US3266402A

US3266402A - Photographic printer

Info

Publication number: US3266402A
Application number: US366390A
Authority: US
Inventors: Harold R Benson
Original assignee: Nuarc Co
Current assignee: Nuarc Co
Priority date: 1964-05-11
Filing date: 1964-05-11
Publication date: 1966-08-16
Anticipated expiration: 1983-08-16
Also published as: GB1032845A

Description

Aug. 16, 1966 H. R. BENSON 3,266,402

PHOTOGRAPHIC PRINTER Filed May 1l, 1964 2 lSlfxee'cs-Sheec. 1

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rroeA/EYS Aug. 16, 1966 Filed May ll 1964 H. R. BENSON PHOTOGRAPHIC PRINTER 2 Sheets-Sheet 2 United States Patent O "ice 3,266,402 PHOTOGRAPHIC PRINTER Harold R. Benson, Lombard, Ill., assigner to The Nuarc Company, Chicago, Ill., a corporation of Illinois Filed May 11, 1964, Ser. No. 366,390 3 Claims. (Cl. 9576) The present invention relates to photographic printers and, more particularly, relates to contact printing apparatus useful in exposing sensitized metallic plates such as photoengraving offset plates.

In order to photoengrave a metallic plate so that it may be used thereafter to reproduce a work of art or the like, a photographic negative is rst made of the work to be reproduced and thereafter a sensitized metal plate is selectively exposed to the pattern of light corresponding to the work of art by interposing the negative between the sensitized surface of the plate and a source of light.

Following the exposure of the plate in this manner, the sensitized surface is subjected to an acid etching which selectively removes the unexposed portions of the sensitized surface, thereby to provide what is commonly referred to as an offset printing plate, the surface of the plate having hills and valleys corresponding to the Work of art being copied.

One improved photographicprinter is disclosed and claimed in my earlier patent, No. 3,043,204, granted July 10, 1962, and assigned to the same assignee .as the present invention. As therein disclosed, there is provided a contact printer comprising a cabinet having a light source mounted in the cabinet, and a reflector fixedly mounted in the cabinet for directing a uniform beam of light toward the top of the cabinet where a printing frame is pivotally mounted about a -central axis thereof. The frame can be pivoted to one position in which one side thereof is toward the light source and in a second position wherein that one side of the printing frame is toward the top of the cabinet away from the light source. Accordingly, the plate and the negative may be loaded into the frame from the top thereof and the frame may then be pivoted into the position wherein the plate is exposed to the light source. The present invention is an improvement over the photographic printer disclosed and claimed in this patent.

Because the printing frame in my earlier photographic printer provides for loading in one side `only of the printing frame, the operator of the printer must first load the photographic plate and the negative into the frame, 'then rotate the top so that the frame is positioned with the plate exposed to the light source, and thereafter expose the plate. During the exposure of the plate, the operator of the photographic printer must wait idly for completion of the exposure. Upon completion of the exposure, the frame is flipped back with the loading side thereof upwardly so that the operator can remove the exposed plate and negative, and reload the photographic printer with the next plate and negative. It would be desirable in order to increase the production of the photographic printer to provide for exposure of one plate while a second plate is being loaded into the photographic frame.

An object of the present invention therefore is to provide a new and improved apparatus for exposing sensitized metal plates and for photoengraving thereof, and which overcomes the above-mentioned difficulty.

A further object of the present invention is the provision of a new and improved contact printer which will provide increased production without increasing the floor space required for the photographic printer.

A further object of the present invention is the provision of a new and improved photographic printer.

Briey, the .above and further objects are realized in accordance with the present invention by providing a photographic printer, including a cabinet having a source of printing light mounted in the lower part for directing light toward the top of the cabinet, and a printing frame forming a top enclosure for the cabinet. The printing frame is mounted for pivotal movement about a central axis of the frame thereby to permit the positioning of the frame with either side thereof facing toward the light source. The frame is provided with a transparent hinged plate on each side, and back-to-back pressure responsive vacuum holding means for holding a light sensitive photographic sheet or plate adjacent to the transparent plate are associated with each of the transparent plates. Advantageously the printer, according to the present invention, provides for exposure -of one `of the vacuum frames, while the other vacuum frame is accessible at the top of the printer for loading the next photographic plate. The present photographic printer converts the normally idle time of the operator during plate exposure into productive working time. It has been found that the output of the photographic printer may be increased over 50% without increasing the floor space of the photographic printer.

Further objects and advantages of the present invention will become apparent as the following description proceeds and the features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming a part of this specication.

FIGURE 1 is an isometric view of a photographic printer according to the present invention;

FIGURE 2 is a fragmentary cross-sectional elevational view of the photographic printer of FIGURE 1 taken along line 2 2 of FIGURE l;

FIGURE 3 is a fragmentary cross-sectional elevational view of the photographic printer of FIGURE 1 illustrating a printer frame taken along the transverse axis of FIGURE 1;

FIGURE 4 is a fragmentary cross-sectional elevational view of the photographic printer of FIGURE 1r also taken along the transverse axis of FIGURE 1.

FIGURE 5 is a fragmentary plan View of the photographic printer of FIGURE 1 illustrating an apertured pintle connection of the printing frame to the photographic printer cabinet.

Referring now to the drawings, there is provided in accordance with the present invention a photographic printer 20 comprising a generally rectangular cabinet 21 having an automatically operated light source such as a carbon arc light mounted in the bottom of the cabinet. The light source may preferably be a xenon lamp as shown in copending Scheppe application Serial No. 340,762 tiled January 28, 1964, and assigned to the same assignee as the present invention. The cabinet and light source construction may be similar to that described and claimed in my above-mentioned Patent No. 3,043,204 and accordingly is not herein described in detail. However, briefly, the light source directs an upward light beam of uniform intensity throughout a predetermined area containing a printing frame 25 pivotally mounted about a central axis thereof to the top of the cabinet 21. As best illustrated in FIGURE 3, the frame 25 comprises a pair of opposed loading stations A and B. In order to place a sensitized plate and negative in the frame for exposure by the light from the light source within the cabinet 21, one station, for example station A, of the frame 2S is first loaded, and then pivoted through so that the loading station A is at the bottom. The loading station A may then be exposed while the other station B may be loaded from the top during the exposure of loading station A. After the station A has been exposed, the frame 25 may again be rotated so that the unexposed station B faces toward the light source, while the exposed station A is at the top of the photographic printer 20 to permit removal thereof of the exposed photographic plate and negative and reloading thereof.

For providing pivotal rotation of the frame 25, the `frame 25 is pivotally mounted by means of a pair of

pintles

83 and 84, FIGURE 2, journaled in a pair of bearings 83a, 84a. The

pintles

83 and 84 are coaxlally mounted along ya central axis of the frame l25 so that the opening in the topof the cabinet 21 is completely covered by theframe 25 in either of its two positions; that is, with either loading station A or B turned downwardly toward thelight source.

To` provide for-'loading the stations A and B, each of `the stations A and B is provided `with a glass frame assemlbly 85, which includes a plate glass pane 86, and which inthe illustrated embodiment ofthe invention ispivotally attached to the rear side of the frame 25 by suitable hinges V87, FIGURE 2. As hereinbefore indicated, during the loading andexposing operation, theframe l25 is turned to a position with one of the loading stations A or B positioned upwardly at the top of the photographic printer20 in order that the negative and sensitized photographic plate may be placed within the frame. The glass frame assembly `85 is pivoted upwardly aboutthe hinge 87. It 'is understood that in other embodiments of the present invention where a very large printing frame is employed, the glass frame`85, instead of being pivotally supported, may'bodily be raised and lowered while disposed in a horizontal plane. Suitable latch and handle means 96 are provided on eachof the glass frame assemblies 85 to provide for latching and unlatching of the glass frame assembly85 from vthe frame 25. To load the frame 25, the glass frame assembly 85 at one of the loading stations, for example loading station A as indicatedin FIGURES 2, 3, and 4, is raised to its .elevated position and the glass 'plate engaging surface of a resilient vacuum blanket 101 .of the respective loading station is exposed, and a sensitized photographic plate may be placed therein.' The `blanket 101 ispreferably a one-piece molding of rubber and, as more'fully illustrated and described inmy abovementioned .earlier patent, may be provided with a plate engaging face which comprises a plurality of square, truncated 'pyramids or protuberances 102. The blanket 101 further includes a peripheral sealing port-ion 103 for engaging the glasspane 86 when the glass'frame 85 is in a 'latched portion, thereby Vto hermetically seal the cavity delined by the glass pane 86 rand the-blanket 101. The seal 103 consists of a generally arcuate bead which is compressed into a generally tubularshapewhen the glass frame 85 is in a latched position. Since the blanketis `formed of a resilient material, the inherentresiliency of the sealing bead S-urges it against the glass pane to provide the desired seal.

Meansare provided'to vacuum seal the blanket 101 against the .glass 86. 'In thepreferred embodiment the vacuum is provided by a pair-of independent vacuum pumps and motors in amannerknown in theart, each similar to .that more fully 'described in my above-mentioned patent. A rst suitable vacuum control switch 106 yis located on a control panel 108 at theitop frontof the cabineti21` and, when actuated, is effective to energize one of the vacuumpumps to draw-a vacuum between the glass pane 186 and the blanket 101 .at loading station A. A second suitable vacuum control switch 107 is also located on-the control panel 108 and, when actuated, is effective to energize the other vacuum .pump to draw avacuum between the glasspane 86 and the resilient blanket-1010i Vloading station B. The drawing of a vacuum between the lglass pane 86 and its respective blanket 101perrnits the atmospheric pressure to force the resilient blanket 101 rrnly against theglass ypane so that vsensitized photographic plates and negative vmaterial resting on the re- -silient blanket will be held rrnly against the inner face Pof the .respective glass pane 86. Accordingly, relative movement between the sensitized photographic plate and vnegative material isprevented, and more importantly, no air pockets yremain between the two which could, of

course, result in distortion of the image projected on the sensitized surface of the plate.

In order to connect each of the vacuum pumps to the cavity between the respective glass panes 86 and the associated blankets 101, each of the

pintles

83 and 84 are tubular and are connected at their outer ends with a rotatable vacuurn iitting 114. The vacuum litting 114 is connected to a respective one of the vacuum pumps by means of suitable flexible conduit 116. The inside of the apertured

pintles

83 and 84 are connected to a T fitting 118 disposed within the frame 25 and two outlets thereof are connected through a pair of respective

flexible conduits

119 and 120, FIGURE 4, to suitable apertures provided in each of the blankets 101. Accordingly, each of the vacuum pumps draws air from the space between its respective blanket 101 and the associated glass pane 86.l

Suitable openings are provided in the side of the frame 25 to provide a large area connection between the back side of each of the blankets 101 and the atmosphere so that when a vacuum is drawn between one of the blankets 101 and the respective glass pane 86, the atmospheric pressure on the back sides of the blankets 101 is effective vto press the respective blanket rmly against its associated glass pane 86.

In order to lock the printing frame 25 in an exposure position with one of the loading stations A, B facing toward the light source, and the other of the loading stations facing the top of the photographic printer, there is provided a spring-loaded, -manually operable latch 142, including a plunger-type bolt 143 which is spring biased into one of a pair ofa suitable loatching members 144 located at respective ends of the frame 25 as best illustrated in FIGURE 3. Each member 144 is attached to the front wall of the printing frame 25, and in order to release the printing frame 25 for rotation thereof, a knob 145, which is threadedly attached to the bolt 143, is pulled out to withdraw the bolt 143 from the aperture in the member144 and thereby to release the frame 25. Since similar latching members 144 are provided on opposite ends of the printing fra-me 25, the frame 25 may be locked in an inverted position with either of the loading stations A, B facing down toward the light source.

From theabove detailed description, the operation of the improved photographic printer is believed clear. However, briey, the operation of the photographic printer will be described. In order to initiallyload sensitized material, negatives, and the like, into the frame 25 of the photographic printer 20, and assuming the toploading station to be loading station A as indicated in FIG- URE 3, the glass frame assembly 85 in the loading station lA is released through manipulation of the latch handles 96 and the glass frame assembly 85 iis pivoted 11pwardly about hinge 87. The sensitized plate and other photographic material is then laid on the blanket 101 in the loading station A and the glass frame assembly 85 is closed andrlocked with the latch handles 96. A- vacuum can then be drawn between the blanket 101 and the glass pane 86 of the loading station A by actuation ofthe vacuum control switch 106. The atmospheric pressure is then effective to force the blanket 101 against the glass pane 86.

With the photographic -material held firmly against the yglass pane 86, the frame 25 may be rotated by iirst releasing the latch 142 and thereafter pivoting the frame 25 so that the loading station A faces downwardly toward the light source. The latch 142 will now lock into the aperture in the opposite latching member 144 to lock the frame 25 in this position. Vacuum will continue `to be drawn at loading station A through the tubes 119 and leading to the pintle 83. The photographic material and loading station A may now be exposed in the desired manner by the manipulation of other controls of the photographic printer.

While exposure of the photographic material at loading station A is taking place, loading station B, which has now been rotated to the top of the photographic printer, may be unloaded and loaded in like manner as loading station A described above. Upon 4completion of the exposure of loading station A and loading of loading station B, the frame 25 may again be flipped through 180 to permit exposure of loading station B while loading station A is unloaded and reloaded.

It will be understood, according to the present invention, that production of photographic plates may be substantially increased by the present photographic printer since the normally idle time of the operator during plate exposures is now turned into productive working time in a form of loading and unloading the Vacuum frames. In other words, one vacu-um frame at one loading station is exposed while the other vacuum frame at the other loading station is being unloaded and reloaded. Thereafter the frame 25 is pivoted to permit exposure of the unexposed frame. During exposure of the second frame at the second loading station, the rst loading station is unloaded and reloaded.

While there has been shown and described a particular embodiment of the present invention, it will be apparent to those skilled in the art that various changes and modications may be made without departing from the invention in its broader aspects, and it is therefore contemplated in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What is claimed as new and desired to be secured by letters patent of the United States is:

1. A printer for use in making photographic plates and the like, comprising a cab-inet, a source of printing light mounted in the lower part of said cabinet for directing light towards the top of Said cabinet, a printing frame, mounting means for mounting said frame in the top of sa-id cabinet for pivotal movement about a central axis of said frame table to permit the positioning of said frame with either side thereof facing towards said light source including a pair of opposed apertured pintles, pump means mounted in said cabinet, a pair of pressure responsive means disposed in said frame, each associated with a respective side of said frame for xedly positioning photographic material in the respective side of said frame, and uid connection means between said pump means and each of said pressure responsive means, said connection means each including the aperture in a respective one of said pintles.

2. A printer for use in making photographic plates and the like, comprising a cabinet, a source of light mounted in the lower part of said cabinet, a printing frame including a pair of glass plates and a pair of imperforate resilient blankets, each blanket being disposed in face-toface relationship with a respective plate and having a cont-inuous seal positioned between a peripheral portion of said plate and said blankets, means for drawing a vacuum selectively between each of said blankets and the respective plates, and mounting means for mounting said frame in the top of said cabinet for pivotal movement about a central axis of said frame, thereby to permit the positioning of said frame with either glass plate thereof facing toward said light source while maintaining a vacuu-m on said side of said frame.

3. A photographic printer comprising a cabinet having side walls forming an interior cavity and defining an upper opening, said opening communicating with said cavity and having a given coniiguration, light means disposed in the lower end of said cavity for supplying light upwardly through said upper opening, a generally uniplanar printing frame of said given configuration disposed in and substantially closing said upper opening to provide the top of said cabinet, said printing frame including a pair of transparent plates, each on one side of said fra-me, and hinged at one end t-o said printing frame, a pair of holding means each associated with one side of sa-id printing frame for holding light sensitive material adjacent a respective one of said transparent plates, and mounting means on said side walls for mounting said printing frame for pivotal movement between two positions spaced approximately from each other in which said frame is effective to substantially close said upper opening, one of said plates being disposed below the top of said cabinet and the other of said plates being disposed above the top of said cabinet in each of said positions with the lower of said plates positioned to receive light from said light source and reflector means, the other of said plates forming the top of said cabinet in each of said positions to permit unobstructed insertion of said material.

No references cited.

JULIA E, COINER, Primary Examiner.

Claims

1. A PRINTER FOR USE IN MAKING PHOTOGRAPHIC PLATES AND THE LIKE, COMPRISING A CABINET, A SOURCE OF PRINTING LIGHT MOUNTED IN THE LOWER PART OF SAID CABINET FOR DIRECTING LIGHT TOWARDS THE TOP OF SAID CABINET, A PRINTING FRAME, MOUNTING MEANS FOR MOUNTING SAID FRAME IN THE TOP OF SAID CABINET FOR PIVOTAL MOVEMENT ABOUT A CENTRAL AXIS OF SAID FRAME TABLE TO PERMIT THE POSITIONING OF SAID FRAME WITH EITHER SIDE THEREOF FACING TOWARDS SAID LIGHT SOURCE INCLUDING A PAIR OF OPPOSED APERTURED PINTLES, PUMP MEANS MOUNTED IN SAID CABINET, A PAIR OF PRESSURE RESPONSIVE MEANS DISPOSED IN SAID FRAME, EACH ASSOCIATED WITH A RESPECTIVE SIDE OF SAID FRAME FOR FIXEDLY POSITIONING PHOTOGRAPHIC MATERIAL IN THE RESPECTIVE SIDE OF SAID FRAME, AND FLUID CONNECTION MEANS BETWEEN SAID PUMP MEANS AND EACH OF SAID PRESSURE RESPONSIVE MEANS, SAID CONNECTION MEANS EACH INCLUDING THE APERTURE IN A RESPECTIVE ONE OF SAID PINTLES.