Web attachment means for spools

Claim 1

A SPOOL, ADAPTED FOR USE AS A TAKE-UP DEVICE FOR A WEB: COMPRISING AN OUTER SUBSTANTIALLY CYLINDRICAL SURFACE AROUND A LONGITUDINAL AXIS WITH AT LEAST ONE LONGITUDINAL SLOT IN SAID SURFACE COMPRISING A PAIR OF FACING WALLS DISPOSED INWARDLY FROM SAID SURFACE, AT LEAST ONE SUBSTANTIALLY SHARP BEARING EDGE FORMED AT THE CORNER OF THE FIRST OF SAID WALLS AND THE SURFACE OF THE CYLINDER, AT LEAST ONE OTHER SUBSTANTIALLY SHARP BEARING EDGE FORMED ON THE SECOND OF SAID WALLS SUBSTANTIALLY PARALLEL TO SAID FIRST MENTIONED BEARING EDGE AND AT A SMALLER RADIUS FROM SAID AXIS THAN SAID FIRST MENTIONED BEARING EDGE, SAID SECOND MENTIONED BEARING EDGE BEING DISPLACED FROM A PLANE WHICH INCLUDES SAID FIRST MENTIONED BEARING EDGE AND SAID AXIS OF SAID SPOOL, AND BEARING MEANS CONTIGUOUS WITH SAID FIRST WALL SUBSTANTIALLY IN A PLANE AT AN OBTUSE ANGLE TO THE PLANE OF SAID FIRST WALL AND CUTTING THROUGH THE PLANE IN WHICH SAID FIRST MENTIONED EDGE AND SAID AXIS LIE.