Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F21/00—Devices for conveying sheets through printing apparatus or machines
  • B41F21/10—Combinations of transfer drums and grippers
  • B41F21/106—Combinations of transfer drums and grippers for reversing sheets, e.g. for perfecting machine

Definitions

• Turning device for a printing press in particular a sheet-fed offset printing press
• the invention relates to a turning device for a printing press, in particular a sheet-fed offset printing press, according to the preamble of claim 1.
• a turning device is known in which the sheet is passed with its leading edge ahead from a transfer drum to a storage drum which has suction devices in the area of the sheet trailing edge which suck and tension the sheet at its trailing edge before it is gripped with its trailing edge ahead of the pincer gripper device of a downstream turning drum and transported further.
• a turning device in which the sheet is transferred from an upstream impression cylinder with its leading edge ahead to the first gripper device of a transfer drum, the trailing edge of the sheet is sucked against the peripheral surface of the transfer drum by a suction device and the sheet trailing edge is gripped by a plier turning gripper system before the first gripper device releases the leading edge of the sheet.
• the leading edge of the sheet is then fed to a suction belt which is curved and guides the sheet. Subsequently, the sheet is transferred from the pliers reversing gripper device with its rear edge to a downstream impression cylinder.
• the object of the invention is to provide a turning device with which the sheet can be turned safely, reliably and without greasing, as well as with a high degree of precision and register accuracy, and which has a high speed both in straight printing operation and in perfecting operation Printing press allowed.
• the device according to the invention also has the advantage that the accelerations acting on the sheet and the associated mass forces during the turn are comparatively small, which results in a low material stress and the risk of damage to the sheet material is reduced.
• Fig. 1 shows a turning device according to the invention with a below one
• Transfer cylinder located register cylinder and a subordinate intermediate storage system at the time of the sheet transfer from the transfer drum to the register cylinder
• Fig. 2 shows the device according to the invention of Fig. 1 in a state in which the
• a register gripper device of the transfer drum guides the sheet from the register cylinder into the intermediate storage system
• FIG. 3 shows a schematic representation of a further embodiment of a turning device according to the invention, with a register cylinder arranged between an upstream impression cylinder and a downstream impression cylinder and an intermediate storage system arranged above the registration cylinder,
• Fig. 4 is a schematic cross-sectional view of a register cylinder with a
• Fig. 5 is a schematic longitudinal section through the register cylinder of Fig. 4 and
• FIG. 6 shows a schematic spatial representation of a further embodiment of a register cylinder, in which the suction openings are connected to a vacuum source via a rotary valve arranged on the end face of the cylinder, k
• FIG. 7 shows an enlarged detailed view of a preferred embodiment of a temporary storage system according to the invention
• FIG. 8 shows a schematic top view of the temporary storage system from FIG. 7.
• the 1 comprises a transfer drum 2, which is arranged between a first impression cylinder 4 of an upstream printing unit and a second impression cylinder 6 of a downstream printing unit.
• the transfer drum 2 and preferably also the impression cylinders 4, 6 have a double-large diameter with respect to the associated blanket cylinder and / or printing plate cylinder, but in another embodiment of the invention (not shown), they can be used in the same way as single or multiple sizes, e.g. triple or quadruple sized cylinders. So it is conceivable that the transfer drum 2 has a diameter three times larger, whereas the impression cylinders 4, 6 are only twice large.
• a first and a second gripper device 8a, 8b are provided opposite one another on the ÜTjer guide drum 2, which take over a sheet 10 to be printed in the area of the gripper center 12 represented by a dashed line from the upstream impression cylinder 4 at the leading edge of the sheet.
• the leading edge of the sheet 10 is fed to a register cylinder 16 according to the invention arranged below the transfer drum 2, in the circumferential surface 18 of which a plurality of suction openings 20 which can be acted upon by suction air are arranged and which suck the sheet onto the circumferential surface 18 of the register cylinder 16 and keep on this.
• the register cylinder 16 rotates at the same peripheral speed as the transfer drum 2 in the direction of arrow A, so that the sheet 10 is taken over by the register cylinder 16 and 5 is transported further.
• the suction of the sheet onto the circumferential surface 18 of the register cylinder 16 also advantageously leads to smoothing and Tightening of the sheet 10 on the cylinder surface 18, which additionally improves the guided guidance through the register cylinder 16.
• the register cylinder 16 can furthermore have a gripper device 14 shown in FIG. 1, which takes over the leading edge of the sheet 10 in a known manner from the gripper device 8a or 8b of the transfer drum 2 in a known manner, which further improves the register accuracy when the sheet 10 is transferred can be achieved by the transfer drum 2 to the register cylinder 16.
• the register cylinder 16 transfers the sheet leading edge to an intermediate storage system 19 after the cylinder has been rotated through an angle of, for example, 5-60 °.
• the intermediate storage system 19 has a first sheet guiding device 24 equipped with blowing nozzles 22, on which the sheet is guided in an essentially elongated form.
• the sheet guiding device 24 has comb-like projections 26 which are arranged in parallel next to one another and which engage in corresponding grooves or recesses 28 formed in the register cylinder 16. This ensures a safe removal of the sheet 10 from the circumferential surface 18 of the register cylinder 16 without causing damage to the leading edge of the sheet when the sheet is transferred from the register cylinder 16 to the intermediate storage system 19. Due to the blowing air emerging from the blowing nozzles 22, preferably essentially tangential to the arc, the arc 10 is in a well-defined floating state above the
• Sheet guiding device 24 is held while it is being transported by the register cylinder 16 into the intermediate storage system 19 at substantially constant speed. After the sheet has been deposited essentially in its entire length in an elongated form on the sheet guide device 24 of the intermediate storage system 19, the trailing edge of the sheet 10 becomes known from the prior art
• Reversible gripper device 30 preferably a pliers reversible gripper device, as shown in Fig. 2, gripped and progressing the trailing edge of the sheet, as by the Dashed line indicated in Fig. 2, lifted from the peripheral surface 18 of the register cylinder or from the sheet guide 24.
• the pliers reversible gripper device 30, which, as indicated by the double arrows B, is adjustable, transfers the rear edge of the turned sheet 10 to a known gripper device 34 of the downstream impression cylinder 6, which uses the turned sheet for printing on the back of the sheet to the printing gap (not shown) of the downstream printing unit feeds.
• a second sheet guiding device 38 is further provided below the second impression cylinder 6, as is shown, for example, in FIGS. 1 and 2.
• the second sheet guiding device 38 is preferably also equipped with blowing nozzles 36 which, by means of a tangential blowing direction to the sheet guiding plane, produce both a blowing and a suction effect according to the so-called "hydrodynamic paradox" and through which the sheet 10 is sucked in so far that it is drawn from the first Sheet guide device 24 is lifted off and brought into a stable floating position above the second sheet guide device 38, in which the sheet 10 does not touch the second sheet guide device 38.
• the first sheet guiding device 24 consists of a first subsystem 24a and a second subsystem 24b.
• the first subsystem 24a consists of blowing nozzles 22a; in Fig. 8 floating strips 23, which at the same time the comb-like in the front area Form projections 26 which engage in the associated grooves or recesses 28 of the register cylinder 16.
• the second subsystem 24b preferably also consists of strips 25 which engage in the interspaces between the floating strips 23 of the first subsystem 24a in a comb-like or finger-like manner.
• the second subsystem 24b can be equipped with blowing nozzles 22b in the same way as the first subsystem 24a, as is indicated, for example, in FIG. 8 by some blowing nozzles 22b shown as examples.
• the second subsystem 24b is preferably rounded at its rear end section in such a way that a transition to the second sheet guiding device 38 is created in such a way that the rounding affects a plane d parallel to the surface of the second guiding device 38, as is shown, for example, in FIG 7 is shown.
• the second subsystem 24b is preferably motor-displaceable relative to the first subsystem 24a of the sheet guiding device 24, so that sheets 10 of different format lengths always lie with their leading edge at the reference point E of the rounding at the end section of the second subsystem 24b, while the trailing edge of the sheet is gripped by the gripper reversible gripper system 30.
• the sheet guiding device 38 is arranged such that it can be pivoted for the format setting on the one hand about the downstream impression cylinder 6 without substantially changing the tangential transition of its guiding plane to the impression cylinder 6, and on the other hand with such
• Swiveling movement parallel to the sheet guiding plane of the second sheet guiding device 38 essentially always affects the outlet curvature of the end section of the second subsystem 24b at the reference point E and at the distance d.
• an adjustment gear 27, for example shown in FIG. 7, can be provided, which at the same time carries out a displacement of the subsystems 24a and 24b and at the same time adjusts the second sheet guide device 38 in such a way that it always depends on the format length is arranged in such a way that the previously described distance d between the curvature of the end section of the second subsystem 24b and the surface or guide surface of the second sheet guide device 38 is maintained.
• the second sheet guiding device 38 can preferably be formed by a first subsystem 38a arranged in the vicinity of the downstream counter-pressure cylinder 6 and a second subsystem 38b which is movably arranged with respect to this first subsystem 38a.
• the first and the second subsystem 38a, 38b of the second sheet guiding device 38 are designed in such a way that the first subsystem 38a, based on the position for the smallest format length to be selected, is then also preferred, preferably by means of the adjusting mechanism 27, is pivotable when the second subsystem 38b and the subsystems 24a and 24b of the first sheet guiding device 24 have already assumed their end position.
• rollers 40 are provided on both sides of the first subsystem 38a, which are guided in a corresponding cam track 41 arranged below the downstream counter-pressure cylinder 6, as is shown schematically in FIG. 7. Furthermore, it can be provided that the first section 38a of the second sheet guiding device 38 is rounded off in the area below the downstream impression cylinder 6, as shown, for example, in FIG. 7.
• the first sheet guiding device 24 and the subsystem 38b are moved together by the adjusting mechanism 27 to the shortest format length and the first subsystem 38a is further extended by means of the cam rollers 40 and the cam track 41, which are shown in FIG 7 Moving the fine print position shown by broken lines.
• the blowing / suction nozzles 36 of the second sheet guide device 38 are directed against the peripheral surface of the transfer drum 2, as a result of which the sheet 10 in particular in the region of its Bow end is stable and flutter-free.
• the first sheet guide device 24 and the tongs reversing gripper device 30 of the register cylinder 16 are deactivated in the preferred embodiment of the invention during the straight printing operation.
• the sheet guiding devices 24, 38 can be formed in the same way by rollers arranged over the surface, on which the sheet is moved along.
• the first sheet guiding device 24 can design as suction belts rotating at the peripheral speed of the register cylinder 16, on which the sheet is sucked in and carried along in register.
• the suction belts can either be designed as continuous suction belts, or similar to the subsystems 24a and 24b behind the register cylinder 16, or they can consist of a plurality of suction belts running parallel to one another and guided around the register cylinder 16, which are guided in corresponding grooves in the register cylinder 16 are.
• it can be provided in the area of the first sheet guiding device to provide a chain gripper system, not shown in the figures, which continues the sheet leading edge after taking over from the register cylinder 16 or the transfer drum 2 in register.
• the intermediate storage system 1 is not limited to use in a turning device with a register cylinder according to the invention, but can accordingly also be used in the known turning devices according to the prior art.
• the register cylinder 116 is directly between the first impression cylinder 104 and the second impression cylinder 106 arranged.
• the transfer drum 2 of the previously described embodiment of the invention is therefore omitted.
• the register cylinder 116 is preferably designed as a double-sized cylinder. However, it can also have a different size and be designed, for example, as a triple, quadruple or five-fold cylinder.
• the embodiment of the invention is described below using a double-sized register cylinder 116.
• the double-sized register cylinder 116 has two known, opposing gripper devices 114a and 114b which take over the sheet 110 from the upstream impression cylinder 104 in a known manner and hold it up to the gripper centers 132 at the front edge and guide them in register. After 5 passes through the gripper center 132, the sheet 110 reaches the
• the respective gripper device 1 14a, 1 14b of the register cylinder 116 opens and transfers the leading edge of the sheet to a buffer system 1 19 arranged above the register cylinder 1 16, which has a first sheet guiding device 124, equipped with 0 blowing nozzles 122, on which the sheet 1 10 with its this time printed side floating down along.
• the sheet guide device 124 can have projections 126 which engage in corresponding grooves 128, indicated by a dash-dotted line, in the peripheral surface 118 of the 5 register cylinder 116.
• the first sheet guiding device 124 equipped with 0 blowing nozzles 122
• Sheet guiding device 124 a second further sheet guiding device 138 can be provided, which acts on the upper side of the sheet 110 via blowing / suction nozzles 136 with blowing air.
• the sheet guiding devices 124 and 138 can be used in an analogous manner to those previously described Sheet guiding devices 24 and 38 can be provided with appropriate format adjustments, roller and / or chain gripping devices or be formed by them, with the additional possibility that the lower first sheet guiding device 124 is designed as a suction belt as described above, or comprises one.
• the register cylinder 116 has a peripheral surface 118 provided with suction openings 120, on which the sheet 110 is sucked and held.
• the sheet 110 sucked on the peripheral surface 1 18 is guided into the intermediate storage system 1 19 by the register cylinder 116 after opening the gripper devices 1 14a or 1 14b, the sheet 110 following with its printed side is moved below on an air cushion over the first sheet guide 124.
• this is gripped by a known pincer-reversing gripper device 134 of the second downstream impression cylinder 106.
• the pliers reversible gripper device 134 then lifts the sheet 110, beginning with its rear edge, from the circumferential surface 118 of the register cylinder 116, as indicated by the broken lines in FIG. 3, and guides the turned sheet 110 with the trailing edge ahead of the printing gap of the downstream printing unit to where the back of the sheet 1 10 is printed.
• a preferred embodiment of a register cylinder is described below, as is used, for example, in the embodiments according to FIGS. 1 and 2 or the embodiment according to FIG. 3.
• the register cylinder 16, 116 shown in cross section in FIGS. 4 and 5 consists of a core 204 which is mounted so as to be stationary relative to the side wall 200a, 200b of the printing press or by means of a pneumatic or electrical adjusting device 202, around which a substantially hollow cylindrical casing body 206 is disposed Bearing 208a, 208b is freely rotatable.
• the casing body 206 can, for example, as shown in FIG.
• the peripheral surface 18, 1 18 in the preferred embodiment of the invention preferably has a rough structure, whereby the friction between the sheet 10, 1 10 and the peripheral surface 18, 1 18 is increased, which leads to an improved register stability during transport of the sheet 10, 110 leads into the intermediate storage system 19, 119.
• the core 204 has one or more recesses 218 which are connected via a line 219 and a valve 221 to a vacuum source 220 and, as indicated by the broken lines in FIG. 5, with ambient air are ventilated.
• the suction openings 20, 120 which are located above the recess 218 and which communicate with the recess 218, are accordingly acted upon by suction air from the vacuum source 220.
• the remaining, not communicating with the recess 218, infant openings 20, 120 are closed by the outer peripheral surface 222 of the core 204, so that they are not acted upon by suction air.
• recesses 224 and 226, which are arranged upstream and / or downstream in the rotational direction A of the register cylinder 16, 16, are provided, which are separated from the recess 218 by intermediate walls, which are not described in more detail.
• the recesses 224 and 226 can preferably be subjected to a different pressure than that Recess 218.
• a negative pressure is likewise generated in the upstream recess 224 when the sheet 10 is transported in register, so that the sheet 10 is sucked into the associated circumferential surface section ⁇ he follows.
• the negative pressure can be less than, equal to or greater than the negative pressure in the recess 218.
• the recess 224 can be ventilated via a valve, not shown, before or while the pliers reversible gripper device 30 of the transfer drum 2 grips the trailing edge of the sheet and lifts the sheet 10 from the register cylinder 16. This advantageously removes the suction of the sheet when the trailing edge of the sheet is lifted off the register cylinder 16, as a result of which the sheet 10 can be more easily detached from the peripheral surface 18, 118 of the register cylinder.
• the openings 224, 218 and 226 are automatically ventilated by the release of the suction openings 20 below the sheet 10, so that the sheet 10 is also without an additional external ventilation of the recesses can be easily lifted from the peripheral surface 18 of the register cylinder 16.
• the suction openings 20, 120 on the side of the sheet 10 are covered in this case, for example, by a sleeve, sleeve or bandage or closed in some other way, or for example switched off by valves.
• the recess 226 is also subjected to a reduced, the same or increased negative pressure compared to the recess 218, or possibly also blown air. It is advantageous, for example, if the vacuum in the recess 226 is slightly lower than the vacuum in the recess 218 during the sheet transport, so that the sheet does not extend in the region ⁇ of the peripheral surface 18, 118 of the register cylinder 16, 116 is sucked so strongly onto the peripheral surface 18, 118 and can be detached from it more easily.
• the recess 226 is preferably ventilated by a valve, not shown, or even blown air.
• the recess 218 and / or the recess 224 can be acted upon by blown air during the lifting of the trailing edge of the sheet by the gripper reversing gripper device 30.
• the register cylinder 116 in the embodiment of the invention shown in FIG. 3 can also be provided in a corresponding manner with recesses 218, 224 formed in the core 204, which correspond to them
• Circumferential surface sections ⁇ , ⁇ and ⁇ are assigned.
• all sections ⁇ , ⁇ and ⁇ can be subjected to negative pressure during the insertion of the sheet leading edge of the sheet 110 into the intermediate storage system 119, in particular after the gripper device 1 14 has released the sheet leading edge, so that the sheet is sucked in over a large area the peripheral surface 1 18 of the register cylinder 116 is ensured.
• the suction air supply to the recesses 218 and 226 is interrupted or the recesses 218, 226 are ventilated or optionally blown air is applied, so that in the sections ⁇ and ß no suction of the sheet 1 10 on the peripheral surface 1 18 of the register cylinder 116 takes place.
• the sheet can be gently removed by the pliers reversing gripper device 134 without undue stresses Register cylinder 1 16 are lifted off.
• the circumferential surface sections ⁇ , ⁇ and ⁇ can also be changed in size by means of adjusting devices (not shown).
• a register cylinder 16, 116 in a further embodiment of a register cylinder 16, 116 according to the invention shown in FIG. 6, it can further be provided that the suction openings 20, 12 communicate with chambers 230 formed in the casing body 206, which preferably extend in the axial direction parallel to the cylinder longitudinal axis.
• the chambers 230 are connected through an opening or bore 232 to the vacuum source 220, which is formed in a fixed flange element 234 arranged on the end face of the register cylinder 16, 116.
• the bore 232 in the flange element 234 forms a rotary valve together with the axial chambers 230 in the casing body 206 of the register cylinder 16, 116. It can further be provided that 5 recesses 318, 324 and 326 corresponding to the recesses 224 and 226 of the previously described embodiments are formed in the flange connection 234, which communicate with one or more of the axial bores 230 and thus to provide a negative pressure supply for circumferential Surface sections ⁇ ', ß' and ⁇ 'lead the
• Circumferential surface portions ⁇ , ⁇ and ⁇ correspond to the previously described embodiments.
• the recesses 318, 324 and 326 can furthermore be ventilated independently of one another via valves (not shown) and, in addition, can be changed in size, for example, by slide devices, not shown, etc.

Landscapes

• Feeding Of Articles By Means Other Than Belts Or Rollers (AREA)
• Supply, Installation And Extraction Of Printed Sheets Or Plates (AREA)
• Registering Or Overturning Sheets (AREA)
• Separation, Sorting, Adjustment, Or Bending Of Sheets To Be Conveyed (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Related Child Applications (1)

Publications (1)

Family

ID=7791900

Family Applications (1)

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Citations (3)

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• 1996
  • 1996-04-20 DE DE19615730A patent/DE19615730A1/de not_active Ceased
• 1997
  • 1997-03-21 CN CN97193957A patent/CN1216501A/zh active Pending
  • 1997-03-21 WO PCT/EP1997/001424 patent/WO1997039896A1/de not_active Ceased
  • 1997-03-21 JP JP9537645A patent/JP2000508594A/ja active Pending
  • 1997-03-21 DE DE59701011T patent/DE59701011D1/de not_active Expired - Lifetime
  • 1997-03-21 EP EP97914281A patent/EP0900143B1/de not_active Expired - Lifetime
  • 1997-03-21 CZ CZ19983209A patent/CZ292390B6/cs not_active IP Right Cessation

Patent Citations (3)

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