This application claims foreign priority of DE 102004022889.2, filed on May 6, 2004, which is incorporated herein by reference in its entirety.
The invention relates to a system for driving a damping roller in a rotary printing machine. The rotary printing machine may have one or more printing units.
Damping rollers, as components of damping systems in rotary printing machines, have the task of transferring damping fluid to the printing plate. They not only keep the printing plate moist, but also remove excess water and continuously free the printing plate from dust and ink particles. These moisture-application rollers are particularly effective if they are driven at a rate different from that of the printing plate cylinder. For this reason, many rotary printing machines are offered with an option for switching from the normal operation (printing plate cylinder and damping roller have the same peripheral speed) to the so-called delta operation (peripheral speed of printing plate cylinder and damping roller are different).
Such a differential drive is known from U.S. Pat. No. 4,724,764. The damping roller, driven at a rate different from that of the surface of the printing plate cylinder, produces a wiping effect on the surface of the printing plate cylinder. This effect frees the cylinder from the deposits formed during the printing process. A damping system having a damping roller driven by the friction cause by the plate cylinder, and having an optional delta operation is described in DE 4414269 C2, wherein the plate cylinder is driven over the main driving gear train and the delta operation can be selected through two clutches.
EP 08 12 683 B1 discloses a driving mechanism for a sheet-fed printing press, for which the cylinders and drums are driven by a main drive motor over a common driving gear train, wherein at least the plate cylinder or the rubber cylinder, which is mechanically uncoupled from the driving gear train, is driven by an individual driving mechanism.
If the damping roller of a rotary printing machine is operated in the delta mode, that is, with a peripheral speed lower than that of the plate cylinder, the plate cylinder is acted upon by a braking moment. If the plate cylinder is driven by an individual driving mechanism and the damping roller is driven by a different motor, such as a main driving mechanism over the driving gear train, the plate cylinder motor, in the delta operation of the damping roller, must provide the frictional moment between the damping roller and the plate cylinder until the plate surface slips with respect to the damping roller. This moment can be very high, depending on the pressing settings.
Individual driving mechanisms of plate cylinders, while the damping system is driven by means of the driving gear train, accordingly have the disadvantage that, in order to realize the delta mode of operation, a very high driving power is required for the individual driving mechanism of the plate cylinder. Furthermore, there is a disadvantageous effect that, by supplying the power of the plate cylinder driving mechanism over the damping roller, the bracing in the driving gear train is decreased and, as a result, stable tooth flank contact is no longer assured.
It is therefore an object of the present invention to develop a driving mechanism for a damping roller, the plate cylinder being driven separately, in such a manner that the disadvantages of the prior art are eliminated.
This object is accomplished by a system and device for driving a damping roller in rotary printing machines in accordance with the present invention, wherein the cylinder, drums and rollers of at least one printing unit are driven over a continuous driving gear train of at least one main driving mechanism and at least one plate cylinder is not driven over the driving gear train. In the system and device of the present invention,
In accordance with another aspect of the present invention, the driving mechanism of the damping roller can be disconnected over a switchable transmission from the drive train for the second mode of operation and connected with the individual driving mechanism. The switchable transmission comprises
Alternatively, the switchable transmission comprises:
The switchable transmission may further comprise:
The present invention is directed to a system for driving a damping roller in a rotary printing machine, comprising a driving gear train; a plate cylinder having a printing plate, the plate cylinder not being driven by the driving gear train; a plate cylinder drive assigned to the plate cylinder, the plate cylinder being drivable with an individual driving mechanism of the plate cylinder drive; a damping roller which is drivable by the driving gear train, the damping roller making surface contact with the printing plate of the plate cylinder, the damping roller being drivable with a driving mechanism at a peripheral speed, which is approximately the same as that of the plate cylinder for realizing a first mode of operation, or at a peripheral speed which deviates from that of the plate cylinder for realizing a second mode of operation; wherein the damping roller can be connected with the individual driving mechanism of the plate cylinder drive. In the second mode of operation, the driving mechanism of the damping roller is disconnected over a switchable transmission from the driving gear train and connected with the individual driving mechanism of the plate cylinder drive. The plate cylinder drive may be synchronized with the driving gear train. The rotary printing machine may comprise at least one cylinder, at least one drum and rollers in at least one printing unit which are driven over the continuous driving gear train.
The switchable transmission comprises a plate cylinder drive shaft; an idler gear disposed on the plate cylinder drive shaft meshing with a gear of the driving gear train; a damping roller drive shaft; a damping roller driving gear disposed on the damping roller drive shaft and engages with the idler gear; a delta driving gear connected to the plate cylinder drive shaft, the delta driving gear engaging with the damping roller driving gear; a delta transmission gear; and a clutch disposed on the damping roller drive shaft, the clutch being unable to rotate independently but being able to shift axially, the clutch being able to in a first position, engage with the damping roller driving gear for the first mode of operation, in a second position, engage with the delta transmission gear for the second mode of operation, or in a third position, not be connected with either the damping roller driving gear or the delta transmission gear.
Alternatively, the switchable transmission comprises a plate cylinder drive shaft; an idler gear disposed on the plate cylinder drive shaft and meshing with a gear of the driving gear train; a damping roller drive shaft; a damping roller driving gear disposed on the damping roller drive shaft and engaging with the idler gear; a first clutch disposed on the damping roller drive shaft, the first clutch being unable to rotate independently but being axially displaceable, the first clutch being able to connect the damping roller driving gear with the damping roller drive shaft; a delta driving gear on the plate cylinder drive shaft so that it cannot rotate independently; and a clutch gear connected to the damping roller drive shaft. The switchable transmission may further comprise a clutch shaft; a delta transmission gear disposed on the clutch shaft; a second clutch disposed on the clutch shaft, wherein the clutch shaft can be connected with the delta transmission gear through the second clutch; an idler gear mounted on a frame of the rotary printing machine; a clutch gear mounted on the damping roller drive shaft, the clutch gear engaging with the idler gear, the idler gears meshing with the clutch gear.
The invention has the advantage that, when the driving mechanism of the damping roller is coupled with the individual driving mechanism of the plate cylinder, because of the difference in the transmission ratio between the rpm of the damping roller drive shaft and the rpm of the plate cylinder and between the peripheral speed of the damping roller and the peripheral speed of the printing block of the plate cylinder, bracing results between the damping roller and the plate cylinder as well as between their driving mechanisms. Thus, the frictional moment at the surface of the damping roller has a relieving effect on the driving mechanism of the plate cylinder and therefore, reduces the driving power required. By uncoupling the damping roller from the driving gear train, the frictional moment supplied by the driving motor of the plate cylinder is no longer passed onto the driving gear train of the system. Thus, the decrease in the bracing of the driving gear train is avoided.
The present invention can be better understood from the following description of preferred embodiments, taken in conjunction with the accompanying drawings. It should be apparent to those skilled in the art that the described embodiments of the present invention provided herein are merely exemplary and illustrative and not limiting. All features disclosed in the description may be replaced by alternative features serving the same or similar purpose, unless expressly stated otherwise. Therefore, numerous other embodiments of the modifications thereof are contemplated as falling within the scope of the present invention and equivalents thereto.
As shown in
As shown in
Normal Operation:
For operating the damping roller 6 in the normal manner, the clutch 8 is pushed in the direction of the damping roller 6 and engages with the damping roller drive the 61. Starting out from the driving gear train 7, the damping roller 6 is driven over the idler gear 71 and the damping roller driving gear 61. At the same time, the clutch 8 passes on the torque, which is transmitted from the idler gear 71 to the damping roller driving gear 61, to the damping roller drive shaft 62. The plate cylinder 1 is driven by the plate cylinder drive motor 9 over the plate cylinder drive shaft 11. The delta transmission gear 64 is likewise driven over the delta driving gear 63, but does not transmit any torque to the damping roller drive shaft 62, since the delta transmission gear 64 is not coupled to the clutch 8.
Delta Drive Operation:
In order to operate the damping roller 6 in the delta driving mode, the clutch 8 is pushed in the direction of the delta transmission gear 64 and engages with it. The damping roller 6 is now driven by the plate cylinder drive motor 9. At the same time, the torque is transferred from the delta driving gear 63 to the delta transmission gear 64. Due to the position of the clutch 8, the torque can be transferred to the damping roller drive shaft 62. The peripheral speed of the damping roller 6, required for the delta operation and deviating from the peripheral speed of the plate cylinder 1, can be achieved by selecting the appropriate gearwheel transmission ratio. The plate cylinder 1 is driven by the plate cylinder drive motor 9 over the plate cylinder drive shaft 11.
Friction Drive Operation:
The clutch 8 assumes an intermediate position. Torque is not provided either from the driving gear train 7 or from the plate cylinder drive motor 9 to the damping roller 6. The damping roller 6 is in contact with the plate cylinder 1 and is driven by friction.
The transmission diagram of
As shown in
The mode of operation of the system is determined by the positions of the two clutches 8.1, 8.2 in the following manner:
Normal Operation:
For operating the damping roller 6.1 in the normal mode of operation, the clutch 8.1 is pushed in the direction of the damping roller 6.1 and engages the damping roller drive gear 61.1. Starting out from the driving gear train 7.1, the damping roller 6.1 is driven over the idler gear 71.1 and the damping roller driving gear 61.1. At the same time, the clutch 8.1 passes the torque, transmitted from the idler dear 71.1 to the damping roller driving gear 61.1, onto the damping roller drive shaft 62.1.
The plate cylinder 1.1 is driven by the plate cylinder drive motor 9.1 over the plate cylinder drive shaft 11.1. The delta transmission gear 64.1 is also driven over the delta driving gear 63.1. However, it does not transmit a torque to the damping roller drive shaft 62.1, since the second clutch 8.2 is not engaged and thus, there is no connection between the second clutch 8.2 and the delta transmission gear 64.1
Delta Operation:
For operating the damping roller 6.1 in the delta driving mode, the clutch 8.1 is pushed in the direction of the coupling gear 824, with which it disengages. The first clutch 8.1 is disconnected from the damping roller driving gear 61.1. The second clutch 8.2 is moved in the direction of the delta transmission gear 64.1 and thus connects the delta transmission gear 64.1 with the coupling shaft 82.1. The torque, produced by the plate cylinder drive motor 9.1, is transferred over the delta driving gear 63.1, the clutch gear 822, the idler gear 823 and the clutch gear 824 to the damping roller drive shaft 62.1 and accordingly to the damping roller 6.1. The peripheral speed of the damping roller 6.1 necessary for the delta operation and deviating from the peripheral speed of the plate cylinder 1.1, can be achieved by the appropriate selection of the gearwheel transmission ratios. The plate cylinder 1.1 is driven by the plate cylinder drive motor 9.1 over the plate cylinder drive shaft 11.1.
Friction Drive Operation:
When both clutches are disengaged, torque is not transmitted from the driving gear train 7.1 or from the plate cylinder drive motor 9.1 to the damping roller 6.1. The damping roller 6.1 is driven by friction by the plate cylinder 1.1.
While various embodiments and individual features of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the present invention. As will also be apparent to those skilled in the art, various combinations of the embodiments and features taught in the foregoing description are possible and can result in preferred executions of the present invention. Accordingly, it is intended that such changes and modifications fall within the scope of the present invention as defined by the claims appended hereto.
Number | Date | Country | Kind |
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10 2004 022889.2 | May 2004 | DE | national |