WO2021033213A1

WO2021033213A1 - Mechanism for calibrating pipette intake volume, pipette, and method for calibrating same

Info

Publication number: WO2021033213A1
Application number: PCT/JP2019/032126
Authority: WO
Inventors: 俊一森本; 佐々木　潤
Original assignee: 株式会社ニチリョー
Priority date: 2019-08-16
Filing date: 2019-08-16
Publication date: 2021-02-25
Also published as: CN114222629B; JPWO2021033213A1; JP6788311B1; CN114222629A

Abstract

Provided are a mechanism for calibrating a pipette intake volume, a pipette, and a method for calibrating same, that make the calibration of the intake volume of a pipette easy, with a simple mechanism.　In a pipette for causing liquid to be taken into/discharged from the inside of a nozzle housing (4) with reciprocal movement of a shaft (2) and a plunger (3) in the axial direction through the inside of an enclosure (1), this mechanism for calibrating a pipette intake volume is furthermore provided with: a stroke screw (7) that is threaded to an inner circumference of the enclosure (1) or the like between the enclosure (1) and the shaft (2), and that is fitted so as to be able to move in the axial direction in a manner relative to the shaft (2); a volume display mechanism (8) that is driven in conjunction with rotation of the stroke screw (7) and is capable of a variable display of an intake volume numerical volume; a variable intake volume setting screw member (9) that is threaded onto the stroke screw (7) and determines a stop location in a direction of return of the shaft (2). If the displayed numerical value of the volume display mechanism (8) and an actual intake volume numerical value are different, then calibration is performed by adjusting the stroke screw (7) by manual rotation, with the variable intake volume setting screw member (9) being inhibited from rotating, thereby driving the volume display mechanism (8) and causing the displayed numerical value thereof to match the numerical value of the actual intake volume.

Description

Pipette suction capacity calibration mechanism ・ Pipette and its calibration method

The present invention relates to a mechanism for calibrating the suction capacity of a pipette, a pipette, and a method thereof.

With a variable pipette, the amount of liquid to be sucked into the pipette is variably set in advance. At this time, the stroke screw, which is relatively movable with respect to the vertically movable central shaft of the pipette and is screwed into the housing or the like, is manually rotated in the axial direction to adjust the movement. The movement adjustment at this time is performed until the numerical display of the capacitance display mechanism driven in conjunction with the rotation of the stroke screw changes from, for example, 100 μl to 200 μl, which is a desired set amount. At the same time, the plunger is moved and adjusted in the axial direction with respect to the cylinder based on the rotation of the stroke screw, and the actual suction capacity is variably set from 100 μl to 200 μl corresponding to the above-displayed suction capacity value. As a result, the actual suction capacity and the displayed suction capacity value are always consistently and variably set.

However, while using the pipette, the actual inhalation capacity and the displayed inhalation capacity may differ from each other, so it is sometimes necessary to match the two, and this work is called the pipette inhalation capacity calibration work. Refer to.

Patent No. 2554666 is the first conventional example of pipette calibration work. According to this calibration work, after loosening the set screw 13 that suppresses the rotation of the fine adjustment screw 12 that is screwed into the stroke screw (hollow shaft 9 in the patent publication), the fine adjustment screw 12 is moved left and right by a special driver. Rotate it to either direction to move it slightly in the axial direction relative to the stroke screw by a predetermined distance, and then tighten the rear set screw 13. As a result, the central shaft 25, which is in contact with the fine adjustment screw 12 and whose return position is determined, moves in the minute axial direction by the predetermined distance, and the actual suction capacity is finely adjusted. , The display value of the capacity display mechanism remains constant, and the actual suction capacity is finely adjusted to match the above display value, and the calibration work is completed. (Refer to the description in column 10, lines 23 to 31 of Japanese Patent No. 254666).

However, according to this, (1) in order to rotate the fine adjustment screw 12, it is necessary to loosen the set screw 13 and then tighten the set screw 13 after the adjustment, and also tighten the set screw 13. If you forget it, the capacitance accuracy will shift and you will not be able to maintain the accuracy error. (2) When you rotate the fine adjustment screw 12 and make a slight movement in the axial direction, the actual suction capacity you want to adjust is the number of rotations of the fine adjustment screw 12. There was a problem that it was not known whether it was, and a large number of adjustment work was required by trial and error.

As a second conventional example, there is Japanese Patent Application Laid-Open No. 2008-253980. According to this, the members corresponding to the fine adjustment screw 12 and the set screw 13 of the first conventional example are the clutch pipe 3 and the variable capacity setting and calibration pipe (hereinafter, simply referred to as the calibration pipe) 4. It is replaced with a member (the calibration pipe 4 is urged downward by the pipe holding spring 13 and meshes with the clutch pipe 3 like a clutch so that it can rotate integrally). Then, during the calibration work, the calibration pipe 4 and the stroke screw are manually moved against the spring 13 in the upper axial direction to disengage the clutch pipe 3 and hold the calibration pipe 4. By integrally rotating 5, the actual suction capacity remains unchanged, and the capacity display mechanism 51 linked with the calibration pipe 4 is driven to change only the numerical display until it matches the numerical value of the actual suction capacity. I was doing calibration work. (See paragraph 0058 of JP-A-2008-253980).

Patent No. 25546666 JP-A-2008-253980

However, according to the second conventional example, (3) during the calibration work, it is necessary to always hold the calibration pipe 4 by applying an upward force against the spring 13 so that the engagement does not occur. A certain amount of labor is required, and (4) the calibration pipe 4 and the clutch pipe 3 are engaged by the meshing clutch, so that the coupling position is not stepless in the rotation direction. Therefore, after the calibration work, the calibration pipe 4 and the clutch pipe 3 are connected. There is a problem that an angle change error corresponding to the division angle of the meshing clutch claw may occur when meshing again.

An object of the present invention is to provide a mechanism / pipette and a method thereof that can easily and simply provide a calibration work of the suction capacity of a pipette to solve the problems of the above two conventional examples.

According to the present invention, at the time of calibration work of the suction capacity, the work can be simplified by adjustingly rotating the stroke screw 7 while simply suppressing the movement of the adjusting screw member 9 in the rotational direction, and the numerical value can be steplessly set. It can be adjusted for accurate calibration work.

It is sectional drawing of the pipette apparatus to which the suction capacity calibration mechanism of the pipette which concerns on 1st Embodiment of this invention is applied. It is an exploded perspective view of the pipette device of FIG. It is an enlarged exploded perspective view of the part shown by III in FIG. It is an enlarged exploded perspective view of the part shown by IV in FIG. It is an enlarged exploded perspective view of the part shown by V in FIG. It is a vertical sectional view of the said pipette device. It is an enlarged vertical sectional view of the suction capacity variable setting and calibration setting mechanism part of the said pipette device. FIG. 7 is a cross-sectional view taken along the line VIII-VIII in FIG. It is a top view of the stroke screw. It is a side view of a stroke screw. It is a vertical cross-sectional view at the time of one-stage discharge of the said pipette device. It is a vertical cross-sectional view at the time of two-stage discharge of the said pipette device. It is a vertical cross-sectional view which shows the preparatory stage of the calibration work of the said pipette apparatus. It is a vertical cross-sectional view which shows in the calibration work of the said pipette device. FIG. 13 is a plan view seen in the direction of arrow XIV in FIG. It is a perspective view which shows the main part during the calibration work using an example of the jig of the pipette apparatus. It is a perspective view which shows the state before attachment of the main part during the calibration work using another example of the jig of the pipette apparatus. It is a perspective view which shows the state after mounting of FIG.

Hereinafter, the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional perspective view of a pipette device to which the inhalation volume calibration mechanism of the pipette according to the first embodiment of the present invention is applied, FIG. 2 is an exploded perspective view of the pipette device of FIG. 1, and FIGS. An enlarged exploded perspective view of portions III to V in FIG. 2, respectively, and FIG. 6 is a vertical sectional view of the pipette device.

Reference numeral 1 denotes a housing of the pipette device, which has a grip portion 1a, a window portion 1b, and an inner peripheral screw portion 1c. A transparent window 42 is attached to the window portion 1b so that the display numerical value of the capacity display mechanism 8 described later can be visually recognized.

Reference numeral 2 denotes a central shaft having a circular cross section, which has an upper contact step portion 2a and a lower contact step portion 2b, and penetrates a circular through hole 7b (see FIG. 4) of a stroke screw 7 described later and a plunger cap 3a. Is urged upward (to the left in FIG. 1) by the one-step spring 18 via the above, and the upper step portion 2a abuts on the lower end 9d of the adjusting screw 9 described later (see also FIG. 7) and moves upward. The return position has been decided.

Reference numeral 3 denotes a plunger, in which the plunger cap 3a is fixedly fitted, fitted in the upper cylinder portion 4a of the lower nozzle housing 4 so as to be vertically movable, and urged upward by the one-step spring 18, and the plunger cap 3a is the central shaft. 2 It is in contact with the lower end. An O-ring 32 and an O-ring retainer 33 are urged and stored between the plunger 3 and the lower nozzle housing 4 by a seal spring 34 to achieve a seal between the plunger 3 and the lower nozzle housing 4. ..

Reference numeral 4 denotes a lower nozzle housing, which has an upper cylinder portion 4a and a lower nozzle portion 4b, and is fixed to the lower end of the upper nozzle housing 5 by a stop nut 6. A nozzle cap 31 is fitted to the upper nozzle housing 5, and an outer peripheral screw 5a is screwed into an inner peripheral screw portion 1c of the housing 1 and attached to the housing 1.

Reference numeral 7 denotes a stroke screw, which has a shaft portion 7a having a substantially quadrangular cross section, a through hole 7b having a circular cross section (an inner peripheral screw portion 7c screwed by an adjusting screw 9 at the upper end (see FIGS. 4 and 7), and a circular cross section. It is inserted by the shaft 2) and has a lower end flange screw portion 7d. In the stroke screw 7, the flange screw portion 7d is screwed into the inner peripheral screw portion 14a1 of the capacity display mechanism housing 14a, and the shaft portion 7a having a quadrangular cross section is at the lowermost part of the capacity display mechanism 8 in order to drive the capacity display mechanism 8. The first rotating drum 15a is engaged with the oval-shaped hole 15a1 (see FIG. 4) in cross section so that it can rotate integrally. The reason for screwing the flange screw portion 7d and the inner peripheral screw portion 14a1 is that when the stroke screw 7 is integrally rotated with the setting sleeve 10 at the time of variable setting of the suction capacity described later, the shafts of the stroke screw 7 and the adjusting screw 9 are used. It enables directional movement, thereby allowing axial movement of the shaft 2 and enabling actual variable suction capacity. Since the target to which the outer peripheral screw portion 7d of the stroke screw 7 is screwed may be a fixed system, it may be screwed directly not only to the capacity display mechanism housing 14a but also to the screw provided on the inner circumference of the housing 1. Often, this fixed system is hereinafter referred to as "housing 1 etc.".

Reference numeral 8 denotes a known capacitance display mechanism, which is a pair of capacitance mechanism housings 14 (14a and 14b) and four display rotating drums 15 (15a to 15d: each of which is housed inside and fitted to a stroke screw 7: for example, an outer circumference, for example. The three pinions 17a to 17c are attached to the shaft 16 supported between the

housings

14a and 14b) and the three pinions 17a to 17c are the second to 17c, respectively. It meshes with the gear portions 15b1 to 15d1 of the fourth rotating drums 15b to 15d.

Therefore, as described later, when the setting sleeve 10 described later is manually rotated integrally with the stroke screw 7 both during the variable setting of the suction capacity and during the calibration work, the cross section of the shaft portion 7a having a square cross section and the rotating drum 15a. Based on the engagement of the oval-shaped holes 15a1, only the first rotating drum 15a is integrally rotated to variably display the numerical value of the smallest digit, which is sequentially rotated through the rotations of the pinions 17a to 17c to display the second to fourth digits. It is transmitted to the rotating drums 15b to 15d in a carry-up manner, and a total of four digits are variably displayed.

Reference numeral 9 denotes an adjusting screw, which has an upper end flange portion 9a (having a plurality of engaging recesses 9b), an outer peripheral screw portion 9c, and a lower end contact portion 9d. While the adjusting screw 9 is fitted to the upper end of the central shaft 2, the outer peripheral screw portion 9c is screwed into the upper end inner peripheral screw portion 7c of the stroke screw 7. (See Fig. 7)

Reference numeral 10 denotes a capacity setting sleeve, which is composed of a setting sleeve main body 10a (having a through hole 10c having a substantially oval cross section and an outer peripheral flange portion 10d) and a setting sleeve cover 10b integrally attached to the through hole 10c. In the capacity setting sleeve 107, the through hole 10c having an oval cross section is fitted to the shaft portion 7a having a quadrangular cross section with respect to the stroke screw 7, whereby the stroke screw 7 can be integrally rotated and relatively movable in the axial direction. It has become. (See Fig. 8)

It should be noted that when the suction capacity is variably set (both the actual suction capacity and the indicated suction capacity change accordingly) and during the calibration work (the actual suction capacity remains unchanged and only the displayed suction capacity changes). The difference is that when the setting sleeve 10 and the stroke screw 7 are integrally rotated at the time of variable setting, the adjusting screw 9 also rotates integrally, so that the adjusting screw 9 moves in the axial direction integrally with the stroke screw 7 and hits the lower end of the adjusting screw 9. The shaft 2 that comes into contact with the contact portion 9d also apparently moves integrally. That is, the change in the actual suction capacity value due to the axial movement of the shaft 2 and the suction capacity display value due to the rotation of the stroke screw 7 both change correspondingly. On the other hand, when the suction capacity is calibrated, the rotation of the adjusting screw 9 is suppressed from the outside, so that even if the setting sleeve 10 and the stroke screw 7 rotate integrally, the shaft 2 does not move in the axial direction. In other words, the actual inhalation capacity remains unchanged, and only the inhalation capacity display value changes until it matches the actual inhalation capacity.

Further, the capacity setting sleeve 10 is pressed upward via the torque plate 26 by the torque spring 25 housed in the capacity display mechanism housing 14b, and therefore, the lock ring 27 and the lock ring in which the collar portion 10d is fixed to the housing 1 It is in contact with the washer 28. As a result, the capacity setting sleeve 10 is applied with torque in the rotation direction and does not generate unnecessary free rotation.

Reference numeral 11 denotes an ejector button, which is connected to the ejector pipe 13 via an ejector connection sleeve 12 (fitted to the lower end of the housing so as to be movable in the axial direction). These

ejector members

11, 12 and 13 can integrally move downward against the ejector spring 41 at the time of ejecting the tip 43 (see FIG. 6) to eject the tip 43.

21 is a lower two-stage spring receiver, 22 is an upper two-stage spring receiver, and is fitted and stored in the shaft 2 between the nozzle cap 31 of the upper nozzle housing 5 and the capacity display mechanism housing 14a in the housing 1. The step spring 23 urges the upper two-step spring receiver 22 upward via its flange portion 22a to bring it into contact with the stop ring 24.

Reference numeral 29 denotes a push button, which is composed of a push button sleeve 29a and a push button cover 29b, and is fixed to the upper end of the shaft 2 by a set screw 30.

Reference numeral 51 denotes a jig for calibration work, which has a grip portion 51a, a bent portion 51b, and a pair of engaging claw portions 51c.

Next, the operation of the pipette device will be described.

First, from the state shown in FIG. 6, the tip 43 is immersed in the liquid with the push button 29 pushed downward (to the right in FIG. 6) against the one-step spring 18 together with the shaft 2 and the plunger 3. Subsequently, when the pushing force is released, the

members

29, 2 and 3 return to the upper motion and return to the state of FIG. 6, and at this time, a predetermined amount of liquid is sucked into the tip 43 and the lower nozzle housing 4.

In this state, the pipette device is moved to a dispensing point at a different position, the push button 29, the shaft 2 and the plunger 3 are pushed down again by the dimension a1 (see FIG. 10), and the lower step portion 2b of the shaft 2 is moved upward. The two-stage spring receiver 22 is brought into contact with the flange portion 22a. As a result, the first-stage discharge of the predetermined amount of liquid is completed. The completion of the first-stage discharge means that when the

members

29, 2 and 3 are subsequently moved downward, the urging force of the two-stage spring 23 via the flange portion 22a of the upper two-stage spring receiver 22 is increased. It can be identified because there is a click feeling that is added.

Then, when the

members

29, 2 and 3 are pushed down by the dimension a2 (see FIG. 11) against the one-step spring 18 and the two-step spring 23 from the position of FIG. 10, the upper two-step spring receiver 22 is on the lower side. It comes into contact with the two-stage spring receiver 23 and stops. As a result, the liquid adhering to and remaining on the inner surfaces of the lower nozzle housing 4 and the chip 43 is also discharged by the flow at the time of air discharge. Therefore, there is no error in the liquid volume between suction and discharge, and an accurate amount can be dispensed.

Next, the variable setting work of the liquid suction capacity will be described.

First, suppose that the set capacity of liquid suction / discharge is variably set from, for example, 90 μl to 100 μl. As described above, the housing 1 of the pipette device is gripped by the grip portion 1a, and the setting sleeve 10 is rotated in a predetermined direction (for example, counterclockwise when actually increasing the suction capacity, and counterclockwise when the suction capacity is actually increased). When the stroke screw 7 is rotated integrally with the setting sleeve 10, the rotating drum 15 of the capacity display mechanism 8 is driven in an interlocking manner and by an amount corresponding to the movement amount of the plunger 3, and the displayed value is also from 90 μl. It changes to 100 μl.

On the other hand, the stroke screw 7 moves up and down in the axial direction based on the screw screwing to the fixed system housing 1 and the like (in this case, the capacity display mechanism housing 14a) during the above rotation. At this time, since the adjusting screw 9 is integrally rotating with the stroke screw 7 based on the screw friction, it moves up and down together with the stroke screw 7. Along with this, the shaft 2 in contact with the lower end contact portion 9d of the adjusting screw 9 moves up and down, so that the plunger 3 also moves up and down, and the actual suction capacity corresponds to the change in the above displayed value. It changes from 90 μl to 100 μl.

Next, the calibration work of the liquid suction capacity will be described. Now, it is assumed that the actual inhalation capacity is 105 μl even though the display of the volume display mechanism 8 is 100 μl, and there is a discrepancy between the two.

First, as shown in FIG. 12, after removing the push button cover 29b of the push button 29, loosen the set screw 30 and remove the push button sleeve 29a. After that, as shown in FIGS. 13 to 15, the operator grips the grip portion 51a of the calibration work jig 51 by hand, inserts the bent portion 51b into the setting sleeve 10, and inserts the pair of engaging claw portions 51c. Is engaged with the engaging recess 9b of the adjusting screw 9 to suppress and fix the rotation of the adjusting screw 9.

Therefore, in this state, when the setting sleeve 10 is rotated in a predetermined direction (for example, counterclockwise when increasing the capacitance value, and counterclockwise when increasing the capacitance value), the stroke screw 7 rotates integrally with the setting sleeve 10 to form the housing. It moves relative to the 1st class and the adjusting screw 9 by screwing each. At this time, since the adjusting screw 9 is restrained from rotating by the jig 51 and does not move in the axial direction as described above, only the stroke screw 7 is eventually moved with respect to the fixed system housing 1 and the like. That is, on the one hand, since the adjusting screw 9 does not move up and down, the shaft 2 does not move up and down, so that the actual suction capacity remains unchanged, and on the other hand, the rotating drum 15 of the capacity display mechanism 8 is interlocked by the rotation of the stroke screw 7. Driven by. Then, the setting sleeve 10 is manually rotated until the display value of the capacitance display mechanism 8 reaches 105 μl. As a result, 100 μl of the displayed value is changed to 105 μl, which is the same as the actual suction capacity, and the calibration work is completed.

After the work is completed, the calibration work jig 51 is removed, and the push button 29 is reattached to the shaft 2. The work of attaching and detaching the set screw 30 in the present embodiment is only for the purpose of securing a working space for the jig 51, and it is possible to eliminate this work, according to the first conventional example. It does not constitute an essential part of the invention as in the work of attaching and detaching the set screw 13.

According to this, in the second conventional example, the calibration pipe 4 had to be kept separated from the clutch pipe 3 against the spring throughout the period of the calibration work. Since it is sufficient to suppress the movement of the adjusting screw 9 in the rotational direction by the tool 51, the burden on the operator is reduced.

Further, since the division angle is not limited due to the engagement of the calibration pipe 4 and the clutch pipe 3 in the second conventional example, the rotational direction accuracy once determined in the calibration work is maintained as it is, and the calibration work accuracy is improved. obtain.

In the first conventional example (Patent No. 254666), the screw pitch of the fine adjustment screw 12 (for example, 0) is larger than the screw pitch of the stroke screw (hollow shaft) 9 (for example, two types of 0.64 mm and 0.8 mm). Since .5 mm) was smaller, the conversion table was used to convert how many rotations of the stroke screw 9 (which directly corresponds to the capacitance value) corresponds to one rotation of the fine adjustment screw 12. However, in the present embodiment, since the screw pitches of the stroke screw 7 and the adjusting screw 9 are substantially the same, one rotation of the adjusting screw 9 directly corresponds to one rotation of the stroke screw 7, so that the capacitance is calibrated. It is convenient because it can be intuitively known from the display value of the capacity display mechanism 8.

In the above embodiment, in order to suppress the rotation of the adjusting screw 9 during the calibration work, it is necessary for the operator to continue to hold the calibration work jig 51 by hand during the calibration work period. FIG. 17 shows another jig 52 as an alternative. In the figure, the jig 52 has an L-shaped arm portion 52a (having a pair of engaging claw portions 52b, but only one in FIG. 16 is shown) protruding downward from the side of the jig main body and an engaging recess in the lower part of the main body. It has 52c. At the time of calibration, the pair of engaging claws 52b of the jig 52 are engaged with the engaging recess 9b of the adjusting screw 9, and the engaging recess 52c at the bottom of the main body is integrated with the grip portion 1a of the housing 1 (integrated with the housing 1). If it is, other parts may be used). As a result, the adjusting screw 9 is restrained and fixed so as to be relatively non-rotatable with respect to the housing 1, and it is not necessary for the operator to keep holding the jig during the calibration work period, which reduces the labor. To. In short, any kind of jig other than the jig 52 can be used as long as the adjusting screw 9 and the housing 1 can be detachably connected to each other to suppress the rotation of the adjusting screw 9.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications are made within the scope of claims and the technical ideas described in the specification and drawings. Is possible. It should be noted that any shape or material not directly described in the specification or drawings is within the scope of the technical idea of the present invention as long as the action and effect of the present invention are exhibited.

Some of the forms disclosed in this specification are described below.

According to the first aspect, in a pipette in which a shaft (2) and a plunger (3) reciprocate in the axial direction in a housing (1) to suck and discharge a liquid into a nozzle housing (4). A stroke screw that is screwed between the body (1) and the shaft (2) to the inner circumference of the housing (1) or the like and is fitted so as to be movable in the axial direction relative to the shaft (2). (7), a capacity display mechanism (8) driven in conjunction with the rotation of the stroke screw (7) and capable of variably displaying the suction capacity value, and the shaft screwed into the stroke screw (7). Further equipped with a suction capacity variable setting screw member (9) that determines the stop position in the return direction of (2).
When the displayed value of the capacity display mechanism (8) and the actual suction capacity value are different, the stroke screw (7) is manually adjusted and rotated while the suction capacity variable setting screw member (9) is suppressed to be non-rotatable. This is a pipette suction capacity calibration mechanism that drives the capacity display mechanism (8) to match the displayed value with the actual suction capacity value to perform calibration work.

The second form is the first form, preferably further comprising a setting member (10) integrally rotatably attached to the stroke screw (7), and the setting member (10) is manually rotated. The stroke screw (7) is adjusted and rotated.

The third form is the first form or the second form, and preferably, the capacity display mechanism (8) has a capacity display rotating drum (15) housed in the housing (14), and the suction capacity adjustment. The screw member (9) is urged in the upward return direction of the shaft (2) by a torque spring (25) interposed between the suction capacity adjusting screw member (9) and the housing (14). ..

In the fourth form, in any of the first to third forms, the suction capacity variable setting screw member (9) is provided with the first engaging portion (9b), which is separate when the suction capacity calibration is performed. By engaging the second engaging portion (51c, 52b) of the calibration work jig (51, 52) provided in the above with the first engaging portion (9b), the suction capacity variable setting screw The non-rotatable suppression of the member (9) can be realized.

In the fifth form, in the fourth form, more preferably, the calibration work jig (52) further has a third engaging portion (52c), and the second engaging of the jig (52). The portion (52b) engages with the first engaging portion (9b) of the suction capacity variable setting screw member (9), and the third engaging portion (52c) becomes a part of the housing (1). By engaging, it is possible to suppress the non-rotation of the suction capacity variable setting screw member (9).

In any of the first to fifth forms, the sixth form is more preferably a screw pitch screwed into the inner circumference of the housing (1) of the stroke screw (7) and the suction capacity variable setting. The screw pitch of the screw member (9) screwed into the stroke screw (7) is substantially the same.

The seventh form is a pipette having the mechanism described in any of the first to sixth forms.

According to the eighth embodiment, the shaft (2) and the plunger (3) reciprocate in the axial direction in the housing (1) to suck and discharge the liquid into the nozzle housing (4). Between the housing (1) and the shaft (2), it is screwed directly or indirectly to the inner circumference of the housing (1) and fitted to the shaft (2) so as to be integrally rotatable and separately movable in the axial direction. The combined stroke screw (7), the capacity display mechanism (8) that is driven in conjunction with the rotation of the stroke screw (7) and can variably display the suction capacity value, and the stroke screw (7). In the pipette further including a suction capacity variable setting screw member (9) which is screwed and determines a stop position in the return direction of the shaft (2).
When the displayed value of the capacity display mechanism (8) and the actual suction capacity value are different, the stroke screw (7) is manually adjusted while the suction capacity variable setting screw member (9) is suppressed to be non-rotatable. This is a method for calibrating the suction capacity of a pipette, in which the capacity display mechanism (8) is driven by rotation to match the displayed value with the value of the actual suction capacity and perform calibration work.

In the ninth form, in the eighth form, the stroke is further provided with a setting member (10) integrally rotatably fitted to the stroke screw (7), and the stroke is manually rotated by manually rotating the setting member (10). This is the method for adjusting and rotating the screw (7).

In the tenth form, in the eighth form or the ninth form, the capacity display mechanism (8) includes a capacity display rotating drum (15) housed in a housing (14), and the suction capacity adjusting screw member (9). ) Is the method described above, wherein the shaft (2) is urged in the returning direction by a torque spring (25) interposed between the suction capacity adjusting screw member (9) and the housing (14).

In the eleventh form, in any of the eighth to tenth forms, the suction capacity variable setting screw member (9) is provided with the first engaging portion (9b), which is separate when the suction capacity calibration is performed. By engaging the second engaging portion (51c, 52b) of the fixing jig (51, 52) provided in the above with the first engaging portion (9b), the suction capacity variable setting screw member ( 9) This is the method that can realize the non-rotatable suppression.

In the twelfth form, in the eleventh form, the fixing jig (52) further has a third engaging portion (52c), and the second engaging portion (52b) of the jig (52) is said. By engaging the first engaging portion (9b) of the suction capacity variable setting screw member (9) and the third engaging portion (52c) engaging with a part of the housing (1). This is the method that can realize the suppression of non-rotation of the suction capacity variable setting screw member (9).

In any of the eighth to twelfth forms, the thirteenth form includes a screw pitch screwed into the inner circumference of the housing (1) of the stroke screw (7) and the suction capacity variable setting screw member (9). ) Is substantially the same as the screw pitch screwed into the stroke screw (7).

1 Housing 1a Grip 1b Window 1c Inner peripheral thread 2

Shaft

2a, 2b Contact step 3 Plunger 3a Plunger cap 4 Lower nozzle housing 4a Cylinder 4b Nozzle 5 Upper nozzle housing 5a Outer thread 6 Stop nut 7 Stroke screw 7a Square cross-section shaft 7b Through hole 7c Inner peripheral thread 7d Fitting thread 8 Capacity display mechanism 9 Adjusting screw 9a Fitting

9b Engagement recess

9c Outer thread 9d Contact 10 Capacity setting sleeve 10a Setting sleeve body 10b Setting sleeve cover 10c Oval cross-section through hole 10d Outer peripheral flange 11 Ejector button 12 Ejector connection sleeve 13 Ejector pipe 14 (14a, 14b) Capacity display mechanism housing 14a1 Inner peripheral thread 15 (15a to 15d) Rotating drum 15a1 Axial key Groove 16 Shaft 17 (17a to 17c) Pinion 18 One-stage spring 21 Lower two-stage spring receiver 22 Upper two-stage spring receiver 22a Flange 23 Two-stage spring 24 Stop ring 25 Torque spring 26 Torque plate 27 Lock ring 28 Lock ring washer 29 Push button 29a Push button sleeve 29b Push button cover 30 Set screw 31 Nozzle cap 32 O ring 33 O ring retainer 34 Seal spring 41 Ejector spring 42 Transparent window 43 Chip 51 Calibration work jig 51a Grip 51b Bent 51c Engagement Claw 52 Jig 52a Arm 52b Engagement Claw 52c Engagement recess

Claims

In a pipette in which the shaft (2) and the plunger (3) reciprocate in the axial direction in the housing (1) to suck and discharge the liquid into the nozzle housing (4).
Between the housing (1) and the shaft (2), the housing (1) and the like are screwed together and fitted so as to be movable in the axial direction relative to the shaft (2). Stroke screw (7) and
A capacity display mechanism (8) that is driven in conjunction with the rotation of the stroke screw (7) and can variably display the suction capacity value, and
Further provided with a suction capacity variable setting screw member (9) screwed into the stroke screw (7) to determine a stop position in the return direction of the shaft (2).
When the displayed value of the capacity display mechanism (8) and the actual suction capacity value are different, the stroke screw (7) is manually adjusted and rotated while the suction capacity variable setting screw member (9) is suppressed to be non-rotatable. A suction capacity calibration mechanism for a pipette, which drives the capacity display mechanism (8) to match the displayed value with the actual suction capacity value to perform calibration work.
The mechanism according to claim 1 further includes a setting member (10) integrally rotatably attached to the stroke screw (7), and the stroke screw (7) is manually rotated by manually rotating the setting member (10). ) Is adjusted and rotated.
In the mechanism according to claim 1 or 2, the capacity display mechanism (8) has a capacity display rotating drum (15) housed in a housing (14), and the suction capacity adjusting screw member (9) has a suction capacity adjusting screw member (9). The mechanism, which is urged in the upward return direction of the shaft (2) by a torque spring (25) interposed between the suction capacity adjusting screw member (9) and the housing (14).
In the mechanism according to any one of claims 1 to 3, a first engaging portion (9b) is provided on the suction capacity variable setting screw member (9), and is provided separately when the suction capacity calibration is performed. By engaging the second engaging portion (51c, 52b) of the calibration work jig (51, 52) with the first engaging portion (9b), the suction capacity variable setting screw member ( 9) The mechanism that can realize the suppression of non-rotation.
In the mechanism according to claim 4, the calibration work jig (52) further has a third engaging portion (52c), and the second engaging portion (52b) of the jig (52) has. By engaging with the first engaging portion (9b) of the suction capacity variable setting screw member (9) and engaging the third engaging portion (52c) with a part of the housing (1). The mechanism capable of suppressing the non-rotation of the suction capacity variable setting screw member (9).
In the mechanism according to any one of claims 1 to 5, the screw pitch screwed into the inner circumference of the housing (1) of the stroke screw (7) and the suction capacity variable setting screw member (9). The mechanism, which is substantially the same as the screw pitch screwed into the stroke screw (7).
A pipette having the mechanism according to any one of claims 1 to 6.
A pipette in which the shaft (2) and the plunger (3) reciprocate in the axial direction in the housing (1) to suck and discharge the liquid into the nozzle housing (4).
Between the housing (1) and the shaft (2), it is screwed directly or indirectly to the inner circumference of the housing (1) and fitted to the shaft (2) so as to be integrally rotatable and separately movable in the axial direction. With the combined stroke screw (7),
A capacity display mechanism (8) that is driven in conjunction with the rotation of the stroke screw (7) and can variably display the suction capacity value, and
In the pipette further provided with a suction capacity variable setting screw member (9) which is screwed into the stroke screw (7) and determines a stop position in the return direction of the shaft (2).
If the displayed value of the capacity display mechanism (8) is different from the actual suction capacity value, the stroke screw (7) is manually adjusted while the suction capacity variable setting screw member (9) is suppressed from being rotatable. A method for calibrating the suction capacity of a pipette, which drives the capacity display mechanism (8) by rotating the pipette to match the displayed value with the value of the actual suction capacity to perform calibration work.
The stroke screw according to claim 8, further comprising a setting member (10) integrally rotatably fitted to the stroke screw (7), and manually rotating the setting member (10). (7) The method for performing the adjustment rotation.
In the method according to claim 8 or 9, the capacity display mechanism (8) has a capacity display rotating drum (15) housed in a housing (14), and the suction capacity adjusting screw member (9) has a suction capacity adjusting screw member (9). The method, wherein the shaft (2) is urged in the return direction by a torque spring (25) interposed between the suction capacity adjusting screw member (9) and the housing (14).
In the method according to any one of claims 8 to 10, the suction capacity variable setting screw member (9) is provided with a first engaging portion (9b), which is separately provided when the suction capacity calibration is performed. By engaging the second engaging portion (51c, 52b) of the fixing jig (51, 52) with the first engaging portion (9b), the suction capacity variable setting screw member (9) The method that can realize the non-rotatable suppression of the above.
In the method according to claim 11, the fixing jig (52) further has a third engaging portion (52c), and the second engaging portion (52b) of the jig (52) sucks. By engaging with the first engaging portion (9b) of the capacity variable setting screw member (9) and engaging the third engaging portion (52c) with a part of the housing (1), the said The method described above, which can realize the suppression of non-rotation of the suction capacity variable setting screw member (9).
In the method according to any one of claims 8 to 12, the screw pitch screwed into the inner circumference of the housing (1) of the stroke screw (7) and the suction capacity variable setting screw member (9). The method according to the method, which is substantially the same as the screw pitch screwed into the stroke screw (7).