US2569318A

US2569318A - Sail for sailing craft

Info

Publication number: US2569318A
Application number: US98889A
Authority: US
Inventors: Herbert H Kersten
Original assignee: Individual
Current assignee: Individual
Priority date: 1949-06-13
Filing date: 1949-06-13
Publication date: 1951-09-25
Anticipated expiration: 1968-09-25

Description

Sept. 25, 1951 H. H KERSTEN SAIL FOR SAILING CRAFT 2 Sheets-Sheet 1 Filed June 13, 1949 Inventor Herbe rf H. Kersren H- H. KERSTEN SAIL FOR SAILING CRAFT Sept. 25, 1951 2 Sheets-Sheet 2 Filed June 13, 1949 Inventor Herbert H. kelslen Patented Sept. 25, 1951 UNITED" STATES OF v fzgssaais smronsmrN-eunnrr Herbert HsKersten, Iowa City, Iowa AppI-ica'tiOnJime-IS, 1949;'SerialNo.'o8;889

" This invention relates to-novel andzusefulimprovements in sail constructions for use on variousan'd sundrytyp'es of 'sa-iling'craftr An object of thisinventionistoprovide a flexi ble; airfoiltyp'e' of sail body which; will-- alter" its contour in response to various airr'pressures in such a way as to improvethe-sailing'characteristics ofa craftand to improve: theaerody-nam-ic qualities 1' and behavior of the sail as itvpasses through the air and asthe; sail together withthe craftisurged throughthe waterby meansof the air pressure occasioned-bythewind currents-incident to the sail body.

- Conventional sails; consisting-of-a singlesheet of: canvas whichbecomes:arcamberedvsurface in response to wind pressures are-aerodynamically ineiiicient. This inventiomprovides-a sailebody which will assumethecontour otanairfoii in action. It willthen-have much highen aerodynamic efliciency asregardseitszeffective'thrust to drag ratio. Itis so designed thats'iu willra utoma-tically assume the, proper contour in response to incident'winds i Y r a The feature oi the invention resides inthe-com struction which includes a curved: leading: --edge member, or -mast, having an, opem-bac'kand' at leastone vertical guide but: pretera-bly two disposed within the leading edge memberiandeshoes mounted for slidable amovement disposedon the guide or guides with; tubesecarriedtby the shoes so that a flexible memberma-y'pass-through-reaoh tube and be directed: rearwardly, the flexible member having attached at its ends a long batten which may be of one or two piece. construction but whichiis carried by a flexible body andrspecifically in long batten pockets formed by; suitable material securedthereto disposed between spaced sail surfaces of the body; and'cross members connecting' the battens. r v :1 Ancillary'objectslandfeatures-of novelty" will become apparent'ito-those 1skiilediin the-art; in following the description not the preferred'iform of -"the: invention, illustrated imtheraccompmying drawinggwherein; V 7

Figure l is anxelevationaliviewrof the sail construction; p

Figure 2 is a sectional view-taken substantially on the' line 2-2 of Figure 1"- seem the direction of the arrows;

Figure 3 is a fragmentary perspective view of the sail construction;

Figure 4 is a fragmentary transverse sectional view in enlarged scale showing internal structure of the sail mechanism;

Figure 5 is an enlarged detail of construction unl ims (01, 114-103) 2 g taken on the-line 5-5'1 of Figure: 1 and: in the di rection of the arrows: and 1 Figure 61s a seriesa-of 'schema'tic views: showing the functional operation of the structure The structure of the present invention. "has been made" with a view to commercial feasibility. To this end it is necessary that the structure be relatively simplified; easily fabricated and removed. Accordingly; a-vleading' edge member H! which is smoothly curved inacross section: and which'has an open back, is adaptedfor substantially vertical disposition: on: a craft. It i's so mounted on the craft as to be capable of rotary motion on its vertical axis so: as tmpermit proper alignment of'the sail structure with incident air currents. The said '"leadingedge member has a vertical partition '12 with a plurality 0f cross members disposed therein "supporting rails or guides l4 and It;-re'sp'ectimely'. These' rai-Is or g'uides have pairs of shoes l8 and 20; respectively, mounted 1 for sl idable "movement/ thereon; The guides are preferably formed with side=- grooves therei'n and the-shoes have complemental tongues disposed in the grooves so that the: shoesare capable of onI-y vertical'movement. There are a flared ends' M and 26 respectively; directed backwardtowa'rd the trailing edge of the structure. flexible element ormember as a cabl'e- ZWis cii's posed each tube; At-eachend of the flexible member Z8 t'he're is afastener 30 releasably fixed to a ring-32 provided on sail surfaces S S-and 36, respectively, of a flexible bodymember.

T-he sai'd "flexible' -body member is preferably ma deof a conventional materiahand is of two spaced SBJiI-Sl-IITQCBS 34 and 36', joined together" at the-trailing edge bymeans' of stitching on the The 'bo'dy is outta the desired specifica ti ons' to forrn'--a substantially conventional sail shapedmemb'er: v

Spaced stripstll of amaterialrsimilan tothat ofjfthe .sail: surfacesJare stitched or otherwise 'secured tonthe interior aspect of .each sail surface 3!, and 3'6}; forming"batteng pockets; forthe dispositiomof; flexible battens. 12'- and, respec,

tively. It is noted that the illustration shows the batten made of one piece. However, it is contemplated to use either one or two piece construction. In the single piece construction as disclosed in Figure 2, the two halves of the batten generally are considered individual battens.

The leading edge portions of the body are In operation various wind pressures applied" to the sides of the sail construction force'the sail construction to assume the position as shown at 50 in Figure 6, or at 52 in Figure 6. When there is a direct head wind, thesailstructure,-

assumes the position 56 shown in Figure 6.

At the lower edge of the body there is an elastic strip 58 fastened, having eyelets 60 therein so that the string or rope 62 may pass therethrough so that it also may be wrapped around the boom or pole 64. This boom is attached to the leading edge member or mast in the conventional disposition. The elastic strip 58 permits a certain degree of vertical resiliency in said

surface

34 and 36 permitting them to maintain an aerodynamically smooth contour in all positions relative to incident air currents.

The sail construction will, in operation, be made to function as an airfoil by properly adjusting its angle of incidence to wind currents.

It will thus provide a higher degree of impelling thrust to the forward motion of the sailing craft in proportion to its drag than would a conventional single surface, cambered sail. This behavior characteristic will materially increase the efliciency of the sailing craft when it is sailing close-hauled or on a broad reach.

The general construction will permit removal of the sail construction from the sailing craft when not in use. Having described the claimed as new is:

1. A sail construction comprising a leading edge member adapted for substantially vertical disposition on a boat, a flexible double surfaced sail body, means operatively connected with said body for restraining the body from flexure beinvention, what is yond'a predetermined position in response to air pressure, meansadjustably supported by said leading edge member for retaining said restraining means including rails, shoes slidably disposed on said rails, tubes carried by said shoes, and said body restraining means having a part thereof'carried by and slidably disposed insaid tubes.

2. A sail construction comprising a leading edge member adapted for substantially vertical 4 therein and secured to said shoes for slidably supporting said elements.

3. The combination of claim 2, and a boom operatively connected at an angle with said leading edge member, and resilient means secured to said flexible body connecting said sail body with said boom.-

4. In a sail construction, a substantially airfoil shaped flexible body movable in response to various directional air pressures to assume various corresponding positions and a leading edge member having one pair of edges of the body disposed therein, pairs of battens carried by said ,body and means connecting opposite battens of each pair, flexible elements secured to the ends of the battens of each pair, and means carried by saidgleading edge member securing said element to said leading edge member including a plurality of shoes and vertical guides having said shoes disposed thereon.

5. A sail construction comprising a curved leading edge member having an open back and at least one vertical guide disposed within said leading edge member, shoes disposed on said uide and tubes carried by said shoes, a sail body formed of two thickness of flexible ma-/ terial joined at the trailing edges thereof form'- ing two sail surfaces, longitudinal members carried by said material and forming pockets, and means disposed in said pockets and said tubes for transmittingmovement of one of the thicknesses to movement of the other thickness of material.

6. A sail construction comprising a curved leading edge member having an open back and at least one vertical guide disposed within said leading edge member, shoes disposed on said guide and tubes carried by said shoes, a sail body formed of two sheets of flexible material joined at the trailing edges thereof, members carried by the inside surfaces of said sheets forming pockets, and means disposed in said pockets and said tube for transmitting movement of one of the sheets to movement of the other sheet of material and including pairs of battens, the battens in each pair being connected together at the leading edge by flexible elements disposed in said tubes.

7. The combination of claim '6, and a plurality of cross members disposed between said sheets and secured to said pairs of battens.

' HERBERT H. KERSTEN.

REFERENCES CITED The following references are of record in the file of this patent: V V

. UNITED STATES PATENTS 7