Method and apparatus for controlling a moving web

Apparatus for controlling lateral position of a moving textile web comprising:

• a. a driven roll across a path of travel of said moving textile web and being supportive of same, said roll being driven in a direction of rotation opposite the direction of web travel and having at least one helical element thereon to move said web in a lateral direction under predetermined conditions;
• b. pressure applicator means located adjacent said driven roll and at least along a medial portion of said path of travel thereat, said pressure applicator means being actuatable to make contact with said web on said roll and cooperate with said roll to drive said web in a lateral direction while avoiding any substantial axial forces on said web with respect to the direction of web travel;
• and
• c. web detector means located along said path of web travel for detecting lateral position of said web, said detector means being operatively associated with said pressure applicator means to actuate and deactuate same responsive to the lateral position of said web.

A method of controlling the lateral position of a moving textile web comprising the steps of:

• a. feeding a textile web over a driven roll, in engagement across the width of said textile web with at least one helical element thereon;
• b. sensing the lateral position of the web;
• c. applying pressure on said web at said roll upon sensing a lateral misalignment of same, said pressure being applied on said web at a lateral location of same opposite the lateral misalignment in an amount insufficient to create any substantial axial force on said web with respect to the direction of web travel, whereby said web is driven laterally towards the location of applied pressure so long as said pressure continues;
• and
• d. releasing said pressure when said web is sensed as being back in proper lateral alignment.