Cutting – Tool or tool with support – Joint or connection
Reexamination Certificate
2000-10-02
2003-11-25
Ashley, Boyer D. (Department: 3724)
Cutting
Tool or tool with support
Joint or connection
C083S659000, C083S678000, C083S332000, C083S393000, C083S397000, C101S226000, C101S136000, C270S021100, C493S367000, C493S324000
Reexamination Certificate
active
06651539
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to a perforating, grooving or punching apparatus for multi-color or single color sheet-fed rotary presses.
BACKGROUND OF THE INVENTION
Multi-color sheet-fed rotary presses comprise several printing and/or varnishing units, each of which is equipped with a rubber cylinder and an appertaining holding system for a blanket. The utilization of such multi-color, offset printing presses for perforating, grooving or punching of sheets is known in the prior art.
U.S. Pat. No. 3,554,070 which issued to Harry S. Boyd on Jan. 12, 1971 discloses a method of gluing perforation strips on a counter-pressure cylinder of a printing and/or varnishing unit and of using this to perforate a sheet supported by the elastic rubber blanket of the rubber cylinder. In this method the perforation strips must be installed on the poorly accessible and non-removable counter-pressure cylinder so that the tasks are difficult and time consuming. Also the correct position of the perforation strips on the built-in counter-pressure cylinder is difficult to find, so that expensive position corrections of the glued perforation strips before the start of priming are frequently necessary. This results in considerable set-up and installation times.
It is also a disadvantage with the Boyd method that the perforation strips are installed on the counter-pressure cylinder for only one print application and must then be removed once more. All the expenses for long setup and installation times and the costs of perforation strips are incurred again with a later print application with the same perforations.
In addition, the perforation strips press themselves into the rubber blanket of the rubber cylinder and cause abrasion with a negative contour so that such a relatively expensive rubber blanket can no longer be used.
A perforation in combination with a running printing is only possible in a non-printed area, since otherwise arching of the sheet and adhesion to the rubber blanket near the perforation strip occur so that the printing image is damaged. For a perforation in a printed sheet area, drying and an expensive additional passage through the machine is therefore necessary.
Furthermore, every sheet arches disadvantageously near the perforation because of impressions into the yielding rubber blanket so that the sheet output and stacking can be impeded considerably.
Printing presses with counter-pressure cylinders twice the size of rubber cylinders are also known. In these printing presses a double perforation form can be installed at still considerably higher cost, which is no longer economically sound.
Grooving forms cannot be produced by the above-described methods with satisfactory results, especially since printed sheets in particular become badly frayed in the area of the groove because of the yielding support in the rubber blanket.
Furthermore, DE-OS 23 41 326 discloses a method of gluing perforation strips on the rubber blanket of the rubber cylinder to perforate a sheet with this in the direction of the counter-pressure cylinder, whereby the counter-pressure cylinder is covered by a special, removable stretched foil/sheeting. To mount such a special foil/sheeting, foil holding devices are required on the counter-pressure cylinder so that said counter pressure cylinder can be converted from the normal printing process without a sheet to a perforation process with a sheet. The method described here can therefore only be used with presses with suitably equipped counter-pressure cylinders.
It is also a disadvantage here that the perforation form is removed after a print application from a relatively expensive rubber blanket that can normally be re-used and must again be installed for a later possible print application with the same perforation form. Since the perforation strips press into the relatively soft rubber blanket in this case during the perforation process, a print application and a perforation can be carried out with this arrangement in one machine passage only if the perforation can take place in a non-imprinted sheet area.
According to the description, the perforation strips are to be glued on the rubber blanket outside of the machine, i.e. when the blanket has been removed. Installation with the required dimensional precision is hardly possible in practice, since the position of the rubber blanket with the perforation form applied outside of the press can no longer be corrected after assembly in the press, and dimensional deviation of the outer contour of the raised perforation strips with a rubber blanket mounted cylindrically into the machine from the position of the outer contour when the rubber blanket lies fiat occurs. Thus, when attaching perforation strips on a rubber blanket outside the press, at least a rough dimensional precision must be achieved for the perforations, or the position of the perforation strips must be corrected at high cost in the press as in the previously mentioned method, so that no simplification or improvement can be achieved here in this respect.
This process is described especially in combination with a five-cylinder construction of the printing groups, whereby two rubber cylinders interact with a counter-pressure cylinder and wherein particular perforation lines crossing each other are to be attached to a rubber cylinder. This application is restricted to the special five-cylinder. construction.
Treatment profiles in multiple parts are known from the book printing industry in the form of a tint-printing process, and these consist of a first perforation, grooving or punching strip which can be glued on, of a connection layer connected in a detachable manner to same, and a counter-punch strip or counter-grooving strip connected to the former and also being detachable. Such a counter-punch strip or counter-grooving strip is serf-adjusting as it is placed on a counter-pressure plate during the first passage, and for this an adhesive surface with a pull-off protective foil is provided. For the further treatment of the sheets, the connection layer is pulled off and removed. Such perforation, grooving or punching processes are carried out at relatively slow speed in the book printing industry in separate machine passages. The known multi-part treatment profiles used for this have a large cross-section and it has been practically impossible to use them until now in combination with multi-color sheet-fed rotary, presses, in particular because of the yielding support yielding counter stops or the yielding counter-pressure application.
It is an object of the present invention to provide a perforation, grooving or punching device for multicolor sheet-fed rotary presses that will reduce the cost for such sheet treatment. This object is attained by the invention as set forth in claim
1
.
SUMMARY OF THE INVENTION
According to claim
1
the apparatus of the invention comprises a rectangular base plate made of a flexible and shape-retaining material on which can be stretched in place on a rubber cylinder instead of a rubber blanket by means of the blanket holding system. In addition a rectangular base foil/sheeting is provided which is made of a flexible and shape-retaining material, over which it is possible to stick embossed treatment profiles as perforation, and/or grooving and/or punching profiles corresponding to given perforation and/or grooving and/or punching forms. At least two attachment strips are provided on the base plate at a distance from each other (in the built-in state in the circumferential direction of an appertaining rubber cylinder), preferably in opposed marginal areas of the base plate, and the foil/sheeting can be detachably attached to opposed marginal areas by means of same in a stretched condition.
A great number of improvements and advantages are achieved with such a device:
The base plate can be installed very rapidly and easily instead of a rubber blanket on a rubber cylinder, since the blanket holding system provided on the rubber cylinder on the machine side is designed for rapid and easy replacement. Accordi
Eicher Friedrich
Füessl Detlef
Ashley Boyer D.
McNair Law Firm, P.A.
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