CN111229349A - A pipette that can automatically cover the tip - Google Patents

Abstract

The invention discloses a pipette capable of automatically covering a suction head, comprising: a base plate, a three-dimensional movement mechanism arranged on the base plate, a suction head grabbing mechanism arranged on the three-dimensional movement mechanism, and a suction head grabbing mechanism arranged on the base plate. The pipette pipette on the bottom plate and the installation slot for placing the tip box on the bottom plate; the three-dimensional motion mechanism is used to drive the suction head grabbing mechanism to move in three dimensions; the suction head grabbing mechanism includes a fixed sleeve A pipe and a gripper assembly arranged on the fixed sleeve, the pipette is communicated with the upper end of the fixed sleeve, and the gripper assembly is used for grabbing a specified position in the tip box. A suction head, the lower end of the fixed sleeve is used for communicating with the suction head grasped by the gripper assembly. The invention drives the suction head grasping mechanism to move three-dimensionally through the three-dimensional motion mechanism, can realize the function of automatically covering the suction head with the pipette, can ensure the stability of the suction head, and can also well protect the suction head and the suction head. Pipette.

Description

A pipette that can automatically cover the tip

technical field

The invention relates to the field of pipetting equipment, in particular to a pipette that can automatically cover a pipette tip.

Background technique

Micropipette tips (or pipette tips) are commonly found in biological and medical laboratories and are the most commonly used consumables in experiments. In the prior art, there are a large number of manually-operated pipettes, but their pipetting efficiency is low, time-consuming and labor-intensive, so there are also some automatic pipetting devices, which usually load pipetting components through a two-dimensional or three-dimensional motion mechanism ( Including the pipette and the external liquid circuit unit connected to it, some pipettes may also be connected with a needle), so as to drive the movement of the pipetting assembly to the designated position, and then use the pipette cover to take the tip, and then carry out Related pipetting work. After the pipette cover takes the tip, it is necessary to ensure that the tip and the pipette can be firmly connected to prevent it from falling during the pipetting process, so it can generally be achieved through the following schemes, one of which is: design the size of the end of the pipette It is smaller than the pipette tip, and the pipette is squeezed into the pipette head by pressure. At this time, when taking the pipette tip, it is necessary to exert a large force on the pipette tip to ensure that the pipette tip is firmly sheathed in the pipette. However, it is easy to deform or damage the tips and the tip box containing the tips, and it is also easy to damage the pipette. Another way is to set a related fitting structure on the suction head and/or the pipette, and realize the connection between the suction head and the pipette through the fitting mechanism; however, it has the following disadvantages, usually the fitting structure is more complicated, and in addition When connecting, the pipette needs to be rotated relative to the tip to be firmly connected, which will increase the complexity of the movement mechanism. Therefore, a more reliable solution is now required.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a pipette that can automatically cover a pipette tip in view of the above deficiencies in the prior art.

In order to solve the above-mentioned technical problems, the technical solution adopted in the present invention is: a pipette capable of automatically sheathing a suction head, comprising: a bottom plate, a three-dimensional motion mechanism arranged on the bottom plate, and a three-dimensional motion mechanism arranged on the three-dimensional motion mechanism. a suction-tip grabbing mechanism, a pipette pipette arranged on the suction-tip grabbing mechanism, and a mounting groove arranged on the bottom plate for placing the suction-tip box;

The three-dimensional motion mechanism is used to drive the suction head grasping mechanism to move three-dimensionally;

The suction head grasping mechanism includes a fixed sleeve and a grasping claw assembly arranged on the fixed sleeve, the pipette is communicated with the upper end of the fixed sleeve, and the grasping claw assembly is used for grasping the The suction head at the designated position in the suction head box, and the lower end of the fixed sleeve is used to communicate with the suction head grasped by the gripper assembly.

Preferably, the three-dimensional motion mechanism includes an X-axis motion component provided on the base plate, a Y-axis motion component provided on the X-axis motion component, and a Z-axis motion component provided on the Y-axis motion component components;

The Z-axis motion assembly includes a Z-axis mounting plate disposed on the Y-axis motion assembly, a Z-axis motor disposed on the Z-axis mounting plate, a Z-axis screw drivingly connected to the Z-axis motor, and A Z-axis sliding sleeve matched with the Z-axis screw thread;

The suction head grabbing mechanism is fixed on the Z-axis sliding sleeve through a connecting plate.

Preferably, a mounting bracket is provided on the base plate, and the X-axis motion assembly includes an X-axis motor arranged on the mounting bracket, an X-axis screw drivingly connected with the X-axis motor, and an X-axis screw sleeved on the mounting bracket. The X-axis slider on the X-axis screw and threadedly matched with the X-axis screw;

The Y-axis motion assembly includes a Y-axis mounting plate disposed on the X-axis slider, a Y-axis motor disposed on the Y-axis mounting plate, a Y-axis screw drivingly connected to the Y-axis motor, and a Y-axis slider sleeved on the Y-axis screw and threadedly matched with the Y-axis screw;

The Z-axis mounting plate of the Z-axis motion component is arranged on the Y-axis slider.

Preferably, the lower end of the fixing sleeve is connected with a cone pipe section, and the cone pipe section is used to be inserted into the suction head grasped by the gripper assembly.

Preferably, the gripper assembly comprises two grippers symmetrically arranged on the outer wall of the fixed sleeve or four grippers symmetrically arranged on the outer wall of the fixed sleeve;

The upper end of the gripping claw is rotatably connected with the outer wall of the fixing sleeve, a tension spring is connected between the middle part of the gripping claw and the outer wall of the fixing sleeve, and the inner side of the lower end of the gripping claw has a guiding slope, The lower end of the gripper rotates outward when the guide slope is in contact with the suction head and is stressed.

Preferably, the gripping claw comprises a claw body and a claw head connected to the lower end of the gripping body, the inner side of the claw body is provided with a accommodating groove along the length direction, and the inner side walls of the claw body on both sides of the accommodating groove An arc surface for fitting with the outer wall of the fixed sleeve is provided on it;

The upper end of the claw body is provided with a shaft hole;

The guide slope is formed on the inner side wall of the claw head, the width of the claw head is larger than the width of the claw body, and a fixed plane is formed on the upper surface of the claw head on the inner side of the claw body.

Preferably, the suction head includes a suction head body and an annular convex edge disposed on the upper end of the suction head body, and after the gripper assembly grabs the suction head, the annular convex edge is clamped on the fixing plane .

Preferably, a rotating connecting block and a spring mounting block are sequentially arranged on the outer wall of the fixed sleeve from top to bottom, and the rotating connecting block is provided with a connecting shaft for rotatingly connecting the upper end of the claw body;

One end of the tension spring is connected with the spring mounting block, and the other end is connected with the inner wall of the accommodating groove.

Preferably, the outer circumference of the installation groove is provided with four fixing blocks for fixing the tip box placed in the installation groove;

The inner wall of the fixing block is provided with an elastic sheet groove, and an arc-shaped elastic sheet is arranged in the elastic sheet groove.

Preferably, a positioning ball is provided on the outer surface of the arc-shaped elastic sheet, and a compression spring is provided on the inner surface of the arc-shaped elastic sheet;

The outer wall of the suction head box is provided with a positioning hole for the matching insertion of the positioning ball.

The beneficial effects of the present invention are as follows: the pipette capable of automatically sheathing the pipette of the present invention drives the grabbing mechanism of the pipette to move in three dimensions through the three-dimensional motion mechanism, which can realize the function of automatically sheathing the pipette with the pipette, and can To ensure the stability of the pipette tip, and also to protect the tip and pipette well;

When the suction head grabbing mechanism of the present invention covers the suction head, it only needs to apply a slight downward pressure to the suction head to firmly grasp the suction head, which can avoid the suction head or the suction head due to excessive downward pressure. The box is deformed or damaged; the pipette will not be in direct contact with the tip during the extraction process, which can prevent damage to the pipette.

Description of drawings

1 is a schematic structural diagram of a pipette that can automatically cover a tip according to the present invention;

FIG. 2 is a schematic structural diagram of another perspective of the pipette capable of automatically covering the tip of the present invention;

3 is a schematic structural diagram of the suction head grabbing mechanism of the present invention;

4 is a schematic structural diagram of a gripper of the present invention;

5 is a schematic structural diagram of a fixed sleeve of the present invention;

6 is a schematic structural diagram of the fixing sleeve and the gripper of the present invention;

Fig. 7 is the structural schematic diagram of the suction head of the present invention;

8 is a schematic diagram of a state in which the suction head grabbing mechanism of the present invention grabs the suction head;

9 is a schematic diagram of another state in which the suction head grasping mechanism of the present invention grasps the suction head;

Fig. 10 is the structural representation of the bottom plate of the present invention;

11 is a schematic structural diagram of the tip box of the present invention;

12 is a schematic structural diagram of a fixed block of the present invention;

FIG. 13 is a schematic cross-sectional structural diagram of the fixing block of the present invention.

Description of reference numbers:

1—bottom plate; 10—installation bracket; 11—installation slot; 12—fixed block; 13—shrapnel slot; 14—arc shrapnel; 15—positioning top ball; 16—compression spring;

2—X-axis motion components; 20—X-axis motor; 21—X-axis screw; 22—X-axis slider; 23—X-axis optocoupler; 24—X-block;

3-Y-axis motion components; 30-Y-axis mounting plate; 31-Y-axis motor; 32-Y-axis screw; 33-Y-axis slider; 34-Y-axis optocoupler; 35-Y-block;

4—Z-axis motion components; 40—Z-axis mounting plate; 41—Z-axis motor; 42—Z-axis screw; 43—Z-axis sliding sleeve; 44—connecting plate; 45—Z-axis optocoupler; 46—Z block piece;

5—Suction head grabbing mechanism; 50—Fixed sleeve; 51—Gripper assembly; 52—Gripper; 53—Claw body; 54—Claw head; 500—Conical pipe section; 501—Rotating connecting block; 502—Spring Mounting block; 503—tensioning spring; 504—connecting shaft; 505—connecting hole; 506—arc notch; 530—accommodating groove; 531—arc surface; 532—shaft hole; ;

6—pipette;

7—tip box; 70—tip hole; 71—positioning hole;

8—Suction head; 80—Suction head body; 81—Annular convex edge.

Detailed ways

The present invention will be further described in detail below with reference to the embodiments, so that those skilled in the art can implement according to the description.

It should be understood that terms such as "having", "comprising" and "including" as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

As shown in FIG. 1 , a pipette capable of automatically covering a suction head 8 according to the present embodiment includes: a base plate 1 , a three-dimensional motion mechanism arranged on the base plate 1 , and a suction head grasping mechanism arranged on the three-dimensional motion mechanism The mechanism 5, the pipette 6 arranged on the tip grabbing mechanism 5, and the mounting groove 11 arranged on the bottom plate 1 for placing the tip box 7;

The three-dimensional motion mechanism is used to drive the suction head grasping mechanism 5 to move three-dimensionally;

The tip grabbing mechanism 5 includes a fixed sleeve 50 and a gripper assembly 51 arranged on the fixed sleeve 50. The pipette 6 communicates with the upper end of the fixed sleeve 50, and the gripper assembly 51 is used to grab the tip box 7 The lower end of the fixed sleeve 50 is used to communicate with the suction head 8 grasped by the gripper assembly 51 .

In the present invention, the pipette 6 is communicated with the upper end of the fixed sleeve 50, and the three-dimensional motion mechanism drives the fixed sleeve 50, the gripper assembly 51 and the pipette 6 to perform three-dimensional movement together to move to the tip box 7 Above the suction head 8 at the designated position in the pipette, and then move down together, grab the suction head 8 through the grasping claw assembly 51, at this time, the lower end of the fixed sleeve 50 is communicated with the grasped suction head 8, so that the pipette pipette 6 communicates with the suction head 8, and then can move to other positions for related pipetting operations. In the present invention, instead of using the conventional pipetting device to grab the tip 8 through the pipette 6 itself, a special gripper assembly 51 is used to grab the tip 8, and then fix and make the pipette 6 communicates with the suction head 8 . The stability of the suction tip 8 can be ensured, and at the same time, the suction tip 8 and the pipette 6 can be well protected. It is understood that the end of the pipette 6 can also be connected to a needle. In addition, the upper end of the pipette 6 is connected to an external necessary conventional liquid circuit system (not described in detail in the present invention), so as to realize the function of liquid suction. The above is the basic idea of the present invention, and further detailed embodiments are provided on the basis of the above.

In a preferred embodiment, referring to FIGS. 1 and 2 , the three-dimensional motion mechanism includes an X-axis motion component 2 provided on the base plate 1 , a Y-axis motion component 3 provided on the X-axis motion component 2 , and a Y-axis motion component 3 provided on the X-axis motion component 2 . The Z-axis motion assembly 4 on the motion assembly 3; the Z-axis motion assembly 4 includes a Z-axis mounting plate 40 provided on the Y-axis motion assembly 3, a Z-axis motor 41 provided on the Z-axis mounting plate 40, and a Z-axis motor 41 drives the connected Z-axis screw rod 42 and the Z-axis sliding sleeve 43 threadedly matched with the Z-axis screw rod 42 ; The Z-axis screw 42 is driven to rotate by the Z-axis motor 41 , thereby realizing the up and down movement of the Z-axis sliding sleeve 43 threaded with the Z-axis screw 42 .

A mounting bracket 10 is provided on the base plate 1, and the X-axis motion assembly 2 includes an X-axis motor 20 arranged on the mounting bracket 10, an X-axis screw 21 drivingly connected with the X-axis motor 20, and sleeved on the X-axis screw 21. and the X-axis slider 22 threadedly matched with the X-axis screw rod 21;

The Y-axis motion assembly 3 includes a Y-axis mounting plate 30 disposed on the X-axis slider 22 , a Y-axis motor 31 disposed on the Y-axis mounting plate 30 , a Y-axis screw 32 drivingly connected to the Y-axis motor 31 , and a sleeve The Y-axis slider 33 is provided on the Y-axis screw 32 and is threadedly matched with the Y-axis screw 32 ; the Z-axis mounting plate 40 of the Z-axis motion assembly 4 is arranged on the Y-axis slider 33 .

In this embodiment, three-dimensional driving is realized by a motor screw mechanism, so as to move the gripper assembly 51 and the pipette 6 to a designated position.

In a further embodiment, a position detection mechanism is provided in the three directions to realize the positioning of the zero position in the three directions of X, Y, and Z, and the position detection mechanism includes a slot-type optocoupler and a blocking plate. Specifically, the mounting bracket 10 is provided with an X-axis optocoupler 23, the X-axis slider 22 is provided with an X-block 24 matched with the X-axis optocoupler 23; the Y-axis mounting plate 30 is provided with a Y-axis optocoupler 34, The Y-axis slider 33 is provided with a Y-block 35 that cooperates with the Y-axis optocoupler 34; The Z-block 46.

Further, the lower end of the fixing sleeve 50 is connected with a conical pipe section 500 , and the conical pipe section 500 is used to be inserted into the suction head 8 grasped by the gripper assembly 51 . The gripper assembly 51 includes two grippers 52 symmetrically arranged on the outer wall of the fixed sleeve 50 or four grippers 52 symmetrically arranged on the outer wall of the fixed sleeve 50; in this embodiment, there are two; the grippers 52 The upper end of the gripping claw 52 is rotatably connected to the outer wall of the fixing sleeve 50, a tension spring 503 is connected between the middle part of the gripper 52 and the outer wall of the fixing sleeve 50, and the inner side of the lower end of the gripping claw 52 has a guiding inclined surface 540, and the guiding inclined surface 540 is connected to the suction head. The lower end of the gripping claw 52 rotates outward when it is in contact and is stressed. A communication hole 505 is opened in the fixed sleeve 50 .

The gripping claw 52 includes a claw body 53 and a claw head 54 connected to the lower end of the gripping body. The inner side of the claw body 53 is provided with an accommodating groove 530 along the length direction. A shaft hole 532 is formed on the upper end of the claw body 53 ; a guide slope 540 is formed on the inner side wall of the claw head 54 . The guide slope 540 is preferably an arc guide slope 540 . The width of the claw head 54 is larger than the width of the claw body 53 , and a fixed plane 541 is formed on the upper surface of the claw head 54 and the inner part of the claw body 53 . Further, the inner side of the fixing plane 541 has an arc-shaped notch 506, and the arc-shaped notch 506 can fit with the outer wall of the suction head body 80. When the fixing plane 541 of the claw head 54 is below the annular convex edge 81, the arc-shaped notch 506 The design facilitates the claw head 54 to be close to the outer wall of the suction head body 80 .

The suction head 8 includes a suction head body 80 and an annular convex edge 81 disposed at the upper end of the suction head body 80. After the gripper assembly 51 grabs the suction head 8, the annular convex edge 81 is clamped on the fixed plane 541, so that the suction The head 8 can be firmly gripped on the gripper 52 .

Among them, the outer wall of the fixed sleeve 50 is provided with a rotating connecting block 501 and a spring mounting block 502 in order from top to bottom, and the rotating connecting block 501 is provided with a connecting shaft 504 for rotating the upper end of the connecting claw body 53; It is connected with the spring mounting block 502 , and the other end is connected with the inner wall of the accommodating groove 530 .

The spring tension has an inward pulling force on the gripping claw 52, so that the gripping claw 52 will be retracted to the middle when there is no external force. 541 is kept horizontal, and the distance between the two claw heads 54 is smaller than the outer diameter of the annular convex edge 81 , so as to ensure that the two fixing planes 541 can hold the suction head 8 firmly when the two fixing planes 541 are on the bottom surface of the annular convex edge 81 .

The working principle of the gripper assembly 51 is as follows: after the gripper assembly 51 is moved above the suction head 8 at the designated position through the X-axis motion assembly 2 and the Y-axis motion assembly 3, the Z-axis motion assembly 4 drives the gripper assembly 51 to fix the gripper assembly 51. The sleeve 50 moves downward; the guiding inclined surface 540 on the inner side of the claw head 54 contacts the outer wall of the annular convex edge 81 on the upper end of the suction head 8. With the downward movement of the grabbing claw 52, under the cooperation of the guiding inclined surface 540, the claw head 54 edge The downward moving edge expands outward (the claw body 53 of the grasping claw 52 rotates outward around the rotating connecting block 501), as shown in Figure 8; The gripping claw 52 has an inward pulling force, so that the claw body 53 rotates inwardly around the rotating connecting block 501, and the claw head 54 also rotates inwardly and returns to the original position. And hold the annular convex edge 81 of the suction head 8, the inner side of the claw head 54 presses the suction head body 80, so that the suction head 8 is firmly fixed on the claw assembly 51; The body tube section 500 is inserted into the suction head 8, so that the pipette 6 at the upper end of the fixed sleeve 50 is communicated with the suction head 8. After moving the suction head 8 to the corresponding working position, the relevant liquid can be sucked through the suction head 8.

In this embodiment, when the suction head 8 is sheathed, it is only necessary to apply a slight downward pressure to the suction head 8 to firmly grasp the suction head 8, which can avoid the suction head 8 or the suction head 8 caused by excessive downward pressure. The head box 7 is deformed or damaged; during the extraction process, the pipette 6 will not be in direct contact with the pipette tip 8, which can prevent damage to the pipette 6 (especially when a needle is connected to the pipette 6).

In addition, it can be understood that, in this preferred embodiment, the suction head 8 is provided with an annular convex edge 81, which can have a good effect of pulling. However, the suction head 8 can also be grasped when the annular convex edge 81 is not provided on the suction head 8. At this time, it is only necessary to satisfy the requirement that when the claw heads 54 are closed, the distance between the two claw heads 54 is smaller than that of the suction head 8. diameter.

In a further embodiment, the outer periphery of the installation groove 11 is provided with four fixing blocks 12 for fixing the tip box 7 placed in the installation groove 11 . The inner wall of the fixing block 12 is provided with an elastic sheet groove 13 , and an arc-shaped elastic sheet 14 is arranged in the elastic sheet groove 13 . A positioning ball 15 is arranged on the outer surface of the arc-shaped elastic sheet 14, and a compression spring 16 is arranged on the inner surface of the arc-shaped elastic sheet 14; The compression spring 16 has an outward pressing effect on the arc-shaped elastic piece 14 . The tip box 7 is provided with a number of tip holes 7070 for storing the tip 8.

The four fixing blocks 12 are symmetrically arranged on the four sides of the installation groove 11. The suction head box 7 is inserted into the installation groove 11 downward, and the arc-shaped elastic sheet 14 is squeezed outward and inserted in place; the arc-shaped elastic sheet 14 and the compression spring 16 In order to provide the top pressure for the positioning balls 15, the four positioning balls 15 are inserted into the four positioning holes 71, so that the suction head box 7 can be firmly installed in the installation groove 11.

Although the embodiment of the present invention has been disclosed as above, it is not limited to the application listed in the description and the embodiment, and it can be applied to various fields suitable for the present invention. For those skilled in the art, it can be easily Therefore, the invention is not limited to the specific details without departing from the general concept defined by the appended claims and the scope of equivalents.

Claims (10)

1. A pipette that can automatically cover a suction head, comprising: a base plate, a three-dimensional movement mechanism arranged on the base plate, a suction head grabbing mechanism arranged on the three-dimensional movement mechanism, a a pipette on the suction head grabbing mechanism and a mounting groove on the bottom plate for placing the suction head box; The three-dimensional motion mechanism is used to drive the suction head grasping mechanism to move three-dimensionally; The suction head grasping mechanism includes a fixed sleeve and a grasping claw assembly arranged on the fixed sleeve, the pipette is communicated with the upper end of the fixed sleeve, and the grasping claw assembly is used for grasping the The suction head at the designated position in the suction head box, and the lower end of the fixed sleeve is used to communicate with the suction head grasped by the gripper assembly. 2 . The pipette capable of automatically covering a tip according to claim 1 , wherein the three-dimensional motion mechanism comprises an X-axis motion component arranged on the base plate, an X-axis motion component provided on the X-axis motion component. 3 . The Y-axis motion assembly on the upper and the Z-axis motion assembly arranged on the Y-axis motion assembly; The Z-axis motion assembly includes a Z-axis mounting plate disposed on the Y-axis motion assembly, a Z-axis motor disposed on the Z-axis mounting plate, a Z-axis screw drivingly connected to the Z-axis motor, and A Z-axis sliding sleeve matched with the Z-axis screw thread; The suction head grabbing mechanism is fixed on the Z-axis sliding sleeve through a connecting plate. 3 . The pipette capable of automatically covering a tip according to claim 2 , wherein a mounting bracket is provided on the bottom plate, and the X-axis motion component comprises an X-axis arranged on the mounting bracket. 4 . a motor, an X-axis screw drivingly connected to the X-axis motor, and an X-axis slider sleeved on the X-axis screw and threadedly matched with the X-axis screw; The Y-axis motion assembly includes a Y-axis mounting plate disposed on the X-axis slider, a Y-axis motor disposed on the Y-axis mounting plate, a Y-axis screw drivingly connected to the Y-axis motor, and a Y-axis slider sleeved on the Y-axis screw and threadedly matched with the Y-axis screw; The Z-axis mounting plate of the Z-axis motion component is arranged on the Y-axis slider. 4 . The pipette capable of automatically covering a tip according to claim 2 , wherein the lower end of the fixed sleeve is connected with a cone pipe section, and the cone pipe section is used for inserting the gripper assembly. 5 . Grab inside the tip. 5 . The pipette capable of automatically sheathing a tip according to claim 1 , wherein the gripper assembly comprises two grippers symmetrically arranged on the outer wall of the fixed sleeve or symmetrical in two. 6 . Set 4 grippers on the outer wall of the fixed sleeve; The upper end of the gripping claw is rotatably connected with the outer wall of the fixing sleeve, a tension spring is connected between the middle part of the gripping claw and the outer wall of the fixing sleeve, and the inner side of the lower end of the gripping claw has a guiding slope, The lower end of the gripper rotates outward when the guide slope is in contact with the suction head and is stressed. 6 . The pipette capable of automatically covering a tip according to claim 5 , wherein the gripping claw comprises a claw body and a claw head connected to the lower end of the gripping body, and the inner edge of the claw body is 5 . 7 . An accommodating groove is opened in the length direction, and the inner side walls of the claw bodies on both sides of the accommodating groove are provided with arc surfaces for fitting with the outer wall of the fixing sleeve; The upper end of the claw body is provided with a shaft hole; The guide slope is formed on the inner side wall of the claw head, the width of the claw head is larger than the width of the claw body, and a fixed plane is formed on the upper surface of the claw head on the inner side of the claw body. 7 . The pipette capable of automatically covering a tip according to claim 6 , wherein the suction tip comprises a tip body and an annular convex edge disposed on the upper end of the tip body, and the gripper After the assembly grabs the suction head, the annular convex edge is clamped on the fixed plane. 8 . The pipette capable of automatically covering a tip according to claim 7 , wherein a rotating connection block and a spring mounting block are sequentially arranged on the outer wall of the fixed sleeve from top to bottom, and the rotating connection The block is provided with a connecting shaft for rotatably connecting the upper end of the claw body; One end of the tension spring is connected with the spring mounting block, and the other end is connected with the inner wall of the accommodating groove. 9 . The pipette capable of automatically sheathing a pipette according to claim 1 , wherein the outer periphery of the installation groove is provided with four fixing pipettes for fixing the pipette box placed in the installation groove. 10 . piece; The inner wall of the fixing block is provided with an elastic sheet groove, and an arc-shaped elastic sheet is arranged in the elastic sheet groove. 10 . The pipette capable of automatically covering a tip according to claim 9 , wherein a positioning ball is provided on the outer surface of the arc-shaped elastic piece, and a positioning ball is provided on the inner surface of the arc-shaped elastic piece. 11 . compression spring; The outer wall of the suction head box is provided with a positioning hole for the matching insertion of the positioning ball.

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