US2925025A - Photocopying machine - Google Patents

Description

Feb. 16, 1960 w. c. CONNER PHoTocoPYING MACHINE 4 Sheets-Sheet 1 Filed Jan. l28, 1958 1N VEN TOR.

Feb. 16, 1960 w. c. coNNER PHoTocoPYING MACHINE 4 Sheets-Sheet 2 Filed Jan. 28, 1958 www# lm m Mm, www@ Q: .Q Q

ml\\ TIM NQ l QQ IMQ INVENTOR.

Feb. 16, 1960 w. c. coNNER PHOTOCOPYING MACHINE FiledJan. 28, 1958 Feb. 16, 1960 w. c. CONNER 2,925,025

PHOTOCOPYINGIMACHINE 4 Sheets-Sheet 4 6 all@ INVENTOR.

Filed Jan. 28, 1958 United States Patent 2,925,025 PHOTOCOPYING MACHINE William C. Conner, Dobbs ease Corporation, Delaware Ferry, N.Y., assignor to Cop- New York, N.Y., a corporation of This invention relates to photocopying machines and more specically to a novel type of photocopying machine in which both exposing and developing operations are performed in sequence in a single transit through the machine.

The photocopying process per se which is involved is disclosed more fully in French Patent No. 870,995 granted December 10, 1952 to I. G. Farbenindustrie A.G., and in U.S. Patent No. 2,352,014 granted .Tune 20, 1944 to Andre Rott. In this process, the master sheet to be copied is placed with the copy side in face-toface contact with the emulsion side of a photosensitive (silver halide) negative sheet, and light is directed through the back side of the negative sheet against the copy side of the master. The light reliected from the master against the emulsion side of the negative exposes the latter to form in its emulsion a latent image which is a pagereversed (i.e., mirror) image. Then the master is separated from the negative and the negative and a positive sheetbearing a non-photosensitive emulsion are placed briey in a developing solution; this develops the latent image on the negative, reducing the silver halide grains in the exposed areas ofthe lm (corresponding to the light areas on the master) to metallic silver, leaving the unexposed portions of the negative (corresponding to the dark areas on the master) undeveloped. Then, while the two sheets are still imbibed with the developing solution, they are pressed together in intimate face-to-face contact, and the silver halide grains in the unexposed portions of the negative are dissolved from the photosensitive emulsion and diffused into the emulsion of the positive where a fogging agent reduces them to produce blackened areas corresponding to the dark areas on the original-a positive copy. The second mirror reversal produced by this transfer operation makes this positive copy page-correct,-i.e. readable. A In the operation of pressing the positive and negative sheets together, most of the liquid is expressed from them so that they are only slightly damp, and while still in -this condition they may be readily peeled apart.

U.S. Patent No. 2,657,618 issued November 3, 1953 to' Walter Eisbein discloses a developing appara-tus for performing the developingA steps of the aforementioned process. In `this apparatus, the posi-tive and negative sheets are conducted between guide elements down `through a developing tank, an intermediate guide plate maintaining their separation at least until they have been wet by the developing liquid, and then upwardly between a pair of rollers, the nip of which is located above the level of the developing liquid. The rollers press the sheets together and wring out the excess developing solution and deliver the sheets pressed together out of the machine. This developing machine must be used in conjunction with a separate exposure apparatus, for example either a flat-bed exposure apparatus in which the master and negative sheets are held stationary while they are pressed together and light is directed through the back of the negative, or a rotary exposure apparatus in which the master and negative sheets are fed around a drum during the exposure operation.

To make a single copy, it has been necessary to handle the sheets several times in succession: first the negative sheet has to be placed in faceto-face Contact with the master sheet and these sheets inserted into the exposure apparatus for the exposure operation, which requires a period of the order of three to eight seconds. Upon completion of the exposure operation, the operator takes the negative and master sheets and separates them, laying the master to one side; then he places the negative and positive sheets into the developing machine.` The movement of these sheets through the developing apparatus requires live to ten seconds. Then the sheets must he left in contact with each other for an additional period of fteen to thirty seconds before they may be peeled apart. The entire operation including the exposure and developing steps thus requires on the order of a full minute. Since the operator is required to handle the papers several times during this interval, as a practical matter it is difficult for the operator to perform any other operations simultaneously; most of the operators time is thus wasted in mere waiting. Therefore, even in volume production, it has not been possible for a single operator to produce copies at a rate much greater than one per minute.

The present invention provides for the first time a unitary machine in which both exposing and developing operations are performed in a single pass of the papers through the machine. The operator merely places the master, negative and positive sheets into the machine and all of the other operations are performed automatically in proper sequence, including exposure of the negative to the master, separation' of the master from the negative, delivery of the master out of `the machine, placing of the positive and negative sheets in proper registration into the developer portion of the machine, developing the negative and transferring of a reversed image to the positive sheet, and delivery of the positive and negative sheets out of the machine. In the use of such a machine, the operator, immediately after having fed one set of papers into the machine need not wait to perform any subsequent operations, but may immediately feed a second set of papers into the machine while the first set of papers is still in it. A typical speed of operation of the machine is such that the operator -may feed in a set of papers every six to ten seconds, and a pair of operators working together, one feeding the papers into the machine and the other stripping apart the positives and negatives, may maintain a production rate of six to ten copies per minute over an indefinite period. These things are accomplished in a machine which is compact, portable, inexpensive and substantially troublefree in operation, assuming instructions'are followed within reasonable limits.

'in general terms, the machine is provided with three inlet slots for feeding in the master, negative and original respectively, these slots leading to three separate guideways defined, forA example, by metal or plastic guide elements. Power-driven feed elements, such as rollers, extend through feed openings through the guide elements and convey the sheets through the machine. All of the feed elements are coupled to a single drive so that they are driven in unison and feed the papers through the machine at uniform speeds. In the exposure portion of the machine there is a light source and the intermediate and guide members are provided with opposed exposure portions in illuminated relation to the light source to expose the negative sheet to the master across their entire width while keeping them separate across at least a portion of their Width at all times. In one embodiment of the invention, there are successive exposure Y Y of the base 12 and overlap the same.

areas in each of which there are discrete, transversely spaced exposure openings in the guide plates through which the master and the negative may be pressed together across only a portion of their width while being separated in the remaining portion of their width. The exposure openings in the several exposure areas are staggered transversely of the machine so that in traversing the exposure areas, the master and negative sheets are exposed to each other across their entire width, the exposure openings being so shaped and their proximate ends being so positioned relative Vto one another that the degree of exposure is uniform. ln another embodiment, the exposure portion of the intermediate guide member is formed of very thin, transparent sheet material which permits a reex exposure of the `negative sheet to the master across their entire width-simultaneously while keeping the sheets physically separated. In both embodiments, since the master and negative are never allowed to come together across their entire width at any instant, separational control of them is maintained and theyv may be completely separated and directed along different paths by bifurcation of the intermediate guide plate, with the master being conducted out of the machine. During movement of the negative sheet through the exposure portion of the machine, the positive sheet is moving at the same speed over an equal distance and the two sheets are brought together at the input of the developing portion of the machine in proper registration. They are fed through separate guideways until they reach the surface of the developing liquid and they are conducted through the developing liquid to the nip of the pressure rollers, which press them together, express the surplus liquid-from them and deliver them pressed together out of the machine; After l to 30 seconds, the positive and negative sheets are manually peeled apart. I f

In the accompanying drawings:

Figure l is a horizontal sectional View of an illustrative machine constituting a iirst embodiment of the presentY invention, with the positions of certain internally concealed parts being shown by broken lines.

VFigure 2 is a Vertical-longitudinal sectional view taken generally along the line 2-2 of Figure 1.

Figure 3 is a vertical-transverse sectional view taken generally along theline 3-3 of Figure 2.

Figure 4 is an enlarged fragmentary vertical sectional view taken on the line 4 4 of Figure 1.

Figure 5 is an enlarged fragmentary sectional View taken on the line 5--5 of Figure 2.

Figure 6 is an exploded perspective view of the three guide plates which define the two upper guideways, and of the adjustable masking plates which are superposed above them to illustrate their shape and relative positions.

Figure 7 is an enlarged fragmentary vertical-longitudinal sectional view of the exposure portion of Van illustrative machine representing an alternative embodiment of this invention.

Figure 8 is a fragmentary horizontal-transverse sec-V Most of the mechanism of the machine is supported in the removable upper portion 16 of the casing on a pair of side plates 2t) (Figure l). This mechanism includes an upper set of three guide plates-a lower guide plate 22, an intermediate guide plate 24 and an upper guide plate 26 (Figure 2) which are spaced apart to define between them lower and upper guideways 28 and 30, respectively. s may be seen in Figure 5, the lateral edges of these guide plates 22, 24 andV 26 are supported on the side platesnZil by means of a supporting block 32 and screws 36, being spaced apart by spacer strips34. A lower set of guide plates 37 and 3S (Figure 2) which are spaced apart to define a single guideway 40, are similarly supported. The front ends of all of the guide plates 22, 24 and 26, 37 and 38 extend through an opening 16a in the front wall of the upper portion 16'of the casing and areopen to serve as slots through which the sheets are fed into the respective gu-idepaths 2S, 30 and d0, the ends of the guide plates being iiared, as shown in Figure 2, to increase the spacing between them and facilitate insertion of the leading edges of the sheets into the slots. l

For feeding the papers along the guidepaths, four sets of rollers are provided. The rst set comprises four identical rollers 41, 42, 43 and 44, formed of rubber, neoprene or other resilient material and fixed on shafts 45 which are rotatably journaled in the side frames 20 (Figurerl). These rollers are arranged parallel to 4011e another in a single vertical row with the surfaces of adjacent rollers in tangential engagement. The second set also comprises four identical rollers 46, 47, 48 and 49 which are of the same diameter as the first set and are similarly supported. Each'of the other two set-s of rollers comprises only a single matched pair of rollers 50, 51 and 52,53. Y Y Y Y Y As may be seen in Figure 1, the shaft 45 of each of the rollers in the machine hasiixed on i-ts'end projecting through the side plate 20 at one side of the machine, spur gear 46 whose pitch diameter is equal to the diameter of its respective roller so that the gears mesh to Y insure the uniform rotational speed of all of the rollers tional viewV taken generally along the line 8 8 ofV Figure 7. Y

As may be seen in Figures i, 2, and 3, the first machine Y includes a casing generally designated 1d comprising a base portion 12'('Figures 2 and 3) provided with sup-V porting feet 14, and a removable upper portion 16 which is supported yon the base portion 12. As may be seen Vbyrco'mparin'g Figures 2 and 3, the base portion 12 has, at therfront and rear ends of the machine, vertical ilanges 12a and 12b projecting upwardly from. the horizontal lportion 12C across its entire width. There are noV such upstanding flanges at the sides of the machine, where Vthe sides of the removable upper portion 16 of the casing extend all the way down to the horizontal portion 12C As best shown in Figure 3, handles 17 are provided at either side of the'.v upper portion 16 te vfacilitate lifting it offV of the base 12.

in each set, even when the frictional engagement between the surfaces of adjacent rollers' is impaired by the passage of pairs of sheets between them.

All of the rollers in the machine are driven by an electric motor l56 which'is mounted on a channel 5S extending between the side plates 20 in the upper rear portion of the machine. This motor, through a reduction gear 60, a sprocket-62 and a chain 64, whose path is indicated in dot-and-dash lines in-Figure 2, engages a sprocket (Figure 1) on the end of one of the shafts 45 in each set of rollers opposite tothe end on which the gear 46 is mounted, to drive the rollers in the direction indicated by arrows in Figure 2. There is a uniform ratio between the number of teeth in the sprockets 62 and the diameters-of their respective rollers, so that all of the rollers are driven in synchronism by the motor 6i) at the same peripheral speed to feedthev'papers through the machine at a constant rate. Y Y

All of the guide plates are provided with feed openings to receive 'the rollers and permit the papers to be pressed between the rotating rollers and-fed along the' respective guideways.l The pattern of kopenings inI the guide plates in the exposureV portion of the `machine can best be understood by reference to Figure 6, which shows each of the individual guide plates, and to Figure 1 which illustrates their relative positions.V VAs best shown in. Figure 6, the lower guide plate 22 of the upper set is provided only with feed openings 22a large enough to admit the rollers 42 (Figure 2)." The upper guide ,plate 26 is provided with'. similar feed openings 26a Y which are in opposition with the feed opening 22arin the lower guide 22. The intermediate guide sheets 24, are provided with considerably larger openings 24a, b, c-,Yd and e, which, as best shown in Figure l, are arranged so that the rollers 41 and 42 are spaced a short distance from the front ends of the openings 24a and 24b while the rollers 46 and 47 are spaced a short distance from the rear ends of the openings 24e, d, and e. Each of the rollers is discontinuous, being cut down between the feed openings so as to permit the enlarged portions 41a, etc. of the rollers to extend down through the opposed openings in the three guide plates and engage the sheets While the reduced portions 41b etc. clear the intervening webs 241, g, and h (Figures l and 6) of the intermediate guide plate 24, and corresponding webs 26b (Figure 6) in the upper guide plate 26 and 22b in the lower guide plate 22.

The negative sheet is inserted into the uppermost guideway 3) between the guide plates 24 and 26 of the upper set, fthe master is inserted into the guideway 28 between the guide plates 22 and 24 of the upper set and the positive is inserted into the guideway 40 between the guide plates 37 and 38 of the lower set. These sheets are inserted with their leading edges in registration and perpendicular to their direction of movement through the machine, and with the sheets approximately centered laterally in the input slots. The papers are pushed manually through Ithe guideways to the point where their leading edges reach the respective pairs of rollers 41, 42 and 43, 44 of the first set of rollers. The upper and lower sets of guide plates are symmetrically arranged so that the distance from their input ends to the nips of the first set of rollers are equal. Thus, the leading edges of the master and negative reachk the nip of the rollers 4l. and 42 simultaneously with the arrival of the leading edge of the positive sheet at the nip of the rollers 43 and 44. These continuously rotating rollers thereupon engage the sheets and feed them along their respective guideways. v

The enlarged openings 24a-e (Figure 6) in the intermediate guide plate 24 permit the negative and master sheets to come together over substantial portions of their width, while the webs 24f, g and h keep them` apart in other portions. The upper guide plate 26 is additionally provided with exposure openings 26e which are opposite the central portions of the enlarged openings 24a-e in the intermediate guide, and in each of these openings 26e is received a rectangular presser block 70 (see particularly Figures 4 and 5).

When no sheets are being fed through the machine, as shown in Figure 4, the presser blocks 70 are supported on the lower guide sheet 22. As sheets are fed past the exposure areas, their leading edges engage the front edges of the blocks 70 which, a-s best shown in Figure 4, are bevelled at a considerable angle so `that the sheets will cam up the front edges of the presser blocks 70 and pass beneath them. The presser blocks 70 are only slightly smaller in size than the exposure openings 26e in the upper guide plate 26 so that the upper guide plate maintains them in proper lateral position. The weight of the presser blocks 7l? presses the negative `and master sheets into intimate surface contact with one another throughout substantially the entire area of the presser blocks. The presser blocks are formed of transparent or translucent glass or plastic, so that light may be transmitted through them to expose the negative sheets to the master as they pass beneath.

As best shown in Figure 6, positioned above the upper guide 26 and the presser blocks '70 are a pair of relatively adjustable masking plates 72 and 74. These two'masking plates are provided with apertures 72a and 74a respectively which are slightly smaller than and -are centered over the presser blocks 7i). As shown in Figure 5, the lower masking plate 74 is supported at its edges on the uppermost spacer strip 34, and is fixed in position by the recessed-head screws 36, The upper masking plate 72 lies ilat on the lower plate 74 and is slida-ble forwardly and rearwardly of the machine to permit adjustment of thesize of the exposure apertures, Movement ofthe upper masking plate 72 in this manner is accomplished by means of racks 76 which project upwardly from its opposite ends and which are engaged by pinions 78 (Figure 1) fixed on a shaft 80 rotated by means of a knurled wheel 82 which projects through a slot in -a cover plate 83 at the top of the machine. Even at the widest aperture setting, the masks 72 and 74'overlap the edges of the presser blocks 70 at all four sides so that the exposure is not affected by edge refraction.

As a light source, a pair of lluorescent bulbs 84 are provided, these bulbs extending transversely of the machine and being supported at their ends by sockets 85 secured to the side plates 20. A reilector 86 extends above the fluorescent bulbs S4 to reflect all of the light emitted thereby downwardly toward the exposure areas. This reector 86 is attached to the cover plate 83 by spacing brackets 87 and is removed through an opening 16b in the upper portion 16 of the casing 10 when the cover plate is lifted. This permits ready access to the fluorescent bulbs 84 to replace a defective bulb.

The effective exposure areas with the apertures at their widest setting may be seen in full lines in Figure l, in which the aperture areas are designated 72a and 74a respectively. The five apertures are divided into two sets, the first set comprising the two apertures 72a and the second set comprising the three Iapertures 74a, these two sets being respectively centered beneath the fluorescent bulbs 84. The apertures in each set are discrete and ltransversely spaced, with the apertures 72a in the first set being transversely staggered relative to the apertures 74a in the second set, and with the proximate ends of the adjacent apertures of the two sets in approximate longitudinal alignment.

As the negative and master sheets move past the two exposure areas, the portions of the width of the two sheets opposite the first set of apertures 72a are exposed. Then as the sheets pass the second exposure area, the re maining portions of the two sheets are exposed.

As many be seen in Figure 5, because of the spacing of the masking plates 72 and 74 from the lower guide plate 22 against which the two negative and master sheets are pressed during exposure, the edges of exposed areas are not sharply dened. Thus the exposure is not abruptly terminated at the point A directly beneath the longitudinal edge of the aperture 72a, but instead there is a diminishing degree of exposure all the way over to the point B, some distance behind the edge of the aperture. This is due to the fact that the fluorescent bulbs 84 extend across the entire width of the machine and radiate light not only vertically but also o-bliquely and horizontally. Moreover, the exposure does reach its maximum at point A, because the masking plate cuts olf therefrom light rays from portions ofthe bulb to the right, as viewed in Figure 5, of the edge of the aperture 72er. Thus, the intensity of illumination gradually increases in more or less linear fashion from the minimum at point B to the maximum at point C.

The two exposure areas each have these twilight zones at each longitudinal edge of each aperture, and each twilight zone is longitudinally aligned with `another zone in the other exposure area, in which the relative positions of the maximum and minimum exposure points are reversed, due to the staggering of the apertures. Thus, any point on the negative and master sheets which passes near the minimum exposure point B in one exposure area will pass near the maximum exposure point C in the other exposure area. Therefore, assuming these sheets move through the exposure areas in a perfectly straight line, any point which passes through twilight zones in the two exposure areas will receive a total exposure which is sub stantially equal to that which it would receive if it passed through the center of an aperture in one of the two exposure areas. This avoids any possibility that -a minute laterial creepage of the two sheets in passing from one exposure area to the other might cause a particular portion of the lm to be either totally unexposed or doubly exaeaaoae posed. With the arrangement described, the maximum anticipated creepage might, for example, produce an exposure above or below the optimum, but this is well within the exposure latitude of the photosensitive emulsion on the negative sheet.

A similar result can be achieved by complementarily tapering the ends of the exposure areas and overlapping them in such geometric relation that in passing straight through the overlapping tapered end portions of a pair of apertures in the respective exposure areas, the negative and master are exposed over a total longitudinal distance equal to the maximum longitudinal dimension of each of the apertures.

From the foregoing description `it will be appreciated that in passing through the exposure areas, the negative sheet isuniforrnly exposed to the -master across their en` tire width, although separational control of the two sheets is maintained. That is to say, the sheets are separated by the intermediate guide plate 24 across at least a portion of their width at all times, the points of separation being shifted from one exposure area to the next.

As may be seen in Figures l and 6, the rear edge of each of the openings 24a to 24e, inclusive, in the inter mediate guide 24 is inclined at an angle relative to a line perpendicular to the path of the sheets. This is to insure that the leading edges of the moving sheets cannot come into abutment with an edge of the opening which is perpendicular to their direction of movement-Le., parallel to their leading edges-which might cause the leading edge to snag and perhaps to jam the machine.-

For the purposes ofillustration, assume that the negative sheet, which rides on top of the intermediate guide plate 24, Vis curled downwardly at one of its leading corners; assume further that the paper is inserted slightly crooked, so that the downwardly curled corner is ahead of the rest of the leading edge. During passage of the sheet through the exposure portion of the machine, the path of this downwardly guide plate 24. if this edge of the opening were perpendicular to the path of the paper, the downwardly curled corner of the negative sheet would be apt topass beneath rather than above it, up to the point where the leading edge of the sheet would come into directabutment with the rear edge of the opening. This would cause the paper to buckle and possibly tear or crumple or even jam in the machine, which might render it necessary Vto at least partially disassemble the machine in order to remove the paper. To avoid this possibility, the rear edges Vof the openings in the intermediate guide 24 are inclined, as shown in Figures l and 6, away from the webs 24f, g and h by which the sheet is supported between the openings 24a-e. When the sheet reaches the rear edges of the openings, the width of the supporting surface is'gradually increased, camming upwardly the leading edgeV of the sheet until the entire leading edge, including any downwardly curled corner, rests on top of the intermediate guide plate 24.

As shown in Figures 2 and 6, the rear edges of the feed openings 22a and 26a in theY lower and upper guide members 22 and 26 respectively are flared outwardly to ,funnel the leading edges'of Vthe sheets into the guide paths and prevent snagging of the sheets.

VIt will be understood `that the'transverse dimensionof the sheets fed into the machine must be at least as great as the width of the openings 24a-e in the intermediate guide platey 24, so that the sheets cannot passV through theopenings and get into the wrong guide path, and that the sheets should be at least as long as the greatest spacing between adjacent sets of rollers, so that Ythey may be fed from one set of rollers to the next. Moreover, for most reliable handling of narrow sheets, the' sheets should'be placed into the machine as near the center of the input slots as possible to insure that their lateral edges will overlap the webs 24g and 24h at either l curled edge would Vcross theV rear edge of one of the openings in the intermediate side ofthe center openings 24d in thersecond exposure area, and eliminate the possibility that one of their leading `corners might engage a portion of the rear edge of this opening which was inclined in the wrong direction to Aachieve the camming action previously described.

After the sheets have passed the exposure areas, there are no more openings in the intermediate guide plate and the separation of the negative and master sheets becomes complete.

As best shown in Figure 2, the lower guide plate 22 is bent around a generally cylindrical curve and the intermediate guide plate 24 and upper guide plate 26 follow it for some distance to a point where the intermediate guide plate 24 is divided, as best shown in Figure 6, into alternately arranged fingers 24j and 24k. The ngers 24j are bent down, following the contour of the lower guide plate 22, and overlap the generally coplanar interdigitated fingers a of an intermediate guide extension plate 90. The lower guide 22 continues on around through a net angle of and extends back toward the front of the machine, with the extension plate 96 closely following the contour to form an effective continuation of the lower guideway 28. This causes the master sheet to reverse its course, passing iirst between the rollers 47 and i8 and the rollers 42 and 43, which extend through feed openings in the two'plates. As indicated by the arrows in Figure 2, these rollers rotate in such direction as to feed the paper back toward the front of the machine. The guide plates 22 and 9i) conduct the master sheet through a narrow outlet slit 92 between the upper and lower sets of guide plates, the opposed surfaces of the innermost guide plates 22 and 33 of the upper and lower sets being inclined toward one another to funnel the master sheet through the narrow slit 92. The fact that the outlet slit 92-is Very narrow prevents accidental insertion therein of one of the sheets being fed into the machine through the input slots above and below. Thus, the master sheet, after being exposed to and then separated from the negative sheet, is conducted out of the front of the machine.

While the negative sheet is passing through the exposure portion of the machine and is being exposed to the master sheet, the positive sheet will have been conveyed along the guideway 4i?, through a path of exactly the same distance, being driven by the rollers 43 and 4 and therrollers 48 and 49, which rotate in such directionV to'feed the paper to the rear of the machine. This path also includes an offset portion itu of the same shape and dimensionsas the hump 36a where the upper guideway bends around the cylindrical curve in the lower guideway 28. Thus the leading edges Vof the negative and positive sheets arriveV simultaneously between the rollers 59 and 51.' As may be seen in Figure l, the rollers 50 and 51 are provided with alternate sections of enlarged and reduced diameter, the enlarged sections, such as Stia (Figure l) projecting into notches 26d, etc. out in the ends of all three guide members 26, 24 and 37, with the lingers 26e, etc. between these notches extending between the Venlarged portions 56a of the rollers to guide the negative and positivesheets While maintaining their separation.

These fingers 26e, etc. overlap fingers 94a and'95a of aY pair of upper and lower guide plates and 96 (Figure 2)Y which are supported in the' developing tank int) hetween end plates 98 slidably received between guide `bosses 16Go Vat the inner faces Vof the'V end walls of the Vtank. This arrangement permits the guide plates 94 Y and 96 to be lifted out ofthe tank 190 for'cleaning and to be readily replaced into proper position.

As shown in Figure 2, the front or input ends of the ingers 94a and ,96a are ared outwardly, to Vinsure that they will'gather the leading edges of the sheets and direct them between the guide plates 94 and 56. The lingers 24k (best shown in'Figure 6) at' the rear end of the lower `guide 24 terminate just short of the surfacevof the-liquid VA1021(as maybe'seen in'Figure y2) in'thefdeveloper tank 100 to maintain the separation of the negative and positive sheets at least until they have reached the surface of the liquid and have been moistened by it. In certain types of machines it may be necessary to provide an intermediate guide plate between the upper and lower guide plates 94 and 96 to separate the positive and negative sheets through some or all of their passage through the .tank 100. Such an intermediate guide plate could be provided at its input end with iingers which interdigitate in coplanar relation with the lingers 24k of the intermediate guide plate 24, preferably with the output ends of the lingers 24k being ared in thickness so as to direct the positive and negative sheets toward the upper and lower guide plates 94 and 96 and insure that the leading edges of these sheets will not strike the input ends of the fingers of the intermediate guide plate, even though they may be slightly misaligned relative to the lingers 24k.

As best shown in Figure 3, the end walls of the tank 100 extend beneath the end plates 20 of the machine the end plates being provided with cut outs 20a (Figure 2) to receive the end portions of the tank.

The tank 100 rests on the horizontal portion 12C of the base 12, being removably held in proper lateral position therein between the rear flange 12b of the base 12, an upstanding guide ange 101 at its forward side `and similar anges 102 (Figure 2) at each end. Thus, when the upper portion of the casing is removed, the tank 100 is exposed and may be lifted by means of handles 103 (Figure 3) which are provided at either end. The tank may then be carried to a sink for emptying and cleaning.

The guide plates 94 and 96 conduct the positive and negative sheet between the pressure rollers 52 and 53, which press them together to effect the transfer of the image from the negative to the positive sheets, to express the surplus moisture therefrom, and to deliver the sheets out of the machine between a pair of guide plates 106 and 108 and through a slot 16b in the upper portion 16 of the casing. As may be seen in Figure l, these guide plates 106 and 108 are provided at their input ends with lingers, such as 10661, which are interdigitated with stripper lingers 110 (Figures l and 2) which are mounted on shafts 112 extending between the end plates 20. The stripper lingers 110 are formed of spring material and are resiliently urged into frictional engagement with the surfaces of the rollers to peel away from the rollers any sheets which tend to stick thereto. The input ends of the lingers 106a, etc. on the guide plates 106 `and 108 are flared outwardly to gather in the sheets and insure that they will pass between the guide plates and be conducted out of the machine by the rollers 52 'and 53.

In Figure 7 the exposure portion of a machine constituting an alternative embodiment of the present invention is shown in cross section; the remaining portions of this machine may be identical with the corresponding portions of the machine illustrated in Figures l6 and therefore the showing of these portions of the machine is not repeated.

In the exposure portion of the machine shown in Figure 7, there are two guide paths 120 and 121 delined by guide members 122, 124 and 126. The lower guide member 122 may be formed of metal and is upwardly bowed or curved with the highest portion of this curve being located beneath the single fluorescent bulb 128 and approximately midway between two sets of rollers 130, 131, 132, 133 and 134, 135, 136, 137. The intermediate guide member 124 and the upper guide member 126 are formed of flexible transparent sheet material such as cellulose acetate sheet and the intermediate guide member 124 at least is formed of a very thin material, for example having a thickness of the'order of from .001 to .010 inch. The input ends of the intermediate and upper guide members 124 and 126 are supported by metal clamping strips 138 and 140 which extend between and are supported by the side plates of the machine.

The rear edge of the intermediate guide member 124 extends adjacent the forward edge of an intermediate guide extension plate 144 which extends between and is supported by the side plates, the two guide members being attached to one another above and below by extremely thin plastic strips 146 which extend along the full length of the guide members and are secured thereto by adhesive or by heat sealing. For example, these stops may be formed of pressure-sensitive adhesive tape. Their extreme thinness prevents snagging of the leading edges of the sheets.

The upper guide member 126 extends beneath a rod 149 which extends transversely of the machine between the side plates and is bent around the rod so that its rear end projects upwardly at a slight angle. The rear edge of the upper guide member 126 is reinforced by a metal clamping strip 150 which is provided with openings through which are hooked the forward ends of helical tension springs 152 whose opposite ends are hooked around stubs 154, to maintain the upper guide member under slight tension. provided with transversely spaced openings 126a through which project fingers 156a on the forward end of the upper guide extension plate 156 the forward ends of these fingers 156a being flared outwardly around the rod 149 to gather in the leading edges of the negative sheets and direct them along the guide path 120.

All of the guide members 122, 124 and 126 are respectively provided with feed openings 122:1, 124a and 126b through which the feed rollers 130, 131 and 134, 135 project into mutual engagement.

The input and output ends of the guide members 124 and 126 are located below the highest point of the curve in the lower guide member 122. Thus, the tension imposed on the upper guide member causes central portions of these two guide members to bear against and follow the contour of the lower guide member 122 throughout the exposure area directly beneath the uorescent bulb 128. However, the spacing of the ends of the intermediate and upper guide members 124 and 126 from the adjacent portions of the lower guide member 122 causes these guide members to diverge from each other at either side of this exposure area.

Thus, as the negative and master sheets are inserted into the input ends of the respective guide paths and 121, they are guided between the upper pair of rollers and 131 of the first set and are pressed together and fed along the guide paths which become progressively narrower as the papers approach the exposure area. The leading edges of the papers wedge apart the guide members in the exposure area, with the springs 152 yielding to permit any slight longitudinal movement of the intermediate and upper guide members 124 and 126 necessary to accommodate such vertical separation of the guide members by the sheets.

During'the passage of the negative and master sheets through the exposure area, the intermediate and upper guide members press them smoothly around the contour of the lower guide member 122 and bring the photosensitive layer of the negative and the copy side of the master into intimate areal engagement with opposite faces of the intermediate guide member 124. Since the intermediate guide member is very thin, the amount of parallax or dilusion which results is negligible, and it is possible to make an accurate reflex exposure of the negative to the master through the intermediate guide member.

As may be seen in Figure 8, the rear edges of the feed openings 122e, 124g and 126b in the guide members 122, 124 and 126 are inclined in ,a direction outwardly The upper guide member 126 is l1 from the center ofthe machine and 'forwardly in the direction of movement of the sheets through the machine to prevent snagging of the leading edges or corners of the sheets. The rollers 130-137 inclusive are interrupted, their enlarged portions 130a etc. (Figure') being relatively short, with the feed openings being correspondingly shortl so that the inclination of the rear edges of the feed openings may be made comparatively steep without extending over a substantial distance lengthwise ofthe machine. This steepening of the rear edges of the openings in the intermediate guide member makes these edges function even more efficiently in properly separating the `.sheets and virtually eliminates any possibility that the sheets could inadvertently be placed in the machine so misaligned that their leading edges were parallel to the rear edges of the openings.

From the foregoing description, it will be apparent that in the single exposure area beneath the fluorescent bulb 128, the negative sheet is exposed to the master across the entire width of thesheets simultaneously, while the intermediate guide member 124 maintains their physical separation. Thus, .after the sheets have passed the exposure area the master may be returned through an opening 156 in the front of the machine while the negative sheet is passed tothe developing-transferring portion. It arrives there in registration with'the positive sheet which has been inserted .through an opening 158 in the front of the machine, the twosheets being inserted simultaneously and moving through paths of the same overall length at equal speeds.

A reflectorl) which extends'around the top and sides of the fluorescent bulb 123 serves to direct all of the light radiated thereby4 downwardly toward the exposure portions of the guide paths.k Light shields 162 and 164 which extend between and are supported Aby the side plates of Ythe machine serve to mask all of the upper guide member 126 beneath the lampexcept a short portion between vthe ends 162:1 and 164a of the shields, the guide members -124 and ,126 lie flush against the contours of thev lower guide member 122, to insure proper exposure of the negative to the master throughout this area. A diaphragm plate 166 is mounted above the inner horizontal portion of the shield 12.2 and as shown in broken lines isy movable to mask varying amounts of the exposure area and vary the degree of exposure.

The machine shown in Figures 7 and 8 has the advantage that since there is `only one exposure area the spacing betweenV the two Sets of rollers 13G- 133 and 1314-137 is quite short. This not only reduces the over-V all length of the machine, but makes it'possible for the machine tohandvle sheets ofi shorter length. Moreover, since the largest openings in the guide members 122, 124 and Vl26are-very narrow as comparedV to the exposure openings Vof the machinejshown in Figure 16, the machine of Figures 7 and 8 can Vhandle much narrower Y sheets. NFor the reasons pointed out above, there is also greater margin for error on the part of the operator in inserting thensheets intothe machine. Moreover, since Y there is only oneiiuoresceutbulb and one exposure area,

i there is never anyproblem with respect to.. matching fluorescent bulbs or ofV varying therelativesizes of Yexposure apertures in twoY separate exposure areas to compensate for difference in actinic lightV output of the two fluorescent bulbsemployed in the respective exposure areas. Y Y

From the foregoing description, it will be seen that the present invention provides ra photocopying machine which is adapted to receive master, negative and positive sheets -Which are inserted simultaneously and in registration at one end of the machine, expose the negative to thefmaster across their entire width while maintainingV separational control ,of them, then separate the negative and the master, deliver the master out'of the machine adjacent the rpoint wheregit was inserted deliver the negative and Y "the" positive' registration tothedeveloping apparatus in which they are maintained separate until they .have been wet by the developing liquid and then are pressed together with the excess fluid being wrung out of them, and then are delivered out of the machine, ready to be stripped apart to produce a readable positive photoprint. All of this is accomplished in a machine which is compact, inexpensive andpractical in construction and operation.

it will thus be appreciated that the aforementioned as well as other desirable objects have been achieved. However, the particular embodiments of the invention which are shown in the accompanying drawings and described in the foregoing specification are intendedr as merely illustrative of the principles of the invention rather than as restrictive of the scope thereof. For example, in the tirst embodiment shown in Figures 1 6, the particular shape, number and arrangement of the exposure openings are subject to almost infinite variation, provided the aforementioned precautions, such as sheet separation and uniform exposure are observed. Additionally, the portionr of the intermediate guide element 24 within the exposure areas, instead of being formed of a rigid, selfsupporting material such as sheet metal or plastic, could Yhe formed of flexible material such as a thin sheet metal to the master, even in the areas where they were sepa-V rated by the webs of the intermediate sheet, to alleviate the problem of pressing them into intimate areal contact through the exposure openings in the intermediate guide sheet, in both embodiments disciosed. Moreover, other types of paper feeding elements may be substituted for those actually shown. It thus should be emphasized that the coverage of this patent is limited only by the appendedV claims and not to the specic illustrative apparatus which is disclosed.

lclairn: Y y

l. In a photocopying machine of the type having developing-transferring means adapted to receive negative and positive Vsheets separately, moisten at least one of said sheets with developer liquid and press them together, the combination therewith of exposure means comprising three guide members superposed in face-to-face relation to deiine two generally parallel guide paths for respectively guiding a master sheet and a photosensitive negative sheet, opposed feed openings in all three of said guide members, movable power driven feed members extending through the feed openings in the inner and outer guide members for pressing said two sheets together through the opening in said intermediate guide member and feeding the same along said guide pathsV at equal speeds, a light source, opposed light-transmitting exposure portions in the intermediate guide member and one of the outer guide members in illuminated relation to said light source, for exposingsaid negative sheet to said Vmaster sheet across their entire width, with said intermediate guide member maintaining the separation of said sheets along at least a portion of their width during Vtheir entire Inove- Y and positive sheets separately, meisten at leastV one of said sheets with developer liquid and press them together,

the combination therewith of exposure means comprising a set of three guide members superposed in face-tofface relation to define two generally parallel guide paths for respectively conveying master and negative sheets, a light source, opposed light-transmitting portions in said intermediate guide member and said outer guide member in illuminated relation to said light source for exposing said negative sheet to said master sheet across their entire width, with said .intermediate guide member maintaining the separation of said sheets across at least a portion of their width during their entire movement along said parallel guide path, guide elements for conducting the master sheet from one of the aforesaid guide paths out of said machine, negative guide members defining a guide path for conducting the exposed negative from the other of said guide paths to'said developing-transferring means, and positive guide members defining a guide path for conducting a positive sheet separately to said developingtransferring means, feed openings in all of said guide members, movable feed elements projecting through said feed openings to engage the sheets therein and feed them along said guide paths, a single motor for driving all of said feed elements to cause them to feed said sheets at equal speeds, the input ends of said set of three guide members and said positive guide members having their input ends located adjacent to one another and the guide paths of the negative and positive sheets being of the same overall length, whereby when all three sheets are inserted simultaneously into the respective input ends of said guide paths in registration, the negative and positive sheets will reach said developing-transferring means in approximate registration.

3. A machine as claimed in claim 2 in which said negative guide members are shaped to define a guide path which makes a 180 turn and leads to a narrow space between the input ends of said dual conveyor means and said positive conveyor means.

4. In a photocopying machine of the type having developing-transferring means adapted to receive negative and positive sheets separately, moisten at least one of said sheets with developer liquid and press them together, the combination therewith of exposure means comprising dual conveyor means for respectively conveying master and negative sheets in separate guide paths, said dual conveyor means including an intermediate guide member separating said guide paths and an outer guide member defining the other side of one of said guide paths, and power driven movable feed means acting upon said sheets to feed them along said guide paths, a light source, op-

posed exposure openings in said intermediate guide member and said outer guide member in illuminated relation to said light source, said openings including portions in different areas along said guide paths, the openings in each of said areas being discrete and transversely spaced and the openings in the several areas being transversely staggered relative to one another, whereby in traversing said areas said photosensitive sheet and said master sheet are exposed across their entire width, with said inner guide member maintaining the separation of said ,sheets in the spaces between said openings in each of said areas, master conveyor means for receiving the master sheet from one of said guide paths and conducting it out of said machine, negative conveyor means for receiving the exposed negative from the other of said guide channels and conducting it to said developing-transferring means, and positive conveyor means for conducting a positive sheet separately to said developing-transferring means in a transit time equal to the total transit time of said` negative sheet.

5. In a photocopying machine of the type having developing-transfering means adapted to receive negative and positive sheets separately, moisten at least one of said sheets with developer liquid and press them together, the combination therewith of exposure means comprising three guide members superposed in face-to-face relation and spaced apart to define two generally parallel guide paths for respectively guiding master and photosensitive sheets, vopposed feed openings in all three of said guide members, movable power driven feed members extending through the feed openings in the inner and outer guide members for pressing said two sheets together through the opening in said intermediate guide member and feeding the same along said guide paths at equal speeds, a light source, opposed exposure openings in the intermediate guide member and one of the outer guide members in illuminated relation to said light source, said openings including portions in different areas along said guide paths, the openings in each of said areas being discrete and Itransversely spaced and the openings in the several areas being transversely staggered relative to one another, whereby in traversing said areas said photosensitive sheet and said master sheet are exposed across their entire width, with said inner guide member maintaining the separation of said sheets in the spaces between said openings in each of said areas, master conveyor means for receiving the master sheet from one of said guide paths and conducting it out of said machine, negative conveyor means for receiving the exposed negative from the other of said guide paths and conducting it to said developing-transferring means, and positive conveyor means for conducting a positive sheet separately to said developing-transferring means in a transit time equal to the total transit time of said negative sheet.

6. In a photocopying machine of the type having developing-transferring means adapted to receive negative and positive sheets separately, moisten at least one of said sheets with developer liquid and press them together, the combination therewith of exposure means comprising three guide members superposed in face-toface relation and spaced apart to define two generally parallel guide paths for respectively guiding master and photosensitive sheets, opposed feed openings in all three of said guide members, movable power driven feed members extending through the feed openings in the inner and outer guide members for pressing said two sheets together through the feed opening in said intermediate guide member and feeding the same along said guide paths at equal speeds, a light source, opposed exposure openings in the intermediate guide member and one of the outer guide members in illuminated relation to said `light source, said exposure openings including a first set of discrete openings spaced apart across the Width of said guide paths and a second set of discrete openings having the same longitudinal dimension and spaced from said first set along said guide paths and arranged to occupy positions corresponding to the spaces between the openings of said rst set, whereby in traversing said exposure openings, the entire width of said sheets is exposed at least through a distance equal to the longitudinal dimension of said sets of openings, with said inner guid'e member maintaining the separation of said sheets in the spaces between the openings in each of said sets, master conveyor means for receiving the master sheet from one of said guide paths and conducting it out of said machine, negative conveyor means for receiving the exposed negative from the other of said guide paths and conducting it to said developing-transferring means, and positive conveyor means for conducting a positive sheet separately to said developing-transferring means in a transit time equal to the total transit time of said negative sheet.

7. In a photocopying machine of the type having developing-transferring means adapted to receive negative and positive sheets separately, moisten at least one of said sheets with developer liquid and press them together, the combination therewith of exposure means comprising three guide members superposed in face-to-face relation and spaced apart to define two generally parallel guide paths for respectively guiding master and photosensitive sheets, opposed -feed openings in all three of said guide members, movable power driven feed members extending through the feed openings in the inner and outer guide members for pressing said two sheets together' i through the opening in .said intermediate guide member and feeding the same along said guide paths at equal speeds, a light source, opposed exposure openings in the intermediate guide member and one of the outer guide members in illuminated relation to said light source, said openings including portions in different areas along said guide paths, the openings in each of said areas being discrete and transversely spaced and the openings in the several areas being transversely staggered relative to one another, whereby in traversing said areas said photosensitive sheet and said master sheet are exposed across their entire width, with said in'ner guide member maintaining the separation of said sheets in the spaces between said'openings in each of said areas, presser elements yieldably engaging at least one of said sheets at said exposure openings to press said sheets into areal face-to-face contact, master conveyor means for receiving the ,master sheet from one of said guide paths and conducting it out of said machine, negative conveyor means for receiving the exposed negative from the other of said guide paths and conducting it to said developingtransferring means, and positive conveyor means for conducting a positive sheet separately to said developingtransferring means in a transit time equal to the total time of said negative sheet. Y

8. ln a photocopying machine of the type having developing-transferring means adapted to receive negative and positive sheets separately, moisten at least one of said sheets with developer liquid and press them together, the combination therewith of exposure means comprising three generally horizontally extending guide members superposed in face-to-face relation and spaced apart to deline two generally parallel guide paths for respectively guiding master and photosensitive sheets, opposed feed openings in all three of said guide members, movable power driven feed members extendingthrough the feed openings in the inner and outer guide members for pressingtsaid two sheets together through the feed openings in said intermediate guide member and feeding the same along said guide paths at equal speeds, a light source, opposed exposure openings in the intermediate and upper guide members said openings including portions in different areas along said guide paths, the openings in each of said areas being discrete and transversely spaced and the openings in the several areas being trans-V normally supported on the lower guide member, but having beveled front surfaces to cause them to be cammed .up by the leading edges of said sheets and permit said sheets to pass beneath said presserblocks and b e pressed byV them into intimate areal'contact, master conveyor means for receiving the master sheet from one of said guide paths and conducting it out of said machine, negaftive conveyor means for receiving the exposed negative from the other of said guide paths and conducting yit to said developing-transferringV means and positive conveyor means for conducting arpositive sheet separately to said developing-transferring means ina transit time equal to theitotal transit time of said negative sheet.

V9. En a .photocopying machine of the type having developing-transferring means adapted to receive negative and positive sheets separately, moisten at least one of said Vsheets with developer liquid and press them together, the combination therewith of exposure means comprising three guide members superposed in face-tolface relation and spacedapart to deiine two generally parallel guide paths for respectively guiding master and ,photosensitivegsheets opposed feed openings in all three of said guide members, movable power driven feed mem- Vbers extending through the feed openings in thev inner and outer guideY members for pressing said twov sheets together through the opening in'said intermediate guide member and feeding the same along said guide paths at equal speeds, a light source, opposed exposure openings in the intermediate and upper guide members, the exposure openings in said intermediate guide member extending beyond those in said upper guide member, said openings including portions in different areas along said guide paths, the openings in each of said areas being discrete and transversely spaced and the openings in the several areas being transversely staggered relative to one another, whereby in traversing said areas said photosensitive sheet and lsaid master sheet are exposed across their entire width, with said inner guide member maintaining the separation of said sheets in the spaces between said openings in each of said areas, translucent presser blocks of approximately the same size as the kexposure openings in said upper guidemember respectivelyreceived in said exposure openings with their weight normally supported on the lower guide member, but having beveled front surfacesto cause them to be cammed up by the leading edges of said4 sheets. and permit said sheets to pass beneath said presser blocks and be pressed by them into intimate areal contact, a mask overlying said upper guide having apertures smaller than presser blocks and arranged to overlap and mask the edges of said presser blocks at all sides, master conveyor means for receiving the master sheet from one of said guide paths and conducting itout of said machine, negative conveyor means for receiving the exposed negative from the other of said guide paths and conducting'it to said,developing-transferring means, and positive conveyor means for conducting a positive sheet separately toV said developing-transferring means in a transit time equal to the total transit time `of said nega- 10. In a photocopying machine of the type having developing-transferring means adapted Vto receive negative and positive sheets separately, moisten at least one of saidV sheets with developer liquid and press them together, the combination therewith of exposure means comprising three guide members superposed in face-tot tending beyond those in said upper guide member, said openingsV including portions in different areas Valong said guide paths, the openings in each of said areas being discrete and transversely spaced and the openings in the several areas being transversely staggered Vrelative to one another, whereby in traversing said areas said photosensitive sheet and said master sheet are exposed across their entire width, with said inner guide member maintaining the separation ofrrsaid'rsh'eets 'inthe spaces between said openings in each of said areas, translucent presser blocks of approximately the same size as the exposure openings in said upper guide member respectively received in said exposure openings with theirY weight normally supported on the lower guide member, but having beveled front surfaces to cause them to be cammed up by the leading edges of said sheets and permit said'sheets to pass beneath said presser blocks and be pressed by them intoV intimate areal contact, a mask overlying said upper'guide having rectangular apertures smaller than presser blocks and arranged tooverlap and mask the edges of said presser blocks at all sides, the proximate edges of the adjacent area-fes ia Said. mask .boeing ,in Substantial. lone'fuinal it outl of said machine, negative conveyor means for receiving the exposed negative from the other of said guide paths and conducting it to said developing-transferring means, and positive conveyor means for conducting a positive sheet separately to said developing-transferring means in a transit time equal to the total transit time of said negative sheet.

11. In a photocopying machine of the type having developing-transferring means adapted to receive negative and positive sheets separately, moisten at least one of said sheets with developer liquid and press them together, thev combination therewith of exposure means comprising three guide members superposed in face-toface relation andv spaced apart to define two generally parallel guide paths for respectively guiding master and photosensitive sheets, opposed feed openings in all three of said guide members, movable power driven feed members extending through the feed openings in the inner and outer guide members for pressing said two sheets together through the opening in said' intermediate guide member and feeding the same along said guide paths at equal speeds, a light source, opposed exposure openings in the intermediate and upper guide members, the exposure openings in said intermediate guide member extending beyond those in said upper guide member, said openings including portions in different areas along said guide paths, the openings in each of said areas being discrete and transversely spaced and the openings in the several areas being transversely staggered relative to one another, whereby in traversing said areas said photosensitive sheet and said master sheet are exposed across their entire width, with said inner guide member maintaining the separation of said sheets in the spaces between said openings in each of said areas, translucent presser blocks of approximately the same size as the exposure openings in said upper guide member respectively received in said exposure openings with their weight normally supported on the lower guide member, but having beveled front surfaces to cause them to be cammed up y by the leading edges of said sheets and permit said sheets to pass beneath said presser blocks and be pressed by them into intimate areal contact, a set of superposed masking members overlying said upper guide having apertures smaller than presser blocks and arranged to overlap' and mask the edges of said presser blocks at all sides, said masking members being longitudinally movable relative to one another to vary the longitudinal dimension of said apertures and thereby control the degree of exposure of said negative sheet, master conveyor means for receiving the master sheet from one of said guide paths and conducting it out of said machine, negative conveyor means for receiving the exposed negative from the other of said guide paths and conducting it to said developingtransferring means in a transit time equal to the total transit time of said negative sheet.

12. In a photocopying machine of the type having developing-transferring means adapted to receive negative and positive sheets separately, moisten at least one of said sheets with developer liquid and press them together, the combination therewith of exposure meanscomprising dual conveyor means for respectively conveying master and negative sheets in separate guide paths, said dual conveyor means including an intermediate guide member separating said guide paths and an outer guide member defining the other side of one of said guide paths, and power driven movable feed means acting upon said sheets to feed them along said guide paths, a light source, opposed exposure openings in said intermediate guide member and said outer guide member in illuminated relation to said light source, said openings including portions in different areas along said guide paths, the openings in each of said areas being discrete and transversely spaced and the openings in the several areas being transversely staggered relative to one 1 another, whereby in traversing said areas said photosensitive sheet and said master sheet are exposed across their entire width, with said inner guide member maintaining the separation of said sheets in the spaces between said openings in each of said areas, and the rear g edges of the openings in said intermediate guide member being inclined away from the webs which separate said openings, whereby, in the direction of movement of said sheets, the separating webs are progressively widened and the openings correspondingly narrowed, master conveyor means for receiving the master sheet from one of said guide paths and conducting it out of said machine, negative conveyor means for receiving the exposed negative from the other of said guide paths and conducting it comprising three guide members superposed in face-toface relation to define two generally parallel guide paths for respectively guiding master and photosensitive sheets,`

opposed feed openings in all three of said guide members, movable power driven feed members extending through the feed openings in the inner and outer guide members for pressing said two sheets together through the opening in said intermediate guide member and feeding the same along said guide paths at equal speeds, a light source, opposed exposure portions in the intermediate guide member and one of said outer guide members in illuminated relation to said light source, said exposure portions being formed of translucent sheet maerial with the exposure portion of at least Said intermediate sheet being formed of a very thin transparent material, and said exposure portions extending across the full width of said sheets, means yieldably urging said exposure portions toward the other guide member to cause said negative and master sheets intimately to engage opposite faces of said intermediate guide member, master conveyor means for receiving the master sheet from one of said guide paths and conducting it out of said machine, negative conveyor means for receiving the exposed negative from the other of said guide paths and conducting it to said developing-transferring means, and positive conveyor means for conducting a positive sheet separately to said developing-transferring means.

14. In a photocopying machine of the type having developing-transferring means adapted to receive negative and positive sheets separately, moisten at least one of said sheets with developer liquid and press them together, the combination therewith of exposure means comprising three guide members superposed in face-toface relation to dene two generally parallel guide paths for respectively guiding master and photosensitive sheets, opposed feed openings in all three of said guide members, movable power driven feed members extending through the feed openings in the inner and outer guide members for pressing said two sheets together through the opening in said intermediate guide member and feeding the same along said guide paths at equal speeds, a light source, a convex curve in the lower one of said guide members opposite said light source, opposed exposure portions in the intermediate and upper guide members adjacent said curve, extending the full width of said sheets the exposure portion of the upper guide member being formed of flexible, translucent material, and the exposure portion of the intermediate guide member being formed of thin, flexible, transparent material, the exposure portions extending around said curve and fanning out at at least the input side thereof and being separable tO-pfer'rhit Said Sheets to Wedge 'tlfel apart `and enter between them, 'master conveyorme'ans for 'receiving vthe master sheet from one of said guide paths and conducting `it out of said machine, negative conveyor means for receiving Vthe exposed negative from the other of said guide paths and conducting it to said developing-transferring means, and positive conveyor means for conducting Va positive sheet separately to said developing-transferring means.

15.1n a photocopying machine of the type having developing-transferring means adapted to receive negative and positive sheets separately, moisten at least one of said sheets with developer liquid and press them together, the combination therewith of exposure means comprising 'three guide members superposed in face-toface relation to define two generally parallel guide paths for respectively guiding master and photosensitive sheets, opposed vfeed openings in all three of said guide members, movable power driven feed members extending through the feed openings in the inner and outer guide members for pressing said two sheets together through the opening in said intermediate guide member and feeding the same alongrsaid guide paths at equalvspeeds, the rear edges of the said feed openings in said intermediate guide member being inclined in a direction outwardly from the centerline of said machine in thedirection of vmovement of said sheets, a light source, opposed exposure 1prt-io1'sV li`n "the 'intermediate v'guide member one of -said outer 'guide members iin illu'ninated felation to said light source, fsaid exposure 'portions being formed of translucent sheet material with theexposu'eportion of at least said intermediate sheet being `formed of 'a very thin transparent material, and said exposure fp'ortions extending across the full width of said sheets, means yieldably urging said exposure portions toward the other guide member to cause said negative and master 'sheets intimately tov engage opposite faces of said intermediate guide member, master conveyor means for Areceiving the master sheet'from one of said guide paths and conduct-` ing it out of said machine, negative conveyor means for s receiving the exposed negative from theV other of'said Y guide paths and conducting it to said developing-transferring means, and -positive'conveyor means -for conducting aV positive sheet separately to said developing-transferring means.

References Cited 'in the file of this patent UNITED STATES PATENTS Switzerland May '3.71, 19516V

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