Patent Application
20060080826
The invention relates to a mounting for a gripper system for the transport of sheets in a sheet processing machine, and contains a gripper shaft which is mounted in a gripper tube. The invention further pertains to a method for producing the mounting.
It is known, for example from German patent DE 43 17 429 C2 (corresponding to U.S. Pat. No. 5,588,773), to mount a gripper shaft such that it can be pivoted in a gripper tube enclosing the latter coaxially. For this purpose, use is made of bronze bushes that are bonded into the gripper tube.
In particular in the case of tongs grippers, there is the problem that both the gripper shaft and the gripper tube bear gripper elements that in each case have to be fixed to the gripper shaft and tube. Fixing the gripper elements to the gripper tube necessarily causes deformations of the gripper tube, which can impair the function of the mountings and thus lead to greater wear and bearing play caused thereby, as well as a shorter lifetime of the mountings.
It is accordingly an object of the invention to provide a sliding-surface mounting and a method of producing the mounting which overcomes the above-mentioned disadvantages of the prior art devices and methods of this general type.
With the foregoing and other objects in view there is provided, in accordance with the invention, a method for producing a pivotable mounting of a gripper shaft in a gripper tube in a sheet-processing machine. The method includes coating the gripper shaft with a release agent in a region of the pivotable mounting, fixing necessary components on the gripper tube, mounting the gripper shaft in the gripper tube, and introducing a liquid resin-hardener system between the gripper shaft and the gripper tube in a region of an envisaged bearing point.
A particular advantage of the invention is that a virtually play-free, low-wear mounting for a shaft/tube system as a functional element for a sheet holding system is provided, it being possible for components to be fixed to the tube with sufficiently high forces at the same time without exerting any disadvantageous effect on the shaft/tube mounting.
Advantageously, as a result of applying a coating of a release agent to the shaft, following the solidification of a liquid resin introduced between shaft and tube, the shaft remains rotatable, while the resin enters into a firm adhesive and/or form-fitting connection with the tube, which is roughened on its inside.
It has proven to be particularly advantageous if the components to be fixed are disposed on the tube before being filled with the liquid resin. Any pipe deformations that may arise in this case can then be compensated for by the resin.
As a result of supplying heat during the solidification of the sliding layer material (resin-hardener systems) or heating the shaft before the filling, a defined minimum play can be produced between the shaft and the tube by utilizing material shrinkage properties.
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 sliding-surface mounting and a method of producing the mounting, 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 rests on a stack board 10 which can be raised under control. The removal of the sheets 7 is carried out from the upper side of the sheet stack 8 by what is known as a suction head 18 which, inter alia, has a number of lifting and dragging suckers 19, 21 for separating the sheets 7. Furthermore, blowing devices 22 for loosening the upper sheet layers and sensing elements 23 for tracking the stack are provided. 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.
A number of sheet transporting cylinders is equipped with gripper systems and transport the sheets through the printing units 3, 4 as far as the deliverer 6. A turner device 26, for example, can be provided between two printing units 3, 4. In the exemplary embodiment, this contains a storage drum 27 with a turner drum 28 disposed downstream. The latter has what is known as a tongs gripper system 29.
The tongs gripper system 29 substantially contains a gripper shaft 31 and a gripper tube 32 enclosing the latter coaxially (
The sliding layer 33 for forming a pivotable bearing point between the gripper tube 32 and the gripper shaft 31 is formed as a resin-hardener system 33, which is introduced between the tube 32 and the shaft 31 in a liquid state and then cures. In order to be able to compensate for distortions of the tube 32, first, components such as the second grippers 36, stops, etc., are fixed to the gripper tube 32. The shaft 31 coated with a release agent is then disposed in the gripper tube 32 and the liquid resin-hardener system 33 is then introduced between tube 32 and shaft 31. For this purpose, the tube 32 has a roughened surface, which ensures good retention of the resin-hardener system 33, while the release agent on the shaft 31 ensures its ability to pivot with respect to the tube 32 and the cured resin-hardener system (sliding layer 33).
During the curing phrase of the resin-hardener system 33, by a specific supply of heat during the solidification of the sliding layer material 33 or heating the shaft 31 before the introduction of the sliding layer material 33, a defined minimum play can be produced by utilizing material shrinkage properties.
Of course, the invention can be used not only in tongs gripper systems but also in conventional gripper systems which need a sliding bearing to produce pivoting movements or between the gripper shaft and the stationary shaft or between a housing and the gripper shaft, in particular in sheet-processing machines, preferably presses.
This application claims the priority, under 35 U.S.C. ยง 119, of German patent application No. 10 2004 050 011.8, filed Oct. 14, 2004; the entire disclosure of the prior application is herewith incorporated by reference.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2004 050 011.8 | Oct 2004 | DE | national |
