US3595190A

US3595190A - Sailboat construction

Info

Publication number: US3595190A
Application number: US861630A
Authority: US
Inventors: Charles W Lapworth
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-09-29
Filing date: 1969-09-29
Publication date: 1971-07-27
Anticipated expiration: 1988-07-27

Abstract

A sailboat construction for an auxiliary-powered sailboat. The construction includes a hull having a bilge and provided at its intermediate portion with a fin keel. A hollow skeg depends from the rear portion of the hull, with the interior of the skeg serving as drain passage means leading to the bilge. A vertically extending rudder post is supported by the hull adjacent the skeg. A spade rudder is secured to the rudder post, the upper front portion of the rudder being formed with a vertically extending rudder surface abutting the rear edge of the skeg and the downwardly and forwardly extending rudder surface abutting the rear portion of the skegs lower edge. A drive shaft extends through the skeg to a supporting strut depending from the skeg.

Description

United States Patent Primary Examiner- Trygve M. Blix .41mrney--Fulwider. Patton. Rieber. Lee & Utecht ABSTRACT: A sailboat construction for an auxiliary-powered sailboat. The construction includes a hull having a bilge and provided at its intermediate portion with a fin keel. A hollow skeg depends from the rear portion of the hull, with the interior of the skeg serving as drain passage means leading to the bilge. A vertically extending rudder post is supported by the hull adjacent the skeg. A spade rudder is secured to the rudder post, the upper front portion of the rudder being formed with a vertically extending rudder surface abutting the rear edge of the skeg and the downwardly and forwardly extending rudder surface abutting the rear portion of the skegs lower edge. A drive shaft extends through the skeg to a supporting strut depending from the skeg.

SAILBOAT CONSTRUCTION BACKGROUND OF THE INVENTION 1. Field of thelnvention The present invention relates generally to the art of sailboat construction and more particularly to a sailboat construction which permits the use ofa spade rudder.

2. Description of Prior Art In recent years the use ofa spade rudder in conjunction with a keel spaced forwardly ofthe rudder has been widely utilized. In such sailboat construction the hull is generally flat between the rear end of the keel and the front edge of the spade rudder.

With this construction there is a tendency of the helmsman to overcontrol. Also, the rudder tends to flutter at higher speeds. Additionally, it has been difficult to balance a boat using such construction so as to eliminate weather helm.

SUMMARY OF THE INVENTION It is a major object of the present invention to provide a sailboat construction utilizing a fin keel and a spade rudder which eliminates the disadvantages of this type of construction while affording all of the advantages thereof.

An additional object of the present invention is to provide a sailboat construction of the aforedescribed nature utilizing a skeg depending from the lower portion of the hull wherein such skeg cooperates with the fin keel and the spade rudder to improve the handling characteristics of the sailboat while permitting an increase in speed thereof.

A further object of the present invention is to provide a sail boat construction of the aforedescribed nature where the skeg is hollow and serves as a drain passage means leading to the bilge of the sailboat, with water being confined against sloshing in said skeg.

Yet another object of the present invention is to provide a sailboat construction of the aforedescribed nature wherein the skeg affords a rigid support for a drive shaft strut so as to reduce the vibration ofthe propeller shaft.

These and other objects and advantages of the present invention will become apparent from the following detailed description when taken in conjunction with the appended drawings.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view showing the hull of a sailboat construction embodying the present invention;

FIG. 2 is a broken rear elevation view of said sailboat con struction; and

FIG. 3 is a broken vertical sectional view taken in enlarged scale along line 3-3 of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to' the drawings, there is shown a sailboat construction utilizing a hull H. A fin keel 12 of conventional construction depends from the intermediate portion of the hull. Preferably, the hull is of fiberglass construction. A skeg, generally designated 20, depends from the rear portion of the hull aft of the keel l2, and has a bilge l3 defined within its confines. The skeg has a generally vertically extending rear edge 22 and forwardly and downwardly extending lower edge 24. The skeg 20 is hollow and is preferably integral with the lower rearportion of the hull. Since the skeg 20 is hollow and its lower edge extends forwardly and downwardly, the interior of the skeg will serve as drain passage means leading to the bilge l3.

A generally vertically extending rudder post is rotatably supported within a tube 32 affixed to the hull H adjacent the rear edge 22 of the skeg 20. The lower portion of the rudder post 30 is rigidly affixed to the upper portion of a spade rudder, generally designated 40. The upper front portion of rudder is formed with a generally vertically extending surface 42 that abuts the rear edge 22 of the skeg 20, and with a downwardly and forwardly extending surface 44 that abuts the rear portion of the lower edge 24 of the skeg 20. Preferably, the vertically extending surface ofthe rudder 40 approximates 20-30 percent of the height of the rudder.

The hull H is provided with a conventional inboard engine 45 that is coupled to a downwardly and rearwardly extending drive shaft 46. The shaft 46 extends through a conventional stuffing box and tube unit 47 mounted upon the lower wall 48 of the skeg 20. The lower portion of the drive shaft is rotatably supported by means of a strut49 provided at its lower end with a bearing 50. The upper end of the strut 49 is rigidly affixed to and depends from the lower wall 48 of skeg 20. A propeller 52 is keyed to the lower end of the drive shaft 46. It will be noted that the propeller 52 is disposed forwardly of the rudder 40 whereby during forward movement of the hull H under power water from the propeller 52 will flowover the rudder 40 so as to enhance steerability of the saiIboaL'A fuel tank 51 is disposed within the lower portion ofthe hull H aft of the engine 45.

-As shown particularly in FIG. 3, water finding its way into the rear lower portion of the hull H will be permitted to flow into the bilge 13 along the lower portion of the skeg 20. To this end the bulkhead 54 immediately aft the fuel tank 51 is formed with a passage 56. Additionally, it should be noted that a pan 58 is disposed beneath the engine 45, with such pan being spaced upwardly from the lower wall 48 of the skeg 20. Water is removed from the bilge 13 by means of a conventional pump 60 having its intake connected to the bilge by means ofa conduit 62.

The sailboat construction of theaforedescribed nature affords important advantages over conventional sailboats utilizing a fin keel. In particular, the use of the skeg 20 affords improved handling characteristics of the sailboat while under sail without reducing the speed thereof and additionally provides important mechanical advantages. Thus, the skeg 20 affords better waterflow to the upper surface of the rudder 40 than is the case where a skeg is not utilized. This improved waterflow reduces water eddies which tend to cause the spade rudder to flutter, such flutter being a characteristicof a spade rudder. The skeg 20 also improves the tracking ability of the boat and eliminates the tendency of a helmsman to overcontrol, as is the case with a normal spade rudder. This feature results from the lateral water resistance afforded by the skeg at the rear portion of the hull. The placement ofthe lateral skeg area well aft in the hull H assists in balancing the boat and in eliminating weather helm. The added tracking afforded by the skeg permits the use of a shorter keel 12 and in this manner reduces the hulls wetted surface so as to afford higher speeds in light winds; The use of the skeg 20 reduces the quarter wave on the weather side of the boat since the water flowing from the hull is restrained from crossing from the leeward side to the weather side of the boat. The reduction of the quarter wave serves to increase the speed of the boat while under sail. The mounting of the strut 48 at the intermediate portion of the skeg provides a stiff support for the drive shaft 42. In this regard, the skeg 20 affords a more rigid platform for the strut 28 than would be the case if the strut 48 were attached directly to the underside of the hull H, inasmuch as the hollow channel configuration of the strut 20 defines a rigid structural member as compared to the generally flatly curved underside of a normal hull. The hollow configuration of the skeg 20 also defines a drain passage to the bilge 13 wherein the water is confined against sloshing about the interior of the hull as is the case with normal generally flat configured hull.

Various modifications and changes may be made with respect to the foregoing detailed description without departing from the spirit of the present invention.

Iclaim:

l. A sailboat construction comprising:

a hull;

a fin keel depending from the intermediate portion of said hull;

a bilge defined in said keel;

a skeg depending from the rear portion of said hull aft of said keel, said skeg having a vertically extending rear edge and a forwardly and downwardly extending lower edge, with the interior of said skeg being hollow to serve as drain passage means leading to said bilge;

a vertically extending rudder post supported by said hull adjacent the edge of said skeg;

a spade rudder secured to said rudder post, the upper front portion of said rudder being formed with a vertically extending surface approximating -30 percent of the height of said rudder that abuts the rear edge of said skeg and with a downwardly and forwardly extending surface that abuts the rear portion ofthe lower edge of said skeg;

an engine disposed within said hull having a downwardly and rearwardly extending drive shaft that protrudes through the bottom of the intermediate portion of said skeg;

a strut depending from said skeg forward of said rudder having its lower portion rotatably supporting said drive shaft;

and a propeller on the rear end of said shaft forward of said rudder.

Claims

1. A sailboat construction comprising: a hull; a fin keel depending from the intermediate portion of said hull; a bilge defined in said keel; a skeg depending from the rear portion of said hull aft of said keel, said skeg having a vertically extending rear edge and a forwardly and downwardly extending lower edge, with the interior of said skeg being hollow to serve as drain passage means leading to said bilge; a vertically extending rudder post supported by said hull adjacent the edge of said skeg; a spade rudder secured to said rudder post, the upper front portion of said rudder being formed with a vertically extending surface approximating 20-30 percent of the height of said rudder that abuts the rear edge of said skeg and with a downwardly and forwardly extending surface that abuts the rear portion of the lower edge of said skeg; an engine disposed within said hull having a downwardly and rearwardly extending drive shaft that protrudes through the bottom of the intermediate portion of said skeg; a strut depending from said skeg forward of said rudder having its lower portion rotatably supporting said drive shaft; and a propeller on the rear end of said shaft forward of said rudder.