Door lock with decorative escutcheon

Claim 1

The combination of a lock and a door; said door having inner and outer sides and having a hole extending therethrough between said sides; said lock comprising an exterior unit for the outer side of said door and an interior unit for the inner side of said door; said exterior unit comprising (1) a cylindrical barrel, (2) a lock cylinder secured rigidly within and coaxial with said barrel and projecting outwardly therefrom, (3) a decorative escutcheon telescoped over the outer end portion of said barrel and having an opening coaxial with said barrel and rotatably receiving the outer end portion of said lock cylinder, and (4) connecting means for preventing axial separation of said escutcheon and said barrel while permitting said escutcheon to rotate relative to said barrel and said lock cylinder; fastening means extending through said hole and connected between said barrel and said interior unit to anchor said interior and exterior units rigidly to said door, and a key-and-slot connection between said escutcheon and said barrel for retaining said escutcheon in a predetermined angular orientation with respect to said lock cylinder, the key of said connection having less shear strength than said fastening means and shearing away when excessive torque is exerted on said escutcheon so as to enable said escutcheon to turn about the axis of said barrel and said lock cylinder and thereby prevent said excessive torque from being transmitted to said barrel and fracturing said fastening means.