U.S. patent number 3,596,673 [Application Number 04/793,498] was granted by the patent office on 1971-08-03 for automatic transfer apparatus.
This patent grant is currently assigned to F. Hoffman-La Roche & Co.. Invention is credited to Robert Laucournet.
United States Patent |
3,596,673 |
Laucournet |
August 3, 1971 |
AUTOMATIC TRANSFER APPARATUS
Abstract
Automatic device for delivering a calibrated quantity of a
liquid from a first receptacle into a second receptacle by
positioning a duct into the liquid to be delivered, aspirating the
liquid into the duct for delivery into the second receptacle
including control means cooperating with detectors of the position
of the duct in the liquid and the aspirating duct.
Inventors: |
Laucournet; Robert
(L'Hay-Les-Roses, FR) |
Assignee: |
F. Hoffman-La Roche & Co.
(Aktiengesellschaft, CH)
|
Family
ID: |
8645052 |
Appl.
No.: |
04/793,498 |
Filed: |
January 23, 1969 |
Foreign Application Priority Data
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|
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Jan 24, 1968 [FR] |
|
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137,316 |
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Current U.S.
Class: |
137/99; 74/89.2;
137/395; 222/21; 250/577; 137/209; 4/507; 137/392; 137/577;
222/400.7 |
Current CPC
Class: |
G01N
35/1016 (20130101); G01N 1/18 (20130101); B01L
3/0293 (20130101); Y10T 137/86236 (20150401); G01N
35/1079 (20130101); G01N 2035/1025 (20130101); Y10T
137/3127 (20150401); Y10T 137/7306 (20150401); Y10T
74/18832 (20150115); G01N 35/10 (20130101); Y10T
137/2516 (20150401); Y10T 137/7313 (20150401) |
Current International
Class: |
B01L
11/00 (20060101); G01N 35/10 (20060101); G01N
1/18 (20060101); B67d 005/54 () |
Field of
Search: |
;250/218
;222/373,21,400.7 ;137/392,395,209,577 ;74/89.2 ;141/67 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Lawrence; James W.
Assistant Examiner: Leedom; C. M.
Claims
What I claim is:
1. Automatic apparatus for the transfer of a predetermined quantity
of a liquid sample contained in a first container to a second
container, comprising: a first tube one end portion of which is
adapted to be immersed in said sample and the other end portion
penetrating said second container, a second tube connected to a
source of gas under pressure with its free end portion adapted to
penetrate said first container, said one end portion of said first
tube being longer than said free end portion of said second tube,
first means for detecting the passage of said liquid sample at a
given point of said first tube, a common support for fixedly
carrying the end portions of said first and second tubes which
penetrate said first container, means for translationally moving
said support relative to the surface level of said liquid sample in
said first container, and means for controlling said translational
movement by said first detecting means.
2. The apparatus as claimed in claim 1 further comprising second
means for detecting contact between the free end portion of the
second tube and the surface level of said liquid sample, and means
for further controlling translational movement of said support by
said second detecting means.
3. The apparatus as claimed in claim 2 wherein said first and
second tube portions penetrating said first container are of
unequal length such that the one end of said first tube is situated
below the surface level of the liquid sample when the free end of
said second tube is substantially flush with said surface,
4. The apparatus as claimed in claim 3 wherein the ends of said
first and second tubes which penetrate said first container are
bevelled.
5. The apparatus as claimed in claim 2 wherein said second
detecting means comprises a conductivity-measuring device
electrically connected between said first and second tubes.
6. The apparatus as claimed in claim 2 wherein said liquid sample
in said first container has a sedimented phase, and further
comprising means for preventing translational movement of said
support below a defined lower level corresponding to the passage of
the one end of the first tube into the sedimented phase of said
sample, thereby to prevent the transfer of sediment from said first
container to said second container.
7. The apparatus as claimed in claim 6 wherein said preventing
means comprises a photoelectric detector and a light source
arranged respectively on opposed sides of said first container,
with said photoelectric detector being unenergized by the light
source when it is adjacent the sedimented phase of the liquid
sample to prevent further downward movement of said tubes with
respect to said first container.
8. The apparatus as claimed in claim 7 wherein said photoelectric
detector is fixed to said support for translational movement
therewith.
9. The apparatus as claimed in claim 8 wherein said translational
movement means for said support comprises an actuator operatively
coupled thereto.
10. The apparatus as claimed in claim 9 wherein said actuator
comprises a driven drum and at least two metal blades each having
first ends fixed to the periphery of said drum and wrapped in
opposite directions, and second ends fixed to said support for
transforming circular movement into rectilinear movement.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus for the automatic
transfer of a given quantity of liquid from a container wherein it
is stored to another container and, more particularly, to the
analysis of a calibrated quantity of the liquid.
2. Description of the Prior Art
Analyses having a high rate of liquid samples are made by means of
automatic analyzing apparatus. The samples generally constitute
either the liquid itself or a mixture in specific proportions of
the liquid and reagents which are appropriate to the analyses to be
carried out.
Thus, many samples have particles in suspension which must not be
transferred into an analysis tank, particularly blood samples.
SUMMARY OF THE INVENTION
The present invention provides an apparatus for the automatic
transfer of a calibrated quantity of samples, for example blood
samples for automatic analysis, while avoiding the contamination of
a liquid sample with another and external pollution. The present
invention also provides an apparatus for the rapid transfer of a
calibrated quantity of samples without taking particles in
suspension from a phase known as the sedimented phase of the said
sample.
The automatic transfer apparatus has a quantity of liquid sample
contained in a first container for transfer to a second container.
A first tube has ends adapted to be immersed respectively in the
sample and directed to the second container. A second tube is
connected to a source of gas under pressure with the free end
adapted to penetrate into the said first container. Means for
detecting the passage of the liquid sample are provided at a given
point of the first tube. The ends of the first and second tubes
which penetrate into the first container are fixed to the same
support which itself is mobile is translational movement relative
to the level of the liquid sample in the first container. The said
support is driven in translational movement by both an element for
detecting contact between a point of the end of the second tube and
the level of the liquid sample, and by the means for detecting the
passage of the sample in the second tube.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a preferred embodiment of the
apparatus according to the invention.
FIG. 2 is a perspective view of the driving element of the
apparatus shown in FIG. 1.
FIG. 3 is a diagram illustrating the control sequences in time of
the element shown in FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1 there is illustrated a first container in which is stored
a sample which is to be transferred to a second container for the
purpose of analysis. The first container 1 is q bottle carrying in
ascending order a sedimented sample phase 4, a liquid sample phase
3 to be analyzed and a portion 2 from which air has been partly
evacuated. This bottle is hermetically closed by two individual
plugs 14 and 15 sealing the enclosure. These plugs are made of a
material which can be readily perforated by hollow needles or the
like, and advantageously retractable. The bottle is positioned
below a needle-carrying element 5 to which two needles 6 and 7 are
fixed.
The first ends of the needles 6 and 7 are intended to pierce the
plugs 14 and 15 and for this purpose are cut in bevelled form.
Advantageously, the portions of the two needles 6 and 7 which are
intended to be positioned in the bottle 1 are of unequal length,
the corresponding portion of the needle 6 being longer than the
corresponding portion of the needle 7 by several millimeters, for
example 2 to 3 millimeters.
The needle-carrying element 5 also supports an arm 8 comprising at
its end, appropriately positioned, a photoelectric cell 9 excited
respectively by light sources 22 arranged vertically at the other
side along the bottle and represented diagrammatically. The cell 9
is connected to a photoelectric detector 10. The needle 6 is
elbowed in such a manner that its second end is positioned in the
second container or bottle forming chamber 18.
Situated in the circuit of the needle 6 between the bottle 1 and
the chamber 18, at a distance corresponding to the calibrated
volume to be transferred, is a detecting gauge 11, in this case
advantageously a conductivity-measuring gauge. This gauge is
connected to a conductivity detector 12. This gauge may also be of
the photoelectic type. The second end of the needle 7 is connected
to a source of air or gas under pressure 19.
Between the two needles 6 and 7 is a device 13 similar to the
detector 12, which supplies a signal, the value of which is in
accordance with the electrical resistance between the two needles 6
and 7. The detector circuits 12 and 13 are connected electrically
to a control unit 16 of actuator 17. The actuator 17 imparts a
rectilinear sequential movement to the needle carrier 5.
Before the electrical control signal appears at the control unit
16, the actuator 17 and the needle carrier 5 are in the upper
position, the needles are also in the upper position and a bottle 1
is positioned mechanically below the needle carrier 5.
When the control signal occurs, the actuator pushes the needles
through the plugs 14 and 15 into the position illustrated in FIG.
1. The needle 6 enters the limpid liquid and a fraction of a second
afterwards the needle 7, in its turn, contacts the liquid. The
electrical resistance between the needles 6 and 7 which is
considerable initially owing to the fact that all the parts in
contact with the needles are of an insulating character has its
resistance lowered and the detector circuit 13 trips, which sends
an electrical signal into the control unit 16, which supplies a
signal to the actuator to stop its downward travel. The needles 6
and 7 stop with the needle 6 below the surface level of the liquid
and the needle 7 just in contact with the surface. The bevel of the
needle 7 permits compressed air to enter the free portion 2 of the
bottle without disturbing the surface of the liquid. The pressure
established in the free portion pushes the liquid 3 in the needle 6
into the duct. When the liquid under pressure reaches the detecting
gauge 11, the conductivity-measuring detector 12 trips and sends a
signal to the control unit which operates the actuator in the
reverse sense. The needles move upwards again until the needle 6 is
above the surface of the liquid 3. At this instant electrical
resistance between the two needles again becomes considerable. The
circuit 13 again trips and by means of the control unit 16 again
stops the upward travel of the actuator. The compressed air within
the free space 2 pushes the liquid which has penetrated into the
needle 6 towards its other end into container 18. A zeroizing
signal represented diagrammatically by the connection 20 is applied
to the control unit 16 and operates the actuator upwards, until the
needles are situated outside the bottle 1. Another sequence can
recommence in the form of a new signal applied to the control unit
16, represented diagrammatically by the connection 21.
In cases where the surface level of the liquid 3 is too low, that
is to say the height of the liquid phase 3 is very slight, there is
a risk that the needle 6 may inspire sediment 4. For this purpose,
the light ray emitted horizontally by the light source 22 does not
pass through the sedimented phase 4 to cell 9 and cell 9 is not
excited before the stopping sequence of the actuator 17 is
completed. Consequently, the operation of the actuator 17 is
effected by the cell 9 by way of the detecting element 10 which
orders the actuator to move into the upper position again. There is
no longer a sample available for analysis, and this can be
indicated to the operator by means of a light indicator, for
example.
The actuator may comprise either a pneumatic jack operated by
rapid-action electromagnetic valves, an electrohydraulic jack, or a
step-by-step motor controlling a rack supporting the needle carrier
5 by means of a reduction gear, or any device for transmitting the
aforesaid sequential movements. The gear-rack system may
advantageously be replaced by a known system of metal blades
associated with a system of cylindrical drums, transforming a
circular movement into an alternating rectilinear movement.
FIG. 2 shows one such embodiment.
In FIG. 2, a motor 23 which may be of a step-by-step type, drives a
drum 25. On this drum there are fixed one end of each flexible
blade 26 and 27. The other end of each blade is fixed to a plate 24
which drives the needle carrier 5 and imparts the sequential
movements to it.
The aforesaid sequential movements are indicated diagrammatically
in FIG. 3 in which the positions of the actuator 17 representing
the succession of sequences S are plotted as ordinates and the
times t as abscissae.
At the beginning of the sequence, the actuator is in the upper
position indicated at the ordinate position P.sub.o. At time A, the
arrival of the control signal 21 triggers the sequence and the
actuator descends. At time B the actuator is at position P.sub.1,
the needle 6 is immersed in the liquid phase 3 of the sample in the
bottle 1 and the end of the needle 7 touches the surface of the
liquid phase; the liquid can be delivered into the needle 6; the
time interval AB corresponds to the descent of the needles into the
bottle 1.
At time C the value of the calibrated volume of the sample forced
into the tube is reached, the actuator which had been in the
position P.sub.1 up to this instant receives from the detector 12 a
control signal to move upwards again; the time BC is the
calibrating time.
At time D the signal coming from the detector 13 is applied to the
actuator which is positioned at P.sub.2, the ends of the needles 6
and 7 are still in the bottle 1 but are no longer in contact with
the liquid phase 3 and the calibrated volume of the liquid inspired
may be transferred into the chamber 18. The time CD is the time
corresponding to that in moving the needles upwards again out of
the liquid. At time E the calibrated volume of liquid is entirely
transferred into the chamber 18, and the actuator can again be
returned to the upper position P.sub.o. At time F the control
signal for zeroizing 20 is applied and the actuator is maintained
in the upper position P.sub.o until a new identical sequence
occurs.
It appears, in the succession of sequences S, that the precision of
the calibration may be affected by the time CD. Thus it is possible
in order to have a good standard of precision either to act on the
gas under pressure, the detector 12 stopping the supply of gas
under pressure, or to take the time CD into account in calibration
if this is chosen to be constant. The present invention affords
many advantages. More particularly, the bottles such as the bottle
1 may constitute a continuous linear chain and be positioned
automatically below the needle carrier 5. Likewise the chambers,
such as the chamber 2, closed or otherwise, may be chambers
comprised by a supporting film. This film may be driven in a
step-by-step movement so that the chambers come successively to the
position under the corresponding end of the needle 6, this end
being also cut in bevelled form so as to pierce through the upper
portion of the closed chamber.
The transfer device as described constitutes, therefore, an
automatic pipette for transfer of liquid substances which can be
provided for a continuous automatic sample-analyzing line.
Furthermore, if external pollution of the samples has been avoided
by the fact that transfer is effected from a bottle to a
hermetically closed chamber, contamination of one sample with
another is also avoided. In fact, the transfer of samples is
effected rapidly and successively by means of the needle 6, the
samples are forced in at one end and ejected at the other end, and
the liquid passes through the needle, which has a smooth internal
surface, by being pushed by a strong blast of air and entirely
discharged. The apparatus also permits transfer only of the liquid
part of the samples with analysis effected solely on a calibrated
volume of this liquid part.
* * * * *