US 4,549,485 AGranted

Paper web seizing apparatus for use with printing machinery

AssigneeMAN Roland Druckmaschinen AG

InventorNikolaus Nawrath

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Abstract

To prevent damage to a printing cylinder, typically the blanket cylinder of rotary offset printing machine, upon tearing of a paper web, which usually occurs within a dryer, a paper web seizing apparatus is positioned downstream of the last printing station. The apparatus includes a roller (15) which is driven at the speed somewhat higher than the linear speed of the paper web by a belt drive (20,21,22) from a friction wheel (18) and held out-of-engagement with the other roller (3) of the pair by a latching mechanism (24, 25, 26--FIG. 2). Upon sensing of a tear, the electromagnetic (26) of the latching mechanism permits a spring (23) to disengage the first roller (15) from the friction drive (18), the roller continuing to rotate due to inertia and engaging the web (A) and then being driven by the positive drive (8,9,10) of the first roller, thus wrapping any torn web about the first roller and preventing damage to the printing cylinders of the printing machine.

Claims13

Dependent claims

Web seizing apparatus for combination with a printing machine having a printing cylinder, to seize a web (A) which may tear as it passes through the printing machine having

a support frame (1, 2);
a pair seizing rollers (3, 15);
bearings (6, 7;
16, 17) supporting said rollers in the support frame, spaced from each other, and located for passage of the web (A) between the rollers without contact therewith;
drive means (8, 9, 10;
18-22) positioned in driving engagement with said rollers to rotate the rollers;
and
means (7', 11, 12, 13) for supporting the bearings of at least one (15) of the rollers in the frame for relative movement with respect to the other roller (3) for clamping the web (A) between the rollers in case of tearing of the web to thereby prevent winding of the web about a printing cylinder of the printing machine
wherein, in accordance with the invention,
the bearing support means (7', 11, 12, 13) for said at least one (15) movable roller are positioned to move said at least one roller out of engagement with the drive means (18-22) for said at least one roller and for subsequent driving engagement with the other roller, with the web interposed, and thereby permit free rotation by spinning inertia of said at least one roller during said movement from engaged position with the drive means to engagement with the other roller.

7 more elements

Dependencies are inferred from the claim text.