United Technologies Corporation

Patent Trials and Appeals Board

Jun 14, 2021

2020006053 (P.T.A.B. Jun. 14, 2021)

UNITED STATES PATENT AND TRADEMARK OFFICE
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.
15/673,635 08/10/2017 Gary D. Roberge 98415US01;
67097-3656PUS1
1537
54549 7590 06/14/2021
CARLSON, GASKEY & OLDS/PRATT & WHITNEY
400 West Maple Road
Suite 350
Birmingham, MI 48009
EXAMINER
BEEBE, JOSHUA R
ART UNIT PAPER NUMBER
3745
NOTIFICATION DATE DELIVERY MODE
06/14/2021 ELECTRONIC
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.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
ptodocket@cgolaw.com
PTOL-90A (Rev. 04/07)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

Ex parte GARY D. ROBERGE

Appeal 2020-006053
Application 15/673,635
Technology Center 3700
____________

Before NINA L. MEDLOCK, KENNETH G. SCHOPFER, and
TARA L. HUTCHINGS, Administrative Patent Judges.

SCHOPFER, Administrative Patent Judge.

DECISION ON APPEAL
Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the
Examiner’s decision to reject claims 1–20.2 We have jurisdiction under
35 U.S.C. § 6(b).
We REVERSE.

1 We use the word “Appellant” to refer to “applicant” as defined in
37 C.F.R. § 1.42. Appellant identifies the real party in interest as Raytheon
Technologies Corporation. Appeal Br. 1.
2 The Examiner has indicated that claims 21–24 recite allowable subject
matter. Final Act. 19.
Appeal 2020-006053
Application 15/673,635

2
BACKGROUND
The Specification states that the “disclosure relates to a fan stage for
gas turbine engines, and more particularly to rotating airfoils that include a
tip pocket.” Spec. ¶ 2.
CLAIMS
Claims 1, 11, and 16 are the independent claims on appeal. Claim 1 is
illustrative of the appealed claims and recites:
1. A fan blade for a gas turbine engine comprising:
an airfoil section including a pressure sidewall and a
suction sidewall that meet together at both a leading edge and a
trailing edge, and extending radially between a root portion and
a tip portion; and
a tip pocket defined by collapsible external walls of the tip
portion, and having a pocket opening at a radially outer face of
the tip portion.
Appeal Br. 10.
REJECTIONS
1. The Examiner rejects claims 1–3, 16, and 17 under 35 U.S.C. § 103 as
unpatentable over Densmore3 in view of Gibson.4
2. The Examiner rejects claims 4 and 5 under 35 U.S.C. § 103 as
unpatentable over Densmore in view of Gibson and Krishnababu.5
3. The Examiner rejects claims 6–8 and 19 under 35 U.S.C. § 103 as
unpatentable over Densmore in view of Gibson and Lim.6

3 Densmore, US 1,828,409, iss. Oct. 20, 1931.
4 Gibson, GB 1,107,024, pub. Mar. 20, 1968.
5 Krishnababu, US 2017/0102004 A1, pub. Apr. 13, 2017.
6 Lim, US 2013/0142651 A1, pub. June 6, 2013.
Appeal 2020-006053
Application 15/673,635

3
4. The Examiner rejects claims 9 and 10 under 35 U.S.C. § 103 as
unpatentable over Densmore in view of Gibson and Opper.7
5. The Examiner rejects claims 11–14 under 35 U.S.C. § 103 as
unpatentable over Liston8 in view of Densmore and Gibson.
6. The Examiner rejects claim 15 under 35 U.S.C. § 103 as unpatentable
over Liston in view of Densmore, Gibson, and Lim.
7. The Examiner rejects claim 18 under 35 U.S.C. § 103 as unpatentable
over Densmore in view of Gibson and Smuland.9
8. The Examiner rejects claim 20 under 35 U.S.C. § 103 as unpatentable
over Densmore in view of Gibson and Ochiai.10
DISCUSSION
With respect to claim 1, the Examiner finds that Densmore teaches a
blade for a turbine engine including an airfoil section as claimed and a
collapsible external wall at a tip portion of the airfoil section. Final Act. 5–6
(citing Densmore Figs. 1, 2; page 1, ll. 78–95). The Examiner acknowledges
that Densmore does not teach that the collapsible wall forms a tip pocket as
required by the claim. Id. at 6. The Examiner relies on Gibson as disclosing
“[r]adially outermost sealing element lip/lips(4) [that] can be very effective
as pockets/sleeves” and that can be provided on the outside of a blade. Id.
(citing Gibson Figs. 3, 4; page 2, ll. 7–13). The Examiner finds that Gibson
teaches that the two sides of the pocket at the tip end “increase[] the
resistance to fluid flow through the clearance space compared to a single

7 Opper, DE 10305351 A1, pub. Aug. 19, 2004.
8 Liston et al., US 5,259,724, iss. Nov. 9, 1993.
9 Smuland et al., US 3,220,697, iss. Nov. 30, 1965.
10 Ochiai et al., US 8,366,400 B2, iss. Feb. 5, 2013.
Appeal 2020-006053
Application 15/673,635

4
element.” Id. (citing Gibson page 1, ll. 68–77). The Examiner also finds
that Gibson is “concerned with clearances and unshrouded rotating blades . .
. as well as the improvements of placing lips on both sides of the airfoil to
form a pocket, [and] that these features can be formed on the blade at
formation, removing the need for a filleted portion by using the sleeve to
serve the function.” Id. (citing Gibson page 2, ll. 5–19).
Based on the teachings of Gibson, the Examiner determines:
It would have been obvious to one of ordinary skill in the
art before the effective filing date of the claimed invention to
modify the blade of [Densmore] such that the bending element
of [Densmore] at the tip was formed all the way around the blade
as a full pocket as taught by [Gibson] for the purpose of this
element being more resistant to fluid flow through the clearance
space. Further, per [Gibson], it would be desirable to apply the
combined teachings to fan blades as well, as [Gibson] discloses
unshrouded fan blades of the system have similar concerns with
loss of flow over their ends as [Gibson] is concerned with and tip
rubbing clearance damage as [Densmore] is concerned with, thus
they would also benefit from improvements to longevity and
performance as [Densmore] and [Gibson] teach. This would
yield collapsible walls at the tip, forming a tip pocket at the
radially outer face portion of fan blades.
Final Act. 6–7. The Examiner relies on substantially the same findings and
conclusion in relying on the combination of Densmore and Gibson to reject
independent claims 11 and 16. See Final Act. 7–8, 14–15.
We are persuaded of error by Appellant’s argument that the Examiner
has not set forth an adequate reason to support the combination proposed.
Obviousness is a legal conclusion involving a determination of
underlying facts.
Under § 103, the scope and content of the prior art are to be
determined; differences between the prior art and the claims at
issue are to be ascertained; and the level of ordinary skill in the
Appeal 2020-006053
Application 15/673,635

5
pertinent art resolved. Against this background, the obviousness
or nonobviousness of the subject matter is determined. Such
secondary considerations as commercial success, long felt but
unsolved needs, failure of others, etc., might be utilized to give
light to the circumstances surrounding the origin of the subject
matter sought to be patented.

KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 406 (2007) (quoting Graham v.
John Deere Co. of Kansas City, 383 U.S. 1, 17–18 (1966)). “[R]ejections on
obviousness grounds cannot be sustained by mere conclusory statements;
instead, there must be some articulated reasoning with some rational
underpinning to support the legal conclusion of obviousness.” Id. at 418
(alteration in original) (quoting In re Kahn, 441 F.3d 977, 988 (Fed.
Cir. 2006)).
Densmore discloses a blade for a turbine including “a blade
portion 11, as usual, and a relatively thin, bendable extension 12.”
Densmore 1, ll. 80–82. Densmore discloses that the bendable extension
projects outwardly from the blade tip, “preferably as a continuation of a
working surface,” and is inclined backwardly with respect to movement of
the blade tip. Id. at 1, ll. 85–95. The extension provides “exceedingly
small” radial clearance “and in the event any rubbing occurs, the point of
contact will always follow the blade and hence, will cause the rubbed metal
to flow in one direction and tend to prevent vibration when the rub takes
place.” Id. at 2, ll. 1–14. With this design, Densmore discloses that rubbing
will result in no serious consequences and that the extension may be
trimmed to restore the original clearance if the extension is damaged. Id.
Gibson discloses “a blade of a turbo-machine fitted at its free end with
a sleeve having an outer profile similar to that of the blade.” Gibson 1,
ll. 29–31. Gibson teaches that a blade with a tip having a reduced cross-
Appeal 2020-006053
Application 15/673,635

6
sectional area that has been damaged by rubbing may be repaired by placing
a sleeve at the free end of the blade, which provides the advantage of not
having to replace the entire blade. Id. at 1, ll. 57–68. Alternatively, Gibson
teaches that blades may be initially provided with such a sleeve such that
there is no need for the blade to be formed with a reduced cross-sectional
area. Id. at 2, ll. 8–13. Gibson also teaches that although the use of a sleeve
increases the profile of the blade, “any loss of performance resulting
[therefrom] . . . is offset by the fact that the presence of two walls of the
sleeve adjacent the wall of the casing or the surface of the rotor, increases
the resistance to fluid flow through the clearance space compared with the
conventional construction.” Id. at 1, ll. 69–78.
Appellant argues that the Examiner has not set forth an adequate
motivation to combine the references. See Appeal Br. 3–7. We agree to the
extent that we determine that the Examiner has not shown why one of
ordinary skill in the art would have had a reason to make the combination
proposed by the Examiner. The Examiner determines that it would have
been obvious to extend Densmore’s collapsible portion around the entirety
of the tip of Densmore’s blade to form a pocket as claimed based on
Gibson’s teachings. See Final Act. 6–7. Yet the Examiner does not
adequately explain how the teachings of Gibson would have led one of
ordinary skill in the art to modify Densmore to extend Densmore’s
collapsible wall around the entirety of the device, rather than providing a
separate sleeve as taught by Gibson, or that doing so would provide any
benefit to Densmore’s device.
As noted above, Densmore teaches the use of a collapsible tip portion
of a blade that provides for minimal clearance, reduced rubbing vibrations,
Appeal 2020-006053
Application 15/673,635

7
and allows for trimming to restore the original clearance in the event that the
collapsible tip is damaged. In contrast, Gibson teaches the use of a sleeve
intended to be placed over the tip portion of a blade, either to repair a
damaged tip portion or to replace a reduced cross-section portion of the
blade. Gibson teaches only the use of a sleeve portion over the tip of a blade
and does not suggest providing a pocket portion as an extension of the walls
of the blade. The Examiner does not adequately explain why a person of
ordinary skill in the art would have had a reason to modify Densmore as
proposed in light of Gibson’s teaching of only the use of a sleeve addition to
a blade. Rather, the combination would seem to only suggest the use of a
sleeve, as taught by Gibson, around the tip of Densmore’s blade as a means
of repairing the blade should Densmore’s tip portion be damaged beyond
repair. Such a combination does not appear to result in a device as claimed,
which is required to have a tip pocket made of collapsible portions of the
external walls of the blade.
Further, to the extent the Examiner finds that one of ordinary skill in
the art would have made the modification proposed “for the purpose of this
element being more resistant to fluid flow through the clearance space,” the
Examiner can only speculate that such would be the case if Densmore’s
collapsible wall were extended as proposed. The Examiner has not provided
any evidence or explanation adequately showing that extending a collapsible
wall as proposed would yield such a benefit. It is not readily apparent to us
that extending Densmore’s collapsible wall would provide such an effect
given that Densmore already discloses minimal clearance between the
collapsible blade wall and the casing and given that Gibson teaches only that
the sleeve may be formed of the same material as the blade, which seems to
Appeal 2020-006053
Application 15/673,635

8
indicate that it is not collapsible. See Gibson 1, ll. 86–87. In short, it is not
clear from the evidence provided how the proposed modification would
affect the performance of Densmore’s blade.
Based on the foregoing, we are persuaded of error in the rejection of
independent claim 1. The Examiner relies on the same findings and
reasoning with respect to the rejection of independent claim 16, and thus, we
are persuaded of error in the rejection of claim 16 for the same reasons.
With respect to the rejection of independent claim 11, the Examiner relies on
the findings and reasoning discussed above and does not provide any further
evidence or explanation with respect to the additional reference, Liston, that
would cure the deficiency discussed above. Thus, we are also persuaded of
error in the rejection of independent claim 11. With respect to the dependent
claims, the Examiner does not provide any additional evidence or
explanation that would cure the deficiency in the rejections of the
independent claims. Thus, we are also persuaded of error in the rejections of
the dependent claims. Accordingly, we do not sustain the rejections of
claims 1–20.
CONCLUSION
We REVERSE the rejections of claims 1–20.
In summary:
Claim(s)
Rejected
35 U.S.C. § Reference(s)/Basis Affirmed Reversed
1–3, 16, 17 103 Densmore, Gibson 1–3, 16,
17
4, 5 103 Densmore, Gibson,
Krishnababu
4, 5
6–8, 19 103 Densmore, Gibson,
Lim
6–8, 19
Appeal 2020-006053
Application 15/673,635

9
Claim(s)
Rejected
35 U.S.C. § Reference(s)/Basis Affirmed Reversed
9, 10 103 Densmore, Gibson,
Opper
9, 10
11–14 103 Liston, Densmore,
Gibson
11–14
15 103 Liston, Densmore,
Gibson, Lim
15
18 103 Densmore, Gibson,
Smuland
18
20 103 Densmore, Gibson,
Ochiai
20
Overall
Outcome
1–20

REVERSED