The Times Mirror Company

John C Darnall, Jr

A flexible thermoplastic printing plate is mounted on a plate cylinder having a given curvature. In its unstressed condition, the printing plate has substantially the same curvature between its ends as the cylinder. The printing plate has laterally extending hooks at its ends. A stationary laterally extending projection on the cylinder engages the hook at one end of the plate. A movable laterally extending projection on the cylinder engages the hook at the other end of the plate; the movable projection is spring-loaded so as to tension the plate longitudinally on the cylinder. A plurality of gussets are formed in each hook and a plurality of recesses for receiving the respective gussets are formed in each projection. Opposite sides of two recesses in each projection are precisely located relative to the cylinder. The opposite sides of the two recesses receive the respective gussets with a close fit to index the plate laterally on the cylinder, while the sides of the remaining recesses receive their respective gussets with a sufficiently loose fit so as not to interfere with such indexing.

Flexible printing plate and attachments therefor

A flexible printing plate is separated from the inner surface of a curved matrix after formation of the plate in a mold by first moving the ends of the plate inwardly away from the matrix, while maintaining the center of the plate in stationary contact with the matrix, and then moving the center of the plate inwardly away from the matrix, while maintaining the ends of the plate away from the matrix. The matrix is held in an outer mold half, and the printing plate is formed in a mating inner mold half having a center section with sloping side surfaces that converge toward the outer mold half, a first end section having a side surface contiguous to one sloping side surface of the center section, and a second end section having a side surface contiguous to the other sloping side surface of the center section.

Method for molding a curved flexible printing plate

A flexible printing plate is separated from the inner surface of a curved matrix after formation of the plate in a mold by first moving the ends of the plate inwardly away from the matrix, while maintaining the center of the plate in stationary contact with the matrix, and then moving the center of the plate inwardly away from the matrix, while maintaining the ends of the plate away from the matrix. The matrix is held in an outer mold half, and the printing plate is formed in a mating inner mold half having a center section wih sloping side surfaces that converge toward the outer mold half, a first end section having a side surface contiguous to one sloping side surface of the center section, and a second end section having a side surface contiguous to the other sloping side surface of the center section.

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Thousand Oaks, CA, United States of America

John C Darnall, Jr