Ex Parte Stegmaier et al

Board of Patent Appeals and Interferences

Jan 14, 2009

10514995 (B.P.A.I. Jan. 14, 2009)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte MATTHIAS STEGMAIER, JUERGEN SOJKA,
MICHAEL WALTER, THOMAS ZEIN,
ANDREAS KRAUTTER and HOLGER PLOTE
____________

Appeal 2009-1019
Application 10/514,995
Technology Center 3700
____________

Decided: January 14, 2009
____________

RICHARD E. SCHAFER, JAMESON LEE and SALLY C. MEDLEY,
Administrative Patent Judges.

MEDLEY, Administrative Patent Judge.
DECISION ON APPEAL
A. Statement of the Case
Robert Bosch GmbH (“Bosch”), the real party in interest, seeks review
under 35 U.S.C. § 134(a) of a Final Rejection of claims 6-15. We have
jurisdiction under 35 U.S.C. § 6(b). We affirm.
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Bosch’s invention is a method for determining the loading of a particle
filter. The method includes determining a flow resistance variable of the
particle filter based on a temperature in the particle filter and a pressure
difference across the particle filter. The temperature in the particle filter is
modeled based on a temperature measured upstream from the particle filter,
and takes into account the thermal capacity of the particle filter, the thermal
capacity of the exhaust gas, and the exhaust-gas mass flow. (Spec. Abs., 3,
6-7).
Representative claim 6, reproduced from the Claim Appendix of the
Appeal Brief, reads as follows:
A method for determining a loading of a particle filter, the
method comprising:
determining a variable characterizing a flow resistance of
the particle filter based on a temperature in the particle filter
and a pressure difference across the particle filter; and
determining a conclusion regarding the loading of the
particle filter based on the flow resistance;
wherein a temperature upstream from the particle filter is
measured, and the temperature in the particle filter is modeled
based on the measured temperature, the model taking into
account a thermal capacity of the particle filter, a thermal
capacity of an exhaust gas, and an exhaust-gas mass flow.

The Examiner relies on the following prior art in rejecting the claims on
appeal:
Cullen et al. (“Cullen”) 5,722,236 Mar. 3, 1998
Christen et al. (“Christen”) 6,405,528 Jun. 18, 2002
Hirota et al. (“Hirota”) 6,588,204 Jul. 8, 2003

The Examiner rejected claims 6-15 under 35 U.S.C. § 103(a) as
unpatentable over Christen, Hirota and Cullen.
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B. Issue
Does Bosch demonstrate that the Examiner erred in determining that the
claimed invention is obvious over the prior art?
C. Findings of Fact (“FF”)
Christen
1. Christen describes diesel particle filter (DPF) [16, 16a, 16b] that
includes a filter [26], a pair of temperature sensors [30], [32], and a pair
of pressure sensors [34], [36] and a mass air flow (MAF) sensor [38].
(Col. 3, ll. 8-39; figs. 2-3).
2. The temperature sensors [30], [32] measure the temperature upstream
and downstream of the DPF [16], [16a], [16b] and produce
corresponding temperature signals [TupDPF], [TdnDPF]. (Col. 3, ll. 11-15).
3. The pressure sensors [34], [36] measure the pressure upstream and
downstream of the DPF [16], [16a], [16b] and produce corresponding
pressure signals [PupDPF], [PdnDPF]. (Col. 3, ll. 15-20).
4. The temperature, pressure, and air mass flow sensors permit
determination of the DPF load (lDPF). (Col. 3, ll. 40-42)
5. The equation for calculating the DPF load (lDPF) includes the
temperature in the DPF (TDPF), the pressure drop across the DPF (ΔpPDF)
and the effective restriction (ADPF (lDPF)). (Col. 4, ll. 23-47; col. 5, ll.
49-58; equations 10, 11).
6. The effective restriction (ADPF (lDPF)) accounts for the clogging of the
DPF by particulate matter which gradually accumulates in the DPF.
(Col. 5, ll. 31-33).
7. The temperature in the DPF (TDPF) used in the DPF load equation can be
either the temperature upstream of the DPF [TupDPF] or the temperature
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downstream of the DPF [TdnDPF] or the average of the two temperatures.
(Col. 5, ll. 59-65).
Hirota
8. Hirota describes that the temperatures of the gas flow-in portion and the
exhaust gas flow-out portion of particulate filter [70] may be estimated
on the basis of the temperature of the exhaust gas, an amount of
reducing materials in the exhaust gas, and the like, that change in
accordance with the engine operating condition. (Col. 22, ll. 29-35).
Cullen
9. Cullen describes a NOx (nitrogen oxides) trap [30] comprising two
bricks [30a], [30b] and a temperature sensor [32] located in the space
“D” between bricks [30a], [30b]. (Col. 2, l. 62-col. 3, l. 2; fig. 1)
10. The sensor [32] provides an accurate measurement of the temperature of
the trap [30] during steady-state condition but has a time constant of
about 15 minutes during which the measurement data is relatively
inaccurate. (Col. 3, ll. 2-6; col. 9, ll. 9-11, 43-45).
11. An estimate [ext_tso] of what the temperature sensor [32] at location
“D” should be reading during the transient state is calculated. (Col. 5, ll.
42-43; col. 9, ll. 32-58; fig. 5a; equations 24, 25).
12. The estimate [ext_tso] of what the temperature sensor [32] should be
reading is based on a filter constant [fk_ntD], a time constant [tc_ntD]
and the steady state temperature [ext_ss_ntD] at location “D” which is
equal to the instantaneous temperature [ext_ntC] near the front face “C”
of the trap. (Col. 8, l. 55-col. 9, l. 12; fig. 5a; equations 20-23).
13. The time constant [tc_ntD] is due to the thermal capacitance of the trap
substrate and material and is calculated based on the total air flow,
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which accounts for the engine air mass flow [am]. (Col. 7, l. 19; col. 9,
ll. 9-15; fig. 5a; equation 21).
14. The instantaneous temperature [ext_ntC] near the front face “C” of the
trap is calculated based on the exotherm temperature [ext_ntr_exo] and
heat capacity of the total heat flow [exh_ht_cap] which ultimately
accounts for the heat capacity of the air [EXP_CP_AIR2] and the engine
air mass flow [am]. (Col. 7, ll. 1-26; fig. 5a; equations 10, 15, 16, 19).
C. Principles of Law
In KSR, the Supreme Court rejected the rigid application of the “teaching
suggestion or motivation” (TSM) test, instead favoring the “expansive and
flexible approach” used by the Court. KSR Int’l Co. v. Teleflex Inc., 127
S.Ct. 1727, 1739 (2007).
In an obviousness analysis, it is not necessary to find precise teachings in
the prior art directed to the specific subject matter claimed because
inferences and creative steps that a person of ordinary skill in the art would
employ can be taken into account. Id. at 1741.
“Non-obviousness cannot be established by attacking references
individually where the rejection is based upon the teachings of a
combination of references.” In re Merck & Co., Inc., 800 F.2d 1091, 1097
(Fed. Cir. 1986).
D. Analysis
Christen
Bosch argues that Christen does not describe “modeling” because the
term requires using characteristic variables of the particle filter such as the
thermal capacity of the particle filter. (App. Br. 5, Reply Br. 3). Bosch
further argues that Christen’s average temperature does not suggest
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modeling because no characteristic variables of the particle filter are taken
into consideration (e.g., particle filter thermal capacity, exhaust gas thermal
capacity, and an exhaust-gas mass flow). (App. Br. 5, Reply Br. 3).
Bosch’s arguments are not persuasive because the Examiner does not rely
upon Christen for describing a model that uses, considers or accounts for
characteristic variables of the particle filter. (Final Rejection 3, Ans. 4).
Instead the Examiner relies on Cullen to teach a temperature model that
accounts for particle filter characteristic variables. (Final Rejection 4, Ans.
4-5). Non-obviousness cannot be established by attacking references
individually where the rejection is based upon the teachings of a
combination of references.
Hirota
Bosch argues that Hirota does not suggest modeling of the temperature in
the particle filter or suggest anything relating to the temperature upstream of
the particle filter. (App. Br. 5, Reply Br. 4). Bosch argues that instead
Hirota describes simulation of the temperature downstream from the filter or
estimation of temperatures outside of the particle filter. (App. Br. 5, Reply
Br. 4).
Bosch’s arguments are unpersuasive. Hirota describes that the
temperatures of the gas flow-in portion and the exhaust gas flow-out portion
of the particulate filter may be estimated on the basis of at least the
temperature of the exhaust gas and an amount of reducing materials. (FF1
8). It would have been obvious to one of ordinary skill in the art that the gas
flow-in portion and the gas flow-out portion of the particulate filter are
merely the portions of the filter that contact the gas flowing into the filter

1 FF denotes Finding of Fact.
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and the gas flowing out of the filter. Thus, the temperatures of the gas flow-
in portion and the exhaust gas flow-out portion of the particulate filter are
also the temperatures in the filter. Further, it would have been obvious to
one with ordinary skill in the art that the temperature of the exhaust gas
described by Hirota is measured upstream from the particle filter following
exit from the engine since Hirota describes that the temperature model is
based on factors that change in accordance with the engine operating
condition. (FF 8).
Bosch further argues that the combination of Christen and Hirota does
not suggest modeling of the temperature in the particle filter or such
modeling based on the thermal capacity of the particle filter, thermal
capacity of an exhaust gas, and an exhaust-gas mass flow. (Reply Br. 3).
Bosch’s argument is not persuasive because the Examiner does not rely upon
Christen or Hirota to describe modeling of the temperature in the particle
filter or the model’s taking into account the particle filter thermal capacity,
exhaust gas thermal capacity, and an exhaust-gas mass flow. Instead, the
Examiner relies on Cullen to teach accounting for catalyst (i.e., particle
filter) thermal capacity, exhaust gas thermal capacity, and an exhaust-gas
mass flow in a temperature model. (Final Rejection 4, Ans. 4-5). Non-
obviousness cannot be established by attacking references individually
where the rejection is based upon the teachings of a combination of
references.
Cullen
Bosch argues that Cullen does not describe measuring the upstream
exhaust gas temperature (i.e., temperature upstream from the particle filter)
with a temperature sensor, but instead describes an approximation of the
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upstream exhaust gas temperature. (App. Br. 6, Reply Br. 4). Bosch’s
argument is not persuasive because it attacks the Cullen reference
individually. The Examiner does not rely on Cullen for describing
measurement of the temperature upstream from the particle filter. Instead,
the Examiner relies on Christen for describing measurement of the
temperature upstream from the particle filter. (Final Rejection 3, Ans. 3-4,
FFs 1-2). Non-obviousness cannot be established by attacking references
individually where the rejection is based upon the teachings of a
combination of references.
Bosch further argues that Cullen does not describe (1) using the specific
heat capacity of the component (i.e., exhaust catalyst or particle filter) for
computing the temperature of the NOx trap; and (2) using the exhaust-gas
mass flow for calculating the temperature at point “C”. (App. Br. 6; Reply
Br. 5). Bosch’s arguments are not persuasive because they are not
commensurate in scope with the claim language. As explained before, the
claim language does not require using the specific heat capacity of the
particle filter or using the exhaust-gas mass flow. The claim language
merely requires the model to take into account the thermal capacity of the
particle filter and the thermal capacity of an exhaust gas. Cullen describes a
time constant [tc_ntD] that is used in the estimate of the temperature at
location “D” [ext_tso], which corresponds to the location of temperature
sensor [32] in the filter, where the time constant accounts for the specific
heat capacity of the trap (i.e., filter) substrate and material. (FFs 9-13).
Cullen also describes using the engine air mass flow [am] (i.e., exhaust-gas
mass flow) for calculating the instantaneous temperature at point “C”
[ext_ntC], which is ultimately used in the estimation of the temperature of
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point “D” [ext_tso]. (FFs 10-12, 14). Therefore, Cullen’s estimate of the
temperature at point “D” [ext_tso] ultimately accounts for the specific heat
capacity of the trap through the use of the time constant [tc_ntD], and also
accounts for the exhaust-gas mass flow [am] through the calculation of the
instantaneous temperature at point “C” [ext_ntC].
Combination of References
Bosch argues that the Examiner has not explained (1) which features of
Cullen and Hirota would be incorporated or how they would be incorporated
into the teachings of Christen; (2) the specific modification to the teachings
of Christen; and (3) why one of ordinary skill in the art would be motivated
to select the specific features taught in Cullen and Hirota for the purpose of
the general modification asserted by the Examiner. (Reply Br. 5).
Bosch’s arguments are not persuasive. The Examiner explains that
Christen is modified by Hirota to estimate the temperature in the filter (i.e.,
the exhaust gas flow-out portion of the filter) based on a thermal model that
takes into account an upstream exhaust gas temperature. (Final Rejection 3-
4, Ans. 4). The Examiner explains that the combination of Christen and
Hirota is further modified by Cullen to model the instantaneous temperature
in the filter based on temperatures upstream of the filter, the detected steady
state temperature of the filter, catalyst (i.e., particle filter) thermal capacity,
exhaust gas thermal capacity, and an exhaust-gas mass flow. (Final
Rejection 4, Ans. 5). The Examiner finds that one of ordinary skill in the art
would have been motivated to do so in order to provide an effective means
to accurately determine the temperature of the filter during a transient
condition of the engine. (Final Rejection 4, Ans. 5). The Examiner’s
rationale is reasonable.
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For all of the foregoing reasons, Bosch has not sufficiently demonstrated
that the Examiner erred.
E. Conclusions of Law
Based on the Findings of Fact and the Analysis above, Bosch has not
sufficiently demonstrated that the Examiner erred in determining that the
claimed invention is obvious.
F. Decision
The decision of the Examiner rejecting claims 6-15 under 35 U.S.C. §
103(a) as unpatentable over Christen, Hirota and Cullen is affirmed.
No time period for taking any subsequent action in connection with the
appeal may be extended under 37 C.F.R. § 1.136(a).
AFFIRMED
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MAT

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