US3557695A - Device for the fastening of a printing plate - Google Patents

Device for the fastening of a printing plate Download PDF

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Publication number
US3557695A
US3557695A US747513A US3557695DA US3557695A US 3557695 A US3557695 A US 3557695A US 747513 A US747513 A US 747513A US 3557695D A US3557695D A US 3557695DA US 3557695 A US3557695 A US 3557695A
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US
United States
Prior art keywords
bar
tension bar
arm
clamping
rod
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
US747513A
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English (en)
Inventor
Friedrich Preuss
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.)
Roland Offsetmaschinenfabrik Faber and Schleicher AG
Original Assignee
Roland Offsetmaschinenfabrik Faber and Schleicher AG
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 Roland Offsetmaschinenfabrik Faber and Schleicher AG filed Critical Roland Offsetmaschinenfabrik Faber and Schleicher AG
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Publication of US3557695A publication Critical patent/US3557695A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41F—PRINTING MACHINES OR PRESSES
    • B41F27/00—Devices for attaching printing elements or formes to supports
    • B41F27/12—Devices for attaching printing elements or formes to supports for attaching flexible printing formes
    • B41F27/1218—Devices for attaching printing elements or formes to supports for attaching flexible printing formes comprising printing plate tensioning devices
    • B41F27/1225—Devices for attaching printing elements or formes to supports for attaching flexible printing formes comprising printing plate tensioning devices moving in the printing plate end substantially rectilinearly
    • B41F27/1231—Devices for attaching printing elements or formes to supports for attaching flexible printing formes comprising printing plate tensioning devices moving in the printing plate end substantially rectilinearly by translatory motion substantially tangential to support surface

Definitions

  • the invention relates to a device for fastening a printing plate on the plate or form cylinder of a rotary printing machine by means of tension bars arranged in a channel in the cylinder parallel to its axis and clamping jaws hingedly connected with the bars.
  • the clamping jaws which are pivotal by means of tensioning eccentrics, press the ends of the printing plate against the tension bars.
  • the tension bars after the clamping of the printing plate ends has taken place, are moved approximately in the peripheral direction of the cylinder for the purpose of tensioning the printing plate.
  • a device for the fastening of printing plates (U.S. Pat. No. 3,156,184), in which the plate end is clamped between a tension bar movable approximately in the peripheral direction of the cylinder and a clamping jaw hingedly connected to the bar.
  • the pressing force necessary for the clamping is exerted upon the plate end by pivoting the clamping jaw by means of a tensioning eccentric.
  • this device has not proven itself in practice, more especially since the large pressing force necessary for clamping the plate cannot be applied solely by rotation of the tensioning eccentric, or the rotation of the tensioning eccentric cannot be carried out by a force which is acceptable with regard to easy and rapid operation of the device. More especially in the case of slightly wavy plate ends, an irregular distribution of the pressure application occurs over the width-of the plate, so that the plate ends while being tensioned are pulled out at some points and torn at other points.
  • the magnitude of the pressing force exerted upon the plate end cannot be limited and varied according to the plate thickness. Moreover, the dependency of the normal force, which is exerted upon the plate end and must reach a specific value to obtain secure clamping of the plate, upon the traction force exerted upon the plate assuming the tensile strength of the plate to be limited necessitates the use of a rod having a small wedge angle. In other words, the rod can have only a slight rise of its profile engaging the plate end in relation to the rotation of the rod. On the other hand, release of the clamping of the plate requires that the rod is rotated against a very high frictional force.
  • the present invention is directed to the problem of providing an easily and rapidly operable plate securing device, avoiding the disadvantageous properties of known devices, wherein the plate ends are held securely even when relatively high tensions are exerted upon the plates, without danger of the plate being damaged.
  • This problem is solved according to the invention by the arrangement of a rod known per se extending along the tension bar, between the printing plate end and the tension bar.
  • This rod abuts against the end of the printing plate between the clamping jaw and the tension bar and is wedged between the printing plate end and the tension bar upon moving the tension bar approximately in the peripheral direction of the cylinder.
  • This initial tension can be applied rapidly and without applying a strong force and effects a very desirable smoothing of the initially possibly wavy printing plate end. It also ensures that the rod clamps the plate uniformly over its whole length, so that no localized overstressing of the plate can occur.
  • the bearing surfaces of the rod seen in the direction of movement of the tension bar, are inclined in relation to one another.
  • the rod On movement of the tension bar in the tensioning direction of the plate the rod is forced into a narrowing cross section and thus a clamping force is exerted upon the plate end.
  • the rod has a noncircular cross section.
  • the surfaces upon which the wedging rod bears can be parallel with one another in this case.
  • a strip is arranged between the rod and the printing plate end to be clamped, the strip surface in contact with the printing plate and being approximately parallel with the clamping surface of the clamping jaw.
  • the pressure exerted upon the plate end can be kept low, that is to say the pressing force can be distributed over a larger clamping area.
  • a rod cross section which is suitable for the intended tilting can be selected, without danger of notching the plate. On tilting of a rod of rectangular cross section which abuts against two diagonally opposite edges, the lowest frictional forces would appear to have to be overcome.
  • a reduction in the friction forces is possible since no external forces, such as pull forces transmitted via the plate, have to be taken up by the tensioning eccentric in its peripheral direction. If the tensioning eccentric is mounted with sufficient play it can be disengaged with a jerk, that is to say the disengagement of the tensioning eccentric can take place by using the so-called hammer stroke effect.
  • a displaceable support for the eccentric is mounted on antifriction roller bodies.
  • the displacement of the support takes place with the lowest possible friction.
  • the rod is pressed into a nonwedging position in the absence of tensioning by the tension bar.
  • introduction and initial tensioning of the plate are precluded when the rod is already wedged.
  • the rod and strip are secured against falling out.
  • the invention also provides that the surface of the clamping jaw which clamps the plate end is less rough than the opposite clamping surface engaging the plate. This ensures that sliding of the clamped-in printing plate end can take place in relation to only one of the two cooperating clamping surfaces.
  • the opposite clamping surface has a slight rise extending along the strip.
  • This rise is disposed opposite to a depression provided in the clamping surface of the clamping jaw and extending in the same direction as the rise.
  • a slight rise of for example 0.1 mm.
  • the connection between plate end and strip can be significantly improved.
  • the strip has a rough and not always uniform surface, such as is formed for example by the application of a granulated material to the surface, tension peaks as may occur at localized points can be avoided.
  • the depression in the clamping surface of the clamping jaw lying opposite to the rise prevents this rise from influencing the conditions prevailing between clamping jaw surface and plate end.
  • FIG. 1 shows a partial cross section through a form or plate cylinder along the line I-l in FIG. 4;
  • FIG. 2 shows a partial cross section, supplementing the par tial cross section in FIG. 1, through a form cylinder, the section having been effected however at a different point over the length of the form cylinder, namely in accordance with the line II-II in FIG. 4;
  • FIG. 3 shows a part of a lateral elevation of a plate fastening device and of a longitudinal section through a form cylinder
  • FIG. 4 shows a plan view of FIG. 3
  • FIG. 5 shows a partial cross section of a plate fastening device in a modified form of the invention and on a larger scale
  • FIG. 6 shows a detail of FIG. 1 showing the plate end to be clamped, on an enlarged scale.
  • Fastening devices 5 and 6 for the front end 3 and the rear end 4 respectively of a printing plate are arranged in a channel 1 in a form cylinder 2.
  • the two devices are completely similar so that the same reference numerals have been used for the same parts.
  • a tension bar 7 is slidingly mounted on a slide rail 8 (see also FIG. 3) extending approximately in the peripheral direction of the cylinder and firmly connected with the cylinder body.
  • the rail engages a groove 9 provided in the tension bar 7.
  • the tension bar 7 is pressed in one direction (upwards in FIG. 4) by a spring 11 bearing on a protuberance secured to the cylinder body, and abuts via the end 12 of a screw 13, protruding from the tension bar 7 against a wall of the cylinder channel 1.
  • the screw 13 is threaded into a threaded bore 15 in the tension bar 7 so that by rotation of the screw 13 in clockwise direction the tension bar 7 is moved in the tensioning direction of the plate, that is to say to the right in FIG. 1, while on rotation of the screw 13 in counterclockwise direction the spring 11 moves the tension bar 7 in the opposite direction.
  • the screw 13 can be locked in relation to the tension bar 7 by means of a nut 14.
  • the position of the tension bar 7 in its longitudinal direction (to the right or left in FIG. 3) is controlled by two screws 16 which determine the distance from the cylinder body (only one screw is shown, since only one tension bar end is illustrated in FIG. 3); the said distance can be modified by appropriate inward or outward rotation of the screws 16.
  • a clamping jaw 17 is pivotal about the center point 18 of a semipherically formed head 19 of a screw 20 screwed into the tension bar 7.
  • the pivotal axis of the clamping jaw 17, which passes through the point 118, can be shifted by screwing screw 20 into or out of the tension bar 7, so that the distance between the clamping jaw 17 and the tension bar 7 can be varied thereby compensating for different thicknesses of the printing plates.
  • a plurality of such screws 20 is provided.
  • One or more compression springs 21, guided in a blind bore 22 provided in the tension bar 7 bias the clamping jaw 17 into its pivotal position ready for insertion of the plate ends 3, 4.
  • a rod 23 of rectangular cross section rests with one of its corners in a groove 24 of triangular cross section in the tension bar 7 (see also FIG.
  • the apex angle of the groove is being somewhat larger than a right angle.
  • the opposite comer of the rod which extends into a further groove 25 of triangular cross section provided in a bar 26; groove 24 also has an obtuse apex angle.
  • the bar 26 is biased toward to the right (see FIG. I) by a leaf spring 27 screwed fast to the tension bar 7, so that the surfaces of the grooves 24, 25 bear on the corresponding surfaces of the rod 23.
  • the plate end 3 or 4 is fitted between a roughened surface 28 of the bar 26 and the clamping surface 29 of the clamping jaw 17.
  • the plate end Upon relative movement of bar 26 and tension bar 7 the plate end is clamped tight due to the fact that the rod 23 tips about is corner in the groove 24 and the edge of the rod 23 lying diagonally opposite to the pivot point describes an arc.
  • the distance of the bar 26 from the clamping surface 29 of the clamping jaw 17 is adjusted according to the thickness of the printing plate by rotation of the screws 20.
  • the tensioning eccentric 30 is formed as an eccentric shaft which is loosely mounted in brackets 31 (only one bracket is shown) secured on the ends of the tensioning bar 7.
  • Eccentric 30 abuts against a protuberance 32 of the clamping jaw 17 and against the tensioning bar 7. Shims 33 are interposed between clamping jaw and the tensioning eccentric and further shims 35 resting on needles 34 are interposed between the tensioning eccentric 30 and the tension bar 7.
  • the tensioning eccentric 30 is further supported over its length by walls 36 screwed to the tension bar 7.
  • For the purpose of rotation of the tensioning eccentric 30 its ends are formed as hexagons 37 in which bores 38 are provided for the engagement of a tool.
  • a pin 39 protruding radially from the shaft limits the angle of rotation of the tensioning eccentric 30, in that it abuts against stop surfaces 40, 41 provided on the mounting brackets 31.
  • the roughened surface 28 of the strip 26 includes a ridge 128 extending along the strip 26, while a depression 129 of equal length is machined into the clamping surface 29 of the clamping jaw 17.
  • FIG. 5 shows a fastening device similar in structure and function to the previously described one except that rod 23 is replaced by a rod 23a.
  • rod 23a is replaced by a rod 23a.
  • the crosssectional outline of rod 23a is such that it perfonns the function of bar 26 also which thus can be eliminated. It coacts with the jaw 17 with a curved roughened surface.
  • a two-arm clamping jaw pivotally supported by one portion of said bar, said jaw being pivotal into and out of a position clamping the end of said plate between the jaw and the tension bar;
  • an eccentric means rotatably disposed between one arm of the jaw and the tension bar and supported by the latter, rotation of said eccentric means pivoting the clamping jaw into and out of its clamping position;
  • said eccentric means comprises a cylindrical roller rotatable about an eccentric axis and said wedge means comprises a rod ex tending parallel to said roller and having a noncircular cross section, the wedging position of said rod being the angular position thereof in which the rod acts with its maximal width upon said other arm of the clamping jaw thereby wedging the interposed plate end against the respective arm of the clamping jaw.
  • a pressure bar is interposed between said other arm of the clamping jaw and said wedge means, said wedge means acting upon one side of the pressure bar, the opposite side of the pressure bar coacting with said other arm of the jaw for clamping the printing plate end between said bar and said other arm.

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  • Supply, Installation And Extraction Of Printed Sheets Or Plates (AREA)
US747513A 1967-07-29 1968-07-25 Device for the fastening of a printing plate Expired - Lifetime US3557695A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE1611258 1967-07-29

Publications (1)

Publication Number Publication Date
US3557695A true US3557695A (en) 1971-01-26

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ID=5681686

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Application Number Title Priority Date Filing Date
US747513A Expired - Lifetime US3557695A (en) 1967-07-29 1968-07-25 Device for the fastening of a printing plate

Country Status (5)

Country Link
US (1) US3557695A (ja)
CH (1) CH472973A (ja)
FR (1) FR1575155A (ja)
GB (1) GB1196506A (ja)
SE (1) SE348146B (ja)

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3795193A (en) * 1971-04-30 1974-03-05 Polygraph Leipzig Kom Veb Device for rapidly and precisely mounting flexible printing plates
US3884147A (en) * 1972-05-26 1975-05-20 Roland Offsetmaschf Device for fastening flexible printing plates
US3896729A (en) * 1974-02-27 1975-07-29 Hercules Inc Positive backing sheet plate lock-up
US3903796A (en) * 1973-03-01 1975-09-09 Heidelberger Druckmasch Ag Means for clamping on flexible printing plates
US4010685A (en) * 1974-06-28 1977-03-08 Roland Offsetmaschinenfabrik Faber & Schleicher Ag Printing plate clamping device
US4130058A (en) * 1976-02-19 1978-12-19 Erich Bock Fastening bar for securing printing plates on a printing machine
US4133264A (en) * 1975-12-01 1979-01-09 K & F Manufacturing Co., Inc. Clamping assembly for thin printing plates
US4391193A (en) * 1980-04-17 1983-07-05 Ryobi Ltd. Plate holding device for offset duplicator
US4724762A (en) * 1985-03-22 1988-02-16 Heidelberger Druckmaschinen Ag Device for clamping and aligning flexible printing plates on a plate cylinder of a rotary printing machine
US4813356A (en) * 1985-09-07 1989-03-21 M.A.N. Roland Druckmaschinen Clamping device for optionally securing a blanket or a printing plate
US4934974A (en) * 1987-12-31 1990-06-19 Zenith Electronics Corporation Factory fixture frame with means for temporarily and removably supporting an in-process tension mask for a color cathode ray tube
EP0767056A2 (en) † 1995-10-04 1997-04-09 Komori Corporation Plate clamping device of printing press
US5922406A (en) * 1996-10-11 1999-07-13 Ludford, Iii; Robert E. Coating method and apparatus
US6354206B1 (en) * 1999-01-18 2002-03-12 Heidelberger Druckmaschinen Ag Printing machine cylinder and clamping device for firmly clamping a cylinder packing

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DD145901A1 (de) * 1979-10-29 1981-01-14 Hans Johne Plattenklemmeinrichtung
DE102008015121B4 (de) * 2007-04-04 2013-10-02 Küster Holding GmbH Schwenkbare Befestigungsvorrichtung für einen Kraftfahrzeug-Fensterheber

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US453862A (en) * 1891-06-09 Plate-ho
US2386214A (en) * 1942-10-09 1945-10-09 Harris Seybold Potter Co Plate clamp
US3119331A (en) * 1961-08-10 1964-01-28 Roland Offsetmaschf Clamping device for clamping printing plates of printing machines
US3156184A (en) * 1962-02-20 1964-11-10 Harris Intertype Corp Plate clamp
US3276365A (en) * 1964-04-25 1966-10-04 Roland Offsetmaschf Printing plate clamping device for a printing press
US3456587A (en) * 1966-04-11 1969-07-22 American Photocopy Equip Co Plate cylinder with retractable register pins

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US453862A (en) * 1891-06-09 Plate-ho
US2386214A (en) * 1942-10-09 1945-10-09 Harris Seybold Potter Co Plate clamp
US3119331A (en) * 1961-08-10 1964-01-28 Roland Offsetmaschf Clamping device for clamping printing plates of printing machines
US3156184A (en) * 1962-02-20 1964-11-10 Harris Intertype Corp Plate clamp
US3276365A (en) * 1964-04-25 1966-10-04 Roland Offsetmaschf Printing plate clamping device for a printing press
US3456587A (en) * 1966-04-11 1969-07-22 American Photocopy Equip Co Plate cylinder with retractable register pins

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3795193A (en) * 1971-04-30 1974-03-05 Polygraph Leipzig Kom Veb Device for rapidly and precisely mounting flexible printing plates
US3884147A (en) * 1972-05-26 1975-05-20 Roland Offsetmaschf Device for fastening flexible printing plates
US3903796A (en) * 1973-03-01 1975-09-09 Heidelberger Druckmasch Ag Means for clamping on flexible printing plates
US3896729A (en) * 1974-02-27 1975-07-29 Hercules Inc Positive backing sheet plate lock-up
US4010685A (en) * 1974-06-28 1977-03-08 Roland Offsetmaschinenfabrik Faber & Schleicher Ag Printing plate clamping device
US4133264A (en) * 1975-12-01 1979-01-09 K & F Manufacturing Co., Inc. Clamping assembly for thin printing plates
US4130058A (en) * 1976-02-19 1978-12-19 Erich Bock Fastening bar for securing printing plates on a printing machine
US4391193A (en) * 1980-04-17 1983-07-05 Ryobi Ltd. Plate holding device for offset duplicator
US4724762A (en) * 1985-03-22 1988-02-16 Heidelberger Druckmaschinen Ag Device for clamping and aligning flexible printing plates on a plate cylinder of a rotary printing machine
US4813356A (en) * 1985-09-07 1989-03-21 M.A.N. Roland Druckmaschinen Clamping device for optionally securing a blanket or a printing plate
US4934974A (en) * 1987-12-31 1990-06-19 Zenith Electronics Corporation Factory fixture frame with means for temporarily and removably supporting an in-process tension mask for a color cathode ray tube
EP0767056A2 (en) † 1995-10-04 1997-04-09 Komori Corporation Plate clamping device of printing press
US5743187A (en) * 1995-10-04 1998-04-28 Komori Corporation Plate clamping device of printing press
EP0767056B2 (en) † 1995-10-04 2006-06-21 Komori Corporation Plate clamping device of printing press
US5922406A (en) * 1996-10-11 1999-07-13 Ludford, Iii; Robert E. Coating method and apparatus
US6354206B1 (en) * 1999-01-18 2002-03-12 Heidelberger Druckmaschinen Ag Printing machine cylinder and clamping device for firmly clamping a cylinder packing

Also Published As

Publication number Publication date
FR1575155A (ja) 1969-07-18
SE348146B (ja) 1972-08-28
GB1196506A (en) 1970-06-24
CH472973A (de) 1969-05-31

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