Method and apparatus to control the lateral motion of a long metal bar being formed by a mechanical process such as rolling or drawing

An apparatus to control the lateral motion of a bar moving along a guidance path, comprising:

• a pair of hubs each being configured to be selectively rotatable about a respective main axis, each hub including (i) at least a first roller and a second roller located at predefined locations around said hub, each roller being freely rotatable about a respective roller axis, said first and second rollers having first and second concave retaining grooves on respective perimeters thereof, said first groove having a first radius that is larger than a second radius associated with said second groove and (ii) at least one guiding element located intermediate said first and second rollers having a guide channel extending in the outer surface thereof;
• a mounting system configured to support said hubs and further configured to allow said hubs to be rotated between a first position and a second position, wherein in said first position, said first roller on one of said pair of hubs is aligned with and opposes said first roller on the other one of said pair of hubs so that said first retaining grooves thereof form a guideway having a first size through which the guidance path extends, and wherein in said second position, said second roller on one of said pair of hubs is aligned with and opposes said second roller on the other one of said pair of hubs so that said second retaining grooves thereof form said guideway having a second size, said second size being smaller than said first size so as to accommodate different sized bars.