Patent ID: 9421754
Filing Date: 2016-08-23
CPC Classification: B41F,B41P

Claim Text:
1. A printing plate unit attached to a printing plate attachment device of a printer that includes a plate cylinder part, the printing plate unit comprising: a printing plate in which a plate section is provided on a part of a front surface of a sheet made of an elastic material, and engaging protrusions that protrude toward a back surface or a front surface and extend in a width direction are provided at longitudinal ends of the printing plate; and a printing plate coupling member that is detachable from the printing plate, and engages with the engaging protrusions of the printing plate which is formed to be cylindrical to couple the longitudinal ends of the cylindrical printing plate to each other, wherein the printing plate coupling member includes an inner clamping member and an outer clamping member that clamp the longitudinal ends of the cylindrical printing plate at radially inner and outer sides, wherein attachment and detachment of the printing plate unit to and from the plate cylinder part fixedly provided at a plate driving shaft of a printer is performed in a state in which the printing plate is kept cylindrical by the printing plate coupling unit, and in a state in which the printing plate unit is detached from the plate cylinder part, with the printing plate coupling member detachable from the printing plate and the printing plate storable in the form of a flat plate, wherein the printing plate coupling member includes screw members, wherein a plurality of threaded holes are formed in the inner clamping member, and screw-insertion through-holes corresponding to the threaded holes are formed in the outer clamping member, wherein the outer clamping member overlaps the inner clamping member and the ends of the printing plate at the radially outer side, and the screw members are inserted into the through-holes and screwed into the threaded holes, thereby being fixed to the inner clamping member, and wherein threaded hole-forming parts each having a predetermined thickness in the radial direction of the cylindrical printing plate are formed at a plurality of places of the inner clamping member, a threaded hole having a female screw penetrating each threaded hole-forming part in the radial direction is formed in each threaded hole-forming part, screw-insertion through holes that correspond to the threaded holes and penetrate the outer clamping member in the radial direction are formed at a plurality of places of the outer clamping member, a plurality of clamping screw members penetrate the screw-insertion through holes from the radially outer side and are screwed into the threaded holes, in the state where the inner and outer clamping members are fixed with the clamping screw members, a retaining stopper is provided at a part of the clamping screw member protruding from the threaded hole inward in the radial direction, the part being away from the threaded hole-forming part inward in the radial direction, and permanent magnets are provided at the inner and outer clamping members so as to repel each other.