US 4,566,162 AGranted

Stretcher/expander roller

AssigneeAmerican Roller Company

InventorGeorge Brands

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Abstract

An improved stretcher/expander roller is disclosed. The roller includes a rigid core which is rotatably mounted downstream from where a traveling web is slit. An elastomeric covering around the core has at least one pair of helical lands formed in it which each spiral outwardly away from the center of the roller. The lands are inclined outwardly away from the center of the roller and progressively increase in flexibility from the center to the ends of the roller. The roller imparts axial forces on the web strips to simultaneously separate the web strips from one another and cross-stretch each web strip. The lands are made progressively more flexible by either progressively increasing the depth of the helical grooves between the lands, by progressively decreasing the helix angle of the lands, or by progressively decreasing the angle subtended by each land and the axis of the roller, from the center to the ends of the roller.

Claims2

Dependent claims

A stretcher/expander roller for cross-stretching and separating the constituent strips of a slit web, comprising:

(a) a rigid inner core suitable to be rotationally mounted downstream from where the web is slit;
and
(b) an elastomeric covering around said rigid core, said elastomeric covering defining a generally cylindrical exterior surface having a constant outer diameter and which is suitable for rolling contact with the slit web;
(c) wherein at least one pair of helical grooves are formed in the exterior surface of the elastomeric covering, each of said helical grooves subtending a slant angle .theta. with a line which is perpendicular to the roller axis and each of said grooves spiraling outwardly away from the center of the roller;
(d) wherein the helical grooves are inclined outwardly at an acute depth angle .alpha. away from the center of the roller, said depth angle .alpha. being constant from the center of the roller to the ends and said helical grooves defining a corresponding number of continuous helical lands of elastomeric material which are inclined outwardly away from the center of the roller at said acute depth angle .alpha.;
and
(e) wherein the depth of each helical groove increases progressively from the center to the adjacent edge of the roller so that the lands are increasingly flexible from the center to the ends of the roller.

4 more elements

Dependencies are inferred from the claim text.