Patents by Inventor Stephen D. Levy

Stephen D. Levy 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).

  • Precise call progress detector
    Patent number: 4742251
    Abstract: A circuit for providing a dynamic noise floor level. An analog to digital converter provides one of a plurality of outputs as determined by the level of an input signal. A comparator compares each digital input signal with the signal latched in a storage device. For an increasing digital signal the value is latched in a storage device. If the signal is decreasing, the value stored in the storage device is decremented by 1. The output of the storage device is coupled to a demultiplexor for digital to analog conversion. The outputs of the demultiplexor are coupled to a plurality of capacitors of varying capacitance so that a range of output signals may be achieved. The analog output of the circuit is used as a noise floor level in a precise call progress detector.
    Type: Grant
    Filed: August 12, 1985
    Date of Patent: May 3, 1988
    Assignee: Silicon Systems, Inc.
    Inventor: Stephen D. Levy
  • Process for deodorizing aqueous effluent derived from the manufacture of organic chemicals
    Patent number: 4263136
    Abstract: A process for the deodorizing and removing organic materials from sulfur containing aqueous effluent obtained in the manufacture of organic chemicals by treatment of said effluent with hydrogen peroxide under controlled conditions.
    Type: Grant
    Filed: April 16, 1979
    Date of Patent: April 21, 1981
    Inventors: George N. Gagliardi, Stephen D. Levy
  • Reductive alkylation of substituted anilines
    Patent number: 4261926
    Abstract: N-alkylated aromatic amines are produced by reductively alkylating an aromatic amine with pressurized hydrogen in the presence of a ketone, a noble metal catalyst and a promoter acid having a pKa between 0.3 and 1.5.
    Type: Grant
    Filed: November 19, 1979
    Date of Patent: April 14, 1981
    Assignee: American Cyanamid Company
    Inventors: Lawrence J. Ross, Stephen D. Levy
  • Preparation of 2,6-dinitroanilines
    Patent number: 4136117
    Abstract: This invention relates to a novel process for the preparation of N-alkylated and N,N-dialkylated 2,6-dinitroaniline herbicidal agents.
    Type: Grant
    Filed: March 14, 1977
    Date of Patent: January 23, 1979
    Assignee: American Cyanamid Company
    Inventors: Robert E. Diehl, Stephen D. Levy, William H. Gastrock