76 of the body 22 of the device 20, wherein the ejection sleeve spring 74 is captured between the

surfaces

72, 76 to be spring loaded to bias the plunger device 70 and attached sleeve 62 in a normal pipette tip ejection state.

The normal pipette tip ejection state is configured to require a force, such as coupling to pipette tip 220, to overcome the ejection sleeve spring force to axially push ejection sleeve 62 to the retracted state shown in fig. 2. Fig. 2 also illustrates that the spring 74 surrounds a central spring guide member 78 for retaining the shape of the spring 74 and preventing buckling of the spring 74.

Additionally, spring 74 is sized such that the force exerted by sleeve 62 on pipette tip 220 during relaxation thereof is sufficient to assist in ejection of tip 220 from expanded mandrel collet coupling device 100.

It should be understood that the expanding mandrel collet coupling device 100 and disposable pipette tips 220 may be implemented in other embodiments of pipette devices, wherein embodiments of pipette device 20 are by way of example only and not by way of limitation.

Expansion mandrel collet coupling 100

Referring to fig. 5-7, the expansion mandrel collet coupling 100 includes an elongated central body member 102; a distal or lower elastomeric element 140 carried at a distal or lower end portion of elongate central body member 102; an expansion collet 170 configured to surround the elongate central body member 102 and comprising a segmented collar 200; and an annular wedge or washer 210.

The annular wedge 210 is configured to receive an upper portion of the elongate central body member 102 therethrough for axially movable passage over an interior of the expansion collet 170 adjacent the segmented collar 200 for radially outward expansion of the segmented collar 200 from an unexpanded state having a first circumference to an expanded state having a second circumference greater than the first circumference, depending on the axial position of the annular wedge 210 relative to the central body member 102, for engaging an interior of a pipette tip 220 as shown in fig. 29 from a disengaged state as shown in fig. 21.

Elongated central body member 102

More specifically, and referring to fig. 7 and 8, the expansion mandrel collet coupling device 100 includes an elongated central body member 102, the elongated central body member 102 extending along a longitudinal central axis 90 between a proximal or upper annular end surface 104 and a distal or lower annular end surface 130.

As shown in fig. 8, the upper annular end face 104 of the central body member 102 includes an outer chamfered perimeter 106, the outer chamfered perimeter 106 transitioning into an elongated tubular upper shank member 108, the upper shank member 108 transitioning distally into an annular tapered portion 110. In one embodiment, the shank member 108 is threaded for assembly with a distal mounting flange 36 having corresponding threads. The annular tapered portion 110 decreases in diameter from the stem member 108 and transitions distally to a cylindrical neck portion 112. The cylindrical neck portion 112 transitions distally into a cylindrical collar 114 having a diameter greater than the diameter of the cylindrical neck portion 112.

The cylindrical collar 114 is followed by a lower cylindrical body member 120 having a diameter greater than the diameter of the cylindrical neck portion 112. Body member 120 extends distally from cylindrical collar 114 to an upper annular shoulder or stop surface 122 of a distal cylindrical shank surface 124, which surface 124 has a diameter greater than the diameter of lower cylindrical body member 120.

As shown in fig. 8, the distal cylindrical shank surface 124 transitions from the upper annular shoulder end 122 to a circular end plate 126, the circular end plate 126 having an upper surface 128 and a lower surface defined by a distal or lower annular end surface 130. As shown, the end plate 126 has a diameter greater than the diameter of the stem surface 124, wherein the distal stem surface 124 defines a distal or lower recessed portion 132 of the expansion mandrel collet coupling 100.

Referring to fig. 8 and 15, the elongate central body member 102 includes an inner cylindrical channel surface 134 defining an open-ended cylindrical central channel or passageway 136, the central channel or passageway 136 extending through the central body member 102 between the upper and lower annular end surfaces 104, 130 along the longitudinal central axis 90 for providing open channel communication through the elongate central body member 102 and to the open-ended pipette channel 40, the open-ended pipette channel 40 extending longitudinally along the longitudinal channel axis 80 of the pipette device assembly 10.

Distal elastomeric element 140

As shown in fig. 7, the expansion mandrel collet coupling device 100 further includes a distal or lower elastomeric element 140 coaxially carried at the distal end portion of the elongate central body member 102.

In one embodiment, and referring to fig. 9, the distal elastomeric element 140 includes an annular body 142. The annular body 142 includes an inner surface 144 defining a central opening 146, a top surface 148, a peripheral outer surface 150, and a bottom surface 152. As shown in fig. 7, the central opening 146 is sized to closely or tightly surround the distal cylindrical stem 124 of the expansion mandrel collet coupling device 100, while it is shaped to reside within the groove 132 and extend circumferentially radially outward beyond the end plate 126. In a relaxed or uncompressed state, the distal elastomeric element 140 includes a circumferentially continuous, generally circular cross-sectional area 154, as shown in fig. 15.

Spacer 160

Referring to fig. 10, the expansion mandrel collet coupling device 100 further includes a spacer 160, the spacer 160 configured to surround or be integrally formed with the elongated central body member 102. As shown, the spacer 160 includes a cylindrical body 162 extending between an upper end 164 and a lower end 165. The cylindrical body 162 includes an interior envelope surface 166 (fig. 15) that defines an open-ended passageway 168 extending through the body 162, wherein the passageway 168 is sized to closely or tightly envelope the lower cylindrical body member 120 of the elongated central body member 102.

Referring to fig. 7, 10 and 15, the spacer 160 is further configured to be surrounded by the expansion mandrel collet 170, wherein the upper end 164 of the spacer 160 abuts against the distal end of the mounting flange 36 and the lower end 165 abuts against an internal annular shoulder stop surface 177 of an annular base portion 172 of the expansion mandrel collet 170, wherein the annular base portion 172 further includes a distal or lower annular end 176 mounted on the distal annular shoulder stop surface 122 of the distal cylindrical stem portion 124 (fig. 8) of the elongated central body member 102 for securing the expansion mandrel collet 170 coaxially with the central body member 102 along the longitudinal central axis 90.

Referring to fig. 15 and 16, and as described above, handle member 108 of expansion mandrel collet coupling device 100 is configured to fit within distal mounting flange 36 of aspiration and dispensing cylinder 34 for operably coupling expansion mandrel collet coupling device 100 to pipette device 20 and removably coupling disposable pipette tips 220 to pipette device 20 through expansion mandrel collet coupling device 100 such that longitudinal channel axis 80 and central axis 90 form a coincident or common longitudinal channel axis.

Expansion mandrel collet 170

Referring to fig. 7 and 11, the expansion mandrel collet 170 includes a plurality of circumferentially spaced upwardly extending collet arms 180, the collet arms 180 transitioning upwardly from an end 184 attached to the lower annular base portion 172 to a free segmented end 200, the free segmented end 200 defining a segmented collar disposed axially above the lower annular base portion 172. The plurality of circumferentially spaced upwardly extending collet arms 180 are separated from one another by one of a plurality of circumferentially spaced upwardly extending slots 182.

As shown in fig. 11 and 12, each of the plurality of upwardly extending collet arms 180 includes a respective lower arm portion 186 that transitions to a respective upper arm portion 190. In one embodiment, the plurality of circumferentially spaced lower arm portions 186 form a generally cylindrical surrounding lower body portion 181, and the plurality of circumferentially spaced upper arm portions 190 form a frustoconical surrounding upper body portion 183 that transitions radially outward and upward from the lower body portion 181. The lower body portion 181 may be configured to have a slight upward taper or increased circumference relative to the distal or lower annular base portion 172.

Base portion 172

Referring to fig. 11 and 12, the distal or lower annular base portion 172 includes a distal or downward facing base surface 171 and a proximal or upward facing base surface 173. The distally facing base portion surface 171 transitions downwardly to a shortened distal or lower annular stem surface 174 terminating at a distal or lower annular base portion end 176 of a lower annular base portion 172. As shown in fig. 14, base surface 171 and base portion 172 define a shortened distal annular recess 178.

Referring to fig. 12 and 15, the lower annular base portion 172 further includes an inner cylindrical surface 175 that transitions upwardly into an inner annular shoulder stop surface 177, as shown in fig. 15, on which the spacer 160 is mounted. In addition, the inner cylindrical surface 175 is sized such that the inner diameter closely surrounds the lower cylindrical body member 120 of the central body member 102 at a location directly above the annular shoulder stop surface 122 of the central body member 102, wherein the annular shoulder stop surface 122 defines an axial stop for the lower annular base portion end 176 of the expansion mandrel collet 170 such that the expansion mandrel collet 170 is centrally mounted on the elongated central body member 102 and surrounds the elongated central body member 102.

Lower arm portion 186

As shown in fig. 11, the lower arm portion 186 includes distal or lower end portions 184 that are circumferentially spaced apart and attached to the lower annular base portion 172. As shown in fig. 12, the lower arm portion 186 further includes an upper end portion defining a middle arm portion having an inner annular recessed segmented surface or recess 191 and an outer radially outwardly extending annular segmented detent disk portion 194.

Referring to fig. 11 and 12, the segmented stopper disk 194 surrounds and extends radially outwardly from intermediate arm portions of the plurality of circumferentially spaced upwardly extending collet arms 180 to define an annular segmented stopper disk.

As shown in fig. 12, each segmented check disk 194 includes a proximally or upwardly facing check disk surface 198 and a distally or downwardly facing check disk surface 196. In addition, the plurality of lower arm portions 186 include an inner cylindrical or inner segment surface 188 that is sized to closely surround the spacer 160 with the spacer 160 surrounding the elongated central body member 102.

The distal or lower end of the inner segment surface 188 transitions radially inward into the inner annular shoulder stop surface 177, which provides a stop surface for the spacer 160, as described above. The proximal or upper end of the inner segment surface 188 transitions into an inner annular recessed segment surface or groove 191.

Upper arm section 190

Referring to fig. 11 and 12, the plurality of circumferentially spaced upper arm portions 190 transition upwardly and radially outwardly from respective lower arm portions 186 and terminate in a plurality of free ends 199 disposed above the lower arm portions 186 and radially outwardly from the lower arm portions 186, wherein the plurality of free ends 199 comprise radially outwardly projecting segments that define a segmented collar 200, wherein each segment comprises an outer outwardly facing surface 202, in one embodiment the outer outwardly facing surface 202 is shaped as an outward circle or arc corresponding to the arcuate recess of the exemplary embodiment of a pipette tip.

Thus, the upper arm portion 190 transitions upwardly and radially outwardly from the segmented stopper disk 194 to a plurality of radially outwardly projecting segments that define a segmented collar 200, wherein the segmented collar 200 is configured to surround the longitudinal central axis 90 of the expansion mandrel collet coupling 100, as shown in fig. 7.

Additionally, the plurality of circumferentially spaced apart radially outwardly and upwardly extending upper arm portions 190 comprising segments each comprise an inner surface 192 forming an inclined segmented inner surface complementary to a proximal inclined annular side surface 216 of the annular wedge 210 (fig. 7), wherein each comprises a distally decreasing circumference relative to the Z axis, and wherein the inner surfaces 192 of the upper arm portions 190 form a radially outwardly and upwardly extending conical gap 204 relative to the elongate central body member 102 (fig. 15).

In particular, and as shown in fig. 15, the upwardly and radially outwardly sloping inner surfaces 192 of the plurality of circumferentially spaced upper arm portions 190 define a distally tapering conical gap 204 between the inner surfaces 192 of the upper arm portions 190 and the combination of the lower portion of the mounting flange 36 and the upper portion of the spacer 160. The tapered conical gap 204 is configured to receive a lower portion of the annular wedge 210 such that an annular wedge-shaped or sloped outer side surface 216 of the annular wedge 210 abuts the inner surface 192 of the plurality of free ends 199, the free ends 199 supporting the protruding segments defining the segmented collar 200.

Annular wedge 210

Referring to fig. 7, 13 and 15, the annular wedge 210 comprises a resilient wedge-shaped annular body having a circumferentially continuous generally wedge-shaped cross-section 211. Annular wedge 210 includes a central inner annular surface 212, the central inner annular surface 212 defining a central annular opening 213 extending through annular wedge 210, the central annular opening 213 configured to movably surround body 102.

In addition, the annular wedge 210 includes a top planar circular surface 214 configured to form an electrical contact switch with the LLD circuit loop end 366 of the LLD circuit 364 and extending radially outward from the central, inner annular surface 212 to surround the outer edge surface 215.

In addition, the annular wedge 210 includes a radially outwardly proximally sloped side surface 216, the side surface 216 extending radially upwardly and outwardly from a bottom annular end 218 to an underside of an annular peripheral lip 219, the annular peripheral lip 219 extending radially outwardly and terminating in a surrounding outer edge surface 215. Thus, the radially outwardly proximally sloped side surface 216 defines a distally tapered wedge surface 216.

As shown in fig. 15, the central annular opening 213 of the annular wedge 210 is sized to allow passage of the distal mounting flange 36 and the elongate tubular upper handle member 108 so as to allow seating abutment of the radially outwardly proximally sloped side surface 216 of the annular wedge 210 with the inner surface 192 of the plurality of radially outwardly projecting segments 200 such that distal axial translation of the annular wedge 210 results in radial projection of the radially outwardly projecting segments 200 of the expansion mandrel collet 170 and subsequent proximal translation of the annular wedge 210 results in radial retraction of the radially outwardly projecting segments 200 of the expansion mandrel collet 170.

As further shown in fig. 15, the handle member 108 of the expansion mandrel collet coupling device 100 is configured to fit within the distal mounting flange 36 of the aspiration and dispensing cylinder 34 for operably coupling the expansion mandrel collet coupling device 100 to a pipette device 20 of the pipette device assembly 10 such that the longitudinal channel axis 80 and the longitudinal central axis 90 form a coincident or common axis.

The expansion collet 170 is further configured to expand the segmented collar 200 radially outward from an unexpanded state having a first circumference (as shown in fig. 7) to an expanded state having a second circumference (as shown in fig. 14) that is greater than the first circumference when the annular wedges 210 are moved axially downward under the force provided by the compression sleeve 46.

Actuation of a squeeze motor

Referring to fig. 15, the expansion mandrel collet coupling device 100 is configured to fit within the distal mounting flange 36 with the top planar circular surface 214 of the annular wedge 210 disposed adjacent the distal end 50 of the crush sleeve 46. Thus, referring to fig. 4 and 15, actuation of the squeeze motor 52 in a first direction causes linear axial translation of the squeeze sleeve 46 in a distal or vertically downward direction for axially applying a force on the top surface 214 of the annular wedge 210, thereby causing the distal tapered wedge surface 216 to slide further axially downward into the tapered gap 204 for forcing the distal tapered wedge surface 216 against the inner surfaces 192 of the plurality of radially outwardly projecting segments 200 for urging the outer radially outwardly facing surface 202 (fig. 11) of the segments 200 radially outward against the spring tension of the upwardly extending gripper arms 180 and into contact with a first working surface of the pipette tip in the form of a surface 244 defining a groove 246 of a disposable pipette tip 220, as illustrated below in fig. 29.

Subsequent actuation of the squeeze motor 52 in a second direction opposite the first direction returns the distal end 50 of the squeeze sleeve 46 to the original position shown in fig. 15, causing the annular wedge member 210 to slide axially upward, resulting in release of the potential energy stored in the upwardly extending gripper arm 180, causing the outer radially outward facing surfaces 202 of the plurality of radially outwardly projecting segments 200 to retract from the groove 246 of the disposable pipette tip 220.

Pipette tip 220

As shown in fig. 2 and 16, and as described above, the expanding mandrel collet coupling device 100 provides an open communicative coupling between a disposable pipette tip 220 and a pipette device 20 of a pipette device assembly 10.

Referring to fig. 16-18, and in one example embodiment, disposable pipette tip 220 includes an elongated tubular pipette tip body 222 having a central longitudinal axis 224. Pipette tip body 222 includes an elongated surrounding sidewall 226 extending longitudinally along central longitudinal axis 224 between a proximal or upper annular end surface 228 and a distal or lower annular end surface 230, defining surrounding open proximal and distal annular ends 232 and 234, respectively. The elongated surrounding sidewall 226 includes an inner surface 236, the inner surface 236 defining a pipette tip passage opening 238, the opening 238 extending longitudinally along the central longitudinal axis 224 of the pipette tip body 222 between the open upper annular end 232 and the open lower annular end 234.

Thus, when coupling device 100 is coupled between pipette device 20 and pipette tip 220, pipette tip channel opening 238 provides open communication through pipette tip 220 and to pipette device channel 40 (fig. 15) from an area outside of open distal annular end 234 (fig. 18) through central channel 136 of expanding mandrel collet coupling device 100 (fig. 16). In this coupled configuration, central longitudinal axis 224 of pipette tip body 222 is coextensive with longitudinal channel axis 80 of pipette device 20.

In an alternative embodiment, when nozzle 3102 and leaf spring coupling 3100 are coupled between pipette device 3020 and pipette tip 220, pipette tip channel opening 238 provides open communication through pipette tip 220 to pipette device channel 3040 (fig. 79) from an area outside of open distal annular end 234 (fig. 18) through central channel 3136 of nozzle 3102 and leaf spring coupling 3100 (fig. 80). In this coupled configuration, central longitudinal axis 224 (fig. 17) of pipette tip body 222 is coextensive with longitudinal channel axis 3080 of pipette device 3020.

A first inner surface section

Referring to fig. 18, and in one exemplary embodiment, an inner surface 236 of the elongated surrounding sidewall 226 includes an uppermost annular chamfered inner surface 240 that extends distally radially inward from the proximal annular end surface 228 of the pipette tip 220 and terminates by a transition to a first substantially cylindrical inner surface section 242 having a first diameter.

Axially arcuate peripheral surfaces defining a groove

As shown in fig. 18, and in one exemplary embodiment, the first substantially cylindrical inner surface section 242 includes an axially arcuate circumferential inner surface 244 formed into the elongated surrounding sidewall 226, the elongated surrounding sidewall 226 defining a circumferential annular groove 246. The annular groove 246 divides the first substantially cylindrical inner surface section 242 into an upper first substantially cylindrical inner surface portion and a lower first substantially cylindrical inner surface portion of substantially equal diameter. Thus, the annular groove 246 provides an arcuate surface longitudinal cross-section for the circumferentially radially outwardly extending concave inner surface discontinuity of the first substantially cylindrical inner surface section 242. The arcuate circumferential inner surface 244 is also configured with alternative surface cross-sections as discussed below. And in one embodiment, the first substantially cylindrical inner surface section 242 does not have an arcuate circumferential inner surface 244 defining a circumferential annular groove 246.

Referring to fig. 18 and 19, the axially arcuate circumferential inner surface 244 defining the annular groove 246 includes an upper annular transition edge 248 that transitions distally to an upper axially arcuate circumferential surface sector 250 of the axially arcuate circumferential inner surface 244. The upper axial arcuate circumferential surface sector 250 then transitions distally to a lower axial arcuate circumferential surface sector 252 of the axial arcuate circumferential surface 244. The lower axially arcuate circumferential surface scalloped portion 252 then terminates in a lower annular transition edge 254.

Upper axially arcuate circumferential surface scallop or upper portion 250 provides annular groove 246 with an increasing radius relative to central longitudinal axis 224 (fig. 17) of pipette tip 220 from upper annular transition edge 248 to the maximum radius of annular groove 246 relative to central longitudinal axis 224, which central longitudinal axis 224 defines the circumferential annular center of annular groove 246. Lower axially arcuate circumferential surface scalloped or lower portion 252 provides annular groove 246 with a decreasing radius relative to central longitudinal axis 224 of pipette tip 220 from a maximum radius defining the circumferential annular center of annular groove 246 to lower annular transition edge 254.

Second inner surface section and annular shoulder stop surface

As shown in fig. 18, the first substantially cylindrical inner surface section 242 is axially distally followed by a second substantially cylindrical inner surface section 262, the second diameter of the second substantially cylindrical inner surface section 262 being smaller than the first diameter of the first substantially cylindrical inner surface section 242 for forming a proximally facing, radially inwardly extending annular shoulder seating or axial stop surface 260 that is sandwiched between the first and second substantially cylindrical

inner surface sections

242, 262.

In an exemplary embodiment, proximally facing axial stop surface 260 is substantially planar and substantially perpendicular to central longitudinal axis 224 of pipette tip body 222, as shown in fig. 17.

Third inner surface section and sealing seat

As also shown in fig. 18 and 19, the second substantially cylindrical inner surface section 262 is axially distally followed by a third substantially cylindrical inner surface section 272, the third diameter of the third substantially cylindrical inner surface section 272 being less than the second diameter of the section 262.

Sandwiched between the second and

third segments

262, 272 is a frustoconical annular seal seat or stop surface 270, the seal seat or stop surface 270 defining a distal working surface 270 angled circumferentially radially inwardly and extending distally. The frustoconical annular seal seat surface 270 includes an upper annular seal seat edge 266 that defines an annular boundary between the second substantially cylindrical inner surface section 262 and the frustoconical annular seal seat surface 270. Additionally, the frustoconical annular seal seat surface 270 includes a lower annular seal seat edge 268 defining an annular boundary between the frustoconical annular seal seat surface 270 and the third inner surface section 272, wherein the upper annular seal seat edge 266 is of a larger diameter than the lower annular seal seat edge 268.

Accordingly, the frustoconical annular seal seat surface 270 defines a circumferentially radially inwardly angled and distally extending second working surface or seal seat surface 270 that is sandwiched between the second substantially cylindrical inner surface section 262 and the third substantially cylindrical inner surface section 272.

As shown, the seal seat surface 270 is disposed at an acute angle relative to the central longitudinal axis 224, wherein the acute angle defines an acute seal seat surface angle relative to the central longitudinal axis 224 (fig. 17). In one embodiment, the preferred acute seal seat surface angle relative to the central longitudinal axis 224 is about 15 degrees to about 35 degrees, with a preferred angle of about 25 degrees. As shown in fig. 41, the acute seal seat surface angle of the alternative seal seat surface 2270 with respect to the central longitudinal axis 224 is approximately 90 degrees.

Lower inner surface portion

Fig. 18 further illustrates the fourth inner surface section 274 after the third substantially cylindrical inner surface section 272, which is distally followed by the fifth inner surface section 275.

In an exemplary embodiment, the diameter of the fourth inner surface section 274 tapers or decreases from the annular distal end 276 of the third substantially cylindrical inner surface section 272 to the annular proximal end 278 of the fifth inner surface section 275. In turn, the fifth inner surface section 275 tapers or decreases distally in diameter from an annular proximal end 278 of the fifth inner surface section 275 to an open distal annular end 234 of the pipette tip 220 intended for submersion. Additionally, and in one exemplary embodiment, the fifth inner surface section 275 has a greater taper than the fourth inner surface section 274.

Outer longitudinal rib

Referring to fig. 17, an exemplary embodiment of a pipette tip 220 includes a plurality of circumferentially spaced longitudinally extending external ribs 280, the external ribs 280 being disposed on the tubular pipette tip body 222 adjacent a periphery of the annular proximal surface 228 and extending longitudinally outward from the annular proximal surface 228 to an external region surrounding the sidewall 226 adjacent the third substantially cylindrical internal surface section 272, as shown in fig. 18.

In an example embodiment, the plurality of circumferentially spaced apart longitudinally extending external ribs 280 may be used to provide support for pipette tip 220 on or in support surface 282 through which pipette body 222 has passed, for example, via support surface aperture opening 284. One exemplary embodiment of the support surface 282 may take the form of, but is not limited to, a laboratory vessel in the form of a pipette holder as is known in the art and informed by the present disclosure.

Automated pipetting station or system

Referring to fig. 5 and 20, and in one example of use and operation, one or more pipette device assemblies 10 are used in an automated pipetting station or system 300 that generally provides, but is not limited to, programmed transfer of inter-container liquids, including one or more disposable pipette tips 220 mounted to an expanding mandrel collet coupling device 100 operably carried by the pipette device 20 for performing, for example, programmed transfer of inter-container liquids and ejection processes.

In one example embodiment, the automated pipetting station 300 generally includes a robotic rack 302 carrying at least one pipette device assembly 10 vertically above a horizontally disposed station deck 304. The pipette device assembly 10 may include a single channel pipetting tip or a multi-channel pipetting tip.

In addition, the robotic gantry 302 typically provides two or three degrees of freedom, wherein the three degrees of freedom include longitudinal translation along an axis defining an X-axis, lateral translation along an axis defining a Y-axis, and vertical (up-down) translation along an axis defining a Z-axis, such that the pipette device assembly 10 may move along the length (X-axis) and width (Y-axis) of the table top, and vertically up-down (Z-axis) relative thereto. With two degrees of freedom, the robotic gantry is typically provided with the ability to translate the pipette device assembly 10 vertically and either longitudinally or laterally.

In one example embodiment, the automated pipetting station 300 further includes a main controller 306, a pipette axis controller 308, and a power source 310 that provides power to the main controller 306, the pipette axis controller 308, and the pipette device assembly 10.

Additionally, and in one example embodiment, a computer/controller 320 may also be employed with the workstation 300 and in communication with the main controller 306 and pipette axis controller 308 for controlling the robot gantry 302 and pipette device assembly 10, including associated process protocols of the pipette device assembly 10, such as the disposable pipette tip 220 attachment and ejection (coupling and decoupling) processes detailed below.

In one example embodiment, the computer/controller 320 generally includes a processor device or Central Processing Unit (CPU) 322, a hardware read-only memory device (ROM) 324, a hardware main memory device (RAM) 326, a hardware storage memory 328 (the hardware storage memory 328 includes a non-transitory computer-readable medium or memory 330 having an operating system 332 and software 334, the software 33 such as a user-defined program 336 for pipette device assembly 10 stored thereby), a user display 338, a user input device 340, an input interface 342, an output interface 344, a communication interface device 346, and a system bus 348, the system bus 348 including one or more conductors or communication paths that allow communication between devices of the computer/controller 320. The computer/controller 320 may also be operably coupled to a LAN and/or server 350. A power supply 352 provides power to the computer/controller 320.

Currently, Hamilton corporation, the assignee of the present patent application (Reynolds energy 4970, Nevada, USA, zip: 89502), manufactures and sells an example of the automated pipetting workstation 300 described above, including software.

Pipette tip picking process with expansion mandrel collet coupling

Fig. 21-31 illustrate details of example embodiments of successive stages of a pipette tip picking process, and in particular a method of fixedly attaching a pipette tip 220 to an expanding mandrel collet coupling device 100 operably carried by a pipette device 20. As described above, and in one example embodiment, pipette tip 220 may be supported by support surface 282.

As shown in fig. 21, expansion mandrel collet coupling device 100 is connected to pipette device 20 and, upon command, coupling device 100 is positioned over open proximal end 232 of pipette tip 220 with their respective central longitudinal axes aligned along the Z-axis. The ejector sleeve 62 is in the ejector position, the compression sleeve 46 is in the uncompressed position, the expansion mandrel collet 170 is in the relaxed state, and the distal O-ring 140 is in the uncompressed state.

Next, fig. 22 illustrates moving the expanding mandrel collet coupling device 100 down the Z-axis into the pipette tip 220 for lowering the distal elastomer bearing portion of the coupling device 100 to penetrate the internal cylindrical proximal portion of the pipette tip 220 in order to bring the distal O-ring 140 into contact with the annular seal seat or stop surface 270 of the tip 220 while maintaining the distal O-ring 140 in an uncompressed state, and then engaging the upwardly facing annular shoulder seat or stop surface 260 of the pipette tip 220 with the downwardly facing axial stop disk surface 196 of the stop disk 194.

Next, fig. 23 illustrates the coupling device 100 further moved downward along the Z-axis. In addition, and referring to fig. 23-25, squeeze sleeve 46 moves downward along the Z-axis and pushes against LLD circuit collar end 366, which collar end 366 contacts and pushes against top surface 214 of annular wedge 210, which top surface 214 is located above expansion mandrel collet 170, while maintaining the plurality of radially outwardly projecting segments 200 in an unexpanded state, as detailed in fig. 24, maintaining distal O-ring 140 in an uncompressed state, as detailed in fig. 25, and prior to engagement of stop surface 260 of pipette tip 220 and axial stop shoulder surface 196 of stop disk 194, such that gap 298 is maintained between stop surface 260 of pipette tip 220 and axial stop shoulder surface 196 of stop disk 194 of expansion mandrel collet 170, as detailed in fig. 23.

Next, fig. 26 illustrates further downward movement of the pressing sleeve 46 along the Z-axis to push the annular wedge 210 against the inner surfaces 192 of the plurality of radially outwardly projecting segments 200, thereby pushing them radially outwardly and abutting the outer radially outwardly facing circular surfaces 202 of the plurality of radially outwardly projecting segments 200 against the upper axially arcuate circumferential surface sectors 250 of the groove 246 of the disposable pipette tip 220, as shown in detail in fig. 27, for initiating the process of pressing or pushing the plurality of radially outwardly projecting segments 200 into the groove 246 and initially into abutment with the upper axially arcuate circumferential surface sectors 250 of the axially arcuate circumferential inner surface 244 defining the groove 246. As shown in fig. 26, the action of the plurality of radially outwardly projecting segments 200 extending or projecting into groove 246, as shown in detail in fig. 27, results in an axially upward force that begins the process of pulling up on pipette tip 220 for the purpose of beginning the process of seating annular shoulder seating surface 260 of pipette tip 220 with axial stop shoulder surface 196 of stop disk 194 to close gap 298 (fig. 23) and compress distal O-ring 140 with seal seat or stop surface 270 of tip 220, as shown in detail in fig. 28.

Fig. 29 illustrates the crush sleeve 46 moved down the Z-axis a predetermined length configured until it locks into place, causing the annular wedge 210 to be stopped and locked into place by the crush sleeve 46.

Thus, the plurality of radially outwardly projecting segments 200 extend radially to a desired distance or value, as illustrated in fig. 30, for seating the axial stop shoulder surface 196 of the expansion mandrel collet coupling 100 fully against the annular shoulder seat surface 260 of the pipette tip 220, with both

surfaces

196, 260 seating along an X-axis that is substantially perpendicular to the Z-axis to form a normal reference between the two axes.

At the same time, compressing distal O-ring 140 to a desired distance or value, as illustrated in fig. 31, serves to seat distal O-ring 140 with annular seal seat surface 270 of tip 220, with its cross-section in its final compressed non-circular shape, thereby completing the attachment of a stationary pipette tip 220 with an expanding mandrel collet coupling 100 operably carried by pipette device 20.

Upon completion of the secure attachment process detailed above, the plurality of radially outwardly projecting segments 200 and distal elastomeric element 140 work in combination to create a segmented and sealed coupling that provides a fluid-tight seal, wherein the plurality of radially outwardly projecting segments 200 are at least partially received within circumferential groove 246 and at least partially seated against circumferential arcuate inner surface 244 defining circumferential groove 246 (fig. 18), and wherein distal elastomeric element 140 seals against surface 270 of pipette tip 220, wherein, in one embodiment, surface 270 provides a radially inwardly angled and distally or downwardly extending surface.

Thus, the plurality of radially outwardly projecting segments 200 move radially outwardly to engage the circumferential groove 246 (fig. 18) to couple with the suction head 220 and move radially inwardly to release the suction head 220 in accordance with the movement of the annular wedge 210. Application of a force to move the annular wedge 210 axially downward causes the plurality of radially outwardly projecting segments 200 to be pushed to a radially outward position, and release of the force on the annular wedge 210 causes energy to be released from the cantilevers 180 (fig. 11) supporting the plurality of radially outwardly projecting segments 200, causing the segments to spring back to a radially inward position from the radially outward position.

Disposable pipette tip ejection process

Fig. 21-31 inversely illustrate details of successive stages of an example method or process of ejecting a pipette tip 220 from an expanding mandrel collet coupling device 100 operably carried by a pipette device 20. This tip ejection process sequence is similar to the attachment or tip pick-up securing process sequence except that instead, fig. 34 illustrates the distal O-ring axial force component of the compressed distal O-ring 140, which provides a force to assist in removing the tip 220 during the ejection process.

In one example embodiment, the ejection process comprises the steps of: (1) positioning the pipette tip in its position to be discarded, such as a waste container; (2) moving the squeeze sleeve 46 upwardly, wherein the force is released from the annular wedge 210 and, as a result, the force is also released from the plurality of radially outwardly projecting segments 200 so as to allow retraction from the groove 246 in the tip 220, the distal O-ring 140 begins to release the stored elastic potential energy or spring energy as a force against the tip 220, and wherein the spring-loaded ejector sleeve 62 also pushes against the tip 220 to push it away, such that the tip begins to be released from the plurality of radially outwardly projecting segments 200; (3) continuing to move the compression sleeve 46 upwardly, wherein the plurality of radially outwardly projecting segments 200 continue to retract from the groove 246 in the tip 220, and wherein the distal O-ring 140 and the spring-loaded ejector sleeve 62 push against the tip 220 to push it away, wherein the tip 220 continues to be released from the plurality of radially outwardly projecting segments 200; and (4) continuing further to move the squeeze sleeve 46 to its uppermost position, wherein the plurality of radially outwardly projecting segments 200 return to their original retracted free state and are completely disengaged from the groove 246 in the pipette tip 220, and wherein the distal O-ring 140 returns to its original shape and the spring-loaded ejector sleeve 62 pushes against the pipette tip 220 until the pipette tip is pushed away from the coupling 100 by the spring-loaded ejector sleeve 62 and the spring-loaded ejector sleeve 62 becomes fully extended.

In view of the foregoing, those skilled in the art will appreciate that these tip installation and ejection processes are applicable to a wide variety of mechanically and/or automatically driven pipette types and designs.

Coupling force and ejection force

Fig. 32 illustrates a diagrammatic vector diagram of a plurality of radially outwardly projecting segments 200 of the expansion mandrel collet coupling 100, the segments 200 initially extending into the groove 246, wherein the radial rounded surfaces 202 of the plurality of radially outwardly projecting segments 200 contact the upper corner of the tip groove above the center of the segment radius, thereby creating an axially upward force that pulls the pipette tip 220 upward. As shown in fig. 32, the segment force (fsegion _ total force) of each of the plurality of radially-outwardly projecting segments 200 is comprised of two components: an axial force (F segment _ axial) component and a radial force (F segment _ radial) component.

As long as the plurality of radially outwardly projecting segments 200 are contacting the upper corner of the tip recess above the center of the segment radius (dimension Z in FIG. 33), segment F _ axial increases as the distance between the segment radius center and the recess corner increases. Thus, at the beginning of the tip picking process, the segment axial force (F segment _ axial) is initially low, as shown in FIG. 32, and in detail in FIG. 33, and increases to its maximum value at the end of the tip picking process, as shown in FIG. 34.

Referring to fig. 33, the ratio of Z/R is equal to SIN (ω), and SIN (co) is equal to (fsegment _ axial)/(fsegment _ total). Thus, (F segments _ axial) is equal to the ratio of (F segments _ total force) multiplied by Z/R. Thus, the result is that (F segment _ axial) increases with increasing Z.

Referring to fig. 34, the segmental axial force (fsegion _ axial) seats the check disk 194 against the seat 260 of the tip 220 and provides the force required to overcome the O-ring axial force (fsekiln _ ringjaxial) and compress the distal O-ring 140. The O-ring 140 has an O-ring force (fsidenjiei _ resultant force) resulting from compression, and this O-ring force includes two components: an axial component (fsistan _ ring _ axial) and a radial component (fsistan _ ring _ radial). In addition, the segment radial force (fsegi _ radial) provides the radial force required to lock the segment into the tip recess 246 (fig. 18), and the distal O-ring radial force component (fseki _ ring _ radial) provides the radial force required to maintain the seal against the tip. Further, as the segments enter the groove (increasing dimension Z), the segment to tip groove geometry that results in an F-segment _ axial increase helps overcome the O-ring axial force (fsekinun _ ringjjjjj) so that the distal O-ring 140 can be fully compressed to the desired extent. In addition, the distal O-ring axial force component (fsemin _ ring _ axial) provides a force to assist in the removal of the tip 220 during the ejection process.

Alignment/misalignment

The axial shoulder surface 196 of the coupling 100 and the axial shoulder seat 260 of the tip 220 are important for proper tip alignment. Thus, the coupling 100 and the suction head 220 are configured such that the plurality of radially outwardly projecting segments 200 push the axial shoulder surface 196 and the axial shoulder seat 260 together to prevent misalignment, as the misalignment error (E) can be significant if the shoulders do not mate properly, particularly if they are tilted.

For example, and as shown in FIGS. 35 and 36, the misalignment angle (C:)

) The relationship between tip axial distance (D) and positional error (E) is: e = D star (TAN: (D) (), (c)

). For example, for a misalignment angle of two degrees: (

) And a tip axial distance of 90 mm, the positional error (E) is 3.14 mm. This is considered to be very high considering that typical position error tolerances are typically plus or minus 0.5 mm.

Fig. 37 illustrates proper tip alignment when axial shoulder surface 196 and axial shoulder seat 260 are in flush contact with each other to provide proper alignment and to maintain a tip axial distance D from tip seat 260 to distal end 230 constant to establish a known and controlled distance of pipette tip end 230 along vertical or axial axis Z and vertical axis X. This is important to allow the pipette device to target small holes and small volumes of liquid. In addition, smaller volumes of liquid may be transferred because the known fixed distance of the pipette tip allows for controlled contact of the pipette tip/liquid with the working surface 290 (the liquid 292 will be transferred onto or from the working surface 290).

Size and relationship

Accordingly, the dimensions between the coupling 100 and the suction head 220 are accordingly related for proper use and operation.

Referring to fig. 15, 38 and 39, the tip recess diameter a must be large enough to allow the segment 200 to pull the tip 220 upward and sufficiently lock the tip 220 in place. Conversely, if too large, the segments 200 may not be pushed in sufficiently to achieve a good lock. In addition, inner diameters B and C must be greater than outer diameter K of the check disk 194 and outer diameter L of the annular base 172, respectively. However, they cannot be too large, as this may result in poor fit and/or misalignment.

Referring to fig. 38 and 39, the tip seat-to-recess dimension S must match the stop disk seat surface 196-to-center dimension M of the segment 200. This relationship is critical to the coupling between the cleaner head 220 and the check disk 194.

Referring to fig. 19, 38 and 39, the dimension of the tip seat surface 260 to the O-ring sealing area 266 in fig. 19 (dimension F in fig. 38) must match the dimension (N) of the retaining disk surface 196 to the distally facing vertical lip surface 171 in fig. 39. These dimensions control the amount that the distal O-ring 140 is compressed and thus whether its seal is good. The tip surface 260 and the check disk seating/coupling surface 196 must be fully mated in order to provide proper alignment and maintain the tip axial distance D.

Referring to fig. 37-39, the dimension D (or axial distance) between tip seat 260 and distal end 230 and the fit of the coupling seat establish a known and controlled distance of the pipette tip end. This is important to allow the pipette device to target small holes and small volumes of liquid. In addition, smaller volumes of liquid may be transferred because the known fixed distance of the pipette tip allows for controlled contact of the pipette tip/liquid with the work surface onto or from which the liquid is to be transferred.

Referring to fig. 15, 38 and 39, the tip inner diameter G must be less than the diameter L of the base 172 in order to provide a seat or region for the distal O-ring 140 to seal against. If the diameter G is too large, the distal O-ring may not seal well. If the diameter is too small, the distal O-ring 140 may not compress fully and may prevent the check disk 194 from seating or may cause damage to the distal O-ring 140. In addition, ramp length H, along with diameter G, controls the seat or region that mates with O-ring 140. These dimensions are critical to provide a good O-ring seal. If the ramp length H is too long, the O-ring may not seal well. If H is too short, the O-ring may not compress fully and may prevent the check disk 194 from seating or may cause damage to the O-ring 140.

Liquid Level Detection (LLD) circuit contact

Referring to fig. 40, and in one example embodiment, the pipette device assembly 10 further includes a liquid level detection circuit assembly. The liquid level detection circuit assembly includes a liquid level detection or LLD circuit board 360 that includes a processing circuit 362 electrically coupled to an LLD circuit contact 364, the LLD circuit contact 364 operatively coupled to the crush sleeve 46, the crush sleeve 46 being made of an electrically non-conductive material so that it is insulated from the rest of the assembly, and wherein the contact 364 terminates in a circuit contact ring end 366 recessed in a bottom region of the crush sleeve 46, the circuit contact ring end 366 configured for selectively contacting the circuit contact ring end 366 with the annular wedge 210, and thus with the plurality of conductive segments or elements coupled with the inner first working surface of the conductive tip 220, between a non-contacting state shown in fig. 22 and a contacting state shown in fig. 29.

As shown in fig. 29, the LLD circuit contact 364 includes a looped end 366 captured between the crush sleeve 46 and the annular wedge 210, wherein electrical closure or electrical contact is made between the processing circuit 362 of the LLD circuit board 360 (fig. 40) and the annular wedge 210 made of a conductive material. The annular wedge 210 pushes the plurality of radially outwardly projecting segments 200 into electrical contact therewith, the segments 200 being formed of an electrically conductive, non-brittle material.

Thus, with the tip attached and the plurality of radially outwardly projecting segments 200 squeezed or pushed and locked into the tip recesses 246 of the tip 220, the plurality of radially outwardly projecting segments 200 make electrical contact with the tip 220, which is also made of an electrically conductive material. As a result, and referring to FIG. 40, this completes the electrical circuit between the processing circuitry 362 of the LLD circuit board 360 and the suction head 220.

Additionally, the stop disk mounting post or distal mounting flange 36 is made of a non-conductive material. Thus, the body member 102 and the plurality of radially outwardly projecting segments 200 are insulated from the rest of the assembly.

In addition, when the tip 220 contacts the liquid, the processing circuitry 362 of the LLD circuit board 360 detects the signal change, thereby having the ability to detect the surface of the liquid being transferred or the surface onto or from which the liquid is being transferred. Again, actuation occurs when the coupling device 100 is attached to the tip 220 and the plurality of radially outwardly projecting segments 200 are pushed radially circumferentially and locked into the tip recesses of the tip 220.

Alternative example embodiments

Fig. 41 illustrates an example embodiment of an expanding mandrel collet coupling device 100 positioned over an example embodiment of a disposable pipette tip 220, the device including an alternative seal seat surface 2270, the seal seat surface 2270 having a substantially 90 degree angle with respect to the central longitudinal Z-axis of the pipette tip 220.

Fig. 42 illustrates an example embodiment of an expansion mandrel collet coupling device 100 positioned in a disposable pipette tip, the device including an alternative seal seat surface 2270, wherein the tip 220 is lifted to its final seated state, and the annular wedge 210 is moved to its final position for defining a final coupled state, wherein the distal elastomeric element 140 is in a final compressed and seated sealing state against the alternative seal seat surface 2270.

Fig. 43 details the final compressed state of the distal elastomeric element 140 against the alternate seal seat surface 2270.

Fig. 44 illustrates an upper interior of disposable pipette tip 220, including another alternative seal seat surface in the form of a circumferential radially concave seal seat surface 3270. FIG. 45 shows in detail the circumferential radially concave seal seat surface 3270 shown in FIG. 44.

Fig. 46 illustrates an example embodiment of a disposable pipette tip 220 illustrating details of another alternative seal seat surface in the form of a circumferential radially convex seal seat surface 4270. FIG. 47 illustrates in detail the circumferentially radially raised seal seat surface 4270 shown in FIG. 46.

Fig. 48 illustrates an example embodiment of a disposable pipette tip 220 illustrating yet another alternative seal seat surface in the form of a circumferentially upwardly facing tooth edge seal seat surface 5270. FIG. 49 shows in detail the circumferentially upwardly facing tooth edge seal seat surface shown in FIG. 48.

Fig. 50 is a partial longitudinal section side elevational view of an exemplary embodiment of an expanding mandrel collet coupling device 100 positioned over an exemplary embodiment of a disposable pipette tip 220 that includes an alternative V-shaped groove 2246 defined by a V-shaped circumferential inner surface 2244 of disposable pipette tip 220, the groove 2246 opening toward the longitudinal Z-axis and having a V-shaped cross section as shown.

Fig. 51 illustrates the expansion mandrel collet coupling device 100 positioned in a disposable pipette tip 220 that includes an alternative V-shaped groove 2246 (fig. 50) wherein the tip 220 is lifted to its final state, the circular surfaces 202 of the plurality of expansion mandrel collet segments 200 extend into the V-shaped groove 2246 and abut against the V-shaped circumferential inner surface, the distal elastomeric element 140 being in a final compressed and seated sealing state against the tip seal seat surface 270.

Fig. 52 illustrates the circular surface 202 of one of the plurality of expansion mandrel collet segments 200 extending into the V-shaped groove 2246 and abutting against the V-shaped circumferential inner surface 2244 defining the V-shaped groove 2246.

Fig. 53 illustrates an example embodiment of an expansion mandrel collet coupling device positioned over a second example embodiment of a disposable pipette tip 1220 that does not have an arcuate circumferential inner surface 244 defining a circumferential annular groove 246 for the disposable pipette tip 1220.

Fig. 54 shows in detail the interior of a second exemplary embodiment of a disposable pipette tip 1220, all parts of which are similar, except that the interrupted inner surface section 242 of the first substantially cylindrical inner surface section 242 shown in fig. 18 is uninterrupted, thereby defining an interrupted inner surface portion 1242 of the disposable pipette tip 1220, wherein the inner surface portion 1242 defines a first working surface.

Fig. 55 illustrates an example embodiment of the expansion mandrel collet coupling device 100 positioned in a second example embodiment of a disposable pipette tip 1220, wherein the stop disk shoulder surface 196 of the coupling device 100 abuts against the axial stop surface 260 of the second example embodiment of the disposable pipette tip 1220, and the circular surfaces 202 of the plurality of expansion mandrel collet segments 200 extend against the inner surface 1242 of the surrounding sidewall of the second example embodiment of the disposable pipette tip 1220, causing deformation 1244 of the inner surface 1242, and the distal elastomeric element 140 is in a final compressed and seated sealing state against the seal seat surface 270 of the second example embodiment of the disposable pipette tip 1220.

Fig. 56 details the rounded surface 202 of one of the plurality of expansion mandrel collet segments 200 of the expansion mandrel collet coupling device 100, which extends against and deforms 1244 the interior surface 1242 of the surrounding sidewall of the second exemplary embodiment of a disposable pipette tip shown in fig. 55.

Fig. 57-67 are partial longitudinal section side elevation views of an exemplary embodiment of a disposable pipette tip including alternative groove shape embodiments with respect to circumferential annular tip grooves of at least the segment 200 shown in fig. 19 and V-shaped groove segments 200 at least shown in fig. 50.

In particular, fig. 57-67 illustrate alternative groove configurations 2251-2261, respectively, for receiving segment 200.

Alternative example embodiment clip 2170

Fig. 68 illustrates a second or alternative embodiment of an expansion mandrel collet 2170 configured as a direct replacement for the expansion mandrel collet 170 (fig. 5) of the expansion mandrel collet coupling device 100 (fig. 5). The expansion mandrel collet 2170 is similar in function to the collet 170, but is configured to improve performance and life.

Referring to fig. 68 and 69, the expansion mandrel collet 2170 includes a plurality of circumferentially spaced apart upwardly extending collet arms 2180, the collet arms 2180 extending radially outwardly from the lower annular base portion 2172 and arcuately transitioning upwardly and terminating in free segmented ends 2200 that define a segmented collar disposed axially above the lower annular base portion 2172. The plurality of circumferentially spaced upwardly extending collet arms 2180 are separated from one another by one of a plurality of circumferentially spaced upwardly extending cutouts or slots 2182.

Referring to fig. 68 and 69, each of the plurality of upwardly extending collet arms 2180 includes a respective lower arm portion 2186 that transitions to a respective upper arm portion 2190. In one embodiment, the plurality of circumferentially spaced lower arm portions 2186 form an enclosing lower body portion 2181 and the plurality of circumferentially spaced upper arm portions 2190 form a frustoconical enclosing upper body portion 2183 that transitions radially outwardly and upwardly from the lower body portion 2181.

Referring to fig. 68 and 69, distal or lower annular base portion 2172 includes a distally or downwardly facing base surface 2171. The distally facing base surface 2171 transitions down to a shortened distal or lower end annular rod surface 2174 that terminates at a distal or lower annular base portion end 2176 of the lower annular base portion 2172. The base surface 2171 and lower annular rod surface 2174 define a shortened distal annular groove.

As shown in fig. 69, the lower annular base portion 2172 further includes an inner cylindrical surface 2175 that transitions up to an inner annular shoulder stop surface 2177.

As further shown in fig. 69, the lower arm portion 2186 includes circumferentially spaced apart lower end portions 2184 that are attached to the lower annular base portion 2172. The lower arm portion 2186 also includes an upper end portion defining an intermediate arm portion having an inner annular recessed segmented surface or groove 2191 and an outer radially outwardly extending annular segmented detent disk portion 2194. The segmented stopper disk 2194 surrounds and extends radially from the outer portion of the intermediate arm portion of the plurality of circumferentially spaced upwardly extending collet arms 2180 that define an annular segmented stopper disk. Each segmented stopper disk 2194 includes a proximally or upwardly facing stopper disk surface 2198 and a distally or downwardly facing stopper disk surface 2196. In addition, the plurality of lower arm portions 2186 include an inner cylindrical or inner segmented surface 2188 that is sized and dimensioned to closely surround the spacer 160 (FIG. 10) with the spacer 160 surrounding the elongated central body member 102 (FIG. 10).

Referring to fig. 68 and 69, the plurality of circumferentially spaced upper arm portions 2190 transition upwardly and radially outwardly from the respective lower arm portions 2186 and terminate in a plurality of free ends 2199, the free ends 2199 disposed above the lower arm portions 2186 and radially outwardly from the lower arm portions 2186, wherein the plurality of free ends 2199 comprise radially outwardly projecting segments that define a segmented collar 2200, wherein each segment comprises an outer outwardly facing surface 2202 that, in one embodiment, is outwardly circular or arcuate in shape. Thus, the upper arm portion 2190 transitions upwardly and radially outwardly from the segmented stop disk 2194 to a plurality of radially outwardly projecting segments that define a segmented collar 2200. In addition, a plurality of circumferentially spaced apart radially outwardly and upwardly extending upper arm portions 2190 comprising segments each include an inner surface 2192 that forms an inclined segment inner surface that is complementary to the proximally inclined annular side surface 216 (fig. 13) of the annular wedge 210 (fig. 13).

Comparing fig. 12 and 69, the expansion mandrel collet 2170 widens the base of each end 2184 of each respective arm 2180 relative to the expansion mandrel collet 170 and extends the end 2184 of the arm 2180 radially outward to increase the radius of each arm 2180 relative to the expansion mandrel collet 170. Pushing the lower ends outward and increasing their diameters allows for a greater chord length or width at the bottom end 2184 of each extension arm 2180, with the increased width of each extension arm 2180 increasing the strength of each extension arm 2180. In addition, increasing the radial extension at the lower end 2184 of the arm 2180 provides increased strength. The coupling function is unchanged.

From an engineering perspective, the extension arm 2180 may also be modeled as a curved cantilever beam. Classical material strength techniques can be used to assess material stresses when the beam is subjected to bending, as occurs when the coupling is engaged and disengaged. In addition, material stresses can be analyzed in terms of fatigue strength when bending is performed repeatedly or cyclically to provide adequate product life. Increasing the width at the beam base and increasing the associated radius are geometric modifications to reduce stress and improve strength.

Apparatus aspect

In one aspect, a pipette tip coupling device or an expansion mandrel collet coupling device 100 may provide an increased service life.

On the other hand, the radially outwardly projecting section 200 of the expansion mandrel collet 170 provides a more rigid coupling for providing a more rigid joint between the pipette tip 220 and the coupler 100.

On the other hand, the radially outwardly projecting section 200 of the expansion mandrel collet 170 pulls the suction head 220 upwardly and efficiently seats it.

On the other hand, the coupling 100 will not be affected by ejection of the cleaner head in free air. The O-ring coupling life is adversely affected when the cleaner head is ejected in free air, as the O-ring is gouged and worn by the grooves in the cleaner head as the cleaner head is pushed out by the spring-loaded ejector sleeve. The hardness of the radially outwardly projecting segments 200 resists the deleterious effects of such scuffing and wear.

On the other hand, the material of the expansion mandrel collet 170 may be readily made of a conductive material to provide a circuit for the pipette tip for level detection or other uses as described in detail above.

On the other hand, the radially outwardly projecting segments 200 of the expansion mandrel collet 170 are made of a hard and durable material, such as, but not limited to, metal or hard plastic, to provide improved longevity, and since the discrete elements or segments are much harder than plastic tips, they work more efficiently into the tip recesses than soft elastomeric materials such as O-rings.

On the other hand, due to the high efficiency of the mechanical design, the radially outwardly protruding segments 200 can be activated with low pressing/axial forces. Lower compression/axial force requirements increase the life of the associated parts providing the axial force. Due to this lower compression/axial force requirement, the radially outwardly projecting segments 200 allow for an increased life of the lower or distal seal 140 because the elastomeric material is not compressed as much.

On the other hand, the coupling 100 allows easy access to the lower or distal seal 140 if replacement is required. Further, the lower or distal seal 140 can be made from a wider variety of materials because it does not need to conduct electricity for the LLD circuit.

On the other hand, maintenance costs are lower due to improved life and easier access to the lower or distal seal.

On the other hand, the alignment of the pipette tip with the pipette device 20 is improved due to the improved seating.

Method aspect

In view of the above, and in another aspect, there is provided an exemplary embodiment of a method for fixedly attaching at least one pipette tip to at least one pipette tip coupler in the form of an expanding mandrel collet coupling device carried by a pipette device, the method comprising: (1) providing a pipette tip comprising a sidewall having an inner enclosing surface defining a channel opening extending between an open distal end intended for immersion in a medium to be pipetted and an open proximal end opposite the open distal end in an axial direction; (2) providing a pipette tip coupler including a distally facing axial stop shoulder surface formed by an axially stepped coupler shoulder of an outer surrounding surface of the pipette tip coupler complementary to a proximally facing axial stop surface formed by an axially stepped shoulder surface of an inner surrounding surface of a pipette tip sidewall; (3) providing a plurality of discrete coupling elements or segments circumferentially spaced apart and disposed on the upper seating surface of the pipette tip coupler body; (4) providing a distal elastomeric element carried by a pipette tip coupler at a location below the axial stepped coupler shoulder; (5) positioning a distal end of a pipette tip coupler over an open proximal end of a pipette tip, wherein a central longitudinal axis of the pipette tip coupler and a central longitudinal axis of the pipette tip are axially aligned; (6) translating a distal end of a pipette tip coupler through an open proximal end of a pipette tip until a distal elastomeric element contacts a circumferentially radially inwardly angled and distally extending inner working surface of an inner enclosing surface of a pipette tip sidewall, the inner working surface being distal from an axially stepped shoulder of the inner enclosing surface of the pipette tip sidewall; and (7) axially pressing or pushing the plurality of discrete coupling elements or segments into a radially extended state abutting an upper axially arcuate circumferential surface segment of an axially arcuate circumferential inner surface defining a groove formed into an inner surrounding surface of a sidewall of the pipette tip at a location above an axial stop surface of the pipette tip for providing a proximally directed radial and axial resultant pre-stress to the pipette tip for energizing the distal elastomeric element into a compressed state configured for providing axial and radial sealing abutment of an outer circumferential portion of the distal elastomeric element with a circumferentially radially inwardly angled and distally extending inner working surface of the inner surrounding surface of the pipette tip sidewall and for abutting a proximally facing axial stop surface of the pipette tip with a distally facing axial stop surface of the pipette tip coupler body To define an axial coupling position of the pipette tip on the pipette tip coupler device.

In light of the present disclosure as set forth above, further structural modifications and adaptations may be made without departing from the scope and fair meaning of the embodiments of the present disclosure as set forth above. For example, fig. 57-67 are partial longitudinal cross-sectional side elevational views detailing different alternative exemplary embodiments of at least the circumferential annular tip groove 246 illustrated in fig. 19 and at least the V-shaped groove segment 200 illustrated in fig. 50. In particular, fig. 57 to 67 illustrate respective alternative groove configurations 2251 to 2261 for receiving a segment 200. Further, the segments of the coupling may comprise radially outward faces that are complementary to the respective different alternative example embodiments of the respective groove configurations 2251 to 2261. Thus, the first working surface is in the form of, but not limited to, the corresponding recess configuration shown in fig. 53-56 or an uninterrupted configuration, wherein the first substantially cylindrical inner surface section 242 is uninterrupted, thereby defining an uninterrupted inner surface section 1242 of the disposable pipette tip 1220. Further, the tip distal O-ring seal 270 may have a variety of geometries in the form of, but not limited to, a flat cone, a concave radius, a convex radius, a step, and the like. Further, the distal O-ring may have an alternative shape to an O-ring, and may be in the form of, but not limited to, a configuration complementary to the tip distal O-ring seal seat 270.

INDUSTRIAL APPLICABILITY

The description of the above systems, assemblies, devices, and methods, including use and operation, demonstrates the industrial applicability of embodiments of the present disclosure.

It is therefore evident that various modifications and changes may be made thereto without departing from the broader and fair meaning of the embodiments of the present disclosure as set forth above and as set forth in the claims that follow. Therefore, the spirit and scope of the appended claims should not be limited to the foregoing description of the embodiments of the disclosure. Also, in the appended claims, reference to an element in the singular is not intended to mean "one and only one" unless explicitly so stated, but rather "one or more". Moreover, it is not necessary for a device or method to address each and every problem sought to be solved by the present disclosure, for it to be encompassed by the present claims.

Alternative pipettor device assembly 3010

Fig. 70-75 illustrate alternative exemplary embodiments of a pipette device assembly 3010, including exemplary embodiments of a pipette device 3020, exemplary embodiments of a nozzle 3102, and exemplary embodiments of a leaf spring coupling 3100 or a pipette tip coupler for use with a disposable pipette tip 220, which disposable pipette tip 220 is removably coupled to pipette device 3020 through nozzle 3102 and leaf spring coupling 3100.

Pipettor device 3020

Referring to fig. 71 and 72, the pipette device 3020 includes a body 3022 supporting an aspiration and dispense device 3024, the aspiration and dispense device 3024 including a plunger 3026 operably coupled to and driven by a motor 3028. The plunger 3026 resides within a plunger cylinder 3030 extending from a distal or lower end 3032 of the body 3022 of the pipette device 3020.

Pipette device 3020 further includes an aspiration and dispensing cylinder 3034 disposed at least partially within plunger cylinder 3030 at a location axially aligned with plunger 3026 and distally below plunger 3026. The plunger cylinder 3030 transitions distally to a distal mounting flange 3036 for attaching the nozzle 3102. The leaf spring coupling 3100 is coupled at one end with the nozzle 3102, and the leaf spring coupling 3100 is removably coupled at the other end with the disposable pipette tip 220.

Referring to fig. 70, 71, 72, 77, and 79, the nozzle 3102 includes a suction and dispensing cylinder 3034. The aspirating and dispensing cylinder 3034 further includes an internally enclosed sidewall 3038 that defines an open-ended pipette channel 3040 extending therethrough. An open-ended pipette channel 3040 extends longitudinally along a longitudinal channel axis 3080 of the pipette device assembly 3010 between an open upper end portion 3042 and an open lower end portion 3044 of the aspiration and dispensing cylinder 3034 for providing open communication between the plunger 3026 and an exterior region adjacent to the distal mounting flange 3036. The distal mounting flange 3036 is operably connected to the nozzle 3102, which nozzle 3102 is in turn connected to the leaf spring coupling device 3100. An open-ended central passage 3136 extends through the nozzle 3102 and the leaf spring coupling 3100 to provide open communication between the suction head 220 and the suction and dispensing cylinder 3034.

Plunger bracket 3063 and ejector sleeve 3062

Referring to fig. 70-74, the aspirating and dispensing apparatus 3024 includes a lead screw 3067 driven by a motor 3028. The lead nut 3054 is operably coupled to the lead screw 3067. In one embodiment, the lead nut 3054 is threaded and threaded onto the lead screw 3067. The plunger carrier 3063 surrounds and is operably coupled to the lead nut 3054 such that movement of the motor 3028 drives the lead nut 3054, which in turn drives the plunger carrier 3063 parallel to the longitudinal channel axis 3080.

The ejector block 3065 surrounds the lead screw 3067 and is located below the plunger bracket 3063. The ejector rod 3069 is operably connected to an end of the ejector block 3065. The ejector rod 3069 extends from the ejector block 3065 through a distal or lower end 3032 of the body 3022 of the pipette device 3020 via a passageway 3021. The ejector spring 3074 surrounds the ejector rod 3069. An ejection spring 3074 is located between the distal end of the ejector rod 3065 and the distal or lower end 3032 of the body 3022 of the pipette device 3020 such that the spring force acts in a direction that pushes the ejector block 3065 away from the plunger carrier 3063.

The pipette device also includes an ejection sleeve 3062 that surrounds the plunger cylinder 3030 and the nozzle 3102, and contains the aspiration and dispense cylinder 3034. The ejector sleeve 3062 is used to eject the disposable pipette tip 220 from the pipette device 3020, wherein the ejector sleeve 3062 is axially movable relative to the suction and dispensing cylinder 3034 and the plunger cylinder 3030, and includes a proximal or upper end 3064, a distal or lower end 3066, and an ejector sleeve arm 3068 attached at a first end to the ejector sleeve 3062 adjacent to the upper end 3064, and having an opposing second end removably attached to the distal end 3071 of the ejector rod 3069.

When no pipette tip 220 is installed, such as after pipette tip 220 has been ejected, ejector sleeve 3062 is in a free state. To install pipette tip 220, the ejection sleeve spring force must be overcome in order to axially push ejection sleeve 3062 into a retracted state, as shown in fig. 71-73. Additionally, spring 3074 is sized long enough so that it provides a force to assist in ejecting pipette tip 220 until pipette tip 220 is fully detached from leaf spring coupling 3100.

Nozzle 3102 and leaf spring coupling 3100

Fig. 74-75 illustrate a nozzle 3102 and a leaf spring coupling 3100 for mounting a pipette tip 220 to a pipette device 3020.

Nozzle 3102

More specifically, nozzle 3102 includes a nozzle mounting portion 3103 at a top end of nozzle 3102, a nozzle stem portion 3107 at a bottom end of nozzle 3102 relative to the nozzle mounting portion, a nozzle body portion 3105 between nozzle mounting portion 3103 and nozzle stem portion 3107, and a nozzle elastomeric element 3135. The nozzle mounting portion 3103 connects the nozzle 3102 to a distal mounting flange 3036 of the pipette device 3020 (fig. 71 and 79).

As further shown in fig. 75 and 79, the nozzle 3102 also includes a nozzle elastomeric element 3135 carried coaxially around the nozzle stem portion 3107 of the nozzle 3102. The nozzle stem portion 3107 is located at the opposite end of the nozzle mounting portion 3103 relative to the longitudinal central axis 3090 of the nozzle 3102. In the exemplary embodiment, nozzle stem portion 3107 also includes a nozzle groove 3109, and a nozzle elastomeric element is carried within nozzle groove 3109. In an example embodiment, nozzle elastomeric element 3135 is an O-ring.

Leaf spring coupling 3100

As shown in fig. 74-77, leaf spring coupling 3100 includes a coupling cylinder 3173, a leaf spring cylinder 3175, a distal stem base 3121, and a distal or lower elastomeric element 3140 carried at distal stem base 3121.

As shown in fig. 76 and 77, the lower end 3171 of the coupling cylinder 3173 is connected to the leaf spring cylinder 3175. The leaf spring assembly 3170 is formed in a leaf spring cylinder 3175. An upper annular stop shoulder end 3177 of leaf spring cylinder 3175 is located at the lower end of leaf spring assembly 3170. A lower portion 3122 of the leaf spring cylinder 3175 is connected to the distal stem base 3121.

As also shown in fig. 76 and 77, distal stem base 3121 includes a distal cylindrical stem surface 3124 that transitions from an upper annular stop shoulder end 3122 to a rounded endplate 3126, the endplate 3126 having an upper surface 3128 and a lower surface defined by a distal or lower annular end surface 3130. As shown, the diameter of the end plate 3126 is greater than the diameter of the narrowest portion of the distal cylindrical stem surface 3124, wherein the distal stem surface 3124 defines a distal grooved portion 3132 of the leaf spring coupling 3100. When pipette tip 220 is coupled with leaf spring coupling 3100, upper annular stop shoulder end 3177 will abut proximally facing axial stop surface 260 of pipette tip 220 to prevent insertion of leaf spring coupling 3100 too far into pipette tip 220.

Distal elastomeric element 3140

As further shown in fig. 76 and 77, leaf spring coupling 3100 further includes a distal or lower elastomeric element 3140 coaxially carried at distal stem 3124. Distal elastomeric element 3140 acts as a seal when pipette tip 220 is coupled to leaf spring coupling device 3100.

In one embodiment, and referring to fig. 77 and 78, distal elastomeric element 3140 includes an annular body 3142. The annular body 3142 includes an inner surface 3144, a top surface 3148, a peripheral outer surface 3150, and a bottom surface 3152 that define a central opening 3146. As shown in fig. 76, the central opening 3146 is sized to closely or tightly surround the distal stem portion 3124 of the leaf spring coupling 3100, while being shaped to reside within the groove 3132 and extend circumferentially radially outward beyond the end plate 3126. In a relaxed or uncompressed state, distal elastomeric element 3140 includes a circumferentially continuous, generally circular cross-sectional area 3154, as shown in fig. 79.

Leaf spring assembly 3170

Referring to fig. 76, 77 and 82, leaf spring assembly 3170 includes a plurality of circumferentially spaced leaf springs 3180, with leaf springs 3180 formed in leaf spring cylinder 3175 and arranged parallel to longitudinal central axis 3090 and separated by open vertical slots 3182. Leaf spring 3180 is flexible. Each pair of adjacent leaf springs 3180 is separated by an open vertical slot 3182. Leaf spring 3180 is flexible and is used to hold pipette tips on leaf spring coupling 3100.

Each leaf spring 3180 includes a retaining protrusion 3202 that protrudes from an outer surface 3185 of the leaf spring 3180. In one embodiment, each of the plurality of retaining protrusions 3202 has a rounded surface protruding from the outer surface 3185. When a pipette tip is coupled to leaf spring coupling 3100, a plurality of retaining protrusions 3202 on leaf spring assembly 3170 expand into groove 246 of pipette tip 220 to retain or retain pipette tip 220 on leaf spring coupling 3100.

Each leaf spring 3180 also includes a stabilizer platform 3183 protruding from an outer surface 3185 of leaf spring 3180. A plurality of stabilizer platforms 3183 on leaf spring assembly 3170 prevent pipette tip wobble when pipette tips are coupled to leaf spring coupling device 3100. The plurality of stabilizer platforms 3183 prevent the tip from rotating on the leaf spring coupling 3100 about retaining protrusions 3202 positioned within groove 246 of pipette tip 220. This rocking or rotation is one of the reasons for misalignment between the end of pipette tip 220 and longitudinal central axis 3090. Furthermore, this type of wobble may cause pipette tip seals to disengage if a side load is applied. To prevent this problem, in one embodiment, the plurality of stabilizer platforms 3183 are placed above each leaf spring 3180, above or closer to the coupling cylinder 3173 relative to the retaining protrusion 3202. When retaining protrusions 3202 have expanded into groove 246 of pipette tip 220, the plurality of stabilizer platforms 3183 have an interference fit with pipette tip 220. The plurality of stabilizer platforms 3183 add another point of contact between pipette tip 220 and leaf spring coupling 3100 to prevent tip wobble.

Pipette tip picking process using leaf spring coupling 3100

Fig. 81-85 show details of an example embodiment of successive stages of a pipette tip picking process, and in particular the method of fixed attachment of pipette tip 220 to leaf spring coupling 3100 operably carried by pipette device 3020. As described above, in an example embodiment, pipette tip 220 may be supported by support surface 282.

As shown in fig. 73, 77, and 81, leaf spring coupling 3100 is coupled to device 3020 via nozzle 3102, and on command, leaf spring coupling 3100 is positioned over open proximal end 232 of pipette tip 220 with their respective central longitudinal axes aligned along the Z-axis. Leaf spring 3180 is in a relaxed state. The ejector sleeve spring 3074 has pushed the ejector block 3065 and the ejector sleeve 3062 to the lowest position. The plunger carriage 3063 is positioned upward to allow the ejector block 3065 to move upward during the pipette tip picking process. Distal elastomeric element 3140 is in an uncompressed state.

Next, fig. 73, 76, 82, 83 and 84 illustrate the downward movement of leaf spring coupling 3100 along the Z-axis (fig. 81) into pipette tip 220 for lowering the distal elastomeric bearing portion of leaf spring coupling 3100 into the inner cylindrical proximal portion of pipette tip 220, thereby bringing distal elastomeric element 3140 into contact with annular seal seat 270 of pipette tip 200 while maintaining distal elastomeric element 3140 in an unpressed state. Leaf spring 3180 has entered pipette tip 220 and is in a compressed state. The pipette tip pushes up on the ejector sleeve 3062 and the ejector block 3065. At this point, a gap 3298 exists between axial stop surface 260 of pipette tip 220 and upper annular stop shoulder end 3177 of leaf spring coupling 3100, as shown in detail in fig. 82. Additionally, and referring to fig. 81 and 82, it is shown that retaining protrusion 3202 begins to move into groove 246 of pipette tip 220.

Next, fig. 77 and 85 illustrate the leaf spring coupling 3100 being moved further down in the Z-axis into the pipette tip 220 until the leaf spring coupling 3100 is firmly seated against the seal seat 270 of the pipette tip 220. Retaining protrusions 3202 on leaf springs 3180 have reached and snapped into grooves 246 on pipette tip 220 to lock the pipette tip in place on leaf spring coupling 3100. Distal elastomeric element 3140 has pressed against seal seat 270 in pipette tip 220. The stabilizer platform engages the tip to prevent rotation of the pipette tip on the leaf spring coupling 3100.

Upon completion of the secure attachment process detailed above, the plurality of leaf springs 3180 and distal elastomeric element 3140 work in combination to create a segment and sealing coupling that provides a liquid-tight seal, wherein the plurality of retaining protrusions 3202 are at least partially received within the groove 246 of pipette tip 220 and at least partially seated on the circumferential arcuate inner surface 244 (fig. 18) defining the pipette tip groove 246, and wherein the distal elastomeric element 3140 seals against seal seat 270, which seal seat 270 provides a surface that is angled radially inward and extends distally or downwardly.

Disposable pipette tip ejection process using leaf spring coupling 3100

Fig. 81-85 conversely illustrate details of successive stages of an example method or process of ejecting a pipette tip 220 from a leaf spring coupling 3100 operably carried by a pipette device 3020. The tip ejection process sequence is similar to the attachment or tip pick-up fixture process sequence, except to the contrary.

As shown in fig. 72, 73, and 81-85, in one example embodiment, the ejection process includes rotating the lead screw 3067, whereupon the plunger bracket 3063 is driven downward into the ejection block 3065. The ejection block 3065 pushes the ejection sleeve 3062 downward via its attachment to the ejection rod 3069. Ejection sleeve 3062 begins to push pipette tip 220 away from leaf spring coupling 3100. Pipette tip 220 does not begin to move until the force is great enough to compress leaf spring 3180 (fig. 77) to allow retaining protrusion 3202 to move out of groove 246 in pipette tip 220.

Next, leaf spring 3180 has been fully compressed within pipette tip 220. Pipette tip 220 is no longer held vertically to leaf spring coupling 3100. At this point during ejection, distal elastomeric element 3140 has lost contact with seal seat 270, and thus the seal has been broken. Plunger carrier 3063 continues to drive ejector sleeve 3062 downward and pushes pipette tip 220 away from leaf spring coupling 3100.

Next, pipette tip 220 continues to be driven off of leaf spring coupling 3100. Retaining protrusion 3202 reaches the opening of pipette tip 220 and leaf spring 3180 begins to expand toward a relaxed state.

At the completion of the ejection process, pipette tip 220 and leaf spring coupling 3100 have lost contact. Leaf spring 3180 is in a relaxed state. The ejector sleeve spring 3074 has pushed the ejector block 3065 and the ejector sleeve 3062 is in the lowermost position. After the pipette tip 220 has been ejected, plunger carrier 3063 is positioned upward to allow the ejector block 3065 space to move upward during the next pipette tip pick up process.

Coupling force and ejection force of plate spring coupling device 3100

Fig. 86 illustrates a diagrammatic vector diagram of a plurality of retaining protrusions 3202 of the leaf spring coupling 3100, which retaining protrusions 3202 initially extend into the groove 246, with the retaining protrusions 3202 on the leaf springs 3180 contacting the upper corners of the tip groove 246 over the center of the retaining protrusion radius, creating an axially upward force that pulls the pipette tip 220 upward. As shown in fig. 86, the retaining lobe force or segment force (fsegment — total force) of each of the plurality of retaining lobes 3202 consists of two components: an axial force (F segment _ axial) component and a radial force (F segment _ radial) component.

As long as the plurality of retaining protrusions 3202 are contacting the upper corners of the tip recess 246 above the center of the retaining protrusion radius (dimension Z in FIG. 87), segment F _ axially increases as the distance between the center of the retaining protrusion radius and the corners of the recess 246 increases. Thus, at the beginning of the pipette tip picking process, the segment axial force (fsegial _ axial) is low at the beginning, as shown in fig. 86, and in detail in fig. 87, and increases to its maximum value at the end of the pipette tip picking process, as shown in fig. 88.

Referring to fig. 87, the ratio Z/R is equal to SIN (ω), and SIN (ω) is equal to (F segment _ axial)/(F segment _ total force). Thus, (F segment _ axial) is equal to the ratio of (F segment _ total force) multiplied by Z/R.

Referring to fig. 88, the segment axial force (fsegie _ axial) seats upper annular stop shoulder end 3177 against axial stop surface 260 of pipette tip 220 and provides the force necessary to overcome the O-ring or distal elastomeric axial force (fsegie _ axial) and compress distal elastomeric element or O-ring 3140. The O-ring 3140 has an O-ring force (fsidenjiei _ ring _ total) resulting from compression, and this O-ring force includes two components: an axial component (fsistan _ ring _ axial) and a radial component (fsistan _ ring _ radial). In addition, the segment radial force (fsegde _ radial) provides the radial force required to lock the retaining protrusion 3202 into the tip groove 246 (fig. 18), and the distal O-ring radial force component (fsiden _ ring _ radial) provides the radial force required to maintain a seal against the pipette tip 220. Furthermore, as the retaining protrusion 3202 enters the groove 246 (increasing dimension Z), the retaining protrusion to tip groove geometry causes the F-segment _ axial to increase, which helps overcome the O-ring axial force (fsidencycle _ axial) so that the distal O-ring 3140 can be fully compressed to a desired extent. In addition, the distal O-ring axial force component (fsemin _ ring _ axial) provides a force to assist in the removal of the tip 220 during the ejection process.

Alignment/misalignment of leaf spring coupling 3100

The upper annular stop shoulder end 3177 of the coupling 3100 and the axial stop surface 260 of the suction head 220 are important to the proper alignment of the suction head. Accordingly, leaf spring coupling 3100 and pipette tip 220 are configured such that the plurality of retaining protrusions 3202 push upper annular stop shoulder end 3177 and axial stop surface 260 together to prevent misalignment, as the same misalignment error (E) as the embodiment shown in fig. 36 may be significant if upper annular stop shoulder end 3177 and axial stop surface 260 are not properly mated, especially if they are tilted.

Leaf spring coupling 3100 size and relationship

Therefore, the dimensions between the leaf spring coupling 3100 and the suction head 220 are relevant for correct use and operation.

Referring to FIGS. 38, 79 and 85, the tip recess diameter A must be large enough to allow the retaining protrusion 3202 to pull the tip 220 upward and adequately lock the tip 220 in place. Conversely, if the tip recess diameter a is too large, the retaining protrusion 3202 may not be pushed in sufficiently to obtain a good lock. In addition, inner diameters B and C must be larger than outer diameters K and L, respectively, of upper annular stop shoulder end 3177. However, they cannot be too large, as this may result in poor fit and/or misalignment.

Referring to fig. 38 and 85, the tip seat-to-recess dimension S must match the upper annular stop shoulder end 3177-to-segment 200 center dimension M. This relationship is important to the coupling between the suction head 220 and the upper annular stop shoulder end 3177.

Referring to fig. 19, 38 and 85, the dimension of the axial stop surface 260 to the O-ring sealing region 266 in fig. 19, dimension F in fig. 38, must match the dimension of the upper annular stop shoulder end 3177 to the distally facing vertical lip surface 3179, dimension N in fig. 85. These dimensions control the amount that distal O-ring 3140 is compressed and, thus, the degree to which it seals. The axial stop surface 260 and the upper annular stop shoulder end 3177 must be fully mated to provide proper alignment and maintain the pipette tip axial distance D.

Referring to fig. 38 and 85, dimension D (or axial distance) between axial stop surface 260 to distal end 230 establishes a known and controlled distance of the pipette tip end. This is important to allow the pipette device to target small holes and small volumes of liquid. In addition, smaller volumes of liquid may be transferred because the known fixed distance of the pipette tip allows for controlled contact of the pipette tip/liquid with the work surface onto or from which the liquid is to be transferred.

Referring to fig. 38, 79 and 85, the suction head inner diameter G must be smaller than the leaf spring coupling diameter L to provide a sealing seat or region for the distal O-ring 3140. If the diameter G is too large, the distal O-ring may not seal well. If the diameter is too small, the distal O-ring 3140 may not compress completely and may prevent the upper annular stop shoulder end 3177 from seating or may cause damage to the distal O-ring 3140. In addition, ramp length H, along with diameter G, controls the seat or region that mates with O-ring 3140. These dimensions are critical to provide a good O-ring seal. If the ramp length H is too long, the O-ring may not seal well. If H is too short, the O-ring may not compress fully and the upper annular stop shoulder end 3177 may be prevented from seating or damage may be done to the O-ring 3140.

Liquid level detection

The pipette device assembly 3010 also includes liquid level detection circuit assemblies as described for the pipette device assembly 10 (fig. 40). In an example embodiment, the material of the nozzle 3102 and the leaf spring coupling 3100 may be readily made of an electrically conductive material to provide an electrical circuit to the pipette tip 220 for level detection or other uses, as detailed above with respect to the pipette device assembly 10.

Alternative example embodiments

Fig. 90 illustrates an example embodiment of a leaf spring coupling device 3100 positioned in a disposable pipette tip including an alternative seal seat surface 2270, wherein the tip 220 is lifted to its final seated state with the distal elastomeric element 3140 in a final compressed and seated sealing state against the alternative seal seat surface 2270.

Fig. 91 details the final compressed state of the distal resilient element 3140 against the alternative sealing seat surface 2270.

Claims

1. A pipette tip coupling device for coupling a pipette tip to a pipette device, the pipette tip coupling device comprising:

a nozzle, comprising:

a nozzle mounting portion at a tip of the nozzle;

a nozzle stem at a bottom end of the nozzle;

a nozzle body portion located between the nozzle mounting portion and the nozzle stem; and

a nozzle elastomer member surrounding the nozzle stem;

a leaf spring coupling device connected to a bottom end of the nozzle, the leaf spring coupling device comprising:

a coupling cylinder for receiving the nozzle;

a leaf spring cylinder comprising:

a leaf spring assembly, comprising:

a plurality of leaf springs, each leaf spring comprising:

an outer surface;

a stabilizer platform projecting from the outer surface;

a retention tab having a rounded surface protruding from the outer surface; and

an upper annular stop shoulder end at a lower end of said leaf spring cylinder; and

a lower portion;

a distal stem base connected to a lower portion of the leaf spring cylinder, the distal stem base comprising:

a distal cylindrical shaft surface;

end plate:

a distal notch portion; and

wherein the distal cylindrical shank surface transitions from the upper annular stop shoulder end into a circular end plate forming the distal recessed portion;

a distal elastomeric element disposed about the distal stem base;

an open-ended central channel forming an open passageway extending longitudinally from a top of the nozzle through a distal stem base of the leaf spring coupling; and

wherein the nozzle stem is inserted into the leaf spring coupling and abuts an inner surface of the leaf spring coupling to form a seal between the nozzle and the leaf spring coupling.

2. The pipette tip coupling device of claim 1, wherein the nozzle stem portion of the nozzle further comprises a nozzle groove, and wherein the nozzle elastomeric element is carried within the nozzle groove.

3. The pipette tip coupling device of claim 1, wherein the nozzle elastomeric element comprises an O-ring and the distal elastomeric element comprises an O-ring.

4. The pipette tip coupling device of claim 1, wherein the nozzle and the leaf spring coupling device each further comprise an electrically conductive material.

5. The pipette tip coupling device of claim 1, wherein the plurality of leaf springs are configured to radially contract relative to a relaxed state when pressure is applied and radially expand when pressure is released.