The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 14, 1992
Filed:
Jan. 24, 1991
Stephen R Speer, Spokane, WA (US);
Nautical Development, Inc., Spokane, WA (US);
Abstract
A self-actuating variable pitch marine propeller which incorporates two or more blades having cylindrical shafts which are rotatably connected to a central hub via cylindrical joints; the blades rotate about and translate radially, relative to the hub center, along the blade shaft, or shank, axis. In operation, the blades move radially outwardly from the hub center as they rotate from lower to higher pitch. The blades are biased towards the lower pitch. As the propeller rotational speed increases, centrifugal forces act on the blade mass creating a radially directed outward force. This radially outward force, upon reaching a sufficient magnitude, causes the blades to move radially outward. A blade positioning mechanism connected between each blade and the hub directs the blades to rotate to a higher pitch angle as the blades move radially outward. There is further provided a holding mechanism to retain, or hold, the blades at least in one discrete pitch position; the holding mechanism is designed such that at a sharply defined combination of parameters, including rotational speed and, optimally, hydrodynamic load on the blades, the blades are released and permitted to move to a second pitch position.