Bi-directional magnetic sample rack conveying system

Abstract

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.

1. A method of transitioning a sample rack along an operating surface from a stationary position to a moving state by:
 locating a magnetic conveyor system beneath the operating surface, the conveyor system comprising a plurality of magnetic housings attached to a linear drive mechanism, the magnetic housings including a magnet slideably contained therein;  
 providing a sample rack having an upper portion and a lower portion on the operating surface, the rack adapted to support one or more containers containing a liquid sample in the upper portion, the rack having a ferromagnetic plate secured in a closed base cavity in the lower portion;  
 placing the sample rack on the operating surface with the lower portion in contact with the operating surface; and,  
 moving the magnetic housings in a single direction beneath the operating surface by activating the pulley driven belt  linear drive mechanism,  
 wherein the magnetic housings are distanced from the magnetic sample rack so that magnetic forces emanating from the slideable magnet and acting on the ferromagnetic plate are sufficiently strong so as to overcome resistive forces between the sample rack and the operating surface and move the sample racks along the operating surface in concert with the activated belt  linear drive mechanism.  
 
     
     
       2. The method of  claim 1  wherein each of said magnetic housings comprise a lower portion attached to the drive mechanism and a closed upper portion containing the slideable magnet. 
     
     
       3. The method of  claim 2  wherein said slideable magnet moves from a first position to a second position in the closed upper portion, the first position being located a relatively greater distance from the sample rack and the second position is located a relatively smaller distance from the sample rack in response to the drive mechanism being activated. 
     
     
       4. The method of  claim 2  wherein said sample rack is transitioned from a stationary position to a moving state after the slideable magnet is moved to the second position. 
     
     
       5. The method of  claim 1  wherein said linear drive mechanism is bi-directional. 
     
     
       6. The method of  claim 1  wherein said linear drive mechanism comprises a pulley driven belt. 
     
     
       7. The method of  claim 1  wherein said containers are open. 
     
     
       8. A method of transporting a sample rack along a operating surface in either of two opposed directions by:
 locating a magnetic conveyor system beneath the operating surface, the conveyor system comprising a plurality of magnetic housings attached to a linear drive mechanism, the magnetic housings including a magnet slideably contained therein;  
 providing a sample rack having a ferromagnetic plate secured in a closed base cavity in the lower portion;  
 placing the sample rack on the operating surface with the lower portion in contact with the operating surface;  
 moving the magnetic housings in a first direction beneath the operating surface by activating the linear drive mechanism in said first direction,  
 wherein the magnetic housings are distanced from the magnetic sample rack so that magnetic forces emanating from the slideable magnet and acting on the ferromagnetic plate are sufficiently strong so as to overcome resistive forces between the sample rack and the operating surface and move the sample racks along the operating surface in concert with the activated linear drive mechanism, and wherein the slideable magnet moves from a first position to a second position in the closed upper portion, the first position being located a relatively smaller distance from the sample rack and the second position is located a relatively large distance from the sample rack while the pulley driven belt  linear drive mechanism is activated; and,  
 moving the magnetic housings in a second direction opposite to said first direction by reversing the linear drive mechanism so as to move said magnetic housings in said second direction.  
 
     
     
       9. The method of  claim 8  wherein the sample rack is transitioned from a stationary position to a moving state after the slideable magnet is moved to the second position. 
     
     
       10. The method of  claim 1  wherein said the operating surface has a friction-reducing layer applied thereover. 
     
     
       11. The method of  claim 8  wherein said the operating surface has a friction-reducing layer applied thereover.