VEHICLE SEAT COMPRISING THREE FOAM LAYERS

• US 3,833,259 A
• Filed: 05/30/1972
• Issued: 09/03/1974
• Est. Priority Date: 05/30/1972
• Status: Expired due to Term

• Current Assignee: Roscoe Louis Pershing
• Original Assignee: Roscoe Louis Pershing
• Inventors: Pershing, Roscoe Louis
• Primary Examiner(s): Lesmes, George F.
• Assistant Examiner(s): Kendell, Lorraine T.
• Application Number:
  US05/257,937
• Time in Patent Office: 826 Days
• Field of Search: 161/159,190 297/195,198,216,229,252,455,456,457,DIG.1,DIG.2,452 244/122R 5/345,355
• US Class Current: 297/452.27
• CPC Class Codes: B60N 2/70 Upholstery springs ; Upholstery
• CPC Class Codes: Y10S 297/01 Foam
• CPC Class Codes: Y10T 428/24967 Absolute thicknesses specified
• CPC Class Codes: Y10T 428/249981 Plural void-containing components

Abstract

A vehicle seat comprises three layers of polymer foams, the upper and lower layers being polyurethane and the center layer being polyethylene. The thicknesses and deformation characteristics of the layers of foam are optimized for a given overall seat thickness range so as to interact with an injury model correlating the deformation characteristics of the human spine such that deformation and hence injury to the spine, occasioned by the impacting of the rider'"'"''"'"'s upper torso upon the seat, will be minimized. A procedure of evaluating a seat in order that the deformation characteristics of the seat may be optimized is set forth.

Claims

1. A vehicle seat comprising:

top and bottom layers of open cell polyurethane foam having a density of approximately three pcf and exhibiting an indentation load deflection characteristic requiring approximately 30 lbs./50 in.2, to deflect a sample thereof through 25 percent of its thickness, as determined by SAE recommended practice, SAE J815 for the year 1972;

said top and bottom layers sandwiching a center layer of closed-cell polyethylene foam having a density of approximately two pcf and exhibiting an indentation load deflection characteristic requiring approximately 300 lbs./50 in.2, to deflect a sample thereof through 25 percent of its thickness, as determined by said SAE recommended practice;

the composite thickness of said layers of foam being no less than four inches nor more than ten inches, said center layer of foam having a thickness between 10 and 25 percent of said composite thickness and being placed in the bottom 60 percent of said composite thickness and said bottom layer being at least three-fourths of an inch thick.

2. The vehicle seat defined in claim 1 wherein the composite thickness of said layers of foam is between four and six inches and the thickness of said center layer of foam is between 20 percent and 25 percent of the composite thickness.

3. The vehicle seat defined in claim 1 wherein the composite thickness of said layers of foam is between six and eight inches, the thickness of said center layer of foam is between 15 and 20 percent of the composite thickness, and the thickness of the bottom layer of foam is at least one inch.

4. The vehicle seat defined in claim 3 wherein the thickness of said top layer of foam is at least four inches.

5. The vehicle seat defined in claim 1 wherein the composite thickness of said layers of foam is between eight and ten inches, the thickness of said center layer of foam is between 10 and 15 percent of the composite thickness, the bottom layer is at least one inch thick and the top layer of foam being at least four inches thick.

6. The vehicle seat defined in claim 1 wherein the composite thickness of the layers of foam increases from the front to the rear of the seat;

said bottom and center layers of foam each being of a constant thickness.

7. The vehicle seat defined in claim 6 wherein the composite thickness of the layers of foam at a central portion intermediate the front and rear of the seat is between five and seven inches.