US3800724A

US3800724A - Winged sailing craft

Info

Publication number: US3800724A
Application number: US00260891A
Authority: US
Inventors: R Tracy
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-06-08
Filing date: 1972-06-08
Publication date: 1974-04-02
Anticipated expiration: 1991-04-02

Abstract

A sailing craft comprises: A. A BODY, AND B. FIRST AND SECOND ELONGATED WINGS CARRIED BY THE BODY, THE FIRST WING EXTENDING GENERALLY UPRIGHT AND THE SECOND WING EXTENDING GENERALLY LATERALLY AT ONE SIDE OF THE BODY, BOTH WINGS HAVING AIRFOIL CONFIGURATION TO RECEIVE WIND THRUST DEVELOPING MUTUALLY COUNTERACTING ROLL MOMENTS AS WELL AS PROPULSION FORCE ACTING ON THE UPRIGHT WING.

Description

United States Patent [1 Tracy [451 Apr. 2, 1974 WINGED SAILING CRAFT [21] Appl. No.: 260,891

[52] US. Cl. 114/39, 114/66.5 H [51] Int. Cl B63h 9/04 [58] Field of Search 114/39, 102, 103, 66.5 R,

[56] References Cited UNITED STATES PATENTS 2,940,688 6/1960 Bland 114/102 X 3,145,954 8/1964 Jenney et a1. 114/66.5 R 3,521,593 7/1970 Pangalila 114/125 3,295,487 l/l967 Smith 114/39 3,580,203 5/1971 Martin 114/39 2,484,687 10/1949 Carl 114/39 3,179,078 4/1965 Popkin 114/39 FOREIGN PATENTS OR APPLICATIONS 524,605 4/1931 Germany 114/39 144,655 3/1954 Sweden 114/39 Primary ExaminerGeorge E. A. I-Ialvosa Assistant Examiner-Edward Kazenske Attorney, Agent, or Firm-Wil1iam W. I-Iaefliger [57] ABSTRACT A sailing craft comprises:

a. a body, and

b. first and second elongated wings carried by the body, the first wing extending generally upright and the second wing extending generally laterally at one side'of the body, both wings having airfoil configuration to receive wind thrust developing mutually counteracting roll moments as well as propulsion force acting on the upright wing.

14 Claims, 8 Drawing Figures WINGED SAILING CRAFT BACKGROUND OF THE INVENTION This invention relates generally to winged sailing craft, and more particularly concerns high speed sailing craft employing multiple wings and having minimum contact with the water.

Wing-type sails have recently been considered for improving the performance of sailing craft, and have been tried in a few instances. Among the problems encountered, two are inherent in the conventional wingsail and act to defeat the desired performance gains: a) the increased heeling moment caused by the greater span of the slender wing, and b) the necessity of using a basically symmetrical airfoil in order to enable tacking in either direction. These difficulties, especially the first, limit the lift and therefore, the forward driving or propulsion force which can be efficiently and safely generated by the wing. Furthermore, even with conventional sails, the substantial heeling moment creates a need for roll stability which leads to the use of undesirably wide beamed, high-drag inducing hull shapes, as well as heavy keels. Tis problem This effectively precluded use, in practical sail boats, of slender monohulls, submerged hulls, and hydrofoils, in the search for improved high speed performance. Multi-hulled craft (e.g. catamarans) provide roll stability more efficiently, and have attained some improvement in speed performance, but suffer from structural and other defects directly related to the separation of the hulls adopted to overcome the heeling moments. Neither the conventional wing-sail, nor the multi-hull treats the basic problem of the aerodynamic heeling moment caused by the sail.

SUMMARY OF THE INVENTION It is a major object of the invention to overcome the above described difficulties through the elimination ofthe heeling moment; and, it is a further object to provide a winged sailing craft characterized by major gains in speed and performance characteristics, even over conventional multi-hulled type craft.

Basically, the sailing craft comprises a body or hull; starboard and port wings having hinge connection to the body characterized as defining two alternate sailing modes; one mode (starboard tack) defined by the first wing extending generally upright while the second wing extends generally laterally, and the other sailing mode (port tack) defined by the first wing extending generally laterally while the second wing extends generally upright, the first wing swinging clockwise (viewed from front looking aft) upwardly into the one sailing mode whereas the second wing swings counterclockwise upwardly into the other sailing mode so that the wings in either sailing mode are oriented to receive wind exerted thrust developing propulsion force acting on the upright wing. Further, the wings are elongated and typically have airfoil configuration, chordwise, such that the wings when extended laterally are presented to develop lift. As a result, the lateral or horizontal wing provides lift to offset the heeling moment developed by wind pressure exertion on the upright wing; also in both of the two modes of sailing each wing provides lift in the direction favored by its camber, for maximum aerodynamic efficiency. This in turn enables use of very efficient, high aspect ratio wing sails.

It is another object of the invention to provide sub structure connected with the body and extending downwardly to project into the water for receiving force exerted by the water over which the body is propelled, to develop lift and lateral force transmitted to the body. Such sub-structure may include a control flap (hydrofoil) with controllable inclination to vary the developed lift, and in certain instances to develop negative lift tending to prevent lifting of the craft completely into the air above the water. The substructure may also include additional foils to assist in supporting the craft above the surface at lower speeds.

Further objects include the application of the invention not only to wind-powered sailing craft, but also to powered boats with sails to provide capability for foilborne cruising with aerodynamic roll-stabilization. In this regard, both wings may at times be deployed horizontally for added lift while the craft is under engine power. A further application of the invention is to flying boats or amphibious with sailing capability.

These and other objects and advantages of the invention, as well as the details of an illustrative embodiment, will be more fully understood from the following description and drawings, in which:

DRAWING DESCRIPTION FIG. 1 is a side elevation of one embodiment of the invention;

FIG. 2 is a front elevation taken on lines 2-2 of FIG.

FIG. 3 is an enlarged section taken on lines 3-3 of FIG. 1;

FIG. 4 is a view like FIG. 3 showing an intermediate mode of actuation;

FIG. 5 is a section taken in plan on lines 55 of FIG.

FIG. 6 is a view like FIG. 3 showing an alternate form of actuating means,

FIG. 7 shows application of the invention to a powered vessel; and

FIG. 8 shows another form of the invention.

DETAILED DESCRIPTION In FIGS. 1-6, the illustrated embodiment of the sailing craft includes a body 10 which may typically be elongated and constructed to float when the craft is at rest or moving slowly. First and second airfoil wings are provided, as for example at

l

1 and 12, each having suitable hinge connection to the body characterized as defining two alternate sailing modes. One sailing mode is for example illustrated by the solid lines in FIG. 2, and defined by the first wing l 1 extending generally upright while the second wing 12 extends generally laterally at one side of the craft; and the alternate sailing mode is defined by the second wing 12 extending generally upright as at while the first wing entends generally laterally as indicated at 11a at the opposite side of the craft. It is clear from the drawings that each wing has inboard and outboard ends and extends lengthwise therebetween, the inboard end of each wing remaining proximate the body in each of said modes.

In this regard, and as viewed from the front of the craft as in FIG. 2, the first wing swings clockwise upwardly into said one sailing mode (starboard tack), whereas the second wing swings counterclockwise upwardly into the other sailing mode (port tack), so that the wings in either sailing mode are oriented to receive wing force developing mutually counteracting roll moments, as well as propulsion thrust due to the forward component of the force acting on the upright wing. Thus, in FIG. 2, with the wind component 14 directed rightwardly against upright wing 11 as during a starboard tack, a clockwise moment is produced tending to heel the craft clockwise, whereas this moment is counterbalanced in substantial part by a counterclockwise moment developed by lift produced by wing 12 acting on the craft. A similar analysis prevails for the alternate sailing mode with the wings in positions 11a and 12a; a counterclockwise moment generated by a leftward wind component acting on wing 12a is counterbalanced to substantial extent by a clockwise moment developed by lift produced by wing 1 la. This condition enables use of extremely elongated wings, without danger of capsizing, and the long upright wing (which may be for example at least twice as long as the craft) receives wind force producing very high craft speed when the body is elevated out of the water, as will be described.

Merely'as illustrative, FIGS. 3-5 depict one form of hinge connection indicated at 16 as including a pivot rod 17 carried by the inboard spar 18 of wing 11, that rod pivoting in bearings 19 mounted by lugs 20. The latter are in turn carried by the craft body 10. Similar structure may be utilized at the inboard end of wing 12, and means to pivot the wings may for example include hydraulic actuators 21 as shown, with rams 22 pivotally attached to the spars at 23. A source 24 of hydraulic fluid is connected with the actuators via hydraulic lines 25-28, and a manually operable control 29 controls the source 24, in such manner that the wings may be rapidly shifted simultaneously between the alternate modes as described, as during coming about, i.e., changing the craft alignment or direction of tack, relative to the wind direction. In furtherance of this objective, the wings may be interconnected, as by a strut 30 pivotally connected with the wings at 31 and 32. This strut also relieves the actuators of the principle bending loads imposed upon the wings. An alternate actuator means is shown in FIG. 6, suitable for cases in which the above mentioned strut is used, to include a sheave 33 powered as by a drive 34, and in turn driving a cable 35 the opposite ends of which are attached at 36 and 37 to the inboard spar ends 18 of the wings.

It will be noted that the laterally extending wing in each of the described modes is presented to develop lift, particularly in view of its chordwise airfoil configuration as better seen in section in FIG. 5. In this regard, the two wings may advantageously be substantially alike, i.e. have like (mirror image) configuration with respect to a plane normal to the span and perpendicular to the plane of the wing passing through the root of the wing. Also, they may be attached to the hull or body as by the hinge connections to provide for presentation to the relative wind at optimum angle of attack, for best lift to drag relationship.

Additional lift, Whether positive or negative, may be developed by substructure connected with the body and extending below the level thereof to project into the water, for receiving force exerted vertically by the water over which the body is propelled.

Such lift, whether developed by the lateral wing or the sub-structure, or both, is typically utilized to elevate the craft body above the water surface level at operating speeds, thereby to reduce drag forces to a minimum (and also to minimize body impacts with waves) with consequent forward acceleration of the craft to relatively very high velocity, as for example well in excess of knots. At high operating speeds, the substructure should be capable of developing downward force to counteract the upward lift produced by the horizontal wing in excess of the crafts weight.

Referring to FIGS. 1 and 2, the illustrated substructure 35 includes a vertical strut 36, fixed horizontal flaps or foils 37 projecting laterally oppositely from strut 36, upwardly diverging struts 38 extending between strut 36 and flaps 37, and a horizontal control flap or hydrofoil 39 at the lower end of strut 36. The foil 39 is mounted to pivot about a horizontal axis 40, and a suitable actuator 41 may be connected with the foil at 42 to vary its inclination relative to the direction of propulsion of the craft. In this manner the degree of positive and negative lift afforded by water passage relatively over the foil may be controlled, to maintain the body 10 at desired elevation over the water surface 43, and under various sailing conditions. Thus, the hydrofoil 39 may with positive angle of attack help support the weight of the craft at low relative wind speeds, or it may with negative angle of attack help maintain a down load to prevent the lift provided by the horizontal wing from raising the foil .39, above the water surface in stronger wind conditions. Alternatively or additionally, water ballast may be supplied to a tank located near the center of gravity as for example at 80, as from an inlet tube 81 carried by strut 36, and suitable pipe connected to the tank. A valve 82 in the piping controls the intake and discharge of the ballast. A very important purpose of the substructure is to react the lateral wind forces exerted on the vertical wing, thereby to prevent leeway.

The hull itself may be stabilized by provision of vertical and horizontal tail surfaces, 50 and 51, carried by the body rearwardly of the wings, these also being characterized as fin and stabilizer elements. At least one of these elements may have controllable angle of attack surfaces, as for example are represented by surface 50a pivotable about a vertical axis by means 53, and by the element 51 which is itself pivotable about a horizontal axis by means 54. These surfaces and controls enable the craft to be held in a generally forwardly directed attitude, as shown, and in particular, for the configuration depicted, enable alignment of the hull into the relative wind so that the wings each maintain the same desired angle of attack thereto. Steering may be accomplished by turning the rudder element 50a, or by turning the vane type strut 36 about a vertical axis, or both. For the latter purpose, the strut 36 may be carried by a vertical shaft 55 driven about a vertical axis as by drive 56.

It should be noted that when the craft is picking up speed, with hull l0 touching the water, the foil 37 is designed to provide lift at low speed and raise the hull clear of the surface. Thereafter, with hull drag eliminated, the craft may rapidly pick up speed, and the foil 37 and diverging struts 38 can be successively lifted clear of the water as the weight of the craft is increasingly borne by the foil 39 and the horizontal wing. Elevation of the craft is then controlled by foil 39 and attitude by elevator surface 51.

The craft wings may also have controllable surfaces such as ailerons 58 seen in FIG. 1. An actuator is indicated at 59 to control pivoting of the aileron about an axis extending lengthwise of the wing. The operator may, of course, manipulate a central control mechanism to operate all of the above described controls.

FIG. 7 shows a sailing craft 60 embodying the

dual wing

61 and 62 features of the invention as described, as well as the substructure 63 with controllable hydrofoil flap 64. In addition, the craft is powered, as for example is represented by the propeller 65 carried by the substructure. The power means might alternatively act through a propellor or jet attached to the craft above waterline.

FIG. 8 shows a modified craft 70, also embodying the

dual wings

71 and 72, excepting that they have a common pivot axis 73. A suitable mechanism is provided, as schematically indicated at 74, to pivot the wings approximately 90 about that axis, as previously described. In addition, the wing mount is provided by a turntable 76 carried by the craft hull 77 for turning about a vertical axis, a suitable drive 78 controlling the extent of such turning. This arrangement provides an additional degree of freedom for the craft wings as respects their orientation relative to the wind, and also relative to the craft hull and substructure 79. In case of such an arrangement, the main hull can remain aligned generally in the direction of travel over the surface, (rather than aligned generally into the relative wind as in the embodiment shown in FIG. 1) while the wings pivot relative to the hull either in response to control by the operator or to a suitable wind vane to maintain proper alignment into the relative wind for optimum performance. One advantage of such an arrangement is that it enables the keel and forepart of the hull to be designed to more smoothly withstand the impact of the surface at high speeds. FIG. 8 also represents application of the invention with pairs of wings attached to a craft with at least two orthogonal pivot axes, as a method for wind propelling any water bome craft.

Finally, the

elongated wings

11 and 12 may be provided with hinge structure enabling folding thereof to reduce their lengths for handling in close quarters, or for storage. Also, wing floats 95 may be provided as for example at the wing tips, to prevent the wings striking the water surface and to support the wings when the craft is at rest.

I claim:

1. A sailing craft, comprising a. a body,

b. first and second wings each having inboard and outboard ends and extending lengthwise therebetween, the inboard end of each wing having hinge connection to the body characterized as defining two alternate sailing modes and remaining proximate the body in each of said modes,

c. means for retaining the first wing to extend substantially horizontally when the second wing extends substantially vertically to define one of said modes, and for alternately retaining the first wing to extent substantially vertically when the second wing extends substantially horizontally to define the other of said modes, and

d. there being substructure extending below and connected with the body and relative to which both wings are swingable in unison about a generally vertical axis in each of said modes.

2. The craft of claim 1 wherein said wings are elongated and have airfoil configuration, chordwise, such that the wings when extended laterally are presented to develop lift.

3. The craft of claim 2 wherein the two wings have substantially like configuration.

4. The craft of claim 1 including means defining said hinge connection for each wing, with separate hinge axes extending generally lengthwise of the body.

5. The craft of claim 1 wherein said substructure includes a strut extending below the body to project into water for receiving force exerted by the water over which the body is propelled.

6. The craft of claim 1 including controllably swingable ailerons on said wings.

7. The craft of claim 1 wherein the body is forwardly elongated, and including vertical and horizontal stabilizer elements carried by the body generally rearwardly of the wings.

8. The craft of claim 7 wherein at least one of said elements has controllable angle of attack surfaces.

9. The craft of claim 1 including means defining said hinge connection for each wing providing at least two orthogonal pivot axes.

10. The craft of claim 1 having a fuel powered, forward thrust developing means thereon.

11. The craft of claim 1 wherein the retaining means comprises actuator mechanism to pivot the wings between said modes and to retain the wings in said modes.

to a ballast tank carried by the craft body.

Claims

1. A sailing craft, comprising a. a body, b. first and second wings each having inboard and outboard ends and extending lengthwise therebetween, the inboard end of each wing having hinge connection to the body characterized as defining two alternate sailing modes and remaining proximate the body in each of said modes, c. means for retaining the first wing to extend substantially horizontally when the second wing extends substantially vertically to define one of said modes, and for alternately retaining the first wing to extent substantially vertically when the second wing extends substantially horizontally to define the other of said modes, and d. there being substructure extending below and connected with the body and relative to which both wings are swingable in unison about a generally vertical axis in each of said modes.

12. Te craft of claim 11 wherein said mechanism is connected with inboard portions of the wings.

13. The craft of claim 1 including floats carried by outboard portions of said wings to at times engage the water surface and prevent wing engagement with the water.

14. The craft of claim 5 including duct means carried by the substructure to receive water intake for supply to a ballast tank carried by the craft body.