US2491090A - Printing plate - Google Patents

Printing plate Download PDF

Info

Publication number
US2491090A
US2491090A US651159A US65115946A US2491090A US 2491090 A US2491090 A US 2491090A US 651159 A US651159 A US 651159A US 65115946 A US65115946 A US 65115946A US 2491090 A US2491090 A US 2491090A
Authority
US
United States
Prior art keywords
plate
drum
printing
areas
web
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US651159A
Other languages
English (en)
Inventor
Davidson William Ward
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
DAVIDSON Manufacturing CORP
Original Assignee
DAVIDSON Manufacturing CORP
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by DAVIDSON Manufacturing CORP filed Critical DAVIDSON Manufacturing CORP
Priority to US651159A priority Critical patent/US2491090A/en
Application granted granted Critical
Publication of US2491090A publication Critical patent/US2491090A/en
Priority to DED6304A priority patent/DE855408C/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41N—PRINTING PLATES OR FOILS; MATERIALS FOR SURFACES USED IN PRINTING MACHINES FOR PRINTING, INKING, DAMPING, OR THE LIKE; PREPARING SUCH SURFACES FOR USE AND CONSERVING THEM
    • B41N1/00—Printing plates or foils; Materials therefor
    • B41N1/16—Curved printing plates, especially cylinders
    • B41N1/22—Curved printing plates, especially cylinders made of other substances

Definitions

  • My invention pertains to planographic printing plates and relates more specifically to a thin ilexible type of planographic plate adapted to preventI buckling of the plate under the influence of lithographie dampenng solutions.
  • One of the primary objects of my invention is to provide a planographlc printing plate ofthe type described formed in such manner as to prevent wrinkling or buckling of the plate on the press under the action of lithographie fluids.
  • Figure 1 is a sectional view of my plate attached to the drum of a rotary lithographie press of the offset type
  • Figure 2 is a partial end view of my plate as applied to the drum
  • Figure 3 is an end section of one form of my invention.
  • Figure 4 is an end section of another form of my invention.
  • Figure 5 is and end section of still another modification of my plate.
  • the second class consists of a thin flexible web of organic material such aS paper treated to render the material more suitable for use as a printing plate and to provide a lithographie surface.
  • the materials employed in forming plates of this class are usually cellulosic in nature.
  • the structure of the cellulose is wholly destroyed as is the case with plates formed of synthetic plastics and in others, the structure may be altered only partially as illustrated by various parchmentized types of planographic plates.
  • coated or impregnated types of plates the fibrous structure of the paper web usually remains substantially undisturbed and since this type of plate is usually the leastl expensive, it is widely used.
  • planographic plate It is essential that a planographic plate be capable of retaining on all non-image areas of its surface a film of moisture and for this reason many types of plates in this class have high water absorption. Although plates of this nature are often treated to render the fibers waterproof without making them waterrepellent, substantially all of the plates of this class exhibit some expansion or stretching when dampened by lithoiol-415.1)
  • This invention is concerned primarily with paper base planographic plates but is equally applicable to other similar plates wherein the expansion upon dampening constitutes a potential source of difficulty.
  • a printing drum I D is rotatably mounted about an axis A and includes a printing surface or periphery Ii. A portion of the printing surface il is cut away. as is common in such drums, to provide recessed areas in which plate clamping means I6 may be positioned.
  • the clamping means may take many forms and are not material to this invention but may suitably comprise a roller or bar l2 mounted parallel to the axis of the drum iii for eccentric rotation and positioned coact with an abutment i3 formed on ends i9 of the drum i@ in such manner that rotation of the bar l2 will bring its surface into contact with that of the abutment i3 thereby clamping a plate iii rinly to the roller.
  • the leading clamping means i@ is fixed, but the following clamping means may be pivotally mounted as at i 'i and urged inwardly by a spring is in order to apply a continuous tension to the plate M.
  • the clamping means i6 will usually extend substantially the entire length of the dr-um i0 and therefore serves to normally restrict the expansion of the plate lf3 parallel to the axis of the drum i0. Furthermore, the dampening rollers do not contact the portion of the plate disposed between the clamp l@ and the end i9 of the drum. Expansion of the plate i4 parallel to the axis A therefore results in a series of folds or buckles unusually forming on the printing surface Il near the ends i9 and graphic fluids. This phenomena is most prowhich project upwardly a distance suillcient to force them into rm contact with the inking rollers. Because of the resulting abrasive action and increased pressure, ink is deposited on these buckles or folds and is in turn deposited by the press on the work.
  • the width and spacing of the mutilated areas is not critical, but I have found that substantially linear areas, that is areas which greatly exceed the width, are highly elective when spaced about one-sixteenth of an inch apart.
  • the mutilated areas may be formed by placing the edge of the plate on a yielding surface such as rubber and embossing or indenting the mutilated areas on the sufrace of the plate with a blunt instrument to form areas of parallel linear indentations 2
  • the indenting or scoring action causes a distortion of the web material immediately below the instrument and is preferably sufficient to cause ridges 24 to appear on the opposite surface of the plate immediately below the indentations 2
  • should be blunt in order to avoid complete rupture or tearing of the web and to insure that small portions of the ber or web material do not project upwardly beyond the general surface of the plate. It is, of course, obvious that the ridges 24 and, to a certain extent, the plate areas lying between the indentations 2
  • may be arranged relative to eachother in a number of ways; for example, as illustrated in Figure 3, the indentations 2
  • Another method of forming mutilated areas is to form a series of slits 22 substantially similar in length and-disposition to the indentations 2
  • the unslit strip 23 should not be of such depth that 4 the slits 22 will be uncovered by the clamping means Il since the most eiilcient operation of my plate requires that the mutilated areas extend substantially to the clamping means Il.
  • could be similarly formed, leaving an unmutilated strip adjacent the end of the plate I4 but since this serves no usef-ul purpose where indentations are employed, I ordinarily prefer to continue the indentations 2
  • Planographic plates treated in accordance with the teachings of my invention can be placed directly on the printing drum without prior treatment without danger of buckling near the drum ends. This not only reduces the degree of skill required by the operator but increases the utility of the plate for, in many instances, the highest degree of skill cannot prevent buckling of ordinary plates. Furthermore, the manufacturer of paper plates is enabled vto employ certain less expensive materials in the manufacture of the plate which have heretofore been considered un usable because of excessive expansion.
  • a flexible printing plate comprising a thin flexible web of material expansible by dampening and adapted for attachment to a rotatable drum, the plate being characterized by a series of substantially uniform linear and parallel mutilated areas adjacent one end of the plate.
  • a flexible printing plate comprising a thin flexible web of material expansible by dampening' and adapted for attachment to a rotatable drum, the plate being characterized by a series of substantially uniform linear mutilated areas adjacent one end of the plate.. said areas being generally normal to the axis of the drum.
  • a flexible planographic plate comprising a thin flexible web of material expansible by dampening and adapted for attachment to a rotatable printing drum, the plate being characterized by a series of substantially linear uniform mutilated areas adjacent one end of the plate. said areas being generally normal to the axis of the drum and of sulcient length to extend onto the surface of the drum.
  • a generally rectangular flexible planographic plate comprising a web of flexible fibrous material expansible by dampening and adapted for attachment to a printing press, the plate being characterized by a plurality of substantially uniform linear mutilated areas approximately parallel to the long dimension of the plate and disposed adjacent one end of the plate.
  • a generally rectangular planographic plate comprising a web of paper expansible by dampening and adapted for attachment to a printing press, the plate being characterized by a plurality of substantially uniform linear mutilated areas approximatelyy parallel to the long dimension of the plate and disposed adjacent one end of the plate.
  • a llexible printing plate comprising a thin flexible web of material expansible by dampening and adapted for attachment to a rotatable printing drum, the plate being characterized by a series of substantially linear surface indentations generally normal to the axis of the drum and extending inwardly from an end of the plate a distance suicient to reach the printing surface when attached to the printing drum.
  • a flexible printing plate comprising a thin flexible web of material expansible by dampening and adapted for attachment to a rotatable printing drum, the plate being characterized by a series of substantially linear surface indentations formed alternately on the face and back of the plate and generally normal to the axis of the drum, said indentations extending inwardly from an end of the plate a distance sufiicient to reach the printing surface of the plate when attached to the printing drum.
  • a ilexible printing plate comprising a thin flexible web of material expansible by dampening and adapted for attachment to a rotatable printing drum, the plate being characterized by a series of slits generally normal to the axis of the drum and of sufcient length to extend from approximately the edge of the printing surface to a point short of the end of the plate when attached to the printing drum.
  • a exible planographic printing plate comprising a paper web adapted for attachment to the drum of a rotary press, a lithographie coating on one surface of the plate, and a series of substantially linear surface indentations generally normal to the axis of the drum extending inwardly from an end of the plate a distance suf- :llcient to reach the supporting plane of the drum.
  • a flexible planographic printing plate comprising a paper web adapted for attachment to the drum of a rotary press, a lithographic coating on one surface of the plate,and a series of substantially linear surface indentations formed alternately on the surface and back of the plate generalLv normal to the axis of the drum extendi'ng inwardly from an end of the plate a distance sumcient to reach ⁇ the supporting plane of the drum.
  • a planographic printing plate comprising a brous web expansible by dampening, a lithographic surface on the web, said web being adapted for attachment to the drum of a rotary press, and a series of substantially parallel linear rotation of the press and characterized by distortion of the ber structure beneath each of said areas, said distortion being of such character as to substantially prevent protrusion of adjacent areas above the plane of the plate surface.
  • a planographic printing plate comprising a web of organic material expansible by dampening, a lithographic surface on the web, said web being adapted for attachment to the drum of a rotary press, and a series of substantially parallel linear mutilated areas adjacent one end of the plate, said areas being generally normal to the axis of rotation of the press and characterized by distortion of the structure of the web beneath each of said areas.

Landscapes

  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Printing Plates And Materials Therefor (AREA)
US651159A 1946-03-01 1946-03-01 Printing plate Expired - Lifetime US2491090A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US651159A US2491090A (en) 1946-03-01 1946-03-01 Printing plate
DED6304A DE855408C (de) 1946-03-01 1950-09-29 Biegsame Flachdruckplatte

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US651159A US2491090A (en) 1946-03-01 1946-03-01 Printing plate

Publications (1)

Publication Number Publication Date
US2491090A true US2491090A (en) 1949-12-13

Family

ID=24611788

Family Applications (1)

Application Number Title Priority Date Filing Date
US651159A Expired - Lifetime US2491090A (en) 1946-03-01 1946-03-01 Printing plate

Country Status (2)

Country Link
US (1) US2491090A (de)
DE (1) DE855408C (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2733656A (en) * 1956-02-07 Gottsching
US2990772A (en) * 1957-08-14 1961-07-04 Davidson Corp Plate clamping means for printing machines

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US833713A (en) * 1906-05-07 1906-10-16 Jacob Gestetner Stencil-printing machine and stencil-sheet to be used therewith.
US1788662A (en) * 1928-12-20 1931-01-13 Gestetner Ltd Duplicating with the aid of stencils
US1980386A (en) * 1931-12-14 1934-11-13 Arthur B Davis Means for mounting printing surfaces

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US833713A (en) * 1906-05-07 1906-10-16 Jacob Gestetner Stencil-printing machine and stencil-sheet to be used therewith.
US1788662A (en) * 1928-12-20 1931-01-13 Gestetner Ltd Duplicating with the aid of stencils
US1980386A (en) * 1931-12-14 1934-11-13 Arthur B Davis Means for mounting printing surfaces

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2733656A (en) * 1956-02-07 Gottsching
US2990772A (en) * 1957-08-14 1961-07-04 Davidson Corp Plate clamping means for printing machines

Also Published As

Publication number Publication date
DE855408C (de) 1952-11-13

Similar Documents

Publication Publication Date Title
US4402267A (en) Method and apparatus for handling printed sheet material
AU576848B2 (en) Perforated sheet cover for printing press cylinders
US3147658A (en) Apparatus for perforating sheets
US2085845A (en) Printing apparatus
US2491090A (en) Printing plate
US4047481A (en) Apparatus for printing indicia on corrugated board and the like
US2775199A (en) Flexible printing plate locking device
US3285799A (en) Smash-resistant offset printing blanket
US2740355A (en) Apron blanket for multicolor printing presses
US2704025A (en) Means for minimizing distorting of duplicating masters in use
US2014043A (en) Printing plate
US3045595A (en) Printing machine and printing blanket therefor
US1521665A (en) Plate-clamping device
US2891470A (en) Dampener for lithographic printing
US3195458A (en) Printing apparatus and method
US1055404A (en) Saturating-machine.
JP2913113B2 (ja) 孔版印刷装置
US1410357A (en) Printing press
US1140511A (en) Blanket for printing-press cylinders.
US2114379A (en) Work decorating method and implement
US2088031A (en) Paper cartridge and method of and means for treatment thereof
US3760616A (en) Rollers
US1930605A (en) Copying device
GB291685A (en) Improved process of and apparatus for joining metal foils
US1938371A (en) Manifolding platen