Ex Parte Clark

Board of Patent Appeals and Interferences

Jul 30, 2003

09671870 (B.P.A.I. Jul. 30, 2003)

1
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was not written for publication and is not binding precedent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. 21
UNITED STATES PATENT AND TRADEMARK OFFICE

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES

Ex parte LARRY T. CLARK

Appeal No. 2003-0470
Application 09/671,870

ON BRIEF

Before FRANKFORT, MCQUADE and NASE, Administrative Patent
Judges.
FRANKFORT, Administrative Patent Judge.
DECISION ON APPEAL
This is a decision on appeal from the examiner's
final rejection of claims 5, 6 and 9 through 13. Claims 1
through 4, 7, 8 and 14 through 21, which are the only other
claims pending in the application, have been withdrawn from
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Application 09/671,870
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further consideration by the examiner pursuant to a
restriction requirement.
Appellant’s invention generally relates to a
device and method for mixing flows to attenuate noise and
augment thrust of a jet engine. More particularly, the
subject matter on appeal is directed to a method for
reducing the noise emitted by a flow of exhaust from an
outlet of a jet propulsion engine having a turbine with a
plurality of turbine stages. The method is set forth in
claim 1 on appeal as comprising the steps of: a) segre-
gating the exhaust flow of the jet propulsion engine into a
plurality of rotating high velocity, low density jets and a
plurality of rotating low pressure voids; and b) employing
the low pressure voids to entrain at least a portion of a
secondary flow of air, with the jets and the entrained
secondary flow mixing to produce a mixed flow having a
relatively higher flow rate and a relatively lower velocity
than the exhaust flow.
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Application 09/671,870
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As can be seen from appellant’s specification, an
arrangement for carrying out the above-noted method (e.g.,
Figure 3A) includes a flow mixing device which appellant has
characterized as “an unsteady flow ejector.” The unsteady
flow ejector (10) includes a multi-blade rotor (30) which is
disposed in a primary exhaust flow of the jet propulsion
engine and rotates in response to a transfer of momentum
from the engine core flow. The specification indicates that
rotation of the rotor (30) in the primary exhaust flow
generates a plurality of rotating high velocity, low density
jets (32) and a plurality of rotating low pressure voids
(34), with each of the voids being spaced between two of the
jets. An example of the rotor (30) is shown in Figure 2A of
the application drawings and includes a plurality of blades
(40) affixed to a hub (42). Appellant notes (specification,
page 7) that in the example shown, the rotor has four blades
(40), with the rotor face angle being about 60° and having
an open area ratio for the jets (32) of about 33%. The
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Application 09/671,870
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specification goes on to note in the paragraph bridging
pages 7 and 8 that
[t]hose skilled in the art will under-
stand, however, that the configuration of
the rotor 30 (e.g., the quantity of the
blades 40, the shape of the blades 40 and
the rotational speed of the rotor 30)
must allow enough time and room for the
entrained portion 18a of the secondary
flow 18 to move into the low pressure
voids 34.
In the context of the embodiment seen in Figure
3A, the specification (page 10) notes that the voids (34)
entrain a portion of the fan flow (82) (i.e., the secondary
flow), causing the engine core flow (80) and the fan flow
(82) to mix and produce a mixed flow (86) having a rela-
tively higher flow rate and a relatively lower velocity than
the exhaust flow (80). The specification goes on to note
that such operation of the “unsteady flow ejector” (10)
attenuates the noise produced by operation of the turbojet
engine core (64). The specification (page 6) indicates that
essentially, the low static pressure of each of the voids
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Application 09/671,870
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(34) causes a portion of the secondary flow of air to rush
into and fill each of the voids, whereby entrainment of
the secondary flow of air is dominated by static pressure
momentum interchange which occurs in an essentially
isentropic manner. It is further noted that, accordingly,
the losses that result from the mixing process are rela-
tively small as compared to other known mixing devices and
ejectors which employ shear forces to mix flows.
A copy of representative claim 5, the only
independent claim on appeal, can be found in Appendix A of
appellant’s brief.
The sole prior art reference of record relied upon
by the examiner in rejecting the appealed claims is:
Paulson 5,203,164 Apr. 20, 1993
Claims 5, 6 and 9 through 13 stand rejected under
35 U.S.C. §102(b) as being anticipated by Paulson.
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Application 09/671,870
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Rather than attempt to reiterate the examiner's
commentary with regard to the above-noted rejection and the
conflicting viewpoints advanced by appellant and the
examiner regarding that rejection, we make reference to the
final rejection (Paper No. 9, mailed February 28, 2002) and
the examiner's answer (Paper No. 15, mailed August 9, 2002)
for the reasoning in support of the rejection, and to
appellant’s brief (Paper No. 14, filed July 29, 2002) and
reply brief (Paper No. 16, filed October 7, 2002) for the
arguments thereagainst.
OPINION
In reaching our decision in this appeal, we have
given careful consideration to appellant’s specification and
claims, to the applied prior art Paulson reference, and to
the respective positions articulated by appellant and the
examiner. As a consequence of our review, we have made the
determination that the examiner’s rejection of claims 5,
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Application 09/671,870
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6 and 9 through 13 under 35 U.S.C. § 102(b) will not be
sustained. Our reasons follow.
The examiner’s position in the final rejection
(Paper No. 9, page 2) appears to hinge on the deter-
mination that Paulson discloses a noise suppressor (10)
attached to the aft end of a turbojet engine (11), wherein
the noise suppressor includes a free-running turbofan wheel
(34), at least a portion (41) of which is located in the
exhaust flow from the jet engine, and the examiner’s stated
conclusion that Paulson discloses “an apparatus identical to
the one disclosed [by appellant], performing the same method
steps as those claimed, and therefore producing the same
flow as the one disclosed [by appellant].” In that regard,
the examiner is apparently of the view that segregation into
a plurality of rotating high velocity, low density jets and
a plurality of rotating low pressure voids in the system of
Paulson “is a result of the rotor rotation, as the axial
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Application 09/671,870
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flow in-between the blades produced the jets and the wakes
of the blades were low pressure voids resulting from the
blade’s vortex dynamics.”
Our problem with the examiner’s position as set
forth in the final rejection is that we find no identity
between the turbofan wheel (34) of Paulson and the rotor
(30) as seen, for example, in Figure 2A of appellant’s
drawings, and can conceive of no reason why one of ordinary
skill in the art would have been led to conclude that the
turbofan wheel (34) of Paulson would perform the same method
steps as those claimed by appellant, or produce the same
flow as the rotor (30) disclosed by appellant.
In the examiner’s answer (page 3), the examiner
merely makes note that claims 5, 6 and 9 through 13 are
rejected under 35 U.S.C. § 102(b), and indicates that such
rejection is set forth in prior Office Action, Paper No. 9.
In the remainder of the answer (pages 3-5), the examiner,
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Application 09/671,870
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for the first time, attempts to elaborate on why the noise
suppressor as seen in Paulson would “inherently” perform the
steps of appellant’s method as set forth in the claims on
appeal, and makes reference to six patents and two textbooks
to support such inherency positions.
Even if we were to agree with the examiner that
free rotation of the turbine section blades (43) of the
turbofan wheel (34) of Paulson in the exhaust flow from the
turbojet engine (11) therein would inherently produce a
segregated flow including a plurality of rotating high
velocity, low density jets and a plurality of rotating low
pressure voids located closely adjacent the trailing edges
of the turbine section blades (43), we see no basis for the
examiner’s further conclusion that any flow around the tips
of fan blades (50) in the fan section (42) located outboard
of the ring (45) of the turbofan wheel (34) in Paulson would
provide a secondary flow of air which, under any set of
Appeal No. 2003-0470
Application 09/671,870
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circumstances, could reasonably be expected to be entrained
in or by the low pressure voids that would be located
immediately downstream of the turbine section blades (43).
As can be seen in the various embodiments of the noise
suppressor of Paulson, and from the description of the
operation thereof, e.g., in column 6, lines 36-59, the fan
section (42) compresses air entering the inlet (53) and
moving through the air flow passage (52), thereby providing
a compressed air flow downstream of the fan section which
forms a generally cylindrical column of compressed air
surrounding the jet exhaust downstream of the turbine
section (41). In our view, this cylindrical column of
compressed air surrounding the jet exhaust stream would
completely block any portion of the air flow from around the
tips of fan blades (50) from reaching the transient low
pressure voids that would be formed immediately downstream
of the turbine section blades (43). In this regard, we
agree with appellant’s arguments as set forth on pages 3-7
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Application 09/671,870
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of the reply brief and the conclusion therein that the
examiner has failed to establish a prima facie case of
anticipation.
In our opinion, the examiner’s position is totally
without support in the applied Paulson patent and is
entirely based on speculation and conjecture on the
examiner's part. In this regard, we note that it is well
settled that inherency may not be established by
probabilities or possibilities, but must instead be "the
natural result flowing from the operation as taught." See
In re Oelrich, 666 F.2d 578, 581, 212 USPQ 323, 326 (CCPA
1981). In the present case, neither the Paulson patent nor
the examiner provides an adequate factual basis to establish
that the natural result flowing from following the teachings
of that patent would be a method for reducing noise emitted
by a flow of exhaust from a jet propulsion engine like that
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Application 09/671,870
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claimed by appellant. Accordingly, since all the limita-
tions of appellant’s claims 5, 6 and 9 through 13 are not
found in Paulson, either expressly or under principles of
inherency, it follows that the examiner's rejection of those
claims under 35 U.S.C. § 102(b) relying on Paulson will not
be sustained.
In accordance with the foregoing, it is clear that
the decision of the examiner is reversed.
REVERSED
CHARLES E. FRANKFORT )
Administrative Patent Judge )
)
)
)
) BOARD OF PATENT
JOHN P. MCQUADE ) APPEALS
Administrative Patent Judge ) AND
) INTERFERENCES
)
)
)
JEFFREY V. NASE )
Administrative Patent Judge )
CEF:psb
Appeal No. 2003-0470
Application 09/671,870
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