Photographic printing apparatus

{
  "publication_number": "US3810694A",
  "country": "US",
  "kind": "A",
  "title": "Photographic printing apparatus",
  "abstract": "A photographic printing apparatus, particularly for exposing lithographic plates to light through films, having a table on which a film may be assembled with a plate in registration therewith, the plate/film assembly then being fed to and gripped by a conveyor, which conveys it to a position within a vacuum frame unit at an exposure station, after which the vacuum frame unit is closed and evacuated for pressurizing the assembly. The plate is then exposed, the vacuum unit is opened, and the conveyor actuated to feed the exposed plate with the film thereon to an output station, at which the grip is released, and a vacuum lift picks up the film from the plate and drops it into a chute for return to the entrance end of the apparatus, the plate being fed forward out of the apparatus by a plate feed roll arrangement. Also, adaptations of this apparatus for contact exposure of lithographic plates to light through film from a roll, and for exposure of lithographic plates via projection of enlarged images from microfilm or other film.",
  "claims": [
    "1. Apparatus for exposing photosensitized plates comprising a conveyor having plate gripping means spaced at intervals along its length each adapted releasably to grip a plate for movement of the plate by the conveyor in a forward direction along a predetermined path, means for intermittently operating the conveyor to index each plate gripping means from a first station for application of a plate thereto to a second station along said path for bringing the gripped plate to an exposure position and thence to a third station farther along said path for discharge of the plate, a light source for exposing the plate in exposure position to light through a film after the plate gripping means has been indexed to the second station, means at the third station for releasing the plate gripping means, and means at the third station operable upon release of the plate gripping means for feeding the released plate forwardly out of the apparatus for further processing.",
    "2. Apparatus as set forth in claim 1 wherein each of said gripping means is adapted to grip a film on a plate, and wherein said apparatus has means for registering the film with the plate.",
    "3. Apparatus as set forth in claim 2 wherein each of said gripping means comprises a set of clamps for clamping a plate with a film thereon at the forward end of the plate and film.",
    "4. Apparatus as set forth in claim 3 having means at the first station for opening the clamps, and means for effecting registration of a film on a plate and feeding the plate and film for entry of their forward ends in the opened clamps at the first station, the clamps then closing to grip the plate and film.",
    "5. Apparatus as set forth in claim 4 wherein said registration and feeding means comprises a table movable away from a retracted position spaced from said first station forward toward said first station and then back to said retracted position, and means carried by the table for effecting registration of a film on a plate applied to the table.",
    "6. Apparatus as set forth in claim 5 wherein said means carried by the table comprises a plurality of registration pins movable up and down between a raised position extending up above the top surface of said table for entry in holes in a plate and a film and a lowered retracted position below said top surface.",
    "7. Apparatus as set forth in claim 6 for exposing one or two single-page newspaper lithographic plates or a double-page newspaper lithographic plate having a first rearward pin and a first forward pin for registering one single-page plate and negative, a second rearward pin and a second forward pin for registering a second single-page plate and negative, and third and fourth rearward pins and third and fourth forward pins for registering a double-page plate and negative.",
    "8. Apparatus as set forth in claim 1 having means for pressing a plate and a film when brought to the exposure position, said first station being rearward of and said third station being forward of said pressing means, said pressing means being adapted to be opened for indexing of the plate gripping means.",
    "9. Apparatus as set forth in claim 8 wherein said pressing means comprises a window movable downwardly from a raised retracted position toward a pressing position with respect to a plate and film, and means at the ends of the window for raising and lowering said window.",
    "10. Apparatus as set forth in claim 1 wherein said feeding means comprises a feed roll engageable by the plate when the plate gripping means moves to the third station, and means for driving the feed roll to feed the released plate forward.",
    "11. Apparatus as set forth in claim 10 having a pinch roll movable from a retracted position toward the feed roll to pinch the plate between the rolls.",
    "12. Apparatus as set forth in claim 1 wherein each of said gripping means is adapted to grip a film on the plate, and having means for picking up the film off the plate after the plate has been exposed and the exposed plate and film have moved forward with the gripping means when the latter moves forward to the third station, and is released.",
    "13. Apparatus as set forth in claim 12 wherein said pick-up means is a vacuum cup means movable downwardly to grip the film by vacuum and upwardly to lift the film from the plate, said vacuum cup means, on release of vacuum, releasing the film to drop down through a space rearward of the third station.",
    "14. Apparatus as set forth in claim 13 having means for pressing a plate and a film when brought to the exposure position, said first station being rearward of and said third station being forward of said pressing means, said pressing means being adapted to be opened for indexing of the plate gripping means, said space being between the forward end of said pressing means and said third station.",
    "15. Apparatus as set forth in claim 14 having a film conveyor below said pressing means for receiving the film dropping down through said space and conveying it out from under said pressing means.",
    "16. Apparatus as set forth in claim 15 wherein the film conveyor returns the film to the entrance end of the apparatus.",
    "17. Apparatus as set forth in claim 16 wherein the film conveyor is movable to set it in a first position for delivering a film to a first tray or in a second position for delivering the film to a second tray.",
    "18. Apparatus as set forth in claim 1 wherein said conveyor comprises a pair of endless chains, and each plate gripping means comprises a bar extending between the chains having a set of clamps on the trailing side thereof for clamping a plate, and said releasing means at the third station comprises means for opening the clamps.",
    "19. Apparatus as set forth in claim 18 having means at said exposure position carrying a flexible blanket, the chains having an upper reach in which they carry the bars over the blanket, and further having a window movable downwardly from a raised retracted position toward the blanket, means for effecting a seal between the window and blanket all around a plate and a film on the blanket in exposure position when the window is moved down, and means for evacuating the space between the blanket and the window when the windOw is moved down, and wherein said first station is rearward of said window and said second station is forward of said window.",
    "20. Apparatus as set forth in claim 19 wherein said plate feeding means comprises a feed roll rotatable in the direction to feed the released plate forward, and having means for operating the conveyor to index a bar forward and around from the upper reach of the chains to a clearance position for clearing the plate to be fed forward by said roll.",
    "21. Apparatus as set forth in claim 20 having a pinch roll movable from a retracted position toward the feed roll to pinch the plate between the rolls, and a discharge conveyor at the forward end of the apparatus for receiving the discharged plate from the feed and pinch roll and conveying it forward away from the apparatus.",
    "22. Apparatus as set forth in claim 20 wherein each set of clamps is adapted to grip a film and a plate, said apparatus further having vacuum cup means for picking up the film off the plate after the plate has been exposed and the exposed plate and film moved forward with a bar when it moves forward to the third station and the clamps are opened.",
    "23. Apparatus as set forth in claim 22 having a space between the forward end of the blanket and the feed roll, and wherein the vacuum cup means is adapted to release the film to drop down through said space.",
    "24. Apparatus as set forth in claim 23 having means for opening the clamps on a bar at the first station, a registration and feed table movable away from a retracted position spaced from the clamps of the bar at the first station toward said clamps to enter a plate and a film in the opened clamps, said clamps thereupon closing, and means carried by the table for effecting registration of a film on a plate applied to the table.",
    "25. Apparatus for exposing photosensitized plates comprising an endless conveyor movable intermittently to convey a plate through a predetermined path from a first position at which the plate is applied to the conveyor to a second exposure position along said path for exposure of the plate and thence to a third position farther along said path, means for feeding a film laterally across the apparatus from one side thereof to the other over the plate in the exposure position, and a light source for exposing the plate in the exposure position to light through the film.",
    "26. Apparatus for exposing photosensitized plates comprising conveyor means movable intermittently to convey a plate through a predetermined path from a first position at which the plate is applied to the conveyor means to a second position along said path constituting an exposure position and to convey an exposed plate away from said exposure position, means for pressing the plate at the exposure position adapted to be opened to permit the conveyor means to move a plate from the first position to the exposure position and to move an exposed plate away from the exposure position, and adapted to be closed for pressing a plate at the exposure position for exposure of the plate while the conveyor means is stopped, said pressing means including a light-transmitting panel engageable with the face of the plate to be exposed, and means for projecting an enlarged image from a film through said panel on to the said face of a plate pressed for exposure by said pressing means at said exposure position.",
    "27. Apparatus as set forth in claim 26 wherein said projecting means includes a film projector and a mirror for reflection of the image from film in the projector on to the said face of a plate at the exposure position.",
    "28. Apparatus as set forth in claim 26 having a first light source for contact exposure of a plate at the exposure position through a film in contact with the plate, said projecting means including a second light source for directing light through a film therein.",
    "29. Apparatus as set forth in claim 27 wherein said projecting means includes a film projector and a mirror for reflection of the image from the film in the projector on to said face of said plate at the exposure position, the second light source being in the projector.",
    "30. Apparatus as set forth in claim 29 wherein said first light source and said mirror are mounted on a common support movable between a first position wherein said mirror is in position for projection of an image by said projector via reflection from the mirror of light emitted by said second light source in the projector, and the first light source is retracted and a second position wherein said first light source is in position for permitting contact exposure by the first light source, and the mirror is retracted.",
    "31. Apparatus as set forth in claim 29 wherein said mirror is movable between a first position for reflection of an image from the film on to the plate at the exposure position and a second position for reflection of light from the first light source on to the plate at the exposure position.",
    "32. Apparatus as set forth in claim 26 having means whereby images may be projected on to different areas of a plate or on to different plates at the exposure position.",
    "33. Apparatus as set forth in claim 26 wherein said projecting means includes a film projector and means for moving the projector to different positions whereby images may be projected on to different areas of a plate or on to different plates at the exposure position.",
    "34. Apparatus as set forth in claim 26 wherein said projecting means includes a film projector and a mirror for reflection of the image from film in the projector on to the said face of a plate at the exposure position, and having means for moving the projector to different positions whereby images may be projected on to different areas of a plate or on to different plates at the exposure position.",
    "35. Apparatus as set forth in claim 34 having means for moving the mirror to different positions of adjustment."
  ],
  "cpc": [
    "B41B 13/00",
    "G03B 27/20"
  ],
  "assignees": [
    "WESTERN LITHO PLATE & SUPPLY"
  ],
  "filing_date": "1972-04-17",
  "publication_date": "1974-05-14",
  "grant_date": "1974-05-14",
  "priority_date": "1970-09-10",
  "application_number": "US-24436472-A",
  "family_id": "26751916",
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    "US3689150A"
  ]
}