초록 ▼

A die cutting press for processing web material is disclosed which is operable to provide very precise alignment of a reciprocable die cutting unit with each succesive area of the web to be die cut. In operation, the web is incrementally advanced toward the work station of the press until the area n

A die cutting press for processing web material is disclosed which is operable to provide very precise alignment of a reciprocable die cutting unit with each succesive area of the web to be die cut. In operation, the web is incrementally advanced toward the work station of the press until the area next to be die cut is substantially but not exactly in the die cut position thereof. The web feed is then placed in a creep mode to advance the web until an optical sensor determines the presence of transverse alignment indicium on one side of the web. Mechanism is thereupon actuated to rotate the die unit as required to bring the die assembly into alignment with related indicium on the opposite side of the web while effecting shifting of the web longitudinally thereof in a direction of travel as necessary to maintain die registration with the first sensed web indicium. Structure then shifts the die unit laterally of the web at the work station as required to bring the die unit into precise registration with longitudinally extending indicium on one side of the web. Only then is a defined area of the web subjected to the die cut unit. A cushion of air is provided for supporting the die unit while it is being rotated, during longitudinal shifting thereof in the creep mode, and as lateral shifting is accomplished with respect to the web. Extremely accurate is thereby accomplished registration of the die unit with the plurality of indicia associated with each area of the web subjected to the die cutting operation. Sensing of the presence or absence of alignment indicia on the web is preferably carried out through the use of photooptical devices associated with light transmitting flexible glass fiber bundles that direct light to the web as well as the light reflected therefrom back to the sensor mechanism. A microprocessor receives inputs from phototransistors to control operation of the die alignment and web advancement mechanism.

대표청구항 ▼

1. A die cutting press for web material having indicia on opposite, longitudinally extending sides thereof associated with each defined area of the web to be die cut, the indicia on opposed sides of the web which are related to a particular defined web area each being provided with a segment which e

1. A die cutting press for web material having indicia on opposite, longitudinally extending sides thereof associated with each defined area of the web to be die cut, the indicia on opposed sides of the web which are related to a particular defined web area each being provided with a segment which extends transversely of the web and at least one of the opposed, related indicia having a section disposed longitudinally of the web, said press comprising: a base platen defining a web material work station; means for mounting a die unit on the base platen below said power operated means in disposition for rotation about an upright axis and shifting of the die unit in a direction at least transversely of the path of travel of a web through the press; means for effecting rotation of the die unit on said base platen; power operated means shiftable toward and away from said platen; web backup means carried by the power operated means cooperable with the die unit to present a web processing work station therebetween; means for shifting the die unit transversely of an area of the web situated at said press work station; means for feeding the web material on an incremental basis to sequentially position successive defined areas of the web at said press work station; first sensing means movable with the die unit and having sensors positionable to sense the presence of indicia on opposite sides of web at said work station, said first sensing means being operable to determine the presence of a segment of an indicium which first presents itself to said first sensing means as the web is moved by the feeding means through a displacement to bring the next defined area of the web to said press work station; means controlled by said first sensing means and coupled to said web feeding means and to said die unit rotating means for effecting rotation of the die unit to an extent as may be necessary and in a direction to bring the segment of the opposed indicium related to be indicium segment first sensed by said first sensing means during movement of a particular defined area of the web to the press work station, into a location where such opposed, related segment is sensed as being present by the first sensing means, while continuing operation of the web feeding means to move the web longitudinally of the length thereof as may be necessary to maintain the presence sensing relationship between the first sensing means and the segment of the indicium which was first sensed by first sensing means as said next defined area of the web is moved to the press work station; second sensing means movable with the die unit and having sensors positionable to sense the presence and relative position to the second sensing means of the indicium section associated with a respective defined area of the web; and means controlled by said second sensing means and coupled to said die unit shifting means for effecting shifting of the die unit transversely of a respective defined area of the web to an extent as may be necessary to bring the section of a corresponding indicium into predetermined relative relationship to said second sensing means whereby the die unit is accurately positioned with respect to each defined area of the web moved into the press work station; and means for actuating the power operated means only after accurate positioning of a defined area of the web at said press work station has occurred. 2. A die cutting press as set forth in claim 1, wherein said indicia sensing means includes photooptical devices. 3. A die cutting press as set forth in claim 1, wherein is provided means for supporting the die unit on a cushion of air as the die unit is rotated about said upright axis. 4. A die cutting press as set forth in claim 1, wherein is provided means for supporting the die unit on a cushion of air as the die unit is shifted in a direction transversely of the web. 5. A die cutting press as set forth in either of claims 3 or 4, wherein said air cushion providing means is operable to provide said cushion of air between the die unit and said base platen. 6. A die cutting press as set forth in claim 3, wherein said die unit mounting means includes a rotatable support member carried by the base platen and engaging the die unit for restricting movement of the latter to rotation about said upright axis while the die unit is supported by said cushion of air. 7. A die cutting press as set forth in claim 6, wherein said rotatable support member is movable to a limited extent along the axis of rotation thereof while preventing lateral shifting the die unit. 8. A die cutting press as set forth in claim 4, wherein said die unit mounting means includes a channel-defining element carried by the base platen with the channel portion thereof oriented in a direction transverse of the path of travel of said web through the press, and a member coupled to the die unit and shiftable in said element with the direction of movement of the member and thereby the die unit being restricted by said element. 9. A die cutting press as set forth in claim 1, wherein said die unit mounting means includes a rotatable support member coupled to the die unit, a channel-defining element carried by the base platen with the channel portion thereof oriented in a direction transverse of the path of travel of said web through the press, and a block shiftably mounted in the channel portion of said element and supporting said member for rotation about said upright axis. 10. A die cutting press as set forth in claim 9, wherein said rotatable support member is movable to a limited extent along the axis of rotation thereof while preventing lateral shifting the die unit, there being selectively operable means for supporting the die unit on a cushion of air as the die unit is rotated about said upright axis. 11. A die cutting press as set forth in claim 10, wherein is provided three separate servomotors individually operable to advance the web toward said work station, effect rotation of the die unit, and cause shifting of the latter laterally of the web while supported on said cushion of air. 12. A die cutting press as set forth in claim 1, wherein said first sensing means includes a support coupled to said die unit adjacent the work station, means carried by said support for receiving and then conveying an indication of the amount of light reflected from a predetermined area of a web positioned at said work station to a location remote from the work station, and means responsive to said indication of the amount of light received at said remote location for sensing the presence or absence of an indicium on said web. 13. A die cutting press as set forth in claim 1, wherein said second sensing means includes a support coupled to said die unit adjacent the work station, means carried by said support for receiving and then conveying an indication of the amount of light reflected from a predetermined area of a web positioned at said work station to a location remote from the work station, and means responsive to said indication of the amount of light received at said remote location for sensing the presence or absence of an indicium on said web. 14. A die cutting press as set forth in claims 12 or 13, wherein said light receiving and conveying means comprises a bundle of flexible light transmitting glass fibers. 15. A die cutting press as set forth in claim 14, wherein said light receiving and conveying means also includes a series of flexible light transmitting fibers for transmitting light from said location to said work station for reflection from the web and conveyance of at least a portion thereof back to the location via said bundle of light transmitting glass fibers. 16. A die cutting press as set forth in claims 12 or 13, wherein said light receiving and conveying means comprises two separate units terminating in receptors adapted to be located adjacent the web in disposition to sense passage of an indicium therebetween, the receptors being spaced a distance such that a substantially equal amount of reflected light in received by each receptor of the pair thereof when a corresponding indicium is equidistantly positioned with respect to said pair of said receptors. 17. A die cutting press as set forth in claim 1 for use in processing web material wherein the segment and section making up one indicium on one side of the web each have opposed margins disposed such that bisecting imaginary lines therebetween are essentially at right angles to one another, and wherein said first and second sensing means each include a support coupled to the die unit adjacent the work station, means carried by a respective support for receiving and conveying an indication of the amount of light reflected from predetermined corresponding areas of a web positioned at said work station to a location remote from the work station, and separate means responsive to said indication of the amount of light received at each of said remote locations for sensing the presence or absence of a segment or section respectively of the indicia sensed thereby. 18. A die cutting press as set forth in claim 17, wherein said light receiving and conveying means each comprise two separate units terminating in receptors and adapted to be located adjacent the web in disposition to sense the presence or absence of a respective segment or section of said one indicium on one side of the web, each of the pair of associated receptors being located such that an imaginary line therebetween is in perpendicular relationship to a respective imaginary line bisecting a corresponding section or segment of said one indicium. 19. A die cutting press as set forth in claim 18, wherein each of said receptors is a bundle of flexible, light transmitting glass fibers, the bundles terminating in light receiving relationship at extremities all of which lie in essentially a common plane parallel to a plane through the upper surface of a defined area of the web at said press work station. 20. A die cutting press as set forth in claim 19, wherein said separate light responsive means each comprise a phototransistor.