Abstract: Web printing apparatus having an impression roll and method of operating the apparatus for printing webs having different characteristics, such as different thickness and/or different modulus of elasticity, in which the speed of the impression roll is adjusted in accordance with the said characteristics and the tension to which the web is subjected in the printing operation to feed forward webs of different characteristics at different speeds for precision in impression length.

Abstract: A magnetic cylinder is formed by stacking ferromagnetic pole disks to which spacer rings are fastened. A circular array of tabs are pierced from the plane of the pole disks. the tabs are angulated relative to said plane and they diverge radially outwardly but their edges terminate on a circle concentric to the rim of the disk to provide a margin on which a concentric spacer ring is applied and is secured to the pole by pressing the tabs back toward the plane of the pole so they wedge tightly against the spacer ring. Permanent magnets are applied to the poles between adjacent pairs of tabs and they form parallel axially extending rows of magnets when the poles are stacked. At least one row is comprised of magnets which are stronger than the other to more forcefully hold down the edges of a die cutting plate of a printing plate which is wrapped around the magnetic cylinder.

Abstract: A magnetic cylinder is formed by stacking ferromagnetic pole disks to which spacer rings are fastened. A circular array of tabs are pierced from the plane of the pole disks. The tabs are angulated relative to said plane and they diverge radially outwardly but their edges terminate on a circle concentric to the rim of the disk to provide a margin on which a concentric spacer ring is applied and is secured to the pole by pressing the tabs back toward the plane of the pole so they wedge tightly against the spacer ring. Permanent magnets are applied to the poles between adjacent paris of tabs and they form parallel axially extending rows of magnets when the poles are stacked. At least one row is comprised of magnets which are stronger than the others to more forcefully hold down the edges of a die cutting plate or a printing plate which is wrapped around the magnetic cylinder.