Patent ID: 6804899
Filing Date: 2004-10-19
Classification: G01B

Abstract:
A retractable rule assembly comprising:a housing assembly; a reel rotatably mounted in said housing assembly; an elongated blade formed of a ribbon of metal having one end connected to said reel, said blade extendable from a position tangential to said reel outwardly through a spaced opening in said housing assembly, said elongated blade having a concavo-convex configuration when extended from said housing assembly, said elongated blade having measuring indicia formed on the concave side thereof, and a clear, protective coating provided on both said concave and convex side of said blade throughout the length of the blade for inhibiting wear of said measuring indicia; a coil spring formed of a ribbon of metal constructed to rotate said reel in said housing assembly in a direction to wind up the elongated blade when extending outwardly of said housing assembly opening in said concavo-convex cross-sectional configuration onto said reel in an abutting volute coil formation in a flattened cross-sectional configuration; and a blade holding assembly constructed to hold the blade in any position of extension outwardly of said housing assembly opening and to release the blade from any position in which it is held; a relatively short free end portion of said blade having a film of plastic material overlying said protective coating on at least one of the convex and concave side of the blade, said film of plastic material having a thickness greater than a thickness of said protective coating, wherein said film is comprised of a material selected from a group consisting of polyurethane, Mylar and Nylon, wherein said film selected from said group is secured to said plastic coating with an acrylic adhesive, and wherein said end portion of said blade having said film being curved in a longitudinal direction of said blade when said blade is fully retracted.