Ex Parte Schaeffer et al

Board of Patent Appeals and Interferences

Jul 19, 2002

08435902 (B.P.A.I. Jul. 19, 2002)

1 The Examiner has indicated that the subject matter of claim 21 was allowable.
However the claim has been objected to as depending on a rejected claim. (Final Rejection, p. 7).
The opinion in support of the decision being entered today was not written for publication and
is not binding precedent of the Board.
Paper No. 16
UNITED STATES PATENT AND TRADEMARK OFFICE
____________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________
Ex parte JON C. SCHAEFFER,
RUSSELL L. MCCARRON and DENNIS M. GRAY
____________
Appeal No. 1998-2295
Application No. 08/435,902
____________
ON BRIEF
____________
Before WALTZ, LIEBERMAN and JEFFREY T. SMITH, Administrative Patent Judges.
JEFFREY T. SMITH, Administrative Patent Judge.
DECISION ON APPEAL
Applicants appeal the decision of the Primary Examiner finally rejecting
claims 1 to 4, 6 to 13 and 15 to 20.1 We have jurisdiction under 35 U.S.C. § 134.
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BACKGROUND
Appellants’ invention relates to materials used in aircraft turbine engines. More
specifically the invention is directed to titanium based alloys coated with a protective
coating. The protective coating is composed of a mixture of matrix metal and ceramic
particles. The ceramic particles are embedded in the matrix metal. The coating is said to
provide protection against diffusionally based oxidation and hot corrosion and hot erosion.
(Specification, pp. 2 and 3). The coating is also said to avoid the creation of thermal strains
and stress that would result due to differences in thermal expansion coefficients of the
coating and metallic substrate. (Specification, p. 3). The coefficient of thermal expansion
of the coating relates to the relative amount of metallic constituents, which have a high
coefficient of thermal expansion, and the ceramic constituents, which have a low coefficient
of thermal expansion. Thus the components of the coating are selected to provide a
coefficient of thermal expansion that matches the substrate. (Specification, p. 4). Claims 1,
9 and 12, which are representative of the claimed invention, appear below:
1. An article comprising:
a substrate formed of a first metal comprising a titanium-based alloy; and
a coating directly in contact with the substrate, the coating being formed of a
mixture comprising a second metal and a ceramic, wherein the ceramic is
selected from the group consisting of an oxide, a nitride, and a silicide.
9. An article comprising:
a substrate which is an uncooled component of a gas turbine engine, the substrate
being formed of a first metal comprising a titanium-base alloy; and
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a coating directly in contact with the substrate, the coating being formed of a mixture
of a ceramic and a second metal, the second metal being selected from the group consisting
of a nickel-base alloy and a cobalt-base alloy, wherein the substrate has a substrate
coefficient of thermal expansion, and the mixture has a mixture coefficient of thermal
expansion, and wherein the relative amounts of the ceramic and the second metal in the
mixture are such that the coefficient of thermal expansion of the mixture is about the same
as the substrate coefficient of thermal expansion over at least some temperature range.
12. A method for preparing an article, comprising the steps of:
providing a substrate made of a first metal comprising a titanium-base alloy; and
applying a coating directly in contact with a surface of the substrate, the coating being
formed of a mixture of a second metal and a ceramic, wherein the step of applying includes
the steps of
determining the thermal expansion coefficient of the substrate, and
selecting a coating proportion of the second metal and the ceramic such that the
thermal expansion coefficient of the coating has a selected relation to the thermal expansion
coefficient of the substrate.
CITED PRIOR ART
As evidence of unpatentability, the Examiner relies on the following references:
Hodshire et al. (Hodshire) 3,785,785 Jan. 15, 1974
Wolfla 3,864,093 Feb. 04, 1975
Wilbers et al. (Wilbers) 4,250,610 Feb. 17, 1981
Blackburn et al. (Blackburn) 4,292,077 Sep. 29, 1981
Quets 5,223,332 Jun. 29, 1993
The Examiner rejected claims 9, 10, 12, 13 and 15 to 20 as unpatentable under 35
U.S.C. § 103(a) as obvious over the combination of Quets and Wilbers. Claim 11 is rejected
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as unpatentable under 35 U.S.C. § 103(a) as obvious over the combination of Quets, Wilbers
and Blackburn. Claims 1, 3, 4, 6 to 9, 12, 13, 15, 16 and 18 to 20 are rejected as
unpatentable under 35 U.S.C. § 103(a) as obvious over the combination of Wolfla and
Hodshire. Claims 2, 10, 11 and 17 are rejected as unpatentable under 35 U.S.C. § 103(a) as
obvious over the combination of Wolfla, Hodshire and Blackburn. (Answer, pp. 4 to 9).
DISCUSSION
We have carefully reviewed the claims, specification and applied prior art, including
all of the arguments advanced by both the Examiner and Appellants in support of their
respective positions. This review leads us to conclude that the rejections of claims 2, 6 and
9 to 20 are not well founded. However, we will sustain the rejection of claims 1, 3, 4, 7
and 8. Our reasons appear below.
The Examiner has rejected claims 1, 3, 4, 6 to 9, 12, 13, 15, 16 and 18 to 20 as
unpatentable under 35 U.S.C. § 103(a) as obvious over the combination of Wolfla and
Hodshire. The subject matter of claim 1 describes an article comprising a titanium substrate
and a coating directly on the substrate that comprises a mixture of a metal matrix and
ceramic particles. Wolfla describes coating substrates, useful as turbine engine blades, with
a coating comprising a metal and ceramic particles. (Col. 1, l. 68 to col. 2, l. 58).
Wolfla discloses suitable substrate material is used in various corrosive environments
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and is selected from a variety of metals and metal alloys. Wolfla discloses refractory metal
alloys are suitable substrate materials however, titanium base alloy is not disclosed. (Col. 3,
ll. 15 to 40). Hodshire describes substrates useful as turbine engine blades. Hodshire
discloses suitable substrates include refractory metal alloys such as titanium alloys. (Col. 1,
ll. 14 to 17 and 52 to 59). Thus, the use of titanium-based alloys as the substrate in the
Wolfla invention would have been obvious to one of ordinary skill in the art because
titanium base alloys are known refractory metal alloys.
Wolfla discloses the coating is usually about 0.003 inches or thicker and formed from
a metal matrix and ceramic particles that include aluminum oxide, chromium oxide and
silicon dioxide. (Col. 2, ll. 29 to 36). Nickel and cobalt alloys are disclosed to be suitable
for the metal alloy matrix coating. (Col. 2, ll. 53 to 58). These disclosures meet the
limitations of claims 3, 4, 7 and 8.
The combination of Wolfla and Hodshire does not render the subject matter of claims
6, 9 and 12 obvious. These claims describe the selection of the substrate and coating so that
there is a relation of the coefficient of thermal expansion for the substrate and the coating.
Neither reference discloses or describes the need for the coefficient of thermal expansion for
the substrate and the coating to be about the same. The references also do not discuss the
determination of the coefficient of thermal expansion for the substrate and the selection of
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the coating based on this determination so that the coefficient of thermal expansion of the
substrate and coating are about the same. Consequently, the rejection of claims 6, 9, 12, 13,
15, 16 and 18 to 20 over Wolfla and Hodshire is reversed.
The Examiner added the Blackburn reference to the combination of Wolfla and
Hodshire to reject claims 2, 10, 11 and 17.
Claims 2, 10, 11 and 17 define the substrate of the claimed invention as comprising
an alloy of titanium and aluminum or titanium, niobium and aluminum. The Examiner relies
on Blackburn to disclose that the use of alloys comprising titanium, aluminum and/or
niobium is known to be used in turbine engines. The Examiner concludes that the teachings
of Hodshire and Blackburn would have rendered obvious the use of a titanium-aluminum-
niobium alloy as the substrate in Wolfla. (Answer, p. 9). The mere fact that the prior art
could be modified would not have made the modification obvious unless the prior art
suggested the desirability of the modification. In re Gordon, 733 F.2d 900, 902, 221 USPQ
1125, 1127 (Fed. Cir. 1984); In re Laskowski, 871 F.2d 115, 117, 10 USPQ2d 1397, 1398
(Fed. Cir. 1989). The record indicates that the motivation relied upon by the Examiner for
selection of a particular substrate comes from the Appellants’ description of their invention
in the specification rather than coming from the applied prior art and that, therefore, the
Examiner used impermissible hindsight in rejecting the claims. See W.L. Gore &
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Associates v. Garlock, Inc., 721 F.2d 1540, 1553, 220 USPQ 303, 312-13 (Fed. Cir. 1983);
In re Rothermel, 276 F.2d 393, 396, 125 USPQ 328, 331 (CCPA 1960). Accordingly, we
reverse the Examiner’s rejection under 35 U.S.C. § 103(a) over Wolfla, Hodshire and
Blackburn.
The Examiner relies on the combined teachings of Quets and Wilbers to reject claims
9, 10, 12, 13 and 15 to 20 under 35 U.S.C. § 103(a). The Examiner adds Blackburn to the
teaching of Quets and Wilbers to reject claim 11 under 35 U.S.C. § 103(a). We reverse each
of these rejections.
Quets describes duplex coatings for various substrates. Suitable substrates include
titanium alloys. (Col. 4). The duplex coating is the combination of an undercoat layer
comprising a metal matrix such as tungsten carbide-cobalt, and a top coat layer formed of a
ceramic material. The coating of Quets differs from the coating of claims 9 and 12 in that
the ceramic material is not mixed with the metal matrix. Quets does not disclose that the top
coat and undercoat are mixed together. The Examiner does not rely on Wilbers to remedy
this deficiency. The Examiner cites Wilbers to teach “matching coefficients of thermal
expansion between gas turbine part substrates”. (Answer, p. 5). The matching of thermal
expansion coefficients would not motivate a person of ordinary skill in the art to form a
coating that is a mixture of a metal matrix and a ceramic material as required by claims 9
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and 12. The addition of the Blackburn reference also does not remedy the deficiency in the
teachings of Quets. We therefore reverse the rejection of claims 9, 10, 11, 12, 13 and 15 to
20.
We note the Examiner has taken official notice regarding several features of the
claimed invention throughout the prosecution of this application. The Examiner has refused
to provide evidence of the various embodiments of the claimed invention even thought the
Appellants have seasonably requested the Examiner provide this information. (See MPEP
§ 2144.03). Once Appellants have seasonably and adequately challenged the facts alleged to
be common knowledge, the burden of proof in on the Examiner to provide evidence to
support his findings. Cf. In re Lee, 277 F3d 1338, 1342-43, 61 USPQ2d 1430, 1433 (Fed.
Cir. 2002).
CONCLUSION
The rejection of claims 1, 3, 4, 7 and 8 under 35 U.S.C. § 103(a) as obvious over the
combination of Wolfla and Hodshire is affirmed. The 35 U.S.C. § 103(a) rejections of
claims 2, 6, 9, 10, 11, 12, 13 and 15 to 20 are reversed.
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No time period for taking any subsequent action in connection with this appeal may
be extended under 37 CFR § 1.136(a).
AFFIRMED-IN -PART
)
)
THOMAS A. WALTZ )
Administrative Patent Judge )
)
)
) BOARD OF PATENT
PAUL LIEBERMAN ) APPEALS
Administrative Patent Judge ) AND
) INTERFERENCES
)
)
JEFFREY T. SMITH )
Administrative Patent Judge )
JTS/kis
Appeal No. 1998-2295
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ANDREW C. HESS
GENERAL ELECTRIC COMPANY
ONE NEUMANN WAY H-17
CINCINNATI, OH 45215-6301