Apparatus for automatic centering of strips

Claim 1

APPARATUS FOR GUIDING A WEB FED ALONG A GIVEN PATH AND IN A GIVEN PLANE, COMPRISING (A) FIRST ROLLER MEANS MOUNTED FOR ROTATION ABOUT A FIRST AXIS OF ROTATION PARALLEL TO AND TO ONE SIDE OF SAID GIVEN PLANE, (B) SECOND ROLLER MEANS MOUNTED FOR ROTATION ABOUT A SECOND AXIS OF ROTATION PARALLEL TO AND ON THE OTHER SIDE OF SAID GIVEN PLANE, (C) SAID FIRST AND SECOND AXES OF ROTATION BEING COPLANAR AND LYING IN A SECOND PLANE PERPENDICULAR TO SAID GIVEN PLANE, (D) PIVOT MEANS MOUNTING SAID FIRST AND SAID SECOND ROLLER MEANS FOR PIVOTAL MOVEMENT, (E) ROCKER MEANS MOUNTING SAID SECOND ROLLER MEANS FOR MOVEMENT TOWARD AND AWAY FROM SAID FIRST ROLLER MEANS, AND (F) BIASING MEANS URGING SAID SECOND ROLLER MEANS INTO ENGAGEMENT WITH SAID FIRST ROLLER MEANS, SAID BIASING MEANS BEING LOCATED BETWEEN AND EQUIDISTANT FROM THE ENDS OF SAID FIRST AND SAID SECOND ROLLER MEANS, (G) SAID FIRST AND SAID SECOND ROLLER MEANS GRIPPING THE WEB ALONG A REFERENCE LINE AS THE WEB PASSES THEREBETWEEN, (H) WHEREBY WALKING OF THE WEB FROM THE GIVEN PATH PIVOTS THE PIVOT MEANS AND THEREWITH THE FIRST AND SECOND ROLLER MEANS TO A POSITION WHERE THE FIRST AND SECOND ROLLER MEANS GRIP THE WEB ALONG A LINE AT AN ANGLE TO THE REFERENCE LINE, SAID FIRST AND SECOND ROLLER MEANS AND THE WEB PRODUCING COACTION FORCES TO AUTOMATICALLY EFFECT THE RETURN OF THE WEB TO THE GIVEN PATH.