ADJUSTABLE KEEL FOR A SAILBOAT
A sailboat, which include an extendable keel having a moveable inner member positioned within a fixed keel and a control system for lowering or retracting the inner member.
This application is a continuation of U.S. patent application Ser. No. 12/534,890, filed Aug. 4, 2009 and Ser. No. 11/788,785, filed Apr. 19, 2007, which claims priority to U.S. Provisional Patent Application Ser. No. 60/900,549 filed on Feb. 8, 2007, and U.S. Provisional Patent Application Ser. No. 60/920,957 filed on Mar. 30, 2007, the contents, which are incorporated herein their entirety.
FIELD OF THE INVENTIONThis invention generally relates to an adjustable keel, and more particularly to an adjustable keel, which includes having a moveable inner member positioned within a fixed keel and a control system for lowering or retracting the inner member.
BACKGROUNDTypically, a sailboat includes a hull that sits in the water, a mast extending upwardly from the hull, sails supported by the mast, and either a centerboard or fixed keel extending downwardly from the hull into the water. The sails catch the wind and cause the hull to move forwardly through the water. Although, a sailboat cannot sail directly into the wind, a sailboat can sail in a generally windward direction. It can be appreciated that with skill and a combination of maneuvers, a sailor can maneuver a sailboat in almost any desired direction.
Because of the design of the sails, a sailboat can sail to windward, which is typically in a direction no less than about 15 to 25 degrees from the wind, depending upon the design of the boat and the skill of the sailor. Headway directly upwind or windward is typically achieved in a series of sequential maneuvers called tacks, in which the boat is first sailed windward with the wind over one side of the bow, and then turned through the wind so that the wind comes over the other side of the bow. In each tack, some headway upwind is achieved even though the boat does not move directly into the wind, and eventually the sailboat reaches an upwind objective after sailing a zig-zag course covering a distance greater than the straight line distance from the initial position to the upwind objective.
When a sailboat sails to windward, the forces on the sails can be resolved into a thrust component that moves the sailboat forwardly through the water and a drift component that pushes the sailboat sideways in a downwind direction. The sailboat therefore moves in a net direction that is forward, but also is slight downwind opposite to the net intended direction of movement. The sideways drift is called leeway or “slide slipping.”
The downwardly projecting centerboard or keel of the sailboat offers resistance to the leeway produced by the sideways sail force, but at least some leeway remains. This leeway is being constantly accumulated, as there is a downwind movement as long as the sailboat is being sailed into the wind. The leeway significantly increases the time required for the sailboat to sail from its downwind starting position to the upwind objective, as it forces the sailboat to sail much further to make up for the accumulated sideways movement.
Attempts have been made to reduce the amount of leeway. For example, a movable centerboard or fixed keel extending into the water below the sailboat presents a broad surface to resist sideways drift. There have also been attempts to modify the shape of the centerboard or keel to provide a lifting force to counteract the sideways drift. These attempts have been based upon the observation that the centerboard or keel moving through the water is somewhat similar to the wing of an airplane that creates a lift as the wing is moved through the air. The lift of an airplane wing causes the airplane to move upward against the force of gravity, and the corresponding lift of a sailboat centerboard or keel that extends downwardly can cause the sailboat to be lifted in the upwind direction, thereby countering the sideways drift producing the leeway.
Fixed keels are typically used in larger sailboats. The keels are usually filled with lead or other dense material to act as ballast for the sailboat. For example, the keels of 12-meter sailboats may extend 10 feet below the surface of the water, and weigh 40,000 to 50,000 pounds.
It would be desirable to have a system or method of adjusting or changing the relative position of the fixed connection of the foresail, such that the angle of attack in the windward direction is slightly altered in the direction of the wind. Accordingly, it would be desirable to have a system and/or method of changing the angle or direction of the boat in a windward direction and/or use of an extendable keel, which is capable of providing a lifting force to counteract leeway, and is sufficiently reliable to be acceptable for general and racing use.
In addition, it would be desirable to have a retractable solar panel system, which can provide a source of energy to the sailboat. The solar panel system can be attached to a nautical stay, wherein the stay is fixed at one end to a hull of the sailboat and at a second end to a mast of the sailboat. The solar panel system includes a plurality of solar panels, which are attached to a system for extending and retracting the plurality of solar panels, such that when not in use, the solar panels can be stacked.
SUMMARYIn accordance with an embodiment, a keel for a sailboat comprising: an extendable keel comprising: an outer member; an inner member, which is extends from within the outer member; and a foil member attached to the inner member; and a control system for lowering or retracting the inner member.
In accordance with a further embodiment, a keel for a sailboat comprising: a fixed keel; a moveable inner member positioned within the fixed keel; and a control system for lowering or retracting the inner member.
In accordance with another embodiment, A keel for a sailboat comprising: a keel member having an inner chamber; an adjustable ballast system within the inner chamber; and a ballast control system for adjusting a depth of the ballast system within the inner chamber.
As described above, because of the design of the sails, a sailboat (or boat) 10 can sail to windward, in a direction no less than about 15 to 25 degrees from the wind, depending upon the design of the boat and the skill of the sailor. Headway directly upwind is achieved in a series of sequential maneuvers called tacks, in which the boat is first sailed windward with the wind over one side of the bow, and then turned through the wind so that the wind comes over the other side of the bow. In each tack, some headway upwind is achieved even though the boat does not move directly into the wind, and eventually the sailboat reaches an upwind objective after sailing a zig-zag course covering a distance greater than the straight line distance from the initial position to the upwind objective.
In addition, when a sailboat 10 sails to windward, the forces on the sails can be resolved into a thrust component that moves the sailboat forwardly through the water and a drift component that pushes the sailboat sideways in a downwind direction. The sailboat 10 therefore moves in a net direction that is forward, but also is slight downwind opposite to the net intended direction of movement. The sideways drift is called leeway.
The downwardly projecting centerboard or keel of the boat offers resistance to the leeway produced by the sideways sail force, but at least some leeway remains. This leeway is being constantly accumulated, as there is a downwind movement as long as the sailboat is being sailed into the wind. It can be appreciated that the leeway can significantly increase the time required for the sailboat to sail from its downwind starting position to the upwind objective, as it forces the sailboat to sail much further to make up for the accumulated sideways movement.
It can be appreciated that the use of the term “sailboat” 10 has a broad meaning and can include yachts, (large sailboats) and smaller vessels of many configurations, which use wind as the primary means of propulsion. Typically, some of the variations other than size are hull configuration (monohull, catamaran, and trimaran), keel type (full, fin, wing, centerboard etc.), purpose (sport, racing, cruising), number and configuration of masts, and the sail plan. The most common sailboat 10 is the “sloop” which features one mast 50 and two sails, a mainsail 30 and a foresail 40 or jib, genoa, or spinnaker. This simple configuration has been proven over time to be very efficient for sailing into the wind. The mainsail 30 is attached to the mast 50 and the boom 60, which is a beam or spar capable of swinging across the sailboat 10, depending on the direction of the wind. Depending on the size and design of the foresail 40, the foresail 40 is called a jib, genoa, or spinnaker. Although not common, a sloop or sailboat 10 can include two foresails from a single forestay 48 at one time (wing on wing). The forestay 48 is a line or cable running from near the top of the mast 50 to a point near the bow 42 (or front of the sailboat 10). It can be appreciated that the forestay 48 is attached at either the top of the mast, or in fractional rigs between about ¼ and ⅛ from the top of the mast 50. The other end of the forestay 48 is attached to the stern or bow 42 of the boat 10. The forestay 48 can be made from stainless steel wire, a solid stainless steel rod, a carbon rod, a galvanized wire or natural fibers.
As shown in
The foresail 40, which is also known as a headsail, jib, genoa, or spinnaker is secured to the top 46 of the mast 50 and is typically secured to the bow 42 of the sailboat 10. Typically, the foresail 40 is secured along its leading edge to a forestay 48 (strong wire) strung from the top 46 of the mast to the bowsprit 42 on the bow (nose) of the boat. Alternatively, the foresail 40 can be a genoa, which is a type of jib that is larger, and cut so that it is fuller than an ordinary jib. It can also be appreciated that fore-and-aft sails can be switched from one side of the sailboat 10 to the other, in order to alter the sailboat's course. When the sailboat's stern crosses the wind, this is called jibing; when the bow crosses the wind, it is called tacking. Tacking repeatedly from port to starboard and/or vice versa, called “beating”, is done in order to allow the boat to follow a course into the wind.
It can be appreciated that a primary feature of a properly designed sail is an amount of “draft”, caused by curvature of the surface of the sail. When the sail is oriented into the wind, this curvature induces lift, much like the wing of an airplane. Modern sails are manufactured with a combination of broadseaming and non-stretch fabric. The former adds draft, while the latter allows the sail to keep a constant shape as the wind pressure increases. The draft of the sail can be reduced in stronger winds by use of a Cunningham and outhaul, and also by increasing the downward pressure of the boom by use of a boom yang. A boom yang is a line or piston system on a sailboat used to exert downward force on the boom and thus control the shape of the sail. In British English, it is known as a “kicking strap”. The yang typically runs from the base of the mast 50 to a point about a third of the way out the boom 60. Due to the great force necessary to change the height of the boom 60 while a boat is under sail, a line based boom yang usually includes some sort of a pulley system. Hydraulic piston vangs are used on larger sailboats and controlled by manual or electric hydraulic pumps.
It can be appreciated that tacking typically describes the position of a sailboat's bow with respect to the wind. For example, if the vessel's bow is positioned so that the wind is blowing across the starboard (right) side of the vessel, then the vessel is said to be on a starboard tack. If the wind is blowing across the port (left) side of the vessel, then the vessel is said to be on a port tack. It can be appreciated that by definition, this is opposite to the side, which the boom is carried, since it can be difficult when a boat is sailing downwind or nearly downwind from which side the wind is coming. In addition, a sailing vessel on a starboard tack always has the right-of-way over another sailing vessel on “port tack” by both the rules of the road and racing rules.
The track system 100 preferably includes a moveable track fixture 110, upon which the forestay 48 is securely fixed or attached, a fixed track 120 configured to receive the track fixture 110, and a control system 130 for securing the location of the track fixture 110 within the track 120 relative to the bow 42 of the boat 10. In accordance with one embodiment, the control system 130 for securing the location of the track fixture 110 can include a winch 140, a flexible wire or rod 150 attached to the track fixture 110, and a guide system 160. The winch 140 is preferably a mechanical device that is used to wind up the flexible wire or rod 150 (also called “cable”). In its simplest form, it consists of a spool and attached crank. The spool can also be called the winch drum. It can be appreciated that the winch 140 can include suitable gear assemblies and can be powered by electric, hydraulic, pneumatic or internal combustion drives. In addition, the winch 150 can include a solenoid brake and/or a mechanical brake or ratchet (not shown) that prevents the winch 150 from unwinding.
It can be appreciated that the system as shown in
As shown in
In accordance with one embodiment, the winch system 360 can include a mechanical device that is used to control the relative position of the inner screw member 350 and the inner member 320 to the outer member 330, which in turn controls the depth of the foil member 310 of the keel 70. In accordance with one embodiment, the winch system 360 consists of a spool or drum and an attached crank. It can be appreciated that the winch 140 can also include suitable gear assemblies and/or can be powered by electric, hydraulic, pneumatic or internal combustion drives. The winch system 360 also preferably includes a solenoid brake and/or a mechanical brake that prevents the winch system 360 from unwinding and/or releasing from a fixed position. The winch system 360 can be positioned below the deck of the sailboat 10 as shown in
It can be appreciated that the extendable keel 300 can also be extendable telescopically, wherein the keel 300 comprises a plurality of inner members 320 having a core containing a plurality of sealed air chambers, which are pressurized when the keel 300 is fully extended. An air compressor, which can be powered by the boat engine or other suitable systems, can be utilized to supply pressurized air to extend or retract the inner members 320. Valves can control the pressure release for extension or retraction. The keel 300 can also be operated hydraulically, by stored or generated pressurized gas, or mechanically through a suitable mechanical system.
As shown in
In accordance with one embodiment, the control system 410 can include a mechanical device that is used to control the relative position of the inner screw member 430, which in turn controls the depth of the weight system 400 within the inner chamber 420 of the keel 70. In accordance with one embodiment, the control system 410 consists of a spool or drum and an attached crank. It can be appreciated that the control system 410 can also include suitable gear assemblies and/or can be powered by electric, hydraulic, pneumatic or internal combustion drives. The control system 410 also preferably includes a solenoid brake and/or a mechanical brake that prevents the system from unwinding and/or releasing from a fixed position.
As shown in
The solar panels 510 are preferably any suitable panel or array of smaller panels, which converts sunlight into an energy source. It can be appreciated that any solar panel 510 can be used including flat solar thermal collector, such as a solar hot water or air panel used to heat water, air, or otherwise collect solar thermal energy, or any photovoltaic module, which is an assembly of solar cells used to generate electricity. The solar panels 510 are preferably flat, and can be various heights and widths. It can be appreciated, however, that the solar panels 510 can be slightly curved or of a suitable flexible design. In addition, each solar panel 510 can be comprised of an array of solar-thermal panels or photovoltaic (PV) modules, which are be connected either in parallel or series depending upon the design objective.
In accordance with one embodiment, the retractable solar panel system 500 preferably includes a plurality of solar panels 510, which are attached to the stay 502 via a connector 520 such as a connecting rod or hook. The system 500 also includes a system for the unfolding the plurality of solar panels 510 and extending the connector 520 (i.e., connecting rod or hook) upward towards the top portion 46 of the mast 50 when in use. It can be appreciated that when not in use, the solar panels 510 can be retracted and stored on the deck of the sailboat 10. The system for extension and retraction of the solar panels 510 is preferably a winch (e.g., 140) or other suitable mechanical device that is used to wind up a rope, or cable. The winch preferably includes a spool (or winch drum) and attached crank. It can be appreciated that the mechanical device or winch can be powered by electric, hydraulic, pneumatic or internal combustion drives, and includes a solenoid brake and/or a mechanical brake or ratchet that prevents it from unwinding.
A protective cover is preferably placed over the stack of solar panels 510 during storage thereof or when the solar panels 510 are not in use. As shown in
In accordance with one embodiment, the solar panels 610 in the form of photovoltaic cells or modules (or a group of cells electrically connected and packaged in one frame), which convert sunlight directly into electricity. The photovoltaic (PV) cells can be made of a semiconductor material such as silicon, such that when light strikes the cell, a certain portion of it is absorbed within the semiconductor material. The energy of the absorbed light is transferred to the semiconductor, and knocks the electrons loose, allowing them to flow freely. In addition, photovoltaic (PV) cells also all have one or more electric fields that act to force electrons freed by light absorption to flow in a certain direction. The flow of electrons is a current, which can be used externally by placing metal contacts on the top and bottom of the PV cell. This current, together with the cell's voltage (which is a result of its built-in electric field or fields), defines the power (or wattage) that the solar cell produces.
The panel system 500 includes a pair of solar panels 522, 524 having a hinge 526, 528 between to allow the plurality of panels 510 to be stacked when not in use. It can be appreciated that the use of the solar panel system 500 and telescoping and/or retractable mast is not limited to sailboats 10, and that the solar panel system 500 and telescoping and/or retractable mast 550 can be placed on any suitable structure including residential and commercial buildings, windmills, water towers, billboards, support structures such as bridges, radio masts, antennas, and towers, and natural landforms, including hills, cliffs, fields, berms, mounds and valleys.
In accordance with one embodiment, the solar panels 720 can be attached to the support member 710 by any suitable means, which allows the solar panels 720 to rotate. For example, as shown in
It will be understood that the foregoing description is of the preferred embodiments, and is, therefore, merely representative of the article and methods of manufacturing the same. It can be appreciated that many variations and modifications of the different embodiments in light of the above teachings will be readily apparent to those skilled in the art. Accordingly, the exemplary embodiments, as well as alternative embodiments, may be made without departing from the spirit and scope of the articles and methods as set forth in the attached claims.
Claims
1. A keel for a sailboat comprising:
- an extendable keel comprising:
- an outer member;
- an inner member, which is extends from within the outer member; and
- a foil member attached to the inner member; and
- a control system for lowering or retracting the inner member.
2. The keel of claim 1, wherein the control system is comprised of an inner screw member and a winch system
3. The keel of claim 2, wherein the winch system comprises a mechanical device that is used to control the relative position of the inner screw member and the inner member to the outer member, which in turn controls the depth of the foil member of the keel.
4. The keel of claim 1, wherein the outer member is fixed.
5. The keel of claim 1, wherein the foil member is a winged foil.
6. The keel of claim 1, wherein the inner member is a telescoping inner member comprised of a plurality of inner members.
7. The keel of claim 6, wherein the plurality of inner members have a core containing a plurality of sealed air chambers, which are pressurized when the plurality of inner members are lowered.
8. The keel of claim 7, further comprising an air compressor, which supplies pressurized air to the plurality of sealed air chambers to lower and retract the plurality of inner members.
9. The keel of claim 8, further comprising at least one valve, which controls the pressurized air upon the lowering and retracting of the plurality of inner members.
10. The keel of claim 1, further comprising an adjustable ballast system positioned within the inner member.
11. The keel of claim 10, wherein the adjustable ballast system is comprised of a moveable weight positioned within the inner member and includes a ballast control system for adjusting a depth of the moveable weight within the inner member.
12. A keel for a sailboat comprising:
- a fixed keel;
- a moveable inner member positioned within the fixed keel; and
- a control system for lowering or retracting the inner member.
13. The keel of claim 12, wherein the control system is comprised of an inner screw member and a winch system
14. The keel of claim 13, wherein the winch system comprises a mechanical device that is used to control the relative position of the inner screw member and the inner member, which in turn controls a depth of the inner member within the keel.
15. The keel of claim 12, further comprising a winged foil member attached to the moveable inner member.
16. A keel for a sailboat comprising:
- a keel member having an inner chamber;
- an adjustable ballast system within the inner chamber; and
- a ballast control system for adjusting a depth of the ballast system within the inner chamber.
17. The keel of claim 16, further comprising a foil member attached to the keel member.
18. The keel of claim 17, wherein the foil member is a winged foil.
19. The keel of claim 16, wherein the adjustable ballast system is comprised of a moveable weight positioned within the inner member.
Type: Application
Filed: Aug 18, 2011
Publication Date: Dec 8, 2011
Inventor: Bradford G. Baruh (Hillsborough, CA)
Application Number: 13/212,702
International Classification: B63B 41/00 (20060101); B63B 43/08 (20060101); B63B 43/04 (20060101);