Patents by Inventor James W. Phelpstead

James W. Phelpstead 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).

  • Tobacco smoke filters
    Patent number: 4754766
    Abstract: A tobacco smoke filtration element having a first smoke-flow passage of filtration efficiency less than that of a second smoke-flow passage, the first smoke-flow passage being provided with a heat deformable material which, upon smoking of a smoking article incorporating such a filtration element, deforms and thereby obturates the first smoke-flow passage causing smoke to pass along the second smoke-flow passage and thereby to be subjected to a higher degree of smoke filtration after the first stages of the smoking cycle.
    Type: Grant
    Filed: July 10, 1986
    Date of Patent: July 5, 1988
    Assignee: British-American Tobacco Company Limited
    Inventors: John A. Luke, James W. Phelpstead
  • Tobacco smoke filters
    Patent number: 4660579
    Abstract: Cigarette filters comprises a filter element, open for smoke flow at the mouth end, and smoke passage of flow impedance less than that of the filter element. The passage is closed at the downstream end so that smoke is constrained to pass into the element at the downstream end of the passage. The passage may be an annular cross-section duct or grooves at the periphery of the element or may be a bore within the element. The filters provide an increasing degree of filtration as smoking proceeds.
    Type: Grant
    Filed: October 24, 1985
    Date of Patent: April 28, 1987
    Assignee: British-American Tobacco Company Limited
    Inventors: Henry G. Horsewell, Martin G. Duke, James W. Phelpstead