Patents by Inventor Alvin J. Stein

Alvin J. Stein 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).

  • Method and apparatus for effecting uniform film thickness
    Patent number: 4209475
    Abstract: The uniformity of the gauge profile of thermoplastic sheet material is improved by means of a method comprising the detection of areas of non-uniform thickness in the sheet after drawing it away from the extrusion die and the redirection of a controlled portion of the cooling fluid by means of adjustable deflector blades which extend into the flowing stream of cooling fluid and alter the angle at which the cooling fluid contacts and quenches the molten extrudate, thereby allowing additional stretching of thick areas or earlier solidification of thin areas, as appropriate to the problem at hand.
    Type: Grant
    Filed: October 20, 1978
    Date of Patent: June 24, 1980
    Assignee: Mobil Oil Corporation
    Inventors: F. John Herrington, Alvin J. Stein