Patents by Inventor Robert W. Sweetser

Robert W. Sweetser 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: 5271236
    Abstract: The system is adapted for saving energy in an ambient air and conventional refrigeration system by independently controlling the compressor, evaporator fans and door heating unit in conjunction with the outdoor temperatures and the unit's internal temperature. The system also provides controls that provide for freeze up protection. The system can be adapted for use with walk in cooler units currently in operation to provide a system that can provide operational cost savings and increased efficiency for the operator.
    Type: Grant
    Filed: December 28, 1992
    Date of Patent: December 21, 1993
    Assignee: Air Enterprises, Inc.
    Inventor: Robert W. Sweetser
  • Patent number: 4838991
    Abstract: A conformal organic layer is used to define spacers on the sidewalls of an organic mandrel. The organic layer (e.g., parylene) can be deposited at low temperatures, and as such is compatible with temperature-sensitive mandrel materials that reflow at high deposition temperatures. The conformal organic material can be dry etched as the same rate as the organic mandrels, while being resistant to wet strip solvents that remove the organic mandrels. This series of etch characteristics make the organic mandrel-organic spacer combination compatible with a host of masking applications.
    Type: Grant
    Filed: June 20, 1988
    Date of Patent: June 13, 1989
    Assignee: International Business Machines Corporation
    Inventors: William J. Cote, Donald M. Kenney, Michael L. Kerbaugh, Michael A. Leach, Jeffrey A. Robinson, Robert W. Sweetser
  • Patent number: 4632724
    Abstract: A method of enhancing first order alignment marks formed in the respective layers of a processed semiconductor wafer in which critical masking steps are carried out. After a given mark is formed, it is tested for visual contrast. If the contrast is insufficient to provide adequate alignment, a block mask is formed on the critical mask. The block mask exposes all of the alignment target areas and protects the product regions of the wafer, and the critical mask only exposes the mark to be enhanced. The mark is then etched for a time period which is a function of the measured visual contrast. This method of selectively enhancing selected ones of the first order alignment marks greatly enhances the utility of such marks, increasing the accuracy of critical masking steps.
    Type: Grant
    Filed: August 19, 1985
    Date of Patent: December 30, 1986
    Assignee: International Business Machines Corporation
    Inventors: Donald G. Chesebro, Robert W. Sweetser