Patents by Inventor Leo Bruce Hempell

Leo Bruce Hempell 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).

  • Remote switching apparatus
    Patent number: 4078236
    Abstract: A remote switching apparatus, in which a transmitter is adapted to transmit a predetermined number of bursts of single frequency signal, to designate a particular digit. Preferably the group of bursts is preceded by a prepulse of particular character which effectively enables the receiver, preparing it to count the bursts which follow and thus to operate a switch corresponding to the digit. The receiver is thus immune to ambient noises except during the short time interval during which it is enabled.
    Type: Grant
    Filed: April 7, 1975
    Date of Patent: March 7, 1978
    Assignee: Quality Technology Ltd.
    Inventor: Leo Bruce Hempell