Inflatable pipette seal

Abstract

The application relates to the field of biological experiment pipetting and discloses an inflatable pipetting sealing device. The application comprises a driving motor, a pipetting head and a head retracting rod. The pipetting head comprises a piston rod and a pipetting piston cavity. The pipetting piston cavity penetrates the pipetting head in the axial direction. The piston rod is slidably arranged in the pipetting piston cavity. The head retracting rod is a hollow tubular structure and is sleeved outside the pipetting head. When the head retracting rod moves downward, the outer cavity space is expanded, the inner cavity air pressure is reduced, the annular elastic part is contracted, the extrusion force between the annular elastic part and the pipetting suction head is greatly reduced, the suction head can be easily separated from the pipetting head, and there is no hard dynamic friction in the whole process. The problems of long-term friction and wear, aging failure and powder dropping of the sealing rubber ring in the traditional structure are avoided. The service life of the annular elastic part and other sealing accessories is prolonged, the cost loss caused by frequent replacement of accessories is eliminated, the risk of friction dust polluting biological samples is avoided, and the cleanliness and detection accuracy of experimental samples are ensured.

Description

Technical Field

[0001] This invention belongs to the field of biological experimental pipetting technology, specifically an air-filled pipetting sealing device. Background Technology

[0002] In the field of biological experimental pipetting, most existing pipetting equipment uses a sealing ring friction cone insertion method to achieve an airtight connection between the pipetting head and the pipetting tip. During routine operation, the pipetting head mainly relies on the sealing ring to be rigidly inserted into the pipetting tip. During the pressing assembly process, the sealing ring continuously contacts and squeezes against the inner wall of the tip and undergoes relative sliding friction, thereby achieving a sealing assembly by forcing the sealing ring to deform.

[0003] Traditional sealing structures, under prolonged and repeated tip removal and removal operations, are prone to wear and dust shedding of the sealing rings due to continuous hard friction. This dust can mix with the transferred biological liquid samples, severely contaminating the experimental samples and directly affecting the accuracy and reliability of biological detection and experimental analysis results. Simultaneously, high-frequency friction wear accelerates the aging, deformation, and failure of the sealing rings, significantly shortening the service life of sealing components, increasing equipment maintenance costs and the frequency of component replacement, making it difficult to meet the demands of high-precision, high-cleanliness, and high-frequency biological pipetting operations.

[0004] In existing technologies, during operation, the pipette tip is equipped with a sealing ring. The pipette tip, carrying the sealing ring, is inserted into the pipette tip via a cone-shaped motion. During this process, the sealing ring gradually comes into contact with the pipette tip. As the pressure continues, relative friction occurs between the two, causing the sealing ring to deform and achieving an airtight connection between the pipette tip and the pipette tip. However, this friction can cause the sealing ring to shed powder, which falls into the transferred liquid and contaminates the biological results. Furthermore, prolonged relative friction significantly reduces the lifespan of the sealing ring. Summary of the Invention

[0005] The purpose of this invention is to provide an inflatable pipetting sealing device in order to solve the problem of the above-mentioned sealing technology that has good sealing effect, long service life and does not produce pollution.

[0006] The technical solution adopted in this invention is as follows: an inflatable pipetting sealing device, comprising: a drive motor, a pipetting head, and a retracting rod, wherein the pipetting head includes a piston rod and a pipetting piston chamber, the pipetting piston chamber extends axially through the pipetting head, the piston rod is slidably disposed in the pipetting piston chamber, and the retracting rod is a hollow tubular structure sleeved on the outside of the pipetting head;

[0007] An inner cavity space is provided between the inner wall and the outer wall of the pipette tip. The inner cavity space includes an annular elastic part that can protrude from the surface of the outer wall of the pipette tip. The annular elastic part is made of a material that generates a sealing effect through deformation, including silicone, fluororubber, nitrile, natural rubber, PU, ​​etc.

[0008] The outer wall of the pipette head is fitted with a first sealing ring, and the inner wall of the pipette head is provided with a second sealing ring. The first sealing ring, the second sealing ring, the outer wall of the pipette head, and the inner wall of the pipette head together form an outer cavity space.

[0009] One or more openings are provided on the outer wall of the pipette corresponding to the inner cavity space, and the inner cavity space and the outer cavity space are connected through the openings;

[0010] The drive motor is used to drive the piston rod and / or the retractor rod to move along a first direction and a second direction, wherein the first direction and the second direction are opposite.

[0011] By adopting the above technical solution, the drive motor drives the lead screw to rotate, and the lead screw nut mechanism drives the piston rod to move up and down. At the same time, the head retraction mechanism realizes the actions of liquid suction, liquid discharge and head retraction. The coupling connects the output shaft of the drive motor and the lead screw, compensates for the coaxiality error between the two shafts, ensures smooth power transmission, and avoids jamming or damage caused by rigid connection.

[0012] In a preferred embodiment, the drive motor is fixedly mounted on the upper end of the body by bolts, a coupling is provided on the inner top wall of the body, the output end of the drive motor is fixedly connected to the coupling, and an elastic sealing ring is provided at the connection between the piston rod and the pipetting piston chamber.

[0013] By adopting the above technical solution, the drive motor is fixedly installed on the main body, and the rotational power of the drive motor is transmitted to the lead screw through the coupling. The elastic sealing ring can effectively enhance the sealing performance at the connection between the piston rod and the liquid transfer piston chamber, and prevent leakage problems.

[0014] In a preferred embodiment, the lower end of the coupling is fixedly connected to a bearing housing, and a lead screw is threaded through the bearing housing at the lower end of the coupling.

[0015] By adopting the above technical solution, the bearing housing is used in conjunction with the installation of the lead screw to provide rotational support for the lead screw, reduce radial runout during lead screw rotation, ensure smooth and wobbly operation of the lead screw, and convert the rotational motion of the motor into the linear motion of the lead screw nut through the lead screw thread transmission to achieve precise displacement control of the piston rod.

[0016] In a preferred embodiment, a fixing block is provided inside the main body, and a piston rod is mounted on the side of the fixing block. The fixing block and the piston rod are fixedly connected by a pin.

[0017] By adopting the above technical solution, the fixing block serves as a connector between the lead screw and the piston rod, transmitting the linear motion of the lead screw to the piston rod to ensure synchronous movement. The fixed block and the piston rod are rigidly fixed by a pin, preventing relative rotation or loosening during operation and ensuring reliable motion transmission. The piston rod moves up and down under the drive of the lead screw, forming a closed piston chamber with the pipetting piston cavity. The negative or positive pressure required for liquid suction and discharge is generated by the change in the volume of the chamber.

[0018] In a preferred embodiment, a lead screw nut is provided at the upper end of the fixing block, and the other end of the lead screw passes through the lead screw nut and the fixing block respectively.

[0019] By adopting the above technical solution, the rotational motion of the lead screw is converted into its own linear motion through the cooperation of the lead screw nut and the lead screw, which drives the fixed block and the piston rod to move synchronously.

[0020] In a preferred embodiment, a circuit board is provided on the inner side wall of the main body, and a plurality of optical switching sensors are fixedly connected to the side of the circuit board, and a head-retracting baffle is provided on the side of the optical switching sensors.

[0021] By adopting the above technical solution, the circuit board serves as the control core, driving the drive motor to operate, receiving signals from the optical sensor, realizing closed-loop position control, and simultaneously processing tip retraction status feedback to ensure accurate action. The optical sensor detects the origin position of the piston rod, the end point of the pipetting stroke, and the tip retraction status of the piston rod by sensing the position of the tip retraction baffle, providing position feedback signals to the control system. The tip retraction baffle and the optical sensor are sensed by the sensor through position changes, thereby providing feedback on whether the pipetting tip is being carried and whether the tip retraction action has been completed.

[0022] In a preferred embodiment, a status bar is provided at the other end of the head-retracting baffle, and the other end of the status bar is fixedly connected to the head-retracting rod.

[0023] By adopting the above technical solution, the status bar connects the retraction rod and the retraction baffle, transmits the displacement of the retraction rod to the retraction baffle, realizes feedback on the retraction status, and cooperates with the control tongue to lock the status of the piston rod.

[0024] In a preferred embodiment, a first spring is installed at the outer end of the status bar, and a protrusion is fixedly connected to the side of the status bar.

[0025] By adopting the above technical solution, the first spring holds the pipette tip extension lever in the natural state, ensuring that the extension lever is in the extended state when no external force is applied, facilitating the ejection of the pipette tip from the body. The protrusion works in conjunction with the control tongue; when the status lever moves, the protrusion pushes the control tongue against the spring force, releasing the lock on the status lever and thus releasing the pipette tip extension lever, triggering the extension action.

[0026] In a preferred embodiment, a control tongue is provided on the side of the protrusion, and a second spring is fixedly connected to the side of the control tongue, the second spring being fixedly installed inside the body.

[0027] By adopting the above technical solution, the control tongue cooperates with the status lever to keep the head-retracting lever in a non-head-retracting state, i.e., the suction head installed state, through elastic locking. When the head-retracting action is triggered, the locking is released and the head-retracting lever is released. The second spring provides elastic support force for the control tongue, so that the control tongue can be stably locked into the slot of the status lever, ensuring reliable locking of the head-retracting lever state and avoiding accidental triggering.

[0028] In a preferred embodiment, the drive motor includes a first drive motor and a second drive motor, wherein the first drive motor is used to drive the piston rod and the second drive motor is used to drive the push-out rod edge.

[0029] In a preferred embodiment, a pipette tip is mounted on the lower end of the pipette tip, the annular elastic portion is located in the middle of the pipette tip and the pipette tip, and the pipette tip and the pipette tip are connected in an airtight manner.

[0030] By adopting the above technical solution, the pipette tip is used in conjunction with the installation of the structure, directly contacts the liquid, draws in the liquid through negative pressure and discharges the liquid through positive pressure, can be replaced to avoid cross-contamination, and is beneficial for subsequent operations.

[0031] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0032] In this invention, an inflatable variable cavity sealing structure optimizes the friction conditions during the assembly and disassembly of the pipette tip, effectively extending the service life of the sealing components. The outer cavity is formed by the first sealing ring, the second sealing ring, the pipette tip, and the retraction rod, and communicates with the inner cavity of the pipette tip via an opening, enabling dynamic adjustment of the internal air pressure. During the retraction process, the retraction rod moves downwards, expanding the outer cavity and reducing the internal air pressure, causing the annular elastic part to contract. This significantly reduces the squeezing force between the annular elastic part and the pipette tip, allowing the tip to easily detach from the pipette tip without any hard dynamic friction. This avoids the problems of long-term friction wear, aging failure, and powder shedding of the sealing rings in traditional structures. It extends the service life of sealing components such as the annular elastic part, eliminates the cost of frequent component replacements, avoids the risk of frictional dust contaminating biological samples, and ensures the cleanliness and accuracy of experimental samples.

[0033] The drive motor, in conjunction with the lead screw and nut mechanism, precisely converts rotary motion into linear motion of the piston rod. A coupling compensates for shaft coaxiality errors, preventing jamming, wobbling, and component damage in rigid transmission, ensuring smooth power transmission. The bearing housing suppresses radial runout of the lead screw, and the fixed block and piston rod structure, rigidly secured by pins, prevent transmission loosening and offset, ensuring precise and controllable piston rod displacement. A circuit board, paired with a photoelectric sensor, forms a closed-loop control system, real-time monitoring of piston rod position, liquid transfer stroke, and retraction status to control the suction and discharge actions.

[0034] The flexible self-locking head removal and disassembly mechanism enables automated and precise switching of the suction head, ensuring stable equipment operation. The self-locking and unlocking are achieved through the cooperation of the status bar, control tongue and double springs. When removing the head, the air pressure expands the annular elastic part to achieve airtight connection of the suction head and automatically lock it to prevent loosening and air leakage. When removing the head, the mechanical linkage can automatically unlock it, and smoothly complete the separation of the suction head. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the pneumatic pipetting sealing structure of the present invention in the state of the pipetting head.

[0036] Figure 2 This is a schematic diagram of the retracted head state of the pneumatic pipetting seal structure in this invention;

[0037] Figure 3 This is a schematic diagram of the head-retracting rod structure in this invention;

[0038] Figure 4 This is a cross-sectional view of the head-retracting rod structure in this invention;

[0039] Figure 5 In this invention Figure 1 Enlarged view of point A in the middle;

[0040] Figure 6 In this invention Figure 1Enlarged view at point B in the middle;

[0041] Figure 7 This is a top view of the main body structure in this invention;

[0042] Figure 8 This is a side view of the main body structure in this invention.

[0043] Marked in the image:

[0044] 1-Drive motor; 2-Coupling; 3-Bearing housing; 4-Lead screw; 5-Lead screw nut; 6-Fixing block; 7-Pin; 8-Piston rod; 9-Circuit board; 10-Optical sensor; 11-Retracting head baffle; 12-Pipette piston chamber; 13-Status rod; 14-First spring; 15-Control tongue; 16-Second spring; 17-First sealing ring; 18-Second sealing ring; 19-Pipette tip; 20-Retracting head rod; 21-Elastic sealing ring; 22-Body; 23-Protrusion; 24-Annular elastic part; 25-Opening; 26-Pipette head; 27-Outer cavity space; 28-Inner cavity space. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] Example:

[0047] Reference Figure 1-8 An inflatable pipetting sealing device includes: a drive motor 1, a pipetting head 26 and a retractor rod 20. The pipetting head 26 includes a piston rod 8 and a pipetting piston chamber 12. The pipetting piston chamber 12 extends through the pipetting head 26 axially. The piston rod 8 is slidably disposed in the pipetting piston chamber 12. The retractor rod 20 is a hollow tubular structure and is sleeved on the outside of the pipetting head 26.

[0048] An inner cavity space 28 is provided between the inner wall and the outer wall of the pipette tip 26. The inner cavity space includes an annular elastic part 24 that can protrude from the outer wall surface of the pipette tip 26. The annular elastic part 24 is made of a material that generates a sealing effect through deformation, including silicone, fluororubber, nitrile, natural rubber, PU, ​​etc.

[0049] A first sealing ring 17 is fitted on the outer wall of the pipette tip 26, and a second sealing ring 18 is provided on the inner wall of the pipette tip retractor 20. The first sealing ring 17, the second sealing ring 18, the outer wall of the pipette tip 26, and the inner wall of the pipette tip retractor 20 enclose and form an outer cavity space 27.

[0050] One or more openings are provided on the outer wall of the pipette 26 corresponding to the inner cavity space, and the inner cavity space 28 and the outer cavity space 27 are connected through the openings 25.

[0051] The drive motor 1 is used to drive the piston rod 8 and / or the head retraction rod to move along the first direction and the second direction of 20. The first direction and the second direction are opposite. The drive motor 1 drives the lead screw 4 to rotate, and the lead screw nut mechanism drives the piston rod to move up and down. At the same time, it works with the head retraction mechanism to realize the actions of liquid suction, liquid discharge and head retraction. The coupling 2 connects the output shaft of the drive motor 1 and the lead screw 4 to compensate for the coaxiality error between the two shafts, ensure smooth power transmission, and avoid jamming or damage caused by rigid connection.

[0052] Reference Figure 1-8 The drive motor 1 is fixedly mounted on the upper end of the body 22 by bolts. A coupling 2 is provided on the inner top wall of the body 22. The output end of the drive motor 1 is fixedly connected to the coupling 2. An elastic sealing ring 21 is provided at the connection between the piston rod 8 and the pipetting piston chamber 12. The drive motor 1 is fixedly mounted on the body 22. The rotational power of the drive motor 1 is transmitted to the lead screw 4 through the coupling 2. The elastic sealing ring 21 can effectively enhance the sealing performance at the connection between the piston rod 8 and the pipetting piston chamber 12 and prevent leakage.

[0053] Reference Figure 1-8 The lower end of the coupling 2 is fixedly connected to a bearing seat 3. The lower end of the coupling 2 is threaded through the bearing seat 3 and connected to a lead screw 4. The bearing seat 3 is used in conjunction with the lead screw 4 to provide rotational support for the lead screw 4, reduce the radial runout of the lead screw 4 when it rotates, and ensure that the lead screw 4 runs smoothly without shaking. The lead screw 4 converts the rotational motion of the motor into the linear motion of the lead screw nut. Through the threaded transmission of the lead screw 4, the precise displacement control of the piston rod is achieved.

[0054] Reference Figure 1-8 The main body 22 has a fixed block 6 inside, and a piston rod 8 is installed on the side of the fixed block 6. The fixed block 6 and the piston rod 8 are fixedly connected by a pin 7. The fixed block 6 serves as a connector between the lead screw 4 and the piston rod 8, transmitting the linear motion of the lead screw 4 to the piston rod to ensure that the two move synchronously. The pin 7 passes through the fixed block 6 and the piston rod 8 to achieve rigid fixation between the two, preventing relative rotation or loosening during operation and ensuring reliable motion transmission. The piston rod 8 moves up and down under the drive of the lead screw 4, and cooperates with the liquid transfer piston chamber 12 to form a closed piston chamber. The negative or positive pressure required for liquid suction and discharge is generated by the change in the volume of the chamber.

[0055] Reference Figure 1-8The upper end of the fixed block 6 is provided with a lead screw nut 5. The other end of the lead screw 4 passes through the lead screw nut 5 and the fixed block 6 respectively. Through the cooperation between the lead screw nut 5 and the lead screw 4, the rotational motion of the lead screw 4 is converted into its own linear motion, which drives the fixed block 6 and the piston rod 8 to move synchronously.

[0056] Reference Figure 1-8 The inner wall of the main body 22 is provided with a circuit board 9. Multiple light-activated sensors 10 are fixedly connected to the side of the circuit board 9. A tip retraction baffle 11 is provided on the side of the light-activated sensor 10. The circuit board 9 serves as the control core, driving the drive motor 1 to operate, receiving signals from the light-activated sensors 10, realizing closed-loop position control, and processing tip retraction status feedback to ensure accurate action. The light-activated sensor 10 detects the origin position of the piston rod 8, the end point of the pipetting stroke, and the tip retraction status of the piston rod 8 by sensing the position of the tip retraction baffle 11, providing position feedback signals to the control system. The tip retraction baffle 11 and the light-activated sensor 10 are sensed by the sensor through position changes, thereby providing feedback on whether the pipetting tip 19 is being carried and whether the tip retraction action has been completed.

[0057] Reference Figure 1-8 The other end of the head retraction baffle 11 is provided with a state rod 13, and the other end of the state rod 13 is fixedly connected to the head retraction rod 20. The state rod 13 connects the head retraction rod 20 and the head retraction baffle 11, and transmits the displacement of the head retraction rod 20 to the head retraction baffle 11 to realize feedback of the head retraction status. At the same time, it cooperates with the control tongue 15 to lock the state of the piston rod 8.

[0058] Reference Figure 1-8 A first spring 14 is installed on the outer end of the status lever 13, and a protrusion 23 is fixedly connected to the side of the status lever 13. In its natural state, the first spring 14 holds the pipette tip 20 in the retracted position, so that the pipette tip 20 is in the extended state when no external force is applied, making it easy to push the pipette tip 19 out of the body. The protrusion 23 works in conjunction with the control tongue 15. When the status lever 13 moves, the protrusion 23 pushes the control tongue 15 to overcome the spring force and lift it, releasing the lock on the status lever 13, thereby releasing the pipette tip 20 and triggering the pipette tip retraction action.

[0059] Reference Figure 1-8 A control tongue 15 is provided on the side of the protrusion 23. A second spring 16 is fixedly connected to the side of the control tongue 15. The second spring 16 is fixedly installed inside the body 22. The control tongue 15 cooperates with the status lever and maintains the non-retracting state of the head-retracting lever 20, i.e., the suction head installation state, through elastic locking. When the head-retracting action is triggered, the locking is released, and the head-retracting lever 20 is released. The second spring 16 provides elastic support for the control tongue 15, so that the control tongue 15 can be stably locked into the slot of the status lever, ensuring that the head-retracting lever 20 is reliably locked and avoiding accidental triggering.

[0060] Reference Figure 1-8The drive motor includes a first drive motor and a second drive motor. The first drive motor is used to drive the piston rod 8, and the second drive motor is used to drive the head-retracting rod along the 20.

[0061] Reference Figure 1-8 A pipette tip 19 is installed at the lower end of the pipette head 26. An annular elastic part 24 is located between the pipette tip 19 and the pipette head 26. The pipette head 26 and the pipette tip 19 are airtightly connected. The pipette tip 19 is used in conjunction with the installation of the structure, directly contacting the liquid. It draws in liquid under negative pressure and discharges liquid under positive pressure. It is replaceable to avoid cross-contamination and facilitates subsequent operations.

[0062] The implementation principle of the pneumatic pipetting sealing device of the present invention is as follows:

[0063] This application mainly has two states: taking the pipette tip 19, with the pipette tip 26 combined with the pipette tip 19, and removing the pipette tip 19, with the pipette tip 26 detached from the pipette tip 19;

[0064] After the liquid aspiration and spraying operations are completed, the process of the pipette tip 26 disengaging from the pipette tip 19 is as follows:

[0065] The pipetting piston chamber 12 is located inside the pipetting head 26; the pipetting head 26 is airtightly connected to the pipetting tip 19; the pipetting piston chamber 12 communicates with the interior of the pipetting tip 19; after the aspiration operation, the liquid is contained in the pipetting tip 19, the motor rotates, and the lead screw nut 5 drives the fixing block 6 to move downward. The fixing block 6 is fixedly connected to the piston rod 8 by a pin. The fixing block 6 drives the piston rod 8 to move downward, pushing the liquid in the pipetting tip 19 to be ejected from the opening at the tip end; the fixing block 6 continues to move downward until it meets the tip retraction baffle. When the 11 contacts the control tongue 15, it pushes the retraction baffle 11, the status lever 13, and the retraction lever 20 downwards. The protrusion 23 on the status lever 13 contacts the inclined surface of the control tongue 15. After continuing to descend and passing the control tongue 15, the second spring 16 is compressed. At this time, the lower end of the retraction lever 20 contacts the pipette tip 19 and continues to move downwards, pushing the pipette tip 19 to disengage from the pipette head 26. The retraction baffle 11 moves down to contact the step on the body 22 and then stops moving. The retraction operation is completed. At this time, the pipette head 26 remains in the retraction state.

[0066] As the retractor rod 20 descends, its end moves continuously downwards from below the opening, gradually increasing the outer cavity space 27 and decreasing the inner cavity air pressure. This causes the annular elastic part 24 to contract, reducing the squeezing force between the annular elastic part 24 and the pipette tip. This makes it easier for the pipette tip 26 to separate from the pipette tip 19, preventing dynamic friction between the retractor and the pipette tip 19, thus improving the service life of the seal. Furthermore, because there is no dynamic friction between the annular elastic part 24 and the pipette tip 19, there is no risk of friction-induced powder shedding or contamination of biological samples.

[0067] The process of combining pipette tip 26 with pipette tip 19:

[0068] After the head retraction operation is completed, the motor drives the lead screw 4 to rotate in the opposite direction, causing the lead screw nut 5 to move upward, which in turn drives the fixed block 6 to move upward, so that the fixed block 6 disengages from the head retraction baffle 11 and maintains a preset distance. At this time, the second spring 16 is compressed to support the state rod 13, so that the head retraction rod 20 is kept in the preset position.

[0069] During pipette tip retrieval: The pipette tip 19 to be retrieved is placed vertically on the table. The pipette tip 26, including one or more pipette tips, is moved above the pipette tip 19 by the robotic arm. The pipette tip 26 is vertically inserted into the pipette tip 19 and continues to move downward. During the descent, the tip of the pipette tip extends into the upper opening of the pipette tip 19, and the retraction lever 20 contacts the upper edge of the pipette tip 19. When the robotic arm continues to move downward in the vertical direction to the preset position, the retraction lever 20 is lifted by the pipette tip 19, and the tip of the retraction lever 20 moves upward, thus opening the outer cavity space 2. As the pipette tip 7 decreases in size, the gas in the outer cavity is compressed, and the gas pressure in the inner cavity increases, causing the annular elastic part 24 to expand and adhere tightly to the pipette tip, forming a seal between the pipette tip 26 and the pipette tip 19. Simultaneously, as the pipette tip retraction rod 20 moves upward, the status rod 13 is also moved upward, and the protrusion 23 on the rod contacts the inclined surface of the control tongue 15, compressing the second spring 16. After passing the protrusion, the status rod 13 is locked by the control tongue and cannot move downward. The pipette tip 26 remains in the tip-removing state and is self-locking. At this time, a reliable seal is formed between the pipette cavity and the pipette tip 19, ensuring the reliability and accuracy of pipetting.

[0070] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An inflatable pipetting sealing device, comprising: The drive motor (1), pipette head (26), and retractor rod (20) are described. The pipette head (26) includes a piston rod (8) and a pipette piston chamber (12). The pipette piston chamber (12) extends axially through the pipette head (26). The piston rod (8) is slidably disposed in the pipette piston chamber (12). The retractor rod (20) is a hollow tubular structure and is sleeved on the outside of the pipette head (26). The characteristics are as follows: An inner cavity space (28) is provided between the inner wall and the outer wall of the pipette head (26). The inner cavity space includes an annular elastic part (24) that can protrude from the outer wall surface of the pipette head (26). The annular elastic part (24) is a material that generates a sealing effect through deformation, including silicone, fluororubber, nitrile, natural rubber, PU, ​​etc. The outer wall of the pipette head (26) is fitted with a first sealing ring (17), and the inner wall of the pipette head (20) is provided with a second sealing ring (18). The first sealing ring (17), the second sealing ring (18), the outer wall of the pipette head (26) and the inner wall of the pipette head (20) enclose and form an outer cavity space (27). One or more openings are provided on the outer wall of the pipette head (26) corresponding to the inner cavity space, and the inner cavity space (28) and the outer cavity space (27) are connected through the openings (25); The drive motor (1) is used to drive the piston rod (8) and / or the push rod to move along a first direction and a second direction (20), the first direction and the second direction being opposite.

2. The pneumatic pipetting sealing device according to claim 1, characterized in that: The drive motor (1) is fixedly installed on the upper end of the body (22) by bolts. A coupling (2) is provided on the inner top wall of the body (22). The output end of the drive motor (1) is fixedly connected to the coupling (2). An elastic sealing ring (21) is provided at the connection between the piston rod (8) and the pipetting piston chamber (12).

3. The pneumatic pipetting sealing device according to claim 2, characterized in that: The lower end of the coupling (2) is fixedly connected to a bearing seat (3), and the lower end of the coupling (2) is threadedly connected to a lead screw (4) through the bearing seat (3).

4. The pneumatic pipetting sealing device according to claim 2, characterized in that: The body (22) has a fixing block (6) inside, and a piston rod (8) is installed on the side of the fixing block (6). The fixing block (6) and the piston rod (8) are fixedly connected by a pin (7).

5. The pneumatic pipetting sealing device according to claim 4, characterized in that: The upper end of the fixing block (6) is provided with a lead screw nut (5), and the other end of the lead screw (4) passes through the lead screw nut (5) and the fixing block (6) respectively.

6. The pneumatic pipetting sealing device according to claim 1, characterized in that: The inner wall of the main body (22) is provided with a circuit board (9), and a plurality of light-on sensors (10) are fixedly connected to the side of the circuit board (9). A head-retracting baffle (11) is provided on the side of the light-on sensor (10).

7. The pneumatic pipetting sealing device according to claim 6, characterized in that: The other end of the head-retracting baffle (11) is provided with a state rod (13), and the other end of the state rod (13) is fixedly connected to the head-retracting rod (20).

8. The pneumatic pipetting sealing device according to claim 7, characterized in that: A first spring (14) is installed at the outer end of the state bar (13), and a protrusion (23) is fixedly connected to the side of the state bar (13).

9. The pneumatic pipetting sealing device according to claim 8, characterized in that: The protrusion (23) has a control tongue (15) on its side, and a second spring (16) is fixedly connected to the side of the control tongue (15). The second spring (16) is fixedly installed inside the body (22).

10. The pneumatic pipetting sealing device according to claim 1, characterized in that: The drive motor includes a first drive motor and a second drive motor. The first drive motor is used to drive the piston rod (8), and the second drive motor is used to drive the push rod edge (20).

Images