Patents by Inventor John A. Larsen

John A. Larsen 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: 5012660
    Abstract: In an arrangement for a tandem cold mill in order to compensate for "speed effect," each stand has a roll force memory unit and an oil film roll force controller unit which operate together, and in conjunction with a tensiometer, to maintain a relatively constant roll gap during the acceleration and deceleration phases of the mill. In threading, in tailing out, and in a full run speed of the mill, the roll force memory unit is constantly operating to obtain a "lock on" roll force reference for the stand prior to the acceleration or deceleration phase. A roll force error signal, which is the difference between a roll force reference of the roll force memory unit and an instantaneous roll force, enters the oil film roll controller. A proportional integrator type controller in the oil film roll force controller unit changes the roll force error signal within a limit of +25% of the desired tension.
    Type: Grant
    Filed: November 29, 1989
    Date of Patent: May 7, 1991
    Assignee: AEG Westinghouse Industrial Automation Corporation
    Inventors: Robert S. Peterson, John A. Larsen
  • Patent number: 4998427
    Abstract: A method for making delivery gauge corrections at low mill speeds during threading and tailing out of a workpiece by varying the interstand tension of the workpiece. The tension between the last two stands is used with a desired tension and the delivery AGC by tension mode of an existing delivery automatic gauge control (AGC) to change the speed of the downstream stands. During the threading and tailing out phases, the delivery AGC by speed is turned off and set to zero. In the full run phase, the interstand regulators are changed to a tension by roll gap mode, and an existing delivery automatic gauge control (AGC) by speed is used to provide a stand speed reference for the downstream stands. In the full run phase, the delivery (AGC) by tension is turned off an set to zero. In the tailing out phase optionally, the tension between each stand is used in a similar manner to provide a speed reference change for each stand immediately downstream from where a tension controller is located.
    Type: Grant
    Filed: November 29, 1989
    Date of Patent: March 12, 1991
    Assignee: AEG Westinghouse Industrial Automation Corporation
    Inventors: Robert S. Peterson, John A. Larsen