BACKGROUND OF THE INVENTION

The present invention relates generally to a seat, in particular to a vehicle seat, and, more particularly, to a tilting system for tilting a seat.

A vehicle seat usually is adjustable to adapt the position and/or ergonomic configuration of the seat to the needs of an occupant of the seat.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an improved system for adapting the position of a seat in order to enhance the comfort of the seat.

According to the invention, the object is solved by a seat tilting system for tilting a seat according to claim 1 . Furthermore, the object is solved by a vehicle seat according to claim 13 comprising such a seat tilting system.

The seat tilting system comprises a seat platform to support and mount the seat, a base platform defining a reference plane, a connecting member mounted rigidly on the base platform, a swivel, e.g. a ball joint or swivel joint, coupling the connecting member to the seat platform, and a plurality of linear actuators coupling the seat platform to the base platform or to the connecting member, respectively. The linear actuators are arranged to tilt the seat platform relative to the base platform and to rotate the seat platform around a perpendicular to the reference plane. In particular, the linear actuators are unlocked at once allowing the seat to pivot on a single center swivel, e.g. a center ball joint, near a center of the seat platform. The seat is mounted on the base platform where the swivel is near the center of the seat platform in particular behind a so-called H-point or hip point of an occupant to allow the occupant to shift his/her weight more easily with a manual system. If the swivel is too far forward, it may give the occupant more of a feeling that he/she will fall back and it would require more spring force to balance the system.

In an exemplary embodiment, there are three linear actuators mounted close to vertical with respective joints, e.g. ball joints, at each end. This almost removes all freeplay but the seat can still swivel (yaw) slightly so for example a fourth linear actuator is added that is mounted almost

horizontally to remove all freeplay. The seat can be locked in any desired position given the travel limits set by the linear actuators so it is infinitely adjustable in all rotational degrees of freedom in any combination.

Alternatively or additionally, the linear actuators are arranged and configured to adjust the seat platform in any combination of a few numbers of degrees of freedom, e.g. of six degrees of freedom, including yaw, pitch and roll, e.g. around a longitudinal axis of the seat platform. In other words: The seat platform turns around its longitudinal axis (roll), rolls backward or forward (pitch) and swings to the side (yaw) by controlling and actuating of the linear actuators respectively.

The seat tilting system according to the invention makes the orientation of a seat adjustable in order to make the seat more comfortable for an occupant of the seat. In particular, the seat tilting system is configured to adjust the seat platform in any combination of a few numbers of degrees of freedom, e.g. of six degrees of freedom including yaw, pitch and roll. In particular the seat tilting system allows to adapt the orientation of a vehicle seat of a vehicle to driving maneuvers of the vehicle such as quick turns of the vehicle, for instance to center an occupant in the seat. In addition the seat tilting system may be used for easier ingress to or egress from the vehicle, and allows an occupant to get to a comfortable position to relax. To this end the seat tilting system comprises a plurality of linear actuators to tilt and rotate the seat platform relative to the base platform.

In an exemplary embodiment, each linear actuator is coupled by a first joint, e.g. a ball joint or swivel joint, to the seat platform and by a second joint, e.g. a ball joint or swivel joint, to the base platform or to the connecting member.

In particular, each linear actuator is telescopic between a first length and a second length.

In another exemplary embodiment, each linear actuator is lockable in any state in which it has a length between the first length and the second length.

Furthermore, at least one linear actuator may be configured as an

adjustable manual locking mechanism or a hydraulic damper or a gas damper or a magnet or heological damper.

According to another aspect, at least one linear actuator is spring-loaded.

In an exemplary embodiment, three main linear actuators couple the seat platform to the base platform, respectively, and one supplementary linear actuator couples the seat platform to the connecting member.

Furthermore, a base platform facing end of each main linear actuator may be closer to the connecting member than a seat platform facing end of the respective main linear actuator.

In an exemplary embodiment, the main linear actuators are distributed around the connecting member. According to another aspect, the connecting member has a plurality of travel stops limiting movements of the seat platform relative to the connecting member.

In an exemplary embodiment, each linear actuator is adjustable manually or power-driven.

According to another aspect a vehicle has at least one vehicle seat and a seat tilting system for tilting the at least one vehicle seat.

In an exemplary embodiment, the seat tilting system is configured to adjust the seat platform in any combination of a few numbers of degrees of freedom including yaw, pitch and roll.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only, and thus, are not limitative of the present invention, wherein:

Figure 1 shows a perspective view of a seat and a seat tilting system with the seat in a first position,

Figure 2 shows a side view of the seat and the seat tilting system with the seat in the first position,

Figure 3 shows a front view of the seat and the seat tilting system with the seat in the first position, Figure 4 shows a top view of the seat and the seat tilting system with the seat in the first position,

Figure 5 shows an enlarged detail of figure 2,

Figure 6 shows a perspective view of the seat and the seat tilting system with the seat in a second position,

Figure 7 shows a top view of the seat and the seat tilting system with the seat in the second position,

Figure 8 shows an enlarged detail of figure 6,

Figure 9 shows a perspective view of the seat and the seat tilting system with the seat in a third position,

Figure 10 shows a top view of the seat and the seat tilting system with the seat in the third position,

Figure 1 1 shows a perspective view of the seat and the seat tilting system with the seat in a fourth position,

Figure 12 shows a side view of the seat and the seat tilting system with the seat in the fourth position,

Figure 13 shows an enlarged detail of figure 1 1 ,

Figure 14 shows a perspective view of the seat and the seat tilting system with the seat in a fifth position,

Figure 15 shows a side view of the seat and the seat tilting system with the seat in the fifth position,

Figure 16 shows a perspective view of the seat and the seat tilting system with the seat in a sixth position,

Figure 17 shows a front view of the seat and the seat tilting system with the seat in the sixth position,

Figure 18 shows an enlarged detail of figure 16,

Figure 19 shows a perspective view of the seat and the seat tilting system with the seat in a seventh position,

Figure 20 shows a front view of the seat and the seat tilting system with the seat in the seventh position, Figure 21 a sectional view of a vehicle having a vehicle seat and a seat tilting system.

Corresponding parts are marked with the same reference symbols in all figures.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Figures 1 to 5 show a seat 1 and a seat tilting system 3 with the seat 1 in a first position which is a standard position. Figure 1 shows a perspective view, figure 2 shows a side view, figure 3 shows a front view, figure 4 shows a top view, and figure 5 shows an enlarged detail of figure 2.

In particular, the seat 1 may be a vehicle seat of a vehicle 25, see figure 21 .

The seat tilting system 3 comprises a seat platform 5 to support and mount the seat 1 , a base platform 7, a connecting member 9 connecting the base platform 7 and the seat platform 5, and a number of linear actuators, in particular four linear actuators 10 to 13.

The base platform 7 defines a reference plane RP which is parallel to an XY-plane of a Cartesian coordinate system with coordinates X, Y, Z, the X- axis running from a rear side to a front side of the seat 1 .

The connecting member 9 is mounted rigidly on the base platform 7. In an exemplary embodiment the connecting member 9 may have a substantially rod-like design or tube-like design. A swivel, e.g. a ball joint 15 or a swivel joint, couples the connecting member 9 to the seat platform 5. The ball joint 15 is arranged near a center of the seat platform 5.

A plurality of linear actuators 10 to 13 couples the seat platform 5 to the base platform 7 or to the connecting member 9, respectively, wherein the linear actuators 10 to 13 are arranged to tilt the seat platform 5 relative to the base platform 7 and to rotate the seat platform 5 around a perpendicular to the reference plane RP.

In particular, when the linear actuators 10 to 13 have been unlocked the seat 1 is pivotably on a single center swivel, e.g. the center ball joint 15 near the center of the seat platform 5.

In particular, the linear actuators 10 to 13 are arranged and configured to adjust the seat platform 5 in any combination of a few numbers of degrees of freedom including yaw YW, pitch P and roll R, e.g. around a longitudinal axis L of the seat platform 5 and/or the seat 1 .

Each linear actuator 10 to 13 is an actuator that creates motion in a straight line, e.g. each linear actuator 10 to 13 comprises a lead screw which rotates while a lead nut and a tube is linearly movable.

Three main linear actuators 10 to 12 couple the seat platform 5 to the base platform 7, respectively. The main linear actuators 10 to 12 are distributed around the connecting member 9, with one front-sided main linear actuator 10 and two rear-sided main linear actuators 1 1 , 12. Each main linear actuator 10 to 12 is angled relative to the connecting member 9. In particular, a base platfornn facing end of the main linear actuator 10 to 12 is closer to the connecting member 9 than a seat platform facing end of the main linear actuator 10 to 12.

Each main linear actuator 10 to 12 is coupled by a respective first joint, e.g. a ball joint 16 or swivel joint, to the seat platform 5 and by a respective second joint, e.g. a ball joint 17 or swivel joint, to the base platform 7.

One supplementary linear actuator 13 couples the seat platform 5 to the connecting member 9. The supplementary linear actuator 13 is coupled by a respective first joint, e.g. a ball joint 18 or a swivel joint, to the seat platform 5 and by a respective second joint, e.g. a ball joint 19 or a swivel joint, to the connecting member 9.

The connecting member 9 has at least two travel stops 21 limiting

movements of the seat platform 5 relative to the connecting member 9. The travel stops 21 are arranged on opposite sides of a longitudinal axis (L) of the connecting member 9 along a line parallel to the Y-axis.

Each linear actuator 10 to 13 is telescopic between a first length and a second length. Furthermore, each linear actuator 10 to 13 is lockable in any state in which it has a length between the first length and the second length. Hence, by the linear actuators 10 to 13 the seat platform 5 is tiltable relative to the reference plane RP in any direction, and rotatable around a

perpendicular to the reference plane parallel to the Z-axis, see figures 6 to 20.

The seat platform 5 can be locked in any state that can be reached by tilting and/or rotating the seat platform 5 using the linear actuators 10 to 13. The front-sided main linear actuator 10 optionally is spring-loaded by a spring 23 to assist in bringing the seat 1 from a reclined position shown in figures 1 1 and 12 to the first position shown in figures 1 to 5. The spring 23 may be an extension spring or a compression spring. In particular, the linear actuator 10 in front can be spring-loaded so that an occupant can more easily bring the seat 1 from a full recline position shown in figures 1 1 and 12 to the first or design position shown in figures 1 to 5.

Each linear actuator 10 to 13 may be an adjustable manual locking mechanism or a lockable hydraulic damper or a lockable gas damper or a magnetorheological damper that e.g. can be locked by energizing an electromagnet.

The linear actuators 10 to 13 may be adjustable manually. The manual controls may be a button or lever that releases all linear actuators 10 to 13 at once using cables or mechatronics.

Alternatively the linear actuators 10 to 13 may be adjustable power-driven via a power controller. In this case the power controls may be a six-way switch, such as a joy stick or a space ball or the like, to adjust the seat 1 . Alternatively, especially when the seat 1 is a vehicle seat, the power controls could be set to an automated function to adjust the seat 1 automatically, for instance in order to keep an occupant of the seat 1 centered in the seat 1 while the vehicle 25 moves. In particular, the linear actuators 10 to 13 could be powered with a control unit that allows them to work together and shift the seat 1 to any desired position. The manual operating unit could be a button or lever on/at the seat 1 . The manual operating unit releases all linear actuators 10 to 13 at once via cables, data buses and/or mechatronics. The power control/s of the linear actuators 10 to 13 could be a unique multi-way, e.g. 3- or 6-way switch, e.g. a joy stick, space ball, mouse. Figures 6 to 8 show the seat 1 and the seat tilting system 3 in a second position in which the seat 1 and the seat platform 5 have been rotated around a perpendicular to the reference plane RP in a negative direction of rotation relative to the first position shown in figures 1 to 5. This might be called a right yaw of the seat 1 . Figure 6 shows a perspective view, figure 7 shows a top view, and figure 8 shows an enlarged detail of figure 6.

Figures 9 and 10 show the seat 1 and the seat tilting system 3 in a third position in which the seat 1 and the seat platform 5 have been rotated around a perpendicular to the reference plane RP in a positive direction of rotation relative to the first position shown in figures 1 to 5. This might be called a left yaw of the seat 1 . Figure 9 shows a perspective view and figure 10 shows a top view.

Figures 11 to 13 show the seat 1 and the seat tilting system 3 in a fourth position in which the seat 1 and the seat platform 5 have been tilted rearwardly around an axis parallel to the Y-axis relative to the first position shown in figures 1 to 5. This might be called a rearward pitch of the seat 1 . Figure 1 1 shows a perspective view, figure 12 shows a side view, and figure 13 shows an enlarged detail of figure 1 1 .

Figures 14 and 15 show the seat 1 and the seat tilting system 3 in a fifth position in which the seat 1 and the seat platform 5 have been tilted forwardly around an axis parallel to the Y-axis relative to the first position shown in figures 1 to 5. This might be called a forward pitch of the seat 1 . Figure 14 shows a perspective view, and figure 15 shows a side view.

Figures 16 to 18 show the seat 1 and the seat tilting system 3 in a sixth position in which the seat 1 and the seat platform 5 have been tilted to the left in a front perspective around an axis parallel to the X-axis relative to the first position shown in figures 1 to 5. This might be called a left roll of the seat 1 . Figure 16 shows a perspective view, figure 17 shows a front view, and figure 18 shows an enlarged detail of figure 16.

Figures 19 and 20 show the seat 1 and the seat tilting system 3 in a seventh position in which the seat 1 and the seat platform 5 have been tilted to the right in a front perspective around an axis parallel to the X-axis relative to the first position shown in figures 1 to 5. This might be called a right roll of the seat 1 . Figure 19 shows a perspective view, and figure 20 shows a front view.

Figure 21 shows schematically a sectional view of a vehicle 25 having a vehicle seat 1 and a seat tilting system 3 as shown in figures 1 to 20. The base platform 7 is mounted onto a vehicle floor 27 of the vehicle 25.

List of References

1 seat

3 seat tilting system

5 seat platform

7 base platform

9 connecting member

10 to 13 linear actuator

15 to 19 joint

21 travel stop

23 spring

25 vehicle

27 vehicle floor

L longitudinal axis

P pitch

R roll

RP reference plane

X, Y, Z Cartesian coordinate

YW yaw