US3732808A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for developing offset printing plates
Assignee: Polychrome Corp
•
Filing: 1971-03-18
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Granted: 1973-05-15
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Expires: 1991-03-18
Abstract
Abstract Apparatus for developing offset printing plates wherein means are provided to simultaneously develop both sides of a two surface planographic offset printing plate or one surface of two single surface planographic offset printing plates placed back to back. The apparatus includes means for dispensing developer solution to opposed plate surfaces at the same time, rubbing means to simultaneously rub the opposed surfaces to assist the chemical action of the developer solution, washing means for removing developer solution from the opposed surfaces and propelling means for moving the plate or plates through the apparatus. The developer solution dispenser supplies developer solution at a uniform hydraulic pressure over the full surface area of the offset printing plate without the use of spray nozzles.
Inventors
- 👤 R Graham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:20
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/26; G03F7/30; G03F7/3042
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
278 words
An apparatus for simultaneously developing opposed surfaces of planographic offset printing plates comprising: means for moving a planographic offset printing plate into, through and out of the apparatus, a developing station within said apparatus for simultaneously developing opposed surfaces of said planographic offset printing plate, said developing station including spaced upper and lower platen members mounted between spaced side wall members defining a developing chamber therebetween, said developing chamber being oriented along the path of travel of planographic offset printing plates through said apparatus and including an entrance end and a discharge end, said entrance end of said developing chamber being provided with opposed flexible membranes adapted to admit a planographic offset printing plate into said chamber while maintaining a fluid tight seal against said planographic offset printing plate to preclude leakage of fluid from said chamber at saiD entrance end, said discharge end of said chamber being provided with fluid flow restricting means to restrict the flow of fluid from said discharge end of said chamber, said chamber being provided with opposed manifolds on the exterior surface of said upper and lower platens to deliver developing fluid under pressure from a source of developing fluid, and each said platen including an opening therein communicating with said manifolds and said chamber to deliver developing fluid under pressure across the width of said chamber to the opposed surfaces of said planographic offset printing plate at substantially 90* to the direction of travel of said plate through said chamber and wherein said developing fluid is dispensed under pressure over the complete surface of each of the opposed surfaces of said planographic printing plate while said plate is within said chamber.
Claim 2
Independent Claim
278 words
An apparatus for simultaneously developing opposed surfaces of planographic offset printing plates comprising: means for moving a planographic offset printing plate into, through and out of the apparatus, a developing station within said apparatus for simultaneously developing opposed surfaces of said planographic offset printing plate, said developing station including spaced upper and lower platen members mounted between spaced side wall members defining a developing chamber therebetween, said developing chamber being oriented along the path of travel of planographic offset printing plates through said apparatus and including an entrance end and a discharge end, said entrance end of said developing chamber being provided with opposed flexible membranes adapted to admit a planographic offset printing plate into said chamber while maintaining a fluid tight seal against said planographic offset printing plate to preclude leakage of fluid from said chamber at saiD entrance end, said discharge end of said chamber being provided with fluid flow restricting means to restrict the flow of fluid from said discharge end of said chamber, said chamber being provided with opposed manifolds on the exterior surface of said upper and lower platens to deliver developing fluid under pressure from a source of developing fluid, and each said platen including an opening therein communicating with said manifolds and said chamber to deliver developing fluid under pressure across the width of said chamber to the opposed surfaces of said planographic offset printing plate at substantially 90* to the direction of travel of said plate through said chamber and wherein said developing fluid is dispensed under pressure over the complete surface of each of the opposed surfaces of said planographic printing plate while said plate is within said chamber.
Claim 3
Dependent Claim
40 words
Apparatus as defined in claim 1 including plate scrubbing means to scrub each opposed surface of said plate after said plate is discharged from said developing chamber to remove exposed portions of the coating on said planographic offset printing plate.
Claim 4
Dependent Claim
86 words
Apparatus as defined in claim 2 wherein said plate scrubbing means comprises opposed cylindrical brush rollers rotatably mounted within said apparatus and oriented so that the path of travel of said planographic offset printing plate passes between said opposed brush rollers and said brush rollers being mounted so as to be in frictional contact with the opposed surfaces of said plate thereby to be rotated by the movement of said plate between said brush rollers as said brush rollers scrub the opposed surfaces of said plate.
Claim 5
Dependent Claim
53 words
Apparatus as defined in claim 2 including a second developing station in said apparatus after said plate scrubbing means to supply developing fluid under pressure to the opposed surfaces of said planographic offset printing plate to rinse the opposed surfaces of said plate to remove loose residual coating material from the plate surface.
Claim 6
Dependent Claim
33 words
Apparatus as defined in claim 4 including wiping means to wipe excess developing fluid from the opposed surfaces of said planographic offset printing plate prior to discharge of the plate from said apparatus.
Claim 7
Dependent Claim
40 words
Apparatus as defined in claim 5 wherein said wiping means comprises opposed roller members covered with a soft elastomeric material and positioned to frictionally engage the opposed surfaces of said plate thereby to wipe said surfaces by a squeegee action.
Claim 8
Dependent Claim
45 words
Apparatus as defined in claim 1 wherein said developing fluid is supplied from a reservoir of developing fluid in said apparatus by a high volume positive displacement pump through branched supply lines to each said manifold at a pressure of from 5 to 40 p.s.i.
Claim 9
Dependent Claim
75 words
Apparatus as defined in claim 1 wherein said flow restricting means at said discharge end of said chamber comprises inwardly facing buffer strips fixed to each said upper and lower platen, said buffer strips being adapted to contact a planographic offset printing plate moving through said chamber thereby to cooperate with the developing fluid flowing into said chamber to build up a fluid head of developing fluid to contact each opposed surface of said plate.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-14 | 1976-11-13 | 1977-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-14 | 1980-11-13 | 1981-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-14 | 1984-11-13 | 1985-05-15 | $7700.00 | Window Closed / Lapsed |