US 3632382 A
Method for applying liquid color to smooth, flexible sheet material in defined areas, said method comprising loading a container, said container having downwardly directed outlets corresponding to the defined areas covered by mesh screen, with the liquid color so that menisci are formed at the lower surface of the screen, and contacting the sheet material to the exterior of said mesh screen so as to break said menisci and transfer the liquid to the surface.
Description (OCR text may contain errors)
United States Patent  Inventors Kenneth James Reed London; Donald Ian McGilvray, Knutsford; Jack Fletcher, Newton-le-Willows, all of England  Appl. No. 871,987
 Filed July 15, 1969  Patented Jan. 4, 1972  Assignee McCorquodale Colour Display Limited London, England  Priority Dec. 22, 1964  Great Britain  APPLICATION OF LIQUID COLORS TO PAPER CARD OR OTHER SMOOTH SURFACES 2 Claims, 12 Drawing Figs.
52 u.s.c1 117/38, 101/126, 118/401, 118/406,40l/196, 401/264 51 1111.01 1305c l/l6, B05c3/20 so FieldoiSearch 118/401,
 References Cited UNITED STATES PATENTS 2,101,464 12/1937 Arndt 1 18/406 2,482,989 9/1949 Mussett 1 18/401 2,598,908 6/1952 Grimson... 1 18/401 2,673,549 3/1954 Frucki 118/401 3,158,080 11/1964 Blazensky et a1. 118/401 X 3,221,649 12/1965 Weiss 101/126 Primary ExaminerRobert F. Burnett Assistant Examiner-Roger L. May AttorneyEstabrook Palmer and Kemon ABSTRACT: Method for applying liquid color to smooth, flexible sheet material in defined areas, said method comprising loading a container, said container having downwardly directed outlets corresponding to the defined areas covered by mesh screen, with the liquid color so that menisci are formed at the lower surface of the screen, and contacting the sheet material to the exterior of said mesh screen so as to break said menisci and transfer the liquid to the surface.
iiill PATENTEUJAH 41972 31632382 SHEET 1 OF 7 I ENTORS KENNETH J. REED NALD I. MC GILVRAY JACK FLETCHER INVENTORS JACK I'L ETCHBR /QQMM/%.
ATTORNEYS KENNETH J. REED DONALD 1. MC GILVRAY SHEET 5 BF 7 PATENTEU JAN 4 I972 E av n mm mm a PATENTEU JM 4 572 SHEET 6 [1F 7 INVKNTORS KENNETH J. REED DONALD I; NC GILVRAY JACK CHER ,ZZ/Z47/Z/ ATTORNEYS Pmmmm 41972 3.632.382
SHEET 7 BF 7 INVESTORS KENNETH J. REED DONALD I. NC GILVRAY ATTORNEYS APPLICATION OF LIQUID COLORS TO PAPER CARD OR OTHER SMOOTH SURFACES This application is a division of our prior application, Ser. No. 466,862 filed June 24, 1965, now US. Pat. No. 3,511,213 dated May 12, I970.
The present invention relates to a method of applying liquid colors to paper, card and like smooth surfaced materials in accurately defined areas, the invention being of particular utility for example in the production of color cards, that is to say sheets of card and commonly preprinted cards, bearing a number of accurately dimensioned patches of various colors in predetermined accurate spaced relationship to one another and to preinscribed matter which may be present on the cards. Such cards are used in large numbers as guides in the selection of paint.
The apparatus according to the invention comprises a container for liquid color the outlet of which is covered by a mesh screen of a mesh capable of retaining the liquid color in the container, a support for a sheet of paper, card or the like, means for imparting relative movement between the mesh screen and the support to effect contact between a surface of a sheet of paper, card or the like carried on the support and the exterior surface of the mesh screen.
The support for the sheet of paper, card or the like may be a roller arranged for movement so as to effect rolling contact between a surface of the sheet of paper or card carried on the roller and the exterior surface of the mesh screen.
Alternatively the support for the paper sheet, card or the like may take the form of a platen, relative movement being effected between the platen and the mesh screen so as to bring a surface of a sheet, card or the like on the platen first into surface contact with he mesh screen and thereafter to part it from the mesh screen.
Where a plurality of depositions of various different colors is required as in the case of color cards a number of containers for the several colors are provided in fixed position with reference to one another and with coplanar outlets covered by a meshed screen common to all the containers so that separated patches of all the colors may be applied to a sheet of paper or card at a single operation.
Usually a stencil is provided on the inner surface of the meshed screen, the stencil being provided with apertures of a shape, size and location corresponding to the form and location of the color patches required on the paper or card, the stencil and screen being mounted in close surface contact with one another and the stencil in sealed engagement with he walls of the containers.
In the at present preferred arrangement for use in depositing a plurality of deposits of various different colors and making use of a roller to bring a sheet, card or the like into contact with the mesh screen, a mesh screen assembly comprising a plurality of containers for the color liquid, a stencil film or plate and a mesh screen is mounted in a fixed position usually with the screen assembly horizontal and means are provided to feed a sheet or card into a position close to but slightly spaced from the fixed mesh screen and a freely rotating roller utilized to move across the surface of the paper or card in such a manner as to effect what may be termed a kiss contact that is to say, contact without or substantially without pressure between the paper or card and the mesh screen, whereby liquid color from within the containers and retained by the mesh screen is transferred to the paper or card, the sheet or card being peeled from the mesh screen in such a manner that unit areas of sheet or card bearing deposited color are parted from the mesh screen immediately or as soon as possible, after the deposition.
The screen assembly and roller are arranged to be movable relative to one another after complete peeling of a sheet or card bearing deposit to permit return of the roller relative to the mesh screen without contact between them, in preparation for a next depositing operation,
A number of forms of machine suitable for carrying out the invention are illustrated by way of example in the accompanying drawings, in which FIG. I is a general view in side elevation of one form of machine according to the invention;
FIG. 2 is a general plan view of the machine of FIG. I,
FIG. 3 is a view in part sectional elevation on the line III-Ill of FIG. 2,
FIG. 4 is a part sectional underside plan showing the screen assembly,
FIGS. 5 and 6 are diagrammatic views in side elevation showing various relative positions taken by moving parts of the machine of FIG. 1,
FIGS. 7 and 8 are diagrammatic views in side elevation of an alternative form of machine according to the invention,
FIGS. 9 to 12 illustrate still another form of machine according to the invention,
FIGS. 9 and 10 being diagrammatic views in side elevation showing moving parts in different relative positions,
FIG. 11 is a view on an enlarged scale and elevation of a part of the machine of FIGS. 9 and 10,
FIG. 12 is a perspective view of a detail.
Referring to FIGS. 1 to 6, the machine here shown comprises a supporting structure 11 including guides 12 in which a carriage frame 13 carrying mesh screen assembly indicated by the general reference 14, of a form intended to enable a plurality of separated patches of color to be deposited simultane ously on a sheet, is arranged for guided horizontal reciprocating movement by any convenient driving means (not shown), a support for a sheet intended to receive deposits of liquid color, in the form of a roller 15 and sheet feed means comprising a guided chain conveyor 16 provided with sheet gripping means for feeding sheets singly from a lay table 17 to the roller 15.
The mesh screen assembly comprises a stiff rectangular screen frame 18 formed of metal tubes of circular section surrounded by pneumatic tube 19 of rubber or the like located against the periphery of the tubular screen frame 18 by corner brackets 20.
The screen frame 18 is supported in fixed position by bolts 21 engaged in bars 22 extending between the side members 23 of the carriage frame 13.
Across the underside of the screen frame 18 is stretched a fine mesh screen 24 with its margins extending upwards about the tubes of the frame 18 and enveloping the pneumatic tube 19 and the edge of the screen 24 are retained by wrapping about metal bars 25 fitting within recesses provided on the upper side of the screen frame 18. With the screen 24 so mounted the pneumatic tube 19 can be inflated so that the screen 24 is stretched taut across the underside of the screen frame 18.
Within the screen frame 18 is located a container body 26 for the liquid to be deposited the said body presenting a number of separate compartments 27 in regular or other desired distribution eg after the manner of a honeycomb as shown in FIG. 4 the compartments being open at top and bot tom.
Against the under surface of the container body 26 is applied a stencil sheet 28 having a number of apertures 29 therein of shapes corresponding to that of the patches of color required to be deposited on a sheet or card, the apertures being located so as to register with the lower ends of individual compartments 27 of the container body 26.
The container body may be formed as a molding or casting in a plastics material of a kind which is unaffected by the color liquid intended to be used and as a particularly suitable material may be mentioned an epoxy-polyamide resin from which a unitary container body 26 can readily be produced by casting on a flat surface having appropriately shaped and distributed mould parts such as wooden blocks mounted thereon.
The stencil may be in the form of an apertured plastic film produced by well known film-producing techniques and again of a material unaffected by the liquid color to be used, and it is applied as shown in FIG. 4, in adhering sealing contact with the underside of the container body 26.
The container body 26 with the stencil sheet 28 attached rests upon the taut mesh screen 24 with close overall surface engagement between the stencil and the mesh screen and the fine mesh screen forms a retaining closure at the outlet ends of the compartments of the container body for liquid.
In the production of color cards, lacquer comprising a pigmerited viscous high polymer solution having a viscosity for example in the range -15 poise and appropriate flow characteristics and solvent balance has been found particularly suitable and good results have been obtained using a mesh screen woven from nylon thread with about 390 threads per inch and an aperture size of about 0.00 I 2 inch square giving a total free surface of about 21.5 percent, in conjunction with such a lacquer. Such a mesh screen will retain the lacquer to a considerable depth in the compartments of the container body 26 with formation of menisci at the mesh screen.
Screws 30, adjustable in further bars 30 connected between the bars 22 on the carriage frame 13 make engagement with their lower ends with the rim of the container body 26 and serve to hold the stencil sheet 28 in engagement with the mesh screen 24 and also permit accurate vertical adjustment of the plane of the mesh screen 24 relative to the screen frame 18.
The carriage frame 13 carrying the screen assembly frame 18 is connected for movement with a rack bar 31 arranged to make guided horizontal straight line reciprocating movement.
The supporting roller for the sheet intended to receive the deposit is mounted for rotation about a fixed axis 32 with the upper part of its peripheral surface adjacent the plane of movement of the mesh screen when moving towards the roller 15. On the ends of the roller 15 are mounted pinion wheels 33 of similar diameter to that of the roller for driven engagement by the rack bars so that the roller is driven by the rack bars 31 with a peripheral speed similar to the speed of linear movement of the mesh screen assembly.
Chain conveyors 34 with grippers 34 of known kind take sheets singly from a lay table 17 to the roller 15 which is also provided with automatically operated grippers 35 of known kind whereby the fed sheet is taken over by the roller.
The carriage frame 13 at the end farthest from theroller 15 is mounted for pivotal movement about a transverse horizontal axis 36 relative to the horizontally guided rack bars 31.
The other end of the carriage frame 13 is provided with slotted extension pieces 37 the slots in which engage over upstanding posts 38 which are rigid with reference to the rack bar 31 so that the carriage frame at that end may rest under its own weight upon platforms 39 adjustable in height upon the posts 38.
On a support 40 which is fixed with reference to the rack bar 31 is mounted an upstanding pin 41 capable of rocking about a transverse axis 42, said pin 41 being biassed by a spring 41' into engagement with the extension piece 37 on the carriage frame 13 and capable of movement into a position beneath said extension piece 37 and into engagement with a stop 43 in a raised position of the adjacent end of the carriage frame 13 and its extension piece 37.
Wedge-shaped elements 44 and 45 are provided in fixed positions for engagement with a roller 46 extending transversely from the carriage-frame 18 to control movements of the carriage frame 18 and the parts carried thereby about the horizontal end pivot axis 36 in a manner permitting the carriage to occupy a lowered position during its movement with the rack bar 31 in one direction and a raised position during its movement with the rack bar in the other direction.
The operation of the above-described machine is as follows:
Liquid color is loaded into the compartments 27 of the container body 26 to an appropriate depth e.g., /a to 3/ 16 of an inch in the case of lacquer the liquid being retained in the compartments by the fine mesh screen 24, menisci of the liquid being formed at the undersurface of the mesh screen within bounded areas corresponding to the apertures 29 in the stencil plate.
Sheets to receive the deposit are taken in single succession from the lay board 17 by the chain conveyor 34 to the roller 15 and are taken up by the grippers 35 on the roller. The grippers may be of known kind and they are operated automatically in timed sequence in a manner and by devices well known in the art of printing.
At the commencement of a depositing operation the carriage frame 18 and the mesh screen assembly 14 carried thereby occupy a position as shown in FIG. 6 in which it is tilted upwards through a small angle to the horizontal through engagement of the roller 46 with the upper inclined surface of the fixed wedge member 45, the pivoted pin 41 however being displaced from beneath the extension 37 on the carriage frame 13 by engagement with a fixed stop (FIGS. 1 and 6).
The rack bar 31 is now moved by any convenient driving means (not shown) so that the roller 15 with a sheet affixed thereto is rotated, in the clockwise direction in the drawings. and the carriage frame 13 moved horizontally. During the early part of this movement the roller 46 on the carriage frame 13 moves down the fixed wedge member 45, FIG. 6 so that the carriage frame moves downwards about its pivot 36 until the extension piece 37 rests upon the adjusted platform 39 on the post 38 so that the surface of the mesh screen 24 is now located and moves in the required horizontal path, determined with great accuracy by means of the adjusting screws 30 applied against the edges of the container body, and such that rolling engagement is made between the sheet on the roller 15 and the surface of the mesh screen without or substantially without pressure, the engagement being an approximate line contact and such that the menisci of liquid color at the screen are broken to effect the color transfer to the sheet. The sheet is led downwards by virtue of its being gripped by the roller grippers 35 so that it is parted from the mash screen with a peeling action immediately or very soon after receiving the liquid color. As the sheet leaves the mesh screen the liquid color menisci reform at the surface of the screen.
As the carriage frame 13 approaches the end of its movement in this direction the roller 46 meets and rides up the other fixed wedge 44 so that it is again tilted upwards about the pivot 36, and it is held in this tilted position by engagement of the pivoted and spring-biased pin 41 beneath the extension piece. Thus, during return movement of the rack bar 31 and the carriage frame 13 the upwardly tilted condition of the latter is maintained and no contact can take place between the mesh screen and the roller.
At the end of the return stroke as indicated in FIG. 6, the roller 46 reengages with the first-mentioned wedge 45, so that the machine is set for commencement of the next succeeding deposition operation.
FIGS. 7 and 8 illustrate a further form of machine suitable for use in carrying out the invention.
The machine here shown comprises a supporting body structure including four fixed vertical columns 47 disposed at the corners of a rectangle, a stiff bedplate or platen 48 arranged for horizontal reciprocation in a fixed plane between a position external of the body structure and beneath a lay board 49 as shown in FIG. 7, and a position within the body structure as shown in FIG. 8 and a moving conveyor 50 movable in unison with the platen 48 between a position within the body structure as shown in FIG. 7 and a position outside the body structure at the side thereof remote from the lay board 49 as shown in FIG. 8.
At the upper end of the body structure is mounted a carriage frame 51 having comer extensions 52 engaged and guided in vertical slots formed in the upper ends of the columns 47.
The extensions 52 rest upon compression springs 53 contained in bores in the upper ends of the columns 47 and they are engaged on their upper sides by cams 54 adapted to move the carriage frame 51 downwards to a predetermined extent, return movement being effected by the springs 53.
The cams 54 are carried by cam shafts 55 mounted in vertically adjustable bearings (not shown) to enable the extent of downwards movement imparted to the carriage frame 51 by the cams to be determined with accuracy.
Within the carriage frame is fixedly mounted a frame and mesh screen assembly comprising container body, stencil plate and a fine mesh screen similar to that described above with reference to the machine of FIGS. 1 to 6.
In operation, with liquid color retained in the container by the mesh screen and the carriage frame 51 in its raised position as shown and the platen 48 beneath the lay board 47 as shown in FIG. 7, a sheet is taken on to the platen 48 by automatically operated gripping devices 56 of conventional form provided on the platen. The platen 48 together with the sheet is now moved to the position within the body structure as shown in FIG. 8, the conveyor 50 at the same time being moved from the position within the body shown in FIG. 7 to the position outside the body structure shown in FIG. 8.
The cam shafts 55 and the earns 54 are now rotated and the carriage frame 51 thereby lowered to an extent effecting contact without or substantially without pressure between the mesh screen and the sheet the engagement being such that the menisci of color at the underside of the screen are broken and color applied to the sheet.
Further rotation of the cams 54 permits the carrying frame to rise under the lift of the springs 53 to disengage the mesh screen from the sheet and the menisci reform at the underside of the screen in readiness for a succeeding operation.
Meantime the grip of the gripper devices 56 of the platen 48 upon the sheet which has received the deposit is released and the sheet gripped by gripping devices 57 on the body structure. The platen 48 is now returned to the position beneath the lay board 49 (FIG. 7) in readiness to receive the next sheet and the conveyor 50 moved into position beneath the sheet bearing the deposit and retained in the body structure by the grippers 57. Thereafter the grip of the grippers 57 is released and upon execution of the next cycle of operations the sheet bearing deposited color is removed from within the body structure.
Conveniently, the conveyor 50 may be provided with driven endless belts in well-known manner adapted to effect transfer of a sheet thereon from the conveyor 50 to a drying zone.
The at present preferred construction of machine for carrying out the invention is illustrated in FIGS. 9 to 12.
The machine here shown comprises a flat bed plate 58 arranged for horizontal reciprocating movement in guides 59, beneath a fixed frame 60 supporting in fixed position a mesh screen assembly 61 of the form similar to that previously described.
On the flat bed plate 58 are mounted fixed posts 62 support ing a platform 63 extending transversely across the machine and beneath the mesh screen assembly 61.
Upon the platform 63 is mounted a pair of upstanding parallel end plated 64 (FIG. 11) having slots 65 therein forming guides for bearing members 66 for the ends of a pair of parallel and freely rotating rollers 67 supporting a third freely rotating roller 68 carried in the valley between the pair of rollers 67.
The bearing members 66 are capable of up and down movement in the slots 65 between a lowered position as shown in FIG. 11 and a raised position determined by an adjustable stop 91.
From the platform 63 extends a table 69 for the reception of sheets intended to receive deposit. said table in one extreme position of the bed plate 58 extending beneath a sheet lay table 70 as shown in FIG. 9.
The end plates 64 on the platform 63 are of a general con vex contour at the upper edges and the roller 68 in its raised position projects above the upper parts of the end plates.
Sheet grippers 71 are provided on a cross-shaft 72 mounted at the side of end plates 64 away from the sheet table 69 (FIG. 11) and at a level at all times below that of the upper part of the surface of the roller 68.
The end plates 64 at the sides away from the grippers 71 are provided with notches 73 also at a level at all times below that of the upper part of the surface of the roller 68, for the reception of a cross bar 74 mounted between arms 75 pivotally connected with the end plates at 76 so that the cross bar 74 may be rocked between a position in the notches 73 as shown in dotted lines in FIG. 11 and a position above the level of the upper part of the surface of the roller 68 and above the grippers 71 as shown in full lines in FIG. 11.
Up and down movements of the roller bearing members 66, opening and closing of the grippers 71 and rocking of the cross bar 74 are effected automatically in timed sequence by means (not shown) provided on the machine.
On the sliding bed plate 58 at the side of the platform 63 away from the sheet table 69 are fixedly mounted a pair of plates 77 one at each side of the machine, said plates being furnished with cam slots 78 of a profile inclined downwards from the platform 63, as shown in FIGS. 9 and 10.
At the end of the machine away from the lay table 70 are mounted a pair of parallel guide bars 79 in fixed positions inclined at a small angle to the vertical and these bars 79 form guides for cam followers 80 (FIG. 12) each provided on one side with antifriction rollers 81 for cooperative engagement with a guide bar 19 and on the other side with a roller 82 for cooperation with a cam slot 78.
Between the cam followers 80 extends a rod 83 carrying automatically actuated sheet grippers 84.
The cam slots 78 effect downward and upward movement of the cam followers 80.
The operation in this case is as follows:
With liquid colors contained to appropriate depth (with lacquers approximately Vs to 3/16 of an inch) in the containers of the container body of the mesh screen assembly 61 and retained therein by the mesh screen, menisci will be present at the underface of the screen of the fixed assembly 61.
With the bed plate 58 in a position in which the sheet plate 69 extends below the lay table 70 and the platform 63 is close to the edge of the lay table i.e., a position further to the left of that shown in FIG. 9, the roller-bearing members 66 and the rollers 67 and 68 are in the down position in the slots 65 in the end plates 64 on the platform 63 and the cross bar 74 is held in its raised position i.e., the full line position in FIG. 11. In this position the edge of a sheet on the lay table 70 extends over the roller 68 and under the cross bar 74 approximately as shown at 85 in FIG. 11 and the grippers 71 on the cross-shaft 72 are operated to grip the loading edge of the sheet.
The bed plate 58 is now moved in the direction away from the lay table 70 and as movement begins the cross bar 74 is moved downwards towards the notches 73 in the end plates 64 on the platform 63 so that the sheet is drawn down in a manner wrapping it closely over the still depressed roller 68 as shown in dotted lines at 86 in FIG. 11. Movement of the bed plate 58 in this direction continues until its other extreme position i.e., that shown in FIG. 10 is reached, the trailing portion of the sheet resting on to the sheet table 69 and the cam followers 82 being caused by the cam slots 73 to rise to the upper ends of the guide bars 79 to the position shown in FIG. 10 in which position the sheet grippers 84 on the crossshaft 83 between the cam followers 80 are opposite and slightly below the upper part of the surface of the roller 68.
Throughout the movement of the bed plate 58 in this direction the roller 68 remains lowered so that no contact takes place between the moved sheet and the mesh screen of the fixed assembly 61.
The sheet grippers 71 on the platform 63 are now opened and the grippers 84 on the cross-shaft 83 between the cam followers 80 closed to take a grip on the leading edge of the sheet.
The bed plate 58 and parts carried thereby are now moved in the reverse direction i.e., to the left from the position of FIG. 10 and the roller-bearing members 66 caused to rise into the position against the stop 91 so that the sheet is lifted by the roller 68 to an extend to bring the part of the sheet over the roller 68 into a position for engagement with the menisci of color at the underside of the mesh screen but without or substantially without pressure against the screen itself so that during this movement of the bed plate color is transferred to the sheet over areas corresponding to apertures in the stencil plate behind the screen.
During movement of the bed plate in this direction the cam followers 80 are caused by the cam slots 78 in the plates 77 moving with the bed plate to move downwards along the guide bars 79 so that the sheet, held by the grippers 84 between the cam followers moves continuously beneath the cross bar 74 retained in the notches 73 on the travelling platform 63 thence upwards over the roller 68 also on the travelling platform and finally downwards by virtue of the grip of the downwardly moving grippers 84.
The contact between the sheet and underside of the mesh screen assembly 61 is a line contact and acquisition of a unit line of color by the sheet is followed immediately by peeling or parting of that unit line from the mesh screen assembly.
With movement of the roller 68 past the end of the sheet the grippers 84 between the cam followers now in their lowered position are opened and the sheet bearing the deposit patches is freed e.g., to fall upon a receiving moving conveyor such as 88 (FIG. 9 and 10) mounted in the bed ofthe machine.
In practice, in a machine of the kind illustrated in FIGS. 9 to 12 a metal roller 68 of about inch in diameter has been found to produce satisfactory results.
The contact between the paper sheet or card and the mesh screen is in all cases arranged to take place without or substantially without the application of liquid-transferring pressure upon the mesh screen, as contrasted with conventional screen printing methods in which force is applied to cause liquid to pass through the screen by what may be described as extrusion, on to the receiving surface.
The utilization of a fine mesh screen of the kind, and in the manner, described, in addition to preventing flow of the liquid from the containers by gravity, enables patches of color to be deposited with desirably straight or near straight edges as viewed by the naked eye as contrasted with edges of saw tooth form obtained with a screen of coarser mesh.
Given an appropriate solvent balance in the lacquer which may readily be determined and adjusted by trial, the wet area of lacquer when first received on the sheet or card is substantially free of flow pattern and the colored area after drying will exhibit the desirable perfectly plain smooth surface.
It is desirable to maintain the depth of liquid in the containers within limits for which purpose replenishment is effected at intervals from suitable sources, for example. by the use of motoring pumps arranged for automatic operation to deliver a fixed quantity of liquid after execution of a predeter mined number of depositing cycles by the machine.
In some cases the containers may be closed at their lower ends and the stencil plate and fine mesh screen located at the upper face of the containers and the sheet or card being ap plied over the assembly and in such case the containers may be connected through U-tubes with suitably located reservoirs to maintain the surface of the liquid in the containers in contact with the mesh screen.
What is claimed is:
l. A method of applying patches of liquid color in accurate ly defined areas on smooth flexible sheet material, said method comprising the steps of:
charging said liquid color into a container having downwardly directed outlets shaped to correspond with the required patches and covered by a mesh screen which prevents flow of said liquid from the containers by gravity while permitting formation of menisci at the lower surface of said screen;
presenting a surface of said sheet to the exterior of said mesh screen substantially without pressure against said screen;
causing said surface to contact said liquid menisci and to break said menisci with resultant transfer of liquid from said menisci to said surface; and withdrawing said surface from the exterior of said mesh screen substantially without relative movement between said surface and said screen in the plane of said screen, to reform said menisci at the lower surface of said screen and leave said transferred liquid on the surface of said sheet.
2. The method of claim 1 in which said sheet is presented to the exterior of said mesh screen in such a manner as to make substantially line contact with said menisci and said line of contact is advanced progressively across said sheet and screen.