Ex Parte HSU

Board of Patent Appeals and Interferences

May 16, 2003

09141891 (B.P.A.I. May. 16, 2003)

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publication and is not binding precedent of the Board.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. 11
UNITED STATES PATENT AND TRADEMARK OFFICE
____________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________
Ex parte HUA CHING HSU
____________
Appeal No. 2001-0379
Application No. 09/141,891
____________
ON BRIEF
____________
Before BARRETT, GROSS, and LEVY, Administrative Patent Judges.
LEVY, Administrative Patent Judge.
DECISION ON APPEAL
This is a decision on appeal under 35 U.S.C. § 134 from the
examiner's final rejection of claims 1-7, 9, 11-18, 20-28, and
30, which are all of the claims pending in this application.
Claims 8, 10, 19, and 29 have been canceled.

Appeal No. 2001-0379
Application No. 09/141,891
Page 2
BACKGROUND
Appellant’s invention relates to an apparatus and method for
detecting flammable gas in a gas mixture. An understanding of
the invention can be derived from a reading of exemplary claims 1
and 11, which are reproduced as follows:
1. An apparatus for detecting a flammable gas in a gas
mixture comprising:
a chamber having an inlet, an outlet and a cavity contained
therein, said cavity being equipped with an ignitor means and a
temperature sensor,
an air pump having an inlet connected to the outlet of said
chamber such that said inlet of the air pump is in fluid
communication with the inlet of said chamber enabling a gas
mixture to flow therethrough at a speed of not less than 5
meter/second, and
a valve means for shutting off said inlet to said chamber
when said ignitor means ignites a flammable gas in said gas
mixture and said temperature sensor senses a temperature rise of
at least 10"C.
11. A method for detecting a flammable gas in a gas mixture
comprising the steps of:
providing a reactor chamber having an inlet, an outlet and a
cavity contained therein,
positioning an ignitor means and a temperature sensor in
said cavity,
flowing a gas mixture through said inlet of said reactor
chamber into said cavity;
igniting said gas mixture by said ignitor means, and
Appeal No. 2001-0379
Application No. 09/141,891
Page 3
stopping said gas mixture flow when said temperature sensor
detects a temperature rise in said cavity.
The prior art references of record relied upon by the
examiner in rejecting the appealed claims are:
Cox 3,913,600 Oct. 21, 1975
Kern 4,381,218 Apr. 26, 1983
Claims 1-7, 9, 11-18, 20-28, and 30 stand rejected under 35
U.S.C. § 103 as being unpatentable over Kern in view of Cox.
Rather than reiterate the conflicting viewpoints advanced by the
examiner and appellant regarding the above-noted rejection, we
make reference to the examiner's answer (Paper No. 10, mailed
June 16, 2000) for the examiner's complete reasoning in support
of the rejection, and to appellant's brief (Paper No. 9, filed
May 31, 2000) for appellant's arguments thereagainst. Only those
arguments actually made by appellant have been considered in this
decision. Arguments which appellant could have made but chose
not to make in the brief have not been considered. See 37 CFR
1.192(a).
OPINION
In reaching our decision in this appeal, we have carefully
considered the subject matter on appeal, the rejection advanced
Appeal No. 2001-0379
Application No. 09/141,891
Page 4
by the examiner, and the evidence of obviousness relied upon by
the examiner as support for the rejection. We have, likewise,
reviewed and taken into consideration, in reaching our decision,
appellant's arguments set forth in the brief along with the
examiner's rationale in support of the rejection and arguments in
rebuttal set forth in the examiner's answer.
Upon consideration of the record before us, we affirm-in-
part.
In rejecting claims under 35 U.S.C. § 103, it is incumbent
upon the examiner to establish a factual basis to support the
legal conclusion of obviousness. See In re Fine, 837 F.2d 1071,
1073, 5 USPQ2d 1596, 1598 (Fed. Cir. 1988). In so doing, the
examiner is expected to make the factual determinations set forth
in Graham v. John Deere Co., 383 U.S. 1, 17, 148 USPQ 459, 467
(1966), and to provide a reason why one having ordinary skill in
the pertinent art would have been led to modify the prior art or
to combine prior art references to arrive at the claimed
invention. Such reason must stem from some teaching, suggestion
or implication in the prior art as a whole or knowledge generally
available to one having ordinary skill in the art. Uniroyal,
Inc. v. Rudkin-Wiley Corp., 837 F.2d 1044, 1051, 5 USPQ2d 1434,
1438 (Fed. Cir. 1988); Ashland Oil, Inc. v. Delta Resins &
Appeal No. 2001-0379
Application No. 09/141,891
Page 5
Refractories, Inc., 776 F.2d 281, 293, 227 USPQ 657, 664 (Fed.
Cir. 1985); ACS Hosp. Sys., Inc. v. Montefiore Hosp., 732 F.2d
1572, 1577, 221 USPQ 929, 933 (Fed. Cir. 1984). These showings
by the examiner are an essential part of complying with the
burden of presenting a prima facie case of obviousness. Note In
re Oetiker, 977 F.2d 1443, 1445, 24 USPQ2d 1443, 1444 (Fed. Cir.
1992). If that burden is met, the burden then shifts to the
applicant to overcome the prima facie case with argument and/or
evidence. Obviousness is then determined on the basis of the
evidence as a whole. See id.; In re Hedges, 783 F.2d 1038, 1039,
228 USPQ 685, 686 (Fed. Cir. 1986); In re Piasecki, 745 F.2d
1468, 1472, 223 USPQ 785, 788 (Fed. Cir. 1984); and In re
Rinehart, 531 F.2d 1048, 1052, 189 USPQ 143, 147 (CCPA 1976).
We begin with claim 1. The examiner's position (answer,
page 3) is that Kern lacks employing the air pump at the outlet
of the chamber, assuring a particular minimum air speed, and a
temperature sensor to sense a temperature rise of at least 10
C.
To overcome this deficiency in Kern, the examiner turns to Cox
for a teaching of using a temperature sensor to detect
temperature increases up to 300
C. In the examiner's opinion
(id.), to place the pump upstream of the combustion chamber
instead of downstream would be a mere matter of designing the
Appeal No. 2001-0379
Application No. 09/141,891
Page 6
apparatus to suit particular design requirements. The examiner
additionally asserts (id.) that it would be a matter of routine
experimentation to arrive at any particular flow rate.
Appellant asserts (brief, page 8) that Cox does not teach an
air pump that has an inlet connected to an outlet of a combustion
chamber, and does not teach flowing a combustible gas through the
chamber at a speed not less than 5 meter/second. It is further
argued (brief, page 11) that neither reference teaches sensing a
temperature rise of at least 10
C by a temperature sensor when
the flammable gas is ignited. Appellant further asserts (brief,
page 12) that “the high flow speed of at least 5 meter/second of
the gas mixture into a reaction chamber is what enables the
present invention method to detect flammable gas in a very rapid
manner. Such criticality of the present invention has been
clearly shown by the Appellant and is clearly not a matter of
routine experimentation to arrive at.”
We observe at the outset that appellant does not argue the
combinability of the references, but rather argues that the
combined teachings of Kern and Cox would not result in the
claimed invention. From our review of Kern and Cox, we find that
neither reference teaches “an air pump having an inlet connected
to the outlet of said chamber such that said inlet of the air
Appeal No. 2001-0379
Application No. 09/141,891
Page 7
1 We interpret "at least 10
C" to mean a range of 10
C and greater.
pump is in fluid communication with the inlet of said chamber
enabling a gas mixture to flow therethrough at a speed of not
less than 5 meter/second,” as recited in claim 1. In addition,
although we find that Cox teaches the use of a temperature sensor
in an apparatus for monitoring and controlling the composition
of potentially flammable gas mixtures (col. 1, lines 10-12, and
col. 4, lines 5-11) we find that Cox does not teach sensing a
temperature rise of at least 10
C because switch 90 of Cox is
calibrated to close on a sensed temperature rise of 300
F (col.
4, lines 36-38)1. Thus, we find that neither Kern nor Cox
discloses (a) an air pump having an inlet connected to the outlet
of the chamber; (b) the air pump enabling a gas mixture to flow
therethrough at a speed of not less than 5 meter/second, and (c)
a temperature sensor that senses a temperature rise of at least
10
C, all as recited in claim 1.
Beginning with (a), we find no suggestion in Kern or Cox for
providing an air pump at the outlet of the chamber. Although Cox
discloses pump assembly 18 for propelling a gas sample stream
through the flammable gas tester (col. 2, lines 66-68), we find
no suggestion of providing an air pump to be connected to the
outlet of the chamber. We find the examiner's rationale (answer,
Appeal No. 2001-0379
Application No. 09/141,891
Page 8
page 4) of "a mere matter of designing the apparatus to suit
particular design requirements" to be a conclusionary statement
unsupported by any evidence in the record.
With respect to (b), we find that appellant's specification
discloses (pages 10 and 11) that:
The present invention apparatus enables the
detection of flammable gases in a very rapid
manner, for instance, within a time period of
0.5 second such that the flow of the gas mixture
can be shut-off immediately to avoid potential
hazard of fire or explosion.. . . A gas mixture
is fed into the reactor chamber at a high flow
speed of at least 5 meter/second, preferably at
a flow speed of at least 10 meter/second, and more
preferably at a flow speed of at least 15 meter/second.
The flow of the gas mixture into the reactor chamber is
induced by a high speed air pump connected to and in
fluid communication with a chamber cavity and a source
of the gas mixture.
Appellant asserts (brief, page 9) that “[t]he Appellant
respectfully submits that the criticality of the present
invention of being able to detect flammable gas in a very rapid
manner which is achieved by flowing a gas mixture into the
reaction chamber at a high flow speed of at least 5 meter/second
is not recognized by either Kern or Cox or in combination
thereof, let alone a solution proposed to such problem.” We
agree. Although Kern discloses the use of a low pressure switch
51, it is disclosed that "[t]he low pressure switch 51 serves to
Appeal No. 2001-0379
Application No. 09/141,891
Page 9
monitor the continued operation of the system with regard to a
cessation of the sample flow stream due to plugging of the
conduit 90 (col. 4, lines 41-45). We are not persuaded by the
examiner's assertion (answer, page 4) that "[g]iven the teachings
of Kern and Cox, to arrive at any particular desirable flow rate
would be a matter of routine experimentation to arrive at an
optimized flow rate." From our analysis of the teachings of Kern
and Cox, supra, we find the examiner's reasoning to be
speculation, unsupported by any evidence in the record.
With respect to (c), we do not agree with the examiner's
assertion (answer, page 4) that in Cox, ignition is detected by a
temperature sensor which detects temperature increases "up to
300
C." We find that Cox discloses (col. 4, lines 36-38) that
the temperature switch 90 closes on a sensed temperature rise to
300
F, and that when the temperature in the combustion chamber
and the temperature switch 90 drop to below 300
F, after a
suitable time delay, the switch 90 opens (col. 8, lines 53-57).
From the disclosure of Cox, we find that the switch 90 closes
when the temperature rises to 300
F, and does not detect
temperature increases up to 300
F, as asserted by the examiner.
In any event, we find no suggestion in either Kern or Cox that
would have suggested sensing a temperature rise of at least
Appeal No. 2001-0379
Application No. 09/141,891
Page 10
10
C, as recited in claim 1. Moreover, we find the examiner's
reliance on In re Aller, 220 F.2d 454, 105 USPQ 233 (CCPA 1955)
to be misplaced, as the general conditions of the claim are not
disclosed in the prior art.
From all of the above, we find that the examiner has failed
to establish a prima facie case of obviousness of claim 1.
Accordingly, the rejection of claim 1 and claims 2-7, and 9,
dependent therefrom, is reversed.
We turn next to independent claim 11. We observe at the
outset that the limitations which distinguished claim 1 from Kern
and Cox, i.e., (a) an air pump having an inlet connected to the
outlet of the chamber; (b) the air pump enabling a gas mixture to
flow therethrough at a speed of not less than 5 meter/second, and
(c) a temperature sensor that senses a temperature rise of at
least 10
C, do not appear in claim 11. We find that Cox
discloses a method for detecting flammable gas in a gas mixture
(col. 1, lines 7-12); providing a reactor chamber (48 and col. 4,
line 42) having an inlet (80), an outlet (84) and a cavity
(figure 1) contained therein; providing an ignitor means (86) and
a temperature sensor (90) in the cavity; flowing a gas mixture
through said inlet of said reactor chamber into said cavity (col.
7, lines 41-47); igniting said gas mixture by said ignitor means
Appeal No. 2001-0379
Application No. 09/141,891
Page 11
(col. 8, lines 12-20); and stopping said gas mixture flow when
said temperature sensor detects a temperature rise in said cavity
(col. 8, lines 42-52). Thus, we affirm the obviousness rejection
of claim 11 over Cox, with Kern being cumulative. We note that
it is permissible to affirm a rejection relying on fewer
references than applied in the rejection. See In re Bush, 296
F.2d 491, 496, 131 USPQ 263, 266-67 (CCPA 1961).
We turn next to claim 12. Both appellant (brief, page 11)
and the examiner (answer, page 4) assert that neither reference
employs a flow meter. Although not brought to our attention by
either the appellant or the examiner, we find that Cox discloses
flow meter 28 which meters non-combustible gas from container 16,
which is delivered to tub 20 before being drawn out along with
the combustible gas mixture by pump 182 and transmitted to the
combustion chamber (col. 9, lines 7-17). Accordingly, the
rejection of claim 12 under 35 U.S.C. § 103(a) is affirmed.
We turn next to claim 13. The claim recites that the gas
mixture is ignited by an electronic ignition means. Both
appellant and the examiner are silent as to this limitation. We
find that Cox discloses a capacitor discharge power unit and
ignition coil assembly 50, an electronic ignition trigger
oscillator assembly (col. 3, lines 24 and 25). From Cox's
Appeal No. 2001-0379
Application No. 09/141,891
Page 12
disclosure of an electronic ignition trigger oscillator assembly,
we find that Cox teaches the claimed electronic ignition.
Accordingly, the rejection of claim 13 under 35 U.S.C. § 103(a)
is affirmed.
We turn next to claim 14. Claim 14 recites the step of
“stopping said gas mixture flow by a solenoid valve and flowing
ambient air into said cavity of the reactor chamber when said
temperature sensor detects a temperature rise in said cavity.”
We find that in Cox, when a rise in temperature is sensed, the
flow of the gas mixture to the reactor chamber is cut off, and
the non-combustible supporting gas CO2 flows into tub 20 (col. 8,
lines 25-30). Thus, Cox does not disclose the flowing of ambient
air into the cavity of the reactor in response to detection of a
rise in temperature. We also find no disclosure in Kern of
adding ambient air to the reactor chamber in response to a
buildup of pressure in the cavity. Accordingly, we find that the
examiner has failed to establish a prima facie case of
obviousness of claim 14. The rejection of claim 14 under 35
U.S.C. § 103(a) is therefore reversed.
We turn next to claim 15. We affirm the rejection of claim
15 because Cox discloses the step of flowing a gas mixture
Appeal No. 2001-0379
Application No. 09/141,891
Page 13
containing a flammable gas into said cavity and igniting the
flammable gas by said ignitor means (col. 8, lines 13-24).
We turn next to claims 16-18 and 20. We reverse the
rejection of these claims based on our earlier findings with
respect to claim 1, supra. With regard to claim 17, we add that
we find no suggestion in the prior art, and none has been
provided by the examiner, for stopping the gas mixture in a time
period of less than 0.5 second when the temperature sensor
detects a temperature rise. Accordingly, the rejection of claims
16-18 and 20 under 35 U.S.C. § 103(a) is reversed.
We turn next to independent claim 21. We find that the
prior art does not suggest the limitations of claim 21 because,
as we found earlier with respect to claim 1, the prior art to
Kern and Cox do not teach or suggest “a gas evacuation means in
fluid communication with said gas outlet of the reactor chamber
capable of withdrawing a gas mixture containing a flammable gas
from said chamber at a flow speed of at least 5 meter/second.”
Accordingly, the rejection of claim 21 and claims 22-28 and 30,
dependent therefrom, under 35 U.S.C. § 103(a) is reversed.
CONCLUSION
To summarize, the decision of the examiner to reject claims
1-7, 9, 14, 16-18, 20, 21-28, and 30 under 35 U.S.C.
Appeal No. 2001-0379
Application No. 09/141,891
Page 14
§ 103(a) is reversed. The decision of the examiner to reject
claims 11-13 and 15 under 35 U.S.C. § 103(a) is affirmed. 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
LEE E. BARRETT )
Administrative Patent Judge )
)
)
)
) BOARD OF PATENT
ANITA PELLMAN GROSS ) APPEALS
Administrative Patent Judge ) AND
) INTERFERENCES
)
)
)
STUART S. LEVY )
Administrative Patent Judge )
SSL/kis
Appeal No. 2001-0379
Application No. 09/141,891
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