Method and system for cutting puzzle cut petals in belts

#This invention relates to electrophotographic printing machines. Specifically, this invention relates to electrophotographic printing machines having seamed intermediate transfer belts. These belts are made from flat sheets formed as a continuous belt using a puzzle cut joint.

#Electrophotographic printing is a well-known and commonly used method of copying or printing documents. Electrophotographic printing is performed by exposing a light image representation of a desired document onto a substantially uniformly charged photoreceptor. In response to that light image the photoreceptor discharges, creating an electrostatic latent image of the desired document on the photoreceptor's surface. Toner is then deposited onto that latent image, forming a toner image. The toner image is then transferred from the photoreceptor onto a receiving substrate such as a sheet of paper. The transferred toner image is then fused with the substrate, usually using heat and/or pressure. The surface of the photoreceptor is then cleaned of residual developing material and recharged in preparation for the production of another image.

#The foregoing generally describes black and white electrophotographic printing machines. Electrophotographic printing can also produce color images by repeating the above process for each color of toner that is used to make the color image. For example, the photoreceptive surface may be exposed to a light image that represents a first color, say black. The resultant electrostatic latent image can then be developed with black toner particles to produce a black toner layer that is subsequently transferred onto a receiving substrate. The process can then be repeated for a second color, say yellow, then for a third color, say magenta, and finally for a fourth color, say cyan. When the toner layers are placed in superimposed registration the desired composite color toner image is formed and fused on the receiving substrate.

#The system and method of this application are described in more detail below with reference to the attached drawing in which:

#FIG. 1 is a top schematic view of the precision cutter station of the system of this application;

#FIG. 2 is a front schematic view of the precision cutter station of the system of this application;

#The system of this application consists of an assembly of three process stations, which are positioned adjacent to each other and are mutually controlled by a main computer controller 14. The stations comprise a precision cutter 1, a pick and place mechanism 2, and a punch station 3. Each of the stations 1-3 sequentially processes a workpiece comprising a flat piece of belt material 17 having a length 1 and a width w. Since contamination of the belt surface is to be avoided, manual manipulation of the belt material 17 is minimized. In addition, because of the need for accurate dimensioning of the belt blank, accurate positioning of the belt material must be maintained. Station 1 cuts the blank of belt material to predetermined dimensions. The width and rectangular shape of the blank are cut to close tolerances, while a limited amount of extra material is provided in the length to facilitate later processing. Station 2 is mainly a transport to move the blank 17 from station 1 to station 3, but it also must maintain the material in position and in a taut condition for accuracy and to avoid damage. Station 3 is a punch press, which uses a pair of die and punch sets to accurately make the puzzle cut at both ends of blank 17. An example of a puzzle cut joint is shown in FIGS. 7a and 7b.

#Precision cutter station 1, as shown in FIGS. 1-3 and the block diagram of FIG. 8, comprises the first work station of the system. As illustrated in FIG. 2, this station is constructed with a cutting table 6 that includes a vacuum hold down system 7. A static blade is mounted on a platform 19 that is moveable in controlled X-Y motions above cutter vacuum table 6. Although a static blade has been found to effectively perform the required cutting steps, a rotating blade could also be used. As shown in FIGS. 1-3, the platform 19 is mounted for longitudinal movement in the Y direction on table 6, while the cutter blade (not shown) is mounted for transverse movement on the platform 19 to provide the X movement. The motion of the cutter is provided by any appropriate computer controllable means, for example stepping motors. A vacuum hold down is constructed in the supporting surface of the table 18. The vacuum may be applied to the belt material 17 by means of a series of orifices 34 drilled in the supporting surface. A pump 15 is connected to the table 18 and is designed to both evacuate a plenum 33 in the table 18 and to provide pressurized air to the plenum 33. In this manner an appropriate releasing force may be applied to assist removal of the blank 17.

#The cutter station 1 may be a commercially available stand-alone unit, such as the Blackman & White, Master Cut Model 2000. The computer control of the cutter station is integrated into the system of this application for common control.