GB2322850A

GB2322850A - Sheet brake

Info

Publication number: GB2322850A
Application number: GB9804923A
Authority: GB
Inventors: Juergen Wenzel
Original assignee: MAN Roland Druckmaschinen AG
Current assignee: Manroland AG
Priority date: 1997-03-06
Filing date: 1998-03-06
Publication date: 1998-09-09
Anticipated expiration: 2018-03-06
Also published as: FR2760444B1; FR2760444A1; GB9804923D0; DE19758446A1; GB2322850B

Abstract

A suction brake for braking sheets 1 as they delivered from a printing press to a pile comprises a series of wheels 5 which, together with suction plates 7, can be individually moved across the printing width by motor-driven pinions 11 engaging a fixed rack in a housing 8. The housing prevents ingress of paper dust or powder, and this is assisted by a brush seal 15 at the front opening 14.

Description

SHEET BRAKE APPARATUS The invention relates to sheet brake apparatus in which axial adjustment of sheet brakes in a delivery of a printing press may be carried out A sheet brake of this type which can be adjusted axially even during print operation is known from DE 34 13 179 C2. In this connection, a sheet brake consists essentially of a suction body (suction wheel holder) with an air supply connection which receives a suction wheel arranged rotatably on a suction wheel shaft. Arranged at distances transversely to the sheet feed direction on the suction wheel shaft are several sheet brakes. To adjust the sheet brakes with reference to the transverse format and/or to print free channels during verso printing, by means of a drive adjustment motor with a pinion via a toothed rod extending axially between side frames, which are taken up on both sides (A and B sides) in guide slots for the longitudinal format adjustment, the suction bodies of the sheet brakes are individually adjustable on a guide cross-member arranged parallel to the toothed rod to the respective position. The relevant means for axial adjustment are freely accessible and can accordingly easily be contaminated.

Furthermore, from DE 40 35 035 C2 and DE 40 35 036 C2, further devices for the axial adjustment of suction rings in sheet brakes are known. In accordance with these documents, a shaft is constructed as an adjusting rod which is linked with a central adjusting unit. Arranged relative to the shaft is a pneumatically operating clamping device which, with corresponding control of the pneumatic cylinder, frees or fixes the sheet brake for axial adjustment (DE 40 35 036 C2). In a further development, a positioning motor is linked with the adjusting unit as well as with the adjusting rod.

Arranged on the adjusting rod is a guide carriage movable transversely to the sheet running direction with an access station and an identification unit. By means of the positioning motor, the steps for adjustment of the sheet brake are introduced. For freeing or fixing the sheet brake, a clamping unit is provided with a pneumatic cylinder (DE 40 35 035 C2). It is disadvantageous in the last-noted documents that very many parts are necessary for the axial adjustment and the construction is relatively complex. Furthermore, many movable parts are liable to failure since, for example, by paper dust or powder (from powdering units) the danger of contamination of the parts used is high.

According to the present invention, there is provided sheet brake apparatus for use in a sheet material delivery of a printing press, the apparatus comprising a plurality of sheet brake units arranged movably on a guide cross-member, the cross-member being movable on guide carriages in or counter to the feed direction of the printed material, extending transversely to the feed direction of the sheets, a toothed rod arranged parallel to the guide cross-member, a drive motor and drive block control or controller and associated with each sheet brake, each drive block including a pinion meshed with the toothed rod, and a housing surrounding the guide cross-member, the toothed rod, and the pinions, drive blocks and drive motors, the housing having a downstream opening running transverse to the sheet feed direction, through which the parts of each sheet brake within the housing are connected to the parts acting on the sheet material prior to its deposition on a delivery pile, and wherein the housing is releasably fixed on both sides to the guide carriages.

Such apparatus enables the axial adjustment of sheet brakes to be achieved while avoiding the noted disadvantages. As well as individual adjustment, the apparatus is preferably constructed to allow positioning of sheet brake units outside the printed areas of the print format. By locating the units partly in a housing, the danger of contamination is notably reduced and marking on the lower side of the printed material is eliminated.

The advantage of the invention is founded in the fact that as well as the adjustment of the sheet brake in the longitudinal format, also individual adjustment of the sheet brakes in the transverse direction (axial adjustment) can be effected also during print operation, wherein the relevant means for the axial adjustment are encapsulated in a housing so that the best possible protection against contamination such as, e.g. by paper dust or powder is guaranteed. Furthermore, the device requires only a small outlay in parts since a complex central adjusting unit as well as clamping and unlocking devices can be dispensed with. A further advantage consists in the fact that by the constructional arrangement, the individual adjustment of each individual sheet brake also permits "parking" of the sheet brakes outside of the printed image or of the maximum print format (transverse to the sheet feed direction). This is possible by the relatively narrow means used for construction for the axial adjustment as well as the housing extending sufficiently past the maximum print format.

The device for the individual axial adjustment of the sheet brakes is not limited to a sheet brake of construction as a suction roller. Rathermore, it is likewise suited for axial adjustment of sheet brakes with circulating pulling means, such as, for example, perforated belts or toothed belts.

The invention is illustrated by way of example with reference to an embodiment which is shown diagrammatically in the accompanying drawings, in which: Figure 1 a side view of a device for the axial adjustment of a sheet brake according to the invention Figure 2 shows in plan view an arrangement of sheet brakes in the region of the A side of a printing press Figure 3 is a diagrammatic side view of a sheet delivery with sheet brakes.

Referring to Figure 3, a sheet delivery 22 is arranged downstream in the feed direction 3 of a finishing unit, e.g. a varnishing unit on an offset rotary printing press for multi-colour printing. The sheet delivery 22 consists in known fashion of a circulating chain conveyor system 25 with gripper systems 2 arranged thereon. The gripper systems 2 transport sheets 1 in the feed direction 3 coming from the finishing unit past a fixed modularly constructed sheet guiding device 23 as well as a sheet guiding device 24 flexibly shiftably in or counter to the feed direction 3 past a multiple arrangement of sheet brakes 5 transverse to the feed direction 3 to the delivery pile 29 and deposits the sheet 1 against front edge stops 27 and rear edge stops 16. The sheet brakes 5 are analogously to the sheet guiding device 24 shiftable in or counter to the feed direction 3 (direction of movement 18) dependent upon the longitudinal format by means of guide carriages and a longitudinal drive 20, e.g. a threaded spindle. A controllable blowing device 26 is arranged in an area above the delivery pile 29 to support the deposition process of the sheet 1. The sheet delivery 22 is furthermore equipped with an auxiliary pile device 28 for non-stop pile change.

In accordance with Figure 1, a sheet brake 5 is illustrated which a suction wheel on a drive shaft 4.

Arranged upstream relative to the feed direction 3 relative to each sheet brake 5 is a suction plate 7 which serves for sucking on (catching) the sheet 1 fed by the gripper system 2. Sheet brake 5 and suction plate 7 have a suction channel wherein a suction channel can supply both constructional parts (5, 7) with suction.

Preferred, however, is that each constructional part (5, 7) has its own suction channel 6, as is evident from Fig.

2. The suction channels 6 are functionally connected with one or several suction sources 21 and are linked with the suction bodies (base bodies) of the sheet brake 5. Preferably the suction body of the sheet brake 5 and the suction plate 7 are constructed as a single part base body.

The separate air supply of sheet brake 5 and suction plate 7 has the advantage that the pressure conditions are individually controllable. Arranged below the sheet brake 5 are rear edge stops 16 which, during non-stop pile change or on lifting or lowering the main pile, are movable in the vertical direction 17.

Arranged parallel to the drive shaft 4 is a guide crossmember 9 (transverse to the feed direction 3). Both components 4 and 9 are received on the A and B side of the side frames 19 in each case in a guide carriage, wherein each guide carriage slot can be shifted with a longitudinal drive 20 in the direction of movement 18.

The longitudinal drive 20 is mounted in the side frame 19. The guide cross-member 9 carries the suction bodies of the sheet brake 5 and is received in a housing 8. The housing 8 extends between the side frames 19, especially between the guide carriages with longitudinal drive 20 transverse to the feed direction 3 of the sheets 1 and is movable together with the sheet brake 5, drive shaft 4 and guide cross member 9 for longitudinal format adjustment in the direction of movement 18 and connected releasably with the guide carriages. Within the housing 8, there is fixed to each suction body of a sheet brake 5 a drive motor 13 which is linked to a drive block 12.

Each drive block 12 carries a pinion 11 which is meshed with a toothed rod 10 arranged parallel to the guide cross member 9. In the present example, the toothed rod 10 is fixed to the housing 8, but analogously to this an arrangement on the guide cross-member 9 is also possible.

The housing 8 has in the feed direction 3 a housing opening 14 through which the suction body of the sheet brake 5 emerges from the guide cross-member 9 in the feed direction 3. The housing opening 14 extends over the entire width (transverse to the feed direction 3) of the housing 8, so that all sheet brakes 5 are adjustable in the transverse direction 30. Arranged on the housing opening 14 is a flexible seal 15. The seal 15 is constructed as a felt or foam material or in particular as a brush arrangement. Since the suction bodies of the sheet brakes 5 are of narrow construction, on each sheet brake 5 only a small region of the flexible seal 15 is displaced. The further elements (felt, foam, brush) of the seal 15 seal the housing opening 14 against contamination such as paper dust or powder sufficiently.

The drive motor 13 of each sheet brake 5 is linked by suitable circuit technology with a control or controller.

This can be a press control and/or a control desk computer (for control or regulation). Likewise, an input unit which can be carried by the operator can be linked via the machine control and/or the control desk computer with each drive motor 13. Preferably within the housing 8, an electrical lead connection system connected with the control/regulation is arranged with which each drive motor 13 is connected.

In Figure 2 only the region of the A side is shown, wherein the housing 8 is not illustrated for reasons of clarity. Evident are the sheet brakes 5 which are not taking part in the print "parked" parallel to the longitudinal drive 20. Only the individually illustrated sheet brake 5 (Figure 2, on the right) takes part in the print. The parking position is achieved in that within the housing 8, not necessary sheet brakes 5 can be moved on both sides in the transverse direction 30 outside of the maximum format of the material to be printed. This has the advantage that especially with verso printing, no danger of smearing off (or the danger of markings in the printed material) arises from not needed sheet brakes 5.

Depending upon the printed image (on verso printing), parking of not needed sheet brakes 5 is, in addition to all of this, possible within the maximum printed material format in print-free regions with the air supply cut off.

The movability in the transverse direction 30 is likewise usable when the mode of operation is recto printing.

The sheet guiding device 24 is preferably made from a plurality of flexible tubular guide elements arranged neighbouring one another and transverse to the feed direction 3, preferably of an elastomer or thermoplastics, wherein the guide elements have a plurality of small openings directed towards the underside of the sheet. The sheet guiding device 24 is linked with an air supply. Furthermore, the sheet guiding device 24 is arranged on the housing 8 or on the suction body of the sheet brake 6 so that the sheet guiding device 24 is adjustable at least in the direction of movement 18 dependent upon the format. If a guide element of the sheet guiding device 24 is arranged on the suction body of the sheet brake 5, then the guide element is additionally movable together with the sheet brake 5 in the transverse direction 30.

The mode of operation is as follows: Starting from the case that the adjustment in the direction of movement 18 correct for the longitudinal format, the adjustment of the sheet brake 5 to the transverse format is first undertaken. In the sheet delivery 22 there are arranged, for example, seven sheet brakes 5 in the format width of sheet 1. By choice exerted manually or from the control side, the selected drive motor 13 of the sheet brake 5 directly via the machine, the press control or with the inter-position of the control desk computer is activated so that via the drive block 12, the pinion 11 is set in rotational movement and moves in the transverse direction 30 towards the A or B side towards the respective side frame 19. In this connection, simultaneously the suction body of the sheet brake 5 is moved with it on the guide cross-member 9 and the drive shaft 4 including the suction plate 7 and the suction channel 6. The adjustment takes place, in this connection, to print-free channels as this is necessary on verso printing (the underside of the sheet 1 is freshly printed), or the sheet brake(s) 5 is/are adjustable to a parking position lying outside the maximum format width. Obviously each sheet brake 5 can be adjusted again out of the corresponding position into a freshly chosen or already once adopted position, e.g.

for the recto printing. Once the correct position is adjusted, the drive motor 13 is stopped. The pinion 11 which stands engaged with the toothed rod 10 is selflocking so that complex clamping devices can be omitted.

This mode of operation can be carried out for all seven sheet brakes 5 individually or in groups. Likewise, either manually or controlled, a fine adjustment, e.g. to print-free channels can be obtained.

During the adjustment of the sheet brake 5 in the transverse direction 30 during moving along on the guide cross-member 9 by the suction body of the sheet brake 5 projecting from the housing 8, the flexible seal 15 is deformed and after the passage of the suction body, the flexible seal 15 takes up again its original sealing function.

Claims

1. Sheet brake apparatus for use in a sheet material delivery of a printing press, the apparatus comprising a plurality of sheet brake units arranged movably on a guide cross-member, the cross-member being movable on guide carriages in or counter to the feed direction of the printed material, extending transversely to the feed direction of the sheets, a toothed rod arranged parallel to the guide cross-member, a drive motor and drive block control or controller and associated with each sheet brake, each drive block including a pinion meshed with the toothed rod, and a housing surrounding the guide cross-member, the toothed rod, and the pinions, drive blocks and drive motors, the housing having a downstream opening running transverse to the sheet feed direction, through which the parts of each sheet brake within the housing are connected to the parts acting on the sheet material prior to its deposition on a delivery pile, and wherein the housing is releasably fixed on both sides to the guide carriages.

2. Sheet brake apparatus according to Claim 1 wherein the housing opening has a flexible seal.

3. Sheet brake apparatus according to Claim 2 wherein the flexible seal is constructed as a felt and/or foam or as brushes.

4. Sheet brake apparatus according to any one of Claims 1 to 3 wherein in front of each sheet brake in the sheet feed direction is a suction plate projecting over the housing.

5. Sheet brake apparatus according to Claim 4 wherein each sheet brake and each suction plate has a suction channel arranged separate from the housing and linked with a suction source.

6. Sheet brake apparatus according to Claim 4 wherein each suction plate and each sheet brake has mutually separate suction channels which are linked with different suction sources.

7. Sheet brake apparatus according to any one of Claims 1 to 6 wherein each sheet brake comprises a rotatable suction wheel and the apparatus includes, arranged in front of the housing parallel to the guide cross-member, a drive shaft for the suction wheels.

8. Sheet brake apparatus according to any one of Claims 1 7 and wherein the transverse extent of the housing is sufficient to enable not needed sheet brakes to be moved in the transverse direction into a parking position in which each sheet brake still lies partly within the housing but is located outside the maximum format width of the material to be printed.

9. Sheet brake apparatus according to any one of Claims 1 to 8 wherein each sheet brake comprises a suction plate and a suction body coordinated to a suction wheel or belt, the plate and body being formed as one piece.

10. Sheet brake apparatus according any one of Claims 1 to 9 and including arranged within the housing, an electrical lead connection system enabling each drive motor to be connected to a control system or controller.

11. Sheet brake apparatus for use in a delivery of a printing press and substantially as hereinbefore described with reference to the accompanying drawings.

12. A printing press including sheet brake apparatus according to any one of the preceding Claims.