APPARATUS FOR TILTING AWAY A PART OF A SIGNATURE TO BE SEPARATED FROM A RACK
An apparatus for tilting away a part of a sheet to be separated, in which apparatus a compressed-air supply is sufficient for operating the tilting sucker. To this end, the tilting sucker of the apparatus is assigned a vacuum generator which can be fed with compressed air and which generates a vacuum from the supplied compressed air.
1. Technical Field
The invention relates to an apparatus for tilting away a part of a signature to be separated from a stack, having at least one sucker which is arranged on a carrier and can be moved, preferably pivoted, by the carrier for tilting away a part of the signature to be separated, and having at least one supply channel in the carrier for supplying the respective sucker with vacuum.
2. Prior Art
In the print further processing of signatures such as individual sheets, covers or quires, individual signatures are to be pulled off from a stack of signatures. In the separation of the signatures which occurs in this way, first of all a part of the signature to be separated, in particular an edge strip or a corner region, is tilted away with respect to the stack. An apparatus of the type which is addressed here serves for this purpose, which apparatus is also known briefly as a tilting sucker in the specialist language.
An apparatus (tilting sucker) of this type is known which has a sucker which is held on a preferably pivotable carrier. The sucker can be loaded with vacuum via a supply line. The known apparatus requires an additional vacuum supply having a vacuum source. While compressed air is available everywhere, vacuum is not always present. Therefore, in order to operate the known apparatus, a vacuum supply having a vacuum generator has to be provided. Moreover, supply lines for compressed air and for vacuum have to be laid to the respective apparatus. Finally, suckers which are fed from a vacuum source are relatively loud.
BRIEF SUMMARY OF THE INVENTIONThe invention is based on the object of providing an apparatus for tilting away a corner or a strip of a signature to be separated, it being possible to load the sucker of the said apparatus with a vacuum in a simple manner.
An apparatus (tilting sucker) for achieving the abovementioned object has the features of an apparatus for tilting away a part of a signature to be separated from a stack, having at least one sucker which is arranged on a carrier and can be moved, preferably pivoted, by the carrier for tilting away a part of the signature to be separated, and having at least one supply channel in the carrier for supplying the respective sucker with vacuum, characterized in that the carrier is assigned at least one vacuum generator for providing the vacuum which is required by the respective sucker. As a result of the fact that the carrier is assigned at least one vacuum generator for the or each sucker, the required vacuum is generated, as it were, “in situ”. The carrier requires no vacuum supply and also no connection for the latter.
According to one preferred refinement of the invention, the at least one vacuum generator is configured in such a way that it generates a vacuum, that is to say a negative pressure, by using compressed air. The vacuum can therefore be formed by compressed air which is present in any case and is required in order to supply compressed air to other parts of the apparatus or to the machine which has the latter, for print further processing, for example to a collating machine, an adhesive binder or a cover feeder.
According to one development of the invention, there is provision for the or each vacuum generator to be supplied with compressed air, the amount and/or the pressure of which can be changed. In this way, the intensity of the vacuum can be changed. The vacuum which is present at the sucker can therefore be adapted to the requirements by being increased or reduced. The negative pressure at the sucker can be changed in a simple manner by a change in the compressed-air supply of the at least one vacuum generator by means of an adjusting throttle in the compressed-air supply line which leads to the vacuum generator or a plurality of valves which can be actuated individually in the compressed-air supply line. The compressed-air supply to the at least one vacuum generator can be changed in stages by opening all or only certain valves. The valves preferably have different cross sections for the passage of compressed air. Precisely graduated amounts of compressed air for supplying the or each vacuum generator can be set individually by targeted opening of a defined valve or a plurality of defined valves.
The vacuum generator is preferably provided on or in the carrier. The vacuum generator, that is to say the location, at which the vacuum is generated, is situated as a result in the vicinity of the sucker, at which the vacuum is required. In this way, the invention permits the shortest possible supply lines between the vacuum generator and the sucker. Only a relatively small amount therefore has to be evacuated, in order to generate a vacuum at the sucker. In known apparatuses of this type, the relatively long supply lines have a large internal volume which requires a great amount of air to be sucked away, until the long supply line is evacuated and a vacuum is available at the sucker. This has the consequence of high energy consumption and is also noise-intensive.
Furthermore, there is provision to supply a supply channel for feeding the or each sucker with vacuum from the vacuum generator which is assigned to the carrier. The vacuum can therefore be fed directly from the vacuum generator into the supply channel of the sucker. As a result, the supply channel can be reduced to a piece which is only very short. To this end, the respective vacuum generator is arranged on or in the carrier in such a way that it is as closely as possible to the sucker.
The or each vacuum generator is preferably configured as at least one vacuum pump. The vacuum pump is expediently one which operates according to the ejector principle. If a great vacuum or a large volume of air under negative pressure is required, it is appropriate to use a vacuum pump which operates according to the multiple-stage ejector principle. However, the invention can also be realized with other vacuum generators, in particular vacuum pumps which do not operate according to the ejector principle, but with moving parts, such as paddle wheels.
In particular, a vacuum pump which operates according to the ejector principle or the multiple-stage ejector principle is particularly compact and can therefore be arranged, according to one preferred refinement of the invention, in a receptacle in the carrier, which receptacle is configured as a simple blind hole or through hole. As a result, it is possible to accommodate the vacuum pump in the carrier in a particularly space-saving manner and the vacuum pump can be placed as closely as possible to the sucker in this way, above all, as a result of which only a short supply line having a low volume is required, with the result that only a small amount of air is to be evacuated out of the supply line in order to generate a vacuum at the sucker and, accordingly, only a relatively small amount of compressed air has to be used in order to generate the vacuum which is required for attracting by suction a part of a signature to be separated.
According to one preferred development of the invention, there is provision for it to be possible also to load the respective sucker with compressed air from time to time, in particular for a short period. As a result, rinsing and, in the process, cleaning of the supply channel, but also of the sucker, takes place. At the same time, the signature is separated from the sucker, which can be required if the surface of the signature still has slightly adhesive properties. Paper dust and/or release agent can also be eliminated by the cleaning of the sucker, before they can block the sucker or the supply channel which leads to it in an operational interruption.
The supply line can be fed for a short period with compressed air in order to load the sucker with compressed air. Here, it can be compressed air which passes into the carrier via the connection for feeding the vacuum pump with compressed air. There is then a valve in the carrier, which valve guides the compressed air alternately to the vacuum pump or directly to the supply channel of the sucker and, accordingly, either feeds the supply channel with compressed air directly or feeds the vacuum pump in order to generate a vacuum in the supply channel. However, it is also conceivable as an alternative to provide the carrier with a second connection for compressed air. One of the two compressed-air connections of the carrier can then optionally be supplied with compressed air by an external, separate controller or valves, to be precise firstly for feeding the vacuum pump and secondly for rinsing the sucker with compressed air.
The invention is also distinguished by a special method for achieving the abovementioned object. According to this method, there is provision for generating the vacuum for supplying the sucker from compressed air. As a result, a separate vacuum supply for the or each sucker is superfluous. One compressed-air supply is sufficient alone, the compressed air being converted according to the invention into a vacuum, with which the sucker can be fed.
One development of the method provides for a vacuum flow from compressed air to be accommodated within the tilting sucker, namely a carrier for the respective sucker which serves as a housing. In this way, the vacuum can be generated in the immediate vicinity of the sucker, as a result of which only an extremely short supply channel is required for loading the sucker with vacuum, which supply channel can be evacuated quickly on account of its shortness, as a result of which the vacuum consumption can be reduced considerably by the method according to the invention, in comparison with known tilting suckers.
Furthermore, there is provision, in terms of the method, for the sucker to be supplied briefly with compressed air after a corner or an edge region of the respective signature has been tilted away from the stack. Here, separation from the sucker of the signature to be separated is assisted and, at the same time, the sucker including the supply channel is cleaned. Contamination of the sucker and the supply line which leads to it with, in particular, adhesive residues is therefore avoided in a simple manner. As a result of the brief loading of the sucker with compressed air, which takes place periodically after each separating process, the tilting sucker does not need to have a filter, in contrast to known tilting suckers.
One preferred exemplary embodiment of the invention will be described in greater detail in the following text using the drawing, in which:
The invention relates to the field of print further processing. Here, these are devices such as collating machines, adhesive binders or cover feeders.
The respectively lowermost folded sheet 14 of the stack 13 is separated in a first step by the apparatus according to the invention which is configured as a tilting sucker 15 in the collating machine 10 which is shown here. An edge region 16 (it also being possible for it to be only a corner region) of the lowermost folded sheet 14 is tilted away from the stack 13 by the tilting sucker 15 (
In the edge region 16 which is tilted away by the tilting sucker 15, the folded sheet 14 is gripped by grippers (not shown) of a haul-off roll 19 and, as a result, the separated folded sheet 14 is transported away from the stack 13 to a collecting channel 20 which is shown in basic form in
The carrier 18 which is shown in
A supply channel for the sucker 17 is arranged in the interior of the carrier 18. In the exemplary embodiment shown, this is a supply hole 25 in the carrier 18, which supply hole 25 opens with an end region 26 into the retaining head 22 of the carrier, with the result that the supply hole 25 is open on the end side of the retaining head 22. The sucker 17 has a through hole 27 which corresponds with the end region 26 of the supply hole 25 in the retaining head 22 and opens into a suction face 28 of the sucker 17, which suction face 28 is shaped like a spherical cap and is set back concavely with respect to the retaining head 22 (
In a particular manner according to the invention, vacuum for the sucker 17 is formed from compressed air, by a vacuum generator which can be supplied with compressed air producing the negative pressure or the vacuum which is required for the sucker 17. In the apparatus according to the invention, namely in the exemplary embodiment shown, this vacuum generator is assigned to the tilting sucker 15 and the carrier 18.
In the present case, the vacuum generator is a vacuum pump. The latter operates according to the principle of an ejector which, when compressed air which flows through nozzles flows through axially, generates suction at the openings of the nozzles, as a result of which the jet of compressed air which flows through the nozzles attracts air by suction and, as a result, generates a vacuum. Both a single-stage ejector and a multiple-stage ejector are suitable as vacuum pump, depending on how great the vacuum requirement of the respective tilting sucker 15 is. In the case where the tilting sucker 15 should have a plurality of suckers 17, which is completely conceivable, a vacuum pump which is formed from a multiple-stage ejector is preferably used.
The vacuum pump 29 shown here has a substantially cylindrical design. The cylindrical vacuum pump 29 is mounted in the carrier 18 of the tilting sucker 15 and is therefore integrated into the tilting sucker 15. Here, the carrier 18 forms a housing which surrounds the vacuum pump 29. As a consequence of the cylindrical design of the vacuum pump 29, it is situated in a hole 30 in the carrier 18. The hole 30 is configured as a multiple-step through hole. The hole 30 has a threaded hole 32 which emanates from an end face 31 of the carrier 18, for screwing in a fixed or releasable connection of a compressed-air line (not shown). From this connection in the threaded hole 32, the compressed air flows through a central intermediate section of the hole 30 into an input side 33 of the vacuum pump 29. After the compressed air has flowed through the vacuum pump 29 in the longitudinal direction, the compressed air passes to the outside via the output end 34 of the vacuum pump 29 which opens into an outer side of the carrier 18, and is mixed there with the surrounding air.
The vacuum which is generated by the vacuum pump 29 passes from the vacuum pump 29 into a transversely oriented connecting hole 35 between the hole 30 for accommodating the vacuum pump 29 and the supply hole 25. The vacuum which is generated by the vacuum pump 29 is guided via a corresponding opening (not shown) in the circumferential face of the vacuum pump 29 via the transversely oriented connecting hole 35 into the supply hole 25 which extends parallel to the vacuum pump 29, and from there to the sucker 17.
The tilting sucker 15 shown here has a second threaded hole 36 in the end face 31, which second threaded hole 36 is situated next to the threaded hole 32 for supplying the vacuum pump 29 with compressed air. The threaded hole 36 is also provided with a releasable or fixed connection for a compressed-air line (not shown). The supply hole 25 opens into the threaded hole 36. In this way, compressed air can pass via the supply hole 25 directly to the sucker 17. This compressed air serves, after the end of a separation process, to clean the sucker 17, in particular its through hole 27, that is to say (in other words) to purge it with compressed air. For this purpose, compressed air is fed to the supply hole 25 briefly via the compressed-air connection which is assigned to the threaded hole 36. After cleaning, this compressed-air supply is closed again, with the result that no more compressed air can pass to the supply hole 25 through the connection of the threaded hole 36. A corresponding valve ensures that no air can pass into the compressed-air line through the compressed-air connection which is assigned to the threaded hole 36 via that end of the supply hole 25 which points towards this connection, nor can any air flow from the compressed-air line into the supply hole 25. In this way, a vacuum can be built up in the supply hole 25 and the connecting hole 35 despite the second connection for compressed air which serves to clean the sucker 17.
It can be seen in
The method on which the invention is based will be explained in greater detail in the following text:
The special feature of the invention consists in that, in an apparatus for tilting away a part of a signature to be separated, the tilting sucker 15 in the exemplary embodiment shown, the vacuum which is required for the sucker 17 is generated from compressed air. The compressed air is converted into vacuum in the immediate vicinity of the sucker 17 by at least one vacuum generator, the vacuum pump 29 in the exemplary embodiment shown. The vacuum pump 29 is assigned directly to the tilting sucker 15, and it is namely situated on or in the tilting sucker 15. The vacuum pump 29 is supplied with compressed air. When the compressed air flows through the vacuum pump 29, the latter generates a vacuum according to the ejector principle, which vacuum is guided through the interior of the carrier 18 to the sucker 17. The generated vacuum at the sucker 17 can be varied by changing the amount of compressed air which is fed to the vacuum pump 29 and/or the pressure of the said compressed air.
When the sucker 17 is moved towards the edge region 16 to be tilted away of the lowermost folded sheet 14, which movement takes place by pivoting of the tilting sucker 15, the compressed-air supply of the vacuum pump 29 is started. On account of the immediate vicinity of the vacuum pump 29 with respect to the sucker 17, only the relatively short supply hole 25 (also the connecting hole 35 in the exemplary embodiment shown) has to be evacuated, until vacuum is present at the central through hole 37 of the suction face 28 of the sucker 17. This is the case, as soon as the suction face 28 of the sucker 17 is in contact below the edge region 16 of the folded sheet 14. As a result, the lower edge of the edge region 16 is attracted by suction and, when the carrier 18 pivots back from the sucker 17, the edge region 16 of the lowermost folded sheet 14 is tilted away from the stack 13 which lies above it.
The vacuum supply of the sucker 17 is cancelled by interruption of the compressed-air supply to the vacuum pump 29 in temporal coordination with the gripping of the tilted-away edge region 16 of the folded sheet 14 by the haul-off roll 19. As a rule, the edge region 16 of the folded sheet 14 is released automatically as a result from the sucker 17, with the result that the folded sheet 14 can be transported further by the haul-off roll 19.
According to one preferred development of the method, the tilting sucker 15 shown is provided with a second connection for compressed air. This connection is assigned to the threaded hole 36 of the carrier 18. The sucker 17 can be cleaned with compressed air through the second compressed-air connection, the release of the tilted-away edge region 16 of the folded sheet 14 from the suction face 28 of the sucker 17 also being assisted.
The above-described purging of the sucker 17 by compressed air takes place after the edge region 16 of the folded sheet 14 has previously been attracted with vacuum by the sucker 17 and has been tilted away. In order to clean the sucker 17, the two compressed-air supplies of the carrier 18 are switched over. The compressed air which is required initially for supplying the vacuum pump 29 is fed to the carrier 18 through the first compressed-air connection (the threaded hole 32). After the edge region 16 has been tilted away, the said first compressed-air supply is closed and, instead, the sucker 17 is supplied briefly with compressed air via the second compressed-air connection (threaded hole 36) through the carrier 18, as a result of which the sucker 17, in particular the through hole 27 in its suction face 28, is cleaned pneumatically. In other words, the sucker 17 is cleaned according to the invention by purging with air. As soon as the cleaning process of the sucker 17 is ended, which only requires a few seconds, the second compressed-air supply (threaded hole 36) is also interrupted.
As soon as the next working cycle begins, that is to say an edge region 16 of a folded sheet 14 to be separated next is to be tilted away by the tilting sucker 15 in order to separate the next folded sheet 14 from the stack 13, the compressed-air supply of the first compressed-air connection (threaded hole 32) is opened again shortly before the underside of the edge region 16 is attracted by suction and, as a result, the vacuum pump 29 is again supplied with compressed air for a certain time, which compressed air is converted by the vacuum pump 29 into vacuum for supplying the sucker 17.
The invention is suitable not only for collating machines 10, but also for other machines for print further processing. While the tilting sucker 16 shown has one sucker 17 and one vacuum pump 29, it is conceivable to assign a plurality of suckers 17 to a tilting sucker for other cases of use, in particular for other machines for print further processing. The carrier of the tilting sucker can then also have a plurality of vacuum generators, in particular vacuum pumps 29. It is also conceivable to supply a vacuum to a plurality of suckers 17 at the same time from one vacuum pump. The vacuum pump 29 is then expediently configured as a multiple-stage ejector pump.
LIST OF REFERENCE NUMERALS
- 10 Collating machine
- 11 Feed station
- 12 Magazine
- 13 Stack
- 14 Folded sheet
- 15 Tilting sucker
- 16 Edge region
- 17 Sucker
- 18 Carrier
- 19 Haul-off roll
- 20 Collecting channel
- 21 Holding face
- 22 Retaining head
- 23 Constriction
- 24 Casing part
- 25 Supply hole
- 26 End region
- 27 Through hole
- 28 Suction face
- 29 Vacuum pump
- 30 Hole
- 31 End face
- 32 Threaded hole
- 33 Input side
- 34 Output side
- 35 Connecting hole
- 36 Threaded hole
Claims
1. Apparatus for tilting away a part of a signature to be separated from a stack (13), having at least one sucker (17) which is arranged on a carrier (18) and can be moved, preferably pivoted, by the carrier (18) for tilting away a part of the signature to be separated, and having at least one supply channel in the carrier (18) for supplying the respective sucker (17) with vacuum, characterized in that the carrier (18) is assigned at least one vacuum generator for providing the vacuum which is required by the respective sucker (17).
2. Apparatus according to claim 1, characterized in that the vacuum generator is configured for generating a vacuum from compressed air.
3. Apparatus according to claim 1, characterized in that the vacuum generator is assigned to the sucker (17).
4. Apparatus according to claim 3, characterized in that the vacuum generator is arranged in the vicinity of the sucker (17).
5. Apparatus according to claim 1, characterized in that the vacuum generator is arranged in the carrier (18).
6. Apparatus according to claim 1, characterized in that the carrier (18) has at least one compressed-air connection for supplying the at least one vacuum generator with compressed air.
7. Apparatus according to claim 1, characterized in that the amount of compressed air which can be fed to the at least one vacuum generator can be changed.
8. Apparatus according to claim 7, characterized in that the amount of compressed air which can be fed to the at least one vacuum generator can be changed by a plurality of valves which are to be actuated individually.
9. Apparatus according to claim 1, characterized in that the pressure of the compressed air which can be fed to the at least one vacuum generator can be changed.
10. Apparatus according to claim 1, characterized in that the supply channel of the at least one sucker (17) can be fed with vacuum which is formed by the vacuum generator.
11. Apparatus according to claim 1, characterized in that the supply channel for the at least one sucker (17) has as low a volume as possible.
12. Apparatus according to claim 1, characterized in that the supply channel for the at least one sucker (17) has as small a length as possible as a result of the vacuum generator being arranged as closely as possible to the sucker (17).
13. Apparatus according to claim 1, characterized in that the respective vacuum generator is configured as at least one vacuum pump (29).
14. Apparatus according to claim 13, characterized in that the vacuum pump (29) is arranged in a receptacle in the carrier (18).
15. Apparatus according to claim 14, characterized in that the receptacle for the vacuum pump (29) in the carrier (18) is configured as at least one hole (36).
16. Apparatus according to claim 13, characterized in that the vacuum pump (29) is configured as a vacuum pump (29) which operates according to the ejector principle.
17. Apparatus according to claim 1, characterized in that the respective sucker (17) can be loaded with compressed air for a short period in order to tilt a signature away.
18. Apparatus according to claim 17, characterized in that, in order to load the respective sucker (17) with compressed air, the supply channel of the sucker (17) can be fed with compressed air for a short period.
19. Apparatus according to claim 14, characterized in that the carrier (18) has an additional connection for compressed air, which additional connection opens into the supply channel for the respective sucker (17) and can be closed if required.
Type: Application
Filed: Aug 2, 2006
Publication Date: Nov 8, 2007
Inventor: Jutta R. Brorken (Wunstorf)
Application Number: 11/461,795
International Classification: B65H 3/08 (20060101);
