Forecarriage of a rolling motor vehicle

A forecarriage of a rolling motor vehicle with three or four wheels, comprising:

• a forecarriage frame,
• at least one pair of front wheels kinematically connected one to each other and to the forecarriage frame by means of a kinematic rolling mechanism which enables the front wheels to roll in a synchronous and specular manner, each wheel being connected to said kinematic rolling mechanism by means of a respective axle journal, said axle journal being mechanically connected to a rotation pin of a respective wheel in order to rotatably support said respective wheel around an rotation axis,
• a roll block system,
• suspension means which provide each axle journal at least one spring suspension movement with respect to said kinematic rolling mechanism,
• a steering device suitable to command the rotation of the axle journals about respective steering axes of each front wheel,
• wherein said roll block system comprises a length extensible rod which directly connects one of said two front wheels in correspondence of the respective axle journal to said forecarriage frame by means of hinging means at both ends of said length extensible rod, said forecarriage frame being suitable to follow the axle journal in rolling movements which are allowed by said kinematic rolling mechanism, said length extensible rod being suitable to passively follow the movements of said axle journal and of said forecarriage frame by varying its orientation in space with respect to them, and
• wherein said roll block system comprises reversible blocking means which is suitable to reversibly block the lying position of said extensible rod on a rolling plane, with respect to said axle journal and/or with respect to said forecarriage frame, so as to be suitable to block the rolling movements allowed by said kinematic rolling mechanism, said lying position being defined by the angle formed by the projection of the rod on a vertical projection plane with a reference plane orthogonal to the rotation axis of the wheel associated to said axle journal, wherein said vertical projection plane is transverse to a centreline plane.