Apparatus for stretching webs

Claim 1

A WEB-STRETCHING APPARATUS COMPRISING A PAIR OF BEDPLATES WHICH ARE CAPABLE OF BEING SEPARATED IN ESSENTIALLY THE SAME PLANE FROM A COMMON PERPENDICULAR AXIS, A SPROCKER OF MINIMUM CHAIN PITCH, A GUIDE ROLLER AND A SPROCKET OF MAXIMUM CHAIN PITCH, EACH REVOLUBLY MOUNTED ON ONE ONLY OF EACH BEDPLATE TO FORM A CIRCUITOUS PATH FOR A CHAIN CAPABLE OF EXTENDING AND CONTRACTING BETWEEN MAXIMUM AND MINIMUM PITCH, EACH CHAIN BEING COMPOSED OF REGULARLY SPACED PINS WHICH MESH WITH SAID SPROCKETS AND EXTEND THROUGH TWO SEPARATED ROWS OF LINKS, EACH LINK HAVING A PIVOT HOLE AND AN ELONGATED SLOT EXTENDING THROUGH FROM THE TOP TO THE BOTTOM SURFACES OF ITS FLAT BODY, THE LOCUS OF THE CENTER OF THE SLOT BEING OFFSET FROM THE PIVOT HOLE, EACH LINK BEING JOINTED IN CHAIN FASHION SO THAT ADJACENT PINS PASS THROUGH THE PIVOT HOLE OF ONE LINK AND ELONGATED SLOT OF ANOTHER, ADJUSTABLE GUIDE RAILS ON EACH BEDPLATE BETWEEN THE GUIDE ROLLER AND SPROCKET OF MINIMUM CHAIN PITCH TO FORM A PATH FOR THE CHAIN PINS AND LINKS, ONE OF SAID RAILS BEING PROVIDED WITH A SLANTING CAM SURFACE ON WHICH THE EDGES OF THE LINKS RIDE TO CONTROL THE DEGREE OF PIVOT AND THE DISTANCE THE LINKS ARE EXTENDED, WEB GRIPPERS MOUNTED ON REGULARLY SPACED PINS, MEANS TO ACTUATE SAID GRIPPERS TO GRIP THE WEB, MEANS TO RELEASE THE GRIPPERS AND GUIDE RAILS TO REALIGN THE LINKS.