Patents by Inventor Donald H. Hockenberry

Donald H. Hockenberry 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).

  • Dual speed rotary vane pump
    Patent number: 4207031
    Abstract: A dual speed mechanical rotary vacuum pump wherein a mechanical rotary vacuum pump is directly connected to a two speed electrical motor which drives the pump and the speed of the motor is controlled by an electrical control circuit which selectively causes the motor to rotate at either a first speed for a predetermined period of time or at a second slower speed. The speed of the motor is automatically switched to the slower speed after the predetermined period of time.
    Type: Grant
    Filed: March 29, 1978
    Date of Patent: June 10, 1980
    Assignee: Leybold-Heraeus GmbH & Co. KG
    Inventors: Alfred E. Maskrey, Donald H. Hockenberry