# US 11,027,808 B2 · Aerofoil sail > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,027,808 B2 - Document ID: US11027808B2 - Status: Granted - Kind: B2 - Application number: 14/411,853 - Filed: 2013-07-01 - Published: 2015-07-09 - Granted: 2021-06-08 - Earliest claimed: 2012-06-29 - Assignees: Windship Technology Limited - Applicants: Windship Technology Limited - Inventors: Simon Mark Rogers - Web page: https://patentgrep.com/patent/US11027808B2 ## CPC - B63H 9/061: Rigid sails; Aerofoil sails - B63B 15/0083: {Masts for sailing ships or boats} - B63H 9/08: Connections of sails to masts, spars, or the like - B63H 9/0621: {Rigid sails comprising one or more pivotally supported panels} - B63H 9/0635: {the panels being pivotable about vertical axes} - B63H: MARINE PROPULSION OR STEERING (propulsion of air-cushion vehicles B60V1/14; specially adapted for submarines, other than nuclear propulsion, B63G; specially adapted for torpedoes F42B19/00) - B63B: SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING (arrangements of vessel ventilation, heating, cooling, or air-conditioning B63J2/00; floating substructures as supports of dredgers or soil-shifting machines E02F9/06) ## Abstract An aerofoil sail (30) for providing motive power to a waterborne vessel, the sail comprising a leading aerofoil portion (35a) and a trailing aerofoil portion (35b), and the sail comprising a spar (32), at least one of the aerofoil portions rotatably positionable, and the sail comprising a controller to control individually the angular position of at least one of the aerofoil portions relative to the spar, and the spar rotationally positionable about its longitudinal axis. ## Claims ### Claim 1 An aerofoil sail assembly for providing motive power to a cargo vessel, comprising three aerofoil sails, each aerofoil sail comprising a leading aerofoil portion and a trailing aerofoil portion, and the aerofoil sail assembly comprising a spar defining a longitudinal axis and a height along the longitudinal axis, at least one of the aerofoil portions rotatably positionable, wherein an angular position of at least one of the aerofoil portions controllable relative to the spar, and the spar rotationally positionable about the longitudinal axis, and each of a leading portion and a trailing portion comprising a respective external aerofoil surface and wherein a distance between distal end regions of the external aerofoil surface of the leading portion in a direction transverse to the height of the spar is longer than a distance between distal end regions of the aerofoil surface of the trailing portion in the direction transverse to the height of the spar, and a gap is provided between the leading portion and the trailing portion, and wherein the three aerofoil sails provided in a side-by-side spaced apart relationship, and a leading aerofoil portion of a central aerofoil sail of said three aerofoil sails having a height, and the spar extending internally of said leading aerofoil portion of said central aerofoil sail and for the height of said leading aerofoil portion of said central aerofoil sail, and the spar comprising an internal volume sized to allow operative access for a major portion of a length of the spar. ### Claim 2 (depends on 1) An aerofoil sail assembly as claimed in claim 1 in which a controller performs automated control of the least one of the leading aerofoil portion and the trailing aerofoil portion and the spar. ### Claim 3 (depends on 2) An aerofoil sail assembly as claimed in claim 2 in which the controller may use feedback signals from one or more sensors, wherein the one or more sensors are operatively connected to the sail in order to determine a suitable control signal. ### Claim 4 (depends on 1) An aerofoil sail assembly as claimed in claim 1 in which one of the leading aerofoil portion and the trailing aerofoil portion is rigid with the spar, and the other aerofoil portion is rotatably positionable relative to the spar. ### Claim 5 (depends on 1) An aerofoil sail assembly as claimed in claim 1 in which both of the aerofoil portions are pivotably positionable relative to the spar. ### Claim 6 (depends on 1) An aerofoil sail assembly as claimed in claim 1 in which when aligned, the leading portion and the trailing portion form an aerofoil profile. ### Claim 7 (depends on 1) An aerofoil sail assembly as claimed in claim 1 in which each portion is of aerofoil shape when viewed in plan. ### Claim 8 (depends on 7) An aerofoil sail assembly as claimed in claim 7 in which the at least one rotatably positionable aerofoil portion is rotatable connected to a fixed aerofoil portion. ### Claim 9 (depends on 1) An aerofoil sail assembly as claimed in claim 1, wherein a set of leading and trailing portions is arranged above another such set. ### Claim 10 (depends on 9) An aerofoil sail assembly as claimed in claim 9 in which each set of a leading portion and a trailing portion is at substantially a same vertical position. ### Claim 11 (depends on 9) An aerofoil sail assembly as claimed in claim 9 in which each of the trailing portions and the leading portions comprises a leading edge and a trailing edge. ### Claim 12 (depends on 1) An aerofoil sail assembly as claimed in claim 1 in which at least one of the leading and trailing portions is pivotable through around sixty degrees. ### Claim 13 (depends on 1) An aerofoil sail assembly as claimed in claim 1 in which a centre of effort of the sail is located anterior of a centreline of the spar. ### Claim 14 (depends on 1) An aerofoil sail assembly as claimed in claim 1 in which the sail is a substantially rigid structure. ### Claim 15 (depends on 1) An aerofoil sail assembly as claimed in claim 1 in which the spar supports the aerofoil portions.