US 5,398,610 A · Anti-wrap device for a web press

Abstract

A system and method for preventing a broken printing web from wrapping about or otherwise fouling the blanket cylinders of printing press units. The system and method includes a web tensioning device located downstream of the printing press units for maintaining tension upon a broken web and pulling the web from the printing press units. The device includes a plurality of web disturbance detectors for detecting a wave, ripple or other disturbance indicative of a web break. A pair of anti-wrap rollers located above and below the web are engaged upon detection of a web break to engage the web between them to exert tension onto the web and pull it from the printing units. The anti-wrap rollers are rotated at a surface speed nominally greater than the surface speed of the printing rolls. The anti-wrap rollers include a plurality of opposed peak and valley portions which enable them to interlock and grip the web along a line of contact.

Claims22

Dependent claims

A system for preventing damage to a printing press for use with a printing unit including printing cylinders, a moving paper web disposed between and in contact with said printing cylinders, monitoring means for monitoring the speed of said rotating printing cylinders and web break detector means for detecting a break in said paper web and staffing power to the printing cylinders, comprising:

(a) a pair of anti-wrap tension rolls attached to said printing unit downstream of the printing cylinders, said pair of anti-wrap tension rolls being disposed one above and one below the moving paper web and being capable of being movable from a first disengaged position wherein said tension rolls are spaced from the running web and a second engaged position wherein said tension rolls rollers are positioned in contact with said running web,
(b) means responsive to said web detector detecting a web disturbance indicating said break for moving said upper and lower tension rolls relative to one another from said disengaged position toward one another to said engaged position;
and
(c) means spaced along the length of said upper and lower tension rolls for causing line contact with said web by said upper and lower tension rolls, said means for causing line contact being offset with respect to one another, said line contact being at predetermined spaced locations along the width of the web in a direction longitudinally of the web.

1 more element

Dependencies are inferred from the claim text.

Anti-wrap device for a web press

Life of this patent

Anti-wrap device for a web press

Life of this patent

Abstract

Claims22