Title:
Rig for sailboats
United States Patent 2107303


Abstract:
The present invention relates to rigs for sail boats or vessels. There are two objects desirable in a sail rig, safety and speed. The two objects are conflicting inasmuch as a high and easy rig is desirable for a great speed while a lower and more sturdy rig is required for as great safety...



Inventors:
Fredrik, Ljungstrom
Application Number:
US4001435A
Publication Date:
02/08/1938
Filing Date:
09/11/1935
Assignee:
Fredrik, Ljungstrom
Primary Class:
International Classes:
B63H9/10
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Description:

The present invention relates to rigs for sail boats or vessels.

There are two objects desirable in a sail rig, safety and speed. The two objects are conflicting inasmuch as a high and easy rig is desirable for a great speed while a lower and more sturdy rig is required for as great safety as possible when meeting heavy weather. For the purpose of complying with the two objects, at least to some extent, it has hitherto been necessary to compromise between them.

If a sailing yacht, for instance, is struck by a sudden squall the sail area must be rapidly reduced. With the means for reefing sails hitherto known this is, however, a procedure requiring considerable time and the sail must therefore have a limited area which as a rule becomes too small in very light weather. By exceeding such size of the sail the details of the rig become too weak to resist, for instance, a storm even with reduced sail area. The numerous rig averages occurring on modern racing yachts give sufficient evidence of the difficulties meeting the constructor in this respect.

It is one object of my invention to provide a sail rig which has a very large sail area available in light airs while said area may be reduced in a very short time to a sufficient degree upon a sudden increase of the force of the wind. Another object of the invention is to improve the speed of a sail boat with a given size of the sail.

Still another object is to provide a sail rig in which the size of the active sail is automatically changed when sailing alternately by and before the wind. Still another object of the invention is to provide a rig such that the sail may be loosened during critical situations without disadvantage so as to become entirely unloaded from the pressure of the wind.

Further objects and advantages of my invention will be apparent from the following description considered in connection with the accompanying drawings which form a part of this specification, and in which:Fig. 1 is a side view of a sail boat provided with a rig in accordance with my invention.

Fig. 2 is a side view of a somewhat modified form of such rig.

Fig. 3 is a similar view of the last mentioned rig but with the sail cloth partly rolled up on the mast.

Fig. 4 is a section through sail and mast on the line 4-- of Fig. 3 on an enlarged scale.

Fig. 5 is a section through the mast and part of the sail on still more enlarged scale.

Fig. 6 is a view, partially in cross-section, of the upper and lower parts of the mast part of the boat.

Fig. 7 is a cross-sectional view showing a modification of means for rotating the mast. Fig. 8 is a top view of a boat provided with means for rotating the mast.

Fig. 9 is a side view on an enlarged scale of a detail of Fig. 8.

Fig. 10 is a rear view of another modification of a rig mounted in a boat and constructed in accordance with my invention.

Fig. 11 is a top view of the boat shown in Fig. 10.

Fig. 12 is a rear view of the boat with the sail partly rolled up on the mast.

Fig. 13 is a section through said mast; and Fig. 14 is a side view of a still further embodiment of a rig in accordance with my invention.

Referring to the drawings reference character 2 designates a sail boat which is provided with a mast 3. On mast 3 is hoisted a sail 4. In the embodiments according to Figs. 1 through 6 the sail 4 is sheeted home to the boat deck by a rope 5 while another rope 6 is slack. Said ropes serve to sheet home the sail at the port and starboard sides of the boat, as is usual with fore sails. Mast 3 is substantially straight, as appears from Fig. 2, but is resiliently bent rearwardly by a back stay 7. The length of stay 7 may be adjusted by a block 8 and a wire 9 which is secured to the deck. Mast 3 is otherwise unstayed along its whole length and as stay 7 is at a greater distance from the mast than the rear edge of the sail, the latter may be allowed freely to blow out in all directions without any risk of coming in contact with and getting entangled in any stays. Mast 3, which is circular in cross-section, has a longitudinal inner recess 10 (Figs. 4 and 5) and an inner circular channel I . The fore edge of the sail is disposed in said channel and is enlarged by a wire 40 or the like so that the sail edge fills the greater part of channel I1. Mast 3 is journalled in boat deck 12 (Fig. 6) by ball bearing 13. A hood 14 may be secured to the mast and an annular sleeve 15 is connected to the deck. These members prevent water from entering the bearing. The lower end of the mast is carried by ball bearing 16 which is arranged in a bridge 18 secured to the bottom IT of the boat. A halyard 19 is disposed in the recesses 10 and 11 of the mast for the purpose of setting the sail.

Halyard 9 runs over a pulley 20 in the top of the mast and another pulley 21 below the mast. The mast is, in the embodiment according to Fig. 6, operated by two wires 22, 23, which in opposed directions are wound on two drums 24 and 25 secured to the mast. By hauling one of these wires the other wire will obviously be rolled up on the corresponding drum. One of the wires may, however, be omitted so that the sail is unfurled when stretched under wind pressure. Other conventional means may of course also be used for rotating the mast, as for instance winches or the like. The sail, by the aforementioned means, may be easily rolled up on or unrolled from the mast so that the sail is given the desired active surface according to wind conditions. The sail may be entirely rolled up on the mast. As the mast if desired is rotatable in either direction such a position of the sail may be chosen, as for instance when sailing by the wind from the one or the other side, that the sail provides an inflowing edge for the air as harmonious as possible regardless of the degree of rolling up the sail. From an aerodynamical point of view the air flow thus meets the sail surface and especially the lee side thereof under the most favorable conditions whereby the sailing capacity is considerably improved. These advantages are adherent to the sail in light as well as in heavy air.

When the sail is being reefed by rotating the mast its rear edge at the same time more and more becomes rolled up at the top of the mast as appears from Fig. 3. In this way the weak top of the tapered mast is unloaded and is substantially released from the increased stresses resulting from storm or strongly increased force of wind. The rear edge of the sail is provided with a leech 26, preferably of thin wire, which with reefed sail and under heavy sail pressing is stretched from the point where the leech just is being wound up on the mast. Consequently, the upper part of the mast may be made higher and thinner than is possible in sail rigs of common type.

The mast is preferably tapered with increasing conicity to the top. When rotating the mast to reef the sail it will be of less width from below and upwardly and the sail therefore retains a high shape. The stay 7 is rotatable relatively to the mast so as to enable rotation of the mast with said stay stretched. It is known that a mast bent rearwardly is advantageous for providing a well standing sail. The rear edge of the sail may be either straight as shown in Fig. 1, or curved inwardly as illustrated in Fig. 2. The wires 5 and 6 are of a length so as to allow the sail to blow out with the wind right ahead from the mast. This is possible in view of the absence of hindering stays. The advantage is gained that the sails without any risk momentarily may be loosened in the case of hurricanes or the like and when sailing before the wind. Thereafter the sail may be reefed to required degree by rotating the mast and then sheeted home so that the wind fills the sail.

The sail may consist of a front and a rear portion of which the former is of thin and light cloth whilst the rear portion is of coarser and heavier cloth. The seam between the two cloths may be parallel to the mast as indicated by 27 in Fig. 2.

When the sail is rolled up on the mast the front weak portion thereof becomes reefed while the rear strong portion takes the wind pressure. In this way the ordinary sail at the same time will be a strong storm sail.

In the embodiment according to Fig. 7 the mast 3 is rotated by means of an endless wire 30 which extends around a grooved wheel secured to the mast and, by means of eyes, rollers 32 or the like, is disposed around the cock pit 33, as appears from Fig. 8. The mast in this manner may be conveniently operated from different points of the boat. Wire 30 may be maneuvered by one or more winches 35 as shown in Figs. 8 and 9.

Locking devices of known kind may be provided for fixing the mast. Wire 30 may be provided with means for adjusting the tension of the same.

The aforesaid means for operating the mast may be arranged within the boat.

The embodiment according to Figs. 10-13 differs from the foregoing by the fact that the mast 3 bears two sails 4. Each sail is secured to the deck by a rope 36. When sailing before the wind the two sails stand out just like a parachute sail as appears from the figures. The area of the two sails may be regulated in the same manner as above described in accordance with wind conditions by rolling up the sails on the mast. On changing course the double sail simply becomes an ordinary triangular sail so that the two sails lay together and the sail then has the appearance and operation described in connection with Figs. 1-3. The sails 4 may either be put in 26 two preferably diametrally opposed recesses iI (Fig. 13) or they may have a common leech disposed in a single recess in the mast so that they will be hoisted together. For setting the sails means as above described may be used. When the two sails stand out they are obviously in all degrees of reefing symmetrical to the mast. As there are no sails in front of the mast it may be placed far afore in the boat.

In the embodiment shown in Fig. 14, a number 85 of laths 37 are provided preferably in the rear as well as in the lower edges of the triangular sail 4.

Of the two laths 37 nearest to the mast the lower one is spaced more apart from the mast than the upper one. However, when the sail is rolled up, the two laths will at the same time be laid on the mast in view of its conical shape. The direction of the laths is such that they will lie parallel to the mast when the sail is rolled up. To this end the laths extend at such angles in the sail relatively to each other and to the mast that these angles converge upwardly.

While I have shown several embodiments of my invention, it is to be understood that these are for purpose of illustration only, and that my invention is not to be limited thereto, but its scope is to be determined by the appended claims viewed in the light of the prior art.

What I claim is: 1. In a boat, a sail rig comprising a single mast, means pivotally mounting the mast in the boat for rotation about the axis of the mast, a sail carried by said mast, and means for rotating the mast a plurality of revolutions whereby to roll the sail on the mast or unroll it therefrom, the portion of said mast above the level of the lower marginal portion of the sail being free from exterior support against lateral movement.

2. In a boat, a sail rig comprising a mast, 65 means pivotally mounting the mast in the boat for rotation about the axis of the mast, a sail carried by said mast, back stay means for said mast arranged at a greater distance from the mast than said sail, said back stay means being rotatably secured to said mast, and means for rotating the mast a plurality of revolutions whereby to roll the sail on the mast or unroll it therefrom, the portion of said mast above the level of the lower marginal portion of the sail being free from exterior support against lateral movement.

3. Sail rig according to claim 2, in which the mast is laterally free from stays.

4. In a boat, a sail rig comprising a mast, means pivotally mounting the mast in the boat for rotation about the axis of the mast, a sail carried by said mast, staying means for bending said mast rearwardly, said staying means being rotatably secured to said mast, and means for rotating said mast a plurality of revolutions, whereby to roll the sail on the mast or unroll it therefrom, the portion of said mast above the level of the lower marginal portion of the sail being free from exterior support against lateral movement.

5. A sail rig comprising a vertical main mast and a main sail carried by said mast, means pivotally mounting the mast in the boat for rotation about the axis of the mast, means for rotating the mast a plurality of revolutions whereby to roll the sail on the mast or unroll it therefrom, and laths connected to said sail and arranged to lie parallel to the mast when the sail is rolled thereon, the portion of said mast above the lower marginal portion of the sail being free from the exterior support against lateral movement.

6. A sail rig for a boat including a mast tapered towards its upper end, means pivotally mounting said mast in the boat for rotation about the axis of the mast, a sail carried by said mast, and means to rotate said tapered mast a plurality of revolutions to roll and unroll the sail on said mast, the portion of said mast above the level of the lower marginal portion of the sail being free from exterior support against lateral movement.

7. A sail rig for a boat including a mast tapered towards its upper end, the degree of taper increasing towards the upper end of the mast, means pivotally mounting said mast in the boat for rotation about the axis of the mast, and means to rotate said tapered mast a plurality of revolutions to roll and unroll the sail on said mast, the portion of said mast above the level of the lower marginal portion of the sail being free from exterior support against lateral movement.

8. A sail rig for a boat including a mast tapered towards its upper end, means pivotally mounting said mast in the boat for rotation about the axis of the mast, a substantially triangular sail, means for securing one edge of said sail to said mast, and means for rotating said mast a plurality of revolutions to roll the sail on the mast whereby the top portion of the sail is wholly rolled up on the mast, the portion of said mast above the level of the lower marginal portion of the sail being free from exterior support against lateral movement.

9. A sail rig for a boat including a mast, a sail carried by said mast and made of a plurality of pieces of material joined together along a sub-. stantially vertical seam, the different pieces of material being of different thicknesses, and means for rotating said mast a plurality of revolutions to roll the sail on the mast, the thinnest piece of material being adjacent to said mast whereby said thinnest piece is rolled up first on the mast.

10. A sail rig for a boat including a mast formed with an internal groove, means pivotally mounting said mast in the boat for rotation about the axis of the mast, a sail carried by said mast and having an edge disposed in said groove, and means for rotating said mast a plurality of revolutions to roll and unroll the sail on the mast.

11. A sail rig for a boat including a mast formed with an internal groove and a narrow slot extending from said groove to the outer surface of the mast, a sail carried by said mast and having an edge extending through said slot and disposed in said groove, the edge of said sail within said groove being thicker than the width of said slot whereby said edge is held in said groove, and means to rotate said mast a plurality of revolutions to roll and -unroll said sail on said mast.

12. A sail rig for a boat including a single rotatable mast, a substantially triangular sail, means for securing the forward edge of said sail to said mast, means for sheeting the lower part of said sail to the boat, means for rotating said mast a plurality of revolutions to vary the effective area of said sail by rolling and unrolling the sail on the mast, and means for securing said mast against rotation, the portion of said mast above the level of the lower marginal portion of the sail being free from exterior support against lateral movement.

13. In a boat, a main rig including a single main mast, means for mounting the mast in the boat, a triangular main sail carried by said mast and having a free foot, means for sheeting said foot to the boat, and means for rotating said mast a plurality of revolutions whereby to roll up and unroll the sail from the mast, said mast being rotatable in either direction to roll up the sail so that the lee side of the sail and mast may be streamlined, the portion of said mast above the level of the lower marginal portion of the sail being free from exterior support against lateral movement.

14. In a boat, a sail rig including a single main mast, two similar main sails having their forward edges secured to said mast, and means for rotating said mast a plurality of revolutions whereby to roll up and unroll both of said sails simultaneously from said mast. 15. In a boat, a sail rig including a single main mast, a single mast leech, two similar main sails having their forward edges secured to said mast by said single leech, and means for rotating said mast a plurality of revolutions whereby to roll up and unroll both of said sails simultaneously from said mast.

FREDRIK LJUNGSTROM.