JPH09281116A - Dispenser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the fitting capability of tip to a nozzle shaft by holding nozzle shaft at a nozzle shaft holding stage capable of horizontally moving against the nozzle shaft holding stage and/or swiveling around an arbitrary center point on the nozzle shaft line when the tip fitting part touches a disposable tip. SOLUTION: A nozzle shaft 21 has a hollow fitting part for fitting a tip at one end. The tip is formed usually by injection molding into cone shape with a resin material such as polypropylene and inserted at thicker opening by a tip holder part of the nozzle shaft for fitting. The tip is arranged on the rack holding means in the state that the opening wherein the nozzle fitting part is inserted, faces upward, and is transported on the nozzle shaft line. The nozzle shaft holding stage 22 is held capable of horizontally moving on the nozzle shaft and/or swiveling around an arbitrary center point of the nozzle shaft line. By this, the tip fitting part can be moved horizontally and spherically on the tip fitting part limiting the movement on vertical direction.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a disposable chip (disposable chip, hereinafter abbreviated as a chip) for a liquid sample.
The present invention relates to a dispensing device for dispensing by using.

[0002]

2. Description of the Related Art In the case of liquid samples used for biochemical analysis or immunochemical analysis, for example, biological samples such as serum, blood and urine, there are 100 samples between samples derived from healthy individuals and those having disease. The concentration of a specific substance may differ by a factor of 10,000 or more. When measuring such substances, if the dispenser that is in direct contact with the sample is contaminated with a sample containing a high concentration of the specified substance, other later dispensed samples, especially low concentration samples, will be contaminated and It is common to use a chip because it will not be possible to make measurements.

That is, in the dispensing apparatus, the portion that comes into contact with the liquid sample is made disposable so that the carry-over of the high-concentration sample as described above is prevented and the propagation of contamination is prevented.

The tip is normally used by being pressed against the lower end of a hollow nozzle shaft connected to a pump.
This nozzle axis can be driven by an XZ direction drive mechanism or by XY
It can be moved in the horizontal and vertical directions by the Z-direction drive mechanism. For example, after the chip is positioned on the nozzle axis by the horizontal movement, it is lowered toward the chip by the vertical movement to mount the chip.

Here, even if the nozzle shaft is lowered to mount the chip, the chip position is displaced, and if the chip is not located on the axis of the nozzle, the chip mounting portion is inserted into the chip. There is a possibility that the tip cannot be attached or the tip is detached during the dispensing operation due to incomplete attachment. Even if the tip is not detached, if the tip is mounted in a tilted manner, a gap may open between the nozzle shaft and the tip, air may leak from the gap, and the dispensing accuracy may deteriorate.

Normally, a nozzle shaft having a tip mounting portion processed into a tapered shape is correctly positioned with respect to a standardized tip and lowered to prevent detachment of the tip and air leakage due to mounting failure. . Further, as disclosed by the applicant in Japanese Patent Application No. 5-275305, the nozzle shaft is lowered while being rotated, and the mountability is improved by screwing the nozzle shaft into the chip opening when mounting the chip. Techniques for preventing desorption and air leakage have also been proposed.
Further, there is also known a technique in which an elastic O-ring is attached to the tip of the nozzle shaft to improve the mountability and prevent detachment of chips and air leakage.

[0007]

In order to improve the mountability of the chip on the nozzle shaft and prevent the chip from coming off and air from leaking, it is necessary to improve the relative positioning mechanism between the nozzle shaft and the chip. Needless to say, it is necessary to improve the driving mechanism for mounting the nozzle shaft on the chip.
That is, in order to improve the mountability of the tip, it is necessary to insert the nozzle shaft into the tip with a large force, or to insert it into the tip while rotating it.

However, in order to insert the nozzle shaft into the tip with a large force, a motor that generates a large force and an XY drive mechanism that can withstand the force are required. If this is realized, on the other hand, a new problem that the manufacturing cost of the device increases and the device becomes large may occur. Also, mounting the nozzle shaft while rotating it requires less force than simply inserting the nozzle shaft into the chip,
The mechanism for lowering the nozzle axis becomes complicated, which causes a problem in cost.

When a large force is applied to the nozzle shaft, the reaction force is applied to the mechanism such as the nozzle shaft holding portion and causes distortion. Therefore, unless the rigidity of the nozzle shaft is increased, the nozzle shaft will be distorted, and eventually the chip will be distorted. It will lead to poor mounting.

The tip is usually arranged with the opening that fits in the nozzle axis facing upward, but it is difficult to match the axis with the axis of the nozzle. As a result, even if the nozzle shaft is simply inserted into the chip with a large force, it is difficult to improve the mountability when the chip faces the direction different from the nozzle shaft.

After dispensing one type of liquid sample, the chip is removed and replaced with another chip before dispensing another liquid sample. The tip cannot be removed unless the appropriate force is applied.
Therefore, if the drive mechanism is improved as described above,
Further, it is necessary to improve the mechanism for removing the tip.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides a tip for a nozzle shaft without significantly improving a relative positioning mechanism for the nozzle shaft and the tip or a nozzle driving mechanism. To improve the wearability of the.

According to the dispensing apparatus of the present invention, a nozzle shaft having a hollow tip mounting portion for mounting a tip at one end, and a gas can be discharged into the hollow portion and sucked from the hollow portion. A pump means communicating with the nozzle shaft, a nozzle shaft holding base for holding the nozzle shaft, a base for holding the nozzle shaft holding base so as to be vertically movable, and a driving means for moving the nozzle shaft holding base in the vertical direction. In a dispensing device having a nozzle shaft holder and / or means for horizontally transferring the chip to position the chip to be held on the nozzle shaft on the axis of the nozzle shaft, the chip mounting portion is a chip. The nozzle shaft is held on the nozzle shaft holder so as to be horizontally movable with respect to the nozzle shaft holder and / or swingable about an arbitrary point on the nozzle axis when contacted. Is that dispensing apparatus. Hereinafter, the present invention will be described in detail.

The present invention is a dispensing device that uses disposable tips. The tip is made of a resin material such as polypropylene, polystyrene, polyethylene, ABS or the like, and is generally injection-molded in a cone shape (conical shape with a narrow tip). The tip holding portion of the nozzle shaft is inserted into the thicker opening to mount it, and the liquid sample is sucked and discharged from the other thin opening.

The tip is one-dimensionally or in a state in which an opening into which the nozzle mounting portion is inserted is directed upward in a tip holding means called a rack, more specifically, so that the axis of the tip and the axis of the nozzle are aligned. It is arranged two-dimensionally and is transferred on the axis of the nozzle shaft. It should be noted that this transfer can be realized by transferring the rack and / or by transferring the nozzle shaft by means of a drive device that transfers the nozzle shaft holding portion described later in the horizontal direction. As a means for this transfer, a drive device equipped with a motor such as a pulse motor or a DC servo motor which is normally used can be used. FIG. 1a shows a state in which the nozzles are arranged one-dimensionally in the rack, and FIG. 2a shows a state in which the nozzles are arranged two-dimensionally. These are examples, and the nozzles are arranged on a disc as a two-dimensional arrangement, for example. You can also The rack may be made of plastic, metal, or the like, but a commercially available rack can also be used.

The nozzle shaft has a hollow tip mounting portion for mounting a tip at one end. The shape of this end is preferably the shape inside the opening of the chip to be mounted, but it is sufficient if airtightness can be maintained when the chip is mounted, and it is strictly the same shape as the shape inside the chip. No need. Further, the tip mounting portion does not have to have the same shape as a whole, and may have a tapered shape with a tapered tip so that it can be easily inserted into the tip, and its root portion may have a shape that maintains airtightness with the tip.

The tip holding portion can be integrally formed with other portions of the nozzle shaft by using a metal material, ABS resin or the like. However, for example, it may be configured by a member different from the other portion, and only this portion may be exchanged when it is worn due to friction generated during insertion into the chip. In this case, it goes without saying that a material different from the other parts can be used. Alternatively, for example, the nozzle shaft may be integrally formed and only the tip mounting portion may be coated with abrasion resistance.

At least the tip holding portion of the nozzle shaft has a hollow structure. That is, the nozzle shaft may have a tip mounting portion having a hollow portion at one end of a simple rod-shaped member. Of course, the whole nozzle shaft may have a hollow portion. This hollow portion is communicated with a pump means described later. The shape of the nozzle shaft is not particularly limited except for the tip mounting portion described above, but it is preferable that the nozzle shaft is a polygonal column such as a column or a hexagonal column in terms of handling and manufacturing cost.

The pump means, which is communicated so as to discharge the gas into the hollow portion and suck the gas from the hollow portion, is a means for sucking and discharging the liquid sample. Specifically, a normal pump such as a syringe pump or a plunger pump can be used, but an accurate amount of liquid sample is aspirated
When discharging, it is particularly preferable to use a syringe pump or a plunger pump driven by a pulse motor, which is easy to control. The pump means may be directly connected to the hollow portion, but in order to simplify the structure around the nozzle axis,
It is also possible to communicate with appropriate piping.

The nozzle shaft holder that holds the nozzle shaft holds the nozzle shaft horizontally and / or so that it can swing about an arbitrary point on the nozzle axis. By holding the nozzle shaft on the nozzle shaft holder in this way, the chip mounting portion can be moved horizontally and on a spherical surface while limiting the movement in the vertical direction. In the present invention, the movement of the nozzle shaft in the vertical direction with respect to the nozzle shaft holding base is limited because the movement in the vertical direction allows the insertion force of the chip mounting portion into the chip due to the lowering of the nozzle shaft to be released, resulting in the mounting property of the chip. This is to prevent aggravation. However, if a sufficient insertion force can be secured for chip mounting, it is possible to allow vertical movement.

The swinging movement of the nozzle shaft is preferably a movement in which the axis of the nozzle shaft can be tilted back and forth by plus or minus 5 degrees with reference to the vertical direction. Further, this swinging movement is preferably a movement centered near the lower end of the nozzle axis so that the axis of the nozzle axis can be tilted in accordance with the axis of the tip. The center of the swing movement is located in the vicinity of the mounting position of the elastic body on the nozzle shaft, which will be described later, but the swing movement around the lower end of the nozzle shaft is centered on the elastic body mounting position on the nozzle shaft. It is obtained by a combination of swinging movement and horizontal movement of the nozzle axis.

The horizontal range of movement of the nozzle shaft is preferably about ± 10 mm, but this value may be changed as appropriate in consideration of the range of swinging motion of the nozzle shaft and the natural bending of the nozzle shaft. If the nozzle shaft is made of a flexible material that bends easily, the mechanism for swinging the nozzle shaft can be omitted, but if it is a hard material, a swing mechanism can be installed. Particularly preferred.

In order to hold the nozzle shaft on the nozzle shaft holder in this way, it is possible to use an elastic body having anisotropic rigidity. Here, anisotropic rigidity means that elasticity is exhibited particularly in the horizontal direction, but rigidity is exhibited in the vertical direction (centering around the attachment position to the nozzle shaft). A small elasticity is sufficient for swinging movements). The elastic body may be directly fixed to the nozzle shaft, or may be fixed to the member after the nozzle shaft is attached to another member.

As the elastic body having anisotropic rigidity, for example, a leaf spring whose surface is oriented in the horizontal direction, a wire spring whose surface is oriented in the vertical direction, rubber, sponge or soft plastics made of metal, hard plastics, plants. Examples of the composite material include thin plates made of fibers and the like, fibers, threads, wires and the like embedded therein. For example, some rubbers are used for seismic structures such as buildings and have rigidity in the vertical direction and elasticity in the horizontal direction. Even a uniform elastic body can be used as an elastic body of the present invention exhibiting rigidity against a vertical force by horizontally sandwiching one or more rigid fibers or thin plates between them. In such an elastic body, if a stretching force is applied in the vertical direction, it causes peeling of the joint, so it is preferable to use it so that a compressive force is applied.
In other words, when the nozzle shaft is pushed into the tip to mount it, and when the tip is removed, the forces acting in opposite directions act on each other. It can be illustrated that the pulling force does not work.

The nozzle shaft holder is held on the base so as to be movable in the vertical direction. As described above, the nozzle shaft may be held on the base so as to be movable in the horizontal direction. In this case, the chip can be moved along the axis of the nozzle axis by moving in the horizontal direction. As the driving means for moving the nozzle axis in the vertical direction, for example, a motor such as a pulse motor, a DC servo motor or an ordinary DC motor, or a normal moving means such as a linear movement mechanism using an air cylinder is used. it can.

The means for transferring the tip onto the axis of the nozzle axis is to change the relative position of the tip and the nozzle axis so that the tip mounting portion will generally reach the opening of the tip when the nozzle axis descends. Anything can be done. Therefore, the nozzle shaft may be moved in the horizontal direction, or the chips arranged on the rack may be moved in the horizontal direction.

In addition to the configuration described above, the present invention also provides a dispensing device in which, for example, a nozzle shaft is attached to an arm rotatably attached to a nozzle shaft holding base in a horizontal direction. In this case, the control of the device and the like can be facilitated by positioning the arm at a predetermined neutral position except when the chip is mounted.

[0028]

In the present invention, the horizontal movement of the nozzle axis is effective when the axis of the nozzle axis and the axis of the chip are parallel but deviated. Therefore, even if the positioning of the nozzle and the tip is not perfect, the mountability of the tip can be improved.

On the other hand, the swinging movement of the nozzle shaft, especially the swinging movement around the lower end of the nozzle shaft due to the combination with the horizontal movement, causes a mismatch between the nozzle axis and the axis of the tip, that is, the tip is tilted. It is especially effective when it is placed in a rack. Moreover, when inserting the nozzle shaft into the chip, it is also effective for absorbing the strain generated in the mechanism for holding the nozzle shaft.

As described above, according to the present invention, the tip of the nozzle shaft,
That is, as long as the chip mounting portion is inserted into the opening of the chip, the nozzle shaft moves in accordance with the chip, so that the mountability can be improved. As a result, according to the present invention,
Since the mounting rate can be improved without inserting the nozzle shaft into the chip with a large force, it is not necessary to give the nozzle shaft driving mechanism such as the XZ mechanism or the XYZ mechanism excessive strength. Further, since the variation in the strength of mounting the chip is reduced, the force required to remove the chip is almost the same, and the chip removing mechanism can be simplified.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described in more detail based on the examples shown in the drawings, but the present invention is not limited to these examples.

FIG. 2 shows a dispensing apparatus of the present invention which uses a leaf spring whose surface is oriented horizontally as an elastic body having anisotropic rigidity. In the figure, 21 is the nozzle axis, 22
Is a nozzle shaft holder, and 23 is a leaf spring which is an elastic body. Since the leaf spring allows the nozzle axis to move in the horizontal direction, as shown in this figure, it is not flat, but can be bent at at least one place, or two or more leaf springs can be angled. Use it so that it can be bent, such as by bonding. Although the thickness, length, and shape of the leaf spring can be appropriately selected, in the present example, a 0.5 mm thick phosphor bronze plate was bent twice in an arc shape of 180 °. In this example, the nozzle shaft is not directly connected to the leaf spring,
It is attached via a nozzle shaft holder 24.

In the dispensing device of this example, the nozzle axis is movable in the horizontal direction by bending the leaf spring in the horizontal direction.
Furthermore, it is possible to swing around the holder. On the other hand, in the vertical direction, the leaf spring does not show elasticity but shows rigidity.

FIG. 3 shows a dispensing device of the present invention using a vertically oriented wire spring as an elastic body having anisotropic rigidity. In the figure, 31, 32 and 34 are the same as those in FIG. 1, and 33 is a wire spring which is an elastic body. In this example also, the nozzle shaft can move in the horizontal direction by bending the wire spring in the horizontal direction, and further, the swinging motion about the holder is also possible. On the other hand, in the vertical direction, the wire spring does not show elasticity but shows rigidity.

FIG. 4 shows the dispensing apparatus of the present invention in which the nozzle shaft is attached to an arm which is attached to a nozzle shaft holder so as to be rotatable in the horizontal direction. In this figure, the nozzle shaft 41 is attached to an arm 46, which is attached to the nozzle shaft holding base 42 in a rotatable manner in the horizontal direction, so as to be rotatable in the horizontal direction around a point of attachment to the arm. The nozzle shaft is directly attached to the nozzle shaft holder 44. In the apparatus shown in the figure, the arm 46 is connected to the nozzle shaft holder 42 at one point by a rotation shaft 47, and is rotatable in the horizontal direction. The nozzle shaft holder 44 is also connected to the arm 46 at one point by a rotation shaft 48, and can rotate in the horizontal direction about the rotation shaft 48. A ball bearing 49 is embedded at the connection point of the rotary shafts 47 and 48 for the purpose of smooth horizontal rotation of the arm 46 and the nozzle shaft holder 44. Furthermore, the arm 46 and the nozzle shaft holder 44 apply a vertical force by fitting the ball 45 of the ball plunger into the hole formed in the nozzle shaft holder so that the nozzle shaft holder 44 does not rotate carelessly. When it is not open, it is configured to be located at a predetermined reference position.

FIG. 5 shows a dispensing apparatus of the present invention using an elastic body in which a thin metal plate is sandwiched between rubbers. FIG.
a shows its appearance, and FIG. 5b shows its cross section. Rubber 510
In between, a plurality of thin metal plates 511 are sandwiched, which makes the nozzle shaft 51 rigid, especially against the vertical force generated when the nozzle shaft 51 is inserted into the chip, while It can be moved horizontally. Reference numeral 52 denotes a nozzle shaft holder, 54 denotes a nozzle shaft holder, and 512 denotes a hollow portion of a nozzle shaft tip mounting portion. In this example, the hollow portion extends to the other end 513 of the nozzle shaft. The end is connected to a pump (not shown) via a pipe 514.

FIG. 6 shows another example of the dispensing device of the present invention using an elastic body in which a thin metal plate is sandwiched between rubbers. The nozzle shaft holding base 62 is clamped by sandwiching it from above and below with an elastic body so as to be resistant to the upward and downward forces acting on the nozzle shaft (force acting when the tip is removed). Therefore, even if an excessive force is applied when the chip is removed, the adhered rubber does not peel off.

FIG. 7 shows a dispensing device of the present invention using rubber as an elastic body. In order to increase the resistance of the rubber of this example to the vertical force, the wire 71
A plurality of 5 are buried. A member having rigidity in the vertical direction may be used instead of the wire.

FIG. 8 is a diagram showing another configuration of the present invention. 8a shows its appearance, FIG. 8b shows a cross section, and FIG. 8c shows a top view. In the example shown in this figure, the nozzle shaft 81 is held by sandwiching the nozzle shaft holding base 82 between the flange 820 and the flat plate 817. The first spring 816 is engaged between the flange 820 of the tip mounting portion of the nozzle shaft and the flat plate 817 movably attached to the nozzle shaft in the vertical direction, and exerts an upward force on the nozzle shaft. Is kept in a certain position.

As shown in FIG. 8b, the nozzle shaft 8
There is a gap between 1 and the nozzle shaft holder 82, and the nozzle shaft is movable in the horizontal direction. In the pipetting device having such a configuration, when the nozzle shaft moves in the horizontal direction, a frictional force is generated between the nozzle shaft holding base and the flat plate, so that they are processed flat so that they easily slide with each other. Using members,
Further, it is preferable to line at least one of them with Teflon or polyacetal, or to sandwich a thin plate of Teflon or polyacetal between them. In the figure, a portion indicated by 818 is a Teflon plate. Similarly, it is preferable to insert a plate 818 made of Teflon into the lower portion of the nozzle shaft holding base 82 and the flange portion 820 of the nozzle shaft for the same reason. The flange portion of the nozzle shaft is a hook for the nozzle shaft holder, and receives the upward force applied to the nozzle shaft by the first spring and the upward force when the chip is mounted. In the example of this figure, in order to facilitate swinging movement of the nozzle shaft about the lower end of the nozzle shaft, the contact surface between the flange 820 and the nozzle shaft holding base 82 and the flat plate 8 are provided.
The contact surface between the nozzle shaft holding base 17 and the nozzle shaft holding base 82 is a spherical surface centered on the lower end of the nozzle shaft.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a rack holding chips.

FIG. 2 shows a dispensing device of the present invention using a leaf spring whose surface is oriented horizontally as an elastic body having anisotropic rigidity.

FIG. 3 shows a dispensing device of the present invention using a vertically oriented wire spring as an elastic body having anisotropic rigidity.

FIG. 4 shows a dispensing device of the present invention in which a nozzle shaft is attached to an arm rotatably attached to a nozzle shaft holder in a horizontal direction.

FIG. 5 shows a dispensing device of the present invention using an elastic body in which a thin metal plate is sandwiched between rubbers.

FIG. 6 shows a dispensing device of the present invention using an elastic body in which a thin metal plate is sandwiched between rubbers.

FIG. 7 shows a dispensing device of the present invention using rubber as an elastic body.

FIG. 8 is a view showing a dispensing device of the present invention in which a spring and a sliding surface are combined.

[Explanation of symbols]

21, 31, 41, 51, 61, 71, 81 Nozzle shaft 22, 32, 42, 52, 62, 72, 82 Nozzle shaft holder 23, 33 Elastic body 24, 34, 44, 54 Nozzle shaft holder 45 ball Ball of plunger 46 Arm 47, 48 Rotating shaft 49 Ball bearing 510, 610 Elastic body 511, 611 Metal plate 512 Nozzle shaft hollow part 513 One end of nozzle shaft 514 Piping 715 Wire 816 Spring 817 Flat plate 818 Teflon plate 819 Spring 820 Flange

Claims (6)

[Claims] 1. A nozzle shaft having a hollow tip mounting portion for mounting a disposable tip at one end, and pump means connected to discharge gas into the hollow portion and to suck gas from the hollow portion. On the axis of the nozzle shaft, a nozzle shaft holding base for holding the nozzle shaft, a base for holding the nozzle shaft holding base so as to be vertically movable, a drive means for moving the nozzle shaft holding base in the vertical direction, In a pipetting device having a nozzle shaft holder and / or means for horizontally transferring the disposable tip in order to position the disposable tip to be held on the nozzle shaft, when the tip mounting part comes into contact with the disposable tip. The nozzle axis can be moved horizontally with respect to the nozzle axis holder and / or can be swung about an arbitrary point on the nozzle axis. Dispensing device, characterized in that held in the shaft holder. 2. The dispensing device according to claim 1, wherein the nozzle shaft is held by the nozzle shaft holding base via an elastic body having anisotropic rigidity. 3. The elastic body having anisotropic rigidity is a leaf spring whose surface is oriented in the horizontal direction.
Dispenser. 4. The dispensing device according to claim 2, wherein the elastic body having anisotropic rigidity is a wire spring oriented in a vertical direction. 5. The apparatus according to claim 2, wherein the elastic body having anisotropic rigidity is a rubber member. 6. The nozzle shaft is fixedly or swingably attached to an arm attached to a nozzle shaft holder so as to be rotatable in a horizontal direction.
Dispenser.