JPS5921867Y2 - pipette - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a pipettor for a small liquid dispenser.

Conventionally, with this type of pipettor, if the piston is suddenly released from the dispensed liquid, the residual liquid remaining in the nozzle may form a fountain and flow back into the cylinder. This has the disadvantage that the piston gets in between the piston and the piston and prevents the piston from sliding inside the cylinder.

Therefore, in the present invention, a holder having a liquid intrusion prevention nozzle is provided at the connecting part between the cylinder and a tip provided with a nozzle at the tip, and the liquid intrusion prevention nozzle is configured to protrude from the holder surface. Even if there is residual liquid in the nozzle due to an operational error, the liquid intrusion prevention holder prevents the liquid from flowing back into the cylinder, and also allows the liquid droplets to remain on the holder surface around the liquid intrusion prevention nozzle. .

According to the present invention, no matter how the operating method is used, residual liquid will not enter the cylinder, so the piston can be operated smoothly.

The embodiments shown in the drawings will be described below.

1 is a body, and a shaft 3 is attached to the end face 2 of the body.
A hole 4 is bored through which the body 1 is inserted, and around the hole 4, a cylinder 6 having a screw 5 carved in the upper part is formed integrally with the body 1.

First, a ring-shaped fine adjustment lock screw 7 is screwed onto the screw 5, and then a hole is bored in the off-center part to have the same diameter as the inner diameter of the cylinder 6.
A cap 9 having a flange 8 is screwed onto the upper edge of the hole.

A hole 10 is formed by screwing the tube 6 and the cap 9 together.
A spring 11 is housed inside, and an ejection button 12 is mounted on the spring 11, and a flange 12a of the ejection button 12 engages with the flange 8 of the cap 9.

The shaft 3, into which the push button 13 is screwed, has a hole 14 drilled in the center of the ejection button 12 and the hole 1 described above.
0, it is inserted into the body 1 through a hole 4 in the body so as to be movable up and down, and a capacity gauge/shaft holder 15 is screwed to the lower end.

A fitting part 18 with the cylinder 16 and a threaded part 19 with the cylinder cover 17 are formed on the lower edge of the body 1. After fitting the flange 20 of the cylinder into the fitting part 18, the cylinder cover 17 is screwed. together to fix the cylinder.

A piston 21 is tightly fitted within the cylinder.

A flange 22 is integrally formed on the top of the piston, and a spring 23 is installed inside the body 1 between the flange 22 and the flange 20 of the cylinder to push up the piston, so the top surface of the piston is always used as a capacity gauge and shaft. It is in contact with the presser foot 15.

The lower part of the cylinder 16 is press-fitted into the upper part of the tip holder 24, and the chip 25 is fitted on the outer surface of the lower part of the tip holder 24, and the liquid intrusion prevention holder 26 is fitted on the inner surface.

Further, a nozzle 27 is fitted to the tip of the tip 25.

The liquid intrusion prevention holder 26 has a hole in the center, and a liquid intrusion prevention nozzle 28 is inserted into this hole about half of the way.

The hole diameter of the liquid intrusion prevention nozzle 28 is formed to be smaller than the suction port diameter of the nozzle 27.

Examples of materials used in manufacturing the pipettor configured as described above include the push button 13 and the cap 9.
, the ejection button 12, the capacity gauge/shaft holder 15, the body 1, and the fine adjustment lock screw 7 are preferably made of Teellin (registered trademark) in view of ease of molding, strength, and other aspects.

The cylinder cover 17, tip holder, intrusion prevention holder 26, tip 25, and nozzle 27 are suitably made of polypropylene, which is strong in strength and has good chemical resistance.

The cylinder 16 and piston 21 are made of hard glass, and the shaft 3 is made of stainless steel.

Since the liquid intrusion prevention nozzle 28 has a small inner diameter, it is necessary to use a material with extremely excellent chemical resistance, and therefore, tetrafluoroethylene (registered trademark Teflon) is suitable.

Now, when using the pipettor of this invention, first push the push button 13 until it touches the top surface of the ejection button, and then press the shaft 3.
By pushing down the piston 21 against the elasticity of the spring 23 through the spring 23, immersing the nozzle 27 in the liquid to be dispensed, and releasing the push button 13, the spring force 23 is used to force the speechee to restore the piston 21. , the liquid can be collected into the chip 25 in a short time.

At that time, adjust the inner diameter of the hole of the liquid intrusion prevention nozzle 28 to the nozzle 27.
Since the suction port diameter is smaller than that of the tip 25, liquid does not flow into the tip 25 in a fountain shape as in the conventional case.

Next, the push button 13 is pressed again to discharge the sampled liquid.

By the way, in conventional pipetters, the sliding distance of the piston when collecting liquid is the same as the sliding distance when discharging the collected liquid, and the piston is operated in one step.

Therefore, when the collected liquid is discharged, the liquid inevitably remains at the tip of the nozzle 27 due to its surface tension.

However, in the embodiment, the ejection button 12 is
Since the device is connected to the device, the liquid can be discharged in a two-step operation.Press the push button 13 down to the top surface of the discharge button 12 to discharge the sampled liquid, and then use the push button 13 to press the drain button 12. By pushing in against the spring force of 11, the sliding distance of the piston is made larger than when collecting the liquid, so that the remaining liquid in the nozzle 27 can be discharged.

Furthermore, when the piston 21 is restored after draining the liquid, the liquid intrusion prevention nozzle 28 is provided in the intrusion prevention holder 26 and its tip protrudes from the holder surface, so that a small amount of residual liquid attached to the inner surface of the nozzle is removed, unlike conventional ones. Since it adheres to the holder surface around the nozzle 28 without entering the cylinder, it does not enter the gap between the nozzle 28 and the piston, and therefore does not interfere with the sliding movement of the piston.

If you want to vary the pipettor's dispensing capacity, you can easily do so by replacing the capacity gauge/shaft holder 15 with one of a different length, as shown in Figure 2, and fine adjustments are possible. This can be easily done by rotating the adjustment lock screw 7 and moving the cap 9 up and down.

In any case, the pipettor of the present invention is capable of collecting and discharging a certain amount of liquid extremely easily and quickly. It has the characteristic that it does not invade.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of the pipettor of the present invention, and FIG. 2 is a front view of capacity gauges and shaft holders of different lengths. 1...Body, 3...Shaft, 7.
... Fine adjustment lock screw, 9 ... Cap, 12 ... Ejection button, 15 ... Capacity gauge and shaft holder, 16 ... Cylinder 1
7...Cylinder cover, 21...Piston, 24...Tip holder, 25...
...chip, 26...liquid invasive prevention holder,
27... Nozzle, 28... Liquid intrusion prevention nozzle.

Claims (3)

[Scope of utility model registration request] (1) A tip with a nozzle at the tip is arranged in series at one end of the cylinder, and a holder with a liquid intrusion prevention nozzle is provided at the joint between the cylinder and the tip, and the liquid intrusion prevention nozzle protrudes from the holder surface. pipettor-0 (2) A pipettor 0 according to claim 1, which is a utility model registration claim, in which a tip holder is attached to one end of the cylinder, and a liquid intrusion prevention holder is attached to the tip holder. (3) Scope of Utility Model Registration Claim Paragraph 1 or 2, in which the diameter of the liquid intrusion prevention nozzle is made smaller than the nozzle diameter of the tip.
Pipettor described in section