Patent Publication Number: US-6668741-B1

Title: High performance sailing craft

Description:
This invention pertains generally to water craft and, more particularly, to a high performance sailing craft. 
     For high performance, a small sailing craft should generally have as little wetted hull area and as much sail area as possible. The hull area must be sufficient to support the craft, and the maximum sail area is limited by forces which can be controlled by the weight of a sailor. 
     Windsurfers, with non-rigid mast connections toward the front of their hulls, are very fast and fun to sail because they have small hulls and large sail forces. However, they are also very tiring because the sailor himself is the connection between the sail and the hull, and he must continuously endure forces such as the heel torque, the drive torque and the main sheet forces. 
     Small sailboats which have a rigid forward mast can also attain good sailing speeds, but in order to transfer the mast forces, the hull must be have substantial depth and stiffness. Such sailboats are larger than windsurfers and are more difficult to store, set up and transport. 
     It is in general an object of the invention to provide a new and improved sailing craft. 
     Another object of the invention is to provide a sailing craft of the above character which overcomes the limitations and disadvantages of the prior art and is capable of high performance sailing. 
     These and other objects are achieved in accordance with the invention by providing a sailing craft which has a hull, a seat disposed toward the rear of the hull and largely outboard of the hull, a mast affixed directly to the seat so that heeling forces applied to the mast are counterbalanced by the weight of a sailor primarily through the seat and not through the hull, a rotatably mounted stay extending between the top of the mast and a forward portion of the hull, a boom affixed to the stay, a sail mounted on the stay, and a rigid control rod connected to the boom for swinging the sail about the axis of the stay. 
    
    
     FIG. 1 is an exploded perspective view of one embodiment of a sail craft incorporating the invention, with the sail and boom removed for clarity of illustration. 
     FIG. 2 is a perspective view of the sail and boom assembly in the embodiment of FIG.  1 . 
     FIG. 3 is an enlarged, fragmentary perspective view, partly exploded, illustrating the connection between the stay and the hull in the embodiment of FIG.  1 . 
     FIG. 4 is an enlarged, fragmentary perspective view illustrating the connection between the stay and the mast in the embodiment of FIG.  1 . 
     FIG. 5 is an enlarged, fragmentary perspective view illustrating the connection between the boom and the stay in the embodiment of FIG.  1 . 
     FIG. 6 is an enlarged, fragmentary perspective view illustrating the connection between the sail and the boom in the embodiment of FIG.  1 . 
    
    
     As illustrated in the drawings, the sailing craft has a hull  11  with a mast  12  located toward the rear of the hull. Rather than being connected directly to the hull, the mast is affixed to a seat  13  which is mounted on top of the hull, with outboard portions of the seat extending laterally beyond the sides of the hull so that a sailor sitting on the seat can hike out on them. In the embodiment illustrated, pontoons  14  are attached to the under side of the seat on either side of the hull to provide additional stability, but they can be omitted, if desired. 
     Seat  13  is a rigid structure which is affixed to the hull by screws  16  which are received in reinforced pads  17  on the hull. The seat can be fabricated of any suitable material such as wood, fiberglass, or another rigid plastic. 
     Mast  12  is mounted to the seat by means of a base  18  which is affixed to the seat by bolts or other suitable means, with a pair of shrouds  19  extending between the mast and the seat to provide addition rigidity. In the embodiment illustrated, the shrouds are connected to the mast by a ring  21  which is clamped onto the mast and to rings  22  which are affixed to the seat. If desired, the shrouds can be tensioned by turnbuckles (not shown) or by other suitable means. 
     With the mast affixed to the seat, rather than to the hull, the majority of the heeling forces and other forces produced by the sail bypass the hull and are counterbalanced by the weight of the sailor directly through the seat. Since it does not have to transfer those forces, the hull does not have to be rigid, and it can be small, extremely lightweight, and inexpensive to manufacture. It can, for example, be inflatable, it can be made of a flexible foam, or it can be formed in a single pour rotomolding process. 
     The centerboard  23  and rudder  24  are also attached to the rigid seat structure. They pass through openings  26 ,  27  in the hull, with a handle  28  affixed to the rudder above the seat. 
     The sail  31  is mounted on a stay  32  which extends between the top of the mast and a forward portion of the hull. The stay is thus inclined forwardly and downwardly, and the luff of the sail is hemmed to form a pocket  33  in which the stay is received. 
     The stay is mounted for rotation about its axis, with the lower end of the stay being connected to the hull by a flexible connector  36  and the upper end being connected to the mast by a line  37  and a fitting  38 . 
     Connector  36  includes a base  39  and a flexible body  41  with pivot pins  42 ,  43  extending from the upper and lower ends of the flexible body. The base is affixed to the hull by rivets  44 , and the body is rotatively mounted on the base by pivot pin  43 . The body is made of rubber and can flex freely in all directions. Pivot pin  42  is rotatively received in a socket  46  in the lower end of the stay, with a detent assembly  47  retaining the pin in the socket. The detent assembly comprises a pin  48  which is mounted on a flat spring  49  affixed to the stay and received in a groove  51  near the upper end of pivot pin  42 . 
     In addition to permitting the stay to rotate freely, connector  36  also permits it to be folded over for raising and lowering of the sail. Moreover, with the flexible connection at the bottom of the stay, there is no transfer of torque through that connection between the sail and the hull. 
     Connector  38  comprises a bushing  53  which is mounted in the upper end of the stay, and a ring  54  with a shank  54   a  which is rotatively mounted in the bushing. Line  37  passes through an opening  56  in the upper portion of the mast and is tied to the ring. This line is pulled from below to raise and lower the sail assembly. 
     The sail is held up on the stay by a strap  58  which loops around a collar  59  that slips over the upper end of the stay. The collar bears against the heads of a ring of screws  61  which are driven into the mast to limit its downward movement. 
     Downhaul stretch for the sail is provided by a line  63  which is trained about a pulley  64  at the lower end of the stay. The pulley is mounted between flanges  66  which extend from the stay and are rigidly connected to it. The line is tied off in a hole  67  in one of the flanges and passed through a grommet  68  in the sail, then around the pulley and back through the grommet. By pulling on the free end of the line, the sailor can stretch the sail tightly along the stay. 
     A boom  71  is affixed to the stay by means of a clamp  72 , as best seen in FIG.  5 . The boom is in the nature of a wishbone or oval shaped boom, with arms  73  that bow outwardly on either side of the sail. The leech of the sail is secured to the boom by a line  74  which trained about a pulley  76  at the rear of the boom. This line is tied off at a grommet  77  in the sail, then trained about the pulley, and passed back through the grommet. Pulling this line provides outhaul stretch to the sail, following which it is tied off to a cleat  78 . 
     The rear mast and pivoting stay have been found to make it surprisingly easy to maneuver the boat. Turning and handling are extremely easy, unlike either a windsurfer or a conventional sailboat, and even an outside jibe, where the boom passes out and over the bow, is quick and easy to do. Because the stay is tilted, gravity provides a restoring force which tends to return the sail to a point where that force balances the wind, and the boat continues to have forward motion and rudder control even if the sail is released. 
     Referring again to FIG. 2, rigid control rods  79  are connected to the arms  73  of the boom on either side of the sail. In the embodiment illustrated, the control rods are pivotally mounted to brackets  81  which are clamped to the arms of the boom for movement between extended and retracted positions. The control rods are urged toward their retracted positions by return springs  82  which can be in the form of elastic cords or other suitable means. The rods are held against the arms in their retracted positions by Velcro fasteners (not shown). In their extended positions, the control rods can be grasped by a sailor who can either push on them or pull on them to swing the sail about the axis of the stay and control the angle between the boom and the centerline of the boat. 
     The rigid control rods give the sailor a better sense of the wind behavior and quicker control of the boom than he would have with conventional boom lines. They also give him the ability to push the boom as well as pulling it, which results in far better balance and overall sailing stability. 
     If desired, a single control rod which extends to the rear of the boom can be employed instead of the two rods on opposite sides of the sail. 
     The invention has a number of important features and advantages. It provides a sailing craft which has a very small, lightweight hull but which also has the ability to easily support and control a sail with sufficient force to provide high performance sailing. It can be manufactured either as a custom boat design, or as an add-on attachment to another watercraft such as a kayak, a windsurfer, or a surfboard. 
     It is apparent from the foregoing that a new and improved sailing craft has been provided. While only one presently preferred embodiment has been described in detail, as will be apparent to those familiar with the art, certain changes and modifications can be made without departing from the scope of the invention as defined by the following claims.