Pipette

Abstract

The utility model relates to the technical field of pipettes, in particular to a pipette. The piston block coaxially slides in an inner cavity of the sleeve, an injector type matching structure is formed between the piston block and the sleeve, an assembling opening for assembling a pipette tip is formed in the front portion of the sleeve, a pipette withdrawing assembly is arranged on the rear portion of the piston block in the radial direction, and the pipette withdrawing assembly is provided with a pipette withdrawing part extending forwards along the outer wall of the sleeve. And the gun withdrawing part is in sliding fit with the periphery of the assembly opening, so that the pipette head positioned on the assembly opening is pushed out by virtue of the sliding fit. According to the utility model, two independent power parts are not needed to respectively realize the operations of pipetting and withdrawing the pipette head, so that two independent driving mechanisms are not needed when the driving mechanisms are arranged in the later period, and a technical platform is provided for the cost control and the failure rate control of the automatic pipette.

Description

Technical Field

[0001] The utility model relates to the technical field of pipettes, and specifically relates to a pipette. Background Art

[0002] A pipette is a type of liquid transfer device, commonly used in laboratories to transfer small or trace amounts of liquid. To avoid cross-contamination of reagents during use or corrosion damage to the pipette, a disposable pipette tip is sleeved at the end of the pipette when taking the test solution. After completing one liquid transfer operation, the pipette tip is replaced, and then the next liquid transfer operation is carried out.

[0003] When the existing pipettes are in use, most of them use two independent power components to complete the liquid transfer and pipette tip ejection operations respectively. As recorded in the text of a pipette automatic liquid transfer device with the Chinese patent publication number CN217490932U, the automatic liquid suction and drainage of the pipette are achieved through the suction and discharge push rod, and the automatic pipette tip ejection action of the pipette is achieved through the pipette tip push rod. In actual implementation, the setting of two independent power components often requires two independent driving mechanisms, which not only increases the cost, but also has the problem of complex control circuits of the driving components, resulting in an increase in the failure rate. Therefore, it needs to be solved urgently. Content of the Utility Model

[0004] In order to avoid and overcome the technical problems existing in the prior art, the utility model provides a pipette, which does not require two independent power components to separately implement the liquid transfer and pipette tip ejection operations, so that when configuring the driving mechanism later, there is no need to configure two independent driving mechanisms, providing a technical platform for cost control and failure rate control of the automatic pipette.

[0005] To achieve the above object, the utility model provides the following technical solutions:

[0006] A pipette includes a sleeve and a piston block that slides coaxially in the inner cavity of the sleeve and forms a syringe-like fitting structure with the sleeve. The front part of the sleeve forms a fitting port for assembling the pipette tip. A pipette tip ejection assembly is radially arranged at the rear of the piston block. The pipette tip ejection assembly has a pipette tip ejection part that extends forward along the outer wall of the sleeve, and the pipette tip ejection part forms a sliding fit with the outer periphery at the fitting port, so as to push out the pipette tip located on the fitting port by relying on the sliding fit.

[0007] As a further scheme of the utility model: the pipette tip ejection assembly includes a thimble radially fixed at the rear of the piston block and a pipette tip ejection sleeve that is separately arranged from the thimble and slidably sleeved coaxially outside the sleeve, and the pipette tip ejection sleeve constitutes the pipette tip ejection part.

[0008] As a further solution of the present utility model: A sealing ring for sealing assembly with a pipette tip is fixedly arranged on the outer periphery of the assembly port on the sleeve. There is a gap between the gun tip withdrawal sliding sleeve and the sealing ring. In the non-working state, the gun tip withdrawal sliding sleeve wraps around the outer periphery of the sealing ring.

[0009] As a further solution of the present utility model: It further includes an installation box. The sleeve is arranged vertically, and the rear part of the sleeve is fixed in the inner cavity of the installation box. And the assembly port section on the sleeve penetrates through the bottom plate of the installation box. A gap is provided at the penetration of the sleeve and the bottom plate. The gun tip withdrawal sliding sleeve is arranged at this gap; An electric cylinder for driving the piston block to lift and slide is installed on the upper surface of the installation box.

[0010] As a further solution of the present utility model: Guide rods arranged parallel to the sleeve are fixedly arranged in the inner cavity of the installation box. The upper end side wall of the gun tip withdrawal sliding sleeve has a convex part bent outward. This convex part slides on the guide rod through a linear bearing. And when the convex part abuts against the upper surface of the bottom plate of the installation box, the gun tip withdrawal sliding sleeve covers the outer periphery of the assembly port.

[0011] As a further solution of the present utility model: A compression spring for pushing the convex part to abut against the installation box is sleeved on the guide rod. The extrusion force of the compression spring is less than the installation friction force between the pipette tip and the assembly port.

[0012] As a further solution of the present utility model: The sleeve has a two-stage stepped shaft structure that is thicker at the top and thinner at the bottom. The small shaft diameter section of the sleeve constitutes the assembly port. The lower end part of the gun tip withdrawal sliding sleeve is distributed in a closed-mouth shape. And the closed-mouth section of the gun tip withdrawal sliding sleeve slides on the small shaft diameter section. The lower end part of the gun tip withdrawal sliding sleeve abuts against the lower end part of the large shaft diameter section of the sleeve to position the upper limit position of the upward sliding of the gun tip withdrawal sliding sleeve.

[0013] As a further solution of the present utility model: An optoelectronic sensor for monitoring the position of the piston block is installed on the installation box.

[0014] Compared with the prior art, the beneficial effects of the present utility model are:

[0015] 1. A gun tip withdrawal assembly driven by a piston block is provided. Only by setting a linear stroke power source to drive the piston block to reciprocate, the pipetting operation and gun tip withdrawal operation of the pipette can be realized. There is no need for two independent power components to separately realize pipetting and gun tip withdrawal operations. When configuring the driving mechanism later, there is no need to configure two independent driving mechanisms, providing a technical platform for cost control and failure rate control of the automatic pipette.

[0016] 2. The ejector pin in the gun ejection assembly is separately arranged from the gun ejection head sliding sleeve. The gun ejection head sliding sleeve constitutes the driving part for gun ejection, and only the ejector pin reciprocates with the piston block. Thus, during the working state, the gun ejection head sliding sleeve does not reciprocate with the piston block, avoiding interference caused by the piston block during the working state.

[0017] 3. A sealing ring for sealing assembly with the pipette tip is fixed on the outer periphery of the assembly port to ensure the stability and sealing performance of the pipette tip assembly. In addition, there is a gap between the gun ejection head sliding sleeve and the sealing ring. In the non - working state, the gun ejection head sliding sleeve wraps around the outer periphery of the sealing ring, providing anti - collision protection for the sealing ring and preventing problems such as insufficient sealing of the pipette tip assembly caused by damage to the sealing ring due to collision in the non - working state.

[0018] 4. The rear end of the sleeve is inside the relatively sealed box body, reducing the problem of increased wear between the piston block and the sleeve caused by dust pollution of the rear end of the sleeve, and further reducing the problem of shortened device life.

[0019] 5. Guide rods arranged parallel to the sleeve are fixed in the inner cavity of the installation box. The protruding part on the upper side wall of the gun ejection head sliding sleeve slides on the guide rods through linear bearings to ensure the stability of the sliding of the gun ejection head sliding sleeve. In addition, by the extrusion spring pressing the protruding part against the upper surface of the bottom plate of the installation box, not only can the sliding position of the gun ejection head sliding sleeve be positioned, but also it can ensure that the gun ejection head sliding sleeve stably wraps around the outer periphery of the assembly port in the non - working state. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is the first structural schematic diagram of the working state in the present utility model.

[0021] Figure 2 It is the second structural schematic diagram of the working state in the present utility model.

[0022] Figure 3 It is the structural schematic diagram of the non - working state in the present utility model.

[0023] Figure 4 It is the structural schematic diagram of the present utility model.

[0024] In the figure: 10. Installation box; 20. Sleeve; 21. Sealing ring; 22. Gun ejection cavity; 23. Pipetting cavity; 30. Piston block; 31. Ejector pin; 40. Electric cylinder; 50. Gun ejection head sliding sleeve; 51. Protruding part; 52. Linear bearing; 60. Guide rod; 61. Extrusion spring. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0026] For the convenience of understanding, the specific structure and working mode of the present invention are further described below in conjunction with the accompanying drawings:

[0027] The specific structure of the present invention is referred to Figures 1-4 As shown, its main structure includes a sleeve 20 and a piston block 30 that slides coaxially in the inner cavity of the sleeve 20 and forms a syringe-like fitting structure with the sleeve 20. The front part of the sleeve 20 forms a fitting port for assembling a pipette tip. When pipetting, after assembling the pipette tip to the fitting port, the device is moved to the liquid storage box, the front end of the pipette tip is placed inside the liquid, and the piston block 30 is driven to move towards the rear part of the sleeve 20, so that a negative pressure is formed inside the sleeve 20, thereby adsorbing the liquid into the pipette tip. Thereafter, the device is moved to the liquid transfer location, and by driving the piston block 30 to move towards the front part of the sleeve 20, a positive pressure is formed inside the sleeve 20, thereby discharging the liquid inside the pipette tip outward.

[0028] For the convenience of quickly removing the hydraulic tip, as Figure 1 shown, a tip-removing assembly is radially arranged at the rear part of the piston block 30. The tip-removing assembly has a tip-removing part that extends forward along the outer wall of the sleeve 20, and the tip-removing part forms a sliding fit with the outer periphery of the fitting port. In the working state, the pipette tip is sleeved and installed at the fitting port. In the non-working state, the pipette tip located on the fitting port is pushed out by relying on the sliding fit. In actual implementation, as Figure 1 shown, the inner cavity of the sleeve 20 is sequentially divided into a tip-removing cavity 22 and a pipetting cavity 23 from front to back. In the working state, the piston block 30 reciprocally slides in the pipetting cavity 23 to realize the suction and discharge of the liquid. Specifically, before the suction preparation, the piston block 30 is located as Figure 2 shown, the front end of the piston block 30 is located at the front end of the pipetting cavity 23. Thereafter, as Figure 1 shown, the piston block 30 moves backward to the rear end of the pipetting cavity 23, thereby generating a negative pressure to realize suction; when discharging, the piston block 30 moves to as Figure 2In the state shown, liquid drainage can be achieved. In the non-working state, the piston block 30 slides into the gun-retracting cavity 22, so that the gun-retracting part slides towards the assembly port, and pushes the hydraulic gun head to separate from the assembly port of the sleeve 20. Therefore, in actual implementation, there is no need for two independent power components to separately perform the operations of liquid transfer and gun head retraction. When configuring the driving mechanism later, there is no need to configure two independent driving mechanisms. Only one linear stroke power source needs to be set to drive the piston block 30 to reciprocate, and the liquid transfer operation and gun head retraction operation of the liquid transfer gun can be achieved, providing a technical platform for cost control and failure rate control of the automatic liquid transfer gun.

[0029] Specifically, as Figure 1 shown, the gun-retracting assembly includes a thimble 31 radially fixed to the rear of the piston block 30 and a gun-retracting head sliding sleeve 50 that is separately arranged from the thimble 31 and coaxially sleeved outside the sleeve 20. The gun-retracting head sliding sleeve 50 constitutes the gun-retracting part. Therefore, in the working state, the gun-retracting head sliding sleeve 50 does not reciprocate with the piston block 30, avoiding interference caused by the piston block 30 in the working state.

[0030] In addition, as Figure 3 shown, a sealing ring 21 for sealing assembly with the liquid transfer gun head is fixed to the outer periphery of the assembly port, ensuring the stability and sealing performance of the liquid transfer gun head assembly. In addition, there is a gap between the gun-retracting head sliding sleeve 50 and the sealing ring 21. In the non-working state, the gun-retracting head sliding sleeve 50 wraps around the outer periphery of the sealing ring 21, which can provide anti-collision protection for the sealing ring 21, preventing problems such as insufficient sealing performance of the liquid transfer gun head assembly caused by collision damage to the sealing ring 21 in the non-working state.

[0031] On this basis, as Figure 1 and Figure 4 shown, the present invention further includes an installation box 10. The sleeve 20 is arranged vertically, and the fixed end of the rear end of the sleeve 20 is fixed in the inner cavity of the installation box 10, and the assembly port section of the sleeve 20 penetrates through the bottom plate of the installation box 10; in addition, a gap is provided at the penetration of the sleeve 20 and the bottom plate, and the gun-retracting head sliding sleeve 50 is arranged at this gap, so that the rear end of the sleeve 20 is in a relatively sealed environment, reducing the problem of increased wear of the piston block 30 and the sleeve 20 caused by dust pollution of the rear end of the sleeve 20, and further reducing the problem of reduced device life. In addition, an electric cylinder 40 for driving the piston block 30 to lift and slide is installed on the upper surface of the installation box 10 to achieve automatic driving of the piston block 30. Of course, in actual implementation, an operating rod penetrating through the top plate of the installation box 10 can also be provided at the rear of the piston block 30 for manually driving the piston block 30 to reciprocate.

[0032] In addition, to further ensure the stable sliding of the gun-retracting head sliding sleeve 50 and position the sliding area of the gun-retracting head sliding sleeve 50, as Figure 1As shown, a guide rod 60 fixed parallel to the sleeve 20 is arranged in the inner cavity of the installation box 10. The upper end side wall of the gun head withdrawal sliding sleeve 50 has a convex portion 51 bent outward. The convex portion 51 slides on the guide rod 60 through a linear bearing 52 to ensure the stability of the sliding of the gun head withdrawal sliding sleeve 50. Moreover, when the convex portion 51 abuts against the upper surface of the bottom plate of the installation box 10, the gun head withdrawal sliding sleeve 50 covers the periphery of the assembly port, and the sliding position of the gun head withdrawal sliding sleeve 50 can be positioned to prevent the gun head withdrawal sliding sleeve 50 from sliding and separating from the sleeve 20.

[0033] Furthermore, as Figure 1 shown, a compression spring 61 for pushing the convex portion 51 to abut against the installation box 10 is sleeved on the guide rod 60. The extrusion force of the compression spring 61 is less than the installation friction force between the pipette tip and the assembly port. Obviously, the extrusion force of the compression spring 61 will not cause the separation of the pipette tip and the assembly port, and also enables the gun head withdrawal sliding sleeve 50 to maintain a stable abutting state with the pipette tip during the working state to prevent the gun head withdrawal sliding sleeve 50 from shaking unstably during the working state; especially in the non-working state, by the compression spring 61 extruding the convex portion 51 to abut against the installation box 10, it can ensure that the gun head withdrawal sliding sleeve 50 stably wraps around the periphery of the assembly port in the non-working state.

[0034] In addition, as Figure 1 shown, the sleeve 20 has a two-stage stepped shaft structure with a thicker upper part and a thinner lower part. The small-diameter section of the sleeve 20 forms the assembly port, so that the diameter of the pipette tip assembled with it will not be too large. Moreover, the lower end part of the gun head withdrawal sliding sleeve 50 is distributed in a closed-mouth shape, and the closed-mouth section of the gun head withdrawal sliding sleeve 50 slides on the small-diameter section. The closed-mouth section of the lower end part of the gun head withdrawal sliding sleeve 50 abuts against the lower end part of the large-diameter section of the sleeve 20 to position the limit position of the upward sliding of the gun head withdrawal sliding sleeve 50 and prevent the gun head withdrawal sliding sleeve 50 from interfering with the pipetting operation of the piston block 30.

[0035] It is worth mentioning that a photoelectric sensor for monitoring the position of the piston block 30 is installed on the installation box 10, ensuring the accuracy of the control of the pipetting accuracy.

[0036] Of course, for those skilled in the art, the present utility model is not limited to the details of the above exemplary embodiments, but also includes the same or similar structures that can be implemented in other specific forms without departing from the spirit or basic characteristics of the present utility model. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present utility model is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present utility model. Any reference signs in the claims should not be regarded as limiting the claims involved.

[0037] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative manner of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0038] The technologies, shapes, and structures not described in detail in the present utility model are all well-known technologies.

Claims

1. A pipette, characterized in that: The invention comprises a sleeve (20) and a piston block (30) which slides coaxially in the inner cavity of the sleeve (20) and forms a syringe-type matching structure with the sleeve (20); the front part of the sleeve (20) forms an assembly port for assembling a pipette tip; the rear part of the piston block (30) is radially arranged with a gun withdrawal assembly, the gun withdrawal assembly has a gun withdrawal portion extending forward along the outer wall of the sleeve (20); the gun withdrawal portion forms a sliding match with the outer periphery of the assembly port, thereby relying on the sliding match to push out the pipette tip located on the assembly port.

2. A pipette according to claim 1, characterized in that: The gun retracting assembly comprises a pin (31) radially fixed to the rear of the piston block (30) and a gun retracting head sliding sleeve (50) which is arranged separately from the pin (31) and coaxially slidably sleeved on the outside of the sleeve (20), and the gun retracting head sliding sleeve (50) constitutes the gun retracting part.

3. A pipette according to claim 2, characterized in that: A sealing ring (21) for sealing with the pipette tip is fixed on the outer periphery of the assembly opening on the sleeve (20), and a gap exists between the pipette tip sliding sleeve (50) and the sealing ring (21). In a non-working state, the pipette tip sliding sleeve (50) is wrapped around the outer periphery of the sealing ring (21).

4. A liquid transfer gun according to claim 1, 2 or 3, characterized in that: It also includes an installation box (10), the sleeve (20) is arranged vertically, and the rear part of the sleeve (20) is fixed in the inner cavity of the installation box (10), and the assembly opening section on the sleeve (20) passes through the bottom plate of the installation box (10), and a gap is provided at the penetration point between the sleeve (20) and the bottom plate, and the gun head retracting sleeve (50) is arranged in the gap; the upper surface of the installation box (10) is installed with an electric cylinder (40) for driving the piston block (30) to rise and fall and slide.

5. A liquid transfer gun according to claim 4, characterized in that: The inner cavity of the installation box (10) is fixed with a guide rod (60) arranged parallel to the sleeve (20), and the upper end side wall of the gun retracting head sliding sleeve (50) has a protrusion (51) bent outward, and the protrusion (51) slides on the guide rod (60) through a linear bearing (52), and when the protrusion (51) abuts against the upper surface of the bottom plate of the installation box (10), the gun retracting head sliding sleeve (50) covers the outer periphery of the assembly port.

6. A liquid transfer gun according to claim 5, characterized in that: The guide rod (60) is sleeved with a compression spring (61) for pushing the protrusion (51) to abut against the installation box (10), and the compression force of the compression spring (61) is smaller than the installation friction force between the pipette tip and the assembly port.

7. A liquid transfer gun according to claim 5, characterized in that: The sleeve (20) is in a two-stage stepped shaft structure with a thick upper part and a thin lower part. The small diameter section of the sleeve (20) constitutes the assembly port. The lower end of the gun withdrawing head sliding sleeve (50) is distributed in a closed shape, and the closed section of the gun withdrawing head sliding sleeve (50) slides on the small diameter section. The lower end of the gun withdrawing head sliding sleeve (50) is positioned to abut against the lower end of the large diameter section of the sleeve (20) to position the gun withdrawing head sliding sleeve (50) to slide upward to an extreme position.

8. A liquid transfer gun according to claim 4, characterized in that: A photoelectric sensor for monitoring the position of the piston block (30) is installed on the installation box (10).

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