US 6,604,463 B1Granted

Device to compensate for print misregister due to paper distortion on web offset printing presses

OwnerRoy Gordon Smithinventor

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Abstract

A printing web distortion device for imposing a measured amount of distortion into a moving web of substrate, such as paper, to compensate for lateral stretching of the substrate during a printing operation includes a post, which can be vertically adjusted, having a gas nozzle disposed at, or adjacent to, the tip of the post for generating a cushion of a gas. A support enclosure for the post has a source for pressurized gas. The post is able to slide longitudinally within the support enclosure, so that the tip of the post is either raised in an operating mode, so that the post imposes a stretch compensating distortion or, in an idle mode, the post is withdrawn from the substrate, so that no elevating force is provided on the substrate. In the operating mode, the stretch compensating distortion results from an elevating force provided by the post between the tip of the post and the moving substrate resulting from the cushion of gas, which is preferably a cushion of air.

Claims23

Dependent claims

A printing web distortion apparatus for imposing a measured amount of distortion into a moving web or a substrate for compensating for lateral stretching thereof during a printing operation, said printing web distortion apparatus comprising:

a vertically adjustable post having a gas nozzle disposed at, or adjacent to, a tip of said vertically adjustable post for generating a cushion of gas;
and,
a support enclosure for said vertically adjustable post having a source for pressurized gas associated therewith, said vertically adjustable post being longitudinally slidable within said support enclosure so that said tip is either raised for approaching the substrate in a first mode, said first mode being an operating mode, wherein said vertically adjustable post imposes a stretch compensating distortion via application of an elevating force exerted by said vertically adjustable post between said tip and the substrate as the substrate is moving, said elevating force being provided by the cushion of gas, or in a second mode, said second mode being an idle mode, wherein said vertically adjustable post is withdrawn from the substrate and no elevating force is exerted on the substrate.

Dependencies are inferred from the claim text.