EP1588967A2 - Conveyor table - Google Patents

Abstract

Described is a Saugbändertisch 1 with endlessly guided around this suction belts 2. For the safe transport of sheet B on the Saugbändertisch 1 ventilation openings 6 are provided laterally of the suction belts 2. To avoid an inappropriate influence on the sheet transport due to too much or too little blowing air, the ventilation openings 6 are supplied individually or in groups with blast air. This can be transported on the suction belt table 1, the sheet B without great effort and disability wear-free on the suction belt table 1.

Description

The invention relates to a device according to the preamble of claim 1.

For feeding sheets to sheet processing machines, z. As sheet-fed presses, the sheets are first separated from the top of a sheet stack in a sheet feeder and offset from one another output as a sheet current. Furthermore, as a rule, after the separation of a sheet, its transport is required over a certain distance up to a contact area of the sheet-processing machine. Usually, the sheets of increased throughput are transported because of in a scale flow to the sheet processing machine. But it is also possible a single sheet feed. When transporting the sheets from the sheet feeder to the sheet-processing machine, therefore, so-called belt tables are in use, which allow a stream of sheets that are unterschuppt against each other, or even sheets safely. Particularly advantageous in this case are so-called suction belt tables. Suction tapes are below the bow leading top of at least one box-shaped cavity, are guided over the conveyor belts in the form of suction belts. Suction belts are usually in the form of apertured flat belts. For transporting the sheets over the suction belt table, the suction belts are driven by at least one shaft arranged at one end of the suction belt, a first so-called belt roller, deflected by a second shaft or belt roller at the other end of the suction belt table and kept in a straight position by a tensioning device , When transporting the sheet by means of the suction belts, a suction air supply is arranged for holding the sheet to the suction belts on the underside of the suction belt, by means of which the cavity is acted upon in the suction belt table. This suction air supply can be designed as a simple fan or as a blower connection.
Subsequent to the end of the belt table a so-called investment table is provided, are arranged on the front or top marks for aligning the sheet leading edge in the transport direction and a so-called side mark for lateral alignment of the sheet.
In the case of large-format sheet-processing machines, it has additionally become known to support the conveyance of the shingled stream of sheets over the belt table with the aid of additional conveyor belts laterally outside the effective range of the suction belts. These additional conveyor belts, also called support belts, are designed as simple flat belts and are not subjected to suction. The additional conveyor belts or support belts usually run around with the surface above the table surface around the belt table and thus facilitate the transport of the sheet in the outside of the suction belts resting on the belt table area.

The suction belt tables known in this way have various disadvantages. Because the laterally arranged additional conveyor belts depending on the sheet format in the Area of the edge of the sheet to be conveyed, it can be normal Sheet transport to disruptions. Therefore, a complicated lateral adjustment The conveyor belts will be required to remove these from the area of To remove sheet edges. This is especially important if the used for the page orientation of the sheet bow edge in the area of Transport belts comes to rest. There is a great danger that the bow edge hang in the direction of the page orientation on one of the conveyor belts remains and the arch warps during the shift. A proper orientation before feeding the sheet to the sheet processing machine is then not possible anymore. In addition, the auxiliary belts tend to sensitive sheets to scratch her bottom.

Furthermore, from DE 44 13 089 C2 discloses a method and an apparatus for unterschuppten supplying sheet-shaped substrates to a printing press known. Therein a conveyor table is described, the exhaust openings in the Has area between and next to the suction belts. This is supposed to be an airflow be generated against the conveying direction of the conveyor table to an adhesion or electrostatic charge of the underside led over the conveyor table Bow to reduce the surface of the conveyor table.

A disadvantage of the device is that the exhaust ports only punctually or linear in the front, the printing press facing area of the conveyor table are arranged. As a very disadvantage has been found that the outflowing Air is directed against the conveying direction of the conveyor table, since so the Leading edge of each arc is subjected to an air flow. This airflow acts particularly strong at the exit point. Therefore, the bow tend to be in this case to flutter because the blast air enters between the leading edges of the sheets.

The aim of the invention is therefore to improve the belt table so that the sheet transport can be designed easily in a safe way, in large formats No delivery resistances occur and the bends are not affected by the delivery process to be damaged.

The object of the invention is to further develop a generic belt table such that the sheet transport in every operating position, especially at the application of very large sheet sizes safely designed and easily readjusted can be at the same time eliminates the risk of scratching the bow shall be.

The solution of this task is designed according to the features of claim 1.

The conveyor table is at least in its lateral guide areas with a pneumatic Equipped for the production of a thin air cushion. These are Blasluftversorgungen and areal distributed blow holes in the Guided areas provided.

The solution to this problem is particularly advantageous in that the bowing without the use of lateral support bands and very simple Fashion is designed and readjusted. Besides, the bows will be so in a lot advantageously guided over the side table area without a risk Scratching on sensitive sheet surfaces. This is especially true for example, in film materials.

The establishment of a flat blown air supply can also be in the range between be provided the conveyor belts, so that here too the beneficial effect the scratch-free guidance comes into its own.

Advantageously, in the blowing openings so-called blow-suction nozzles be used. These are with blowing air under higher pressure but at one supply lower volume flow.

Excess air from the air cushion can be processed at the front of the bow Machine facing end of the conveyor table via special openings in the table surface can be removed from all leading areas. At the same time this can via aeration devices parallel to any suction belts used within the surface of the conveyor table done. A vent can also be active by suction respectively.

In the following, an embodiment will be described with reference to drawings the invention shown in more detail.

Figur 1

eine Gesamtansicht eines Saugbändertisches,

Figur2

einen Längsschnitt durch einen Saugbändertisch,

Figur 3

einen Ausschnitt aus dem Saugbändertisch und

Figur 4

eine Ansicht des Saugbändertisches von unten.

Show:

FIG. 1

an overall view of a suction belt table,

Figur2

a longitudinal section through a suction belt table,

FIG. 3

a section of the suction belt table and

FIG. 4

a view of the Saugbändertisches from below.

FIG. 1 shows a conveyor table or suction belt table 1. The conveyor table or suction belt table 1 has a box-shaped cavity 7, not visible here (see FIG. 2). About this cavity 7, one or more conveyor belts are guided in the form of apertured suction belts 2. The suction belts 2 are mounted on the two arranged in the transport direction and not shown here band rolls 4.1, 4.2 and driven. Furthermore, 2 arrangements of tension rollers 4.3 may be provided in the path of the suction belts. The cavity 7 in the conveyor table or suction belt table 1 is directly connected to a fan 3 (see Fig. 2) or by means of a vacuum hose with a fan and is vented from this. In this way, air is drawn through the suction belts 2 and their openings and each resting on the conveyor table or suction belt table 1 sheet B is held there firmly and moved in the stroke of the suction belts 2 forward.
Parallel to the suction belts 2 1 ventilation means may be provided in the conveyor table or suction belt table. These essentially serve to prevent suction air effects emanating from the suction belts 2 into the guide areas of the conveyor table or suction belt table 1 in addition to the suction belts 2.
Laterally of the suction belts 2, a guide region 5 is provided in each case in the outer region of the conveyor table or suction belt table 1. The guide areas 5 are made of low-friction material with possibly structured surface. The guide areas 5 serve to better guide the area of the sheet B overhanging outside the suction belts 2 on the conveyor table or suction belt table 1 - which grinds on the conveyor table or suction belt table 1. This is especially important for very large sheet sizes.
Furthermore, there is also a guide area between the suction belts 2, on which the sheets B are ground.

In the transport direction T, the sheet B in front of the conveyor table or suction belt table. 1 is usually a sheet feeder (not shown here) arranged in which the Bow B can be singled from the top of a pile of sheets. The bows B are then fed to the conveyor table or suction belt table 1 via a guide plate 11. On the in the transport direction T laxative side may be a sheet processing machine, e.g. a printing press, with a feed table 12 Connect to the conveyor table or suction belt table 1 as shown here. As part of the investment table 12 is a side mark 13 indicated. The page mark 13 leads the bow B with its side edge against a stop to the side Set position before the supply of the sheet B for sheet-processing machine. Another page mark 13 can also be on the opposite side the investment table 12 may be arranged.

In Figure 1, a further to be processed sheet B in its position in front of the Page orientation shown on the page mark 13. Visible is one edge B.1 used for this purpose approximately in the middle of the guide area 5. In the sheet transport over the conveyor table or suction belt table 1 but also in a Seitenausrichtbewegung in the direction of the arrow in the direction of the side mark 13 is the Bogen B so over a relatively large contact surface on the conveyor table or Suction belt table 1 to be moved.

In order to avoid obstructions which can lead to distortion B distorting the sheet B, ventilation openings 6 are provided in the conveyor table or suction belt table 1 in the guide areas 5 substantially over the entire area of the guide areas 5. These ventilation openings 6 can be designed as circular openings or as nozzle-shaped openings. In the embodiment as nozzles, they can be adjustable in their effective direction in the plane of the surface of the conveyor table or suction belt table 1 or relative to its surface. The blowing direction is essentially aligned in the transport direction T, but can also be oriented transversely thereto. The nozzles can also be designed as so-called blow-suction nozzles.
Furthermore, it can be provided that even in a central guide region 5.1 between the suction belts 2 distributed ventilation openings 6 or nozzles are arranged.

In Figure 2, the structure of the conveyor table or Saugbändertisches 1 is now shown in longitudinal section. Here, the ventilation openings 6 are shown only in the sectional view of Figure 3.
The supply of the ventilation openings 6 with blown air is carried out according to Figure 3, preferably in groups, but it can also be provided individually. For this purpose, individual or combined blast air feeds 8 and / or air chambers 9 are arranged on the underside of the conveyor table or suction belt table 1, but in the region of the guide areas 5. The air chambers 9 are then assigned again single or combined Blasluftzuführungen 8. On the other hand, the air chambers 9 can also be designed as part of the table surface of the conveyor table or suction belt table 1. In Figure 3, the air chambers 9 are arranged laterally of the cavity 7 for supplying the suction belts 2 with air. In the case of integration, the cavity 7 could extend over the entire table surface and the air chambers 9 can be separated from the cavity 7.

The air chambers 9 is associated with a common system of air ducts 8. Dashed line is the position of the fan 3 to supply the suction belts 2 with Suction air is shown through the cavity 7.

Preferably, as shown in Figure 2, the ventilation openings 6 within each of the guide portions 5 in parallel to the suction belts 2 arranged rows To be arranged. The blast air supply 8 may be in any shape for each row be summarized. Depending on the sheet format and the overlap of the Conduction areas 5, the Blasluftzuführung 8 to the rows of ventilation openings 6 are switched on or off. This is a control of the blast air supply 8 provided for example via electrically switchable valves 15 (see Figure 4). This control can be from the machine control when entering the sheet format can be influenced influenced.

It is also possible to have groups of ventilation openings 6 via air chambers 9 (10). To supply by means of the air chambers 9 (10) arranged fan with blowing air.

The arrangement and grouping of the air supply facilities may be for in middle guide area 5.1 between the suction belts 2 can in the same way as previously described, done.

FIG. 3 shows a section from the conveyor table or suction belt table 1 according to FIG. 2 shown. Shown is the table surface in the area of the guide area 5. In This guide area 5, the ventilation openings 6 are provided. To the conveyor table or suction belt table 1 is in the area of the ventilation openings 6 an air chamber 9 connected. This is parallel to the cavity 7 at the bottom of the conveyor table or suction belt table 1. To the air chamber 9 is a Blasluftzuführung 8 connected. The Blasluftzuführung 8 contains a switchable Valve 15 for switching on or off the blown air supply.

It is essential that the exiting blown air only a relatively thin layer, so to speak a film, forms on carrying air. It is also important that no blowing air between the Bow B enters. Therefore, the low pressure blast air is at the same time relative high volume to blow

The direction of the exiting the ventilation holes 6 blowing air can for Promotion of the bow B can be used in the transport direction T. Furthermore, at Alignment of the blowing direction of the ventilation openings 6 toward each other opposite lateral edges of the conveyor table or Saugbändertisches 1 or at an angle between 0 and 90 degrees to the direction of the outer edges the conveyor table or Saugbändertisches 1 a tightening effect on the sheets B can be achieved. The nozzles can for this purpose in their effective direction be executed individually or in groups adjustable.

To influence the airborne impact, the nozzles can also in their discharge angle made adjustable to the level of the conveyor table or suction belt table 1 be. For example, for heavy materials or materials with a relatively rough surface a steeper Ausblaswinkel be selected for the nozzles.

In Figure 4, the conveyor table or Saugbändertisch 1 is shown from below. Here, the cavity ventilating fan 3 is arranged centrally. Furthermore, the band rollers 4.1 and 4.2 for guiding the suction belts 2 (not shown here) are shown. Finally, groups of air chambers 9, 10 are arranged laterally of the fan 3.
At the top of the illustration air chambers 9 are arranged in two rows parallel to the transport direction T. These air chambers 9 each hold small partial surfaces of the guide regions 5 for air supply together. The size of these air chambers 9 can be varied, for example, in the transport direction T.
The air chambers 9 are provided with each other with a Blasluftzuführung 8. The one Blasluftzuführung 8 additionally has remotely controllable valves 15 (flaps) in order to limit the air supply volume or local or to be able to switch on or off.
At the bottom of the illustration air chambers 10 are arranged in a row parallel to the transport direction T. These air chambers 10 each hold larger partial surfaces of the guide regions 5 than the air chambers 9 for air supply together. The size of the air chambers 10 has been varied in the transport direction T.
The air chambers 10 are also provided with each other with a Blasluftzuführung 8. The one Blasluftzuführung 8 additionally has remotely controllable valves 15 (flaps) to limit the air supply quantity or local or to be able to switch off or on.
By means of the valves 15 so the air supply is controlled by an air chamber 9, 10 to the next possible. In addition, it may be possible, for example, to supply the foremost air chamber 9, 10 with increased air pressure. Depending on the arrangement of the valves 15 and their controllability various operating modes are possible.

On the whole, it goes without saying that all partial areas of the guide areas 5, the example of chambers 9, 10 coupled to each other ventilation openings 6, both similar and differently supplied with blast air become. It may therefore be that at the outer edges of the guide areas 5 a lower air pressure is set to avoid blowing up the edges. Likewise at the lying in the direction of transport T ends of the conveyor table or Saugbändertisches 1 a lower air pressure can be adjusted. In the same Way can also be an asymmetric pressure distribution over the surface of the conveyor table 1 can be set. The same applies to the attitude of the enforced Air volume, which should carry the bow B.

When submerged with carrying air, there may be problems in aligning the respective foremost sheet B in the area of the feed table 12 of the sheet-processing machine, for example a printing press, because the sheets B may not be secure against the alignment marks because of the air layer. Therefore, in the region of the outlet-side end of the conveyor table or suction belt table 1 near the transition to the feed table 12 following the guide areas 5 and 5.1, one or more arrangements of relief bores 14 can be provided. These relief holes 14 are preferably connected below the conveyor table or suction belt table 1 with the environment and depressurized. By means of the relief bores 14, excess carrying air can escape from the region below the foremost sheet B to be aligned. This ensures that the sheet B safely reaches all the required alignment elements in the feed table 12.
In addition, the guide areas 5 and 5.1 are vented in a simple manner along the suction belts 2, if the suction belts 2 ventilation devices are assigned to eliminate creeping suction, as described above.

Furthermore, the arrangement of the relief holes 14 also with an air discharge be provided to the still existing air cushion from the Actively remove area under the arch B The active air removal can be controlled be and be turned on and off in the bow clock.

Furthermore, the control of the air supply to the conveyor table or suction belt table 1 can be designed so that the blast air is switched off in the guide areas 5 and 5.1 during transport of the last to be processed sheet B sequentially from the inlet end to the downstream end. This avoids that the no longer fully lying under sheet B are lifted off the conveyor table or suction belt table 1 and are conveyed inaccurate.
For this purpose, 8 different controllable valves 15 are arranged in the Blasluftzuführungen in Fig. 4.

In operation, in the process of casserole of the first sheets B and Expiration of the last sheets B from the conveyor table or Saugbändertisch 1 respectively the just covered area, the valves 15 are opened or closed. This ensures that in the surface parts of the guide area 5, the is covered by bow B, still blowing air is blown. On the other hand, in the free or just released area the supply of blown air interrupted, so that individual sheets B are not excited to flutter.

Preferably in the case of transversely aligned nozzles in the running Area of the conveyor table or Saugbändertisches 1, the blown air to the exposed ends of the sheets B, i. at the beginning of the arc of the first sheet B or be strengthened at the bow end of the last bow B, so as the tightening effect of the on the bow B to increase temporarily. For this, the last nozzles can also be designed as so-called blow-suction nozzles. In blow-suction nozzles is due the special contour by the outflowing air in addition to the air cushion in addition achieved a suction effect, which limits the area of the blow-suction nozzle acts.

In an advantageous manner, nozzles in other surface parts or all Nozzles in the guide areas 5 and 5.1 be designed as a blow-suction nozzles. Blow-suction-nozzle are operated with higher air pressure at lower volume flow. Therefore, the air supply for the blow-suction nozzles can be separated from others Ventilation openings 6 take place. This can be done as described in a simple way done by a group arrangement.

With the features described a perfect transport is also very sensitive Sheet materials on conveyor table or Saugbändertische large areas possible. The invention may be further developed within the skill of the art become.

LIST OF REFERENCE NUMBERS

feed table

1

suction belt

2

Fan

3

bands roll

4.1

bands roll

4.2

idler

4.3

conducting region

5

middle guidance area

5.1

ventilation opening

6

cavity

7

blown air

8th

air chamber

9

air chamber

10

baffle

11

feed table

12

page brand

13

relief opening

14

Valve

15

bow

B

Scalloped

B.1

transport direction

T

Claims (24)

Device on a conveyor table (1), preferably on a suction belt table, for transporting sheet material in a submerged sheet stream from a sheet feeder to a sheet processing machine, in particular a sheet-fed rotary printing press, with one or more conveyor belts, for example suction belts (2) , which are drivable and endlessly guided around the conveyor table (1), with a blowing device which blows air under the sheet stream outside the guide region of the conveyor belts in the region of guide areas (5) of the conveyor table (1) arranged laterally and parallel to the conveyor belts.
characterized in that at least in the guide areas (5) on the outside of the conveyor belts (2) a plurality of substantially over the entire surface of the guide areas (5) distributed individual ventilation openings (6) is provided and that a Blasluftzuführung (8) provided is that it is at least partially coupled for ventilation openings (6), so that the guide areas (5) can be acted upon substantially in partial surfaces or over the entire surface with blown air. Device according to claim 1,
characterized in that ventilation openings (6) are provided in the guide areas (5) and / or in a central guide area (5.1) which is arranged between the conveyor belts (2). Apparatus according to claim 1 or 2,
characterized in that the ventilation openings (6) are designed as nozzles. Device according to claim 1,
characterized in that the ventilation openings (6) are designed as blow-suction nozzles. Device according to claims 1 to 4,
characterized in that the ventilation openings (6) are partially designed as a blow-suction nozzle. Device according to claims 3 to 5,
characterized in that the ventilation openings (6) in the region of the outlet-side end of the conveyor table (1) are designed as from the center of the conveyor table (1) respectively to the lateral edges aligned nozzles. Device according to claims 3 to 5,
characterized in that the ventilation openings (6) in the region of the inlet-side end and in the area in front of the outlet end of the conveyor table (1) as in the transport direction (T) of the conveyor table (1) aligned nozzles are executed. Device according to claims 1 to 7,
characterized in that the ventilation openings (6) as in their direction of blowing in the plane of the conveyor table (1) and / or relative to the plane of the conveyor table (1) individually or in groups adjustable nozzles is executed. Device according to claims 1 to 8,
characterized in that the ventilation openings (6) of each guide region (5) can be supplied together with blown air. Device according to claims 1 to 8,
characterized in that ventilation openings (6) of each guide region (5) in groups together with blown air can be supplied. Apparatus according to claims 1 to 10,
characterized in that the ventilation openings (6) are arranged parallel to the conveyor belts in rows and each row can be supplied together with blown air. Device according to claims 1 to 11,
characterized in that each individual ventilation opening (6) or grouped ventilation openings (6) is assigned an air chamber (9, 10) on the supply side, each ventilation opening (6) communicating with an air chamber (9, 10), and that each air chamber ( 9, 10) separately or that groups of air chambers (9, 10) are supplied together with blown air. Device according to claim 12,
characterized in that the air chambers (9, 10) are part of the conveyor table surface of the conveyor table (1). Device according to claims 1 to 13,
characterized in that in the region of the in the transport direction (T) lying downstream end of the guide area (5) or (5.1) of the conveyor table surface of the conveyor table (1) one or more relief openings (14) are provided by the excess air from the to be conveyed sheet (B) can flow below the conveyor table surface. Device according to claim 14,
characterized in that the discharge openings (14) are provided with an air discharge device. Device according to claims 14 and 15,
characterized in that the air discharge device of the discharge openings (14) sucks air and can be operated in the delivery cycle. Device according to one of the preceding claims,
characterized in that a control device is provided, by means of which after detection of the format of an arc to be processed (B) with respect to the position of the edges of the sheet (B) in their positioning within the guide areas (5) an actuating device for influencing the air supply can be controlled in that upon determination of an approach of the edge (B.1) of the sheet (B) to a boundary of an associated guide region (5) the air supply to ventilation openings (6) or groups of ventilation openings (6) can be switched on or off. Device according to one of the preceding claims,
characterized in that a control device is provided, by means of which an adjusting device for influencing the air supply is controlled such that when promoting the first or last to be processed sheet (B) on the conveyor table (1) the air supply to ventilation openings (6) or to Groups of ventilation openings (6) for the corresponding associated guide areas (5) is sequentially switched off substantially according to the freed area of the conveyor table or remains switched in the covered area of the conveyor table (1). Apparatus according to claim 18 or 19
characterized in that valves (15) are provided inside blast air supply lines (8), assigned to groups of ventilation openings (6) or to individual air chambers (9, 10) or to groups of air chambers (9, 10), and that the valves ( 15) by a controller depending on the operating state of the conveyor table (1) for switching on or switching off the air supply to the guide areas (5) or parts of the guide areas (5) are switchable. Device according to one of the preceding claims,
characterized in that the Blasluftversorgung depending on the type of printing material by basis weight and / or surface properties and / or air permeability and / or scratch sensitivity at least with respect to the feed pressure and / or the amount of air supplied is variable. Device according to one of the preceding claims,
characterized in that the blast air supply with respect to the location of the conveying surface within a guide region (5) at least in terms of the supply pressure and / or the amount of air supplied locally varies differently. Method for conveying sheets on a conveyor table (1), preferably on a suction belt table, in a subjacent sheet stream from a sheet feeder to a sheet-processing machine by means of one or more suction belts (2) which can be acted upon by suction and drivable and endless around the conveyor table (1) are guided around, wherein by means of a pneumatic device outside the guide region of the conveyor belts in the region of laterally and parallel to the conveyor belts arranged guide areas (5, 6) of the conveyor table (1) air is blown under the arc stream,
characterized in that at least in the guide areas (5) on the outside of the conveyor belts by means of a plurality of individual ventilation openings (6) substantially over the entire surface of the guide areas (5) a uniform air cushion is generated under the sheet flow, wherein by means of at least partially over Blasluftzuführungen (8) coupled ventilation openings (6) the guide areas (5) can be differently acted upon in partial surfaces with blown air. Method according to claim 22,
characterized in that in the guide areas (5) on the outside of the conveyor belts and / or in central guide areas (5.1) between the conveyor belts by means of a plurality of individual ventilation openings (6) substantially over the entire surface of the guide areas (5) a uniform air cushion is generated under the arc current, wherein by means of at least partially via Blasluftzuführungen (8) coupled ventilation openings (6), the guide areas (5) and (5.1) can be acted upon differently in partial areas differently with blown air. Method according to claim 17,
characterized in that in partial areas within the guide areas (5) or (5.1) by means of the Blasluftzuführungen (8) at the beginning of sheet conveying with the on the conveyor table (1) accumulating first sheet (B) in the transport direction (T), the blast air supply sequentially the overlap by the first sheet (B) is sequentially switched on until the supply of the entire guide areas (5) and / or that in the sub-areas within the guide areas (5) by means of the Blasluftzuführungen (8) at the completion of sheet conveying with that of the conveyor table (1) expiring last sheet (B) in the transport direction (T) the Blasluftzufuhr sequentially with the exposure through the last sheet (B) successively until the shutdown of the entire Leitbereiche (5) or (5.1) is switched off

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