US2147683A - Printing and means employed therefor - Google Patents

Description

Feb. 21, 1939. E. A. WEAVER ET AL 2,147,683

PRINTING AND MEANS EMPLOYED THEREFOR .Filed Dec. 28, 1935 a Sheets-Sheet 1 a Sheets-Sheet 2 F6U67ZZ0716' E. A. WEAVER ET AL PRINTING AND MEANS EMPLOYED THEREFOR Filed Dec. 28; 1955 61.2166; e 1606;526:667 Wilda/ea 3 Mid aega.

Feb. 21, 1939.

Feb. 21 1939. IE. A. WEAVER ET AL 83 PRINTING AND MEANS EMPLOYED THEREFOR w Eu y Caz/ 15'- 21, 1939- E. A. WEAVER ET AL 2,147,683

PRINTING AND MEANS EMPLOYED THEREFOR Filed Dec. 28,- 1935 8 Sheets-Sheet 4 Hil I Feb. 21, 1939. E. A. WEAVER r-z-r AL 2,147,683

PRINTING AND MEANS EMPLOYED THEREFOR Filed Dec. 28, 1955 8 Sheets-Sheet 5 Feb. 21, 1939. E. A. WEAVER ET AL PRINTING AND MEANS EMPLOYED THEREFOR Fi led Dec. .28, 1955 a. Sheets- Sheet e jive? 20 7 "as 2562mm 4'7! oer @IW 1% cam PRINTING AND MEANS EMPLOYED THEREFOR Filed Dec. 28, 1955 8 Sheets-Sheet 7 Z4" agW n M W/////////// A aws'gvzazz a. ma?

Feb. 21, 1939. A, E V R H M 2,147,683

PRINTING AND MEANS EMPLOYED THEREFOR Filed Dec. 28, 1935 8 Sheets-Sheet 8 Patented Feb. 21, 1939 PATENT OFFICE PRINTING AND MEANS EMPLOYED THEREFOR Eastman A. Weaver, Winchester, and Robert Imlay, Cambridge, Mass, assignors to Comstock & Wescott, Inc., Boston, Mass., a corporation of Massachusetts application December 28, 1935, Serial No. 56,480

31 Claims.

This invention relates to the preparation of prints, and particularly colored prints, by transfer or imbibition, and to apparatus and matrices of the type which are employed in such a method. In general the present invention permits the precise adjustment or correction of the color balance and general density of such prints without necessitating the remaking of matrices, while facilitating the rapid reproduction of any desired number of uniform prints. While this invention has been found particularly satisfactory in the making of transfer prints on gelatine-coated paper or Celluloid from gelatine relief matrices colored with acid dyes in acidified aqueous solu- 5 tion, the advantageous features thereof may also be employed with other kinds of matrices, coloring agents or solvents.

Heretofore correction of print density or color balance has commonly necessitated remaking one or more matrices with alteration of the printing exposure or other effective factor, thus involving additional expense and offering no certainty of producing the precise optimum effect. This invention permits simple adjustments in a mechanically operated apparatus to vary the density and color balance in an assortment of trial prints from which a careful selection may be made so that the preferred picture may be reproduced accurately by the machine as many times as desired.

Imbibition printing involves first dyeing the matrix, second, cleaning excess dye solution or the like from the surface of the matrix, third, the imbibition step, and fourth, the separation of the 5 matrix and print, and application, in color work, of other component color .impressions to the print. When the matrix is dyed, it ordinarily is soaked in the coloring material, this step requiring a definite lapse of time for even penetration of the dye. Cleaning the matrix frees the surface of the matrix from surplus dye and foreign particles and may be done in an acidulated bath, the acid preventing the removal ofdye from the inte rior of the gelatirie- When thus performed,- This operation may rather than to alterations of contrast; Lengthto secure accurate registration of the respective matrices with the blank.

Prints made in this way often prove objectionable due to color cast or a general excess of one or more of the component colors or, less often, due 5 to an excess or deficiencyof all of the dyes, thus giving too dark or too light a 'print. Even when quantitatively slight, such defects greatly reduce the practical acceptability of the prints; and several attempts to vary or qualify the steps of the m print-making process in order to avoid remaking matrices have been suggested as, for instance, to lengthen or shorten the dyeing time or the imbibition time, to dilute or acidify or otherwise alter the dye solution, to repeat the application of one or more of the matrices, to remove dye from the finished print by imbibition into a fresh blank, etc.

We have found that none of the above suggestions can advantageously be followed to provide such adjustments of color balance or density as are desirable in making high quality prints. The ideal adjustment should be 'one which corresponds to a change or changes in matrix exposure ening the time of dyeing beyond that required for the dye to reach equilibrium is not effective in any way, and lengthening the time of imbibition beyond a certain period affords no appreciable effect except a possible loss in definition. The shortening of such times tends to spoil the gradations rather than changing general density, since the time which suffices for migration of the smaller amounts of dye into the shallow reliefs is inadequate for the transfer of largeramounts of dye through the deeper relief layers, so that the heavier densities simultaneously suffer disproportionately. Thus the corrections produced cannot balance the colors properly for both dense and light portions of the picture. Alteration of the dye composition alters the contrast rather than the general density, while repeated matrix applications have similar results, upsetting color balance for certain density ranges of the picture even if correcting it for others.

To avoid such disadvantageous results, we have introduced a further step which not only incidentally supplies the cleaning function hitherto aiforded by rinsing, but which also permits the positive and accurate control of the color con trast of the matrices to afford the precise type and amount of image'alteration which is desired.

This new procedure involves, first, melting especially heavy matrices and, second, removing substantial proportions of the coloring matter from the various relief thicknesses of these matrices. The matrices preferably are substantially overprinted or overexposed, ordinarily to the point; for example, which would make them unsuitable for use in the conventional imbibition process. The partial dye removal is then preferably accomplished by means of a washing or spraying process evenly applied to the entire matrix area for a predetermined time. The degree of dye removal achieved depends upon several factors, such as time or duration of the action, temperature, force of liquid impingement, and composition of the liquid. One or more of these factors may be varied to produce the type of correction desired, while the others preferably may be kept rigidly constant to facilitate convenient and accurate control.

This dye-removal step of course is not a complete elimination like hypo removal after photo graphic fixing; neither does it merely rinse off liquid and dirt particles from the surface of the matrix; in fact, its effect for our purpose is independentof the latter function. This controlled dye removal essentially causes the diffusion or migration of dye molecules and ions from the deeper portions of the matrix where the dye concentration is substantial, to the surface of the relief which is kept substantially free from dye by the impinging liquid that removes the dye particles as they reach the surface. It is a smoothly progressive process beginning rapidly and continued more and more slowly until terminated; it may be accurately controlled and later precisely reproduced by maintaining the variable factors constant.

The process of course results in the removal of a greater amount of dye from the thicker relief portions of a single matrix than from the thinner relief portions thereof, but this dye removal is not proportionate to the respective depths of the relief portions, proportionately more dye being removed from the thinner portions.

When different matrices are successively passing through the apparatus, the conditions of dye removal may be adjusted in accordance with the characteristics of the-respective matrices; this is entirely practical, since the dye removal step need not require as long a time as either the dyeing or the imbibition. Such control of the dye removal from the respective matrices is necessary to permit the proper making of various prints in rapid succession.

Our preferred method of correction involves the variation of the time during which the dyeremoving liquid acts upon the matrix,'while the temperature and composition of the liquid and the force of impingement are maintained constant. The temperature may readily be maintained by an ordinary thermostatic control and the composition of tap water is usually constant enough for practical purposes, its alkalinity being the chief factor governing the speed of removal of acid dyes from gelatine. However, in localities where the water is too variable, it can readily be controlled in well-known ways.

To secure strict uniformity of action over the picture area, the dye-removal operation should not end in mere haphazard draining off of the liquid, because this would tend toward irregular dye removal where the liquid stands on: the matrix in drops or flows in narrow streams. This operation can be terminated by a blow-off with compressed air or a stop bath such as an acid solution; but, since either of these would require additional equipment, in machine operation we sired.

prefer to secure definite termination of the dyeremoval step by continuing it up to the start of lmbibition. Therefore, in passing matrices through the successive steps on the machine it is preferable to vary the point at which dye removal begins, ending it always at the point where matrix and blank are brought together for imbibition.

It will be evident that this controlled dyeremoval step has great practical value in a commercial process of imbibition printing. Color originals from which matrices are to be made, such as, for instance, sets of separation negatives, naturally vary somewhat in color balance between the components of each set, besides varying in general density in relation to other sets. Hence the making of matrices usually involves individual judgment regarding exposure times. It is practicable for the negatives to be judged in this way well enough to give fairly satisfactory general density. In color balance,-

however, small variations are very noticeable indeed, and have hitherto required the making of new matrices to make the necessary adjustment by different printing exposures. The present invention involves making each set of matrices too dense for use in any conventional imbibition process, and then substantially reducing the dye content by dye removal, varying the precise degree of removal to obtain by trial the results de- Prolonged dye' removal from an overprinted matrix is effective in changing the characteristic curve of the relief image from a nearly straight line which approaches zero density with practically undiminished slope to a curve much more like that characteristic of ordinary photographic material which approaches zero density with steadily diminishing slope. This change in shape of the low density portion of the characteristic curve we have found takes place rapidly for only a limited time after dye removal is begun. The principal effect of further moderate dye removal is to shift the curve horizontally without substantial change in its shape, particularly if the original curve were very steep at its the relief matrix, and thus it is just the type of correction needed to restore color balance to the pictures made from a set of matrices whose relative printing exposures have not been precisely correct. This is the reason we prefer to give the matrix a relatively heavy exposure, making it dense enough to withstand, without loss of highlight detail, sufficient dye removal to cause the characteristic curve to attain a state where some further dye removal does not greatly change its shape but rather shifts it as a whole horizontally. Corrections may then be made by further moderate dye removal from such of the matrices as may require it without seriously affecting the shape of characteristic curves, to give correct color balance and general density to the picture. Such corrections are approximately the same as might be obtained by remaking one or more of the matrices with altered exposure; but we achieve this result with far less trouble, time and expense, and can continue variations in successive trial transfers without substantial cost until the final picture shows a high degree of perfection.

In order advantageously to employ this principle, it is necessary to overprint each matrix corresponding to each color aspect of the final print. Such overexposure is greater than that which would permit satisfactory employment of the matrices in the conventional imbibition process and is suflicient to permit very substantial dye removal while leaving suificient dye in the low relief portions of the matrix to permit adequate reproduction of the highlight portions of the picture. Thus the overprinting of each matrix of a set is suflicient to permit the very substantial dye removal that will result in the change of shape of the characteristic curve of each matrix of a set, to the point where some further dye removal does not materially affect the shapes of its curve, 1. e., so that the curve is brought into a range of substantial immunity to change in shape when subjected to some additional liquid impingement. When all the matrices are treated to this general extent, 1. e., so that their curves are brought into the range of substantial immunity to further change in shape, a variation in the amount of dye removal from the individual matrices permits adjustment of the relative color densities so that the color aspects of the print are properly balanced, while the contrasts of the highlight and deeper portions of the individual matrices of the set substantially correspond with each other so that there is a proper color balance I in both the highlights and the dense portions of the finished print. I

In order to maintain satisfactory uniformity so that a plurality of prints may be substantially identical in appearance we have found it highly desirable, if not practically essential, to pass the respective. matrices through cycles of operations on circuital carriers, and for this to employ as many carrying circuits as there are colors to be applied, so that each matrix traverses the required steps automatically and repetitively. For simultaneous production of various kinds of prints, each circuit carries various matrices, spaced, of course, in the same order for all the circuits. Accordingly, one aspect of the present invention relates to machines for performing the. method which has been briefly described.

A machine for this purpose may provide a circuit which may be in the form of a matrix conveyor loop extending about suitable supporting and driving means. The lower run of this loop may conveniently be horizontal and may be ar ranged in juxtaposition to a shallow tank containing the dye solution. Preferably the conveyor loop is in the form of two spaced parallel chains which have their lower runs extending along opposite sides of the tank but out of contact with the dye therein. Since the dye solutions ordinarily employed may be acidified and in any case should be kept clean, this out-of-contact position is an important factor in protecting both the chains and the dye from deterioration which would result from their interaction.

The matrix may be supported on a suitable bar assembly which rides on the top edges of the dye tank, having its central portion arranged to support the matrix and hold it in a position to contact the blank or be immersed in the dye solution within the tank. Its end portions are attached to the conveying means. The bar assembly is provided with pins which definitely locate the matrix in relation to the assembly and which also may be employed to assure accurate registry of the successive matrix images impressedon the blank. It should be noted that matrices are usually made of thin flexible Celluloid, and the indexing portions of each of the color-component matrices in a "set will consist of marks such as holes or other openings, or definite-portions of the edges or corners of the matrix cut in a special optical image-registering operation in each Celluloid strip near the end where imbibition contact must first be made in the printing operation. Such indexing portions of the Celluloid may be too delicate to be reliable for bringing a matrix many times into automatic registering contact on a machine and they may be reinforced in such a way that registry will be maintainedthrough the repeated strains of the pressure of the rollers or pressure pads against the matrix as it is being forced into contact with the blank. This may be accomplished by mounting the matrix over its full width at its registering end (i. e., its forward end) on a pin-carrying bar, the pins accurately contacting the indexing openings as much as necessary and an upper bar being provided to hold the matrix tightly on the lower pincarrying bar, not only because the registration must remain positive but because the two-bar assembly now operates as the matrix carrier, preceding it throughout the entire path. Such a register-mark reinforcement is extremely positive and is also removable; and this matrix carrying element is an important part of the machine.

Since this matrix-carrying bar assembly must not only resist the mechanical wear and tear of repeated registering operations but also the chemical action of the dye solution which may be acidified or otherwise corrosive, the material with which they are made or surfaced is of great importance. They might be made of nickel, monel, or stainless steel, but we prefer to make themof more ordinary metals and apply a wearresistant and non-corroding surface by means means an oscillating spray pipe may be arranged to spray dye over the matrices, the dye jets traveling transversely relative to the path of the matrices. We have found that this substantally reduces the time required to dye the matrix to equilibrium. This is apparently due to the constant replenishment of the dye content of the layer of dye solution in contact with the gelatine of the matrix.

From the dyeing region the matrices pass to the region of adjustable removal of dye from the matrix. In the dye-removal portion of the apparatus, we preferably provide means to cause the impingement of water upon the matrix. For this purpose an oscillatoryspray bar may be arranged to direct water, under controlled conditions of temperature and pressure, upon the printing surface of the matrix. Since it is difllcult to make a stationary spray having precisely uniform action over a large area, and particularly difllcult to maintain its uniformity due to the tendency of small orifices to plug up, we prefer to secure uniformity by movement of the spray over the. matrix. Since the matrix preferably has a uni form motion in one direction already, we secure uniform spray action over the whole area by moving the sprays with approximate uniformity in another direction, i e., transversely of the matrix-path and preferably, though not neces sarlly, at right angles thereto. A simple mechanical device for this is a pipe approximately parallel to the matrix-path, with a line of perforations or spray nozzles along one side, held stationary as to its axis but rotated or oscillated to distribute the spray across the matrices as they travel. If the motion is oscillatory, it should extend beyond the edges of the film to avoid acting excessively at the limit of its oscillations, due to the pause between advance and return.

To permit convenient adjustment of the extent of dye removal from the matrix, means may be provided to vary the dye-removal time by altering the' length of the matrix path in which removal takes place. This variation comes preferably at the beginning of the spray path, since after the desired dye removal is completed the matrix should pass promptly to the imbibition zone as aforementioned to minimize bleeding and irregular washing out of dye by the adhering film of liquid. The matrix path should be directed downward at the beginning of the dyeremoval zone, so that the dye-contaminated water will flow to the drain without wetting portions of the matrix which have not yet arrived at the beginning of the wash path.

After dye removal, the matrix may be brought directly into engagement with the blank to be printed. The water-soaked blank is arranged on a support having means to register with the pins of the bar assembly by which the matrix is transported. When registered, the matrix and blank are pressed into firm engagement in the presence of an adequate supply of water to exclude air from between them and are held in engagement during a considerable portion of the matrix cycle. Thus the matrix and blank remain together as they pass along substantial runs of the chains. Upon reaching the end of this portion of the circuit, the blank is separated from the matrix and the latter thereupon returns to the dyeing region.

One important aspect of this invention involves a support for an individual blank so that the wet blank can not readily change its shape or position with regard to its own registering or supporting means in the intervals between successively registering with the respective matrices of a set such as are employed for color printing. For this purpose we preferably secure the back of the blank to a rigid supporting plate. To this end the blank may be removably cemented over its whole area, or at two or more portions, not too near together, to a fiat surface of the plate, this plate being provided with means automatically to engage the bar assembly in a predetermined manher so that the blank may accurately register with each matrix as it passes through successive portions of the apparatus.

For the purpose of illustration a typical embodiment of the invention is shown in the accompanying drawings, in which Fig 1 is a side elevation of apparatus for directing one matrix through its circuit, this figure being somewhat diagrammatic in character and having parts shown in section;

' Fig. 2 is a section of the dye-removal portion of the apparatus illustrated in Fig. 1. being shown upon a larger scale and various parts being shown in elevation;

Fig. 3 is a plan view of the portion of the apparatus shown in Fig. 2 with related parts;

Fig. 4 is an enlarged sectional view taken on line 4-4 of Fig. 2;

Fig. 5 is a plan view of a blank support;

Fig. 6 is an enlarged section on line 66 of Fig; 5;

Fig. '7 is an enlarged sectional detail of a portion of the machine, showing the manner in which the matrix and blank are brought into registration;

Fig. 8 is a similar view showing the parts in a slightly more advanced position;

Fig. 9 is an enlarged section indicated by line Q-El of Fig. 1;

Fig. 10 is a view similar to Figs. 7 and 8, but showing the matrix and blank supported in a still further advanced position;

Fig. 11 is an end elevation of a portion of the machine, one part being shown in section;

Figs. 12 and 13 are elevational details of the pressure rolls which effect the firm engagement of the matrix with the blanks, parts being shown in section;

Fig. 14 is a plan view of the right-hand end portion of the machine illustrated in Fig. 1;

Fig. 15 is a diagrammatic view showing how a plurality of machines may be arranged to receive a blank or blanks in succession thus to print a plurality of colors thereon;

Fig. 16 is an enlarged section indicated by line liili of Fig. 1;

Fig. 17 is a side elevation, diagrammatic in character, showing a portion of a machine provided with automatic means to control the lengths of successive dye-removal treatments;

Fig. 18 is a sectional view indicated by line l8l8 of Fig. 17 and being somewhat diagrammatic in character;

Fig. 19 is a top view of a detail of the conveyor mechanism employed with the embodiment of the machine illustrated in Fig. 1'7; and

Fig. 20 is a wiring diagram with cooperating parts of the mechanism diagrammatically indicated.

In order to facilitate an understanding of the improved method of lmbibitlon printing which we have devised, we will first describe apparatus which may be employed in performing the method. Such apparatus may conveniently comprise a series of similar devices or machines corresponding in number to the number of colors to be printed. Thus, for example, if three colors are to be printed in succession upon the blanks, three similar machines may be employed. In the accompanying drawings a machine of this type is shown somewhat diagrammatically in side elevation in Fig. l.

The machine may comprise a framework including suitable legs I supporting a platform or table portion 2 upon which an elongate shallow tank 3 is disposed. This tank contains dye solution, such, for example, as acid dye in acidified aqueous solution, which is suitable for imbibition printing. Disposed adjoining the mid-portion of the table 2 and at either side thereof are uprights 4, the upper ends of which are connected by a skeleton framework 5. At one side of the machine a pair of uprights 6 are connected to the adjoining uprights 4 by diagonal frame members 1.

Mounted upon the framework are suitable sprockets for supporting and driving a pair of endless bands or chains II. Thus a pair of sprockets I2 is located at each end of the tank 3, the sprockets of each pair being disposed at opposite sides of the tank and slightly spaced therefrom. A pair of sprockets I4 is mounted on a shaft l5 carried by one of the pair of uprights 4, while a shaft l6, supported by suitable journals, carries a pair of sprockets l1, and a shaft l8 carries a pair of sprockets l9 in the region of the other pair of uprights 4. Suitable driving means is associated with the shaft carrying one of the to the matrix and connected by the loop bands to pairs of sprockets. Thus, for example, a driving element such as a belt or chain 20 may be connected to a sprocket or pulley 2| which is mounted on the shaft that supports one pair of the sprockets I2, as indicated at the right of Fig. 1.

Secured to recurrent links of the chains II are matrix carriers 26 including bars 25, each having a substantially straight portion suspended within tank 3 and having end elements 28 extending upwardly and over the sides of the tank with downturned extremities 24 in engagement with the chains (Fig. 9). Thus, it is evident that the chains I I are disposed out of contact with the dye solution and, in fact, may be arranged below the upper edges of the sides of the tank so that they are effectively protected from the acidified solution yet are in the same plane as the matrixcarrier.

In order that the conveyor means may function efficiently in carrying the matrix through the various operations, especially through those of registering and imbibition, it is very helpful to have the matrix travel on or near the pitch circle of all sprockets, guides and chain belts. Energy transmitted through the chain is thus directly applied to moving the matrix forward in the same plane, and much greater smoothness of mechanical operation results especially at the point where the chains drive the matrix-holding bar assembly through the pressure rolls.

It is, however, also essential that the entire matrix area be submerged in the dye tank in order that all of its area expand equally. It is especially important that the area held by the bar assembly should be submerged, because that is the head or registering end of the matrix and any unevenness caused by uneven wetting would immediately show up at the head of. the print in areas of uneven imbibition and in bad register, as well. We have found that a simple way to accomplish this result is to join the matrix-holding bar to the conveyor means by U-shaped end elements which allow the chain to travel on the outside of the dye tank as far below the edge as the matrix is below the edge on the inside of the dye tank.

The bar assembly 26 may also include a removable retaining bar 30 which is provided with openings to register loosely with the pins 21 projecting from bar 25 and whichmay be held in juxtaposed relation to the latter by a spring clip or clips 3| which may conveniently be formed of resilient wire and are received in grooves in the bar 30. The bars 25 and 30 thus afford a clamp to engage and firmly to grip the matrix M. For this purpose the matrices may be provided with openings accurately corresponding with the component images carried and adapted to register with the pins 21 upon the bar 25 on each machine. Thus the matrix is held accurately positioned upon the bar assembly. I

While the bar assembly 26 may be effective in supporting the advance portion of the matrix, it

is desirable, particularly in the case of large matrices, to provide means to Support its opposite end upon the chain. For this purpose a bar 25 (Fig. 14), similarin contour'to the bar 25 but lacking the pins 21, may besecured to links of the chains I I in spaced relation to the bar 25. The bar 25 is provided with notches or slots 29 which may engagesuitable supporting means such as metal or elastic bands that may be looped through openings in the-corners of the matrix. Preferably, however, tabs T of matrix stock are cementitiously or otherwise ifimovably secured upon the relief surface of the matrix.

the bar 25, as shown in Fig. 14. It is thus evident that means is provided to support the matrix substantially in parallel relation to the horizontal chain runs extending along the tank 3.

After the matrix leaves the tank 3 it may pass upwardly along the inclined runs of the chains extending between the sprockets I 2 and sprockets I4. This portion of the apparatus may include additional dyeing means arranged to spray dye Such means as shown may be employed in combination with the dyeing tank, although, if desired, spraying means of this general character may be used in place of, rather than in addition to the tank. For this purpose an inclined tray I10 (Figs. 1 and 16) is arranged adjoining the inclined chain runs to receive the matrix-carrying bars 25 and 25 the chains being juxtaposed to or resting on the side walls of this-tray. A board I86 is disposed in this tank to support the back of the matrix, the carrier 26 moving over this board. Above the inclined tray is an inclined oscillatory spray tube III, which is driven from a shaft I12 having a crank arm I13 connected by a link I14 to an oscillating arm I15 flxedto the tube III. This driving means is of a type which will be more fully described in connection with the oscillatory tube which is employed in the dyeremoving portion of the apparatus.

A sheet metal hood "8 is arranged above the inclined tray I10 and about the spray tube to prevent scattering of the dye, the lower edges of the sides of the hood extending into the U-shaped end elements of the matrix carriers. The ends of the tank I10 are of course cut away to permit the movement of thecarriers 26. The lower end of the tank IIll is provided with a drain I80 which communicates with the tank 3; the latter is connected by a duct I 8| to a pump I82, which supplies a flexible duct I83 with dye, the duct I83 communicating with the lower end of the spray tube "I. With this arrangement the tube is oscillated so that. the entire surface of each matrix is subjected to substantially uniform impingement of sprayed dye.

Such dyeing means isparticularly efi'ective in assuring the rapid absorption of the dye by the relief matrix, since it keeps dye solution having a full proportion of dye in intimate contact with the surface, thus permitting more rapid absorption than occurs in the tank.

After passing the sprockets I4, the matrix passes along downwardly inclined chain runs (Figs. 1 and 2) in the dye-removal portion of the machine, which will now be described. This portion of the machine includes an oscillatory pipe or spray tube 40 which is connected by a flexible duct or hose 4| with a source of water under constant and suitable predetermined pressure and preferably of controlled temperature. The tube on a shaft 43 provided with a pulley 44 which maybe driven by a belt connected toa suitable 40 is provided with an outstanding arm 4Ii which Y is connected by a link 42' to a crank 42 (Fig. 11),

driving pulley. Rotation of the shaft 431s thus eflective in causing the spray tube 40 to oscillate.

The tube 43 is inclined downwardly toward the. right-hand end of the machine as viewed in Figs,

1 and 2 and is provided with a plurality of spray orifices spaced along its length. A trough 50 is arranged in inclined position beneath the upper,

a short endless belt I90 running around two pulleys spaced apart approximately the length of the trough. The larger of these pulleys has a circumference approximately equal to the length of the trough, so that one complete revolution of the large pulley I93, shown in dotted lines in Fig. 1, will move the trough from its maximum position to its minimum.

A rotating shaft I 94 connects the pulley I93 to an operating crank. This crank is provided with a pointer-like extension which moves over a fixed calibrated scale. Any suitable locking means may be provided to hold the pulley and crank in adjusted position, but we prefer to arrange these parts so that friction is effective for this purpose. Obviously movement of the crank causes movement of the trough 50, this varying the duration of the dye-removal time while the dial permits convenient ascertainment of the adjusted position of the trough and thus affords a direct indication of the extent of the dye-removal time.

Disposed at either side of the spray bar and below the same are the walls of a sump I0 which is provided with a drain II. The lower end of the trough 50 ,may be provided with a drain 12 so that the water intercepted by the trough is diverted from the matrix and is received by the sump I0. When the matrix M is being washed, it is carried by inclined portions of the chains II so that it is in an inclined position, as particularly shown in Fig. 2. An inclined panel BI is arranged to support the matrix while it is thus subjected to the water jets. Water readily drains off from the matrix as thus positioned and falls to the bottom of the sump.

A framework or assembly'for properly feeding the blank support into registration with the matrix includes lower frame members 80 supported by a crossbar 8| and brackets 82. A crossbar 84 affords a connection between the members 80 and parallel plates 85 which are particularly shown in Fig. 4, these plates having outwardly flared upper edges and being rabbeted to receive a blank support I00 therebetween. Pivotally connected to the intermediate portion of each plate 00 is an L-shaped member 86, these members being connected to each other by a tie-bar 81. The outer ends of these members support a roller which is normally held by gravity against a blank support I00 mounted on the plates 85. A springpressed ball 88 (Fig. 4) is arranged in the rabbeted portion of one of the plates 05 to engage a suitable recess in the support I00, thus to assure proper positioning of the latter. The blank support I00 accordingly may properly register with the matrix-carrier when the latter reaches this portion of the machine.

The blank support is in the form of a rigid plate IOI which may be conveniently formed of aluminum and which has a beveled advance edge I02, particularly shown in Fig. 6. The plate IOI is provided with a groove I03 adjoining its beveled edge,'and reinforcing blocks I04, which may cenveniently be formed of wear-resistant material such as steel, are secured in this groove. The blocks I04 and the corresponding portion of the plate are provided with openings I05 to register with the pins 21 upon the matrix supporting assembly 26. I

Figs. 7, 8 and 10 illustrate the manner in which the matrix and blank are brought into accurate registration. The pins 21 upon the assembly 26 are shaped substantially as shown in these figures so that their beveled and tapered extremities may I illustrated in Fig. '7.

be initially received by the openings I05, as As the assembly 26 con tinues its movement about the sprockets I9, the beveled end of each pin passes through the corresponding opening I05 so that the blank support is drawn forward as the matrix support continues its movement about the sprockets (Fig. 8). The roller 90 holds support I00 against upward move: ment as this occurs. As the paths of the matrix support and blank support converge, the pins 21 are pressed upwardly so that their lower properly dimensioned portions fit tightly within the openings I05 (Fig. 10),

Rubber pressure rollers H0 and III are arranged so that the beveled end of a support I00 may readily pass through the bite of these rolls which are effective in pressing the surface of the matrix into intimate contact with the surface of the blank. Rollers H0 and III are supported and yiel-dably urged toward each other by U- shaped springs II2; the latter are supported by hangers II 4 secured to diagonal frame members I.

It is evident that the rollers H0 and III readily permit the assembly 26 and pins 21 to pass therebetween, as shown in Fig. 12. Since the blank and. matrix are firmly pressed together, air is excluded and the relief surface of the matrix is pressed into wet engagement with the surface of the blank. In order to cause the contacting surfaces of the matrix and blank to be uniformly wet, a pair of jet elements 200 may be arranged to supply jets of water to the space between the blank and matrix as they approach the bite of rolls H0 and III; see Figs. 3, 10 and 11. Due to the exclusion of air, the external atmospheric pressure aids in holding the matrix and blank together as they move downwardly along the chain runs to the station A, where the blank support with the blank thereon may be lifted out of engagement with the matrix; the blank support may then be transferred to a successive machine, while the matrix returns to the dye bath.

The shafts which support the pair of sprockets about which the chains II are wrapped also each preferably support a pair of rolls or disks I20 (see Figs. 3 and 14) about which the matrix may bend as it follows the curved portions of the chain run. Thus buckling of the matrix is avoided.

Obviously the machines which successively receive the blank may be driven in synchronism, the chains of each machine moving at a uniform speed which is determined by various factors. This speed may vary in accordance with the character of the dye being employed; i. e., a dye that is readily taken up by the matrix and readily transferred to the blank permits a more rapid movement of the matrix. It is to be noted that the longest portion of the cycle is devoted to the dyeing zone, 1. e. the dye bath and/or dye spray so that a substantially even penetration of the various portions of the matrix may be effected. Furthermore, another relatively long portion of the cycle is devoted to the imbibition path where the matrix and blank are held in firm contact. Thus a substantial fraction of the total time of the cycle is employed to permit effective transfer of the dye from the matrix to the blank. This operation may be accomplished more rapidly if the machine is operating under conditions of relatively high temperatures. It is also desirable, for example, to maintain the dye bath at a temperature above normal room temperature to facilitate absorption by the matrix. High humidity pressure of impingement is increased. The ar- 1 is also believed to ensure more accurate registration of the. blank and matrix by effectively reducing the danger of shrinkage of the matrix or blank due to evaporation.

In the use of a machine of this character, the amount of dye removed from a matrix may ordinarily be from 15% to 65% of the original dye content, and more commonly the removed dye will be over 25% of the original content. When good technique is employed in controlling the exposures in making a set of matrices, the percentage of dye removed from one matrix of the set may not diirer by more than about 10% of its original dye content from the percentage of dye removed from another matrix of the set.

A variety of factors affect the dye removal or adjustment portion of the cycle. The washing operation is more effective and consequently can be made to occupy less time if the temperature of the impinging liquid is substantially above room temperature, for example, from to F. Furthermore, 'the effectiveness of the operation may in some cases be increased if the rangement of the oscillatory bar which causes the jets to move transversely of the path of travel of the matrix ensures uniform and effective dye removal in this short period of time. The arrangement of the spraying means assures drainage of excess water from the inclined matrix, and irrespective of variations in the adjustment of trough 50, the periodbetween spraying and contact with the blank is short and uniform.

It is important to maintain evenness of dye image in theinterval between dye removal and imbibition, and we therefore direct some of the water spray jets so that the even washing action is continued to within a very short distance of the point of contact between matrix and blank.

The time from the sweep of the last spraying jet over the matrix till the matrix enters the water of the imbibition contact area should not be so great that bleeding of dye from the matrix becomes appreciable, unless an acidified bath intervenes, or an air blow-off has been used.

Obviously the blank support is positioned so that the matrix supporting assembly 2% and the blank support are first brought into rough registration, as shown in Fig. 7, and finally into very accurate registration, as shown in Figs. 10, 12 and 13. Thus extreme accuracy of most parts of the mechanism is not required in order to assure accurate registration of the matrix and blank.

Machines of this type obviously will carry a number of matrix supports spaced around the entire chain loops, and a mechanically operated adjusting means may be provided to vary the efiectiveness of the wash automatically as the respective matrices reach the washing stage, in accordance with control settings established manually. It is furthermore contemplated that an automatic carrier arrangement may be provided to remove the blank supports from one machine, transport and. fit them to the succeeding machine, without manual labor.

Figs. 1'7, 18, 19 and 20 show an automatic arrangement for controlling the length of the dyeremoval treatment to suit the characteristics of individual matrices. Thus when a plurality of matrices are moving about the circuit of a single machine, the machine may be adjusted so that the extent of dye removal may be automatically adjusted as each matrix approaches the washing zone. Accordingly the necessity for manually resetting the trough 50 is avoided. Fig. 17 is a somewhat diagrammatic view of the dye-removal portion of the machine provided with automatic control means of this character. For this purpose a transverse rod 250 may be disposed between the chain runs in advance of each matrix carrier, and a small support 25l may be secured to one chain in advance of each rod 250. The support 25l carries an upstanding pin 252 which may be engageable with a depending portion of a switch. Similarly a button or pin 254 on the bar 250 may be engageable with one of a row of switches disposed transversely of the path of the chain runs. If, for example, it is desired to provide for adjustments of the trough 50 to three intermediate positions, each bar 250 may be provided with three pin-receiving openings 250, the pin 254 being manually located in the proper opening to give the desired adjustment of the trough 50.

I An electric motor P is arranged to move the trough 50 upwardly to the upper end of its path. For this purpose a small drum 260 may be driven by the motor to wind a cable 261 connected to the trough 50, as shown in Fig. 1'7. A plurality of electrically controllable stops 265 are movable into the path of a pin 210, which is secured to the trough 50 (Fig. 18). Preferably in this embodiment of the invention the trough may be provided with a cover 50 in order to preclude sprayingof any of the washing liquid onto the electrical contacts or the like. Each stop 265 is disposed on an arm 2' depending from a noncircular armature bar 212, which is associated with a double solenoid comprising magnets 213 and 214-. The armature bar preferably is disposed horizontally so that when one magnet, as the magnet 2'13, is energized, the stop member 265 is moved to one position and remains in that position, as, for example, the full-line position of Fig. 18. until the other magnet 214 is energized. It is evident that when the appropriate magnet 2'13, for example, is energized, the corresponding stop member 265 moves into the path of the pin 2'10 so that the downward movement of the trough 50 is thus limited.

A suitable cut-out switch 2'18 is arranged so that it may be closed by the trough 5t as the latter approaches the upper end of its path, this switch being efiective through suitable motor control means in deenergizing the motor so that the trough is released for downward movement under the influence of gravity. The motor control means includes a solenoid assembly somewhat similar to that shown in Fig. 18, having opposite magnets 284 and 285 with a horizontal armature bar 2536 controlling a mercury switch 281. The magnet 2% may be controlled by a switch 288, which is engageable by the pin 25!, while the magnet 285 is controlled by the cut-out switch 218.

An understanding of the operation of this apparatus may be best obtained by having reference to Fig. 20, which is a wiring diagram with certain cooperating parts shown diagrammatically. It.

will be understood that the pin 254, which is located in one of the openings 250 engages one of the switches 290, which are disposed in the paths of pins disposed in the openings 250 of bars 250. Thus, as shown in Fig. 19, the bar 250 is provided with three openings, the pin 254 being illustrated as disposed in the middle opening so that the pin will engage the middle switch 290, shown in Fig. 20. The switches 290 and the switch 288 may be disposed in a transverse row,

and suitably supported by a frame member 300 on the machine.

Since the pin 25I is disposed in advance of the bar 250, the switch 288 is first closed. Switch 288 has one contact connected to a lead l at one side of the electrical supply line, this lead being provided with branches 302 extending to contacts of the switches 290, and a branch 303 extending to a contact of the switch 288. When the latter is closed by the pin 25!, current can flow from the lead 30l through the branch 303 and switch 288 to a lead 304 which is connected to the magnet 284 of the motor control mechanism. A return lead 301 extends from this magnet at the opposite side of the supply line. Thus the magnet 284 is energized and the armature bar 286 is moved toward the left, as viewed in Figs. 17 and 20, thus closing the mercury control switch 281. One contact of the latter is connected to the lead 301 and its other contact is connected by leads 3H and 3I2 to the motor P. A lead 3l6 extends from the latter to the lead 30 I. Thus when the switch 281 is closed, current may flow from the lead 30! through the lead M6 to the motor P, thence'through leads 3|2, 3 to the switch 281, and from the latter to the opposite side of the line, i. e. to lead 301.

The lead 3H is also provided with a continuation 3| I which has branches connected to the magnets 214 of the solenoid assemblies of the stop mechanism. Thus when the motor P is energized, current also passes from lead 301 through lead 3|B to each of the magnets 214, and from the latter through leads 3| I, 3| I, thence through the switch 281 to the main return lead 301. Accordingly, when the motor is operating, the magnets 214 are also energized. thus tending to draw eachof the stop elements 285 out of the path of the pin 210, i. e., to the position indicated by dotted lines in Fig. 18.

When the trough 50 is drawn by the motor to the upper end of its path, the cut-out switch 218 is closed, this switch having one side connected by a lead 330 to the magnet 285, and the latter being connected by a lead 33| to the main lead 35. The opposite side of switch 281 is connected by leads 334 and 335 to the opposite main lead 301. Thus when the switch 218 is closed by the trough 50, the magnet 285 is energized by current received through leads 30l 33l and passing through lead 330 to switch 218, and from the latter through leads 334 and 335 to the lead 301. Accordingly, when the switch 218 is closed, the magnet 285 opens the switch 281, which causes interruption of the operation of motor P and deenergization of magnets 214. By the time that this has occurred, the switch 290 to control the appropriate stop element 210 has been closed by the pin 254. As previously explained, one side of each switch 290 is connected by a lead '303 to the main lead 30! at one side of the line. The opposite side of each switch 290 is connected by a lead 331 to one of the magnets 213 which are connected by leads 336 and 335 to the lead 301 at the other side of the line. Thus, for example, the intermediate switch 290 may have been closed to cause the energization of the magnet 213 of the intermediate stop mechanism.

The intermediate stop member 255 accordingly is moved into the path of the pin 210, so that as the trough 50 moves downwardly, it is stopped intermediate its upper and lower positions, thus affording the desired adjustment for the dye-removal mechanism.

It is evident that the parts remain in this position until another pin 25E engages the switch 288, whereupon the magnet 284 is again energized to cause operation of the motor P and the movement of the intermediate stop member 265 to its inoperative position, whereupon the cycle of operations is repeated, the particular stop member 265 which is next disposed in the path of the pin 210, however, being determined by the location of the pin 254 upon the next bar 250.

It is evident that the motor P may be provided with a suitable electromagnetically controlled clutch automatically to release the trough 50 for its downward movement if such an arrangement is preferred. It is furthermore evident that, while for purposes of illustration we have shown three switches I90 and three stop assemblies, in practice a substantially larger number of these switches and assemblies may be provided to permit finer automatic adjustment of the extent of dye removal.

In order to mount the blank in proper position upon its support and to properly condition the same for imbibition printing, the blank B is first wetted thoroughly and then secured, for example, by a suitable temporary cementitious material, such as a rubber cement, to the surface of the supporting plate HJI, care being taken that wrinkles and foreign particles are avoided. To aid in cementing the wet blank to the support, its rear surface may be waxed before wetting, if desired. Obviously the blank may be in the form of paper with a gelatine coating capable of absorbing dye, although transparent blanks may also be employed.

In using machines of the type described to perform the method of this invention, a blank support is first prepared in the manner described and, in practice, if runs of prints from various matrix sets are to be made, as is commonly the case, a plurality of successive supports is provided with blanks secured thereto. The first support with the blank thereon is then mounted in the position shown in Fig. 1 and the matrix is connected to the bar assembly 26 in the manner described and preferably connected to a bar support 25. The matrix then passes through the tank 3 which is partially filled with a dye solution of the desired color. It is evident that the matrix is immersed in or in contact with the dye solution for a considerable fraction of its total path so that a relatively long period is provided during which the matrix may absorb dye to approximate equilibrium. Agitation of dye or matrix is highly desirable during this period and heating may also be advantageous.

Then the matrix passes upwardly along the chain runs between the sprockets l2 and I 4 where it may, if desired, receive additional dye. The matrix then passes along the inclined chain runs in the adjustment portion of the machine. Here a substantial proportion of the contained dye is removed by impingement of-water from the oscillating spray bar 40. Due to the oscillatory movement of the latter, all parts of the matrix are exposed to a substantially uniform total washing action in traversing the entire wash path. The forcible impingement of the water upon the matrix permits an effective washing which assures highly dependable and uniform results. The adjustment of the amount of dye removal by suitable variation of the position of trough 50 is a singularly important factor. This adjustment may be varied successively for the component matrices, to make a number of slightly differing proof prints among which the best may be chosen for reproduction; adjustment may be made by trial and error. Alternatively, these two methods may be combined, trial and error giving an approximately correct print; then a few prints differing slightly in different ways from this may be prepared. For instance, one darker, one lighter, one more yellowish, one more pinkish, one more bluish, might be prepared, and a careful selection made, then the apparatus be adjusted to provide duplicates.

The use of the continuous endless band conveyor mechanism in this case is not merely for the purpose of eliminating or reducing hand labor, as is often true of machines, but it is needed to give the absolutely precise control of dyeremoval times that is essential to produce identical duplicate prints with certainty.

In transfer printing of the present type, dyeingup times, dye-removal times, interval between dye removal and beginning of imbibition, length of transfer period, are all more or less critical because the color carrier is three-dimensional, and solid, and has migration taking place within it in a direction perpendicular to its surface; and variation may result in a change of color balance if not carried out for each successive similar print in an identical way. The machine needed for this work can not be stopped for a substantial time without spoiling to a degree some or all of the next succeeding prints which will be made from the matrices which are in various stages on the various circuits. For practical operation the carrying means should preferably take the form of endless flexible bands. The continuous synchronized cyclic operation of these endless bands so as to control the timing of each repeated operation precisely is an important aspect of this invention.

Each of the machines corresponding to the respective colors to be printed may be adjusted as regards its dye-removal step, to permit the desired color balance of the corresponding print or in compensating for any other factor which has influenced the preparation of the matrix and tended to cause it to print with too great or too little intensity.

It is evident that the present invention permits color balance corrections to be made while the matrices are actually in the printing apparatus, it being possible to make such corrections and to adjust or reverse the same while the apparatus is actually operating.

It should be understood that the present disclosure is for the purpose of illustration only and that this invention includes all modifications and. equivalents which fall within the scope of the appended claims.

We claim:

1. The method of printing pictures in natural colors with imbibition matrices which comprises the formation of over-exposed matrices corresponding to different color aspects of the scene, dyeing the matrices with dyes of appropriate colors respectively, counteracting the over-exposure by removing from the matrices enough dye not only to change the shapes of their characteristic curves correspondingly but also bodily to shift the curves relatively to each other, while regulating the color balance between the matrices by varying the relative degrees of dye removal from the respective matrices.

2. The method of printing pictures in natural colors with imbibition matrices which comprises the formation of over-exposed matrices corresponding to different color aspects of the scene, dyeing the matrices with dyes of appropriate colors respectively, removing more than 25% of the dye, while regulating the color balance between the matrices by varying the relative degrees of dye removal from the respective matrices.

3. Method of transfer printing, comprising preparing a set of greatly over-exposed colored matrices, washing all the matrices to remove 15% to 65% of the coloring therefrom, While selectively terminating the extent of wash of indivldual matrices to obtain proper color balance.

4. Method of transfer printing by imbibition, comprising preparing a set of dyed matrices by over-exposure to an extent great enough so that they may be subjected to thorough dye removal to bring their characteristic curves into a range of substantial immunity to change in shape upon further appreciable dye removal,-subjecting each of the matrices to individual dye removal to bring their curves into said range of immunity while controllably regulating the extent of the dye removal treatment of each individual matrix to obtain color balance and proper intensity in the high lights.

5. Apparatus for printing still pictures by imbibition comprising a blank holder, a matrix holder, means for accurately registering the blank holder with the matrix holder, means for conveying the matrix holder throughout an orbit including, in succession, means for applying dye to the matrix on the matrix holder, 2. station for attaching the blank holder to the matrix holder, and an imbibition stretch.

6. Apparatus for printing still pictures by imbibition comprising a blank holder, a matrix holder, means for accurately registering the blank holder with the matrix holder, means for conveying the matrix holder throughout an orbit including, in succession, means for applying dye to the matrix on the matrix holder, blank feeding means for supporting a blank holder in position to be automatically picked up by the matrix holder as the latter passes said station.

7. Apparatus for printing still pictures by imbibition comprising a blank holder, a matrix holder, means for accurately registering the blank holder with the matrix holder, means for conveying the matrix holder throughout an orbit including, in succession, means for applying dye to the matrix on the matrix holder, means for controllably removing dye from the matrix, a station for attaching the blank holder to the matrix holder and an imbibition stretch for transferring dye from the matrix to the blank.

8. Apparatus for printing still pictures by imbibition comprising a blank holder, matrix holder, conveyor means to direct the matrix holder through an orbit including, in succession, means for applying dye to a matrix carried by the matrix holder, means for controllably removing dye from the matrix, said last-named means being adjustable to vary the extent of the dye-removal time,

a station for registering the blank holder and the matrix holder and an imbibition run for transferring dye from the matrix to the blank.

9. Apparatus for printing still pictures by imbibition comprising a blank holder, matrix holder, conveyor means to direct the matrix holder through an orbit including, in succession, means for applying dye to a matrix carried by the matrix holder, means forcontrollably removing dye from the matrix, said last-named means being arranged to subject the matrix to an oscillating liquid spray moving transversely of the path of the matrix, a station for registering the blank holder and the matrix holder and an imbibition run for transferring dye from the matrix to the blank.

10. A transfer printing machine comprising means for removing a substantial quantity of dye from over-printed matrices, said means being arranged to wash all portions of the surface of each matrix uniformly under controlled conditions of temperature, said means being adjustable to vary the time of beginning of the washing period, and

means sharply to terminate said washing period and to feed a blank into register with the matrix and to hold the same in engagement for a definite lapse of time, whereby a plurality of matrices may be uniformly treated for dye removal or the extent of dye removal may be controllably varied for the respective matrices.

11. Apparatus comprising a conveyor, a matrix holder movable along the conveyor, a dye tank, a spray tube arranged adjacent the conveyor, means to supply dye under pressure from the tank to the tube, means to cause motion of the tube transversely of the path of the conveyor, said tank being arranged to receive dye draining from a matrix carried by the matrix holder.

12. Method of printing a multicolored picture blank by imbibition, comprising causing each matrix to absorb dye, partially decolorizing the matrix by forcible impingement of liquid thereon at a controlled pressure to determine the amount of dye remaining upon the matrix, then moving the matrix into registration with a blank, retaining the blank and matrix in registration to permit printing of the blank by imbibition, and separating the matrix and blank.

13. Machine of the class described comprising a pair of parallel endless flexible supporting elements, means to drive and support the elements, said elements each having a lower substantially horizontal run, an elongate dye tank disposed between the lower runs of said elements, a matrix support connecting said elements and having a central portion disposed below the edges of the tank and end portions extending over said edges.

14. Machine of the class described comprising a pair of similar endless, parallel bands, means supporting and driving the bands, an elongate dye tank, said bands having horizontal runs adjoining the tank, a matrix supporting assembly extending between the bands and capable of carrying a matrix so that it is immersed in dye within the tank, said bands having inclined runs disposed above the first-named run, matrix washing means above said inclined runs, and blank feeding means to feed a blank into registration with a matrix that has left the washing means.

15. Method of transfer printing, comprising preparing a set of greatly over-exposed matrices, dyeing the matrices respectively with difierent colored dyes, removing a substantial proportion of the dye from all of the matrices by means of liquid impingement while controlling the factors of force of impingement, of temperature of the liquid, of the character of the liquid,'and of duration of the washing, but selectively varying at least one of said factors to effect somewhat different dye removal from individual matrices, thus reducing the amount of dye on all the matrices to between 35% and of the original amount of dye respectively thereon, and successively effecting the transfer of dye from the individual matrices to a single blank.

16. Apparatus of the class described comprising a conveyor provided with a matrix carrier, dyeing means, dye-removal means, and blank feeding means stationed along the conveyor, said dye-removal means being adjustable to vary the extent of dye removal from a dyed matrix supported by the carrier, said feeding means being effective to direct a blank into registering engagement with the matrix supported by the carrier.

17. Method of printing pictures in natural colors comprising preparing a set of over-exposed matrices, dyeing each of said matrices, then removing at least fifteen per cent of the dye from each of said matrices while selectively varying the exact amount of dye removal from the respective matrices to obtain proper color balance and leaving enough dye in their thinner relief portions to maintain adequate high-light detail.

18. Apparatus of the class described comprising a conveyor provided with a matrix carrier, dyeing means, dye-removal means, and blank feeding means stationed along the conveyor, said dye-removal means including means to cause uniform liquid impingement upon a matrix supported by the carrier and being provided with an adjustment to vary the length of the zone of liquid impingement, thus to vary the amount of dye removal.

19. Apparatus of the class described comprising a movable conveyor to move a dyed matrix along a definite path, and dye-removal means constructed and arranged to cause the impingement of liquid sprays moving transversely of said path.

20. Apparatus of the class described comprising a movable conveyor to move a dyed matrix along a definite path, dye-removal means constructed and arranged to cause the impingement of liquid sprays moving transversely of'said path, and means to selectively vary the extent of the zone of liquid impingement thereby to vary the extent of dye removal.

21. Apparatus of the class described comprising a movable conveyor to move dyed matrices along a definite path, dye-removal means constructed and arranged to cause the impingement of liquid sprays moving transversely of said path, and means automatically to vary the effective liquid impingement upon successive matrices, thereby to vary the extent of dye removal from the respective matrices.

22. Apparatus of the class described comprising a circuital conveyor, a plurality of matrix carriers movable about the conveyor circuit, dyeing means, dye-removal means, blank feeding means each stationed along the conveyor, said dye-removal means being adjustable automatically to control the extent of the dyeremoval treatment to which each of the matrices supported by the respective carriers is subjected, said feeding means being effective to direct a blank into registration with each matrix after the latter leaves the dye-removal means, whereby each matrix during successive circuital movements may be subjected to similar dye-removal treatments which may differ from the dye-removal treatments of the other matrices.

23. Method of printing pictures in natural c01 ors comprising preparing a set'of over-exposed matrices, dyeing each of said matrices, then re; moving from 15% to 65% of the original included dye from the matrices, while selectively varying the exact amount of dye removal from the respective matrices to obtain proper color balance and leaving enough dye in their thinner relief portions to maintain adequate high-light detail.

24. Apparatus of the class described comprising a movable conveyor to move a dyed matrix along a definite path, and dye-removal means constructed and arranged to cause the impingement of liquid sprays moving transversely of said path, means selectively to vary the point at which the liquid impingement begins to act upon the moving matrix, and blank feeding means to direct a blank into registration with a matrix as it leaves the region of liquid impingement.

25. Apparatus of the class described comprising a conveyor-provided with a matrix carrier, said carrier comprising a metal member to engage one end of a matrix and accurately to fit in engagement with indexing portions thereof, said member having a part to interfit with a cooperating blank holder, and means to direct a rigid blank holder into interfitting engagement with said carrier and to press the blank holder and a blank supported thereby against the matrix supported by said carrier.

2 Apparatus of the class described comprising a conveyor provided with a matrix carrier, said carrier comprising a metal member to engage.

one end of a matrix and accurately to fit in engagement with indexing portions thereof, said member having a part to interfit with a cooperating blank holder, means to direct a rigid blank holder into interfittingv engagement with said carrier and to press the blank holder and a blank supported thereby against the matrix supported by said carrier, and means to direct liquid sprays between the matrix and blank as they move into engagement.

27. Apparatus of the class described comprising a movable conveyor to move dyed matrices along a definite path, dye-removal means constructed and arranged to cause the impingement of liquid spray upon said path, adjustable means for varying the extent of the zone of impingement, and means controlled by the said movement of the conveyor and associated with said dyed matrices for determining said amount of spray removed from said path, thereby to vary the extent of dye removal from the respective matrices.

28. Apparatus of the class described comprising a movable conveyor to move dyed matrices along a definite path, dye-removal means constructed and arranged to cause the impingement of liquid spray upon said path, adjustable means for protecting a portion of the length of said path against said impingement, and means controlled by the said movement of the conveyor and associated with, said dyed matrices for selecting said protected length of said path, thereby to vary the extent of dye-removal from the respective matrices.

29. Apparatus of the class described comprising a movable conveyor to move dyed matrices along a definite path, dye-removal means constructed and arranged to cause the impingement of liquid spray upon said path, adjustable means colloid matrices, washing all the matrices with water to remove 15% to of thepcoloring therefrom, and selectively terminating the extent of wash of individual matrices with a stop bath promoting retention of coloring matter by the colloid to obtain proper color balance.

31. Method of printing pictures in natural colors comprising preparing a set of over-exposed colloid matrices, dyeing each of said matrices, then removing with a washing agent at least fifteen per cent of the dye from each of said matrices while selectively varying the exact amount of dye removal from the respective matrices to obtain proper color balance, leaving enough dye in their thinner relief portions to maintain adequate high-light detaihand terminating the decolorization with a stop bath p'romoting the retention of dye by said matrices.

EASTMAN A. WEAVER. ROBERT IY.

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