Ex Parte Lifson et al

Board of Patent Appeals and Interferences

Jul 29, 2009

10886383 (B.P.A.I. Jul. 29, 2009)

UNITED STATES PATENT AND TRADEMARK OFFICE
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BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________________

Ex parte ALEXANDER LIFSON and MICHAEL F. TARAS
____________________

Appeal 2009-006211
Application 10/886,383
Technology Center 3700
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Decided:1 July 29, 2009
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Before RICHARD E. SCHAFER, JAMESON LEE, and MICHAEL P.
TIERNEY, Administrative Patent Judges.

TIERNEY, Administrative Patent Judge.

DECISION ON APPEAL

1 The two-month time period for filing an appeal or commencing a civil
action, as recited in 37 C.F.R. § 1.304, begins to run from the decided date
shown on this page of the decision. The time period does not run from the
Mail Date (paper delivery) or Notification Date (electronic delivery).
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A. STATEMENT OF THE CASE
This is a decision on appeal by the real party in interest, Carrier
Corporation under 35 U.S.C. § 134(a) from a final rejection of claims 1, 4, 7,
11-15, 18, and 27. Claims 2-3, 5-6, 8-10, 16-17, and 19-26 were withdrawn
prior to this appeal. Appellants request reversal of the Examiner’s final
rejection. We have jurisdiction under 35 U.S.C. § 6(b). We affirm.

References Relied on by the Examiner
Shimoya 5,632,161 May 27, 1997
Eber 6,381,970 May 7, 2002
Hebert 6,460,358 Oct. 8, 2002
Noble 6,467,300 Oct. 22 2002
Ito 6,935,126 Aug. 30, 2005

The Rejections on Appeal
The Examiner rejected claims 1, 4, 7, 11, 15, 18, and 27 under
35 U.S.C. § 103(a) as unpatentable over Hebert and Eber.
The Examiner rejected claim 12 under 35 U.S.C. § 103(a) as
unpatentable over Hebert and Eber further in view of Ito.
The Examiner rejected claim 13 under 35 U.S.C. § 103(a) as
unpatentable over Hebert and Eber further in view of Noble.
The Examiner rejected claim 14 under 35 U.S.C. § 103(a) as
unpatentable over Hebert and Eber further in view of Shimoya.
Appellants argue the patentability of claim 1, collectively with claim
11. Appellants provide separate arguments for the patentability of claims 4,
7, and 12-14. Appellants argue that claims 15 and 27 are patentable for the
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same reasons as claims 1 and 7. Appellants argue that claim 182 is
patentable for the same reasons as claims 4 and 15.

The Invention
The invention relates to a refrigerant system having an auxiliary heat
exchanger that provides both subcooling and reheating functions. (Br., 8-10,
Claims App’x.; Spec., ¶ 0007-83). Claims 1, 4, 7, and 12-14 are illustrative
of the claimed invention. Claim 1 is reproduced below along with a
summary of claims 4, 7, and 12-14:
1. A refrigerant system comprising:
a compressor for compressing refrigerant and delivering the
refrigerant to a condenser;
a main expansion device positioned downstream of said
condenser, and an evaporator positioned downstream of said main
expansion device, and an air moving device for passing air over said
evaporator; and
an auxiliary heat exchanger, a first refrigerant stream being
subcooled in said auxiliary heat exchanger by a second refrigerant
stream returning toward said compressor, and at least one of said first
or second refrigerant streams placed in a path of air driven by said air
moving device over said evaporator to provide a reheat function.

Claim 4, depends from claim 1 and further requires that the auxiliary
heat exchanger be placed in the path of air to provide the reheat function.

2 Appellants’ argument states among other things that claim 18 is dependent
from claim 15 and has features similar to those found in claim 4. However,
Appellants state that claim 18 is allowable for the reasons set forth with
regard to claims 15 and 14. Based on the context of the claim and the
structure recited in claims 4 and 14 we understand that Appellants meant to
state that claim 18 was allowable for the reasons set forth above with respect
to claims 15 and 4, rather than claims 15 and 14.
3 References to the specification are to U.S. Publication 2006/0005571.
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Claim 7, also depends from claim 1 and further requires that a return
line for returning refrigerant is placed in the path of air.
Claims 12-14 additionally depend from claim 1 and recite various
arrangements for the refrigeration streams within the auxiliary heat
exchanger.
(Br., 8-10, Claims App’x.).

B. ISSUE

1. Have Appellants shown that the Examiner erred in determining that it
would have been obvious to combine known heat exchange systems in an
energy efficient manner in order to transfer heat from an undesirable
location to a desirable location?
2. Have Appellants shown that the Examiner erred in determining that it
would have been obvious to substitute known heat exchangers for the heat
exchanger taught by Hebert and Eber?

C. FINDINGS OF FACT

Terminology Relevant to the Art and Decision
1. Overcooling, for purposes of this decision, refers to cooling the liquid
refrigerant on its way to the evaporator, so as to provide the evaporator with
a greater cooling capacity. (Spec., ¶ 0007).
2. Reheating, for purposes of this decision, refers to reheating at least a
portion of the air supplied to the conditioned space after it has been
overcooled by the evaporator. (Id. at ¶ 0003).
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3. Hebert, discussed in further detail below, provides a good overview of
how conventional refrigeration systems operate. (Hebert, col. 1, ll. 34-61).
Hebert
4. Hebert teaches a refrigeration system having a subcooling function
where heat is transferred from a stream entering an evaporator (subcooled
stream) to a stream exiting the evaporator and returning to the compressor.
(Hebert, Abstract, col. 2, ll. 27-44).
5. Hebert teaches that subcooling refrigerant on its way to the evaporator
is desirable as it increases system efficiency, by increasing the evaporator’s
heat transfer capacity. (Hebert, Abstract, col. 2, ll. 27-44, col. 4, l. 66 to col.
5, l. 8, Fig. 2).
6. Herbert teaches that the refrigerant stream exiting the evaporator and
returning to the compressor retains an ability to absorb heat from the
refrigerant stream on its way to the evaporator. (Id. at col. 7, l. 7 to col. 8,
l. 1).
7. Hebert Figure 2, depicts Hebert’s subcooler (auxiliary heat exchanger
10) and related refrigeration circuit, and is reproduced below.

Hebert Figure 2 is reproduced above and shows Hebert’s subcooler
(auxiliary heat exchanger 10) and related refrigeration circuit.
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8. Hebert’s subcooler (auxiliary heat exchanger 10) has two refrigerant
streams: (1) a low pressure suction side and (2) a liquid refrigerant side. (Id.
at col. 2, l. 61 to col. 3, l. 16, col. 6, ll. 22-33, Fig. 2). The low pressure
suction side stream is located downstream of the evaporator 30 but upstream
of the compressor 36, meaning it is located on the return line of the
compressor. (Id. at col. 6, ll. 22-33, Fig. 2). The liquid refrigerant side
stream is located downstream of the condenser 20, but upstream of the
expansion valve 26. (Id.).
9. Hebert warns against overheating the refrigerant stream returning to
the compressor as a result of its absorption of heat from the subcooled
refrigerant stream going to the evaporator. (Id. at col. 2, ll. 48-56).
Specifically, Hebert warns that both the volumetric efficiency and
operational life of the compressor will be reduced if the refrigerant returning
to the compressor becomes overheated. (Id.).
Eber
10. Eber teaches the desirability of warming cold air prior to its
introduction into cooled spaces and the desirability of cooling a refrigerant
stream entering an evaporator.
11. Eber discloses a refrigeration system with a subcooler 102
arrangement that provides both a subcooling function and a reheat function.
Specifically, Eber teaches that placing a subcooler 102 in a path of air 80
driven by an air moving device over an evaporator 44 (indoor heat exchange
coil) provides a reheat function. (Eber, col. 6, ll. 17-34, col. 6, l. 62 to col. 7,
l. 3, Fig. 2).
12. Eber teaches that a reheating function is “beneficial from an indoor air
quality standpoint” and helps to prevent overcooling of a cooled space, by
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ensuring that cold saturated air flowing over the evaporator is given a more
comfortable drybulb temperature before it is reintroduced into the cooled
space. (Id. at col. 2, ll. 13-17, col. 6, l. 62 to col. 7, l. 3).
13. Eber also teaches that the above subcooling arrangement is beneficial
because it allows subcooling to be reliably maintained over a wide variety of
operating conditions. (Id. at col. 6, ll. 26-29).

D. PRINCIPLES OF LAW

An invention is not patentable under 35 U.S.C. § 103 if it is obvious.
KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 406 (2007). The combination
of familiar elements according to known methods is likely to be obvious
when it does no more than yield predictable results. Id. at 416.
Additionally, obviousness, is not limited to the express teachings of a single
prior art reference, but is based upon what the combined teachings of the
prior art suggests to the person of ordinary skill in the art. In re Keller, 642
F.2d 413, 425 (CCPA 1981).
E. ANALYSIS

1. Claims 1, 4, 7, 11, 15, 18, and 27
As discussed above, the Examiner rejected claims 1, 4, 7, 11, 15, 18,
and 27 under 35 U.S.C. § 103 as unpatentable over the combination of
Hebert and Eber. The Examiner found that the combination of Hebert and
Eber taught the specific heat exchange systems required by claims 1, 4, 7,
11, 15, 18, and 27. (Final Rejection, 2-6). Claims 1 and 11 are argued
together. The Examiner reasoned that it would have been obvious to one of
ordinary skill in the art to combine the known heat exchange systems of
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Hebert and Eber to provide an energy efficient manner of transferring heat
while providing suitable indoor air quality. (Final Rejection, 3).
Appellants contend that the Examiner erred in determining that the
claims were obvious over the prior art. Particularly, Appellants contend that
the Examiner erred in determining that Eber teaches a refrigeration line 32
that is in the path 80 of air passing over the evaporator 44. (Br., 4).
Essentially, we understand Appellants to be contesting the Examiner’s
determination that the prior art teaches moving air over the evaporator and
onto a refrigerant stream to cool the refrigerant stream.
Hebert teaches a refrigeration system having a subcooling function.
(FF 4). Specifically, Hebert teaches that subcooling refrigerant on its way to
the evaporator is desirable because doing so increases efficiency of the
system by increasing the capacity for heat transfer within the evaporator.
(FF 5). Hebert cools the subcooled refrigerant stream by transferring its heat
to the refrigerant stream returning to the compressor. (FF 4 and 6). Hebert
teaches that care must be taken, however, to not overheat the refrigerant
stream returning to the compressor as both the volumetric efficiency and
operational life of the compressor will be reduced if the refrigerant returning
to the compressor becomes overheated. (FF 9). Hebert employs an
auxiliary heat exchanger 10 to achieve this balance and transfer heat
between the two streams (streams entering evaporator and returning to
compressor). (See FF 7-8). Hebert teaches that the auxiliary heat exchanger
improves the efficiency of the system. (FF 5). Hebert, however, does not
teach moving air over the evaporator past a refrigerant stream to provide a
reheat function.
Eber teaches moving air over an evaporator past a refrigerant stream
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to provide a reheat function to improve indoor air quality. (FF 10-11).
Specifically, Eber discloses a refrigeration system with a subcooler 102
arrangement that provides both a subcooling function and a reheat function.
Eber teaches that placing the subcooler 102 in the path of air 80 driven by an
air moving device over an evaporator 44 (indoor heat exchange coil)
provides a reheat function. (FF 11). Eber teaches that the reheating function
improves indoor air quality and helps to prevent overcooling of a cooled
space, by ensuring that cold saturated air flowing over the evaporator is
given a more comfortable drybulb temperature before it is reintroduced into
the cooled space. (FF 12). In addition to the benefits of the reheating, Eber
also teaches that the above subcooling arrangement is beneficial because it
allows subcooling to be reliably maintained over a wide variety of operating
conditions. (FF 13).
One of ordinary skill in the art would have understood that combining
the auxiliary heat exchanger of Hebert with the air moving device of Eber
provides multiple benefits. The combination improves air quality standards
in an energy efficient manner. (Final Rejection, 3). Specifically, the
combination improves the dry bulb temperature and avoids overcooling the
cooled space while ensuring that refrigerant stream subcooling is reliably
maintained over a wide variety of operating conditions. (See FF 12-13).
Dependent claim 4 further limits claim 1 by requiring that the
auxiliary heat exchanger be placed in the path of air driven over the
evaporator. Appellants contend that the Examiner’s rejection of claim 4 is
based on hindsight. (Br., 5). We disagree. As articulated above, it would
have been obvious to one of ordinary skill in the art to combine the known
heat exchange systems of Hebert and Eber for their known purpose
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(subcooling and reheating) to achieve the predictable result of providing
suitable air quality in an energy efficient manner.
Dependent claim 7 further limits claim 1 by requiring the return line
for returning refrigerant to the compressor be placed in the path of the air
moved over the evaporator. Appellants contend that Eber fails to teach this
limitation. The Examiner’s rejection is based not only on the express
teachings of Eber but also on the combined teachings of Hebert and Eber
whereby the combination leads one of ordinary skill in the art to move the
air over the auxiliary exchanger and hence, over the return line.4 This
combination provides the benefit of ensuring that the temperature of the
return line is not so high as to reduce the life of the compressor. (FF 9).
Appellants contend that claims 15, 18, and 27 are patentable for the
same reasons as claims 1, 4, and 7 and provide no further specific arguments
as to these claims. Since, we held that Appellants have not shown that the
Examiner erred in rejecting claims 1, 4 or 7 we also hold that the Examiner
has not erred in rejecting claims 15, 18, or 27.

2. Claims 12-14

Claims 12-14 depend from claim 1 and respectively require that
specific refrigerant streams within the auxiliary heat exchanger are exposed
to air. (Br., 8-9, Claims App’x.). The Examiner found that Ito, Noble, and
Shimoya taught heat exchangers having the respective required refrigerant

4 Appellants defined “return line” as including lines placed within a heat
exchanger. Specifically, Appellants defined return line as including
“enhanced heat transfer surfaces to promote heat transfer between the
refrigerant in said return line and air in said air path.” (Original claim 8,
which depended from claim 7, Claims, July 7, 2004).

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streams exposed to air. (Final Rejection., 6-8). The Examiner further
determined that it would have been obvious to one of ordinary skill in the art
to have utilized the above heat exchangers as auxiliary heat exchangers in
the refrigeration system taught by Hebert and Eber. (Id.).
Appellants do not dispute the Examiner’s finding that the heat
exchanger systems of claims 12-14 were known in the art. Appellants,
however, contend that the Examiner’s combination of references relies upon
improper hindsight and that the claimed invention provides synergistic
benefits. (Br., 6-7).
Regarding alleged hindsight, as discussed above, Hebert and Ebert
teach the benefits of (1) cooling the refrigerant stream entering the
evaporator and, (2) avoiding overheating the refrigerant stream returning to
the compressor. Accordingly, the Examiner did not rely upon hindsight in
combining the references as the references themselves identify reasons for
cooling both the refrigerant stream entering the evaporator and the stream
returning to the compressor. In re McLaughlin, 443 F.2d 1392, 1395 (CCPA
1971)(Reconstruction is proper when only taking into account knowledge at
time invention was made).
Appellants contend that the claimed refrigerant system “provides
benefits and synergies.” (Br., 6). Appellants, however, do not identify the
alleged synergies. The prior art identifies energy efficiency and improved
air quality benefits associated with auxiliary heat exchangers and using air
moved over the evaporator to cool refrigerant streams. Appellants mere
allegation of unidentified synergistic benefits fails to demonstrate that their
claimed refrigerant system provides unexpected benefits as compared to the
prior art. In re Huellmantel, 324 F.2d, 998, 1003 (CCPA 1963)( “[W]e
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attribute no magic status to synergism per se since it may be expected or
unexpected.”).

F. CONCLUSION

1. Appellants have not shown that the Examiner erred in determining
that it would have been obvious to combine known heat exchange systems in
an energy efficient manner in order to transfer heat from an undesirable
location to a desirable location.
2. Appellants have not shown that the Examiner erred in determining
that it would have been obvious to substitute known heat exchangers for the
heat exchanger taught by Hebert and Eber.
H. ORDER

The rejections of claims 1, 4, 7, 11, 15, 18, and 27 under
35 U.S.C. § 103(a) as unpatentable over Hebert and Eber are affirmed.
The rejection of claim 12 under 35 U.S.C. § 103(a) as unpatentable
over Hebert and Eber further in view of Ito is affirmed.
The rejection of claim 13 under 35 U.S.C. § 103(a) as unpatentable
over Hebert and Eber further in view of Noble is affirmed.
The rejection of claim 14 under 35 U.S.C. § 103(a) as unpatentable
over Hebert and Eber further in view of Shimoya 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)(1)(iv).

AFFIRMED
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