Patent Application
20050184452
It is known to provide leading edge stops for sheets that are to be deposited onto a stack in a deliverer of sheet processing machines. The sheets that are conveyed to the stack come into contact with the leading edge stops and thereupon come to lie exactly on the sheet stack.
As is known, the leading edge stops are disposed on a common crossmember—what is known as a leading edge stop shaft—and mounted so as to be pivotable, for example, about a rotational axis which is arranged below the leading edge stops.
Published, non-prosecuted German patent application DE 34 23 265 A1 (corresponding to U.S. Pat. No. 4,662,275) shows, for example, leading edge stops with a leading edge stop shaft lying underneath. Here, it is disadvantageous that bridging boards or rakes can be inserted only below the leading edge shaft, for example for nonstop operation, as the access to the upper stack region is impeded by the leading edge stops and the leading edge shaft.
It is known, for example, from German patent DE 195 07 370 C2 (corresponding to U.S. Pat. No. 5,697,605) to dispose the leading edge stops so as to be vertically displaceable.
It is accordingly an object of the invention to provide an apparatus for aligning sheets which are deposited on a sheet stack which overcomes the above-mentioned disadvantages of the prior art devices and methods of this general type, which offers the possibility of introducing auxiliary stack devices into the stack in the upper stack region, in particular for nonstop operation.
With the foregoing and other objects in view there is provided, in accordance with the invention, an apparatus for aligning sheets. The apparatus includes a common vertically displaceable leading edge shaft having support devices, leading edge stops disposed on the leading edge shaft, and an auxiliary stack carrier having a lifting device. The supporting devices of the leading edge shaft are disposed for being brought into operating contact with the lifting device for vertically displacing the leading edge shaft.
It is an advantage of the invention that the leading edge stops and the leading edge shaft are disposed such that they can be displaced upward vertically, as a result of which it is possible to free the upper stack region for the introduction of rakes or bridging boards for a nonstop stack change, while the function of the leading edge stops is maintained. In order to initiate the vertical displacement of the leading edge shaft, there is provision according to the invention for at least one supporting element, for example a rotatably mounted roller, to be provided on the leading edge shaft, which roller comes into contact with a component of the rake or of the bridging board in such a way that the leading edge shaft is raised in linear guides. In a first exemplary embodiment, the component is a run-up slope that is disposed on rake frames or bridging board frames.
In a second exemplary embodiment, there is provision for the leading edge shaft to be raised by a sensor-controlled actuator, preferably by a pneumatically acting operating cylinder.
Other actuators are of course conceivable, such as hydraulically actuable operating cylinders, actuating motors, etc.
In an advantageous refinement, a switch that can be actuated by the movement of the leading edge shaft is provided which brings the main stack lifting device to a standstill in the event of an undesirably great deflection of the leading edge shaft.
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 an apparatus for aligning sheets which are deposited on a sheet stack, 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 board 10 which can be raised in a controlled manner. The sheets 7 are removed from the upper side of the sheet stack 8 by what is referred to as a suction head 18 which, inter alia, has a number of lifting and dragging suckers 19, 21 for separating the sheets 7.
Moreover, blowing devices 22 are provided for loosening the upper sheet layers, and sensing elements 23 are provided for tracking the stack. In order to align the sheet stack 8, in particular the upper sheets 7 of the sheet stack 8, a number of lateral and rear stops 24 are provided.
The deliverer 6 has, inter alia, a main stack board 26 for accommodating a sheet stack 27. The sheets 7 are fed to the sheet stack 27 by a chain gripper system 28. Leading edge stops 29 are disposed on a stack leading edge 31 in the upper stack region and assist exact stack formation.
As shown in
In a second exemplary embodiment according to
In order to introduce the auxiliary stack device (rakes 42, 43), the sheet interceptor 53 is initially introduced into the stack region. The rake 42, 43 is introduced almost simultaneously into or over the main stack 27 by a horizontal displacement movement. Here, the run-up slopes 44, 46 come into contact with the rollers 38, 39 and lift the leading edge shaft 32. Here, the rollers 38, 39 roll on the upper side of the frame 43 that is configured as a control contour 54 (
This application claims the priority, under 35 U.S.C. § 119, of German patent application No. 10 2004 008 079.8, filed Feb. 19, 2004; the entire disclosure of the prior application is herewith incorporated by reference.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2004 008 079.8 | Feb 2004 | DE | national |
