Device for collecting printed products on a collecting cylinder

A device for collecting printed products includes a rotating collecting cylinder to and a controllable holding device that holds and releases the printed products collected in a peripheral area of the collecting cylinder. A diverter includes an exposed end and a support roller. The diverter has an operational position to lift the products off the collecting cylinder and transfer them onto a conveying device, and a non-operational position for collecting the products on the collecting cylinder. A control unit moves the diverter from the non-operational position during an interval between two successive printed products and with the timing of the supplied printed products, to the operational position in which the diverter's exposed end is inserted in the surface area of the collecting cylinder. A circulating control member is drive-connected to the collecting cylinder and includes at least one control cam associated with the support roller in the non-operational and operational positions of the diverter.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority of European Patent Application No. 07405089.9, filed on Mar. 20, 2007, the subject matter of which is incorporated herein by reference together with each U.S. and foreign patent and patent application mentioned herein.

BACKGROUND OF THE INVENTION

The invention relates to a device for collecting digitally and preferably sequentially printed products, which are supplied to a collecting cylinder that rotates around an axis, the device comprising a drive, a holding device for holding and releasing the printed products collected in the peripheral area of the collecting cylinder, an activation device for controlling the holding device, and a diverter with a pivoting axis that extends parallel to the collecting cylinder axis and can be used for lifting the collected printed products off the collecting cylinder, such that they can be transported away with the aid of a conveying device. For the collecting of the printed products, the diverter can be displaced by a control unit to a non-operating position during the interval between two successively following printed products and with the timing of the supplied printed products. For the conveying away of the printed products from the collecting cylinder, the diverter can be displaced to an operating position, in which the exposed end of the diverter is inserted into the surface area of the collecting cylinder.

German patent document DE 103 15 443 A discloses a device for collecting printed products, for example signatures for producing a newspaper, in the peripheral area of a collecting cylinder. The collected products can be released jointly and can be supplied, for example, to a folding machine. The collecting cylinder can simultaneously be embodied as a folding cylinder that is provided with folding blades in the peripheral area.

In order to collect the printed products in the peripheral area of the collecting cylinder, this cylinder is provided with a holding device that can be activated relative to the peripheral area of the collecting cylinder.

European patent document EP 1 471 022 A1 discloses a device for holding in place the printed products collected on a collecting cylinder with the aid of a holding mechanism, which comprises holding elements for holding down the printed products arriving at an end stop. A conveying belt that follows the collecting cylinder is provided for transporting away the printed products collected on the collecting cylinder. In order to transfer the collected printed products to the conveying belt, several transfer-out elements are provided, which form a diverter and can be pivoted around a pivoting axis extending parallel to the axis of rotation for the collecting cylinder. The transfer-out elements are inserted in the area of the collecting cylinder under the printed products to be transferred out. During the process of collecting the printed products, the transfer-out elements are pivoted away, such that they cannot enter the area of the collecting cylinder and are not operational. In one embodiment, the device is designed for assembling printed products that are sequentially printed in a digital printer.

SUMMARY

It is an object of the present invention to provide a device which can be used with a digital printer, but which makes possible a high output.

The above and other objects are accomplished according to the invention wherein there is provided, according to one embodiment, a device for collecting printed products, including a collecting cylinder that rotates around an axis and has a peripheral area to collect sequentially supplied printed products, a drive mechanism to rotate the collecting cylinder, a holding device operative to hold and release the printed products collected in the peripheral area of the collecting cylinder, and an activation device operative to control the holding device. The device also includes a diverter which includes a pivoting axis that extends parallel to the axis of the collecting cylinder, an exposed end and a support roller, such that the diverter has an operational position to lift the products off the collecting cylinder and transfer the products onto a conveying device, and a non-operational position to enable collection of the products on the collecting cylinder. A control unit is coupled to move the diverter from the non-operational position during an interval between two successively following printed products and with the timing of the supplied printed products, to the operational position in which the exposed end of the diverter is inserted in the surface area of the collecting cylinder. A concentrically circulating control member is drive-connected to the collecting cylinder. The control member includes at least one control cam operatively associated with the non-operational and operational positions of the diverter and which acts upon the support roller of the diverter.

With the device according to the invention, the diverter can be secured in a non-operating position for the collection of printed products by using a locking mechanism that is controlled by the control unit. In addition to controlling the device, the control unit with the connected locking mechanism for the diverter, also controls the printer and other devices used for producing the printed products. The printer is installed upstream of the collecting cylinder. The data required for producing the printed products are stored in the control unit and can be used with the device for controlling the diverter.

The device allows for the production of printed products at high output rates, which are comparable to the output rates of digital printers.

Another advantage of the device is that it allows collecting a variable number of sheet sections to form partial products with variable page numbers, especially in combination with a digital printer. The data required for this operation are stored in the control unit and the data can be used for controlling a printer, in particular a digital printer, and for controlling the diverter. The device is therefore especially suitable for collecting digitally printed sheets that are supplied sequentially, meaning one after another. On a dual-use collecting cylinder, for example, it is therefore possible to collect two products A and B which are different and have different formats.

According to one embodiment, the diverter can be pivoted to a non-operating position with the aid of the control member that rotates about the axis of the collecting cylinder. The diverter can respectively be pivoted to the non-operating position during an interval between two printed products, which are fed successively to the collecting cylinder or have already been collected thereon. For the process of collecting the printed products, the diverter is secured in the non-operating position by engaging in a locking mechanism. Once released from the locked position, the diverter is pivoted to an operating position, the collected printed products are lifted off the collecting cylinder, and the products are then conveyed by a conveying device. The control unit controls the steps of locking in place and releasing the diverter from the locking mechanism, thereby making possible the high output, flexibility, and comparably simple and secure control, as previously mentioned.

According to another embodiment, a particularly easy and secure control is possible if the control member is a circular disc with a radially outward pointing control cam.

This respectively allows the control cam to pivot the diverter to the non-operating position during an interval between two printed products.

According to another embodiment, the diverter can be secured if the diverter is detachably engaged in the locking mechanism for the non-operating position. A different embodiment provides for a movable latch on the locking mechanism for engaging the diverter, wherein this latch can be moved ahead of time with the timing for the supplied printed products. In this embodiment, the diverter is engaged detachably in the latch.

An especially easy and secure release from the locked position is possible according to a different embodiment of the invention, if a resetting force acts upon the latch and moves the latch to an idle position once the diverter is disengaged from the latch. The latch can be disengaged simply by pivoting the diverter with the aid of the control member, thereby removing the load from the latch. The resetting force subsequently pivots the latch immediately to an idle position, thereby releasing the diverter.

According to yet another embodiment of the invention, the locking mechanism comprises an adjustment element, which secures the latch in a position where the diverter is engaged, such that it cannot be disengaged. In this way, the latch can be locked in place easily and the collecting position determined. The adjustment element is connected to the control unit and is preferably embodied as an adjustment cylinder, in particular as a pneumatic cylinder. The latch can be held in the locked position and/or can be released from this position with the piston rod of the preferably dual-action adjustment cylinder.

According to a modified embodiment, the diverter is a control lever wherein the control lever operates jointly with the locking mechanism.

According to a different embodiment of the invention, a particularly easy and secure control is possible if the control lever pivots and has a support roller that moves along the adjustment elements for controlling the diverter.

The control lever comprises a locking mechanism, for example a locking disc, which engages in a latching nose of the latch when the diverter is pivoted to the non-operating position.

Another embodiment provides that the control lever can be pivoted counter to the resetting force, for example the force exerted by a spring element. If the control lever is no longer locked in place, the control lever automatically and immediately pivots to the operating position, in which the printed products are transported by the collecting cylinder.

A different embodiment comprises a control unit for controlling the locking mechanism. The control unit furthermore controls a printer, preferably a digital printer. This embodiment is particularly suitable for the sequential printing at high speeds of products composed of sequentially supplied digitally printed sheets. The printed products can furthermore be composed of partial products with variable page numbers. In this way, different types of printed products, for example newspapers, so-called broad sheets, but also tabloids, can be produced one after another.

According to one modified embodiment, the device is provided with an activation device for controlling the mechanism for holding and releasing of the printed products. As a result, the holding and releasing of the printed products can also be controlled with the aid of information supplied by the control unit, which permits an even higher output. The activation device advantageously operates jointly with a stationary first cam. The first cam has a different cam section for releasing the holding device. The holding device can at least approximately be compensated for by another cam section of a second cam. According to a different modification of the invention, the control of the holding device is particularly easy and secure if the second cam can moves between an inactive position and an active position. In the inactive position, the holding device is released. In the active position, the deviating cam section is approximately compensated for and the holding device is effective. The second cam can be advanced parallel to or approximately radial to the axis of rotation for the collecting cylinder. This configuration makes it possible to control the holding and releasing mechanism with the aid of a comparatively small lift, which can be achieved easily and quickly by using an adjustment cylinder.

The adjustment cylinder is preferably a pneumatic cylinder. However, a different type of adjustment cylinder and/or a different drive mechanism can in principle be used for displacing the cam.

DETAILED DESCRIPTION

The device1as shown inFIG. 1, comprises a collecting cylinder2having a shaft22, which can rotate in a clockwise direction around an axis22a. According toFIG. 8, the shaft22ais positioned with both ends on a machine frame30, such that it can rotate. A drive motor13, in particular a servo motor, is used to drive the collecting cylinder2with the aid of a belt14. The belt14is provided with toothing on both sides. The toothed belt14is fitted around a wheel58, as shown inFIG. 1. The wheel58is arranged to the side and outside of the machine frame30, as shown inFIG. 8. The wheel58is fixedly connect to the shaft22of the collecting cylinder2. With the toothed belt14and a toothed belt15, the drive motor13furthermore also drives a lower conveying belt44which is fitted over rollers45and46. A counter-pressure cylinder12is operatively connected to the toothed belt14and the toothed belt15. With the aid of the toothed belt14, the drive motor13furthermore drives an acceleration element11, which operates jointly with the counter-pressure cylinder12for accelerating a printed product17to be collected. The acceleration element11is provided for this with a peripheral area49that rotates around an axis47in the direction of arrow48. With the aid of the toothed belt14and a toothed belt59, the drive motor13also drives an upper wheel51, a spur wheel, which engages in a different, lower spur wheel52of a conveying device6. The upper wheel51drives an upper conveying belt10while the lower wheel drives a belt53.

The collecting cylinder2, the acceleration element11, as well as the belts10,44and53intended for the transport are therefore driven with synchronized speed and with the same timing by the drive motor13. The drive motor13is supplied with the necessary information by a control unit16, which is schematically indicated inFIG. 1, and also controls a printer56and a cross cutter57. The printer56is preferably a digital printer. As indicated inFIG. 1, the cross cutter57cuts the paper web67in transverse direction into individual printed products17. The paper web67is imprinted by the printer56. The printed products17are transported from the left to the right inFIG. 1, as shown with the arrow50. The rotational speed of the cross cutter57, which is provided with a knife blade in the peripheral area, precisely corresponds to the speed of the acceleration element11and/or half the speed of the collecting cylinder2, on which two sheet stacks18and18′ can be formed in the peripheral area3. The collecting cylinder2is therefore embodied for a dual use. However, a design is also conceivable where the collecting cylinder2is embodied for only one use.

Several holding devices5are provided for holding the printed products17in place on the collecting cylinder2. As shown inFIG. 3, the holding device5can be embodied as punching needles which are respectively attached to the end of a lever4. The acceleration element11and the needles on the collecting cylinder2are adjusted relative to each, such that the printed products17are speared by the extended needles at a location approximately 1 cm behind a leading edge. Once the collecting operation is completed, the levers4with the holding device5are pulled back, thereby releasing the printed products17that are collected into a sheet stack18on the collecting cylinder2. A final printed product17is placed directly onto the sheet stack18that is collected on the cylinder2, without being held down by the holding device5and being guided around the collecting cylinder2. The collecting of the printed products17with the aid of the holding device5is explained further in the following paragraphs.

The continuously drawn lines inFIG. 1show the position of the holding device5and the lever4, in which the holding device5is effective for collecting printed products17. The dashed line of lever4inFIG. 1shows the pulled-back position, in which the collected printed products17on the collecting cylinder2are not held down. At a distance to the holding device5, the levers4are fixedly connected to the shaft28that is shown inFIG. 3. The shaft28is positioned rotating in the collecting cylinder2. As shown inFIGS. 2 and 3, an activation device19is attached to one end of shaft28, and is provided at a distance to the shaft28with two cam rollers20. The cam roller20a, shown inFIG. 3, runs at least in some sections along a cam section23bof a cam23while the cam roller20bruns along a cam section24bof a cam24. The cam23and the cam24are stationary, meaning they do not rotate along with the collecting cylinder2. However, the cam24can be displaced, for example in axial direction, with the aid of the stroke illustrated in FIG.3by double arrow29. The one position of the cam24is shown inFIG. 3with continuous lines while the other position is shown with dashed lines. The cam24can also be advanced either parallel or radial to the axis of rotation for the collecting cylinder2. It is furthermore conceivable that the cam24is positioned so as to pivot around the axis of rotation22or an axis that is parallel to the axis of rotation22. The cam23cannot be displaced and is attached with several bolts27to the machine frame30. The cam24is guided linearly by a guide element25. A pneumatic cylinder26, which is attached to the machine frame30, is responsible for the movement in the axial direction. The cam24is connected directly to a piston rod60of the pneumatic cylinder26(FIG. 2), wherein a different drive element can also be used in place of a pneumatic cylinder. A control unit16is responsible for the timely activation of the pneumatic cylinder26. The control unit16also controls the digital printer56and the cross cutter57. The necessary information is stored in the control unit16, for example relating to the number of pages required for each partial product of a newspaper, meaning the number of printed products17which must be collected with the device to form a sheet stack18.

According toFIG. 2, the cam23has a deviating cam section23a, meaning the track21is not completely circular.FIG. 2also shows that the cam24is positioned in front of this deviating cam section23aand is provided with a cam section24a, which at least approximately compensates for the deviating cam section23aof the cam23.FIG. 3shows that if the cam23is in the position indicated with the continuous lines, then the deviating curve section23ais not effective since the activation device19with the cam roller20bis lifted in this cam section23ato be above the cam section24aof the cam24. The deviating cam section23ais thus compensated at least approximately by the cam24. The respective position of the activation device19is shown inFIG. 2with continuous lines. However, if the cam24is in the position shown with dashed lines inFIG. 3, it does not become effective and the cam roller20baccordingly is not activated. In that case, the activation device19is controlled solely by the cam roller20a, which then enters the area of the deviating cam section23a. As shown inFIG. 2, when the cam roller20aenters this area, the activation device19moves radially downward causing the levers4with the holding device5to also move downward in radial direction. The holding device5consequently releases the printed products17collected on the collecting cylinder2.

The belts9run over the rollers61and are driven by the collecting cylinder2. The holding device5is located in a gap that respectively exists between two belts9, offset in the axial direction of the collecting cylinder axis22, and the deflection rollers61,62and63. The position of the holding device5can thus be controlled easily by axially displacing the cam24with the pneumatic cylinder26. To collect the printed products17, the cam24is thus moved to the position shown inFIG. 3with continuous lines. Once the collecting operation is completed, the cam24is displaced with the aid of the pneumatic cylinder26in the axial direction and linearly toward the outside, so that the cam roller20acan withdraw into the deviating cam section23aand the collected printed products17can be released by the holding device5. As previously mentioned, the pneumatic cylinder26is activated by the control16.

FIG. 1shows that opposite the levers4the collecting cylinder2is provided with additional levers4′. The levers4and4′ comprise holding devices5and are also controlled by the cams23and24, as explained in the above. The levers4′ function to hold in place the printed products17of the sheet stack18′ while the levers4function to hold in place the printed products17of the sheet stack18.

Once the holding devices5have released the sheet stacks18and18′, these are lifted off the collecting cylinder by a diverter7and are transferred out with a conveying device6. During the collecting operation, the diverter7is in the non-operating position shown with continuous lines inFIG. 1. For the transfer-out operation, the diverter7is pivoted to the operating position, shown with dashed lines inFIG. 1. The diverter7is controlled with the aid of a rotating control member35, shown inFIGS. 4 to 8. A control lever31moves along the control member35. A diverter spar34with a pivoting axis8fixedly connects the diverter7and the control lever31. At a distance to the diverter spar34, the control lever31is provided with a support roller32proximate an exposed end31a. The exposed end31amoves in the peripheral area of the rotating control member35. Control member35, control lever31and support roller32are arranged outside of machine frame30. The diverter spar34is extended up to the outside of machine frame30, as shown by pivoting axis8inFIG. 8. Between the diverter spar34and the support roller32, a spring element33acts upon the control lever31. The support roller32is pressed against the control member35with the aid of this spring element33, for example a compression spring. According toFIGS. 4 and 5, the control member35has a radially outward pointing control cam36. The control cam36functions to slightly lift the support roller32each time. The diverter7accordingly is pivoted radially toward the outside. The control cam36is arranged such that the pivoting always occurs during an interval between the two sheet stacks18and18′. This prevents the diverter7from coming in contact with the collected printed products on the collecting cylinder. Preferably, the control member35comprises a plurality of control cams36operatively associated with a respective one of the printed products, only one control cam36being show for ease of illustration.

As shown inFIG. 6, during the collecting of the printed products17into sheet stacks18, the diverter7is kept in a raised position by a latch37of a locking mechanism65. In this position, the diverter7consequently does not extend into the collection cylinder2. According toFIG. 4, the latch37can be pivoted around an axis64from a position shown with continuous lines to a position shown with dashed lines. However, the pivoting movement cannot be realized if a piston rod41of a pneumatic cylinder40is extended, as shown inFIGS. 5 and 6. A resetting force38, for example generated by a tension spring that acts upon the latch37, effects a rotational moment in a clockwise direction. An end stop39limits the movement in the counter-clockwise direction. The latch37is in the position shown inFIG. 7if the piston rod41is retracted. The latch37is in the position shown inFIG. 5if the piston rod41is extended.

A snap-in mechanism43that operates jointly with the latch37is arranged on the control lever31. If the latch37is in the position shown inFIG. 5, the snap-in mechanisms43engages in a latch nose66on the latch37as soon as the support roller32moves onto the control cam36. The piston rod41moves back only slightly during the engagement. If the piston rod41remains extended, then the diverter7is secured in the position shown inFIG. 6. The printed products17can thus be collected on the collection cylinder2while the diverter7is in the non-operating position.

For the transfer of a completed sheet stack18or18′, the piston rod41is retracted to the position shown inFIG. 4as soon as the control cam36that is assigned to the leading sheet stack18or18′, leaves the area of the locking mechanism and/or the support roller32. However, the diverter7remains for the time being in the raised position because the comparatively strong spring element33still presses the snap-in mechanism43against the latch nose66. The comparatively weak resetting force38is not able to pull the latch37away from the snap-in mechanism43. If the control cam36, which is assigned to the sheet stack18and/or18′ to be transferred out, moves into the area of the support roller32, then this support roller and thus also the snap-in mechanism43are raised up slightly in radial direction. As a result, the pressure exerted by the snap-in mechanism43onto the latch37is reduced. Thus, the resetting force38can pivot the latch37into the position shown inFIG. 4with dashed lines. The snap-in mechanism43is thus released and the diverter7is pivoted into the position shown inFIG. 7. This is caused as a result of the pressure exerted by the spring element33, which presses the support roller32against the control member35. In this position, the exposed end7aof the diverter7extends into the plane for the surface of the collecting cylinder2and the sheet stack18or18′ is then lifted off the collecting cylinder2. The sheet stack18or18′ is transferred with the aid of the belts10and53of the conveying device6. The control unit16is therefore also responsible for the correct and timely activation of the adjustment element40by an electromagnetic valve that is not shown herein.

Upon completion of the transfer operation and to restart the collecting of printed products17into stacks18,18′, the piston rod41of the adjustment element40is extended as soon as the control cam36, associated with the preceding use, leaves the area of the locking mechanism and/or the support roller. If the support roller32is lifted in radial direction off the following control cam36, the snap-in mechanism43is also lifted up. As previously explained, the snap-in mechanism43is secured immovably in the locking mechanism65.

The device provides a comparatively long time interval for activating the adjustment element40of the locking mechanism65. The piston rod41can be moved to the position necessary for the following use, as soon as the control cam36of the control member35leaves the area of the locking mechanism and/or the support roller32. The time interval between two successively following control cams36of the circulating control member35is thus available for the advance control of the adjustment element40. The holding device5for holding and releasing the printed products collected in the peripheral area3of the collecting cylinder2can also be activated in advance, as described in the above. The cam24can be advanced and/or withdrawn immediately after the circulating cam rollers20leave the area of the deviating cam section23a. The circulating cam rollers20are connected to the collecting cylinder2. The adjustment operation must be completed before the following use, meaning by the time the circulating cam rollers pass through the area of the deviating cam section23aof the cam23. As a result, the device is particularly suitable for the high printing speeds of digital printers, for example speeds more than approximately 2 m/s. The collecting of printed products17on the collecting cylinder2is a separate operation from the cross cutting and folding. The device is therefore especially suitable for use in connection with a digital printer for the sequential production of partial products with a varying number of pages, for example for the production of newspapers. A variable number of printed products can thus be compiled into partial products having a different number of pages and no manual intervention is required for different formats. The device consequently makes possible a high digital printing output and, simultaneously, provides a high flexibility for assembling the printed products.