A hat retaining mechanism has a flexible tether, a clip mechanism attached to one end of the flexible tether to be located on the outside of a hat, and a slidable retraction component on the flexible tether located on the inside of the hat between the other end of the flexible tether that is secured...http://www.google.es/patents/US6446265?utm_source=gb-gplus-sharePatente US6446265 - Hat tether apparatus and method
