Ex parte Naumann

Board of Patent Appeals and Interferences

Apr 20, 2001

08829699 (B.P.A.I. Apr. 20, 2001)

The withdrawal of the appeal as to claim 2 operates as an1
authorization to cancel claim 2 from the application. Manual of Patent
Examining Procedure (MPEP) § 1215.03.
1
The opinion in support of the decision being entered today was not written for
publication and is not binding precedent of the Board.
Paper No. 13
UNITED STATES PATENT AND TRADEMARK OFFICE
____________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________
Ex parte ULRICH NAUMANN
____________
Appeal No. 2000-1638
Application No. 08/829,699
____________
ON BRIEF
____________
Before McQUADE, BAHR and LAZARUS, Administrative Patent Judges.
BAHR, Administrative Patent Judge.
DECISION ON APPEAL
This is a decision on appeal from the examiner's final
rejection of claims 1,3 and 6-30. Appellant has withdrawn the
appeal as to claim 2 (brief, page 2). No other claim is1
pending in this application.
Appeal No. 2000-1638
Application No. 08/829,699
2
BACKGROUND
The appellant's invention relates to an exchanger tube
for a heat exchanger. Claim 1, the only independent claim on
appeal, reads as follows:
1. An exchanger tube for a heat exchanger having a
longitudinal axis, an exterior surface, and an
interior surface comprising:
rows of primary ribs running at an angle (")
with respect to the longitudinal tube axis, the
primary ribs having a radial height H1 and inclined
flanks;
rows of secondary ribs running at an angle with
respect to the longitudinal tube axis, the secondary
ribs having a radial height H2 and inclined flanks;
channels that are delimited laterally by the
primary and secondary ribs; and
troughs that extend transversely through the
primary and secondary ribs, said troughs including
inclined flanks, wherein the troughs extend at an
angle (() with respect to the longitudinal tube
axis;
wherein H1 is greater than H2.
The prior art references of record relied upon by the
examiner in rejecting the appealed claims are:
Schmidt et al. (Schmidt) 5,682,946 Nov. 4,
1997
(filed Mar. 18, 1996)
Asaumi et al (Asaumi) 58-8995 Jan. 19, 1983
(Japanese published patent application)
Appeal No. 2000-1638
Application No. 08/829,699
English language translations of the Asaumi and Yamamoto references,2
prepared by the Patent and Trademark Office, are appended hereto.
3
Yamamoto et al. (Yamamoto) 2-161290 Jun. 21, 19902
(Japanese patent publication)
The following rejections are before us for review.
(1) Claims 1, 3, 6-22 and 24-30 stand rejected under 35
U.S.C. § 103(a) as being unpatentable over Yamamoto in view
of Asaumi.
(2) Claim 23 stands rejected under 35 U.S.C. § 103(a) as
being unpatentable over Yamamoto in view of Asaumi, as applied
to claim 1, and further in view of Schmidt.
Reference is made to the brief (Paper No. 10) and the
first Office action and answer (Paper Nos. 5 and 12) for the
respective positions of the appellant and the examiner with
regard to the merits of these rejections.
OPINION
In reaching our decision in this appeal, we have given
careful consideration to the appellant's specification and
claims, to the applied prior art references, and to the
respective positions articulated by the appellant and the
Appeal No. 2000-1638
Application No. 08/829,699
4
examiner. For the reasons which follow, we cannot sustain the
examiner's rejections.
Yamamoto discloses an inner-worked heat transfer pipe
adapted for use in both evaporation and condensation
applications, such as heat-pump applications. Yamamoto
discusses some of the shortcomings of prior art heat transfer
pipes in achieving acceptable performance in both evaporative
and condensation applications (translation, page 4). The
objective of Yamamoto's invention is to offer an inner-worked
heat transfer pipe that has better evaporation performance
than inner-grooved heat transfer pipes in the prior art and
has better condensation performance than the types of prior
art heat transfer pipes discussed on page 4 of the
translation.
Yamamoto's heat transfer pipe 1 comprises, on its inner
surface, a series of parallel grooves 11 separated by fins 12
that have an 18 lead angle to the pipe axis and projectionso
13, which are 3/5 or less, preferably 1/5 to 1/2, the height
of the fins 12, on the floor of the grooves 11. These
projections increase surface tension inside grooves 11 and
prevent coolant inside grooves 11 from escaping from the inner
Appeal No. 2000-1638
Application No. 08/829,699
5
walls due to coolant vapor flowing inside the pipe. As a
result, the dry-out point is delayed to a higher dryness
region and evaporation performance is improved. Condensation
performance also is improved by increasing the heat transfer
area and turbulence effect by the projections (translation,
pages 7-8).
Asaumi discloses another heat exchanger pipe that can
selectively perform a condensation and an evaporation in the
same pipe at high performance (translation, page 1). Asaumi's
heat exchanger pipe 1 is provided with spiral fins 2 on the
inner surface thereof. The fins are notched (notches 4) at
the intersection with a virtual spiral in the reverse
direction (translation, page 3). As explained by Asaumi
(translation, page 4), the spiral fins 2 increase the
effective heat exchange area; however, when continuous fins 2
are used, a liquid film of condensation liquid can form in the
grooves 6 between the fins. The notches 4 in the fins 2
permit the condensation liquid to quickly flow down. This
improves condensation performance. However, as pointed out on
page 6 of the translation, a pipe with spiral notch fins,
while achieving good condensation performance, is unacceptable
Appeal No. 2000-1638
Application No. 08/829,699
We understand the "boiling core" alluded to by Asaumi to be nucleation3
sites for promoting or permitting nucleate boiling.
The fins 12 respond to the recited "primary ribs" and the projections4
13 respond to the recited "secondary ribs."
We find no express disclosure of such a function of the notches or5
cross-cuts in Asaumi. Rather, as discussed above, the stated function of the
notches appears to be condensation liquid drainage.
6
for evaporation type applications. Thus, in order to improve
evaporation performance of the pipe, Asaumi also provides
"multiple fine rough sections at about 50 to 800 µ" between
fins. These fine rough sections markedly promote "the
formation of a boiling core during evaporation" (translation,3
page 5). The resulting pipe, having both notch fins and fine
rough sections, achieves excellent condensation and
evaporation performance (translation, page 6).
The examiner finds that Yamamoto discloses the invention
recited in appellant's claim 1 with the exception of the
recited troughs. According to the examiner,4
[i]t is well known in the art of such textured
surface tubes to cross cut through spirally
extending ribs to form turbulence generating
interruptions, breaking up laminar flow and
improving heat transfer efficiency (see Asaumi et
al). Thus, it would have been obvious to one of5
ordinary skill in the art to provide such cross cut
troughs in the spirally ribbed tube of Yamamoto et
Appeal No. 2000-1638
Application No. 08/829,699
The test for obviousness is what the combined teachings of the6
references would have suggested to one of ordinary skill in the art. See In
re Young, 927 F.2d 588, 591, 18 USPQ2d 1089, 1091 (Fed. Cir. 1991) and In re
Keller, 642 F.2d 413, 425, 208 USPQ 871, 881 (CCPA 1981).
7
al. for improved performance [first Office action,
pages 3-4].
Appellant points out on page 3 of the brief that the
stated purpose of Yamamoto's invention is to strengthen
surface tension on the inner face of the tube to prevent
coolant held inside the grooves from escaping from the inner
walls and argues that cross-cutting (notching) the grooves as
taught by Asaumi would necessarily attenuate the desired
surface tension of the grooves and radically alter the desired
flow pattern. According to appellant, the modification
proposed by the examiner would result in a device which would
not act as Yamamoto intended. Thus, appellant urges that the
examiner's rejection is grounded in "an impermissible exercise
of hindsight." After carefully reviewing the combined
teachings of Yamamoto and Asaumi, we find ourselves in6
agreement with appellant.
The examiner asserts, in essence, that a person of
ordinary skill in the art at the time of appellant's invention
Appeal No. 2000-1638
Application No. 08/829,699
8
would have appreciated from the teachings of Asaumi the
condensation-enhancing benefits of cross-cuts or reverse-
spiral notches in heat transfer pipes having fins and grooves
on their inner surface, such as the one taught by Yamamoto
(answer, page 4). Even accepting the examiner's assertion,
however, such a person would also have inferred from Asaumi's
teachings (translation, page 6) that the provision of such
notches or cross-cuts through the fins and/or projections of
Yamamoto's pipe would adversely affect the evaporation
performance of Yamamoto's pipe. In particular, the provision
of the notches would appear to facilitate escape of liquid
coolant from the grooves in an evaporation application, an
effect which Yamamoto seeks to prevent.
It is clear from the teachings of Yamamoto that Yamamoto
is primarily concerned with improving the evaporation
performance of the heat transfer pipe and that the arrangement
disclosed therein (in particular, the provision of projections
in the grooves between the fins) improves both evaporation
performance and condensation performance. Moreover, Yamamoto
teaches that inner crossed-grooved pipes have unbalanced
evaporation and condensation performance (translation, page
Appeal No. 2000-1638
Application No. 08/829,699
9
4). Thus, it is not apparent to us why one of ordinary skill
in the art, in the absence of appellant's disclosure, would
have been motivated to modify the Yamamoto pipe in an attempt
to improve condensation performance, a mode in which
Yamamoto's pipe is not recognized in the art as being
deficient, by adding a feature which both Yamamoto and Asaumi
appear to recognize would be deleterious to the evaporation
performance of the Yamamoto pipe.
In light of the above, it is our opinion that the prior
art evidence relied upon by the examiner does not justify a
conclusion that the subject matter of claim 1 as a whole would
have been obvious at the time the invention was made to a
person having ordinary skill in the art. Accordingly, we
cannot sustain the examiner's rejection of claim 1, or claims
3, 6-22 and 24-30 which depend from claim 1, as being
unpatentable over Yamamoto in view of Asaumi.
With regard to rejection (2), the deficiency noted above
finds no cure in the teachings of Schmidt. Therefore, we
shall also not sustain the examiner's rejection of claim 23,
which depends from claim 1, as being unpatentable over
Yamamoto in view of Asaumi and Schmidt.
Appeal No. 2000-1638
Application No. 08/829,699
10
CONCLUSION
To summarize, the decision of the examiner to reject
claims 1, 3 and 6-30 under 35 U.S.C. § 103 is reversed.
REVERSED
JOHN P. McQUADE )
Administrative Patent Judge )
)
)
)
) BOARD OF PATENT
JENNIFER D. BAHR ) APPEALS
Administrative Patent Judge ) AND
) INTERFERENCES
)
)
)
RICHARD B. LAZARUS )
Administrative Patent Judge )
jg
Appeal No. 2000-1638
Application No. 08/829,699
11
RICHARD L. MAYER
KENYON & KENYON
ONE BROADWAY
NEW YORK, NY 10004