Slip sheet removal

{
  "publication_number": "US9227392B2",
  "country": "US",
  "kind": "B2",
  "title": "Slip sheet removal",
  "abstract": "A method of removing slip sheets from a printing plates stack is disclosed, wherein the slip sheets are interspersed between the printing plates includes moving at least two parallel energy chains. Each of the energy chains carries a plurality of vacuum cups over the stack of printing plates. The vacuum cups are attached to a top slip sheet placed on top of the printing plates stack and peel off sheets while vacuum is maintained and transferring the top slip sheet into a slip sheet bin.",
  "claims": [
    "1. A method of removing slip sheets from a stack of printing plates wherein said slip sheets are interspersed between said printing plates, comprising: moving at least two parallel chains, wherein each of said chains carries a plurality of vacuum cups, over said stack of printing plates; contacting said vacuum cups to a top slip sheet placed on top of said stack of printing plates; applying vacuum to said vacuum cups to attach the top slip sheet to said vacuum cups; peeling said top slip sheet off said vacuum cups while vacuum is maintained by moving said chains with said top slip attached to said vacuum cups away from said stack of printing plates and by a slip sheet separator to separate said top slip sheet from said vacuum cups; and directing said top slip sheet into a slip sheet bin using said slip sheet separator.",
    "2. The method according to claim 1 wherein said chains are provided in plurality of sizes to match the length of said printing plate.",
    "3. The method according to claim 1 wherein a distance between said chains matches a width of said printing plate.",
    "4. The method according to claim 1 comprising: turning off vacuum after removal of slip sheet.",
    "5. The method according to claim 4 comprising: picking up said plate after removal of slip sheet and moving said plate to an imaging device using separate plate picking mechanism.",
    "6. The method according to claim 5 comprising: rotating said chains back into position over said stack of printing plates after removal of plate.",
    "7. The method according to claim 6 comprising: restoring said vacuum.",
    "8. The method according to claim 6 comprising: rotating said chains in a clockwise direction to move said vacuum cups into position over said stack of printing plates.",
    "9. The method according to claim 6 comprising: rotating said chains in a counter clockwise direction to move said vacuum cups into position over said stack of printing plates."
  ],
  "description_excerpt": "The invention relates to systems for handling flat sheets of media and more particularly to a system for holding and conveying a sheet from a stack of sheets.\n\nPlates, films, and proofing media for imaging systems, such as computer-to-plate (CTP) systems which are used in the graphic arts industry, are commonly stacked in boxes with slip sheet sheets interspersed between adjacent media sheets. The slip sheet primarily functions to protect the media surface from damage and to prevent adjacent media sheets from adhering to each other. The slip sheet is particularly important when the active emulsion on the media is either sticky or particularly sensitive to damage. In the development of media for imaging tasks, particularly plates for lithographic printing operations, a number of often conflicting parameters such print run length, exposure sensitivity, exposure latitude and processing requirements must often be traded off against one another to achieve the best results. Some media have particularly good performance in relation to the abovementioned parameters, but suffer from extreme delicacy of the unexposed media emulsion. In a specific case, some LH-PI lithographic plates have a particularly delicate emulsion and may be scratched even by the action of removing the slip sheet. However, once exposed, the emulsion is durable and the plate images have good on-press performance.\n\nOther commonly available media may have similar problems with delicate emulsion surfaces although, depending on the thickness and particular characteristics of the emulsion, scratches may or may not remain visible after subsequent processing.",
  "cpc": [
    "B41F 21/00",
    "B41P 2227/50",
    "B41P 2227/60",
    "B65G 17/323",
    "B65H 2701/18264",
    "B65H 3/0816",
    "B65H 3/124",
    "B65H 5/085",
    "B65H 5/224",
    "G03F 7/0012"
  ],
  "ipc": [
    "B41F 21/00",
    "B65G 17/32",
    "B65H 3/08",
    "B65H 3/12",
    "B65H 5/08",
    "B65H 5/22"
  ],
  "assignees": [
    "GUTTMANN YOEL",
    "ANDREW GORDON D",
    "EASTMAN KODAK CO"
  ],
  "inventors": [
    "GUTTMANN YOEL",
    "ANDREW GORDON D"
  ],
  "filing_date": "2014-05-21",
  "publication_date": "2016-01-05",
  "grant_date": "2016-01-05",
  "priority_date": "2014-05-21",
  "application_number": "US-201414283296-A",
  "family_id": "54555435",
  "citations": [
    "EP1382552A1",
    "US2006261537A1",
    "US3584866A",
    "US3682469A",
    "US3912253A",
    "US3926427A",
    "US4311304A",
    "US5655452A",
    "US6422801B1",
    "US6688591B2",
    "US6776097B2",
    "US7144009B2",
    "US7604231B2"
  ]
}