Patent Application
20140345401
The invention relates to a printing press, particularly a flexographic printing press in which the print roller is pressed against or pulled from the counter-pressure roller, and the screen roller is pressed against or pulled from the print roller and the ink roller is pressed against or pulled from the screen roller. At the same time, a wear-independent zero-backlash state between the spindle and the nut is preferred. Quick adjustment is always sought when greater clearances must be quickly bridged, such as for format changes or when the printing function is on or off. Fine adjustment is helpful when exact and even pressure is to be set.
Published application DE 10242009 comes closest to the proposed solutions for quick adjustment. It describes a printing machine in which for quick adjustment various spindles are coupled to shafts and provide various gear ratios.
Disadvantages of the existing solutions for quick adjustment are additional actuating, force transfer, bearing, and coupling elements. In addition, no sufficient precise predetermining of individual formats and no simultaneous automatic and manual operation are possible. The required space and the construction costs of the known solutions for additional quick adjustment are also very substantial. The necessary special adaptation to circumstances, in other words the lack of universality, is another shortcoming of the known solutions.
For that reason, the object of the invention is to find a universal solution with minimal construction costs and the least amount of required space, that can be manually driven or motor-driven, and at the same time is very rigid and not sensitive to external influences such as dirt.
The object is attained as follows according to the invention as in claim 1 and the following. The invention is a quick-adjustment device of printing press components to each other with an integrated fine adjustment for the exact positioning of each position as well as the optional zero-backlash state of each force transfer circuit. To save on space and components, the fine and quick-adjustment devices are located on a spindle. The precise fine adjustment of the printing press components while exposed simultaneously to high-stress loading preferably results by typical is drive train threads such as trapeze or ball screw spindles or a combination of various threads. Critical are low friction loss and the possibility of zero backlash in the direction of movement. To be able to implement a quick adjustment by means of threads, a large pitch and thus generally an appropriate diameter are necessary. A large spindle diameter is also necessary for the transfer of high forces and a solid construction. For especially large pitches, multiple screwthreads are provided. To execute the fine adjustment, they are on a threaded spindle that can optionally also consist of multiple parts, at least two different pitch sections into which nuts with a corresponding identical pitch engage. For the fine adjustment, one turns the threaded spindle, or synchronously nuts A and B. The distance change of the nuts to each other corresponds per rotation only to the pitch difference between pitch parts A and B. This applies in both movement directions. Of these systems, several may be stacked on top of each other, as well as nested in each other or they may be coupled to each other rigidly, in a force-dependent manner, in an elastic manner, and/or detachably. For eliminating backlash, it is proposed to use, between nuts A and B or the components force-limited by the actuators, such as springs, cylinders, and so on. In addition, it is proposed to eliminate backlash by bracing the nuts against each other in a slotted or divided and elastic manner. Zero backlash is then also maintained in the event of wear and heat expansion.
An exemplary embodiment is further explained below by means of drawings.
The views show the particular type of quick-adjustment device or quick displacement and alternatively the exact fine adjustment of the print roller relative to the counter-pressure roller and the screen roller relative to the counter-pressure roller, for example for format changes. In the same way, additional components or rollers can be positioned, such as the ink roller to the screen roller. The rollers are driven together or individually. Between the base frame, the slide, and the bearing blocks, there are guides that absorb the transverse forces and torques and impose an exact movement direction. The guides are equipped with clamping or fixing elements so that the base frame can be interconnected to the slide and bearing blocks in a force- and/or form-locking manner. For the exact repetition of positions, stops can be set near the guides.
For a stable connection between the rollers and for good force transfer, thick spindles with correspondingly large threads and consequently large pitches are proposed. The large pitch means that a large distance can be covered with few rotations, which means a very fast adjustment of the distances.
This quick adjustment takes place when the spindle with pitch part B rotates in nut B and nut A seated in the slide rotates in the slide and is firmly seated on a pitch part A of the spindle. The firm seating on the spindle results for example from spreading of the slotted nut by means of the machine element. With each rotation of the spindle, or of the nut B, the distance between counter-pressure roller and print roller is changed corresponding to a step of 4 mm for example. For the fine adjustment, the nut A is no longer firmly seated on the pitch part A of the spindle, but in the slide. This occurs for example by actuating the same machine element oppositely as for clamping on the spindle by which the machine element seated in the nut no longer acts on the spindle but on the slide. Now, the spindle moves both in the nut A as well as in the nut B. The distance change between the counter-pressure roller and the print roller thus amounts only to the difference of the pitch parts A and B, in other words for example only 0.1 mm per rotation.
One can also proceed similarly for all other components of the printing press that have a relatively variable position allocation.
Should quick adjustment occur centrally for example for a format change, and should the fine adjustment occur manually, then for example all of the nuts A or B for adjusting the print rollers and the screen rollers are interconnected by drive elements, such as articulated shafts, belts, chain gear wheels. The manually driven or motor-driven torque introduced at a location is sufficient to create the format-dependent distances between the counter-pressure roller, the print roller, and the screen roller of an inking unit or an entire printing tower.
There are many additional possible drive combinations depending on where the larger pitch is, whether the spindle or both nuts are driven, or one spindle with a nut is driven.
The zero-backlash state between a nut and the spindle as well as between nuts and a base element, slide, and bearing block results for example by dividing the nut. At the radial dividing point for example, the nut has ramps running across the angle of rotation, with for example the same pitch as the thread, which change, with the angle of rotation, the distance of the nut parts. One part of the nut is secured against rotation, while the other part can rotate and is engaged by the friction torque or spring torque until zero backlash exists between the housing walls and the thread turns. Backward movement in a reverse direction of rotation is prevented by a fine grating on the ramps or a commercially available backstop in the form of an eccentric roll body.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2012 000 752.3 | Jan 2012 | DE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/DE2013/000020 | 1/16/2013 | WO | 00 | 7/17/2014 |
