Patents by Inventor John Derek Gilbert

John Derek Gilbert 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).

  • Unidirectional self-starting electrical motors with shaded poles and shaded magnetic shunt
    Patent number: 4012652
    Abstract: A unidirectional self-starting synchronous motor comprises a stator having pole teeth of alternating polarity some of which are shaded to provide shaded pole groups alternating with unshaded pole groups. The shaded groups are angularly displaced from a symmetrical position. The total number of effective poles equals the theoretical synchronous number and these are poles divided substantially evenly between the groups. In one case, a shaded shunt is provided as an addition to the shaded groups and a rotor is provided from radially-polarized, anisotropic, ferrite.
    Type: Grant
    Filed: April 24, 1974
    Date of Patent: March 15, 1977
    Assignee: Electrical Remote Control Company, Ltd.
    Inventor: John Derek Gilbert