Ex Parte Lifson et al

Patent Trial and Appeal Board

Dec 21, 2012

10732134 (P.T.A.B. Dec. 21, 2012)

UNITED STATES PATENT AND TRADEMARK OFFICE
__________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
__________

Ex parte ALEXANDER LIFSON, MICHAEL F. TARAS,
and THOMAS J. DOBMEIER
__________

Appeal 2010-001517
Application 10/732,134
Technology Center 3700
___________

Before CARL W. WHITEHEAD, JR., ERIC S. FRAHM, and
ANDREW J. DILLON, Administrative Patent Judges.

DILLON, Administrative Patent Judge.

DECISION ON APPEAL
Claims 21-28 are pending. (App. Br. 2; Ans. 2.)1 Claims 1-20 are
canceled. (Id.) Appellants appeal under 35 U.S.C. § 134(a) from the final

1 We refer to the Appeal Brief filed June 12, 2006 (“App. Br.”), the
Examiner’s Answer mailed January 30, 2007 (“Ans.”), and the Reply Brief
filed December 11, 2007 (“Reply Br.”). We do not refer to:
(i) the Corrected Appeal Briefs filed May 11, 2007
and June 26, 2007, which were submitted to correct document
headings and claim summaries (see Notices of Non-Compliant

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Application 10/732,134

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rejections of claims 21-28. (App. Br. 6.) We have jurisdiction under 35
U.S.C. § 6(b).
We affirm.

THE INVENTION
Appellants disclose a refrigerant system that monitors superheating of
the refrigerant to detect a shortage (e.g., due to a leak or valve malfunction).
(Spec. ¶ [0022].) “Superheating” is the temperature difference between a
refrigerant’s saturation temperature (i.e., boiling point) and operation
temperature (i.e., actual temperature) at a given pressure. (Spec. ¶ [0020].)

Appeal Brief mailed April 11, 2007 and June 20, 2007,
respectively);
(ii) the Corrected Examiner’s Answer mailed October
11, 2007, which does not identify the correction and was
deemed deficient by this Board (see Order Returning
Undocketed Appeal to Examiner, Jul. 17, 2009);
(iii) the Supplemental Examiner’s Answer mailed
January 8, 2008, which was ordered to be vacated by this Board
(see Order Returning Undocketed Appeal to Examiner, Jul. 17,
2009); and
(iv) the Reply Brief filed March 10, 2008, which was
responsive to the vacated Supplemental Examiner’s Answer.
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THE REJECTIONS
Claims 21, 23, 25, and 27 stand rejected under 35 U.S.C. § 103(a) as
obvious over Blair (U.S. Patent No. 5,457,965) and Zheng (U.S. Patent No.
6,758,054 B2). (App. Br. 6; Ans. 2.)
Claims 22 and 26 stand rejected under 35 U.S.C. § 103(a) as obvious
over Blair, Zheng, and Lord (U.S. Patent No. 4,523,435). (Id.)
Claims 24 and 28 stand rejected under 35 U.S.C. § 103(a) as obvious
over Blair, Zheng, and Pham (U.S. Patent No. 6,467,280 B2). (Id.)

OBVIOUSNESS REJECTION OF
CLAIMS 21, 23, 25, AND 27 OVER BLAIR AND ZENG
Appellants address claims 21 and 25 collectively. (App. Br. 8.)
Appellants do not address claims 23 and 27, which respectively depend from
claims 21 and 25. We select claim 21, reproduced below, as representative
of claims 21, 23, 25, and 27. See 37 C.F.R. § 41.37(c)(1)(iv).
21. A method of determining an undesirable condition
in a refrigerant system that includes a compressor, at least one
evaporator heat exchanger and an economizer heat exchanger,
the method comprising:
automatically determining a superheat value by
determining a difference between a saturated vapor temperature
and an actual operating vapor temperature as the superheat
value;
determining if a difference between the determined
superheat value and an expected superheat value exceeds a
selected threshold; and
at least one of
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determining the actual operating vapor temperature
by determining a temperature of the refrigerant between the
compressor and at least one of the economizer heat exchanger
or the at least one evaporator heat exchanger, or
determining the saturated vapor temperature by
determining a vapor temperature within at least one of the
economizer heat exchanger or the at least one evaporator heat
exchanger.
The Examiner found that Blair’s vehicle A/C system includes all but
the required economizer heat exchanger (hereafter “economizer”). (Ans. 4.)
In view of the economizer 43 of Zheng’s vehicle A/C system, the Examiner
determined that it would have been obvious to add an economizer to Blair’s
system for increased performance. (Id.) In addition, the Examiner noted
that economizers were known to increase system efficiency. (Id.)
We find no error in the Examiner’s determinations. Zheng shows that
economizers were known to improve the capacity of vehicle A/C systems,
particularly by further subcooling the refrigerant supplied to an evaporator.
(Zheng, col. 7, ll. 30-33.) Given this benefit, the proposed addition of an
economizer to Blair’s vehicle A/C system constitutes a prima facie obvious
“application of a known technique to a piece of prior art ready for the
improvement.” KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 417 (2007).
Appellants argue that addition of an economizer would not have been
obvious, for three alleged reasons. First, Blair’s system would likely include
a variable speed motor that sufficiently increases capacity when needed.
(App. Br. 7.) Second, Blair’s system lacks an auxiliary evaporator, while
Zheng teaches the economizer as warming an auxiliary evaporator. (Reply
Br. 1-2.) Third, the added economizer would increase the weight and size of
Blair’s system. (App. Br. 7.)
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Appellants’ arguments are not persuasive. Appellants fail to present
evidence that Blair’s system would not have been understood as benefiting
from subcooling by an added economizer. For example, Appellants allege
but fail to establish that, despite Zheng’s express teachings of increased
capacity, vehicle A/C economizers would not have been understood as
increasing capacity.2 See Estee Lauder Inc. v. L’Oreal S.A., 129 F.3d 588,
595 (Fed. Cir. 1997) (arguments cannot take the place of factual evidence).
For the above reasons, the obviousness rejections of claims 21, 23, 25,
and 27 are sustained.

OBVIOUSNESS REJECTION OF CLAIMS 22 AND 26
OVER BLAIR, ZHENG, AND LORD
Appellants address claims 22 and 26 collectively. (App. Br. 8.) We
select claim 22, reproduced below, as representative of claims 22 and 26. 37
C.F.R. § 41.37(c)(1)(iv).
22. The method of claim 21, comprising:
determining the actual operating vapor temperature by
determining a temperature of the refrigerant between the
compressor and at least one of the economizer heat exchanger
or the at least one evaporator heat exchanger; and
determining the saturated vapor temperature by
determining a vapor temperature within at least one of the

2 Even assuming arguendo such evidence were provided, it would still be
prima facie obvious to add an economizer and auxiliary evaporator to
Blair’s vehicle A/C system in view of Zheng, i.e., such as paired by Zheng’s
system for their aggregate benefits.
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economizer heat exchanger or the at least one evaporator heat
exchanger.
The Examiner found that Lord determines the superheating of its
refrigerant by setting the saturation temperature as the refrigerant
temperature within an evaporator. (Ans. 4.) Based on this finding, the
Examiner determined that it would have been obvious to determine the
superheating of Blair’s refrigerant by likewise setting the saturation
temperature as the refrigerant temperature within the evaporator 20. (Id.)
We find no error in the Examiner’s finding and determination. Blair
and Zheng teach alternative techniques for determining the superheating of
refrigerant. Blair calculates the difference between:
(i) the refrigerant’s operation temperature downstream of
the compressor 4 (sensed by the thermistor 34); and
(ii) the refrigerant’s saturation temperature deduced from the
pressure downstream of the compressor 4 (determined from the
known refrigerant type and pressure sensed by the pressure
transducer 32)
(Blair, col. 3, ll. 23-31.) Zheng calculates the difference between:
(i) the refrigerant’s operation temperature when passing
from the evaporator to the compressor 4 (sensed by thermistor
34); and
(ii) the refrigerant’s saturation temperature deduced from the
temperature near or within the evaporator 10 (sensed by the
thermistor 32).
(Zheng, col. 3, ll. 28-41.) Given that Blair’s and Zheng’s techniques were
known alternatives for superheating calculation, it would have been obvious
to employ Zheng’s measurements (i) and (ii) in addition to or in lieu of
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Blair’s measurements (i) and (ii). See KSR, 550 U.S. at 415-16 (2007)
(“‘[A] combination which only unites old elements with no change in their
respective functions ... obviously withdraws what already is known into the
field of its monopoly and diminishes the resources available to skillful
men.’” (quoting Great Atlantic & Pacific Tea Co. v. Supermarket Equipment
Corp., 340 U.S. 147, 152–153 (1950))). As claimed, Zheng’s added
measurements would: “determin[e] the actual operating vapor temperature
by determining a temperature of the refrigerant between the compressor and
… evaporator heat exchanger” (cf., Appellants’ Figure 2 for meaning of
“between”) and “determin[e] the saturated vapor temperature by determining
a vapor temperature within … [the] evaporator heat exchanger.”
Appellants argue:
The Blair reference at column 3, line 12, states, “The thermistor
measures the temperature of the refrigerant, preferably at or
near the point of the pressure transducer 32.” If one were to
substitute in the teachings of the Lord reference, that would
require changing the position of the thermistor [34] of the Blair
reference and, therefore, it would no longer be “at or near the
point of the pressure transducer 32.”
(App. Br. 9.) Appellants’ argument is not persuasive. The modification
does not entail a mere relocation of Blair’s thermistor 34 to within the
evaporator 20. As discussed above, the modification entails an
incorporation of Zheng’s measurements (i) and (ii) and respective
components within Blair’s system, which satisfies both of the claimed
determining steps.

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OBVIOUSNESS REJECTON OF
CLAIMS 24 AND 28 OVER BLAIR, ZHENG, AND PHAM
Appellants address claims 24 and 28 collectively. (App. Br. 9-10.)
We select claim 24, reproduced below, as representative of claims 24 and
28. 37 C.F.R. § 41.37(c)(1)(iv).
24. The method of claim 21, wherein the refrigerant
system includes an expansion valve, the undesirable condition
comprises an expansion valve malfunction and comprising
determining that the expansion valve is malfunctioning when
the determined difference exceeds the selected threshold.
In rejecting claim 24, the Examiner found that Pham’s duty cycle
monitors superheating to detect expansion valve malfunctions. (Ans. 5.)
Based on this finding, the Examiner determined that it would have been
obvious to detect an expansion valve malfunction of Blair’s system by
monitoring whether the refrigerant’s superheating exceeds a threshold. (Id.)
We find no error in the Examiner’s determinations. According to
Pham, if the moving average SH of a superheat value (To - Ti) (Pham, col.
16, ll. 59-61) is above a threshold (e.g., SH greater than 20), that average
“indicate[s] an off-tuned expansion valve or an undersized valve or the valve
is stuck closed.” (Pham col. 17, ll. 23-25). Thus, Pham shows that
excessive superheating was known to indicate an expansion valve
malfunction. Given this understanding, the proposed detecting of an
expansion valve malfunction within Blair’s system, by monitoring whether
the superheating exceeds a threshold, constitutes an obvious “application of
a known technique to a piece of prior art ready for the improvement.” KSR,
550 U.S. at 417.
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Appellants argue that “[t]here is no use for the duty cycle monitoring
of the Pham reference in the Blair reference.” (App. Br. 10.) Appellants’
argument is not persuasive. The Examiner has not relied on Pham as
suggesting a wholesale application of its duty cycle teachings to Blair’s
system. The Examiner has relied on, and proposes to implement, solely
Pham’s teaching “that a large differential between actual temperature and
expected temperature can be due to a loss of refrigerant charge, stuck
thermal expansion valve, or various other malfunctions.” (Ans. 5 and 7.)
For the above reasons, the obviousness rejection of claims 24 and 28
is sustained.

DECISION
The Examiner’s decision rejecting claims 21-28 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).

AFFIRMED

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