JPH0225659B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an automatic variable volume pipettor for automatically aspirating and dispensing liquid.

(Summary of the Invention) The present invention provides an automatic variable volume pipette for automatically aspirating and discharging liquid, in which a driving body for driving a piston of a syringe and the piston are detachable, each having a different volume range. It is configured such that a plurality of syringes can be operated by the driving body, thereby making it possible to aspirate and discharge with high accuracy over a wide capacity range.

(Prior Art) Conventionally, in automatic variable volume pipettes, the piston of the syringe and the drive unit for driving the piston are integrated, and the piston cannot be replaced depending on the suction and discharge volumes.

(Problem to be Solved by the Invention) Therefore, the capacity range is limited, and if a wide range of suction and discharge capacities is required, for example from 1 μ to 1 ml, multiple drive units each having a different variable range are required. An integrated automatic variable volume pipette was required. Furthermore, when suctioning and dispensing small volumes with a pipette having a large piston diameter, highly accurate suction and dispensing could not be performed due to drive errors in the drive unit.

(Means for Solving the Problems) The present invention has been made for the purpose of quickly solving the above-mentioned drawbacks, and it is an automatic variable volume pipettor that is equipped with a motor provided on the base and a longitudinal direction. A plurality of syringes each having a different capacity range, each consisting of a driving body having a chuck at one end and driven in the longitudinal direction by the motor, and a piston having a removably attachable holding part at the chuck of the driving body. and a revolver that holds the plurality of syringes and is rotatably supported on a base so that the chuck portion and any one syringe are coaxially located, and a controller that drives the motor by a predetermined amount. It is characterized by the fact that

(Function) To explain the function of this configuration, first, a syringe with a piston diameter most suitable for the required suction/discharge capacity is selected from the revolver, and by rotating the revolver, the syringe is connected to the chuck of the drive body. position on the same axis as the Subsequently, the controller drives the motor to move the driving body, and causes a chuck formed at one end of the driving body to hold a holding part formed at the upper end of the piston of the syringe. In this state, by placing liquid at the tip of the syringe and driving the driver by a predetermined amount in the direction of pulling out the piston from the piston outer cylinder, the required amount of liquid is sucked. Next, the sucked liquid is discharged by driving the driving body in the opposite direction, that is, in the direction of pushing the piston into the piston outer cylinder. After the ejection is completed, the holding of the chuck portion is released, the driving body is returned to the initial position, and the next suction/ejection begins.

(Example) A preferred example of the present invention will be described in detail below based on the drawings. The drawing is a sectional view of an automatic variable volume pipettor according to the invention. In the drawings, reference numeral 1 denotes a piston drive motor provided on a base 2 and whose rotation angle can be controlled. A motor shaft 3 of the motor 1 is connected to a drive screw 5 via a joint 4. Reference numeral 6 denotes a drive body that is slidably held by the base body 2 and screwed into the drive screw 5 at one end. The other end of the driving body has a chuck hole 7 formed in a cylindrical shape, and a plurality of holes are penetrated through the side wall near the tip of the chuck hole 7, and holding balls 8 are housed in each hole. A ball retainer 9 is slidably inserted into the chuck hole 7 to prevent the holding ball 8 from falling into the inside, and a ball retainer 9 is slidably inserted between the ball retainer 9 and the bottom of the chuck hole 7. A ball holding spring 10 is interposed in the ball holding spring 10. The outer periphery of the chuck hole 7 is surrounded by a slidably provided sleeve 11. The tip of the sleeve 11 is gently widened. The sleeve 11 is urged toward the tip by a sleeve spring 12, and its gently expanded portion holds the holding ball 8 against the ball retainer 9. Further, a rotary lever 13 is rotatably attached to the sleeve 11. 14 is one end 14. A is a release attached to the base body 2 so that the rotating lever 13 can be pushed down. other end 1
4. b is pushed up by an actuator 16 of a solenoid 15 attached to the base body 2. Further, a groove is formed in the drive body 6 in the drive direction so that a rotation stopper pin 17 fixed to the base body 2 is engaged therewith. Reference numeral 18 denotes a syringe consisting of a piston 19 and a piston outer cylinder 20, and a holding portion 21 to be inserted into the chuck hole 7 is formed in the head of the piston 19. The holding portion has a substantially cylindrical shape,
The distal end side portion thereof is formed into a concave shape so as to be received by the holding ball 8. 22 is a revolver that holds a plurality of pipettes 13 in a circumferential manner. Each of the plurality of syringes has the piston 1.
9 and the piston outer cylinder 20 have different diameters and therefore have different displacement ranges. The revolver 22 is supported by the base body 2 so that the chuck hole 7 and the holding part 21 of any syringe 18 can be positioned coaxially, and a timing pulley 23 is attached to the upper end of the support part. . 24 is a revolver rotation motor. The rotational movement of the motor 24 is transmitted to the timing pulley 23 via a timing belt 25. 2
6 denotes the piston drive motor 1, the revolver rotation motor 24, and the solenoid 1.
This is the controller that controls 5. The controller 26 includes at least a suction/discharge capacity, a ready signal for starting an operation for causing the drive body 6 to hold the holding section 21, a suction signal for starting a suction operation, and a suction signal for starting a discharge operation. A pipetting signal is being input.

In such a configuration, the operation is explained as follows.
Based on the input suction/discharge volume, the controller 26 selects the most suitable syringe 18 for that volume from the revolver 22, and controls the revolver drive motor 24 so that the holding portion 21 of the selected syringe 18 is connected to the chuck hole. Rotate until it is coaxial with 7.

Thereafter, the controller 26 drives the piston drive motor 1 by a predetermined amount in a predetermined rotational direction, thereby rotating the directly connected drive screw 5. The drive body 6, whose one end is screwed onto the drive screw 5, is prevented from rotating by a rotation stopper pin 17.
Therefore, the driver 6 descends along the axial direction of the drive screw. By descending by a predetermined amount, the holding part 21 formed at the upper part of the piston 19 of the syringe 18 is inserted into the chuck hole 7. At that time, the tip of the holding portion 21 pushes up the ball retainer 9, and the holding ball 8 is pushed up into the chuck hole 7.
allows you to move inside. The holding ball 8
is moved inside the chuck hole 7 by the sleeve 11 and fits into the concave portion of the inserted holding portion 21.

As described above, the driving body 6 and the piston 19
are combined and the preparation for suction is completed. Next, a container containing liquid is placed at the tip of the syringe 18, and a suction operation start signal is input to the controller 26, thereby executing the suction stroke. That is, the controller 26 again outputs a drive signal to the motor 1 and controls the drive body 6 according to the suction amount, the piston 19, and the piston outer cylinder 2.
Drive upward by an amount determined by the diameter of 0. The prefilling piston 19 is connected to a driving body, and as a result is pulled up and liquid is drawn into the syringe. When discharging the liquid sucked into the pipette, a discharging operation start signal is input to the controller 26. In response to this, the controller 26 outputs a drive signal to the motor 1. At this time, the motor 1 is driven in the opposite direction to that during suction, and the driving body 6 is lowered. As a result, the piston 19 connected to the drive body 6 is pushed down,
The liquid held within the syringe is discharged. When the discharge is finished, the controller 26 drives the solenoid 15, and the holding part 21 and the driving body 6
Unbind. That is, the solenoid 1
5, its actuator 16 pushes down one actuating end 14a of the release 14, thereby causing the other end 14b to push down the rotary lever 13. The depressed pivot lever 13 causes the sleeve 11 to which it is attached to slide upwards. The holding ball 8 loses its grip on the outside, is pushed by the ball retainer 9 and escapes from the concave portion of the holding portion 21, and the fitting is released. At this time, the holding ball 8 is held by the outer circumferential portion of the ball retainer 9 and the inner wall of the widened portion of the sleeve 11. In this state, the controller 26 again drives the motor 1 in the direction of moving the driving body upward. Thereby, the connection between the holding part 21 and the driving body 6 is released. Then controller 2
6 returns the driving body 6 to its initial position and waits for the next input.

(Effects of the invention) With the above-described structure and operation, the suction/discharge capacity can be varied over a wider range compared to a pipette with an integrated drive unit, and a syringe with a piston diameter most suitable for the capacity can be selected. This has made it possible to aspirate and dispense with high precision.

[Brief explanation of drawings]

The drawing is a front view showing the overall structure of an automatic variable volume pipettor according to the present invention. DESCRIPTION OF SYMBOLS 1...Piston drive motor, 5...Drive screw, 6...Driving body, 7...Chuck hole, 8...Holding ball, 9...Ball holding down, 11...Sleeve, 13
... Rotating lever, 14 ... Release, 15 ... Solenoid, 19 ... Piston, 20 ... Piston outer cylinder, 21 ... Holding part, 22 ... Revolver, 2
4...Revolver rotation motor, 26...Controller.

Claims (1)

[Scope of Claims] 1. A motor provided on a base body, a driving body having a chuck portion at one end in the longitudinal direction and driven in the longitudinal direction by the motor, and a driving body that can be attached and detached at the chuck portion of the driving body. A plurality of syringes each having a different capacity range are each formed by a piston having a holding portion to be held, and the plurality of syringes are held such that the chuck portion and any one syringe are located coaxially. An automatic variable volume pipette comprising a revolver rotatably supported on a base and a controller that drives the motor by a predetermined amount. 2. A chuck hole in which the chuck portion is formed in a cylindrical shape; a sleeve that is coaxially slidably provided on the outer periphery of the chuck hole and has a widened portion that is gently widened at its lower end; The automatic variable capacity type according to claim 1, comprising a slidably provided ball holder and a plurality of holding balls held by the outer circumference of the ball holder and the inner wall of the widened part of the sleeve. Pipe ivy. 3. The automatic variable volume pipettor according to claim 1, wherein the holding portion formed on the piston is approximately cylindrical and has a concave distal end side. 4. A first motor provided on a base body, a driving body having a chuck portion at one end in the longitudinal direction and driven in the longitudinal direction by the motor, and a driving body detachably held by the chuck portion of the driving body. A plurality of syringes each having a different capacity range are formed by a piston having a holding part, and the plurality of syringes are held and rotated around a base so that the chuck part and any one syringe are coaxially located. A revolver supported in a freely movable manner and a second
An automatic variable capacity pipette comprising a motor and a controller that drives the first motor and the second motor by an amount according to input suction and discharge amounts. 5. A chuck hole in which the chuck portion is formed in a cylindrical shape, a sleeve that is coaxially slidably provided on the outer periphery of the chuck hole, and has a widened portion that is gently expanded at its lower end; The automatic capacity variable device according to claim 4, comprising a ball retainer slidably provided on the ball retainer, and a plurality of holding balls held by the outer peripheral portion of the ball retainer and the inner wall of the widened portion of the sleeve. Expression pipette. 6. The automatic variable volume pipette according to claim 4, wherein the holding portion formed on the piston has a substantially cylindrical shape with a concave distal end thereof.