Detailed Action
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
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Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claims 1, 2, 4, and 9 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by US Patent No. 5,551,248 to Derosier.
Derosier teaches limitations from claim 1 in fig. 1, shown above, a defrost system comprising:
a vapor compression system (shown in fig. 1 and taught in col. 4, lines 9-24) including a compressor (23), a condenser (22), an expansion valve (24), an evaporator (21), and a quantity of refrigerant (a “heat transfer fluid (e.g. a vapor compression refrigerant)” taught in col. 4, lines 13-14);
a defrost heater (34) operably connected to the evaporator (21) and configured to melt accumulated ice or frost from coils of the evaporator upon activation (taught in col. 4, lines 50-52);
a plurality of sensors (28, 29, 30, and 31, taught in col. 4, lines 36-46 and sensor 33 taught in lines 47-52) operable to gather signals indicative of a need for a defrost cycle (with the sensor 33 particularly taught as a “defrost temperature sensor”), the sensors including an air temperature sensor in fluid communication with an airflow pathway over the coils (particularly the sensor 31, taught to measure the temperature of ambient air to be cooled and thus air at the inlet of the cooling system of Derosier), a surface temperature sensor (33) operably coupled to the coils (of the evaporator 21 as taught lines 47-52),
a controller (25) programmed to:
receive the signals from the plurality of sensors (particularly from the defrost sensor 33);
process the signals to determine whether a defrost cycle is needed (Derosier teaches in col. 5, lines 31-39 that a duration between defrost cycles may be programmed in an exemplary embodiment, but teaches in col. 3, lines 27-29 that the defrost cycle may be initiated “in response to a condition indicating a need for system defrost” with the sensor 33 of col. 4, lines 47-52 particularly taught as a defrost sensor); and
upon determination that the defrost cycle is needed, initiate the defrost cycle via control over at least one component of the vapor compression system (as taught in col. 3, lines 27-29, the controller (here designated a “master controller”) “transmits a defrost on signal to initiate a system defrost cycle in response to a condition indicating a need for system defrost” and as indicated in table II in col. 8 of Derosier, various components such as the compressor 23, fans 26 and 27, and expansion valve 24 which are operated during the cooling mode are turned off in the defrost mode).
Derosier teaches limitations from claim 2 in fig. 1, shown above, the defrost system of claim 1, wherein the controller is further programmed to:
process the signals to determine whether the defrost cycle is complete (as taught in col. 5, lines 31-39, a “defrost end temperature” is programmed for the controller and as taught in col. 6, lines 55-63, the controller acquires data from the sensors to compare to this value); and
upon determination that the defrost cycle is complete, terminate the defrost cycle via control over the at least one component of the vapor compression system (as taught in col. 7, line 49-55, the defrost cycle is ended when the evaporator reaches this programmed defrost end temperature. As indicated in table II in col. 8 of Derosier, various components such as the compressor 23, fans 26 and 27, and expansion valve 24 which are off during the defrost mode are turned on for cooling after this mode).
Derosier teaches limitations from claim 4 in fig. 1, shown above, the defrost system of claim 1, wherein initiating the defrost cycle comprises: deactivating the compressor; and activating the defrost heater (as taught in table II in col. 8 of Derosier, the compressor 23 is on and the heater 34 is off during the cooling operation, but the compressor is turned off and the heater turned on during the defrost operation).
Derosier teaches limitations from claim 9 in fig. 1, shown above, the defrost system of claim 1, further comprising: an evaporator fan (indoor fan 26) is positioned and oriented to blow over the coils of the evaporator (21, as taught in col. 4, lines 18-20), the fan including a fan motor and a plurality of fan blades (as shown in fig. 1).
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1, 2, 4, and 9 are rejected under 35 U.S.C. 103 as being unpatentable over US Patent No. 5,551,248 to Derosier in view of US Publication No. 2017/0176072 A1 to Gokhale et al.
The additional ground of rejection set forth below presents Gokhale as a secondary reference to more clearly teach the use of a sensor input in determining the need for the initiation of a defrost operation. This rejection does not indicate any deficiency in the rejection of the claims as being anticipated by Derosier set forth above but instead demonstrates that instant independent claim 1 remains unpatentable, even if Derosier is given the narrower reading applicant appears to assert. See the response to arguments set forth below.
Derosier teaches limitations from claim 1 in fig. 1, shown above, a defrost system comprising:
a vapor compression system (shown in fig. 1 and taught in col. 4, lines 9-24) including a compressor (23), a condenser (22), an expansion valve (24), an evaporator (21), and a quantity of refrigerant (a “heat transfer fluid (e.g. a vapor compression refrigerant)” taught in col. 4, lines 13-14);
a defrost heater (34) operably connected to the evaporator (21) and configured to melt accumulated ice or frost from coils of the evaporator upon activation (taught in col. 4, lines 50-52);
a plurality of sensors (28, 29, 30, and 31, taught in col. 4, lines 36-46 and sensor 33 taught in lines 47-52) operable to gather signals indicative of a need for a defrost cycle (with the sensor 33 particularly taught as a “defrost temperature sensor”), the sensors including an air temperature sensor in fluid communication with an airflow pathway over the coils (particularly the sensor 31, taught to measure the temperature of ambient air to be cooled and thus air at the inlet of the cooling system of Derosier), a surface temperature sensor (33) operably coupled to the coils (of the evaporator 21 as taught lines 47-52),
a controller (25) programmed to:
receive the signals from the plurality of sensors (particularly from the defrost sensor 33).
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Derosier teaches in col. 3, lines 27-29 that the defrost cycle may be initiated “in response to a condition indicating a need for system defrost” but does not explicitly teach the inputs of the sensor (33) being used to determine this “need for system defrost” or initiating the defrost on the basis of this determination. Gokhale teaches in ¶ 14, in discussing the deficiencies of prior art systems, that a defrost algorithm which does not consider environmental conditions and operates, for example, only on the basis of the time since a previous defrost cycle in determining when a new defrost cycle should be initiated runs the risk of initiating unnecessary defrost cycles and wasting energy. In fig. 3, shown above, and ¶¶ 35, 37, 47, a defrost algorithm for a heat pump air conditioning system in which both the conditions of ambient air (as represented by a dew point temperature of that air) and the surface temperature of evaporator coils are used (in steps 312 and 304) in order to initiate a defrost cycle (in step 320, which cannot be initiated without the results of steps 304 and 312). It would have been obvious to one of ordinary skill in the art before the application was effectively filed to modify Derosier with the sensor-based defrost initiation taught by Gokhale in order to account for environmental conditions and prevent the waste of energy by performing defrost operations which aren’t necessary as taught in Gokhale’s ¶ 14.
Derosier teaches limitations from claim 2 in fig. 1, shown above, the defrost system of claim 1, wherein the controller is further programmed to:
process the signals to determine whether the defrost cycle is complete (as taught in col. 5, lines 31-39, a “defrost end temperature” is programmed for the controller and as taught in col. 6, lines 55-63, the controller acquires data from the sensors to compare to this value); and
upon determination that the defrost cycle is complete, terminate the defrost cycle via control over the at least one component of the vapor compression system (as taught in col. 7, line 49-55, the defrost cycle is ended when the evaporator reaches this programmed defrost end temperature. As indicated in table II in col. 8 of Derosier, various components such as the compressor 23, fans 26 and 27, and expansion valve 24 which are off during the defrost mode are turned on for cooling after this mode).
Derosier teaches limitations from claim 4 in fig. 1, shown above, the defrost system of claim 1, wherein initiating the defrost cycle comprises: deactivating the compressor; and activating the defrost heater (as taught in table II in col. 8 of Derosier, the compressor 23 is on and the heater 34 is off during the cooling operation, but the compressor is turned off and the heater turned on during the defrost operation).
Derosier teaches limitations from claim 9 in fig. 1, shown above, the defrost system of claim 1, further comprising: an evaporator fan (indoor fan 26) is positioned and oriented to blow over the coils of the evaporator (21, as taught in col. 4, lines 18-20), the fan including a fan motor and a plurality of fan blades (as shown in fig. 1).
Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Derosier taken alone or in combination with the teachings of Gokhale as applied to claim 1 above and further in view of WIPO Publication No. 2004/088222 A1 to Manettas et al. An English translation of Manettas has been provided with this Office Action and citations to specific passages and paragraphs of this reference are directed to this translation rather than to the German-language original document.
Regarding claim 3, Derosier teaches a refrigeration cycle cooling system in which an evaporator is provided with a defrost sensor among a plurality of refrigerant and air temperature sensors and a controller for determining when defrosting of the evaporator is needed and initiating a defrosting mode based on this determination. Derosier does not teach the initiating of the defrost cycle including issuing a notification to a user to initiate the defrost cycle. Manettas teaches in ¶¶ 3 and 12 that in a refrigeration device, automated defrosting may not be expedient in some circumstances as the heat emitted for defrosting an evaporator can adversely heat refrigerated goods stored by the device and that, for this reason, it can be preferable for a monitoring system to signal the need for defrosting to a user via a display. It would have been obvious to one of ordinary skill in the art before the application was effectively filed to modify Derosier with the defrosting notifications taught by Manettas in order allow the user to ensure that defrosting is performed at convenient times, whether for stored goods in a refrigeration system or for user comfort in an air conditioning system, thus ensuring that effective operations are not hampered by a poorly timed defrost operation while still allowing the user to initiate defrosting to maintain effective and efficient operation of the system.
Claims 5-8 are rejected under 35 U.S.C. 103 as being unpatentable over Derosier taken alone or in combination with the teachings of Gokhale as applied to claim 1 above and further in view of WIPO Publication No. 2019/243591 A1 to Izadi-Zamanabadi et al. and US Publication No. 2015/0204589 A1 to Liu.
Regarding claim 5, Derosier teaches a refrigeration cycle cooling system in which an evaporator is provided with a defrost sensor among a plurality of refrigerant and air temperature sensors and a controller for determining when defrosting of the evaporator is needed and initiating a defrosting mode based on this determination. Derosier does not teach the system including upstream and downstream temperature sensors disposed upstream and downstream of the evaporator in an airflow path respectively, or the controller determining a frost-free temperature differential between these temperatures measured by these sensors while the evaporator is in a frost-free condition, determining an operational temperature differential as an equivalent differential while the system is in operation, and initiating the defrost cycle when the operational differential reaches a threshold level below the frost-free temperature differential. Izadi-Zamanabadi teaches in fig. 3, shown above, and in pg. 12, lines 10-27 a system and method for the defrosting of an evaporator (104), the system including two temperature sensors (205 and 206) measuring respective an inlet and outlet temperature of air flowing through the evaporator and teaches in pg. 12, lines 28-33 these sensors being used to establish a setpoint temperature value and a control temperature value the comparison of which is used to determine when ice has accumulated on the evaporator. It would have been obvious to one of ordinary skill in the art before the application was effectively filed to modify Derosier with the temperature comparison as a basis for frost detection taught by Izadi-Zamanabadi in order to detect specifically and accurately when frost has formed and is impacting the performance of the system rather than merely when frost might form or will soon form in order to insure that defrost operations and the associated interruptions of cooling are not performed more frequently than required and thus maintain performance of the system.
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Neither Derosier nor Izadi-Zamanabadi explicitly teaches the temperature values used in such a comparison being a temperature difference taken across the evaporator. Liu teaches in fig. 2, shown above, a defrost initiating method for the evaporator (50) of a vapor compression system, teaching in ¶ 29 that two sensors (106 and 104) are respectively provided at an air flow inlet and outlet of the evaporator (50) and teaches in ¶ 36 that defrosting may be initiated when the magnitude of the difference between sensed values from theses sensors at least equals a set point threshold magnitude (that is, when the difference exceeds or falls below a target difference by this threshold magnitude). It would have been obvious to one of ordinary skill in the art before the application was effectively filed to modify Derosier with the difference-based temperature control of Liu in order to prevent false-positive frost determinations which might result from, for example, a sudden change in the temperature of the space in which the system operates and from which return air is drawn, thus ensuring that defrosting is performed when and only when it is required by the system.
Regarding claim 6, none of Derosier, Izadi-Zamanabadi, and Liu teach the threshold temperature difference being between 5º and 6º F when the frost-free equivalent differential is between 6.5º and 7.5º F. One of ordinary skill in the art before the application was effectively filed would have recognized the particular threshold temperature and the relationship between this temperature and the sensed temperatures of the system will determine how often a detection of frost is made and how much frost is required to accumulate prior to such a detection, thus determining the frequency and accuracy with which defrosting is carried out and would therefore recognize these values to be result effective variables. It has been held that determining an optimum or workable value for a result effective variable by routine experimentation is a matter of routine skill in the art. See In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 and MPEP 2144.05 II. Obviousness of Ranges.
Derosier teaches limitations from claim 7 in fig. 1, shown above, the defrost system of claim 1, further comprising a plurality of surface temperature sensors (28 and 29, taught in col. 4, lines 36-39 to be “positioned on inlet and outlet sides of evaporator 21 for measuring evaporator inlet temperature and evaporator outlet temperature, respectively.”) in direct thermal communication with coil tubing of the evaporator (per col. 4, lines 36-39), each of the plurality of surface temperature sensors (28 and 29) operably connected to the controller (as taught in table I in line 5 of Derosier).
Derosier teaches these sensors being used to calculate a temperature difference across the evaporator as a level of superheat in col. 4, lines 39-41 but does not teach the process of performing such a calculation in a frost-free state and an operational state and determining the presence of frost to initiate the defrost cycle when the operational value reaches a programmed threshold level below the frost-free value. Izadi-Zamanabadi teaches in fig. 3, shown above, and in pg. 12, lines 10-27 a system and method for the defrosting of an evaporator (104), the system including two temperature sensors (205 and 206) measuring respective an inlet and outlet temperature of air flowing through the evaporator and teaches in pg. 12, lines 28-33 these sensors being used to establish a setpoint temperature value and a control temperature value the comparison of which is used to determine when ice has accumulated on the evaporator. It would have been obvious to one of ordinary skill in the art before the application was effectively filed to modify Derosier with the temperature comparison as a basis for frost detection taught by Izadi-Zamanabadi in order to detect specifically and accurately when frost has formed and is impacting the performance of the system rather than merely when frost might form or will soon form in order to insure that defrost operations and the associated interruptions of cooling are not performed more frequently than required and thus maintain performance of the system.
Derosier teaches limitations from claim 8 in fig. 1, shown above, the defrost system of claim 7, wherein:
a first one (28) of the plurality of surface temperature sensors is at a first location downstream of a fluid inlet of the evaporator (21, on an inlet side of the evaporator as taught in col. 4, lines 36-39);
a second one (29) of the plurality of surface temperature sensors is at a second location downstream of the fluid inlet of the evaporator (21) and downstream of the first location (on an outlet side of the evaporator as taught in col. 4, lines 36-39).
Regarding the exact positions of the sensors at, on, or downstream of the inlet of the evaporator, MPEP 2144.04 (VI)(C) Legal Precedent as Source of Supporting Rationale: Rearrangement of Parts and In re Japikse, 181 F.2d 1019, 86 USPQ 70 (CCPA 1950) state that the rearrangement of the working parts of a system is a matter of obvious design choice when it does not modify the operation of the device. In this case, a temperature sensor (28) such as that taught by Derosier will measure the same evaporator inlet temperature at, or, or near the inlet of the evaporator as refrigerant has not had sufficient time in the evaporator to increase substantially in temperature and because when used in calculating a temperature difference across the evaporator for comparison to other such differences, all of the corresponding temperatures being taken at the same location will resolve any slight temperature differences which might be introduced by the selection of that location.
Derosier but does not teach the process of performing a temperature calculation (described as a “temperature curve”) in a frost-free state and an operational state and determining the presence of frost to initiate the defrost cycle when the operational value reaches a programmed threshold level below the frost-free value (that is, when the curve “reaches a predetermined level of flattening”). Izadi-Zamanabadi teaches in fig. 3, shown above, and in pg. 12, lines 10-27 a system and method for the defrosting of an evaporator (104), the system including two temperature sensors (205 and 206) measuring respective an inlet and outlet temperature of air flowing through the evaporator and teaches in pg. 12, lines 28-33 these sensors being used to establish a setpoint temperature value and a control temperature value the comparison of which is used to determine when ice has accumulated on the evaporator. It would have been obvious to one of ordinary skill in the art before the application was effectively filed to modify Derosier with the temperature comparison as a basis for frost detection taught by Izadi-Zamanabadi in order to detect specifically and accurately when frost has formed and is impacting the performance of the system rather than merely when frost might form or will soon form in order to insure that defrost operations and the associated interruptions of cooling are not performed more frequently than required and thus maintain performance of the system.
Regarding the description of the temperature difference as a “temperature curve” and of the operational curve “reach[ing] a programmed threshold level of flatness”, the claim has been given its broadest reasonable interpretation consistent with the specification and has particularly been interpreted such that a greater (i.e. steeper) temperature difference across the evaporator demonstrates a lower degree of flatness between the two measured temperatures so that the teachings of Izadi-Zamanabadi of the target temperature being less than the threshold by a greater magnitude to determine the presence of frost reads on this limitations as interpreted.
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Derosier taken alone or in combination with the teachings of Gokhale as applied to claims 1 and 9 above, and further in view of WIPO Publication No. 2015/162696 A1 to Tani et al. An English translation of Tani has been provided with this Office Action and citations to specific passages and paragraphs of this reference are directed to this translation rather than to the Japanese-language original document.
Regarding claim 10, Derosier teaches a refrigeration cycle cooling system in which an evaporator is provided with a defrost sensor among a plurality of refrigerant and air temperature sensors and a controller for determining when defrosting of the evaporator is needed and initiating a defrosting mode based on this determination and further teaches the evaporator being provided with an indoor fan having a motor. Derosier does not teach the controller receiving a signal indicative of the current drawn by the fan motor or this current being used in comparison to a frost-free current draw to determine the presence of frost and initiate a defrost cycle. Tani teaches in ¶ 50, a heat exchanger of an air conditioning system being provided with a fan and the current draw of the fan being monitored such that the current drawn before and after frost formation is obtained and a ratio between them calculated to estimate the amount of frost formation on the heat exchanger based on previously recorded data. It would have been obvious to one of ordinary skill in the art before the application was effectively filed to modify Derosier with the fan current-based determination of frost formation in order to effectively reflect the flow of air through the evaporator to accurately reflect the presence of obstructing frost without potential influence of temperature fluctuations as may occur in a temperature-based method of frost detection.
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Claims 11-12 are rejected under 35 U.S.C. 103 as being unpatentable over Derosier taken alone or in combination with the teachings of Gokhale as applied to claim 1 above, and further in view of US Patent No. 3,774,406 to Reitblatt.
Regarding claim 11, Derosier teaches a refrigeration cycle cooling system in which an evaporator is provided with a defrost sensor among a plurality of refrigerant and air temperature sensors and a controller for determining when defrosting of the evaporator is needed and initiating a defrosting mode based on this determination. Derosier does not teach the system including a fluid collector and drain line disposed under the evaporator and provided with a drain line heater connected to the controller to melt accumulated ice and ensure liquid passing through the drain line does not freeze, the drain line heater being activated in concert with the initiation of the defrost cycle. Reitblatt teaches in figs. 1 and 2, shown above, and in col. 2, lines 26-40, an evaporator 14 of a refrigeration system being provided with a condensate collector (62), taught in col. 1, lines 10-13 as a drain pan for guiding melted ice to a drain line. Reitblatt further teaches the condensate collector being warmed by an electric resistance heater (64) taught elsewhere as a “condensate collector heater” taught in col. 3, lines 18-22 “to heat the condensate collector 62 so that particles of ice in the collector pan may be melted, and so that water still dripping from coil 14 is prevented from freezing in the pan and thereby clogging the drain” and teaches in col. 2, lines 26-40 that the heater is energized during the defrost cycle. It would have been obvious to one of ordinary skill in the art before the application was effectively filed to modify Derosier with the drain pan and heater of Reitblatt in order to ensure that ice melted from the evaporator during the defrosting mode is able to flow away from the evaporator and does not refreeze, thus reducing the frequency with which defrosting is required and preventing the accumulation of moisture which can lead to the growth of mold and bacteria on and around the evaporator.
Derosier as modified by Reitblatt teaches limitations from claim 12 in Reitblatt’s figs. 1 and 2, shown above, the defrost system of claim 11, wherein the controller (the control circuit of fig. 2 of Reitblatt and associated thermostats, timers, and similar which control the switches for example as taught in col. 1, lines 51-59) is programmed to activate the drain line heater upon activation of the defrost heater (Reitblatt teaches in col. 2, lines 26-40 that the heater is energized during the defrost cycle).
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Derosier and Reitblatt with or without the additional teachings of Gokhale as applied to claims 1 and 11 above, and further in view of Korean Publication No. 2017-0091198 A to Noh et al. An English translation of Noh has been provided with this Office Action and citations to specific passages and paragraphs of this reference are directed to this translation rather than to the Korean-language original document.
Regarding claim 13, Derosier teaches a refrigeration cycle cooling system in which an evaporator is provided with a defrost sensor among a plurality of refrigerant and air temperature sensors and a controller for determining when defrosting of the evaporator is needed and initiating a defrosting mode based on this determination. Reitblatt teaches a defrosting system for a refrigeration cycle in which a condensate collector pan is provided for the evaporator to receive water melted during a defrost cycle and further teaches the condensate collector being provided with a heating element for preventing water from freezing in the collector and the drain thereof. Neither Derosier nor Reitblatt teaches the heater of the drain pan being activated at a predetermined time before the activation of a defrost heater of the evaporator. Noh teaches in the Abstract and ¶ 9 of his invention a refrigerator having a defrost heater, a drain for draining defrost water resulting from the defrost heater’s operation, and a drain heater for preventing freezing of draining water. Noh further teaches in ¶ 28 that a control unit of the system “may drive the drain heater 420 a predetermined time before the defrost heater is operated.” It would have been obvious to one of ordinary skill in the art before the application was effectively filed to modify Derosier with the drain heater timing and control taught by Noh in order to ensure that water draining from the evaporator is able to drain effectively as soon as the defrost cycle is initiated and will not freeze and block the drain as it contacts the drain pan.
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Derosier and Reitblatt with or without the additional teachings of Gokhale as applied to claims 1 and 11 above, and further in view of US Patent No. 5,172,561 to Hanson et al.
Regarding claim 14, Derosier teaches a refrigeration cycle cooling system in which an evaporator is provided with a defrost sensor among a plurality of refrigerant and air temperature sensors and a controller for determining when defrosting of the evaporator is needed and initiating a defrosting mode based on this determination. Reitblatt teaches a defrosting system for a refrigeration cycle in which a condensate collector pan is provided for the evaporator to receive water melted during a defrost cycle and further teaches the condensate collector being provided with a heating element for preventing water from freezing in the collector and the drain thereof. Neither Derosier nor Reitblatt teaches the controller of the system monitoring the current of the drain heater, determining malfunction when the current shows the circuit to be completely open or closed, and delaying the defrost operation until the current draw of the heater is normal. Hanson teaches in the abstract of his invention an electrical monitoring system and method for a refrigeration system, the method including measuring the current draw of electrical components of the system and delaying starting of the operation of the system until this current draw is measured to be normal. It would have been obvious to one of ordinary skill in the art before the application was effectively filed to modify Derosier with the electrical monitoring of the system of Hanson, particularly applied to the drain heater taught by Reitblatt as discussed above, in order to prevent operation of the defrost mode and the drain heater used therein when there is an abnormality in the operation of the heater to prevent operation which might lead to damage or further malfunction, or to ineffective operation and clogging of the drain.
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Claims 15 and 16 are rejected under 35 U.S.C. 103 as being unpatentable over Derosier taken alone or in combination with the teachings of Gokhale as applied to claim 1 above, and further in view of US Publication No. 2006/0107671 A1 to Yoshida.
Regarding claim 15, Derosier teaches a refrigeration cycle cooling system in which an evaporator is provided with a defrost sensor among a plurality of refrigerant and air temperature sensors and a controller for determining when defrosting of the evaporator is needed and initiating a defrosting mode based on this determination. Derosier does not teach the system comprising a suction-stop valve positioned between the evaporator and compressor and operated by the controller to slow or stop the flow of fluid through the vapor compression system, the initiating of the defrost cycle including the closing of the valve to halt the circulation of the refrigerant. Yoshida teaches in fig. 2, shown above, a cooling system having an evaporator (23) and a compressor (11) and having an on-off valve (26) disposed between the evaporator (23) and the compressor (11) on a return conduit (28) as taught in ¶ 20 and further teaches in ¶ 22 that, during the defrost operation of the system, the on-off valve is controlled to be closed. It would have been obvious to one of ordinary skill in the art before the application was effectively filed to modify Derosier with the return path on-off valve of Yoshida in order to allow for the use of hot gas bypass, using heat from the circulating refrigerant to defrost the evaporator, reducing the inefficiency and wear and tear caused for the compressor by repeatedly cycling it off and on for electric heat defrosting as is taught by Derosier.
Derosier teaches limitations from claim 16 in fig. 1, shown above the defrost system of claim 15, further comprising: a liquid solenoid (“solenoid-operated valve 35” taught in col. 4, lines 54-56) positioned downstream of the condenser (22) and upstream of the expansion valve (24) (as shown in fig. 1).
Claim 19 is rejected under 35 U.S.C. 103 as being unpatentable over Derosier and Yoshida with or without the additional teachings of Gokhale as applied to claims 1 and 15 above, and further in view of Liu.
Regarding claim 19, Derosier teaches a refrigeration cycle cooling system in which an evaporator is provided with a defrost sensor among a plurality of refrigerant and air temperature sensors and a controller for determining when defrosting of the evaporator is needed and initiating a defrosting mode based on this determination. Derosier does not teach the expansion valve used in such a refrigeration cycle being “an electronic expansion valve configured to modulate its throughput based on a signal from the controller”. Liu teaches in ¶ 18 and fig. 2, shown above, a refrigerant vapor compression cycle provided with two expansion devices (45 and 55) disposed between a condenser (40) and an evaporator (50) of the system, teaching that each of these expansion devices is “such as for example an electronic expansion valve” and teaches in ¶ 29 that the system includes a controller (100) “operatively associated with the plurality of flow control devices 45, 55 and 65”. It would have been obvious to one of ordinary skill in the art before the application was effectively filed to modify Derosier with the electronic expansion valve and control thereof taught by Liu in order to allow the expansion of refrigerant in the vapor compression cycle to be optimized during operation to ensure desirable refrigerant properties including evaporation temperature for efficient and effective operation.
Claim 20 is rejected under 35 U.S.C. 103 as being unpatentable over Derosier in view of US Publication No. 2010/0107667 A1 to Petrenko et al. and Izadi-Zamanabadi.
Derosier teaches limitations from claim 20 in fig. 2, shown above, a defrost system comprising:
a vapor compression system (shown in fig. 1 and taught in col. 4, lines 9-24) including a compressor (23), a condenser (22), an expansion valve (24), an evaporator (21), and a quantity of refrigerant (a “heat transfer fluid (e.g. a vapor compression refrigerant)” taught in col. 4, lines 13-14);
a defrost heater (34) operably connected to the evaporator (21) and configured to melt accumulated ice or frost from coils of the evaporator upon activation (taught in col. 4, lines 50-52);
a [sensor] (defrost sensor 33); and
a controller (25) programmed to:
receive the [signals from the sensor];vibration signals from the vibration monitor;
initiate a defrost cycle via control over at least one component of the vapor compression system (as taught in col. 3, lines 27-29, the controller (here designated a “master controller”) “transmits a defrost on signal to initiate a system defrost cycle in response to a condition indicating a need for system defrost” and as indicated in table II in col. 8 of Derosier, various components such as the compressor 23, fans 26 and 27, and expansion valve 24 which are operated during the cooling mode are turned off in the defrost mode).
Derosier does not teach the sensor used to determine the presence or absence of frost being a vibration sensor sensing a vibration amplitude of the evaporator, this vibration measurement being used to detect the presence of frost. Petrenko teaches in ¶ 47, a refrigerant evaporator and an evaporator thereof in connection with a controller (150) “capable of detecting ice and/or frost accumulation on the evaporator” and teaches that in some embodiments, “the controller does so … by detecting changes in response of the evaporator to vibration”. It would have been obvious to one of ordinary skill in the art before the application was effectively filed to modify Derosier with the vibration sensing as a method of detecting frost as taught by Petrenko in order to directly and effectively reflect the physical state of the evaporator the evaporator to accurately reflect the presence of obstructing frost without potential influence of temperature fluctuations as may occur in a temperature-based method of frost detection.
Neither Derosier nor Petrenko teaches the steps of measuring frost-free and operational values of this sensed vibration and determining the need for defrosting based on the degree of variation of the current operational value from the previously-measured frost-free value. Izadi-Zamanabadi teaches in fig. 3, shown above, and in pg. 12, lines 10-27 a system and method for the defrosting of an evaporator (104), the system including a number of sensors (205 and 206) measuring data pertaining to the evaporator and the formation of frost thereof (particularly an inlet and outlet temperature of air flowing through the evaporator) and teaches in pg. 12, lines 28-33 these sensors being used to establish a setpoint temperature value and a control temperature value the comparison of which is used to determine when ice has accumulated on the evaporator. It would have been obvious to one of ordinary skill in the art before the application was effectively filed to modify Derosier with the comparison of current and pre-frost values of sensed data as a basis for frost detection taught by Izadi-Zamanabadi in order to detect specifically and accurately when frost has formed and is impacting the performance of the system rather than merely when frost might form or will soon form in order to insure that defrost operations and the associated interruptions of cooling are not performed more frequently than required and thus maintain performance of the system.
Allowable Subject Matter
Claims 17-18 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Particularly, claim 17 depends upon claims 15 and 16, requiring the valves taught in those claims, and further teaches the system including a hot-gas solenoid valve “configured and positioned to admit a flow of hot gasses into the evaporator from the defrost heater during defrost cycles” and teaches the initiation of the defrost cycle to include the following steps:
“pump-out step comprising closing the liquid solenoid, opening the suction-stop valve, and activating the evaporator fan”
“a hot-gas step comprising closing the suction-stop valve and deactivating the evaporator fan, and then opening the hot-gas solenoid to allow the hot gasses to flow to the evaporator”
“a bleed step comprising maintaining the configuration of the vapor compression system from the pump-out step until a pressure difference between an inlet of the compressor and a pressure in the evaporator is reduced to a predetermined threshold”, and
“a refreeze step comprising opening the suction-step valve and opening the liquid solenoid while keeping the fan deactivated, for a time sufficient to allow any residual moisture to refreeze on the coils of the evaporator.”
This control of the valves and evaporator fan of the refrigeration system is not taught, suggested, or rendered obvious in the prior art references made of record in this office action.
Claim 18 depends upon claim 17 and therefore includes the same limitations indicated to be allowable.
Response to Arguments
Applicant’s arguments with respect to claims 1-20 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Applicant argues on pp. 10-11 of the reply that Derosier does not teach the limitations of claim 1 for which it is relied upon under 35 U.S.C. 102 in the Non-Final Rejection of 14 July 2025. Particularly, applicant argues that Derosier does not teach the use of a temperature measured by the defrost temperature sensor (33) in initiating a defrost operation, asserting that it is used only in “monitoring and terminating its defrost process”.
In response, examiner disagrees. As applicant notes in pg. 10 of the reply, Derosier teaches “The master controller transmits a defrost on signal to initiate a system defrost cycle in response to a condition indicating a need for system defrost.” (col. 3, lines 27-29) Although Derosier does not explicitly teach that this “need” is determined on the basis of the temperature sensed by the sensor 33, this sensor is taught (e.g. in col. 4, lines 48-49) as “a defrost temperature sensor”, with none of the other sensors (e.g. 28, 29, 30, and 31) taught to have any roll in initiating the defrost process, let alone determining this “need” leaving only this temperature sensor as an instrument for such a determination.
Applicant further argues on pg. 11 that Derosier explicitly teaches that defrost is initiated “only by using time between defrost cycles” in col. 5, lines 31-34 but examiner notes that Derosier teaches in this passage the programming of a time only as an “example” regarding the control initiation of the defrost operation so that this teaching appears to present an alternative to the need-based defrost recited in col. 4, lines 48-49 rather than negating this teaching by mandating that defrost be initiated by a timer.
In order to advance prosecution and without finding error in the rejection of the claims as being anticipated by Derosier, examiner presents above an additional grounds of rejection in which Gokhale is relied upon in combination with Derosier to explicitly teach the use of a temperature signal in the initiation of a defrost operation. Because the rejection of claim 1 as being anticipated by Derosier has not been found to be deficient, it is also maintained and presented in this Office Action to demonstrate that the claim is unpatentable regardless of whether the teachings of Derosier are taken as teaching the sensor’s use in initiating of the defrost operation. Nevertheless, because the rejection of claim 1 as being obvious over Derosier as modified by Gokhale is not necessitated by amendment of the claim, this action is not made final.
Applicant argues on pp. 11-13 that the Izadi-Zamanabadi and Liu references relied upon in combination with Derosier in the rejection of claim 5 “are not properly combinable with the primary Derosier reference”, arguing that because “Derosier already provides for detecting frost” (pg. 13 of the remarks) the motivation to modify Derosier with the difference-based temperature control taught by Liu is improper as there would be no need for the detection of Liu in addition to that taught by Derosier.
In response, examiner disagrees. Firstly, applicant’s argument in this passage appears to contradict the argument discussed above with regard to the rejection of claim 1 as being anticipated as applicant argues on pg. 11 that Derosier does not detect frost on the evaporator to initiate defrost but must rely only upon a determination that a predetermined duration of time has elapsed since a previous defrost operation. Setting this aside and taking the assertion as it is presented, examiner does not find the argument persuasive. Even if Derosier already teaches a mode of frost detection, the method taught by Izadi-Zamanabadi which relies upon comparing two sensed air temperatures at different times, or the use of two sensors at positions upstream and downstream of the evaporator as taught by Liu each provide improvements over the use of a single measurement from a single evaporator temperature sensor taught by Derosier in terms of accuracy and reliance. For this reason, even if all of these techniques achieve the same goal of determining the presence of frost, one of ordinary skill in the art before the application was filed would still recognize a benefit in modifying Derosier to use the techniques taught by Izadi-Zamanabadi and Liu rather than that originally taught by Derosier.
Regarding the assertion that because both techniques produce the end-result of detecting frost, there would be “no reason to combine the features of both devices into a single device” (quoted from Kinetic Concepts, Inc. V. Smith & Nephew, Inc., 688 F.3d. 1342 (Fed. Cir. 2012) on pg. 12 of the reply), examiner disagrees. The rejection was based around the use of two sensors as taught by Liu in place of the single-sensor approach taught by Derosier and the use of two differently-timed measurements in comparison as taught by Izadi-Zamanabadi and does not “combine the features of both devices into a single device” as applicant asserts. Further, MPEP 2143 Examples of Basic Requirements of a Prima Facie Case of Obviousness makes it clear that, rather than being improper as applicant asserts, the “Simple substitution of one known element for another to obtain predictable results” (substituting the frost detection apparatus and techniques of Izadi-Zamanabadi and Liu for those taught by Derosier) or “Use of known technique to improve similar devices (methods, or products) in the same way” (using the known techniques of Izadi-Zamanabadi and Liu to improve the less accurate device of Derosier) are exemplary rationales to support a finding of obviousness.
For all of these reasons, applicant’s arguments that the combination of references is improper are not found to be persuasive and the rejection of claim 20 is maintained.
Applicant argues on pg. 14 of the reply that “Petrenko is insufficient to meet” the portion of claim 20 regarding determination of frost-free vibration response of the evaporator.
In response, although examiner agrees with this characterization of Petrenko, it is noted that the measurement of sensor data in a frost-free state for comparison to late measurements to determine the presence of frost is taught by Izadi-Zamanabadi. Applicant has not addressed the combined teachings of Derosier, Petrenko, and Izadi-Zamanabadi relied upon in rejecting claim 20 beyond asserting that, for the same reasons discussed above, Izadi-Zamanabadi may not be relied upon in combination with Derosier. For the same reasons set forth above with regarding claim 5, these arguments are not found to be persuasive with regard to claim 20. Further, as Izadi-Zamanabadi is relied upon for this teaching of comparing measurements taken at different times, and the modification of Petrenko with this feature is not addressed, applicant’s argument amounts to a mere piecemeal attack against the individual reference and is not persuasive as it does not address the combination of teachings upon which the rejection is based.
Conclusion
As noted above, the rejection of claim 1 as being obvious over Derosier in view of Gokhale is not necessitated by amendment and thus this action is not made Final.
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/DANIEL C COMINGS/Examiner, Art Unit 3763
/JERRY-DARYL FLETCHER/Supervisory Patent Examiner, Art Unit 3763