Bi-directional magnetic sample rack conveying system

• US 6,571,934 B1
• Filed: 11/14/2001
• Issued: 06/03/2003
• Est. Priority Date: 11/14/2001
• Status: Expired

• Current Assignee: Siemens Healthcare Diagnostics Incorporated (Siemens AG)
• Original Assignee: Dade Behring, Inc. (Siemens AG)
• Inventors: Vijay, Tumkur R., Thompson, David R., Dunfee, William D., Gillund, Daniel E.
• Primary Examiner(s): Ellis, Christopher P.
• Assistant Examiner(s): RIDLEY, RICHARD W L
• Application Number:
  US09/992,917
• Publication Number:
  US 20030089581A1
• Time in Patent Office: 566 Days
• Field of Search: 198/619
• US Class Current: 198/619
• CPC Class Codes: B65G 2201/0261 Puck as article support
• CPC Class Codes: B65G 23/18 Suction or magnetic elements
• CPC Class Codes: B65G 47/1485 using suction or magnetic forces
• CPC Class Codes: G01N 2035/0477 Magnetic
• CPC Class Codes: G01N 35/026 having blocks or racks of reaction cells or cuvettes
• CPC Class Codes: G01N 35/04 Details of the conveyor system G01N35/021 - G01N35/028 take precedence

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.

Claims

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,

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.

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.

10. The method of claim 1 wherein said the operating surface has a friction-reducing layer applied thereover.

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 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.

11. The method of claim 8 wherein said the operating surface has a friction-reducing layer applied thereover.