Questo è il testo di un brevetto depositato negli States:
A sailing craft has a rigid sail assembly mounted for free rotation about an upright axis and a tail vane rotatably carried on the assembly for adjusting the incidence of upright aerofoil elements to the apparent wind. A counterweight for mass balancing the assembly is arranged above the bottom of the assembly so as to balance, with respect to the main upright pivot axis, the products of inertia about each of the two orthogonal axes which are orthogonal to the main axes. In the preferred form, a triplane arrangement is used for the aerofoil elements with the centre element forward of the outer elements. Use is made of aerofoil sections of larger leading edge radius than normal. A control system for the tail vane has two control levers, for use respectively on port and starboard tacks, which are interconnected to move in opposite senses so as to give a simple control connection. A governor is provided for limiting the maximum tail vane movement in accordance with wind strength.
Questa foto non centra nulla ma è divertente ..... guarda il timoniere ......
Del triplano che dicevi non ho trovato nulla ma era roba anni 60/70
Ciao
Francesco