Kristof Adrien Laura Martens

Patent Trials and Appeals Board

Sep 15, 2020

2020000982 (P.T.A.B. Sep. 15, 2020)

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.
12/922,924 09/16/2010 Kristof Adrien Laura Martens MART3007/TJM/TL 4849
23364 7590 09/15/2020
BACON & THOMAS, PLLC
625 SLATERS LANE
FOURTH FLOOR
ALEXANDRIA, VA 22314-1176
EXAMINER
LETTMAN, BRYAN MATTHEW
ART UNIT PAPER NUMBER
3746
NOTIFICATION DATE DELIVERY MODE
09/15/2020 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):
MAIL@BACONTHOMAS.COM
PTOL-90A (Rev. 04/07)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

Ex parte KRISTOF ADRIEN LAURA MARTENS

Appeal 2020-000982
Application 12/922,924
Technology Center 3700
____________

Before ANTON W. FETTING, ULRIKE W. JENKS, and AMEE A. SHAH,
Administrative Patent Judges.

JENKS, Administrative Patent Judge.

DECISION ON APPEAL
Pursuant to 35 U.S.C. § 134(a), Appellant1 files this appeal from
Examiner’s decision to reject claims 21, 26, 27, 32, 35–37, 41, and 45–48 as
obvious. We have jurisdiction under 35 U.S.C. § 6(b).
We REVERSE.

1 Appellant identifies the real party in interest as “Atlas Copco Airpower,
Naamloze Vennootschap.” Appeal Br. 2. We use the word “Appellant” to
refer to “applicant” as defined in 37 C.F.R. § 1.42(a).
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STATEMENT OF THE CASE
Claims 21, 26, 27, 32, 35–37, 41, and 45–48 are on appeal, and can be
found in the Claims Appendix of the Appeal Brief. Claim 21, the sole
independent claim, is representative of the claims on appeal, and reads as
follows:
Claim 21. A method for cooling a liquid-injected air compressor
element having a compression chamber into which an oil or
water is injected via a first injection valve and a second injection
valve, said method comprising the steps:
compressing air in the compression chamber of the air
compressor element;
collecting the oil or water from the compressed air and
recycling the oil or water from a liquid separator;
injecting a first quantity of the oil or water from the liquid
separator into the compression chamber via the first injection
valve including a first injection opening on or in the compressor
element;
injecting a second quantity of the oil or water from the
liquid separator into the compressor chamber via the second
injection valve including a second injection opening on or in the
compressor element;
controlling a total quantity of the oil or water injected into
the compression chamber through both the first injection valve
and the second injection valve and adjusting the total quantity as
a function of a specific adjusting parameter, irrespective of any
other possible adjustments, wherein the total quantity of the oil
or water comprises the first quantity and the second quantity of
the oil or water, and wherein the total quantity of the oil or water
is greater than the first quantity of oil or water,
wherein the total quantity of oil or water injected into the
compression chamber is only adjusted by means of said second
injection valve that is configured as an adjustable valve having a
continuously variable flow-through opening and controlled by a
control unit to control the second quantity of oil or water into the
compressor chamber,
wherein the specific adjusting parameter is a temperature
measurement at a compressed air outlet and a measured ambient
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Application 12/922,924
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temperature, wherein the total quantity of oil or water which is
injected is adjusted based on said temperature measurement at
the compressed air outlet and the measured ambient temperature;
and
adjusting a temperature at the compressed air outlet to a
pre-set desired value by controlling the total quantity of oil or
water that is injected,
wherein said pre-set desired value for the temperature
measurement at the compressed air outlet is calculated based on
an algorithm which includes a function of the measured ambient
temperature.
Appeal Br. 16– 17 (Claims App.) (emphases added).
REFERENCES
The prior art relied upon by Examiner is:
Name Reference Date
Ignatiev et al.
(“Ignatiev”)
US 2008/0078192 A1 Apr. 3, 2008
Heimonen et al.
(“Heimonen”)
WO 2007/076213 Al July 5, 2007
JP-711 JPS498711 June 23, 1974

Obviousness over Heimonen, JP-711, and Ignatiev
Appellant requests review of Examiner’s rejection of claims 21, 26,
27, 32, 35–37, 41, and 45–48 under pre-AIA 35 U.S.C. § 103(a) over
Heimonen in view of JP-711 and Ignatiev.
The issue is whether the preponderance of evidence of record supports
Examiner’s conclusion that the claimed method of cooling a liquid-injected
air compressor based on an adjusting parameter that uses the temperature at
the compressor outlet in conjunction with ambient temperature is obvious.
A. Findings of Fact (FF)
FF1. Heimonen teaches “[a] rotary screw compressor with an oil
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feed system that has a plurality of oil orifice nozzles to feed oil
to the compressor rotors and the compressor bearings.”
Heimonen, Abstr. Heimonen’s system contains an air intake, at
least one compressor, and an air/oil separator. Id. ¶¶ 67, 144.
FF2. Heimonen teaches using multiple oil nozzles to feed oil into the
compression chamber with one inlet nozzle configured to
always have an oil flow. Id. ¶ 76, ¶ 79 (“Oil line U(d) is always
open and delivers oil to compressor oil orifice nozzles N4 and
NS.”). The other orifice nozzles are sized differently and
contain on/off valves. Id. ¶ 76.
FF3. Heimonen teaches that by using three oil inlet lines, the system
has four (4) normal modes of operation. The four (4) normal
modes of operation in this three-line system are: (1) Base oil
feed, (2) Base + A, (3) Base + B, and (4) Base + A + B. Id.
¶¶ 83–88.
FF4. “The control logic [for Heimonen’s system] is if T3 > 215 °F
then the system needs to step up the oil flow. If T3 < 185 °F the
system needs to step down the oil flow. If T3 is between 185 °F
and 215 °F it stays in that state.” Id. ¶ 96.
FF5. Heimonen teaches that the system also contains five (5)
thermistors: T1 is an ambient temperature thermistor; T2 is an
interstate temperature thermistor; T3 is a second stage discharge
temperature thermistor; T4 is a separator temperature
thermistor; T5 is a package discharge temperature thermistor.
Id. ¶¶ 34–38. Temperature thermistor T2 is positioned near the
discharge point of compressor C and reads the discharge
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temperature of compressor C. Id. ¶ 143. “The position of the
temperature thermistor T3 is prior to the air/oil separator E.” Id.
FF6. Heimonen teaches that “[i]deally the ai[r]/oil mixture being
discharged from the second stage compressor D is at a
temperature above the dew point and below the temperature at
which the lubricant breaks down too rapidly.” Id. ¶¶ 75, 143
(“It is important that the air and air/oil exiting the compressor D
and that within the separator E is above the pressure dew point
to prevent condensation of water which is detrimental to the
compressor assembly.”).
FF7. Examiner finds that JP-711 teaches “a first injection valve (14)
including a first injection opening on or in the compressor
element.” Ans. 8.
FF8. Examiner finds that Ignatiev teachers “an electrically
controllable valve, wherein said second injection valve is
adjustable in a continuous manner, and wherein said second
injection valve is adjustable in a number of stages.” Ans. 8–9.
B. Analysis
Examiner finds that Heimonen teaches all the elements of the claimed
invention but for “an injection valve in the first injection path such that all
compressor injection lines having an injection valve, or the second injection
valve being an adjustable valve having a continuously variable flow-through
opening.” Ans. 8; FF1–FF6. Examiner relies on Ignatiev and JP-711 for
teaching these limitations. Ans. 8; FF7, FF8. Examiner concludes that “[i]t
would be obvious to one of skill in the art, at the time of invention, to
modify the method taught by Heimonen with the valve taught by JP S49-
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84711 in order to allow the injection path to be closed to the compressor at
times such as shutdown and during maintenance.” Ans. 8.
Appellant argues that “Heimonen only discloses controlling the
amount of oil based on the discharge temperature thermistor,” but does not
make calculations based on a combination of ambient temperature and
discharge temperature. Appeal Br. 9.
“An examiner bears the initial burden of presenting a prima facie case
of obviousness.” In re Huai-Hung Kao, 639 F.3d 1057, 1066 (Fed. Cir.
2011). The burden is on Examiner to explain why the Heimonen’s system
necessarily makes calculations based on ambient temperature readings.
Examiner finds that Hemionen’s T3 thermistor provides the claimed
“temperature measurement at a compressed air outlet” (Final Act. 5), but it
is not clear what Examiner relies on to teach the “measured ambient
temperature” (see id.). Rather, Examiner cites to Heimonen’s paragraphs
96–100 and 143 for teaching “wherein the ambient temperature is sensed
and the outlet temperature is adjusted to control condensation T3.” Id. at 6.
In response to Appellant’s argument “that ‘Heimonen is silent with respect
to any specific control regime in which the ambient temperature, e.g., T1, is
used to control the oil-flow’,” Examiner finds
in order to calculate the “pressure due point” the ambient
temperature must be known and factored into the determination.
In other words, in order to determine if the discharge temperature
will result in condensation, the ambient temperature must be
determined in order to determine the conditions at which
condensation will occur and which must be avoided.
Id. at 8. Examiner further reasons that “[t]he ‘pressure dew point’ is a
function of the measured ambient temperature because it is the dew point
temperature of a gas at a measured pressure and the dew point temperature
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of a gas is a function of the measured dry bulb temperature (measured
ambient temperature) and the relative humidity.” Ans. 10.
Heimonen teaches a screw compressor with an oil feed system that
has multiple thermistors including one located at the air inlet that measures
ambient temperature. FF1–FF5. Heimonen teaches that the thermistors and
pressure transducers are connected to appropriate controls and processors to
regulate the oil feed and temperature. Heimonen ¶ 143. Heimonen’s
thermistor T3 measures the temperature after the second stage discharge.
FF5. Heimonen teaches that the temperature exiting the compressor and
entering the separator must be above the pressure dew point of the air in the
system in order to prevent condensation. FF6. Heimonen does not disclose
how the information collected at the T1 thermistor, the ambient temperature
thermistor, is processed.
We agree with Appellant that Examiner has not established, with
evidence in the record, how Heimonen teaches the limitation that “said pre-
set desired value for the temperature measurement at the compressed air
outlet is calculated based on an algorithm which includes a function of the
measured ambient temperature,” as recited in the claim. See Appeal
Br. 9–10. To the extent Examiner finds that Heimonen teaches that “[t]he
pre-set desired value is calculated using an algorithm which includes a
function of maintaining the measured temperature at the compressed air
outlet ‘above the pressure dew point’ which is a function of the measured
ambient temperature” (Ans. 10), we agree with Appellant that this does not
teach the pre-set desired value calculated as claimed. See Appeal Br. 10. We
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note that the dew point2 of a gas depends on temperature and pressure.
Increasing the pressure of a gas also increases the dew point temperature of
the same gas. The dew point pressure of a gas does not rely on temperature
readings of the same gas at a different temperature, such as ambient
temperature. See above footnote 2. In Heimonen, the air in the system
exiting compressor D, as measured by thermistor T3, is under pressure; the
dew point of the gas under pressure at that point in the system is higher than
the dew point of the same gas at the inlet, which is at ambient pressure and
temperature. Moreover, Heimonen teaches “[i]t is important that the air and
air/oil exiting the compressor D and that within the separator E is above the
pressure dew point to prevent condensation of water which is detrimental to
the compressor assembly.” Heimonen ¶ 143; FF6. Examiner does not
explain how the measured temperature of the air exiting compressor D by
thermistor T3 is used to ensure the air exiting is above the pressure dew
point or how the dew point is used to determine the operating temperature of
the compressor. See Appeal Br. 9–10.
Further, Heimonen provides that the control logic for changing the oil
flow into the compressor is based on temperature readings at the thermistor
T3 which is at compressor D’s outlet. FF4 and FF5; see also Appeal Br. 9.
Examiner has not explained how the control logic for changing the oil flow
into the compression chamber in Heimonen’s system takes into account the

2 Dew point: “The temperature and pressure at which a gas begins to
condense to a liquid.” Dew-point pressure: “The gas pressure at which a
system is at its dew point, that is, the conditions of gas temperature and
pressure at which the first dew or liquid phase occurs.” McGraw-Hill
Dictionary of Scientific and Technical Terms, Sybil P. Parker editor, 5th ed.
(1993).
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ambient temperature reading at thermistor T1 as well. Because Examiner has
not provided adequate evidence or sound technical reasoning to show how
Heimonen’s method meets all of the limitations of Appellant’s independent
claim 21, we reverse the rejection of the claim under 35 U.S.C. § 103(a).
C. Conclusion
The evidence of record does not support Examiner’s conclusion that
claim 21 and any of its dependent claims are obvious over Heimonen,
Ignatiev, and JP-711.

DECISION SUMMARY
In summary:
Claims
Rejected
35 U.S.C.
§
Reference(s)/Basis Affirmed Reversed
21, 26, 27,
32, 35–37,
41, 45–48
103(a) Heimonen,
Ignatiev, JP-711

21, 26, 27,
32, 35–37,
41, 45–48

REVERSED