Patents by Inventor Paul Stiefel

Paul Stiefel has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4910682
    Abstract: A peristaltic pump controller provides control of a positive displacement pump as either an uncalibrated or calibrated flowmeter, or a calibrated dispenser. A calibration constant is calculated, after the pump is primed, to determine the amount of volume output produced by an increment of angular rotation of the pump. The constant is determined during a calibration operation where an arbitrary calibration volume is metered. The controller has a low flow and high flow mode where the low flow mode provides a higher resolution for dispensing. The flow mode of operation is determined by the value of the calibration constant and is automatically set when the constant is calculated. DUring a dispensing operation, the controller will meter fluid to within a predetermined amount of the final volume dependent upon the speed of the pump motor and then dribble in the remaining amount of a batch for precision.
    Type: Grant
    Filed: December 18, 1987
    Date of Patent: March 20, 1990
    Assignee: Cole-Parmer Instrument Company
    Inventors: Donald L. Wolff, Porter T. McCauley, Paul Stiefel, Gyoergy J. Takacs, Roman A. Adams
  • Patent number: 4715786
    Abstract: A peristaltic pump controller which provides control of a positive displacement pump as either an uncalibrated or calibrated flowmeter, or a calibrated dispenser. A calibration constant is calculated, after the pump is primed, to determine the amount of volume output produced by an increment of angular rotation of the pump. The constant is determined during a calibration operation where an arbitrary calibration volume is metered. The controller has a low flow and high flow mode where the low flow mode provides a higher resolution for dispensing. The flow mode of operation is determined by the value of the calibration constant and is automatically set when the constant is calculated. During a dispensing operation, the controller will meter fluid to within a predetermined amount of the final volume dependent upon the speed of the pump motor and then dribble in the remaining amount of a batch for precision.
    Type: Grant
    Filed: December 14, 1984
    Date of Patent: December 29, 1987
    Assignee: Cole-Parmer Instrument Company
    Inventors: Donald L. Wolff, Porter T. McCauley, Paul Stiefel, Gyoergy J. Takacs, Roman A. Adams