Vehicle seat assembly including head restraint that folds and unfolds with seat back

1. A seat assembly comprising:

a seat bottom;

a seat back connected to the seat bottom and configured to pivot relative to the seat bottom between an unfolded position and a folded position;

a head restraint connected to the seat back and configured to pivot relative to the seat back between an unfolded position and a folded position, wherein the head restraint is configured to automatically pivot from its folded position to its unfolded position when the seat back pivots from its folded position to its unfolded position, and the head restraint is configured to automatically pivot from its unfolded position to its folded position when the seat back pivots from its unfolded position to its folded position;

a cable having a first end connected to the seat back and a second end connected to the head restraint, wherein the cable pivots the head restraint from its unfolded position to its folded position when the seat back pivots from its unfolded position to its folded position; and

a first spring captured between the head restraint and the seat back and configured to bias the head restraint toward its unfolded position, wherein the cable allows the first spring to pivot the head restraint from its folded position to its unfolded position when the seat back pivots from its folded position to its unfolded position, and the cable prevents the first spring from pivoting the head restraint from its folded position to its unfolded position when the seat back is in its folded position.

2. The seat assembly of claim 1 further comprising:

a seat frame configured to be fixed to a floor of a vehicle;

a mounting bracket fixed to the seat frame; and

an outer sheath disposed around the cable and mounted to the mounting bracket in a manner that allows the cable to translate within the outer sheath.

3. The seat assembly of claim 1 further comprising:

a pair of head restraint rods that extend vertically from an upper end of the seat back, each of the head restraint rods having a lower end connected to the seat back and an upper end opposite of the lower end; and

a pivot rod extending between the upper ends of the head restraint rods and fixed thereto, wherein the head restraint is pivotally mounted to the pivot rod.

4. The seat assembly of claim 3 further comprising:

a mounting bracket projecting radially from the pivot rod; and

an outer sheath disposed around the cable and attached to the mounting bracket in a manner that allows the cable to translate within the outer sheath.

5. The seat assembly of claim 3 wherein the head restraint includes:

a pair of end caps, each of the end caps defining a hole through which the pivot rod extends; and

a first spacer rod extending between the end caps and connecting the end caps to one another.

6. The seat assembly of claim 5 further comprising:

an annular cam mounted on the pivot rod and fixed to the head restraint; and

a lock bracket pivotally mounted on the first spacer rod and defining a slot that captures the second end of the cable, wherein when the cable is tensioned due to the seat back moving from its unfolded position to its folded position, the cable rotates the lock bracket into contact with the annular cam, which causes the head restraint to rotate about the pivot rod in a first direction from its unfolded position to its folded position.

7. The seat assembly of claim 6 further comprising an annular flange fixed to the pivot rod and defining a groove that extends into a perimeter of the annular flange, wherein the lock bracket includes a locking pawl that is configured to engage the groove in the annular flange to lock the head restraint in its unfolded position.

8. The seat assembly of claim 7 further comprising a second spring captured between one of the end caps and the lock bracket and biasing the locking pawl of the locking bracket toward the groove in the annular flange fixed to the pivot rod.

9. The seat assembly of claim 7 wherein when the cable is tensioned due to the seat back moving from its unfolded position to its folded position, the cable rotates the lock bracket and thereby disengages the locking pawl from the groove in the annular flange, which allows the head restraint to rotate about the pivot rod.

10. The seat assembly of claim 9 wherein when slack is provided in the cable due to the seat back moving from its folded position to its unfolded position, the first spring rotates the head restraint in a second direction opposite of the first direction until the locking pawl reengages the groove in the annular flange.

11. The seat assembly of claim 10 further comprising:

a second spacer rod extending between the end caps and connecting the end caps to one another, wherein the second spacer rod is disposed aft of the pivot rod when the head restraint is in its unfolded position; and

a stopper mounted to the second spacer rod and configured to stop rotation of the annular cam in the second direction.

12. The seat assembly of claim 11 further comprising a third spacer rod extending between upper ends of the end caps and connecting the end caps to one another, wherein the first spacer rod is disposed vertically between the third spacer rod and the pivot rod when the head restraint is in its unfolded position.

13. A seat assembly comprising:

a seat bottom;

a seat back connected to the seat bottom and configured to pivot relative to the seat bottom between an unfolded position and a folded position;

a head restraint connected to the seat back and configured to pivot relative to the seat back between an unfolded position and a folded position; and

a pivot mechanism connected to the seat back and the head restraint and configured to pivot the head restraint from its folded position to its unfolded position when the seat back pivots from its folded position to its unfolded position, wherein:

the pivot mechanism includes a cable having a first end connected to the seat back and a second end connected to the head restraint;

when the seat back pivots from its unfolded position to its folded position, the cable rotates the head restraint from its unfolded position to its folded position;

the pivot mechanism further includes a first spring captured between the head restraint and the seat back and configured to bias the head restraint toward its unfolded position;

the cable allows the first spring to pivot the head restraint from its folded position to its unfolded position when the seat back pivots from its folded position to its unfolded position; and

the cable prevents the first spring from pivoting the head restraint from its folded position to its unfolded position when the seat back is in its folded position.

14. The seat assembly of claim 13 wherein:

the seat back includes a pair of head restraint rods and a pivot rod, the head restraint rods extending vertically from an upper end of the seat back, the pivot rod extending between the head restraint rods and fixed thereto, wherein the head restraint is pivotally mounted to the pivot rod;

the head restraint includes a pair of end caps and a first spacer rod, each of the end caps defining a hole through which the pivot rod extends, the first spacer rod extending between the end caps and connecting the end caps to one another; and

the pivot mechanism includes an annular cam and a lock bracket, the annular cam being mounted on the pivot rod and fixed to the one of the end caps, the lock bracket pivotally mounted on the first spacer rod and defining a slot that captures the second end of the cable, wherein when the cable is tensioned due to the seat back moving from its unfolded position to its folded position, the cable rotates the lock bracket into contact with the annular cam, which causes the head restraint to rotate about the pivot rod in a first direction from its unfolded position to its folded position.

15. The seat assembly of claim 14 wherein when slack is provided in the cable due to the seat back moving from its folded position to its unfolded position, the first spring rotates the head restraint in a second direction from its folded position to its unfolded position.