US3677091A - Apparatus for transferring liquids - Google Patents

Abstract

An apparatus for transferring a liquid via a liquid conducting means from a donor receptacle to a receiving receptacle, which includes cleaning and drying means for the liquid conducting means.

Description

[151 3,677,091 [451 July 18, 1972 United States Patent Guigan APPARATUS FOR TRANSFERRING LIQUIDS [72] Inventor:

Jean Gulgan, Paris, France Hoffman-La Roche Inc.,

Nutley, NJ.

[73] Assignee:

Primary Examiner-S. Clement Swisher Attorney-Samuel I... Welt, Jon S. Saxe, Bernard S. Leon, William G. Isgro, Margaret C. Bogosian and Jacob Frank 0 7 9l 7 .w W 7 A6 Q N 1 0. MP FA .4H 22 ....73/423 A, 23/253 ABSTRACT G0ln 1/14 73/423 A 421 B; 356/244, 246; An apparatus for transferring a liquid via a liquid conducting 52 US. 511 InLCl.

[58] field of Search means from a donor receptacle to a receiving receptacle, which includes cleaning and drying means for the liquid conducting means.

14Clalrm,5Drawlngl1gures PATENTEU JUL 1 8 I972 SHEET 3BF 3 FIG. 3

APPARATUS FOR TRANSFERRING LIQUIDS BRIEF SUMMARY OF THE INVENTION The invention relates to an apparatus which comprises a support means, a carrying member mounted on said support means for vertical and horizontal movement, a plurality of liquid conducting means, preferably hollow, double pronged needles, secured to said carrying member and a plurality of cleaning and drying means disposed on said support means and adapted to receive the liquid conducting means, whereby the latter can be cleaned and dried. In operation, the liquid conducting means cooperates in the transfer of a liquid substance from a donor container to a receiving container and then moves upwardly, horizontally and then downwardly into the cleaning receptacle, where it is cleaned by liquid means. It then again moves upwardly, horizontally and ten downwardly through predetermined distancesiinto the drying means, where any residual liquid substance is removed by drying. Preferably, the substance is a sample taken from a human, and the sample is destined for analysis for diagnostically significant features.

DETAILED DESCRIPTION OF THE INVENTION It is known to cause the transfer of a liquid by means of a hollow, double pronged needle, one branch of which dips into a donor container and the other branch of which dips into a receiving container, under the influence of a compressed gas introduced into the donor container by another needle. In many instances, in such an operation, the hollow, double pronged needle traversed by the liquid is contaminated so that it is important to effect a careful cleaning of said needle prior to its re-use. This is particularly true in the case of medical analyses where microbiological contamination from one sample to the next must be avoided. The aim of the invention is an apparatus whereby this cleaning, drying and transferring is accomplished automatically.

The invention has for its object an apparatus for transferring liquid samples by liquid conducting means, which is put into communication simultaneously with the donor container and a receiving container. A hollow needle directs a pressure means into the donor container, whereby the interior of the donor container is put under pressure and including cleaning and drying means for said liquid conducting means. The apparatus of the invention is characterized by the fact that it includes: (a) a support means which may comprise a base and a first horizontal member connected to the base by vertical mountings; (b) a plurality of hollow, double pronged needles, preferably n in number, carried by a second horizontal member and positioned on said second member equadistant radially from the vertical axis thereof, the said second horizontal member being operatively disposed on the support means, for example, between the said base and first horizontal member, whereby relative horizontal and vertical movement thereof is permitted; (c) a plurality of cleaning and drying vessels or troughs, for the liquid conducting means equal, preferably, in number to at most n-l, said vessels or troughs being disposed on the base of the said support means in the path of vertical movement of the liquid conducting means effected concurrently with the vertical movement of the said second member; (d) a hollow conducting member connected to a source of positive pressure and resiliently mounted in relation to said support means on a guiding member for movement in a downward vertical direction upon coaction with said second horizontal member and disposed opposite a double hollow needle which is not in vertical communication with a cleaning or drying vessel or trough; (e) a first actuating means operatively connected to said second horizontal member and energized to effect rotational movement of said second member relative to said support means in successive rotatory movements with an angle equal to 2 1r/n; and (f) a second actuating means also operatively connected to said second horizontal member and energizable to effect movement of said second member in a vertical direction relative to said support means.

In a preferred embodiment,

the movement in a vertical direction of said second horizontal member is guided by means oflongitudinal projections integral with, and extending from the said second horizontal member, said projections being slidably received in longitudinal grooves of the vertical mountings disposed on the base of the supporting means, these grooves opening laterally at the upper extremity of the mountings thereby removably receiving said projections so that they can move laterally;

the said rotary movement with an angle equal to 2 rr/n of the said second horizontal member about its vertical axis may be effected by a motor of the step-by-step type fixed on said support means, the axis of the said motor passing through the axis of the said second horizontal member and the latter being connected in rotation but free in vertical movement;

the means for moving the said second horizontal member in vertical direction include a screw-jack or an electromag net acting thereon; the means for moving the hollow conducting member consist, in descent, in the action of the second horizontal member on a small plate supporting the said hollow needle and, in rising, in the action of a return spring, disposed below said small plate; the cleaning vessels or troughs include two cavities into each of which there dips one branch of one, double needle; the first cavity being provided with an inlet and an outlet conduit for compressed gas; and with an inlet conduit for a cleaning liquid which is renewed and maintained at a substantially constant level, the second cavity being provided with a conduit for evacuating cleaning liquid transferred thereto by the double needle;

the said drying vessels or troughs include two cavities into each of which dips a branch of a double needle; a first cavity being provided with an inlet conduit for hot gas; the second cavity being provided with an escape conduit for the said gas after its transfer through the said needle.

In a variant embodiment, a level detector, connected to the plate supporting the hollow pressure conducting needle, stops the descent of the second horizontal member when the free surface of the liquid contained in the donor container is detected; the positioning of the said detector relative to the plate permits predetermination of the quantity of liquid to be transferred.

The present invention will be better understood by consideration of the exemplary embodiment given hereinafter with reference to the accompanying drawings wherein:

FIG. 1 is an embodiment of the apparatus of the invention in perspective view;

FIG. 2 is an exploded perspective view of the apparatus corresponding to FIG 1;

FIG. 3 is a longitudinal sectional view of an embodiment of the donor and receiving containers;

FIG. 4 is a longitudinal sectional view of an embodiment of the cleaning means;

FIG. 5 is a longitudinal sectional view of an embodiment of the drying means.

Referring to the drawings, more particularly, FIG. 1, the apparatus comprises:

The fixed support comprises a base member 1 and a firsthorizontal member 2. The firsthorizontal member 2 is provided with an opening about its central vertical axis and comprises five radially extending arms positioned about the opening. Fourupstanding mountings 3 are fixedly secured to the base member 1 at one end thereof and to thehorizontal member 2 at the other end of the mountings. The mountings are preferably annular in configuration and are provided at their upper ends with a semi-circular reducedportion 5.Mountings 3 also have formed along the length of the nonreduced portion thereof, a longitudinally extendinggroove 4.

A secondhorizontal member 6 supports five sets of hollow, double pronged liquid conducting means on five radially extending arms. Said liquid conducting means comprises five double prongedhollow needles 7.Member 6 is provided with longitudinal projections; namely, lugs 8, which are slidably and guidably received ingrooves 4.Member 6 has a central opening in which is fixedly received, ahollow axle 9. Axle 9 is connected on one end with the piston of anactuator 10. Theactuator 10 may comprise a screw-jack such as a pneumatic jack operated by rapid-action electromatic valves, an electrohydraulic jack or any device for transmitting the required movements. The other end ofaxle 9 receives interiorly, the axle orshaft 11 of amotor 12.Shaft 11 is rectangular in configuration and is received in a corresponding opening in thehollow axle 9. Thus, relative rotational movement about the vertical axis ofaxle 9 andshaft 11 is precluded but relative sliding movement along the vertical axis thereof is permitted.

The apparatus also comprises cleaning and dryingtroughs 13 disposed directly opposite to four of thehollow needles 7 when in operative position.

A single prongedhollow needle 14 is fixedly secured to aplate 15. One end ofneedle 14 is connected to a source of gas or air under pressure throughconduit 62. Theplate 15 is mounted on amount 16 for vertical movement.Mount 16 is fixed to aprojection 17, formed integrally withmember 2 and extending downwardly frommember 2. Mount carries astop 18. A biasing means such ashelical spring 22 is disposed aboutmount 16 between the underside ofplate 15 and the upper surface ofstop 18, wherebyplate 15 is biased in an upward direction under the influence ofspring 22.Plate 15 has a downwardly extendingleg 60. To the free end ofleg 60,detector 23 is fixed. Movement ofplate 15 is limited byprojection 17 andstop 18.

Adonor container 20 and a receivingcontainer 21 are removably fed belowneedle 7 by any suitable means. In operation,containers 20 and 21 are positioned on the apparatus so that the branch of theneedle 7 adjacent toneedle 14 is abovedonor compartment 20 and the other branch ofneedle 7 is above receivingcompartment 21. Theactuator 10 is then energized by any suitable means causing the secondhorizontal member 6 to descend. One branch ofneedle 7 penetratesdonor container 20, and the other branch penetratescontainer 21. Theother needles 7 as described hereinafter, enter a cleaning trough or a drying trough. The second horizontal member orneedle carrying member 6 engagesplate 15 as shown in FIG. 3, as it moves downwardly causingneedle 14 to enter thedonor compartment 20, while also causing compression ofspring 22.

As FIG. 3 indicates,needle 14 and one branch of adouble needle 7 enters thedonor container 20 and the other branch of the last-mentioned double needle enters the receiving container-21. Theneedle 14 is connected to a source of compressed gas or air throughconduit 62 as indicated above. The liquid contained in thedonor container 20 is driven into thecontainer 21 viahollow needle 7. Theoptical level detector 23 disposed below thesmall plate 15 additionally permits, by controlling the drive of thepiston 10, the predetermination of the volume of liquid substance to be transferred. To accomplish this latter purpose, it is sufiicient to adjust the difference of level between thedetector 23 and the extremity of the double needle; as the detector stops the descent of the secondhorizontal member 6 when it detects the initial level of the liquid in thecontainer 20, then the volume transferred is equal to that comprised between this initial level and the extremity of the double needle.

Simultaneously, with the transfer operation carried out byneedle 7 toadjacent container 21, the four other needles are cleaned and dried as indicated in FIGS. 4 and 5, respectively, and described hereinafter.

Referring to the drawings, more particularly to FIG. 4, one

, of the needles dip into cleaningtrough 47, including twocavities 40 and 41.Cavity 40 contains a cleaningliquid 45 which can be replaced and maintained at a substantially constant level byconduits 42 and 43. Conduit 44 permits the liquid contained incavity 40 to be put under pressure, whereby the liquid contained therein circulates through the interior of the dollow, doublepronged needle 7. The liquid transferred is removed fromcavity 41 viaconduit 46.

Referring to the drawings, more particularly to FIG. 5, another set of hollow, doublepronged needles 7, clips into a dryingtrough 54 analogous to acleaning trough 47 except for the liquid feed circuit.Conduit 50 introduces a hot gas intocavity 51, this circulates through the interior of thedouble needle 7 and escapes fromcavity 52 byconduit 53.

The movement of a set of hollow, double pronged needles from one position to the next is effected by means ofmotor 12. When the secondhorizontal member 6 is in its uppermost position, the projections 8 are situated adjacent the semi-circularlyreduced positions 5 free fromgrooves 4. Themotor 12 which is operatively connected toplate 6 viaaxles 9 and 11 cause the flat carryingmember 6 to rotate to the next operative portion. Each projection 8 is then adjacent agroove 4, and eachneedle 7 is above either a sample container, a cleaning trough, or a drying trough. It should be evident that a cleaned and driedneedle 7 is above the donor container and theneedle 7 which last transferred the sample is above a cleaning trough.

It is to be noted that the relative number of cleaning and drying troughs can be two or more depending upon the result desired. Likewise, the total number of positions can be modified by changing in the same fashion the number of the corresponding elements such as mountings, needles, and the like.

The apparatus described herein can be particularly useful in conjunction with the automatic transfer apparatus described in U.S. Pat. Application Ser. No. 793,498, filed Jan. 23, 1969 in the name of Robert Laucournet.

In a more detailed operation, when a control signal occurs, theactuator 10 pushes the needles throughplugs 70 positioned in all of the containers, i.e., the donor receiving container; the cleaning trough or the drying troughs, into the position illustrated in FIG. 1. One branch of theneedle 7 enters thedonor container 21 and contacts the liquid substance contained therein. Theneedle 14 arrives at a position above the surface of the liquid sample. The opening of theneedle 14 permits compressed air to enter the free portion of thedonor container 20 without disturbing the surface of the liquid. The pressure established in the free portion pushes the liquid in thedonor container 20 into the open end ofneedle 7. When the designated amount of liquid is transferred from thedonor container 20 to the receivingcontainer 21, theactuator 10 causes upward movement ofplate 6, downward movement being stopped when thedetector 23 senses the upper surface of the sample. Theplate 6 and theneedles 7 associated therewith, moves upwardly until the lugs 8 are no longer in communication with thegrooves 4. Thereafter, themotor 12 rotates about its vertical axis causing concurrent rotation of theplate 6. Rotation is continued until the device is in a position whereby the needles can penetrate the plugs or resiliently deformable covers 70 contained in the receptacle disposed next adjacent the container, cleaning or drying trough where they were last positioned. In this way, there can be provided a means for transmitting an aliquot of sample into a system which is to analyze it for diagnostically significant factors. For example, the apparatus defined herein can be utilized with a system described in application Ser. No. 793,498, referred to above. In the system, a compartment contained upon a film strip is charged with a material to be analyzed for diagnostically significant factors, such as the presence of urea in blood and the like. The apparatus herein defined is also well suited for providing a transfer of liquid into such compartment. Therefore, in the embodiment, in lieu ofcompartment 21, a receiving compartment contained on a film strip can be utilized.

I claim:

1. An apparatus for transferring a liquid substance from a donor container to a receiving container via a liquid conducting means comprising a support means, a carrying member mounted on said support means for relative rotational movement about its vertical axis through a 360 angle and for relative vertical movement along its vertical axis, a plurality of said liquid conducting means secured to said carrying member at positions radial to the vertical axis of said carrying member, said liquid conducting means extending downwardly from said carrying member, and cleaning and drying means for the said liquid conducting means, including at least one cleaning trough and one drying trough, said troughs being disposed on the support means in the path of relative vertical movement of said liquid conducting means with respect to said troughs.

2. An apparatus as in claim 1 wherein the liquid conducting means comprises hollow, double pronged needles extending downwardly from said carrying member.

3. An apparatus as inclaim 2 above wherein there is associated with the liquid conducting means, a hollow conducting member connected to a pressure supplying means whereby the liquid substance to be transferred is transferred through the hollow, double pronged needles under the influence of the pressure provided by the pressure supplying means.

4. An apparatus for transferring a liquid substance from a donor container to a receiving container comprising a support means, a carrying member mounted on said support means for relative rotational movement about its vertical axis and for relative vertical movement along its vertical axis, a plurality of liquid conducting means, n in number, carried by said carrying member and fixed to the carrying member at positions equadistant radially from the vertical axis of the carrying member, said liquid conducting means extending downwardly from said carrying member, cleaning and drying means for the liquid conducting means, including at least one cleaning trough and one drying trough, said troughs being disposed on the support means in the path of relative vertical movement of the liquid conducting means with respect to the said trough, a pressure means supplying member comprising a guide fixed against movement relative to the support means, and a hollow conducting member operatively connected to the guide for vertical movement relative thereto, said hollow conducting member being disposed adjacent a liquid conducting means which liquid conducting means does not have a trough disposed in the path of relative vertical movement thereof, a first actuating means operatively connected to said carrying member and being energizable to effect rotational movement of said carrying member about its vertical axis relative to said support means in equal rotary increments, a second actuating means also operatively connected to said carrying member and being energizable to effect movement of said carrying member in a vertical direction relative to said support means and means for effecting relative vertical movement of the hollow conducting member with respect to said guide.

5. Apparatus as defined inclaim 4 wherein the support means comprises a base, an upper member positioned above the base and vertical mounting means secured on the lower portion thereof to the base and on the upper portion thereof to the upper member whereby relative movement of the base and the upper member is precluded.

6. Apparatus as defined inclaim 5 in which said carrying member is adapted to move vertically in response to actuation of said second actuation means, and said mounting member and said carrying member are provided with cooperating means for guiding said carrying member along its path of vertical movement.

7. Apparatus as defined inclaim 6 in which said cooperating means includes a projection formed at the periphery of said carrying member, and a vertical groove formed along a portion of the length of a vertical mounting means, said projection adapted to be slidably received in said vertical groove during the vertical movement of said carrying member.

8. An apparatus as inclaim 7 in which the vertical mounting means include a reduced portion adjacent said upper member and a non-reduced portion containing said vertical groove, said non-reduced portion being disposed in the path of horizontal movement of said projection, said reduced portion being out of the path of horizontal movement of said projection, whereby when said projection is received in said groove, vertical but not horizontal movement of the carrying member is permitted, but when said projection is received in the space defined by the reduced portion, vertical and horizontal move ment of the carrying member is permitted.

9. Apparatus for transferring a liquid substance in accordance withclaim 5, in which the said horizontal movement of the carrying member is through an angle equal to 2 1r/n and the first actuating means is a motor of the step-by-step type secured to said base, the vertical axis of an axle driven by said motor being coincident with the vertical axis of the carrying member, said axle being operatively connected to said carrying member for relative vertical movement and for conjoint rotational movement.

10. Apparatus for transferring a liquid substance in accordance withclaim 4, in which said second actuating means includes a screw-jack or an electromagnet acting thereon.

11. Apparatus for transferring a liquid substance in accordance withclaim 4, in which the said pressure means sup plying member includes a supporting plate slidably mounted on said guide for movement in a vertical direction, said hollow conducting member being secured to said supporting plate and extending downwardly therefrom, a biasing means mounted on said guide and biasing said supporting plate in an upward direction, said supporting plate being disposed in the path of vertical movement of the carrying member whereby vertical movement of the carrying member in a downward direction effects vertical movement of the supporting plate in a corresponding direction against the bias of said biasing means.

12. Apparatus for transferring liquid substances in accordance withclaim 11, in which a level detector is connected to the said supporting plate for vertical movement therewith, said detector being adapted to sense the upper level of the liquid substance to be transferred and to cause a signal to be sent to the second actuating means when such level is detected whereby downward vertical movement of said carrying member ceases, the position of the detector relative to the said supporting plate predetermines the quantity of liquid substance to be transferred.

13. Apparatus for transferring liquid substances in accordance withclaim 4, in which the said liquid conducting means comprises a double branched hollow needle and the said cleaning troughs include two cavities into each of which dips one branch of said double needle, the walls of one of said cavities being provided with openings adapted to receive inlet and outley cleaning liquid conduits, whereby a cleaning liquid can be provided, renewed and maintained at a substantially constant level, said one cavity also being provided with an opening adapted to receive a compressed gas conduit; and the walls of the other cavity being provided with an opening adapted to receive an evacuating conduit whereby the cleaning liquid transferred into said other cavity by the said hollow needle can be evacuated.

14. Apparatus for transferring liquid substances in accordance withclaim 4, in which the said liquid conducting means comprises a double branched, hollow needle, said drying troughs include two cavities, into each of which dips one branch of said double needle, one of said cavities having secured to the wall defining this cavity, an inlet conduit for hot gas and the wall defining the other of said cavity being provided with an escape conduit for the said gas after its transfer through the said hollow needle.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTWN Patent No. 5,677,091 Dated July 18, 1972 lnvent fl Jean Guiggn It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Cover page, Column 1, following "[21] Appl. No. 67,519" and before "[52] U.S. c1. .....'('3/ 23A, 23/253" should read:

[30] Foreign Application Priority Data France September 4, 1969 No. 6930205 Signed and sealed this 3rd day of April i973.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents F ORM PO-1050 0-69) USCOMM-DC 60376-P6Q U.5. GOVERNMENT PRINTING OFFICE 1989 O-36S-334

Claims (14)

1. An apparatus for transferring a liquid substance from a donor container to a receiving container via a liquid conducting means comprising a support means, a carrying member mounted on said support means for relative rotational movement about its vertical axis through a 360* angle and for relative vertical movement along its vertical axis, a plurality of said liquid conducting means secured to said carrying member at positions radial to the vertical axis of said carrying member, said liquid conducting means extending downwardly from said carrying member, and cleaning and drying means for the said liquid conducting means, including at least one cleaning trough and one drying trough, said troughs being disposed on the support means in the path of relative vertical movement of said liquid conducting means with respect to said troughs.

2. An apparatus as in claim 1 wherein the liquid conducting means comprises hollow, double pronged needles extending downwardly from said carrying member.

3. An apparatus as in claim 2 above wherein there is associated with the liquid conducting means, a hollow conducting member connected to a pressure supplying means whereby the liquid substance to be transferred is transferred through the hollow, double pronged needles under the influence of the pressure provided by the pressure supplying means.

4. An apparatus for transferring a liquid substance from a donor container to a receiving container comprising a support means, a carrying member mounted on said support means for relative rotational movement about its vertical axis and for relative vertical movement along its vertical axis, a plurality of liquid conducting means, n in number, carried by said carrying member and fixed to the carrying member at positions equadistant radially from the vertical axis of the carrying member, said liquid conducting means extending downwardly from said carrying member, cleaning and drying means for the liquid conducting means, including at least one cleaning trough and one drying trough, said troughs being disposed on the support means in the path of relative vertical movement of the liquid conducting means with respect to the said trough, a pressure means supplying member comprising a guide fixed against movement relative to the support means, and a hollow conducting member operatively connected to the guide for vertical movement relative thereto, said hollow conducting member being disposed adjacent a liquid conducting means which liquid conducting means does not have a trough disposed in the path of relative vertical movement thereof, a first actuating means operatively connected to said carrying member and being energizable to effect rotational movement of said carrying member about its vertical axis relative to said support means in equal rotary increments, a second actuating means also operatively connected to said carrying member and being energizable to effect movement of said carrying member in a vertical direction relative to said support means and means for effecting relative vertical movemEnt of the hollow conducting member with respect to said guide.

5. Apparatus as defined in claim 4 wherein the support means comprises a base, an upper member positioned above the base and vertical mounting means secured on the lower portion thereof to the base and on the upper portion thereof to the upper member whereby relative movement of the base and the upper member is precluded.

6. Apparatus as defined in claim 5 in which said carrying member is adapted to move vertically in response to actuation of said second actuation means, and said mounting member and said carrying member are provided with cooperating means for guiding said carrying member along its path of vertical movement.

7. Apparatus as defined in claim 6 in which said cooperating means includes a projection formed at the periphery of said carrying member, and a vertical groove formed along a portion of the length of a vertical mounting means, said projection adapted to be slidably received in said vertical groove during the vertical movement of said carrying member.

8. An apparatus as in claim 7 in which the vertical mounting means include a reduced portion adjacent said upper member and a non-reduced portion containing said vertical groove, said non-reduced portion being disposed in the path of horizontal movement of said projection, said reduced portion being out of the path of horizontal movement of said projection, whereby when said projection is received in said groove, vertical but not horizontal movement of the carrying member is permitted, but when said projection is received in the space defined by the reduced portion, vertical and horizontal movement of the carrying member is permitted.

9. Apparatus for transferring a liquid substance in accordance with claim 5, in which the said horizontal movement of the carrying member is through an angle equal to 2 pi /n and the first actuating means is a motor of the step-by-step type secured to said base, the vertical axis of an axle driven by said motor being coincident with the vertical axis of the carrying member, said axle being operatively connected to said carrying member for relative vertical movement and for conjoint rotational movement.

10. Apparatus for transferring a liquid substance in accordance with claim 4, in which said second actuating means includes a screw-jack or an electromagnet acting thereon.

11. Apparatus for transferring a liquid substance in accordance with claim 4, in which the said pressure means supplying member includes a supporting plate slidably mounted on said guide for movement in a vertical direction, said hollow conducting member being secured to said supporting plate and extending downwardly therefrom, a biasing means mounted on said guide and biasing said supporting plate in an upward direction, said supporting plate being disposed in the path of vertical movement of the carrying member whereby vertical movement of the carrying member in a downward direction effects vertical movement of the supporting plate in a corresponding direction against the bias of said biasing means.

12. Apparatus for transferring liquid substances in accordance with claim 11, in which a level detector is connected to the said supporting plate for vertical movement therewith, said detector being adapted to sense the upper level of the liquid substance to be transferred and to cause a signal to be sent to the second actuating means when such level is detected whereby downward vertical movement of said carrying member ceases, the position of the detector relative to the said supporting plate predetermines the quantity of liquid substance to be transferred.

13. Apparatus for transferring liquid substances in accordance with claim 4, in which the said liquid conducting means comprises a double branched hollow needle and the said cleaning troughs include two cavities into each of which dips one branch of said double needle, the walls of one of said cavities being provided with openings adapted to receive inlet and oUtley cleaning liquid conduits, whereby a cleaning liquid can be provided, renewed and maintained at a substantially constant level, said one cavity also being provided with an opening adapted to receive a compressed gas conduit; and the walls of the other cavity being provided with an opening adapted to receive an evacuating conduit whereby the cleaning liquid transferred into said other cavity by the said hollow needle can be evacuated.

14. Apparatus for transferring liquid substances in accordance with claim 4, in which the said liquid conducting means comprises a double branched, hollow needle, said drying troughs include two cavities, into each of which dips one branch of said double needle, one of said cavities having secured to the wall defining this cavity, an inlet conduit for hot gas and the wall defining the other of said cavity being provided with an escape conduit for the said gas after its transfer through the said hollow needle.

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