JPS6155423B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pipetting device for collecting and dispensing liquid, and more particularly, the present invention relates to a pipetting device for collecting and dispensing a liquid, and more particularly, the present invention includes a substantially tubular casing, a cylinder attached to the casing, a piston that reciprocates within the cylinder, and a pipette that includes a piston. An operating rod provided on the casing for operation and whose upper end protrudes from the upper end of the casing, an operating button attached to the upper end of the operating rod, and a reciprocating stroke of the operating rod relative to the casing is adjusted by rotating the operating rod. The present invention relates to a pipetting device of the type including an adjustment mechanism for adjusting the amount of liquid to be dispensed and a display device for digitally displaying the amount of liquid to be dispensed in response to rotation of the operating rod.

For example, a pipette device for this formation is disclosed in Japanese Patent Application Laid-open No. 57.
- There is something described in Publication No. 16332. Although this type of pipetting device works fairly satisfactorily, the cylinder is usually a glass tube, so it is easily damaged during use, and it is difficult to correctly position the piston and cylinder when replacing the glass tube, so it is difficult to properly position the piston and cylinder when replacing the glass tube. There is a drawback that errors occur in the amount of collection and distribution.

The invention aims to obviate this drawback and provides a pipetting device of the type described above, in which the adjustment mechanism is reciprocatably and non-rotatably guided in a guide provided in the casing.
and includes a slider having an inner thread that threadably engages with the operating rod, the lower end of the slider and the upper end of the piston rod fixed to the piston are connected by an adjusting screw, and the adjusting screw is guided so as to be reciprocally movable but not rotatable. an adjusting sleeve is provided, the upper end of the adjusting sleeve is fixed to the casing by a tightening nut, the cylinder is fixed to the lower end of the adjusting sleeve, and the tightening nut is loosened to rotate the adjusting sleeve relative to the casing. A pipetting device is provided which allows adjusting the position of the piston relative to the cylinder and thereby zeroing the display.

Preferably, a spring is provided between the adjusting sleeve and the tightening nut which presses the upper end of the adjusting sleeve upwardly. This makes it possible to prevent the adjustment sleeve from changing its position in the vertical direction when it is rotated, so that the position of the piston relative to the cylinder can be precisely and accurately adjusted.

Preferably, the locking device for releasably inhibiting rotational movement of the operating rod comprises a locking piece slidably and non-rotatably fitted to the operating rod, and a locking arm engageable to inhibit rotation of the locking piece. , including an operating knob connected to the lock arm and protruding from the upper end of the casing.

The invention will now be described with reference to the accompanying drawings, in which embodiments of the invention are shown.

FIG. 1 is a schematic vertical cross-sectional view, in which 1 has a flange portion 1A serving as a finger rest portion at the upper end and a lateral bulge portion 1B adjacent thereto, but is generally tubular in shape, and includes a top cover 2, a partition wall 3 , 4, constitutes a casing together with the end cover 5. In addition, main body 1
A transparent window 6 is provided on a part of the side surface of the screen to enable reading by a display device, which will be described later. Reference numeral 7 denotes an operating rod, which has a non-circular cross section, has a threaded portion 7A integrally provided at its lower end, and has an operating button 8 attached to its upper end. The threaded portion 7A is threadedly engaged with the slider 10, and the slider 10 has a substantially rectangular cross section and is guided by the guide 9 to non-rotatably slide vertically. Guide 9
is fixed to the inner surface of the main body 1. Therefore, as the operating rod 7 moves up and down, the slider 10 moves up and down, and as the operating rod 7 rotates, the slider 10 moves up and down with respect to the operating rod 7. An end cap 1 that positions and fixes the guide 9 and limits the downward movement of the slider 10.
1 is screwed into the lower end of the main body 1. The end cap 11 has a stepped cup shape, and the upper step restricts the downward movement of the slider 10, and a return spring 13 is stretched between the bottom of the cup shape, that is, the lower step and the slider 10. Press the rod 7 and slider 10 upward. The upper end of a connecting pipe 12 that loosely passes through the center hole of the end cap 11 is fixed to the slider 10. An adjusting screw 14 is screwed into the lower end of the connecting pipe 12, and a piston rod 21 of a piston 20, which will be described later, is connected to the adjusting screw 14. The head of the adjusting screw 14 is slidably and non-rotatably guided in the inner bore of the adjusting sleeve 15 in the vertical direction. The upper end flange of the adjusting sleeve 15 is in contact with the end cap 11, and the tightening nut 16 that holds the adjusting sleeve 15 in this abutting position screws into the end cap 11, thereby tightening the casing together with the main body 1. It is screwed into the aforementioned end cover 5. Spring 17 is the adjustment sleeve 1
The adjusting sleeve 15 is disposed between the flange at the upper end of the adjusting sleeve 5 and the tightening nut 16 so that the adjusting sleeve 15 maintains a state of contact with the end cap 11 even when the tightening nut is loosened. A cylinder 19 shown as a small diameter glass tube is fixed to the lower end of the adjustment sleeve 15 via a cap nut 22, and the piston 20 operates within the cylinder 19.

A lock device 31 including a digital display device 30 and an operation knob 32 is provided on the top of the main body 1, and an outline thereof will be explained with reference to FIG. 4.

Reference numeral 35 indicates drive drums 36 and 37, which are driven drums arranged coaxially with the operating rod 7, and each having a zero diameter on the outer peripheral surface.
~3 when viewed from the transparent window of main body 1 with the number 9
They are connected together by pinion gears 38 to provide a digital display of the digits. An adjustment ring 34 is arranged for fine adjustment of the drive drum 35.
38 and 39 are spacers arranged between the partition walls 3 and 4, and 40 is a shaft that supports the pinion gear 38.

The locking device 31 is arranged within the partition wall 3 configured as a block, and includes a locking piece 41 that is slidably but non-rotatably attached to the operating rod 7 and is pressed against the outer peripheral surface of the locking piece 41. A lock arm 42 that prevents the rotation thereof, and an operation knob 3 that operates the lock arm.
2.

In the present invention having the above-described configuration, the initial adjustment is such that the display device 30 indicates 500 indicating a predetermined maximum sampling/dispensing amount, for example, 50 microns in the inoperative state shown in FIG.
At this time, the piston 20 is located at the reference line 1 of the cylinder 19.
9A, loosen the tightening nut 16 and rotate the adjustment sleeve 15 to remove the cylinder 19.
Align the piston 20 with the reference line 19A of
Tighten the tightening nut 16. Spring 17 prevents downward movement of adjusting sleeve 15 when it is rotated. The pipetting device then collects a predetermined amount of liquid by the upward movement of the return spring 13 when the operating button 8 is pressed down, and then discharges the collected liquid when the operating button 8 is pressed down continuously. When collecting and dispensing liquid less than a predetermined sampling and dispensing amount, for example, 30μ, the locking device 31 is set to the unlocked state, the operation button 8 is rotated so that the display device 30 displays the number 300, and the locking device is moved to the locked position. And it is sufficient. The slider 10 and the piston 20 are positioned below the position shown in FIG.

The device according to the invention has high operational reliability, is easy to handle, and parts can be easily replaced.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing a specific example of a pipetting device according to the present invention. Figure 2 is a partially enlarged view of Figure 1.
FIG. 3 is a sectional view taken along the line - in FIG. 2. FIG. 4 is an exploded perspective view showing a display device and a lock device. DESCRIPTION OF SYMBOLS 1...Body, 5...End cover, 7...Operation rod, 7A...Threaded part, 8...Operation button, 9...Guide, 10...Slider, 11...End cap, 1
2... Connection pipe, 13... Return spring, 14... Adjustment screw,
15... Adjustment sleeve, 16... Tightening nut, 17...
Spring, 19...Cylinder, 20...Piston, 21...
Piston rod, 30...display device, 31...lock device, 32...operation knob.

Claims (1)

[Claims] 1. A substantially tubular casing, a cylinder attached to the casing, a piston that reciprocates within the cylinder, and a piston provided in the casing for operating the piston, the upper end of which protrudes from the upper end of the casing. an operating rod, an operating button mounted on the upper end of the operating rod, an adjustment mechanism for rotating the operating rod to adjust the reciprocating stroke of the operating rod relative to the casing, and an adjusting mechanism for rotating the operating rod to adjust the reciprocating stroke of the operating rod relative to the casing; and a display device for digitally displaying the amount to be collected and dispensed, the adjustment mechanism being reciprocatably and non-rotatably guided within a guide provided in the casing;
and includes a slider having an inner thread that threadably engages with the operating rod, the lower end of the slider and the upper end of the piston rod fixed to the piston are connected by an adjusting screw, and the adjusting screw is guided so as to be reciprocally movable but not rotatable. an adjusting sleeve is provided, the upper end of the adjusting sleeve is fixed to the casing by a tightening nut, the cylinder is fixed to the lower end of the adjusting sleeve, and the tightening nut is loosened to rotate the adjusting sleeve relative to the casing. Pipetting device, by which the position of the piston relative to the cylinder can be adjusted, thereby making it possible to zero the display device. 2. The pipetting device according to claim 1, characterized in that a spring is provided between the adjusting sleeve and the tightening nut to press the upper end of the adjusting sleeve upward. 3. A locking device for inhibiting the rotational movement of the operating rod is connected to a locking piece that is slidably and non-rotatably fitted to the operating rod, a locking arm that is engageable to inhibit rotation of the locking piece, and the locking arm. 2. The pipetting device according to claim 1, further comprising an operating knob projecting from the upper end of the casing.