The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 30, 2001
Filed:
Feb. 04, 1998
John M. Welch, Wichita, KS (US);
Thomas D. Popp, Wichita, KS (US);
Leonard L. Baca, Mulvane, KS (US);
The Boeing Company, Seattle, WA (US);
Abstract
A method of forming a composite acoustic panel (,). The method begins by arranging a perforated sheet (,) on a convex lay-up mandrel (,), arranging a core material (,) on the perforated sheet (,), and curing the perforated sheet (,) and the core material (,) to form a composite acoustic core (,) having a lay-up mandrel side and an opposite upper side. Composite sheets (,) are then arranged on a concave lay-up mandrel. The composite acoustic core (,) is arranged on the composite sheets (,) with the opposite upper side of the acoustic core (,) against the composite sheets (,). The composite acoustic core (,) and the composite sheets (,) are then cured so as to form the acoustic panel (,). A sacrificial sheet (,) can be added to upper side of the core material (,) prior to curing the perforated sheet (,) and the core material (,). The sacrificial sheet (,) preferably has a low coefficient of thermal expansion. The sacrificial sheet (,) is machined off as the upper side of the core material (,) is shaped. The use of the sacrificial sheet (,) permits the acoustic core (,) to maintain its shape during curing without warpage from residual thermal stresses (R). The perforated sheet (,) thus maintains a contour that is substantially matched to the outer surface of the convex lay-up mandrel (,).