Abstract Mechanism for correcting any tendency for a moving web such, for example, as a strip of material being wound onto, or unwound from a roller, or an endless belt to deviate from a required path. The mechanism includes a rotatable roller around the periphery of which the web passes so as to be in frictional contact therewith through a predetermined arc. The periphery of the roller is in part constituted by a plurality of angularly spaced bars which are slidable longitudinally in a direction parallel to the axis of the rotation of the roller. At opposite ends of the roller respectively are a pair of relatively fixed cams for ensuring that the bars take up a predetermined longitudinal position whilst they move through the arc in which they are in frictional contact with the web. Means is provided for sensing any deviation of the web from its required path as it approaches the roller and a second pair of cams at opposite ends of the roller respectively are movable by said means to displace the bars longitudinally by an amount determined by said means whilst the bars are moving through the arc in which they are not in contact with the web.
Mechanism for correcting any tendency for a moving web to deviate from a required path comprising in combination a rotatable roller around the periphery of which the web passes so as to be in frictional contact therewith throughout a predetermined arc, the periphery of said roller being in part constituted by a plurality of angularly spaced bars which are slidable longitudinally in a direction parallel to the axis of rotation of the roller, a pair of relatively fixed cams at opposite ends of the roller respectively for ensuring that the bars take up a predetermined longitudinal position whilst moving through the arc in which they are in frictional contact with the web, means for sensing any deviation of the web from its required path as it approaches said roller, and a second pair of cams at opposite ends of the roller respectively, said second pair of cams being movable by said means to displace the bars longitudinally by an amount determined by said means during their movement through the arc in which they are not in contact with the web.
Claim 2
Dependent Claim
180 words
Mechanism for correcting any tendency for a moving web to deviate from a required path comprising in combination a rotatable roller around the periphery of which the web passes so as to be in frictional contact therewith throughout a predetermined arc, the periphery of said roller being in part constituted by a plurality of angularly spaced bars which are slidable longitudinally in a direction parallel to the axis of rotation of the roller, a pair of relatively fixed cams at opposite ends of the roller respectively for ensuring that the bars take up a predetermined longitudinal position whilst moving through the arc in which they are in frictional contact with the web, means for sensing any deviation of the web from its required path as it approaches said roller, and a second pair of cams at opposite ends of the roller respectively, said second pair of cams being movable by said means to displace the bars longitudinally by an amount determined by said means during their movement through the arc in which they are not in contact with the web.
Claim 3
Dependent Claim
68 words
Mechanism for correcting any tendency for a moving web to deviate from a required path as claimed in claim 1 in which the means for sensing any deviation of the web from its required path comprises a pair of brackets engaging opposite marginal edges of the web, a member displaceable laterally of the web to which the pair of Brackets and the second pair of cams are connected.
Claim 4
Dependent Claim
51 words
Mechanism for correcting any tendency for a moving web to deviate from a required path as claimed in claim 2 in which the brackets are adjustable in a direction at right angles to the member to enable the degree of correction for a given deviation of the web to be varied.
Claim 5
Dependent Claim
42 words
Mechanism for correcting any tendency for a moving web to deviate from a required path as claimed in claim 3 in which portions of the operative surfaces of the pair of relatively fixed cams are constituted by the peripheries of rotatable rollers.