Patent Grant
11084030
The invention relates to the field of sampling pipettes, also called laboratory pipettes or even liquid transfer pipettes, for sampling and dispensing liquid in containers or the like.
The pipettes concerned by the present invention are manual pipettes and motor pipettes. These pipettes are intended to be held in the hand by an operator, during liquid sampling and dispensing operations. For manual pipettes, these operations are made by moving a pipetting control knob, obtained by applying an actuation pressure on the same knob which is mechanically transferred to a control rod. On motor pipettes, the pressure of the operator onto the control knob generates a signal which is transmitted to the control unit of the pipette, such that the same triggers the movement of the control rod through an appropriate motor embedded in the pipette.
It is noted that the manual pipettes concerned by the present invention can have an electronic counter and/or display, the pipette thereby having a “hybrid” nature because it combines both a mechanical aspect and an electronic aspect.
Since many years, designing sampling pipettes has undergone many improvements, essentially aiming at simplifying the pipettes designing, or even enhancing their ergonomies.
Usually, to benefit from an acceptable precision, the volume range that can be sampled by a pipette is between about 10% of the nominal volume, and 100% of this nominal volume corresponding to the maximum volume that the pipette can sample.
Consequently, when an operator has to pipette different samples extending on a wide range, these operations require the use of several pipettes. By way of example, when a series of operations require pipetting volumes falling within a range from 3 to 1,250 μl, it can be required to have the following three pipettes:
Under this situation, the plurality of pipettes ensures precision and accuracy performance, but it results in taking too much room on the lab bench.
One purpose of the present invention is thus to overcome at least partially the drawback identified above.
For this, the object of the invention is a sampling pipette comprising:
According to the invention, the pipette also includes:
The invention is thus remarkable in that it enables the volume range that can be sampled to be extended, by implanting several pistons within the pipette as well as a module for coupling the control rod with each of these pistons. Consequently, during a pipetting operation, the number of operating pistons is a function of the volume to be sampled.
This solution has the advantage of reducing the required number of pipettes when the pipetting operations require to sample various volumes, without altering the accuracy and precision performance of the pipette. As a result, there is advantageously a room gain on the lab bench. In addition, by replacing several pipettes by a single pipette, this offers a traceability possibility of a protocol by recording all the pipetting operations made with this same pipette.
Further, the pipette according to the invention has a reduced bulk, by virtue of a concentric arrangement of its pistons.
On the other hand, the present invention has at least any of the following optional characteristics, taken alone or in combination.
It is provided:
that the coupling module comprises at least one piston attachment finger radially extending relative to the longitudinal axis of the pipette,
that at least N−1 pistons each have an attachment slot circumferentially oriented and open, the slots having different circumferentially lengths for each of said at least N−1 pistons,
and that said pipette is configured such that the attachment finger is capable of being circumferentially moved in and out of the slots radially facing each other.
In other words, coupling/uncoupling each piston with the control rod is made by a bayonet type connection, with the finger making up the lug of this connection. By virtue of the inventive design which has been developed, the number of pistons coupled to the control rod simply depends on the relative angular position between the finger and the slots radially facing each other. This angular relative position can be manually obtained by the operator using an appropriate control member positioned on the pipette, or more preferentially, in an automatic way by virtue of motor means controlled by a control unit of the pipette.
However, the coupling module can take any other form supposed to be appropriate, without departing from the scope of the invention. By way of example, this module can be based on a mechanical, magnetic gripping, etc.
The coupling module comprises a coupling rotary member provided at its bottom end with said finger, and rotatably mounted at its top end to the control rod, along the longitudinal axis of the pipette.
The coupling rotary member is preferably made using two parts slidably mounted with respect to each other, along the longitudinal axis of the pipette, an expansion spring being arranged between both these parts so as to generate a strain tending to move them away from one another.
The coupling module includes a control rod extension translationally integral with the control rod, and said two parts of the coupling rotary member are respectively formed by a top part and a bottom part, the latter being translationally movably mounted along the longitudinal axis, relative to the control rod extension.
The coupling module further comprises a motion transforming body cooperating with the coupling rotary member such that a relative translation movement between them along the longitudinal axis simultaneously results in a relative rotation with respect to each other, also along the longitudinal axis. In other words, the cooperation between the motion transforming body and the coupling rotary member causes a helical motion of the latter.
Preferably, the motion transforming body includes at least one first helical ramp as well as at least one second helical ramp, and the coupling rotary member is provided with a follower roller which, when it cooperates with the first ramp enables the rotation of the coupling rotary member to be caused along a first direction of rotation and which, when it cooperates with the second ramp enables the rotation of the coupling rotary member to be caused along a second direction of rotation. This design enables coupling and uncoupling of the pistons to be achieved in a simple and reliable manner.
The sampling pipette is preferentially designed such that the rotation of the coupling rotary member along the first direction of rotation is achieved by a first overstroke downwards of the control rod from a purge stroke end position thereof, and the rotation of the coupling rotary member along the second direction of rotation is achieved by a second overstroke upwards of the control rod from a top pipetting position of this control rod. Thus, the pipette is designed to achieve coupling and uncoupling of the pistons by simple translations of the control rod, in overstrokes going respectively beyond the purge stroke and retracted from the top pipetting position. One of the advantages relative to this specificity resides in the pipette design simplicity, given that it is the same control rod, in a motion along a same translation degree of freedom, which makes it possible to perform alternately pipetting operations and piston coupling and uncoupling operations.
Preferably, the first overstroke is made acting against a strain generated by a first centring spring tending to repel the coupling rotary member upwardly relative to the motion transforming body, and the second overstroke is made acting against a strain generated by a second centring spring tending to repel the coupling rotary member downwardly relative to the motion transforming body.
Preferably, the pipette is configured such that the movement of the control rod is made manually or in a motorised manner, as previously indicated. In this regard, it is noted that hybrid pipettes are also within the scope of protection of the invention.
Preferably, the number N of pistons is higher than or equal to three, but a solution with two concentric pistons is also possible, without departing from the scope of the invention.
The sampling is preferentially designed so as to be able to sample a volume range from 0.5 to 1,250 μl, or designed so as to be able to sample a volume range from 500 to 10,000 μl.
The inner most piston is permanently integral with the coupling module. Alternatively, it could also be coupled and uncoupled to the control rod, via the coupling module. According to another alternative, it is the outermost piston which could be permanently integral with the coupling module.
The pipette comprises a control member for adjusting the volume to be sampled, of the knob, button-type or any other conventional form.
Finally, it is noted that the sampling pipette can be a single-channel or multi-channel pipette.
Further advantages and characteristics of the invention will appear in the non-limiting detailed description below.
This description will be made with regard to the appending drawings in which:
b depict the coupling module switching from the second to the third configuration;
In reference to
Conventionally, this motor pipette 1 is intended to be held by an operator's hand who, using his/her thumb, is capable of actuating a control knob of the pipette to generate dispensing a liquid which has been sucked beforehand.
More precisely, the single-channel pipette 1 comprises a handle 6 forming the upper body of the pipette, and above which the pipetting control button 3 is located, the upper part of which is intended to undergo the operator's thumb pressure. By way of indicating purposes, it is noted that an electronic display screen 4 is provided on the handle 6, as well as control members 8 such as knobs or buttons, and in particular a control member for adjusting the volume to be sampled.
The top part of the pipette is also provided with an electronic control unit 10 and a motor 11, the latter being preferentially a direct current motor controlled by the unit 10.
The output shaft 13 of the motor 11 is mechanically coupled to a device 15 for translating a control rod 12 of the pipette, along a longitudinal axis 9 of the pipette also corresponding to the longitudinal direction of the same. It is noted that most of the elements making up the pipette are of revolutionary shapes, and centred on this axis 9.
Under the handle 6, the pipette 1 includes a removable bottom part 14, which downwardly terminates with a cone-carrying tip 16 accommodating a consumable 18, also called a sampling cone.
A cone ejector 20 opens downwardly of the handle 6. Conventionally, the ejector 20 can be moved relative to the handle 6 and the bottom part 14, both forming a fixed body 22 of the pipette.
One of the features of the invention lies in the fact that the pipette is equipped with several concentric pistons, here three pistons referenced 24a, 24b, 24c. The number N of pistons could however be higher or lower than 3, without departing from the scope of the invention.
The three pistons are housed in the bottom part 14, and centred on the longitudinal axis 9. The first piston 24a, located inside, has a circular shaped cylindrical cross-section. The second piston 24b has an annular transverse cross-section, surrounding the first piston 24. The top end 24b′ of the second piston 24b defines an upwardly open axial housing 26, and the bottom of which is equipped with an O-ring 28 through which the first piston 24a passes. However, usually for the second piston 24b, a small radial clearance is provided between both pistons 24a, 24b, such that air can penetrate therethrough. It is indicated that throughout the description, the terms “top” and “bottom” are to be considered with respect to the pipette maintained in the operator's hand, with an orientation such as that assumed during pipetting operations, that is with the control knob 3 upwardly oriented.
Analogously to that set out above, the top end 24c′ of the third piston 24c defines an upwardly open axial housing 30, and the bottom of which is equipped with an O-ring 32 through which the second piston 24b passes. However, usually for the third piston 24c, a small radial clearance is provided between both pistons 24b, 24c, such that air can penetrate therethrough.
The third piston 24c has a bottom end equipped with a lip seal 40 snuggly fitting the internal surface of the fixed body 22.
Each of the second and third pistons 24b, 24c has lugs 34 outwardly radially extending and slidably mounted in vertical internal grooves 36 of the fixed body 22, as is visible in
The pistons participate with their lower ends in delimiting a single suction chamber 42, the bottom part of which communicates with a channel 44 passing through the cone-carrier 16.
By way of indicating example, the pipette is intended to enable liquid to be sampled in a volume range from 0.5 to 1,250 μl, or in a volume range from 500 to 10,000 μl. In the first case for example, a first piston 24a is provided, the intrinsic sampling capacity of which is in the order of 50 μl, and a second piston 24b is provided which, when associated with the first piston 24a, has together an intrinsic sampling capacity in the order of 350 μl, and finally a third piston 24c is provided which, when associated with the first and second pistons 24a, 24b, has an intrinsic sampling capacity in the order of 1,250 μl.
Depending on the desired volume, adjusted by the operator via the dedicated control member on the pipette, the control unit 10 is capable of commanding switching ON either:
For this, the pipette 1 is equipped with a coupling module 50 specific to the invention, enabling each of the pistons to be coupled and uncoupled with the control rod 12. More precisely, the module 50 is configured so as to be able to be brought into three distinct configurations in which it provides coupling of the control rod 12 with the first piston 24a only, the first and second pistons 24a, 24b, and finally the first, second and third pistons 24a, 24c respectively.
More specifically in reference to
First, the module 50 includes a control rod extension 52 translationally integral with the control rod 12, and downwardly extending from the same rod. Preferably, the extension 52 is mounted screwed at its top end to the bottom end of the control rod 12.
The bottom end of the extension 52, centred on the axis 9, fixedly and permanently carries the first piston 24a, a screwed, glued connection or else, being for example provided between their respective ends.
Further, the module 50 includes a coupling rotary member 56, arranged about the control rod extension 52. Preferably, this member 56 is made using two parts slidably mounted with respect to one another, along the axis 9. There is first a top part 56a translationally fixed with respect to the rod 12 and its extension 52, but rotatably movable relative to the same, along the axis 9. There is then a bottom part 56b rotatably coupled to the top part 56a, for example through a key 60.
An expansion spring 62 is arranged between both parts 56a, 56b, so as to generate a strain tending to move them away from one another. This expansion spring 62 presses against an internal pressing surface of the bottom part 56b, and a ring for coupling the upper ends of the top part 56a and the extension 52.
The bottom part 56b is thus translationally movably mounted along the axis 9, relative to the extension 52 and to the control rod 12. It is additionally equipped, at its bottom end, with at least one piston attachment finger 64, preferably two diametrically opposite fingers as is shown in
Each attachment finger 64 radially outwardly extends from the bottom part 56b. As will be described hereinafter, the angular position of these fingers 64 conditions the number of pistons coupled to the module 50.
To vary the angular position of the fingers 64, the coupling module 50 further includes a motion transforming body 66, for transforming a translational motion into a rotational motion along the same axis 9. Indeed, this body 66 cooperates with the top part 56a of the coupling rotary member 56 such that a relative translation movement between both of them along the axis 9 simultaneously results in a relative rotation between them along the same axis. The aim is therefore to obtain a helical motion of the coupling rotary member 56, which is made possible thanks to ramps provided on the body 66 as well as follower rollers carried by the rotary member 56.
More precisely, the member 56 is equipped with two follower rollers 68 arranged in a diametrically opposite way, and rotatably mounted along a same transverse axis 76 orthogonal to the axis 9. A first helical ramp 70a located inside the body 66, as well as a second helical ramp 70b also located inside the body 66, facing the first ramp, are associated with each follower roller 68. The design is such that when each follower roller 68 cooperates with its associated first ramp 70a, it enables the rotation of the rotary member 56 to be caused along the first direction of rotation 72a about the axis 9. Reversely, when it cooperates with its associated second ramp 70b, it enables the rotation of the rotary member 56 to be caused along a second direction or rotation 72b opposite to the first direction.
It is additionally noted that each follower roller 68 is carried by a rotational support pin 74 centred on the axis 76, this pin opening into a radial opening 76 of the motion transforming body 66.
The axial positioning of the coupling rotary member 56 with respect to the body 66 is ensured by two compression springs, that is a first centring spring 80a tending to repel upwardly the member 56 relative to the body 66, and a second centring spring 80b tending to repel downwardly the coupling rotary member relative to the motion transforming body 66.
For this, the first spring 80a is housed inside the body 66 between a bottom end thereof and a shoulder 82 located at the top end of the rotary member 66, whereas the second spring 80b is housed inside the body 66 between a top end of the same and the same shoulder 82. It is additionally noted that it is on this shoulder that the follower rollers 68 are preferentially mounted, via the pins 74.
In reference now to
At its top end 24b′, the second piston 24b has two diametrically opposite attachment slots 84b (a single one being visible in
Analogously, at its top end 24c′, the third piston 24c has two diametrically opposite attachment slots 84c (a single one being visible in
The slots 84b, 84c are gathered by pairs. For a same pair of slots 84b, 84c as that visible in
The width of the slots 84b, 84c is preferentially identical, and provided such that the attachment fingers 64 can be circumferentially moved in and out these slots. Preferably, the slot width is slightly higher than the diameter of the fingers.
With this configuration, the number of pistons coupled to the bottom part 56b of the module 50 thus depends on the relative angular position between each finger 64 and its associated pair of slots 84b, 84c.
In a second configuration of the module 50, represented with the finger 64 in dotted line in the middle of
In a third configuration of the module 50, represented with the finger 64 in dotted line in
In reference now to
Dispensing the sucked liquid is then controlled by the control knob, which causes actuation of the motor resulting in the control rod 12 to be downwardly moved. During this dispensing stroke, the downward motion of the rod 12 drives the module 50 which therefore also slides along the fixed body 22. As regards the pistons 24b, 24c, they remain stationary, unlike the first piston 24a which moves down. The state of the pipette at the dispensing stroke end is represented in
In reference now to
Dispensing the sucked liquid is then controlled by the control knob, which causes actuation of the motor resulting in the control rod 12 being downwardly moved. During this dispensing stroke, the downward motion of the rod 12 drives the module 50 which therefore also slides along the fixed body 22. The pistons 24c remains stationary, unlike the pistons 24a, 24b which simultaneously move down. The state of the pipette at the dispensing stroke end is represented in
In reference now to
Dispensing the sucked liquid is then controlled by the control knob, which causes actuation of the motor resulting in the control rod 12 to be downwardly moved. During this dispensing stroke, the downward motion of the rod 12 drives the module 50 which therefore also slides along the fixed body 22. The three pistons 24a-24c then simultaneously move down, pushed by the rod 12 and the module 50. The state of the pipette at the dispensing stroke end is represented in
The body 66 first abuts down against the fixed body 22. As the first overstroke continues, the top part 56a of the rotary member 56 is rotated because of the follower rollers 68 pressing against their ramps 70a. This helical motion is transmitted to the bottom part 56b, as well as to its attachment fingers 64. It is made against the return strain generated by the first centring spring 80a, by compressing the same. During this motion, the fingers 64 of the bottom part 56b also axially abut down against the top ends 24b′, 24c′ of the pistons 24b, 24c, this state corresponding to that represented in
During this rotation the angular extent of which is perfectly controlled because it directly depends on the extent of the axial overstroke of the control rod 12, the attachment fingers 64 penetrate the slots 84b. However, this angular movement of the fingers 64, for example in the order of 22.5°, is not sufficient for them to penetrate the slot 84c. The insertion of the fingers 64 into the slots 84b causes the second piston 24b to be coupled with the module 50. This mechanical coupling state is represented in
Once the coupling is made, the control unit of the pipette commands the rod 12 to be lifted back to the purge end position, which results in simultaneously lifting back the first and second pistons 24a, 24b, as is shown in
Then, pipetting operations can be commanded conventionally, for volumes corresponding to the range associated with all of the two pistons 24a, 24b.
c and
The body 66 first abuts down against the fixed body 22. As the first overstroke is continued, the top part 56a of the rotary member 56 is rotated because the follower rollers 68 press against their ramps 70a. This helical motion is transmitted to the bottom part 56b, as well as to its attachment fingers 64. During this motion, the fingers 64 of the bottom part 56b then axially abut down against the top end 24c′ of the piston 24c, this state corresponding to that represented in
Then, the first overstroke is continued and the top part 56a continues to be helically driven downwardly, whereas the bottom part 56b only undergoes a rotation along the axis 9 in the first direction 72a, since it is translationally blocked. During this rotation the angular extent of which is perfectly controlled because it directly depends on the extent of the axial overstroke of the control rod 12, the attachment fingers 64 penetrate the slots 84c. This angular movement of the fingers 64 is for example in the order of 22.5°, and sufficient to come against or in the proximity of the bottom of the slots 84b, 84c. The insertion of the fingers 64 into the slots 84c causes the third piston 24b to be coupled with the module 50. This mechanical coupling state is represented in
Once the coupling is made, the control unit of the pipette commands the rod 12 to be lifted back to the purge end position, which results in simultaneously lifting back the three pistons 24a-24c, as is shown in
Of course, it is noted that directly switching from the first to the third configuration can be commanded by the control unit of the pipette, by adapting the amplitude of the first downward stroke accordingly.
In this state of sampling the nominal volume associated with the third configuration, the body 66 is abutting up against the fixed body 22. As the second overstroke is continued upwardly, the top part 56a of the rotary member 56 is rotated because the follower rollers 68 press on their ramps 70b, as is depicted in
Then, the control unit of the pipette commands a downward movement of the control rod 12, such that the fingers 64 repel the third piston 24c in its bottom position, abutting against the fixed body 22. This phase is represented in
Then, pipetting operations can be commanded conventionally, for volumes corresponding to the range associated with all of the two pistons 24a, 24b.
In this state of sampling the nominal volume associated with the second configuration, the body 66 is abutting up against the fixed body 22. As the second overstroke is continued upwardly, the top part 56a of the rotary member 56 is rotated because the follower rollers 68 press on theirs ramps 70b, as is depicted in
Then, the control unit of the pipette commands the downward movement of the control rod 12, such that the fingers 64 repel the second piston 24b in its bottom position, abutting against the fixed body 22 or against the third piston 24c already in a down abutting position. This phase, similar to that represented in
Then, pipetting operations can be commanded conventionally, for volumes corresponding to the range associated with the single first piston 24a.
Once again, it is noted that directly switching from the third to the first configuration can be commanded by the control unit of the pipette, by adapting the amplitude of the second upward stroke accordingly.
Of course, various modifications can be provided by those skilled in the art to the invention just described, only by way of non-limiting examples.
| Number | Date | Country | Kind |
|---|---|---|---|
| 16 53223 | Apr 2016 | FR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2017/058597 | 4/11/2017 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2017/178448 | 10/19/2017 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 3741732 | Stanfield | Jun 1973 | A |
| 3757585 | Heller | Sep 1973 | A |
| 4036064 | Hydo | Jul 1977 | A |
| 4056360 | Risch | Nov 1977 | A |
| 4128009 | D'Autry | Dec 1978 | A |
| 4133211 | Sarstedt | Jan 1979 | A |
| 4141250 | D'Autry | Feb 1979 | A |
| 5696330 | Heinonen | Dec 1997 | A |
| 6021680 | Inagaki | Feb 2000 | A |
| 6428750 | Rainin | Aug 2002 | B1 |
| 9919306 | Fuchs | Mar 2018 | B2 |
| 20050220676 | Tran | Oct 2005 | A1 |
| 20130291660 | Wilmer | Nov 2013 | A1 |
| 20150209777 | Petrek | Jul 2015 | A1 |
| 20170028397 | Dudek | Feb 2017 | A1 |
| 20170113219 | Kim | Apr 2017 | A1 |
| 20180178211 | Dudek et al. | Jun 2018 | A1 |
| 20180250667 | Dudek et al. | Sep 2018 | A1 |
| 20190224666 | Tajima | Jul 2019 | A1 |
| Number | Date | Country |
|---|---|---|
| 3 019 895 | Oct 2015 | FR |
| H02218961 | Aug 1990 | JP |
| Entry |
|---|
| International Search Report for International Application No. PCT/EP2017/058597 dated May 12, 2017. |
| Written Opinion for International Application No. PCT/EP2017/058597 dated May 12, 2017. |
| Preliminary French Search Report for French Patent Application No. 16 53223 dated Nov. 30, 2016. |
| Translation of Office action dated Feb. 24, 2021 for Japanese application No. 2018-553193. |
| Number | Date | Country | |
|---|---|---|---|
| 20190151839 A1 | May 2019 | US |
