A micropipette

Abstract

The present invention relates to the technical field of pipettes, and specifically provides a micropipette, comprising a shell, a push rod is arranged inside the shell, a first piston and a second piston are arranged at both ends of the push rod, the upper end of the shell has a first sealed cavity, the lower end has a second sealed cavity, the first piston and the second piston are both slidably sealed and connected in the first sealed cavity and the second sealed cavity, a bellows is arranged at the top end of the shell, the bellows is connected to the first sealed cavity, an operator presses the bellows to make the oil inside the bellows push the first piston, the oil can act vertically on the upper end surface of the first piston, so as to avoid the force acting on the push rod deviating from the axial direction of the push rod, so as to avoid the wear of the second piston caused by the force deviating from the axial direction of the push rod, and at the same time avoid the rotation of the push rod, and because the bellows is elastic, the bellows fits the operator's fingers better, which significantly improves the comfort.

Description

Technical Field

[0001] The invention relates to the technical field of pipettes, in particular to a micropipette. Background Art

[0002] A pipette, also called a pipette gun, is a measuring tool that transfers liquid from the original container to another container within a certain range. It is widely used in biology, chemistry and other fields.

[0003] For example, Chinese patent CN202015624U discloses a precision fine-tunable pipette, in which the amount of liquid transferred in the pipette is determined by the distance moved by a well-coordinated piston rod in the inner cavity of the pipette. The piston rod uses the principle of air displacement to move a fixed distance in the pipette to generate negative pressure and suck in a fixed amount of liquid. A fine-tuning knob and a fine-tuning spring are provided, which structurally realize fine-tuning and calibration of the measurement reference point, eliminating the cumulative errors caused by assembly and manufacturing, etc. At the same time, the measurement reference point can also be fine-tuned and calibrated for the cumulative errors caused by long-term use, thereby increasing the service life of the pipette.

[0004] However, the piston rod in the above scheme can both adjust the range and absorb liquid. When the operator presses the piston rod, it may cause the piston rod to rotate, thereby affecting the adjusted range and causing errors in the amount of liquid absorbed. At the same time, the operator cannot ensure that the pressing force is always along the axial direction of the piston rod when pressing, so a force deviating from the axis of the piston rod will be generated, which will cause the movement of the piston to be obstructed, and over time it will cause increased wear and tear, thereby affecting the accuracy of pipetting. Summary of the invention

[0005] Based on this, it is necessary to provide a micropipette to address the problem that the current piston rod affects the pipetting accuracy when being pressed by an operator.

[0006] The above purpose is achieved through the following technical solutions:

[0007] A micropipette, comprising:

[0008] A housing, wherein a handle is disposed on the upper end of the housing, a viewing window is provided on the side wall of the housing, and a tip is provided at the bottom of the housing to be able to receive a pipette tip;

[0009] A push rod, the push rod is axially slidably arranged inside the housing, the upper end of the housing has a first sealed cavity, the lower end of the housing has a second sealed cavity, the two ends of the push rod are respectively provided with a first piston and a second piston, the first piston and the second piston are respectively located in the first sealed cavity and the second sealed cavity;

[0010] A bellows, wherein the bellows is connected to the top of the housing, one end of the bellows is connected to the first sealing chamber, the other end of the bellows is sealed, the bellows and the first sealing chamber are filled with oil, the bellows is shortened to squeeze the oil to push the first piston to move, the second sealing chamber is connected to the bottom of the housing, and the second piston pushes and moves to squeeze out the air inside the second sealing chamber;

[0011] A reset elastic member is sleeved on the push rod, the first piston moves to compress the reset elastic member, and the reset elastic member can push the push rod to reset so as to suck the liquid into the pipette tip.

[0012] Furthermore, a damping component is provided between the bellows and the first sealing cavity, and the damping component can adjust the flow speed of the oil between the first sealing cavity and the bellows.

[0013] Furthermore, the damping assembly includes a sealing plate and an adjusting disk, the sealing plate is located between the bellows and the first sealing cavity, a damping hole is provided at an eccentric position of the sealing plate, the adjusting disk is coaxially and rotatably connected to the lower end surface of the sealing plate, a semi-arc through groove with gradually increasing width is provided on the adjusting disk, the maximum width of the semi-arc through groove is the same as the diameter of the damping hole, the damping hole is located above the semi-arc through groove, and the rotation of the adjusting disk can change the width of the semi-arc through groove contacted by the damping hole.

[0014] Furthermore, two sealing rings distributed up and down are provided on the outer periphery of the second piston, and a cavity is provided between the upper and lower sealing rings. A first oil flow channel and a second oil flow channel are opened inside the push rod. The upper openings of the first oil flow channel and the second oil flow channel are both located on the upper end surface of the first piston. The lower openings of the first oil flow channel and the second oil flow channel are both located on the outer periphery of the second piston and in the cavity. A connecting pipe is slidably inserted into the upper end opening of the first oil flow channel, and the other end of the connecting pipe is connected to the bellows.

[0015] Furthermore, a spiral plate is provided on the outer periphery of the second piston, and the spiral plate is located in the cavity, with the lower end of the spiral plate close to the lower opening of the first oil flow channel, and the upper end of the spiral plate close to the lower opening of the second oil flow channel.

[0016] Furthermore, an adjustment component is also provided on the shell, and the adjustment component can adjust the air intake volume of the bottom tip of the shell.

[0017] Furthermore, the adjustment assembly includes an adjusting knob, an adjusting sleeve and a fixed sleeve, the adjusting knob is rotatably connected to the upper end of the shell, the fixed sleeve is fixedly connected in the shell, the adjusting sleeve is sleeved on the outer periphery of the push rod and slidably inserted into the inner periphery of the fixed sleeve, the fixed sleeve is axially slidably connected to the adjusting sleeve, a limiting ring is provided on the outer periphery of the push rod, the upper end of the limiting ring abuts against the lower end of the adjusting sleeve, and the rotation of the adjusting knob can adjust the axial movement distance of the adjusting sleeve.

[0018] Furthermore, the outer circumference of the adjusting sleeve is spirally connected to a driving sleeve, the inner circumference of the driving sleeve has an internal thread, the outer circumference of the adjusting sleeve has an external thread, and the driving sleeve rotates synchronously with the adjusting knob.

[0019] Furthermore, a scale display assembly is also provided in the shell, and the scale display assembly includes a plurality of rotating wheels, each rotating wheel has numbers engraved on its outer circumference, and the driving sleeve can drive the rotating wheels to rotate to display the adjusted range.

[0020] Furthermore, a pressing block is provided at the upper end of the shell, and a pushing sleeve is provided on the outer periphery of the tip of the bottom of the shell. The pressing block is connected to the pushing sleeve. The pressing block moves downward to push the pushing sleeve to extend, and the pushing sleeve pushes the pipette tip to detach from the tip. A reset spring is provided in the pushing sleeve, and the reset spring pushes the pushing sleeve to reset.

[0021] The beneficial effects of the present invention are:

[0022] The present invention is connected to the first sealing cavity through a bellows and the interior is filled with oil. The operator presses the bellows to make the oil inside the two push the first piston. The oil can act vertically on the upper end surface of the first piston, thereby preventing the force acting on the push rod from deviating from the axial direction of the push rod. Therefore, it is possible to avoid the wear of the second piston caused by the force deviating from the axial direction of the push rod, and at the same time avoid the push rod from rotating. Moreover, since the bellows is elastic, the bellows fits the operator's fingers better. Compared with the traditional hard pressing head, the flexible structure of the bellows reduces the pressure on the fingers during long-term operation, significantly improves the comfort, and is particularly suitable for experimental environments that require frequent operations.

[0023] The present invention provides a damping component between the bellows and the first sealed cavity. The damping component can regulate the flow rate of oil entering the bellows or the first sealed cavity. Since the operator cannot press the bellows with the same force and speed, the damping component is provided to ensure that the overall flow rate of the oil is uniform. This design improves the accuracy and controllability of the pipette.

[0024] The present invention provides two sealing rings on the outer periphery of the second piston, the two sealing rings are distributed up and down, and there is a cavity between the two sealing rings, the cavity can be filled with oil to reduce the wear of the two sealing rings, and a first oil flow channel and a second oil flow channel are opened in the push rod, so that the oil flows through the two in the cavity to lubricate the inner wall of the second sealing cavity, thereby reducing the wear of the two sealing rings.

[0025] The present invention arranges a spiral plate on the outer periphery of the second piston so that the oil can be guided through the spiral plate when flowing out from the lower opening of the first oil flow channel or the lower opening of the second oil flow channel. The spiral plate guides the oil in a spiral direction, thereby improving the lubrication effect of the oil on the inner wall of the second sealing cavity and further reducing the wear of the two sealing rings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of the structure of a micropipette provided in one embodiment of the present invention;

[0027] Figure 2 for Figure 1 A partial enlarged view of part A of the micropipette provided in one embodiment;

[0028] Figure 3 for Figure 1 A front view of a micropipette provided in an embodiment;

[0029] Figure 4 A cross-sectional view of a micropipette provided by one embodiment of the present invention;

[0030] Figure 5 for Figure 4 A partial enlarged view of part B of the micropipette provided in one embodiment;

[0031] Figure 6 for Figure 4 A partial enlarged view of part C of the micropipette provided in one embodiment;

[0032] Figure 7 for Figure 4 A partial enlarged view of part D of the micropipette provided in one embodiment;

[0033] Figure 8 A schematic diagram of the structure of an adjustment disk of a micropipette provided in one embodiment of the present invention;

[0034] Fig. 9 A schematic structural diagram of a second piston on a portion of a push rod of a micropipette provided in one embodiment of the present invention.

[0035] in:

[0036] 100, housing; 110, handle; 120, pressing block; 130, viewing window; 140, tip; 150, first sealed cavity; 160, second sealed cavity; 170, blocking plate; 171, damping hole; 180, adjusting plate; 181, semi-arc groove; 182, adjusting convex plate; 190, bellows; 191, connecting pipe;

[0037] 200, push rod; 210, first piston; 220, second piston; 221, sealing ring; 222, cavity; 223, spiral plate; 230, limit ring; 240, limit plate; 250, resetting elastic member; 260, first oil flow channel; 270, second oil flow channel;

[0038] 300, adjusting knob; 310, adjusting sleeve; 320, fixing sleeve; 330, driving sleeve; 340, connecting sleeve; 350, rotating wheel; 360, transmission gear;

[0039] 400, pushing sleeve; 410, connecting rod; 420, return spring. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below through embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0041] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in the present invention, unless otherwise specified, include direct and indirect connections (couplings). In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0042] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0043] Refer to the following Figure 1-Figure 9 A micropipette provided by the present invention is described.

[0044] A micropipette, suitable for quantitative transfer of liquid, comprises a housing 100, and a handle 110 is provided at the upper end of the housing 100. Figure 1 As shown, the handle 110 has an anti-slip sticker for easy gripping, a viewing window 130 is provided on the side wall of the housing 100, and the viewing window 130 is used to view the range, and the bottom of the housing 100 has a tip 140 for connecting a pipette tip (not shown in the figure), and a push rod 200 is arranged in the housing 100, and the push rod 200 is specifically axially slidably arranged inside the housing 100, and the two ends of the push rod 200 are respectively provided with a first piston 210 and a second piston 220, and the upper end of the housing 100 has a first sealed cavity 150, and the lower end has a second sealed cavity 160, and the first pistons 210 at both ends of the push rod 200 The second piston 220 is respectively slidably and sealedly connected in the first sealing cavity 150 and the second sealing cavity 160. The second piston 220 is communicated with the bottom tip 140 of the shell 100. A reset elastic member 250 is sleeved on the outer periphery of the push rod 200. When the second piston 220 slides downward in the second sealing cavity 160, it can push the air in the bottom tip 140 of the shell 100 and compress the reset elastic member 250, and then release the reset elastic member 250. When the reset elastic member 250 drives the second piston 220 to move upward, negative pressure is formed in the bottom tip 140 of the shell 100, so that the liquid can be sucked into the pipette tip.

[0045] The prior art does not use a push rod 200 with pistons at both ends, but only uses a push rod 200 with a piston at one end, which is similar to only having a second piston 220. Pushing the second piston 220 downward is achieved by the operator directly pressing the top of the push rod 200. Such direct pressing cannot ensure that the pressing force is always along the axial direction of the push rod 200, so a force that deviates from the axis of the push rod 200 will be generated, which will cause the movement of the second piston 220 to be obstructed and affect the accuracy of the second piston 220.

[0046] In the present invention, a first piston 210 is provided above the push rod 200, and the first piston 210 is located in the first sealed cavity 150. At the same time, a bellows 190 is connected to the top of the housing 100, one end of the bellows 190 is connected to the first sealed cavity 150, and the other end of the bellows 190 is sealed. The bellows 190 and the first sealed cavity 150 are both filled with oil. The operator presses the bellows 190 to shrink the bellows 190, and the oil in the bellows 190 enters the first sealed cavity 150, thereby pushing the first piston 210 to move downward, and the first piston 210 drives the push rod 200 to move downward synchronously, and the push rod 200 then pushes the second piston 220 to move downward, thereby pushing the air inside the tip 140.

[0047] It can be understood that the bellows 190 and the first sealing chamber 150 are connected and filled with oil. The operator presses the bellows 190 to make the oil inside the two push the first piston 210. The oil can act vertically on the upper end surface of the first piston 210, thereby avoiding the force acting on the push rod 200 deviating from the axial direction of the push rod 200, thereby avoiding the wear of the second piston 220 caused by the force deviating from the axial direction of the push rod 200. At the same time, since the bellows 190 is elastic, the bellows 190 fits the operator's fingers better. Compared with the traditional hard pressing head, the flexible structure of the bellows 190 reduces the pressure on the fingers during long-term operation, significantly improves the comfort, and is particularly suitable for experimental environments that require frequent operations.

[0048] In a further embodiment, a damping assembly is provided between the bellows 190 and the first sealed cavity 150, and the damping assembly can regulate the flow rate of the oil entering the bellows 190 or the first sealed cavity 150. Since the operator cannot press the bellows 190 with the same force and speed, the damping assembly is provided to ensure that the overall flow rate of the oil is uniform. This design improves the accuracy and controllability of the pipette.

[0049] Specifically, the damping assembly includes a sealing plate 170 and an adjusting disk 180. The sealing plate 170 is fixedly connected between the bellows 190 and the first sealing chamber 150 to separate the first sealing chamber 150 from the bellows 190. A damping hole 171 is provided at an eccentric position of the sealing plate 170. The damping hole 171 allows oil to pass through, thereby playing a damping role, so that the force and speed of the oil pushing the first piston 210 are as uniform as possible, and the adjusting disk 180 is coaxially and rotatably connected to the lower end surface of the sealing plate 170. A semi-arc through groove 181 with a gradually increasing width is provided at an eccentric position on the adjusting disk 180, and the maximum width of the semi-arc through groove 181 is the same as the diameter of the damping hole 171.

[0050] Specific as Figure 8As shown, the width of the semi-arc groove 181 is in the clockwise direction (in Figure 8 The outer periphery of the adjusting disk 180 is also provided with an adjusting convex plate 182, and the outer end of the adjusting convex plate 182 is provided with an anti-skid protrusion. The operator rotates the adjusting disk 180 by anti-skid toggling the adjusting convex plate 182, and the damping hole 171 on the blocking plate 170 is located above the semi-arc groove 181. The oil needs to flow through the damping hole 171 and the semi-arc groove 181. When the adjusting disk 180 rotates clockwise, the width of the semi-arc groove 181 contacted by the damping hole 171 gradually decreases, thereby reducing the oil The amount of liquid flowing through the damping hole 171 and the semi-arc groove 181, that is, the damping effect is enhanced, makes the flow of oil more uniform, thereby improving the pipetting accuracy, but the pipetting efficiency is slightly reduced; when the adjusting disk 180 rotates counterclockwise, the width of the semi-arc groove 181 contacted by the damping hole 171 gradually increases. At the maximum, the damping hole 171 contacts the semi-arc groove 181 at the maximum width position, so that the amount of oil flowing through the damping hole 171 and the semi-arc groove 181 increases, reducing the damping effect, and can improve the pipetting efficiency, but the accuracy is slightly reduced.

[0051] It should be noted that the accuracy and efficiency can be balanced according to actual needs, and no specific limitation is made here.

[0052] In a further embodiment, a sealing ring 221 is installed on the outer periphery of the piston in the prior art, thereby improving the sealing performance of the piston and reducing the wear of the piston. However, when used for a long time, the sealing ring 221 on the outer periphery of the piston will be worn and the sealing performance will be reduced, affecting the accuracy of pipetting. At this time, a new sealing ring 221 needs to be replaced, but the replacement process is relatively cumbersome. Therefore, it is urgent to reduce the wear of the sealing ring 221 during use, thereby increasing the service life of the sealing ring 221 and reducing the frequency of replacement of the sealing ring 221.

[0053] Specifically, two sealing rings 221 are arranged on the outer circumference of the second piston 220, and the two sealing rings 221 are distributed up and down. Figure 7 As shown, the upper and lower sealing rings 221 are respectively close to the upper and lower ends of the second piston 220, and there is a cavity 222 between the two sealing rings 221. The cavity 222 can be filled with oil to reduce the wear of the two sealing rings 221. Since the second piston 220 reciprocates in the second sealing cavity 160, the outer peripheries of the two sealing rings 221 reciprocate with the inner wall of the second sealing cavity 160. At this time, filling the cavity 222 between the two sealing rings 221 with oil can lubricate the inner wall of the second sealing cavity 160, thereby reducing the wear of the two sealing rings 221.

[0054] More specifically, the present invention provides a first oil flow channel 260 and a second oil flow channel 270 inside the push rod 200, and the upper openings of the first oil flow channel 260 and the second oil flow channel 270 are both located on the upper end surface of the first piston 210, while the lower openings of the first oil flow channel 260 and the second oil flow channel 270 are located on the outer periphery of the second piston 220, specifically between the two sealing rings 221, and a connecting pipe 191 is slidably inserted in the first oil flow channel 260, and the other end of the connecting pipe 191 is fixed. Inside the bellows 190 and connected to the bellows 190, the connecting tube 191 slides axially relative to the first oil flow channel 260 when the first piston 210 moves axially but does not separate from the first oil flow channel 260. The first oil flow channel 260 and the connecting tube 191 work together to connect the bellows 190 and the cavity 222, while the second oil flow channel 270 connects the first sealed cavity 150 and the cavity 222, so that the oil can flow through the cavity 222 and lubricate the inner wall of the second sealed cavity 160.

[0055] It should be noted that, since the operator presses the bellows 190, the oil pressure inside the bellows 190 will be greater than the oil pressure in the first sealed chamber 150. At this time, a small amount of oil in the bellows 190 will enter the first oil flow channel 260 through the connecting pipe 191 and finally enter the cavity 222, so that when the second piston 220 moves, the two sealing rings 221 on the outer periphery of the second piston 220 are lubricated by the oil, thereby reducing wear. The oil then flows into the first sealed chamber 150 through the lower opening of the second oil flow channel 270; and when the push rod 200 moves upward, the oil in the first oil flow channel 260 and the second oil flow channel 270 flow in opposite directions, and the specific flow process will not be described in detail.

[0056] By providing the first oil flow channel 260 , the second oil flow channel 270 and the connecting pipe 191 , the oil in the first sealing cavity 150 and the bellows 190 can flow through the cavity 222 , thereby reducing the use of additional oil.

[0057] In a further embodiment, Fig. 9 As shown, a spiral plate 223 is also provided on the outer periphery of the second piston 220. The spiral plate 223 is specifically spirally connected to the outer periphery of the second piston 220 and is located between the two sealing rings 221. The lower end of the spiral plate 223 is close to the lower opening of the first oil flow channel 260, and the upper end of the spiral plate 223 is close to the lower opening of the second oil flow channel 270, so that when the oil flows out from the lower opening of the first oil flow channel 260 or the lower opening of the second oil flow channel 270, it can be guided through the spiral plate 223. The spiral plate 223 guides the oil in a spiral direction, thereby improving the lubrication effect of the oil on the inner wall of the second sealing cavity 160, and further reducing the wear of the two sealing rings 221.

[0058] In a further embodiment, an adjusting component is further disposed in the housing 100 of the present invention, and the adjusting component can adjust the suction volume of the bottom tip 140 of the housing 100, that is, adjust the pipetting volume.

[0059] Specifically, the adjustment assembly includes an adjustment knob 300, an adjustment sleeve 310 and a fixed sleeve 320. Figure 4 and Figure 6 As shown, the adjusting knob 300 is rotatably connected to the upper end of the shell 100, and the fixed sleeve 320 is fixed in the shell 100. A through hole is provided on the fixed sleeve 320, and the push rod 200 slides through the through hole. The adjusting sleeve 310 is sleeved on the outer periphery of the push rod 200, and the adjusting sleeve 310 is slidably inserted in the through hole of the fixed sleeve 320 at the same time. An axial sliding groove (not shown in the figure) is provided on the inner wall of the through hole of the fixed sleeve 320, and an axial protrusion (not shown in the figure) is provided at the sliding connection part between the adjusting sleeve 310 and the fixed sleeve 320. The axial protrusion is located in the axial sliding groove to limit the relative rotation of the adjusting sleeve 310 and the fixed sleeve 320, so that the adjusting sleeve 310 can only move axially relative to the fixed sleeve 320. When the adjusting knob 300 is rotated, it can drive the adjusting sleeve 310 to move axially, thereby changing the position of the adjusting sleeve 310.

[0060] It should be noted that a limit ring 230 is fixedly provided on the outer periphery of the push rod 200, and the reset elastic member 250 abuts against the lower end surface of the limit ring 230. The other end of the reset elastic member 250 is fixed inside the shell 100. The reset elastic member 250 is a compression spring. When the push rod 200 moves downward, the limit ring 230 on the push rod 200 compresses the reset elastic member 250, and when the reset elastic member 250 is released, it pushes the push rod 200 to move upward, so that the upper end of the limit ring 230 on the push rod 200 abuts against the lower end surface of the adjusting sleeve 310. The distance that the push rod 200 moves upward can determine the amount of liquid sucked into the pipette tip. Therefore, the amount of liquid sucked by the pipette tip can be changed by changing the distance that the adjusting sleeve 310 moves in the axial direction.

[0061] More specifically, in order to facilitate the above-mentioned adjusting knob 300 to drive the adjusting sleeve 310 to move axially, a driving sleeve 330 is spirally connected to the outer periphery of the adjusting sleeve 310, the inner periphery of the driving sleeve 330 has an internal thread, and the outer periphery of the adjusting sleeve 310 has an external thread. The driving sleeve 330 and the adjusting sleeve 310 are spirally connected, and the outer periphery of the driving sleeve 330 is fixedly connected to the adjusting knob 300 through the connecting sleeve 340. The specific adjustment process is that when the adjusting knob 300 rotates, the connecting sleeve 340 is driven to rotate synchronously. Since the connecting sleeve 340 is fixedly connected to the driving sleeve 330, the driving sleeve 330 also rotates synchronously. The driving sleeve 330 and the adjusting sleeve 310 are spirally connected, and the adjusting sleeve 310 cannot rotate circumferentially but can only move axially. Therefore, when the driving sleeve 330 rotates, the sleeve 330 can drive the adjusting sleeve 310 to move axially and then adjust the upward movement distance of the push rod 200, that is, adjust the amount of liquid sucked by the pipette tip.

[0062] It should be noted that another compression spring is also provided on the push rod 200, which is sleeved on the outer periphery of the second sealing chamber 160. A limiting plate 240 is fixedly provided at a position of the push rod 200 close to the second piston 220, and the upper end of the compression spring abuts against the bottom of the limiting plate 240, and the other end of the compression spring is fixedly connected to the bottom end inside the shell 100. The compression spring and the reset elastic member 250 work together to prevent the push rod 200 from being unable to reset when the reset elastic member 250 fails.

[0063] In a further embodiment, in order to display the pipetting volume adjusted by the adjusting knob 300 in digital form in the viewing window 130, a scale display assembly is provided in the housing 100, and the scale display assembly includes a plurality of rotating wheels 350, each of which is engraved with numbers 0-9 on the periphery of the rotating wheel 350, and the plurality of numbers are evenly distributed on the periphery of the rotating wheel 350, and the plurality of rotating wheels 350 are coaxially distributed from top to bottom, and the periphery of the driving sleeve 330 is connected to the bottom group of rotating wheels 350 through a transmission gear 360, and the adjusting knob 300 drives the connecting sleeve 340 to rotate. At the same time as the rotation of the adjusting knob 300, the connecting sleeve 340 drives the rotating wheel 350 to rotate. In this embodiment, three groups of rotating wheels 350 are taken as an example. When the lowest rotating wheel 350 rotates one circle, that is, when the lowest rotating wheel 350 rotates from 0 to 0 again, the middle rotating wheel 350 rotates one scale, that is, from 0 to 1, and when the middle rotating wheel 350 rotates one circle, that is, when the middle rotating wheel 350 rotates from 0 to 0 again, the uppermost rotating wheel 350 rotates from 0 to 1, thereby displaying how much the adjusting knob 300 has been rotated, and the number can be viewed through the viewing window 130.

[0064] In a further embodiment, a pressing block 120 is further provided at the upper end of the housing 100. Figure 1 and Figure 4As shown, the pressing block 120 can slide along the axial direction of the shell 100, and a pushing sleeve 400 is sleeved on the outer periphery of the bottom tip 140 of the shell 100. The pushing sleeve 400 can move along the axial direction of the shell 100. The pushing sleeve 400 and the pressing block 120 are connected by a connecting rod 410. A reset spring 420 is sleeved on the connecting rod 410. One end of the reset spring 420 is fixed on the connecting rod 410, and the other end of the reset spring 420 is fixedly connected in the shell 100. When the operator pushes the pressing block 120, the pressing block 120 moves downward to compress the reset spring 420. At the same time, the pressing block 120 drives the pushing sleeve 400 to move downward through the connecting rod 410, thereby pushing the pipette tip installed on the bottom tip 140 of the shell 100 to fall off.

[0065] The specific use process of a micropipette provided by the present invention is described in combination with the above embodiments:

[0066] Adjust the pipetting volume:

[0067] The operator rotates the adjusting knob 300, and the adjusting knob 300 drives the connecting sleeve 340 to rotate synchronously, and the connecting sleeve 340 drives the driving sleeve 330 to rotate synchronously. Since the driving sleeve 330 and the adjusting sleeve 310 are spirally connected, and the adjusting sleeve 310 can only move along the axial direction of the fixed sleeve 320 under the action of the fixed sleeve 320, the adjusting sleeve 310 is driven to move axially when the driving sleeve 330 rotates. The axial movement of the adjusting sleeve 310 changes the upper limit position of the upper limit ring 230 of the push rod 200. At the same time, the outer periphery of the connecting sleeve 340 is transmission-connected with the rotating wheel 350, so when the adjusting knob 300 is rotated, multiple rotating wheels 350 are driven to rotate and then the adjusted numbers are displayed. The adjusted amount of pipetting can be known through the numbers.

[0068] Adjust damping:

[0069] Adjust the width of the semi-arc groove 181 that the damping hole 171 contacts according to the experimental requirements. If the experiment requires a large number of pipetting times and the accuracy requirement is not very high, you can rotate counterclockwise (with Figure 8 The damping hole 171 is rotated counterclockwise from top to bottom as shown to appropriately increase the width of the semi-arc groove 181 in contact with the damping hole 171, so that the speed at which the oil passes through is appropriately increased, thereby improving the efficiency of pipetting. If the experiment requires a small number of pipetting times and a high precision requirement, the damping hole 171 is rotated clockwise to appropriately reduce the width of the semi-arc groove 181 in contact with the damping hole 171, so that the oil flows more slowly, thereby improving the precision of pipetting.

[0070] Installing the pipette tip:

[0071] A suitable pipette tip is selected according to the adjusted pipetting volume, and the pipette tip is sleeved on the bottom tip 140 of the housing 100 , so that the second sealed cavity 160 is communicated with the internal cavity of the pipette tip.

[0072] Quantitative aspiration:

[0073] The operator presses the bellows 190, and the oil in the bellows 190 enters the first sealed chamber 150 through the damping hole 171 and the semi-arc groove 181. The oil pushes the first piston 210 in the first sealed chamber 150 to move downward, and the first piston 210 drives the push rod 200 to move downward. The limiting ring 230 on the push rod 200 compresses the reset elastic member 250, and at the same time, the limiting plate 240 on the push rod 200 compresses the compression spring, and the push rod 200 drives the second piston 220 to move downward, so that the pipette tip can be squeezed out. The operator presses the bottom to vertically extend the aspirating end of the pipette tip into the liquid from top to bottom, releases the pressure on the bellows 190, and the reset elastic member 250 and the compression spring on the push rod 200 are released at the same time to push the push rod 200 to move upward. The push rod 200 drives the second piston 220 to move upward so that the inside of the pipette tip is in a negative pressure state, and the pipette tip starts to absorb liquid. When the limit ring 230 on the push rod 200 abuts against the lower end of the adjusting sleeve 310 whose position has been adjusted, the quantitative aspiration is completed.

[0074] Quantitative pipetting:

[0075] After the quantitative pipetting is completed, the housing 100 is slowly moved upward to separate the pipette tip from the liquid, and then the liquid tip is moved to the position where the pipette needs to be pipetted. The operator slowly presses the bellows 190, and the second piston 220 squeezes out all the liquid inside the pipette tip, thereby completing the quantitative pipetting.

[0076] After the quantitative pipetting is completed, the operator pushes the pressing block 120 so that the pressing block 120 drives the pushing sleeve 400 to move downward, and the pushing sleeve 400 pushes the pipette tip to separate from the bottom tip 140 of the housing 100. Then the pressing block 120 and the pushing sleeve 400 are reset under the reset action of the reset spring 420.

[0077] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0078] The above-described embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. A micropipette, characterized in that: include: A housing, wherein a handle is disposed on the upper end of the housing, a viewing window is provided on the side wall of the housing, and the bottom of the housing has a pointed end capable of receiving a pipette tip; A push rod, the push rod is axially slidably arranged inside the housing, the upper end of the housing has a first sealed cavity, the lower end of the housing has a second sealed cavity, the two ends of the push rod are respectively provided with a first piston and a second piston, the first piston and the second piston are respectively located in the first sealed cavity and the second sealed cavity; A bellows, wherein the bellows is connected to the top of the housing, one end of the bellows is connected to the first sealing chamber, the other end of the bellows is sealed, the bellows and the first sealing chamber are filled with oil, the bellows is shortened to squeeze the oil to push the first piston to move, the second sealing chamber is connected to the bottom of the housing, and the second piston pushes and moves to squeeze out the air inside the second sealing chamber; A reset elastic member is sleeved on the push rod, the first piston moves to compress the reset elastic member, and the reset elastic member can push the push rod to reset so as to suck the liquid into the pipette tip.

2. The micropipette according to claim 1, characterized in that A damping component is provided between the bellows and the first sealing cavity, and the damping component can adjust the flow speed of the oil between the first sealing cavity and the bellows.

3. The micropipette according to claim 2, characterized in that The damping assembly includes a sealing plate and an adjusting disk, the sealing plate is located between the bellows and the first sealing cavity, a damping hole is provided at an eccentric position of the sealing plate, the adjusting disk is coaxially and rotatably connected to the lower end surface of the sealing plate, a semi-arc through groove with gradually increasing width is provided on the adjusting disk, the maximum width of the semi-arc through groove is the same as the diameter of the damping hole, the damping hole is located above the semi-arc through groove, and the rotation of the adjusting disk can change the width of the semi-arc through groove contacted by the damping hole.

4. The micropipette according to claim 1, characterized in that: Two sealing rings distributed up and down are arranged on the outer periphery of the second piston, and a cavity is provided between the upper and lower sealing rings; a first oil flow channel and a second oil flow channel are opened inside the push rod; upper openings of the first oil flow channel and the second oil flow channel are both located on the upper end surface of the first piston; lower openings of the first oil flow channel and the second oil flow channel are both located on the outer periphery of the second piston and in the cavity; a connecting pipe is slidably inserted into the upper end opening of the first oil flow channel, and the other end of the connecting pipe is connected to the bellows.

5. The micropipette according to claim 4, characterized in that: A spiral plate is disposed on the outer periphery of the second piston. The spiral plate is located in the cavity. The lower end of the spiral plate is close to the lower opening of the first oil flow channel, and the upper end of the spiral plate is close to the lower opening of the second oil flow channel.

6. The micropipette according to claim 1, characterized in that: The shell is also provided with an adjustment component, and the adjustment component can adjust the air intake volume of the bottom tip of the shell.

7. The micropipette according to claim 6, characterized in that: The adjustment assembly includes an adjusting knob, an adjusting sleeve and a fixed sleeve. The adjusting knob is rotatably connected to the upper end of the shell, and the fixed sleeve is fixedly connected in the shell. The adjusting sleeve is sleeved on the outer periphery of the push rod and slidably inserted into the inner periphery of the fixed sleeve. The fixed sleeve is axially slidably connected to the adjusting sleeve. A limiting ring is provided on the outer periphery of the push rod, and the upper end of the limiting ring abuts against the lower end of the adjusting sleeve. The axial movement distance of the adjusting sleeve can be adjusted by rotating the adjusting knob.

8. The micropipette according to claim 7, characterized in that: The outer circumference of the adjusting sleeve is spirally connected with a driving sleeve, the inner circumference of the driving sleeve has an internal thread, the outer circumference of the adjusting sleeve has an external thread, and the driving sleeve rotates synchronously with the adjusting knob.

9. The micropipette according to claim 8, characterized in that: A scale display assembly is also provided in the shell, and the scale display assembly includes a plurality of rotating wheels, each of which has numbers engraved on its outer circumference, and the driving sleeve can drive the rotating wheels to rotate to display the adjusted range.

10. The micropipette according to claim 1, characterized in that: A pressing block is provided at the upper end of the shell, a pushing sleeve is provided on the outer periphery of the tip of the bottom of the shell, the pressing block is connected to the pushing sleeve, the pressing block moves downward to push the pushing sleeve to extend, the pushing sleeve pushes the pipette tip away from the tip, a reset spring is provided in the pushing sleeve, and the reset spring pushes the pushing sleeve to reset.

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