Patents by Inventor Albert Stern

Albert Stern 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).

  • Wireless burglar alarm system
    Patent number: 3969709
    Abstract: A radio intrusion alarm system utilizing a high frequency carrier signal having an audio subcarrier which may be modulated by two tone signals, the first tone signal causing actuation of an alarm, the second tone signal causing actuation of a time delay means which inhibits operation of the alarm to permit an authorized entry, for example, at the transmitter location without giving the alarm.
    Type: Grant
    Filed: June 26, 1969
    Date of Patent: July 13, 1976
    Inventors: Roger Isaacs, Albert Stern