An installation for processing a web of plastic material

Abstract: In an installation for processing a plastic web plural work stations are disposed on an elongated beam (4). The web is provided with positioning holes cooperating with complementary pins in at least one work station. As the distance spacing allocated holes may vary due to shrinking the beam (4) may be bent about a transverse axis into a ring sector shape thereby adapting the pin distances to the actual hole distances.

Description: The present invention relates to an installation for processing a web of plastic material comprised of "uses" separated by a punch grid. The uses may be e.g. plastic cards, as credit cards, telephone cards, or so-called smart cards having an embedded chip. When processing such webs extreme accuracy requirements must be met. For this reason, the web may be provided with positioning holes punched into transverse straps of the punch grid. The holes mate with positioning pins provided in the individual processing stations so as to present the individual "uses" in proper report. EP 0 726 219 A falling within the terms of Art. 54(3) EPC and thus not being prepublished discloses a method to fabricate plastic cards wherein a substrate tape is perforated with evenly spaced holes, and when placed in a working station, positioning pins engage into the holes. The spacing between two sets of pins is then slightly increased thereby tensioning the tape without stretching it thereby providing for highly accurate alignment. Frequently, such cards are manufactured by laminating a plurality of films, the positioning holes then being utilized to bring the films together in proper report and to guide them through the laminating apparatus. The films are heated and pressed in the laminating apparatus and then cooled down. A web so produced undergoes a shrinking process thereby varying the spacing which separates the positioning holes. Even if the shrinking of, say, a few tenths of a millimeter for a card having a standard length of 86 millimeters is in the range of tenths percent this affects nevertheless the processing. Under certain conditions, a number of e.g. ten cards ("uses") may be present between two successive positioning pins while the holes inbetween are not utilized; the shrinking may then be great enough that the capturing range of the pins is left. There would be an obvious remedy to the problem discussed above, that is, to adapt the pin distance to the shrunk distance of the web holes. However, this means is not practical because the shrinking varies depending upon the material and may even vary when a fresh batch of one of the films is processed and even when it is supplied by the same supplier. Conventionally, the individual work stations of a processing unit through which the web travels are arranged on an elongated support, and the positioning pins are provided in each such station. It is an object of the invention to provide such a unit or installation wherein the distances spacing the pins can be easily and simply adapted to varying shrink dimensions. Instead of individually adjusting each pair of cooperating pins, according to the invention the adjustment is performed simultaneously for all pins, by elastically deforming the entire support of the work stations. Such a support may be a beam sufficiently solid and stiff to carry all the work stations. When producing chip cards, those stations may include a milling station where recesses are milled into the card, a further station where glew is dispensed into the recess, a still further station where a chip is placed into the recess, and so on. An elastic deformation of the beam by stretching does not appear a practical means of adjustment. In a preferred embodiment of the invention, therefore, the beam is bent about an axis extending perpendicular to the conveying direction of the web through the stations. The bending forces are substantially smaller than those which would be needed for linear stretching. Upon bending, the length of the neutral center line does not vary but the upper side of the beam is stretched while its lower side is compressed provided the bending center is below the beam. Thus, the pin distances of the work station mounted on top of the beam are increased upon bending. Preferably, the geometry of the bending means is adapted to the geometry of the beam such that the latter is bent -- at least approximately -- into the shape of a circular ring sector whereby the pin distances of all work stations are regularly increased. In a preferred embodiment of the invention, the (originally) horizontal beam is placed on two supporting elements which in turn are disposed on a base frame. At both ends of the beam, depending legs are mounted, the free ends of the legs being subjected to forces tending to bend the beam. Preferably, links are pivotably connected to the leg ends and extend towards one another. The inner ends of the links are connected to a power driven crank. Preferably, at the inlet end of the installation, the distance spacing successive pin holes is measured and the crank position is selected to adapt the beam to the measured values. The attached drawing is a schematic side view of the installation in question, the appliances for the various work stations not being shown. Two bearing brackets 2, 3 are mounted on a base frame 1. The vary beam 4 is loosely supported by brackets 2, 3. Depending legs 5, 6 are mounted on the ends of beam 4. In front of base frame 1 (or behind it, or in front and behind) links 7, 8 are pivotably coupled respectively to legs 5 and 6. The other ends of links 7 and 8 are pivotable coupled to crank 9. Crank 9 is mounted on the driven output shaft of gear means driven by a motor, not shown. By pivoting crank 9, pull forces are transmitted to legs 5, 6 via links 7, 8 and converted into bending torque acting on beam 4.

Claims: An installation for processing a plastic web comprising successive uses separated by transverse straps of a punch grid, said transverse straps being provided with positioning holes, said installation comprising individual processing stations mounted on a common support (4), each station being provided with positioning pins, said positioning holes mating with said positioning pins, said installation comprising means adapted to elastically deform said support (4) for simultaneous adjustment of distances spacing cooperating pins of all processing stations with respect to the distances spacing allocated holes of the web. The installation of claim 1 wherein said means are adapted to bend said support (4) about an axis extending transverse to a web travel path through said stations. The installation of claim 2 wherein said support (4) is a beam resting on two supporting elements (2, 3), depending legs (5, 6) being fixed on ends of said beam, and deforming forces acting on said legs (5, 6). The installation of claim 3 wherein links (7, 8) having a first and a second ends are coupled with their first ends to one leg (5, 6) each, said second link ends being coupled to a common power driven crank (9). The installation of claim 2 wherein actual hole distances are measured and said bending is controlled to adjust the pin distances to the hole distances. The installation of claim 3 wherein positions of said supporting elements (2, 3) and dimensions of said legs (5, 6) are selected such that said beam is bent to assume a shape of a ring sector.

Inventors: MELZER RAINER, MELZER ROLAND, MELZER, RAINER, MELZER, ROLAND
Applicants: MELZER MASCHB GMBH, MELZER MASCHINENBAU GMBH
Application year: 1996
Main classification: B65H23
IPC codes: B65H23, B42D15, B65H20