United States Patent 2444526

This invention relates to sail boats and has for its object to provide a sail boat which will under wind velocities of increasing intensity tend to lift out of the water, or "plane," in the same manner as a motor-propelled speed boat of modern design. Various attempts have heretofore been made...

Pawley Jr., William D.
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Pawley Jr., William D.
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US Patent References:
2361409Ship hull1944-10-31
2312567Sailing craft1943-03-02
1856803Fore and aft rigged vessel1932-05-03
1729446Ship hull1929-09-24
1670936Sailing craft1928-05-22

Foreign References:

This invention relates to sail boats and has for its object to provide a sail boat which will under wind velocities of increasing intensity tend to lift out of the water, or "plane," in the same manner as a motor-propelled speed boat of modern design. Various attempts have heretofore been made to design hulls for sail boats to obtain this effect, but so far as I am aware none of them has proved successful because the sail plans employed in such boats as heretofore designed have been of a type such as to develop, in addition to the forward component from the force of the wind, a downward component at the bow of the boat, thus offsetting any lifting effect that might otherwise result from the hull design.

My improved sail boat presents novelty both in the hull design and in the sail plan, the two cooperating so that the force of the wind when transmitted to the boat has an upward and not a downward component at the bow, thereby assisting in lifting the boat out of the water under increasing wind velocities.

In the accompanying drawings I have shown my invention as applied to a single-masted small boat of the shallow-draft, broad beam type.

In the said drawings, Figure 1 is a perspective view showing the boat as it appears afloat under a light breeze; Fig. 2 shows the hull in plan; 3( Fig. 3 shows in cross section the outline of the hull amidships; and Figs. 4 and 5 are diagrammatic views showing respectively the position of the hull under a light breeze and when heeled over.

Referring to the drawings, parcuulaiy xla . the boat here illustrated comprises a light deckedover hull I, which in the actual craft represented in the drawings is 19 feet overall including the stern-sprit and has an 8-foot beam. The single 4 mast 2, which is 24 feet high, is stepped at a point about 3 feet forward of the stern. The mast is braced by a stay 3 extending from the top to the bow 4 which, as shown, is of the blunt or scow type. Stays 5 also extend from the top of the mast to the gunwales 6 on each side and to the rear of the mast step. A third stay 5 extends from the top of the mast to a stern-sprit 7 consisting, as shown, of two timbers extending rearwardly from the stern-transom 8, although of course a single stern-sprit may be employed if desired.

The rigging consists of a mainsail 9 of righttriangular shape having eyes along its hypotenuse which ride on the forward stay 3 extending from the top of the mast to the bow. The right angle corner of the sail carries the sheet 9' which passes through a pulley 10' mounted on the mast. The sail is hoisted by a halliard which passes over pulley 10. The mainsail 9 has 114-39) 2 a generally vertical trailing edge 9a and a lower generally horizontal edge or foot 9b. The edges 9a and 9b are at right angles. The mainsail has I leading edge 9c, which is inclined or diagonal.

At the rear corner, the mainsail is connected with a sheet, as stated which passes through the pulley 10', mounted upon the mast 2. This sheet 9' is used to trim the mainsail 9, as is well known.

The mainsail has its lower edge or foot 9b free and flexible, which means that such lower edge is not attached to a boom or other rigid element.

The leading edge 9e of the mainsail is inclined and diagonal, as stated, and is longer than the lower horizontal edge or foot 9b or the rear edge 9a. The mast 2 is mounted upon the hull near the stern and rearwardly of amidship and is nearer the stern than the amidship. By virtue of the arrangement of the mast 2 near the stern, the forestay 3 has an increased length and is inclined further from the perpendicular, which imparts a corresponding increased length to the leading edge 9c of the mainsail and increases the inclination of the edge 9c from the perpendicular. By providing the leading edge 9c with increased length the mainsail 9 creates the maximum lifting force.

The second and smaller sail I is also of right angle shape. Its base is attached in the usual manner to a rearwardly projecting boom I1' conSnected to the mast in the usual manner, preferably below the point of attachment of the pulley carrying the sheet for the mainsail. The boom I 1' is controlled by a sheet leading to a pulley 12 carried at the end of the stern-sprit. The boat is provided with the usual rudder 13, here shown as projecting rearwardly from the stern between the timbers making up the sternsprit.

The hull is decked over except for a small L0 cockpit 15 adjacent the mast. The hull design is shown in Figs. 1 to 3. The design provides the boat in effect with three bottoms and three separate keels. The middle keel 16 extends in the usual manner longitudinally along the mid line 45 of the bottom. One each side of this mid keel are side keels 17 extending also from the bow transom 4 to the stern transom 8 and so shaped and positioned with respect to the mid keel that when the boat is heeled over to approximately 50 300 the bottom formed by the planking intermediate the mid keel and the side keel and the planking between the side keel and the gunwale will be of substantially the same contour as the bottom formed by the planking extending on 55 each side of the mid keel. The rear transom is larger than the bow transom and the intermediate ribs are so shaped that the plane of the hull inclines upwardly from the stern to the bow, the angle of incline increasing toward the bow. 60 The operation of the boat is as follows: As2,444,526 sumig that the boat is sailing forwardly with Du This mainsail is ordinarily trimmed further out ing f than is the. case.,,with the conventional mainsail .. on th having the "'igid' boom at its ,lower edge.. The g is lift wind blowing against the mainsail passes about creasi the forestay 3 and leading diagonal edge Sc of -e tal, ti the mainsail Producing a low pressure about vidint such leading edge 9c, which in turn produces .ing ef a resultant upward and forward force. -This up-o 10 ýwithir ward and forward force is increased by the in- boat c creased length of the leading edge Sc;: hich in o.winds turn results from the arrangement of the mast 2, course as stated. The direction of this lifting and for- ing th ward force is always. perpendicular to the fore- 1 tain t - stay 3 or leading edge 9c, and since the leading -predet -i"dge has an increased length and an increased the ju ýin'clination from the perpendicular, the lifting shifted -""force is-materially increased. This results in approx --'eIevating the front end of the hull. When-the 2 he otl - 'Wind blows abeam, the:mainsail 9 is concaved in In - t iv- direction perpendicular to the forestay a3 and going : leading edge 9c, thus producing the camber at scribed the. leading edge of the mainsail. Since' the erated lower edge or foot Sb of the mainsail is:free and- 25 inventic j:flexible,:it will follow. the curvature of the main- pended .s ail :perpendicular to the leading- edge 9Sc and 'ative di "'-tlhemainsail will be substantially flat in a di- I. clai :-trection parallel with the leading edge ci This w-:ill eliminate the: camber produced at the lower: 30 and wi Sedge ofthe conventional mainsail caused by the mast m 'presence of the rigid boom. If this camber is than to S:-produced at the lower edge f the mainsail, it the mas -' -will'exert:a down.ward pulling force, for the same 'a mains - reason that-- the forestay and leading edge c of, 35 cured tc :*the mainsail produce the camber and the upg - * free and -ward pulling force. This disadvantage is elimi- and a s ae sted in my construction by omitting the boom. its lower SThe air currents discharge or slip over the .lower .2. In -.:edle 9b of the mainsail, and :a somewhat simi5; 4 and wid lar action occurs at the trailing edge Sat It is mast mo rthus, seen that the air currents are-free to spill ship an "aWide beam. This is the type of hull usually em- stay:and, ::ployed in connection with a pawer-driven speed is free an - boat.. As far as 1 am awarei this type of-bot- ing..disp -tomn is not used-with -sailirng:boats'. My hull has relation t a ispeed boat :bottom, which means thate thatk eo the main --Portion of the keel which engages with the water the 2 rain during the travel is straight, with no rocker in the stern. The bottom is also V-shaped in cross- isection, rat the keeloor keels.

The Purpose in changing the'designfrom the-r Snormal rig is to. change the distribution and di- The fo -:rection of forces exerted by the sails so that the file f thi rig-might be used on what is commonly:known "as ýa standard motor speed hull. The normal rig '-'cannot be successfully used on that type of hull. 80 Number :Wel are enabled to attain materially- 'increased '-1670,936 In operation under light winds. the boat-floats u1,856,803 on its- middle bottom and the. mid keel serves 2,312,567 with the rudder to maintain the course of- the 65- 2,361,409 -boat. Under a stiff: wind the: boat heels over to '30; at- which angle it will be-maintained by : shifting the:ballast - and setting the: sails; - and in Number - this- position it rides on, the bottom- composed '..86,294 of a bottom symmetrical to one or-the- other of - the side keels, whereby the boat has a- true planing: effect under-stiff winds as well as-light- winds. "Sailing -:When running heeled over the side keelP serves .- .Macmillan with the rudder to maintain- the course of the - "Boat Bu --boat. 7" Norton& C e to the position of the mast near the stern ;he use of a sail running on a stay extendrom the bow to the mast instead of running e mast -inthe conventional manner, the bow ;ed by the force of. the wind,- thereby inng the angle of the bottom to the horizonius aiding in the planing effect, and by prothree keels as shown, the maximum planfect will be obtained at all wind velocities a substantial range. That is to say, the an be maintained on its true bottom in all Sup to a certain velocity, depending of on the direction of the wind, by shifte ballast and trimming the sails to mainhe mast substantially upright. Above a ermined velocity, selected according to igment of the operator, the ballast will be I and the sail set to heel the boat over imately 300 so that it will ride on one or er of the two side bottoms.

ie accompanying drawings and the forespecification I have illustrated and dea boat as actually constructed and opby me, but it will be understood that my on may also, within the scope of the apclaims, be applied to boats of other relmensions and types.

a boat, a hull having a shallow draught le beam and a speedboat type bottom, a ounted upon the hull closer to the stern the bow, a diagonal forestay secured to t near its top and to the bow of the hull, ;ai having a leading diagonal edge sethe forestay and having a foot which is 1 flexible and also having a trailing edge, heet connected with the mainsail near corner.

a boat, a hull having a shallow draught e: beam and a speedboat type bottom, a unted upon the hull at the rearof amidI nearer the stern: than the. amidship, al forestay secured to the mast -near its to the bow of the hull,, a mainsail havding diagonal edge secured to-the.forea trailing edge and a lower foot-which id flexible, the trailing edge and foot be>sed at substantially right' angles-1-with o each other, and means- connected with sail near its lower rear corner So that sail may be trimmed out.


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