Ex Parte Luce

Board of Patent Appeals and Interferences

Sep 8, 2011

11331506 (B.P.A.I. Sep. 8, 2011)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________________

Ex parte WILLIAM E. LUCE
____________________

Appeal 2010-002064
Application 11/331,506
Technology Center 3600
____________________

Before: STEFAN STAICOVICI, PHILLIP J. KAUFFMAN, and
MICHAEL L. HOELTER, Administrative Patent Judges.

KAUFFMAN, Administrative Patent Judge.

DECISION ON APPEAL

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STATEMENT OF CASE
Appellant appeals under 35 U.S.C. § 134 from the rejection of claims
1-26. We have jurisdiction under 35 U.S.C. § 6(b). We affirm.
THE INVENTION
Appellant’s claimed invention “relates to aircraft shock struts for
absorbing and damping shock forces, such as during landing, taxiing or
takeoff, and particularly improved bearings for an aircraft shock strut.”
Spec. 1:5-7. Independent claim 1, reproduced below, is representative of the
claimed subject matter:
1. An aircraft shock strut comprising:
a cylinder;
a piston telescopically movable within the cylinder; and
a first bearing on one of the cylinder and the piston, the
first bearing having a first bearing surface providing sliding
engagement with the other of the cylinder and the piston;
wherein the first bearing comprises a support structure
and a porous layer on the support structure, the first bearing
surface being formed by an extruded bearing material layer
impregnated into the porous layer, wherein the bearing material
layer is a continuous consolidated structure comprising a lead-
free continuous polytetrafluoroethylene (PTFE) matrix and
discrete particles of an additive material, and wherein the
bearing material layer has a portion above the porous layer.
REJECTIONS
1. Claims 1-7, 9-20, and 22-26 are rejected under 35 U.S.C. § 103(a) as
being unpatentable over Hartel (US 3,652,040; issued March 28, 1972) and
Kim (US 2004/0228555 A1; published November 18, 2004).1

1 The heading of this rejection in the Final Rejection, mailed Dec. 12, 2008,
does not refer to the Examiner’s Official Notice, while the heading in the
Answer does. Final Rejection at 2; Ans. 3-4.
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2. Claim 8 is rejected under 35 U.S.C. § 103(a) as being unpatentable over
Hartel, Kim, and Del Monte (US 5,333,816; issued August 2, 1994).
3. Claim 21 is rejected under 35 U.S.C. § 103(a) as being unpatentable over
Hartel, Kim, and Hart (US 6,981,439 B2; issued January 3, 2006).
CONTENTIONS AND ISSUES
Appellant argues claims 1-7, 9-19, and 23-26 as a group, and we
select claim 1 as the representative claim.2 See App. Br. 6-10, 13-14; see
also 37 C.F.R. § 41.37(c)(1)(vii).
Independent claim 1 is directed to an aircraft shock strut that includes
a first bearing having a bearing surface comprised of a lead-free continuous
polytetraflouroethylene (PTFE) matrix.
The Examiner found that Hartel discloses an aircraft shock strut that
includes a first bearing (upper bearing 19) having a bearing surface
comprised of an undisclosed material. Ans. 4. The Examiner further found
that Kim discloses a bearing having a bearing surface comprised of a lead-
free continuous PTFE matrix, and concluded that it would have been
obvious to modify Hartel’s bearing to include a bearing surface comprised of
a lead-free continuous PTFE matrix, as taught by Kim, in order to create “a
low friction, strong bearing surface.” Id.
The issues regarding claim 1 are:
Does Kim disclose lead-free PTFE as called for in claim 1?
Did the Examiner articulate adequate reasoning based on a rational
underpinning to explain why a person of ordinary skill in the art would have
been led to modify Hartel’s bearing surface to be comprised of a lead-free

2 Regarding claims 23-26, Appellant merely points out what claim 23 recites
and repeats the arguments of claim 1 without explaining any manner in
which the alleged error regarding claim 23 differs from the alleged error of
claim 1. App. Br. 13-14. Thus, we group claims 23-26 with claim 1.
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continuous PTFE matrix, as taught by Kim, in order to reach the subject
matter of independent claim 1?
Did the Examiner improperly fail to consider the invention as a whole
by failing to consider the problem solved by Appellant?
Appellant argues claims 20 and 22 as a group, and we select claim 20
as the representative claim. See App. Br. 11-13; see also 37 C.F.R.
§ 41.37(c)(1)(vii).
The issue regarding claim 20 is whether the Examiner failed to make a
prima facie case by failing to provide a reference for the Official Notice
relied upon in the rejection.
ANALYSIS3
Rejection of claims 1-7, 9-20, and 22-26 under 35 U.S.C. § 103(a)
Claims 1-7, 9-19, and 23-26
Appellant reasons that in the context of the written description
requirement of 35 U.S.C. § 112, first paragraph, the absence of a positive
recitation of a limitation in the Specification is an insufficient basis for a
negative limitation in a claim, and that such logic is applicable to evaluating
what a reference discloses in an obviousness determination. App. Br. 7.
Based on this reasoning, Appellant asserts that the Examiner’s finding that
Kim discloses lead-free PTFE is erroneous because Kim fails to explicitly
state that PTFE is lead-free. Id.
We are unpersuaded by this argument for several reasons. First,
Appellant has not cited, nor are we aware of, any authority for applying this

3 The Reply Brief filed September 10, 2009, is not in compliance with
37 C.F.R. § 41.41(a)(2) as it introduces new evidence into the record. See
Reply Br. 3 and attached GGB Bearing Technology document. Pursuant to
37 C.F.R. § 41.41(b), we do not consider the new evidence or the arguments
based thereon in the Reply Brief.
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concept of written description analysis to evaluation of a reference in an
obviousness determination.
Second, the Examiner correctly found that Kim discloses a bearing
surface comprising PTFE and that Kim does not disclose that the PTFE
contains lead. See Ans. 4, 7; see also Kim 1, paras. [0004]; [0010].
Third, the Examiner found that that PTFE, without additives, does not
contain lead. Ans. 7. The Examiner stated, and we agree, that if Appellant
believed that at the time of the claimed invention, most or all PTFE
contained lead, or that lead-free PTFE was a novel idea, then Appellant
should submit evidence of such. See id. However, Appellant simply asserts
that Kim’s PTFE contains lead. This assertion is not supported by the
reference because Kim makes no such disclosure. Further, this assertion is
not supported by other evidence because Appellant failed to submit evidence
in the form of an affidavit or declaration. Appellant’s arguments and
conclusory statements, which are unsupported by factual evidence, are
entitled to little probative value. See, e.g., In re Geisler, 116 F.3d 1465,
1470 (Fed. Cir. 1997); In re De Blauwe, 736 F.2d 699, 705 (Fed. Cir. 1984).
In light of this, by a preponderance of the evidence, Kim discloses
lead-free PTFE as called for in claim 1.  
Appellant asserts that the Examiner has not provided an adequate
rationale for modifying Hartel’s bearing surface to be comprised of a lead-
free continuous PTFE matrix, as taught by Kim because the Examiner has
not provided a reasonable basis for selecting Kim’s material from the
hundreds or thousands of potential bearing materials available, and has not
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provided a reasonable basis for using Kim’s bearing surface in the hydraulic
fluid environment of an aircraft strut. App. Br. 8; Reply Br. 1-64.
Regarding the selection of Kim’s bearing surface material, the
Examiner found that Hartel discloses an aircraft shock strut that includes a
first bearing (upper bearing 19) having a bearing surface comprised of an
undisclosed material. Ans. 4; see also Hartel, col. 2, ll. 1-3; fig. 1.
Appellant does not contest this finding. The Examiner also found that Kim
discloses a bearing surface comprised of lead-free PTFE that improves wear
and erosion while maintaining low friction. Ans. 4; see also Kim 1, para.
[0010]. Appellant’s only challenge to this finding is to allege that Kim’s
PTFE contains lead. App. Br. 7-8. In light of these findings, the Examiner’s
rationale that the proposed modification would create “a low friction, strong
bearing surface” is reasonable. See Ans. 4. Because Hartel does not
disclose what material comprises the bearing surface, a person of ordinary
skill in the art would search for a suitable bearing surface material, such as
disclosed in Kim. Further, given that Appellant has not alleged that the
proposed modification is beyond the level of skill in the art, a person of
ordinary skill in the art would recognize that use of a low friction, wear
resistant bearing surface such as disclosed by Kim, is a technique that would
improve Hartel’s similar device (upper bearing 19) in a similar way. See
KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 417 (2007).
Regarding the selection of Kim’s bearing material for use in the
hydraulic fluid environment of an aircraft strut, Appellant mischaracterizes
the reference. Kim discloses a bearing surface that “may be useful in
applications where the use of externally supplied lubricants may be difficult
or undesirable.” Kim 1, para. [0003]. A person of ordinary skill in the art

4 Excluding arguments based on the excluded evidence as discussed supra.
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would interpret this disclosure as an example of an appropriate use implying
there are other appropriate uses. Kim does not disclose that the bearing
surface is inappropriate for use in an environment that includes external
lubricants, such as an aircraft shock strut. Further, Appellant’s argument
suggests that Kim’s bearing surface material (lead-free PTFE) is unsuitable
for use in the hydraulic fluid environment of an aircraft strut. We find this
assertion uncompelling given that Appellant’s Specification describes use of
a bearing surface comprised of lead-free PTFE in the hydraulic fluid
environment of an aircraft strut. Spec. 1: 23-25; 2:18-20.
Additionally, Appellant’s argument that the Examiner has not
provided as an adequate rationale is unpersuasive in that it fails to directly
address the reasonable rationale set forth by the Examiner (i.e., to provide “a
low friction, strong bearing surface”). See Ans. 4.
Appellant asserts that the inventor discovered that lead within the
bearing material was the source of the problem of darkening hydraulic fluid
in aircraft struts. App. Br. 9-10. Appellant argues that solving this problem
weighs in favor of a finding of nonobviousness, and that the Examiner’s
failure to consider the problem solved by Appellant is improper failure to
consider the invention as a whole. Id. (citing In re Sponnoble, 405 F.2d 578,
585 (CCPA 1969)).
In Sponnoble, there was evidence that a person of ordinary skill in the
art would not have been aware of the nature of the problem solved by the
claimed invention. Sponnoble, 405 F.2d at 585. However here, Appellant’s
Specification describes that leaded bearing assemblies aid in the reduction of
stiction5 problems, but “are problematic in that, as the bearing wears, it

5 Stiction is “a phenomenon where the shock struts would stick then slip,
then stick, etc., during taxi.” Spec. 2:1-2.
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releases particles of lead within the hydraulic fluid, which cause the fluid to
darken.” Spec. 2:9-15. Appellant’s Specification does not describe that a
person of ordinary skill in the art would have been unaware of the nature of
this problem at the time of the claimed invention. The lack of such evidence
distinguishes Sponnoble from the case at hand. See In re Kahn, 441 F.3d
977, 989, n.4 (Fed. Cir. 2006) (distinguishing Sponnoble based on the lack
of evidence that a person of ordinary skill in the art would have been
unaware of the nature of the problem solved by the claimed invention).
As such, we sustain the rejection of claim 1, and claims 2-7, 9-19, and
23-26 fall with claim 1.
Claims 20 and 22
Independent claim 20 is similar to independent claim 1 in that it is
directed to an aircraft shock strut that includes a first bearing having a
bearing surface that is comprised of a lead-free continuous PTFE matrix.
Claim 20 differs from claim 1 in that it adds the limitation that the
coefficients of static and dynamic friction of the bearing surface differ by
less than 0.045.
Appellant repeats the arguments used against the rejection of claim 1.
App. Br. 11. For the reasons explained in the analysis of claim 1, supra,
those arguments are unconvincing here as well.
Appellant also argues that the Examiner’s Official Notice does not
establish a prima facie case of obviousness. App. Br. 11-13. For the reasons
that follow, we are unpersuaded by this argument because the Official
Notice has become admitted prior art.
In the Office Action mailed April 16, 2008,, the Examiner took
Official Notice that the difference between the static and dynamic
coefficient of friction for PTFE is less than 0.045. Office Action dated April
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16, 2008, at 6. In response, Appellant purported to “seasonably challenge”
the Official Notice by requesting documentary evidence from the Examiner.
Appellant’s Response dated August 18, 2008, at 7. However, Appellant’s
argument does not state why the noticed fact is not considered to be common
knowledge or well-known in the art, and thus is not a proper traverse of such
notice. See In re Chevenard, 139 F.2d 711, 713 (CCPA 1943); see also 37
C.F.R. § 1.111(b) and MPEP § 2144.03C (to adequately traverse such a
finding, Appellant must specifically point out the supposed errors in the
examiner’s action, including stating why the noticed fact is not considered to
be common knowledge or well-known in the art). Because Appellant’s
response did not specifically point out the supposed error in the Examiner’s
action, at that point, it became admitted prior art that the difference between
the static and dynamic coefficient of friction for PTFE is less than 0.045.
Appellant’s Brief also fails to state why the noticed fact is not considered to
be common knowledge or well-known in the art. See App. Br. 11-13. For
this reason as well, it is admitted prior art that the difference between the
static and dynamic coefficient of friction for PTFE is less than 0.045.
Consequently, we sustain the rejection of claim 20, and claim 22 falls
with claim 20.
Rejection of claim 8 under 35 U.S.C. § 103(a)
Claim 8 is argued based on dependency from claim 1. App. Br. 15.
For the reasons explained in the analysis of the rejection of claim 1, supra,
we affirm the rejection of claim 8.
Rejection of claim 21 under 35 U.S.C. § 103(a)
Claim 21 is argued based on dependency on claim 20. App. Br. 15.
For the reasons explained in the analysis of the rejection of claim 20, supra,
we affirm the rejection of claim 21.
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CONCLUSIONS
Kim discloses a lead-free continuous PTFE matrix as called for in
claim 1.
The Examiner articulated adequate reasoning based on a rational
underpinning to explain why a person of ordinary skill in the art would have
been led to modify Hartel’s bearing surface to be comprised of a lead-free
continuous PTFE matrix, as taught by Kim, in order to reach the subject
matter of independent claim 1.
The Examiner did not improperly fail to consider the invention as a
whole by failing to consider the problem solved by Appellant.
The Examiner did not fail to make a prima facie case by failing to
provide a reference for the Official Notice relied upon in the rejection.
DECISION
We affirm the Examiner’s decision to reject claims 1-26.
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)(1)(iv).

AFFIRMED

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