Patent ID: 7146921
Filing Date: 2006-12-12
Classification: B63H

Abstract:
1. A retractable thruster for a vessel having a hull, the thruster comprising: a propulsion assembly having a propeller and a rigid structure secured to a cylindrical turbine; a plate for closing the hull, said plate being disposed beneath said turbine and secured thereto; and displacement means to move said propulsion assembly between a retracted position in which it is at rest inside the hull and a deployed position in which the propeller is immersed beneath the hull; wherein said displacement means enable uniform circular movement of said propulsion assembly between said retracted and deployed positions about an axis of rotation that is not physically embodied in the hull and situated substantially no higher than the level of said hull; wherein said displacement means include first and second guide elements suitable for co-operating with said propulsion assembly to enable said propulsion assembly to be moved between said retracted and deployed positions by said propulsion assembly about said axis of rotation situated substantially no higher than said hull, said uniform circular movement being determined by the shape of said guide elements; wherein said first guide element is secured to said propulsion assembly for describing the same uniform circular movement as said propulsion assembly and suitable for co-operating with said second guide element; wherein said second guide element is stationary and secured to said hull; and wherein said uniform circular movement is defined by the shape of said first and second guide elements, said first and second guide elements co-operating by displacement of said first guide element relative to said second guide element to enable said propulsion assembly to be moved between said retracted and deployed positions.