Stiffened structural laminate and method of molding laminate with stiffener beads

• US 4,053,667 A
• Filed: 09/09/1974
• Issued: 10/11/1977
• Est. Priority Date: 09/09/1974
• Status: Expired due to Term

• Current Assignee: Lockheed Aircraft Corporation
• Original Assignee: Lockheed Aircraft Corporation
• Inventors: Smith, Bruce W.
• Primary Examiner(s): Lesmes, George F.
• Assistant Examiner(s): Epstein, H. F.
• Application Number:
  US05/504,441
• Time in Patent Office: 1,128 Days
• Field of Search: 161/68, 161/69, 52/615, 52/618, 52/144, 29/455 LM, 138/148, 138/172, 156/143, 156/144, 156/195, 156/197, 156/245, 156/285, 156/292, 156/382, 156/172, 156/212, 220/71, 220/72, 264/90, 264/94, 264/220, 428/35, 428/36, 428/73, 428/116, 428/117, 428/118, 220/71, 220/72
• US Class Current: 428/36.1
• CPC Class Codes: B29C 43/12 using bags surrounding the moulding material or using membranes contacting the moulding material
• CPC Class Codes: B29C 70/342 using isostatic pressure
• CPC Class Codes: B29C 70/44 using isostatic pressure, e.g. pressure difference-moulding, vacuum bag-moulding, autoclave-moulding or expanding rubber-moulding
• CPC Class Codes: B29D 24/001 formed of hollow ridges or ribs, e.g. separate ridges; continuous corrugated structure B29D24/008 takes precedence
• CPC Class Codes: B29D 24/005 the structure having joined ribs, e.g. honeycomb
• CPC Class Codes: B29L 2023/00 Tubular articles B29L2024/00 takes precedence ; catheters B29L2031/7542
• CPC Class Codes: B64C 1/12 Construction or attachment of skin panels
• CPC Class Codes: B64C 2001/0072 from composite materials
• CPC Class Codes: Y02T 50/40 Weight reduction
• CPC Class Codes: Y10T 428/1314 Contains fabric, fiber particle, or filament made of glass, ceramic, or sintered, fused, fired, or calcined metal oxide, or metal carbide or other inorganic compound [e.g., fiber glass, mineral fiber, sand, etc.]
• CPC Class Codes: Y10T 428/1362 Textile, fabric, cloth, or pile containing [e.g., web, net, woven, knitted, mesh, nonwoven, matted, etc.]
• CPC Class Codes: Y10T 428/236 Honeycomb type cells extend perpendicularly to nonthickness layer
• CPC Class Codes: Y10T 428/24149 Honeycomb-like

Abstract

A novel stiffened structural laminate formed by contacting at least one layer of a curable resin-impregnated fabric with at least one strip of cellular honeycomb core, disposing another piece of said curable resin-impregnated fabric over said strip of core, and curing said resin under laminating conditions to bond said honeycomb core to said fabric and produce a unitary laminate which includes said strip as a stiffening bead.

Claims

1. A rib-stiffened laminate formed by:

contacting a primary structure of at least one layer of a curable resin-impregnated fabric with at least one strip of cellular honeycomb core;

disposing another piece of said fabric over said strip of core in engagement with said core and said primary structure to define at least one reinforcing rib upon said primary structure; and

partially crushing said core and curing said resin under laminating conditions such that said core is bonded to said fabric and said fabric piece is bonded to said primary structure.

2. The rib-stiffened laminate of claim 1 in planar form.

3. The rib-stiffened laminate of claim 1 in tubular form, said rib being a single rib disposed spirally relative to said tubular form, each subsequent revolution thereof being spaced from the last.

4. The stiffening laminate of claim 1 in tubular form wherein a plurality of said ribs are provided, said ribs being annular and spaced apart.

5. The method of forming a rib-stiffened laminate which comprises simultaneously laminating under heat and pressure a primary structure of at least one layer of a curable resin-impregnated fabric with at least one strip of a cellular honeycomb core, another piece of said fabric being disposed over said strip of core in engagement with said primary structure, while partially crushing said cellular honeycomb core during laminating said laminate being cured to define a stiffening rib upon said primary structure.

6. The method of claim 5 wherein said layer is in tubular form and said core and said other piece of fabric are spirally disposed about said layer.