The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 23, 1990
Filed:
Mar. 18, 1985
Robert W Allington, Lincoln, NE (US);
Jon L Curran, Lincoln, NE (US);
Jerold B Schmidt, Lincoln, NE (US);
Isco, Inc., Lincoln, NE (US);
Abstract
To control with precision and repeatability the amount of fluid dispensed or aspirated by a pumping system, a volume disk rotates with the output shaft of a DC motor that drives a reciprocating dispensing pump. A sensor detects indicia on the disk and provides periodic signals spaced-apart in time by an amount: (1) an amount proportional to the volume of fluid pumped; (2) proportional to the angle between indicia; (3) less than one-third of the length of the total stroke of the piston as the piston moves linearly in its working portion of a cycle; (4) necessary for the piston to sweep out a volume of less than five milliliters. The speed of the pump is controlled by a second disk having equally spaced indicia that are sensed to provide signals proportional to the motor speed. During dispensing or aspirating large volumes, the motor speed is increased to a high speed, run at the high speed and then decreased before stopping and during dispensing smaller volumes, it is maintained at a constant lower speed.