Method of manufacturing a seat back cushion assembly

1. A method of manufacturing a seat cushion for a vehicle seat assembly, the seat cushion having side edges and top and bottom edges, the method comprising:

providing an outer material to define a surface that faces a seat occupant;

sewing a backing material to the outer material using a linear first longitudinally oriented sewing line;

placing a first wadding material adjacent to the linear first longitudinally oriented sewing line in a centrally located region of the backing material;

sewing the backing material to the outer material using a linear second longitudinally oriented sewing line so that the first wadding material is secured between the linear first and second sewing lines, the first and second linear longitudinally oriented sewing lines defining therebetween a central region;

making a tiered sewing line confined to the central region between the linear first and second sewing lines, the tiered sewing line running between the top and bottom edges;

disposing a second wadding material between the outer and backing materials and between the linear first sewing line and an edge of the seat cushion;

disposing a third wadding material between the outer and backing materials and between the linear second sewing line and an opposite edge of the seat cushion;

sewing along the side, top and bottom edges of the seat cushion to further secure the first and second wadding material;

making a plurality of laterally oriented sewing lines between the side edges of the seat back cushion; and

sewing the outer and backing materials together using additional sewing lines respectively disposed proximate the top and bottom edges of the seat cushion.

2. The method of claim 1 , wherein the laterally oriented sewing lines in the central region are generally perpendicular to the linear first and second sewing lines.

3. The method of claim 1 , wherein the outer material includes leather and the backing material includes a woven tulle.

4. The method of claim 1 , wherein the outer and backing materials have generally parallel longitudinal perimeters joined by generally parallel top and bottom edges that are joined by rounded corners.

5. The method of claim 1 , wherein the first, second and third wadding material include a foam having constituents selected from the group consisting of a urethane material, a bio-based material and mixtures thereof.

6. The method of claim 1 , wherein the first, second and third wadding material include foam having a thickness in an un-deflected state of about 15 mm and a density of about 33 Kg/cubic meter.

7. The method of claim 1 , wherein the tiered sewing lines include a lateral segment and a longitudinal segment.

8. The method of claim 7 , wherein a lateral segment has a left end and a right end, and a longitudinal segment has a top end and a bottom end.

9. The method of claim 8 , wherein the right end of a lateral segment is connected to the top end of a longitudinal segment and the bottom end of a longitudinal segment is connected to a right end of a next segment.

10. The method of claim 1 , wherein the plurality of laterally oriented sewing lines includes a left stitch segment that runs across a left portion of the outer material, a middle segment that runs across the central region of the outer material and a right stitch segment that runs across a right portion of the outer material.

11. The method of claim 10 , wherein left and right stitch segments are inclined in relation to middle segments.

12. The method of claim 1 , further including a step of applying a glazing on an underside of the outer material.