US 4,686,922 A · Swing wing keel

Abstract

A laterally extending hydrofoil wing is supported in pendulum fashion in a cutout section of a planar keel of a sailing vessel. The pendulum support, in combination with the distribution of mass in the swing wing attempts to maintain the plane of the wing, which is under the surface of a body of water in a position parallel to the surface of a body of water regardless of any rolling or heeling of the vessel. The wing is canted or tilted downwardly into the water in the fore direction of the vessel to plane deeper into the water. When the vessel attempts to roll about its fore and aft axis from its original upright position, the flow of water acting on the canted wing develops a large downward force on the wing and on the keel from which the wing is suspended. The downward force attempts to rotate the keel of the vessel about its fore and aft axis to restore the vessel to its upright position.

Claims8

Dependent claims

In a sailing vessel having a hull adapted to float on a body of water and a central keel member attached to the hull thereof and projecting vertically downwardly therefrom into the water on which said hull rests, the improvement comprising, a swing wing for said keel,

(a) said swing wing comprising in combination a generally rectangular hydrofoil planar wing section having smoothly tapering leading and trailing edges,
(b) an upstanding generally rectangular web support section joined to said wing section at the longitudinal center thereof and transversely thereto, said web section being perpendicular to said wing section, said web section and said wing section defining a generally inverted T configuration,
(c) and mounting means on the upstanding end of said web section to suspend said swing wing so that the plane of said keel member is perpendicular to said wing section,
(d) said mounting means being adapted to suspend said swing wing in a pendulum arrangement during heeling motion of the vessel during which the said wing section attempts to take up and maintain a position parallel to the surface of the water on which said hull rests.

1 more element

A boat having a longitudinally extending hull adapted to float on a body of water,

(a) a planar keel member projecting downwardly from said hull with the plane of said keel being perpendicular to the surface of said body of water,
(b) said keel member having a large rectangular cutout section therein,
(c) said cutout section being defined by a pair of spaced fore and aft vertical walls, and a transverse horizontal wall interconnecting said vertical walls to define the rectangular cutout section,
(d) and a support shaft parallel to but spaced from said horizontal wall and having one end supported in said fore end wall and the other end supported in said aft end wall,
(e) said support shaft spanning the rectangular cutout section, and
(f) a swing wing pivotally mounted on said support shaft,
(g) said swing wing comprising a generally narrow rectangular hydrofoil wing section,
(h) a generally rectangular web section joined at one end to said wing section in a transverse position at the mid point of the length of said wing section so that the web section and wing section provide the appearance of an inverted T section,
(i) the other end of said web section being formed to provide a journal support for said shaft,
(j) said swing wing being free to pivot and swing about said support shaft,
(k) the mass of said swing wing being appropriately distributed so that the web section is suspended vertically from said support shaft in said cutout section and said wing section maintains a horizontal relationship perpendicular to said web section to project laterally from each side of said keel to plane through the water as the vessel sails along,
(l) said wing section and said web section being formed so that the wing section is canted downwardly with the leading edge thereof being downwardly below the trailing edge with respect to a horizontal line defined by said support shaft spanning said cutout,
(m) said swing wing being free to swing as a pendulum from said support shaft in the port and starboard directions.

10 more elements

In a sailing vessel having an elongated hull and a longitudinally extending keel attached to said hull, said keel being a large planar member attached to said hull along the centerline thereof in the fore and aft directions and projecting away from said hull into a body of water, and

said planar keel having a large rectangular cutout section therein below the surface of said water, and
said cutout section being defined by a pair of spaced fore and aft keel walls as two vertical sides of said rectangular cutout section and a transverse wall therebetween as the third side of said rectangular section, the fourth side of said cutout section being open to the water, the improvement comprising in combination
(a) a swing wing pivotally mounted in said cutout section,
(b) said swing wing comprising a narrow rectangular hydrofoil wing,
(c) and a rectangular upstanding web section having one side edge attached transversely to said rectangular wing section at a mid point thereof to provide a general configuration of an inverted T section,
(d) the opposite unattached side edge of said web section having a journal formed thereon extending along the said unattached side edge,
(e) and a support shaft having one end affixed to the said fore keel wall and the other end affixed to said aft keel wall,
(f) the said support shaft being parallel with and spaced from said transverse keel wall to span said cutout section in the fore and aft directions,
(g) said support shaft passing through said journal on said web section to support said swing wing in said cutout section with the said web section taking up a vertical position to be parallel with the plane of said keel and in alignment with said spaced fore and aft keel walls,
(h) the wing section of said swing wing taking up a horizontal position perpendicularly to the plane of said keel and extending laterally away from said keel in both the port and starboard directions,
(i) said swing wing being free to swing as a pendulum in the port and starboard directions by means of its support shaft and journal mounting,
(j) the said wing section and web section being so formed that when suspended from the support shaft the leading edge of said wing section is displaced downwardly from said hull a distance greater than the trailing edge,
(k) the mass distribution of said swing wing being such that the pendulum action at rest keeps the web section parallel to the plane of the keel and the wing section extending in the port and starboard directions outwardly from and perpendicular to the plane of the keel so that as the vessel sails along on the surface of said body of water with the plane of the keel perpendicular to the plane of the surface of the body of water, the canted leading edge of the wing section attempts to penetrate further into the water exposing a large upper surface area thereof to the flow of water therealong and generating a large force acting on the wing section to force it in a direction deeper into the water.

10 more elements

Dependencies are inferred from the claim text.

Swing wing keel

Life of this patent

Swing wing keel

Life of this patent

Abstract

Claims8