WO1998008683A1 - Printing unit - Google Patents
Printing unit Download PDFInfo
- Publication number
- WO1998008683A1 WO1998008683A1 PCT/SE1997/001380 SE9701380W WO9808683A1 WO 1998008683 A1 WO1998008683 A1 WO 1998008683A1 SE 9701380 W SE9701380 W SE 9701380W WO 9808683 A1 WO9808683 A1 WO 9808683A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- printing unit
- bearing brackets
- frame side
- rollers
- gap
- Prior art date
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41F—PRINTING MACHINES OR PRESSES
- B41F13/00—Common details of rotary presses or machines
- B41F13/08—Cylinders
- B41F13/24—Cylinder-tripping devices; Cylinder-impression adjustments
- B41F13/26—Arrangement of cylinder bearings
- B41F13/30—Bearings mounted on sliding supports
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41F—PRINTING MACHINES OR PRESSES
- B41F5/00—Rotary letterpress machines
- B41F5/24—Rotary letterpress machines for flexographic printing
Definitions
- the present invention relates to a printing unit for printing a continuous web.
- the invention relates especially, but not exclusively, to so-called flexo- graphic printing units.
- Printing units of the above-mentioned type are well- known to those skilled in the art and usually comprise a machine frame having two parallel frame sides, between which transverse, rotatable rollers or cylinders are supported in bearing brackets.
- roller and cylinder will below be used as synonyms.
- a flexographic printing unit comprises as a rule the following rollers/cylinders: (a) an inking roller which is inked by, for instance, a chamber doctoring system, (b) a stereo roller, and (c) an impression cylinder.
- the bearing brackets of the rollers/cylinders are set, such that the cylinders/ rollers rotate towards each other, the generatrices being related to each other in a manner which is optimal for transferring ink from the inking roller to the web to be printe .
- the ink is transferred from the inking roller to the web to be printed by means of a compressible stereo arranged as a jacket on the stereo roller.
- This stereo jacket which covers either the whole periphery of the stereo roller or a part thereof, usually has a thickness of a few millimetres.
- the height of the ink-transferring parts of the stereo always deviates more or less from the ideal height. Therefore, the stereo must be compressed, on the one hand, when being inked by the inking roller and, on the other hand, when applying ink to the web to be printed, to an extent corresponding to the difference in height between the lowest printing point and the highest print- ing point (apex).
- the web to be printed is supported by the impression cylinder so as to be correctly positioned relative to the stereo when ink is transferred from the stereo.
- the stereo can be damaged if the web that is being printed dries and gets stuck to the stereo, the ink acting as adhesive, or if the inking roller drags itself along the stereo when, during the interruption, rotated by a separate motor, such that the ink does not dry on the inking roller.
- Printing units of this type are disclosed in Applicant's Patent Publications DE-C-2, 746, 878, EP-A-132,246 and EP-A-280, 668.
- the force providing the clamping of the bearing brackets and, thus, the rollers/ cylinders is generated by means of lever mechanisms and/ or chains passed around guide pulleys.
- this clamping can be felt to be complicated and inefficient, and therefore there is a need of a new, simplified and improved clamping technique.
- Each of the bearing brackets of the stereo roller and the inking roller is horizontally displaceable by a power unit in the form of pneumatic cylinders in combination with precise adjustment members.
- the nominal adjustment of each bearing bracket is determined by a rod preselected from a set of rods of different lengths.
- the purpose of the precise adjustment member is to adjust the distance of the rollers/cylinders in respect of devia- tions of stereo thicknesses and varying material thicknesses.
- the purpose of the power units is on the one hand to lock, together with the rods adapted to the diameter of the impression cylinder, the bearing brackets relative to each other when the printing unit is operative and, on the other hand, to move the bearing brackets of the stereo roller and the inking roller between the operative and the non-operative position.
- a further problem in printing units having an L-shaped stereo roller bearing bracket is that supplementary locking mechanisms in the form of screws or other power units are required to lock the bearing brackets of the stereo roller and the inking roller relative to the bearing brackets of the impression cylinder when the printing unit is operative.
- rollers/cylinders so as to obviate the above-mentioned problems.
- various bearing bracket arrangements are utilised.
- EP-A- 363,293 discloses a flexographic printing unit which, for the above-mentioned purpose, is provided with devices for rough and precise adjustments, respectively. These adjustment devices, however, are complicated and besides connected to each other, which renders a separate nominal or correction adjustment impossible.
- the object of the present invention thus is to provide a printing unit while obviating the above-mentioned drawbacks, the clamping of the bearing brackets being possible without requiring any complicated lever mechanisms and/or chain arrangements and the rollers/cylinders being easily replaceable for different printing jobs, and nominal adjustment and correction adjustments being inde- pendent of one another. Moreover, the clamping of the bearing brackets should be of such a type that neither horizontal nor vertical forces (for instance, exerted by gear wheels ) can affect the set mounting position of the cylinders/rollers during operation.
- a further object of the invention is to provide a reliable printing unit which is composed of as few and simple components as possible.
- the inventive printing unit is of simple mechanical design and will therefore be easy to manufacture.
- the replacement of rollers/cylinders as well as the adjustment can be carried out very easily and quickly.
- Internal forces compression of the stereos
- the bearing brackets are horizontally locked by a horizontal force, while vertical locking is provided by the friction between the bearing brackets that arises when they are compressed by the horizontal force. Owing to the large force-transmitting surfaces which absorb the horizontal force, the bearing brackets are not deformed, i.e. the nominal measurement is affected negligibly by the clamping force.
- Fig. 1 is a side view of a printing unit according to a first embodiment of the invention in its operative position.
- Fig. 2 shows a spring means and is an enlargement of a detail of Fig. 1.
- Fig. 3 is a part-sectional view of a power means and is an enlargement of a detail of Fig. 1.
- Fig. 4 is a view, corresponding to Fig. 1, of the printing unit in its non-operative, idle-running position.
- Figs 5 and 6 show the spring means and the power means in Fig. 4 and are enlargements of details similar to Figs 2 and 3.
- Fig. 7 is a view of the printing unit in the position for replacement of rollers, corresponding to Figs 1 and 4.
- Figs 8 and 9 illustrate the spring means and the power means in Fig. 7 and are enlargements of details corresponding to Figs 2-3 and 5-6, respectively.
- Fig. 10 is a sectional view taken along line X-X in Fig. 1.
- Fig. 11 is a side view of a printing unit according to a second embodiment of the invention.
- Fig. 12 is an end view XII-XII of a frame side of the printing unit illustrated in Fig. 11. Description of the Preferred Embodiments
- Figs 1-10 illustrate a first embodiment of the invention in the form of a flexographic printing unit which comprises a machine frame having two parallel frame sides, which are generally designated 1 and 2 and between which transverse, rotatable rollers or cylinders are supported.
- An impression cylinder 3 has its stub shafts 4 and 5 mounted in bearing brackets 6 and 7.
- a stereo roller 8 has its stub shafts 9 and 10 mounted in bearing brackets 11 and 12, and an inking roller 13 has its stub shafts 14 and 15 mounted in bearing brackets 16 and 17.
- an inking device preferably a chamber doctoring system (not shown), which need not be described in more detail here.
- the machine frame also comprises two crossbars 18, 19 connecting the frame sides 1, 2 with each other.
- first spacers or gauge blocks 20-21 Between the bearing brackets 16, 17 of the inking roller 13 and the bearing brackets 11, 12 of the stereo roller 8, there are first spacers or gauge blocks 20, 21, and between the bearing brackets 6, 7 of the impression cylinder 3 and the bearing brackets 11, 12 of the stereo roller 8, there are second spacers or gauge blocks 22, 23.
- the gauge blocks 20-23 are included in a device for nominal adjustment of the bearing brackets 6, 7, 11, 12, 16, 17 according to the diameter of the rollers/cylinders 3, 8, 13, as will be described below.
- an eccentric-acting lever mechanism 24, 25 which preferably is of the type as described in EP-A-280,668 which was mentioned by way of introduction and which is incorporated herein by reference.
- a continuous web of material 26, which is to be printed between the impression cylinder 3 and the stereo roller 8, is indicated by a dash-dot line in Figs 1, 4 and 7.
- the bearing brackets 6, 11, 16 of the rollers/cylinders 3, 8, 13 and the gauge blocks 20-23 are arranged in a rectangular recess 27, which has an open side (here upwardly open) and which is defined by two upright, opposite and spaced- apart counterportions or abutment portions 28 and 29.
- the recess 27 is also defined by a horizontal bottom portion 30, which extends between the vertical abutment portions 28 and 29 and on which the bearing brackets 6, 11 are slidably displaceable in the plane of the frame side 1, as well as the gauge blocks 20 and 22 arranged therebetween.
- the frame side 1 thus can be regarded as a U-shaped cradle, in which the bearing brackets 6, 11, 16 and the gauge blocks arranged therebetween are placed.
- a pressure cylinder 31 is arranged in the bearing bracket 16.
- the pressure cylinder 31, which preferably is hydraulic or pneumatic and of standard type, cooperates with a screw 32 which is screwed in a threaded hole in the abutment portion 28.
- Some sort of spacer 33 is preferably arranged between the pressure cylinder 31 and the screw 32.
- the pressure cylinder 31 For clamping into the operative position of the printing unit, the pressure cylinder 31 is activated and extended from the bearing bracket in the direction of the abutment portion 28. The end of the pressure cylinder 31 then abuts the spacer 33 of the screw 32 and thus has a contact point in or adjacent to a gap 34 between the abutment portion 28 and the neighbouring bearing bracket 16, as will be best seen from the part-sectional view in Fig. 3.
- a pressure cylinder 31 in each frame side 1, 2, as will be seen from Fig. 10.
- the two pressure cylinders 31 thus form a power unit for generating the clamping force discussed above.
- this power unit can, of course, be designed in some other manner.
- the pressure cylinders can instead be arranged in the opposite abutment portions and abut the neighbouring bearing brackets .
- the longitudinal axes of the rollers/cylinders 3, 8, 13 extend in substantially the same plane as the longitudinal axes of the pressure cylinders 31 and the screws 32, and said force contact point is also positioned in this plane. This results in a very simple distribution and absorption of forces. Horizontal forces are absorbed directly by the pressure cylinder 31, and vertical forces by frictional forces between the bearing brackets and the gauge blocks, which results in reliable clamping and absorption of forces as well as moments.
- a spring arrangement Adjacent to the bearing bracket 11 of the stereo roller 8, there is a spring arrangement comprising four spring means in the form of helical springs 36, of which one is shown in detail in Figs 2, 5 and 8.
- the springs 36 In the operative position (Fig. 1) of the printing unit, the springs 36 are pressed against the gauge blocks 20 and 22 arrang- ed on both sides of the bearing bracket 11, and apply bias on these.
- the idle-running position (Fig. 4) of the printing unit when the web is not being printed, the impression cylinder 3, the stereo roller 8 and the inking roller 13 are separated from each other, such that the stereo does not contact the web 26 and the inking roller 13.
- Fig. 7 the printing unit is shown in its position for replacement of a roller, for instance replace- ment of the stereo roller 8.
- the clamping forces are completely relieved by loosening the adjustment screws 32, and the contact between their spacers 33 and the neighbouring pressure cylinder 31 ceases completely and a gap forms therebetween (Fig. 9).
- the springs 36 are also out of contact with the neighbouring gauge blocks 20 and 22 (see Fig. 8).
- the eccentric-acting lever mechanism 24 is removed by simple operations, whereupon the stereo roller 8 and the associated bearing blocks 11, 12 can be taken out of the recess 27.
- the replacement of a roller can be carried out in a much simpler and quicker manner than in prior-art printing units.
- gauge blocks and bearing brackets can be made as a single unit, having dimensions adapted to the diameter of the roller/cylinder. Of course, also the width of the bearing brackets can be adapted to the desired clamping.
- the gauge blocks 20, 22 thus form, together with the adjustment screws 32, a device for nominal adjustment.
- the spacers 33 arranged at the two ends of the adjustment screws are replaceable, which means that such spacers 33 of different thicknesses (dimensions) can be used for the nominal adjustment.
- the two abutment portions 28, 29 defining the recess 27 constitute fixed parts of each frame side 1 and 2.
- an alternative is presented as shown in Figs 11 and 12.
- one abutment portion 29' still constitutes a fixed part of the frame side 1
- the other abutment portion 28 ' is movable (arrow A).
- the distance between these two abutment portions 28 ' and 29 ' which define the recess 27' for the bearing brackets and the gauge blocks, thus is adjustable.
- the movable abutment portion 28' carrying the adjustment screw 32' constitutes an upright part of an L-shaped element generally designated 38, whose horizontal part 39 is adjustably arranged in or adjacent to the frame side 1.
- there is no power means adjacent to the gap 34 between the abutment portion 28 ' and the neighbouring bearing bracket 16 ' but instead the clamping force indicated by arrow F is generated by means of a schematically illustrated power means 40 which is connected to the horizontal part 39 of the L-shaped element 38.
- the printing unit designed according to the second embodiment will thus function substantially according to the principle of a vice.
- the L-shaped element of the second embodiment is arranged in another way, its horizontal part being arranged on and overlaying the brackets and the gauge blocks.
- the outer abutment por- tion thus extends downwardly.
- the overlaying L-shaped element is removable for replacement of rollers and bearing brackets .
- the features that are essential to the invention, however, are the same for both embodiments by the bear- ing brackets being arranged in a recess 27, 27' defined by two preferably upright, spaced-apart abutment portions 28, 28' and 29, 29', respectively, between which the clamping force acts.
- the clamping-force-generating power unit 31, 40 of the two embodiments has in each frame side a contact point in or adjacent to the gap 34 between one abutment portion 29, 29' and the neighbouring bearing bracket 16, 16'.
- the operative power means 40 is spaced from said contact point adjacent to the gap 34.
- the power means preferably consist of fluid-operated pressure cylinders, especially pneumatic or hydraulic such cylinders, but the expert rea- uses that alternative power means can be used.
- alternative solutions of details can be used to provide the nominal adjustment and the correction adjustment.
- a plurality of printing units can be arranged successively, horizontally or vertically. It may be convenient that the recesses in the frame sides are not horizontally arranged, but make a suitable angle with the horizontal plane. When printing units coupled together are used for printing the same web, it is suit- able that the recesses in the frame sides make a certain angle with each other.
- the invention is not bound to the arrangement of rollers as described above, but several alternatives are feasible within the scope of the invention. According to the desired printing, for instance the impression cylinder and the inking roller can change places, and additional rollers and cylinders may be included in the printing uni .
- the number of gauge blocks may also vary, and it should espe- cially be mentioned that gauge blocks can be arranged between the outer abutment portion and the neighbouring bearing bracket.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Inking, Control Or Cleaning Of Printing Machines (AREA)
- Accessory Devices And Overall Control Thereof (AREA)
- Rotary Presses (AREA)
Abstract
Description
Claims
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP97935974A EP0921945B1 (en) | 1996-08-26 | 1997-08-22 | Printing unit |
DE69704622T DE69704622T2 (en) | 1996-08-26 | 1997-08-22 | PRINTING DEVICE |
AU38751/97A AU3875197A (en) | 1996-08-26 | 1997-08-22 | Printing unit |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
SE9603083A SE9603083D0 (en) | 1996-08-26 | 1996-08-26 | Printing unit |
SE9603083-8 | 1996-08-26 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1998008683A1 true WO1998008683A1 (en) | 1998-03-05 |
Family
ID=20403655
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/SE1997/001380 WO1998008683A1 (en) | 1996-08-26 | 1997-08-22 | Printing unit |
Country Status (6)
Country | Link |
---|---|
EP (1) | EP0921945B1 (en) |
AU (1) | AU3875197A (en) |
DE (1) | DE69704622T2 (en) |
ES (1) | ES2155695T3 (en) |
SE (1) | SE9603083D0 (en) |
WO (1) | WO1998008683A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2000058096A1 (en) * | 1999-03-30 | 2000-10-05 | Tetra Laval Holdings & Finance Sa | A method and an apparatus for locking the rollers in a printing unit |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
SE454664B (en) * | 1983-07-18 | 1988-05-24 | Jan Stenqvist | PRESSURE EFFECTS |
EP0363293A1 (en) * | 1988-10-04 | 1990-04-11 | H.I. HOLWEG INTERNATIONAL, Société Anonyme dite: | Printing unit for a flexographic printing machine with a single impression cylinder |
GB2276124A (en) * | 1993-03-18 | 1994-09-21 | Windmoeller & Hoelscher | Displacement of roller bearing blocks mounted on carriages |
-
1996
- 1996-08-26 SE SE9603083A patent/SE9603083D0/en unknown
-
1997
- 1997-08-22 DE DE69704622T patent/DE69704622T2/en not_active Expired - Lifetime
- 1997-08-22 ES ES97935974T patent/ES2155695T3/en not_active Expired - Lifetime
- 1997-08-22 EP EP97935974A patent/EP0921945B1/en not_active Expired - Lifetime
- 1997-08-22 WO PCT/SE1997/001380 patent/WO1998008683A1/en active IP Right Grant
- 1997-08-22 AU AU38751/97A patent/AU3875197A/en not_active Abandoned
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
SE454664B (en) * | 1983-07-18 | 1988-05-24 | Jan Stenqvist | PRESSURE EFFECTS |
EP0363293A1 (en) * | 1988-10-04 | 1990-04-11 | H.I. HOLWEG INTERNATIONAL, Société Anonyme dite: | Printing unit for a flexographic printing machine with a single impression cylinder |
GB2276124A (en) * | 1993-03-18 | 1994-09-21 | Windmoeller & Hoelscher | Displacement of roller bearing blocks mounted on carriages |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2000058096A1 (en) * | 1999-03-30 | 2000-10-05 | Tetra Laval Holdings & Finance Sa | A method and an apparatus for locking the rollers in a printing unit |
US6718876B1 (en) | 1999-03-30 | 2004-04-13 | Tetra Laval Holdings & Finance S.A. | Method and an apparatus for locking the rollers in a printing unit |
Also Published As
Publication number | Publication date |
---|---|
SE9603083D0 (en) | 1996-08-26 |
DE69704622T2 (en) | 2001-09-13 |
AU3875197A (en) | 1998-03-19 |
EP0921945A1 (en) | 1999-06-16 |
ES2155695T3 (en) | 2001-05-16 |
EP0921945B1 (en) | 2001-04-18 |
DE69704622D1 (en) | 2001-05-23 |
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