CA1186956A - Fluid foil system - Google Patents
Fluid foil systemInfo
- Publication number
- CA1186956A CA1186956A CA000423019A CA423019A CA1186956A CA 1186956 A CA1186956 A CA 1186956A CA 000423019 A CA000423019 A CA 000423019A CA 423019 A CA423019 A CA 423019A CA 1186956 A CA1186956 A CA 1186956A
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- Canada
- Prior art keywords
- foil
- mast
- fluid
- cross bar
- tilt
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Abstract
IMPROVED FLUID FOIL SYSTEM
OLSEN, ERIC
Abstract of the Disclosure An improved fluid foil system which is particularly adapted yet not limited to use in sail craft. When used in e.g. a sailboat, the foil is rotationally supported with respect to a mast and laterally tiltable about a longitudinal axis in either direction to receive the wind which in turn powers the boat on which the mast is supported. The mast can be supported in the boat at the other end thereof so as to enable free rotation with respect thereto. In addition, the system is provided with self-leveling means for the foil so as to continually urge such to its rest or non-tilted position, that is, in a position generally parallel to the water, i.e., at a zero attack angle with respect to the wind. This combination of a self-leveling, tiltable, and freely rotationable foil enables the foil to be securely attached to the mast with a minimum of structural weight.
This in turn enables both simplified and improved control of the foil and the boat which it powers and otherwise enables maximazation of both light and heavy winds in a herethereto unachieved manner.
OLSEN, ERIC
Abstract of the Disclosure An improved fluid foil system which is particularly adapted yet not limited to use in sail craft. When used in e.g. a sailboat, the foil is rotationally supported with respect to a mast and laterally tiltable about a longitudinal axis in either direction to receive the wind which in turn powers the boat on which the mast is supported. The mast can be supported in the boat at the other end thereof so as to enable free rotation with respect thereto. In addition, the system is provided with self-leveling means for the foil so as to continually urge such to its rest or non-tilted position, that is, in a position generally parallel to the water, i.e., at a zero attack angle with respect to the wind. This combination of a self-leveling, tiltable, and freely rotationable foil enables the foil to be securely attached to the mast with a minimum of structural weight.
This in turn enables both simplified and improved control of the foil and the boat which it powers and otherwise enables maximazation of both light and heavy winds in a herethereto unachieved manner.
Description
~ s Background and Ob~e~
This invention relates to an improved foil system which is capable of receiving energy from the flow of a fluid mediun and efficientiy transferring a portion of such energy to the structure on wnich such foil system is supported. More particularly, che invention is directed to an improved sail system for sailboats and the like, although it should be pointed out tnat the invention is not so limited DUt has utility to efficiently,!extract or divert dynamic forces generated ~rom fluid flow conditions regardless of tne medium of such fluid flow, i.e., whether it be wind, water current, etc. Other applications of the device other than operating a sail craft include power generation~ irrigation, littoral deposit:s,agricultural anti-frost and drying air movernent. However, inasmucil as the use of t;le in~.proved fluid Poil systeln of the present invention in connection with a sail craft is an easily understood and recognized example, it will be used hereinafter as the means by wnich thP present invention will be described.
In the art of sail cra*t, constant effort thro~gh the years has been utilized to decrease the difficulties o accomModating varled wind strengths and to increase the freedom to maneuve~_sail craft despite wind direction and strength. EfEort has also been r~lade and continues towards extractins wind power and water power especially at low flow rates while retaining the ability to acco~nodate sub-stantially higher velocitles thereof.
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This invention relates to an improved foil system which is capable of receiving energy from the flow of a fluid mediun and efficientiy transferring a portion of such energy to the structure on wnich such foil system is supported. More particularly, che invention is directed to an improved sail system for sailboats and the like, although it should be pointed out tnat the invention is not so limited DUt has utility to efficiently,!extract or divert dynamic forces generated ~rom fluid flow conditions regardless of tne medium of such fluid flow, i.e., whether it be wind, water current, etc. Other applications of the device other than operating a sail craft include power generation~ irrigation, littoral deposit:s,agricultural anti-frost and drying air movernent. However, inasmucil as the use of t;le in~.proved fluid Poil systeln of the present invention in connection with a sail craft is an easily understood and recognized example, it will be used hereinafter as the means by wnich thP present invention will be described.
In the art of sail cra*t, constant effort thro~gh the years has been utilized to decrease the difficulties o accomModating varled wind strengths and to increase the freedom to maneuve~_sail craft despite wind direction and strength. EfEort has also been r~lade and continues towards extractins wind power and water power especially at low flow rates while retaining the ability to acco~nodate sub-stantially higher velocitles thereof.
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Various attempts have also been made to utilize foils ranging from airplane wings to sail simulations or ancient 5amoan craft, tilted to either side of a mas~ or the like in changing tacks and seeking an increasing stability by varying the lateral tilt angle so as to control the above indicated parameters. Each said syste~ however introduces unmanageable difficult mechanical compiications such as heavy structural stresses and large control forces as well as introducing unreasonably complicated manipulation or timiny mechanisms in order to control such foils.
5Ome attempts to utilize tiltable foils in connection ~ith sail craft includ~ U. S. Patent 2,170,914 to Rummler issued August 29, 1939 which, although generally lS indicative of rigging concepts in this area, fails to present structural, areodynamic or operational solutions of a feasible commercial nature. Other patents include U. S. Patent 2,319,999 to Jennings issued May 25, 1943 directed to a wing flap control; U. S. Patent 1,670,936 issued May 22, l9Z8 to McIntyre et al; U. S. Patent 2,126,665 to Rowland issued August 9l 1938 and directed to a complex system of multiple booms pivoting on the hull for sail support and operation; U. S. Patent 2,387,907 to Hook issued October 30, 1945 which includes a sail foil which ~an 25 vary its la~eral attitude; U. S. Patent 4,177,345 issuea March 7, 1978 to Guxley direc~ed to a sail supported by two spars directly mounted on a revolving mount located ~x ~ w 5~
proximate to the hull and controlled through torsional means ~orking on its shaft; U. S. ~atent 3,858,542 issued January 7, 1975 to Lenoble directed to a hand supported foil; U. S. Patent 3,924,870 issued December 9, ~9~5 to Spivak et al and also directed to hand supported sail;
U. S. Patent 3,455,261 issued July 15, 1969 to Perrin also directed to a foil structure having particular utility for a sail board; U. S. Patent 2,329,220 issued July 12, 1939 to Rummler directed to a ,v!ariable spread sail/spar structure which is cumbersome and limiting, that is, utilizes a 45~ pivot in order to alternate the two sail support spars in hori~ontal and vertical positioning depending on which tack the vessel is on a~d thus causes the air flow to essentially flow normal to the vertical spar and 15 parallel to the other; U. ~. Patent 2,106,432 issued January 28, 1938 to McIntyre which is directed to a multi-hull craft, the hulls of which can be skewed relative to one another so as to align the wind loads on its two inclined sails relative to its two inclined centerboards.
The above recitation and discussion of these patents an~ other prior structures constitues applicant's Prior Art Statement; and in that regard, a copy of each such ` patent is enclosea herewith.
It also may be apparent from the above discussion that the underlying objectives of the present invention are not accomplished by presently available devices in the intended manner. Accordingly, a basic object of th~
present invention is to provide an improved fluid ~o~l .
~stem which can be used to extract or divert substantial dynamic forces generated from fluid flow conditions in such a manner tha-t such foil can be controlled adequately and simply by extremely light and straightforward structural means which can be provided at a reasonable cost.
An additional object of the present invention is the provision of a fluid foil system which operates in a greatly simplified manner and which, accordingly, ]0 reduces the learning effort and experience which an operator must acquire to operate the system and yet which has wide adaptablility and usefulness when applied to water sail craft such as sailboats.
A further object of the present invention is the provision of an improved fluid foil system which can be used in fixed location power generating systems which is effective in very light winds or in slow water currents as well as in fluids of higher velocity and when assuming different flow directions.
These and other objects of the present invention are accomplished by a fluid foil system for imparting power from a moving fluid medium to a supporting body which body in turn is supported by means other than said moving fluid medium said system including a generally laterally symmetrical fluid foil connected to a mast along a longitudinal axis thereof, said mas-t supported for free, unlimited rotational movement with respect to said body, said foil further adapted for major lateral tilt approach-ing 90~ in either direction with respect to said mast about said longitudinal axis from a fluid power-off or .
lb/~-P 5 level" rest position where said foil is generally aligned with the directional flow of said fluid medium to a tilt-ed position wherein said fluid imparts power to said foil, operational control means for moving said foil to various tilt attitudes and self-leveling means for said foil connected to both said foil and said mast and adapted to automatically return said foil to said rest position when free from said operational control.
Other objects, features and advantages of the invention shall become apparent as the description there-of proceeds when considered in connection with the accompanying illustrative drawings.
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Various attempts have also been made to utilize foils ranging from airplane wings to sail simulations or ancient 5amoan craft, tilted to either side of a mas~ or the like in changing tacks and seeking an increasing stability by varying the lateral tilt angle so as to control the above indicated parameters. Each said syste~ however introduces unmanageable difficult mechanical compiications such as heavy structural stresses and large control forces as well as introducing unreasonably complicated manipulation or timiny mechanisms in order to control such foils.
5Ome attempts to utilize tiltable foils in connection ~ith sail craft includ~ U. S. Patent 2,170,914 to Rummler issued August 29, 1939 which, although generally lS indicative of rigging concepts in this area, fails to present structural, areodynamic or operational solutions of a feasible commercial nature. Other patents include U. S. Patent 2,319,999 to Jennings issued May 25, 1943 directed to a wing flap control; U. S. Patent 1,670,936 issued May 22, l9Z8 to McIntyre et al; U. S. Patent 2,126,665 to Rowland issued August 9l 1938 and directed to a complex system of multiple booms pivoting on the hull for sail support and operation; U. S. Patent 2,387,907 to Hook issued October 30, 1945 which includes a sail foil which ~an 25 vary its la~eral attitude; U. S. Patent 4,177,345 issuea March 7, 1978 to Guxley direc~ed to a sail supported by two spars directly mounted on a revolving mount located ~x ~ w 5~
proximate to the hull and controlled through torsional means ~orking on its shaft; U. S. ~atent 3,858,542 issued January 7, 1975 to Lenoble directed to a hand supported foil; U. S. Patent 3,924,870 issued December 9, ~9~5 to Spivak et al and also directed to hand supported sail;
U. S. Patent 3,455,261 issued July 15, 1969 to Perrin also directed to a foil structure having particular utility for a sail board; U. S. Patent 2,329,220 issued July 12, 1939 to Rummler directed to a ,v!ariable spread sail/spar structure which is cumbersome and limiting, that is, utilizes a 45~ pivot in order to alternate the two sail support spars in hori~ontal and vertical positioning depending on which tack the vessel is on a~d thus causes the air flow to essentially flow normal to the vertical spar and 15 parallel to the other; U. ~. Patent 2,106,432 issued January 28, 1938 to McIntyre which is directed to a multi-hull craft, the hulls of which can be skewed relative to one another so as to align the wind loads on its two inclined sails relative to its two inclined centerboards.
The above recitation and discussion of these patents an~ other prior structures constitues applicant's Prior Art Statement; and in that regard, a copy of each such ` patent is enclosea herewith.
It also may be apparent from the above discussion that the underlying objectives of the present invention are not accomplished by presently available devices in the intended manner. Accordingly, a basic object of th~
present invention is to provide an improved fluid ~o~l .
~stem which can be used to extract or divert substantial dynamic forces generated from fluid flow conditions in such a manner tha-t such foil can be controlled adequately and simply by extremely light and straightforward structural means which can be provided at a reasonable cost.
An additional object of the present invention is the provision of a fluid foil system which operates in a greatly simplified manner and which, accordingly, ]0 reduces the learning effort and experience which an operator must acquire to operate the system and yet which has wide adaptablility and usefulness when applied to water sail craft such as sailboats.
A further object of the present invention is the provision of an improved fluid foil system which can be used in fixed location power generating systems which is effective in very light winds or in slow water currents as well as in fluids of higher velocity and when assuming different flow directions.
These and other objects of the present invention are accomplished by a fluid foil system for imparting power from a moving fluid medium to a supporting body which body in turn is supported by means other than said moving fluid medium said system including a generally laterally symmetrical fluid foil connected to a mast along a longitudinal axis thereof, said mas-t supported for free, unlimited rotational movement with respect to said body, said foil further adapted for major lateral tilt approach-ing 90~ in either direction with respect to said mast about said longitudinal axis from a fluid power-off or .
lb/~-P 5 level" rest position where said foil is generally aligned with the directional flow of said fluid medium to a tilt-ed position wherein said fluid imparts power to said foil, operational control means for moving said foil to various tilt attitudes and self-leveling means for said foil connected to both said foil and said mast and adapted to automatically return said foil to said rest position when free from said operational control.
Other objects, features and advantages of the invention shall become apparent as the description there-of proceeds when considered in connection with the accompanying illustrative drawings.
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Description of the Drawin~
Fig. 1 is a perspective view showing the fluid foil system of the present invention utilizad in conjunction with a boat to power the same and depicted _ in its rest position with respect to wind currents generally assumed to be parallel to the surface of the water;
Pig. 2 is a view similar to Fig. 1 but showing the foil in a tilted position i,~to the wind;
Fig. 3 is a perspective view showing a manner 1~ in which the foil ~ay be torsionally connected to the mast;
Fig. 4 is a somewhat s~hematic elevational view showing the attitudes of tilt which the foil may take with respect to the mast as well as the manner in which the mast may rotate with respect to the boat;
Fig. 5 is a view similar to Fig. 4 but showing a particular manner in which the self-leveling means for the foil operates;
Fig. 6 is a partial plan view of a means for controlling the attitude of the foil including a sheet or line attached thereto and a fairlead mounted on the upper rail of the boat;
Fig. 7 is a partial elevational view of th~
fairlead shown in Fig. 6;
Fig. 8 is an elevational view showing another form of a foil self-laveling means;
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., Fig. 9 is an elevational view of tne mea~s shown in Fig. 8 but turned 90;
Fig. 10 is an elevational view on an enlarged scale showing a form of tilt limiting means that may be used in conjunction with the fluid foil system of the present . _ 5 invention;
Fig. 11 is a cross-sectional view taken along the line 11 11 of the Fig. 10;
Fig. 12 is a cross-s~ctional view taken along the line 12-12 of Fig. 10;
Fig. 13 is partially sectioned elevational view showing another structural form in which the seli-leveling means of the present foil system may assume;
Fig. 14 is a view similar to Fig. 13 but showing the foil in a tilted position;
Pig. 15 shows another structural form in which the self-leveling system for the foil may take;
E'ig. 16 is a view similar to Piy. 15 but showing the supporting cross bar of the foil laterally displace~
with regard to Fig. 15;
Fig. i7 is a cross-sectional view along the line 17-17 of Fig. 15;
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Fig. 18 is a perspectlve view showing ~
modified fluid foil system particularly adapted for use with a sailboard and shown mounted in conjunction therewith;
Fig. 19 is a ~ide elevational view of the sail-board and fluid foil system shown in Fig. 18 but disposed in its rest position with respect to wind currents generally assumed to be parallel with the surface of the water; ~!
Fig. 20 is an enlarged partially sectioned elevational view showing the manner which the fluid foil is connected to the r,last; and Fig. 21 is a detail eleva,tional view showing the manner in which the rod shown in Fig. 20 is connected to the cross bar sleev~.
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Description of the Invention Turning now to the drawings and particul~xly Fig. 1 thereof, the improved fluid foil system 10 of the present invention is depicted as part of a sailboat con-struction including a hull 12 of any suitable construction.
The foil system 10 includes a oil 14 including a pair of flexible A-frame spars 16 which serve to stretch a delta-form sail 18 therebetween. The foil 14 may be otherwise constructed including,~formation from rigid sheet material and the like. The foil 14, accordingly, e~hibits a nose portion 20 and a trailing edge 22. ~ cross bar 24 extending between the spars 16 serves to stretch the sail 18 and maintain it in such conditionr The foil 14 is torsionally mounted to a mast 26 generally along its longitudinal axis of lateral symetry such that the foil 14 may assume various positions of lateral tilt with respect to the mast as shown by the arrows in Figs. 4 and 5. Such connection is accomplis~hed by MeanS
of a sleeve 28 fixed in position to the cross bar 24 at its midpoint and from which a pin 30 rearwardly extends through the hollow interior of the ~ast 26. A connector 32 of any suitable construction such as the screw cap_shown serves to fasten the Pin_30 on the other side of the mast 26 such that the cross bar 24 and, accordingly, the foil 14 is free to assume the lateral tilt in either direction .
as above-described. It will be apparent in thi~
construction that the lateral aerodynamic lift forces are largely counterbalanced about the flexible mast mount which in this case is a pivotal connection. Accordingly, , '' :
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the foil 14, when otherwise unconstrained, is free to seek a luffing attitude of pitch where the angle of attack of the foil 14 in regard to .he wind forces ~assumed to be generally parallel to the surface of the water on which the sailboat is supported) essentially neutralizes the lift forces of such fluid medium against the foil.
A strut 34 is attached to a collar 36 so as to enable pivotal motion in a vertical plane of such str~t.
The collar 36 is in turn adjustably fixedly connected to the mast 26 at one end and extends upwardly to the nose 20 of the foil 14 at its other end. Accordingly, $his strut 34 extending between the leading nose 20 o~ the foil 14 serves to position the pitch of the fvil's longitudinal axis. `~ormally such pitch is set such that the foil assumes a hori~ontal, i.e., position parallel to the water, such that foil has a neutral lift when disposed in its normal lufing or level atti~ude as shown in Fig. 1.
The mast 26 is supported by being appropria~ely "stepped" in the hull 12 and is free for multi-rotational movement with regard thereto. Thus, the mast 26 has a rotational degree of freedom greater than 360 with respect to the hull 12 in either direction. It thus may be seen that the combination of the ability of the mast to rotate in the above-indicated manner with the ability of the foil 14 to tilt about the mast in either lateral direction e~ables the foil lA to assume a wide range of directional headings and,positions vis-a~is the directional flow of the wind such that the desired degree of its force may be harnessed in any particular case. Also, the torsional link between the foil 14 and mast 26 elminates any complication or entanglement of these means of attitude positioning and control since they rotate in unison to any dixectional heading, including multi-rotational weathervaning.
Also, the ability of the foil 14 to weathexvane as above described coincidentally places the required portion of its drag towards its trailing edge 22.
The above described support or connection o~ the foil 14 to the mast 26 need not however be a direct connectiGn.
Thus the foil could be connected to a sleeve or some other member in turn supported by the mast and capable of free or at least multi-rotational movement with respect to the mast. In such case the mast itself ~ould not need to be capable of actual rotation with respect to the boat or Gther support. Accordingly,the term mast as used herein and including the claims oE this application is used in a broad sense which would include such an intermediate member such as a sleeve, etc.~ in other words, the mast supports the foil for multi-rotational movement.
In order to control the degree o lateral tilt of the foil 14, a continuous sheet 40 is attached to the spar 16 some distance behind the cross bar 24. The bight or loop of this sheet 40 passes over a fairlead 41 opening to the rear and mounted on opposite sides of a hull rail 43 to the rear of the position of the mast 26 and thence to a retractor (not shown) attached to the mast and elastically drawing the sheet slacX to the lower portion of the mast. When the sheet 40 is released from the fair-leads, it is able to completely rotate with the foil syste~
10~ tha~ i~, with the mast and foil 14 without entangling the crew, passengers, or boat ~ear. Partial rotation of ~ the mast occurs without entangler,lent even with the sheet engaging the fairleads.
Also, due primarily to the largely counterbalanced longitudinal pitch forces of aer~dynamic lift upon the foil 14, the sheet 40 control forces are minimized. In thiR
regard, it should be pointed out that the aerodyn~mic lift forces applied to the foil 14 are also generally late~ally balanced about its longitudinal axis o lateral symetry because its pivotal mount is centrally located on this axis.
The foil may, however, be purposely unbalanced to enable aerodynamic leveling as for instance shown in Figs. 15 - 17.
Thus balanced, a minimum force is required to mechanically induce a leveling or horizontal-seeking lateral attitude towards which the foil tendc to return when otherwise unconstrained, i.e., by the force application to the control sheet 40 in either direction. Force applicati~n is accomplished simply by the operator grasping and pulling the appropriate side of the sheet and released by the operator flipping the sheet aftward to clear the sheet from the fairleads 41.
A self-leveling asserably 42 is provided such that the foil when otherwise unconstrained will seek a rest, level, or luffing attitude generally normal to the saast 26 and parallel with the direction of wind force. ~he term level, leveling, etc. as used herein means in ~
preselected attitude with respect to the mast which ls generally but not necessarily normal thereto. Such leveling systera 42 includes a V-shaped yo~e 44 attached to oppos~ta `~ 'A.
sides of the cross bar 24 by means of sleeves 4fi. The apex 46 of such yoke 42 is attached to a cord 4B e~tending into ~he hollow interior of the mast 26 ~hrough an opening 50 proximal the yoke apex 46 when the foil 14 is in the normal re~t attitude. The cord 48 is connected in turn to a spring 52 mounted in the interior of the mast 26 and, accordingly, the cord 48 serves to place a continual downward and inward force upon the yoke 92. Instead of a separate spring 52, the cord 48 could be an elastic cord commonly referred to as a "shock cord". Also, the term spring encompasses members which apply a spring-like forcet!e.g., spring reels, cylinders, e~c. It may be thus apparent that when the foil 14 assumes a lateral tilt with respect to the mast such as shown iD
Fig. S that the downward force applied thereto by the self-leveling means 42 tends to return the foil to its level or rest position shown in Fig. 4. It should, of course, be brought out that the force of such leveling system is not great enough so as to present difficulty in being overcome by the control sheet 40 but that when the foil is otherwise unconstrained, that is, not being held in a lateral tilt attitude by the control sheet 40, that it will seek its normal lateral or rest disposition automatically. The term "cord" as used above and hereinafter includes flexible tensile members, e.g., flexible joined links, e.g., chain, wire cable, and the like.
The self-leveling means may also be integral with the connection of the foil 14 ~o the mast as by incorporation of a leveling spring therein ~see Fig. 20), connected with the foil as described witn regard to the system 42 above or separate but in operational contact as with the self-leveling means 60 illustrated in Figs. 8 and 9. In Figs. e and 9 the c~oss bar 24 of the foil is pivotally connected to the r~last 26 by a pin 62 extending to opposite s~des of a bifuracted upper mast tPrminus. A sleeve 64 18 adap~ed for slidable movement on the mast from a point proximate a fixed collar 66 to a point proximate the pivotal connection with the cross bar 24. A compressed coil spring 68 is disposed between the collar and the sleeve so as to continually urge the sleeve upwardly where a pair of arms 70 upwardly outwardly extending from the sleeve 64 are adapted to respectively contact opposite sides of the cross bar 24 dependent on the tilt attitude thereof so as to continually urge such to a level position~ As the foil is ~lted into the wind by the,lsheet 40t the sleeve 64 is similarly forced to move downwardly against the action of the spring 68. It should be noted that although self-levellng means 42 as well as self-leveling means 60 have been illustrated as disposed below the position at which the foil is supported by the maat, there is no reason to limit such disposition since the self-leveling means could be positioned above the foil in those cases where the mast projects a suitable distance above the foil connection.
In such caces, the self-leveling means 42 would be in effect mounted upside down in the mast projection and the sleeve 64 of the self-leveling means 60 mounted above the cross bar 24. Similar adjustments can be made for other forms of foil le~eling and limiting systems that will hereinafter be described.
The manner in which the foil system 10 as abo~e-described in relationship to Figs. 1 through 5~ operates to power the boat 12 will now be described. Since either sailing across the wind or downwind are more easily accomplished than "upwind" or "close hauled" such upwind condltion 18 described. The wind is thus assumed to strike the boat ~rom forward and or one side or the other. To initiate sail propulsion or to get under way when the sail foil 14 is in its weathervaning or level rest position, that portion of the sheet 40 which tilts the foil 14 to leeward of the mast is engaged and trimmed in. Th~ foil, accordingly, both tilts and swings its ~railing edge 22 towards _ 5 the trimming pcsition aft of the mast 26, thus filling away to the wind. The tilt angle is adjustably limited by further control by tha operator on the sheet 40 depe'ndent upon wind strength, operator capability, passenger loading or other preference. Tilt may ~so be adjustably limited 1~ by changiny the effective length of cord 48.
Once tilted to this selected limit, further trim or easing on the sheet 40 enables the foil system 10 to act entirely as a conventional fore 'n aft sail rig except when the sail is being allowed to luff sub-stantially. Then, it has a slack sheet 40 and will seek its unconstrained rest position automatically. When shifting tacks either by tacking or jibing, the sheet A0 is released and the boat swung through its wind axis.
'..'hen the previously unused sheet portion is trimmed as when getting under way. The procedure is simple, and the usual hazard or inconvenience of avoiding unpredicable swinging of a low boom is totally eliminated. There i~ no severe s~il shift or heeling forces or crucial timinq necessary during a tack or ji~e.
' .~lso, the present foil system provides an inherent mechanism by which the wind force acting upon the foil can be immediately and automatically be shut off regardless of wind orientation as by disengaging the sheet 40 from the fairlead being used and upon which it will assume its rest or -lh-luffing position. Such is important especially i~
mooring or making landings in cramped quarters or in difficult wind circumstances. Thus, the present foil can shut off its sail power in any directional - heading and in widely veering winds simply_ by releasing the sheet so that the foil automatically levels to its weathervane or rest position.
In many cases it is aesirable to be able to limit in a positive manner ~he degree of tilt which the foil 12 may assume. Such may be accomplished by a tilt limiting system 76 such as shown in Figs. 10 t~rough 12 of the drawings. ~uch system includes a sleeve 78 slidably supported on the mast 2~ but fixed in position with respect thereto in a manner which will be hereinafter indicated. The sleeve includes a vertically extenaing open slot 80 on one side thereof. A series of vertically aligned, spaced bolts outwardly extend from the sur~ace of the mast 26. These bolts 82 are oriented with respect to the slot 80 such that the sleeve 78 may slide up and . down on the mast but will not rotate with respect thereto inasmuch as the contact betveen the heads of the bolts 82 and the opposed edges of the sleeve 78 which form the slot 80 prevents such action.
The slee~Je 78 is further provided with a pair ~. .
of upwardly outwardly extending tubular arms 84, each of which terminates in a headed portion 86 As best shown in Fig. 12, the head 86 which i~
preferably formed of some shoc~ absorbin~ material such as a high density foamed polymer includes a concave Qaddle 87 . .
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which is adapted to contact the cross member 24 in such a manner so as to limit its downward tilt, or in those cases wherein the tilt l.imiting mechanism 76 is mounted on a mast portion extending above the foil--~hen limiting its upward possible tilt. Thus, 1t may be seen that by moving the sleeve 78 closer to the pivotal connection between the cross bar 24 and the mast 26 that the resultant degree of tilt of the foil carried by the cross ~ar 24 may be reduced; and, accordingay, the potential powe~
that may be derived from the wind source limited. similarlY
by moving the sleeve downwardly, the potential tilt of the foil rnay be increased. In this regard, the bolts 82 ser~e as markers such that the degree of tilt may be readily :,:
determined by the position of the sleeve vis-a-vis tbe bolts 82; and, accordingly, the desired position of the tilt limiting system 76 calibrated according to wind conditions, position of the boat, and expe:rience of its operator. Thus in extremely high winds, it ~ight be desirable to place the tilt limiting mechanism 76 adjacent the uppermost bolt 82, but in light winds such can be placed adjacent the lowermost bolt. The sleeve may be set within .. the desired predetermined limits by a line 88 which is secured at one end thereof. to the sleeve 78 preferably at the rear side thereof, ihat is, opposite the slot 80 as through an eyelet 90 and thence to a directional change eyelet 92 mounted above the highest desired position of the sleeve and thence downwardly to a conventional attachnent point such as a cleat (not shown).mounted on the lowex portion of the mast 26. It will thus be seen that as the mast rotates with respect to the boat, that the tubular ar~s 84 are always aligned in the same plane as the cross bar 24 such that the desired tilt limiting contact ~s ?~ `~e ,~
achieved therehetween such as shown by the phantom line representation in ~ig. 10. The cross bar 24, i8, a8 in the previous er,lbodiment described in connection with Figs. 1 through 5, pivotally connected to the mast 26 via a sleeve 28 which in turn includes a rearwardly extending stub 30 which is connected on the other side o~ the ma~t ;_ by a fastening device such as the lock washer 33 shown.
Generally it is desirable that, as previously indicated, a strut 34 is utilized to adjustably restrict rotation of the cross bar 24 with respect to the sleeve 28 (longitudinal or pitch rotation); however, means such as pins (not shown) may r'~ extend through the sieeve into the cross bar to lock the two together and thus prevent this added rotational motion if not desired. When permitting such pitch rotation Meanq such lS as collars, pins and the like may be used to restrict lateral sliding movement of the oross bar relative to the sleeve. Of . ., ~. .
course, such lateral sliding motion can be desirable (see, e.g., Figs. 15 - 17).
Turning now to Figs. 13 and 14 of the drawings, 20 an alternate form of a self-leveling system 96 is depicted.
Such system includes lines 98 and 99 connected at opposite free ends thereof to the cross bar 24 at locations out-wardly spaced from its pivotal connection with the mast 26. The lines pass through openings 100 provided vn 25 opposite sides of the mast 26 and over rollers 102 and thence downwardly to a ring 104 to which the other ends of these lines are attached as by whipping 105. The ring in turn is attached by Means of a rod 106 to a spring 108 all internally mounted within the mast 26 so as to place a 30 predetermined amount of downward tension upon the lines 98 and 99 so as to continually urge tbe cross bar 24 and thu~
the foil mounted thereon to its rest position in an attitude normal to the mast 26. In such a system when the foil is _14 _ .
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forced into the wind by manipulation of the control sheet 40 such as depicted in Fig. 14, such causes the line 99 to move upwardly (to the left as shown in Fig. 14) and to cauqe slack in the right hand line 98. When such control sheet 40 constraint is removed, the predetermined tension supplied by the spring 108 acting upon the line 99 via the rod 106 automatically urges the cross bar to its rest position. In skrong winds or when it is otherwise desired to increase the amount of such predetermined tension upon the lines 98 and 99, a control line 110 is additionally attached to the ring 104 and passes outwardly of the ma3t 26 through an opening 112 provided for such purpose. The other end of the control line 110 can be fixed to a cl~at or other attach~ent device (not sho~n) on the mast, and in such manner the amount of slack and or tension in either line can be .selectively limited to the extent desired.
Referring now to Figs. 15 through 17, an alternate iorm of tilt limiting mechanism 116 is depicted.
Therein the cross bar 24 is slidably supported within a sleeve 118, in turn pivotally fixed to the mast 26. In this regard, the sleeve 118 includes a downwardly extending tab 120 having an opening provided therethrough and adapted to fit ~ithin an open-ended slot 122 provided in the 25 bifurcated end of the mast 26. A pin 124 extends through openings provided in the bifurcated end as well as through the opening provided in the tab ~20. It may thus be apparent that the cross bar 24 lS supported on the mast ~ . I
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, r., ~
26 for pivotal or torsional movement as in some o the previously described embodiments. A hollow sleeve 126 i8 supported by the mast 26 and is slidably adjustable to a variety of fixed positions therealong. Lines 128 of equal fixed length are attached at opposite ends respectively to the sleeve 126 and to the cross bar 24. ~n this manner as the cross bar is subject to an outside constraint so as to, for example, tilt it downwardly to the right as shown in Fig. 16, the cross bar 2q is then forced by tbe length of the then uppPrmost line (the left line as shown in Fig. 16) to slide downwardly to the right relative to the tube 118 until it reaches a point where one of the lines 128 is taut or the sleeve 118 conta~ts some limiting means such as the collars 129 shown. This displacement of the foil area towards whichever side is tilted downward gives this side aerodynamic lift over the other resulting in added leveling tendency which is especially helpful when wind strength increases. This, in effect, provides automatic aerodynamic leveling to counteract increased heeling foxce on the foil supporting body.
Turning now to Figs. 18 through 21 of the drawings, a still further alternate for~m of a self-leveling system 136 is depicted. Such system has particular utility with lighter rigs such as may be fashioned for use with a hand supported and manipulated foil, i.e., for use with sailboards or wind surfers and the like, although not limited to such use. In such system, a foil 14, a8 . ~1 ~
3~
utilized in the previous embodiments and including a cross bar 24, may be utilized. Instead of control sheets 40, however, the foil 14 is manipulated by a hand-held generally V-shaped bar 1~8 which is fixedly connected to the cross bar 24 at intermediate locations on opposite sides of its connection to the mast 26. The mast 26 is in turn generally supported in a somewhat forward position in the sailboard 140 by means of a cowl 142 prefexably of inverted conical shape and permitting the mast 26 to angularly tilt with regard to the upper surface 144 of the sailboard. The mast 26 may be stepped into the cowl 142 in any acceptable manner and, accordingly, a~le to assume a tilt within the limits of the sidewalls of the cowl 142 in a full 360 path. ~he sailboard 140 i5 also conventionally provided with a centerboard 146 ~
and a stabilizing fixed rudder 148. Also, although a limited vertical tilt of the mast with respect to the sailboard in a full 360 circle is desirable for full flexibility, advantages can be obtained by utilizing ~
more limited degree of tilt facility; thus, the cowl 142 may assume the configuration of a longitudinally elongated slot of a width just slightly greater than the mast such that only forward and reverse tilt is permitted.
The r.~anner in which the cross bar 24 is connected to the mast 26 in the self-lPveling system 136 under consideration ~s best shown by reference to Figs. 20 and 21 of the drawings. Therein the cross bar 24 i~ -rotationally supported within a sleeve 150 and additionally x~
slid~ble therein within the limits defined by the collars 152 fixedly connected to the cross bar 24 at locatisns slightly spaced from the ends of the sleeve 150 in ord~r that some lateral play of the cross bar 24 with respect to the sleeve 150 is afforded for a purpose which will hereinafter be apparent. In addition, the bottom of the sleeve 150 is provided with an elonyated open slot 154 which in turn is adapted to rest upon the upper surface of a plug 156 which includes a downwardly extending boss portion which fits in*o the upper open end of the tubular mast 26. The plug 156 includes a central bore 160 in which a rod 162 is positioned for vertical slida~le ntovement with respect thereto. The lower surface o~
the plug boss 15~ is provided with a washer 169 against which the upper end of a spring 166 abuts. rrhe low~r end of the spring similarly contacts a washer 168 adjustably held in a fixed position relative to the rod 162 by r~leans of a nut 17 n threaded on the threaded lower terminal end 172 of the rod 162. Inasmuch as the plug 156 is fixed in relationship to the mast 26, the force of the spring 166 continually urges the rod 162 downwardly into the open upper end of the mast 26. The upper end of the rod 162 terminates in an eyelet 174 through whioh a pin 176 e~tends through the sleeve 150 so as to position the upper end of the rod within the hollow interio~ of the sleeve 150. Prom such description it may be apparent -~
that the cross bar and, accordingly, the foil 14 is held in position on top of the r.last 26 by the action of the spring 166 and thus is continually urged to the position shown in the full lines in Fig. 20 by such sprlng action.
~3 Such attitude is the rest or level position previously referred to and is the position which is continually sought by the action of the spring when free from other const~aints.
The foil lg, however, may be manipulated in a number of directional attitudes vis-a-vis the mast 26 either by the effect of wind upon the foil or by manipulation of the control bar 138 by the rider or a combination of both. It, accordingly, will be apparent that the cross bar 24 can be tilted to assume the positio~
shown by the dotteu lines in Fig. 20 or ~ny intermediate position by force application thereupon by the control bar 138. When such is accomplis~ed, the lower end o$
the sleeve 150 contacts the rounded plug surface 156;
and at the same time, the rod 162 is vertically extended upwardly so as to compress the spring 166. In that regard, the outer ends of the sleeve 150 are slightly spaced from the collars 152 such that such tilting action does not cause interference contact between the outer ends of the sleeve and the collars 152. This tilti~g action may assume various angular displacements and in a full rotational directional, that is, the foil 14 is free to rotate with respect to the mast 26 at the upper end thereof by frictional contact on the plug 156 when such rotational force is brought about either by manipulation of the control bar 138 or by wind force application to the foil 14 or any combination thereof. In addition, it is also possible to change the front to rear attitude of the foil 14 with respect to the sailboard ' by application of a swinginy or arcuate movement to tbe cGntrol bar 138 with respect to the main planar configuration of the foil 14. This action irnparts a rotational movement of the cross bar 24 with respect to the 51 eeve 150 and enables the surfboarder to qui~kly manipulate the oil surface 14 in an up and down movement as may be desirable in riding the crest of waves and the like. In this.reqard, it should be pointed out that the cross bar 24 aoes not extend entirely through the sleeve 150 but comprises of stubs 180 secured to the inside surface of the sleeve 150 by conventional means such as the inclusion of an expàndable ring 182 adapted to extend into a circular seat 184 formed in the inside surface of the sleeve.
Other conventional means may be utilized, however, to insure the connection of the stub ens of the cross bar 24 in the slee~re 150.
I~hile there is shown and described llerein certain specific structure embodying this in~rention, it will be manifest to those skilled in the art that various modifications and rearrangements of the parts may be made without departing from the spirit and scope of the underlying inventive concept and that the same is not limited to the particular forms herein shown and described except insofar as indicated by the scope of the appended claims.
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Description of the Drawin~
Fig. 1 is a perspective view showing the fluid foil system of the present invention utilizad in conjunction with a boat to power the same and depicted _ in its rest position with respect to wind currents generally assumed to be parallel to the surface of the water;
Pig. 2 is a view similar to Fig. 1 but showing the foil in a tilted position i,~to the wind;
Fig. 3 is a perspective view showing a manner 1~ in which the foil ~ay be torsionally connected to the mast;
Fig. 4 is a somewhat s~hematic elevational view showing the attitudes of tilt which the foil may take with respect to the mast as well as the manner in which the mast may rotate with respect to the boat;
Fig. 5 is a view similar to Fig. 4 but showing a particular manner in which the self-leveling means for the foil operates;
Fig. 6 is a partial plan view of a means for controlling the attitude of the foil including a sheet or line attached thereto and a fairlead mounted on the upper rail of the boat;
Fig. 7 is a partial elevational view of th~
fairlead shown in Fig. 6;
Fig. 8 is an elevational view showing another form of a foil self-laveling means;
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., Fig. 9 is an elevational view of tne mea~s shown in Fig. 8 but turned 90;
Fig. 10 is an elevational view on an enlarged scale showing a form of tilt limiting means that may be used in conjunction with the fluid foil system of the present . _ 5 invention;
Fig. 11 is a cross-sectional view taken along the line 11 11 of the Fig. 10;
Fig. 12 is a cross-s~ctional view taken along the line 12-12 of Fig. 10;
Fig. 13 is partially sectioned elevational view showing another structural form in which the seli-leveling means of the present foil system may assume;
Fig. 14 is a view similar to Fig. 13 but showing the foil in a tilted position;
Pig. 15 shows another structural form in which the self-leveling system for the foil may take;
E'ig. 16 is a view similar to Piy. 15 but showing the supporting cross bar of the foil laterally displace~
with regard to Fig. 15;
Fig. i7 is a cross-sectional view along the line 17-17 of Fig. 15;
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Fig. 18 is a perspectlve view showing ~
modified fluid foil system particularly adapted for use with a sailboard and shown mounted in conjunction therewith;
Fig. 19 is a ~ide elevational view of the sail-board and fluid foil system shown in Fig. 18 but disposed in its rest position with respect to wind currents generally assumed to be parallel with the surface of the water; ~!
Fig. 20 is an enlarged partially sectioned elevational view showing the manner which the fluid foil is connected to the r,last; and Fig. 21 is a detail eleva,tional view showing the manner in which the rod shown in Fig. 20 is connected to the cross bar sleev~.
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Description of the Invention Turning now to the drawings and particul~xly Fig. 1 thereof, the improved fluid foil system 10 of the present invention is depicted as part of a sailboat con-struction including a hull 12 of any suitable construction.
The foil system 10 includes a oil 14 including a pair of flexible A-frame spars 16 which serve to stretch a delta-form sail 18 therebetween. The foil 14 may be otherwise constructed including,~formation from rigid sheet material and the like. The foil 14, accordingly, e~hibits a nose portion 20 and a trailing edge 22. ~ cross bar 24 extending between the spars 16 serves to stretch the sail 18 and maintain it in such conditionr The foil 14 is torsionally mounted to a mast 26 generally along its longitudinal axis of lateral symetry such that the foil 14 may assume various positions of lateral tilt with respect to the mast as shown by the arrows in Figs. 4 and 5. Such connection is accomplis~hed by MeanS
of a sleeve 28 fixed in position to the cross bar 24 at its midpoint and from which a pin 30 rearwardly extends through the hollow interior of the ~ast 26. A connector 32 of any suitable construction such as the screw cap_shown serves to fasten the Pin_30 on the other side of the mast 26 such that the cross bar 24 and, accordingly, the foil 14 is free to assume the lateral tilt in either direction .
as above-described. It will be apparent in thi~
construction that the lateral aerodynamic lift forces are largely counterbalanced about the flexible mast mount which in this case is a pivotal connection. Accordingly, , '' :
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the foil 14, when otherwise unconstrained, is free to seek a luffing attitude of pitch where the angle of attack of the foil 14 in regard to .he wind forces ~assumed to be generally parallel to the surface of the water on which the sailboat is supported) essentially neutralizes the lift forces of such fluid medium against the foil.
A strut 34 is attached to a collar 36 so as to enable pivotal motion in a vertical plane of such str~t.
The collar 36 is in turn adjustably fixedly connected to the mast 26 at one end and extends upwardly to the nose 20 of the foil 14 at its other end. Accordingly, $his strut 34 extending between the leading nose 20 o~ the foil 14 serves to position the pitch of the fvil's longitudinal axis. `~ormally such pitch is set such that the foil assumes a hori~ontal, i.e., position parallel to the water, such that foil has a neutral lift when disposed in its normal lufing or level atti~ude as shown in Fig. 1.
The mast 26 is supported by being appropria~ely "stepped" in the hull 12 and is free for multi-rotational movement with regard thereto. Thus, the mast 26 has a rotational degree of freedom greater than 360 with respect to the hull 12 in either direction. It thus may be seen that the combination of the ability of the mast to rotate in the above-indicated manner with the ability of the foil 14 to tilt about the mast in either lateral direction e~ables the foil lA to assume a wide range of directional headings and,positions vis-a~is the directional flow of the wind such that the desired degree of its force may be harnessed in any particular case. Also, the torsional link between the foil 14 and mast 26 elminates any complication or entanglement of these means of attitude positioning and control since they rotate in unison to any dixectional heading, including multi-rotational weathervaning.
Also, the ability of the foil 14 to weathexvane as above described coincidentally places the required portion of its drag towards its trailing edge 22.
The above described support or connection o~ the foil 14 to the mast 26 need not however be a direct connectiGn.
Thus the foil could be connected to a sleeve or some other member in turn supported by the mast and capable of free or at least multi-rotational movement with respect to the mast. In such case the mast itself ~ould not need to be capable of actual rotation with respect to the boat or Gther support. Accordingly,the term mast as used herein and including the claims oE this application is used in a broad sense which would include such an intermediate member such as a sleeve, etc.~ in other words, the mast supports the foil for multi-rotational movement.
In order to control the degree o lateral tilt of the foil 14, a continuous sheet 40 is attached to the spar 16 some distance behind the cross bar 24. The bight or loop of this sheet 40 passes over a fairlead 41 opening to the rear and mounted on opposite sides of a hull rail 43 to the rear of the position of the mast 26 and thence to a retractor (not shown) attached to the mast and elastically drawing the sheet slacX to the lower portion of the mast. When the sheet 40 is released from the fair-leads, it is able to completely rotate with the foil syste~
10~ tha~ i~, with the mast and foil 14 without entangling the crew, passengers, or boat ~ear. Partial rotation of ~ the mast occurs without entangler,lent even with the sheet engaging the fairleads.
Also, due primarily to the largely counterbalanced longitudinal pitch forces of aer~dynamic lift upon the foil 14, the sheet 40 control forces are minimized. In thiR
regard, it should be pointed out that the aerodyn~mic lift forces applied to the foil 14 are also generally late~ally balanced about its longitudinal axis o lateral symetry because its pivotal mount is centrally located on this axis.
The foil may, however, be purposely unbalanced to enable aerodynamic leveling as for instance shown in Figs. 15 - 17.
Thus balanced, a minimum force is required to mechanically induce a leveling or horizontal-seeking lateral attitude towards which the foil tendc to return when otherwise unconstrained, i.e., by the force application to the control sheet 40 in either direction. Force applicati~n is accomplished simply by the operator grasping and pulling the appropriate side of the sheet and released by the operator flipping the sheet aftward to clear the sheet from the fairleads 41.
A self-leveling asserably 42 is provided such that the foil when otherwise unconstrained will seek a rest, level, or luffing attitude generally normal to the saast 26 and parallel with the direction of wind force. ~he term level, leveling, etc. as used herein means in ~
preselected attitude with respect to the mast which ls generally but not necessarily normal thereto. Such leveling systera 42 includes a V-shaped yo~e 44 attached to oppos~ta `~ 'A.
sides of the cross bar 24 by means of sleeves 4fi. The apex 46 of such yoke 42 is attached to a cord 4B e~tending into ~he hollow interior of the mast 26 ~hrough an opening 50 proximal the yoke apex 46 when the foil 14 is in the normal re~t attitude. The cord 48 is connected in turn to a spring 52 mounted in the interior of the mast 26 and, accordingly, the cord 48 serves to place a continual downward and inward force upon the yoke 92. Instead of a separate spring 52, the cord 48 could be an elastic cord commonly referred to as a "shock cord". Also, the term spring encompasses members which apply a spring-like forcet!e.g., spring reels, cylinders, e~c. It may be thus apparent that when the foil 14 assumes a lateral tilt with respect to the mast such as shown iD
Fig. S that the downward force applied thereto by the self-leveling means 42 tends to return the foil to its level or rest position shown in Fig. 4. It should, of course, be brought out that the force of such leveling system is not great enough so as to present difficulty in being overcome by the control sheet 40 but that when the foil is otherwise unconstrained, that is, not being held in a lateral tilt attitude by the control sheet 40, that it will seek its normal lateral or rest disposition automatically. The term "cord" as used above and hereinafter includes flexible tensile members, e.g., flexible joined links, e.g., chain, wire cable, and the like.
The self-leveling means may also be integral with the connection of the foil 14 ~o the mast as by incorporation of a leveling spring therein ~see Fig. 20), connected with the foil as described witn regard to the system 42 above or separate but in operational contact as with the self-leveling means 60 illustrated in Figs. 8 and 9. In Figs. e and 9 the c~oss bar 24 of the foil is pivotally connected to the r~last 26 by a pin 62 extending to opposite s~des of a bifuracted upper mast tPrminus. A sleeve 64 18 adap~ed for slidable movement on the mast from a point proximate a fixed collar 66 to a point proximate the pivotal connection with the cross bar 24. A compressed coil spring 68 is disposed between the collar and the sleeve so as to continually urge the sleeve upwardly where a pair of arms 70 upwardly outwardly extending from the sleeve 64 are adapted to respectively contact opposite sides of the cross bar 24 dependent on the tilt attitude thereof so as to continually urge such to a level position~ As the foil is ~lted into the wind by the,lsheet 40t the sleeve 64 is similarly forced to move downwardly against the action of the spring 68. It should be noted that although self-levellng means 42 as well as self-leveling means 60 have been illustrated as disposed below the position at which the foil is supported by the maat, there is no reason to limit such disposition since the self-leveling means could be positioned above the foil in those cases where the mast projects a suitable distance above the foil connection.
In such caces, the self-leveling means 42 would be in effect mounted upside down in the mast projection and the sleeve 64 of the self-leveling means 60 mounted above the cross bar 24. Similar adjustments can be made for other forms of foil le~eling and limiting systems that will hereinafter be described.
The manner in which the foil system 10 as abo~e-described in relationship to Figs. 1 through 5~ operates to power the boat 12 will now be described. Since either sailing across the wind or downwind are more easily accomplished than "upwind" or "close hauled" such upwind condltion 18 described. The wind is thus assumed to strike the boat ~rom forward and or one side or the other. To initiate sail propulsion or to get under way when the sail foil 14 is in its weathervaning or level rest position, that portion of the sheet 40 which tilts the foil 14 to leeward of the mast is engaged and trimmed in. Th~ foil, accordingly, both tilts and swings its ~railing edge 22 towards _ 5 the trimming pcsition aft of the mast 26, thus filling away to the wind. The tilt angle is adjustably limited by further control by tha operator on the sheet 40 depe'ndent upon wind strength, operator capability, passenger loading or other preference. Tilt may ~so be adjustably limited 1~ by changiny the effective length of cord 48.
Once tilted to this selected limit, further trim or easing on the sheet 40 enables the foil system 10 to act entirely as a conventional fore 'n aft sail rig except when the sail is being allowed to luff sub-stantially. Then, it has a slack sheet 40 and will seek its unconstrained rest position automatically. When shifting tacks either by tacking or jibing, the sheet A0 is released and the boat swung through its wind axis.
'..'hen the previously unused sheet portion is trimmed as when getting under way. The procedure is simple, and the usual hazard or inconvenience of avoiding unpredicable swinging of a low boom is totally eliminated. There i~ no severe s~il shift or heeling forces or crucial timinq necessary during a tack or ji~e.
' .~lso, the present foil system provides an inherent mechanism by which the wind force acting upon the foil can be immediately and automatically be shut off regardless of wind orientation as by disengaging the sheet 40 from the fairlead being used and upon which it will assume its rest or -lh-luffing position. Such is important especially i~
mooring or making landings in cramped quarters or in difficult wind circumstances. Thus, the present foil can shut off its sail power in any directional - heading and in widely veering winds simply_ by releasing the sheet so that the foil automatically levels to its weathervane or rest position.
In many cases it is aesirable to be able to limit in a positive manner ~he degree of tilt which the foil 12 may assume. Such may be accomplished by a tilt limiting system 76 such as shown in Figs. 10 t~rough 12 of the drawings. ~uch system includes a sleeve 78 slidably supported on the mast 2~ but fixed in position with respect thereto in a manner which will be hereinafter indicated. The sleeve includes a vertically extenaing open slot 80 on one side thereof. A series of vertically aligned, spaced bolts outwardly extend from the sur~ace of the mast 26. These bolts 82 are oriented with respect to the slot 80 such that the sleeve 78 may slide up and . down on the mast but will not rotate with respect thereto inasmuch as the contact betveen the heads of the bolts 82 and the opposed edges of the sleeve 78 which form the slot 80 prevents such action.
The slee~Je 78 is further provided with a pair ~. .
of upwardly outwardly extending tubular arms 84, each of which terminates in a headed portion 86 As best shown in Fig. 12, the head 86 which i~
preferably formed of some shoc~ absorbin~ material such as a high density foamed polymer includes a concave Qaddle 87 . .
b~
which is adapted to contact the cross member 24 in such a manner so as to limit its downward tilt, or in those cases wherein the tilt l.imiting mechanism 76 is mounted on a mast portion extending above the foil--~hen limiting its upward possible tilt. Thus, 1t may be seen that by moving the sleeve 78 closer to the pivotal connection between the cross bar 24 and the mast 26 that the resultant degree of tilt of the foil carried by the cross ~ar 24 may be reduced; and, accordingay, the potential powe~
that may be derived from the wind source limited. similarlY
by moving the sleeve downwardly, the potential tilt of the foil rnay be increased. In this regard, the bolts 82 ser~e as markers such that the degree of tilt may be readily :,:
determined by the position of the sleeve vis-a-vis tbe bolts 82; and, accordingly, the desired position of the tilt limiting system 76 calibrated according to wind conditions, position of the boat, and expe:rience of its operator. Thus in extremely high winds, it ~ight be desirable to place the tilt limiting mechanism 76 adjacent the uppermost bolt 82, but in light winds such can be placed adjacent the lowermost bolt. The sleeve may be set within .. the desired predetermined limits by a line 88 which is secured at one end thereof. to the sleeve 78 preferably at the rear side thereof, ihat is, opposite the slot 80 as through an eyelet 90 and thence to a directional change eyelet 92 mounted above the highest desired position of the sleeve and thence downwardly to a conventional attachnent point such as a cleat (not shown).mounted on the lowex portion of the mast 26. It will thus be seen that as the mast rotates with respect to the boat, that the tubular ar~s 84 are always aligned in the same plane as the cross bar 24 such that the desired tilt limiting contact ~s ?~ `~e ,~
achieved therehetween such as shown by the phantom line representation in ~ig. 10. The cross bar 24, i8, a8 in the previous er,lbodiment described in connection with Figs. 1 through 5, pivotally connected to the mast 26 via a sleeve 28 which in turn includes a rearwardly extending stub 30 which is connected on the other side o~ the ma~t ;_ by a fastening device such as the lock washer 33 shown.
Generally it is desirable that, as previously indicated, a strut 34 is utilized to adjustably restrict rotation of the cross bar 24 with respect to the sleeve 28 (longitudinal or pitch rotation); however, means such as pins (not shown) may r'~ extend through the sieeve into the cross bar to lock the two together and thus prevent this added rotational motion if not desired. When permitting such pitch rotation Meanq such lS as collars, pins and the like may be used to restrict lateral sliding movement of the oross bar relative to the sleeve. Of . ., ~. .
course, such lateral sliding motion can be desirable (see, e.g., Figs. 15 - 17).
Turning now to Figs. 13 and 14 of the drawings, 20 an alternate form of a self-leveling system 96 is depicted.
Such system includes lines 98 and 99 connected at opposite free ends thereof to the cross bar 24 at locations out-wardly spaced from its pivotal connection with the mast 26. The lines pass through openings 100 provided vn 25 opposite sides of the mast 26 and over rollers 102 and thence downwardly to a ring 104 to which the other ends of these lines are attached as by whipping 105. The ring in turn is attached by Means of a rod 106 to a spring 108 all internally mounted within the mast 26 so as to place a 30 predetermined amount of downward tension upon the lines 98 and 99 so as to continually urge tbe cross bar 24 and thu~
the foil mounted thereon to its rest position in an attitude normal to the mast 26. In such a system when the foil is _14 _ .
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forced into the wind by manipulation of the control sheet 40 such as depicted in Fig. 14, such causes the line 99 to move upwardly (to the left as shown in Fig. 14) and to cauqe slack in the right hand line 98. When such control sheet 40 constraint is removed, the predetermined tension supplied by the spring 108 acting upon the line 99 via the rod 106 automatically urges the cross bar to its rest position. In skrong winds or when it is otherwise desired to increase the amount of such predetermined tension upon the lines 98 and 99, a control line 110 is additionally attached to the ring 104 and passes outwardly of the ma3t 26 through an opening 112 provided for such purpose. The other end of the control line 110 can be fixed to a cl~at or other attach~ent device (not sho~n) on the mast, and in such manner the amount of slack and or tension in either line can be .selectively limited to the extent desired.
Referring now to Figs. 15 through 17, an alternate iorm of tilt limiting mechanism 116 is depicted.
Therein the cross bar 24 is slidably supported within a sleeve 118, in turn pivotally fixed to the mast 26. In this regard, the sleeve 118 includes a downwardly extending tab 120 having an opening provided therethrough and adapted to fit ~ithin an open-ended slot 122 provided in the 25 bifurcated end of the mast 26. A pin 124 extends through openings provided in the bifurcated end as well as through the opening provided in the tab ~20. It may thus be apparent that the cross bar 24 lS supported on the mast ~ . I
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26 for pivotal or torsional movement as in some o the previously described embodiments. A hollow sleeve 126 i8 supported by the mast 26 and is slidably adjustable to a variety of fixed positions therealong. Lines 128 of equal fixed length are attached at opposite ends respectively to the sleeve 126 and to the cross bar 24. ~n this manner as the cross bar is subject to an outside constraint so as to, for example, tilt it downwardly to the right as shown in Fig. 16, the cross bar 2q is then forced by tbe length of the then uppPrmost line (the left line as shown in Fig. 16) to slide downwardly to the right relative to the tube 118 until it reaches a point where one of the lines 128 is taut or the sleeve 118 conta~ts some limiting means such as the collars 129 shown. This displacement of the foil area towards whichever side is tilted downward gives this side aerodynamic lift over the other resulting in added leveling tendency which is especially helpful when wind strength increases. This, in effect, provides automatic aerodynamic leveling to counteract increased heeling foxce on the foil supporting body.
Turning now to Figs. 18 through 21 of the drawings, a still further alternate for~m of a self-leveling system 136 is depicted. Such system has particular utility with lighter rigs such as may be fashioned for use with a hand supported and manipulated foil, i.e., for use with sailboards or wind surfers and the like, although not limited to such use. In such system, a foil 14, a8 . ~1 ~
3~
utilized in the previous embodiments and including a cross bar 24, may be utilized. Instead of control sheets 40, however, the foil 14 is manipulated by a hand-held generally V-shaped bar 1~8 which is fixedly connected to the cross bar 24 at intermediate locations on opposite sides of its connection to the mast 26. The mast 26 is in turn generally supported in a somewhat forward position in the sailboard 140 by means of a cowl 142 prefexably of inverted conical shape and permitting the mast 26 to angularly tilt with regard to the upper surface 144 of the sailboard. The mast 26 may be stepped into the cowl 142 in any acceptable manner and, accordingly, a~le to assume a tilt within the limits of the sidewalls of the cowl 142 in a full 360 path. ~he sailboard 140 i5 also conventionally provided with a centerboard 146 ~
and a stabilizing fixed rudder 148. Also, although a limited vertical tilt of the mast with respect to the sailboard in a full 360 circle is desirable for full flexibility, advantages can be obtained by utilizing ~
more limited degree of tilt facility; thus, the cowl 142 may assume the configuration of a longitudinally elongated slot of a width just slightly greater than the mast such that only forward and reverse tilt is permitted.
The r.~anner in which the cross bar 24 is connected to the mast 26 in the self-lPveling system 136 under consideration ~s best shown by reference to Figs. 20 and 21 of the drawings. Therein the cross bar 24 i~ -rotationally supported within a sleeve 150 and additionally x~
slid~ble therein within the limits defined by the collars 152 fixedly connected to the cross bar 24 at locatisns slightly spaced from the ends of the sleeve 150 in ord~r that some lateral play of the cross bar 24 with respect to the sleeve 150 is afforded for a purpose which will hereinafter be apparent. In addition, the bottom of the sleeve 150 is provided with an elonyated open slot 154 which in turn is adapted to rest upon the upper surface of a plug 156 which includes a downwardly extending boss portion which fits in*o the upper open end of the tubular mast 26. The plug 156 includes a central bore 160 in which a rod 162 is positioned for vertical slida~le ntovement with respect thereto. The lower surface o~
the plug boss 15~ is provided with a washer 169 against which the upper end of a spring 166 abuts. rrhe low~r end of the spring similarly contacts a washer 168 adjustably held in a fixed position relative to the rod 162 by r~leans of a nut 17 n threaded on the threaded lower terminal end 172 of the rod 162. Inasmuch as the plug 156 is fixed in relationship to the mast 26, the force of the spring 166 continually urges the rod 162 downwardly into the open upper end of the mast 26. The upper end of the rod 162 terminates in an eyelet 174 through whioh a pin 176 e~tends through the sleeve 150 so as to position the upper end of the rod within the hollow interio~ of the sleeve 150. Prom such description it may be apparent -~
that the cross bar and, accordingly, the foil 14 is held in position on top of the r.last 26 by the action of the spring 166 and thus is continually urged to the position shown in the full lines in Fig. 20 by such sprlng action.
~3 Such attitude is the rest or level position previously referred to and is the position which is continually sought by the action of the spring when free from other const~aints.
The foil lg, however, may be manipulated in a number of directional attitudes vis-a-vis the mast 26 either by the effect of wind upon the foil or by manipulation of the control bar 138 by the rider or a combination of both. It, accordingly, will be apparent that the cross bar 24 can be tilted to assume the positio~
shown by the dotteu lines in Fig. 20 or ~ny intermediate position by force application thereupon by the control bar 138. When such is accomplis~ed, the lower end o$
the sleeve 150 contacts the rounded plug surface 156;
and at the same time, the rod 162 is vertically extended upwardly so as to compress the spring 166. In that regard, the outer ends of the sleeve 150 are slightly spaced from the collars 152 such that such tilting action does not cause interference contact between the outer ends of the sleeve and the collars 152. This tilti~g action may assume various angular displacements and in a full rotational directional, that is, the foil 14 is free to rotate with respect to the mast 26 at the upper end thereof by frictional contact on the plug 156 when such rotational force is brought about either by manipulation of the control bar 138 or by wind force application to the foil 14 or any combination thereof. In addition, it is also possible to change the front to rear attitude of the foil 14 with respect to the sailboard ' by application of a swinginy or arcuate movement to tbe cGntrol bar 138 with respect to the main planar configuration of the foil 14. This action irnparts a rotational movement of the cross bar 24 with respect to the 51 eeve 150 and enables the surfboarder to qui~kly manipulate the oil surface 14 in an up and down movement as may be desirable in riding the crest of waves and the like. In this.reqard, it should be pointed out that the cross bar 24 aoes not extend entirely through the sleeve 150 but comprises of stubs 180 secured to the inside surface of the sleeve 150 by conventional means such as the inclusion of an expàndable ring 182 adapted to extend into a circular seat 184 formed in the inside surface of the sleeve.
Other conventional means may be utilized, however, to insure the connection of the stub ens of the cross bar 24 in the slee~re 150.
I~hile there is shown and described llerein certain specific structure embodying this in~rention, it will be manifest to those skilled in the art that various modifications and rearrangements of the parts may be made without departing from the spirit and scope of the underlying inventive concept and that the same is not limited to the particular forms herein shown and described except insofar as indicated by the scope of the appended claims.
` ' ~ Z
Claims (25)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A fluid foil system for imparting power from a moving fluid medium to a supporting body which body in turn is supported by means other than said mov-ing fluid medium said system including a generally later-ally symmetrical fluid foil connected to a mast along a longitudinal axis thereof, said mast supported for free, unlimited notational movement with respect to said body, said foil further adapted for major lateral tilt approach-ing 90° in either direction with respect to said mast about said longitudinal axis from a fluid power-off or "level" rest position where said foil is generally aligned with the directional flow of said fluid medium to a tilt-ed position wherein said fluid imparts power to said foil, operational control means for moving said foil to various tilt attitudes and self leveling means for said foil connected to both said foil and said mast and adapted to automatically return said foil to said rest position when free from said operational control means.
2. The fluid foil system of claim 1 wherein said foil is torsionally connected to said mast.
3. The fluid foil system of claim 2 wherein said torsional connection comprises said self-leveling means.
4. The fluid foil system of claim 1 wherein said longitudinal axis is the axis of lateral symetry of said foil.
5. The fluid foil system of Claim 1 where in said mast is supported by said body for multi-rotational move-ment with respect thereto at a point spaced from said foil connection thereto.
6. The fluid foil system of claim 1 wherein the longitudinal attitude of said foil is adustably fixed in a position generally parallel to the flow direction of said fluid medium.
7. The fluid foil system of claim 1 wherein said foil is generally disposed at its gravity balance center with respect to said mast.
8. The fluid foil system of claim 1 wherein said self-leveling means includes a spring for automatically re-turning said foil to its rest position when free from other constraints.
9. The fluid foil system of claim 1, including means separate from said self-leveling means for limiting the extent of lateral tilt which said foil may exhibit.
10. The fluid foil system of claim 9, said tilt limiting means being mounted on said mast so as to adjust the extent of possible foil tilt between predetermined limits dependent on the position of said limiting means with respect to said mast.
11. The fluid foil system of claim 10, said tilt limiting means including a sleeve positioned on said mast and adjustable between fixed positions with respect thereto, said sleeve including a pair of outwardly extend-ing arms each terminating in a head adapted to respectively engage a portion of a foil supporting cross bar dependent on the tilt assumed by said foil with respect to the mast and thus limit the possible maximum tilt thereof, said mast being freely rotatable and said sleeve rotatable with said mast so as to insure continual alignment and possible contact between said heads and said cross bar portions.
12. The fluid foil system of claim 11, said sleeve having an open verticalslotin which means outwardly extending from said mast is adapted to engage such that said mast and said sleeve rotate as a unit.
13. The fluid foil system of claim 3, including a supporting cross bar in turn having a rigid yoke term-inating in a apex distal from said foil connection with said mast, spring means mounted in said mast and means connecting said yoke apex with said spring means for auto-matically returning said foil to its rest position when free from other constraints.
14. The fluid foil system of claim 13, said spring means being an extensible shock cord connected to said mast and said yoke respectively.
15. The fluid foil system of claim 13, said spring means being a coil spring mounted in said mast and connected to said yoke by a line connected to said spring at one end thereof and extending through an opening formed in said mast, said opening disposed proximate said yoke apex when such is aligned in the rest position of said foil.
16. The fluid foil system of claim 1, said foil including a supporting cross bar pivotally connected to said mast, said self-leveling means including a sleeve vertically sidably mounted on said mast and continually urged towards said cross bar by spring means, said sleeve having a pair of outwardly extending arms adapted to contact said cross bar at portions thereof on opposite sides of said mast connection dependent on the tilt there-of so as to continually urge said foil to its rest position.
17. The fluid foil system of claim 1, said foil including a supporting cross bar supported by said mast by means of a sleeve through which said cross bar extends and which sleeve is pivotally connected to said mast, said cross bar laterally slidable in said sleeve within limits and said self-leveling means in part defining said limits.
18. The fluid foil system of claim. 1, said foil including a supporting cross bar pivotally connected to said mast, said self-leveling means including a pair of lines fixedly connected at one end thereof to said cross bar and portions thereof on either side of said connection and extending into said mast where other ends thereof are connected to spring means mounted in said mast.
19 The fluid foil system of claim 18, the tension of said spring means being adustably fixed.
20. The fluid foil system of claim 8, said means for moving said foil to a tilted position being a hand manipulatable bar in turn connected to said foil.
21. The fluid foil system of claim 20, said foil including a supporting cross bar, said cross bar mounted on the top of said mast by said self-leveling means, said cross bar being able to tilt with respect to said mast in a full 360° attitude.
22. The fluid foil system of claim 21, said cross bar supported and adapted to frictionally engage a plug disposed in the open top of said mast, said plug including a bore through which a downwardly spring biased rod extends and is connected to said cross bar
23. The fluid foil system of claims 1 and 21, said foil adapted to assume movement with respect to said mast in three directions, that is, rotation, lateral tilt, and longitudinal tilt.
24. The fluid foil system of claim 1 including means for adjustably fixing the lingitudinal tilt attitude of said foil with respect to said mast.
25. The fluid foil system of claim 1, said operational control means being a single sheet attached at opposite ends to laterally opposed sides of said foil.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000423019A CA1186956A (en) | 1983-03-07 | 1983-03-07 | Fluid foil system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000423019A CA1186956A (en) | 1983-03-07 | 1983-03-07 | Fluid foil system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1186956A true CA1186956A (en) | 1985-05-14 |
Family
ID=4124728
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000423019A Expired CA1186956A (en) | 1983-03-07 | 1983-03-07 | Fluid foil system |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1186956A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4788924A (en) * | 1986-10-13 | 1988-12-06 | Renald Hamel | Sailing system |
-
1983
- 1983-03-07 CA CA000423019A patent/CA1186956A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4788924A (en) * | 1986-10-13 | 1988-12-06 | Renald Hamel | Sailing system |
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| MKEC | Expiry (correction) | ||
| MKEX | Expiry |