Patents by Inventor Alan W. Hametta

Alan W. Hametta 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: 4263553
    Abstract: A discriminating metal detector that can compensate for ground minerals includes an oscillator circuit having at least two attenuation coils physically located in a probe of the metal detector for ground control. The probe also includes a resonant LC circuit having an inductive coil on the same plane as the attenuation coils but on a different axis than the attenuation coils. The attenuation coils of the oscillator circuit have no magnetic effect on the inductive coil or on the natural response of the inductive coil to metal objects. The attenuation coils of the oscillator operate at a substantially higher frequency than the inductive coil of the resonant LC circuit. As the resonant frequency of the discriminating LC circuit varies due to mineral changes in the ground the oscillator frequency shifts likewise proportionally in order to maintain a constant separation between the two frequencies.
    Type: Grant
    Filed: May 30, 1978
    Date of Patent: April 21, 1981
    Inventors: Kenneth M. Cook, Alan W. Hametta