Ex Parte Doll et al

Board of Patent Appeals and Interferences

May 6, 2011

10926155 (B.P.A.I. May. 6, 2011)

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.
10/926,155 08/25/2004 Martin Luther Doll JR. 26425-0014 7351
65885 7590 05/06/2011
MCNEES WALLACE & NURICK LLC
100 PINE STREET
P.O. BOX 1166
HARRISBURG, PA 17108-1166
EXAMINER
PETTITT, JOHN F
ART UNIT PAPER NUMBER
3744
MAIL DATE DELIVERY MODE
05/06/2011 PAPER
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.
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
__________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
__________

Ex parte Martin Luther Doll, Jr. and John C. Hansen
__________

Appeal 2009-008431
Application 10/926,155
Technology Center 3700
___________

Before: RICHARD E. SCHAFER, ROMULO H. DELMENDO, and
SALLY C. MEDLEY, Administrative Patent Judges.

SCHAFER, Administrative Patent Judge.

DECISION ON APPEAL
Applicants appeal a Final Rejection of Claims 19-31. 35 U.S.C. §§
6(b) and 134(a).
STATEMENT OF THE CASE
Claims 19-31 stand rejected as follows:
1. Claims 19, 20, and 27-30 under 35 U.S.C. § 102(b) as
anticipated by Thatcher1.
2. Claim 22 under 35 U.S.C. § 103(a) as unpatentable over
Thatcher.
3. Claim 21 under 35 U.S.C. § 103(a) as unpatentable over the
combined teachings of Thatcher and Beaverson2.

1 U.S. Patent 6,209,338.
2 U.S. Patent 5,079,930.
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4. Claims 23-26 and 31 under 35 U.S.C. § 103(a) as unpatentable
over the combined teachings of Thatcher and Cantley3.
App. Br. 2 and 5; Ans. 2.4
We affirm the rejections of Claims 19-27 and reverse the rejections of
Claims 28-31.
Subject Matter of the Claimed Invention
Applicants claim methods for monitoring the condition of a
refrigeration or cooling system such as an air conditioner system. Like
typical cooling systems, Applicants’ system cools by evaporating and
condensing refrigerant. In an evaporator, liquid refrigerant evaporates to a
gas. The evaporation absorbs heat. In the condenser, the gas condenses
back to a liquid giving up the absorbed heat. The refrigerant circulates
through the evaporator and condenser using known techniques. Written
Description, ¶¶ 16-19.
Applicants’ system monitors refrigerant temperature and pressure to
detect a low refrigerant charge and condenser malfunction. Written
Description, ¶ 5. More particularly, sensors monitor refrigerant temperature
and/or pressure (“T/P”) at refrigerant lines entering and exiting the
condenser. Written Description, ¶ 21. The sensors also monitor other
system conditions, such as system load and ambient temperature. Written
Description, ¶ 21.

3 U.S. Patent 4,325,223.
4 We refer to the Appeal Brief (“App. Br.”) filed July 28, 2008 and
Examiner’s Answer (“Ans.”) filed October 1, 2008. All references to the
claims are to the Claims Appendix of the Appeal Brief. App. Br. 20-22.
The Examiner has certified those claims as correct. Ans. 2.
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In one embodiment, the system monitors operational condenser
“subcooling” temperatures to detect low refrigerant charge. “Subcooling”
refers to the refrigerant’s drop in temperature when passing through the
condenser. The magnitude of subcooling is said to be an indicator of the
refrigerant charge level. Written Description, ¶ 25. During system
installation and initialization, when the cooling system is known to be fully
charged and fully operational, the system detects subcooling values under a
variety of different system operating conditions. These initialization values
are recorded as reference values. Written Description, ¶¶ 24 and 28. During
operation, if a detected subcooling value falls a prescribed amount below a
reference subcooling value for a particular set of system conditions, the
system generates a low refrigerant charge signal. Written Description, ¶ 26.
In another embodiment, the system monitors refrigerant pressure to
detect condenser degradation. Written Description, ¶ 31. The pressure is
said to be an indicator of condenser function. During installation, when the
system is known to be functioning correctly, the system records refrigerant
pressure under a variety of different system operating conditions. Written
Description, ¶ 31. During operation, if the refrigerant pressure value rises a
prescribed amount above its corresponding initial pressure value for a
particular set of operating conditions, the system generates a condenser
malfunction signal. Written Description, ¶ 31.
In the event of a low refrigerant charge or condenser malfunction, the
system generates a system alert that, e.g., may provide a signal to
maintenance personnel by displaying a message. Written Description, ¶ 26.
The signal may also cause the refrigeration system to shut down to prevent
hardware damage. Written Description, ¶¶ 30 and 32.
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Independent Claim 19 is representative:
19. A method of detecting performance degradation in
a refrigeration system, the method comprising:
initializing the refrigeration system by operating
the refrigeration system with a full refrigerant charge at
specific operating conditions, the specific operating
conditions including a plurality of loads and a plurality
of ambient conditions;
measuring initialization data relating to a plurality
of operational parameters of the refrigeration system
during the initialization of the refrigeration system;
storing the measured initialization data at the
specific operating conditions;
operating the refrigeration system after
initialization of the refrigeration system;
measuring operational data relating to at least one
of the plurality of operational parameters at a particular
operating condition of the operating refrigeration system;
comparing the measured operational data to the
corresponding stored initialization data for the particular
operating condition of the refrigeration system; and
generating a low refrigerant charge alert upon the
measured operational data being outside a predetermined
range of the corresponding stored initialization data.

Thatcher
The patent to Thatcher is used in each of the rejections.
Thatcher relates to controlling and monitoring cooling systems.
Thatcher’s system detects a low refrigerant charge by monitoring T/P at
refrigerant lines entering and exiting a condenser. Fig. 3 (see condenser 60
and temperature and pressure sensors 56.h and 56.e). Thatcher’s system also
monitors other system operational conditions such as load and ambient
temperature. Thatcher, 3:64-4:31; Fig. 1 (see condenser 60 and T/P sensors
56.h and 56.e). Thatcher’s system compares operational refrigerant T/P (i.e.,
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values measured after system installation) to reference T/P indicative of
proper operation at the same system conditions. Thatcher, 7:54-8:10. The
reference values can be pre-programmed by the manufacturer. Or, using
detected T/Ps, the reference values may be self-generated and/or refined by
the system to optimize performance for the given location (i.e., for the local
operating conditions). Thatcher, 6:7-23; 7:8-28
A controller monitors the differences between the operational and
reference T/Ps. If the differences from the reference values exceed a
predetermined “margin” or “magnitude,” the controller sends a signal
causing the addition or removal of refrigerant to maximize system efficiency
or maintain a desired level of heat exchange. Thatcher, 7:54-57; 8:10-29.
The controller also ensures that high and low “worst case extremes” of
refrigerant pressure are not exceeded. Thatcher, 1:28-31; 7:37-38.
Thatcher’s Figure 6, reproduced right, shows a schematic of the
controller’s actions. Upon original
power up and initialization, the
system is initialized creating a
profile of reference T/Ps (step 90).
During operation, measured T/Ps
(step 92) are compared to the
reference values for the same
conditions (step 94). If those
comparisons indicate a high
refrigerant charge, a signal is sent
to a high pressure valve that
removes refrigerant --steps 96
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“yes” and 102. If those comparisons indicate a low refrigerant charge, a
signal is sent to a low pressure valve that adds refrigerant --steps 104 “yes”
and 106. If the refrigerant charge is neither too high nor too low, i.e., within
an acceptable range –Figure 6, steps 96 “no” and 104 “no”-- no refrigerant is
added or removed. Thatcher, 5:55-6:6. The guidelines for determining
whether the data values are appropriate are determined and preselected by
the system designer based upon the functional requirements of the particular
system and application involved. Thatcher, 6: 38-48. Thus, Thatcher
implicitly teaches that there is a preselected range of acceptable values as
well as preselected ranges of too high and too low values, i.e., all values that
are above or below the acceptable range, that trigger removal or addition of
refrigerant. Thatcher, 6: 23-31.
OPINION
Claims 19, 20, and 27
The Examiner rejected Claim 19 and its dependent Claims 20 and 27
as anticipated by Thatcher.
Applicants argue that “Thatcher does not disclose the use of the
measured operational data being outside a predetermined range of the
corresponding stored initialization data.” App. Br., p. 7.
We disagree. As shown in Thatcher’s Figure 6, the system determines
whether the operational data indicates whether the refrigerant charge is too
high or too low. Figure 6, steps 96 and 104. There is necessarily a range of
acceptable values for which the answer to the inquiry of both steps is no.
The remaining values, those for which the answer to either inquiry is yes,
constitute ranges of too high and too low values. The thresholds for
determining whether the values are too high or too low are determined and
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preset by the system designer for each installation of the system. Thatcher,
6: 38-48. Thus, Thatcher implicitly uses measured operational data outside
of the predetermined range of acceptable values to trigger a system alert for
the removal or addition of refrigerant. Thatcher, 6: 23-35.
When the operational data is outside the acceptable reference
parameter limits, Thatcher’s system generates a signal or “alert” that is sent
to the pressure reservoir control valves. More particularly, when the
operational refrigerant T/P falls outside the accepted range, the system
transmits a control signal to the valve that adds refrigerant. Thatcher, 5:55-
6:6; Fig. 6 (steps 102 and 106).
Applicants argue that this signal is not an “alert” sent to a user
interface (App. Br. 7). In support, Applicants direct us to the following part
of their written description (Reply Br. 4):
If a system defect is detected, the control 140
preferably records and stores the data relating to the
defect. More preferably, the control 140 generates a
system alert. Most preferably, the system alert is also
transmitted to maintenance personnel, such as by
transmitting the alert to a user interface 180
communicably connected to the control 140.
Written Description, ¶ 26 (emphasis added).
Applicants’ above-quoted excerpt indicates that a “system alert” is
preferably, i.e., not necessarily, recorded and stored data relating to the
defect or an alert communicated to a user interface. Thus, the system alert
required by the claims is not limited to recorded and stored data or a signal
sent to a user interface. Limitations appearing only in the written description
may not be read into the claims. Renishaw PLC v. Marposs Societa' Per
Azioni, 158 F.3d 1243, 1248 (Fed.Cir. 1998).
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Giving the phrase its broadest reasonable construction consistent with
the specification, we construe it to encompass a signal that communicates a
change or provides a warning to the system, not necessarily to a user. Under
this construction, the signals sent by Thatcher’s controller to the system to
open the high or low pressure reservoir valves are “system alerts.”
We affirm the rejection of Claim 19.
Claims 20 and 27 depend from Claim 19. Applicants state that
Claims 20 and 27 rise or fall with Claim 19. Thus, we also affirm the
rejection of Claims 20 and 27.5
Claim 21
Claim 21 depends from Claim 19 and additionally requires that the
low refrigerant alert be sent when the operational subcooling value is
between 20 and 90% of the initialization value. The Examiner rejected the
claim under 35 U.S.C. § 103(a) as unpatentable over the combined
disclosures of Thatcher and Beaverson. We affirm the rejection.
The examiner found that Thatcher taught all of the limitations of
Claim 21 except for the use of a subcooling temperature difference of 90 –
20% of the initialization value as the threshold for generating a low
refrigerant alert. Ans. p. 6. The examiner relied upon Beaverson as teaching
the use of the subcooling temperature difference as an indicator of the level
of refrigerant charge and for generating an alert signal. Ans. p. 7. See
Beaverson at 7:58 – 8:2 and 6:25-29. The Examiner also found that
Beaverson teaches that the subcooling temperature difference used to
activate a low refrigerant alert can be adjusted to a desired value by the user.

5 See Ex Parte Frye, 94 U.S.P.Q.2d 1072, 1075 (BPAI 2010) (precedential) (“If an appellant fails to present
arguments on a particular issue . . . the Board will not, as a general matter, unilaterally review those
uncontested aspects of the rejection.”).
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Ans. 7, referring to Beaverson at 6:25-27. The examiner concluded that
using the subcooling difference value as an operational parameter and the
particular subcooling difference that triggers an alert would have been
obvious. Ans. 7-8.
Applicant argues that there is no reason to combine Beaverson’s
method for detecting low refrigerant with Thatcher’s system because
“Thatcher already has a system in place to determine low refrigerant . . . .”
App. Br., p. 12.
We disagree. Beaverson shows that the hypothetical person having
ordinary skill in the art knows that the subcooling temperature difference
may be used as an indicator of refrigerant charge level. Beaverson also
shows that a low refrigerant alert can be sent when the subcooling
temperature difference reaches a predetermined level below the initial level.
From the combined teachings of the references, one having ordinary skill in
the art would have recognized that Beaverson’s technique for determining
low refrigerant is an alternative to the technique disclosed by Thatcher. A
person having ordinary skill in the art has good reason to pursue the known
options within his or her technical grasp. KSR Intern. Co. v. Teleflex Inc.,
550 U.S. 398, 421 (2007). In other words, it is not unobvious to substitute
one alternative known in the art for determining low refrigerant for another
also known in the art for that purpose. In our view, it would have been
obvious to use the subcooling temperature difference as taught by Beaverson
as an indicator of low refrigerant charge in Thatcher’s system.
Applicants also argue that neither Thatcher nor Beaverson teach the
percentage range used as a subcooling threshold for sending an alert signal:
“Since neither Thatcher nor Beaverson discloses the use of range data (only
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stored or predetermined values), Thatcher and Beaverson cannot disclose
Appellant's recited limitation in claim 21.” App. Br., p. 12.
Applicants’specified “percentage range” merely identifies a
predetermined range of possible temperature difference values that trigger a
low refrigerant alert for any particular refrigerant system. Beaverson teaches
that temperature difference that triggers an alert may be set by the user. It is
reasonable to infer from Beaverson’s teachings that the person of ordinary
skill knows how to determine the appropriate and optimum temperature
difference for triggering a low refrigerant alert for any particular system.
Applicants have neither argued nor presented evidence that the ability to
determine the appropriate temperature difference for triggering an alert
presents any particular difficulties for those working in the art. In this
regard, we note that Applicants’ own written description is silent on how to
determine the appropriate percentage difference for triggering a low
refrigerant alert. Instead, Applicants merely recite a series of preferred and
more preferred ranges. Written description, p. 10. The determination of
the magnitude of the temperature difference from the initialization value for
triggering a low refrigerant alert is within the level of ordinary skill in the art
and would have been obvious.
We affirm the rejection of Claim 21.
Claims 23-25
Claim 23 depends from Claim 19 and additionally requires the
generation of a condenser fault alert based on a comparison of operational
data and initialization data for condenser performance. Claims 24 and 25
depend from Claim 23. The Examiner rejected Claims 23-25 under 35
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U.S.C. § 103(a) as unpatentable over the combination of Thatcher and
Cantley.
The Examiner found that Thatcher taught all the limitations of Claim
19 except for generating a condenser fault alert when the operational data
varied too far from the initialization data. Ans., p. 8.
Cantley describes a system for maintaining efficiency of refrigeration
system by detecting and avoiding condenser malfunctions such as condenser
fouling. To detect a malfunction, Cantley’s system compares operational
condenser T/P to reference T/P indicative of a properly functioning
condenser under the same conditions. Cantley, 6:16-44. When the
refrigeration system is “in good operating condition,” its condenser
temperatures and pressures have operational values of those in its profile of
corresponding reference values. Cantley, 6: 16-24. Deviations between
those operational and reference values “indicate a problem in the system”
and, accordingly, an “appropriate alarm” such as a “condenser fouling
alarm” is generated. Cantley, 6: 31-40. Cantley’s condenser alarm is
generated if the measured operational values exceed the reference value
threshold. Cantley, 6: 33-35.
One having ordinary skill in the art would have recognized the
efficiency benefits taught by Cantley with respect to controlling and
monitoring condenser condition. The person having ordinary skill in the art
would also have recognized that the efficiency benefits brought by Cantley’s
system would make an advantageous addition to Thatcher’s refrigeration
system. It would have been obvious to incorporate Cantley’s system into
Thatcher’s.
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Appellants argue that Cantley does not teach triggering an alarm when
the measured system operation values are outside “a predetermined range.”
We disagree. Cantley teaches the use of threshold values to generate
a condenser alarm. Cantley, 6:36-44. The alarm thresholds are set by the
system operator. Cantley, 6:40-42 (“I prefer a relative low threshold such
that the condensers can be cleaned before excessive fouling can take place.”)
The alarm threshold values are preselected and programmed into the system
memory. Cantley, 13:5-17, especially, lines 15-17.
The threshold value provides a boundary separating a range of
acceptable values that will not trigger an alarm from a range of unacceptable
values that will. Thus, Cantley’s system, in setting a threshold value
necessarily triggers an alarm when the operational value is outside the
predetermined acceptable range.
We affirm the rejection of Claim 23. Applicants do not present
separate arguments for dependent Claims 24 and 25, but rather argue they
are patentable in view of their dependence on Claim 23. App. Br. 14. We
therefore also affirm the rejection of Claims 24 and 25.
Claims 22 and 26
Claims 22 and 26 each add requirements that the system be shut down
when the operational data falls below a minimum threshold value. Claim 22
depends from Claim 19. Claim 26 depends from Claims 23 and 19. The
Examiner rejected the subject matter of Claim 22 under 35 U.S.C. § 103(a)
as unpatentable over Thatcher. Claim 26 was rejected under § 103(a) as
unpatentable over the combined teachings of Thatcher and Cantley. The
examiner used the same rationale relying on Thatcher as providing the basis
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for the obviousness conclusion for both claims. Compare Ans., pp. 8, ¶ 5
with the paragraph bridging pp. 9-10.
Thatcher notes that refrigeration systems are designed to avoid
damage due to operating parameter extremes. Thatcher, 1:28-31. Thatcher
also teaches that the system may be operated, for example, at a constant
temperature while modifying the refrigerant charge as necessary to avoid
extremes that would damage system hardware. Thatcher, 7:32-38. It is
apparent from Thatcher that one having ordinary skill in the art is aware that
operating the refrigeration equipment at significant deviations from design
operational parameters may damage the refrigeration equipment. Thatcher
expressly teaches an approach where refrigerant is added or removed to
prevent the system parameters from getting out of line. In our view, one
having ordinary skill in the art would have also recognized that system
damage could be avoided by shutting the system down prior to the
operational parameters reaching the extremes of the system’s design
capabilities. This is simply a common sense and conventional approach,
well within the level of ordinary skill in the art, for avoiding damage to
operating equipment if the operating conditions become inappropriate.
Shutting down Thatcher’s system when the operational data deviates below
a “predetermined minimum threshold” from the initialization data based
upon the design capabilities of the equipment would have been obvious.
Applicants challenge the examiner’s conclusions of obviousness of
the Claim 22 and 26 subject matter by attacking the details of examiner’s
scenario relating to a continually low refrigerant charge being the basis of a
shut down. App. Br., p. 13. Applicants stated that the scenario (1) “failed to
show Appellant’s limitation” and establish a shutdown based upon stored
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data and (2) identify how to modify Thatcher to include shutting down the
system when a dangerous threshold was reached. App. Br., pp. 13-14.
It is not necessary that every limitation be expressly taught in the art
to establish obviousness. “[T]he [obviousness] analysis need not seek out
precise teachings directed to the specific subject matter of the challenged
claim, for a court can take account of the inferences and creative steps that a
person of ordinary skill in the art would employ.” KSR, 550 U.S. at 418.
The essence of the examiner’s reasoning is that the person having ordinary
skill in the art would have recognized that the “blatant need to shut down the
system” when certain operational parameters, such as too low refrigerant
charge, are so far out of line that it would be necessary to shut down the
system. Ans., p. 19-20. We think this is an inference on the level of
ordinary skill in the art reasonably supported by the teachings of the
references. We also think it is reasonable to infer that the person of
ordinary skill in the art of refrigeration system control would have possessed
the knowledge of how to shut the system down.
The rejection of Claims 22 and 26 is affirmed.
Claims 28-31
Claim 28 depends from Claim 19. Claims 29 and 30 are dependent on
Claim 28. Claim 31 is dependent upon Claim 25. The Examiner rejected
Claims 28-30 as anticipated by Thatcher and Claim 31 under § 103(a) as
unpatentable over Thatcher combined with Cantley.
All of these claims require that the system compare currently
measured operation data, not with initialization data, but with earlier
measured operation data. If the trend in the measured operation data is
decreasing for the refrigerant charge or increasing for the saturated
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refrigerant temperature, the system generates a low refrigerant charge alert
or a condenser fault alert, respectively.
The examiner points to various points in Thatcher as supporting the
description of a trend in the data. We have reviewed Thatcher including the
portions specifically identified and cannot glean a disclosure of the
generation of a system alert based upon a trend of decreasing or increasing
data values.
We reverse the rejection of Claims 28-31.

DECISIONS
We affirm the rejection of Claim 22 under 35 U.S.C. § 103(a) as
obvious over Thatcher.
We affirm the rejection of Claims 19, 20, and 27 under 35 U.S.C. §
102(b) as anticipated by Thatcher.
We affirm the rejection of Claim 21 under 35 U.S.C. § 103(a) as
obvious over the combined teachings of Thatcher and Beaverson.
We affirm the rejection of Claims 23-26 under 35 U.S.C. § 103(a)
over the combined teachings of Thatcher and Cantley.
We reverse the rejection of Claims 28-30 under 35 U.S.C. § 102(b) as
anticipated by Thatcher.
We reverse the rejection of Claim 31 under 35 U.S.C. § 103(a) over
the combined teachings of Thatcher and Cantley.
The two-month time period for filing an appeal or commencing a civil
action, as recited in 37 C.F.R. § 1.304, or for filing a request for rehearing,
as recited in 37 C.F.R. § 41.52, begins to run from the “MAIL DATE”
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(paper delivery mode) or the “NOTIFICATION DATE” (electronic delivery
mode) shown on the PTOL-90A cover letter attached to this decision.
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-IN-PART