Closed and open tube sampling apparatus

• US 5,216,926 A
• Filed: 08/05/1992
• Issued: 06/08/1993
• Est. Priority Date: 04/18/1990
• Status: Expired due to Fees

• Current Assignee: Dade Behring, Inc. (Siemens AG)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Lipscomb, James H.
• Primary Examiner(s): NOLAND, THOMAS
• Application Number:
  US07/924,636
• Time in Patent Office: 307 Days
• Field of Search: 73/863.01, 73/863.02, 73/863.03, 73/863.83, 73/863.84, 73/863.85, 73/864.21-864.25, 73/864.73, 73/864.74 , 73/864.34, 73/864.35, 422/63-67, 436/43, 436/45, 436/47-51, 436/54
• US Class Current: 73/864.25
• CPC Class Codes: G01N 2035/0451 composed of interchangeable sectors
• CPC Class Codes: G01N 2035/0479 hydraulic or pneumatic
• CPC Class Codes: G01N 35/1004 Cleaning sample transfer devices
• CPC Class Codes: G01N 35/1079 with means for piercing stoppers or septums
• CPC Class Codes: G01N 35/1083 with one horizontal degree of freedom

Abstract

An automatic sampling apparatus is constructed to use bang-bang fluid driven actuators whose control system is modified to permit accurate positioning over its range of motion. The actuators are positioned to aspirate liquid contents held within stoppered sample containers and equilibrate pressure in the sample containers to atmospheric prior to aspiration.

Claims

1. In a sampling apparatus having a sample carrier adapted to move a plurality of sample containers into a sampling position, a lateral translator located to have a path of movement over the sampling position, a vertical translator mounted to be positioned laterally by the lateral translator, a sampling probe adapted to be positioned vertically by the vertical translator into and out of the sample containers, a liquid pump connected to the probe to aspirate sample from the sample containers, and controller means to actuate the translators and pump to effect such aspirations, the improvement wherein the translators are fluid driven actuators, the sample containers are upright, and at least one sample container is closed, and wherein the pump is connected by a conduit to the probe and which includes a valve positioned in the conduit and responsive to the controller means to open the conduit to atmospheric pressure immediately prior to sample aspiration to equilibrate the pressure in the closed sample container.

2. The sampling apparatus of claim 1 wherein each translator includes a fluid driven actuator connected to a position encoder and responsive to the position of the translator, servo valves to drive the actuator in opposite directions, and a digital positioning circuit responsive to the controller and the position encoder for controlling the servo valves to position the probe in accordance with a position designated by the controller.

3. In a sampling apparatus having a sample carrier adapted to move a plurality of sample containers into a sampling position, a lateral translator located to have a path of movement over the sampling position, a vertical translator mounted to be positioned laterally by the lateral translator, a sampling probe adapted to be positioned vertically by the vertical translator into and out of the sample containers, a liquid pump connected to the probe to aspirate sample from the sample containers, and controller means to actuate the translators and pump to effect such aspirations, the improvement wherein the translators are fluid driven actuators, the sample containers are upright, and at least on sample container is closed and which includes a retaining bracket for the sample containers positioned to limit their upward movement during probe withdrawal from the container, and wherein the pump is connected by a conduit to the probe and which includes a valve positioned in the conduit and responsive to the controller means to open the conduit to atmospheric pressure immediately prior to sample aspiration to equilibrate the pressure in the closed sample container.

4. The sampling apparatus of claim 3 wherein each translator includes a fluid driven actuator connected to a position encoder responsive to the position of the translator, servo valves to drive the actuator in opposite directions, and a digital positioning circuit responsive to the controller and the position encoder for controlling the servo valves to position the probe in accordance with a position designated by the controller.

5. In a sampling apparatus having a sample carrier adapted to move a plurality of sample containers into a sampling position, a lateral translator located to have a path of movement over the sampling position, a vertical translator mounted to be positioned laterally by the lateral translator, a sampling probe adapted to be positioned vertically by the vertical translator into and out of the sample containers, a liquid pump connected to the probe to aspirate sample from the sample containers, and controller means to actuate the translators and pump to effect such aspirations, the improvement wherein the translators are fluid driven actuators, the sample containers are upright, and at least one sample container is closed and which includes a retaining bracket for the sample containers positioned to limit their upward movement during probe withdrawal from the container,

a transfer vessel located along the path of movement of the lateral translator, said controller means operating the lateral translator to position the probe over the transfer vessel, the vertical translator and pump operating to discharge aspirated sample into the transfer vessel,

a wash receptacle located along the path of movement of the lateral translator, said controller means operating the lateral translator to position the probe over the wash receptacle, a source of wash liquid, the pump being coupled to the source, the vertical translator and pump operating to discharge wash liquid into the receptacle and to dip the probe into the receptacle to wash the probe, and the pump connected by a conduit to the probe, and

a valve positioned in the conduit and responsive to the controller means to open the conduit to atmospheric pressure immediately prior to sample aspiration to equilibrate the pressure in the closed sample container.

6. The sampling apparatus of claim 5 wherein each translator includes a fluid driven actuator connected to a position encoder and responsive to the position of the translator, servo valves to drive the actuator in opposite directions, and a digital positioning circuit responsive to the controller and the position encoder for controlling the servo valves to position the probe in accordance with a position designated by the controller.