Web handling system and vacuum roller for use in conjunction therewith

摘要

A vacuum roller for a web handling system comprises a hollow, cylindrical, rotably driven drum and an end cap threadingly mounted onto the rear end of the drum. Together, the drum and the end cap define a plurality of individual, externally communicable vacuum paths. A spherical, metal movable element is internally disposed within each vacuum path and regulates the passage of air therethrough. A plurality of magnetic elements is fixedly mounted on a stationary annular holder. In use, each magnetic element selectively displaces each movable element when disposed in close proximity thereto to the extent necessary so as to permit the passage of air through its corresponding vacuum path. As such, the vacuum roller is provided with a predefined range of suction, or vacuum zone, about the outer surface of its rotating drum that directly corresponds to the angular arrangement of the plurality of stationary magnetic elements.

主权项

1. A vacuum roller for a web handling system, the vacuum roller comprising:
(a) a drum, the drum having an inner surface, an outer surface, a front end and a rear end, the drum being shaped to at least partially define a plurality of externally communicable vacuum paths; (b) a plurality of movable elements, each movable element being disposed within an associated vacuum path and serving to regulate the passage of air therethrough, wherein each of the plurality of movable elements is metallic and is adapted for displacement between a first position and a second position, wherein air is at least substantially restricted from passing through its associated vacuum path when the movable element is disposed in its first position and air is permitted to freely pass through its associated vacuum path when the movable element is disposed in its second position; and (c) at least one stationary magnetic element for selectively displacing each movable element.