Constant contact side bearing

A side bearing for use in a railway car truck, comprising:

• a base having a bottom section and an upwardly extending cylindrical raised section,
• a cup-shaped cap having a circular top section and a downwardly extending cylindrical wall section that extends into the raised section of the base in a telescoping fashion with a predetermined spatial gap therebetween precisely controlled to be between about 0.006 in. to 0.046 in. and
• at least one resilient spring member provided within the base extending between the base and the cap, the at lease one urging member having a combined load rating between about 2,500 to 6,000 lb/in. and a travel length from a loaded static height to a fully compressed solid height of over ⅝″,
• wherein the wall of the cap and base are configured so as to retain an overlap at the loaded static height state and allow at over ⅝″ of spring travel length before parts of the cap and base abut each other and prevent further travel,
• wherein an interior of the base raised section and an exterior of the cap wall section have a complementary elongated, vertically extending ridge and opening to prevent rotation of the cap within the base.

A side bearing for use in a railway car truck, comprising:

• a base having a bottom section and a cylindrical raised section,
• a cup-shaped cap having a circular top section and a downwardly extending cylindrical wall section that extends into the wall section of the base section in a telescoping fashion with a predetermined spatial gap therebetween precisely controlled to be between about 0.006″ to 0.046″ to improve control and hunting characteristics of the railway car truck, the top surface of the cap including a substantially flat surface that is generally centrally located and rounded edges extending from the substantially flat surface of the outer surface of the generally cylindrical wall section of the cap,
• at least one coil spring provided within the base extending between the base and the cap, the at least one coil spring having a combined load rating between about 2,500 to 6,000 lb/in. and a travel length from a loaded static height to a fully compressed solid height of over ⅝″,
• wherein the walls of the cap and base are configured so as to retain an overlap at the loaded static height state and allow over ⅝″ of spring travel length before parts of the cap and base about each other and prevent further spring travel, and
• wherein an interior section of the base raised section and an exterior of the cap wall section have a complementary elongated, vertically extending ridge and opening to prevent rotation of the cap in the base, and
• wherein the base includes first openings on the bottom section and corresponding second openings in the wall section to allow wrench access to bolt heads in the first openings in the bottom section.