Patent Application
20060070541
In turning configurations of sheet-processing machines, in particular printing machines, there is the problem that the grippers of the turning and storage drums follow different closing and opening times during turning from those during recto printing. As is known, these closing and opening times are generated by different control cams for verso and recto printing.
It is known from German patent DE 40 04 352 C1, corresponding to U.S. Pat. No. 5,136,946, for example, in order to initiate an opening and closing movement of the grippers, to dispose a carrier for the control rollers axially displaceably in such a way that, depending on the operating mode, the grippers can be brought into operative contact with two control cams disposed in parallel. For this purpose, the carrier is released, displaced into the desired position and detained there.
In the prior art according to German patent DE 40 04 352 C1, corresponding to U.S. Pat. No. 5,136,946, there is provision for a slide-shaped carrier to be drawn into the channel bottom by armatures and detained by friction. In this case, the holding forces act counter to the reaction forces of the cam rollers. For this reason, when the cam roller force is increased, for example when the turning configuration is configured for higher processing speeds, the holding forces also have to be increased.
In the known systems, an increase in the roller forces leads to deformations of the slide and therefore also to deformations and angular errors of the elements, such as, for example, toothing, fastened to the slide, in relation to the gripper bridge pinion. Such deformations and angular errors are detrimental to service lives and in the worst case may even lead to sheet transport problems.
It is accordingly an object of the invention to provide a device for changing over gripper control in a turning configuration of a sheet-processing machine which overcomes the above-mentioned disadvantages of the prior art devices of this general type.
With the foregoing and other objects in view there is provided, in accordance with the invention, a device for changing over a gripper control from recto printing to verso printing on a transfer device such as a drum or a cylinder of a turning configuration in a sheet-processing machine. The transfer device has channel formed therein. The device contains a control unit for actuating grippers, radial stops radially disposed in the channel of the transport device, spring-loaded force accumulators disposed in the channel, and an axially adjustably disposed slide carrying the control unit. The slide is guided axially displaceably in the channel of the transport device by the radial stops. In each operating state, the slide is pressed, free of play, against the radial stops by the spring-loaded force accumulators.
The object on which the invention is based is, therefore, to provide a device for fastening the gripper roller carrier, the device allowing a fault free detention of the slide even in the case of high cam roller forces.
It is a particular advantage of the invention that handling is also simplified at the same time. Whereas, in the prior art, it was necessary to set the tooth play between the toothed quadrant fastened to the slide and the gripper pinion disposed on the cylinder laboriously by washers which were introduced between the cylinder channel and slide, this measure may now advantageously be dispensed with, since easily accessibly, eccentrically adjustable stops are provided for mounting, thus appreciably simplifying handling during the mounting operation.
In an advantageous refinement, the slide has a two-part configuration, the two parts being coupled to one another only by one joint. This measure ensures a compensation of angular errors between the pinions and toothed quadrants.
A further advantageous measure is the configuration of a frictional coating between slide and cylinder, the frictional coating counteracting an axial displacement of the slide. The frictional coating is advantageously produced from, for example, EKA GRIP. Alternatively, positive fixing by a spring/ball system is provided.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a device for changing over gripper control in a turning configuration of a sheet-processing machine, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
Referring now to the figures of the drawing in detail and first, particularly, to
The sheet stack 8 lies on a stack plate 10 capable of being raised in a controlled manner. The extraction of the sheet 7 takes place from the top side of the sheet stack 8 by what is known as a suction head 18 which has inter alia a number of lifting and dragging suckers 19, 21 for separating the sheets 7 singly. Furthermore, a blowing unit 22 for loosening the upper sheet layers and tracer elements 23 for the stack follow-up are provided. For the alignment of the sheet stack 8, in particular of the upper sheets 7 of the sheet stack 8, a number of lateral and rear stops 24 are provided.
The sheet 7 conveyed through the printing machine 1 is conveyed from a supply cylinder 26 as far as the chain systems 27 of the delivery 6 by gripper-carrying cylinders and drums, a turning configuration for recto and verso printing being provided between the printing units 3 and 4. This includes a storage drum 28 and a turning drum 29. The turning drum 29 is adjustable in such a way that, during turning, grippers 31 take over the sheet 7 at its trailing edge from the storage drum 28, in contrast to recto printing. For this purpose, inter alia, the gripper opening and closing movement must take place differently from recto printing.
During recto printing, the gripper opening and closing movement is controlled by two control cams 32, 33 (
To change over the gripper opening and closing times, the control rollers 41, 42, which co-operate with the control cams 32, 33 during recto printing, must be brought into operative contact with the control cams 34, 36. For this purpose, the slide 37 is displaced axially until the control rollers 41, 42 come into operative contact with the control cams 34, 36. The end positions of an eccentric 76 limit the two end positions of the slide 37 and thus simplify the changeover. The pinions 48, 49 are configured with a width such that the toothed quadrants 46, 47 remain constantly in toothed engagement with the pinions 48, 49 (
The slide 37 is guided in the cylinder channel 38. The guide is formed by lateral stops 52, 53 which are screwed to the cylinder body 29. The stops 52, 53 each have a guide groove 54, 56 serving as a radial stop for guide elements 57, 58 which are disposed laterally on the slide 37. The stops 52, 53 are disposed in such a way that they absorb the operationally acting radial forces, for example centrifugal forces or roller forces, of the slide 37. The guide elements 57, 58 each have an eccentric adjustment 50, 55 for adapting the height or the radial position of the slide 37 with respect to the cylinder 29 or for setting the tooth play between the toothed quadrant 46, 47 and the pinion 48, 49. So as always to press the guide elements 57, 58 against the stops 52, 53 with a defined minimum force, a spring-supported plate 65 is used, on which the slide 37 can be moved axially with low friction by a roller 60. One or more helical springs 79 generating the spring force are supported in the cylinder channel 38 on the cylinder body 29.
To secure the slide 37 against undesirable axial displacement in the cylinder channel 38, it is sufficient to have a frictional layer (for example, EKA GRIP) which is applied to the underside of the slide 37 and/or to the bottom of a supporting device 74.
Alternatively, a device for detaining the slide 37 in the respective recto or verso printing position according to
If a detaining device 61, 63, 64 is arranged, the frictional coating is dispensed with.
The slide 37 is configured in two parts essentially over its axial length and the two parts are connected to one another only by a joint 73.
The supporting device 74 is screwed approximately centrally to part of the slide 37 in such a way that one end of the supporting device 74 is supported slidably on the channel bottom 38. By virtue of this measure, the slide 37 is supported height-adjustably in the middle and can thus absorb the forces which are applied in each case at the end of the slide 37 by the toothed quadrants 46, 47. By the height being adjusted, angular errors between the pinion 48, 49 and the toothed quadrant 46, 47 can be corrected. The normal force required for detaining the slide axially via the supporting device 74 is applied via the rod 66, the lever 68 and the tie 75.
In a preferred embodiment according to
This application claims the priority, under 35 U.S.C. §119, of German patent application No. 10 2004 048 111.3, filed Oct. 4, 2004; the entire disclosure of the prior application is herewith incorporated by reference.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2004 048 111.3 | Oct 2004 | DE | national |
