Patent ID: 7762772

Claim:
A marine propeller, comprising: an outer hub; a plurality of blades extending from said outer hub in a radial direction; an inner hub attached to said outer hub, said inner and outer hubs being configured to be coaxial with each other and with an axis of rotation of said marine propeller, said inner and outer hubs defining a passage therebetween; an opening extending radially through said outer hub; and a valve disposed in said opening and extending into said passage, said valve comprising a piston slidably disposed in a central cavity of a housing, a resilient member disposed within said cavity and configured to urge said piston in a radially inward direction toward said axis of rotation, said housing having an aperture through said housing, said aperture connecting said passage in fluid communication with said central cavity, said aperture and said piston being configured to cause said piston to progressively block said aperture in response to movement of said piston away from said axis of rotation, said housing having a first end and a second end, said first end being disposed farther from said axis of rotation than said second end, said housing having a first port formed through said first end, said first port being configured to connect said central cavity with a region radially outward from said outer hub, wherein said housing has a second port formed through said second end.