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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 6/9/2026 has been entered.
Information Disclosure Statement
The information disclosure statement submitted on 6/9/2026 has been considered by the examiner.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 32, 33, 35-37 and 40 are rejected under 35 U.S.C. 103 as being unpatentable over U.S. Patent Application Publication 2005/0217346 by Nagarkatti et al. (“Nagarkatti’) in view of U.S. Patent 6,427,517 issued to McMillan (“McMillan”), U.S. Patent 2,892,346 issued to Sargent (“Sargent”), WO 2017-125499 by Leberre et al. (“Leberre”), DE 10-2018-219230 by Wahl et al. (“Wahl”) and NL 1015995 by Van Der Beek (“Van Der Beek”).
As for claim 32, Nagarkatti discloses a flow reference (Fig. 2) comprising:
an enclosure (130) including an interior surface that defines a cavity (inside 130), the cavity having a flow inlet (132);
a first pressure sensor (135) in fluid communication with the cavity;
a slidable element (120) located within the cavity;
an actuator (140) mechanically coupled (via 145) to the slidable element and arranged to move the slidable element within the cavity (paragraph [0026]); and
a controller (controller; paragraphs [0023] and [0029]) electrically coupled to the actuator and the first pressure sensor, the controller configured to perform actions comprising:
receiving a first pressure measurement signal from the first pressure sensor, the first signal corresponding to a pressure within the cavity (paragraph [0026]), and
actuating the actuator to reposition the slidable element within the cavity to maintain a selected pressure based on the first signal (paragraph [0026]).
Nagarkatti does not disclose that the first signal corresponds to a first absolute pressure within the cavity because Nagarkatti does not disclose that the first pressure sensor is an absolute pressure sensor.
However, McMillan discloses a pressure sensor (150) that is an absolute pressure sensor (col. 4, lines 31-34).
Because Nagarkatti and McMillan both disclose first pressure sensors, it would have been obvious for one having ordinary skill in the art before the effective filing date of the present application to substitute the first pressure sensor of Nagarkatti for the absolute first pressure sensor of McMillan to achieve the predictable result of measuring an absolute pressure of a cavity.
Nagarkatti does not disclose a second pressure sensor in fluid communication with the flow inlet and external to the cavity, in part, because Nagarkatti does not disclose measuring a differential pressure. Instead, Nagarkatti discloses measuring a pressure so that the pressure in the cavity, when compared to a reference, can be used to adjust the position of the piston (Nagarkatti: paragraph [0024] and [0026]).
However, Sargent discloses measuring a differential pressure using a differential pressure sensor in fluid communication with the flow inlet and external to a cavity (see the Figure and col. 2, lines 25-32). Sargent discloses measuring a differential pressure so that the differential pressure, which compares the pressure in the cavity and a reference pressure at the flow inlet, can be used to adjust a position of a piston (col. 2, lines 25-32 and col. 2, lines 60-68). Furthermore, Leberre discloses (see the paragraph beginning “Fig. 2 is a variant of the system …”) a second pressure sensor (21) along with a first pressure sensor (20), and that two pressure sensors can be used to measure a differential pressure (see the paragraph beginning “Fig. 2 is a variant of the system …”). Wahl also discloses (see the paragraph beginning “In the exhaust are 45 downstream …”) a second pressure sensor (101) along with a first pressure sensor (100), and that two pressure sensors can be used to measure a differential pressure (see the paragraph beginning “In the exhaust are 45 downstream …”). Wahl discloses that the differential pressure can be calculated and used to generate a control signal based on the differential pressure (see the paragraph beginning “In the exhaust are 45 downstream …”).
Because Sargent and Nagarkatti both disclose methods of using a pressure to adjust a position of a piston, and Leberre and Wahl both disclose that a second pressure sensor can be used along with a first pressure sensor to measure a differential pressure, it would have been obvious for one having ordinary skill in the art before the effective filing date of the present application to substitute the method of Sargent which uses a differential pressure measurement, and to include the second pressure sensor of Leberre and Wahl to make the differential pressure measurement, for the method of Nagarkatti which uses a single pressure sensor to achieve the predictable result of providing a pressure measurement so that the position of the piston can be adjusted.
Nagarkatti as modified by McMillan, Sargent, Leberre and Wahl discloses:
an actuator (Nagarkatti: 140 and Sargent:11) mechanically coupled (Nagarkatti: via 145) to the slidable element and arranged to move the slidable element within the cavity (Nagarkatti: paragraph [0026]), the actuator at least partially to apply a force to the slidable element that substantially equals the amount of friction between the slidable element and the cavity (inherent; to maintain a differential pressure of about zero while the slidable element moves; Nagarkatti: paragraphs [0025] and [0026] and Sargent: col. 2, line 60 - col. 3, line 5); and
a controller (Nagarkatti: controller; paragraphs [0023] and [0029]) electrically coupled to the actuator (Nagarkatti: 140) and the first pressure sensor (Nagarkatti:135 and Leberre: 20 and Wahl: 100) and the second pressure sensor (Leberre: 21 and Wahl: 101), the controller configured to perform actions comprising:
receiving a first signal from the first pressure sensor (Nagarkatti: 135 and Leberre: 20 and Wahl: 100), the first signal corresponding to an absolute pressure (McMillan: col. 4, lines 31-34) within the cavity (Nagarkatti: paragraph [0026]),
receiving a second pressure measurement signal from the second pressure sensor (Leberre: 21 and Wahl: 101), the second signal corresponding to a second absolute pressure (McMillan: col. 4, lines 31-34) external to the cavity (Nagarkatti: paragraph [0026] and Sargent: col. 2, lines 25-32 and col. 2, lines 60-68),
calculating a differentia pressure based on the first pressure measurement signal and the second pressure measurement signal (Leberre: see the paragraph beginning “Fig. 2 is a variant of the system …” and Wahl: see the paragraph beginning “In the exhaust are 45 downstream …”), and
actuating the actuator to reposition the slidable element within the cavity to maintain a selected differential pressure based on the calculated differential pressure (Nagarkatti: paragraph [0026] and Sargent: col. 2, lines 25-32 and col. 2, lines 60-68 and Wahl: see the paragraph beginning “In the exhaust are 45 downstream …”).
In the case that Nagarkatti as modified by McMillan, Sargent, Leberre and Wahl does not inherently disclose that the actuator applies a force that substantially equals the amount of friction between the slidable element and the cavity, Van Der Beek discloses that frictional forces are compensated by the drive device (see the paragraph beginning: “Based on these insights, the present invention …”).
It would have been obvious for one having ordinary skill in the art before the effective filing date of the present application to modify the actuator of Nagarkatti, McMillan, Sargent, Leberre and Wahl to apply a force equal to friction as disclosed by Van Der Beek in order to ensure that the flow rate is measured with very little uncertainty (Beek: see the paragraphs beginning “Secondly, the measuring piston must be arranged …” and “In the foregoing, the advantages of the invention …”).
As for claim 33, Nagarkatti as modified by McMillan, Sargent, Leberre, Wahl and Van Der Beek discloses a seal (Nagarkatti: 38) located between a perimeter surface of the slidable element and the interior surface of the enclosure (Nagarkatti: paragraphs [0015] and [0040]).
As for claim 35, Nagarkatti as modified by McMillan, Sargent, Leberre, Wahl and Van Der Beek discloses that the actuator is a stepper motor or a linear actuator (Nagarkatti: paragraph [0024]).
As for claim 36, Nagarkatti as modified by McMillan, Sargent, Leberre, Wahl and Van Der Beek discloses an encoder (Nagarkatti: 133) electrically coupled to the controller, the encoder configured to transmit an encoder signal to the controller corresponding to a position of the slidable element (Nagarkatti: paragraphs [0029] and [0030]).
As for claim 37, Nagarkatti as modified by McMillan, Sargent, Leberre, Wahl and Van Der Beek discloses that the actions further comprise calculating a volumetric flowrate of a unit under test based at least on actuation of the actuator (Nagarkatti: paragraphs [0028] and [0029]).
As for claim 40, Nagarkatti as modified by McMillan, Sargent, Leberre, Wahl and Van Der Beek discloses the flow reference of claim 32 (see the rejection of claim 32).
Nagarkatti as modified by McMillan, Sargent, Leberre, Wahl and Van Der Beek does not disclose a timer electrically coupled to the controller. Instead, Nagarkatti discloses using a velocity sensor to determine when the volume of the enclosure has been changed by the piston (Nagarkatti: paragraph [0029]).
However, Van Der Beek disclose a timer (59) electrically coupled to a controller (50). Van Der Beek discloses that the timer, along with an optical ruler, is used to determine when a volume of an enclosure has been changed by a piston (page 7 of the provided English translation).
Because Nagarkatti and Van Der Beek both disclose structures for determining when a volume of an enclosure has been changed by a piston, it would have been obvious for one having ordinary skill in the art before the effective filing date of the present application to substitute the timer and optical ruler of Van Der Beek for the velocity sensor of Nagarkatti to achieve the predictable result of providing a structure that determines when the volume of the enclosure has been changed by the piston.
Claim 34 is rejected under 35 U.S.C. 103 as being unpatentable over U.S. Patent Application Publication 2005/0217346 by Nagarkatti et al. (“Nagarkatti’) in view of U.S. Patent 6,427,517 issued to McMillan (“McMillan”), U.S. Patent 2,892,346 issued to Sargent (“Sargent”), WO 2017-125499 by Leberre et al. (“Leberre”), DE 10-2018-219230 by Wahl et al. (“Wahl”) and NL 1015995 by Van Der Beek (“Van Der Beek”) as applied to claim 33, further in view of U.S. Patent 4,766,759 issued to Cohrs et al. (“Cohrs”).
As for claim 34, Nagarkatti as modified by McMillan, Sargent, Leberre, Wahl and Van Der Beek discloses the flow reference of claim 33 (see the rejection of claim 33).
Nagarkatti as modified by McMillan, Sargent, Leberre, Wahl and Van Der Beek does not disclose that the seal includes an O-ring or a mercury seal. Instead, Nagarkatti discloses a seal of unspecified structure to seal the piston (paragraph [0040]).
However, Cohrs discloses a seal that includes an O-ring (104, 106, 112, 114, 116, 118) or a mercury seal. Cohrs discloses that the O-ring seals a piston (col. 5, lines 30-63).
Because Nagarkatti and Cohrs both disclose seals for sealing a piston, it would have been obvious for one having ordinary skill in the art before the effective filing date of the present application to substitute the O-ring seal of Cohrs for the seal of Nagarkatti to achieve the predictable result of sealing the piston.
Claims 38 and 39 are rejected under 35 U.S.C. 103 as being unpatentable over U.S. Patent Application Publication 2005/0217346 by Nagarkatti et al. (“Nagarkatti’) in view of U.S. Patent 6,427,517 issued to McMillan (“McMillan”), U.S. Patent 2,892,346 issued to Sargent (“Sargent”), WO 2017-125499 by Leberre et al. (“Leberre”), DE 10-2018-219230 by Wahl et al. (“Wahl”) and NL 1015995 by Van Der Beek (“Van Der Beek”) as applied to claim 37, further in view of U.S. Patent 11,112,294 issued to Ahmad et al. (“Ahmad”).
As for claim 38, Nagarkatti as modified by McMillan, Sargent, Leberre, Wahl and Van Der Beek discloses the flow reference of claim 37 (see the rejection of claim 37 above) and a temperature sensor (Nagarkatti: 137) electrically coupled to the controller, wherein the actions further comprise:
receiving a temperature signal from the temperature sensor, the temperature signal corresponding to a temperature of a fluid within the cavity (Nagarkatti: paragraphs [0024] and [0027])
Nagarkatti as modified by McMillan, Sargent, Leberre, Wahl and Van Der Beek does not disclose that the actions further comprise calculating a mass flowrate based at least on the temperature of the fluid and the pressure within the cavity,.
However, Ahmad discloses calculating a mass flowrate based at least on a temperature of a fluid and a pressure (col. 13, lines 2-4).
It would have been obvious for one having ordinary skill in the art before the effective filing date of the present application to modify the actions of Nagarkatti, McMillan, Sargent, Leberre, Wahl and Van Der Beek to include calculating a mass flowrate as disclosed by Ahmad in order to allow a user to know the mass flow rate if desired, especially because Nagarkatti discloses a mass flow measurement system (paragraph [0013]).
Nagarkatti as modified by McMillan, Sargent, Leberre, Wahl, Van Der Beek and Ahmad discloses that the actions further comprise calculating a mass flowrate based at least on the temperature of the fluid (Ahmad: col. 13, lines 2-4) and the pressure (Ahmad: col. 13, lines 2-4) within the cavity (Nagarkatti: detected by 235).
As for claim 39, Nagarkatti as modified by McMillan, Sargent, Leberre, Wahl and Van Der Beek discloses the flow reference of claim 32 (see the rejection of claim 32 above) and a temperature sensor (Nagarkatti: 137) electrically coupled to the controller, wherein the actions further comprise:
receiving a temperature signal from the temperature sensor, the temperature signal corresponding to a temperature of a fluid within the cavity (paragraph [0027])
Nagarkatti as modified by McMillan, Sargent, Leberre, Wahl and Van Der Beek does not disclose that the actions further comprise calculating a mass flowrate based at least on the temperature of the fluid and the pressure within the cavity.
However, Ahmad discloses calculating a mass flowrate based at least on a temperature of a fluid and a pressure (col. 13, lines 2-4).
It would have been obvious for one having ordinary skill in the art before the effective filing date of the present application to modify the actions of Nagarkatti, McMillan, Sargent, Leberre, Wahl and Van Der Beek to include calculating a mass flowrate as disclosed by Ahmad in order to allow a user to know the mass flow rate if desired, especially because Nagarkatti discloses a mass flow measurement system (paragraph [0013]).
Nagarkatti as modified by McMillan, Sargent, Leberre, Wahl, Van Der Beek and Ahmad discloses that the actions further comprise calculating a mass flowrate based at least on the temperature of the fluid (Ahmad: col. 13, lines 2-4), the pressure (Ahmad: col. 13, lines 2-4) within the cavity (Nagarkatti: detected by 235), and the distance traveled by the piston (Nagarkatti: paragraphs [0028] and [0029]).
Claims 42, 43, 45, 48, 52, 53 and 55 are rejected under 35 U.S.C. 103 as being unpatentable over U.S. Patent Application Publication 2005/0217346 by Nagarkatti et al. (“Nagarkatti’) in view of U.S. Patent 6,427,517 issued to McMillan (“McMillan”), NL 1015995 by Van Der Beek (“Van Der Beek”), U.S. Patent 2,892,346 issued to Sargent (“Sargent”), WO 2017-125499 by Leberre et al. (“Leberre”) and DE 10-2018-219230 by Wahl et al. (“Wahl”).
As for claim 42, Nagarkatti discloses a flow reference (Fig. 2) comprising:
a cylinder (130) including an interior surface that defines a cavity and a flow inlet;
a first pressure sensor (135) in fluid communication with the cavity,
a piston (120) located within the cavity;
an actuator (140) mechanically coupled (via 145) to the piston and arranged to move the piston in a linear direction within the cavity; and
a controller (controller; paragraphs [0023] and [0029]) electrically coupled to the actuator and the first pressure sensor, the controller configured to perform actions comprising:
receiving a first signal from the first pressure sensor, the first signal corresponding to a pressure within the cavity (paragraph [0026]),
actuating the actuator to reposition the piston within the cavity to maintain a selected pressure (paragraph [0026]),
determining a distance traveled by the piston due to actuation of the actuator (paragraph [0029]).
Nagarkatti does not disclose that the first signal corresponds to a first absolute pressure within the cavity because Nagarkatti does not disclose that the first pressure sensor is an absolute pressure sensor.
However, McMillan discloses a pressure sensor (150) that is an absolute pressure sensor (col. 4, lines 31-34).
Because Nagarkatti and McMillan both disclose first pressure sensors, it would have been obvious for one having ordinary skill in the art before the effective filing date of the present application to substitute the first pressure sensor of Nagarkatti for the absolute first pressure sensor of McMillan to achieve the predictable result of measuring an absolute pressure of a cavity.
Nagarkatti as modified by McMillan does not explicitly disclose determining a time for the piston to travel the distance. Instead, Nagarkatti discloses using a velocity sensor to determine when the volume of the enclosure has been changed by the piston (Nagarkatti: paragraph [0029]).
However, Van Der Beek discloses determining a time for the piston to travel the distance (page 7 of the provided English translation). Van Der Beek discloses that a timer, along with an optical ruler, is used to determine when a volume of an enclosure has been changed by a piston (page 7).
Because Nagarkatti and Van Der Beek both disclose methods for determining when a volume of an enclosure has been changed by a piston, it would have been obvious for one having ordinary skill in the art before the effective filing date of the present application to substitute the method and structures of Van Der Beek for the method and structures of Nagarkatti to achieve the predictable result of determining when the volume of the enclosure has been changed by the piston.
Nagarkatti as presently modified by McMillan and Van Der Beek does not explicitly disclose determining a volumetric flowrate of a fluid entering the flow inlet based on a cross-sectional area of the piston in contact with the fluid. Instead, Nagarkatti discloses determining a volumetric flowrate of a fluid entering the flow inlet based on the change of position of the piston (Nagarkatti: paragraph [0029]).
However, McMillan further discloses determining a volumetric flowrate of a fluid entering a flow inlet based on a cross-sectional area of a piston in contact with the fluid (col. 1, lines 20-37). McMillan discloses that the cross-sectional area of the piston is used with the change of position of the piston to determine the volumetric flowrate (col. 1, lines 20-37).
Because Nagarkatti and McMillan both disclose methods of using the change of piston to determine a volumetric flowrate, it would have been obvious for one having ordinary skill in the art before the effective filing date of the present application to substitute the method of McMillan, which explicitly uses the cross-sectional area of the piston, for the method of Nagarkatti to achieve the predictable result of determining the volumetric flowrate.
Nagarkatti as modified by McMillan and Van Der Beek discloses determining a volumetric flowrate of a fluid entering the flow inlet based on the distance traveled by the piston, a cross-sectional area of the piston in contact with the fluid, and the time for the piston to travel the distance (McMillan: col. 1, lines 20-37).
Nagarkatti as modified by McMillan and Van Der Beek does not disclose a second pressure sensor in fluid communication with the flow inlet and external to the cavity, in part, because Nagarkatti does not disclose measuring a differential pressure. Instead, Nagarkatti discloses measuring a pressure so that the pressure in the cavity, when compared to a reference, can be used to adjust the position of the piston (Nagarkatti: paragraph [0024] and [0026]).
However, Sargent discloses measuring a differential pressure using a differential pressure sensor in fluid communication with the flow inlet and external to a cavity (see the Figure and col. 2, lines 25-32). Sargent discloses measuring a differential pressure so that the differential pressure, which compares the pressure in the cavity and a reference pressure at the flow inlet, can be used to adjust a position of a piston (col. 2, lines 25-32 and col. 2, lines 60-68). Furthermore, Leberre discloses (see the paragraph beginning “Fig. 2 is a variant of the system …”) a second pressure sensor (21) along with a first pressure sensor (20), and that two pressure sensors can be used to measure a differential pressure (see the paragraph beginning “Fig. 2 is a variant of the system …”). Wahl also discloses (see the paragraph beginning “In the exhaust are 45 downstream …”) a second pressure sensor (101) along with a first pressure sensor (100), and that two pressure sensors can be used to measure a differential pressure (see the paragraph beginning “In the exhaust are 45 downstream …”). Wahl discloses that the differential pressure can be calculated and used to generate a control signal based on the differential pressure (see the paragraph beginning “In the exhaust are 45 downstream …”).
Because Sargent and Nagarkatti both disclose methods of using a pressure to adjust a position of a piston, and Leberre and Wahl both disclose that a second pressure sensor can be used along with a first pressure sensor to measure a differential pressure, it would have been obvious for one having ordinary skill in the art before the effective filing date of the present application to substitute the method of Sargent which uses a differential pressure measurement, and to include the second pressure sensor of Leberre and Wahl to make the differential pressure measurement, for the method of Nagarkatti which uses a single pressure sensor to achieve the predictable result of providing a pressure measurement so that the position of the piston can be adjusted.
Nagarkatti as modified by McMillan, Van Der Beek, Sargent, Leberre and Wahl discloses:
an actuator (Nagarkatti: 140 and Sargent:11) mechanically coupled (Nagarkatti: via 145) to the slidable element and arranged to move the slidable element within the cavity (Nagarkatti: paragraph [0026]), the actuator at least partially to apply a force to the slidable element that substantially equals the amount of friction between the slidable element and the cavity (inherent; to maintain a differential pressure of about zero while the slidable element moves; Nagarkatti: paragraphs [0025] and [0026] and Sargent: col. 2, line 60 - col. 3, line 5); and
a controller (Nagarkatti: controller; paragraphs [0023] and [0029]) electrically coupled to the actuator (Nagarkatti: 140) and the first pressure sensor (Nagarkatti:135 and Leberre: 20 and Wahl: 100), the controller configured to perform actions comprising:
receiving a first signal from the first pressure sensor (Nagarkatti: 135 and Leberre: 20 and Wahl: 100), the first signal corresponding to an absolute pressure (McMillan: col. 4, lines 31-34) within the cavity (Nagarkatti: paragraph [0026]),
receiving a second pressure measurement signal from the second pressure sensor (Leberre: 21 and Wahl: 101), the second signal corresponding to a second absolute pressure (McMillan: col. 4, lines 31-34) external to the cavity (Nagarkatti: paragraph [0026] and Sargent: col. 2, lines 25-32 and col. 2, lines 60-68),
calculating a differential pressure based on the first pressure measurement signal and the second pressure measurement signal (Leberre: see the paragraph beginning “Fig. 2 is a variant of the system …” and Wahl: see the paragraph beginning “In the exhaust are 45 downstream …”),
actuating the actuator to reposition the slidable element within the cavity to maintain a selected differential pressure (Nagarkatti: paragraph [0026] and Sargent: col. 2, lines 25-32 and col. 2, lines 60-68).
In the case that Nagarkatti as modified by McMillan, Van Der Beek, Sargent, Leberre and Wahl does not inherently disclose that the actuator applies a force that substantially equals the amount of friction between the slidable element and the cavity, Van Der Beek discloses that frictional forces are compensated by the drive device (see the paragraph beginning: “Based on these insights, the present invention …”).
It would have been obvious for one having ordinary skill in the art before the effective filing date of the present application to modify the actuator of Nagarkatti, McMillan, Sargent, Leberre and Wahl to apply a force equal to friction as disclosed by Van Der Beek in order to ensure that the flow rate is measured with very little uncertainty (Beek: see the paragraphs beginning “Secondly, the measuring piston must be arranged …” and “In the foregoing, the advantages of the invention …”).
As for claim 43, Nagarkatti as modified by McMillan, Van Der Beek, Sargent, Leberre and Wahl discloses an encoder (Van Der Beek: optical ruler; page 7) electrically coupled to the controller, the encoder configured to transmit an encoder signal to the controller corresponding to a position of the slidable element (Van Der Beek: page 7),
wherein the actuator is a linear actuator (Nagarkatti: paragraph [0124]), and
wherein determining the distance traveled by the piston includes utilizing the encoder signal to determine the distance traveled (Van Der Beek: page 7).
As for claim 45, Nagarkatti as modified by McMillan, Van Der Beek, Sargent, Leberre and Wahl discloses a timer (Van Der Beek: 59) electrically coupled to the controller, the timer used for determining the time for the piston to travel the distance (Van Der Beek: page 7).
As for claim 48, Nagarkatti as modified by McMillan, Van Der Beek, Sargent, Leberre and Wahl discloses a seal (Nagarkatti: 38) located between a perimeter surface of the piston and the interior surface of the enclosure (Nagarkatti: paragraphs [0015] and [0040]).
As for claim 52, Nagarkatti as modified by McMillan, Van Der Beek, Sargent, Leberre and Wahl discloses that the controller is configured to calculate a volumetric flowrate based on a maintained differential pressure and a parameter including a piston movement parameter (Sargent: col. 2, lines 25-32 and col. 2, lines 60-68 and McMillan: col. 1, lines 20-37).
As for claim 53, Nagarkatti as modified by McMillan, Van Der Beek, Sargent, Leberre and Wahl discloses:
maintaining the selected differential pressure at a substantially constant value during measurement (Sargent: col. 2, lines 60-68);
calculating an enclosed volume based on the cross-sectional area of the piston multiplied by the distance travelled (McMillan: col. 1, lines 28-31); and
dividing the enclosed volume by the time for the piston to travel the distance (McMillan: col. 1, lines 31-34).
As for claim 55, Nagarkatti as modified by McMillan, Van Der Beek, Sargent, Leberre and Wahl discloses:
measuring the distance traveled by the piston using an encoder electrically coupled to the controller (Nagarkatti: paragraphs [0029] and [0030] and McMillan: col. 1, lines 20-37);
measuring the time using a timer electrically coupled to the controller (Van Der Beek: page 7); and
calculating the volumetric flowrate as a product of:
cross-sectional area of the piston,
the measured distance traveled by the piston, and
the inverse of the measured time (McMillan: col. 1, lines 20-37).
Claim 44 is rejected under 35 U.S.C. 103 as being unpatentable over U.S. Patent Application Publication 2005/0217346 by Nagarkatti et al. (“Nagarkatti’) in view of U.S. Patent 6,427,517 issued to McMillan (“McMillan”), NL 1015995 by Van Der Beek (“Van Der Beek”), U.S. Patent 2,892,346 issued to Sargent (“Sargent”), WO 2017-125499 by Leberre et al. (“Leberre”) and DE 10-2018-219230 by Wahl et al. (“Wahl”) as applied to claim 42, further in view of U.S. Patent 4,823,598 issued to Carpenter et al. (“Carpenter”).
As for claim 44, Nagarkatti as modified by McMillan, Van Der Beek, Sargent, Leberre and Wahl discloses the flow reference of claim 42 (see the rejection of claim 42 above).
Nagarkatti as modified by McMillan, Van Der Beek, Sargent, Leberre and Wahl does not disclose that the actuator is driven by a stepper motor and determining the distance traveled by the piston includes counting a number of steps taken by the stepper motor. Instead, Nagarkatti discloses using a linear motor to drive the piston (paragraph [0024]).
However, Carpenter discloses an actuator (26) that is driven by a stepper motor (15) and determining a distance traveled by a piston includes counting a number of steps taken by the stepper motor (col. 2, line 45 - col. 3, line 4). Carpenter discloses that the stepper motor drives a piston (see Fig. 2).
Because Nagarkatti and Carpenter both disclose structures for driving a piston, it would have been obvious for one having ordinary skill in the art before the effective filing date of the present application to substitute the stepper motor of Carpenter for the linear motor of Nagarkatti to achieve the predictable result of providing a structure that can drive the piston.
Claim 47 is rejected under 35 U.S.C. 103 as being unpatentable over U.S. Patent Application Publication 2005/0217346 by Nagarkatti et al. (“Nagarkatti’) in view of U.S. Patent 6,427,517 issued to McMillan (“McMillan”), NL 1015995 by Van Der Beek (“Van Der Beek”), U.S. Patent 2,892,346 issued to Sargent (“Sargent”), WO 2017-125499 by Leberre et al. (“Leberre”) and DE 10-2018-219230 by Wahl et al. (“Wahl”) as applied to claim 42, further in view of U.S. Patent 11,112,294 issued to Ahmad et al. (“Ahmad”).
As for claim 47, Nagarkatti as modified by McMillan, Van Der Beek, Sargent, Leberre and Wahl discloses the flow reference of claim 42 (see the rejection of claim 42 above) and a temperature sensor (Nagarkatti: 137) electrically coupled to the computing device, wherein the actions further comprise:
receiving a temperature signal from the temperature sensor, the temperature signal corresponding to a temperature of a fluid within the cavity (Nagarkatti: paragraph [0027]).
Nagarkatti as modified by McMillan, Van Der Beek, Sargent, Leberre and Wahl does not disclose that the temperature sensor is located within the cavity. Instead, Nagarkatti discloses a temperature sensor (Nagarkatti: 137) near the entrance to the cavity (Nagarkatti: see Fig. 2). Nagarkatti discloses that the temperature sensor monitors the temperature of the fluid in the cavity (Nagarkatti: paragraph [0024]).
However, McMillan discloses a temperature sensor (McMillan: 160) that is located with a cavity (see Fig. 2).
Nagarkatti as modified by McMillan, Van Der Beek, Sargent, Leberre and Wahl does not disclose that the actions further comprise calculating a mass flowrate based at least on the temperature and the volumetric flow rate.
However, Ahmad discloses calculating a mass flowrate based at least on a temperature and a volumetric flow rate (col. 13, lines 2-4).
It would have been obvious for one having ordinary skill in the art before the effective filing date of the present application to modify the actions of Nagarkatti, McMillan, Van Der Beek, Sargent, Leberre and Wahl to include calculating a mass flowrate as disclosed by Ahmad in order to allow a user to know the mass flow rate if desired, especially because Nagarkatti discloses a mass flow measurement system (paragraph [0013]).
Claims 49 and 51 are rejected under 35 U.S.C. 103 as being unpatentable over U.S. Patent Application Publication 2005/0217346 by Nagarkatti et al. (“Nagarkatti’) in view of U.S. Patent 6,427,517 issued to McMillan (“McMillan”), NL 1015995 by Van Der Beek (“Van Der Beek”), U.S. Patent 2,892,346 issued to Sargent (“Sargent”), WO 2017-125499 by Leberre et al. (“Leberre”) and DE 10-2018-219230 by Wahl et al. (“Wahl”) and U.S. Patent 4,996,869 issued to Cohrs et al. (“Cohrs ‘869”).
As for claim 49, Nagarkatti discloses a method for measuring a volumetric flowrate of a flow produced by a unit under test (paragraph [0013], the method comprising:
fluidly connecting the unit under test to a flow inlet of an enclosure, the enclosure defining a cavity and the flow inlet (see Figs. 1 and 2);
measuring a first pressure (using 135) in fluid communication with the cavity (paragraph [0026]),
applying a force (paragraph [0026]) to a slidable element (120) located within the cavity that substantially equals the amount of friction between the slidable element and the cavity (inherent; to maintain a differential pressure of about zero while the slidable element moves; Nagarkatti: paragraphs [0025] and [0026]);
repositioning the slidable element located within the cavity to maintain a selected pressure (paragraph [0026]),
determining a distance traveled by the slidable element in order to maintain the selected pressure (paragraph [0029]).
Nagarkatti does not disclose that the first pressure is an absolute pressure.
However, McMillan discloses a first pressure (measured by 150) that is a first absolute pressure (col. 4, lines 31-34).
Because Nagarkatti and McMillan both disclose first pressures, it would have been obvious for one having ordinary skill in the art before the effective filing date of the present application to substitute the first pressure of Nagarkatti for the absolute first pressure of McMillan to achieve the predictable result of providing a pressure with which to measure a pressure of a cavity.
Nagarkatti as modified by McMillan does not explicitly disclose determining a time for the slidable element to travel the distance. Instead, Nagarkatti discloses using a velocity sensor to determine when the volume of the enclosure has been changed by the slidable element (Nagarkatti: paragraph [0029]).
However, Van Der Beek discloses determining a time for a slidable element to travel a distance (page 7 of the provided English translation). Van Der Beek discloses that a timer, along with an optical ruler, is used to determine when a volume of an enclosure has been changed by a slidable element (page 7).
Because Nagarkatti and Van Der Beek both disclose methods for determining when a volume of an enclosure has been changed by a slidable element, it would have been obvious for one having ordinary skill in the art before the effective filing date of the present application to substitute the method and structures of Van Der Beek for the method and structures of Nagarkatti to achieve the predictable result of determining when the volume of the enclosure has been changed by the slidable element.
Nagarkatti as presently modified by McMillan and Van Der Beek does not explicitly disclose determining a volumetric flowrate of a fluid entering the cavity based on a cross-sectional area of the slidable element in contact with the fluid. Instead, Nagarkatti discloses determining a volumetric flowrate of a fluid entering the cavity based on the change of position of the slidable element (Nagarkatti: paragraph [0029]).
However, McMillan further discloses determining a volumetric flowrate of a fluid entering a flow inlet based on a cross-sectional area of a slidable element in contact with the fluid (col. 1, lines 20-37). McMillan discloses that the cross-sectional area of the slidable element is used with the change of position of the piston to determine the volumetric flowrate (col. 1, lines 20-37).
Because Nagarkatti and McMillan both disclose methods of using the change of position of a slidable element to determine a volumetric flowrate, it would have been obvious for one having ordinary skill in the art before the effective filing date of the present application to substitute the method of McMillan, which explicitly uses the cross-sectional area of the slidable element, for the method of Nagarkatti to achieve the predictable result of determining the volumetric flowrate.
Nagarkatti as modified by McMillan and Van Der Beek discloses determining a volumetric flowrate of a fluid entering the flow inlet based on the distance traveled by the slidable element, a cross-sectional area of the slidable element in contact with the fluid, and the time for the slidable element to travel the distance (McMillan: col. 1, lines 20-37).
Nagarkatti as modified by McMillan and Van Der Beek does not disclose a measuring a second pressure of fluid external to the cavity and coupled to the flow inlet, in part, because Nagarkatti does not disclose measuring a differential pressure. Instead, Nagarkatti discloses measuring a pressure so that the pressure in the cavity, when compared to a reference, can be used to adjust the position of the piston (Nagarkatti: paragraph [0024] and [0026]).
However, Sargent discloses measuring a differential pressure of a fluid external to a cavity and coupled to a flow inlet (see the Figure and col. 2, lines 25-32). Sargent discloses measuring a differential pressure so that the differential pressure, which compares the pressure in the cavity and a reference pressure at the flow inlet, can be used to adjust a position of a piston (col. 2, lines 25-32 and col. 2, lines 60-68). Furthermore, Leberre discloses (see the paragraph beginning “Fig. 2 is a variant of the system …”) a second pressure sensor (21) along with a first pressure sensor (20), and that two pressure sensors can be used to measure a differential pressure (see the paragraph beginning “Fig. 2 is a variant of the system …”). Wahl also discloses (see the paragraph beginning “In the exhaust are 45 downstream …”) a second pressure sensor (101) along with a first pressure sensor (100), and that two pressure sensors can be used to measure a differential pressure (see the paragraph beginning “In the exhaust are 45 downstream …”). Wahl discloses that the differential pressure can be calculated and used to generate a control signal based on the differential pressure (see the paragraph beginning “In the exhaust are 45 downstream …”).
Because Sargent and Nagarkatti both disclose methods of using a pressure to adjust a position of a piston, and Leberre and Wahl both disclose that a second pressure sensor can be used along with a first pressure sensor to measure a differential pressure, it would have been obvious for one having ordinary skill in the art before the effective filing date of the present application to substitute the method of Sargent which uses a differential pressure measurement, and to include the second pressure sensor of Leberre and Wahl to make the differential pressure measurement, for the method of Nagarkatti which uses a single pressure sensor to achieve the predictable result of providing a pressure measurement so that the position of the piston can be adjusted.
Nagarkatti as modified by McMillan, Van Der Beek, Sargent, Leberre and Wahl discloses:
fluidly connecting the unit under test to a flow inlet of an enclosure, the enclosure defining a cavity and the flow inlet (Nagarkatti: see Figs. 1 and 2);
measuring (Nagarkatti: paragraph [0026]) a first absolute pressure (McMillan: col. 4, lines 31-34) in fluid communication with the cavity (also see Nagarkatti: 135 and Leberre: 20 and Wahl: 100),
measuring (Nagarkatti: paragraph [0026]) a second absolute pressure (McMillan: col. 4, lines 31-34) of a fluid external to the cavity and coupled to the fluid inlet (Sargent: see the Figure and col. 2, lines 25-32 and Leberre: using 21 and Wahl: using 101);
applying a force (Nagarkatti: paragraph [0026]) to a slidable element (Nagarkatti: 120) located within the cavity that substantially equals the amount of friction between the slidable element and the cavity (inherent; to maintain a differential pressure of about zero while the slidable element moves; Nagarkatti: paragraphs [0025] and [0026] and Sargent: col. 2, line 60 - col. 3, line 5);
repositioning the slidable element located within the cavity to maintain a selected absolute pressure (Nagarkatti: paragraph [0026]) based on the first absolute pressure and the second absolute pressure (Sargent: col. 2, lines 25-32 and col. 2, lines 60-68);
determining a distance traveled by the slidable element in order to maintain the selected differential pressure (Nagarkatti: paragraph [0029]);
determining a time for the slidable element to travel the distance (Van Der Beek: page 7 of the provided English translation);
determining the volumetric flowrate of the fluid entering the cavity based on the distance traveled by the slidable element, a cross-sectional area of the slidable element in contact with the fluid, and the time for the slidable element to travel the distance (McMillan: col. 1, lines 20-37).
In the case that Nagarkatti as modified by McMillan, Van Der Beek, Sargent, Leberre and Wahl does not inherently disclose that the actuator applies a force that substantially equals the amount of friction between the slidable element and the cavity, Van Der Beek discloses that frictional forces are compensated by the drive device (see the paragraph beginning: “Based on these insights, the present invention …”).
It would have been obvious for one having ordinary skill in the art before the effective filing date of the present application to modify the actuator of Nagarkatti, McMillan, Sargent, Leberre and Wahl to apply a force equal to friction as disclosed by Van Der Beek in order to ensure that the flow rate is measured with very little uncertainty (Beek: see the paragraphs beginning “Secondly, the measuring piston must be arranged …” and “In the foregoing, the advantages of the invention …”).
Nagarkatti as modified by McMillan, Van Der Beek, Sargent, Leberre and Wahl does not disclose varying a control setting of the unit under test; and determining a volumetric flowrate for each control setting.
However, Cohrs ‘869 discloses varying a control setting (col. 1, lines 47-52 and col. 4, lines 59-61) of a unit under test; and
determining a volumetric flowrate for each control setting (col. 4, lines 11-46).
It would have been obvious for one having ordinary skill in the art before the effective filing date of the present application to modify the method of Nagarkatti, McMillan, Van Der Beek, Sargent, Leberre and Wahl to include the steps as disclosed by Cohrs ‘869 in order to obtain accurate readings from a flowmeter for different flow conditions (Cohrs ‘869: col. 1, lines 18-24 and col. 1, lines 47-52).
As for claim 51, Nagarkatti as modified by McMillan, Van Der Beek, Sargent, Leberre, Wahl and Cohrs ‘869 discloses creating a calibration factor (Cohrs ‘869: k-factor) for the unit under test as a function of the control setting (Cohrs ‘869: col. 4, lines 11-46).
Claim 50 is rejected under 35 U.S.C. 103 as being unpatentable over U.S. Patent Application Publication 2005/0217346 by Nagarkatti et al. (“Nagarkatti’) in view of U.S. Patent 6,427,517 issued to McMillan (“McMillan”), NL 1015995 by Van Der Beek (“Van Der Beek”), U.S. Patent 2,892,346 issued to Sargent (“Sargent”), WO 2017-125499 by Leberre et al. (“Leberre”) and DE 10-2018-219230 by Wahl et al. (“Wahl”) and U.S. Patent 4,996,869 issued to Cohrs et al. (“Cohrs ‘869”) as applied to claim 49, further in view of U.S. Patent 11,112,294 issued to Ahmad et al. (“Ahmad”).
As for claim 50, Nagarkatti as modified by McMillan, Van Der Beek, Sargent, Leberre, Wahl and Cohrs ‘869 discloses the method of claim 49 (see the rejection of claim 49 above) and measuring a temperature (Nagarkatti: using 137) of the fluid within the cavity (Nagarkatti: paragraphs [0024] and [0027]).
Nagarkatti as modified by McMillan, Van Der Beek, Sargent, Leberre, Wahl and Cohrs ‘869 does not disclose calculating a mass flowrate based on the temperature and the volumetric flow rate of the fluid.
However, Ahmad discloses calculating a mass flowrate based on a temperature and a volumetric flow rate of a fluid (col. 13, lines 2-4).
It would have been obvious for one having ordinary skill in the art before the effective filing date of the present application to modify the actions of Nagarkatti, McMillan, Van Der Beek, Sargent, Leberre , Wahl and Cohrs ‘869 to include calculating a mass flowrate as disclosed by Ahmad in order to allow a user to know the mass flow rate if desired, especially because Nagarkatti discloses a mass flow measurement system (paragraph [0013]).
Response to Arguments
Applicant’s arguments, see page 8 of the Remarks, filed 6/9/2026, with respect to the rejections under 35 USC 112(a) have been fully considered and are persuasive. The rejections under 35 USC 112(a) have been withdrawn.
Applicant's arguments, filed 6/9/2026, with respect to rejections under 35 USC 103 have been fully considered but they are not persuasive.
On page 10 of the Remarks, Applicant argues that modifying Nagarkatti to measure differential pressure based on Sargent requires replacing Nagarkatti’s control loop with Sargent’s diaphragm transducer. The examiner respectfully disagrees. Sargent is not bodily incorporated into Nagarkatti. Applicant argues that the one having ordinary skill in the art would not extract features of Leberre and Wahl. The examiner respectfully disagrees. Instead, the examiner has demonstrated that the prior art discloses structures that perform the same functions recited in the claims and that can be substituted with the structures of Nagarkatti to achieve predictable results.
Conclusion
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/JUSTIN N OLAMIT/ Primary Examiner, Art Unit 2853
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