Ex Parte Spangler et al

Patent Trial and Appeal Board

Feb 15, 2019

11679958 (P.T.A.B. Feb. 15, 2019)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR
11/679,958 02/28/2007 Brandon W. Spangler
54549 7590 02/20/2019
CARLSON, GASKEY & OLDS/PRATT & WHITNEY
400 West Maple Road
Suite 350
Birmingham, MI 48009
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
ATTORNEY DOCKET NO. CONFIRMATION NO.
67097-763PUS1;0003746 4429
EXAMINER
DAVIS, JASON GREGORY
ART UNIT PAPER NUMBER
3745
NOTIFICATION DATE DELIVERY MODE
02/20/2019 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 BRANDON W. SP ANGLER,
CORNEIL S. P AAUWE, and DOMINIC J. MONGILLO
Appeal2018-003800
Application 11/679,958
Technology Center 3700
Before JENNIFER D. BAHR, BENJAMIN D. M. WOOD, and
HYUN J. JUNG, Administrative Patent Judges.
BAHR, Administrative Patent Judge.
DECISION ON APPEAL
STATEMENT OF THE CASE
Brandon W. Spangler et al. (Appellants) 1 appeal under 35 U.S.C.
§ 134(a) from the Examiner's decision rejecting claims 1, 3, 4, 10, 12, 14,
and 23-26 under 35 U.S.C. § 103(a) as unpatentable over Bouchard
(US 5,971,703, issued Oct. 26, 1999) and Stec (US 6,171,058 Bl, issued
Jan. 9, 2001). We have jurisdiction under 35 U.S.C. § 6(b). We AFFIRM.
1 According to Appellants, United Technologies Corporation is the real party
in interest. Appeal Br. 1.
Appeal2018-003800
Application 11/679,958
THE CLAIMED SUBJECT MATTER
Appellants' invention relates to "a featherseal for turbine engine
components such as vanes and blade outer air seals." Spec. ,r 2. Multiple
blade outer air seals, which form part of an outer case of a gas turbine
engine, define "the outer radial flow path boundary" and "accommodate
thermal and dynamic variation typical in a high pressure turbine (HPT)
section of the gas turbine engine." Id. ,r 6. The blade outer air seals are
"suspended in close proximity to the rotor blade tips to seal between the tips
and the outer case." Id. "A featherseal is captured circumferentially
intermediate each [blade outer air seal] to span the intervening gap and
minimize fluid leakage due to relative excursions of each [blade outer air
seal]." Id. Claims 1, 10, and 14 are independent. Appeal Br. 8-10 (Claims
App.). Claim 1, reproduced below, is representative of the claimed subject
matter.
1. A featherseal for engagement with a turbine engine
component comprising:
a featherseal having a first side, a second side opposite
said first side, a first end, and a second end opposite said first
end, wherein said first side is normal to said first and second
ends, said second side is parallel to said first side, and said
second end is parallel to said first end, wherein a longitudinal
axis is defined between said first and second sides, said
longitudinal axis being parallel to said first side and said second
side, and wherein said first side is a linear longitudinal side
defined by a continuous, straight edge without any tabs, said
first side extending parallel to said longitudinal axis from said
first end to said second end;
a first lateral tab extending from said second side in a
direction transverse to said longitudinal axis, wherein said first
lateral tab is provided a first distance from said first end; and
a second lateral tab which extends from said second side
in a direction transverse to said longitudinal axis, said first
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Application 11/679,958
lateral tab spaced from said second lateral tab, said first lateral
tab being shorter, relative to said longitudinal axis, than said
second lateral tab, and wherein said second lateral tab is
provided a second distance from said second end, said second
distance greater than said first distance.
DISCUSSION
Appellants argue all of the claims together. Appeal Br. 4--7. We
decide the appeal on the basis of claim 1, and claims 3, 4, 10, 12, 14, and
23-26 stand or fall with claim 1. See 37 C.F.R. § 4I.37(c)(l)(iv) (permitting
the Board to select a single claim to decide the appeal as to a single ground
of rejection of a group of claims argued together).
The Examiner finds that Bouchard discloses a featherseal (seal 55)
having first and second opposed and parallel sides and first and second
opposed and parallel ends, wherein the featherseal is adapted to be engaged
in adjacent featherseal slots (adjacent slots 63A, 63B) of adjacent blade
outer air seals (shroud segments 19A, 19B). Final Act. 4--5 (including an
annotated version ofBouchard's Fig. 1). However, the Examiner finds that
Bouchard's featherseal (seal 55) lacks first and second tabs extending from
the second side as recited in claim 1. See id. at 5.
The Examiner finds that Stec teaches a featherseal ( damper 28)
including first and second lateral tabs ( side tabs 3 6) of substantially
rectangular shape for engaging a transverse post (rib 46) in a slot (pocket 26)
to axially position and retain the featherseal. Id. at 6 ( citing Stec 4:51-57;
6:52-54; Fig. 2). The Examiner determines it would have been obvious to
modify Bouchard's blade outer air seal assembly "by adding first and second
lateral tabs to one side of' the featherseal (seal 55) and "associated posts
within the featherseal slot as taught by Stec for the purpose of axially
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Application 11/679,958
retaining the featherseal within the featherseal slot." Id. Appellants do not
contest the Examiner's determination that it would have been obvious, based
on the combined teachings of Bouchard and Stec, to provide first and second
lateral tabs on one side of Bouchard's featherseal (seal 55). See Appeal Br.
4--7; Reply Br. 1-3.
The Examiner reasons that because Appellants have not disclosed that
the particular relative lengths and locations of the tabs along the second side
of the featherseal "solves any stated problem or is for any particular purpose,
and it appears that the featherseal of Bouchard as modified by Stec would
perform equally well with tabs of different lengths and different [spacings]
from their respective ends ... , it would have been an obvious matter of
design choice" to resize and reposition the first and second tabs so that they
have different lengths and are spaced different distances from the first and
second ends, respectively, as claimed, "which would yield predictable
results," namely, "a featherseal which fits within a groove with a matching
shape and whose axial movement is prevented by the presence of the tabs."
Final Act. 6-7.
Appellants assert that the Examiner's reliance on design choice is
improper because Appellants establish "that the tab arrangement is critical."
Appeal Br. 5---6 ( citing Spec. ,r,r 27-29 in support of this assertion). We
agree with the Examiner that Appellants' Specification "does not provide
support for criticality for the length of the tabs or the spacing of the tabs
from the seal ends." See Ans. 2.
Appellants' Specification explains that, in prior art gas turbine
engines, a radial tab is provided at the aft end of each featherseal to prevent
the featherseal from being dislodged in the forward and aft directions during
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Application 11/679,958
movement of each blade outer air seal. Spec. ,r 7. "The radial tab is
typically hardcoated to minimize wear from the brushseal." Id. Appellants'
Specification discloses that, in Appellants' invention, first tab 80 and second
tab 82 extend from tab side 96 with tab space 84 therebetween, and tab space
84 engages post 88 in first featherseal slot 86 defined by blade outer air seal
body 70 as featherseal 76 is slideably engaged into first featherseal slot 86,
thereby locking featherseal 7 6 into the blade outer air seal to prevent fore-aft
movement of the featherseal. Id. ,r 28. According to the Specification, tabs
80, 82 provide a locking feature that obviates the need for a radial tab and,
thus, hardcoating of the featherseal and radial tab. Id. f 29. Eliminating the
hardcoating process and the bending operation to form the radial tab reduces
the cost of manufacturing featherseal 7 6 and also reduces leakage by
permitting a more uniform surface to featherseal 7 6, thereby providing a
closer fit within slots 86, 90. Id. Eliminating the radial tab also permits the
brushseal to ride directly upon the blade outer air seal rather than the
featherseal, thus providing "a more continuous, consistent and wear reducing
sealing interface to still further minimize leakage and maintenance
requirements." Id.
Thus, Appellants' Specification establishes "that there are benefits to
the disclosed featherseal," and, in particular, to the tabs provided on
Appellants' featherseal. See Reply Br. 3; Ans. 4 ( acknowledging such
benefits). However, the tabs perform the disclosed locking function by
providing a tab space therebetween for engaging a post of a commensurate
length provided in a commensurate location in the featherseal slot of one of
the adjacent blade outer air seals. The relative sizes and particular locations
of the tabs are immaterial to providing this locking feature and, thus, are not
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Application 11/679,958
critical to Appellants' invention. In other words, the features of the first tab
being shorter than the second tab, and the distance of the second tab from the
second end of the featherseal being greater than the distance of the first tab
from the first end of the featherseal are not critical to the operation of the
claimed invention. In this regard, the Examiner's position that the relative
sizes and particular locations of the tabs along the second side of the
featherseal are an obvious matter of design choice is consistent with cases in
which reliance on such an obviousness rationale was held to be appropriate.
See In re Rice, 341 F.2d 309, 314 (CCPA 1965) ("Appellants have failed to
show that the [ differences in the claimed invention], as compared to [ the
reference], result in a difference in function or give unexpected results."); In
re Kuhle, 526 F.2d 553, 555 (CCPA 1975) ("Use of such a means of
electrical connection in lieu of those used in the references solves no stated
problem and would be an obvious matter of design choice within the skill of
the art.").
Appellants assert that "the Examiner is resorting to mere speculation,
unfounded assumptions, and hindsight reconstruction," and that "the only
real evidence cited by the Examiner is Stec, and Stec does not support the
Examiner's position," "especially when Stec suggests that there are benefits
to having a symmetrical end-to-end featherseal, which is contrary to the
claim language." Appeal Br. 6.
As Stec points out, damper 28 must be installed with first notch 34
adjoining shank bulge 30 in blade shank 20. Stec 5:16-18. Stec recognizes
that the side-to-side asymmetry of side notches 34, 48 eliminates (as not
achievable) two of the four possible orientations of installing damper 2 8 in
pocket 26. Id. 5:34--43. Of the two remaining possible orientations, both are
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correct orientations if tabs 3 6 are each spaced the same distance from the
adjacent end of the damper, but there is only one correct orientation if the
tabs are spaced different distances from the adjacent end of the damper.
Stec recognizes that symmetry about neck 50 of damper 28 along axis 38 is
not required to provide axial self-retention against rib 46. Id. 5:51-55
(teaching that a single tab 36 is sufficient to perform this function); see also
id. 6:50-54 (teaching that side notch 34 and cooperating aft side tab 36
collectively provide axial self-retention of damper in pocket 26); id., Fig. 2.
Stec discloses that, at least for the particular configuration of
adjoining blades shown (i.e., with only one rib 46 for engaging one tab 36),
"[t ]he damper is preferably symmetrical end-to-end for permitting two
correct installation orientations, with two Murphy-proofed incorrect
installation orientations which prevent assembly." Id. 6:42--43, 54--57.
However, Stec also teaches that damper 28 "may be suitably modified for
different applications," such as using two ribs 46 to adjoin respective ones of
two side tabs 36 for axially retaining damper 28 in both forward and aft
directions. Id. 6:43--47.
Persons having ordinary skill in the art would have readily appreciated
that, in applications in which two ribs 46 ( or other means associated with the
pocket for providing retention in both the forward and aft directions) are
provided, ribs 46 (or other retention means in the pocket) and tabs 36 may be
arranged either symmetrically end-to-end to permit two correct installation
orientations or asymmetrically end-to-end to permit only one correct
installation orientation. "A person of ordinary skill is also a person of
ordinary creativity, not an automaton." KSR Int'! Co. v. Teleflex Inc., 550
U.S. 398,421 (2007). More specifically, ribs 46 and tabs 36 may be
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Application 11/679,958
arranged symmetrically about the center of bulge 30 and neck 50,
respectively, to permit two correct installation orientations and two
Murphy-proofed incorrect installation orientations. Alternatively, ribs 46
and tabs 36 may be arranged asymmetrically (i.e., with different spacings
from the forward and aft ends of the pocket and damper, respectively) to
permit only one correct installation orientation and three Murphy-proofed
incorrect installation orientations. Whether configured (in cooperation with
retention means in pocket 26) to permit only one correct installation
orientation or to permit two correct installation orientations, Stec' s tabs 3 6
would perform equally well to retain damper 28 axially in pocket 26. Thus,
although Stec expresses a preference for a symmetrical arrangement
permitting two correct installation orientations, Stec' s teachings generally
support the Examiner's position that the particular relative sizes and
positioning of the tabs specified in claim 1 solve no stated problem and are
an obvious matter of design choice.
For the above reasons, Appellants fail to persuade us that the
Examiner's determination that the particular relative lengths and positioning
of the tabs solve no stated problem and would have been an obvious matter
of design choice is incorrect or that Stec' s teachings are contrary to the claim
language. Accordingly, Appellants do not apprise us of error in the rejection
of claim 1 as unpatentable over Bouchard and Stec, which we, thus, sustain.
We also sustain the rejection of claims 3, 4, 10, 12, 14, and 23-26, which
fall with claim 1, as unpatentable over Bouchard and Stec.
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Application 11/679,958
DECISION
The Examiner's decision rejecting claims 1, 3, 4, 10, 12, 14, and
23-26 is AFFIRMED.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a). See 37 C.F.R.
§ 1.136(a)(l )(iv).
AFFIRMED
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