Apparatus for automatically trimming and cutting images on sheets of paper and other graphic and photographic supports

Apparatus for automatically trimming and cutting images on support sheets, which comprises two cutting devices (1, 2) arranged upstream and downstream, respectively, a conveying device (3) which is suitable for conveying to the second cutting device (2) the sheet portions cut by the first cutting device (1) and comprises one or more conveyor belts (12) tight between a pair of rollers (13), at least one being mechanically connected to a motor (14), a plurality of sensors (16, 17, 18) suitable for detecting the presence of a sheet portion on the conveyor belts (12), as well as one or more conveying rollers (25) suitable for taking a sheet portion placed on the conveyor belts (12) and conveying it to the second cutting device (2).

BACKGROUND OF THE INVENTION

The present invention relates to an apparatus for automatically trimming and cutting images on sheets of paper and other graphic and photographic supports, and in particular images, also with different formats, arranged on said sheets along several rows and columns.

U.S. Pat. No. 5,586,479 to Roy et al. discloses an apparatus for trimming and cutting images of the same format arranged on a sheet of photographic paper along several rows and columns parallel to each other, but not necessarily parallel to the edges of the same sheet. This known apparatus comprises two cutting devices arranged perpendicular to each other upstream and downstream, respectively, of a conveying device which aligns the strips of images coming from the first cutting device before sending them to the second cutting device. However, in this known apparatus the sheet to be cut must be carefully guided, since if it is not conveyed with the edges arranged perfectly parallel to the feed direction, the images can be not precisely cut along their edges. For avoiding this drawback, the patent applications EP 951973 and PCT/IT01/00131 of the same applicant disclose two cutting devices wherein the sheet to be cut can be inserted and/or conveyed with the edge not necessarily parallel to the feed direction, even when the same sheet is very large. However, these known cutting devices can cut the images from the sheet only along one axis, so that a manual intervention is necessary when the images are arranged along several rows and columns.

BRIEF SUMMARY OF THE INVENTION

Therefore, an object of the present invention is to provide a cutting apparatus which is free from the drawbacks of the above mentioned known apparatus, i.e. a cutting apparatus which can automatically cut sheets which are not perfectly aligned as in the above mentioned known cutting devices. Said object is achieved with a trimming and cutting apparatus, the main features of which are disclosed in the first claim and other features are disclosed in the following claims.

The apparatus according to the present invention, thanks to the particular conveying device which is provided with, allows to arrange upstream and downstream of this conveying device two cutting devices suitable for precisely cutting images arranged along several rows and columns on sheets also having the edges not perfectly aligned to their feed direction, so as to obtain, always and in a completely automatic manner, images perfectly cut along their edges.

Furthermore, the conveying device of the apparatus according to the present invention, thanks to its mobile stops, allows to automatically handle sheet portions with different formats, thereby discarding, if necessary, the portions which are too big for the second cutting device. With this arrangement, it is possible to precisely cut the images arranged on several rows and columns, even when they have different sizes, always keeping their sequence order.

Another advantage of the apparatus according to the present invention lies in its high speed obtained thanks to the possibility of handling sheets with the edges not perfectly aligned to their feed direction even when they are going to be cut by the cutting devices.

DETAILED DESCRIPTION OF THE INVENTION

Referring toFIG. 1, it is seen that the apparatus according to the present invention comprises in a known way two cutting devices1,2arranged perpendicular to each other upstream and downstream, respectively, a device3for conveying the portions of a sheet, in particular a graphic or photographic support, which are cut and ejected by the first cutting device1. The conveying device3can align these portions before conveying them to the second cutting device2, which provides for cutting them in several further portions.

In particular, the cutting device1can comprise in a known way one or more conveying rollers4which can be rotated by a motor5by means of a transmission system6for conveying a sheet to be cut (not shown in the figure) to a cutting mechanism7arranged substantially parallel to the rotation axis of rollers4. However, the cutting mechanism7is pivoted for rotating around a vertical axis Y and thus for being arranged slightly slantwise with respect to the rotation axis of rollers4by a motor8, for instance by means of an endless screw. The cutting mechanism7is further provided with a motor9for driving a mobile blade suitable for cutting the sheets conveyed by rollers4. At least one pair of sensors10suitable for locating one or more marks printed on the sheet to be cut, in particular optical sensors suitable for locating barcodes printed with the bars parallel to the cut lines, is arranged close to rollers4. Electronic calculation means (not shown in the figure) process the signals transmitted by sensors10and send corresponding control signals to motor8for arranging the cutting mechanism7parallel to the cut lines. If the sheet to be cut is very wide, the cutting device1can be also provided with encoders37suitable for detecting and correcting in the cutting mechanism7possible displacements of the sheet before the cut but after sensors10have detected the marks thereon. Finally, the cutting device1can also be provided with a sensor11for detecting the presence of the sheet to be cut close to rollers4.

According to the invention, the conveying device3, which comprises one or more conveyor belts12tight between a pair of rollers13, at least one connected to a motor14by means of a transmission system15, is arranged downstream the cutting device1. The rotation axis of rollers13of the conveying device3is preferably parallel to the axis of rollers4of the cutting device1. A plurality of sensors, in particular five sensors16,17,18,19,20suitable for detecting the presence of a sheet portion coming from the cutting device1, is arranged at different distances from the latter between two belts12. A bar21provided with one or more stops22is arranged close to the fourth sensor19and can be rotated by a motor23through a transmission system24for arranging stops22perpendicular, parallel or slantwise with respect to belts12, so as to obtain different stop points for the sheet portions conveyed by belts12, or not stopping them at all and continuing their feeding up to the end of belts12at the end of the conveying device3. For this purpose, the free end of stops22is shaped for allowing a secure stop of the sheet portion even when they are slanted forwards. One or two conveying rollers25, horizontal and preferably perpendicular to rollers13, are suitably arranged between belts12, in particular in the free space comprised between the two belts12closest to the cutting device2. The conveying rollers25are mounted on mobile supports26and can be translated and rotated by at least one motor27by means of a transmission system integral with the mobile supports26. The latter, when motor27is working, translate the shafts of rollers25so as to bring them near to each other for lifting, taking and transporting a sheet portion placed on belts12.

For arranging said sheet portion substantially in the middle of the cutting device2, sensors16,17,18send to electronic calculation means (not shown in the figure) signals according to the presence of this portion above them. Said electronic calculation means determine, according to the signal received from sensors16,17,18, the width of the sheet portion and then send a control signal to motor23, which moves stops22by rotating bar21so that the sheet portion is conveyed by belts12until it does not hit against stops22.

Sensors19and/or20detect and signal the presence of the sheet portion stopped by stops22to said electronic calculation means, which, once these signals are received, send a control signal to motor27for mutually drawing up and rotating rollers25with opposite rotating directions, so as to lift and take the portion for transporting it to the cutting device2.

Also the cutting device2, as the cutting device1, can comprise in a known way one or more conveying rollers28which can be rotated by a motor29by means of a transmission system30for conveying the sheet portion coming from the conveying device3to a cutting mechanism31, preferably pivoted for rotating around a vertical axis Y and therefore for being arranged, if necessary, slightly slantwise with respect to the rotation axis of rollers28by a motor32, for instance by means of an endless screw. The cutting mechanism31is provided with a motor33for driving a mobile blade suitable for cutting the sheet portions conveyed by rollers28. At least one pair of sensors34suitable for locating the marks printed on the sheet portion to be cut is arranged close to rollers28. Electronic calculation means (not shown in the figure) process the signals transmitted by sensors34and send corresponding control signals to motor32for arranging the cutting mechanism31perfectly parallel to the cut lines. If the sheet portion to be cut is very wide, the cutting mechanism2can be also provided with encoders38suitable for detecting and correcting in the cutting mechanism31possible displacements before the cut but after sensors34have detected the marks. Finally, the cutting device2can also be provided with a sensor35for detecting the presence of the sheet portion to be cut close to rollers28.

Devices1and2can consist of a cutting device for wide sheets as the one described in the application PCT/IT01/00131, or of a cutting device for smaller sheets, for instance strips of images, as the one described in the application EP 951973.

InFIG. 2it is also seen that one or more microswitches36sending signals to the electronic calculation means of the conveying device3can be arranged around the rotating bar21to precisely determine the rotation angle of the same bar, and consequently of stops22. The perpendicular and parallel positions of stops22are shown with broken lines.

Referring now toFIG. 3, it is seen that during the use, a sheet comprising a plurality of images A, B, C, D arranged along several rows and columns is inserted, also slightly slantwise, in the cutting device1, which provides for automatically rotating the cutting mechanism7for precisely cutting portions of said sheet along the edges of the columns of images, thanks to the marks printed between said rows and columns. In the figure, the sheet portion containing the column of images B has been just cut by the cutting device1and is at the beginning of the conveyor belts12, while the portion containing the column of images A is in the cutting device2.

If sensors16and18were simultaneously obscured, the sheet portion to be cut in the cutting device2would be too big to be inserted therein, so that stops22would be lifted and this portion would have been ejected by belts12from the side of the conveying device3opposite to the cutting device1. Instead, if sensors17and18were simultaneously obscured, but sensor16were not obscured, stops22would be slanted of 45° for stopping a large sheet portion. Finally, if only sensor18were obscured, stops22would be arranged vertically for stopping a smaller sheet portion, such as the one containing the column of images A and shown in the figure. The latter portion, stopped by stops22, is lifted, taken and conveyed by rollers25into the cutting device2, which provides for cutting each image A of the column after orienting the cutting mechanism31, if this were necessary.

Possible modifications and/or additions may be made by those skilled in the art to the invention embodiment hereinabove described and illustrated while remaining within the scope of the same invention.