Patents Examined by Eugene A. Powell, Jr.
  • Patent number: 4021142
    Abstract: A pitch-change apparatus for a ducted thrust fan having a plurality of variable pitch blades employs a rotatable ring bearing a plurality of camming members, and each of the plurality of blades is connected with a pitch-change horn engaged by one of the camming members. The ring and camming members rotate coaxially about a hub axis with the blades and rotate about the hub axis relative to the blades to collectively change blade pitch. The rotatable ring, the camming members and the pitch-change horns develop a variable mechanical advantage, and the pitch horns are connected with their respective blades so that the minimum mechanical advantage corresponds with the low-load, feathered pitch position of the blades and greater mechanical advantages correspond with the higher load, forward and reverse pitch positions of the blades.
    Type: Grant
    Filed: October 9, 1974
    Date of Patent: May 3, 1977
    Assignee: United Technologies Corporation
    Inventor: John A. Violette