U.S. Patent Specifications

In combination, a driving shaft subject to variable torques about its axis, a propeller mounted on said shaft and subject to variable reaction torques about the axis of said shaft and also subject to variable axial thrusts and pulls, means on said shaft comprising a pair of annular faces which extend circumferentially about the axis of said shaft, said propeller being provided with a pair of complemental annular faces substantially axially spaced with respect to the first‐mentioned faces and symmetrically arranged with respect to the axis of said shaft, annular bodies of resilient distortable material interposed between said co‐operating faces, said bodies being of sufficient thickness to allow a substantial tilting of said propeller, said distortable material being in distorted condition and bonded to said faces whereby to establish a driving connexion between said shaft and propeller and forming the sole means inter‐connecting said propeller with said shaft, said bodies of distortable material being generally symmetrically arranged axially with respect to the centre of mass of said propeller whereby said propeller will be capable of limited, resiliently resisted, oscillatory movement about its centre of mass both circumferentially and axially with respect to said shaft.