Abstract

Apparatus for controlling the lateral movement of a travelling web to automatically compensate for web conicity and angular deviation of the web velocity vector. A preferred embodiment of the apparatus comprises a steering roller about which a travelling web is at least in part entrained. An assembly supports the steering roller for rotation about its longitudinal axis, and mounts the steering roller for angular adjustment about a caster axis perpendicular to such longitudinal axis at the mid-point of the steering roller. The assembly is, in turn, supported for rotation about a gimbal axis intersecting, and perpendicular to, the caster axis. Lateral movement of a web supported on the steering roller is sensed relative to the steering roller in the direction of the longitudinal axis of the steering roller. The mechanism for sensing lateral movement of the web moves in a corresponding direction to the sensed lateral movement of the web. The sensing mechanism is interconnected with the supporting and mounting assembly for angularly adjusting the steering roller about the caster axis in response to movement of the lateral movement sensing mechanism, in a direction to counteract sensed lateral movement of the web.