A beverage cup lid is disclosed that comprises a circular closure panel, circumscribed by a side wall that terminates in a resilient, restricted diameter edge for capturing a brim of a beverage cup, and a frustro-conical skirt connected around the restricted diameter edge for increasing the hoop strength...http://www.google.es/patents/US5460286?utm_source=gb-gplus-sharePatente US5460286 - Beverage cup lid having an annular flange extension for increased cap retention force, and method of manufacture
Beverage cup lid having an annular flange extension for increased cap ...
