Patent ID: 7062862

Claim:
In a retractable rule assembly including a housing and reel rotatably mounted in the housing and having an elongated blade formed from ribbons of metal having one end connected to said reel and extending from a position tangential to said reel outwardly through an opening in said housing assembly and when retracted within said housing assembly being in the form of an abutting volute coil spring, wherein when coiled, said ribbons are in substantial contact with one another and when extended from said housing assembly, said ribbons assume a tube-like structure, the improvement comprising said elongated metal blade being in the form of first and second ribbons of elongated metal being joined to one another along their lengths and each having a thickness wherein the thickness of the first ribbon is greater than the thickness of the second ribbon and wherein upon forming said abutting volute coil, said first ribbon is coiled inside of said second ribbon.