This invention relates to a propulsive wing for pulling or lifting a load that comprises flexible sails that are connected, at the front, to an oval-shaped leading edge, flattened at its base, and, at the rear, to an elliptical trailing edge, whereby the sails have a conical shape with an axis that is offset downward and opposing propulsive ranges; the wing also comprises three or four control lines distributed over the leading edge.
Propulsive wings for pulling or lifting a load are currently used for certain sports where the user is towed by the wing while his feet rest on a board on the water (kiteboarding), on snow (snowkite) or on wheels (mountainboard). These wings are of several types:
They have the common characteristic of exerting their pulling at a high speed that is perpendicular to the direction of the wind, so that upon stopping, the propulsive force is intermittent, and upon moving, the user has the task of maneuvering the wing frequently, which requires controlling its balance, its supports and its edge setting while frequently modifying the orientation of the wing. The practice of these sports is therefore elitist and requires a long apprenticeship.
The wing according to the invention produces continuous traction while being immobile in flight when the user is stopped, allows movements of the latter without moving the wing to maintain consistent traction, and leads to simplified handling of the board or the towed device.
In contrast, this new wing has the advantages of an important adjustment of the angle of incidence of the upper propulsive range for a significant loss of power and therefore increased safety for the user, a take-off and a landing that can be easily carried out without using a third party, as well as optionally shorter flight lines because the wing does not require movements from top to bottom.
Finally, this wing is an advantageous alternative to the sail-mast system of the pleasure sailboats: the larger sails for a boat of the same size, the lightened structure of the design and the upward traction produce a lower resistance of the hull on the water and therefore a greater speed. Likewise, the wing represents a source of energy savings for merchant motor ships.
The invention is characterized in that it comprises flattened-cone-shaped sails with an axis offset downward and therefore several sail ranges whose aerodynamic force resultants are opposite one another.
The base of these sails is connected to the leading edge that preferably, but not necessarily, consists of an inflatable oval-shaped flange with a rectilinear and horizontal base that is parallel to the largest axis that can rest on the ground or on water in a stable manner.
The other side of the sails constitutes the trailing edge; the sails at this location are perforated in a shape like a water droplet with the tip oriented toward the leading edge.
This shape thus delimits a propulsive range of the largest upper sails, two propulsive ranges of lateral sails of intermediate sizes, and a lower propulsive range of smaller size.
Four control lines are distributed into two so-called upper control lines and two so-called lower control lines. They have one of their ends attached around the leading edge and the other connected to a control system that is designed to keep the two left lines separated from the two right lines and to vary the length of the upper lines relative to that of the lower lines.
From the equilibrium position of the wing at rest on the ground or on the water, the user lightly holds the lines before shortening the length of the upper control lines relative to the length of the lower lines until the wing takes off and rises to a stable and immobile flight position if the user is stopped. The wing then exerts continuous traction in the direction of the wind.
An additional shortening of the upper control lines makes the wing lose power, and said wing remains at altitude or comes in for a soft landing if the action is continued.
A reduction of the length of the lower lines increases the power of the wing that remains at altitude or quickly drops if the action is continued.
Tension of the left lines orients the wing toward the left relative to the direction of the wind up to a stabilized position. The wing then exerts continuous traction toward the left relative to the direction of the wind. Tension of the right lines produces the same effects on the wing toward the right.
According to particular embodiments, the propulsive wing comprises one or more of the following characteristics:
The propulsive wing will be explained in detail taking into account the accompanying drawings that are provided by way of examples that show the wing in a flight setting, seen from the same height and in which:
The wing is always shown inflated by the wind. Its size may vary enormously depending on use, from several meters to several tens of square meters.
To ensure the stability of the wing in flight, the greatest length of the sails (3) is positioned at the highest part and reaches approximately the value of the small axis of the leading edge (1).
These flexible and light sails (3) consist of a low-deformable synthetic material that is fairly impervious to water and appropriately resistant to wear and tear. It is connected at its base to the leading edge (1) of the constant circular section that consists of, for example, an inflatable sheath with an air chamber. The material should be flexible, light and resistant so as not to become deformed under the inside air pressure and facing multiple folds. This leading edge may assume an oval shape with a rectilinear and horizontal base that is parallel to the largest axis that can rest on the ground or on the water in a stable manner.
The other end of the sails (3) constitutes the trailing edge (2) in the form of a recess that represents a water droplet with the tip oriented toward the leading edge (1).
For their manufacturing, the sails can be drawn and cut out flat in the shape of a half-disk whose radius corresponds to the greatest length of the sails, i.e., approximately the value of the small vertical axis of the leading edge (1).
Owing to its design, the sails in flight are systematically stretched by the wind. It is advisable, however, to place several inflatable transverse slats (6), as indicated in
The other side of the leading edge—facing the wind—is, in contrast, equipped with an inflatable arch (7) that is placed along the small axis of the leading edge (1) (as indicated in
These transverse slats (6) and the arch (7) can be connected to the leading edge (1) so as to require only one inflation orifice.
In contrast, tightening straps (8), as shown in
Other tightening straps (15), as shown in
The piloting of the wing can be ensured by:
The attachment points of these lines (5) should be sufficiently separated from the axes to ensure the stability of the wing in flight while allowing the pivoting of the wing under good conditions of precision and amplitude around its axes.
In contrast, in the case of a leading edge that consists of an inflatable flange or a semi-rigid structure, each line is held by several shroud lines (4) that are mounted to slide so as to limit the deformation of the profile of the leading edge (1) and to keep the shroud lines (4) stretched during the variation of the incidence of the wing.
The other end of the lines is connected to a control system that is designed to keep the two left lines separated from the two right lines and to vary the length of the upper lines relative to that of the lower lines.
In the case of the smallest wings, this can be two handles that bring the two left lines together to be held in the one hand and the two right lines to be held in the other.
In the case of the larger wings, it is advantageous to use a bar as indicated in
The passage of the control lines (5) through guides (11) consists of a material that is fairly flexible to allow the movement of lines when the bar is rotated and fairly resistant to lock the lines the remainder of the time. This device maintains the good winding of the lines (5) around the rollers (10) when the lines are slack.
Finally, two braces (12) that freely rotate around the bar (9) and that are held in translation make it possible to connect the unit to the user's harness by means of a rope (13). Thus, tension from the left side of the bar (9) brings together the left control lines of the user and therefore orients the wing to the left. The tension from the right side creates the reverse effect.
The length of the control lines (5) can vary greatly from several meters for a facilitated implementation and use to several tens of meters to take advantage of a stronger and more uniform wind than at the surface of the ground or the water.
Before take-off, the wing rests on the horizontal base of the leading edge (1) and on its transverse slats (6), facing the wind. The leading edge is therefore inclined and a portion of the upper range of the sails (3) is picked up by the wind. The user then moves by rotating the bar (9) until the upper and lower control lines (5) are slightly stretched. The bar is consequently rotated to shorten the upper lines (and to lengthen the lower lines—direction of the arrow from the top of
A release of the upper lines increases the incidence of the upper range of the sails (3). The wing then loses a little altitude and reaches a flight position that is close to that of
From this strong traction position, a shortening of the upper lines decreases the incidence of the upper sail range and decreases the power of the wing, which takes on a little altitude. Additional shortening then makes the wing slowly drop, and said wing then loses all power. This procedure guarantees high safety for the user in the event of a wind gust and also makes it possible to bring together the wind of the ground or the water before fully releasing the upper lines to swing the wing around the large axis of the leading edge (1) and to put it beside its sails (3) that are supported by the transverse slats (6).
An emergency procedure, if necessary, consists in fully releasing the upper lines from a flight position to drop the wing that quickly falls to rest in its stable position on the ground or on the water, balanced on the horizontal base of its leading edge (1) and its transverse slats (6).
In flight position, the large axis of the leading edge (1) is horizontal when the wing is in the axis of the wind (representation of
Several examples of angles are provided purely by way of indication to identify approximately the position of the wing in flight; they actually depend on the particular conditions of the implementation of each wing and the flight circumstances:
This wing with constant propulsion has many possible applications. The most obvious relate to the sports that involve a user who rests on a board and is towed by this wing (kiteboarding, snowkite, mountainboard) and sailing, whereby this wing partially or completely takes the place of the sails or the engine.
Number | Date | Country | Kind |
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0513308 | Dec 2005 | FR | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/FR2006/002702 | 12/12/2006 | WO | 00 | 6/25/2008 |