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:
Nov. 29, 1994
Filed:
Nov. 15, 1993
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 which are rotatably connected to a central hub; the blades rotate relative to the hub center about the shank axis. In operation, the blades are biassed towards the lower pitch, both by mechanical means, such as a spring, and optionally also by hydrodynamic load means. As the propeller rotational speed increases, centrifugal forces act to move the blades towards the higher pitch position. In one alternative mode the hydrodynamic load also acts towards the higher pitch position. There is further provided a holding mechanism to retain or hold the blades at least preferably in the lower pitch position, the holding mechanism being so designed that at a sharply defined combination of parameters, including rotational speed and optimally hydrodynamic load acting on the blades, the holding mechanism is caused to be released and the blades permitted to move to a second higher pitch position.