Propeller with kort nozzle

Claim 2

A propeller assembly comprising a rotatable shaft, a plurality of propeller blades secured to and disposed in angularly spaced relationship on said shaft for rotation therewith, said propeller blades extending outwardly from said shaft, said propeller blades extending in the propulsion direction of the assembly and having a leading surface facing in the propulsion direction and a trailing surface facing in the opposite direction, a Kort nozzle circumferentially enclosing the outer edges of said propeller blades and said Kort nozzle extending forwardly of the leading surface of said propeller blades and rearwardly from the trailing surface of said propeller blades, the inner surface of said Kort nozzle intermediate its leading edge and trailing edge forms an annular groove aligned opposite and spaced outwardly from the outer edges of said propeller blades, and an annular member secured to the outer edges of said propeller blades for rotation therewith and disposed opposite said annular groove, the dimension of said annular member in the propulsion direction being sufficient to form a covering substantially closing the opening to said annular groove and arranged to provide a narrow circumferentially exTending opening to said annular groove along its leading and trailing edges, the inner surface of said annular member being arranged in general alignment with the inner surface of said Kort nozzle, said leading edge of said annular member sloping from its inner surface to its outer surface in the propulsion direction and the juxtaposed surface of said Kort member at the inner edge of said annular groove is closely spaced from and slopes in the same direction as the leading edge of said annular member forming the opening to the leading end of said annular groove, and the trailing edge of said annular member extends in the direction opposite to the propulsion direction so that it is spaced outwardly from and coextends for a portion of the inner surface of said Kort nozzle extending from said annular groove toward the trailing edge thereof and provides the opening therebetween for the trailing end of said annular groove.

Claim 3

A propeller assembly comprising a rotatable shaft, a plurality of propeller blades secured to and disposed in angularly spaced relationship on said shaft for rotation therewith, said propeller blades extending outwardly from said shaft, said propeller blades extending in the propulsion direction of the assembly and having a leading surface facing in the propulsion direction and a trailing surface facing in the opposite direction, a Kort nozzle circumferentially enclosing the outer edges of said propeller blades and said Kort nozzle extending forwardly of the leading surface of said propeller blades and rearwardly from the trailing surface of said propeller blades, the inner surface of said Kort nozzle intermediate its leading edge and trailing edge forms an annular groove aligned opposite and spaced outwardly from the outer edges of said propeller blades, and an annular member secured to the outer edges of said propeller blades for rotation therewith and disposed opposite said annular groove, the dimension of said annular member in the propulsion direction being sufficient to form a covering substantially closing the opening to said annular groove and arranged to provide a narrow circumferentially extending opening to said annular groove along its leading and trailing edges, the inner surface of said annular member being arranged in general alignment with the inner surface of said Kort nozzle, said leading edge of said annular member sloping from its inner surface to its outer surface in the propulsion direction and the juxtaposed surface of said Kort nozzle at the inner edge of said annular groove is closely spaced from and slopes in the same direction as the leading edge of said annular member forming the opening to the leading end of said annular groove, and the inner and outer surfaces of said annular member tapered to and meet in an apex at the trailing edge thereof, and the trailing edge extends in the direction opposite to the propulsion direction so that it is closely spaced inwardly from and coextends for a portion of the inner surface of said Kort nozzle extending from said annular groove toward the trailing edge thereof and provides the opening therebetween from the trailing end of said annular groove.

Claim 4

A propeller assembly comprising a rotatable shaft, a plurality of propeller blades secured to and disposed in angularly spaced relationship on said shaft for rotation therewith, said propeller blades extending outwardly from said shaft, said propeller blades extending in the propulsion direction of the assembly and having a leading surface facing in the propulsion direction and a trailing surface facing in the opposite direction, a Kort nozzle circumferentially enclosing the outer edges of said propeller blades and said Kort nozzle extending forwardly of the leading surface of said propeller blades and rearwardly from the trailing surface of said propeller blades, the inner surface of said Kort nozzle intermediate its leading edge and trailing edge forms an annular groove aligned opposite and spaced outwardly from the outer edges of said propeller blades, and an annular member secured to the outer edges of said propeller blades for rotation therewith and disposed opposite said annular groove, the dimension of said annular member in the propulsion direction being sufficient to form a covering substantially closing the opening to said annular groove and arranged to provide a narrow circumferentially extending opening to said annular groove along its leading and trailing edges, the inner surface of said annular member being arranged in general alignment with the inner surface of said Kort nozzle, said leading edge of said annular member sloping from its inner surface to its outer surface in the propulsion direction and the juxtaposed surface of said Kort nozzle at the inner edge of said annular groove is closely spaced from and slopes in the same direction as the leading edge of said annular member forming the opening to the leading end of said annular groove, and the inner and outer surfaces of said annular member tapered to and meet in an apex at the trailing edge thereof, and the trailing edge extends in the direction opposite to the propulsion direction so that it is closely spaced inwardly from and coextends for a portion of the inner surface of said Kort nozzle extending from said annular groove toward the trailing edge thereof and provides the opening therebetween from the trailing end of said annular groove.

Claim 5

A propeller assembly comprising a rotatable shaft, a plurality of propeller blades secured to and disposed in angularly spaced relationship on said shaft for rotation therewith, said propeller blades extending outwardly from said shaft, said propeller blades extending in the propulsion direction of the assembly and having a leading surface facing in the propulsion direction and a trailing surface facing in the opposite direction, a Kort nozzle circumferentially enclosing the outer edges of said propeller blades and said Kort nozzle extending forwardly of the leading surface of said propeller blades and rearwardly from the trailing surface of said propeller blades, the inner surface of said Kort nozzle intermediate its leading edge and trailing edge forms an annular groove aligned opposite and spaced outwardly from the outer eDges of said propeller blades, and an annular member secured to the outer edges of said propeller blades for rotation therewith and disposed opposite said annular groove, the dimension of said annular member in the propulsion direction being sufficient to form a covering substantially closing the opening to said annular groove and arranged to provide a narrow circumferentially extending opening to said annular groove along its leading and trailing edges, the inner surface of said annular member being arranged in general alignment with the inner surface of said Kort nozzle, said inner leading edge of said annular groove is spaced radially inwardly relative to the trailing edge of said annular groove, the leading edge inner surface of said annular member is spaced closely outwardly from the adjacent inner surface of said Kort nozzle and the trailing edge of the inner surface of said annular member extends in the direction opposite to the propulsion direction rearwardly beyond the trailing edge of said annular groove and is spaced closedly inwardly from the inner surface of the portion of said Kort nozzle extending from said annular groove to the trailing edge thereof so that the opening to the trailing end of said annular groove is positioned between the outer trailing edge surface of said annular member and the juxtaposed inner surface of said Kort nozzle extending rearwardly from the inner trailing edge of said annular groove.

Claim 6

A propeller assembly comprising a rotatable shaft, a plurality of propeller blades secured to and disposed in angularly spaced relationship on said shaft for rotation therewith, said propeller blades extending outwardly from said shaft, said propeller blades extending in the propulsion direction of the assembly and having a leading surface facing in the propulsion direction and a trailing surface facing in the opposite direction, a Kort nozzle circumferentially enclosing the outer edges of said propeller blades and said Kort nozzle extending forwardly of the leading surface of said propeller blades and rearwardly from the trailing surface of said propeller blades, the inner surface of said Kort nozzle intermediate its leading edge and trailing edge forms an annular groove aligned opposite and spaced outwardly from the outer eDges of said propeller blades, and an annular member secured to the outer edges of said propeller blades for rotation therewith and disposed opposite said annular groove, the dimension of said annular member in the propulsion direction being sufficient to form a covering substantially closing the opening to said annular groove and arranged to provide a narrow circumferentially extending opening to said annular groove along its leading and trailing edges, the inner surface of said annular member being arranged in general alignment with the inner surface of said Kort nozzle, said inner leading edge of said annular groove is spaced radially inwardly relative to the trailing edge of said annular groove, the leading edge inner surface of said annular member is spaced closely outwardly from the adjacent inner surface of said Kort nozzle and the trailing edge of the inner surface of said annular member extends in the direction opposite to the propulsion direction rearwardly beyond the trailing edge of said annular groove and is spaced closedly inwardly from the inner surface of the portion of said Kort nozzle extending from said annular groove to the trailing edge thereof so that the opening to the trailing end of said annular groove is positioned between the outer trailing edge surface of said annular member and the juxtaposed inner surface of said Kort nozzle extending rearwardly from the inner trailing edge of said annular groove.