Steering and control fin for surfboard underside - has sector shape pivoted by lever and holding ratchet mechanism which can be built within board

摘要

The surfboard has a swivelling fin on its underside. This fin can be retracted and it is loaded with a spring holding the fin in an extended position. Ratchet elements are provided for keeping this fin in different tilted positions. The fin is rapidly adjusted for example for varying the course or the speed. On the upper side of the board (1) is arranged the mechanism for arbitrary retraction of the fin (2). This mechanism can be built within the board. The fin (2) is an obtuse angled sector and it is pivoted in the slot (5) which passes through the board. The wall of the slot (5) facing the curved part of passes through the board. The wall of the slot (5) facing the curved part of the fin is also accordingly curved. A lever (6) is connected between the fin top and an actuating arrangement connected to the ratchet mechanism.