JP6780338B2 - Connection structure between the pipette tip and the nozzle attached to the pipette tip - Google Patents

Description

The present invention relates to a pipette tip including a pipette tip body and a filter used when conducting an experiment or inspection using a pipette, a dispenser, an inspection device, or the like.

Pipette tips used in experiments and inspections are commercially available in capacities of 10 to 300 μL or more and various sizes, large and small, depending on the intended use, such as pipettes, dispensers, and inspection equipment. Most of them are disposable pipette tips that are discarded after use, and most of them are made of plastic.

The nozzle portion of the pipette or the like is formed in a tapered shape, and the inner diameter surface of the pipette tip is also formed in a tapered shape. However, the taper angles are different from each other, and some pipette tips are larger than the taper angle of the nozzle portion. At the time of use, the tapers are press-fitted together and attached, but there is only one airtight part (sealed) on the circumference (ring shape), and there is a gap in the unsealed part, so that amount of play The axes of the pipette and the pipette tip are easily misaligned, and when a lateral force is applied, they are easily disengaged, which may affect the airtightness.

If the taper angles are the same, the airtight part (sealed) extends over the entire tapered part, making it difficult to form an airtight part (sealed) on the circumference (ring shape). There is a risk that (sealing) will be formed. In this case, it may interfere with the functioning fixed-quantity injection into the original pipette.

Japanese Unexamined Patent Publication No. 60-137443

In this conventional technique, a seating shelf (shoulder) as a stop is provided at the inner diameter of the pipette tip, and when the pipette is attached to the pipette tip, the tip (nozzle) of the pipette is the seating shelf (shoulder). Contact with. As a result, the distance from the tip of the pipette tube to the tip of the pipette tip becomes constant. Further, a circumferential seal is provided on the inner diameter of the pipette tip, and the pipette is frictionally fitted to the side wall (outer peripheral surface) of the pipette to ensure airtightness.
However, when mounting the pipette tip on the pipette, it is necessary to set the pipette straight and coaxial with the pipette tip, that is, the proper mounting state cannot be maintained unless a mounting jig or the like is used. There was a challenge.

Also, if the pipette tip is attached to the pipette by hand without using a jig, there will be a gap in the radial direction due to the taper before attachment, that is, the pipette tube will be displaced from each other. The side wall (outer peripheral surface) of the pipette is inserted while contacting the inner diameter surface of the pipette tip, and the corner of the tip (nozzle) is in contact with the circumferential seal provided on the inner diameter of the pipette tip and is damaged, resulting in airtightness. There was a risk of damaging.
Since regular maintenance of the mounting jig is also added to the work, we had to be careful and pay attention to things other than experiments and inspections.

The present invention relates to a coupling structure between the nozzles mounted pipette tip and its pipette tip, than the taper angle of the external diameter of the nozzle portion of the nozzle, larger the taper angle of the rear inner diameter portion of the pipette tip , The front position of the tapered outer diameter portion of the outer diameter of the nozzle portion is brought into contact with the tapered inner diameter portion of the rear inner diameter portion of the pipette tip to provide an airtight portion on the circumference, and the inner diameter portion behind the pipette tip is provided. The gist is that a circumferential rib that abuts in a circumferential shape is provided at a position behind the tapered outer diameter portion of the outer diameter of the nozzle portion .

The present invention relates to a coupling structure between the nozzles mounted pipette tip and its pipette tip, than the taper angle of the external diameter of the nozzle portion of the nozzle, larger the taper angle of the rear inner diameter portion of the pipette tip , The front position of the tapered outer diameter portion of the outer diameter of the nozzle portion is brought into contact with the tapered inner diameter portion of the rear inner diameter portion of the pipette tip to provide an airtight portion on the circumference, and the inner diameter portion behind the pipette tip is provided. By providing a circumferential rib that abuts in a circumferential shape behind the tapered outer diameter portion of the outer diameter of the nozzle portion, the tapered portion of the nozzle portion, the airtight portion (sealed) of the tapered portion of the pipette tip, and the nozzle portion Since it is in contact with the tapered portion of the pipette and the circumferential ring, and is press-fitted and fixed and in contact at two places, it is difficult to bend even if a lateral force is applied, and further, there is play when the nozzle and the pipette tip are attached. Provided is a pipette tip that can be accurately and accurately dispensed into a container such as a preparation or a test tube after quantitatively injecting a reagent or various liquids into the pipette tip because the pipette has a coaxial core. be able to.

Perspective view after the assembly of this embodiment is completed Front view of FIG. Vertical sectional view of FIG. Bottom view of FIG. An exploded perspective view of this embodiment Front view of pipette tip body 2 Vertical sectional view of FIG. Front view of filter 3 Sectional view of FIG. Front view of the nozzle portion 4a of this embodiment before mounting Vertical sectional view of FIG. Front view after mounting the nozzle 4a of this embodiment Vertical sectional view of FIG. Enlarged view of FIG. 13 (part A)

A mode for carrying out the present invention will be described with reference to the drawings. 1 to 14 are examples in the present invention.
The pipette tip 1 is composed of a pipette tip body 2 and a filter 3. The pipette tip 1 has a conical cylinder shape on the outer surface and a conical shape on the inner surface. The narrow and pointed side is the front, and the wide side is the rear. The pipette tip main body 2 has a conical cylinder shape on the outer surface and a conical shape on the inner surface. The narrow and pointed side is the front, and the wide side is the rear. The pipette tip body 2 is an injection molded product made of plastic.
The filter 3 has a cylindrical shape, has no front-rear directionality, is a water-repellent resin fiber bundle, and has breathability.
The filter 3 is inserted from the rear opening 2a of the pipette tip body 2, and the step portion 2b formed in the intermediate portion of the pipette tip body 2 comes into contact with the end surface 3a of the filter 3 to go further forward. There is no such thing. Further, the outer diameter portion 3b of the filter 3 is formed larger than the inner diameter portion 2c of the pipette tip 2. As a result, the filter 3 is in a state of being press-fitted and fixed in the pipette tip 2. Due to this press-fitting state, the filter 3 does not move backward and does not fall out of the rear opening 2a. It should be noted that this pressure input may be a force that does not come off during vibration or use due to transportation. The porosity of the filter 3 is used in the range of 20 to 80%, but varies depending on the liquid (viscosity) used and the size of foreign matter.
A plurality of vertical ribs 2d are evenly arranged in a convex shape on the outer diameter surface on the circumference with respect to the axial center behind the appearance of the pipette tip body 2. Since the pipette tip body 2 is an injection-molded product made of plastic, the wall thickness U is doubled or more with respect to the rib width T of the vertical rib 2d in order to suppress the occurrence of sink marks on the inner diameter portion 2c. The vertical rib 2d is provided for various purposes such as receiving a load applied when the nozzle is mounted and preventing rolling.
The pipette tip body 2 is an injection-molded product made of plastic, and the material of this embodiment is PP resin (polypropylene), but PE resin (polyethylene), PC resin (polyethylene), PS resin (polypropylene) can be used according to the application. ), PMMA resin (acrylic), PET resin (polyethylene terephthalate) may be used. Further, a transparent color, a translucent color, a coloring, or the like can be appropriately selected. The filter 3 is a fiber bundle made of a resin having water repellency in this embodiment, but the material thereof can be appropriately selected from polyester fiber, acrylic fiber, nylon fiber, polypropylene fiber, etc. according to the application, and others. Porous material (urethane, sponge, sintered body, etc.) may be used as long as the material is breathable such as resin, metal, ceramic or activated charcoal, or the shape is other than the cylindrical shape, depending on the application. Therefore, a conical shape, a spherical shape, an elliptical shape, or the like can be appropriately selected. Moreover, you may combine each of the above.
The circumferential groove 2f formed in the middle portion of the tapered inner diameter portion 2e behind the pipette tip main body 2 is a groove required for mold release during injection molding, and the tapered inner diameter portion 2d is one taper. It is formed at an angle.
The pipette 4 for dropping a liquid or the like onto the pipette body 2 has the same specifications as a general micropipette, and the suction amount is set with a dial, and a fixed amount is sucked and discharged.
Further, the taper angle α of the taper inner diameter portion 2e of the pipette tip body 2 is slightly larger than the taper angle β of the taper outer diameter portion 4b of the nozzle portion 4a of the pipette 4, and the difference in taper angle is 3 ° or less. (Α> β, α-β ≦ 3 °).

Next, the usage will be described. The nozzle portion 4a of the pipette 4 moves forward from the rear to the front to start mounting on the pipette tip 1. At this time, since the taper angle α of the tapered inner diameter portion 2e of the pipette tip body 2 is formed to be slightly larger than the taper angle β of the tapered outer diameter portion 4b of the nozzle portion 4a, the nozzle portion 4a and the pipette are formed. Even if the axis of the tip 1 is deviated, the corner portion 4c arranged in front of the taper outer diameter portion 4b starts to come into contact with the taper inner diameter portion 2e and is guided, and is inserted along the tapers without being damaged. The axes are aligned little by little. Further, when the nozzle 4a is advanced, the tapered inner diameter portion 2e and the front tapered outer diameter portion 4d of the tapered outer diameter portion 4b are press-fitted and fixed, and the tapered inner diameter portion 2e and the front tapered outer diameter portion 4d are shafts. An airtight portion (sealed) 2 g is provided on the circumference (ring shape) and in a band shape with respect to the center. That is, the tapered inner diameter portion 2e becomes an air tight portion (sealed) 2 g. At the time of use, air does not flow in and out from 2 g of the air tight portion (sealed) and does not interfere with the function of the pipette 4 (injection and injection of a fixed amount). At the same time, the circumferential rib 2h arranged behind the tapered inner diameter portion 2e and the rear tapered outer diameter portion 4e of the tapered outer diameter portion 4b are arranged on the circumference (ring shape) with respect to the axial center. The contact portion 2i is fitted in a band shape by light press fitting.
As a result, the pipette tip 1 and the nozzle portion 4a are press-fitted and fixed and abutted at two places, so that there is no play at the time of mounting and the pipette tip has a coaxial center. Therefore, reagents and various liquids are attached to the pipette tip. After a fixed amount of injection, it is possible to accurately and accurately dispense into a container such as a preparation or a test tube. At this time, a gap is formed between the tapered inner diameter portion 2c and the nozzle outer diameter portion 4b, but since the airtight portion (sealed) 2g is provided on the circumference (ring shape) and in a band shape. No liquid leakage occurs.
In this embodiment, the pipette tip 1 has a filter 3, but it may be removed if it is not particularly necessary for use in order to prevent a chemical solution or a foreign substance from entering the pipette at the time of injection.
The cross-sectional shape of the circumferential rib 2h provided to prevent backlash when the nozzle is mounted is semicircular, but it may be triangular, trapezoidal, or elliptical, and there are two points on the circumference instead of the entire circumference. It may be arranged at multiple points such as 4, 8 points, or may be combined with each of the above.

1 Pipette tip 2 Pipette tip body 2a Rear opening 2b Step 2c Inner diameter 2d Vertical rib 2e Tapered inner diameter 2f Circumferential groove 2g Air tight part (sealed)
2h Circumferential rib 2i Contact part 3 Filter 3a End surface 3b Outer diameter part 4 Pipet 4a Nozzle part 4b Tapered outer diameter part 4c Square part 4d Front taper outer diameter part 4e Rear taper outer diameter part T Rib width U Wall thickness α Tapered angle β taper angle

Claims (1)

It is a connection structure between the pipette tip and the nozzle mounted on the pipette tip, and the taper angle of the rear inner diameter portion of the pipette tip is formed larger than the taper angle of the outer diameter of the nozzle portion of the nozzle portion. The front position of the tapered outer diameter portion of the outer diameter is brought into contact with the tapered inner diameter portion of the rear inner diameter portion of the pipette tip to provide an airtight portion on the circumference, and the inner diameter portion behind the pipette tip is the nozzle portion. Tapered outer diameter A connection structure between a pipette tip provided with a circumferential rib that contacts the rear position of the outer diameter and a nozzle attached to the pipette tip.

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