US Patent 7779580 Guiding device for masts which telescopes within each other

A device fixed to a first mast cooperates with a contact area located on the outside face of a second mast sliding substantially coaxially in the first mast. The device includes guide units including a roller mounted free to rotate about an axis orthogonal to the axis of the masts, a pad with a bearing face, and a device for displacing the axis of the roller perpendicular to the contact area of the mast, as a function of forces applied by the mast on the roller. The bearing area of the unit on the mast is thus formed by the roller only, or the roller and the pad.