Headrest for Protecting Against Whiplash

• US 20100072795A1
• Filed: 05/24/2006
• Published: 03/25/2010
• Est. Priority Date: 06/23/2005
• Status: Active Grant

• Current Assignee: Volkswagen AG
• Original Assignee: Volkswagen AG
• Inventors: Rademacher, Horst, Pfortner, -Ing Dirk, Luhring, Ralf, Schmuda Von Trzebiatowski, Peter, Helm, Manfred, Meixner, Armin, Hoffmeister, Andreas
• Granted Patent: US 7,926,871 B2
• Time in Patent Office: Days
• US Class Current: 297/216.120
• CPC Class Codes: B60N 2/80 Head-rests
• CPC Class Codes: B60N 2/888 with arrangements for protecting against abnormal g-forces, e.g. by displacement of the head-rest

Abstract

The invention relates to a headrest (10) for a vehicle seat, in particular for a backrest for a motor vehicle seat, said headrest essentially comprising a headrest frame or headrest casing (14) and a foam base body (356) that surrounds the headrest frame or casing (14). In the event of a rear impact on the motor vehicle, the headrest remains fixed in relation to the backrest (conventional headrest) or at least part of the headrest is immediately displaced towards the vehicle occupant (active headrest). According to the invention, the head of a vehicle occupant can be brought into contact with the headrest (10) at least at two different heights (k1_z, k2_z), (two-point contact), to reduce or neutralize a torque (M_y) about a y-axis (y-y) in the vicinity of the vertebral column and to prevent accident-related injuries to the seat occupant, in particular to prevent cervical spine syndrome or a whiplash injury in the event of a front and/or rear impact. A head centre of gravity (HCG) is also configured between the two heights (k1_z, k2_z) of the headrest (10).

Claims

1. Headrest (10) for a vehicle seat, in particular for a backrest of an automobile seat, which comprises a headrest frame/headrest box (14) and a foam base body (36) surrounding the headrest frame/headrest box (14), wherein in the event of a rear impact on the automobile, the headrest is stationary relative to the backrest (conventional headrest) or at least a portion of the headrest is movable immediately towards the vehicle occupant (active headrest), characterized in that for reducing or neutralizing a torque (M_y) about a y-axis (y-y) in the region of the cervical spine and for preventing injuries caused by an accident of a seat occupant, in particular for preventing cervical spine syndrome and/or whiplash at the moment of a frontal and/or rear end impact, the head of a vehicle occupant can be moved into contact with the headrest (10) at least two different heights (k1_z, k2_z) of the headrest (10) (two-point support) so as to form a head center of gravity (HCG) between these heights (k1_z, k2_z) of the headrest (10).

2. Headrest according to claim 1, characterized in that contact with the headrests (10) in the at least two different heights (k1_z, k2_z) occurs across an area, along a line or at a point.

3. Headrest according to claim 1, characterized in that for guiding the head and for reducing or neutralizing a torque (M_y) about a y-axis (y-y) in the region of the cervical spine and for preventing injuries caused by an accident of a seat occupant, in particular for preventing cervical spine syndrome and/or whiplash at the moment of a frontal and/or rear end impact, the foam base body (36) of the headrest (10) is made, at least in a front section (24) of the foam base body (36) and therefore on a contact surface (38), which stabilizes the head (100, 100′

) in the event of a crash, of a first foam (16) disposed essentially in an upper region (20) of the headrest (10) and a second foam (18) disposed essentially in an lower region (20) of the headrest (10), wherein the foams have different dynamic characteristics.

4. Headrest according to claim 3, characterized in that the foams (16, 18) have different densities and/or firmness and/or viscosities and therefore different dynamic characteristics.

5. Headrest according to claim 4, characterized in that the first foam (16) has a lower viscosity than the second foam (18) and a lesser firmness.

6. Headrest according to claim 5, characterized in that the second foam (18) is a viscoelastic foam with a velocity-dependent spring characteristic and a constant spring constant (c).

7. Headrest according to claim 6, characterized in that the second foam (18) (viscoelastic foam) provides greater damping of the head (100′

) on the headrest (10) at higher velocity due to the velocity-dependent spring characteristic.

8. Headrest according to claim 1, characterized in that for guiding the head and for reducing or neutralizing a torque (M_y) about a y-axis (y-y) in the region of the cervical spine and for preventing injuries caused by an accident of a seat occupant, in particular for preventing cervical spine syndrome and/or whiplash at the moment of a frontal and/or rear end impact, a crash beam (26, 28, 30, 32, 34) is arranged in or on the headrest frame/headrest box (14) of the headrest (10) substantially in a lower region (22) of the headrest (10) in the interior of the foam base body (36) near a contact surface (38) which stabilizes the head (100, 100′

) in the event of a crash.

9. Headrest according to claim 8, characterized in that the crash beam is a wire or a wire mesh (26), a metal plate (28), a profile (30) or a plastic body (32), or a foam body (34), or the like.

10. Headrest according to claim 6, characterized in that the crash beam is integrated in the headrest frame/headrest box (14) (one-piece), or is connectable with the headrest frame/headrest box (14) (two-piece).

11. Headrest according to claim 6, characterized in that the crash beam is configured as a foam body (34) inside the headrest frame/headrest box (14), wherein the crash beam and the foam base body have different densities and/or firmness and/or viscosities and therefore different dynamic characteristics.

14. Headrest according to claim 1, characterized in that the head is guided and a torque (M_y) about a y-axis (y-y) in the region of the cervical spine is thereby reduced or neutralized so as to prevent injuries of a seat occupant caused by the rear end impact, in particular with respect to a cervical spine syndrome and/or whiplash of the vehicle occupant, by applying during the head (100, 100′

) movement in an x-z plane a force pair (F1_kx, F1_kz) and (F2_kx, F2_kz) with corresponding lever arms (k_1z, k_1x) and (k_2z, k_2x), respectively, from the head center of gravity (HCG) of the headrest (10) in opposition to the inertia forces (F_gz) and (F_gx).

12. Headrest (10) for a vehicle seat, in particular for a back rest of an automobile seat, which includes essentially a headrest frame (14) and a foam body surrounding the headrest frame (14), wherein in the event of a rear end impact on the automobile, the headrest is stationary relative to the backrest (conventional headrest) or at least a portion of the headrest is movable immediately towards the vehicle occupants (active headrest), characterized in that for guiding the head and for reducing or neutralizing a torque (M_y) about a y-axis (y-y) in the region of the cervical spine and for preventing injuries caused by an accident of a seat occupant, in particular for preventing cervical spine syndrome and/or whiplash at the moment of a frontal and/or rear end impact, the headrest (10) is implemented such that the foam base body (36) of the headrest (10) is made, at least in a front section (24) of the foam base hod (36) and therefore on a contact surface (38), which stabilizes the head (100, 100′

) in the event of a crash, of a first foam (16) disposed essentially in an upper region (20) of the headrest (10) and a second foam (18) disposed essentially in an lower region (20) of the headrest (10), wherein the foams have different dynamic characteristics and a crash beam (26, 28, 30, 32, 34) is arranged in or on the headrest frame/headrest box (14) of the headrest (10) substantially in a lower region (22) of the headrest (10) in the interior of the foam base body (36) near a contact surface (38) which stabilizes the head (100, 100′

) in the event of a crash.

13. Headrest according to claim 12, characterized in that contact with the headrests (10) in the at least two different heights (k1_z, k2_z) occurs across an area, along a line or at a point and the crash beam is a wire or a wire mesh (26), a metal plate (28), a profile (30) or a plastic body (32), or a foam body (34), or the like.