US2971488A

US2971488A - Sail boat sails

Info

Publication number: US2971488A
Application number: US699552A
Authority: US
Inventors: Ray J Morissette
Original assignee: Individual
Current assignee: Individual
Priority date: 1957-11-29
Filing date: 1957-11-29
Publication date: 1961-02-14
Anticipated expiration: 1978-02-14

Description

Feb. 14, 1961 R. J. MORISSETTE SAIL BOAT SAILS Filed Nov. 29, 1957 R m w m RA Y J. MGR/SSE 7' TE BY by m 147' TORNEVS 1 f rn,

United States Patent 9 i SAIL BOAT SAILS Ray J Morissette, 3915 Madison, Riverside, Calif.

Filed Nov. 29, 1957, Ser. No. 699,552

3 Claims. (Cl. 114-103) This invention relates generally to sail boats and more particularly to a new and improved sail for sail boats. It is well known that in any air foil and, in particular, in the sails of sail boats there is a great deal of drag from the aerodynamic forces and the air foil characteristics.

It has always been the desire of boat designers to increase the speed of their vessels by various means; however, it has never been possible heretofore to radically change the nature of airfoil particularly to eliminate any appreciable portion of the drag.

It is well known that the maximum lift of an airplane wing can be increased by the use of slots on the leading edge of the wing, and flaps on the trailing edge. Up to the present time it has not been possible to apply these principles to sails due to their flexible nature and the fact that they must be constantly reversed due to changes in direction and wind direction.

I have devised a means for venting the edge of sails and combining with it a trailing edge flap arrangement. I accomplish this by simple arrangement of holes in the trailing edge of the sail and by a sectional boom combined with sail bats to make a true trailing edge flap.

It is a major object of my invention to provide sails for sailing vessels in which the drag will'be reduced.

It is a further object of my invention to provide sails for sail boats having a vented leading edge effect combined with a trailing edge flap.

It is a still further object of my invention to provide sail boat sails in which a vented leading edge effect and trailing edge "flap are combined to reduce the drag and in which the trailing edge may be easily reversed as the tack is changed.

The foregoing and other objects and advantages of my invention will be clear from the following description when read in conjunction with the attached drawings in which:

Figure l is a perspective view of a sail boat having installed thereon sails embodying the principlesi of my invention, and I Figure 2 is a plan view of the same embodiment.

A sail boat is depicted in the drawings, and is seen to consist of a hull 10, having attached thereto a mast 11 with a mast stay 12, a main sail designated generally by the reference numeral 20, and a jib shown generally by the figure 30.

The main sail 20 is composed of a large, triangular sheet of canvas or the like 21 fastened in a conventional manner along one edge to the mast 11, and at the bottom edge to a boom 13. The boom 13 is fastened in the usual manner to the mast 11, and is swingable with respect thereto in the horizontal plane.

The large sheet of canvas 21 has a number of vertically spaced holes 22 along the approximate line (shown as dotted line 23) through the forward ends of sail bats 24. The sail bats 24 are flat pieces of wood or the like fastened to the edge of the sail as shown by canvas pockets or the like of customary construction. The line 2,971,488 Patented Feb. 14, 1961 23 represents a line of demarcation between the main portion of the sail 20 and a slender trailing edge portion 25, which is more or less analogous to the flap of an airplane wing. The line 23 extends from a short distance forward of the rear end of the boom up to the apex of the sail, in converging relationship with the trailing edge of the sail. The trailing edge portion 25 is thus in the form of a vertically elongated triangle, and is normally bent at an angle to the main part of the sail 20, in the same way that the flap is bent downwardly with respect to an airplane wing.

The boom 13 is hinged at 14 to a trailing portion 15 of the boom 13 at the point where the latter is intersected by the dotted line 23. This hinge joint is of any customary construction providing means for adjusting the angular relation of the boom 13 with its trailing portion 15. The joint 14 may be held in any desired angular relationship by means of thumbscrew 16 or the like if desired.

The boom 13 is controlled in the usual manner by lines 40, which extend from the trailing boom end 15 through the

pulleys

41, 42, and 43 to a stanchion 44 or i the like, on the deck of the boat.

A sail edge control rope 50 extends from a stanchion 51 through a number of

pulleys

52, 53 and 54 fastened to the mast 11. A number of feeder ropes 55, 56 and 57 are attached at one of their ends to rope 50 at the approximate location of the

pulleys

52, 53 and 54. The other end of each of said

feeder ropes

55, 56 and 57 is attached to the trailing edge of the sail 20, adjacent the ends of the sail bats 24.

Another sail edge control rope 60 extends from a stanchion 61, up the mast 11 on the side opposite the rope 50, and is fastened to feeder ropes corresponding to the

feeder ropes

55, 56 and 57, except that they are disposed on the reverse side of the mast and sail, and therefore cannot be seen in the drawings. The purpose of this arrangement is to enable the sail to be controlled from either side of the centerline of the boat, as will be understoodby those skilled in the art.

The jib 30 is of customary jib construction, formed of canvas 31 or the like, and attached along its bottom edge to a jib boom 32. The jib is attached along its forward edge to the stay 12 in the customary manner, and the boom 32 is controlled by means of a rope 33, which is attached to a stanchion 34.

In operation, the holes 22 in the sails help prevent the so-ca1led break-down, or turbulence in the flow of air over the surface of the sail and in cooperation with the trailing edge, greatly increases the workable pressure on the sail. The actual aerodynamic principles employed are well known to those skilled in the art, being well described in the Aeronautics section of Marks Mechanical Engineers Handbook, 5th edition; beginning on page 1475. The exact theories, ratios, and formulas indicated in the Marks Handbook reference are not directly applicable to the present invention due to the nature of the sail. The principles, however, remain the same and by combining holes within the sail material itself and a trailing edge boom, together with the control ropes to provide a break over point for a trailing edge, I have accomplished what has heretofore been impossible in the field in increasing the working pressure on the sail airfoil.

When the sail boat embodying my invention as shown in the attached drawings and described herein, is in use, the jib is controlled in the usual manner by the rope 33. Thejib is of customary construction and performs in a manner identical to that of the ordinary jib. The main sail is controlled through the use of the rope 40, which is attached to the boom as shown through

pulleys

41, 42 and 43 and fastened to the deck of the boat at 44.

The boom joint 14 joining the main boom 13 and the boom trailing edge 15 i set at any desired angle either manually or through the influence of the controlled

ropes

55, 56 and 57. The boom is controlled in the customary manner by use of the rope 40- and thus-the angleof the sail is adjusted, set and controlled.

The angle of break of the trailing edge of the sail is controlled by appropriate tightening and loosening of the

control ropes

50 and 60 on opposite sides of the sail. When the ropes 50 are pulled and the ropes 60 are relaxed, a force is exerted in a forward direction against the edge of the sail at the outer ends of the bats 24. This, combined with the holes 22 in the sail along the line 21, cause the edge of the sail to flex and to give the same effect as a trailing edge flap in an airplane.

The natural function of the jib in conjunction with the sail 20 provides, in effect, a slotted leading edge which cooperates with the slotted or vented trailing edge to provide maximum aerodynamic efliciency for the sails. By using this system, the angle of attack of the sail with respect to the wind may be greatly increased, and the forward motion of the boat is greatly increased.

When the direction of the boat is changed to take a new tack, the angle of the trailing edge of the sail may be completely reversed or altered, as desired, by appropriately tightening and loosening respectively the control ropes 50 and 60, and also by adjustment of the boom trailing end 15.

While the embodiment of my invention shown and described is fully capable of performing the objects and advantages of this invention, it will be obvious to those skilled in the art that many modifications may be made without departing from the broad scope of the invention, as defined by the appended claims.

I claim:

1. In a sail boat having a vertical mast and a horizontal boom adjacent the lower end thereof, a flexible sail attached along one edge to said mast and along its bottom edge to said boom, said sail being provided with a plurality of vertically spaced apertures adjacent the rear edge thereof, said boom having a short extension hinged adjacent its outer end for horizontal swinging movement, and a rope secured to the outer end of said boom and passing through a pulley on the center line of the boat below the hinge point on said boom and through a pulley adjacent the hinge point on said boom and through another pulley on said boom forward of said hinge point, the portion of said sail rearwardly of said apertures being attached to said hinged extension of said boom whereby that portion of the sail aft of said apertures may be deflected at an angle with respect to the main portion of said sail.

2. In a sail boat having a vertical mast and a horizontal' boom adjacent the lower end. thereof, a flexible sail attached along one edge to said mast and along its bottom edge to said boom, said sail being provided with a plurality of vertically spaced apertures adjacent the rear edge thereof, said apertures being arranged in a line extending from a short distance forward of the rear end of said boom to the topapex of said sail, and two sets of control ropes attached to the trailing edge of said sail and extending forwardly on.bothsides of said sail and downwardly along said mast for deflecting that portion of the sail aft of said apertures angularly with respect to the main portion of said sail,

3. In a sail boat, the combination of a hull; a mast fastened in an upright position upon said hull; a boom fastened at approximately right angles to said mast; a stay for said mast running from a point near its upper extremity downward to and fastened upon the front end of said hull; a jib sail fastened to said mast stay at its front edge and having a jib boom fastened to said mast stay and the lower edge of said jib sail; a rope fastened to the end of said jib boom to control said jib; a flexible main sail fastened at its front edge to said mast and at its lower edge to said first-named boom; said sail having a number of bats consisting of flat slats fastened to its rear edge at vertically spaced intervals and running generally forward from said rear edge for a short distance; two sets of control ropes fastened to the edge of the said sail at each of said bats and running forward on opposite sides of said sail; each of said ropes being fastened to one of two main controls running on either side of said mast and fastened to stanchions on said hull; said main sail having a plurality of apertures provided therein along a 'line approximately running through the front edge of said bats along said sail; a rope fastened at one of its ends to said first named boom at a point near its outer edge, passing through a pulley fastened to apoint on the boat deck, and having its other end free to be held by the operator of the boat to control the angular position of said boom with respect to said hull for defleeting that portion of said main sail aft of said apertures so that it is angled inwardly with respect to the remainder of the sail.

References Cited in the file of this patent UNITED STATES PATENTS 700,520 Lundquist May 20, 1902 2,319,999 Jennings May 25, 1943 2,620,760 Melges Dec. 9, 1952 FOREIGN PATENTS 3,210 Great Britain of 1894 198,649 Great Britain May 1, 1924