Magnetic cylinder with surface gripping

In a magnetic cylinder and plate of magnetic material for printing, in which the cylinder has a peripheral surface and the plate is wrapped around the cylinder with an inner surface of the plate being in direct contact with the cylinder peripheral surface, the plate being subject to circumferential movement around the cylinder as the plate is subject to localized pressure, with or without additional forces due to ink tack, from another cylinder in a nip, the improvement comprising,

• at least one of the cylinder peripheral surface and the plate inner surface being defined by means for suppressing local sliding by surface gripping with the other of said surfaces wherein the one said surface includes a plurality of circumferentially spaced, generally axially extending ridges and is of a greater hardness than the other said surface.

In a magnetic cylinder and plate of magnetic material for printing, in which the cylinder has a peripheral surface and the plate is wrapped around the cylinder with an inner surface of the plate being in direct contact with the cylinder peripheral surface, the plate being subject to circumferential movement around the cylinder as the plate is subject to localized pressure, with or without additional forces due to ink tack, from another cylinder in a nip, the improvement comprising,

• at least one of the cylinder peripheral surface and the plate inner surface being defined by means for suppressing local sliding by surface gripping with the other of said surfaces, wherein the cylinder peripheral surface includes a plurality of circumferentially spaced, generally axially extending ridges and wherein said cylinder peripheral surface is plated with a hardening material.

In a magnetic cylinder and plate of magnetic material for printing, in which the cylinder has a peripheral surface and the plate is wrapped around the cylinder with an inner surface of the plate being in direct contact with the cylinder peripheral surface, the plate being subject to circumferential movement around the cylinder as the plate is subject to localized pressure, with or without additional forces due to ink tack, from another cylinder in a nip, the improvement comprising,

• at least one of the cylinder peripheral surface and the plate inner surface being defined by means for suppressing local sliding by surface gripping with the other of said surfaces, wherein the cylinder peripheral surface includes a plurality of circumferentially spaced, generally axially extending ridges and the cylinder surface is of a greater hardness than the plate.

In a magnetic cylinder and a resilient blanket bonded to a carrier plate of magnetic material for offset web printing, in which the cylinder has a peripheral surface and the plate is wrapped around the cylinder with an inner surface of the plate being in direct contact with the cylinder peripheral surface, the carrier plate and blanket being subject to circumferential movement around the cylinder as the blanket is subject to localized pressure, with or without additional forces due to ink tack, from another cylinder in a nip, the improvement comprising;

• the cylinder peripheral surface being defined by means for suppressing lifting waves by surface gripping of the plate inner surface.
• wherein the cylinder surface includes a plurality of circumferentially spaced, generally axially extending ridges.

The method of assembling a magnetic cylinder and resilient blanket sheet bonded to a carrier plate of magnetic for offset web printing, comprising the steps of:

• providing the magnetic cylinder including a peripheral surface having a plurality of circumferential spaced, generally axially extending ridges, and
• wrapping the carrier plate and blanket sheet around the cylinder with an inner surface of the carrier plate being in direct contact with the cylinder peripheral surface, the cylinder peripheral surface suppressing lifting waves by surface gripping of the carrier plate inner surface.

In a magnetic cylinder and resilient blanket bonded to a carrier plate of magnetic material for offset web printing, in which the cylinder has a peripheral surface and the plate is wrapped around the cylinder with an inner surface of the plate being in direct contact with the cylinder peripheral surface, the carrier plate and blanket being subject to circumferential movement around the cylinder as the blanket is subject to localized pressure, with or without additional forces due to ink tack, from another cylinder in a nip, the improvement comprising,

• the cylinder peripheral surface being defined by means for enhancing a vacuum effect to suppress lifting wave initiation,
• wherein the cylinder surface includes a plurality of circumferentially spaced, generally axially extending ridges.