US2858788A - Water craft - Google Patents

Description

J. LXMAN WATER CRAFT Nov. 4, 1958 2 Sheets-Sheet 1 Filed May 23, 1955 J. LYMAN WATER CRAFT Nov. 4, 1958 2 Sheets-Sheet 2 Filed May 23, 1955 Unit I WATER CRAFT Application May 23, 1955, Serial No. 510,161

6 Claims. (Cl. 114-39) My invention relates generally to improvements in water craft, and more particularly to water craft deriving its propellant force from the wind, i'. e., sailing craft.

Sailboats of more conventional design are provided with keels of various shapes, depths, and contours, all for the purpose of preventing drifting or skidding, which keels are sometimes weighted to provide some roll stability. However, while sailing, and particularly while tacking, more conventional sailboats heel or roll about a crafts longitudinal axis in an amount proportional to the strength of the wind and to the craftsheading relative to the wind direction. Also, heeling or rolling is produced by the action of the waves. In either case such heeling, not only being a source of passenger discomfort, also reduces greatly the efliciency of the craft. In the first place, the sail of a heeling craft spills the wind, i. e., it does not derive the full driving force of the wind; and in the second place, the hull in most boat designs offers greater resistance to Water when heeled than when upright. Furthermore, craft having more conventional keels tend to slip or skid downwind, sometimes referred to as leeway, caused by the action of the Wind on the sail which produces a force component on the hull parallel to the wind direction. Sailing craft have been designed in which heeling has been reduced by providing two or more hulls or a single hull having long, laterally extending, but cumbersome, Outriggers. However, such craft while reducing rolling, correspondingly increase water resistance by increasing the hull Wetted surface.

It is therefore a principal object of the present, invention toprovide a water craft which overcomes the above disadvantages by providing means for not only preventing heeling of the craft but also for greatly reducing the Wetted hull area and thereby greatly reducing water-hullresistance and also for substantially reducing any slipping or skidding of the craft downwind and hence enable the same to point'upwind moreeifectively.

Itis another object of the invention to provide a single-hulled sailboat having a keel with control surfaces thereon for counteracting heeling and skidding, andhydrofoils for lifting the hull out of-the water therebysubstantially eliminating water resistance and wave action on the hull.

supporting'the sail extends vertically upward in a straight line-with the leading edge of the sail secured thereto atentO ice by means of tracks and slides whereby the leading edge of the sail is caused to flutter and thereby lose efficiency due to eddy currents produced by the mast. In the sailboat of my invention I have eliminated this disadvantage by shaping the mast in the form of a how, the luff rope, and hence the leading edge of the sail, extending in a straight line from the top of the mast to the base thereof whereby the leading edge is spaced from and thus isolated from the efiects of the mast.

It is therefore another object of the present invention to provide a sailboat of increased efficiency, i. e., the leading edge of the sail is maintained spaced or separated from the mast.

Further objects and advantages of the present invention will become apparent as the description of a preferred embodiment thereof proceeds, reference being made therein to the accompanying drawings wherein:

Fig. 1 is a perspective view of a water craft designed in accordance with the teachings of my invention;

Fig. 2 is a sectional view of the boat of my invention as viewed from the stern and illustrating the wind and water forces acting thereon;

Fig. 3 is a perspective view, partially brokenaway, of the craft of my invention showing the internal and external details thereof;

Fig. 4 is a view of one form of apparatus for automatically controlling the anti-roll and anti-skidding control surfaces of the craft;

Fig. 5 is a view of another form of apparatus for automatically controlling the anti-roll, anti-skidding control surfaces; and

Fig. 6 is a view of a modification of my invention.

Referring now to Fig. 1, I have illustrated a water craft comprising a hull 10 adapted to be propelled through the water by means of a sail 11 supported on the hull by a mast 12. The hull, mast, and other structural elements of the craft may be constructed of any suitable, preferably light, strong material. The method and apparatus for producing or fabricating the structural elements of the craft may be the'same as that disclosed in my copending application Serial No. 520,208, filed July 6, 1955, for Method and Apparatus for Producing Structural Elements of Glass Fiber Reinforced Plastics. As disclosed in this copending application, these structural elements are made from fiberglas impregnated with a suitable thermosetting resin, such as, for example, a polyester resin. Of course the structural elements may also be fabricated from wood, aluminum, etc.

The mast 12 is rigidly secured at the bow 13 of the hull 10 and is so constructed as to be relatively flexible. As shown, the mast is bowed by means of a bowing cable 14 secured at the masthead 12 and at the base 12 thereof in a manner similar to the bow string of an archers bow. Further rigging cables or stays 14 are provided for maintaining the masthead 12 at a position longitudinally displaced from the mast base and preferably substantially directly above the center of gravity of the hull 10. For this latter purpose the stern of the hull It) is provided with fins 8, 8' which extend outwardly from said hull at an angle of approximately 45 from the horizonal such that the cables 14', being secured at the top thereof, form a triangle and hence provide fore and aft as well as lateral stability for the mast 12. A suitable tie rod 9 is also provided for strengthening the fins and also for providing a support for the main sheet if desired, as will be explained hereinafter. With this novel mast configuration, the sail 11 may be of triangular configuration. In the illustrated embodiment the sail is in the general form of an equilateral triangle, the base thereof supporting boom 7 which is pivoted to the mast by any of a number of conventional goosenecks. The

the bottom of the keel.

luff rope which defines the leading edge of sail 11 extends from the tip of the mast to the base thereof; but, due to the bowed configuration of the mast, theluff rope is completely separated or isolated from the latter and in no way interferes with the aerodynamic functioning of the sail, that is, the mast will not in any way cause fluttering or loss of efliciency of the sail adjacent its leading edge as in most sailboat designs.

Hull 10 has a generally round cross-section at its center of gravity as illustrated in Fig. 2, which section is carried out over its length except that it tapers towards the bow and becomes generally flatter towards the stern (see dotted sections in Fig. 1). It will be noted that its beam is relatively narrow as compared to its overall length and hence presents a very low frontal area to the 'water. In order to provide stability to the craft about its longitudinal axis 1, have provided an elongated keel 16 which in the illustrated embodiment is approximately /3 the overall length of the hull 10 and is located generally amid-ships and preferably at a position adjacent the center'of gravity thereof. Static longitudinal stability is provided by suitably weighting the keel as at 16. The weight may be lead, for example, which is preferably of streamlined shape and secured to the bottom of the keel as shown.

In the embodiment illustrated in Fig. 1 the keel 16 has mounted thereon a hydrofoil means 17 'which extends substantially horizontally athwartship from the keel and thus provides means for reducing the wetted surface of the hull When the craft is under way at slow speeds and for completely lifting the hull from the water at higher speeds. In other words, the hydrofoil 17 provides hull lifting forces which are capable of at least partially and under certain conditions completely lifting the hull out of the water. Hydrofoil 17 is preferably located on keel 16 at a position considerably below the hull so that the hull may be lifted free of water and waves. In the illustrated embodiment, hydrofoil 17 is located at a position approximately Va of the distance from hull to The hydrofoil 17 may be of any suitable configuration, consistent with its lift characteristics and its stability. However, I have found that the hydrofoil configuration providing the largest range of dynamic stability is that of a delta plane form. The dimension of the hydrofoil is determined in part by the total weight of the craft and passengers, and in part by the craft speeds attainable. With a hull, mast, and other structural elements of the craft constructed in accordance with the teaching of my above-noted copending application the athwartship span of hydrofoil 17 is approximately equal to or only slightly greater than the dimension of the beam of the hull 1t) amidships.

In accordance with the teachings of the present inven- I tion I have provided an aft horizontal surface 18 having a controllable portion or elevator 18' located at the stern of the hull and supported on a vertical fin 19 (see Fig. 3). Thus, deflection of elevator 18 produced by means to be hereinafter described, will change the pitch attitude of the hull and hence will change the pitch angle and angle of attack of hydrofoil 17 which in turn will increase or decrease the effective lift of the latter, and thus enable a substantially constant lift to be obtained for various craft speeds.

Since hydrofoil 17 should be maintained substantially horizontal in order to maintain substantially equal volumes of water over the hydrofoil surface area on each side of the hull, and since hull 10 is relatively narrow with respect to its length in order to minimize water resistance, I provide means on the keel 16 for providing forces or torques which counteract or oppose rolling or heeling motions of the craft due to wind pressure on the sail 11. As illustrated in Fig. 1, this means comprises a control surface 20 articulated on keel 16 near the lower trailing edge thereof for movement about an axis substantially parallel to the vertical axis of the craft. Control surface 20 is preferably located as low as possible on keel 16 in order to provide a maximum torque arm. Means, to be hereinafter more fully described, are provided for moving control surface 20 in response to rolling or heeling of the craft about its longitudinal axis. As illustrated in Fig. 2, if the wind produces a force of the magnitude W on sail 11, and hence to hull 10 through mast 12, tending to heel the craft about a longitudinal axis thereof, the control surface 20 is moved in a direction to produce a counteracting force F. If the magnitud of forces W and F are made equal by controlling the magnitude of control surface deflection, the craft cannot heel or rotate about its longitudinal axis and hence the hull 10 will remain in a substantially veritical or upright position such that the hydrofoil 17 will be maintained substantially horizontal.

Pivoted as close to the upper end as possible of fin or keel 16 is a second control surface 21 which also is articulated thereon near the trailing edge thereof for pivotal movement about an axis substantially parallel to the vertical axis of the craft. As will be hereinafter described, control surface 21 is rotated in a direction opposite to that of the control surface 20. The functlon of this second control surface will be clear from-inspection of Fig. 2. Since wind force W and force F produced by water pressure on control surface 20 are in the same direction with respect to the water the craft will tend to slip or skid downward, that is, the craft will be translated downwind. Control surface 21 is adapted to produce a force F in the direction indicated which tends to counteract this skidding or translational force. As a result, skidding or slipping of the craft will be greatly reduced or substantially eliminated and therefore the craft may be pointed much closer to the wind.

In Fig. 3 I have shown a cut-away view of the hull 10 illustrating a control mechanism for operating control surfaces 20 and 21 in the manner hereinabove set forth. As shown, rolling motion of the craft is controlled by means of a control stick 25 pivoted as at 26 on a torque shaft 27 for rotation about an axis parallel to the athwartship axis of the hull 10. Shaft 27 is fitted in suitable journals 28 in hull bulkheads29 and 30 for movement about an axis parallel to the fore and aft axis of the hull. For operating the control surfaces 20 and 21 upon rotation of stick 25 and shaft 27, I provide a horn 31 to which is fastened or suitably secured a control cable 32 connected through suitable pulley arrangements to triangular shaped members 33, 34. Member 33 is pivoted in the keel 16 as at 35 such that upon rotation thereof surface 20 is caused to pviot about its vertical support axis through reciprocating 'motion of shaft or link 36 and control surface horn 37. Similarly, triangular member 34 is pivoted as at 38 such that upon rotation thereof control surface 21 is rotated about its support axis by means of shaft or link 39 and surface horn 40. It will be noted that control cable 32 is crossed to thereby provide differential or opposite movement of control surfaces 20 and 21 as described. The sense of the control action is such that if the craft is caused to heel to starboard due to the action of the wind on the sail 11 the operator rotates control column 25 to the left, thereby deflecting control surface 20 to port to produce a counteracting torque on keel 16, the magnitude of deflection being sufficient to maintain the hull 10 upright.

Connected to control shaft 25, at points above and below pivot 26 thereof, are control cables which pass through suitable tubular members or conduits 46 to the stern of the craft where they pass over suitable pulleys to a similar triangular member 47 pivotally mounted as at 48 in vertical fin 19 in a manner such that upon move ment of control column 25 forward and backward triangular member 47 will cause elevator 18 to be moved down and up in accordance therewith through born 49 and link or shaft 50. With the craft under way such movement will change the angle of attack of hydrofoil 1 7 and thereby change the liftcharacteristics thereof resulting in a control action which will maintain a desired hydrofoil depth for changes in craft speed.

As shown in Fig. 3, the reach of sail 11 may be controlled by means of main sheet 51 which may pass over a suitable pulley or deck block 51 on strut 9 and be secured to a cleat fastened to the side of the hull 10 in each reach of the operator.

In order to control the directional stability of the hull 10 I have provided rudder 22 which may be operated by means of suitable pedal 'bar 53 which is pivotally supported as at 54 for movement about a craft vertical axis. Secured to pedal bar 53 are control cables 55 which, like control cables 45, pass through suitable tubes or conduits 56, one of which is not shown for the sake of clarity of illustration. Control cables 55 are attached to rudder horn 57, whereby upon rotation of pedal bar 53 in one direction or the other the rudder 22 will likewise be similarly rotated about its support axis for steering the craft.

The operation of the apparatus hereinabove set forth is believed to be evident from the foregoing description. Assume that the sail is adjusted for a close reach or close tack position. Wind pressure on sail 11 will, of course, tend to heel the craft. However, the operator controls column 25 to actuate anti-heeling surface 29 in a direction and to an amount to counteract the heeling torque produced by the wind on the sail. As the craft gets under way and its speed increases, elevator 18 is deflected to produce a positive angle of attack of hydrofoil 17 which in turn produces a lift vector on hull 10. At a predetermined speed this lift vector will raise the hull from the surface of the water. The resulting elimination of hull friction will result in an increase in the speed of the craft. As the speed increases less and less deflection of surface 20 will .be required, thereby further reducing drag due to surfacedefiection. Due to the fact that the craft is prevented from heeling, the sail will produce a much greater forward thrust on the craft and hence very high speeds may be attained. The high speeds attainable enable a very eflicient hydrofoil action,

that is, it will reduce the required design area of the hydrofoil and thereby still further reduce drag on the hull due to the hydrofoil and further increase the attainable speed of the craft.

Although manual control of control surfaces 20 and 21 is desirable from a sporting aspect, requiring skill on the part of the operator, it is contemplated that automatic control of these control surfaces may be provided. In the modification illustrated in Fig. 4, I have shown such an automatic control means for controlling the operation of control surfaces 20 and 21. In this modification torque shaft 27 is extended as at 70 into a stern compartment of hull 10. To the end of shaft 70 is rigidly attached a lever 71 which extends normally vertically upward and projects through a suitable slot 72 in the bull to a point preferably just above the top surface thereof. The boom rope or sheet rope 73 is attached to the upper end of lever 71 and is passed over a pulley 74 secured to the boom 75 of sail 11. From pulley 74 boom rope 73 is brought to within convenient reach of the operator, as at a point just forward of the craft cockpit 76, where it is adjustably secured to a suitable cleat 77. Although water pressure on control surfaces 20 and 21 will provide a restoring force to tend to maintain the surfaces streamline, I may additionally provide centering springs 78, 73 fastened between lever 71 and the hull sides.

In operation, the boom may be initially adjusted by the operator by adjusting boom rope 73 while maintaining control surfaces 2% and 21 undefiected through manual restraint of control column 25. After the desired boom position is attained, rope 73 is secured to cleat '77 and control column 25 released. Thereafter lever arm 71 will actuate control surfaces 29 and 21 in such a way as to make deflection of the surfaces proportional to'the force of the wind on sail 11. Since main sheet exact balance to the torque created by the wind action against the sail, the proportionality constant being provided by proper selection of the length of lever arm 71 or,' if' necessary, by suitable-gearing or lever arrangements connected between lever 71 and torque shaft 72.

In Fig. 5 I have illustrated another embodiment of the present invention whereinanother form of automatic means are provided for actuating control surfaces 20, 21, in order to maintain the craft substantially upright. As in Fig. 4, torque tube 27 is extended toward the stern of the hull 10 as at 70, to. the end of which is secured a pulley 86. Thus upon' rotation of pulley .fins 20, 2.1 will be displaced through yoke 31 and cables 32. If desired, a suitable clutch 81 may be inserted between torque tube 27 and extension 80 thereof for rendering the automatic control apparatus inoperative so that the operator may control the control surfaces manually through vcontrolhandle 25. In this modification, I have illustrated means responsive to the heeling or rolling motionof the craft for applying a torque to shaft 27. This means comprises a relatively large pendulous mass 82 fixed or suitably secured to a shaft 83 pivoted in suitable journals 84,84 in hull bulkheads 29, 29 (see Fig. 3) for rotation about an axis substantially parallel to the longitudinal axis of the hull 10. Also fixed to shaft 83 is a horn or pulley 85 to which is fastened-a suitable cabie 86 reeved on pulley 80. It will be noted that the diameter. of-horn 85 visilarge relative to the diameter 80 so that relatively small angular displacements. of mass 82 will produce a correspondingly large deflection of control surfaces 20, 21. The proportionality constant between pulleys 85 and 80 is so selected that deflection of pendulum 82 is very close to the vertical .or upright position for relatively large wind forces on sail 11.

The operation of the automatic craft erecting means of Fig. Sis believed clear from the foregoing description thereof. With clutch 81 engaged, placing the craft under automatic control, any heeling of the .craft due to. wind force on the sail willbe detected by the pendulum 82 swinging away from the vertical. Such swing of the pendulum 82 will rotate torque arm 27 of the control system and apply a deflecting force on control surface 20 through cable 32 in a direction to counteract the heel ing motion. It will be noted that the mass 82 is relatively large, i. e., capable of producing sufficient force on control cables 32 to perform the above erecting or righting function.

In Fig. 6 I have illustrated a modification of the present invention. Since vertical control surface 20 and, control column 25 are caused to maintain the craft vertical, I provide in this modification a pair of hydrofoil members 60 and 61 arranged in tandem on the hull 10, hydrofoil 60 being mounted on a suitable vertically extending fin 62 adjacent the bow of the hull and hydrofoil 61 being supported on vertical fin 63 adjacent the stern thereof. The trailing edge of stern hydrofoil 61 is controllable and thus serves as an elevator for the purposes set forth above in regard to elevator 18 in the embodiment of Fig. 1. It will be understood that the tandem hydrofoils may be of any suitable shape. However, I prefer to construct them in the same shape as hydrofoil 17, i. e., a delta plane form. Furthermore, it will also .be understood that the tandem hydrofoils 60, 61 may be used alone or in combination with a main hydrofoil such as hydrofoil 17 of Figs. 1 to 5. Hydrofoils arranged as shown in Fig. 6 tend to increase the pitch stability of the craft.

Although in the foregoing I have illustrated preferred embodiments of the present invention, other modifications thereof will be apparent to those skilled in the art. Instead of a single fin or keel having a control surface thereon for providing anti-rolling forces, the craft'may alternatively be provided with two or more keels each having such a control surface. For example, the craft may have a keel such as keel 16 mounted on the hull near the bow and stern, each keel having a hydrofoil such as hydrofoil 17 for raising the hull from the water as above described.

Since many changes could be made in the above described construction and many apparently widely different embodiments of this invention could be made without departure from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. In a sailing craft having a hull and sail means for propelling said hull through the water, the combination comprising an elongated keel mounted on said hull at a position thereon substantially adjacent the center of gravity thereof, a hydrofoil means fixed relative to said hull for supporting said hull at least partially out of the water, a first control surface pivoted adjacent the lower.

trailing edge of said keel for producing anti-rolling couples about a longitudinal craft axis, and a second control surface pivoted adjacent the upper trailing edge of said keel for reducing skidding of said craft when tacking.

2. The combination set forth in claim 1 wherein said hydrofoil is mounted on said keel adjacent said upper control surface.

3.'A water craft comprising a hull, means for propelling said hull through the water, a vertical keel, a control surface pivotally mounted on said keel and adapted when deflected to produce couples on said craft about a longitudinal axis thereof whereby to counteract rolling motions of said craft, means responsive to rolling motions of said craft about said axis for actuating said control surface, and substantially horizontally extending hydrofoil means fixed relative to said hull for lifting said hull when said craft is under way.

4. A sailing craft having a hull and sail means for propelling said hull through the water, an elongated keel extending substantially downward from said hull at a point thereon substantially adjacent the center of gravity thereof, vertical control surfaces pivoted on said keel adjacent the lower trailing edge thereof for producing anti-rolling couples about a longitudinal axis, means responsive to rolling of said craft for actuating said control surfaces whereby automatically to maintain said craft substantially vertical, and means fixed relative to said hull for supporting said hull out of the water when said craft is under way.

5. A sailing craft of the character set forth in claim 4 wherein said roll responsive means includes a pendulum pivoted in said craft for movement about a longitudinal axis thereof, and means coupling said pendulum with said control surfaces whereby said control surfaces will be deflected upon relative movement between said pendulum and said hull.

6. In a sailing craft having a hull and sail means for propelling said hull through the water, the combination comprising an elongated keel mounted on said hull at a position thereon substantially adjacent the center of gravity thereof, a hydrofoil means fixed relative to said hull for supporting said hull at least partially out of the Water when the craft is under way, a first control surface pivoted adjacent a lower substantially vertical edge of said keel, means for controlling said first surface in a sense to produce anti-rolling couples about a longitudinal craft axis, a second control surface pivoted adjacent an upper substantially vertical edge of said keel, and means for controlling said second surface in an opposite sense from that of said first surface.

References Cited in the file of this patent UNITED STATES PATENTS 1,410,876 Bell Mar. 28, 1922 2,139,303 Greg Dec. 6, 1938 2,491,744 Link Dec. 20, 1949 2,646,763 Sveinsson July 28, 1953 2,689,540 Kasey Sept. 21, 1954 2,703,063 Gilruth Mar. 1, 1955 2,703,064 Hill Mar. 1, 1955 2,709,979 Bush June 7, 1955 2,724,356 Szakacs Nov. 22, 1955 FOREIGN PATENTS 293,226 Germany July 22, 1916 908,583 Germany Apr. 8, 1954

Images