US 5,350,623 A · Compressible blanket assembly

Abstract

A void-free, latex rubber cushion layer is interposed between the blanket cylinder and the base layer of a compressible printing blanket in an offset printing press. The latex cushion layer has a thickness of from 8 to 12 mils, and has a spring modulus which is substantially less than the spring modulus of the compressible layer in the printing blanket. The latex cushion layer will compress slightly, about 1 mil, in response to preloading at typical preload impression pressure. This means that a good quality print may be obtained at a substantially reduced impression pressure level, since it is not necessary to preload the blanket. During a printing operation, the latex cushion layer is under preload compression and applies a back pressure force which assures a quality imprint. The compressible layer of the blanket, which has a greater spring constant, is not compressed at the typical printing pressure setting. However, the compressible layer in the printing blanket is yieldable and will compress by about 3-4 mils when the loading is increased in response to a misfeed situation, for example, when two sheets or two envelopes are fed through simultaneously. This arrangement also permits envelopes and flat sheets to be printed in successive printing runs without buildup modification of the impression cylinder surface.

Claims9

Dependent claims

A blanket assembly for attachment to the blanket cylinder of an offset printing press comprising, in combination:

a compressible blanket having a base carrier layer, a compressible intermediate layer and an ink transfer layer;
and,
a cushion layer of compressible material adapted for wraparound assembly onto the blanket cylinder intermediate the base carrier layer of the compressible blanket and the external surface of the blanket cylinder wherein
the cushion layer has a spring modulus which is substantially less than the spring modulus of the compressible layer and
the cushion layer is not attached to, secured to, or otherwise connected to the base carrier layer whereby the compressible blanket effectively floats on the cushion layer permitting radial deflection of the blanket in response to preloading impression pressure and circumferential displacement of the blanket relative to the cylinder in response to misfeed contact.

2 more elements

Dependencies are inferred from the claim text.

Compressible blanket assembly

Life of this patent

Compressible blanket assembly

Life of this patent

Abstract

Claims9