This application claims the priority, under 35 U.S.C. ยง119, of German Patent Application DE 10 2012 014 807.0, filed Jul. 26, 2012; the prior application is herewith incorporated by reference in its entirety.
The invention relates to a device for guiding sheets in a sheet-processing machine such as a printing press or diecutting machine. The invention also relates to a sheet brake, a diecutter and a printing press having the sheet guiding device.
U.S. Pat. No. 7,384,035 B2 discloses a sheet-guiding plate that has suction or blower nozzles to generate throttled suction air or throttled blown air. Each of the suction or blower nozzles includes a channel with multiple vortex chambers for generating throttled blown or suction air.
German Patent Application DE 1 917 616, corresponding to U.S. Pat. No. 3,659,839, discloses a sheet-guiding plate in the region of a sheet brake. Suction air is applicable to the sheet-guiding plate. Suction openings are provided to act on the sheet to be braked. The suction openings are closable in accordance with the operating cycle of the machine by using a control belt. An additional slide member is provided to allow a modification of the cross section of the suction opening.
It is accordingly an object of the invention to provide a sheet guiding device and a sheet brake, a diecutter and a printing press having the sheet guiding device, which overcome the hereinafore-mentioned disadvantages of the heretofore-known devices, brakes, diecutters and printing presses of this general type and which provide an alternative configuration for modification of a nozzle cross section in a sheet-guiding plate.
With the foregoing and other objects in view there is provided, in accordance with the invention, a device for guiding sheets in a sheet-processing machine. The device comprises a guide plate having blower or suction openings formed therein, a cover plate disposed parallel to the guide plate and having passages formed therein, a flexible intermediate layer disposed between the guide plate and the cover plate and having other passages formed therein, and throttle nozzles formed by the blower or suction openings in the guide plate, the other passages in the intermediate layer and the passages in the cover plate.
A particular advantage of the invention is that a nozzle cross section is adjustable. This feature permits adaptation of a suction or blower performance to different operating parameters such as the characteristics of the material to be processed or the machine speed.
In particular, the nozzle cross section may be enlarged for cleaning purposes. A particular advantage of the invention over the prior art is that no actuators are required to control the nozzle cross section because the nozzle cross section is automatically controlled in a particularly advantageous way through the operating pressure which is provided.
In accordance with an advantageous alternative, an additional control pressure is provided to control a nozzle cross section independently of the operating pressure. In this way, both throttled suction air and throttled blown air may be provided depending on the operating pressure.
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 sheet guiding device and a sheet brake, a diecutter and a printing press having the sheet guiding device, 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 drawings in detail and first, particularly, to
The sheet stack 8 rests on a main stack plate 10 that is liftable in a controlled manner. The sheets 7 are removed from the top of the sheet stack 8 by using a suction head 18 which, among other components, includes a number of lifting and dragging suction elements to separate the sheets 7. In addition, blower devices are provided to aerate the upper sheet layers and push buttons are provided to lift the sheet stack as needed. A number of lateral and rear stops are provided in order to align the stack 8 of sheets, in particular the uppermost sheets 7 of the stack 8 of sheets.
Sheet-guiding elements 21 in the form of sheet-guiding plates are provided to guide the sheets 7 in the region of the printing units 3, 4 or in the delivery 6, in particular at a sheet brake 19 provided for forming the stack.
The passages 27 are commonly connected to a pressure chamber 31, which is in turn connected to a pressure generator 32.
The control plate 26 is displaced to a greater or lesser extent to increase or decrease the volume of the pressure chamber 31 in a corresponding way, in dependence on an amount of operating pressure pB (pressure in the pressure chamber 31) provided by the pressure generator 32. The flexible intermediate layer 28 is compressed at an increased operating pressure pB, thus reducing the cross section of a throttle or throttle nozzle 30. This measure results in a throttling of blown air by increasing the operating pressure pB.
When the operating pressure pB is reduced, the flexible intermediate layer 28 displaces the control plate 26 in such a way that the volume of the pressure chamber 31 is reduced and the throttle cross section is increased. The blown air emerging from the throttles 30 may thus emerge from the nozzles 30 in a largely unimpeded way, allowing the throttles 30 to be cleaned at a low operating pressure pB.
An exemplary embodiment shown in
This measure allows the throttle cross section to be continuously adjusted independently of the operating pressure pB.
In order to generate throttled suction air, for example at the sheet brake 19, in a device in accordance with
Number | Date | Country | Kind |
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102012014807.0 | Jul 2012 | DE | national |