DAIDO METAL COMPANY LTD.

Patent Trials and Appeals Board

Dec 30, 2020

2020000831 (P.T.A.B. Dec. 30, 2020)

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.
15/432,439 02/14/2017 Takayoshi YAMAUCHI 0220-0007 9966
96180 7590 12/30/2020
Snyder, Clark, Lesch and Chung, PLLC
Yukiko O. Maekawa
205 Van Buren Street
Suite 110
Herndon, VA 20170
EXAMINER
GOLOBOY, JAMES C
ART UNIT PAPER NUMBER
1771
NOTIFICATION DATE DELIVERY MODE
12/30/2020 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):
PTO@SnyderLLP.com
docket@snyderllp.com
pto.archive@sclclaw.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte TAKAYOSHI YAMAUCHI
Appeal 2020-000831
Application 15/432,439
Technology Center 1700
Before LINDA M. GAUDETTE, JEFFREY B. ROBERTSON, and
GEORGE C. BEST, Administrative Patent Judges.
GAUDETTE, Administrative Patent Judge.

DECISION ON APPEAL1
The Appellant2 appeals under 35 U.S.C. § 134(a), from the
Examiner’s decision finally rejecting claims 1 and 4–7 under 35 U.S.C.
§ 103 as unpatentable over Kawakami (US 4,898,905, iss. Feb. 6, 1990) in
view of Mukai (US 2013/0116157 A1, pub. May 9, 2013).3
We REVERSE.

1 This Decision includes citations to the following documents: Specification
filed Feb. 14, 2017 (“Spec.”); Final Office Action dated Mar. 22, 2019
(“Final Act.”); Appeal Brief filed June 6, 2019 (“Appeal Br.”); and
Examiner’s Answer dated Aug. 29, 2019 (“Ans.”).
2 We use the word “Appellant” to refer to “applicant” as defined in 37
C.F.R. § 1.42. Appellant identifies the real parties in interest as Daido Metal
Company, Ltd., and its subsidiary companies. Appeal Br. 3.
3 We have jurisdiction under 35 U.S.C. § 6(b).
Appeal 2020-000831
Application 15/432,439

2

CLAIMED SUBJECT MATTER
The invention relates to a sliding member, for example, a bearing’s
sliding member, a surface of which interacts with a counterpart shaft’s
surface in an air conditioner compressor. See Spec. 2:8–14. When the
present application was filed, using solid lubricants comprising graphite
particles between these surfaces was known in the art. See, e.g., id. at 1:7–8.
A problem with known solid lubricants comprising spherical graphite
particles is that during system start-up, when insufficient oil is present, “a
surface of a counterpart shaft is easily scratched . . . lead[ing] to generation
of wear.” Id. at 2:15–19. In addition, particles exposed to the sliding surface
during sliding are subject to cracking. Id. at 2:20–21. According to the
Specification, the inventive sliding layer overcomes these problems by using
spheroidal and flake-like graphite particles that have specific features,
including specific cross-sectional structures. See, e.g., id. at 2:25–4:10.
Claim 1, reproduced below, is illustrative of the claimed subject
matter:
1. A sliding member comprising:
a back metal layer; and
a sliding layer on the back metal layer, the sliding layer
comprising a synthetic resin matrix and graphite particles
dispersed in the synthetic resin matrix, the graphite particles
having a volume ratio of 5 to 50% of a volume of the sliding
layer,
wherein the graphite particles include spheroidal graphite
particles and flake-like graphite particles having a thin plate
shape, the flake-like graphite particles having a volume ratio of
10 to 40% of a total volume of the graphite particles,
wherein the spheroidal graphite particles have a cross-
sectional structure in which a plurality of AB planes of a
Appeal 2020-000831
Application 15/432,439

3

graphite crystal are laminated along a curved particle surface,
from the particle surface toward a center direction,
wherein the flake-like graphite particles have a cross-
sectional structure in which the plurality of AB planes are
laminated in a thickness direction of the thin plate shape,
wherein the spheroidal graphite particles have an average
particle size of 3 to 50 μm, and the flake-like graphite particles
have an average particle size of 1 to 25 μm,
wherein the spheroidal graphite particles have an average
aspect ratio of 1.5 to 4.5,
wherein the flake-like graphite particles have an average
aspect ratio of 5 to 10, and
wherein an anisotropic dispersion index of the flake-like
graphite particles is not less than 3, the anisotropic dispersion
index being defined as an average value of a ratio X1/Y1 of
each of the flake-like graphite particles, where
X1 is defined as a length of each flake-like graphite
particle in a direction parallel to a sliding surface when viewed
in a cross-sectional structure perpendicular to the sliding
surface of the sliding layer, and
Y1 is defined as a length of each flake-like graphite
particle in a direction perpendicular to the sliding surface when
viewed in the cross-sectional structure perpendicular to the
sliding surface of the sliding layer.
Appeal Br. 13–14 (Claims Appendix) (emphasis added).
OPINION
Claim 1 recites a sliding member comprising a sliding layer on a back
metal layer. The sliding layer comprises graphite particles dispersed in a
synthetic resin matrix. The graphite particles include spheroidal and flake-
like particles. Claim 1 specifies the cross-sectional structures, aspect ratios,
and volume ratios of each type of graphite particle.
Appeal 2020-000831
Application 15/432,439

4

The Examiner found that Kawakami discloses a sliding layer
comprising graphite particles. Final Act. 2. The Examiner found that the
graphite particles’ shapes are spherical or flaky, and their diameters are
preferably 250 µm or less, which encompasses the claimed ranges of 3 to
50 μm and 1 to 25 μm, respectively. Final Act. 2–3. The Examiner
acknowledged that “Kawakami does not disclose the specific claimed
mixture of spheroidal and flake graphite,” but found that Mukai discloses a
similar graphite-containing resin sliding layer comprising a mixture of
spheroidal and non-spheroidal shaped particles. Id. at 3. The Examiner found
that Mukai’s particles have aspect ratios that overlap the claimed ranges, and
the non-spheroidal shaped particles are present in a volume ratio of up to
30%, which overlaps the claimed volume ratio of flake-like graphite
particles. Id. at 3. The Examiner determined that one of ordinary skill in the
art would have modified the graphite mixture in Kawakami’s sliding layer
by including flaky graphite in the claimed ratio, based on Mukai’s teaching
that a graphite mixture containing more than 70% spheroidal shaped
particles provides enhanced seizure resistance. Id. at 4.
The Appellant argues that the Examiner’s findings as to the aspect
ratios of Mukai’s particles is insufficient to support a finding that the
particles have the claimed cross-sectional structures. Appeal Br. 9 (citing
Final Act. 4–5). More specifically, the Appellant argues that claim 1 requires
that “the spheroidal graphite particles have a cross-sectional structure in
which a plurality of AB planes of a graphite crystal are laminated along a
curved particle surface, from the particle surface toward a center direction,”
and “the flake-like graphite particles have a cross-sectional structure in
which the plurality of AB planes are laminated in a thickness direction of the
Appeal 2020-000831
Application 15/432,439

5

thin plate shape.” Id. (quoting claim 1). The Examiner responds that this
argument is not persuasive because Kawakami, not Mukai, is relied upon for
a teaching of the claimed spheroidal and flake-like graphite particles, and
Mukai is cited merely for a teaching of a suitable ratio of spherical to flake-
like graphite in Kawakami’s graphite mixture. Ans. 7.
Regardless of whether the Examiner is relying on Kawakami or
Mukai for a teaching of the graphite particle shapes, the Examiner does not
provide evidence or sufficient explanation to support a finding that the
applied prior art discloses or suggests graphite particles having the claimed
cross-sectional structures. The Examiner does not clearly identify a teaching
or suggestion of these claim limitation in either the Final Office Action or
the Answer. Accordingly, we do not sustain the rejection of claim 1 and its
dependent claims 4–7.
DECISION SUMMARY
Claims
Rejected
35 U.S.C. § Reference(s)/Basis Affirmed Reversed
1, 4–7 103 Kawakami,
Mukai
1, 4–7
REVERSED