JPH09127134A - Dispensing head for dispensation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent unbalance between the right and left sides of a spring in the spring return. SOLUTION: A spring is installed in the outer peripheral parts of plungers 14a-14e, so that the dispensing head can be reduced in size by the length of the conventional special strut, and by arranging plunger return springs 17a, 17b, which have been one in the prior art, symmetrically and uniformly to each center of many nozzles, imbalance between the right and left sides in the spring return can be prevented and the contact between the springs 17a, 17e and the plungers 14a-14e can be prevented so as to conduct the smooth operation.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to reagent, sample dispensing,
The present invention relates to a dispensing device for automatically performing dilution, and relates to the structure of the dispensing head.

[0002]

2. Description of the Related Art FIG. 4 discloses the structure of a dispensing head in a conventional dispensing device. In a dispensing head, and in particular a head 100 having a plurality of dispensing nozzles, a cylinder 103 for inserting a plurality of plungers 102 planted in a plunger fixing bar 101, and these bars 101 are generally used. , Plunger 102 and cylinder 103
A casing block 104 for accommodating the same, a dispensing tip 105 provided at the tip of the cylinder 103, and a dedicated column 106 connected to the fixed bar 101 at its upper portion.
A pillar slide guide 107 provided on the upper part of the block 104 for guiding the pillar, a spring stopper 108 fitted on the upper part of the dedicated pillar 106, and interposed between the guide 107 and the stopper 10. A plunger return spring 109 which is inserted through the column 106,
The plunger drive shaft 110 is located above the column 106 and pushes the column 106 downward.

[0003]

In such a structure,
Since the plunger return spring 109 is provided around the dedicated column 106 and is installed around this, the dispensing head is lengthened by the length dimension of the column 106, which is an obstacle to downsizing of the dispensing device.

In particular, in a head having a large number of dispensing nozzles, it is necessary to return a large number of plungers with a single spring, which causes imbalance between the left and right sides of the springs.
There was a problem that the recovery work could not be executed well.

[0005]

In order to solve the problems of the prior art, the present invention adopts a structure in which the conventional support rod dedicated to the plunger return spring is removed and the spring is installed on the outer peripheral portion of the plunger. .

With such a structure, the dispensing head can be downsized by the length of the conventional dedicated column. Further, according to the present invention, by arranging a plurality of plunger return springs, which are conventionally one, symmetrically and symmetrically with respect to the center of a large number of nozzles, left and right imbalance at the time of spring return can be prevented,
The contact between the spring and the plunger can also be prevented, and smooth operation can be performed.

With these configurations, the dispensing accuracy can be improved.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION A dispensing head of a dispensing apparatus of the present invention will be described in detail below with reference to an embodiment thereof.

As shown in FIG. 1, the dispensing apparatus 1 is provided with a Y-axis moving rail 3 on a vertical support plate 2 and a Y-axis moving arm 4 movably installed on the rail 3. The dispensing head 5 is connected to the Y-axis moving arm so as to be movable in the X-axis direction, and can be moved up and down via a column 6 that serves as the Z-axis so that it can be moved in the Z-axis direction. There is.

That is, the dispensing head 5 can freely move in space in the XYZ directions. A horizontal base 7 is provided orthogonal to the vertical support plate 2, and a pipette chip holder 8, a reagent container holder 9, and a plurality of microplates 10 are held on the base 7 in a positioned state. Has been done.

In the pipette tip holder 8, resinous pipette tips are mounted in a line, and the number of rows is adjusted by the number of nozzles described later. The reagent holder 4 is stored in a state in which various reagents sucked by a chip described later are put in a container such as a test tube.

The microplate 10 is provided with a large number of recesses (not shown) on its surface, and the sample is accommodated in the recesses. The reagent aspirated by the pipette is dispensed into this recess and reacted with the sample.

Although not shown in the figure, this apparatus is provided with a controller for controlling the movement of the dispensing head 5 and the dispensing amount, the pipette tip holder 8 on the horizontal base 7, the reagent container, and the like. All the positional information of the holder 9 and the microplate 10 is given to the dispensing head 5, and the dispensing head 5
Can quickly move in the XYZ directions based on this position information.

A casing block 12 is held in the lower part of the dispensing head 5 via a cylinder 11a which accommodates the plunger drive shaft 11 therein, and the tip of the drive shaft 11 is connected to a plunger fixing bar 13. ing.

As shown in FIG. 2, the plunger fixing bar 13 has a large number of plungers 14 (14a to 14l).
Cylinders 15 (15a to 15l) serving as guides for lifting and lowering the plunger 14 are fixedly provided to the casing block 12.

At each tip of the cylinder 15, tips 16 (16a-1 to 16a-1) of the pipette tip holder 8 are respectively provided.
6l) is installed. Further, the plunger 1 is provided between the plunger fixing bar 13 and the cylinder 15.
A number of coil springs 17 (17a to 17b) for inserting 4 are evenly provided in a symmetrical position centered on the central portion of the bar 13 in total.

The larger the number of the springs 17, the better the ability to absorb the left and right imbalances. However, if the number is too large, the biasing force becomes too large and the smooth operation of the plunger 14 is hindered. Is suitable.

FIG. 3 is an enlarged view of the periphery of the plunger 14. The plunger 14 may be directly implanted in the bar 13, but as shown in FIG.
If it is attached via, the displacement of the upper end of the spring can be prevented.

Similarly, the cylinder 15 also has a spring 17
May be brought into direct contact with the upper end of the spring, but if it is attached via the spring position fixing block 19 as shown in FIG. 3, the lower end of the spring can be prevented from shifting.

Reference numeral 20 is an O-ring for ensuring an airtight state inside the cylinder 15. In this way, the interior of the cylinder 15 is kept airtight, and
By vertically moving 4, the reagent can be sucked or discharged.

The procedure of the dispensing operation in the dispensing apparatus having the above structure will be described. First, the dispensing head 5 is moved and stopped at the position of the pipette tip holder 8, and the head 5 is lowered to mount the tip 16 on the tip of the cylinder 15.

Next, the dispensing head 5 is raised again and then moved, stopped at the position of the reagent holder 4 and lowered. Then, the plunger 15 is raised to suck a predetermined amount of the reagent into the chip 16. Especially when the suction amount is large, it is also possible to suck the reagent into the cylinder 15.

Thereafter, the dispensing head is raised again and moved to be stopped at the position of one of the four microplates 10, and the plunger 14 is pushed on the drive shaft 11 while lowering the head 5. By lowering, the spring 17 is lowered against the spring 17, and a predetermined amount of the sucked reagent is dispensed into each recess. At this time, the inclination of both ends of the bar during the pushing operation of the plunger 14 is absorbed by the springs 17, and the displacement amount of each plunger 14 becomes uniform so that the dispensing amount can be made uniform. Time accuracy improves.

When the dispensing of one microplate 10 is completed, the dispensing head 5 is raised, moved to the next microplate 10 and the same operation is repeated. When the dispensing operation of all the microplates 10 is completed, the dispensing head 5
Is moved up to a predetermined place on the base, and the chip 16 is discarded in a waste box (not shown) at that place by using a chip removing mechanism (not shown).

[0025]

As described above, according to the present invention, the spring for returning the plunger is not attached to the conventional spring-dedicated strut, but is attached to the outer peripheral portion of the plunger, so that the dedicated strut can be omitted and the dispensing head can be miniaturized. It is possible to improve the dispensing accuracy by equalizing the displacement amount of the plunger in the head of the type in which multiple plungers are integrated by providing the springs evenly on the left and right. Becomes

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a dispensing device equipped with a dispensing head of the present invention.

FIG. 2 is a sectional view of a main part of a dispensing head.

FIG. 3 is an enlarged configuration diagram around a plunger.

FIG. 4 is a sectional view of a main part of a conventional dispensing head.

[Explanation of symbols]

 1 Dispensing device 5 Dispensing head 11 Plunger drive shaft 13 Plunger fixing bar 14 Plunger 15 Cylinder 16 Tip 17 Plunger return spring

Claims (3)

[Claims] 1. A plurality of cylinders, a plurality of plungers which move up and down in the cylinders, a plunger drive bar which is connected to each of the plungers and drives the plungers to move up and down at the same time, the drive bar and the A dispensing head of a dispensing device comprising a return spring which is interposed between a cylinder and which returns the plunger to its original position after the dispensing operation is completed. 2. The return spring is a coil spring having an upper end abutting against the drive bar and a lower end abutting against an upper end surface of the cylinder in a state where the plunger is inserted. The dispensing head of the dispensing device according to claim 1. 3. The dispensing head of the dispensing device according to claim 1, wherein the return springs are provided in the same number on the left and right with the central portion of the drive bar as an axis of symmetry.