Seat assembly with adjustable height

1. A seat assembly comprising:

a seat bottom having a seat frame;

an air bladder mounted to the frame;

a seat cushion spaced vertically from the seat frame by the air bladder at height-adjustment distance being variable, the cushion defining a seating surface; and

a seat back pivotally attached to the seat bottom;

wherein a height-adjustment distance between the frame and the seating surface is increased as the air bladder is inflated, thereby adjusting a height of the seating surface without adjusting the frame, and

wherein the seat back is moved with the cushion by the height-adjustment distance when the air bladder is inflated.

2. The seat assembly of claim 1 further comprising a rigid reaction plate positioned between the air bladder and the seat cushion, wherein the reaction plate is displaced the height-adjustment distance as the air bladder is inflated.

3. The seat assembly of claim 2 wherein the reaction plate extends a length distance being generally equal to a length of the cushion.

4. The seat assembly of claim 3 wherein the air bladder extends the length distance.

5. The seat assembly of claim 2 wherein the reaction plate integrally formed along a lower surface of the cushion.

6. The seat assembly of claim 2 wherein the reaction plate is welded to a top surface of the air bladder.

7. The seat assembly of claim 1 wherein the cushion is moved away from the frame by the height-adjustment distance along a length of the cushion extending from a forward edge to a rearward edge.

8. The seat assembly of claim 6 wherein the air bladder has a wedge shape such that a first portion of the bladder adjacent the rearward edge of the cushion inflates the height-adjustment distance and a second portion of the bladder inflates a second distance being less than the height-adjustment distance.

9. The seat assembly of claim 1 wherein the height-adjustment distance varies by at least twenty millimeters.

10. The seat assembly of claim 1 wherein the height-adjustment distance extends in the range of twenty-five to fitly millimeters.

11. The seat assembly of claim 1 wherein the air bladder comprises a multi-stage bladder having multiple chambers in fluid communication for varying the height-adjustment distance.

12. A seat assembly comprising:

a seat frame;

an air bladder mounted to the frame along a lower surface;

a seat cushion assembly having a central cushion positioned between at least two bolster cushions defining a seating surface, wherein the cushion assembly is positioned on the air bladder along a lower reaction surface being generally rigid,

wherein an adjustment distance between the frame and reaction surface is increased as the air bladder is inflated, thereby adjusting the position of the seating surface without adjusting the frame.

13. The seat assembly of claim 12 further comprising:

a compressor in fluid communication with the air bladder; and

a controller in electrical communication with the compressor and programmed to inflate and deflate the air bladder based on a signal to change the position of the seating surface.

14. The seat assembly of claim 12 wherein the seat frame includes a seat bottom.

15. The seat assembly of claim 12 wherein the seat frame includes a seat back.

16. The seat assembly of claim 12 further comprising a seat bottom and a seat back attached to the seat bottom, wherein the cushion assembly is provided along one of the seat bottom or the seat back, and the other of the seat back or seat bottom is moved with the seat cushion assembly when the air bladder is inflated.

17. A seat assembly comprising:

a seat frame defining a seat bottom and a seat back extending from the seat bottom;

an air bladder mounted to the frame;

a seat cushion assembly provided along one of the seat bottom or the seat back and spaced from the seat frame by the air bladder at an adjustment distance being variable, the cushion assembly defining a seating surface; and

wherein an adjustment distance between the frame and the seating surface is increased as the air bladder is inflated, thereby adjusting the adjustment distance of the seating surface without adjusting the frame, and

wherein the other of the seat back or seat bottom is moved with the cushion assembly by the adjustment distance when the air bladder is inflated.

18. The seat assembly of claim 17 further comprising a rigid reaction plate positioned between the air bladder and the cushion assembly, wherein the reaction plate is displaced by the adjustment distance as the air bladder is inflated.

19. The seat assembly of claim 17 wherein the air bladder comprises a multi-stage bladder having multiple chambers in fluid communication for varying the adjustment di stance.

20. The seat assembly of claim 17 wherein the adjustment distance comprises one of a height-adjustment distance of the seat bottom in an upright direction or a fore-aft adjustment distance of the seat back in the fore-aft direction.