Double-quantity pipette

Abstract

The utility model belongs to the field of experimental equipment, and particularly relates to a double-quantity pipette which comprises a shell, a liquid suction rod and a liquid suction nozzle are arranged at the lower end of the shell, a piston rod is arranged in an inner cavity of the shell, the lower end of the piston rod is inserted into an inner cavity of the liquid suction rod, and a reset spring is sleeved on the piston rod. A first limiting sliding block is arranged on the surface of the piston rod sleeve, a first limiting sliding groove matched with the first limiting sliding block is formed in an inner cavity of the shell, the upper end of the piston rod sleeve is inserted into a cavity of the operating rod, the upper end of the operating rod extends out of the upper end of the shell to be provided with a pressing cap, and a second limiting sliding block is arranged on the side face of the middle of the operating rod. A limiting clamping ring is arranged on the inner cavity of the shell, and a second limiting clamping groove is formed in the second limiting clamping ring. The device has the advantages of being simple in structure, low in cost, flexible and convenient to use and wide in application range.

Description

Technical Field

[0001] The utility model belongs to the field of experimental equipment, and particularly relates to a dual-volume liquid transfer gun. Background Art

[0002] In modern biological science and biotechnology, pipettes are indispensable in the laboratory. They appear in all links: sample processing, testing, etc. The accuracy of the pipette plays a vital role in discovering scientific research results.

[0003] Pipettes are currently divided into manual pipettes and electric pipettes. Electric pipettes are expensive, so most experimenters still use manual pipettes. The principle of manual pipettes is to achieve liquid aspiration through the movement of the piston rod. Although current pipettes can change the pipetting volume by adjusting the movement distance of the piston rod, the adjustment of the movement distance of the piston rod is before pipetting. After the adjustment, the volume of a single pipetting remains unchanged. In experiments, it is sometimes necessary to push out the aspirated liquid in two volumes, and manual pipettes with traditional structures cannot complete the above operations.

[0004] In order to solve the above problems, those skilled in the art have invented a dual-volume pipette, such as the utility model patent technology of dual-range pipette authorized for disclosure by the China Patent Office on August 15, 2023, with announcement number CN219518898U, which includes a mounting frame, a first pipette component, a second pipette component, a connecting plate, a nozzle and a sealing plate. The first pipette component and the second pipette component have different pipette ranges, and the first pipette component and the second pipette component are connected through the connecting plate. The bottom of the first pipette component is provided with a nozzle for pipetting, and the bottom of the second pipette component is sealed by a sealing plate.

[0005] Although the dual-range pipette of the above structure can change the range and improve efficiency, its dual range is achieved by relying on two pipette guns (liquid suction components). At the same time, in order to work, it also requires components such as a motor, a screw, a connecting plate, a nozzle and a sealing plate, which has the following defects: complex structure and high cost. Utility Model Content

[0006] The utility model aims to provide a dual-volume liquid-discharging gun with a simple structure. Through a simple rotation operation, a dual-volume liquid-discharging operation can be realized on one liquid-discharging gun.

[0007] The utility model is realized through the following technical solutions:

[0008] That is a dual-volume pipette, comprising a shell, a liquid suction rod and a liquid suction nozzle at the lower end of the shell, a piston rod at the inner cavity of the shell, the lower end of the piston rod is inserted into the inner cavity of the liquid suction rod, and a return spring is mounted on the piston rod, characterized in that the upper end of the piston rod is mounted on a piston rod sleeve, the surface of the piston rod sleeve is provided with a first limiting slider, the inner cavity of the shell is provided with a first limiting groove matching the first limiting slider, the upper end of the piston rod sleeve is inserted into the cavity of the operating rod, the upper end of the operating rod extends out of the upper end of the shell and is provided with a pressing cap, the middle side of the operating rod is provided with a second limiting slider, the inner cavity of the shell is provided with a limiting clamping ring, the second limiting clamping ring is provided with a second limiting clamping groove, and in the initial state, the second limiting slider is located above the limiting clamping ring.

[0009] When the piston rod of the present invention moves downward, when the lower end surface of the second limit slider is flush with the limit clamping ring, it is defined as the first stroke (corresponding to the first capacity); when the second limit slider and the second limit clamping groove are aligned, and the second limit slider enters the second limit clamping groove, the piston rod continues to move downward to the lowest point, which is defined as the second stroke (corresponding to the second capacity). The sum of the two strokes is defined as the maximum stroke.

[0010] The utility model has multiple usage methods according to the stroke of the piston rod.

[0011] 1) Aspirate the first volume of liquid at a time and pipette

[0012] The first-stage volumetric pipetting operation can be completed by using only the first-stage stroke, that is, the second limit slider and the second limit slot are always in a misaligned state;

[0013] 2) Take up the maximum volume of liquid at one time and pipette

[0014] Using the first stroke and the second stroke at the same time can complete the maximum capacity pipetting operation, that is, the second limit slider and the second limit slot are always in an aligned state;

[0015] 3) Absorb the maximum volume of liquid at one time and pipette it in two volumes

[0016] When the second limit slider and the second limit slot are in an aligned state, the pressing cap is pressed downward to drive the operating rod and the piston rod downward until the stroke ends. This stroke is the maximum stroke of the piston rod. The pressing cap is released. Under the action of the reset spring, the piston rod, the operating rod and the pressing cap are reset upward to complete the liquid suction operation. When the absorbed liquid needs to be pushed out in two sections, the pressing cap is rotated so that the second limit slider and the second limit slot are in an offset state. The pressing cap is pressed downward until the second limit slider is against the limit clamping ring to complete the first section of liquid discharge. Maintain the above state, rotate the pressing cap to drive the operating rod and the second limit slider to rotate together. When the second limit slider and the second limit slot are in an aligned state, the operating rod and the piston rod continue to move downward to complete the second section of liquid discharge.

[0017] The utility model uses the first limiting slider and the first limiting slot to limit the rotation of the piston rod to prevent the piston rod from rotating when the pressing cap is rotated. At the same time, a piston rod sleeve is provided to facilitate the rotation of the pressing cap and the operating rod.

[0018] When the piston rod of the present invention moves downward, the second limit slider of the operating rod enters the second limit slot until the piston rod moves downward to the lowest position, ensuring that the second limit slider and the second limit slot do not separate during the entire stroke.

[0019] Furthermore, a stroke control sleeve is sleeved on the operating rod of the present invention, a second limit slider is provided on the outer side of the stroke control sleeve, and a fastening bolt is also provided on one side of the stroke control sleeve.

[0020] Through the above arrangement, the height of the second limit slider can be adjusted, and the ratio of the two capacities can be changed.

[0021] Furthermore, a plane thrust bearing is provided between the piston rod sleeve and the operating rod of the utility model.

[0022] By arranging the bearing, the operating lever can rotate more flexibly.

[0023] Furthermore, the distance from the upper end of the pressing cap to the upper end of the shell is greater than the distance between the lower end surface of the second limiting slider and the limiting clamping ring.

[0024] That is, when the second limiting slider is aligned with the second limiting slot, the pressing cap is fully pressed and the piston rod can continue to move downward for a distance.

[0025] Furthermore, a rotation indicating arrow is provided on the pressing cap of the present invention, and an alignment indicating arrow is provided on the upper end surface of the shell.

[0026] When the rotation indication arrow of the pressing cap is aligned with the alignment indication arrow, the second limit slider and the second limit slot are in an aligned state; when the rotation indication arrow of the pressing cap is not aligned with the alignment indication arrow, the second limit slider and the second limit slot are in a misaligned state.

[0027] The utility model has the advantages of simple structure, low cost, flexible and convenient use, and wide application range. When using the utility model, it only needs to rotate the pressing cap to realize multiple use methods, which is simple to operate and has a wide application range. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic structural diagram of Example 1 of the present utility model;

[0029] Figure 2 for Figure 1 AA cross-sectional structural diagram in;

[0030] Figure 3 for Figure 1 BB cross-sectional structure diagram in;

[0031] Figure 4 for Figure 1 Schematic diagram of CC cross-section structure in;

[0032] Figure 5 for Figure 1 The D-direction schematic diagram in FIG.

[0033] Figure 6 This is a schematic structural diagram of Example 2 of the present utility model;

[0034] Figure 7 for Figure 6 Schematic diagram of the EE cross-section structure.

[0035] As shown in the figure: 1. Washing nozzle; 2. Suction rod; 3. Piston rod; 4. Return spring; 5. First limit slide; 6. Piston rod sleeve; 7. Housing; 8. Operating lever; 9. Press cap; 10. Second limit slider; 11. Limit clamping ring; 12. Second limit slide; 13. First limit slider; 14. Rotation indicator arrow; 15. Alignment indicator arrow; 16. Stroke control sleeve; 17. Fastening bolt; 18. Plane thrust bearing. DETAILED DESCRIPTION

[0036] The following is a detailed description of the embodiments of the technical solution of the present invention in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention and are therefore only examples and are not intended to limit the scope of protection of the present invention. It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should have the common meanings understood by those skilled in the art to which the present invention belongs. Example 1

[0037] like Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 As shown: the lower end of the shell 7 is provided with a liquid suction rod 2 and a liquid suction nozzle 1, the inner cavity of the shell is provided with a piston rod 3, the lower end of the piston rod 3 is inserted into the inner cavity of the liquid suction rod 2, the piston rod 3 is provided with a return spring 4, and the upper end of the piston rod 3 is provided with a piston rod sleeve 6. The surface of the piston rod sleeve 6 is symmetrically provided with two first limit sliders 13, and the inner cavity of the shell 7 is provided with two symmetrical first limit slide grooves 5 matching the first limit slider 13. The upper end of the piston rod sleeve 6 is inserted into the cavity of the operating rod 8, and the upper end of the operating rod 8 extends out of the upper end of the shell and is provided with a pressing cap 9. Two symmetrical rotation indication arrows 14 are provided on the pressing cap 9, and two symmetrical alignment indication arrows 15 are provided on the upper end surface of the shell 7. Two symmetrical second limit sliders 10 are provided on the side surface of the middle part of the operating rod 8, a limit clamping ring 11 is provided on the inner cavity of the shell 7, and two symmetrical second limit clamping grooves 12 are provided on the second limit clamping ring 11.

[0038] In the initial state of the pipette gun of this embodiment, under the action of the reset spring 4, the second limit slider 10 is located above the limit clamping ring 11, and the distance from the upper end of the pressing cap 9 to the upper end of the shell 7 is greater than the distance between the lower end surface of the second limit slider 10 and the limit clamping ring 11.

[0039] When the piston rod 3 moves downward, when the lower end surface of the second limit slider 10 is flush with the limit clamping ring 11, it is defined as the first stroke (corresponding to the first capacity). When the second limit slider 10 and the second limit clamping groove 12 are aligned, and the second limit slider 10 enters the second limit clamping groove 12, the piston rod 3 continues to move downward to the lowest point, which is defined as the second stroke (corresponding to the second capacity). The sum of the two strokes is defined as the maximum stroke.

[0040] When using this embodiment, there are three ways of using it:

[0041] 1) Aspirate the first volume of liquid at a time and pipette

[0042] The first-stage volumetric pipetting operation can be completed by using only the first-stage stroke, that is, the second limiting slider 10 and the second limiting slot 12 are always in a misaligned state;

[0043] 2) Take up the maximum volume of liquid at one time and pipette

[0044] Using the first stroke and the second stroke at the same time can complete the maximum capacity pipetting operation, that is, the second limit slider 10 and the second limit slot 12 are always in an aligned state;

[0045] 3) Absorb the maximum volume of liquid at one time and pipette it in two volumes

[0046] In the initial state, the rotation indicator arrow 14 is aligned with the alignment indicator arrow 15, and the second limit slider 10 is aligned with the second limit slot 12. The pressing cap 9 is pressed downward to drive the operating rod 8 and the piston rod 3 downward until the stroke ends. This stroke is the maximum stroke of the piston rod. The pressing cap 9 is released. Under the action of the reset spring 4, the piston rod 3, the operating rod 8, and the pressing cap 9 are reset upward to complete the maximum capacity liquid suction operation. When the above-mentioned sucked liquid needs to be pushed out in two sections, the pressing cap 9 is rotated so that the rotation indicator arrow 14 is not aligned with the alignment indicator arrow 15 , so that the second limit slider 10 and the second limit slot 12 are in a misaligned state, press the pressing cap 9 downward until the second limit slider 10 presses on the limit collar 11, completing the first section of capacity push-out and discharge, maintaining the above state, rotate the pressing cap 9, drive the operating rod 8 and the second limit slider 10 to rotate together, when the rotation indicator arrow 14 aligns with the alignment indicator arrow 15, the second limit slider 10 and the second limit slot 12 are in an aligned state, press the pressing cap 9 downward, the operating rod 8 and the piston rod 3 continue to move downward, completing the second section of capacity push-out and discharge. Example 2

[0047] like Figure 4 、 Figure 5 As shown, a planar thrust bearing 18 is provided between the piston rod sleeve 6 and the operating rod 8 , a stroke control sleeve 16 is provided in the middle of the operating rod 8 , two second limit sliders 10 are symmetrically provided on the outer side of the stroke control sleeve 16 , and fastening bolts 17 are symmetrically provided on both sides of the stroke control sleeve 16 . The stroke control sleeve 16 has bolt holes that match the fastening bolts. The bolt holes are countersunk. When the fastening bolts 17 are tightened, they are completely hidden in the stroke control sleeve 16 . Grooves that match the fastening bolts 17 are provided on both sides of the operating rod. When the fastening bolts 17 are tightened, the stroke control sleeve 16 will not rotate relative to the operating rod 8 . Loosening the fastening bolts 17 allows the height of the stroke control sleeve 16 to be adjusted. Other features are the same as those of Example 1.

[0048] Compared with Example 1, a plane thrust bearing 18 is provided between the piston rod sleeve 6 and the operating rod 8 in this embodiment, so that the operating rod 8 can be rotated more flexibly. By adjusting the height of the stroke control sleeve 16, the ratio of the two capacity sections can be changed.

[0049] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention.

Claims

1. A dual-volume pipette, comprising a housing, a pipette rod and a pipette nozzle provided at the lower end of the housing, a piston rod provided in the inner cavity of the housing, the lower end of the piston rod being inserted into the inner cavity of the pipette rod, and a return spring being sheathed on the piston rod, characterized in that The upper end of the piston rod is fitted with a piston rod sleeve, the surface of the piston rod sleeve is provided with a first limit slider, the inner cavity of the shell is provided with a first limit slide groove matching the first limit slider, the upper end of the piston rod sleeve is inserted into the cavity of the operating rod, the upper end of the operating rod extends out of the upper end of the shell and is provided with a pressing cap, the middle side of the operating rod is provided with a second limit slider, the inner cavity of the shell is provided with a limit clamping ring, and the second limit clamping ring is provided with a second limit clamping groove.

2. A dual-volume pipette according to claim 1, characterized in that A stroke control sleeve is sleeved on the operating rod, a second limiting slider is arranged on the outer side of the stroke control sleeve, and a fastening bolt is also arranged on one side of the stroke control sleeve.

3. A dual-volume pipette according to claim 1, characterized in that A plane thrust bearing is provided between the piston rod sleeve and the operating rod.

4. A dual-volume pipette according to claim 1, characterized in that The distance between the upper end of the pressing cap and the upper end of the shell is greater than the distance between the lower end surface of the second limiting slider and the limiting clamping ring.

5. A dual-volume pipette according to claim 1, characterized in that A rotation indicating arrow is arranged on the pressing cap, and an alignment indicating arrow is arranged on the upper end surface of the shell.

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