A full-range pump head

Abstract

This invention relates to the field of liquid handling equipment technology, specifically a full-range pump head, comprising a housing, a fixing component, an air chamber, a first plunger, a second plunger, a drive mechanism, a suction nozzle, and a nozzle retraction assembly. The fixing component is fixedly disposed inside the housing. The air chamber is located below the fixing component and contains a first chamber and a second chamber that are interconnected. The first plunger is slidably disposed within the first chamber and is sealed to it. The second plunger is slidably disposed within the second chamber and is sealed to it. The drive mechanism drives the two plungers to reciprocate independently. The suction nozzle is mounted at the lower end of the air chamber and communicates with the second chamber. The nozzle retraction assembly is used to retract the nozzle. This invention, by integrating two independently driven plungers, achieves wide-range pipetting, balancing accuracy in small volumes with a large volume range, thus improving the applicability of pipetting workstations.

Description

Technical Field

[0001] This invention relates to the field of liquid handling equipment technology, specifically a full-scale pump head. Background Technology

[0002] In automated pipetting workstations used in fields such as biology, chemistry, and medical testing, pipetting channels are the core component for liquid transfer. Commercially available pipetting channels are typically categorized by volumetric capacity, such as 30μL, 70μL, 200μL, and 1000μL. In practice, users need to select the appropriate channel volume based on the target volume to ensure pipetting accuracy and effectiveness.

[0003] This forces users to either configure multiple pipetting channels with different capacities on a single device, increasing the complexity and cost of the equipment, or to purchase multiple instruments with different capacities to handle different experimental procedures, which takes up space and reduces the flexibility of equipment use. Therefore, existing pipetting channels have significant shortcomings in terms of capacities, making it difficult to meet users' needs for wide-capacity, high-precision, and low-cost integrated devices. In response to the above situation, there is an urgent need to develop a full-capacity pump head to overcome the shortcomings in current practical applications. Summary of the Invention

[0004] The purpose of this invention is to provide a full-range pump head to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A full-scale pump head, comprising:

[0007] shell;

[0008] The fastener is fixedly installed inside the outer casing;

[0009] An air chamber is fixedly disposed inside the outer shell, the air chamber is located below the fixing member, and the air chamber has a first chamber and a second chamber that are interconnected.

[0010] The first plunger is slidably disposed in the first chamber and is sealed to the inner wall of the first chamber;

[0011] The second plunger is slidably disposed in the second chamber and is sealed to the inner wall of the second chamber;

[0012] A drive mechanism is mounted on the fixing member and connected to the first plunger and the second plunger respectively, for driving the first plunger and the second plunger to slide independently back and forth in their respective chambers;

[0013] A suction nozzle is installed at the lower end of the air chamber and extends from the outer shell, and the suction nozzle communicates with the second chamber;

[0014] The nozzle ejection assembly includes a nozzle ejection rod, a nozzle ejection plate, and a resilient reset member. The nozzle ejection rod passes through the air chamber and slides within the air chamber. The top end of the nozzle ejection rod is located on the upper outer side of the air chamber and is positioned opposite to the drive mechanism. The lower end of the nozzle ejection rod extends from the lower end of the air chamber and is fixedly connected to the nozzle ejection plate. The nozzle ejection plate is fitted onto the outer side of the nozzle. The resilient reset member is positioned between the nozzle ejection rod and the air chamber and is used to drive the nozzle ejection rod to reset upwards.

[0015] As a further aspect of the present invention: the driving mechanism includes a motor, a transmission component and a push plate, the motor is mounted on the fixing component, the transmission component is connected between the output end of the motor and the push plate, the push plate is respectively connected to the first plunger and the second plunger, and the top end of the ejector rod is disposed opposite to the lower surface of the push plate.

[0016] As a further aspect of the present invention: the driving mechanism is provided in two sets, namely a first driving mechanism and a second driving mechanism, the first driving mechanism is connected to the first plunger, the second driving mechanism is connected to the second plunger, and the two sets of driving mechanisms are controlled independently of each other.

[0017] As a further aspect of the present invention: the upper end of the first plunger is connected to the push plate through a pressure block and an elastic element, and the elastic element presses against the upper end surface of the first plunger, so that the first plunger can float in the horizontal direction and is limited in the vertical direction.

[0018] As a further aspect of the present invention: the upper end of the second plunger is provided with a groove, and the push plate is provided with a notch that engages with the groove, so as to realize the synchronous movement of the second plunger and the push plate.

[0019] As a further aspect of the present invention: the air chamber is provided with a process hole for connecting the first chamber and the second chamber. The process hole is sealed after the air chamber is assembled to maintain the communication between the first chamber and the second chamber.

[0020] As a further aspect of the present invention, it also includes a guide member, the two ends of which are respectively fixed to the fixing member and the air chamber, and slide in cooperation with the push plate to guide the push plate to move in the vertical direction.

[0021] As a further aspect of the present invention, it also includes an origin detection component for detecting the initial position. The origin detection component includes an origin sensor and an origin positioning plate. The origin sensor is fixed on the fixing member, and the origin positioning plate is fixed on the push plate. The origin sensor and the origin positioning plate cooperate to detect the initial zero position of the push plate.

[0022] As a further aspect of the present invention: the first plunger and the first chamber, and the second plunger and the second chamber, are respectively sealed by sealing rings to achieve sliding seals.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] This invention achieves continuous pipetting over a wide range, from 0.5 μL to 1000 μL and even wider, by integrating a first plunger (small volume) and a second plunger (large volume) within the same pump head and designing independent drive structures. In small volume mode, only the first plunger operates, offering advantages such as high precision and low dead volume. In large volume mode, the first plunger first lifts to close the small volume passage, and then the second plunger performs suction and discharge, ensuring sealing and high flow rate. The two plunger systems do not interfere with each other, allowing users to freely switch between volume ranges as needed without changing channels or equipment, significantly improving the applicability and economy of the pipetting workstation. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of a full-range pump head.

[0026] Figure 2 This is a side view of the full-scale pump head.

[0027] Figure 3 This is a cross-sectional view of the full-scale pump head.

[0028] In the diagram: 1. Motor; 2. Origin sensor; 3. Guide component; 4. Transmission component; 5. Push plate; 6. Transmission fixing component; 7. Air chamber; 8. Nozzle; 9. Retracting nozzle plate; 10. Retracting nozzle rod; 11. Fixing component; 12. Motor base; 13. Notch; 14. Drive control; 15. Origin positioning plate; 16. Small range plunger; 17. Large range plunger; 18. First seal; 19. Pressure block; 20. Second seal; 21. Elastic component; 7a. Hole 1; 7b. Hole 2; 7c. Process hole. Detailed Implementation

[0029] The technical solution of this application will be further described in detail below with reference to specific embodiments.

[0030] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0031] Please see Figures 1 to 3 In one embodiment of the present invention, a full-range pump head includes: a housing, a fixing member 11, an air chamber 7, a small-range plunger 16 (as a first plunger), a large-range plunger 17 (as a second plunger), a drive mechanism, a suction nozzle 8, and a nozzle retraction assembly.

[0032] The outer casing serves as the mounting base for the entire machine, housing and securing all components. The fixing member 11 is fixedly positioned at the upper part of the outer casing. The air chamber 7 is fixedly positioned inside the outer casing, below the fixing member 11. The air chamber 7 has a first hole 7a (serving as the first chamber) and a second hole 7b (serving as the second chamber). The first hole 7a and the second hole 7b are interconnected through a process hole 7c. After assembly, the process hole 7c is sealed, but the connection between the first hole 7a and the second hole 7b remains intact.

[0033] The drive mechanism includes a first motor, a second motor (both motors 1), a first transmission component, a second transmission component (both transmission components 4), and a push plate 5. Motor 1 is fixed to the fixing component 11 via a motor mount 12. The transmission component 4 connects the output end of motor 1 and the push plate 5. In this embodiment, the transmission component 4 is a lead screw and nut transmission pair, wherein the lead screw is connected to the output shaft of motor 1, the nut is fixedly connected to the push plate 5, and the bottom end of the lead screw is rotatably connected to the transmission fixing component 6 fixedly installed at the top of the air chamber 7. Motor 1 drives the lead screw to rotate, which in turn drives the push plate 5 to move vertically via the nut. Two sets of motors 1 and transmission components 4 are provided, independently driving the small-range plunger 16 and the large-range plunger 17 respectively. A drive control 14 is also included, which is fixedly installed inside the housing and electrically connected to motor 1, used to receive external control signals and drive motor 1 to operate.

[0034] The two ends of the guide member 3 are fixed to the fixing member 11 and the air chamber 7, respectively. The push plate 5 is provided with guide holes that cooperate with the guide member 3, so that the push plate 5 slides up and down along the guide member 3 to ensure motion accuracy and stability. In this embodiment, the guide member 3 is a guide rod. As an alternative, the guide member 3 can also be a linear guide rail.

[0035] The origin detection component includes an origin sensor 2 and an origin positioning plate 15. The origin sensor 2 is fixed to the fixing member 11, and the origin positioning plate 15 is fixed to the push plate 5. When the origin positioning plate 15 moves with the push plate 5 to trigger the origin sensor 2, the system records that the position is the origin of the pipetting channel. In this embodiment, the origin sensor 2 is a photoelectric sensor or a Hall sensor.

[0036] The upper end of the small-range plunger 16 is connected to the push plate 5 via a pressure block 19 and an elastic element 21, while the lower end extends into the hole 7a. Specifically, the pressure block 19 is fixed to the push plate 5, with its lower end pressing against the upper end of the elastic element 21. The lower end of the elastic element 21 abuts against the upper end surface of the small-range plunger 16, allowing the small-range plunger 16 to float slightly in the horizontal direction to eliminate assembly errors, while being limited and fixed in the vertical direction by the elastic element 21 and the pressure block 19. A sliding seal is achieved between the small-range plunger 16 and the hole 7a via a second sealing element 20. In this embodiment, the second sealing element 20 is an O-ring.

[0037] The large-range plunger 17 is a sleeve structure, fitted over the small-range plunger 16. The upper end of the large-range plunger 17 has a first groove that engages with the corresponding notch 13 in the push plate 5, enabling synchronous movement between the large-range plunger 17 and the push plate 5. The large-range plunger 17 also has a second groove for fixing the first sealing element 18. The lower end of the large-range plunger 17 extends into the second hole 7b, achieving a sliding seal between the first sealing element 18 and the inner wall of the second hole 7b. In this embodiment, the first sealing element 18 is an O-ring.

[0038] The suction nozzle 8 is installed at the lower end of the air chamber 7 and extends out from the outer shell. The suction nozzle 8 is directly connected to the second hole 7b and is used to insert a disposable suction head.

[0039] The ejector head assembly includes an ejector head rod 10, an ejector head plate 9, and a resilient reset member. The ejector head rod 10 passes through the air chamber 7 and slides within it. The top end of the ejector head rod 10 is located on the outer side of the upper end of the air chamber 7 and is positioned opposite to the lower surface of the push plate 5. The lower end of the ejector head rod 10 extends from the lower end of the air chamber 7 and is fixedly connected to the ejector head plate 9. The ejector head plate 9 is fitted onto the outside of the suction nozzle 8, with an inner diameter larger than the outer diameter of the suction nozzle 8 but smaller than the outer diameter of the suction head, so that the suction head can be ejected from the suction nozzle 8 when pushed downwards. The resilient reset member is fitted onto the ejector head rod 10, with one end abutting against the air chamber 7 and the other end abutting against the flange of the ejector head rod 10, and is used to push the ejector head rod 10 and the ejector head plate 9 upwards to reset after the ejector head action is completed.

[0040] The working principle of this full-range pump head is as follows:

[0041] After the entire machine is assembled, process hole 7c is sealed, leaving only hole 7a and hole 7b connected. Upon power-up, the two motors 1 drive their corresponding transmission components 4, which in turn move the push plate 5 and the origin positioning plate 15. When the origin positioning plate 15 triggers the origin sensor 2, motor 1 stops; this position serves as the origin of the pipetting channel. Subsequently, the two motors 1 drive the small-range plunger 16 and the large-range plunger 17 downwards to their respective suction preparation positions.

[0042] When the user uses a small volume, motor 1 drives the small volume plunger 16 upward. Due to the sealing effect of the second seal 20 and hole 7a, a negative pressure is formed in hole 7a, which is transmitted to the nozzle 8 through the connected process hole 7c and hole 7b, thereby drawing liquid from the inserted suction head and achieving small-volume liquid suction. When draining, motor 1 drives the small volume plunger 16 downward. After draining, motor 1 continues to drive the small volume plunger 16 downward. The lower surface of the push plate 5 contacts and pushes the top of the nozzle retraction rod 10, thereby pushing the nozzle retraction rod 10 and nozzle retraction plate 9 downward. The downward movement of nozzle retraction plate 9 pushes the suction head inserted by the user onto the nozzle 8. When motor 1 drives the small volume plunger 16 upward again, the spring force of the elastic reset member drives the nozzle retraction rod 10 and nozzle retraction plate 9 back to their original positions.

[0043] When the user uses the large range, motor 1 first moves the small range plunger 16 upward a certain distance and then stops to close the small range passage. Then, motor 1 moves the large range plunger 17 upward, and due to the sealing effect between the first seal 18 and the second hole 7b, liquid is drawn through the nozzle 8. Motor 1 then moves the large range plunger 17 downward, which is the discharge. Discharge ends when the large range plunger 17 moves downward to its lowest point. If emptying is required, the small range plunger 16 is simultaneously moved downward until the push plate 5 just touches or is about to touch the top of the nozzle retraction rod 10. The nozzle retraction operation is the same as in the small range mode.

[0044] This full-range pump head achieves seamless coverage from micro to large volumes through independent dual-plunger drive and gas path switching, greatly improving the versatility and ease of operation of pipetting equipment.

[0045] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these should also be considered within the scope of protection of the present invention. These will not affect the effectiveness of the implementation of the present invention or the practicality of the patent.

Claims

1. A full-scale pump head, characterized in that, include: shell; The fastener is fixedly installed inside the outer casing; An air chamber is fixedly disposed inside the outer shell, the air chamber is located below the fixing member, and the air chamber has a first chamber and a second chamber that are interconnected. The first plunger is slidably disposed in the first chamber and is sealed to the inner wall of the first chamber; The second plunger is slidably disposed in the second chamber and is sealed to the inner wall of the second chamber; A drive mechanism is mounted on the fixing member and connected to the first plunger and the second plunger respectively, for driving the first plunger and the second plunger to slide independently back and forth in their respective chambers; A suction nozzle is installed at the lower end of the air chamber and extends from the outer shell, and the suction nozzle communicates with the second chamber; The nozzle ejection assembly includes a nozzle ejection rod, a nozzle ejection plate, and a resilient reset member. The nozzle ejection rod passes through the air chamber and slides within the air chamber. The top end of the nozzle ejection rod is located on the upper outer side of the air chamber and is positioned opposite to the drive mechanism. The lower end of the nozzle ejection rod extends from the lower end of the air chamber and is fixedly connected to the nozzle ejection plate. The nozzle ejection plate is fitted onto the outer side of the nozzle. The resilient reset member is positioned between the nozzle ejection rod and the air chamber and is used to drive the nozzle ejection rod to reset upwards.

2. The full-scale pump head according to claim 1, characterized in that, The driving mechanism includes a motor, a transmission component, and a push plate. The motor is mounted on the fixing component. The transmission component is connected between the output end of the motor and the push plate. The push plate is connected to the first plunger and the second plunger respectively. The top end of the ejector rod is disposed opposite to the lower surface of the push plate.

3. The full-range pump head according to claim 2, characterized in that, The drive mechanism is provided in two sets, namely a first drive mechanism and a second drive mechanism. The first drive mechanism is connected to the first plunger, and the second drive mechanism is connected to the second plunger. The two sets of drive mechanisms are controlled independently of each other.

4. The full-scale pump head according to claim 2, characterized in that, The upper end of the first plunger is connected to the push plate through a pressure block and an elastic element. The elastic element presses against the upper end face of the first plunger, so that the first plunger can float in the horizontal direction and is limited in the vertical direction.

5. The full-range pump head according to claim 2, characterized in that, The upper end of the second plunger is provided with a groove, and the push plate is provided with a notch that engages with the groove, so as to realize the synchronous movement of the second plunger and the push plate.

6. The full-scale pump head according to claim 1, characterized in that, The air chamber has a process hole for connecting the first chamber and the second chamber. The process hole is sealed after the air chamber is assembled to maintain the connection between the first chamber and the second chamber.

7. The full-scale pump head according to claim 3, characterized in that, It also includes a guide member, the two ends of which are fixed to the fixing member and the air chamber respectively, and slide in cooperation with the push plate to guide the push plate to move in the vertical direction.

8. The full-scale pump head according to claim 1, characterized in that, It also includes an origin detection component for detecting the initial position. The origin detection component includes an origin sensor and an origin positioning plate. The origin sensor is fixed on the fixing member, and the origin positioning plate is fixed on the push plate. The origin sensor and the origin positioning plate cooperate to detect the initial zero position of the push plate.

9. The full-scale pump head according to claim 1, characterized in that, The first plunger and the first chamber, and the second plunger and the second chamber, are respectively sealed by sealing rings to achieve sliding seals.

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