Tread centering method and apparatus

An apparatus for centering an annular tread on a casing having an equatorial plane, the apparatus comprising:

• a frame;
• a wheel mounted on the frame and adapted for receiving and mounting a casing;
• a tread expander adapted for receiving an annular tread at a location axially spaced from said wheel;
• means for determining the axial location of the equatorial plane of a casing mounted on said wheel;
• means for establishing a first plane location axially spaced a fixed distance from and parallel to the equatorial plane of the casing or wheel;
• means for providing relative axial movement between said tread expander and a casing mounted on said wheel to bring the circumferential centerline of a tread into coincidence with the equatorial plane of the casing, said tread being positioned on the tread expander assembly such that the circumferential centerline is coincident with said established first plane prior to relative axial movement, said relative axial movement being a fixed distance equal to the fixed distance between said established first plane and the determined equatorial plane of a casing mounted on said wheel.