JPH03146842A - Liquid sample dispenser - Google Patents

Abstract

PURPOSE:To prevent the splash of a sample from occurring by elevating a liquid level sensor synchronizing with a probe in performing sample suction and probe cleaning, and ejecting the sample by inserting the probe to the reac tion vessel even when a vessel is a small reaction vessel. CONSTITUTION:The probe 4 which sucks and ejects a liquid sample is mounted at the tip part of an arm 2. A syringe pump performs the suction and ejection of the sample with the probe 4. A sample vessel 30, a cleaning pot 26, and the reaction vessel 32 are arranged on the rotational locus of the probe 4 in above sequence. The liquid level sensor 36 which detects the liquid level of the vessel 30 is provided so as to be located at a position neighboring the probe 4 within the range of the vessel 30 and the pot 26 at the tip of an arm 34 moving with the arm 2 only within the range of them. When the sample suction and probe cleaning are performed, such control that the sensor 36 is elevated and rotated synchronizing with the probe 4 is applied. Meanwhile, when the sample is ejected to the vessel 32, the sensor 36 is separated from the probe 4, and rotation and elevation are controlled so as to insert only the probe 4 into the vessel 32.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a dispensing device for dispensing a liquid sample into a reaction container in an automatic analyzer, and particularly to a dispensing device for dispensing a liquid sample into a reaction container in an automatic analyzer. The present invention relates to a dispensing device equipped with a liquid level sensor.

(Prior art) Liquid sample dispensing devices used in automatic analyzers and the like detect the presence or absence of a liquid sample in a sample solution, or when a probe is immersed in a liquid sample more than necessary. In order to minimize contamination, an electrode-type liquid level sensor is fixedly attached to the probe.

The electrode of the liquid level sensor is placed at approximately the same height as the probe. In order to prevent a short circuit between the probe and the electrode of the liquid level sensor due to a bridge of the sample liquid, the distance between the probe and the electrode is set to about 2 to 3 mm.

(Problem to be solved by the invention) Since the conventional liquid level sensor is fixed to the probe,
When aspirating a sample from a sample container with a probe and discharging it into a reaction container, if the opening of the reaction container is small, the probe and liquid level sensor cannot be inserted into the reaction container, so the sample is discharged from above the reaction container. In this case, a problem arises in which the sample is scattered.

Further, when it is necessary to insert the probe into the reaction container, the liquid level sensor must also be inserted into the reaction container, which is an obstacle to downsizing the reaction container.

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid sample dispensing device that can eject a sample by inserting a probe into a reaction vessel even if the reaction vessel is small, and can prevent the sample from scattering.

(Means for Solving the Problems) In the present invention, the probe and the liquid level sensor are attached so that they can be separated, and when aspirating the sample from the sample container, the probe and the liquid level sensor are brought close together and inserted into the sample container. However, when discharging a sample, the liquid level sensor is separated from the probe, and only the probe is inserted into the reaction vessel to discharge the sample.

Therefore, in the present invention, a probe that aspirates and discharges a liquid sample is attached to the tip of a first arm whose base end is fixed to a shaft that is controlled to move up and down and rotate. A sample container, a washing pot, and a reaction container are arranged in this order, and a second arm whose base end is rotatably attached to the shaft and moves together with the first arm only within the range of the sample container and the washing pot. A liquid level sensor for detecting the liquid level of the liquid sample in the sample container is provided at the tip of the arm at a position close to the probe in the range.

(Function) During sample suction and probe cleaning, the drive of the liquid level sensor is controlled so that it descends and rotates in synchronization with the probe.

On the other hand, when discharging a sample into a reaction container, the liquid level sensor is separated from the probe, and its rotation and elevation are controlled so that only the probe is inserted into the reaction container.

(Embodiment) FIG. 1 is a plan view showing one embodiment, and FIG. 2 is a vertical sectional view of the same embodiment.

Reference numeral 2 denotes a first arm, and a probe 4 for sucking and discharging a liquid sample is attached to the tip thereof. Reference numeral 5 denotes a syringe pump for aspirating and discharging a liquid sample by the probe 4. The base end of the arm 2 is fixed to a shaft 6, and the shaft 6 is rotatably supported by a support fitting 8 in which a rack 8a is formed in the vertical direction. The rotation direction of the lower end of the shaft 6 is restricted, and a bearing 10 is movable in the axial direction.
It is supported by the sleeve 12 via. Sleeve 12
is supported by a fixed member 22 via a rotatable bearing.

A lifting drive pulse motor 1 is mounted on the rack 8a of the support fitting 8.
Gears attached to the rotating shaft 2 are engaged with each other, and the rotation of the pulse motor 12 causes the shaft 6 to move up and down through the vertical movement of the support fitting 8.

A pulley 16 is attached to the lower end of the sleeve 12, and a belt 20 is placed between the pulley 16 and the pulley attached to the rotating shaft of a rotational drive pulse motor 18. The rotation of the pulse motor 18 causes the shaft 6 to rotate through the rotation of the sleeve 12.

A sample container 30, a washing pot 26, and a reaction container 32 are arranged in this order on the rotation trajectory of the probe 4 at the tip of the arm 2. The sample container 30 is arranged on the circumference of the sample table 24, and the position 30a of the sample container on the rotation locus of the probe 4 is the sample suction position. The reaction container 32 is arranged on the circumference of the reaction table 28, and a position 32a of the reaction container on the rotation trajectory of the probe 4 is a sample discharge position. The probe 4 can move in the range X (A-C) from the sample suction position 32a to the sample discharge position 32a via the washing pot 26.

The rotational drive of arm 2 is controlled.

34 is a second arm, the base end of which is rotatably attached to the shaft 6 via a bearing 35, and so as to move together with the shaft 6 in the downward direction. Arm 3
An electrode-type liquid level sensor 36 is attached to the tip of 4. 38 is a liquid level detection mechanism that detects the liquid level by measuring electrical resistance between the liquid level sensor 36 and the probe 4.

A spring 40 is applied to the base end of the arm 34.
Therefore, a rotational force is always applied to the arm 34 so that it rotates clockwise in FIG. 1. A stopper 42 is provided at a position where the liquid level sensor 36 comes into contact with the arm 34 when it comes to the position of the cleaning pot 26, and the arm 34 comes into contact with the stopper 42 and stops at the cleaning position. The arm 2 also includes a contact member 44 that comes into contact with the arm 34 when it is pulled by a spring 40 and rotates clockwise.
is provided. As a result, the arm 34 is rotated in synchronization with the arm 2 by the contact member 44 of the arm 2 in the range Y (A-B) from the cleaning position to the sample suction position 3 (La).

When the arm 34 is in contact with the abutting member 44 of the arm 2, the probe 4 and the liquid level sensor 36 are brought close to each other.
The probe 4 and the liquid level sensor 36 are positioned.

Next, the operation of this embodiment will be explained.

At the cleaning position, the probe 4 and the liquid level sensor 36 come close to each other and are both cleaned by the cleaning pot 26. The arm 34 is pulled by the force of the spring 40 and remains in contact with the abutting member 44,
After the arm 2 and the arm 34 are rotated counterclockwise in FIG. 1 from the cleaning position to the sample suction position 30a by the rotational drive pulse motor 18, the arm 2 and the arm 34 are lowered by the elevation drive pulse motor 14. It will be done.

The probe 4 and the liquid level sensor 36 are inserted into the sample container,
After the liquid level of the sample is detected by the liquid level sensor 36 and the sample is sucked into the probe 4, the probe 4 and the liquid level sensor 36 are raised by the rotation of the pulse motor 14. After that, the arm 2 and the arm 34 are moved by the pulse motor 18.
is rotated clockwise in FIG. The arm 34 comes into contact with the stopper 42 and stops at the cleaning position, but the arm 2
rotates to the sample discharge position 32a. Thereafter, the probe 4 is lowered by the pulse motor 14 (at this time, the liquid level sensor 36 is lowered even though it is located away from the probe 4), the probe 4 is inserted into the reaction container, and the sample is discharged. When dispensing is completed, the probe 4 (also the liquid level sensor 36) is raised by the pulse motor 14,
After the arm 2 is rotated counterclockwise to the cleaning position, the probe 4 and the liquid level sensor 36 are both lowered and cleaned in the cleaning pot 26.

- Thereafter, the sample table 24 and the reaction table 28 are rotated, and the same operation is repeated to discharge the sample at the sample suction position 32a into the reaction container at the sample discharge position ii32a.

In the examples, sample containers are shown arranged on the sample table, and reaction containers are shown arranged on the reaction table. The present invention can also be applied to automatic analyzers having transfer means of other types.

(Effects of the Invention) In the present invention, when aspirating a sample, both the probe and the liquid level sensor are inserted into the sample container, and when discharging the sample into the reaction container, the liquid level sensor is separated and only the probe is inserted into the reaction container. Since the probe can be inserted, the sample can be discharged by inserting the probe into the reaction container even in a reaction container with a small opening, and scattering of the sample can be suppressed.

Moreover, as a result, the reaction container can be downsized.

8- One set of drive control device for lifting and rotating the arm is sufficient,
The configuration is simplified, the size can be reduced, and costs can also be reduced.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing one embodiment, and FIG. 2 is a vertical sectional view of the same embodiment. 2... First arm, 4... Probe, 6... Axis, 14... Lifting drive pulse motor, 18... Pulse motor for rotational drive,
24...Sample table, 26...Washing pot, 28...Reaction table, 30...
...Sample container, 30a...Sample suction position, 32
...Reaction container, 32a...Sample discharge position, 34...Second arm, 42...
Stopper, 44...Abutting member.

Claims (1)

[Claims] (1) A probe that aspirates and discharges a liquid sample is attached to the tip of a first arm whose base end is fixed to a shaft that is controlled to move up and down and rotate, and the sample is placed on the rotational trajectory of this probe. A container, a washing pot, and a reaction container are arranged in this order, and a second arm whose base end is rotatably attached to the shaft and moves together with the first arm only within the range of the sample container and the washing pot. A liquid sample dispensing device, wherein a liquid level sensor for detecting the liquid level of the liquid sample in the sample container is provided at the tip of the liquid sample so as to be located close to the probe in the range.