Foam mattress with symmetrical wavy foam layers

• US 10,548,411 B2
• Filed: 06/10/2019
• Issued: 02/04/2020
• Est. Priority Date: 02/28/2013
• Status: Active Grant

• Current Assignee: Zinus Incorporated
• Original Assignee: Zinus Incorporated
• Inventors: Oh, Suk Kan
• Primary Examiner(s): Kurilla, Eric J
• Application Number:
  US16/436,375
• Publication Number:
  US 20190290014A1
• Time in Patent Office: 239 Days
• CPC Class Codes: A47C 27/144 inside the mattress or cushion
• CPC Class Codes: A47C 27/146 on the outside surface of the mattress or cushion
• CPC Class Codes: A47C 27/148 of different resilience
• CPC Class Codes: A47C 27/15 consisting of two or more layers A47C27/16 takes precedence

Abstract

A symmetrical zoned foam mattress includes an upper foam layer with a wavy lower side and a lower foam layer with a wavy upper side. The lower layer has top, middle and bottom lateral valleys. The wavy lower side of the upper layer is glued to the wavy upper side of the lower layer. The top lateral valley has a minimum located within eighteen inches of the top head end of the lower layer. The bottom lateral valley has a minimum located within eighteen inches of the bottom foot end of the lower layer. A center plane intersects the lower foam layer at a minimum of the middle lateral valley. The minimum of each of the top and bottom lateral valleys is about fifteen inches from the end of the mattress regardless of whether the consumer chooses to use the top or bottom end as the head of the mattress.

Claims

1. A method of making a mattress, comprising:

cutting a first slab of foam to form a first top lateral valley, a first top lateral hill and a middle lateral valley of an upper side of a first foam layer;

cutting a second slab of foam to form a second top lateral hill, a second top lateral valley and a middle lateral hill of a lower side of a second foam layer; and

placing the lower side of the second foam layer over the upper side of the first foam layer such that the second top lateral hill fits into and is adjacent to the first top lateral valley, and the middle lateral hill fits into the middle lateral valley, wherein the first top lateral valley has a minimum located between twelve and eighteen inches from a maximum of the first top lateral hill, and wherein the first foam layer together with the second foam layer have a combined thickness that is constant.

2. The method of claim 1, further comprising:

cutting the first foam layer to form a first planar top side that is approximately forty inches from the middle lateral valley.

3. The method of claim 2, further comprising:

cutting the second foam layer to form a second planar top side that is approximately forty inches from the middle lateral hill, wherein the first planar top side and the second planar top side are coplanar after the placing the lower side of the second foam layer over the upper side of the first foam layer.

4. The method of claim 2, further comprising:

cutting the first foam layer to form a first planar bottom side that is approximately forty inches from the middle lateral valley, wherein the upper side from a minimum of the middle lateral valley towards the first planar top side is a mirror image of the upper side from the minimum of the middle lateral valley towards the first planar bottom side.

5. The method of claim 1, wherein the first foam layer has a top, wherein the minimum of the first top lateral valley is located between twelve and eighteen inches from the top of the first foam layer.

6. The method of claim 1, wherein the first foam layer has a center plane, and wherein the center plane intersects the upper side of the first foam layer at a minimum of the middle lateral valley.

7. The method of claim 1, wherein the cutting the first slab forms a top piece and a bottom piece, wherein the first top lateral valley and the first top lateral hill are on the bottom piece, further comprising:

forming the first foam layer by attaching the bottom piece to the top piece at a minimum of the middle lateral valley.

8. The method of claim 7, wherein the top piece has a first bottom lateral valley, and wherein the first top lateral valley and the first bottom lateral valley are disposed symmetrically to a center plane of the first foam layer that intersects the upper side of the first foam layer at the minimum of the middle lateral valley.

9. The method of claim 1, wherein an indentation load deflection (ILD) above the top lateral valley is lower than above other lateral regions immediately adjacent to the top lateral valley after the lower side of the second foam layer is placed over the upper side of the first foam layer.

10. The method of claim 1, wherein the first foam layer is made of high-density polyurethane foam, and wherein the second foam layer is made of memory foam.

11. The method of claim 10, wherein the memory foam of the second foam layer over the top lateral valley of the first foam layer imparts an indentation load deflection (ILD) to the mattress above the top lateral valley that allows a person'"'"'s shoulders to sink into the mattress so as to keep the person'"'"'s spine straight.

12. A method of making a mattress, comprising:

forming a first top lateral valley, a first top lateral hill and a middle lateral valley on an upper side of a first foam layer;

forming a second top lateral hill, a second top lateral valley and a middle lateral hill on a lower side of a second foam layer;

cutting the first foam layer to form a first planar top side that is approximately forty inches from the middle lateral valley;

cutting the second foam layer to form a second planar top side that is approximately forty inches from the middle lateral hill; and

placing the lower side of the second foam layer over the upper side of the first foam layer such that the second top lateral hill fits into and is adjacent to the first top lateral valley, and the middle lateral hill fits into the middle lateral valley, wherein the first planar top side and the second planar top side are coplanar after the placing the lower side of the second foam layer over the upper side of the first foam layer;

wherein the first top lateral valley has a minimum located between twelve and eighteen inches from the first planar top side, and wherein the first foam layer together with the second foam layer have a combined thickness that is constant.

13. The method of claim 12, wherein the first top lateral valley, the first top lateral hill and the middle lateral valley are formed by cutting a first slab of foam.

14. The method of claim 12, wherein the second top lateral hill, the second top lateral valley and the middle lateral hill are formed by cutting a second slab of foam.

15. The method of claim 12, wherein an indentation load deflection (ILD) above the top lateral valley is lower than above other lateral regions immediately adjacent to the top lateral valley after the lower side of the second foam layer is placed over the upper side of the first foam layer.

16. The method of claim 12, wherein the first foam layer is made of high-density polyurethane foam, and wherein the second foam layer is made of memory foam.

17. The method of claim 12, wherein the first foam layer is made of high-density polyurethane foam, and wherein the second foam layer is made of memory foam.

18. The method of claim 17, wherein the memory foam of the second foam layer over the top lateral valley of the first foam layer imparts an indentation load deflection (ILD) to the mattress above the top lateral valley that allows a person'"'"'s shoulders to sink into the mattress so as to keep the person'"'"'s spine straight.