GB2348871A

GB2348871A - Movable blow air unit for sheet delivery in a rotary printing press

Info

Publication number: GB2348871A
Application number: GB0009047A
Authority: GB
Inventors: Reinhard Rueckert; Thomas Walther
Original assignee: MAN Roland Druckmaschinen AG
Current assignee: Manroland AG
Priority date: 1999-04-13
Filing date: 2000-04-12
Publication date: 2000-10-18
Anticipated expiration: 2020-04-12
Also published as: FR2792248A1; GB0009047D0; FR2792248B1; DE29906505U1; GB2348871B

Abstract

A delivery for a rotary printing press with a circulating conveyor system in which the sheets fixed in gripper closures are released while being deposited on to a sheet pile has a blown air device arranged above the sheet pile for assisting the sheet deposition. At least a part of the blown air unit (6) is variable in its position so that the distance between blown air unit (6) and the upper edge of the sheet pile can be increased. All or part of the unit may be swung upwards or may be raised as a whole by carrier elements. By constructing the delivery in this way, especially on a paper jam, prevents damage to the blown air device and the removal possibilities for waste sheets improved.

Description

DELIVERY FOR A ROTARY SHEET PRINTING PRESS This invention relates to a delivery for a rotary sheet printing press.

A delivery of this type is known from DE 34 13 179 C2 discloses a delivery for use in such a press and comprising an endlessly circulating conveyor system which releases sheets fixed in the gripper closure in the feed direction over a delivery sheet pile, so that the sheets are transported against front sheet stops and deposited on the sheet pile. Arranged across an area above the sheet pile is a blown air device known as a blowing frame. The blowing frame is constructed from several blowing tubes and fans which serve for the accelerated deposition of the sheets on to the sheet pile by means of blown air. The blowing tubes are linked with an air supply and can be subjected cyclically controlled to pulses of compressed air. The fans are, in contrast, controllable in their rotational speed. The blown air device is arranged fixed to the side frames. Disadvantageous in this connection is that on a paper jam in the delivery, the sheets can be trapped between the circulating gripper system and the fixed blowing frame. Not only are the sheets waste, but such trapping can lead to damage to components of the delivery.

A delivery for a rotary sheet printing press is known from DE-PS 1 963 712 which discloses, among other details, the use of take-off grippers fitted to the front stops of the sheet pile, denoted after-grippers therein.

The object underlying the invention is to create a delivery for a rotary sheet printing press, the press comprising a circulating conveyor system by which the sheets fixed in a gripper closure can be fed in a feed direction against a front stop and can be deposited on to a sheet pile, wherein the delivery comprises an essentially horizontally arranged blown air unit arranged in an area above the sheet pile in use and for assisting the sheet deposition, and wherein the height of at least a part of the blown air unit is variable to enable the distance between at least part of the blown air unit and the upper edge of the sheet pile to be increased.

If, when such a delivery unit is installed in a press, there is a paper jam at the delivery, lifting at least part of the blown air unit prevents damage to it as well as to any further components in the delivery, and improves the ease with which the waste sheet or sheets may be removed by providing easier access and more space.

The blown air unit is arranged in an area above a sheet pile, and can be constructed exclusively from blown air tubes or four fans or from a combination of fans and blown air tubes. This blown air unit is arranged essentially horizontally between the lower run and the upper run of an endlessly circulating conveyor system.

In accordance with the invention, at least part of the blown air unit is partially variable in its position, so that the distance between the blown air unit and the upper edge of the sheet pile on to which the sheets are being deposited can be increased. Stops are preferably provided to ensure that no part of the blown air unit is raised so high that it risks being impacted by the upper run of the circulating conveyor system.

A first advantage of the delivery with the blown air unit in accordance with the invention is founded in the fact that on a paper jam in the delivery, at least a part of the blown air unit is arranged so its position can be varied, particularly vertically, so that the distance between the blown air unit or parts of the blown air unit and the upper edge of the sheet pile can be increased. As a result of improved space conditions by means of the change in position, waste sheets can accordingly be more easily removed.

Furthermore of advantage is that on a paper jam, damage, particularly to the blown air unit and the gripper systems, can be avoided. If the delivery is additionally constructed with take-off gripper systems, damage is accordingly also avoidable here.

Further advantageous is that if a paper jam occurs in the delivery, the positional changes of the blown air unit can be triggered in the simplest fashion by the jamming sheet material itself. For example, in a further development, a sensor system is arranged preferably on the blown air unit for detecting the distance position of sheets to be deposited, which, using circuit technology, is linked with an actuation unit, e. g. a pneumatically activatable working cylinder, in order to change at least a part of the blown air device in its position, e. g. raise it if a sheet is misfed or jams.

A paper jam in the delivery can arise for several reasons. For example, a paper jam arises if the previously running sheet located in the deposition phase collides with a subsequent gripper system. The sheet material is jammed or trapped e. g. between the gripper system and the blown air unit, or between take-off grippers and blown air unit. In either case, a press stoppage may be automatically triggered and at the same time all or part of the blown air unit raised to enable easier removal of the jammed or misfed sheet.

The invention is explained in more detail with reference to some exemplary embodiments which are illustrated schematically in the accompanying drawings in which: Figure 1 shows a delivery of an offset sheet printing press, in side view, and with a blown air unit to assist sheet deposition, Figure 2 shows a first construction of a blown air unit, in side view, Figure 3 shows a second construction of a blown air unit in side view, and Figure 4 shows a third construction of a blown air unit in side view.

Referring to Figure 1, a delivery 1 in a rotary sheet printing press consists essentially of an endlessly circulating conveyor system 4 on which several gripper systems 3 are fitted for guiding sheets 2 each fixed in a gripper closure for transport from a final printing or finishing unit to a delivery pile. Arranged at the end of the delivery 1 as shown in Figure 1 is a sheet pile 5 on to which the arriving sheets 2, are deposited by means of conveyor system 4. In this connection, the sheets 2 are guided in the feed direction 9 past fixed preferably pneumatically operating sheet guiding units 8 and a format variable adjustable preferably pneumatically operated sheet guiding unit 10, braked at a format variable sheet brake device 7 and deposited against front stops 18 on to the sheet pile 5. For supporting the deposition process, there is arranged above this sheet pile 5 across an area an essentially horizontally arranged blown air unit 6 consisting of a combination of fans and blowing tubes. Unit 6 is merely schematically indicated in Figure 1. Details of possible constructions in accordance with the invention are evident from Figures 2 to 4.

In a first construction (Figure 2), the blown air unit 6 is essentially formed of two parts 11,12. Each part 11,12 has a combination of blowing tubes and fans with corresponding supply conduits. Part 11, arranged first in the feed direction 9, is arranged fixed in the delivery 1, preferably fixed on the press side frames.

The second, subsequently arranged part 12 is arranged variably in its position by mounting it on at least one hinge 14 fast with respect to the frame. This enables part 12 to be swivelled vertically e. g. into the position 12', so in this embodiment a part 12 of the blown air device 6 can be varied in its position to move it out of the region of a possible paper jam. The danger of paper jamming arises particularly in the region in front of the front stops 18 (above the sheet pile 5) so that, at least in this region, it is desirable that the part 12 of the blown air unit 6 is variable in its position. The part 12 is preferably constructed as a frame with fans and blowing tubes, with their electrical and/or pneumatic supply leads being sufficiently elastically flexible or movable in position to enable operation in the normal position (shown in full lines in Figure 2), or when in position 12'.

In a second construction shown in Figure 3, the blown air unit 6 is formed as a single movable unit 11,12.

The blown air unit 6 is preferably, as before, constructed as a frame with fans and blowing tubes. The blown air unit 6 is swivellably arranged at one end by means of at least one fixed hinge 14 fast with respect to the frame and located approximately above the sheet brake unit 7. The freely swingable other end of the blown air unit 6 is movable vertically against a stop 17 in order to avoid a collision with the upper run of the circulating conveyor system 4 (position 11', 12').

In a third construction (Figure 4), the blown air unit 6 is constructed again as a single part, denoted 11, 12.

Again, the blown air unit 6 is preferably constructed as a frame with fans and blowing tubes. In this embodiment, the unit 6 is supported on carrier elements 15 arranged on its ends which are vertically shiftable together, in each case element 15 being located in a guide 16 fast with respect to the frame (Figure 4, double arrow). Preferably analogously to the construction shown in Figure 3, a stop 17 is provided which-in order to avoid collisions-limits the upward travel of the blown air unit 6. This applies likewise for the construction in accordance with Figure 2.

As indicated in all of Figures 2 to 4, the invention can be rotary sheet printing presses where the delivery 1 has take-off grippers 13 for supporting the deposition of sheet 2 on to the sheet pile 5.

The mode of operation is as follows: If a paper jam arises in the delivery 1, then at least one part of the blown air unit 6 is moved in its position in the direction of the upper run of the circulating conveyor system 4. In this construction, only small masses of the blown air unit 6 have to be moved and by the positional change, the distance between at least the part 12 of the blown air unit 6 and the upper edge of the sheet pile 5 is sufficiently increased. The swivelling of the movable part 12 is limited in the vertical direction so that a collision with the upper run of the conveyor system 4 is prevented.

If the blow air unit 6 in accordance with Figures 3 and 4 is movable as a whole, then likewise its position is changed in the vertical direction of the upper run of the circulating conveyor system 4. In this connection, larger masses have to be moved.

The positional change of the or a part of the blown air unit can take place by means of the sheet material itself, or by actuation means connected to part of the unit.

For example, in the case shown in Figure 2, the portion 12 can in fact be lifted up by an incoming sheet of paper which jams between it and pre-gripper 13. In such a case, after removal of the paper jam, the blown air unit 6 (or rather part 12) lowers itself down automatically. If the movement of the blown air unit is effected positively by means of actuation means these can then be further actuated to return the unit to its normal position so that the rotary printing press can then be started up anew.

Claims

CLAIMS 1. A delivery for a rotary printing press, the press comprising a circulating conveyor system by which the sheets fixed in a gripper closure can be fed in a feed direction against a front stop and can be deposited on to a sheet pile, wherein the delivery comprises an essentially horizontally arranged blown air unit arranged in an area above the sheet pile in use and for assisting the sheet deposition, and wherein the height of at least a part of the blown air unit is variable to enable the distance between at least part of the blown air unit and the upper edge of the sheet pile to be increased.
2. A delivery according to Claim 1 wherein the blown air unit is constructed, seen in the feed direction, of a first portion arranged upstream part and a second portion arranged downstream, wherein the portion is arranged fixed in position and the second portion is mounted via a hinge fast with respect to the frame, arranged swivellably around the axis of the hinge to enable that the distance between the second portion and the upper edge of the sheet pile can be increased.
3. A delivery according to Claim 1 wherein the blown air unit is constructed in one piece and is linked at one end to a hinge arranged fast with respect to the frame in the region of a sheet brake device in such a fashion that the entire blown air unit is swivellable about the axis of the hinge in order to increase the distance between part of the blown air unit and the upper edge of the sheet pile.
4. A delivery according to Claim 1 wherein the blown air unit is constructed in one piece and is linked with carrier elements arranged on its ends which are each vertically shiftable in a third guide, enabling the blown air unit to be raised or lowered as a whole.
5. A delivery according to any one of Claims 1 to 4 wherein the vertical change in position all or part of the blown air unit is limited by a stop in order to avoid any part of the blown air unit coming into collision with the upper run of the conveyor system.
6. A delivery according to Claim 1 and substantially as hereinbefore described with reference to the accompanying drawings.
7. A sheet fed rotary printing press including a delivery according to any one of the preceding Claims.