Patents by Inventor Stephen P. Birman

Stephen P. Birman 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: 4880479
    Abstract: A resulfurized and rephosphorized free-machining steel bar formed by cold drawing a hot rolled steel bar has the composition, by weight, C up to 0.08%; Mn 0.6% to 1.4%; Si up to 0.1%; P at least 0.03%; S 0.25% to 0/50%; Cb 0.02% to 0.10%; the sum of Ni, Cr, Mo and Cu up to 0.15%; balance iron. The ratio of %Mn/%S is from 1.6 to 4.0, and the ratio of [%Mn-(1.62.times.%S)]/%Cb is from 2 to 50. The yield strength of the steel bar is further determined by the draft in cold drawing the bar from the hot rolled state and the size and cross section of the bar after draft. The relationship between strength and ductility is further improved by heavy drafting in cold drawing the bar from the hot rolled state.
    Type: Grant
    Filed: June 9, 1988
    Date of Patent: November 14, 1989
    Assignee: Stanadyne, Inc.
    Inventors: Stephen P. Birman, Richard B. Smith, Richard L. Thompson
  • Patent number: 4741786
    Abstract: A cold drawn free-machining steel bar having a composition consisting essentially of, in weight percent, C up to 0.15; Mn 0.7 to 1.3; P 0.03 to 0.09; S 0.30 to 0.50; Bi 0.05 to 0.25; the sum of Ni, Cr, Mo and Cu up to 0.15 and the balance iron. The ratio % Mn / %S is from 1.7 to 3.0 and the %Mn-1.62.times.%S is from 0.05 to 0.40. The ratio %Bi /(%Ni+%Cu) is at least 2.0. The yield strength of the steel bar is further determined by the draft in cold drawing the bar from the hot rolled state and the cross section of the bar prior to draft.
    Type: Grant
    Filed: June 10, 1986
    Date of Patent: May 3, 1988
    Assignee: Stanadyne, Inc.
    Inventors: Stephen P. Birman, Richard B. Smith, Richard L. Thompson