JPS5815065B2 - sampling device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sampling device used in an autosampler or the like.

A sampling device supplies a sample from a sample section to a cuvette section at an arbitrary position, and in most cases of this size, a pipette moves back and forth between two points, the sample section and the cuvette section.

However, to prevent sample contamination,
A process of cleaning the inside and outside of the pipette is required for each cycle, and for this purpose, the pipette has been required to move back and forth between at least three points.

The conventional method is to attach a pipette by stretching a wire, move the pipette in a plane using the wire, detect a predetermined position, and then lower the pipette to carry it to the desired position. There is a method of attaching a pipette to the tip of an arm that extends sideways from the vertical axis, and moving three points on the pipette's circumferential trajectory by combining vertical movement and rotation of the vertical axis. Reproducibility is poor, and there is always a wire above the cuvette, a pulley for stretching the wire, a guide rail, etc., which obstructs maintenance such as cuvette replacement and manual sample injection.

The latter is very expensive. Each point must be on the circumferential locus of the lever tip, so there are significant location constraints.
Lacks speed.

There are disadvantages such as the large area occupied by the movement of the lever.

The present invention has been made in view of the above, and its purpose is to provide a sampling device that has a simple configuration and can perform repeated sampling quickly, accurately, and using a limited space. There is a particular thing.

The feature of the present invention is to use the rotational force of the arm to which the pipette is attached, which rotates reciprocatingly around the motor shaft, to move the motor itself back and forth in a direction perpendicular to the arm rotation surface, so that the pipette can be moved to any direction. The point is that it is made to move back and forth between four points.

FIG. 1 is a schematic diagram showing an embodiment of the sampling device of the present invention.

Reference numeral 1 denotes a motor, which can be reciprocated in the axial direction by a motor seat 9 and a guide shaft 10, and a force in one direction is constantly applied by a spring 12.

An arm 2 is fixed to the shaft of this motor 1, and a pipette 3 is attached to the tip of the arm 2.

A cam 4 is interposed between the motor 1 and the arm 2 and rotates in one direction by the same angle due to the rotational force of the arm 2.

5 is a roller for sliding on the cam surface when the arm 2 reverses in a direction in which the cam 4 does not rotate, and 11 is a cam receiver.

By rotating the arm 2, the pipette 3 repeats a reciprocating motion of sucking up the sample into the sample cup 7, spitting it out into the cuvette 6, and rinsing it with the washing cup 8.
The operation will be explained with reference to FIG.

Figure 2 is a schematic view of Figure 1 seen from above, and shows (1) to (
5) indicates one circus.

The start point is when the arm 2 is in the sample cup 1 in (1).

The roller 5 is located at a lower position of the cam 4, and the cam 4 is configured to rotate by the same amount in the same direction by a claw or the like only when the arm 2 rotates from the sample cup 1 and washing cup 8 side to the cuvette 6 side. There is.

Next, moving to (2), when motor 1 is rotated in the direction of the arrow,
Since the cam 4 rotates by the same amount as the arm 2, the motor 1 does not move axially and the arm 2 correctly reaches the cuvette 6.

Next, moving to (3), when the motor 1 reverses, the cam 4 does not move and the rollers 5 slide on the cam surface from a low position to a high position, so the motor 1 is pulled in the axial direction and moves.
The arm 2 reaches the washing cup 8 with a shift corresponding to the difference in height of the cam surfaces.

Furthermore, when motor 1 is reversed, cam 4 also rotates together with arm 2, so as shown in (4), motor 1 moves f
Arm 2 reaches the opposite side while the trench remains stationary.

Then, when the motor 1 is further reversed as shown in (5), the roller 5 slides on the cam 4 with the arm 2 and moves lower, so the motor 1 also returns to its original position by the force of the spring.
Arm 2 reaches sample cup γ and completes one cycle.

As described above, according to the embodiment of the present invention, the configuration is simple, and the pipette 3 can be reciprocated between any four points simply by reciprocating the arm 2. are directly connected, and the force is always applied in a fixed direction by the spring 12, so position reproduction is very good.

Furthermore, as can be seen in FIG. 1, since the arm 2 moves in a vertical plane, it can be folded compactly and can be easily incorporated into the narrow sample chamber of a conventional measuring instrument.

In the example, only three points were used: sample, cuvette, and washing, but of course all four points could be used, and each point was on the same plane, but it is possible to shift them by making the shape of the cam 4 waveform. is also possible.

In addition, especially when measuring metal elements using organic solvents or automatically diluting them, the conventional method of combining liquids passed through multiple pumps and discharging them from a pipette is difficult.
Since no metal can be used in the flow path system, including the pump part, parts construction is difficult and extremely expensive. However, according to the present invention, the length of the tube from the pipette to the pump can be adjusted to match the required volume. This prevents the sample and diluent from reaching the pump during suction and discharge, making it possible to provide an inexpensive pump that is not limited by material.

As explained above, according to the present invention, the configuration is simple, and there is a remarkable effect that sampling can be performed repeatedly between four points accurately and quickly.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an embodiment of the sampling device of the present invention;
FIG. 2 is a diagram illustrating the operating principle seen from above in FIG. 1. 1...Motor, 2...Arm, 3.
...Pipette, 4...Cam, 5...
...Koro, 9...Motor seat.

Claims (1)

[Claims] 1. A motor attached to a pedestal that can reciprocate in the direction of the rotation axis, an arm that has one end fixed to the shaft of the motor and rotates back and forth about the axis, and a pipette attached to the other end of the arm, a cam that rotates to follow only the rotation of the shaft in one direction and has a cam surface in at least two positions, high and low; and means that contacts the cam surface and reciprocates the base in the direction of the rotation axis. A sampling device comprising: