Ordnance – Shields – Shape or composition
Reexamination Certificate
2001-08-06
2004-06-08
Johnson, Stephen M. (Department: 3641)
Ordnance
Shields
Shape or composition
C089S036110, C428S116000
Reexamination Certificate
active
06745662
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a honeycomb structural design, and more specifically, to a sandwich core having rows of cells between layers at oblique angles to the layers.
2. Prior Art
In order to stop hypervelocity particles from penetrating a structure, several methods have been used to protect crucial components. First, a solid structure of sufficient thickness could stop a hypervelocity particle, however, the extra thickness would necessarily translate into extra weight. Another solution has been to provide a secondary “bumper” shield a distance from the structure to be protected. However, the spacing of a secondary shield apart from the protected structure leads to increased volume.
Various other efforts have been made to absorb the impact of high velocity and hypervelocity particles as taught in U.S. Pat. Nos. 5,848,767, 5,747,721, 5,686,689, 6,624,088, 5,601,258, 5,443,884, 5,221,087, 5,161,756, 5,102,723, and 5,067,388. Of these patents, U.S. Pat. No. 5,484,767 shows a spacecraft frame that utilizes a sandwich core, but the design of the core is not addressed, and is believed to be a traditional honeycomb design where the cell walls are substantially perpendicular to the layers. Other sandwich cores are shown in U.S. Pat. Nos. 5,624,088 and 5,443,884.
The traditional sandwich core is typically a honeycomb design having a top layer spaced apart from a bottom layer by a plurality of cells. The cells have a plurality of walls which are perpendicular to each of the layers. FIG. 5
a
of U.S. Pat. No. 5,443,884 illustrates a typical honeycomb sandwich core. These structures are often utilized in spacecraft design since they are stiffer than a single thin structure of the same mass.
The cells of traditional honeycomb sandwich cores are aligned perpendicularly to the facesheets, or layers. Accordingly, when a hypervelocity particle strikes and breaks through the outer facesheet, a plasma jet may form and be channeled through the cell. This jet will be directed by the cell perpendicularly to the inner facesheet. When the plasma jet breaks through the inner facesheet, the particle is then typically directed at the structure which was to be protected.
A need exists to provide a light weight and sufficiently strong sandwich core which may adequately deflect hypervelocity and high velocity particles from damaging a particular structure.
SUMMARY OF THE INVENTION
Consequently, it is a primary object of the present invention to provide a sandwich core which provides a sufficiently strong structure that is relatively light weight and deflects hypervelocity and high velocity particles in a more preferred manner.
Accordingly, the present invention provides a sandwich core comprising two faceplates separated by a plurality of cells. The cells are comprised of walls positioned at oblique angles relative to the perpendicular direction through the faceplates. The walls preferably form open cells and are constructed from rows of ribbons.
REFERENCES:
patent: 2190490 (1940-02-01), Sendzimir
patent: 3869778 (1975-03-01), Yancey
patent: 4020205 (1977-04-01), Haselbauer
patent: 4027058 (1977-05-01), Wootten
patent: 4471013 (1984-09-01), Welzen
patent: 4923544 (1990-05-01), Weisse
patent: 4923728 (1990-05-01), Snedeker
patent: 5028474 (1991-07-01), Czaplicki
patent: 5067388 (1991-11-01), Crews et al.
patent: 5102723 (1992-04-01), Pepin
patent: 5116688 (1992-05-01), Minamida et al.
patent: 5161756 (1992-11-01), Redmon, Jr. et al.
patent: 5221807 (1993-06-01), Vives
patent: 5398889 (1995-03-01), White et al.
patent: 5443884 (1995-08-01), Lusignea et al.
patent: H1621 (1996-12-01), Ray
patent: 5601258 (1997-02-01), McClymonds
patent: 5624088 (1997-04-01), Fiore
patent: 5686689 (1997-11-01), Snedeker et al.
patent: 5747721 (1998-05-01), Speakes et al.
patent: 5848767 (1998-12-01), Cappa et al.
patent: 6274216 (2001-08-01), Gonidec et al.
patent: 6395372 (2002-05-01), Bach
patent: 172 415 (1986-02-01), None
Johnson Stephen M.
McGroary James J.
Stark Stephen J.
The United States of America as represented by the Administrator
LandOfFree
Cross cell sandwich core does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Cross cell sandwich core, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Cross cell sandwich core will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3356522