Ex Parte Brown

Board of Patent Appeals and Interferences

Mar 26, 2012

11314475 (B.P.A.I. Mar. 26, 2012)

UNITED STATES PATENT AND TRADEMARK OFFICE
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BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
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Ex parte THE BOEING COMPANY

Appellant.
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Appeal 2011-007156
Application 11/314,475
Technology Center 1700
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Before FRED E. MCKELVEY, RICHARD E. SCHAFER, and RICHARD
TORCZON, Administrative Patent Judges.

SCHAFER, Administrative Patent Judge

DECISION ON APPEAL

2

The Boeing Co. (Applicant) appeals from final rejection of Claims 1-5, 7-11,
and 18-24. We affirm.
The Invention
The invention relates to a layered composite system for use as part of the
exterior skin of an aircraft and the method of making the composite. The
composite requires at least four layers: (1) a base or substrate layer; (2) a fiberglass
and resin “isolator” layer, (3) a metal mesh layer and (4) a surfacer layer. The
substrate layer is apparently the surface of the aircraft to which the other layers are
to be applied. Written Description,1 6:15-16. The substrate may be a “composite
structure or a honeycomb structure.” Written Description, 6:24-25. The isolator
includes a carrier and an adhesive resin. The carrier may be fiber glass and the
resin may be epoxy. Written Description, 4:1-3. Suitable isolators include a
number of commercially available S-2 glass/epoxy resin combinations. Written
Description, 7:1-4. “S-2 glass” is a designation of a commercially available high
strength fiber glass. The isolator layer provides electrical (galvanic) insulation
between the substrate layer and the metal mesh layer. Written Description, 8: 19-
21 and 3:6-8. The metal mesh layer is preferably an expanded aluminum foil.
Written Description, 8: 16-19. The metal mesh provides lightning protection by
dissipating the electrical energy from a lightning strike. Written Description, 2:11-
14. The surfacer layer provides a smooth surface for applying a paint or finishing
layer. Written Description, 3:32 - 4:1. The surfacer includes a fabric carrier and a
resin which may be an epoxy. Written Description, 4:17-19. During manufacture
the composite epoxy resin from the isolator and the surfacer penetrates and fills the
openings in the metal mesh embedding the mesh in the epoxy. Written
Description, 4:17-20.

1 All references to the written description are to the version filed on December 12, 2005 and not
to the version published on June 21, 2007.
3

Applicant’s representative claim 18, directed to the composite system, is
reproduced below:
18. A protective fabric system for an exterior of an aircraft
comprising:
a surfacer having a resin and carrier;
a metal mesh substrate having a plurality of holes,
wherein a thickness of the metal mesh is based on
a lightning threat;
an isolator having a resin and carrier, wherein the isolator
is s-glass; and
a base structure
wherein the base substrate, the isolator, and the surface[r] are
co-cured;
wherein the isolator is applied to the base substrate, and the
metal mesh is interspersed between the isolator and the
surfacer, said surfacer, said metal mesh substrate and
said isolator combined so that the resin carrier in said
surfacer and said isolator fill in the plurality of holes in
the metal mesh to provide a surface for priming and
painting the exterior surface.
Brief, 15-16 (Claims Appendix).
Applicant also claims the method of making the fabric system. The process
begins with the substrate. Written Description, 6:15-16. The isolator, which is a
mixture of s-glass fabric and epoxy, is placed on the substrate. Written
Description, 6: 16-17. The metal mesh is placed on the isolator and the surfacer is
placed on the metal mesh. Written Description, 6:18-19. The components are
then co-cured causing the epoxy resin from the isolator and the surfacer penetrates
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the openings in the metal mesh comingling the metal mesh in epoxy resin. 4:17-
20; 8:22-25.
Claim 1 is directed to the method:
1. A method of forming an exterior surface protective structure
for an aircraft comprising:
providing a base substrate including a prepreg material;
applying an isolator having resin and glass fabric to the base
substrate, wherein the isolator is s-glass;
applying a surfacer having a resin carrier onto the isolator;
co-curing the base substrate, the isolator, and the surfacer; and
providing a metal mesh substrate having a plurality of holes in
between the isolator and the surface, wherein a thickness
of the metal mesh is based on a lightning threat; and
combining said surfacer, said metal mesh substrate and said
isolator so that the resin in said surfacer and said isolator
fill in the plurality of holes in the metal mesh to provide a
surface for priming and painting the exterior surface
protective structure.
Brief, 14 (Claims Appendix).
Rejections
In the Answer, the Examiner maintains two rejections:
(1) Claims 1-2, 5, 7-9, 18-19, 21, 23, and 24 stand rejected under 35 U.S.C.
103(a) as unpatentable over the combined teachings of Cedarleaf,2 Arnold,3 and
“Fiber Selection4”; and

2 Patent 5,370,921.
3 Patent 5,417,385
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(2) Claims 3-4, 10, 20, and 22 are rejected under 35 U.S.C. 103(a) as being
unpatentable over the combined teachings of Cedarleaf, Arnold and Prandy.5
Cedarleaf
Cedarleaf relates to lightning strike protective multilayered composite
materials and the method of making them. Referring to Cederleaf’s Figure 2, the
composite may include a honeycomb substrate 38 (Cedarleaf, 6: 4-6), prepreg
layers 34 (Cedarleaf, 6:24-26), metal screen or expanded metal foil 44 (Cedarleaf,
6:20-24), and a surfacer having a carrier sheet 46 and filled resin film sheet 48
(Cedarleaf, 6:20-24). The metal screen or expanded metal foil provides protection
from the lightning strike. Cedarleaf, 3:59-64. “Prepreg” is a term of art referring
to a combination of fibers pre-impregnated with adhesive resin prior to use. The
prepregs suitable for use in the composites include fiberglass carrier with epoxy as
the matrix resin:
The prepregs used for composite structures can be woven or
unidirectional fiber forms. Fiber types include, among others,
carbon, glass, Kevlar TM and quartz. Resin contents of 34-45%
have been used. Typical matrix resins include, among others,
epoxy, polyester and phenolic . . . .
Cedarleaf. 20:20-31 (emphasis added).
Cedarleaf also describes a process for making the composites. The surfacer
layer is formed by bonding a carrier sheet 46 to film 48. The metal screen or
expanded metal foil is placed on bound carrier sheet 46. Prepreg layers 34 and
honeycomb core 38 are laid on top of the metal screen 44. The assembly is co-
cured using standard vacuum bag and autoclave techniques with the cure

4 Fiber Selection is a document published on the internet by About.com at least by September 29,
2000, and available at http://composite.about.com/library/weekly/aa980323.htm#.
5 Patent 5,225,265.
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temperature and pressure matched to the reactivity of both the prepreg resin and
the resin system in the surface film. Cedarleaf, 6:15-32. The resin in the prepreg
layer and from the surface layer flows through the openings in the metal screen or
foil to affect bonding to the rest of the composite. Cedarleaf, 3:37-42; 4:27-32.
Cedarleaf does not teach that the prepreg should act as an isolator, i.e,
provides electrical insulation between the metal layer and the substrate. Cedarleaf
also does not describe s-glass as the fiberglass material for the prepregs.
Arnold
The Arnold patent relates to structural composites for aircraft. The
composites are said to provide protection against lightning strikes. Arnold, 1:10-
14. Arnold describes layered composites that include an electrically conductive
sheet. Arnold, 2: 19-29. The electrically conductive sheet is said to provide the
aircraft with protection from the lightning strikes. Arnold, 7:29-33. The
electrically conductive sheet maybe expanded metal foil or wire mesh. Arnold, 2:
33-36, 7:25-28. A reinforcing layer of electrically non-conducting glass fiber
fabric is adhesively bonded to the metal foil. Arnold, 5:1-7. The metal foil and
glass fabric are bonded to a honeycomb core 18 through additional intermediate
layers. This combination results in
a fibre reinforced bonded honeycomb assembly with
adequate protection against a primary lightning strike . . . .
It can furthermore provide protection against voltage
differentials and electromagnetic fields, caused by
indirect lightning strike effects . . . . It can also provide
resistance to structural penetration from a primary
lightning strike, thereby providing attenuation of radiated
field interference at high frequency.
Arnold, 6:25-36.
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Fiber Selection
The publication discusses the selection of fiber materials for use in making
composites. It shows that fiber glass using s-glass is commercially available and
has higher strength than e-glass. Fiber Selection, 2.
Analysis
Claims 1 and 18
Applicant has not separately argued independent claims 1 and 18. Brief, 9-
12. We also treat them together.
The examiner rejected Claims 1 and 18 under U.S.C. § 103(a) as being
unpatentable over the combined teachings of Cedarleaf, Arnold and “Fiber
Selection.”
Applicant claims a composite fabric system including, in order, a base
substrate, an isolator having a resin and carrier, a metal mesh and a surfacer having
a resin and carrier. The isolator provides electrical insulation between the metal
mesh and the substrate. Applicant’s preferred isolator material is the combination
of S-2 fiber glass carrier and an epoxy resin matrix.
Cedarleaf teaches a composite that includes these same components except
that Cedarleaf includes prepreg layer 34 at the same location in the composite
where applicant includes an isolator. Cedarleaf, 6:1-28. While Cedarleaf’s
suggested prepregs may include a fiber glass carrier and an epoxy resin matrix
(Cedarleaf, 20:20-31), Cedarleaf does not teach that the prepreg should provide
galvanic or electrical insulation between the substrate and the metal mesh. Arnold
teaches that inclusion of a non-conducting fiber glass fabric layer adhesively
bonded to the adjacent expanded metal foil contributes to the lightning protection
capability of the composites. Arnold, 6:18-24. It would have been obvious,
therefore, to use a non-conductive prepreg such as the combination of fiberglass
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and epoxy to provide an electrically insulating layer adjacent Cedarleaf’s metal
mesh.
The claims also require that fiber glass used in the non-conductive layer be
“s-glass.” Neither Cedarleaf nor Arnold elaborate on the nature of the fiber glass
bonded to the metal mesh. S-glass is a commercially available fiber glass product.
S-glass has higher strength than the less expensive e-glass. Fiber Selection, 2.
One having ordinary skill in the art would have recognized that the strength
advantage provided by s-glass would allow strength requirements of the composite
to be met with less material. Thus, it would have been obvious to use s-glass for
Cedarleaf’s fiberglass component 34 to maintain strength requirements while
reducing weight.
Applicant points out various claim limitations that are said to be missing
from the individual references relied upon by the examiner. Thus, Applicant
argues that “Arnold does not teach or suggest the features of, ‘wherein the isolator
is s-glass’, ‘co-curing the base substrate, the isolator, and the surface’, and
‘wherein a thickness of the metal mesh is based on a lightning threat.’” Brief, 9.
One cannot show non-obviousness by attacking references individually
where the rejections are based on a combination of references. In re Keller, 642
F.2d 413, 425 (CCPA 1981). In any event, each of these concepts is taught or
suggested by the other references. The use of the higher strength s-glass is
suggested by the Fiber Selection publication. Fiber Selection, p. 2. Cedarleaf
teaches co-curing:
Upon completion of the layup of the composite assembly, the
composite assembly is subjected to sufficient heat to cure the
prepregs, honeycomb structures and the surface coating to form
a cured composite structure.
Cedarleaf, 3:45-49.
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Cedarleaf also teaches that a commercial metal mesh used for lightning
protection may be supplied in thicknesses of .003 - .015 inch. Cedarleaf, 6:47-52.
Another commercial metal mesh said to be suitable for lightning protection “can be
custom engineered to produce exact amounts of specified conductivity.”
Cedarleaf, 7:15-20. We find that these teachings establish by a preponderance of
the evidence that the person having ordinary skill in the art is aware that thickness
and conductivity of the metal mesh may be adjusted to meet the perceived level of
lightning protection required, i.e., the perceived “lightning threat.”
Applicant argues that “[c]o-curing the components in Arnold would not
produce the desired separation needed for non-conducting reinforcement.”
Brief, 10.
This argument does not address the examiner’s rejection. The rejection is
based upon a modification of Cedarleaf’s teachings, not Arnold’s. As stated by the
Examiner:
It would have been obvious to one of ordinary skill in the art at
the time the invention was made to include an isolator ply of
glass fiber between the core structure of Cedarleaf and the
metal foil layer . . . .
Answer, 4. Cedarleaf teaches that the laid up composites, including the prepregs
34 between the metal mesh and the substrate, may be co-cured. Cedarleaf, 3:45-
49. Cedarleaf’s prepregs may be the combination of fiberglass and epoxy resin.
Cedarleaf, 20:20-31. Applicant’s preferred materials for the isolator are similarly
s-glass and epoxy resin. Applicants have not directed us to evidence showing that
selecting non-conducting prepregs from the combinations listed by Cedarleaf
(which include fiber glass and epoxy resin), would preclude co-curing the
composite.
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Applicant also argues that Arnold and Fiber Selection teach away from the
suggested modification to Cedarleaf. A reference teaches away when a person of
ordinary skill, upon reading the reference, would be discouraged from following
the path set out in the reference, or would be led in a direction divergent from the
path that was taken by the applicant. In re Gurley, 27 F.3d 551, 553 (Fed. Cir.
1994). We see nothing in Cedarleaf, Arnold or Fiber Selection that would dissuade
one skilled in the art from including non-conducting fiberglass generally or s-glass
in particular between the substrate and metal mesh. Indeed, Cedarleaf specifically
teaches including fiberglass between the metal mesh and substrate and Arnold
teaches using non-conducting fiber glass to improve lightning protection. Arnold
provides ample reason for including a non-conducting fiber glass layer between the
substrate and metal mesh in Cedarleaf’s composite. Arnold’s teaching that s-glass
has higher strength provides a basis to use s-glass for that layer.
Applicant argues that Arnold teaches structural reasons in addition to
providing lightning protection for using a fiber glass layer between the base and
metal mesh. These additional functions include fireproofing and puncture
prevention. Brief, 9-10. It is not clear why, in Applicant’s view, these additional
functions would teach away from using a non-conductive fiber glass containing
layer Cedarleaf’s metal mesh and the substrate. Brief, 10. In any event, the
additional benefits attributable to the use of fiber glass support the Examiner’s
obviousness conclusion. As noted by the Examiner (Answer, 4), these
supplemental benefits provide additional reasons for incorporating the non-
conducting fiberglass layer into Cedarleaf’s aircraft composites. Additionally,
obviousness does not require that the prior art teach solving the same problem or
address the same need addressed by Applicant. “[A]ny need or problem known in
the field of endeavor at the time of invention and addressed by the patent can
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provide a reason for combining the elements in the manner claimed.” KSR Int’l
Co. v. Teleflex, Inc., 550 U.S. 398, 420 (2007).
The references establish that the various concepts employed in the claimed
invention are within the ordinary skill of the art. Applicant’s invention employs
each of these concepts in the same way as used in the prior art resulting in no more
than the predicted results. The subject matter of Claims 1 and 18 would have been
obvious. The rejection of Claims 1 and 18 is affirmed.
Claims 2-5, 7-10, and 19-24
Applicant does not provide separate argument as to Claims 2, 5, 7-9, 19, 21,
23, and 24. The rejection of those claims is affirmed for the reasons stated with
respect to Claims 1 and 18.
Applicant’s brief includes a separate section addressing Claims 3, 4, 10, 20
and 22. These claims were rejected over the combined teachings of Cedarleaf,
Arnold and Prandy. Applicant argues that Prandy does not cure the deficiencies of
Cerdarleaf and Arnold. Brief, 12. Since Applicant does not challenge the
examiner’s reliance on Prandy, we affirm the rejection of Claims 3, 4, 10, 20, and
22 for the same reasons as Claims 1 and 18.
AFFIRMED

KMF