Patent ID: 8075051

Claim:
An active headrest device for a vehicle comprising: a headrest portion ( 2 ) rotatably mounted, through rotation means ( 3 ), to a support member ( 4 ) in order to allow the headrest portion ( 2 ) to swing between an extreme front position and an extreme back position in respect to the vehicle; pushing means ( 5 ) engaged by first elastic means ( 6 ) which may be blocked or released by a swinging blocking arm ( 7 ) connected to an inertial mass ( 8 ); wherein in an active condition (A), the blocking arm ( 7 ) blocks the pushing means ( 5 ) in a retracted condition allowing the headrest portion ( 2 ) to swing between the extreme front position and the extreme back position, and in which the first elastic means ( 6 ) transmits to the pushing means ( 5 ) an elastic force directed in the direction of the extreme front position of the headrest portion ( 2 ), the inertial mass ( 8 ), when subjected to a stress larger than a predefined threshold in a front or back direction, causing a rotation of the blocking arm ( 7 ) which releases the pushing means ( 5 ) which, as a result of the elastic force of the first elastic means ( 6 ), rotates and/or stops the headrest portion ( 2 ) in the extreme front position; the headrest portion ( 2 ) being shaped in section substantially as an upside down “U” and containing in an inner cavity an upper portion of the support member ( 4 ), the pushing means ( 5 ), the first elastic means ( 6 ), the blocking arm ( 7 ) and the inertial mass ( 8 ); a lower portion of the support member ( 4 ) being mountable to a seat back; and, wherein the rotating means ( 3 ) has housing means ( 9 ) fixed in an upper part of the inner cavity of the headrest portion ( 2 ), an upper end portion ( 10 ) of the support member ( 4 ) being engaged in a rotating manner in said housing means ( 9 ); the rotating means ( 3 ) having adjustable friction means ( 11 ) fixed in the inner cavity of the headrest portion ( 2 ), for adjustably braking the rotation of the upper end portion ( 10 ).