US3200726A - Method of treating photographic sheet with a liquid - Google Patents

Description

E. H. LAND Aug. 17, 1965 METHOD OF TREATING PHOTOGRAPHIC SHEET WITH A LIQUID 3 Sheets-Sheet 1 Filed Feb. 15, 1962 INVENTOR.

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ATTORNEYS E. H. LAND Aug. 17, 1965 Filed Feb. 15, 1962 Aug. 17, 1965 E. H. LAND 3,200,726

METHOD OF TREATING PHOTOGRAPHIC SHEET WITH A LIQUID Filed Feb. 15, 1962 3 Sheets-Sheet 3 INVENTOR.

EMH4- ATTORNEYS United States Patent sesame METHOD OF TREATING PHQTUGRAPHHC SHEET WITH A LIQUID Edwin H. Land, Cambridge, Mass assignor to Polaroid Corporation, (Iambridge, Mass., a corporation of Delaware Fiied Feb. 15, 1962, Ser. No. 173,496

8 Claims. (CI. 95-43) This invention relates to photographic processes and particularly to a photographic process in which a sheet is treated with a liquid distributed in a layer on said sheet.

A number of photographic processes are performed by superposing a pair of sheets and distributing a processing liquid in a layer between the superposed sheets. Many of these processes employ a photographic image-recording sheet and are performed in photographic apparatus such as a camera in which the image-recording sheet is photographically exposed and processed to produce a visible image. The processing liquid may be distributed between the sheets by movement of the sheets along convergent paths into superposition between a pair of-juxtaposed members while a fluid is introduced between the sheets through a suitable nozzle such as is disclosed in copending US. application Serial No. 159,234, filed December 14, 1961, in the name of Edwin H. Land, now Patent No. 3,142,243, issued July 28, 1964. The liquid is usually supplied to the nozzle under pressure and disrtributed by moving the sheets past the nozzle between the juxtaposed members. the apparatus to effect exposure and processing of successive areas of the image-recording sheet is accomplished by engaging at least one of the sheets either manually or by some means (e.g. rolls) and drawing the sheets befi l/631 the juxtaposed members (which may be driven ro s The invention has as an object, the provision of a novel and improved photographic process in which a pair of photographic sheets are advanced through photographic apparatus into superposition between a pair of juxtaposed members; a processing liquid is distributed between the superposed sheets, and the fluid is introduced between the sheets through a nozzle in such a way as to effect the movement of the sheets through the apparatus and between the juxtaposed members.

Other objects of the invention are: to provide a photographic process as described in which the energy required to perform the process, i.e., to move the sheets and distribute the fluid, is initially imparted to the fluid and is transferred thereby to the sheets; and to provide a photographic process as described in which the energy required to perform the process is imparted to the fluid by the container in which the fluid is supplied.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the process involving the several steps and the relation and order of one or more of such steps with respect to each of the others which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings wherein:

FIGURE 1. is a sectional view, of photographic paratus in the form of a camera for of the invention;

FIG. 2 is a perspective view, partially in section, illustrating components of the apparatus of FIGURE 1;

FIGS. 3 and 4 are somewhat schematic, sectional views appracticing the method Movement of the sheets through 3,269,726 Patented Aug. 17, 1965 2 illustrating the operation of components of the apparatus of FIGURE 1;

FIG. 5 is a sectional view of shown in FIG. 2;

FIG. 6 is a fragmentary perspective view of other components of the apparatus of FIGURE 1; and

FIG. 7 is a view similar to FIG. 3 of another embodiment of means for practicing the invention.

In photographic processes of the type with which the present invention is concerned, a photographically exposed, photosensitive image-recording sheet comprising, for example, a gelatino silver halide emulsion layer carried on a support, is guided into superposition with a second sheet including, for example, a layer for supporting a silver transfer image, between a pair of juxtaposed pressure-applying members. As the two sheets are moved along convergent paths into superposition at, and between, the juxtaposed members, a processed liquid capable, for example, of effecting a silver halide diffusion-transfer reversal process and including a silver halide developer and a silver halide solvent, is introduced through a nozzle between the sheet at the pressure-applying members which cooperate with the nozzle and sheets to distribute the liquid in a layer between the sheet. Apparatus for performing such processes may comprise, in addition to means for treating the image-recording sheet with the liquid, means for exposing the sheets; and heretofore it has been a practice to advance the sheets through the apparatus by engaging the sheets and drawing them be tween the juxtaposed pressure-applying members. Engagement and advancement of the sheets may be accomplished manually as in currently available hand held cameras of the type produced by Polaroid Corporation; or may be effected by mechanical means such as rollers which engage the sheets and are driven to advance the sheets through the apparatus. In apparatus and processes in which the liquid for treating a succession of exposed areas of the image-recording sheet is supplied from a single container and dispensed by a single nozzle, the apparatus includes, in addition to means for advancing the sheets, means for feeding the liquid to the nozzle under pressure, means for coordinating fluid feeding and sheet advancement, and means for controlling sheet advancement, i.e., indexing means, insuring exposure and processing of predetermined successive areas of the image-recording sheet.

The invention represents a novel and improved method of advancing the sheets through the apparatus in which the means for feeding the liquid to the nozzle under pres sure, the nozzle and the liquid itself provide the means and the motive power for advancing the sheets, while control of sheet advancement (indexing) is effected by controlling the flow of the liquid to the sheets. In the copending US. application of Edwin H. Land, Serial No. 169,264, filed January 29, 1962 (now abandoned), it is proposed that the energy required to feed the liquid to the nozzle under pressure be stored and imparted to the liquid by the container in which the liquid is supplied. The container in this instance would comprises an elastomeric material in a stretched condition and makes possible the concept envisioned by the present invention of apparatus such as a camera, the operation of which is substantially automatic and which is powered by a container of processing liquid supplied with the sheet materials employed in the camera.

Reference is now made to FIGURE 1 of the drawings in which is shown photographic apparatus in the form of a small, compact, handheld camera 10 of a type in which the method of the invention is practiced. Camera ltlcomprises a housing including a forward wall 12, having a recessed or re-entrant section 14, extending rearwardly to an inner forward Wall 16, side walls 18, and a rear wall 20. The walls of the housing coopera portion of the apparatus ate to provide chambers designated 22 and 2d at opposite ends of the housing, and an exposure chamber located between inner forward Wall in and rear wall 2%. Camera Ill includes a conventional lens and shutter assembly designated 26, coupled to the camera by a bellows 28 joined to assembly and to inner forward 'wall 16, around the edges of an exposure aperture dd, provided in inner forward wall lid for transmittinglight from the lens to a photographic image-recording sheet positioned within the exposure chamber between inner forward wall 16 and rear wall 26% The bellows and the camera housing are preferably constructed so that the shutter assembly can be displaced from the extended operative a position shown in FIGURE 1 to a folded or closed posi* tion at which the bellows is collapsed within the recess described, and the shutter assembly is also dispensed within the recess.

The photosensitive image-recording sheet herein designated 32 is preferably supplied in a coiled condition on a spool 36 which is mounted for rotation within chamber 22. The image-recording sheet extends from chamber 252 at one end of inner forward wall 16, between the latter and the rear wall2ti, across exposure aperture and the rear surface of wall 15 to chamber 24 at the opposite end of the camera housing. The rear or inner surface of wall 16 is preferably located at the focal surface of the lens of assembly 2d and a guide and indexing roll 38 i provided within chamber 22 near the entrance to the exposure chamber for holding sheet 32 in position for exposure against the rear surface of wall 16 and performing other functions Whichwill be described hereinafter. 1

As previously indicated, the photosensitive image-recording sheet is treated, following exposure, with a liquid distributed between the image-recording sheet and a second sheet superposed therewith. A supply of this second sheet, designated 4%, is provided within chamber 24 together with means in the form of a pair of juxtaposed members for superposing the photosensitive and second sheets and aiding in the distribution of a processing liquid in a layer between the sheets. In the form shown, the

juxtaposed members comprise a pair of pressure-applying rolls 42' and 44, mounted in juxtapositionwithin chamber 24, adjacent an end of wall 16 near the entrance to the exposure chamber between wall 16 and rear wall 20. Image-recording sheet 32 is guided from spool 36 Within chamber 22, between roll 33 and an end portion of inner forward wall 16, through the exposure chamber across exposure aperture 3d, and around pressure-applying roll 44 between rolls 42and 44 toward the rear of the camera. Second sheet 4t extends within chamber 24 into superposition with image-recording sheet 32 at the bite of rolls 42 and 44- and extends in superposition with the image-recording sheet between the pressure-applying rolls. a An exit passage 46 is provided in rear wall 29 in alignment with the gap between'rolls 42 and 44 to permit movement of sheets '32 and from the housing. The sheets, as shown, are guided along convergent paths into superposition at the bite of the pressure-applying rolls, and it is between the convergent portions of the sheets at the bite of the rolls that the fluidprocessing liquid is dispensed.

The'sheets and processing liquid maybe provided as part of a product shown in FIGS. 2 and 5 of the drawings as comprising, in addition to image-recording sheet 32, spool 36 and second sheet 40, means in the form of a nozzle 43 for dispensing a processing liquid as a layer between the photosensitive and second sheets at the bite rubber are suited for this purpose and include, for example, high density polyethylene, polypropylene, polyvinylidene chloride and polyethylene terephthalate resins. The nozzle, shown in detail in FIGS. 3 and 4, includes an elongated generally cylindrical body section 5i? having end walls 52 cooperating with the body to provide an elongated chamber 54 within the body section and extending from end to end thereof. The body section is substantially rigid and is provided along one side with a pair of thin flexible lips 56 extending substantially from end to end of the body section. End walls 52 include tapered portions cooperating with lips 56, which converge toward one another, to define a tapered passage 58 between the lips coupled with chamber 54 and terminating at the edges of the lips in a very narrow elongated discharge mouth til) through which a liquid introduced into chamber 54 is dispensed. The material comprising lips 56 and end walls 52, and the construction of the lips and the tapered portions of the end walls, are such that mouth 69 can be sealed by the application of compressive pressure to the edge portions of the lips. For details and a further description of nozzles similar to nozzle 43 and adapted to incorporation in a structure for practicing the method of 'the invention, reference may be had to the aforementioned US. Patent No. 3,142,243.

In the form of product designed for performing the method of the invention and shown in the drawings, the processing liquid is supplied and stored under pressure in a container designated 66 comprising an elongated and generally cylindrical tube open'at one end, closed at its other end, and having, in its unextended condition, an inside diameter comparable to its wall thickness and equal to a fraction of its outside diameter. Corn I tainer dis formed of an elastomeric material such as natural rubber (polyisoprene) or synthetic rubber (synthetic isoprene) and filled with the processing liquid under pressure so that the liquid maintains the con tainer in a stretched and expanded condition while the elasticity of the material comprising the container causes pressure to be exerted on the liquid. The container may be filled, and designed and constructed in such a way as to dispense the liquid at a substantially constant and predetermined pressure. For a more complete description of the container, its manner of assembly, and filling, and it function and operation, reference may be had to the aforesaid copending U.S. Application Serial No. 169,264.

Container 66, in its fully expanded condition, is shown with its open end engaged around tube 68 and enclosed within a cylindrical tube 7! which serves to confine the container and protect the container from damage. Tube 76 also functions as a support around which second sheet 4% is coiled; and as means for retaining second sheet 40 in a coiled condition on tube '75 there are provided enclosures 72 and 74 engaged in opposite ends of tube 76 and each having a flange 76 the diameter of which is greater than the diameter of tube 70 and cooperates with the tube to define a spool on which the second sheet is coiled. Closure 74 of tube 70 may be provided with an air vent (not shown), formed to permit the expansion and contraction of container 66 with 7 78. The outer end of closure 72 is provided with an on of the pressure-applying rolls, and means for holding a supply of the processing liquid, delivering the liquid to the nozzle under pressure and supporting the nozzle in proper position to perform its liquid-dispensing'function. Nozzle 48 ispreferably formed of a material which i is impervious to the liquid and to air and has some flexibility and resiliency. Various organic plastics and larged recess Sil separated from a recess 32 defined by tube 68, by a dividing wall 84, and connected with recess 82 by way of a relatively small bore 86 through wall 34. Recesses 8i and 32 and bore 86am substantiallycylindrical and disposed coaxially, and closure '72is designed to be formed as a single element of an organic plastic material such as employed to form nozzle 48. The a in the chamber defined by tube 7%) and closures 72 and valve comprises a valve member 83 to which is attached a valve stem 95? extending from recess 32 through bore 86 into recess 80 and having a shape and dimension which permit the flow of liquid through bore 8d around the valve stem. An O-ring 92 is provided as a seal between valve member b8 and the surface of wall 84 at the periphery of bore 86; and inwardly projecting axial ribs 9 3 are provided on the inner surface of tube 63 for guiding the valve member for axial movement within recess 32 while permitting flow of the liquid around the valve member. Valve member 33 is biased into the closed position shown in PEG. 5 by a coil spring 96, retained in recess $2. by a retaining washer 98, engaged in a circum ferential recess in the inner surface of tube 68. As a means for displacing the valve member to an open position and conducting the liquid from recess 89 to the nozzle, there is provided a cap 100 having a skirt 102 engaged within recess and an end wall the including annular flexible section and a tube 1% connecting with recess 80. The end of valve stem 90 is enlarged and is engaged within recess at the center of end wall 104, while the annular flexible section permits the valve stem to be displaced inwardly by pressure on end wall 104 to open the valve and allow the liquid to How from recess 82 through bore 86 into recess lid.

Nozzle all is provided at one end with an Ls-haped tubular conduit 62 communicating with chamber 54 for conducting the liquid into the chamber and for supporting one end of the nozzle. A similar tube or a solid rod 64 is provided at the opposite end of nozzle 48 projecting from end wall 52 for supporting the opposite end of the nozzle. Conduit d2 is engaged in tube 166 while rod 64 is engaged in a tube 1% extending from closure 74 so that tubes 1% and 108 cooperate with conduit 62 and rod 64 for mounting and supporting the nozzle in position for dispensing the fluid contents of container 66 between the sheets at the bite of the pressure-applying rolls.

Nozzle a3 is mounted for operation with lips 56 extending toward the bite of the rolls between convergent portions of sheets 32 and 40 with the outer surfaces of at least the edge portions of the lips located in face to face contact with the facing surfaces of the sheets. Rolls 42 and 4d are movable between an operative, liquid-spreading position shown in FIG. 3, and an inoperative, nozzlesealing position shown in FIG. 4. In the operative, liquidspreading position of the rolls, the maximum width of the gap between the rolls at the narrowest portion of the gap is fixed and is approximately equal to the combined thicknesses of the two sheets and the layer of liquid to be distributed between the sheets. Lips 56 extend between the convergent portions of the sheets to a position just short of the narrowest portion of the gap so that the width of mouth tilt is substantially equal to the thickness of the layer of liquid. The length of the mouth, i.e., the distance between end walls 52, is preferably equal to the width of the area of the photosensitive sheet to be treated with the liquid.

The image-recording and second sheets are guided, as shown, around and between portions of pressure-applying rolls 42 and 44 through a gap between the rolls, and movement of the sheets through the apparatus into superposition between the rolls is accomplished by introducing the processing liquid through the nozzle between the sheets under sufficient pressure to cause the advancement of the sheets. In the operation of camera 10, an area of imagerecording sheet 52 positioned across aperture 33 is exposed; and this area is then advanced into superposition with a corresponding areas of second sheet 40 between pressure-applying rolls 42 and 4-4 while the processing liquid is distributed from nozzle through mouth 60 in a thin layer between the sheets to form a sandwich. Advancement of the sheets through the apparatus is continued until the exposed area has been advanced entirely between the pressure-applying rolls and preferably from the camera and is then discontinued to permit the next succeeding area of the photosensitive sheet to be exposed through aperture 30. The portion of the sandwich comprising the previously exposed area of the image-recording sheet may be severed from the remainder of the sandwich extending between rolls 42 and 44, preferably as close as possible to the rolls in order to conserve sheet materials.

The pressure on the liquid, in addition to advancing the sheets, obviously presses the lips outwardly against the sheets thereby efiectively preventing entrapment of air between the lips and the sheets and escape of the processing liquid. The liquid, as previously indicated, is dispensed from mouth 65 substantially in the form of a layer which is immediately engaged between the opposed surfaces of the sheet and causes the movement of the sheets by pressing against the layer of fluid engaged between the sheets. In order to facilitate movement of the sheets by the liquid, the latter is preferably quite viscous, having a viscosity at 24 centigrade in excess of 1,000 centipoises and ranging from 1,000 to 200,000 centipoises. The viscosity-causing ingredient may comprise, for example, sodium carboxymethyl cellulose which, as components (e.g., water) of the liquid are absorbed by the sheets, also functions in the nature of an adhesive for maintaining the integrity of the sandwich comprising the two sheets and layer of liquid and providing means against which the liquid dispensed from the nozzle can exert pressure for moving the sheets. For the details and for ulations of processing liquids suitable for use in the method of the invention and particularly for effecting silver halidediffusion transfer reversal processes, reference may be had to US. Patents Nos. 2,543,181, issued February 27, 1951, and 2,662,822, issued December 15, 1953, both in the name of Edwin H. Land.

In a camera of the construction illustrated, when the camera is not in use for treating an exposed area of the image-recording sheet with the liquid and the sheets are not being moved between the pressure-applying rolls, the rolls are moved to their inoperative, nozzle-sealing position at which the rolls compress the lips of the container toward one another so as to seal mouth 60. In this sealing action the rolls, as illustrated in FIG. 4, are displaced from the operative position of FIG. 3 in a direction opposite to the direction of movement of the sheets between the rolls so that the edge portions of lips 55 are located within the bite of the rolls at the narrowest portion of the gap. As the rolls are displaced from operative to inoperative position in a direction opposite to the direction of movement of the sheets and the flow of liquid and toward the nozzle, the lips remain substantially stationary supported by body section 50 of the nozzle; and the rolls may be displaced apart slightly so as to accommodate the combined thickness of the lips between the sheets as this thickness maybe greater than the thickness of the layer of fiuid and the gap between the sheets.

Camera 10 is operated to advance the sheets and treat an exposed area of the image-recording sheet with a liquid by opening valve 88 and simultaneously moving the pressure-applying rolls into operative, fluid-spreading position. This opening of the valve and movement of the rolls need be the only operation, except for tripping the shutter, that the operator must perform, the processing being otherwise automatic with the apparatus being operated by the pressure on the fluid exerted thereon by the container. The camera includes a mechanism which may be actuated manually to open the valve and move the pressure-applying rolls into operative, fluid-spreading position, and which is thereafter operated in response to movement of the sheets through the apparatus for closing the valve and moving the pressure-applying rolls into inoperative, nozzle-sealing position and thereby arresting the movement of the sheets when a predetermined ex posed area of the photosensitive sheet has been treated with the processing fluid. This mechanism includes means for mounting the rolls comprising a pair of arms 7 1111 each mounted at one end on a pivot 112 secured to the camera housing, with roll 1-2 mounted for rotation at its ends on arms 11% intermediate their ends. Roll 44 is mounted at its ends near the free ends on a pair of levers 114, which are mounted for pivotal movement intermediate their ends on pivots 116 having a common axis and secured to the camera housing. The free end of each of arms 1111 is pivotally connected at a pivot 118 to the free end of one of levers 114 at a position intermediate rolls 42 and 44. In the operative, fluid-spreading position of rolls 4;? and id, the axes of therolis and pivots 112, 116, and 113 lie substantially in a plane with the axis of pivot-s 118 being located equidistant from the axes of pivots 112 and 116 and the axes of rolls 4?. and dd. This arrangement insures that any movement imparted to roll 44 by levers 114 will be imparted to roll so that the latter will describe the same movement as roll 44 simultaneously with the movement of roll 44. A spring 1211 is provided coupled between each of levers 11d and the camera housing for biasing each lever (in a clockwise direction viewing FIG. 6) so as to bias rolls 4-2 and 4 for movement into inoperative nozzle-sealing position.

Means are provided for retaining the pressure-applying rolls in operative, fluid-spreading position and in theform shown comprise a pair of cams 122mounted on a shaft 124 and each located in engagement with an end section 125 of one of levers 114, which end section acts as a cam'follower. Each of cams 12.2 is designed to coact with a lever 114 so as to pivot the lever in such a way as to position rolls 42 and 44 in the operative position shown in FIG. 6. The mechanism for moving the rolls and actuating the valve is operated in response to movement of the sheets through the apparatus and derives its motive power from'roll 38 which is located in frictional engagement with the image-recording sheet so as to be rotated thereby during movement of the sheet through the apparatus. Roll 38 is provided with a gear (not shown) which is meshed with a gear 128 keyed to shaft 124. The ratio or" the numbers of teeth on the two gears is such that gear 128 is rotated through one revolution (360) in response to movement of an exposed area of the image-recording sheet from exposure position, between the pressure-applying rolls and from the camera. Cams 122 are coupled with gear 123 through shaft 124, each of cams 122 being mounted on shaft 124 for limited movement with respect to the shaft through a conventional spring devicewhich permits shaft 124 to rotate through a few degrees while cams 122 are held against rotation (in a clockwise direction viewing in FIG. 6); and when cam 122 is released for rotation, the spring will cause the cam to rotate so as to catch up to the shaft. Each of cams 122 is designed to function as a sheetarresting mechanism, that is, to permit the rolls to move into inoperative nozzle-sealing position each time a predetermined length of the image-recording sheet has moved through the apparatus. provided with an abrupt recess 13% into which end section 126 of lever 114 moves under the bias of spring 126 when recess 1% comes into alignment with the end section of the lever. This immediately stops the rotation of the cam which in turn arrests the rotation of shaft 124 and roll 38 at the end of a few more degrees of a revolution thereof and permits the rolls to move into inoperative position under the bias of springs 121B.

aaeograe 538. The opposite end of lever 132 is in the form of a cam follower 13% positioned in engagement with a cam 14% secured to and comprising a part of cam 122. Cam 1 1i) is designed to hold lever 132 pivoted in such a position as to hold valve 33 open, and includes a recess 1 52, aligned with recess 13%, into which cam follower 133' may project permitting lever 132 to pivot in such a Way as to allow valve 38 to close.

An operating or sheet-advancing cycle of the apparatus is commenced (and terminated) with end section 126 of each of levers 114 engaged in a recess 13% of a can 122 and with cam follower 13S engaged in recess 142 of cam 1411. The camera includes a manually operated device for pivoting levers 11 iand 132 so as to disengage the ends of the levers from the recess in the cams and simultaneously'open valve 88 and move rolls i2 and 44 into operative, fluid-spreading position. This manually operated means may also be coupled with the shutter so that only one element need be actuated by the operator to both make an exposure and process the exposed area of the image-recording sheet. Upon disengagement of end section 126 from recess 13% and cam follower 138 from recess 142,, the cams immediately rotate in a clockwise direction under the bias of the spring connecting the cams with shaft 124 thereby moving the recesses out of alignment with end sections 126 and cam follower 138, so that the end sections and cam followers cannot return to engagement in the recesses until the cams have completed a full revolution. The device (not shown) for pivoting levers 114 and 132 is designed to momentarily engage and pivot the levers so that the levers are free to return to their positions prior to pivotal movement, which return movement is prevented by the cams.

The form of liquid-dispensing nozzle shown and described herein is designed for intermittent operation in which the lips of the nozzle are pressed together to seal the nozzle when it is not in use. Because of the type of operation for which the nozzle is intended, the area of contact between the liquid within the nozzle and the convergent portions of the sheets between the For this purpose, cam 122 is The mechanism also includes means for opening valve 88 at the commencement of the processing cycle and close the valve simultaneously with the movement of the pressure-applying rolls into inoperative position at the end of a process cycle. This last-mentioned means includes a lever 132 pivotally mounted intermediate its ends on a pivot 13d mounted in fixed position on the camera housing. One end, designated 13%, of lever 132 is designed to engage the center of end wall 1% for displacing the end wall and valve stem so as to open valve sheets between the pressure-applying members.

pressure-applying members is minimized and this restricts, to some extent, the force which can be applied to the sheets by the liquid tending to move the sheets through the apparatus. The pressure exerted by the liquid within the nozzle on the convergent portions of the sheets located between the pressure-applying members can be resolved into components normal to the surfaces of the sheets and parallel with the surfaces of the sheets, with the latter components tending to move the The total force exerted on the sheets and tending to advance the sheets is a function of the'area of the convergent portions of the sheets in contact with the liquid and, as already noted, the viscosity of the liquid.

Reference is now made to FIG. 7 of the drawings in which there is illustrated a nozzle designed for continuous, rather than intermittent, fluid distributing operation and constructed to provide for a maximum area of contact between the liquid under pressure in the nozzle and the convergent portions of the sheets. This form of nozzle designated 144, comprises a body 1146 providing a chamber 148 into which the liquid is introduced under pressure. Body 146 includes a pair of flexible lips 150 which are positioned against the surfacesof sheets 32 and 4-19 extending around and between pressure-applying rolls 4'2 and d4. Lips 150 extend only slightly into the convergent passage between the rolls and define a relatively wide mouth 152 through which the liquid from chamberldfi is dispensed between convergent portions ofthe sheets 32' and 40 located within the bite of the rolls. The rolls themselves,being part of an apparatus designed for continuous operation, can be fixed against movement with respect to one another and the nozzle while lips of the nozzle are provided for the purpose of forming a liquid and air-tight seal between the nozzle and the sheets and do not function to seal the nozzle. The nozzle also includes end walls 154 which extend beyond the longitudinal edges of the lips into the bite of the rolls for preventing escape of the liquid from between the sheets at their lateral edges.

It is apparent that the pressure exerted on the liquid is required to do the work involved in feeding the liquid to the nozzle and advancing the sheet; and that the work involved in advancing the sheet is expended primarily in overcoming friction between the sheets and the apparatus and between components of the apparatus which are moved by the sheets. The energy expended feeding the liquid, from the container in which it is stored, to the nozzle is a function of the viscosity of the liquid and can be minimized by employing a liquid having the lowest possible viscosity. Of course, the friction between the sheets and apparatus and between components of the apparatus should be reduced as much as possible in order to minimize the energy required to be imparted to the liquid as compressive pressure. It is contemplated that in some embodiments of the apparatus, the frictional forces may be so great that they cannot be entirely overcome by pressure on the fluid alone, and it may be necessary to provide mechanical means for assisting the fluid to advance the sheets. For example, a motor of some type (e.g., a spring motor) might be provided for continuously applying torque to the pressure-applying rolls, which torque is insufficient in itself to advance the sheets, but which assists in overcoming the frictional forces resisting sheet movement. In such an embodiment, sheet movement would be effected and controlled by a flow of the processing liquid in the manner described, with the motor, in effect, merely reducing frictional resistance to sheet movement.

The invention contemplates additional forms of juxtaposed pressure-applying members as well as modified types of nozzles and other means for feeding the liquid to the nozzle under pressure. Many of these additional types of pressure-applying members are shown and described in the aforementioned US. Patent No. 3,142,243 and include, for example, juxtaposed members which do not rotate, but may be fixed with respect to one another and/or moved with respect to one another in different manners between liquid-spreading and nozzlesealing positions. The nozzles hereto incorporating flexible lips may take a number of different forms which adapt them to use with the particular type of pressureapplying members being employed. As for feeding the liquid to the nozzle under pressure, this may be accomplished in a number of different ways including, for example, compressing a flexible liquid container, employing gas pressure to empty the container, and pumping the liquid from the container to the nozzle. In each embodiment, however, sheet movement is effected by the liquid itself and is controlled by the pressure on the liquid at the nozzle which, in turn, is controlled by a valve or the means for pressurizing the liquid.

Since certain changes may be made in the above processes without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. In the treatment of a photographic sheet with a liquid distributed in a layer in contact with said sheet, the method comprising:

guiding said photographic sheet and a second sheet along convergent paths into superposition with one another between a pair of members having opposed surfaces defining said paths and supporting superposed portions of said sheets against movement apart w from one another with said superposed portions disposed a predetermined distance apart; supporting a nozzle, having a discharge mouth bounded by a pair of lips which are at least equal in length to the width of the area of said sheets to be treated, between said convergent portions of said sheets and holding said lips in substantially liquid-tight contact with said convergent portions of said sheets; and

introducing a viscous photographic processing liquid through said nozzle between said lips into contact with the adjacent surfaces of said sheets, said liquid being introduced under pressure sufficient to cause the movement of said sheets along said convergent paths past said lips into superposition between said members in the direction of flow of said liquid between said lips.

2. A method of photography as defined in claim 1 in which said liquid is contained under pressure in an extended elastic container coupled with said nozzle, a force is applied to said sheets tending, but insufficient by itself, to move said sheets in the direction of flow of said liquid from said mouth, and movement of said sheets is commenced and arrested, respectively, by commencing and arresting the flow of said liquid from said container to said nozzle.

3. The method of producing a visible photographic im age comprising:

positioning a photographic image-recording sheet within photographic apparatus with a first portion of said sheet located in position for exposure and another portion of said sheet located between a pair of members having opposed surfaces converging to a gap of a predetermined width;

supporting said other portion of said image-recording sheet against one of said surfaces;

supporting a portion of a second sheet against the other of said surfaces;

positioning a nozzle, having a discharge mouth bounded by a pair of lips which are at least equal in length to the width of said first portion of said image-recording sheet to be exposed, between convergent portions of said sheets between said members, and holding said lips in substantially liquid-tight contact with the opposed surfaces of said convergent portions of said sheets supported on said surfaces of said members;

exposing said first portion of said image-recording sheet to actinic light;

introducing a viscous photographic liquid, including reagents capable of reacting with said image-recording sheet following exposure thereof to produce a visible Image in said sheet, through said nozzle between said lips into contact with said opposed surfaces of said sheets;

exerting pressure on said liquid within said nozzle sufficient to cause the movment of said sheets through said apparatus past said lips between said members in the direction of flow said liquid between said lips;

continuing to introduce said liquid under pressure through said nozzle into contact with said sheets until said first portion of said image-recording sheet has been advanced into superposition with a portion of said second sheet and has moved through said gap; and

reducing the pressure exerted on said fluid within said nozzle after said first portion of said sheet has passed through said gap between said members.

4. A method of photography as defined in claim 3 in which said lips are pressed against one another simultaneously with the reduction of pressure on said liquid to close said mouth and prevent the flow of said liquid from said mouth.

. 1 l i '5. A method of photography as defined in claim 4 in which said lips are pressed against one another by moving at least one of said members relative to said nozzle.

6. In photography, the method of advancing a pair of sheets into superposition and treating said sheets with a liquid distributed in a layer therebetween, said method posed portions disposed a predetermined distance apart; I V locating a nozzle, having a discharge mouth bounded by lips which are at least equal in length to the width of the area of said sheets to be treated, between said convergent portions of said sheets and holding said lips in substantially liquid-tight contact with said sheets; introducing a viscous photographic processing liquid through said nozzle between said lips into contact with adjacent surfaces of said sheets under pressure sufficient to cause the movement of said sheets along said convergent pathspast said lips and into superposition in the direction of flow of said liquid between said lips; and applying torque to said roll tending to move said sheets in the direction of flow of said'liquid between said lips, said torque being insufficient by itself to cause movement of said sheets relative to and between said members. p I 7. A method of photography. as defined in claim 1 in which said liquid'is contained under pressure in an extended elastic container. coupled with said nozzle, a force is applied to said sheet by moving one of said members in engagement with one of said sheets, said force tending but being insuflicient by itself to move said sheets in the direction of flow of said liquid from said mouth.

8. In the treatment of a photographic sheet with a liquid distributed in a layer in contact with said sheet, the method comprising:

guiding said photographic sheet and a second sheet along convergent paths into superposition with one another between a pair of members having opposed surfaces defining said paths and supporting superposed portions of said sheets against movement apart from one another with said superposed portions dis posed a predetermined distance apart; supporting a nozzle, having a discharge mouth bounded by a pair of lips which are at least equal in length to the width of the area of said sheets to be treated, between said convergent portions of said sheets and holding said lips in substantially liquid-tight contact with said convergent portions of said sheets;

' introducing a photographic processing liquid through said nozzle between said lips into contact with the adjacent surfaces of said sheets, said liquid being introduced under pressure sufiicient to cause the movement of said sheets along said convergent paths past said lips into superposition between said members in the direction of flow of said liquid between said lips;

said liquid being fed to said nozzle under pressure and movement of said sheets being arrested by reducing the pressure on said liquid within said nozzle; and

simultaneously with the reduction of pressure on said liquid within said nozzle, pressing said lips against one another to close said mouth and prevent flow of said liquid from said mouth.

References Cited by the Examiner UNITED STATES PATENTS 1,161,346 11/15 Schmidt 2647 8/50 Land 95-13 NORTON ANSI-1BR, Primary Examiner.

40 JOHN M. HORAN, Examiner.

Claims (1)

1. IN THE TREATMENT OF A PHOTOGRAPHIC SHEET WITH A LIQUID DISTRIBUTED IN A LAYER IN CONTACT WITH SAID SHEET, THE METHOD COMPRISING: GUIDING SAID PHOTOGRAPHIC SHEET AND A SECOND SHEET ALONG CONVERGENT PATHS INTO SUPERPOSITION WITH ONE ANOTHER BETWEEN A PAIR OF MEMBERS HAVING OPPOSED SURFACES DEFINING SAID PATHS AND SUPPORTING SUPERPOSED PORTIONS OF SAID SHEETS AGAINST MOVEMENT APART FROM ONE NOTHER WITH SAID SUPERPOSED PORTIONS DISPOSED A PREDETERMINED DISTANCE APART; SUPPORTING A NOZZLE, HAVING A DISCHARGE MOUTH BOUNDED BY A PAIR OF LIPS WHICH ARE AT LEAST EQUAL IN LENGTH TO THE WIDTH OF THE AREA OF SAID SHEETS TO BE TREATED, BETWEEN SAID CONVERGENT PORTIONS OF SAID SHEETS AND HOLDING SAID LIPS IN SUBSTANTAILLY LIQUID-TIGHT CONTACT WITH SAID CONVERGENT PORTIONS OF SAID SHEETS; AND INTRODUCING A VISCOUS PHOTOGRAPHIC PROCESSING LIQUID THROUGH SAID NOZZLE BETWEEN SAID LIPS INTO CONTACT WITH THE ADJACENT SURFACES OF SAID SHEETS, SAID LIQUID BEING INTRODUCED UNDER PRESSURE SUFFICIENT TO CAUSE THE MOVEMENT OF SAID SHEETS ALONG SAID CONVERGENT PATHS PAST SAID LIPS INTO SUPERPOSITION BETWEEN SAID MEMBERS IN THE DIRECTION OF FLOW OF SAID LIQUID BETWEEN SAID LIPS.

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