CN220657586U - Liquid-transfering gun head displacement mechanism and liquid-transfering device - Google Patents

Abstract

The utility model discloses a liquid-transferring gun head distance-changing mechanism and a liquid-transferring device, and relates to the technical field of molecular detection. The device comprises a mounting frame, a plurality of pipette tip assemblies, a variable-pitch shaft and a driving device. The liquid-transferring gun head assembly comprises a sliding seat and a liquid-transferring gun head, wherein the sliding seat is in sliding fit with the mounting frame, and the liquid-transferring gun head is connected with the sliding seat and used for mounting a suction head; the variable-pitch shaft is rotatably connected with the mounting frame and is arranged in parallel with the moving direction of the sliding seat, a plurality of spiral grooves are formed in the surface of the variable-pitch shaft, and the sliding seat comprises a sliding block which is in sliding fit with the spiral grooves; the driving device is used for driving the variable-pitch shaft to rotate. According to the utility model, the spiral groove drives the sliding block to move to realize variable pitch through the rotation of the variable pitch shaft, so that the variable pitch device is simple in structure, less in number of parts and more convenient to assemble.

Description

Liquid-transfering gun head displacement mechanism and liquid-transfering device

Technical Field

The utility model relates to the technical field of molecular detection, in particular to a pipette tip distance-changing mechanism and a pipette device.

Background

In the field of molecular detection and the like, transfer and mixing of reagents are often required, and in order to improve efficiency and degree of automation, pipetting devices capable of automatically pipetting liquid for performing operations such as liquid medicine transfer, mixing and the like have been developed. Typically, pipetting devices include a plurality of pipette tips to simultaneously connect a plurality of pipette tips for reagent aspirating and discharging operations. However, due to different specifications of various containers (such as a deep well plate, a micro well plate, etc.), the distance between adjacent cavities of the containers at the liquid taking position may be different from the distance between adjacent cavities of the containers at the liquid adding position, so the distance changing mechanism needs to be arranged on the liquid transferring device to change the distance between the liquid transferring gun heads so as to adapt to the containers with different specifications.

For example, chinese patent publication No. CN219072986U discloses a multichannel equal-distance-changing pipetting device and a gene processing apparatus, which are provided with a plurality of pipette tips, and the distance between the pipette tips is changed by driving the plurality of pipette tips to move by a distance-changing mechanism.

However, the structure disclosed in the above patent has some drawbacks, for example, it realizes the pitch change through the connecting rod structure, its spare part quantity is many, the structure is complicated, it is comparatively difficult to assemble. In addition, during the process of retracting the tips, all tips will be unloaded simultaneously, and unloading only a portion of the tips is not possible, making it difficult to transfer reagents between two containers having different numbers of chambers per row.

Accordingly, there is a need for an improvement over the prior art to overcome the deficiencies described in the prior art.

Disclosure of Invention

The utility model aims to provide a liquid-transferring gun head distance-changing mechanism and a liquid-transferring device, which can conveniently realize the distance-changing between liquid-transferring gun heads.

In order to achieve the above object, the present utility model provides a pipette tip distance changing mechanism, comprising:

a mounting frame;

the plurality of pipette tip assemblies comprise sliding seats capable of sliding along linear movement relative to the mounting frame and pipette tips connected with the sliding seats, and the pipette tips are used for mounting suction heads;

the distance-changing shaft is rotatably connected with the mounting frame and is arranged in parallel with the moving direction of the sliding seat, a plurality of spiral grooves are formed in the surface of the distance-changing shaft, and the sliding seat comprises a sliding block which is in sliding fit with the spiral grooves; the method comprises the steps of,

and the driving device is used for driving the variable-pitch shaft to rotate.

Further, the spiral grooves are arranged in one-to-one correspondence with the sliding seats, and in the rotation process of the variable-pitch shaft, the center distances between two adjacent pipette tips are always the same.

Further, along the rotation direction of the pitch-changing shaft, the center distance between two adjacent spiral grooves is increased or decreased at the same time, and the increased or decreased distances are the same.

Further, a plurality of the spiral grooves extend in the same direction; or,

the variable-pitch shaft comprises two symmetrically arranged spiral groove groups, and each spiral groove group comprises one or more spiral grooves extending towards the same direction.

Further, the device also comprises a guide shaft connected with the mounting frame, and the sliding seat is in sliding fit connection with the guide shaft;

the section of the guide shaft is non-circular, and the sliding seat is provided with a guide hole matched with the guide shaft; or alternatively;

the number of the guide shafts is at least two, the two guide shafts are arranged in parallel, and the sliding seat is simultaneously in sliding fit with the at least two guide shafts.

Further, the driving device comprises a motor and a speed reducing mechanism connected with the motor, and the speed reducing mechanism is connected with the variable-pitch shaft.

Further, it also comprises a position detection device for detecting the rotation position of the variable-pitch shaft, wherein the position detection device can at least detect the original position of the variable-pitch shaft;

the position detection device comprises a magnet and a Hall sensor, one of the magnet and the Hall sensor is fixed relative to the mounting frame, and the other one of the magnet and the Hall sensor rotates along with the variable-pitch shaft.

Further, the pipette tip comprises a rod part and a convex part which is arranged on the rod part and used for clamping the suction head;

the number of the convex parts is at least two, and the convex parts are rotationally symmetrical with the axis of the pipette tip as the center;

the pipette tip further comprises a groove located between two adjacent convex parts.

Further, the convex portion comprises a first surface and a second surface which are obliquely arranged, and the first surface and the second surface are connected with the surface of the rod portion.

The utility model also provides a pipetting device which comprises the pipetting gun head distance changing mechanism.

Further, the pipette tip removing device further comprises a pipette tip removing assembly and a linear driving device, the pipette tip removing assembly comprises a pushing frame, a long hole is formed in the pushing frame, the pipette tip penetrates through the long hole, the width of the long hole is smaller than the diameter of the connection part of the pipette tip and the pipette tip, and the linear driving device is used for driving the pushing frame to move along the axis of the pipette tip.

Further, the surface of the suction head returning assembly facing the suction head comprises a plurality of step surfaces, each step surface corresponds to at least one suction head, and the distances between two adjacent step surfaces and the suction head are different;

the moving area of the suction head, which is driven by the liquid-transferring gun head distance-changing mechanism to move, does not exceed the corresponding step surface of the suction head.

Compared with the prior art, the utility model has the following beneficial effects: according to at least one embodiment of the utility model, a pipette tip displacement mechanism comprises a mounting frame, a plurality of pipette tip assemblies, a displacement shaft and a driving device, wherein the pipette tip assemblies comprise a sliding seat and a pipette tip, and the pipette tip is used for mounting a suction head. The surface of the displacement shaft is provided with a plurality of spiral grooves, the sliding seat is provided with a sliding block matched with the spiral grooves, when the displacement shaft rotates, the sliding block of the sliding seat slides along the corresponding spiral grooves so as to realize the displacement of the pipette tip and the pipette tip, the structure is simple, the number of parts is less, and the assembly is more convenient.

Drawings

FIG. 1 is a front view of a pipette tip displacement mechanism according to one embodiment of the present utility model.

Fig. 2 is a front view of a pipette tip displacement mechanism according to one embodiment of the utility model.

Fig. 3 is a schematic view of a pipette tip displacement mechanism according to an embodiment of the present utility model.

FIG. 4 is a schematic view of a displacement shaft, carriage and pipette tip combination of a pipette tip displacement mechanism according to one embodiment of the present utility model.

Fig. 5 is a schematic view of a displacement shaft of a pipette tip displacement mechanism according to an embodiment of the present utility model.

Fig. 6 is a cross-sectional view of a displacement shaft, a slide and a guide shaft of a pipette tip displacement mechanism according to one embodiment of the present utility model.

FIG. 7 is a schematic illustration of a carriage and pipette tip combination of a pipette tip displacement mechanism according to one embodiment of the present utility model.

FIG. 8 is a cross-sectional view of a carriage and pipette tip combination of a pipette tip displacement mechanism according to one embodiment of the present utility model.

Fig. 9 is a right side view of a pipette tip displacement mechanism according to one embodiment of the utility model.

Fig. 10 is a left side view of a pipette tip displacement mechanism according to one embodiment of the utility model.

FIG. 11 is a cross-sectional view of a pipette tip, and push rack combination of a pipette tip displacement mechanism according to one embodiment of the present utility model.

Fig. 12 is a partial enlarged view of i in fig. 11.

Fig. 13 is a schematic view of a pipetting device according to one embodiment of the utility model.

Fig. 14 is a schematic view of a pipetting device according to one embodiment of the utility model with a portion of the housing removed.

Fig. 15 is a schematic view of a pipetting device according to one embodiment of the utility model with a portion of the housing removed.

Fig. 16 is a schematic view of a pipette tip assembly of a pipetting device in accordance with one embodiment of the utility model.

Fig. 17 is a schematic view of a pipette tip assembly of a pipetting device in accordance with one embodiment of the utility model.

Fig. 18 is a schematic perspective view of a pusher of a pipetting device according to one embodiment of the utility model.

Fig. 19 is a schematic perspective view of a pusher of a pipetting device according to one embodiment of the utility model.

Fig. 20 is a bottom view of the pusher shown in fig. 19.

Fig. 21 is a front view of the pusher shown in fig. 19.

Fig. 22 is an exploded view of a pipetting cylinder of a pipetting device in one embodiment of the utility model.

Fig. 23 is a cross-sectional view of a cylinder body of a pipetting cylinder of a pipetting device according to one embodiment of the utility model.

Fig. 24 is a schematic view of a piston moving plate of a pipetting device according to one embodiment of the utility model.

Detailed Description

In order to make the above objects, features and advantages of the present application more comprehensible, embodiments accompanied with figures are described in detail below. It is to be understood that the specific embodiments described herein are for purposes of illustration only and are not limiting. It should be further noted that, for convenience of description, only some, but not all of the structures related to the present application are shown in the drawings. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.

The terms "comprising" and "having" and any variations thereof herein are intended to cover a non-exclusive inclusion. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those listed steps or elements but may include other steps or elements not listed or inherent to such process, method, article, or apparatus.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.

As shown in fig. 1 to 4, a pipette tip pitch changing mechanism according to a preferred embodiment of the present utility model includes a mounting frame 1, a plurality of pipette tip assemblies 3, a pitch changing shaft 4, and a driving device 5. The mounting frame 1 is used for connecting the pipette tip displacement mechanism to other components, such as a bracket 6 mounted to a pipetting device, and the mounting frame 1 is made of hard materials, such as hard plastics or stainless steel.

The pipette tip pitch-changing mechanism comprises a plurality of pipette tip assemblies 3, each pipette tip assembly 3 comprises a sliding seat 30 capable of sliding along a straight line relative to the mounting frame 1 and a pipette tip 31 connected with the sliding seat 30, and the pipette tip 31 is used for mounting a suction head 32. In some embodiments, as shown in FIG. 8, the carriages 30 also include mounting holes 302, and pipette tips 31 are mounted in the mounting holes 302, with one pipette tip 32 being attached to each carriage 30.

The variable-pitch shaft 4 is rotatably connected with the mounting frame 1 and is parallel to the moving direction of the sliding seat 30, a plurality of spiral grooves 40 are formed in the surface of the variable-pitch shaft 4, the sliding seat 30 comprises sliding blocks 300 which are in sliding fit with the spiral grooves 40, the spiral grooves 40 and the sliding seat 30 are arranged in one-to-one correspondence, and the sliding blocks 300 of each sliding seat 30 are in sliding fit with one spiral groove 40.

The driving device 5 is fixed relative to the mounting frame 1 and is used for driving the variable-pitch shaft 4 to rotate, and can be indirectly connected with the mounting frame 1 through parts or can be directly connected with the mounting frame 1.

The spacing distance of the cavities for holding the medicaments of different medicament containers (such as deep hole plates, micro hole plates and the like of different models) may be different, and in order to adapt to various medicament containers, in the application, the surface of the variable-pitch shaft 4 is provided with a spiral groove 40 for driving the sliding seat 30 to move, when the variable-pitch shaft 4 rotates, the sliding block 300 moves along the spiral groove 40, so that the sliding seat 30 moves along the axis direction of the variable-pitch shaft 4, and when the variable-pitch shaft 4 rotates by a certain angle, the distance of each sliding seat 30 moving along the axis direction of the variable-pitch shaft 4 can be controlled by controlling the shape of the spiral groove 40, so that the variable-pitch is realized. The shape of the spiral grooves 40 may be designed as desired, and two adjacent spiral grooves 40 may be connected to each other, and in the structure shown in fig. 5, a first spiral groove 40a is connected to a second spiral groove 40b after extending a certain distance. Compared with the moment changing realized by the link mechanism, the moment changing structure realized by the spiral groove 40 is simpler, the number of parts is less, the assembly is convenient, and the whole structure is more compact.

In some embodiments, the helical groove 40 is configured such that the plurality of pipette tips 31 are equally spaced throughout the rotation of the pitch axis 4 to accommodate a wider variety of equally spaced containers.

In some embodiments, the spacing between adjacent helical grooves 40 increases or decreases simultaneously along the direction of rotation of the pitch axis 4, and the distance of the increase or decrease is the same, thereby ensuring that the distance between adjacent tips 32 varies the same throughout the pitch. In fig. 6, the pitch D of the spiral grooves 40 is shown, and when the pitch between the tips 32 is the same in the initial position, the distance L between the tips 32 after the rotation of the pitch change shaft 4 is always equal (as shown in fig. 1 and 6), that is, the tips 32 are always arranged at equal pitches.

In some embodiments, the pipette tip displacement mechanism includes a plurality of helical grooves 40 extending in the same direction. In other embodiments, the pipette tip displacement mechanism comprises two symmetrically disposed sets of spiral grooves, each set comprising one or more spiral grooves 40 extending in the same direction, and obviously, the two sets of spiral grooves extend in opposite directions. As shown in fig. 5, in the embodiment shown in fig. 5, the pitch-variable shaft 4 includes two spiral groove groups, four spiral grooves 40 on the left and right, four spiral grooves 40 on the right are respectively a first spiral groove 40a, a second spiral groove 40b, a third spiral groove 40c and a fourth spiral groove 40d, and the two spiral grooves 40 on both sides are symmetrical about the center line 4 a. When the variable-pitch shaft 4 rotates, the eight liquid-transferring gun heads 31 are divided into two groups to be dispersed towards two sides or to be close towards the center, and in the moving process, all the liquid-transferring gun heads 31 are arranged at equal intervals all the time, so that the length of the spiral groove is reduced, and the processing difficulty is reduced.

In some embodiments, as shown in fig. 1 to 3, the pipette tip displacement mechanism further comprises a guide shaft 2 connected with the mounting frame 1, and the slide 30 is slidingly coupled with the guide shaft 2. The axis of the guide shaft 2 is parallel to the axis of the pitch-changing shaft 4, the axis of the guide shaft 2 is perpendicular to the axis of the pitch-changing shaft 4 and the axis of the pipette tip 31, the guide shaft 2 and the pitch-changing shaft 4 are arranged at intervals up and down, the guide shaft 2 is closer to the suction head 32 than the pitch-changing shaft 4, and the guide shaft 2 is used for guiding the sliding seat 30 during pitch changing, so that the sliding seat 30 can only move along the direction of the guide shaft 2. As shown in fig. 7, the slide 30 includes a guide hole 301, and in some embodiments, the pitch assembly 7 includes only one guide shaft 2, and in order to prevent the slide 30 from rotating about the axis of the guide shaft 2, the cross section of the guide shaft 2 is non-circular such as elliptical or rectangular, and the cross section of the guide hole 301 of the slide 30 is the same as the cross section of the guide shaft 2. In other embodiments, the number of the guide shafts 2 is at least two, as shown in fig. 3, the pitch varying assembly 7 includes two guide shafts 2, the two guide shafts 2 are arranged in parallel, the slide 30 is provided with two guide holes 301, and since the two guide shafts 2 can prevent the slide 30 from rotating, the shape of the guide holes 301 is not limited, for example, may be circular, in the case shown in fig. 7 and 8, the section of one guide hole 301 is in a long hole shape, and the section of the other guide hole 301 is in a spline shape, which is beneficial to reducing the processing cost and facilitating the assembly.

It will be appreciated that the pipette tip assembly 3 need not be coupled to the mounting frame 1 via the guide shaft 2 for movement, and in other embodiments, the pipette tip assembly 3 may be configured to slidingly engage the rack 6 of the pipetting device when the pipette tip displacement mechanism is mounted to the pipetting device. In a possible embodiment, the slide 30 of the pipette tip assembly 3 is provided with a projection towards the surface of the support 6, the support 6 is provided with a chute, the chute is arranged in parallel with the displacement axis, the projection of the slide 30 is arranged in the chute of the support 6, and the slide 30 is driven by the displacement axis to move in the chute along the direction of the axis of the displacement axis 4. In another embodiment, the slide 30 is connected to the support 6 by means of a rail, which is arranged in the direction of the axis of the pitch-changing shaft 4.

As shown in fig. 2 and 9, the driving device 5 includes a motor 50 and a reduction mechanism 51 connected to the motor 50, the motor 50 is preferably a reduction motor, the reduction mechanism 51 includes a first gear 510 and a second gear 511, and the first gear 510 is meshed with the second gear 511. The first gear 510 is connected to the motor shaft of the motor 50, the second gear 511 is connected to the pitch-changing shaft 4, and the motor 50 is further decelerated by the transmission of the first gear 510 and the second gear 511, so that the adjacent suction heads 32 can smoothly change pitch.

In order to be able to detect the pitch of the tips 32, the pipette tip displacement mechanism comprises position detection means for detecting the rotational position of the displacement shaft 4, which are able to detect at least the initial position (home position) of the displacement shaft 4; as shown in fig. 10, a disc 41 is arranged on the other side of the variable-pitch shaft 4, at least one magnet 43 is arranged on the disc 41, at least one hall sensor 42 is arranged on the mounting frame 1, the rotation of the variable-pitch shaft 4 drives the magnet 43 on the disc 41 to rotate, the hall sensor 42 feeds back a detection signal through the magnet, the pipetting device determines whether the suction head 32 has returned to the original position through the detection signal, and the rotation angle of the variable-pitch shaft 4 can be obtained through calculation of the rotation angle of a motor shaft; in other embodiments, an angle sensor may be provided to determine the position between the tips 32 by detecting the angle of rotation of the pitch horn 4.

As shown in fig. 7 and 8, the pipette tip 31 includes a lever 312 and a projection 310 provided on the lever 312 for catching the pipette tip 32; in some embodiments, the protrusion 310 is in the form of a continuous ring that encircles the axis of the pipette tip 31. In other embodiments, the number of the protrusions 310 is at least two, the grooves 311 are disposed between two adjacent protrusions 310, and the protrusions 310 are rotationally symmetrical about the axis of the pipette tip 31, preferably, the protrusions 310 are uniformly distributed about the axis of the pipette tip 31.

As a possible embodiment, the number of grooves 311 is three, the number of projections 310 is also three, and the three projections 310 are rotationally symmetrically arranged with respect to the axis of the pipette tip 31. The diameter of the protrusion 310 is larger than the inner diameter of the suction head 32, so that the suction head 32 can be caught by the protrusion 310. Preferably, the inner wall of the suction head 32 is provided with an annular positioning groove 320 (as shown in fig. 11 and 12), and the positioning groove 320 is clamped with the convex portion 310, so as to reliably connect the suction head 32 to the pipette tip 31. As shown in fig. 8, the protrusion 310 includes a first surface 313 and a second surface 314 that are disposed obliquely, the first surface 313 is located above the second surface 314, the first surface 313 and the second surface 314 are both connected to the surface of the pipette tip 31 and extend outward, preferably, the first surface 313 and the second surface 314 are connected to each other, and in other embodiments, other surfaces may be disposed between the first surface 313 and the second surface 314. The first surface 313 can guide the pipette tip 32 to be retracted from the pipette tip 31, and the second surface 314 can guide the pipette tip 32 to be engaged with the convex portion 310.

As shown in fig. 13 to 15, the present utility model also proposes a pipetting device comprising a pipetting gun head pitch changing mechanism as described above.

In some embodiments, the pipetting device further comprises a pipette tip assembly 7, a linear drive device 8 and a pipetting assembly comprising a pipetting cylinder 9 and a linear drive 99.

As shown in fig. 14 and 15, the suction head assembly 7 is connected to the linear driving device 8, and the suction head assembly 7 can push down the suction head 32 from the pipette tip 31 under the driving of the linear driving device 8, thereby automatically withdrawing the suction head 32. As shown in fig. 18 to 20, the suction head withdrawal assembly 7 includes a pushing frame 70, the pushing frame 70 is provided with a long hole 700, specifically, the pushing frame 70 includes a plate portion 702, the long hole 700 is formed on the plate portion 702, the pipette tip 31 is inserted into the long hole 700, when the linear driving device 8 drives the suction head withdrawal assembly 7 to move along the direction of the pipette tip 32, in order to ensure that the long hole 700 can push the pipette tip 32 away from the pipette tip 31, the width a of the long hole 700 is set smaller than the outer diameter B (as shown in fig. 11) of the connection portion between the pipette tip 32 and the pipette tip 31, the pushing frame 70 abuts against the pipette tip 32 under the action of the linear driving device 8, and the pipette tip 32 is pushed down from the pipette tip 31 under the pushing of the pushing frame 70 of the suction head withdrawal assembly 7.

The linear actuator 99 and the linear driving device 8 may be, for example, a linear driving mechanism formed by an electric push rod, an air cylinder, an electric cylinder, or a motor plus a transmission mechanism; the drive mechanism may be, for example, a screw drive, a rack and pinion drive, a belt drive, a chain drive, or the like.

As shown in fig. 15, in the embodiment shown in fig. 15, the linear actuator 99 is an electric push rod, and the push rod 990 is connected to the suction cylinder 9 directly through the top plate 73. The linear driving device 8 comprises a first motor 80, a screw rod 81 driven to rotate by the first motor 80, and a screw rod nut 82 matched with the screw rod 81, wherein the first motor 80 can be a stepping motor or a servo motor, and the screw rod 81 is driven to rotate through the rotation motion of the motor, so that the screw rod nut 82 moves along the axis of the screw rod 81, and the screw rod nut 82 is connected with the top plate 73 of the suction head assembly 7, so that the suction head assembly 7 is driven to move along the axis direction of the pipette head 31. As shown in fig. 15 to 17, the suction head assembly 7 is slidably coupled to the bracket 6 along the axial direction 31a of the pipette tip 31, so as to ensure that the suction head assembly 7 always moves along the axial direction 31a of the pipette tip 31, and the suction head assembly 7 further includes a connection plate 71 connected between the top plate 73 and the push frame 70 with the linear driving device 8, and a side plate 72 connected to the connection plate 71 and/or the top plate 73. In the embodiment shown in the drawings, the number of the connecting plates 71 and the number of the side plates 72 are two, wherein the two connecting plates 71 are respectively positioned on the front side and the rear side of the suction head assembly 7, and the two side plates 72 are respectively positioned on the front side and the rear side of the suction head assembly 7.

The connecting plate 71 is connected with the bracket 6 through a slide rail 62, and the slide rail 62 is arranged along the axial direction 31a of the pipette tip 31; specifically, as shown in fig. 16 and 17, the bracket 6 includes a base plate 60 and a plate body 61 connected to the base plate 60, where the plate body 61 is opposite to the side plate 72, preferably two opposite planes of the plate body 61 and the side plate 72 are parallel, and the slide rail 62 is connected between the plate body 61 and the side plate 72, so that the suction head assembly 7 can move along a vertical direction relative to the bracket 6 under the drive of the linear driving device 8, where the vertical direction is the axial direction 31a of the pipette tip 31 in the drawing.

In the embodiment shown in fig. 16 and 17, the two oppositely disposed connection plates 71 and the two oppositely disposed side plates 72 of the suction head assembly 7 form an inner space, the suction cylinder 9 is located between the two connection plates 71 and the two side plates 72 (i.e., disposed in the inner space), and the first driving device 13 is connected to the suction cylinder 9 through the top plate 73, so that the pipetting device is more compact and the overall volume of the pipetting device is reduced. The pipetting operation and the pipetting operation of the pipetting device are performed by the linear driver 99 and the linear driver 8, respectively, which can be performed independently without interference, and after the pipetting operation is completed, the pusher 70 is driven by the linear driver 8 to move along the axis of the pipetting gun head 31, so that the pipette tip 32 is pushed down from the pipetting gun head 31.

As shown in fig. 18, in some embodiments, the outer surface 701 of the pushing frame 70 facing the suction head 32 is a plane, and the outer surface 701 of the pushing frame 70 is equidistant from the suction head 32, and the pushing frame 70 can push down all the suction heads 32 simultaneously when being moved to a certain position under the driving of the linear driving device 8.

In other embodiments, as shown in figure 19, the surface of the ejector assembly 7 facing the suction head 32 is stepped and comprises at least two stepped surfaces 74, each stepped surface 74 corresponding to at least one suction head 32, e.g. one stepped surface 74 may correspond to one, two or more suction heads 32. The adjacent two step surfaces 74 are at different distances from the suction head 32, and the suction head 32 is arranged corresponding to the step surfaces 74, so that the suction head 32 can be pushed down in sequence when the suction head retracting assembly 7 moves towards the suction head 32. Thus, by controlling the height of the step surface 74, the suction heads 32 to be pushed down can be selectively pushed down, for example, the four suction heads 32 on the left side can be pushed down, and the four suction heads 32 on the right side can be remained, so that the container suitable for eight cavities can be changed into the container suitable for four cavities, and the adaptability is wider. In addition, an increase in the distance between adjacent tips 32 can be achieved by pushing on every other tip 32, i.e., by withdrawing the tips. It will be appreciated that the cleaner head 32 may be retracted directly into the cleaner head tray when not in use.

Further, in some embodiments, as shown in fig. 20 and 21, the step surfaces 74 are symmetrically distributed along the axis 70a of the pushing frame 70, the step surfaces 74 are the same as the number of the suction heads 32 and are correspondingly arranged, the step surfaces 74 symmetrically arranged on both sides of the axis 70a are the same as the distance between the suction heads 32, the distances between the step surfaces 74 and the suction heads 32 decrease gradually from the center to the outside, during the process of withdrawing the suction heads, the outer step surfaces 74 contact the suction heads 32 first, and the suction heads 32 are pushed down sequentially from both sides to the middle of the axis 70 a.

In some embodiments, the moving area of the suction head 32 which is driven by the pitch changing assembly 7 does not exceed the width C of the corresponding step surface 74 of the suction head 32, so that the suction head retracting operation is always performed on the same suction head 32 through the same step surface 74 before and after pitch changing, and the sequence of the suction heads 32 is unchanged.

The pipetting device further comprises a position detection assembly for detecting the position of movement of the pipette tip assembly 7 in order to determine whether the pipette tip has been removed or to determine whether the pipette tip assembly 7 has been returned to its home position. The type of the position detection means is not limited, and for example, the position detection may be performed by a distance sensor, a travel switch, a hall sensor, a photoelectric switch, or the like.

In the embodiment shown in fig. 16, the position detecting assembly includes two magnets 43 arranged at intervals along the moving direction of the retraction head assembly 7 and two hall sensors 42 arranged in parallel corresponding to the two magnets 43, the center distance of the two hall sensors 42 is the same as the center distance between the two magnets 43, the two hall sensors 42 and the two magnets 43 are arranged along the axial direction 31a of the pipette tip 31, the two hall sensors 42 are arranged on the plate body 61, and the two magnets 43 are arranged on the connection plate 71. The first position of the suction head returning assembly 7 is the position where the two Hall sensors 42 and the two magnets 43 are opposite to each other; the second position of the suction head retracting assembly 7 is a position where the suction head 32 is pushed down by the pushing frame 70 (the distance between the two magnets 43 can be controlled to ensure that the suction head 32 is pushed down in the second position), and only the lower hall sensor 42 and the upper magnet 43 are correspondingly arranged. The suction cylinder 9 is connected with the bracket 6, and can be indirectly connected with the bracket 6 through parts or can be directly connected with the bracket 6, for example, a welding or bolt connection fixing mode can be adopted. As shown in fig. 22 and 23, the liquid suction cylinder 9 includes a cylinder body 90 having a plurality of piston chambers 91, a piston rod 93 slidably coupled to the piston chambers 91 of the cylinder body 90, and a piston moving plate 92 connected to the piston rod 93, one piston rod 93 being provided in each piston chamber 91; the cylinder 90 is connected with the bracket 6, thereby fixing the cylinder 90; the linear driver 99 is connected to the piston moving plate 92, and is used for driving the piston moving plate 92 to move along the axial direction 31a of the pipette head 31, and driving all the piston rods 93 to move through one piston moving plate 92 at the same time, so that it is beneficial to ensure that the volumes of the liquid sucked by each suction head 32 are approximately the same, and the accuracy of liquid suction and discharge of the pipetting device is improved. The liquid suction cylinder 9 includes a universal connection shaft 94, the universal connection shaft 94 is fixed on the outer surface of the piston moving plate 92 facing the linear actuator 99, and the push rod 990 is connected with the universal connection shaft 94, so as to drive the piston moving plate 92 to move along the axial direction 31a of the pipette tip 31.

As shown in fig. 22 and 24, the liquid suction cylinder 9 further includes an adapter plate 96, a sealing ring 97 and a cover plate 98, the piston cavity 91 is connected with the cover plate 98, the cover plate 98 is provided with a small hole 980 corresponding to the piston cavity 91, the head of the piston rod, which is close to the piston moving plate 92, is provided with a convex ring 930, the piston moving plate 92 is provided with a clamping groove 920, and the piston rod 93 passes through the small hole 980 and is clamped with the clamping groove 920 of the piston moving plate 92. The sealing ring 97 is disposed at the interface between the piston cavity 91 and the adapter plate 96, so as to improve air tightness, the adapter plate 96 and the pipette tip 31 are connected through a hose (not shown), so as to realize fluid communication between the piston cavity 91 and the pipette tip 31, and as shown in fig. 11 and 22, hose connectors 960 are disposed on the adapter plate 96 and the pipette tip 31 to connect the hoses, so that the connection of the hoses is facilitated. In the embodiment shown in fig. 22 and 24, the number of the piston cavities 91 and the suction heads corresponding to the piston cavities is 8, the piston moving plate 92 comprises two clamping grooves 920 and is arranged in parallel, and the piston rods 93 are arranged in two rows and are arranged in parallel in a staggered manner, so that the structure is more compact.

As shown in fig. 14 and 15, the pipetting device further includes a circuit board 63 disposed on the support 6, where the circuit board 63 is electrically connected with the driving device 5, the linear driver 99, the linear driver 8, and other electrical components, and the circuit board 63 is provided with a control module and a matched circuit (not shown in the drawing), and the pipetting device controls the driving device 5, the linear driver 99, and the linear driver 8 to operate by the circuit board 63 to realize operations such as changing the distance, sucking and discharging liquid, and retracting the suction head 32.

The pipetting device provided by the utility model can be electrically connected with a control system of the molecular detection equipment through the circuit board 63, and the molecular detection equipment can control the pipetting device to work together with a mechanism in the molecular detection equipment.

The foregoing is merely exemplary of the utility model and other modifications can be made without departing from the scope of the utility model.

Claims (10)

1. A pipette tip displacement mechanism, comprising:

a mounting frame (1);

a plurality of pipette tip assemblies (3), wherein the pipette tip assemblies (3) comprise a sliding seat (30) capable of moving along a straight line relative to the mounting frame (1) and a pipette tip (31) connected with the sliding seat (30), and the pipette tip (31) is used for mounting a suction head (32);

the variable-pitch shaft (4) is rotatably connected with the mounting frame (1) and is arranged in parallel with the moving direction of the sliding seat (30), a plurality of spiral grooves (40) are formed in the surface of the variable-pitch shaft (4), the sliding seat (30) comprises sliding blocks (300) which are in sliding fit with the spiral grooves (40), and the spiral grooves (40) and the sliding seat (30) are arranged in one-to-one correspondence; the method comprises the steps of,

and the driving device (5) is used for driving the variable-pitch shaft (4) to rotate.

2. A pipette tip displacement mechanism as claimed in claim 1, characterised in that a plurality of pipette tips (31) are arranged at equal intervals throughout the rotation of the displacement shaft (4).

3. A pipette tip displacement mechanism as claimed in claim 1, wherein a plurality of said spiral grooves (40) extend in the same direction; or,

the variable-pitch shaft (4) comprises two symmetrically arranged spiral groove groups, and the spiral groove groups comprise one or more spiral grooves (40) extending in the same direction.

4. A pipette tip displacement mechanism as claimed in any one of claims 1 to 3, characterized in that it further comprises a guide shaft (2) connected to the mounting frame (1), the slide (30) being slidingly coupled to the guide shaft (2);

the section of the guide shaft (2) is non-circular, and the sliding seat (30) is provided with a guide hole (301) matched with the guide shaft (2); or alternatively;

the number of the guide shafts (2) is at least two, the two guide shafts (2) are arranged in parallel, and the sliding seat (30) is simultaneously in sliding fit with the at least two guide shafts (2).

5. A pipette tip range-changing mechanism according to any one of claims 1 to 3, characterized in that the driving means (5) comprises a motor (50) and a reduction mechanism (51) connected to the motor (50), the reduction mechanism (51) being connected to the range-changing shaft (4).

6. A pipette tip displacement mechanism as claimed in any one of claims 1 to 3, characterized in that it further comprises a position detection device for detecting the rotational position of the displacement shaft (4), which position detection device is capable of detecting at least the home position of the displacement shaft (4);

the position detection device comprises a magnet (43) and a Hall sensor (42), wherein one of the magnet (43) and the Hall sensor (42) is fixed relative to the mounting frame (1), and the other rotates along with the variable-pitch shaft (4).

7. A pipette tip pitch mechanism as defined in any one of claims 1 to 3, wherein the pipette tip (31) comprises a stem (312) and a projection (310) provided on the stem (312) for catching the tip (32);

the number of the convex parts (310) is at least two, and the convex parts are rotationally symmetrical with the axis of the pipetting gun head (31) as the center;

the pipette tip (31) further comprises a groove (311) located between two adjacent protrusions (310).

8. The pipette tip range unit as recited in claim 7 wherein said projection (310) includes a first surface (313) and a second surface (314) disposed obliquely, said first surface (313) and said second surface (314) being connected to a surface of said stem (312).

9. A pipetting device comprising a pipette tip displacement mechanism as recited in any one of claims 1 to 8.

10. Pipetting device according to claim 9, further comprising a pipette tip assembly (7) and a linear drive device (8), the pipette tip assembly (7) comprising a push frame (70), the push frame (70) being provided with a slot (700), the pipette tip (31) being threaded into the slot (700), the slot (700) having a width smaller than the diameter of the part of the pipette tip (32) connected to the pipette tip (31), the linear drive device (8) being adapted to drive the push frame (70) to move along the axis of the pipette tip (31);

the surface of the suction head returning assembly (7) facing the suction head (32) comprises a plurality of step surfaces (71), each step surface (71) corresponds to at least one suction head (32), and the distances between two adjacent step surfaces (71) and the suction head (32) are different;

the moving area of the suction head (32) driven by the pipette tip distance changing mechanism does not exceed the corresponding step surface (71) of the suction head (32).