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The DeltaConic Hull - Harry Schoell

US Patent # -- 4193370
PDF of the original Patent
Planing boat hull
A planing boat hull having a conical contour extending from the bow portion to the stern for a distance equal to substantially one-third the length of the hull at the keel and two-thirds or more at the chine, the after section of the hull consisting of a flat surface on each side of the keel maintaining a constant dead rise angle of 12 to 18 degrees extending to the wide lipped chine, and a chine lip portion extending at the same angle as the dead rise but in a reverse direction.

Background of the Invention
1. Field of the Invention
This invention relates to hull structures for boats and is more particularly directed to a planing boat hull.

2. Description of the Prior Art
The present planing boat hulls are of the V-type construction. These hulls have an arcuate contour extending on either side of the keel from the bow to the stern which effect good riding characteristics to the boat when planing, when moving in the direction of a head or following sea and at a speed for which the hull is designed. When a planing boat having a conventional V-hull is not planing or when moving along a quartering sea, its lateral stability is very poor and high impacts of the hull are experienced as the speed of the planing hull is increased. Also, the bow of the boat tends to ride at an increasing angle thereby increasing the impacts of the hull. Since the water flowing past the boat follows the shape of the hull, the spray created by the forwardly moving boat tends to spray in the direction of the occupants of the boat. The present invention intends to avoid the above indicated poor characteristics of the conventional V-type hulls for planing boats by providing a hull that is partially arcuate and partially flat whose stern is provided with an appropriate dead rise and chines extending about the outer edges of the hull of substantially equal but oppositely extending angle as the dead rise.

Summary of the Invention
Therefore, a principal object of the present invention is to provide a hull for a planing boat whose contour is partially arcuate, namely the surface of a cone, and partially flat thereby increasing its lateral stability at non-planing speeds.

Another object of the present invention is to provide a hull of a planing boat with a conical surface extending from the bow on each side of the keel to a position approximately one-third the length of the boat and flat surfaces extending to the stern on each side of the keel for the remainder of the hull.

A further object of the present invention is to provide a dead rise at the stern of the boat of approximately 12° to 18° with chines on each side of the hull extending from the stern to the bow whose total width is equal to approximately 20 percent of the total width of the hull.

A still further object of the present invention is to provide a hull of a planing boat having a relatively low hull impact at planing speeds in a quartering head or following sea, excellent lateral stability at low and planing speeds, relatively low hull impact at high planing speeds and whose spray is directed away from the hull so as not to wet the occupants of the boat while planing.

With these and other object in view, the invention will be best understood from a consideration of the following detailed description taken in connection with the accompanying drawings forming a part of this specification, with the understanding, however, that the invention is not confined to any strict conformity with the showing of the drawings but may be changed or modified so long as such changes or modifications mark no material departure from the salient features of the invention as expressed in the appended claims.
delta-conic hull patent drawing #1
delta-conic hull patent drawing #2
delta-conic hull ad image #1
delta-conic hull ad image #2

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