Sandwich structure and method of making same

• US 6,291,049 B1
• Filed: 10/20/1998
• Issued: 09/18/2001
• Est. Priority Date: 10/20/1998
• Status: Expired due to Term

• Current Assignee: Aztex Incorporated
• Original Assignee: Aztex Incorporated
• Inventors: Kunkel, Edward, Magee, Constance, Rich, David, Blaney, Eric
• Primary Examiner(s): Copenheaver, Blaine
• Assistant Examiner(s): Paulraj, Christopher
• Application Number:
  US09/175,663
• Time in Patent Office: 1,064 Days
• Field of Search: 428/99, 428/116, 428/119, 428/317.9, 428/318.4, 428/319.3, 442/370, 442/373
• US Class Current: 428/99
• CPC Class Codes: B29C 70/24 oriented in at least three directions forming a three dimensional structure
• CPC Class Codes: B29D 99/0021 provided with plain or filled structures, e.g. cores, placed between two or more plates or sheets, e.g. in a matrix
• CPC Class Codes: B32B 3/06 for securing layers together; for attaching the product to another member, e.g. to a support , or to another product, e.g. groove/tongue, interlocking
• CPC Class Codes: B32B 5/02 characterised by structural features of a fibrous or filamentary layer layer formed of metallic wires B32B15/02; layer formed of natural mineral fibres B32B19/02; layer formed of wood fibres B32B21/02
• CPC Class Codes: B32B 5/18 characterised by features of a layer of foamed material
• CPC Class Codes: Y10T 428/24008 including fastener for attaching to external surface
• CPC Class Codes: Y10T 428/24174 including sheet or component perpendicular to plane of web or sheet
• CPC Class Codes: Y10T 428/249986 Void-containing component contains also a solid fiber or solid particle
• CPC Class Codes: Y10T 428/249991 Synthetic resin or natural rubbers
• CPC Class Codes: Y10T 442/651 Plural fabric layers

Abstract

A sandwich structure including a core having opposing top and bottom surfaces, a plurality of discrete pins disposed through the core and extending beyond the top and bottom surfaces of the core, a face sheet on the top core surface, and a face sheet on the bottom core surface. The ends of each pin are bent over and lie between the respective core surfaces and the face sheets to secure the face sheets to the core, improve the strength of the core, and to provide a physical connection between the two face sheets. Also disclosed is a reinforced core for a sandwich structure which does not yet have the face sheets assembled to it. Also disclosed is a method of making such a reinforced core and completed sandwich structures including such a core.

Claims

1. A sandwich structure comprising:

a core having opposing top and bottom surfaces;

a plurality of discrete pins disposed through the core and extending beyond the top and bottom surfaces of the core;

a face sheet on the top core surface; and

a face sheet on the bottom core surface, the ends of each pin bent over and lying between the respective core surfaces and the face sheets.

2. The sandwich structure of claim 1 in which the core is made of foam.

3. The sandwich structure of claim 1 in which each pin includes strands of fiber.

4. The sandwich structure of claim 3 in which the strands of fiber are separated from each other at the extending bent over ends of each pin.

5. The sandwich structure of claim 1 in which the pins are wires.

6. The sandwich structure of claim 1 in which each face sheet includes an array of fibers in a resin matrix.

7. The sandwich structure of claim 6 in which the array of fibers form a fabric.

8. The sandwich structure of claim 1 in which each face sheet is made of metal.

9. The sandwich structure of claim 1 in which the pins are disposed at an angle in the core forming a truss structure therein.

10. The sandwich structure of claim 9 in which each pin is angled differently from each adjacent pin.

11. The sandwich structure of claim 1 in which the bent over ends of the pins form a repeating pattern of sets of pin ends along the top and bottom surface of the core.

12. The sandwich structure of claim 11 in which each pin in a set of pin ends in the top surface extends to a different set of pin ends in the bottom surface.

13. The sandwich structure of claim 11 in which each pin end in a set of pin ends is bent in a different direction.

14. A sandwich structure comprising:

a core having opposing top and bottom surfaces;

a plurality of discrete pins disposed through the core and extending beyond the top and bottom surfaces of the core wherein each pin includes strands of fiber;

a face sheet on the top core surface; and

a face sheet on the bottom core surface, the ends of each pin bent over and lying between the respective core surfaces and the face sheets wherein the strands of fibers are separated from each other at the extending bents over ends of each pin.

15. An improved core for a sandwich structure, the improved core comprising:

a core body;

a top and bottom surface; and

a plurality of discrete pins each having strands of fiber inserted through the core, the ends of each pin extending from top and bottom surfaces of the core and bent over and lying along the respective top and bottom surfaces of the core wherein the strands of fiber are separated from each other at the bent over ends of each pin.

16. A sandwich structure comprising:

a core having top and bottom surfaces;

a top face sheet material layer on the top core surface;

a bottom face sheet material layer on the bottom core surface; and

a plurality of discrete pins each having strands of fiber disposed through the core and the face sheet material layers and extending beyond the face sheet material layers, the extending ends of each pin bent over and lying along the exterior of the respective face sheet material layers wherein the strands of fiber are separated from each other at bent over ends of each pin.

17. An improved core for a sandwich structure, the improved core comprising:

a core body;

a top and bottom surface; and

a plurality of discreet pins inserted through the core, the ends of each pin extending from the top and bottom surfaces of the core and bent over and lying along the respective top and bottom surfaces of the core, each pin including strands of fiber and wherein the strands of fiber are separated from each other at the bent over ends of the pin.

18. A sandwich structure comprising:

a core having top and bottom surfaces;

a top face sheet material layer on the top core surface;

a bottom face sheet material layer on the bottom core surface; and

a plurality of pins disposed through the core and the face sheet material layers and extending beyond the face sheet material layers, the extending ends of each pin bent over and lying along the exterior of the respective face sheet material layers, each pin including strands of fiber, the strands of fiber separated from each other at the bent over ends of each pin.