Lennox lndustries Inc.

Patent Trials and Appeals Board

Jul 29, 2021

2020005634 (P.T.A.B. Jul. 29, 2021)

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.
14/955,359 12/01/2015 Robert B. Uselton 018635.0284 (P150068-2) 4902
134318 7590 07/29/2021
Baker Botts/Lennox
2001 Ross Avenue
SUITE 900
Dallas, TX 75201
EXAMINER
TRPISOVSKY, JOSEPH F
ART UNIT PAPER NUMBER
3763
NOTIFICATION DATE DELIVERY MODE
07/29/2021 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):
PTOmail1@bakerbotts.com
PTOmail2@bakerbotts.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

Ex parte ROBERT B. USELTON
____________

Appeal 2020-005634
Application 14/955,359
Technology Center 3700
____________

Before MURRIEL E. CRAWFORD, BRUCE T. WIEDER, and
AMEE A. SHAH, Administrative Patent Judges.

SHAH, Administrative Patent Judge.

DECISION ON APPEAL
STATEMENT OF THE CASE
Pursuant to 35 U.S.C. § 134(a), the Appellant1 appeals from the
Examiner’s final decision to reject claims 1, 4, 6, 8, 11, 13, 15, and 18,
which are all of the pending claims. We have jurisdiction under 35 U.S.C.
§ 6(b).
We REVERSE.

1 We use the word “Appellant” to refer to “applicant” as defined in
37 C.F.R. § 1.42. The Appellant identifies the real party in interest as
“Lennox Industries Inc.” Appeal Br. 2.
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CLAIMED SUBJECT MATTER
The Appellant provides that their “disclosure relates generally to a
carbon dioxide (CO2) cooling system that uses subcooling.” Spec. 1.
Claims 1, 8, and 15 are the independent claims on appeal. Claim 1 is
illustrative of the subject matter on appeal, and is reproduced below (with
lettered bracketing added for reference)
1. A subcooling controller comprising:
[(a)] a sensor configured to measure one or more of:
[(a1)] a temperature external to a first heat exchanger
configured to remove heat from carbon dioxide refrigerant, the
first heat exchanger further configured to send the carbon dioxide
refrigerant to a flash tank;
[(a2)] a temperature of the carbon dioxide refrigerant; and
[(a3)] a pressure of the carbon dioxide refrigerant; and
[(b)] a processor configured to:
[(b1)] determine that one or more of the measured
temperature external to the first heat exchanger, the
measured temperature of the carbon dioxide refrigerant,
and the measured pressure of the carbon dioxide
refrigerant is above a threshold;
[(b2)] in response to the determination that one or more of
the measured temperature external to the first heat exchanger, the
measured temperature of the carbon dioxide refrigerant, and the
measured pressure of the carbon dioxide refrigerant is above the
threshold, activate a subcooling system, the subcooling system
comprising:
[(b2(i))] a condenser configured to remove heat
from a second refrigerant;
[(b2(ii))] a second heat exchanger comprising a coil
coiled around an exterior surface of the flash tank, the coil
configured to receive the second refrigerant from the
condenser, wherein heat from the carbon dioxide
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refrigerant stored in the flash tank transfers to the second
refrigerant as the second refrigerant flows through the coil;
[(b2(iii))] an expansion valve configured to direct
the second refrigerant from the condenser to the second
heat exchanger;
[(b2(iv))] a thermal storage material configured to
absorb heat from the carbon dioxide refrigerant in the flash
tank and from the second refrigerant in the second heat
exchanger; and
[(b2(v)] a compressor configured to compress the
second refrigerant from the second heat exchanger, the
compressor configured to send the second refrigerant to
the condenser, wherein activating the subcooling system
comprises opening the expansion valve.
Appeal Br., Claims App. 1–2.
REFERENCES
The prior art relied upon by the Examiner are:
Name Reference Date
Takegami et al.
(“Takegami”)
US 2007/0022777 A1 Feb. 1, 2007
Creed et al. (“Creed”) US 2008/0264080 A1 Oct. 30, 2008
Hockman et al.
(“Hockman”)
US 2011/0252820 A1 Oct. 20, 2011
Joppolo et al. (“Joppolo”) US 2014/0130536 A1 May 15, 2014
REJECTIONS
Claims 1, 4, 8, 11, 15, and 18 stand rejected under 35 U.S.C. § 103 as
being unpatentable over Takegami, Hockman, and Joppolo.
Claims 6 and 13 stand rejected under 35 U.S.C. § 103 as being
unpatentable over Takegami, Hockman, Joppolo, and Creed.
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OPINION
The Examiner finds that the combination of Takegami, Hockman, and
Joppolo teaches the limitations of independent claims 1, 8, and 15. See Final
Act. 3–11. Specifically, the Examiner finds that Takegami teaches the
subcooling controller of claim 1 comprising the sensor of limitation (a)
configured to measure the temperatures and pressure as recited in limitations
(a1) through (a3), and the processor of limitation (b) configured to determine
the temperature, and in response to the determination, activate a subcooling
system, the system comprising a condenser, second heat exchanger,
expansion valve, thermal storage material, and compressor, as recited in
limitations (b1), (b2) and (b2(i)) through (b2(v)). See id. Acknowledging
that Takegami does not teach the second heat exchanger comprising a coil
coiled around the exterior of the flash tank, as recited in limitation (b2(ii)),
the Examiner finds that “Hockman teaches the concept of a tank containing
a fluid (12) can have a heat exchanger with a fluid path comprising a coil.”
Id. at 4. The Examiner determines
One of ordinary skill in the art would recognize substituting the
directly coupled tank heat exchanger of Hockman to exchange
heat with the refrigerant passing through flash tank (45 of
Takegami; Fig. 2) from the condenser (44) of Takegami instead
of the cascade heat exchanger (210) will provide an alternative
improved and integrated heat transfer arrangement to sub-cool
the refrigerant downstream of condenser (44) and expected
results. Therefore, it would have been obvious to one of ordinary
skill in the art at the time of filing to modify the second heat
exchanger in the subcooling circuit of Takegami to have the fluid
path comprise a coil coiled around an exterior surface of the flash
tank taught by the coil around the tank of Hockman in order to
couple the subcooling circuit to the flash tank to provide a large
surface area for good heat transfer and direct cooling of the
refrigerant passing through the flash tank. For clarity, combining
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the fluid path and flash tank of Takegami to comprise a coil
coiled around the tank taught by Hockman would arrive at a coil
coiled around an exterior surface of the flash tank, the coil
configured to receive the second refrigerant from the condenser,
wherein heat from the carbon dioxide refrigerant stored in the
flash tank transfers to the second refrigerant as the second
refrigerant flows through the coil.
Id. at 4–5. The Examiner further acknowledges that Takegami does not
teach the “thermal storage material configured to absorb heat from the
carbon dioxide refrigerant in the flash tank and from the second refrigerant
in the second heat exchanger,” and relies on Joppolo to cure this deficiency.
See id. at 5. The Examiner makes the same findings, determinations, and
conclusions for independent claims 8 and 15 that recite limitations similar to
those of claim 1. See id. at 6–11.
The Appellant contends that the Examiner’s rejection of independent
claims 1, 8, and 15 is improper because Hockman does not qualify as prior
art. See Appeal Br. 9–13; Reply Br. 2–4. Specifically, the Appellant
contends that Hockman is not analogous to the claimed invention. See id.
For a reference to be proper for use in an obviousness rejection under
35 U.S.C. 103, the reference must be analogous to the claimed invention. In
re Bigio, 381 F.3d 1320, 1325 (Fed. Cir. 2004). Whether a reference is
analogous art is an issue of fact. Id. at 1324; see also In re ICON Health &
Fitness, Inc., 496 F.3d 1374, 1378 (Fed. Cir. 2007). “Two separate tests
define the scope of analogous prior art: (1) whether the art is from the same
field of endeavor, regardless of the problem addressed and, (2) if the
reference is not within the field of the inventor’s endeavor, whether the
reference still is reasonably pertinent to the particular problem with which
the inventor is involved.” Id. at 1325.
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This test for analogous art requires the PTO to determine the
appropriate field of endeavor by reference to explanations of the
invention’s subject matter in the patent application, including the
embodiments, function, and structure of the claimed invention.
See [In re] Wood, 599 F.2d [1032] at 1036 [(C.C.P.A. 1979)]
(confining field of endeavor to the scope explicitly specified in
the background of the invention); and [In re] Deminski, 796 F.2d
[436] at 442 [(Fed. Cir. 1986)] (determining the cited references
were within the same field of endeavor where they ‘have
essentially the same function and structure’)).”
Bigio, 381 F.3d 1325–26.
The Examiner characterizes the field of endeavor as “heat transfer
between fluids utilizing coiled heat exchangers with tanks within a vapor
compression system.” Ans. 14–15. The Examiner does not cite evidence
supporting this position, but asserts that “both Hockman and the present
application relate to the same general concept of exchanging heat between
fluids in a refrigeration/heat pump system” and both “include a vapor
compression/heat pump system that circulates a refrigerant through heat
exchangers for exchanging heat between fluids and thus are in the same field
of endeavor.” Id. at 14.
The Appellant asserts that the field of endeavor is “CO2 cooling
systems (e.g., air conditioning systems and refrigeration systems).” Appeal
Br. 10; see also id. at 9 (citing the Spec. 1:10–12, 2:1–6, 7:1–8:11). The
Appellant’s assertion is supported by evidence of the Specification. For
example, the Specification is titled, “CARBON DIOXIDE COOLING
SYSTEM WITH SUBCOOLING.” Spec. 1. Further, the Specification
describes the “TECHINCAL FIELD” as “generally . . . a carbon dioxide
(CO2) cooling system that uses subcooling” (id.) and discusses, in the
“BACKGROUND” section, “[a] cooling system (e.g., air conditioning
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system and/or refrigeration system) may be used to cool a space by cycling
refrigerant through the system” (id. at 2). The “DETAILED
DESCRIPTION” section discusses that “[c]ooling systems such as air
conditioning systems and refrigeration systems may be used to cool a space
by cycling refrigerant through the system” and the Appellant’s “disclosure
contemplates a system that uses both CO2 refrigerant and a subcooling
system that removes heat from the CO2 refrigerant.” Id. at 7. The Appellant
has the better position.
We agree with the Appellant that although “Hockman may involve a
similar scientific principal, such as heat transfer between fluids, to that
involved in the present application[, that] is not sufficient for a finding that
Hockman is analogous art.” Reply Br. 3 (citing In re Van Wanderham, 378
F.2d 981, 984, 988 (C.C.P.A. 1967)); see also In re Clay, 966 F.2d 656, 659
(Fed. Cir. 1992) (finding that simply being in the same “common endeavor”
is not enough to be in the same field of endeavor). As Hockman relates to a
“heat pump water heater includ[ing] a heat pump which generates a hot
refrigerant and a water tank for water to be heated” (Hockman, Abstr.) and
not to CO2 cooling systems, it is not in the same field of endeavor as the
Appellant’s invention.
Even though Hockman is not in the same field of endeavor as the
Appellant’s invention, it may still be properly combined with Takegami if it
is “reasonably pertinent” to the problem the Appellant attempts to solve.
The Examiner finds “Hockman further is reasonably pertinent to the
particular problem of improving heat transfer between the fluids using a
coiled heat exchanger around a tank that helps avoid insufficient heat
exchange between fluids.” Ans. 14. The Examiner further finds “the
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problem at hand is what is the best heat transfer structure to provide such a
heat transfer to a fluid inside a tank to ensure adequate heat transfer between
fluids.” Id. at 15.
The Appellant asserts that the problems the invention attempts to
solve are: (1) “to cool refrigerant” (Appeal Br. 11), (2) “the issue of CO2
refrigerant becoming too hot or pressurized in a cooling system, which may
be unsafe” (id. at 12), (3) “removing heat from a refrigerant in a tank” (id.),
and (4) “providing cooling using CO2 cooling systems” (Reply Br. 3). The
Specification supports the Appellant’s position. For example, in the
“BACKGROUND” section, the Specification discusses that “[w]hen the
system is unable to remove the heat in the refrigerant, pressure in the
refrigerant line may increase. The pressure may be decreased by releasing
refrigerant out of the system, but the refrigerant would have to be refilled at
a later time.” Spec. 2. The “DETAILED DESCRIPTION” section discusses
One problem encountered when using CO2 refrigerant is that it
may become difficult to remove sufficient heat from the CO2
refrigerant. For example, on warm or hot days it may become
more difficult to remove heat from the CO2 refrigerant. As the
temperature of the CO2 refrigerant increases, so does the pressure
in the CO2 refrigerant line. As a result, the pressure in the CO2
refrigerant line may increase to unsafe levels if sufficient heat is
not removed from the CO2 refrigerant.
Id. at 7. The Specification discusses that “[c]ertain systems include a valve
that opens when the pressure in the CO2 refrigerant line reaches particular
thresholds” to release the CO2 refrigerant from the system and reduce the
pressure in the refrigerant line, but that this may require replacing or refilling
the CO2 refrigerant. Id. Thus, the invention provides a solution of a “system
that uses both CO2 refrigerant and a subcooling system that removes heat
from the CO2 refrigerant,” so that “the pressure in the CO2 refrigerant line
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may be maintained at safe levels without having to release CO2 refrigerant
from the system” and “the CO2 refrigerant may not need to be refilled and/or
replaced as frequently.” Id.
Hockman discloses “[a] heat pump water heater” in which “[a]
circulation system puts the heated refrigerant in a heat exchange relationship
with the water in the passageway.” Hockman, Abstr. Hockman describes
the problems of prior heat pump water heaters that “are more efficient than
conventional resistant heat water heaters” as including: (1) “creat[ing] a
safety hazard if there is corrosion or rupture in the tube causing
contamination of the potable water by the refrigerant [used to heat the water
in the tank]” (id. ¶ 3), (2) allowing a rupture in the unit to “render[] the unit
a total loss” (id.), (3) “lead[ing] to corrosion, and calcium and mineral build
up on the tubes, which decreases the heat transfer efficiency of such internal
tubes” (id. ¶ 4), and (4) providing “reduced efficiency of the heat transfer
between the heat coils and the outer tank” (id. ¶ 5). Hockman’s invention
provides “an improved way to transfer heat from the heat pump to the water
with improved efficiency and reduced risk of contamination and calcium
build up.” Id. ¶ 6. To do so, Hockman provides for spiral tubing that
provides “a large surface area for good heat transfer.” Id. ¶ 31.
The Appellant has the better position that Hockman’s problems
regarding better heat transfer to heat water efficiently with less
contamination are not reasonably pertinent to the problems the Appellant is
attempting to solve of removing heat from CO2 refrigerant to prevent unsafe
levels of pressure in the refrigerant line. “[T]he purposes of both the
invention and the prior art are important in determining whether the
reference is reasonably pertinent to the problem the invention attempts to
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solve.” Clay, 966 F.2d at 659. The Appellant’s point that “the Examiner
generalizes the problems addressed by both Hockman and the present
application as one of ‘improving heat transfer between . . . fluids’” whereas
the Appellant’s problems are more specific than that (Appeal Br. 12) is well
taken. Also well-taken is the Appellant’s point that simply because
Hockman “shares components with a reference does not render the reference
pertinent.” Reply Br. 4 (citing In re Klein, 647 F.3d 1343 (Fed. Cir. 2011)).
We agree with the Appellant that Hockman’s reliance “on a similar scientific
principal as the present application is not sufficient for a finding that
Hockman is analogous art.” Id. (citing Wanderham, 378 F. 2d at 984, 988).
We, therefore, do not sustain the rejection under 35 U.S.C. § 103 of
independent claims 1, 8, and 15, and thus, also of dependent claims 4, 6, 11,
13, and 18. We also do not sustain the rejection under 35 U.S.C. § 103 of
dependent claims 6 and 13 that also relies on Hockman as prior art.

CONCLUSION
The Examiner’s decision to reject claims 1, 4, 6, 8, 11, 13, 15, and 18
under 35 U.S.C. § 103 is reversed.
In summary:
Claim(s)
Rejected
35
U.S.C. §
Reference(s)/Basis Affirmed Reversed
1, 4, 8, 11,
15, 18
103 Takegami, Hockman,
Joppolo
1, 4, 8, 11,
15, 18
6, 13 103 Takegami, Hockman,
Joppolo, Creed
6, 13
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Claim(s)
Rejected
35
U.S.C. §
Reference(s)/Basis Affirmed Reversed
Overall
Outcome
1, 4, 6, 8,
11, 13, 15,
18

REVERSED