Method for fabricating impact absorbing safety structure

• US 3,929,948 A
• Filed: 10/19/1973
• Issued: 12/30/1975
• Est. Priority Date: 11/03/1971
• Status: Expired due to Term

• Current Assignee: John A. Welch, Robert W. Mitchell
• Original Assignee: John A. Welch, Robert W. Mitchell
• Inventors: Welch, John A., Mitchell, Robert W.
• Primary Examiner(s): Anderson, Philip
• Application Number:
  US05/408,040
• Time in Patent Office: 802 Days
• Field of Search: 264/45,46,46.7,46.9,45.5,DIG.14,46.4 161/159,160,161 156/78,79
• US Class Current: 264/45.5
• CPC Class Codes: B29C 44/0461 by having different chemical compositions in different places, e.g. having different concentrations of foaming agent, feeding one composition after the other
• CPC Class Codes: B60R 21/045 associated with the instrument panel or dashboard
• CPC Class Codes: Y10S 264/14 forming integral skin on a foamed product

Abstract

A method for fabricating an expanded foam impact absorbing safety structure suitable for use on automobile dashboards including the steps of conforming a flexible surface covering member to the molding surface of a mold; conforming a layer member of flexible, resilient porous foam to the flexible covering member, pouring a foaming mixture of rigid type foam reactants onto the exposed surface of the layer member, allowing a portion of the foaming mixture to permeate into the surface pores of the layer member, and curing the foaming mixture to produce an expanded rigid foam base member joined to the layer member by an intermediate tough rigid and frangible crust comprised of a surface portion of the layer member permeated by a portion of the expanded rigid foam of the base member. An adhesive may be applied between the covering member and the layer member. The covering member may be omitted and the layer member may be provided with an integral skin disposed in conformity with the molding surface.

Claims

1. DISPOSING A FLEXIBLE RESILIENT LAYER MEMBER OF CURED POROUS FOAM, HAVING ITS INTEGRAL SKIN AS INITIALLY FORMED WHEN FOAMED AND CURED REMOVED FROM ONE EXPOSED SURFACE TO EXPOSE A POROUS SURFACE, INTO CONFORMING RELATION WITH THE MOLDING SURFACE OF A MOLD AS A PREFORMED LAYER MEMBER WITH SAID POROUS SURFACE DISPOSED OPPOSITE SAID MOLDING SURFACE;

2. pouring a foaming mixture of thermosetting resin reactants selected to produce a rigid type foam onto said porous surface of said layer member while said mixture is in foaming condition;

3. ALLOWING A PORTION OF SAID FOAMING MIXTURE TO PERMEATE INTO SAID POROUS SURFACE AND PARTIALLY INTO SAID LAYER MEMBER A DISTANCE SUFFICIENT TO FORM A SELECTED APPARENT THICKNESS OF A COMPOSITE LAYER COMPRISING SAID FOAMING MIXTURE AND SAID POROUS FOAM OF SAID LAYER MEMBER;

AND

4. curing said foaming mixture to produce said rigid deformable base member and to convert said composite layer into said rigid composite crust member with said rigid composite crust member being tough yet frangible and adapted to break responsive to impact forces in excess of about 50 lbs., exemplified as a force exerted through said resilient layer member against said crust member by a solid hemispherical surface about 1 inch in diameter, and thereby allow such excess forces to be absorbed through deformation of said base member.

5. The method of claim 4 wherein said resilient layer member has a density of less than about 8 lbs./ft.3 and a thickness of at least about 1/4 inch.

6. The method of claim 1 wherein the integral skin formed during foaming and curing of said resilient layer member is retained on the exposed surface of said layer member which is disposed in conforming relation with the molding surface of said mold, said integral skin becoming the outer surface of said resilient outer layer member of said safety structure.