Patent ID: 8146494
Filing Date: 2012-04-03
Classification: B26D,B26F,B41F,B44B

Abstract:
1. A graphic arts die assembly for mounting on a graphic arts impression apparatus, said assembly comprising: a die plate formed at least partially of ferromagnetic material and including a die; and a chase including a plurality of magnet assemblies disposed along an engagement surface thereof, said die plate and magnet assemblies being configured to provide a magnetic coupling force for selectively securing the die plate to said engagement surface of the chase such that relative movement between the chase and the die plate is restricted during such magnetic securement, said chase including an actuatable releasing assembly operable to exert a disengagement force in opposition to the magnetic coupling force so as to selectively lift the die plate from the chase when the releasing assembly is actuated, thereby releasing the magnetic securement between the chase and the die plate and facilitating relative movement between the plates, said releasing assembly comprising a shiftable element with a die plate engaging portion operable to move between a recessed position, wherein the die plate engaging portion of the shiftable element is below the engagement surface of the chase, and an extended position, wherein the die plate engaging portion of the shiftable element extends above the engagement surface of the chase, said releasing assembly further including a drive system to move the shiftable element to the extended position, said disengagement force being exerted by the die plate engaging portion of the shiftable element when moved to the extended position, with the die plate engaging portion pushing upwardly against the die plate to lift the plate, said shiftable element comprising a reciprocating piston, at least part of which defines the die plate engaging portion, said drive system including a pressurized fluid manifold within the chase to associate a pressurized fluid with the piston, such that the pressurized fluid is caused to provide an extension force that urges the piston into the extended position, said chase further including a plurality of alignment assemblies to facilitate disposition of the die plate on the chase in aligned registration, each alignment assembly comprising a reciprocating pin with a die plate aligning portion operable to move between a projecting position, wherein the die plate aligning portion of the pin projects upwardly from the engagement surface of the chase, and a retracted position, wherein the die plate aligning portion of the pin is below the engagement surface of the chase, each of said alignment assemblies including a pin stop disposed within the chase, such that contact between the stop and a corresponding portion of the pin defines an uppermost projecting position and restricts further upward movement of the pin, each of said alignment assemblies further including an activation spring to bias the pin toward the projecting position against the pin stop; and an actuatable return system to move the pin to the retracted position, said return system including the pressurized fluid manifold configured to associate pressurized fluid with at least a portion of the pin, such that the pressurized fluid is caused to provide a retracting force that urges the pin into the retracted position, whereby said manifold causes the pressurized fluid to simultaneously move the alignments pins downward to the retracted position and move the pistons upward to the extended position.