1. Field of the Invention
The present invention relates to a method and to an apparatus for marking e.g. boardlike objects in a pile.
2. Description of Background Art
In the manufacture of various board products, such as e.g. chipboards, the board may be provided with a marking giving information such as manufacturer, type, date of manufacture of the board or the like. There are systems in which such a marking is made in an individual board, e.g. on an edge of the board. Systems are also known in which the marking is made on the edge of the boards while the boards are in a pile. The marking is produced using e.g. an ink jet print head or equivalent.
A drawback regarding the marking of boards is that the piles of boards may have air gaps between boards due e.g. to bending of the boards, a consequence of which is e.g. that the text is not always printed in the right place in the printing area and that the printing ink used for the marking may spread between the boards, staining the surface of the product. Because of the gaps, the height dimension of the pile is undeterminable.
The object of the present invention is to achieve a new type of method and apparatus for marking objects in a pile that make it possible to avoid the drawbacks of prior art.
The invention is mainly characterized in that, according to the invention, the boards in the pile of boards are pressed together especially to eliminate errors caused by air gaps between the boards. In a solution according to the invention, pressure is applied from the top of the pile of boards by using a pressing element that compresses the pile of boards by its own weight. In this situation, the pile is e.g. on a conveyor at a marking station.
In more definite terms, the invention is characterized by what is presented in the claims.
The invention makes it possible to achieve a substantial improvement of the print quality. In addition, the invention allows the pile height to be more accurately determined in the printing station because air gaps between boards have been eliminated.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
In the following, the invention will be described in detail by the aid of an embodiment example with reference to the attached drawings, wherein
The pile of boards 12 is brought e.g. on a chain conveyor 21 (
In addition to this, the frame part is provided with vertical guide bars 28 with a pressing element 30 fitted on them and moved vertically by means of an electric motor drive and cogged belts 29. The pressing element 30, typically weighing 100-150 kg, compresses the pile of boards from above in its edge area while the pile is on the conveyor. For this purpose, the electric drive is provided with a freewheel clutch mounted e.g. on its shaft, allowing the pressing element 30 to be first lowered with a restrained movement against the upper surface of the pack of boards 12 and then released so that it exerts a pressure on the pile of boards by its own weight. The movements of the pressing element are controlled by the control unit (not shown in the figure).
It is obvious to the person skilled in the art that the invention is not limited to the embodiment described above, but that it may be varied within the scope of the following claims. The compression of the pile of boards can also be effected using e.g. a hydraulic or pneumatic cylinder or similar actuating devices and their combinations. The pack of boards may also be compressed e.g. by placing a fixed stop above the pack and lifting the pack from below against the top stop e.g. by means of a scissor table. The pack may also be compressed by pressing it simultaneously from both the lower and upper surfaces and so on. The sphere of application of the invention is not limited to boardlike objects; instead, it can also be applied in the case of other objects of suitable shape.
Number | Date | Country | Kind |
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20011064 | May 2001 | FI | national |
This application is the national phase under 35 U.S.C. § 371 of PCT International Application No. PCT/FI02/00432 which has an International filing date of May 21, 2002, which designated the United States of America.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/FI02/00432 | 5/21/2002 | WO | 00 | 2/20/2004 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO02/09457 | 11/28/2002 | WO | A |
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1715167 | McDonough | May 1929 | A |
4043458 | Schott, Jr. | Aug 1977 | A |
4324519 | Moore | Apr 1982 | A |
4437655 | Bijttebier et al. | Mar 1984 | A |
5249917 | Neumann et al. | Oct 1993 | A |
5775397 | Lippincott | Jul 1998 | A |
6146084 | Doyle | Nov 2000 | A |
6529799 | Paulk et al. | Mar 2003 | B1 |
Number | Date | Country | |
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20040159253 A1 | Aug 2004 | US |