CN114849805A

CN114849805A - Novel manual mechanical pipettor

Info

Publication number: CN114849805A
Application number: CN202110163132.6A
Authority: CN
Inventors: 高磊; 周雪峰; 郑雪凝; 张桂娣
Original assignee: Suzhou Sainitegeer Laboratory Technology Co ltd
Current assignee: Suzhou Sainitegeer Laboratory Technology Co ltd
Priority date: 2021-02-05
Filing date: 2021-02-05
Publication date: 2022-08-05

Abstract

The invention discloses a novel manual mechanical pipettor, which comprises a pipettor body and a capacity adjusting assembly, wherein the capacity adjusting assembly is used for adjusting the stroke of a piston; the position monitoring module is used for acquiring a stroke signal of the piston; the conversion module is used for converting the piston stroke signal acquired by the position monitoring module into an electronic signal; the microprocessor module is used for carrying out data processing on the electronic signal to obtain a set capacity value; the information feedback module is used for feeding back the set capacity value to the user; and the power module is used for providing electric energy for the liquid transfer device body. The liquid transfer device provided by the invention provides friendly capacity reading display, control on set capacity precision, friendly calibration operation and a function of mistaken touch reminding.

Description

Novel manual mechanical pipettor

Technical Field

The invention relates to the technical field of laboratory equipment, in particular to a novel manual mechanical pipettor.

Background

The pipettor is mainly used for operations such as liquid removal and distribution, is one of the most commonly used instruments in a laboratory, and is also one of the instruments most likely to influence an experimental result. The liquid transfer device commonly used at present is mainly a manual mechanical liquid transfer device, and is widely used due to low price and simple use. The mechanical pipettor has the realization principle that: the piston stroke is changed by rotating the capacity adjusting knob so as to adjust the pipetting capacity, the piston stroke is related to the reading of the mechanical counting wheel through the mechanism, and the reading of the counting wheel is changed along with the change of the piston stroke due to the corresponding relation between the piston stroke and the reading of the capacity of the counting wheel. Because the traditional mechanical pipettor is realized by the mechanical parts, the following defects are inevitably existed:

1. reading problems. The reading of the capacity of the liquid level sensor is provided by a mechanical counter and limited to the volume of the mechanical pipettor, the windows of most of the mechanical counters are small, and the provided numbers are low in 0-9 identification degree, so that the set capacity is not easy to read by a user;

2. pipetting accuracy and calibration problems. According to the design principle of a mechanical pipettor, the pipetting precision of the mechanical pipettor has higher requirements on the precision, the material, the assembly, the manufacture and the like of parts; although mechanical pipettors also provide a calibration function, the calibration operation is complicated, and the general operation process is as follows: the counting wheel is separated from the stroke by using a tool, so that the calibration can be completed only by adjusting the reading of the mechanical counter to be consistent with the actual pipetting volume after the linkage of the piston rod and the adjusting wheel is cancelled, and only one calibration point can be provided, so that the requirement of high precision in the full-scale range cannot be met.

Therefore, the present inventors have earnestly demanded to conceive a new technology to improve the problems thereof.

Disclosure of Invention

In order to solve the technical problems, the invention provides a novel manual mechanical pipettor which combines a mechanical structure with an electronic technology, obtains a capacity value through data calculation and calibration processing of a microprocessor, and finally displays the capacity value through a screen, so that the pipettor has higher capacity adjustment precision, is easy to operate, and is convenient for reading numerical values and the like.

In order to achieve the purpose, the invention adopts the following technical scheme:

a novel manual mechanical liquid transfer device comprises a liquid transfer device body and

the capacity adjusting assembly is used for adjusting the stroke of the piston;

the position monitoring module is used for acquiring a stroke signal of the piston;

the conversion module is used for converting the piston stroke signal acquired by the position monitoring module into an electronic signal;

the microprocessor module is used for carrying out data processing on the electronic signal to obtain a set capacity value;

the information feedback module is used for feeding back the set capacity value to the user;

and the power module is used for providing electric energy for the liquid transfer device body.

Preferably, the position monitoring module is a rotary encoder, and a code disc of the rotary encoder and a capacity adjusting knob in the capacity adjusting assembly synchronously rotate; the rotary encoder is an incremental encoder or an absolute encoder.

Preferably, the microprocessor module includes:

the calibration unit calibrates at least two capacity calibration points and performs linear fitting on calibration data;

and the dormancy unit is used for awakening the microprocessor module when the rotary encoder regulates the capacity and updating the capacity value to be displayed on a screen, and when the rotary encoder does not regulate the capacity, the microprocessor module executes a dormancy instruction to reduce the power consumption.

Preferably, the encoder is an incremental encoder, and at least one physical reference point is arranged in the pipette body to convert the absolute position of the piston.

Preferably, the physical reference point is a physical structure touch point, and the pipette body acquires the physical touch point through prompting of the microprocessor module or key input to initialize parameter setting of the pipette.

Preferably, the physical reference point is a physical trigger device arranged in the pipette body, and the physical trigger device is located at a set position where the adjusting stroke of the piston can be triggered; the pipettor can trigger the physical trigger device in the process of adjusting the piston capacity, and obtains the absolute position of the piston according to the signal of the physical trigger device so as to carry out initialization operation automatically.

Preferably, the physical trigger device is one or more of a touch switch, an optoelectronic switch, a reed switch or a magnetic switch.

Preferably, the physical trigger device has a correction unit built therein for automatically correcting an error in the position of the piston at the time of triggering.

Preferably, the information feedback module is one or more of auditory feedback, light feedback and visual feedback.

Preferably, a misoperation threshold value is set in the pipette, and when the rotation amount of the volume adjusting knob or the displacement amount of the piston is smaller than the misoperation threshold value within a set time, the information feedback module triggers a misoperation prompt signal.

Preferably, the power module is a detachable disposable battery or a rechargeable battery.

The invention has the beneficial effects that:

the manual mechanical pipettor of the invention provides friendly capacity reading display and control on set capacity precision, can carry out calibration operation through the microprocessor, and has better anti-interference characteristic, higher capacity regulation precision and better reliability because the capacity regulation part monitors the stroke and the capacity setting of the piston by a manual driving rotary encoder, and particularly, an absolute encoder is used, so that the mechanical position corresponds to the uniqueness of each piston regulation position, no memory is needed, and no reference point is needed to be found. The incremental encoder has the characteristics of small volume, high precision and high cost performance.

The novel manual mechanical pipettor provided by the invention provides friendly capacity reading display and control on set capacity precision, can be calibrated by the microprocessor module, and is manually driven to rotate the rotary encoder and monitor the stroke of the piston so as to realize capacity setting. The novel manual liquid transfer device adopts multi-point calibration, so that the precision requirement of a system on mechanical parts can be reduced, and higher liquid transfer precision can be achieved.

Drawings

In order that the present invention may be more readily and clearly understood, reference is now made to the following detailed description taken in conjunction with the accompanying drawings, in which:

fig. 1 is a functional block diagram of a novel manual mechanical pipettor of the present invention;

fig. 2 is a schematic cross-sectional structure of the mechanical pipette of the present invention;

fig. 3 is a schematic front view of a mechanical pipettor removal pipetting head of the present invention;

FIG. 4 is a schematic view of the capacity adjustment assembly of the present invention in cooperation with a piston press cap and a capacity adjustment knob;

FIG. 5 is a partial enlarged view of portion A of FIG. 4;

fig. 6 is a schematic view of the configuration of the pipette evacuation assembly of the present invention in cooperation with a piston press rod;

FIG. 7 is a cross-sectional structural schematic view of the capacity modulating assembly of the present invention in axial projection;

fig. 8 is a diagram of the encoder output signal of the present invention.

The reference numbers in the figures denote:

100-a pipette body; 101-stroke space; 1-a shell; 2-a piston pressing cap; 3-a piston pressing rod; 31-a limiting groove; 32-piston pressing retainer ring; 33-evacuating the support; 34-a travel guide arm; 35-a limiting plate; 36-a guide groove; 37-an elastic pad; 4-a piston; 5-a piston cavity; 6-pipetting head; 71-a first return spring; 72-a second return spring; 73-a third return spring; 8-capacity adjusting knob; 9-a capacity modulation assembly; 91-adjusting the linkage rod; 92-a conditioning cylinder; 920-external threads; 93-a support cylinder; 930-internal threads; 11-a rotary encoder; 12-a battery; 13-a display screen; 15-pushing the head; 16-a push head connecting rod; 17-pushing the cap with a pushing head; 18-multifunctional keys; 19-trigger switch.

Detailed Description

Referring to fig. 1, a novel manual mechanical pipette includes a pipette body, and a volume adjusting assembly, a position monitoring module, a microprocessor module, a conversion module, an information feedback module, and a power module, which are disposed in the pipette body; the capacity adjusting assembly is used for adjusting the stroke of the piston; the position monitoring module is used for acquiring a stroke signal of the piston; the conversion module is used for converting the piston stroke signal acquired by the position monitoring module into an electronic signal; the microprocessor module is used for carrying out data processing on the electronic signal to obtain a set capacity value; the information feedback module is used for feeding back the set capacity value to a user, and comprises visual feedback, auditory feedback, light feedback of an indicator light and other forms, such as a display screen, a buzzer, an indicator light and the like; the power module is used for providing electric energy for the pipettor body, and the preferred battery of power module of this embodiment can be detachable disposable battery or rechargeable battery (including the setting of function of charging and the interface that charges etc.).

The position monitoring module is a rotary encoder, a coded disc of the rotary encoder and a capacity adjusting knob in the capacity adjusting assembly rotate synchronously, and the rotary encoder is an incremental encoder or an absolute encoder. The incremental encoder has the characteristics of small volume, high precision and high cost performance; the absolute encoder corresponds to the piston position one by one due to the uniqueness of the output signal of each position point, and an additional physical reference point device is not needed, so that the absolute encoder does not need any reset operation under the condition that the system needs to be restarted when a battery is powered off and the like.

The microprocessor module includes: the calibration unit calibrates at least two capacity calibration points and performs linear fitting on calibration data; and the dormancy unit is used for awakening the microprocessor module when the rotary encoder regulates the capacity and updating the capacity value to be displayed on a screen, and when the rotary encoder does not regulate the capacity, the microprocessor module executes a dormancy instruction to reduce the power consumption.

In order to realize low power consumption, the microprocessor module only calculates the position of the piston and updates the display screen in real time when the capacity is adjusted.

The signal of the encoder is connected with the microprocessor module, once the encoder rotates, the encoder generates a signal, the microprocessor is in an IO pin interrupt mode, and when the signal on the pin changes, the microprocessor wakes up, identifies the encoder signal and then converts and displays the encoder signal.

At least one physical reference point is arranged in the pipette body to convert the absolute position of the piston. The physical reference point is a physical structure touch point, and the pipette body acquires the physical touch point in a prompt or key input mode through the microprocessor module so as to initialize parameter setting of the pipette.

The physical reference point can also be a physical trigger device arranged in the pipettor body, and the physical trigger device is positioned at a set position where the adjusting stroke of the piston can be triggered; the pipettor can trigger the physical trigger device in the process of adjusting the piston capacity, and obtains the absolute position of the piston according to the signal of the physical trigger device so as to carry out initialization operation automatically. The physical trigger device is one or more of a touch switch, a photoelectric switch, a reed switch or a magnetic switch.

In order to further improve the pipetting accuracy, the physical trigger device is provided with a correction unit which automatically corrects the position error of the piston during triggering. The correction unit can be used for correcting the physical structure and can also be used for correcting the embedded programming software. After the pipettor is operated for a long time, the system must be extremely stable to the extent that each encoder signal can correctly detect if once there is an encoder signal detection error or interference, the piston position will be calculated to have a deviation, and this physical trigger device just plays a role in calibration because theoretically every time the capacity is adjusted, the count value of the encoder should be theoretically consistent through the physical trigger device, and if there is a deviation, then automatic correction can be carried out, and the error is corrected.

In this embodiment, the information feedback module is one or more of auditory feedback, light feedback, and visual feedback.

In order to prevent misoperation in the process of pipetting operation, a misoperation threshold value is arranged in the pipettor, and when the rotation amount of the volume adjusting knob or the displacement amount of the piston is smaller than the misoperation threshold value within a set time, the information feedback module triggers a misoperation prompt signal.

The manual mechanical pipettor provided by the invention combines the current advanced electronic and sensor technologies, provides friendly capacity reading display, control on set capacity precision, and friendly calibration operation and false touch reminding functions; the manual pipettor consists of a position sensor, a microprocessor, a battery, a display screen and the like; the piston stroke signal provided by the position sensor is sampled and converted into a digital signal, and an extremely high set capacity value can be obtained through the calculation of the microprocessor and the fitting algorithm of calibration data and is displayed through a display screen.

The design and working principle of the manual pipette of the invention are explained as follows:

according to the structural design, capacity adjustment is carried out by rotating a capacity adjustment knob, the capacity adjustment knob drives a piston to displace and a coded disc of an encoder to rotate while rotating, the encoder also rotates for one circle when the capacity adjustment knob rotates for one circle, and the piston moves for a displacement of one pitch; the set volume can thus be determined by establishing a relationship between the encoder count and the piston stroke. Of course, in other embodiments, the volume adjustment knob may be rotated one revolution, corresponding to two or more pitch displacements of the piston.

Referring to fig. 8, according to the principle of the encoder, A, B two phases have a phase difference, and the forward rotation and the reverse rotation of the encoder can be distinguished by comparing the phase a with the phase B, so as to obtain the adjustment direction of the capacity; the jumping signal output by the encoder triggers the pin of the microprocessor to interrupt and awakens the microprocessor; the microprocessor can obtain the number of turns by obtaining the state of the jumping edge signal, such as a hollow encoder (model: EC21A1540401) of the Japan ALPS company, and the microprocessor can obtain 30 pulse count values every turn;

only the relative position can be obtained by the pulse count value of the encoder, so a physical reference datum position is needed to position the absolute position of the piston; for example: assuming that when the encoder knob is adjusted to the physical reference position, corresponding to the maximum piston position, the encoder count value of the microprocessor is reset to zero, i.e. when the count value is zero, corresponding to the maximum piston stroke, it is obvious that for each rotation of the encoder knob, the corresponding piston stroke is reduced by one pitch, and thus the encoder count value and the piston stroke establish a corresponding relationship.

Detailed design description:

according to the structural design of the piston pipettor, the linear relation exists between the counting value of the encoder and the set capacity, and the microprocessor can obtain the set capacity by obtaining the counting value of the encoder. The parameters of the structure of the liquid transfer device and the detailed theoretical calculation process are defined as follows: the piston cross-sectional area is S, unit: mm is ² (ii) a The current stroke of the piston is L, unit: mm; capacity is set to V, V ═ S × L, unit: mm is ³ The maximum capacity is Vmax, the minimum capacity is Vmin, and the corresponding maximum stroke is Lmax under the maximum capacity and the minimum capacity; the corresponding minimum stroke is Lmin; the pitch of the piston screw is P, unit: mm; the encoder rotates for one circle, and the counting value is changed into N; the real-time counting value of the encoder is CNT; for the purpose of theoretical explanation and calculation, it is assumed that:

1. when the capacity adjusting wheel rotates for one circle, the piston moves for one pitch, and the encoder also rotates for one circle;

2. as the capacity decreases, CNTs increase, and as the capacity increases, CNTs decrease;

3. when the piston is at the Lmax position in the system initial state, CNT is initialized to C1 (normally, C1 is set to 0);

the relationship between the change in the count value of the encoder and the change in the stroke can be found as follows:

Δ L is the number of revolutions of the capacity adjustment wheel and pitch is the number of revolutions of the encoder and pitch is the amount of change in the count value of the encoder;

the relationship between the current piston stroke and the current encoder count value can be obtained as follows:

Lmax-L ═ (CNT-C1)/N × P, that is: l ═ Lmax- (CNT-C1)/N × P;

in summary, only the initial conditions need to be set: the volume is adjusted to the maximum by the volume adjusting wheel, and the CNT is set to C1, wherein Lmax, N, C1 and P are known quantities, so that the piston position L can be obtained only by obtaining the encoder count value CNT, and further the volume set by the current pipettor is obtained.

However, in practice, due to many errors in the precision, assembly, etc. of the mechanical parts, the capacitance theoretically calculated only by software deviates from the true capacitance value, and further calibration is required. Because we have adopted sensor and microelectronic technique for the calibration becomes very convenient, and accessible software carries out the multiple spot calibration moreover, very big improvement the precision of pipettor, this is incomparable with traditional manual mechanical pipettor, and the calibration actual operation is as follows:

1. a calibration mode is entered. Through specific modes such as long-press multi-functional button or PC communication command, get into calibration mode, can show alone on the pipettor screen: calibrate mode and prompt further action, such as reset.

2. And (5) resetting and initializing. After the system is initialized, the encoder count value variable of the microprocessor does not have a corresponding relation with the actual piston position, for example: after initialization, CNT is 0, but at this time, the piston is not at the position of the maximum capacity, so that reset initialization operation is required; the piston position is adjusted to the maximum capacity point (often the maximum limit position for capacity adjustment), at which time the operating button can be pressed and the system initializes the CNT value to C1; then, displaying and displaying the capacity value obtained according to theoretical calculation on a screen;

3. and collecting and storing calibration point data. At the moment, according to the calibration operation under the ISO _8655-6_2002EN standard, the volume adjusting wheel is operated to reach a standard point (the numerical value displayed at the moment is a theoretical calculation value), the microprocessor obtains the current encoder count value at the moment, the moved liquid is weighed and metered to obtain the actual liquid moving volume, the volume data is input to the microprocessor in a multifunctional key or PC software mode and the like, the calibration operation of one point is completed, and a plurality of volume calibration data can be obtained according to the method in sequence according to the requirement; obviously, the more data points, the higher the precision after software fitting; in general, 3-point calibration is adopted, and after the acquisition is completed, calibration data is stored in Flash and exits from a calibration mode through a multifunctional key.

4. Fitting calculation and capacity display. And the microprocessor carries out fitting calibration algorithm processing through the current encoder counting value and the calibration data, and then the accurate set capacity can be obtained. Now by way of an example to illustrate that the current capacity is obtained using calibration data, which is shown below, a 3-point calibration has been completed:

encoder count value	Actual pipetting volume
		CNTA (minimum)	VA (maximum)
CNTB (middle)	VB (middle)
		CNTC (maximum)	VC (minimum)

Rotating the capacity adjustment wheel at this time for capacity adjustment, assuming that the encoder count value at this time is CNTx (CNTA < CNTx < CNTB), the actual capacity Vx is (CNTx-CNTA)/(VA-Vx) ═ CNTB)/(VA-VB); of course, more linear and multiple equations may be used for the fitting, and the above is just one of the algorithms.

When the battery is replaced or the system is powered off due to no electricity of the battery, and the like, the pulse counting value of the encoder can only provide the relative position, so that whether the pulse counting value is correctly corresponding to the piston position or not can not be ensured after the microprocessor system is restarted, particularly, the piston position is adjusted in the power-off process, and therefore, after the system is restarted, the relationship between the pulse counting value of the encoder and the absolute position of the piston needs to be reestablished, and the absolute position reference point can be obtained by providing a physical reference point to establish the relationship, and then the piston position is obtained; and for the absolute encoder, the reset operation is not needed, and because the encoder value obtained by the system and the piston position always have a corresponding relation even after the power is cut off, the current set capacity is obtained by directly reading calibration data and adopting a fitting calibration algorithm. For an incremental encoder, this aspect of the invention provides two solutions:

scheme 1: the structure touch point is used as a physical reference point, if the capacity of the liquid-moving device is adjusted to the maximum, the limit touch of the piston and the mechanical structure is generally the limit position of the capacity adjusting wheel, so that the limit position is easy to obtain, the counting value of the encoder can be initialized through the multifunctional key on the liquid-moving device body, the initialized value corresponds to the maximum stroke position of the piston, and therefore the correspondence with the position of the piston is completed. The advantage of this scheme is that can accomplish initialization operation through the pipettor body, need not provide extra positioner, the shortcoming is that must carry out initialization through input device, for example multi-functional button notification system carries out initialization.

Scheme 2: at a fixed position of the piston at which the stroke is adjusted, a physical trigger device is provided, such as a touch switch or a photoelectric switch or a reed switch or a magnetic switch, and a trigger, such as a stop or a magnetic steel, is placed on the piston transmission member. Because the position of the trigger device is fixed, and the relative distance between the piston position and the trigger is also fixed, when the microprocessor obtains a trigger signal of the trigger device, the absolute position of the piston can be obtained, at the moment, the counting value of the encoder is initialized, and the counting value also generates a corresponding relation with the piston position, so after the software of the microprocessor is reset, the position of the piston is moved by only rotating the encoder, and when the physical trigger device is triggered, the corresponding with the piston position is automatically completed. The scheme has the advantages that the initialization of the count value of the automatic encoder can be completed only by rotating the knob of the encoder to move the piston and carrying out one-time physical device triggering in the initialization process, and meanwhile, the physical triggering device can also be used for feeding back and correcting the count value of the encoder; theoretically, after initialization is completed, capacity adjustment is performed every time, as long as the piston triggers the physical device, the counting value of an encoder of the physical device is consistent with the initialization value, and if the counting value of the encoder is inconsistent with the initialization value, numerical correction can be performed, so that the stability and the anti-interference capacity are improved; the disadvantage of this solution is that additional physical trigger devices are required, increasing the cost and the difficulty of manufacturing the structure.

The current microprocessor module adopts a low-power consumption singlechip, such as: MSP430 series single-chip microcomputer of TI company; under the condition that the capacity is not adjusted, the singlechip is in a dormant state, and because the display module adopts an LCD liquid crystal segment code screen, even if the screen is always in a display state, the power consumption of the whole singlechip is still kept in an extremely low state, and the singlechip can be used for a long time;

the manual pipettor of the present invention can also provide a false touch detection function, and the implementation process thereof is as follows: the microprocessor can monitor the change of the set capacity in real time; the system provides voice or indicator light prompt when each capacity adjustment amount is carried out, and no matter whether the capacity adjustment is carried out by mistake or normal, the user can obtain feedback through the voice or the indicator light as long as the adjustment occurs.

In order to further reduce power consumption, misoperation actions can be identified through software, and the scheme is as follows: only a small capacity change exists within a set time t (for example, within 1 s), and at the moment, the system can think that the user is likely to touch by mistake, and prompts the user through an indicator light and a buzzer; if the capacity change is large within the set tongue time t, the capacity adjustment in a normal state can be considered, at the moment, sound and indicator lamp feedback do not need to be provided, the electric energy is saved, and the time t and the corresponding small capacity threshold value can be set by a user for providing better operation experience.

The battery in the power module uses replaceable batteries, such as No. 7 alkaline dry batteries and No. 5 alkaline dry batteries, and can be standby for a long time; rechargeable batteries may also be used and provide a charging function, especially where frequent use is convenient.

Based on the above technical principle of the pipette of the present invention, the following will be further described in conjunction with the structure of a specific pipette:

referring to fig. 2 to 7, the manual mechanical pipette of the present embodiment includes a pipette body 100 and a pipette head 6 disposed at a lower end of the pipette body 100, a volume adjusting assembly 9 for adjusting a piston stroke is disposed in the pipette body 100, and the volume adjusting assembly 9 is driven by a volume adjusting knob 8 at an upper end of the pipette body 1; a rotary encoder 11 is arranged in the pipette body 100 near the upper end, a code disc of the rotary encoder 11 and the volume adjusting knob 8 rotate synchronously, a microprocessor is further arranged in the pipette body 100, an electric signal conversion module is arranged on the microprocessor, the piston stroke signal detected by the rotary encoder 11 is converted into an electronic signal and then transmitted to the microprocessor, and the microprocessor calculates a set volume value according to the stroke signal of the piston 4 and displays the set volume value on a display screen 13 of the pipette body 100.

The mechanical liquid transfer device adopts a combination mode of manual adjustment and electronic signal acquisition and display, overcomes the problems of low adjustment precision, inconvenient operation and inaccurate reading of the traditional manual liquid transfer device, has obvious price and cost advantages compared with a pure electronic liquid transfer device, has better market space and is suitable for great popularization and application of laboratory workers.

The mechanical pipettor body 100 comprises a pipettor shell 1, wherein a piston pressing cap 2 is arranged at the upper end of the pipettor shell 1, the lower end of the piston pressing cap 2 is connected with the upper end of a piston pressing rod 3, the lower end of the piston pressing rod 3 is connected with the upper end of a piston 4, the piston 4 is arranged in a piston cavity 5, the lower end of the piston cavity 5 is connected with a liquid-transferring head 6 for extracting liquid, the piston pressing rod 3 is arranged in the shell 1, a first return spring 71 for returning the piston 4 upwards is arranged on the piston 4, a capacity adjusting knob 8 is sleeved outside the piston pressing cap 2, a rotary encoder is arranged at the lower end of the capacity adjusting knob, the capacity adjusting assembly 9 and the capacity adjusting knob 8 synchronously rotate forwards or backwards, and the capacity adjusting assembly 9 adjusts the capacity according to the rotation condition of the capacity adjusting knob 8, and then the piston pressing rod 3 and the piston 4 are driven to move upwards or downwards, so that the piston cavity 5 is adjusted to the set pipetting capacity stroke.

Referring to fig. 2 and 4-5, the volume adjusting assembly 9 of this embodiment includes an adjusting linkage rod 91 that rotates synchronously with the volume adjusting knob 8, the adjusting linkage rod 91 is a hollow rod, the piston pressing rod 3 is disposed inside the adjusting linkage rod 91 and coaxially disposed, an adjusting cylinder 92 is sleeved outside the adjusting linkage rod 91, the adjusting cylinder 92 rotates synchronously with the adjusting linkage rod 91, a supporting cylinder 93 is sleeved outside the adjusting cylinder 92, the supporting cylinder 93 is fixed inside the housing 1, an internal thread 930 is disposed in an inner cavity of the supporting cylinder 93, and an external thread 920 engaged with the internal thread 930 is disposed outside the adjusting cylinder 92. The adjustment cylinder 92 is axially moved by being rotated in the circumferential direction. A limiting groove 31 is formed in the piston pressing rod 3 at the position where the lower end of the adjusting cylinder 92 is matched with the piston pressing rod 3, a piston pressing retainer ring 32 is installed in the limiting groove 31, the piston pressing retainer ring 32 is abutted with the bottom of the adjusting cylinder 92, and when the capacity adjusting knob 8 drives the adjusting cylinder 92 to move downwards, the adjusting cylinder 92 is abutted downwards and presses the piston pressing retainer ring 32, the piston pressing rod 3 is driven to move downwards, and then the piston 4 is driven to move downwards, so that the purpose of adjusting the liquid displacement in the piston cavity 5 is achieved; conversely, when the capacity adjustment knob 8 drives the adjustment cylinder 92 to move upward, the piston 4 moves upward under the action of the first return spring 71.

Still set up trigger switch 19 in the pipettor body 100 of this embodiment, trigger switch 19 sets up adjust a 92 upper end and fix the inboard at casing 1, after equipment replacement battery, as long as adjust a 92 topmost, adjust a 92 meeting trigger switch for the encoder in the pipettor can be to count value initialization, thereby realizes that count value and piston position correspond, also can carry out the count value and correct.

The mechanical pipette body 100 of the present embodiment is provided with a stroke space 101 adapted to the axial movement of the adjustment cylinder 92, and the axial length of the stroke space 101 is greater than the volume adjustment stroke of the piston 4; a pipette emptying assembly is disposed at the bottom of the stroke space 101, and a pipetting capacity adjusting stroke is formed between the upper side of the pipette emptying assembly and the adjusting cylinder 92. After the pipetting capacity is set, the piston pressing cap 2 is pressed downwards, the piston pressing rod 3, the piston pressing retainer ring 32 and the piston 4 are driven to move downwards, when the piston pressing retainer ring 32 just abuts against the pipette emptying assembly, the set capacity is just reached, then the pipetting head is immersed into liquid to be pipetted, the piston pressing cap is loosened, the piston 4 and the piston pressing rod 3 reset upwards under the elastic action of the first reset spring 71, negative pressure is formed in the piston cavity 5 due to the upward resetting of the piston 4, and then the liquid is sucked into the pipetting head 6 simultaneously. When the liquid sucked in is discharged to the relevant container, due to the capillary effect at the tip of the pipette tip, if the piston pressing cap is still pressed until the piston pressing retainer ring 32 contacts with the pipette emptying assembly, it is difficult to completely discharge the liquid sucked in at this time. The purpose of setting the liquid transfer device emptying assembly is to increase an emptying stroke, so that the liquid transfer device emptying assembly can be further compressed when liquid is discharged, and the piston can be further pressed downwards for a certain stroke on the basis of setting the volume so as to completely discharge the liquid in the piston cavity.

Referring to fig. 2 and 6, the pipette emptying assembly of the present embodiment specifically includes an emptying holder 33, the evacuation support 33 is coaxially disposed with the piston pressing rod 3, the evacuation support 33 is installed at the bottom of the stroke space 101, and is embedded in the inner side of the casing 1, two stroke guide arms 34 vertically extending to one side of the adjusting cylinder 92 are arranged on the side edge of the emptying support 33, a second return spring 72 is arranged in a space enclosed between the two stroke guide arms 34, the compression stroke of the second return spring 72 is an evacuation stroke, the second return spring 72 is a coil spring, the lower end of the second return spring 72 is fixedly connected to the emptying support 33, a limiting plate 35 is connected to the upper end of the second return spring 72, and the adjusting cylinder 92 is moved downwards until the piston pressing retainer ring 32 contacts with the upper surface of the limiting plate 35; and the piston pressing retainer ring 32 is further pressed downwards after contacting with the limit plate 35, and enters an emptying stroke when the second return spring is pressed and contracted.

Referring to fig. 6, the position of the position-limiting plate 35 corresponding to the stroke guide arm of this embodiment is provided with a guide groove 36, and the stroke guide arm 34 is partially embedded in the guide groove, so that the position-limiting plate can move up and down under the guidance of the stroke guide arm.

Referring to fig. 6, because structural errors caused by process problems exist inevitably in the assembling process, and further errors are generated in the pipetting capacity adjustment, in order to further reduce the errors and improve the pipetting accuracy, an elastic pad 37 is arranged at the bottom of the emptying support 33, and an O-shaped sealing ring is preferably arranged on the elastic pad 37, so that when the piston is pressed to press the cap for pipetting, normal operation force can be applied to the limiting plate by pressing the retainer ring 32 through the piston, the structural errors can be compensated, and the purpose of further improving the pipetting accuracy is achieved.

The rotary encoder 11 of the present embodiment is electrically connected to the microprocessor, the microprocessor calculates the displacement of the piston and the set pipetting capacity based on the rotation amount of the capacity adjustment knob 8 detected by the rotary encoder 11, and displays the set pipetting capacity on the display 13 outside the housing 1; the microprocessor, the rotary encoder 11, is powered by a battery 12. The piston stroke of the mechanical pipettor with the display screen of the embodiment is calculated by detecting the rotation amount of the capacity adjusting knob through the rotary encoder to obtain the adjusting capacity, and finally the adjusting capacity is displayed through the display screen. The manual pipettor of this embodiment sets for the capacity precision higher, and it is convenient to read the registration, has greatly made things convenient for the operator to use.

Referring to fig. 2, in the present embodiment, a push head 15 for ejecting the liquid-moving head 6 is sleeved outside the piston cavity 5, the push head 15 is connected to a lower end of a push head connecting rod 16, the push head connecting rod 16 is disposed in the housing 1, an upper end of the push head connecting rod 16 is connected to a push head pressing cap 17, the push head pressing cap 17 is disposed on one side of an upper end of the housing 1, and a third return spring 73 for returning the push head pressing cap 17 upward after being pressed is disposed inside the housing 1.

Referring to fig. 3, in order to facilitate the user's operations of calibration, initialization, setting, etc., a multifunction key 18 is provided on the outside of the housing 1. The manual mechanical pipettor adopts the LCD segment code display screen, and the screen is always in a lighting state, so that a multifunctional key 18 is arranged instead of a screen wakeup key and is used for entering a calibration mode, adjusting and setting calibration data and the like. Of course, it may also be designed that when the pipette is not operated within the set time, the microprocessor automatically closes the screen, and if the parameter on the display screen needs to be quickly checked, the multi-function key 18 is directly pressed.

The piston pressing cap 2 of the present embodiment is provided at the upper end of the piston pressing rod 3; the capacity adjusting knob 8 is of a cylindrical structure, and the lower end of the piston pressing cap 2 is arranged in a cylindrical cavity of the capacity adjusting knob 8 and is suitable for pressing up and down along the inner cavity of the capacity adjusting knob 8.

The above embodiments are merely to explain the technical solutions of the present invention in detail, and the present invention is not limited to the above embodiments, and it should be understood by those skilled in the art that all modifications and substitutions based on the above principles and spirit of the present invention should be within the protection scope of the present invention.

Claims

1. A novel manual mechanical pipettor which characterized in that: comprising a pipette body, and

the capacity adjusting assembly is used for adjusting the stroke of the piston;

2. The novel manual mechanical pipette of claim 1, characterized in that: the position monitoring module is a rotary encoder, and a coded disc of the rotary encoder and a capacity adjusting knob in the capacity adjusting assembly synchronously rotate; the rotary encoder is an incremental encoder or an absolute encoder.

3. A novel manual mechanical pipette according to claim 1 or 2, characterized in that: the microprocessor module includes:

4. A novel manual mechanical pipette according to claim 1 or 2, characterized in that: the encoder is an incremental encoder, and at least one physical reference point is arranged in the pipette body to convert the absolute position of the piston.

5. The novel manual mechanical pipette of claim 4, characterized in that: the physical reference point is a physical structure touch point, and the pipette body acquires the physical touch point in a prompt or key input mode through the microprocessor module so as to initialize parameter setting of the pipette.

6. The novel manual mechanical pipette of claim 4, characterized in that: the physical reference point is a physical trigger device arranged in the pipettor body, and the physical trigger device is positioned at a set position where the adjusting stroke of the piston can be triggered; the pipettor can trigger the physical trigger device in the process of adjusting the piston capacity, and obtains the absolute position of the piston according to the signal of the physical trigger device so as to carry out initialization operation automatically.

7. The novel manual mechanical pipette of claim 6, wherein: the physical trigger device is one or more of a touch switch, a photoelectric switch, a reed switch or a magnetic switch.

8. The novel manual mechanical pipette of claim 6, wherein: and a correcting unit for automatically correcting the position error of the piston during triggering is arranged in the physical triggering device.

9. The novel manual mechanical pipette of claim 1, characterized in that: the information feedback module is one or more than two of auditory feedback, light feedback and visual feedback.

10. A novel manual mechanical pipette according to any of claims 1 to 9, characterized in that: and when the rotating amount of the volume adjusting knob or the displacement of the piston is smaller than the misoperation threshold value within set time, the information feedback module triggers a misoperation prompt signal.

11. The novel manual mechanical pipette of claim 1, characterized in that: the power module is a detachable disposable battery or a rechargeable battery.