Patent Application
20070257417
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.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202006000358.4 | Jan 2006 | DE | national |
| 202006005312.3 | Mar 2006 | DE | national |
