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:
Apr. 22, 1997
Filed:
Feb. 28, 1996
John G Walker, St Mellion, Cornwall, GB;
Other;
Abstract
A wingsail assembly in which at least one thrust wing is mounted for free rotation about an upright axis and defining by its free rotation a trimming circle. The assembly includes a first control airfoil freely pivoted on a first boom extended upstream of a thrust wing, the first boom being of a length such that the first auxiliary control airfoil is within the trimming circle and a second control airfoil mounted downstream of the first control airfoil within the trimming circle and settable for controlling the angle of attack of the first control airfoil to the wind which in turn provides a turning moment for controlling the angle of attack of the thrust wing to provide thrust levels required for all normal sailing conditions. The assembly further moves the thrust wing to bring the instantaneous center of pressure of the thrust wing at different angles of attack into closer proximity to the upright axis and reduces the turning moment required of the first control airfoil, and in which the first control airfoil is freely pivoted about an axis ahead of all combined center of pressure locations for the first and second control airfoils.