Hydrodynamically balanced and retractable rudder for small boats

Abstract

A hydrodynamically balanced and fully retractable rudder for small boats for creating a device which enhances small boat performance (kayaks, small sailing craft, canoes and similar craft) which provides a high power, low drag, and low input force mechanism to aid control performance of small boats—by creating a particularly boomerang shaped, retractable rudder blade which can travel from the deck or other stowed position of the boat to the underside, generally rear of the boat, and align under with the hinge pin of the rudder providing a fully ‘balanced’ rudder effect, with the shaft of the hinge mating to the wide section of the foil that comprises the rudders ideal, most effective cross section.

Description

RELATED APPLICATIONS [0001] The present invention claims the benefit of U.S. Provisional Patent Application Ser. No. 06 / 492,034 filed on Aug. 1, 2003 entitled “HYDRODYNAMICALLY BALANCED AND RETRACTABLE RUDDER FOR SMALL BOATS”, which is incorporated herein by reference.FIELD OF THE INVENTION [0002] The present invention relates generally to deck retractable rudders for small boats, and more specifically, to a hydrodynamically balanced and fully retractable rudder for small boats. The present invention enhances performance of small boat (e.g., kayaks, small sailing craft, canoes and similar craft) by providing a high power, low drag, and low input force mechanism to aid control performance. RELEVANT BACKGROUND [0003] Retractable rudders have been in use with small boats, particularly kayaks, for years. Typically, retractable rudders include fully retractable rudders, partially retractable rudders, with variations including spring loaded rudders, and cam wheel rudders. A rudder is a ge...

AI Technical Summary

Benefits of technology

[0010] In view of the foregoing disadvantages inherent in the known types of deck retractable rudders for small boats now present in the prior art, the present invention provides a new hydrodynamically balanced and fully retractable rudder for small boats which enhances performance of small boats (kayaks, small sailing craft, canoes and similar craft). The present invention provides a high power, low drag, and low input force mechanism to aid control performance of small boats. A unique cantilevered shape′′, retractable rudder blade is provided that is able to travel from the deck or other stowed position of the boat to the underside, generally rear of the boat. When in the deployed position, the rudder blade aligns under with the hinge pin of the rudder providing a leading edge of the rudder blade which pivots opposite the trailing edge of the same rudder blade. In the deployed position the rudder blade aligns under the hinge pin of the rudder providing a generally ‘balanced’ rudder effect, with the shaft of the hinge preferably mating to the wide section of the foil that comprises the rudder's most effective cross section.

Problems solved by technology

A significant problem with conventional deck retractable rudders for small boats is that they are positioned fully to the rear side of the rudder's hinge pin (i.e., unbalanced), causing dynamic effects that increase the effort required to operate the rudder.

The rudder system shown in U.S. Pat. No. 6,739,276 is an unbalanced rudder in which the leading edge is positioned aft of the pivot mechanism used to operate the rudder.

On long passages a boater may need to run with the rudder set off center for long distances and experience the undesirable self-centering oppositional torque created by the rudder's extension to the rear of the rudder pin.

This greatly reduces the ‘self centering’ force which an unbalanced rudder creates.

These gains are not available to existing retractable rudders.

Unfortunately, in the field of conventional rudders for small boats balanced rudders are not retractable, and small boat ‘retractable’ rudders are not balanced.

Another problem with conventional deck retractable rudders for small boats is that rudders have a tendency to lift up, rotating backwards, while under speed because of the drag force exerted upon them by the boat's movement through the water.

This situation is exacerbated by unbalanced rudders not ‘wrapping’ under the rudder hinge to operate more forward under the tail hull rather than behind it.

The former problem of rotating backwards creates additional longitudinal ‘torquing’ force on the rudder, and thus more control force is needed by the operator to steer the rudder.

The later problem reduces the amount of control the rudder exerts in steering the boat because the rudder itself engages less with the water with which it creates force.

While conventional devices may be suitable for the particular purpose to which they address, they are not as suitable for creating a device that enhances small boat performance (kayaks, small sailing craft, canoes and similar craft) which provides a high turning power, low drag, and low input force mechanism to aid control performance of small boats.

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