US 3754654 A
Apparatus for linear application of a liquid along the surface of a plate utilized in conjunction with chromatographic investigations includes a pipette arranged to be moved back and forth along the plate. The pipette is mounted pivotally in order that a capillary liquid application prong thereon can be maintained in contact with the surface of the plate when moving in one direction while it is raised from the surface when the pipette is moved in the opposite direction.
Description (OCR text may contain errors)
waited States Patent [191 Nyhom DEVICE FGR APPLYING A LIQUED ALONG A LINE ON A SUPPORT  Inventor: Ethel Barbra Louise Nybom,
Kristianstad, Sweden  Assignee: AB Instruments, Lund, Sweden  Filed: Apr. 7, 1971 21] Appl. No.: 131,904
 Foreign Application Priority Data Apr. 13, 1970 Sweden 4960/70  111.8. Cl. 210/198 C  int. Cl Bold 15/08  Field of Search 210/198 C, 31 C;
 1 References Cited UNITED STATES PATENTS Rodder 210/198 C  3,754,654 [451 Aug. 28, 1913 FOREIGN PATENTS OR APPLICATIONS 1,032,096 6/1966 Great Britain 210/198 C Primary Examiner-John Adee Attorney-Pierce, Scheffler & Parker ABSTRACT Apparatus for linear application of a liquid along the surface of a plate utilized in conjunction with chro matographic investigations includes a pipette arranged to be moved back and forth along the plate. The pipette is mounted pivotally in order that a capillary liquid application prong thereon can be maintained in contact with the surface of the plate when moving in one direc-' tion while it is raised from the surface when the pipette is moved in the opposite direction.
I 7 Claims, 5 Drawing Figures Patented Aug. 28, 1973 I5 Sheets-Sheet 1 Patented Aug. 28, 1973 3,754,654
5 Sheets-Sheet 2 "J IIIHHE L Patented Aug. 28, 1973 3 Sheets-Sheet 5 DEVICE FOR APPLYING A LIQUID ALONG A LINE ON A SUPPORT The present invention relates to a device for linear application of a liquid on a carrier means such as a plate intended to be used in connection with a chromatographic investigation, and comprising a dose means in the form of a pipette or the like for the liquid, a support for said dose means, and means to move said support in parallel with the line to be coated.
The device according to the invention is characterized in that said support is pivotally mounted in such a manner that said pipette while moving in one direction is maintained in contact with the carrier means but is maintained out of contact while moving in the opposite direction. Preferably, the dose means comprises a pipette which consists of a cylindrical receptacle and a capillary prong preferably angularly disposed in relation to said receptacle. The support is mounted so as to maintain the capillary prong directed obliquely downwards to the carrier means and backwards in relation to the motion direction while moving in contact with the carrier means and to maintain the capillary prong I directed obliquely upwards and forwards in relation to the motion direction while moving in the opposite direction.
' The invention primarily is adapted to be used in connection with chromatography and will accordingly be described in connection with this method. For those skilled in the art, however, it is obvious that the inven? tion also may be used in many other applications.
In order to separate different chemical components in solutions and extracts of various kinds by means of chromatography (paper chromatograpy or thin-layerchromatography) it is frequently required to apply large volumes (l ml or more) in suitable small doses which in manual operation not only is a very timeconsuming work but also easily results in a damaging of the chromatographic carrier means.
By means of the device according to the invention it is possible to move a pipette backward and forward over a carrier means while applying liquid in the one direction and with intermediate drying while the pipette is moving back to the initial position. This may be accomplished by means of an motor'driven motion and by application of a uniform pressure on the carrier means. By repeating said motion it is possible to enrich large amounts of dry substance along a narrow start line for subsequent chromatographic processing. If desired the device according to the invention may be fully automated in order to considerably facilitate the operation. 7
The invention is more exactly described in the following specification with reference to the accompanying drawings which by way of exampleshow a preferred embodiment of the invention.
FIG. Ia shows a portion of the device according to line on a carrier means. Said carrier means for instance may be a plate I, which is shown in FIG. 1 by dashed lines. In the embodiment shown said plate therefore consists of a glass tile serving as carrier means and being provided with a thin chromatographic layer of, for instance, silica gel.
In the present embodiment the device is provided with a pipette which also is shown by dashed lines and generally indicated by 2. The pipette comprises a cylindrical receptacle portion 3 and a capillary prong portion 4. The pipette is mounted in a support 5. The support is pivoted on a shaft 6. By means of a set screw 7 the angular position of the support in relation to the shaft 6 is adjustable.
As appears from FIG. 3 the shaft is journalled inbearings 8 in a carriage 9. The carriage 9 by means of a belt 10 is movably mounted on bars 11 extending between a motor housing 12 and an operating housing 13 (FIGS. la and lb).
Upon movement to the right (according to FIG. 1)
the support 5 is maintained in the shown position so that the capillary prong 4 is in contact with the plate 1. Immediately before the carriage arrives at an end position to the right in FIG. 1 an operating arm 14 engages an actuating member in the form of a projection or stop 15. The projection 15 is secured to an angel plate 16 which in turn is secured to a bottom plate 17. A second portion of said angel plate l6.is indicated by 18 and serves to actuate a microswitch 19. The microswitch 19 by means of suitable electrical controls causes reversal of the motion direction of the carriage. A corresponding microswitch 20 is mounted at the opposite side of the carriage in order to reverse the motion direction at the opposite end position of the carriage. When the projection 15 comes into contact with the operating arm 14 the support is pivoted from the position in FIG. 1 into a position in which the prong 4 is directed obliquely upwards and to the left (according to FIG. I) so that the content of the pipette cannot flowout any more.
During the motion of the carriage to the left according to FIG. 1 the support with the pipette 2 is maintained in the new position solely by the friction in the system. As shown in FIG. 3 said friction is reinforced. by means of a spring 21 disposed between one of the bearings 8 and a shoulder 22.
As appears from FIG. 2, the operating arm 14 extends on both sides of the shaft 6. The upper portion of the arm 14 is provided with a pin 23 which magnetically contacts a magnet 24. The magnet 24 is slidable in a channel the cross section of which best appears from FIG/4. At-the rotation of the operating arm 14 due to the contact with the projection 15 the magnet 24 accompanies the pin 23. When the carriage 9 arrives at the left end position in FIG. 1 the magnet comes into contact with a member 45 stationarily mounted in the motor housing, and said member will also be magnetically contacted by the magnet. At the same time the microswitch 20 comes into contact with a stop 26 through which the motion directionis reversed. When the carriage now is moving to the right the metal member 45 holds the magnet 24in the end position. In this way the operating arm 14 and the shaft 6 are rotated back to the position shown in FIG. 1 and the content of the pipette will again start to flow out.
The plate I is in contact with a guide rule 27 so that the pipette all the time coats the same line on the plate.
As appears from FIG. I, the operating housing is provided with various control means for the speed to the left, i. e., the return speed, and the speed to the right, i.e., the coating speed. The hand wheels of said control means are indicated by 28 and 29. By this means it is possible to change partly the coating speed in relation to the viscosity of the liquid and partly the drying period between the coatings. For said control conventional control means (not shown) are used which actuate the motor 30.
The position of the capillary prong 4 in relation to the plate 1 is adjustable not only by means of the set screw 7 but also by means of a hand wheel 31 (FIG. 1). The hand wheel 31 is mounted on a shaft 32 (FIG. 3) having a prolongation tip 33 (FIG. 2) which rests on one of the guide bars 11. Turning of the shaft 32 which is screwed into a bearing 34 will change the height of the carriage in relation to said guide bar 11. By this means it is therefore possible to raise or lower the prong 4.
At the bottom to the left in FIG. 3 a locking device 35 is shown by means of which a pin 36 stationary mounted on the shaft 6 may be locked. Said locking device is used only when it is desired by means of the set screw 7 to adjust the position of the support in relation to the shaft 6. In the drawing (FIG. 1) 37 reference numeral indicates a hand wheel secured to a shaft 38 by means of which the locking device 35 is actuated.
In the drawings also various brackets, screws, protective housings etc. are shown which are of less importance for the invention and therefore do not need to be more exactly described.
Naturally, the invention is not restricted solely to the embodiment described above but may be varied within the scope of the appended claims. Thus, for instance, without departing from the scope of the invention the shape of the individual components may be varied within broad limits.
l. A device for applying a liquid linearly onto a carrier means comprising a carriage, means for moving said carriage reciprocally and for supporting said carriage over and in parallel relation to the carrier means, a pipette means including a cylindrical receptacle and a capillary prong extending therefrom at an angle to the axis thereof for applying a dose of the liquid linearly onto the carrier means, a support for said pipette means mounted on said carriage for pivotal movement about an axis transverse to the path of movement of said carriage, and means at opposed ends of the path of movement of said carriage for reciprocally pivoting said support, whereby said pivotable support for said pipette means maintains said capillary prong obliquely downwards onto the carrier means at an acute angle thereto and backwards to the direction of movement over said carrier means while linearly applying liquid thereonto and maintains said capillary prong obliquely upwards away from the carrier means when the direction of movement is opposite to the first mentioned direction of movement to prevent flow of the liquid onto the carrier means.
2. A device as claimed in claim 1 wherein said support for said pipette means comprises a shaft rotatably mounted on said carriage and wherein said means for pivoting said support comprises separate means for rotating said shaft in opposite directions at each end of the path of reciprocal movement so as to raise said capillary prong away from the carrier means at one end of the path and to lower said prong onto the carrier means at the other end of the path.
3. A device as claimed in claim 2 wherein one means for rotating said shaft to lower said pipette means comprises a first operating arm extending radially from said shaft, a magnet movably mounted on said carriage and in magnetic contact with said first operating arm, a fixed metal contact at one end of the path of movement, said magnet and said metal contact being attracted to each other at the one end of the path whereby upon reversal of movement of said carriage at the one end of the path, said metal contact will restrain said magnet and operating arm for sufficient time to cause said operating arm to rotate said shaft and thus lower said pipette means onto the carrier means.
4. A device as claimed in claim 3 wherein the other means for rotating said shaft to raise said pipette means comprises a second operating arm extending radially from said shaft, a fixed projection at the other end of the path of movement, whereby when said second operating arm strikes said projection said operating arm rotates said shaft to raise said pipette means away from the carrier means and also rotates the first operating arm to move said movable magnet to its initial position.
5. A device as claimed in claim 2 and further comprising means for pivotally mounting said support on said shaft and for permitting fine angular adjustment of said support and said pipette means in relation to the carrier means.
6. A device as claimed in claim 5 and further comprising means for locking said shaft in a fixed position while making said fine angular adjustment of said pipette means.
7. A device as claimed in claim 4 and further comprising means for increasing frictional resistance to accidental rotation of said shaft after said pipette means has been positioned by said separate means.