CN220900489U - Pipette rack - Google Patents

Abstract

The application relates to the field of commodity shelves, in particular to a pipette rack, which comprises a base (10); a support shaft (20), the support shaft (20) being provided on the base (10); the at least two object placing discs (30) are correspondingly arranged on the supporting shaft (20) and are provided with at least one group of object placing through holes (31) which are vertically corresponding, wherein the at least two object placing discs (30) comprise a lowest supporting disc (30 a) and at least one limiting disc (30 b) above the lowest supporting disc; the flexible component (32), flexible component (32) with pore wall (312) sealing connection of putting thing through-hole (31) of supporting disk (30 a), be equipped with support through-hole (321) that run through from top to bottom in flexible component (32), the lower aperture of support through-hole (321) is less than the upper aperture. Through the technical scheme, the protection of the nozzle of the pipette can be realized when the pipette is placed on the pipette rack.

Description

Pipette rack

Technical Field

The application relates to the field of commodity shelves, in particular to a pipette rack.

Background

A pipette is an instrument used to accurately transfer a specific volume of liquid to another container. There are commonly used pipettes and graduated pipettes. In particular, in the case of a pipette, there is a certain requirement for accuracy in pipetting since it is used to measure a single, fixed volume of liquid. Taking an AS grade 10mL pipette AS an example, its volumetric error is + -0.02 mL. Pipettes are typically glass materials and the nozzle of the pipette is typically a relatively fragile part because of the relatively small diameter of the tube wall, which is typically designed to accurately aspirate liquid.

The pipette is usually stored on a pipette rack, and most of the conventional pipette racks exist in a form that a storage tray provided with through holes is used as a carrier for carrying the pipette, and in the use process, due to the relatively rigid material of the storage tray, the nozzle of the pipette can be damaged due to the touch, impact and other reasons with the wall of the through holes when the pipette is fetched and placed, so that the pipette is inaccurate in pipette sample and even damaged.

Disclosure of utility model

Accordingly, it is an object of the present application to provide a multi-functional pipette rack that reduces impact on the nozzle during use.

In order to achieve the above object, the present application provides a pipette rack comprising: a base; the supporting shaft is arranged on the base; the at least two object placing discs are correspondingly arranged on the supporting shaft and are provided with at least one group of object placing through holes which correspond up and down, wherein the at least two object placing discs comprise a lowest supporting disc and at least one limiting disc above the lowest supporting disc; the flexible component is in sealing connection with the hole wall of the object placing through hole of the supporting disc, a supporting through hole penetrating up and down is arranged in the flexible component, and the lower aperture of the supporting through hole is smaller than the upper aperture. By adopting the technical scheme, the protection of the nozzle of the pipette can be realized when the pipette is placed on the pipette rack.

The support shaft may be arranged at any suitable position on the base. The tray may have any suitable shape, such as circular, oval, rectangular, polygonal, rounded rectangular, etc. The number of storage through holes may be one or more, and may be at any suitable location of the storage tray, for example, may be evenly distributed around the periphery of the storage tray. The lower aperture of the support through-hole being smaller than the upper aperture is understood here to mean that, since the diameter of the nozzle of the pipette is smaller than the diameter of the tube shaft, in order to be able to achieve a supporting effect, the upper aperture of the support through-hole should be such that the tube shaft of the pipette should be able to pass, at least the nozzle of the pipette should be able to pass, while the lower aperture of the support through-hole should ensure that the nozzle of the pipette can be supported, i.e. at least the tube shaft of the pipette cannot pass, whereby the supporting effect of the pipette is achieved, for example in a snap-in manner. For example, the upper aperture may be 2cm and the lower aperture may be 0.2cm, but is not limited thereto. The flexible member may be made of, for example, a flexible material such as rubber or silicone, but is not limited thereto.

In a further design, the flexible component comprises a flexible collar, one end of the flexible collar is provided with a flexible gasket extending outwards along the radial direction, the flexible collar is plugged in the storage through hole, and the bottom surface of the flexible gasket is abutted against the upper surface of the supporting disc. The detachable connection of the flexible member to the wall of the hole can thereby be achieved, in order to facilitate replacement or cleaning of the flexible member, for example after it has been worn or contaminated.

Optionally, a circumferential flexible protrusion extending outwards along the radial direction is provided on the outer wall of the flexible collar, and when the flexible component is plugged into the storage through hole, the protrusion is extruded on the wall of the storage through hole. Thereby enabling a more secure mounting of the flexible member.

Optionally, a circumferential groove corresponding to the protruding portion is configured on a hole wall of the storage through hole, and when the flexible component is plugged into the storage through hole, the protruding portion extends into the circumferential groove. A more stable mounting of the flexible component can thereby be further achieved, for example to avoid an unintentional slipping of the flexible component from the storage opening.

Alternatively, the lower aperture of the storage through hole may be equal to the upper aperture. Thereby facilitating the manufacture of the storage tray. Optionally, the lower aperture of the storage through hole may be smaller than the upper aperture. This allows a better guidance of the insertion of the pipette through the tray or stopper. In this case, the lower aperture of the storage opening of the stop plate should at least ensure that the tube body of the pipette can pass through, so that the pipette can pass through the storage opening of the stop plate. The shape of the object placing through hole of the supporting disc can be the same as that of the object placing through hole of the limiting disc, and can also be different from that of the object placing through hole of the limiting disc. It should be noted that the lower aperture of the storage through hole of the support tray cannot be smaller than the lower aperture of the support through hole, i.e. the lower aperture of the storage through hole of the support tray is at least equal to the sum of the lower aperture of the support through hole and the wall thickness of the flexible collar.

In one embodiment, the bearing shaft comprises a lower section, a middle section and an upper section, the lower end of the lower section is connected with the base, the upper end of the lower section is connected with the lower end of the middle section, the upper end of the middle section is detachably connected with the lower end of the upper section, the support disc is arranged on the middle section, and the limit disc is arranged on the upper section. The supporting plate can be fixedly connected to the middle section, and the limiting plate can be fixedly connected to the upper section. Furthermore, the connection between the parts may be a detachable connection, such as a threaded connection. Whereby the above parts can be removed for routine cleaning and replacement, e.g. after damage.

Optionally, the lower section comprises a lower subsection and an upper subsection, an upper end of the lower subsection being rotatably connected with a lower end of the upper subsection. By adopting the technical scheme, the object placing disc can rotate around the central axis of the supporting shaft. Therefore, when the pipette far away from an operator is taken, the pipette rack can be rotated to avoid moving the position or the direction of the pipette rack, so that the possible vibration of a pipette stored on the pipette rack is avoided, and the damage to the nozzle of the pipette or even the tube body caused by the collision of the pipette with the hole wall can be avoided.

In a further embodiment, a connecting projection is provided on the lateral surface of the lower end of the upper subsection, a bearing is provided on the upper end of the lower subsection, and the lower end of the upper subsection is connected with the inner ring of the bearing in a friction locking manner through the connecting projection.

In one embodiment, the lower end of the upper section or the upper end of the middle section is provided with a shaft neck, the upper end of the middle section or the lower end of the upper section is provided with a hollow part at least corresponding to the shaft neck, the side surface of the shaft neck is provided with at least two positioning holes, the side wall surrounding the hollow part is provided with a positioning through hole extending in the radial direction, and the positioning piece is inserted into the positioning holes through the positioning through hole. By adopting the technical scheme, the upper section can move along the axial direction relative to the middle section, and the depth of the shaft neck inserted into the hollow part can be limited in different gears, so that the distance of different gears between the limiting disc and the supporting disc can be limited, and the pipette rack can receive pipettes of different specifications or more specifically different lengths.

The positioning holes may be designed here in the form of positioning elements, for example radial holes. Optionally, the positioning member may be designed as a positioning bolt, and the positioning hole may be designed as a threaded hole, the positioning through hole may be designed as a threaded through hole, and the external thread of the positioning bolt is matched with the internal threads of the threaded hole and the threaded through hole, so that the threaded connection of the positioning bolt and the threaded hole and the threaded through hole is realized, and therefore, the threaded connection of the positioning bolt and the shaft neck and the side wall is realized. The stability of the pipette rack can thereby be further improved, thereby further reducing impact on the pipette during use of the pipette rack. Further, in this way, the positioning bolt can be held on the edge of the threaded through hole at the time of height adjustment without removing the positioning bolt each time, thereby reducing the installation steps and the installation time.

Optionally, the upper annular end surface of the side wall is provided with a limit protrusion or a limit groove, and the outer annular surface of the bottom of the journal, which is jointed with the annular end surface of the side wall, is provided with a corresponding limit groove or limit protrusion. In this case, one limit projection and limit recess may be provided, or more than one, for example two limit projections and limit recesses, which are symmetrical with respect to the central axis of the bearing shaft, or three limit projections and limit recesses may be provided, which are unevenly distributed in the circumferential direction. By adopting the technical scheme, the assembling of the correct positions of the upper section and the middle section can be rapidly realized, so that the installation time is shortened, and the pipette is convenient to insert into the storage tray.

In one embodiment, the bearing shaft can be provided with a receiving element. The receiving member may be provided at any accessible location of the support shaft, for example at the top of the support shaft, and may have any suitable shape, for example funnel-shaped or U-shaped. The holder may be used, for example, to hold objects suitable for use with pipettes, such as ear-washing balls, which are typically provided for use with pipettes, so that they are centrally located on the same pipette rack for ease of use, aesthetics and practicality. In addition, in other embodiments, the receiving element can be removed, for example, to facilitate routine cleaning and replacement, for example after damage.

Optionally, at least one retaining ring is provided in the hollow extending radially inwardly from the side wall to the journal to prevent the journal from rocking relative to the hollow when inserted therein. The stability of the pipette rack can thereby be further improved, thereby further reducing impact on the pipette during use of the pipette rack. The retaining ring may be a separate component and fixedly attached to the side wall or may be integrally formed with the side wall, for example.

In summary, the present application includes at least one of the following beneficial technical effects:

1. The flexible member on the wall of the storage aperture of the storage tray carries the pipette nozzle, protecting the nozzle from, or at least reducing, impact by the aperture wall.

2. The upper subsection and the lower subsection of the lower section of the supporting shaft are connected in a rotating mode, the pipette can be selected conveniently in a rotating mode, and the movement of the position and the direction of the pipette rack is reduced.

3. The accommodating part can put the ear washing ball in, and is convenient to use.

4. The length of the middle section of the supporting shaft is adjustable, and positioning is realized through the positioning holes and the positioning pieces, so that the pipette rack can receive pipettes of different specifications.

5. The accommodating part, the flexible part, the supporting shaft and the base are all detachable, so that daily cleaning and replacement of damaged accessories are facilitated.

6. The joint of the upper section and the middle section adopts a concave-convex positioning point connection mode, so that the assembly of the correct position can be realized rapidly, and the insertion of the pipette is facilitated.

Drawings

Fig. 1 is a schematic view of the overall structure of a pipette rack according to an embodiment of the present application.

Fig. 2 is a schematic view of one embodiment of a flexible member according to the present application.

Fig. 3 is a partially exploded view of the lower section and second shaft section of the embodiment of the pipette rack shown in fig. 1.

Fig. 4 is a cross-sectional view of the embodiment of the pipette rack shown in fig. 1.

Fig. 5 is an enlarged partial view of a region a of the sectional view of the pipette rack shown in fig. 4.

Fig. 6 is an enlarged partial view of a region B of the sectional view of the pipette rack shown in fig. 4.

Fig. 7 is a partially exploded view of the area shown in fig. 6.

Fig. 8 is a partially exploded view of the area shown in fig. 6.

Reference numerals illustrate: 1. a suction pipe rack; 10. a base; 20. a support shaft; 21. a lower section; 210. a connection protrusion; 211. a lower subsection; 212. an upper subsection; 213. a bearing; 22. a middle section; 221. a hollow portion; 222. a sidewall; 223. positioning the through hole; 224. a limit groove; 23. an upper section; 231. a journal; 233. positioning holes; 234. a limit protrusion; 30. a storage tray; 30a, a support plate; 30b, a limiting disc; 31. a storage through hole; 312. a hole wall; 313. a circumferential groove; 32. a flexible member; 320. a flexible gasket; 321. a support through hole; 322. a flexible collar; 323. a protruding portion; 40. a receiving member; 50. a positioning piece; 60. a positioning ring; C. a central axis.

Detailed Description

The application is described in further detail below with reference to fig. 1-8.

Referring to fig. 1, one embodiment of a pipette rack according to the present application is shown. The pipette rack 1 comprises a base 10, and a supporting shaft 20 is detachably connected to the base 10. In other embodiments, the support shaft 20 may also be fixedly connected to the base 10 or integrally extend from the base 10, for example.

Referring to fig. 1, a receiving member 40, such as a screw connection, is detachably coupled to the top of the support shaft 20. In other embodiments, the receiver 40 may be fixedly attached to other suitable locations of the support shaft 20, such as the side of the support shaft, for example. The receiving member 40 is funnel-shaped, and in other embodiments, the receiving member 40 may have other shapes, such as a U-shape.

Referring to fig. 1, a loading tray 30 is connected to the support shaft 20. In some embodiments, the support shaft 20 passes through the center of the tray 30 and is coaxial with the tray 30. In other embodiments, the tray 30 may be attached to one or both sides of the support shaft 20, for example. The number of the storage trays 30 is two, wherein the lower part is a supporting tray 30a, and the upper part is a limiting tray 30b. In other embodiments, more trays 30 may be attached, including a lowermost tray 30a and at least one upper tray 30b.

The tray 30 is configured with 10 storage through holes 31, and in other embodiments, other numbers of storage through holes 31 may be configured, such as 2-20, such as 4-10.

At the storage through hole 31 of the support tray 30a, a flexible member 32 is installed. The structure and mounting of the flexible member 32 will be described below with reference to fig. 2 and 5.

In some embodiments, the support shaft 20 includes a lower section 21, a middle section 22, and an upper section 23. The lower end of the lower section 21 is in threaded connection with the base 10, the upper end of the lower section 21 is in threaded connection with the lower end of the middle section 22, the supporting disc 30a is fixedly arranged on the middle section 22, and the limiting disc 30b is fixedly arranged on the upper section 23. The manner in which the upper end of the middle section 22 is connected to the lower end of the upper section 23 will be described in detail below with reference to fig. 6-8.

The lower section 21 comprises a lower subsection 211 and an upper subsection 212, the upper end of the lower subsection 211 being rotatably connected to the lower end of the upper subsection 212 in a manner which will be described hereinafter with reference to fig. 3.

Referring to fig. 2, a schematic diagram of one embodiment of the flexible member 32 is shown. The flexible member 32 includes a flexible collar 322, one end of the flexible collar 322 being provided with a flexible washer 320 extending outwardly in a radial direction. In some embodiments, the flexible collar 322 and the flexible gasket 320 may be integrally formed. In other embodiments, the flexible gasket 320 may also be a separate component and attached at the upper periphery of the flexible collar 322.

Referring to fig. 2, a support through hole 321 penetrating up and down is provided in the flexible member 32, and a lower aperture of the support through hole 321 is smaller than an upper aperture. In particular, since the diameter of the nozzle of the pipette is smaller than the diameter of the tube body, in order to enable the support function, the upper aperture of the support through hole 321 should be such that the tube body of the pipette should be able to pass, at least the nozzle of the pipette should be able to pass, while the lower aperture of the support through hole 321 should ensure that the nozzle of the pipette can be supported, i.e. at least the tube body of the pipette should not pass, thereby enabling the support function of the pipette, for example in a snap-fit manner. The shape of the outer wall of the flexible collar 322 will be described below with reference to fig. 5.

In some embodiments, a circumferential flexible projection 323 may also extend radially outwardly on the outer wall of the flexible collar 322. The protrusion 323 may be integrally formed with the outer wall or may be a separate component and attached to the outer wall.

Referring to fig. 3, a partially exploded view of the lower section 21 is shown. In some embodiments, the lower section 21 comprises a lower subsection 211 and an upper subsection 212, the lateral surface of the lower end of the upper subsection 212 is provided with a connecting protrusion 210, the upper end of the lower subsection 211 is provided with a bearing 213, the lower end of the upper subsection 212 is in friction locking connection with the inner ring of the bearing 213 through the connecting protrusion 210, so that the upper subsection 212 and other parts connected with the upper subsection 212 can rotate around the central axis C relative to the lower subsection 211. In some embodiments, the connection protrusion 210 is designed as a protruding stripe. In other embodiments, the connection protrusion 210 may be designed in other forms, such as a bump, an irregular pattern, etc.

Fig. 4 shows a cross-sectional view of an embodiment of the pipette rack shown in fig. 1. The shape of the storage through hole 31 on the storage tray 30 can be seen from the figure. In some embodiments, the placement through hole 31 may extend vertically, i.e., the lower aperture of the placement through hole 31 is equal to the upper aperture, as shown in fig. 4 for the shape of the placement through hole 31 of the limiting tray 30 b. In some embodiments, the storage through hole 31 may extend, for example, in an inverted frustoconical shape, i.e., the lower aperture of the storage through hole 31 is smaller than the upper aperture. In particular, in this case, the lower aperture of the storage through hole 31 of the stopper plate 30b should at least ensure that the tube body of the pipette can pass therethrough, thereby enabling the pipette to pass through the storage through hole 31 of the stopper plate 30 b. The shape of the through hole 31 of the support plate 30a may be the same as the shape of the through hole 31 of the limit plate 30b, or the shape of the through hole 31 of the support plate 30a may be the same as the shape of the through hole 321. In this case, the hole wall 312 of the storage through hole 31 may be parallel to the outer wall of the flexible collar 322, for example, as shown in fig. 4 for the shape of the storage through hole 31 of the support plate 30a and the flexible member 32 mounted therein. It should be noted that the lower aperture of the storage through hole 31 of the support plate 30a cannot be smaller than the lower aperture of the support through hole 321, i.e., the lower aperture of the storage through hole 31 of the support plate 30a is at least equal to the sum of the lower aperture of the support through hole 321 and the wall thickness of the flexible collar 322.

Due to the above-described different shapes of the storage through hole 31, in order to ensure that the flexible member 32 can be stably mounted on the hole wall 312, the outer wall of the flexible collar 322 should have a shape corresponding to the hole wall 312 and abut against the hole wall 312 in the mounted state to achieve a sealed connection.

Fig. 5 shows an enlarged partial view of the area a of the sectional view of the pipette rack shown in fig. 4, i.e. an example mounting of the flexible member 32 to the hole wall 312 of the storage through hole 31 of the support plate 30 a. In some embodiments, the flexible member 32 may be removably coupled to the aperture wall 312, such as by a flexible collar 322 that is plugged into the storage aperture 31. In other embodiments, the flexible member 32 may be coupled to the aperture wall 312 in other ways, such as a fixed connection, such as an adhesive connection.

When mounting the flexible member 32, the flexible member 32 may be pressed down into the storage through hole 31 from above the support plate 30a along the hole wall 312 of the storage through hole 31 until the flexible washer 320 abuts against the upper surface of the support plate 30a and the outer wall abuts against the hole wall 312. In the case where the flexible member 32 has the protruding portion 323, a circumferential groove 313 corresponding to the protruding portion 323 may be formed on the hole wall 312, the protruding portion 323 protruding into the circumferential groove 313 due to its flexibility.

If it is necessary to detach the flexible member 32, the flexible member 32 can be pushed from below the support plate 30a, and the protruding portion 323 is disengaged from the circumferential groove 313 due to the flexibility of the flexible member 32, in such a manner that the detachment of the flexible member 32 can be achieved.

Referring to fig. 6, there is shown an enlarged partial view of region B of the cross-sectional view of the pipette rack of fig. 4, i.e., one example manner of connection of the upper section 23 to the middle section 22. In some embodiments, a journal 231 extends downwardly from the lower end of the upper section 23. Extending downwardly from the upper end of the middle section 22 is a hollow 221, and the depth of the hollow 221 may correspond to the length of the journal 231. In other embodiments, the depth of the hollow 221 may be greater than the length of the journal 231. The diameter of the hollow 221 corresponds at least to the diameter of the journal 231, so that the journal 231 can be inserted into the hollow 221. In some embodiments, the diameter of the hollow 221 is slightly larger than the diameter of the journal 231.

In some embodiments, 2 radially extending locating holes 233 are provided on the side of journal 231. A radially extending positioning through hole 223 is provided in the side wall of the middle section 22 surrounding the hollow 221. In order to position the upper section 23 with respect to the middle section 22, a positioning member 50 is provided, and the positioning member 50 is inserted into the positioning hole 233 through the positioning through hole 223.

When the upper section 23 is moved in the axial direction to a position where the different positioning holes 233 are aligned with the positioning through holes 223, the positioning member 50 can be inserted into the positioning holes 233. In this way, it is possible to define different depths of insertion of the journal 231 into the hollow 221, thereby defining different heights of the upper section 23 with respect to the middle section 22. In other embodiments, the number of locating holes 233 may be more than 2, thereby achieving more different heights of upper section 23 relative to middle section 22.

In some embodiments, the positioning member 50 is designed as a positioning bolt, the positioning hole 233 is designed as a threaded hole, the positioning through hole 223 is designed as a threaded through hole, and the external threads of the positioning bolt are mated with the threaded hole and the internal threads of the threaded through hole, thereby achieving a threaded connection of the positioning bolt with the threaded hole and the threaded through hole, and thus the threaded connection of the positioning bolt with the journal 231 and the sidewall. In other embodiments, a nut may be inserted into the positioning through hole 223, with the internal thread of the nut corresponding to the external thread of the positioning bolt.

In some embodiments, a limit groove 224 is provided in the upper annular end face of the side wall 222, and a corresponding limit projection 234 is provided in the outer annular face of the bottom of the journal 231 that engages the annular end face of the side wall 222.

In some embodiments, the limit projection 234 and the limit groove 224 are symmetrical about the central axis C. In the state shown in fig. 6, the limit projection 234 and the limit groove 224 are connected by the dot groove to rapidly realize circumferential limit, whereby circumferential alignment of the positioning hole 233 and the positioning through hole 223 can be rapidly ensured.

Fig. 7 shows a partial top exploded view of the area shown in fig. 6. Fig. 8 shows a partial bottom exploded view of the area shown in fig. 6. The position and shape of the limit projection 234 and the limit groove 224 can be seen from fig. 7 and 8.

In addition, as can also be seen in fig. 6-8, in some embodiments, a retaining ring 60, such as two retaining rings 60, extending between the journal 231 and the sidewall is provided in the hollow 221 to prevent the journal 231 from rocking relative to the hollow 221. In some embodiments, the retaining ring 60 is a separate component and is fixedly connected to the sidewall and the number of retaining rings 60 is not limited to 2.

The foregoing are all preferred embodiments of the present application, and are not intended to limit the scope of the present application in this way, therefore: all equivalent changes in structure, shape and principle of the application should be covered in the scope of protection of the application.

Claims (10)

1. A suction pipe support, its characterized in that: the pipette rack includes:

A base (10);

A support shaft (20), the support shaft (20) being provided on the base (10);

The device comprises at least two object placing discs (30), wherein the at least two object placing discs (30) are correspondingly arranged on a supporting shaft (20) and are provided with at least one group of object placing through holes (31) which are vertically corresponding, and the at least two object placing discs (30) comprise a lower supporting disc (30 a) and at least one upper limiting disc (30 b);

The flexible component (32), flexible component (32) with pore wall (312) sealing connection of putting thing through-hole (31) of supporting disk (30 a), be equipped with support through-hole (321) that run through from top to bottom in flexible component (32), the lower aperture of support through-hole (321) is less than the upper aperture.

2. The pipette holder as recited in claim 1 wherein: the flexible component (32) comprises a flexible sleeve ring (322), one end of the flexible sleeve ring (322) is provided with a flexible gasket (320) extending outwards along the radial direction, the flexible sleeve ring (322) is plugged in the storage through hole (31), and the bottom surface of the flexible gasket (320) is abutted against the upper surface of the supporting disc (30 a).

3. The pipette holder as recited in claim 2 wherein: the outer wall of the flexible sleeve ring (322) is provided with a circumferential flexible protruding part (323) which extends outwards along the radial direction, and when the flexible part (32) is plugged into the storage through hole (31), the protruding part (323) is extruded on the hole wall (312) of the storage through hole (31).

4. A pipette holder as defined in claim 3, wherein: the hole wall (312) of the object placing through hole (31) is provided with a circumferential groove (313) corresponding to the protruding portion (323), and when the flexible component (32) is plugged into the object placing through hole (31), the protruding portion (323) protrudes into the circumferential groove (313).

5. The pipette holder as recited in claim 1 wherein: the supporting shaft (20) comprises a lower section (21), a middle section (22) and an upper section (23), wherein the lower end of the lower section (21) is connected with the base (10), the upper end of the lower section (21) is connected with the lower end of the middle section (22), the upper end of the middle section (22) is detachably connected with the lower end of the upper section (23), the supporting disc (30 a) is arranged on the middle section (22), and the limiting disc (30 b) is arranged on the upper section (23).

6. The pipette holder as recited in claim 5 wherein: the lower section (21) comprises a lower subsection (211) and an upper subsection (212), and the upper end of the lower subsection (211) is rotatably connected with the lower end of the upper subsection (212).

7. The pipette holder as recited in claim 6 wherein: a connecting protrusion (210) is arranged on the side surface of the lower end of the upper subsection (212), a bearing (213) is arranged at the upper end of the lower subsection (211), and the lower end of the upper subsection (212) is in friction locking connection with the inner ring of the bearing (213) through the connecting protrusion (210).

8. The pipette holder as recited in claim 5 wherein: the lower end of the upper section (23) or the upper end of the middle section (22) is provided with a shaft neck (231), the upper end of the middle section (22) or the lower end of the upper section (23) is provided with a hollow part (221) at least corresponding to the shaft neck (231), the side surface of the shaft neck (231) is provided with at least two positioning holes (233), a positioning through hole (223) extending radially is arranged on a side wall (222) surrounding the hollow part (221), and a positioning piece (50) penetrates through the positioning through hole (223) and is inserted into the positioning hole (233).

9. The pipette holder as recited in claim 8 wherein: the upper annular end face of the side wall (222) is provided with a limit protrusion (234) or a limit groove (224), and the outer annular surface of the bottom of the journal (231) and the annular end face of the side wall (222) are connected with each other and provided with a corresponding limit groove (224) or limit protrusion (234).

10. The pipette holder as recited in claim 1 wherein: the supporting shaft (20) is provided with a receiving member (40).