Vehicle seat assembly

• US 5,988,757 A
• Filed: 10/01/1998
• Issued: 11/23/1999
• Est. Priority Date: 08/29/1996
• Status: Expired due to Fees

• Current Assignee: Lear Corporation
• Original Assignee: Lear Corporation
• Inventors: Walkowski, Michael, Baisch, Ashley L., Vishey, Gregory J.
• Primary Examiner(s): BARFIELD, ANTHONY DERRELL
• Application Number:
  US09/164,917
• Time in Patent Office: 418 Days
• Field of Search: 297/DIG. 2, 297/452.31, 297/452.36, 297/452.29, 297/452.65, 297/452.14
• US Class Current: 297/452.31
• CPC Class Codes: B60N 2/23 by linear actuators, e.g. linear screw mechanisms
• CPC Class Codes: B60N 2/4235 transversal
• CPC Class Codes: B60N 2/4249 fixed structures, i.e. where neither the seat nor a part thereof are displaced during a crash
• CPC Class Codes: B60N 2/4256 the shape of the seat being specially adapted for a particular purpose or for particular vehicles
• CPC Class Codes: B60N 2/686 Panel like structures
• CPC Class Codes: B60N 2/986 Side-rests B60N2/2872, B60N2/885 take precedence
• CPC Class Codes: Y10S 297/02 Molded

Abstract

A vehicle seat assembly includes an aluminum lower seat frame with first and second side supports having a thickness of less than four mm throughout a substantial portion thereof. The seat back frame is pivotally connected to the lower seat frame and comprises a contoured structural reaction injection molded (SRIM) material. In an alternative embodiment, the back frame comprises a plurality of glass mat layers enclosed within a molded urethane material. Extra glass mat layers are provided in high stress concentration areas for added structural integrity.

Claims

1. A vehicle seat back frame having an upper portion and first and second lower attachment portions for attachment of the back frame in a vehicle, comprising:

a high density structural injection molded polyurethane material with glass reinforcement fibers, said reinforcement fibers comprising;

a plurality of glass mat layers formed generally in the shape of the back frame, said glass mat layers being most numerous in said first and second lower attachment portions for added structural integrity;

said polyurethane material being molded over said plurality of glass mat layers to form the seat back frame;

said plurality of glass mat layers comprising a first glass mat layer formed generally in the shape of the back frame and having first and second lower attachment portions and first and second side curvature portions extending longitudinally along opposing sides of the back frame;

a second glass mat layer positioned over said first glass mat layer at said first and second lower attachment portions and extending at least partially along said side curvature portions;

a third glass mat layer positioned over said second glass mat layer at said first and second attachment portions and extending at least partially along said side curvature portions;

a fourth glass mat layer positioned over said third glass mat layer at said first and second lower attachment portions and extending at least partially along said side curvature portions; and

fifth and sixth glass mat layers positioned at said first and second lower attachment portions;

said back frame having a first spring rate and being flexible with respect to a vertical reference center plane of said back frame;

said back frame having spring rates that differ from said first spring rate with respect to vertical reference planes between said vertical reference center plane and lateral sides of said back frame;

said back frame being flexible with respect to lateral reference planes, the spring rates of said back frame at said lateral reference planes being lower adjacent said upper portion of said back frame relative to the spring rate at lateral reference planes below said upper portion;

said glass reinforcement fibers being positioned in said back frame to effect plastic deformation as said back frame flexes due to impact forces on said back frame, thereby absorbing impact energy as said energy is stored in said seat back due to flexing of said back frame at said vertical and lateral reference planes.

2. The vehicle seat back frame of claim 1 wherein said first glass mat comprises opposing two-ounce per square foot layers of glass with a layer of polypropylene-spun fibers therebetween to allow the polymer material to flow between the opposing two-ounce per square foot layers of glass mat.

3. The vehicle seat back frame of claim 1 wherein said second glass mat layer comprises a four-ounce per square foot glass mat.

4. The vehicle seat back frame of claim 1 wherein said third glass mat layer comprises a four-ounce per square foot glass mat.

5. The vehicle seat back frame of claim 1 wherein said fourth glass mat layer comprises a four-ounce per square foot glass mat.

6. The vehicle seat back frame of claim 1 wherein said fifth and sixth glass mats each comprise opposing two-ounce per square foot layers of glass with a layer of polypropylene-spun fiber therebetween to allow the polymer material to flow between the opposing two-ounce per square foot layers of glass mat.

7. A vehicle seat back frame having an upper portion and first and second lower attachment portions for attachment of the back frame in a vehicle, comprising:

a high density structural injection molded polyurethane material with glass reinforcement fibers, said reinforcement fibers comprising a plurality of glass mat layers formed generally in the shape of the back frame, said glass mat layers being most numerous in said first and second lower attachment portions for added structural integrity;

said polyurethane material being molded over said plurality of glass mat layers to form the seat back frame;

said plurality of glass mat layers comprising a first glass mat layer formed generally in the shape of the back frame and having first and second lower attachment portions and first and second side curvature portions extending longitudinally along opposing sides of the back frame;

a second glass mat layer positioned over said first glass mat layer at said first and second lower attachment portions and extending at least partially along said side curvature portions;

a third glass mat layer positioned over said second glass mat layer at said first and second attachment portions and extending at least partially along said side curvature portions;

a fourth glass mat layer positioned over said third glass mat layer at said first and second lower attachment portions and extending at least partially along said side curvature portions; and

said back frame having a first spring rate and being flexible with respect to a vertical reference center plane of said back frame;

said back frame having spring rates that differ from said first spring rate with respect to vertical reference planes between said vertical reference center plane and lateral sides of said back frame;

said back frame being flexible with respect to lateral reference planes, the spring rates of said back frame at said lateral reference planes being lower adjacent said upper portion of said back frame relative to the spring rate at lateral reference planes below said upper portion;

said glass reinforcement fibers being positioned in said back frame to effect plastic deformation as said back frame flexes due to impact forces on said back frame, thereby absorbing impact energy as said energy is stored in said seat back due to flexing of said back frame at said vertical and lateral reference planes; and

a high density injection molded polymer material enclosing the mat layers;

said glass mat layers comprising woven glass fiber material with glass fibers extending in the direction of each of perpendicular reference axes corresponding to orientation of said glass fibers and a glass chop material with random glass fiber orientation, said woven glass fiber material being located primarily at the surface of said back frame and said glass chop being disposed within the interior of said back frame whereby the number of said mats at each location of said back frame, the thickness of said mats and the orientation of said woven material being variable in accordance with predetermined design requirements.

8. The vehicle seat back frame of claim 7 wherein said polymer material comprises urethane.