NZ543383A - Sail boat keel with swing keel portion and interacting trim tab portion - Google Patents

Abstract

A keel is composed of the main keel (1), the swing keel (2) hinged (5) to the bottom of the main keel, the bulb or ballast (3) attached to the bottom of the swing keel, the keel rudder (4) hinged (5) to the bottom rear end of the main keel, whereby the swing keel gear (6) and the keel rudder gear (7) make the swing keel and the keel rudder move opposite to each other, the keel wings (8) being attached to the main keel so as to limit the angle of the keel rudder, and dampers or shock absorbers (9) being attached to the keel wings. Cables (11) and pulleys (10) can also be used instead of gears where the cables are connected on the tips of the swing keel and keel rudder while the pulleys are connected to the tips of the keel wings.

Description

1 KEEL 543383 Technical Field The invention relates to the field of Naval Architecture of Sailboats and Yachts and their Keels in particular, the appendage that projects below the boat down in to the water which enables the boat to sail upwind, prevents leeway and helps prevent the boat from capsizing. Background Art The closest semblance of the invention is the canting keel, which is manually, hydraulically or mechanically swung towards the weather side to offset the center of gravity and improve the sailboat's stability. Another semblance to the inventions is the winged keel, which can improve lift and stability.

It is an object of the present invention to provide a type of keel that will reduce the required bulb or ballast weight of sailboat and reduce the probability of capsizing or at least to provide the public with a useful choice.

Disclosure of the Invention In a fir si aspect, the present invention provides a keel that reduces the required bulb or ballast weight of sailboat and reduces the probability of capsizing comprising a main keel, a swing keel hinged to the bottom of the main keel, a bulb or ballast attached to the bottom of the swing keel, a keel rudder hinged to the bottom rear end of the main keel, a swing keel gear and a keel rudder gear, which enables the swing keel and the keel rudder to move opposite to each other.

In a further aspect, the present invention provides a keel that reduces the required bulb or ballast weight of sailboat and reduces the probability of capsizing comprising a main keel, a swing keel hinged to the bottom of the main keel, a bulb or ballast attached to the bottom of the swing keel, a keel rudder hinged to the bottom rear end of the main keel, cables attached to the opposite ends of the swing keel and the keel rudder that go through pulleys attached to the tips of the keel wings which enables the swing keel and the keel rudder move opposite to each other, keel wings attached to the main keel that limit the angle of the keel rudder to the desired specifications or as restricted by regulators, dampers or shock absorbers attached to the keel wings to prevent the keel rudder from shattering the keel wings during rough weather. 2 543383 The invention differs from the canting keel because the invention not only makes use of the weight of the bulb or ballast at the bottom of the keel but also makes use of a keel rudder and onrushing water to right the boat or prevent the boat from capsizing which mean a reduction in the dependence on bulb weight translating to lighter and faster sailboats. The invention also differs from the winged keel because the invention makes use of keel wings not only to add stability but also to limit the angle of keel rudder and prevent unnecessary drag.

The invention will enable the sailboat to move on a more upright position when die wind is coming from the portside or starboard or when tacking. When a portside wind forces the sailboat to move forward and list to its starboard, gravity will force the bulb and swing keel to swing in relation to the hull and mast to the starboard and force the keel radder to swing to the portside where the onrushing water will force the invention to counter the list caused by the wind. The drag caused by the keel rudder will be offset by a lighter bulb and by the sail efficiency of a more uptight inast. The lateral force exerted by the onrushing water to the invention and the weight of the invention should be equal (or greater than for sailboats for novice sailors and pleasure trips) to the expected lateral force the wind will apply to the sails. However, lie weight of the bulb should always be greater than the maximum expected lateral force exerted by the onrushing water to the keel rudder. The height of the mast and the surface area of the mainsail and foresail or headsail will dictate the length of the keel, surface area of the keel rudder and weight of the bulb based on the air and water density ratio. The invention is a function of the sails.

Further, the gear ratios of the swing keel gear and keel rudder gear (or position of pulleys and cable connection points along the swing keel and keel rudder if cables are used instead of gears) mil depend on the desired sensitivity of the keel rudder to the swing keel.

Brief Description of Drawings Figure 1 shows a side view of a keel of the invention.

Figure 2 shows a side view of an alternative embodiment of the invention.

Detailed Description of the Invention 3 543383 The invention is composed of the main keel, the swing keel hinged to the bottom of the main keel, the bulb attached to the bottom of Hie swing keel, the keel rudder hinged to the bottom rear end of the main keel, the swing .keel gear and the keel rudder gear make the swing keel and the keel rudder move opposite to each other, the keel wings attached to die main keel limits the angle of the keel radder to the desired specifications or as restricted by regulators, and dampers or shock absorbers attached to the keel wings to prevent the keel rudder from shattering the keel wings during rough weather. Cables and pulleys may also be used instead of gears.

Industrial Applicability The invention is applicable to the manufacture and design of performance, pleasure and trainer sailboats and may be also applicable to self-propelled vessels.

Examples With reference to the drawings, a keel is composed of the main keel (1), the swing keel (2) hinged (5) to the bottom of the main keel, the bulb or ballast (3) attached to the bottom of the swing keel, the keel rudder (4) hinged (5) to the bottom rear end of the main keel, whereby the swing keel gear (6) and the keel rudder gear (7) make the swing keel and the keel rudder move opposite to each odier, the keel wings (8) being attached to the main keel so as to limit the angle of the keel rudder, and dampers or shock absorbers (9) being attached to the keel wings.

Cables (11) and pulleys (10) can also be used instead of gears where the cables are connected on the tips of the swing keel and keel rudder while the pulleys are connected to the tips of the keel wings.

Claims (8)

543383 4 WHAT I CLAIM IS:

1. A keel that reduces the required bulb or ballast weight of sailboat and reduces the probability of capsizing comprising a main keel, a swing keel hinged to the bottom of the main keel, a bulb or ballast attached to the bottom of the swing keel, a keel rudder hinged to the bottom rear end of the main keel, a swing keel gear and a keel rudder gear, which enables the swing keel and the keel rudder to move opposite to each other.

2. A keel as claimed in claim 1, which further comprises keel wings attached to me main keel that limit the angle of the keel rudder to desired specifications or as restricted by regulators, and dampers or shock absorbers attached to the keel wings to prevent the keel rudder from shattering the keel wings during rough weather.

3. A keel that reduces the required bulb or ballast weight of sailboat and reduces the probability of capsizing comprising a main keel, a swing keel hinged to the bottom of the main keel, a bulb or ballast attached to the bottom of the swing keel, a keel rudder hinged to the bottom rear end of the main keel, cables attached to the opposite ends of the swing keel and the keel rudder that go through pulleys attached to the tips of the keel wings such that the swing keel and the keel rudder move opposite to each other, keel wings attached to the main keel that limit the angle of the keel rudder to the desired specifications or as restricted by regulators, dampers or shock absorbers attached to the keel wings to prevent the keel rudder from shattering the keel wings during rough weather.

4. A keel as claimed in any one of the preceding claims, whose dimensions may be varied to suit a wide array of watercrafts. 543383 5

5. A keel as claimed in claim 4, wherein the keel dimensions are varied by altering one or more of the following attributes: length of keel, surface area of flap, surface area of the rudder, weight of bulb, distance of the bulb from the hinge, and gear ratios and positions of pulleys.

6. A keel as claimed in any one of the preceding claims, wherein the length of the main keel, the weight of the bulb or ballast, and the surface area of the keel rudder is determined by the height of the mast and the surface area of the sails.

7. A keel substantially as herein described with reference to any example thereof.

8. A keel substantially as herein described with reference to the drawings.