Patents by Inventor Norval Stapefeld

Norval Stapefeld 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: 6229988
    Abstract: In a signal receiving apparatus as, for example, that used in the monitoring in a stolen vehicle transceiver of the presence of sequential transmitted signals specifically requesting that transceiver to respond to enable tracking the vehicle, wherein the receiver is powered by a consumable energy source of predetermined budgeted lifetime and adapted to operate between quiescent energy-saving and energized energy-consuming states for performing such sequential signal monitoring, desired signal identifying and related functions, a method of and apparatus for insuring the availability of energy to be able to perform such functions within said predetermined budgeted life time, that comprises, allocating budget time intervals for periodically operating the receiver intermittently in energized state to enable the performing of such functions as monitoring for such signals; and, in the event of inordinate energy consumption during such operation, that, if continued, would render the operation out of overall allocate
    Type: Grant
    Filed: May 20, 1998
    Date of Patent: May 8, 2001
    Assignee: LoJack Corporation
    Inventors: Norval Stapefeld, Dan Kotlow, Sheldon Apsell