Title:
SAILING VESSEL
United States Patent 3870004
Abstract:
A sailing vessel having no centerboard, no rudder and no fixed mast. The vessel has a loosely stepped mast or kingpost, an outwardly extending arm, and a stabilizer hull pivoted to the outer end of the arm, the stabilizer hull having an angled submerged blade. All overturning forces on the sail are countered by the resistance of the water against the inner side of the blade. This permits the sailing vessel to have many unusual features adding to its speed.
US Patent References:
Sailing craft
McIntyre - January 1938 - 2106432
Hydrofoil sailboat
Smith - January 1967 - 3295487
HIGH SPEED SAILBOAT
Shutt - October 1973 - 3762353
Sailing craft
McIntyre - January 1938 - 2106432
Hydrofoil sailboat
Smith - January 1967 - 3295487
HIGH SPEED SAILBOAT
Shutt - October 1973 - 3762353
Application Number:
05/426940
Publication Date:
03/11/1975
Filing Date:
12/20/1973
View Patent Images:
Export Citation:
Primary Class:
Other Classes:
280/7.130, 114/122, 114/102.180, 114/43
International Classes:
B63B1/14; B63B15/02; B63B39/06; B63B1/00; B63B15/00; B63B39/00; B63B39/00
Field of Search:
114/39,43,121-123,126 280/7.13,16,28
Primary Examiner:
Blix, Trygve M.
Assistant Examiner:
Sotelo, Jesus D.
Attorney, Agent or Firm:
Thompson, Birch, Gauthier & Samuels
Claims:
I claim
1. A sailing vessel comprising:
2. The sailing vessel of claim 1 wherein said kingpost is stepped vertically and below the center of buoyancy in said support hull.
3. The sailing vessel of claim 1 wherein said support hull is free to wobble about the lower end of said kingpost.
4. The sailing vessel of claim 1 wherein said support hull has a fixed centered tail fin mounted on its stern to maintain forward direction.
5. The sailing vessel of claim 1 wherein said stabilizer hull has a long thin shape in which its length is at least ten times its width.
6. The sailing vessel of claim 1 wherein said fixed acute angle is in the range of 10° to 45°.
7. The sailing vessel of claim 1 wherein said sail frame is positioned at said fixed acute angle relative to the vertical.
8. The sailing vessel of claim 1 wherein said sail frame is further pivotally attached to the upper end of said kingpost, said pivotal attachment having both a horizontal and a vertical axis.
9. The sailing vessel of claim 1 wherein said vessel is symmetrical about a vertical section taken through said stabilizer arm.
10. A sailing vessel comprising:
11. The sailing vessel of claim 10 wherein said support means includes two freely pivoting support hulls, and said kingpost means has two depending posts, each said post being loosely stepped below the center of buoyancy in one of said support hulls, each said support hull being free to pivot and wobble about the lower end of its support means depending post.
12. The sailing vessel of claim 10 wherein said support means includes two freely pivoting support skates, and said kingpost means has two depending posts, each said post being stepped in one of said support skates, each said skate being free to pivot about the lower end of its support means depending post.
1. A sailing vessel comprising:
2. The sailing vessel of claim 1 wherein said kingpost is stepped vertically and below the center of buoyancy in said support hull.
3. The sailing vessel of claim 1 wherein said support hull is free to wobble about the lower end of said kingpost.
4. The sailing vessel of claim 1 wherein said support hull has a fixed centered tail fin mounted on its stern to maintain forward direction.
5. The sailing vessel of claim 1 wherein said stabilizer hull has a long thin shape in which its length is at least ten times its width.
6. The sailing vessel of claim 1 wherein said fixed acute angle is in the range of 10° to 45°.
7. The sailing vessel of claim 1 wherein said sail frame is positioned at said fixed acute angle relative to the vertical.
8. The sailing vessel of claim 1 wherein said sail frame is further pivotally attached to the upper end of said kingpost, said pivotal attachment having both a horizontal and a vertical axis.
9. The sailing vessel of claim 1 wherein said vessel is symmetrical about a vertical section taken through said stabilizer arm.
10. A sailing vessel comprising:
11. The sailing vessel of claim 10 wherein said support means includes two freely pivoting support hulls, and said kingpost means has two depending posts, each said post being loosely stepped below the center of buoyancy in one of said support hulls, each said support hull being free to pivot and wobble about the lower end of its support means depending post.
12. The sailing vessel of claim 10 wherein said support means includes two freely pivoting support skates, and said kingpost means has two depending posts, each said post being stepped in one of said support skates, each said skate being free to pivot about the lower end of its support means depending post.
Description:
BACKGROUND OF THE INVENTION
Many efforts have been made in the past to build a high speed sailing vessel. Examples are shown in Smith, U.S. Pat. No. 3,295,487; McIntyre, U.S. Pat. No. 2,106,432; and a book by Bernard Smith entitled "The 40 Knot Sailboat", published by Grosset and Dunlop in 1963. None of these past efforts has achieved significant success.
There are many reasons why these past efforts have not been fully successful. Many had ballasted, large displacement, hulls which caused great frictional resistance in the water. Others were slowed because their hulls sailed an angled course through the water. Still others were slowed because of heeling and pitching.
SUMMARY OF THIS INVENTION
It is an object of this invention to provide a vessel which does not heel or pitch from the action of the wind on the sail.
It is another object of this invention to provide a vessel which has a load bearing hull which sails a true course through the water because it has no stabilizing or steering functions. Therefore, the hull cuts through the water with virtually no side slip and thereby with reduced drag.
It is another object of this invention to provide a vessel which is steered by neither an air rudder nor a water rudder, but rather by a balancing of the centers of effort and resistance.
Other features will become apparent from the following description of the preferred embodiment of the sailboat having a single main hull, the alternate embodiment of the sailboat having two independent main hulls, and the embodiment of the iceboat.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view from above of a conventional sailboat;
FIG. 2 is a perspective view from off the starboard bow of the conventional sailboat shown in FIG. 1;
FIG. 3 is a water level perspective view from off the starboard bow of the preferred embodiment of the sailing vessel;
FIG. 4 is a top plan of the preferred embodiment shown in FIG. 3;
FIG. 5 is a schematic view of the horizontal and vertical countering line planes and the kitesail and drogueboard planes with respect to the horizontal;
FIG. 6 is an upper level perspective view from off the starboard bow of the preferred embodiment shown in FIG. 3;
FIG. 7 is a front elevation of the preferred embodiment shown in FIG. 3;
FIG. 8 is a water level perspective view of a larger version of the preferred embodiment of the sailing vessel, said larger version having a passenger cabin or pod attached to the stabilizer arm;
FIG. 9 is an upper level perspective view from off the starboard bow of the alternative embodiment of the sailing vessel;
FIG. 10 is an upper level perspective view from off the starboard bow of the embodiment of the iceboat; and
FIGS. 11-13 are schematic views of the "wearing" maneuver.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The invention will now be described in detail with reference to the drawings. First, the theory of this invention will be discussed. Then, the three embodiments shown in FIGS. 6, 9 and 10 will be described. Finally, the operation of the embodiments will be described after each of their respective descriptions.
Referring now to FIGS. 1 and 2, the conventional sailboat has a fixed mast 20 which supports a sail 22. A centerboard 24 reduces side slip and a rudder 26 provides steering. The conventional sailboat heels sharply in response to the force of the wind against the sail. It will be seen in FIG. 2 that the wind continuously tends to overturn the conventional sailboat. This overturning force is sluggishly countered by rapid shifting of the crew to the windward side of the hull. Other means for countering this heeling tendency include the provision of a weighted keel, the provision of multiple hulls, or the provision of an extremely wide single hull. Obviously, the greater the wetted hull surface, the slower the boat for a given water line length. Also, heeling destroys the symmetry of the hull shape as it cuts through the water and reduces the effective sail area. In summary, a conventional sailboat requires a sideslip resisting centerboard which is positioned with respect to the sail such that the boat tends to heel. Usual heel countering measures tend to increase the hull displacement and wetted surface. Both heeling and increased wetted surface cause the speed of the boat to be reduced. Moreover, the hull of the conventional sailboat does not follow the course steered, but rather a sideslipping course which increases drag.
In contrast, the preferred embodiment of the sailboat of this invention does not heel and its main hull follows a true course through the water. This combination of features is produced by a sailboat construction which eliminates the overturning or heeling force on the sail. The construction also removes the steering and sideslip resisting functions from the hull.
The theory which forms the basis of this invention is that overturning due to the force of the wind on the sail can be prevented by creating a countering or opposing force of the water on an attached submerged blade if the latter is properly located with respect to the sail. That is, if a sail is attached at its center to the upper end of an inclined boom and a submerged blade is attached at its center to the lower end of the same boom, the opposed forces generated by the wind striking the sail and the water striking the blade can be balanced by control of the relative attitudes of the sail and the blade.
FIG. 3 shows the sailing vessel having a relatively thin long support hull 28 provided with a fixed trailing fin 30. A vertical kingpost 32 (forming a stub mast) is loosely stepped in a socket formed in the hull. The socket is located amidship below the center of buoyancy. In this fashion, the lower end of the kingpost, being shaped as a ball 34, allows the support hull 28 to pivot in all directions and to wobble in response to wave action while being restrained by the socket against vertical or horizontal displacement. Stepping of the ball 34 below the center of buoyancy maintains stability of the support hull 28.
A stabilizer arm 36, having substantial rigidity, is rigidly attached at its upper near end 38 to the upper end of the kingpost 32 at a fixed acute countering angle (e.g., 30°) relative to the horizontal. The attachment is fixed with regard to the vertical plane, but the stabilizer arm is free to pivot about the vertical axis of the kingpost 32.
A buoyant stabilizer hull 40, having a long thin shape, is attached to the lower far end 42 of stabilizer arm 36. The attachment is by means of a vertical hinge 44 so that the stabilizer hull 40 can pivot in the horizontal plane about the far end of stabilizer arm 36.
A blade-like drogueboard 46 is fixed to the undersurface of floating stabilizer hull 40 so that it is submerged beneath the water surface. The drogueboard is mounted at the countering angle (e.g., 30°) to the vertical and extends downwardly and to the support hull side of the vertical. The major dimensions of the drogueboard and the stabilizer hull are in alignment. The length of the stabilizer hull is at least three times that of the drogueboard. A relatively long stabilizer hull is important for maintaining stability of the vertical attitude of the kingpost 32.
The angle which stabilizer arm 36 makes with the horizontal and the angles which the drogueboard 46 and the kitesail 54 make with the vertical are all equal and are referred to as the countering angle, here, 30°.
A sail frame 48 is comprised of a horizontal member 50, and a substantially vertical member 52 fastened to the horizontal member at the latter's midpoint. The sail frame can take other configurations, but must supportably carry kitesail 54. The kitesail can be made of fabric (natural or synthetic) or it can be made of a solid plastic material. The sail frame's vertical member 52 is pivotally attached to the upper end of kingpost 32. The attachment is by means of a vertical hinge 56 so that the horizontal member 50 of sail frame 48 can pivot in the horizontal plane.
The kitesail 54 is positioned by means of the sail frame 48 so that its plane approximately forms the countering angle, e.g., 30°, to the vertical. The kitesail 54 extends upwardly and to the stabilizer hull side of the vertical and extends downwardly and away from the stabilizer hull side of the vertical. Preferably, the plane of the sail frame 48 and the plane of the kitesail 54 coincide, both at the countering angle, e.g. 30°, to the vertical.
It will now be seen that the planes of the drogueboard 46 and the kitesail 54 are parallel, as shown in FIG. 5, when the stabilizer arm-stabilizer hull angle and the stabilizer armsail frame angle are equal. The planes can be caused to become nonparallel (though their angle to the vertical remains constant) when the various control lines are operated. The stabilizer arm-stabilizer hull angle is controlled by a pair of lines 58 running to the tips of the stabilizer hull 40. The stabilizer arm-sail frame angle is controlled by a pair of lines 60 running to the tips of horizontal member 50. Preferably, all of the control lines converge at a single point (e.g., on arm 36) so that they can then be run back together to the helmsman's location.
An additional feature is the provision of a horizontal hinge 62 mounted on the top of kingpost 32 in combination with the vertical hinge 56. The sail frame's vertical member 52 is pivotally attached to the top of the kingpost 32 by means of this combined vertical and horizontal hinge 56/62 so that the sail frame 48 can pivot into the horizontal plane as well as the vertical plane, as shown in FIG. 7. A pair of control lines 64 running to the tips of vertical member 52 are operated to control the pivoting action.
It will be appreciated that the sailing vessel of this invention is approximately bilaterally symmetrical about a vertical plane taken through the stabilizer arm 36. The stabilizer arm is located approximately on an imaginary straight line drawn between the center of effort of the kitesail and the center of resistance of the drogueboard. By angling the arm at the countering angle (e.g., 30°) relative to the horizontal, the kitesail can be maintained above the water and the drogueboard can be maintained below the water. In practice, since the stabilizer arm must meet the stabilizer hull above the water surface to avoid fouling by flotsam and jetsam, the stabilizer arm is not attached at the geometric center but rather above it as shown in FIG. 6. In other words, FIG. 5 shows the theoretical angular arrangement in which the countering line intersects the drogueboard center of resistance below the water surface. FIGS. 6-7 show the practical arrangement in which the stabilizer arm intersects the top edge of the submerged drogueboard above the water surface.
An important feature is the pivotable mounting of the lower end of the kingpost 32. The kingpost remains vertical so long as the stabilizer hull remains on the water because of the fixed angular relationship of the stabilizer arm 36 and the kingpost 32. However, the support hull is free to follow the motion of the waves without affecting the vertical attitude of the kingpost. Thus, the pivotal mounting of the mast in the support hull permits the hull to ride smoothly on a straight and true rather than a sideslipping course through the water. This is a great advantage over conventional sailboats in that it allows the support hull to have an extremely streamlined shape.
Steering of the sailboat is accomplished by manipulating the control lines so as to establish the angles that the planes of the kitesail and the drogueboard take with respect to the stabilizer arm and thus with respect to each other. Moreover, the angle made by the kitesail with relation to the drogueboard, as viewed from overhead, will be approximately the same as that made by the kitesail with relation to the centerboard of a conventional sailboat for any equivalent course sailed.
On a pointing course, the angle of kitesail to drogueboard, as viewed from overhead, is extremely acute, and the drogueboard and kitesail are slightly toed-in with respect to the forward motion of the vessel. That is, the angle would be approximately 30° with respect to each other and approximately 75° each with respect to one side of the stabilizer arm.
On a reaching course, the toeing-in is more extreme, and the angle would be approximately 45° with respect to each other.
On a near running course (direct running is not possible with this vessel), a 60° angle with respect to each other would be approached.
With the angles set and equilibrium with respect to the wind attained, the direction of the vessel is fixed. It is a self-correcting steering system; the center of effort and center of resistance automatically remain opposed.
The stabilizer hull, and therefore the drogueboard, are always kept windward of the kitesail. This means that tacking, which is commonly used by conventional sailboats to maneuver to windward, cannot be used here. Instead, this vessel, when on a port tack, must "wear" in order to assume the starboard tack, and vice versa.
The wearing maneuver is depicted in FIGS. 11-13. The drogueboard is first shifted by the control lines from its acutely angled position, as viewed from overhead (FIG. 11), to a neutral position perpendicular to the stabilizer arm (FIG. 12). The kitesail is then quickly reversed from forming an acute angle with respect to one side of the stabilizer arm to forming an angle with respect to the opposite side of the stabilizer arm. The angle of the drogueboard with respect to the stabilizer arm is then shifted further (FIG. 13) so that its acute angle with respect to the stabilizer arm is on the same side of the stabilizer arm as is that of the kitesail. The support hull has meanwhile rotated 180° and the vessel then sails in the reverse direction.
Heeling is eliminated by the positions in which the kitesail and drogueboard are maintained in relation to one another. The forces emanating from the centers of effort and resistance are at the opposite ends of the stabilizer arm and are directed always outwardly and within the horizontal countering-line plane 68, as shown in FIG. 5. This is the very basis of eliminating overturning moments in these embodiments.
In the embodiments herein described, the relative positions of the drogueboard and kitesail are maintained in the countering relationship following the above-stated theory. However, the stabilizer arm is attached to the stabilizer hull above the countering line, as can be seen in FIG. 6, and thus above the water surface to avoid becoming fouled by flotsam and jetsam. This compromise places only a slight bending stress on the stabilizer arm.
Several design features will now be mentioned. The stabilizer hull 40 should be quite narrow relative to its length to minimize its drag. Likewise, the support hull 28 should be quite narrow because it does not have to provide lateral stability against heeling. Because of the rigid connection between the kingpost and the stabilizer arm, no stays are needed to support the kingpost. Furthermore, the support hull follows a true course through the water with the aid of fixed tail fin 30. This greatly reduces drag.
With regard to the horizontal hinge feature 62, the kitesail can be tilted, as shown in FIG. 7, from a vertical position in light winds, to a tipped position in heavy winds, to a horizontal position when luffing. This allows the helmsman to obtain the maximum desired effect from the wind.
FIG. 6 shows another important design feature. Preferably, when the horizontal hinge 62 is employed, the top of kingpost 32 should be attached to the sail frame 48 just above the geometric center of the kitesail. This position of attachment allows the wind to continuously seek to lift the bottom of the sail and to lift the weight of the kitesail itself. In high winds, this prevents stress and acts as a safety measure.
With regard to the position of the helmsman and crew, FIG. 6 shows fore and aft cockpits in the support hull. FIG. 8 shows a suspended cabin or pod under the stabilizer arm (e.g., in a larger vessel). Other possible positions include cockpits in the stabilizer hull or a cabin mounted within a hollow rigid sail.
DESCRIPTION OF THE ALTERNATE EMBODIMENT
The alternate embodiment of the sailboat is shown in FIG. 9. This embodiment is essentially similar to the preferred embodiment in many respects. For example, angled stabilizer arm 36 is pivoted to stabilizer hull 40 by means of vertical hinge 44, and drogueboard 46 is mounted to the underside of the stabilizer hull at the countering angle of approximately 30° to the vertical and at an angle of 90° to the stabilizer arm 36. Control lines 58 run from the stabilizer hull tips to the midpoint of the stabilizer arm 36 and thence to the helmsman's position.
However, the remaining components are somewhat different from those of the preferred embodiment. Instead of a single support hull, the alternate embodiment has two identical support hulls 70 and 72. These hulls are provided with centered tail fins to assist the hulls to sail a straight and true course through the water. Instead of a vertical kingpost, the alternate embodiment has an inverted U-shaped kingpost 74 having free lower ends 76 and 78. The free lower ends are loosely stepped below center of buoyancy in support hulls 70 and 72, respectively, in the same free pivoting arrangement utilized by the preferred embodiment.
Kingpost 74 actually forms the horizontal member of the sail frame in the alternate embodiment. Instead of a single vertical member, an eliptical frame member 80 is fixed to kingpost 74 and a horizontal cross member 82 structurally stiffens the sail frame. The sail 84 is preferably made of a plastic material such as polystyrene or another similar plastic material. It will be understood that a fabric sail could alternatively be used instead of the plastic sail.
The helmsman and crew are carried in seats 86 and 88 which are pivotally suspended on swivels from the sail frame 74. Obviously, other locations are possible, as suggested with regard to the preferred embodiment.
The upper near end 38 of stabilizer arm 36 is pivotally attached to the sail frame horizontal cross member 82 by means of a swivel or universal jointed hinge 112. The 30° countering angle which the kitesail forms with the vertical is constantly maintained by stay 113, running from the midpoint of stabilizing arm 36 to the midpoint of horizontal sail frame member 74, regardless of the angle which kitesail 84 forms with the stabilizer arm 36.
As the kitesail 84 is pivoted about its swivel 112 on stabilizer arm 36 by means of control lines 90 running to the tips of kingpost 74, the support hulls 70 and 72 follow the kingpost's free ends 76 and 78 and sail a true course through the water. The hulls do not sideslip to generate additional drag because they are pivoted instead of being fixed to the mast (kingpost).
In this alternate embodiment, the rigid plastic sail is preferred, and the sail frame and sail are preferably incorporated into an integral unit. The rigid sail has a good aerodynamic shape and can be quite large in area. By attaching the stabilizer arm to the sail frame just above the geometric center of the sail, the center of effort is located slightly below the attachment point. This arrangement reduces stress on the arm and gives a lifting effect to the kitesail which is desirable. This embodiment allows a larger kitesail to be employed than that employed in the preferred embodiment and, thus, a more powerful craft can be constructed.
DESCRIPTION OF THE ICE BOAT EMBODIMENT
The embodiment of the ice boat is shown in FIG. 10. This embodiment has certain similarities to the alternate sailboat embodiment of FIG. 9. For example, the inverted U-shaped kingpost 74 forms the horizontal member of the sail frame which is rigidly fixed to the elliptical sail frame member 80. A vertical cross member 92 provides structural stiffening for the sail frame. A solid plastic or flexible fabric kitesail 94 is attached to the sail frame, and the vertical cross member 92 is pivotally attached by means of vertical hinge 56 to the stabilizer arm 36. This causes the kitesail to assume the countering angle, e.g., 30° to the vertical.
Instead of the twin support hulls 70 and 72 of the alternate embodiment, the ice boat is provided with freely pivoting support skates having blades 96 and 98. Because ice is flat and rigid, and because center of buoyancy has no meaning with respect to ice, the kingpost free ends 76 and 78 are not loosely stepped in the support skates. However, the skates are free to pivot about the free ends 76 and 78, in the horizontal plane. The kingpost free ends are pivoted to the support skates at points forward of the midpoints of the blades so that the skates and their blades freely follow the true course sailed.
Instead of a stabilizer hull, the ice boat has a steerable skate 104 which is pivotally attached to the lower far end 42 of the stabilizer arm 36 by means of a vertical hinge 44. The steerable skate 104 with its blade 106 has steering and side-slip-resisting and stabilizing functions much like the sailboat's drogueboard. Blade 106 is mounted at a fixed acute countering angle (e.g., 30°) to the vertical and extends downwardly and to the support skate side of the vertical. This angled mounting permits the blade to continuously dig in to balance the force of the wind against the sail much as a turning skater digs in his outside blade to balance the generated centrifugal force which tends to cause him to sideslip and overturn. Blade 106 should be located at its center of resistance in line with the countering line for maximum effectiveness.
Furthermore, the weight of the helmsman in his fixed seat 114, with its footrest 118, greatly contributes to the stability of the ice boat. Preferably, the seat location is outboard of steerable skate 104, as shown, but other locations are also feasible. From his seat, the helmsman can operate skate control wheel 115 which steers skate 104 about its vertical hinge axis. Also, the helmsman can operate sail control wheel 116 which pulls control lines 117 to shift the angle of the sail frame about its hinge axis 56. Control wheels 115 and 116 can be operated simultaneously by the helmsman to steer the ice boat.
In operation, the ice boat handles much like the two embodiments of the sailboat and the principles of this invention apply similarly to all of the embodiments.
In summary, this invention provides a very fast and maneuverable sailing vessel which does not heel. This feature is accomplished by hinging the sail and the blade at the opposite ends of a stabilizer arm so that the overturning or sideslipping moment produced by the wind against the sail is countered and equalized by the effect of the water or ice against the blade.
The above description obviously suggests many possible variations and modifications of this invention which would not depart from its spirit and scope. It should be understood, therefore, that the invention is not limited in its application to the details of structure specifically described or illustrated and that within the scope of the appended claims, it may be practiced otherwise than as specifically described or illustrated.
Many efforts have been made in the past to build a high speed sailing vessel. Examples are shown in Smith, U.S. Pat. No. 3,295,487; McIntyre, U.S. Pat. No. 2,106,432; and a book by Bernard Smith entitled "The 40 Knot Sailboat", published by Grosset and Dunlop in 1963. None of these past efforts has achieved significant success.
There are many reasons why these past efforts have not been fully successful. Many had ballasted, large displacement, hulls which caused great frictional resistance in the water. Others were slowed because their hulls sailed an angled course through the water. Still others were slowed because of heeling and pitching.
SUMMARY OF THIS INVENTION
It is an object of this invention to provide a vessel which does not heel or pitch from the action of the wind on the sail.
It is another object of this invention to provide a vessel which has a load bearing hull which sails a true course through the water because it has no stabilizing or steering functions. Therefore, the hull cuts through the water with virtually no side slip and thereby with reduced drag.
It is another object of this invention to provide a vessel which is steered by neither an air rudder nor a water rudder, but rather by a balancing of the centers of effort and resistance.
Other features will become apparent from the following description of the preferred embodiment of the sailboat having a single main hull, the alternate embodiment of the sailboat having two independent main hulls, and the embodiment of the iceboat.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view from above of a conventional sailboat;
FIG. 2 is a perspective view from off the starboard bow of the conventional sailboat shown in FIG. 1;
FIG. 3 is a water level perspective view from off the starboard bow of the preferred embodiment of the sailing vessel;
FIG. 4 is a top plan of the preferred embodiment shown in FIG. 3;
FIG. 5 is a schematic view of the horizontal and vertical countering line planes and the kitesail and drogueboard planes with respect to the horizontal;
FIG. 6 is an upper level perspective view from off the starboard bow of the preferred embodiment shown in FIG. 3;
FIG. 7 is a front elevation of the preferred embodiment shown in FIG. 3;
FIG. 8 is a water level perspective view of a larger version of the preferred embodiment of the sailing vessel, said larger version having a passenger cabin or pod attached to the stabilizer arm;
FIG. 9 is an upper level perspective view from off the starboard bow of the alternative embodiment of the sailing vessel;
FIG. 10 is an upper level perspective view from off the starboard bow of the embodiment of the iceboat; and
FIGS. 11-13 are schematic views of the "wearing" maneuver.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The invention will now be described in detail with reference to the drawings. First, the theory of this invention will be discussed. Then, the three embodiments shown in FIGS. 6, 9 and 10 will be described. Finally, the operation of the embodiments will be described after each of their respective descriptions.
Referring now to FIGS. 1 and 2, the conventional sailboat has a fixed mast 20 which supports a sail 22. A centerboard 24 reduces side slip and a rudder 26 provides steering. The conventional sailboat heels sharply in response to the force of the wind against the sail. It will be seen in FIG. 2 that the wind continuously tends to overturn the conventional sailboat. This overturning force is sluggishly countered by rapid shifting of the crew to the windward side of the hull. Other means for countering this heeling tendency include the provision of a weighted keel, the provision of multiple hulls, or the provision of an extremely wide single hull. Obviously, the greater the wetted hull surface, the slower the boat for a given water line length. Also, heeling destroys the symmetry of the hull shape as it cuts through the water and reduces the effective sail area. In summary, a conventional sailboat requires a sideslip resisting centerboard which is positioned with respect to the sail such that the boat tends to heel. Usual heel countering measures tend to increase the hull displacement and wetted surface. Both heeling and increased wetted surface cause the speed of the boat to be reduced. Moreover, the hull of the conventional sailboat does not follow the course steered, but rather a sideslipping course which increases drag.
In contrast, the preferred embodiment of the sailboat of this invention does not heel and its main hull follows a true course through the water. This combination of features is produced by a sailboat construction which eliminates the overturning or heeling force on the sail. The construction also removes the steering and sideslip resisting functions from the hull.
The theory which forms the basis of this invention is that overturning due to the force of the wind on the sail can be prevented by creating a countering or opposing force of the water on an attached submerged blade if the latter is properly located with respect to the sail. That is, if a sail is attached at its center to the upper end of an inclined boom and a submerged blade is attached at its center to the lower end of the same boom, the opposed forces generated by the wind striking the sail and the water striking the blade can be balanced by control of the relative attitudes of the sail and the blade.
FIG. 3 shows the sailing vessel having a relatively thin long support hull 28 provided with a fixed trailing fin 30. A vertical kingpost 32 (forming a stub mast) is loosely stepped in a socket formed in the hull. The socket is located amidship below the center of buoyancy. In this fashion, the lower end of the kingpost, being shaped as a ball 34, allows the support hull 28 to pivot in all directions and to wobble in response to wave action while being restrained by the socket against vertical or horizontal displacement. Stepping of the ball 34 below the center of buoyancy maintains stability of the support hull 28.
A stabilizer arm 36, having substantial rigidity, is rigidly attached at its upper near end 38 to the upper end of the kingpost 32 at a fixed acute countering angle (e.g., 30°) relative to the horizontal. The attachment is fixed with regard to the vertical plane, but the stabilizer arm is free to pivot about the vertical axis of the kingpost 32.
A buoyant stabilizer hull 40, having a long thin shape, is attached to the lower far end 42 of stabilizer arm 36. The attachment is by means of a vertical hinge 44 so that the stabilizer hull 40 can pivot in the horizontal plane about the far end of stabilizer arm 36.
A blade-like drogueboard 46 is fixed to the undersurface of floating stabilizer hull 40 so that it is submerged beneath the water surface. The drogueboard is mounted at the countering angle (e.g., 30°) to the vertical and extends downwardly and to the support hull side of the vertical. The major dimensions of the drogueboard and the stabilizer hull are in alignment. The length of the stabilizer hull is at least three times that of the drogueboard. A relatively long stabilizer hull is important for maintaining stability of the vertical attitude of the kingpost 32.
The angle which stabilizer arm 36 makes with the horizontal and the angles which the drogueboard 46 and the kitesail 54 make with the vertical are all equal and are referred to as the countering angle, here, 30°.
A sail frame 48 is comprised of a horizontal member 50, and a substantially vertical member 52 fastened to the horizontal member at the latter's midpoint. The sail frame can take other configurations, but must supportably carry kitesail 54. The kitesail can be made of fabric (natural or synthetic) or it can be made of a solid plastic material. The sail frame's vertical member 52 is pivotally attached to the upper end of kingpost 32. The attachment is by means of a vertical hinge 56 so that the horizontal member 50 of sail frame 48 can pivot in the horizontal plane.
The kitesail 54 is positioned by means of the sail frame 48 so that its plane approximately forms the countering angle, e.g., 30°, to the vertical. The kitesail 54 extends upwardly and to the stabilizer hull side of the vertical and extends downwardly and away from the stabilizer hull side of the vertical. Preferably, the plane of the sail frame 48 and the plane of the kitesail 54 coincide, both at the countering angle, e.g. 30°, to the vertical.
It will now be seen that the planes of the drogueboard 46 and the kitesail 54 are parallel, as shown in FIG. 5, when the stabilizer arm-stabilizer hull angle and the stabilizer armsail frame angle are equal. The planes can be caused to become nonparallel (though their angle to the vertical remains constant) when the various control lines are operated. The stabilizer arm-stabilizer hull angle is controlled by a pair of lines 58 running to the tips of the stabilizer hull 40. The stabilizer arm-sail frame angle is controlled by a pair of lines 60 running to the tips of horizontal member 50. Preferably, all of the control lines converge at a single point (e.g., on arm 36) so that they can then be run back together to the helmsman's location.
An additional feature is the provision of a horizontal hinge 62 mounted on the top of kingpost 32 in combination with the vertical hinge 56. The sail frame's vertical member 52 is pivotally attached to the top of the kingpost 32 by means of this combined vertical and horizontal hinge 56/62 so that the sail frame 48 can pivot into the horizontal plane as well as the vertical plane, as shown in FIG. 7. A pair of control lines 64 running to the tips of vertical member 52 are operated to control the pivoting action.
It will be appreciated that the sailing vessel of this invention is approximately bilaterally symmetrical about a vertical plane taken through the stabilizer arm 36. The stabilizer arm is located approximately on an imaginary straight line drawn between the center of effort of the kitesail and the center of resistance of the drogueboard. By angling the arm at the countering angle (e.g., 30°) relative to the horizontal, the kitesail can be maintained above the water and the drogueboard can be maintained below the water. In practice, since the stabilizer arm must meet the stabilizer hull above the water surface to avoid fouling by flotsam and jetsam, the stabilizer arm is not attached at the geometric center but rather above it as shown in FIG. 6. In other words, FIG. 5 shows the theoretical angular arrangement in which the countering line intersects the drogueboard center of resistance below the water surface. FIGS. 6-7 show the practical arrangement in which the stabilizer arm intersects the top edge of the submerged drogueboard above the water surface.
An important feature is the pivotable mounting of the lower end of the kingpost 32. The kingpost remains vertical so long as the stabilizer hull remains on the water because of the fixed angular relationship of the stabilizer arm 36 and the kingpost 32. However, the support hull is free to follow the motion of the waves without affecting the vertical attitude of the kingpost. Thus, the pivotal mounting of the mast in the support hull permits the hull to ride smoothly on a straight and true rather than a sideslipping course through the water. This is a great advantage over conventional sailboats in that it allows the support hull to have an extremely streamlined shape.
Steering of the sailboat is accomplished by manipulating the control lines so as to establish the angles that the planes of the kitesail and the drogueboard take with respect to the stabilizer arm and thus with respect to each other. Moreover, the angle made by the kitesail with relation to the drogueboard, as viewed from overhead, will be approximately the same as that made by the kitesail with relation to the centerboard of a conventional sailboat for any equivalent course sailed.
On a pointing course, the angle of kitesail to drogueboard, as viewed from overhead, is extremely acute, and the drogueboard and kitesail are slightly toed-in with respect to the forward motion of the vessel. That is, the angle would be approximately 30° with respect to each other and approximately 75° each with respect to one side of the stabilizer arm.
On a reaching course, the toeing-in is more extreme, and the angle would be approximately 45° with respect to each other.
On a near running course (direct running is not possible with this vessel), a 60° angle with respect to each other would be approached.
With the angles set and equilibrium with respect to the wind attained, the direction of the vessel is fixed. It is a self-correcting steering system; the center of effort and center of resistance automatically remain opposed.
The stabilizer hull, and therefore the drogueboard, are always kept windward of the kitesail. This means that tacking, which is commonly used by conventional sailboats to maneuver to windward, cannot be used here. Instead, this vessel, when on a port tack, must "wear" in order to assume the starboard tack, and vice versa.
The wearing maneuver is depicted in FIGS. 11-13. The drogueboard is first shifted by the control lines from its acutely angled position, as viewed from overhead (FIG. 11), to a neutral position perpendicular to the stabilizer arm (FIG. 12). The kitesail is then quickly reversed from forming an acute angle with respect to one side of the stabilizer arm to forming an angle with respect to the opposite side of the stabilizer arm. The angle of the drogueboard with respect to the stabilizer arm is then shifted further (FIG. 13) so that its acute angle with respect to the stabilizer arm is on the same side of the stabilizer arm as is that of the kitesail. The support hull has meanwhile rotated 180° and the vessel then sails in the reverse direction.
Heeling is eliminated by the positions in which the kitesail and drogueboard are maintained in relation to one another. The forces emanating from the centers of effort and resistance are at the opposite ends of the stabilizer arm and are directed always outwardly and within the horizontal countering-line plane 68, as shown in FIG. 5. This is the very basis of eliminating overturning moments in these embodiments.
In the embodiments herein described, the relative positions of the drogueboard and kitesail are maintained in the countering relationship following the above-stated theory. However, the stabilizer arm is attached to the stabilizer hull above the countering line, as can be seen in FIG. 6, and thus above the water surface to avoid becoming fouled by flotsam and jetsam. This compromise places only a slight bending stress on the stabilizer arm.
Several design features will now be mentioned. The stabilizer hull 40 should be quite narrow relative to its length to minimize its drag. Likewise, the support hull 28 should be quite narrow because it does not have to provide lateral stability against heeling. Because of the rigid connection between the kingpost and the stabilizer arm, no stays are needed to support the kingpost. Furthermore, the support hull follows a true course through the water with the aid of fixed tail fin 30. This greatly reduces drag.
With regard to the horizontal hinge feature 62, the kitesail can be tilted, as shown in FIG. 7, from a vertical position in light winds, to a tipped position in heavy winds, to a horizontal position when luffing. This allows the helmsman to obtain the maximum desired effect from the wind.
FIG. 6 shows another important design feature. Preferably, when the horizontal hinge 62 is employed, the top of kingpost 32 should be attached to the sail frame 48 just above the geometric center of the kitesail. This position of attachment allows the wind to continuously seek to lift the bottom of the sail and to lift the weight of the kitesail itself. In high winds, this prevents stress and acts as a safety measure.
With regard to the position of the helmsman and crew, FIG. 6 shows fore and aft cockpits in the support hull. FIG. 8 shows a suspended cabin or pod under the stabilizer arm (e.g., in a larger vessel). Other possible positions include cockpits in the stabilizer hull or a cabin mounted within a hollow rigid sail.
DESCRIPTION OF THE ALTERNATE EMBODIMENT
The alternate embodiment of the sailboat is shown in FIG. 9. This embodiment is essentially similar to the preferred embodiment in many respects. For example, angled stabilizer arm 36 is pivoted to stabilizer hull 40 by means of vertical hinge 44, and drogueboard 46 is mounted to the underside of the stabilizer hull at the countering angle of approximately 30° to the vertical and at an angle of 90° to the stabilizer arm 36. Control lines 58 run from the stabilizer hull tips to the midpoint of the stabilizer arm 36 and thence to the helmsman's position.
However, the remaining components are somewhat different from those of the preferred embodiment. Instead of a single support hull, the alternate embodiment has two identical support hulls 70 and 72. These hulls are provided with centered tail fins to assist the hulls to sail a straight and true course through the water. Instead of a vertical kingpost, the alternate embodiment has an inverted U-shaped kingpost 74 having free lower ends 76 and 78. The free lower ends are loosely stepped below center of buoyancy in support hulls 70 and 72, respectively, in the same free pivoting arrangement utilized by the preferred embodiment.
Kingpost 74 actually forms the horizontal member of the sail frame in the alternate embodiment. Instead of a single vertical member, an eliptical frame member 80 is fixed to kingpost 74 and a horizontal cross member 82 structurally stiffens the sail frame. The sail 84 is preferably made of a plastic material such as polystyrene or another similar plastic material. It will be understood that a fabric sail could alternatively be used instead of the plastic sail.
The helmsman and crew are carried in seats 86 and 88 which are pivotally suspended on swivels from the sail frame 74. Obviously, other locations are possible, as suggested with regard to the preferred embodiment.
The upper near end 38 of stabilizer arm 36 is pivotally attached to the sail frame horizontal cross member 82 by means of a swivel or universal jointed hinge 112. The 30° countering angle which the kitesail forms with the vertical is constantly maintained by stay 113, running from the midpoint of stabilizing arm 36 to the midpoint of horizontal sail frame member 74, regardless of the angle which kitesail 84 forms with the stabilizer arm 36.
As the kitesail 84 is pivoted about its swivel 112 on stabilizer arm 36 by means of control lines 90 running to the tips of kingpost 74, the support hulls 70 and 72 follow the kingpost's free ends 76 and 78 and sail a true course through the water. The hulls do not sideslip to generate additional drag because they are pivoted instead of being fixed to the mast (kingpost).
In this alternate embodiment, the rigid plastic sail is preferred, and the sail frame and sail are preferably incorporated into an integral unit. The rigid sail has a good aerodynamic shape and can be quite large in area. By attaching the stabilizer arm to the sail frame just above the geometric center of the sail, the center of effort is located slightly below the attachment point. This arrangement reduces stress on the arm and gives a lifting effect to the kitesail which is desirable. This embodiment allows a larger kitesail to be employed than that employed in the preferred embodiment and, thus, a more powerful craft can be constructed.
DESCRIPTION OF THE ICE BOAT EMBODIMENT
The embodiment of the ice boat is shown in FIG. 10. This embodiment has certain similarities to the alternate sailboat embodiment of FIG. 9. For example, the inverted U-shaped kingpost 74 forms the horizontal member of the sail frame which is rigidly fixed to the elliptical sail frame member 80. A vertical cross member 92 provides structural stiffening for the sail frame. A solid plastic or flexible fabric kitesail 94 is attached to the sail frame, and the vertical cross member 92 is pivotally attached by means of vertical hinge 56 to the stabilizer arm 36. This causes the kitesail to assume the countering angle, e.g., 30° to the vertical.
Instead of the twin support hulls 70 and 72 of the alternate embodiment, the ice boat is provided with freely pivoting support skates having blades 96 and 98. Because ice is flat and rigid, and because center of buoyancy has no meaning with respect to ice, the kingpost free ends 76 and 78 are not loosely stepped in the support skates. However, the skates are free to pivot about the free ends 76 and 78, in the horizontal plane. The kingpost free ends are pivoted to the support skates at points forward of the midpoints of the blades so that the skates and their blades freely follow the true course sailed.
Instead of a stabilizer hull, the ice boat has a steerable skate 104 which is pivotally attached to the lower far end 42 of the stabilizer arm 36 by means of a vertical hinge 44. The steerable skate 104 with its blade 106 has steering and side-slip-resisting and stabilizing functions much like the sailboat's drogueboard. Blade 106 is mounted at a fixed acute countering angle (e.g., 30°) to the vertical and extends downwardly and to the support skate side of the vertical. This angled mounting permits the blade to continuously dig in to balance the force of the wind against the sail much as a turning skater digs in his outside blade to balance the generated centrifugal force which tends to cause him to sideslip and overturn. Blade 106 should be located at its center of resistance in line with the countering line for maximum effectiveness.
Furthermore, the weight of the helmsman in his fixed seat 114, with its footrest 118, greatly contributes to the stability of the ice boat. Preferably, the seat location is outboard of steerable skate 104, as shown, but other locations are also feasible. From his seat, the helmsman can operate skate control wheel 115 which steers skate 104 about its vertical hinge axis. Also, the helmsman can operate sail control wheel 116 which pulls control lines 117 to shift the angle of the sail frame about its hinge axis 56. Control wheels 115 and 116 can be operated simultaneously by the helmsman to steer the ice boat.
In operation, the ice boat handles much like the two embodiments of the sailboat and the principles of this invention apply similarly to all of the embodiments.
In summary, this invention provides a very fast and maneuverable sailing vessel which does not heel. This feature is accomplished by hinging the sail and the blade at the opposite ends of a stabilizer arm so that the overturning or sideslipping moment produced by the wind against the sail is countered and equalized by the effect of the water or ice against the blade.
The above description obviously suggests many possible variations and modifications of this invention which would not depart from its spirit and scope. It should be understood, therefore, that the invention is not limited in its application to the details of structure specifically described or illustrated and that within the scope of the appended claims, it may be practiced otherwise than as specifically described or illustrated.