Patent ID: 7530569

Claim:
A vacuum assembly for a rotating roll for handling sheet or web material, the rotating roll including a plurality of holes in an outer surface and passages that open onto a face of the roll that are in communication with the plurality of holes, wherein the holes are adapted to communicate a vacuum for holding and releasing the sheet or web material, comprising: a vacuum manifold located in line with and outwardly of the roll face, wherein the vacuum manifold defines an internal cavity that is supplied with vacuum from a vacuum source; and a valve assembly positioned between the roll face and the vacuum manifold, wherein the valve assembly includes a passage arrangement configured to communicate vacuum throughout a portion of the rotation of the roll from the internal cavity of the vacuum manifold to the passages that open onto the roll face, wherein the valve assembly includes an intake region that communicates vacuum from the internal cavity of the vacuum manifold to the passages that open onto the roll face, and further includes an adjustment arrangement for adjusting the location of the intake region and the position of a pair of ends defined by the intake region that define the range of movement of the roll through which the passages that open onto the roll face are exposed to vacuum during rotation of the roll, wherein the valve assembly includes: an outer slug plate; an inner slug plate; a spool mounted to the inner slug plate, the spool having an opening; and a cover coupled to the spool, wherein the cover and the spool cooperate to define the internal cavity, wherein the internal cavity is in communication with the spool opening; wherein the outer slug plate and the inner slug plate are rotatably adjustable relative to the spool and to one another; and wherein the outer slug plate and the inner slug plate are configured to regulate the supply of vacuum from the internal cavity to the holes of the rotating roll.