Gerald C Stephens

US Patent:

46718419, Jun 9, 1987

Filed:

Jan 6, 1986

Appl. No.:

6/816359

Inventors:

Gerald E. Stephens - Anaheim CA

Assignee:

Rohr Industries, Inc. - Chula Vista CA

International Classification:

B32B 3112
E04B 174
E04B 182

US Classification:

156292

Abstract:

A method of producing an open, triaxial woven, acoustic face sheet useful in acoustic energy absorbing panels for aircraft engines or the like. The composite face sheet is formed from carbon fibers in an epoxy resin matrix and has about 25 to 33% open area. This face sheet has lower weight and superior and more uniform strength and stiffness than biaxial composite face sheets. The face sheet is made by first weaving carbon fiber tows at warp angles of +30. degree. and -30. degree. and a fill angle of 90. degree. The woven sheet is impregnated with epoxy as other resins in a manner which produces no rich or starved areas and no blocked openings. The resulting prepreg material may be stored for extended periods at reduced temperatures. The prepreg material is shaped on a suitable mold surface and the resin is fully cured, preferably in a vacuum bag assembly in an autoclave. The resulting sheet has very light weight, an excellent percentage of openings and high strength and stiffness.

US Patent:

51036770, Apr 14, 1992

Filed:

Aug 20, 1990

Appl. No.:

7/570053

Inventors:

Gerald E. Stephens - Anaheim CA

Assignee:

Northrop Corporation - Hawthorne CA

International Classification:

G01N 332

US Classification:

73812

Abstract:

A system for testing the properties of a material used in sealing gaps between aircraft panels. The system includes a first device having a pair of interior plates positionable on opposite sides of a first specimen, a pair of intermediate plates located on the sides of the interior plates remote from the first specimen, a pair of exterior plates located on the sides of the intermediate plates remote from the specimen, drive shafts coupled to the exterior plates, a first mechanism connected to the drive shafts for imparting motion thereto, and a first electrical device connected to the interior plates for testing the properties of the first specimen during the operation of the first mechanism. The system also includes a second device having a pair of primary plates with interior portions spaced from each other, a pair of secondary plates secured to the interior portions of the primary plates on opposite sides of a second specimen, the second specimen being formed in a specimen-receiving space located entirely over only the interior portion of one of the primary plates, a second mechanism connected to the primary plates for imparting motion to at least one of the primary plates and its secured secondary plate, and a second electrical device connected to the secondary plates for testing the properties of the second specimen during the operation of the second mechanism. Also disclosed is a method of testing such specimen.