Ex Parte Awtar et al

Patent Trial and Appeal Board

Mar 28, 2013

11652076 (P.T.A.B. Mar. 28, 2013)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________________

Ex parte SHORYA AWTAR, TIMOTHY R. KEMP,
KURT N. LAURER, and FREDERICK G. BAILEY
____________________

Appeal 2011-001356
Application 11/652,076
Technology Center 3700
____________________

Before JOHN C. KERINS, NEIL T. POWELL, and BEVERLY M.
BUNTING, Administrative Patent Judges.

POWELL, Administrative Patent Judge.

DECISION ON APPEAL

Appeal 2011-001356
Application 11/652,076

2
STATEMENT OF CASE
Appellants appeal under 35 U.S.C. § 134(a) from a rejection of claims
1, 3-7, 10-12, 14-16, and 18-21.
1
We have jurisdiction under 35 U.S.C.
§ 6(b).
We AFFIRM-IN-PART.

THE CLAIMED SUBJECT MATTER
Independent claim 1, reproduced below, is illustrative of the appealed
subject matter.
1. An active retractable seal assembly
for use between rotating and non-rotating
turbomachinery components comprising:
at least one seal ring mounted to the non-
rotating component, said at least one seal ring
movable toward and away from the rotating
component between respective closed and open
positions as a function of pressure drop across the
seal ring said at least one seal ring biased toward
said open position by one or more actuators;
a fluid bypass circuit for directing fluid
around said at least one seal ring to reduce the
pressure drop across the seal ring;
wherein said fluid bypass circuit includes a
conduit extending from an inlet at a location
upstream of said at least one seal ring and
terminating at an outlet location downstream of

1
Both the Appeal Brief and the Answer identify claim 17 as rejected (Br.
12; Ans. 3). However, other portions of the Appeal Brief and Answer
consistently indicate that this is in error. The Appeal Brief indicates claim
17 has been cancelled and omits claim 17 from the Claims Appendix. Br. 5
and 24. Consistent with this, the Answer omits claim 17 from the “list of
claim that are rejected and pending in the application.” Ans. 2.
Appeal 2011-001356
Application 11/652,076

3
said at least one seal ring, and wherein a bypass
control valve is located in said fluid bypass circuit,
between said inlet and said outlet, said control
valve enabling active control of pressure drop
across the seal ring such that said at least one seal
ring can be moved via said one or more actuators
to said open position during operation and under
any operating conditions of the turbomachinery.

REFERENCES
The prior art relied upon by the Examiner in rejecting the claims on
appeal is:
Chevrette 6,022,027 Feb. 8, 2000
Hogg 7,559,554 B2 Jul. 14, 2009

REJECTIONS
Appellants seek our review of the following rejections.
1. Claims 1, 3-7, 10-12, 14-16, and 18-21 stand rejected under 35
U.S.C. § 103(a) as unpatentable over Chevrette and Hogg.
2

ANALYSIS
Rejection of Claims 1, 3-7, 10, and 11
Finding that Chevrette discloses a retractable seal assembly that meets
most of the limitations of claim 1 but does not include Appellants’ claimed
fluid bypass circuit, the Examiner determines that it would have been
obvious to modify Chevrette to include Hogg’s fluid bypass circuit and
pressure relief valve 42. Ans. 3-5. Appellants argue that the Examiner’s

2
Claim 4 was previously rejected under 35 U.S.C. § 112, second paragraph,
but the Examiner withdrew that rejection in the Answer. Ans. 3.
Appeal 2011-001356
Application 11/652,076

4
proposed combination of Chevrette and Hogg would not meet the limitations
of claim 1. Br. 15-18. Specifically, Appellants argue that the type of valve
the Examiner identifies as an obvious addition to Chevrette – Hogg’s
pressure relief valve 42 – would not allow the modified version of Chevrette
to move at least one seal “to an open position during operation and under
any operating conditions as required by independent claim 1.” Id. at 17.
Appellants base this argument on the observation that Hogg’s pressure relief
valve 42 opens only under one set of operating conditions – when the
pressure exceeds the biasing force provided by the spring 47 of the pressure
relief valve 42. Id.
In response, the Examiner asserts that opening Hogg’s valve opens a
seal during operation, and that this meets the claim language because
“[r]eading the claim broadly the limitation ‘under any operating conditions’
merely means that during operation the valve is capable of opening.” Ans.
13. The Examiner also indicates that the combination meets the claim
limitations because “Hogg can use one spring during operation and if needed
can have the spring change to meet another condition after the machine is
shut down.” Id. Appellants counter that a configuration that requires
shutting down the machine and changing the spring in a pressure relief valve
each time one wants the valve to open under different operating conditions
does not meet the disputed claim language. Br. 17.
Resolution of this dispute turns on the proper interpretation of the
claim language. We consider first the Examiner’s position that the claim
language “under any operating conditions” merely requires the capability of
the valve to open during operation. Ans. 13. We decline to adopt this
interpretation because it would render the claim recitations “during
Appeal 2011-001356
Application 11/652,076

5
operation” and “under any operating conditions” redundant. See Merck &
Co. v. Teva Pharms. USA, Inc., 395 F.3d 1364, 1372 (Fed. Cir. 2005)
(citation omitted) (“A claim construction that gives meaning to all the terms
of the claim is preferred over one that does not do so.”).
More generally, the arguments require us to consider whether the
disputed claim language 1) requires that the specific components included in
the assembly at a given time provide the flexibility to open the valve and
seal under any operating conditions (as indicated by Appellants’ arguments),
or 2) requires only that the assembly can open the valve and seal under any
operating conditions in an abstract sense that the design allows changing the
specific components of the system to open the valve and seal under any one
operating condition selected from all possible operating conditions (as
indicated by the Examiner’s assertions). Within the claim itself, the
recitation that the control valve allows “active control” suggests that the first
meaning applies.
The Specification also supports this interpretation. The Specification
indicates that operation of turbomachinery presents a variety of different
operating conditions in which it may prove useful to open a seal. Spec., para
[0004]. Accordingly, the Specification discloses that:
[i]t would be desirable to provide an ‘actively controlled’ seal
positioning arrangement in which the seal segments are held
open not just during no- or low-flow conditions, . . . but can be
opened at any other operating condition, when rubbing might
occur, and for any desired period of time.
Id. The Specification further states that “[t]he use of active retractable
seals . . . enables the retraction of seal segments under any machine
operating conditions such as start-up, speed ramp-up, load ramp-up,
Appeal 2011-001356
Application 11/652,076

6
forward-flow/reverse flow, steady state operation, shut-down or trip.” Id. at
para. [0033].
Given the recitation of “active control” in the claim and the
Specification’s consistent indication that “active control” provides the ability
to respond to a wide variety of operating conditions by opening the seal, we
conclude that the disputed claim language requires that the specific
components included in the assembly at a given time provide the flexibility
to open the seal under any operating conditions that may occur during
operation of the turbomachinery. Accordingly, we cannot agree with the
Examiner that the combination of Hogg’s pressure relief valve 42 with
Chevrette would meet the claim language simply because the fixed opening
pressure of the valve could be changed to any different fixed opening
pressure by shutting down the turbomachinery and changing the pressure
relief spring 47. Consequently, we cannot sustain the rejection of
independent claim 1, or the rejection of dependent claims 3-7, 10, and 11
depending therefrom.

Rejection of Claims 12 and 14-16
The Examiner and Appellants take the same substantive positions
with respect to the rejection of claim 12 as they do with respect to claim 1.
See Ans. 7-9 and 14; Br. 19. Accordingly, for substantially the same reasons
as discussed above in connection with claim 1, we cannot sustain the
rejection of claim 12 or of claims 14-16 depending therefrom.

Appeal 2011-001356
Application 11/652,076

7
Rejection of Claims 18-20
Appellant argues claims 18-20 as a group. See Br. 19-20. We select
claim 18 as representative and treat claims 19 and 20 as standing or falling
with representative claim 1. See 37 C.F.R. § 41.37(c)(1)(vii).
As with the rejection of claims 1 and 12, the Examiner determines that
it would have been obvious to modify Chevrette with Hogg’s bypass circuit
and pressure relief valve 42 (Ans. 10-11), and Appellants argue that the
combination would fail to meet certain limitations of claim 18 (Br. 19-20).
In claim 18, however, the disputed claim limitation is “during operation of
the turbo-machine, controlling the bypass circuitry to selectively admit
process fluid into said bypass circuit to thereby reduce the pressure drop
across said . . . sealing ring, resulting in said at least one sealing ring moving
away from the rotating component . . . .” Br. 19. See Br. 19-20; Ans. 14.
Appellants argue that including Hogg’s valve in Chevrette would not
meet these claim limitations because Hogg’s valve opens at a fixed pressure
threshold and therefore has “no capability for selective control during
machine operation.” Br. 20. The Examiner responds that Hogg’s pressure
relief valve 42 “selectively admits fluid,” as recited by the claim, because
“[t]he point of release is ‘selected’ by the type of spring used . . . .” Ans. 14.
We first note that Appellants’ argument that Hogg’s valve does not
allow “selective control during machine operation” is factually unavailing
because it is not commensurate in scope with the claim language, which
does not recite “selective control.” Nonetheless, to address the general
thrust of Appellants’ argument, we will begin by considering the correct
interpretation of the disputed claim language.
Appeal 2011-001356
Application 11/652,076

8
The dispute revolves particularly around the meaning of “selectively,”
as Appellants do not dispute that Hogg’s valve admits process fluid into a
bypass circuit. See Br. 19-20. Appellants do not point to and we do not find
any explicit or implicit definition of the term “selectively” in the
Specification.
Where the Specification does not assign or suggest a particular
definition for a claim term, it is appropriate to consult a general dictionary
definition of the term for guidance in determining the ordinary and
customary meaning thereof as viewed by a person of ordinary skill in the art.
Comaper Corp. v. Antec, Inc., 596 F.3d 1343, 1348 (Fed. Cir. 2010) citing
Phillips v. AWH Corp., 415 F.3d, 1303, 1322-23 (Fed. Cir. 2005). In the
dictionary, the term “selectively” is identified as the adverbial form of the
term “selective,” one definition of which is: “Of or characterized by
selection; discriminating.” THE AMERICAN HERITAGE® DICTIONARY OF THE
ENGLISH LANGUAGE (4
th
ed. 2000), accessed at
http://www.thefreedictionary.com/selective (last visited March 26, 2013).
And one definition of the term “selection” is: “The act or an instance of
selecting or the fact of having been selected.” THE AMERICAN HERITAGE®
DICTIONARY OF THE ENGLISH LANGUAGE (4
th
ed. 2000), accessed at
http://www.thefreedictionary.com/selection (last visited March 26, 2013).
Given these definitions, we conclude that an ordinary meaning of
“selectively” is: characterized by the fact of having been selected.
Accordingly, we conclude that an ordinary meaning of “controlling the
bypass circuit in a manner to selectively admit process fluid into said bypass
circuit” is: controlling the bypass circuit in a manner to admit process fluid
into the bypass circuit in a manner that has been selected.
Appeal 2011-001356
Application 11/652,076

9
We consider next whether the operation of Hogg’s pressure relief
valve 42 meets this ordinary meaning. Consistent with the Examiner’s
finding, Hogg indicates that the pressure at which its pressure relief valve 42
opens to admit working fluid into the bypass circuit is selected by selecting
the biasing force of the pressure relief spring 47 and the working areas of the
pressure relief valve 42, thus ultimately selecting whether to admit fluid into
the bypass circuit based on pressure. See Hogg, col. 4, l. 66-col. 5, l. 3; col.
5, ll. 48-52. Thus, Hogg’s pressure relief valve 42 admits fluid into the
bypass circuit in a manner that has been selected, specifically whenever the
pressure reaches the selected opening point of the valve. Accordingly,
Appellants’ arguments do not apprise us of error in the Examiner’s
determination that the combination of Hogg’s pressure relief valve 42 with
Chevrette meets the claim limitations “during operation of the turbo-
machine, controlling the bypass circuit to selectively admit process fluid into
said bypass circuit to thereby reduce the pressure drop across said at least
one sealing ring, resulting in said at least one sealing ring moving away from
the rotating component.”

Rejection of Claim 21
The Examiner determines that the combination of Chevrette and Hogg
meets the claim limitation “cycling said at least one sealing ring between
said open and closed positions in a sealing ring cleaning mode” because
Chevrette discloses that the sealing ring of its assembly moves between open
and closed positions. Ans. 12 (citing Chevrette, col. 7, ll. 20-29).
Appellants argue that Chevrette does not meet these limitations of claim 21,
stating specifically that “neither the words ‘cycling’ nor ‘cleaning’ appear in
Appeal 2011-001356
Application 11/652,076

10
either reference.” Br. 20. The Examiner responds that the cited portion of
Chevrette meets the claim limitation because it discloses that the assembly
performs the action required to accomplish cleaning: opening and closing
the seals. Ans. 14.
Aside from noting that Chevrette does not use the same words as the
claim, Appellants provide no specifics regarding what the claim language
requires and Chevrette’s disclosed operation lacks. The Specification
discloses that “the packing rings in a steam turbine may be cycled from open
to closed and vice versa, essentially creating a ‘cleaning’ mode for the
retractable seals in units that have poor steam quality.” Spec., para. [0035].
This indicates that moving a sealing ring from open to closed, i.e., closing
the sealing ring, constitutes cycling the sealing ring between open and closed
positions.
3
Likewise, this portion of the Specification indicates that moving
the sealing ring from closed to open, i.e., opening the sealing ring, also
constitutes cycling the sealing ring between open and closed positions.
Accordingly, we agree with the Examiner that Chevrette’s disclosure of
opening and closing a sealing ring meets the claim limitation “cycling said at
least one sealing ring between said open and closed positions.”
The portion of the Specification quoted above also indicates in an
unqualified manner that cycling a sealing ring between the open and closed
positions constitutes operating in a “cleaning mode,” as recited in the claim.
Accordingly, we agree with the Examiner that Chevrette’s disclosure of the
action of cycling the sealing ring between the open and closed positions

3
The Specification indicates that a “packing ring” constitutes a sealing ring.
See, e.g., Spec., paras. 0002, 0004, 0007, 0019.
Appeal 2011-001356
Application 11/652,076

11
meets the claim “cleaning mode” limitation in the claim. Consequently,
Appellants’ arguments do not apprise us of error in the rejection of claim 21.

DECISION
We reverse the Examiner’s decision regarding claims 1, 3-7, 10-12,
and 14-16.
We affirm the Examiner’s decision regarding claims 18-21.
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)(iv).

AFFIRMED-IN-PART

ELD