MADDALON VALTER (IT)
| WO2001076833A1 | 2001-10-18 |
| EP0951973A1 | 1999-10-27 | |||
| EP0947880A1 | 1999-10-06 | |||
| DE4107801A1 | 1992-09-17 | |||
| US20030118389A1 | 2003-06-26 | |||
| US5790168A | 1998-08-04 | |||
| DE4416522A1 | 1994-11-17 |
| 1. | An automatic device for the cutting and finishing, simultaneously on two axes (X, Y) perpendicular to each other, of paper and other graphic or photographic substrates (10) with series of images marked by marks being detectable by optical sensors (3, 3') located near feeding rollers (1) of said substrate (10), driven by a first motor (2), a movable cutting unit (4) being provided for being suitable for cutting said substrate (10) along the transverse direction (X), perpendicular to the feed in the direction of an arrow (F), along a cutting line (Tx) being adjustable by means of a second motor (5) driven by possible nonalignment signals produced by said optical sensors (3, 3') and processed by a microprocessor, said cutting unit (4) being driven by a third motor (6), characterized by further comprising a longitudinal cutting assembly (14) for the cut of said substrate (10) along at least two cutting lines (Ty) in a direction (Y) parallel to said feeding direction along arrow (F), comprising a cutting element (14a) for each cutting line (Ty) being provided, each of them being mounted in adjustable position on a single axis of said cutting assembly (14), all said cutting elements (14a) being driven by a fourth motor (7), and a further fifth motor (8) being provided for the doubledirectional shift along axis (X) of said cutting assembly (14) in response to possible signals of nonparallelism of the image to the substrate edge, being detected by an optic cell (9). |
| 2. | A device according to claim 1, characterized in that said longitudinal cutting assembly (14) is integral with the horizontal cutting unit (4). |
| 3. | A device according to claim 1 or 2, characterized in that said optic cell (9) is integral with said cutting assembly (14). |
| 4. | A device according to claim 1 or 3, characterized in that said optic cell (9) is of the reflection type and at the margin of the image to be cut a longitudinal mark (M) is provided for, comprising alternated white and black bands. |
| 5. | A device according to claim 4, characterized in that said optic cell (9) is formed of two components intended to detect possible deviations from a correct percentage value, respectively of white and black area of said mark (M), being detected in order to transmit such deviation signals to a microprocessor suitable for driving said motor (8) for the axial shifting of the whole cutting assembly (14) and thereby of the elements (14a) according to a doublearrow (F") in direction (X). |
| 6. | A device according to claim 1 or 2, characterized in that said transverse cutting unit (4) comprises pairs of rotating blades and counter blades (12, 13) mounted on a sliding block (11) in perpendicular direction to the forward direction arrow (F), along a path having one fixed end and the other end, being subject to the action of said second motor (5), being able to perform small clockwise and counterclockwise rotations according to a doublearrow (F') in order to grant the alignment of the same path with the desired cutting line (Tx) also as a consequence of random deviations of the feeding of substrate (10) from the direction of said arrow (F). |
| 7. | A device according to claim 6, characterized in that said block (11) carrying the two pairs of blades and counter blades (12, 13) slides by means of a transmission system (16, 17, 18, 18a) by means of said third motor (6) drive along a guide (16') accomplishing said path being fixed at one end and movable at the other one upon drive of said second motor (5). |
WOUND IN ROLLS ON TWO PERPENDICULAR AXES SIMULTANEOUSLY
WITH AUTOMATIC ERRORS CORRECTION"
The present invention relates to a device for the automatic finishing and cutting, on two perpendicular axes simultaneously, of paper and other graphic substrates in roll, provided with automatic correction of the errors due to skiddings of the substrate, particularly for substrates printed with digital rendering systems and for large formats.
It is known that the photographic technique, including that of digital rendering, is undergoing a deep transformation and development, abandoning the printing with traditional optical systems in order to tend more and more towards ink-jet technology from digital "file" on rolls of substrates having the most varied features and dimensions. While, as to printing, remarkable speeds at a high definition have been obtained, the finishing technology of such printed substrates has been limited to developing paper cutters being able to cut along the two axes, but having great limits. In particular it was impossible to correct skiddings of the roll, if badly rewinded, or inaccuracies due to the image itself, if printed not perfectly parallel to the edge of the substrate. Further, it was impossible to cut along the X-axis, parallel to the image in horizontal direction, if due to one or both the above-mentioned reasons, this side, when cut, is not perfectly at right angles with the paper cutter.
It is true that devices have been recently developed, particularly according to European patents 0.951.973 and 1.268.143 both in the name of the same applicant, which have made it possible to automatically perform a precise cut of such substrates in roll, however having two great limits, i. e., concerning the dimensions, a maximum format of 157 cm, and the drawback of being obliged to manually rotate the sheet by 90 degrees and reintroduce it into the paper cutter in order to obtain a perfect cut along all the four sides. Given the greater and greater penetration into the market of this kind of printing, which is replacing the offset technology thanks to its flexibility and reduced costs for short runs, there has been a great increase of the processed volumes, whereby the manual finishing is no more acceptable and it is thereby essential to automatize the finishings of the prints. In addition, while for small formats the consequences of
possible skiddings of the roll or of the image can be unimportant, in large formats these are not acceptable and their correction is made essential.
An object of the present invention is thus to overcome the drawbacks of the prior art for what concerns the non-perfect correction of the consequences of a bad rewinding of the roll or of parallelism defects of the image with respect to the edges, rendering possible to automatically cut the substrate on both the perpendicular axes simultaneously, without manual interventions.
Another important object of the present invention is that of being able to overcome the above-mentioned drawbacks and obtain the listed advantages also for formats larger than 157 cm width.
These objects are achieved with an automatic cutting device having the characteristics specified at least in claim 1, with possible further aspects, optional or preferred, resulting from the dependent claims.
Other objects, advantages and characteristics of the device according to the invention will result more clearly from the following detailed description of a preferred embodiment thereof, set forth by way of non-limiting example with reference to the annexed drawings, wherein:
Figure 1 shows a schematic top plan view of an automatic cutting device according to the present invention during its normal operation; Figures 2a and 2b show the same device of Figure 1 during operation, respectively with correction of an oblique forward movement of the paper, schematized by the curved double arrow F', and a correction for a transverse right-left skidding, as schematized by the double arrow F";
Figures 3a and 3b show, respectively in front and side view, a preferred embodiment of the transverse movable cutting unit along the X-axis; and
Figure 4 shows an example of substrate with printed images thereon and the respective cutting lines, as well as the longitudinal mark with double black band provided for the alignment along the Y-axis.
With reference to the drawings, the automatic cutting device according to the present invention comprises a pair of rollers 1 (of which only the upper roller is illustrated) for the forward movement of a web substrate 10, being fed from a roll, in the
direction of arrow F, and a motor 2 for the driving thereof. In a known way, as for example from EP 0.951.973, a pair of optical sensors 3, 3', being positioned, in particular, at two sections of reduced diameter of said rollers, detects a mark (not illustrated) provided between two subsequent images printed on substrate 10. Said mark can advantageously be, although not necessarily, of the type described in the above- mentioned European patent in order to allow to easily determine its angulation with respect to the cutting line T x .
The cut is performed by means of a movable cutting unit 4, driven by a motor 6 and carried in alignment with the desired cutting line T x according to of the deviation signal detected by optical the sensors 3, 3' and of the resulting input on a motor 5 in consequence of the processing of the signal itself by a microprocessor controlling the whole system, not shown in the drawings. Driven in such a way, motor 5 determines, in a known way, an angular shift of the cutting path, e. g., for the correction of an oblique trend as in Figure 2a. For this purpose, while one end of the sliding guide 14 of the paper cutter is movable in the double clockwise/counterclockwise direction of arrow F', under the action of motor 5, the other end is fixed and advantageously works as a pivot for the resulting rotation.
The cut is determined by the horizontal driving of the movable blade of the cutting unit 4 (along X-axis), which can be accomplished in any known way, preferably according the embodiment that will be described more in detail with reference to Figures 3a and 3b.
A motor 7 is also provided for the driving of the longitudinal cutting assembly 14, with a motor 8 for its axial shifting in both directions according to arrow F" of Figure 2b. While the correction according to curved arrow F' of Figure 2a occurs in a known way, as previously said, by means of two optical sensors 3 and 3', said transverse correction for the longitudinal cutting assembly 14 occurs, according to the present invention, simultaneously with the alignment of the cut along the X-axis, but independently from the fact that the two cutting assemblies are integral with each other, hi fact, the position of the longitudinal cut Ty is automatically corrected with respect to the edge of the image, by keeping its perpendicularity with respect to cutting X-axis not only in this embodiment, but also providing for the longitudinal cutting assembly being
integral with the rest of the device, although being able to shift in the two directions of arrow F'.
In fact, in its preferred embodiment, said longitudinal cutting assembly 14 is formed of two or more rotating blades located above the substrate 10 to cut and finish along cutting lines Ty provided for (there may be at least another cutting line at the center of substrate 10 when the images are printed in pairs in side-by-side relation along X-axis). Said rotating blades 14a, being driven in any known way by motor 7, are mounted at predetermined positions, according to the dimensions of the images to be cut, on a single shaft transversally moving and driven by said motor 8. For this purpose, with particular reference to Figure 4, during the feed of the paper or substrate 10 a reflection optic cell 9, being assembled, e. g., on the same longitudinal cutting assembly 14 at the edge of the image, where a mark M is provided preferably with two vertical black bands and an intermediate white one, detects the positioning of the paper by measuring the reflection in a restricted area designated by My in the drawing. Upon the image being no more parallel to the paper edge, the sensor detects the change of state thereof and sends a directional signal to the system microprocessor for the suitable driving of the motor 8. It is preferred to use an optic cell with two different elements, one white-responsive and one black-responsive, in order to detect percentage variations of the two colors, indicia of the prevalence of one or the other black band or of the intermediate white band. In such a way, by crossing the related data still through the microprocessor processing, the input suitable for obtaining the necessary correction will be determined, by driving motor 8 for a rightward (F "R) or a leftward (F"L) shift of the cutting assembly 14, whereby all the rotating blades elements 14a consequently determine the corresponding cutting lines T YR and T YL bringing them back to the respective correct positions.
In Figures 3 a and 3b a preferred embodiment of the transverse cutting unit 4 is shown, which provides for two pairs of blade and counter blade 12, 13 mounted in close positions, in the X-axis direction perpendicularly to the feed direction F, onto a block 11 with an appendix 12a supporting the upper blades 12. The lower or counter blades 13 are driven by a cogged pulley suitable for moving while rotating along, e. g., a cogged belt 16' fixed to the ends, with the help of two idle pulleys 18 being present underneath,
whose support 18a is integral with a ring belt 16 tense between two end pulleys 17 and 17', one of which is driven by said motor 6. It is noted that, of course, the system of pulleys and belts 14, 15, 16 could be replaced by an equivalent anti-backlash drive system. The cogged belt 16', along which the paper cutter holder block 11 slides, is the guide of the cutting assembly 14, being able to move at one end and pivoting at the opposite one, as previously stated.
Possible modifications can be made by those skilled in the art to the above- described and illustrated embodiment of the automatic cutting device according to the present invention, without going out of the scope of the same invention. Particularly, the optic cell 9 may not be integral with the longitudinal cutting assembly 14, although accomplishing the same functions with suitable expedients being within the abilities of one skilled in the art, and further the transverse cutting unit 4 can be differently accomplished from what shown in Figures 3a and 3b, according to constructional ways known in the field.