Water sport device having a fin

Abstract

The invention relates to a water sport device having a sitting or standing surface (2) for a person practicing water sports, a jet drive (8) and a pivotable nozzle (13), wherein a fin (23) is disposed at the nozzle (13) and is arranged in a fixed position relative to said nozzle.

Claims

1. A surfboard, comprising: a sitting or standing surface (2) for a person practicing water sports, a jet drive (8), a pivotable nozzle (13), wherein a fin (23) is provided on the pivotable nozzle (13) and is mounted in a fixed position relative to the pivotable nozzle (13) and by an inlet (19) in an underwater surface (16) of the surfboard and wherein water is sucked in through the inlet (19) and is accelerated by a propeller (21) provided in a water channel between the inlet (19) and the nozzle (13) and is pushed out of the pivotable nozzle (13); and wherein the fin (23) has a rear control surface (23a) located behind the axis of rotation (D) of the nozzle (13) in a direction of movement of the surfboard and a front control surface (23b) provided in front of an axis of rotation (D) of the nozzle (13) in the direction of movement.

2. The surfboard according to claim 1, wherein the nozzle (13) the fin (23) are mounted to pivot around an axis of rotation (D).

3. The surfboard according to claim 1, wherein the sitting or standing surface (2) for a person practicing water sports and in that the axis of rotation (D) perpendicularly oriented to the sitting or standing surface (2).

4. The surfboard according to claim 1, wherein the fin (23) is fixed to a water side of the nozzle (13) by nylon screws (22a, 22b).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a top view of a surfboard according to the invention,

(2) FIG. 2 shows a bottom view of the surfboard in FIG. 1,

(3) FIG. 3 shows a sectional view of the rear of the surfboard in FIGS. 1 and 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(4) The invention will be described by means of the surfboard 1, however it is not limited to a surfboard. It is also conceivable to transfer the invention to other water sport devices, in particular to jet skis.

(5) In FIG. 1, the surfboard 1 according to the invention is shown with a standing surface 2 for a person practising water sports, which surface is horizontally orientated during operation. On a nose 3 of the surfboard 1, which in FIG. 1 is on the right-hand side, an eyelet 4 for a leash 6 is provided. One end of the leash 6 is tied in a knot to the eyelet 4. On another end of the leash 6, a controller 7 is tied in a knot. The controller 7 comprises a wireless radio link or a Bowden cable or a connection with a cable to a drive 8 integrated in the surfboard. The radio link is indicated by the dotted line. Further, a foot strap 9 is fastened to the standing surface 2 of the surfboard 1. For practising the sport, a person practising water sports can insert their foot into the foot strap 9 and can grasp and hold the controller 7 with one hand and can get additional hold on the surfboard 1 by the leash 6. In this case, the controller 7 is merely used for controlling the force of the propulsion of the surfboard, i.e. the speed of the surfboard 1. The controller may have a gyroscope function, so that the propulsion is modified via a tilting movement, or is implemented as a lever, a type of joystick.

(6) A gyro sensor 11 is provided in the surfboard, which registers tilting movements about a longitudinal direction L of the surfboard 1. The gyro sensor 11 is linked to a pivoting device 12, 17, 18 that acts on the nozzle 13 mounted in the tail 14 and pivots the nozzle 13 in a plane that is parallel to the standing surface 2.

(7) The pivot drive comprises an arm 17 provided on the nozzle 13, which has an actuator rod 18 articulated thereto. The actuator rod 18 is linked to a servomotor 12. The servomotor 12 allows the actuator rod 18 to be extended and retracted, so that a pivoting movement of the nozzle 13 can be carried out via the arm 17 in the plane of the drawing in FIG. 1.

(8) FIG. 2 shows the surfboard 1 in FIG. 1 in a view from the bottom. In FIG. 2, an underwater surface 16 of the surfboard 1 is shown. The underwater surface 16 has an inlet 19 for the water. For generating propulsion, according to FIG. 3 water is sucked to the underwater surface 16 of the surfboard 1 and is accelerated by means of a propeller 21 and is ejected from the nozzle 13. Depending on which position the nozzle 13 has been pivoted to, the surfboard 1 can negotiate a right-hand or a left-hand bend.

(9) FIG. 3 shows the tail 4 of the surfboard 1 in FIGS. 1 and 2 in a sectional view. During operation, water is sucked in through the inlet 19 on the underwater surface 16, is accelerated by the propeller 21 provided in a water channel between the inlet 19 and the nozzle 13 and is pushed out of the nozzle 13. The propulsion of the surfboard 1 consists of the repulsion generated as a result of the ejection. The nozzle 13 is mounted to be pivotable about the axis of rotation D on the tail 14 of the surfboard 1 and terminates the water channel on the tail side. On the water side of the nozzle 13, a fin 23 is fixed to the nozzle 13. The fin 23 can be pivoted with the nozzle 13. The fin 23 is on the one hand screwed onto the axis of rotation D of the nozzle 13 by means of a nylon screw 22a, and on the other hand it is screwed to a water side of the nozzle 13 at a further point using a further nylon screw 22b. The axis of rotation D is perpendicularly oriented to the standing surface 2.

(10) The fin 23 carries out the pivoting movement of the nozzle 13 about the same axis of rotation D as the nozzle 13. The nozzle 13 has a rear control surface 23a provided behind the axis of rotation D in the direction of movement of the surfboard 1 and a front control surface 23b provided in front of the axis of rotation D in the direction of movement. The two control surfaces 23a, 23b form the entire control surface of the fin 23. When the fin 23 is positioned at an angle in the water whilst cornering, a force is thus applied both onto the rear 23a and the front 23b control surfaces, and the torques on the axis of rotation D that form as a result substantially completely cancel each other out. As a result, the servo motor 12 carrying out the pivoting movement needs to exert less force in order to carry out the pivoting movement.

(11) The fin 23 allows controlled cornering, even if the jet drive does not generate any propulsion, i.e. if no water is sprayed out of the nozzle 13.

(12) According to FIG. 2, the fin 23 is supported by two further fins 24a, 24b which additionally stabilise the movement of the surfboard 1 and, due to their outwardly bent shape, generate additional propulsion.

LIST OF REFERENCE NUMERALS

(13) 1 Surfboard 2 Standing surface 3 Nose 4 Eyelet 6 Leash 7 Controller 8 Drive 9 Foot strap 11 Gyro sensor 12 Pivoting unit servomotor 13 Nozzle 14 Tail 16 Underwater surface 17 Arm of the pivoting unit 18 Actuating rod of the pivoting unit 19 Inlet 21 Propeller 22a Nylon screw 22b Further nylon screw 23 Fin 23a Rear control surface 23b Front control surface 24a Further fin 24b Further fin L Longitudinal direction D Rotary axis