A sealing structure for manual pipette

Abstract

The utility model discloses a sealing structure for a manual pipette, comprising a piston rod located in a housing handle, the piston rod comprising an upper piston part and a lower piston part, wherein the upper end of the upper piston part is connected to an adjusting nut, the lower end of the lower piston part is inserted into the liquid suction cavity of a ring tube connector, an annular mounting groove is provided on the upper end surface of the ring tube connector, a rubber O-ring is installed in the annular mounting groove, a polytetrafluoroethylene pad is provided at the upper end of the rubber O-ring, the polytetrafluoroethylene pad is sleeved on the lower end of the upper piston part, an annular connecting groove 1 is provided at the lower end of the polytetrafluoroethylene pad, two end surfaces of the annular connecting groove 1 are uniformly in contact with the rubber O-ring, an annular connecting groove 2 is provided at the upper end of the polytetrafluoroethylene pad, a compression spring is connected in the annular connecting groove 2. The sealing structure of the present application can enhance the wear resistance of the piston, reduce the loss of the rubber O-ring, increase the life of the entire pipette, and improve the accuracy of pipetting.

Description

Technical Field

[0001] The utility model relates to the technical field of manual pipettes, in particular to a sealing structure used for manual pipettes. Background Art

[0002] Currently in the pipette industry, most manual pipettes form a vacuum state by closely cooperating with a rubber O-ring and a piston, and then the piston moves up and down to form an air negative pressure to complete the suction and discharge of liquids. This method has an unavoidable disadvantage that the rubber itself is soft, which will cause delays and discomfort when the piston moves up and down. The operating buttons feel tight, the pipetting accuracy cannot be guaranteed, and long-term frequent work will cause fatigue. Utility Model Content

[0003] In view of the above technical problems in the related art, the utility model provides a sealing structure for a manual pipette, which can solve the above problems.

[0004] In order to achieve the above technical purpose, the technical solution of the utility model is implemented as follows:

[0005] A sealing structure for a manual pipette comprises a piston rod located in a housing handle, the piston rod comprising an upper piston part and a lower piston part, wherein the upper end of the upper piston part is connected to an adjusting nut, and the lower end of the lower piston part is inserted into a liquid suction cavity of a ring tube connector, an annular mounting groove is provided on the upper end surface of the ring tube connector, a rubber O-ring is installed in the annular mounting groove, a polytetrafluoroethylene pad is provided at the upper end of the rubber O-ring, the polytetrafluoroethylene pad is sleeved on the lower end of the upper piston part, an annular connecting groove 1 is provided at the lower end of the polytetrafluoroethylene pad, two end surfaces of the annular connecting groove 1 are evenly in contact with the rubber O-ring, an annular connecting groove 2 is provided at the upper end of the polytetrafluoroethylene pad, and a compression spring is connected to the annular connecting groove 2.

[0006] Furthermore, the upper piston part is a hollow cylindrical structure, and the outer diameter of the upper piston part is greater than the outer diameter of the lower piston part.

[0007] Furthermore, a travel space for movement of the upper piston part is provided on the inner side of the upper end of the annular tube connector, and a clamping piece is connected to the outer side of the upper end of the annular tube connector.

[0008] Furthermore, the upper end of the compression spring abuts against the protrusion of the clamping plate, and the lower end of the compression spring is located in the annular space formed by the second annular connecting groove and the clamping plate.

[0009] Furthermore, the rubber O-ring is located in an annular space formed by the annular mounting groove and the annular connecting groove.

[0010] The beneficial effects of the utility model are as follows: the sealing structure of the present application can enhance the wear resistance of the piston, reduce the loss of the rubber O-ring, increase the life of the entire pipette, and improve the accuracy of pipetting. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0012] The utility model is further described in detail below with reference to the accompanying drawings.

[0013] Figure 1 is a cross-sectional view of the manual pipette described in the embodiment of the utility model;

[0014] Figure 2 yes Figure 1 Enlarged view of point A in the middle.

[0015] In the figure:

[0016] 100, housing handle; 200, piston rod; 210, upper piston part; 220, lower piston part; 300, adjusting nut; 400, annular tube connector; 410, liquid suction cavity; 420, annular mounting groove; 430, travel space; 500, rubber O-ring; 600, polytetrafluoroethylene gasket; 700, compression spring; 800, clamping plate; 810, bump; 900, operating button. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the utility model.

[0018] like Figure 1-2As shown, according to the utility model, a sealing structure for a manual pipette is disclosed, comprising a piston rod 200 located in a housing handle 100, wherein the piston rod 200 comprises an upper piston portion 210 and a lower piston portion 220, wherein the upper end of the upper piston portion 210 is connected to an adjusting nut 300, and the lower end of the lower piston portion 220 is inserted into a liquid suction cavity 410 of a ring tube connector 400, and an annular mounting groove 420 is formed on the upper end surface of the ring tube connector 400, and the annular mounting groove 420 is formed on the upper end surface of the ring tube connector 400. A rubber O-ring 500 is installed in 20, and a polytetrafluoroethylene pad 600 is provided at the upper end of the rubber O-ring 500. The polytetrafluoroethylene pad 600 is sleeved on the lower end of the upper piston part 210. An annular connecting groove 1 is provided at the lower end of the polytetrafluoroethylene pad 600, and the two end surfaces of the annular connecting groove 1 are evenly in contact with the rubber O-ring 500. An annular connecting groove 2 is provided at the upper end of the polytetrafluoroethylene pad 600, and a compression spring 700 is connected to the annular connecting groove 2.

[0019] Embodiment 1:

[0020] In the present application, by pressing the operating button 900, the piston rod 200 moves up and down to form air negative pressure to complete the suction and discharge of liquid. During the up and down movement of the piston rod 200, the lower end of the upper piston part 210 moves in the stroke space 430. In order to ensure good air negative pressure, the upper end of the annular tube connector 400 and the lower end of the upper piston part 210 need to be sealed. In the present application, a composite sealing structure of a rubber O-ring 500 and a polytetrafluoroethylene pad 600 is used to seal them. Specifically, an annular mounting groove 420 is opened on the upper end surface of the annular tube connector 400, and a A rubber O-ring 500 forms the first seal, and a polytetrafluoroethylene pad 600 is arranged on the upper end of the rubber O-ring 500, so that the entire polytetrafluoroethylene pad 600 is sleeved on the lower end of the upper piston part 210 to form a second seal. The rubber O-ring 500 is covered in the annular space formed by the annular mounting groove 420 and the annular connecting groove 1. The sliding surface of the upper piston part 210 does not contact the rubber O-ring 500, but directly contacts the polytetrafluoroethylene pad 600, thereby avoiding direct friction between the piston rod 200 and the rubber O-ring 500. The polytetrafluoroethylene pad 600 is smooth and light while also ensuring sealing.

[0021] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A sealing structure for a manual pipette, comprising a piston rod (200) located in a housing handle (100), characterized in that: The piston rod (200) comprises an upper piston part (210) and a lower piston part (220), wherein the upper end of the upper piston part (210) is connected to an adjusting nut (300), and the lower end of the lower piston part (220) is inserted into a liquid suction cavity (410) of a ring tube connector (400). An annular mounting groove (420) is formed on the upper end surface of the ring tube connector (400), and a rubber O-ring (500) is installed in the annular mounting groove (420). A polytetrafluoroethylene pad (600) is provided at the upper end of the rubber O-ring (500), and the polytetrafluoroethylene pad (600) is sleeved on the lower end of the upper piston part (210). An annular connecting groove 1 is provided at the lower end of the polytetrafluoroethylene pad (600), and two end surfaces of the annular connecting groove 1 are evenly in contact with the rubber O-ring (500). An annular connecting groove 2 is provided at the upper end of the polytetrafluoroethylene pad (600), and a compression spring (700) is connected to the annular connecting groove 2.

2. A sealing structure for a manual pipette according to claim 1, characterized in that: The upper piston part (210) is a hollow cylindrical structure, and the outer diameter of the upper piston part (210) is greater than the outer diameter of the lower piston part (220).

3. A sealing structure for a manual pipette according to claim 1, characterized in that: A travel space (430) for movement of the upper piston part (210) is provided on the inner side of the upper end of the annular tube connecting piece (400), and a clamping piece (800) is connected to the outer side of the upper end of the annular tube connecting piece (400).

4. A sealing structure for a manual pipette according to claim 3, characterized in that: The upper end of the compression spring (700) abuts against the protrusion (810) of the clamping plate (800), and the lower end of the compression spring (700) is located in the annular space formed by the second annular connecting groove and the clamping plate (800).

5. A sealing structure for a manual pipette according to claim 1, characterized in that: The rubber O-ring (500) is located in an annular space formed by the annular mounting groove (420) and the annular connecting groove.

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