US Patent 10385939 Spring assembly with a protected attachment site

A spring assembly includes a coil spring having one or more helical coils between two longitudinally spaced ends, and an attachment site disposed at at least one of the longitudinally spaced ends. The attachment site includes a casing enclosing the at least one of the longitudinally spaced ends, the casing having a casing passage therethrough between a first side and a second side. The attachment site also includes a washer disposed on the first side and having a washer passage aligned with the casing passage, and a base disposed on the second side and having a base passage aligned with the casing passage.