Ex Parte Mukherji et al

Board of Patent Appeals and Interferences

May 18, 2012

11611173 (B.P.A.I. May. 18, 2012)

UNITED STATES PATENT AND TRADEMARKOFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
11/611,173 12/15/2006 Tapas K. Mukherji 67,008-160; 2523 3942
26096 7590 05/18/2012
CARLSON, GASKEY & OLDS, P.C.
400 WEST MAPLE ROAD
SUITE 350
BIRMINGHAM, MI 48009
EXAMINER
KIECHLE, CAITLIN ANNE
ART UNIT PAPER NUMBER
1733
MAIL DATE DELIVERY MODE
05/18/2012 PAPER
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
PTOL-90A (Rev. 04/07)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte TAPAS K. MUKHERJI, MICHAEL E. DANDORPH,
BRUCE D. HANSEN and EDWARD J. KAREDES
____________

Appeal 2011-002127
Application 11/611,173
Technology Center 1700
____________

Before JEFFREY T. SMITH, LINDA M. GAUDETTE and
DONNA M. PRAISS, Administrative Patent Judges.

SMITH, Administrative Patent Judge.

DECISION ON APPEAL

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STATEMENT OF THE CASE
This is an appeal under 35 U.S.C. § 134 from a final rejection of
claims 1 through 16, 18 through 21, 23 and 24. We have jurisdiction under
35 U.S.C. § 6.
Appellants’ invention is directed to a method for surface-hardening a
particular metal alloy composition and the surface-hardened component
resulting from the method. App. Br. 2. Claims 1 and 12 are illustrative of
the subject matter on appeal and are reproduced below:
1. A surface hardening method comprising the step
of:
increasing, by carburization, a surface hardness of a
metal having a composition that includes about 0.21-0.25 wt%
carbon, about 2.9-3.3 wt% chromium, about 11-12 wt% nickel,
about 13-14 wt% cobalt, about 1.1-1.3 wt% molybdenum, and a
balance of iron from a first hardness to a second hardness.
12. A surface-hardened component comprising:
a core section comprising steel having a composition that
includes about 0.21-0.25 wt% carbon, the core section having a
first hardness between about 51 HRc and 55 HRc; and
a carburized case section having a surface carbon
concentration between about 0.5-065 wt% carbon a second
hardness that is greater than the first hardness.
The Examiner relied on the following references in rejecting the
appealed subject matter:
Hemphill US 5,087,415 February 11, 1992
Burris US 5,536,335 July 16, 1996
Yamaguchi US 2004/0250921 A1 December 16, 2004
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S. Lampman, Introduction to Surface Hardening of Steels-Diffusion
Methods of Surface Hardening, 4 ASM HANDBOOK 3 (1991).

Appellants, App. Br. 3, request review of the following rejections
from the Examiner’s final office action:1
I. Claims 1-11 stand rejected under 35 U.S.C. § 103(a) as being
unpatentable over Yamaguchi, Hemphill and Lampman.
II. Claims 12-16 and 18-20 stand rejected under 35 U.S.C. § 103(a) as
being unpatentable over Hemphill, Yamaguchi and Lampman.
III. Claims 1 and 11-24 stand rejected under 35 U.S.C. § 103(a) as being
unpatentable over Burris, Hemphill and Lampman.

OPINION
Rejections I and III

The dispositive issue on appeal for these rejections under 35 U.S.C.
§ 103(a) is: Did the Examiner err in determining that the combination of
either Yamaguchi or Burris with Hemphill and Lampman would have led
one skilled in the art to a surface hardening method of carburizing a low
carbon metal alloy from a first hardness to a second hardness and a surface
hardened metal alloy component with a core section and a carburized case
section where the hardness of the case section is greater than the hardness of

1 The rejections under appeal listed correspond to the new grounds of
rejection presented by the Examiner in the Answer mailed July 8, 2010 that
rely on a newly added secondary reference to Lampman. Ans. 3.
Appellants properly addressed these rejections in the Reply Brief entered
September 8, 2010 and acknowledged by the Examiner in a communication
mailed November 12, 2010.
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the core section as respectively required by the subject matter of independent
claims 1, 12 and 19?2
After thorough review of the respective positions provided by
Appellants and the Examiner, we answer this question in the negative and
AFFIRM.
The Examiner found that Yamaguchi and Burris both disclose a
surface hardening method comprising the step of increasing a surface
hardness of a steel from a first hardness to a second hardness by
carburization. Ans. 4, 12. The Examiner found that both Yamaguchi and
Burris do not teach the composition of the metal alloy required by the
subject matter of independent claim 1. Id. The Examiner found that
Hemphill discloses a metal alloy composition comprising components in
amounts that overlap the metal alloy required by the claimed invention. Id.
at 4-5, 12. The Examiner additionally found that Lampman discloses it is
well known in the art to carburize steels with a carbon concentration of up to
0.50 wt%. Id. at 5, 12. The Examiner found that it would have been
obvious to one of ordinary skill in the art to carburize the metal alloy of
Hemphill using the processes of either Yamaguchi or Burris. Id.
Appellants argue that the Examiner has not shown that the
composition of the metal alloy of Hemphill would react equivalently to the
composition of the metal alloy carburized by Yamaguchi (App. Br. 3) or
Burris (id. at 4-5) and, thus would destroy the suitability of Hemphill’s metal

2 We will limit our initial discussion to independent claim 1. Our analysis is
also applicable to independent claims 12 and 19. We note that Appellants
have not argued some of the dependent claims separately. Accordingly,
those dependent claims stand or fall together with their respective
independent claim. Claims argued separately will be addressed.
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alloy composition (id. at 3). In support of this position, Appellants argue
that Hemphill discloses the metal alloy composition is hardened by age
hardening, which is different from surface hardening. Id. at 4. Appellants
further argue that carburization is typically conducted with metal alloys that
have a much lower carbon concentration than Hemphill’s metal alloy
composition. Id.
We agree with the Examiner’s determination that Hemphill’s metal
alloy composition in not limited to hardening by age hardening. Ans. 16.
Moreover, Lampman discloses that metal alloys, such as steel, that “usually
have base-carbon contents of about 0.2%” can be subjected to carburization.
Lampman 4. The carbon content of the metal alloy compositions disclosed
in Hemphill of 0.2-0.33 % (Hemphill col. 2, Table I) and in Burris of 0.07 to
0.33% (Burris col. 2 l. 65) fall within the suitable ranges disclosed by
Lampman (4). Thus, one skilled in the art would understand that both
Hemphill and Burris encompass metal alloy compositions that can be
subjected to carburization.
We note that Appellants rely on general statements from their
Specification (Spec ¶ [0004]; App. Br. 4) and on the reference to Walenta
(App. Br. 4) to support the contention that carburizing Hemphill’s metal
alloy composition using the processes of either Yamaguchi or Burris would
result in a product containing carbide phases that weaken the product.
However, these statements are unpersuasive because they do not explain
why the metal alloy compositions of Hemphill with a carbon content of at
least 0.2% cannot be carburized by the process of either Yamaguchi or
Burris in view of Lampman’s disclosure.
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Appellants also argue that Burris suggests that in order to carburize
such alloys, the alloy must meet other compositional requirements not met
by the metal alloy composition of Hemphill. App. Br. 5. We are
unpersuaded by this argument because Appellants have not pointed to any
portion of Burris which supports the contention that Hemphill’s metal alloy
composition was unsuitable for the carburization process of Burris.

Claim 11
While Appellants argue that the composition disclosed in Hemphill
does not overlap the claimed composition of sulfur, titanium, and aluminum
as recited in claim 11 (Reply Br. 3), we find that the Examiner has presented
an adequate explanation of why one skilled in the art would have found the
claimed metal alloy composition obvious in view of Hemphill (Ans. 5).
Appellants have not adequately addressed the Examiner’s reasoning.

Claims 21, 23 and 24
Appellants argue that Burris’ carburization and diffusion steps are
directed to achieve a desired deep case depth and not to merely infuse the
alloy with as much carbon as possible. App. Br. 5. Appellants also argue
that there is no desire to increase the carbon content because the
carburization step of Burris uses carbon above the saturation level of carbon
in the alloy that would lead to the formation of undesirable carbides due to
an alleged propensity of exceeding the solubility limits of the carbon in the
alloy. Id. at 5-6. Appellants additionally argue that the Examiner did not
provide an adequate reason for combining the elements of the prior art in the
manner claimed because neither of the cited references teach further
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increasing carbon concentration at the surface of the steel by using multiple
cycles of carburizing and diffusing. Reply Br. 5.
The Examiner responds that it would have been obvious to one of
ordinary skill in the art to repeat the cycle if necessary in order to further
increase the carbon concentration at the surface of the steel based on the
desired final product. Ans. 18.
As the Supreme Court has held
[o]ften, it will be necessary for a court to look to interrelated
teachings of multiple patents . . . ; and the background
knowledge possessed by a person having ordinary skill in the
art, all in order to determine whether there was an apparent
reason to combine the known elements in the fashion claimed
by the patent at issue. To facilitate review, this analysis should
be made explicit.
KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 418 (2007). We find that the
Examiner has presented an adequate explanation of why one skilled in the
art would have modified the process of Burris to include multiple cycles of
carburizing and diffusing. Appellants have not adequately addressed the
Examiner’s reasoning. With respect to the alleged formation of carbides
resulting from the inclusion of multiple cycles of carburizing and diffusing
in the process of Burris, we refer to our discussion above on this issue and
agree with the Examiner (Ans. 18) that Appellants have not supported their
argument with adequate evidence to show that so modifying the process of
Burris would lead to the formation of undesirable carbides in the metal alloy
compositions of Hemphill.

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Rejection II
Appellants rely on the same arguments presented for the rejection of
independent claims 1, 12 and 19 above. App. Br. 5; Reply Br. 4.
Accordingly, we will also sustain this rejection for the reasons given above.

ORDER
The rejection of claims 1-11 under 35 U.S.C. § 103(a) as unpatentable
over Yamaguchi, Hemphill and Lampman is affirmed.
The rejection of claims 12-16 and 18-20 under 35 U.S.C. § 103(a) as
unpatentable over Hemphill, Yamaguchi and Lampman is affirmed.
The rejection of claims 1 and 11-24 under 35 U.S.C. § 103(a) as
unpatentable over Burris, Hemphill and Lampman is affirmed.

TIME PERIOD
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a)(1).

AFFIRMED

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