Bi-directional magnetic sample rack conveying system

A magnetic sample rack adapted to support liquid containers is urged along a surface by means of a magnetic conveyor system located beneath the surface. The magnetic conveyor system comprises a plurality of magnetic housings driven by a belt, the magnetic housings including a magnet slideably contained in a closed upper cavity. Magnetic forces emanating from the magnet overcome frictional resistive forces between the sample racks and the operating surface and move the sample racks along input and output lanes defined in the operating surface. Abrupt movements of the sample racks are eliminated because the housing magnet slides smoothly towards the sample rack, secures the sample rack, and pulls the rack along the operating surface as the housings are moved at a steady rate by the belt.