Prosecution Insights
Last updated: April 19, 2026
Application No. 18/383,362

DAMPED FLUID LINE FOR AIRCRAFT ENGINE

Non-Final OA §103
Filed
Oct 24, 2023
Examiner
LEARY, JOSHUA DENNIS
Art Unit
3753
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Rtx Corporation
OA Round
1 (Non-Final)
100%
Grant Probability
Favorable
1-2
OA Rounds
3y 2m
To Grant
0%
With Interview

Examiner Intelligence

Grants 100% — above average
100%
Career Allow Rate
1 granted / 1 resolved
+30.0% vs TC avg
Minimal -100% lift
Without
With
+-100.0%
Interview Lift
resolved cases with interview
Typical timeline
3y 2m
Avg Prosecution
8 currently pending
Career history
9
Total Applications
across all art units

Statute-Specific Performance

§103
47.2%
+7.2% vs TC avg
§102
16.7%
-23.3% vs TC avg
§112
30.6%
-9.4% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1 resolved cases

Office Action

§103
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 . 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 1-5, 7-10, and 16-20 are rejected under 35 U.S.C. 103 as being unpatentable over Wang et. al. (US 20230282847) in view of Hansen (US 4314621). Regarding claim 1, Wang et. al. teaches: A method of operation, comprising: directing a fluid through a fluid line servicing a component of an aircraft engine (fuel line 150 which directs fuel from a fuel tank to a component 200 [Fig. 1]). Wang et. al. fails to teach: damping the oscillations in the fluid line via a sleeve in contact with a fluid line. Even though Wang et. al. does not explicitly teach pressure wave oscillations traveling through the fluid line, due to its inclusion of flow regulators and pumps within the fluid line, the operation Wang et. al. would result in the pressure wave oscillations to be created as the two inventions are materially similar and would thus perform in a similar manner. Furthermore, Hansen teaches an attenuating damper device comprising an elastomeric material, such as silicone, which can be tuned to dampen pressure wave oscillations in the frequency range from 100 to 5000 Hz (Col. 3, lines 59-63) which are produced from a control valve (Col. 5, lines 10-16). It would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to combine the teachings of Wang et. al. with the elastomeric damper of Hansen to reduce pressure pulsations as high-pressure fluid circuits have been known to receive pressure pulsations within the circuit (Col. 1, lines 12-18). Furthermore, it was described that components within the engine, similar to those described by Wang et. al., would result in the formation of pressure wave oscillations due to the activation and deactivation of such components (Hansen – Col. 5, lines 10-16). Regarding claim 2, the combination of Wang et. al. and Hansen teaches: The method of claim 1, wherein the fluid comprises a liquid (Wang et. al. teaches fluid contains a liquid [Para. 296]). Regarding claim 3, the combination of Wang et. al. and Hansen teaches: The method of claim 1, wherein the frequency is equal to or greater than one thousand eight hundred hertz (Hansen teaches a sleeve utilizing silicone rubber and further teaches the components created frequency between 100 to 5000 Hz which is mitigated by the silicone compound [Col. 3, lines 59-63]). Regarding claim 4, the combination of Wang et. al. and Hansen teaches: The method of claim 1, wherein the fluid is directed through the fluid line at a pressure equal to or greater than one thousand pounds per square inch (Fuel delivery line may be at a pressure between 100-300 bar [Wang et. al. – Para. 146, lines 20-24]). Regarding claim 5, the combination of Wang et. al. and Hansen teaches: The method of claim 1, wherein the fluid line is fluidly coupled to and downstream of a flow regulator (Fluid line 150A downstream of a flow regulator 274 [Wang et. al. - Fig. 5 and Para. 89, lines 19-25]), and the pressure wave oscillations are generated by operation of the flow regulator (Hansen identifies that oscillations are produced by components within a fluid line including a valve/flow regulator [Col. 5, lines 10-16]). Regarding claim 7, the combination of Wang et. al. and Hansen teaches: The method of claim 5, wherein the flow regulator is a first flow regulator, and the fluid line is fluidly coupled to and upstream of a second flow regulator; and the fluid line extends longitudinally from a first coupling between the fluid line and the first flow regulator and a second coupling between the fluid line and the second flow regulator (Fluid line 150A downstream of a flow regulator 274 and upstream of a control valve 151A [Wang et. al. - Fig. 5 and Para. 89, lines 19-25]). Regarding claim 8, the combination of Wang et. al. and Hansen teaches: The method of claim 1, wherein the elastomeric foam sleeve has a longitudinal length; and the elastomeric foam sleeve contacts the fluid line longitudinally along the longitudinal length (Hansen teaches a damper having a longitudinal length and contacting the fluid line along said length [Fig. 1]). While the percent of length and range was not defined within the prior art, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to prepare a configuration of the modified Wang et. al. device to utilize a damping sleeve along at least 80% of the fluid line in order to test the Wang et. al. device for suitability in its field of intended use, since it has been held that where the general condition of a claim is disclosed in the prior art, discovering the workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233. Regarding claim 9, the combination of Wang et. al. and Hansen teaches: The method of claim 1, wherein the elastomeric foam sleeve contacts the fluid line at least three hundred degrees circumferentially around the fluid line (elastomeric homogenous material is defined as tubular and encompassing the pipe [Hansen – Col. 4, lines 10-13]). Regarding claim 10, the combination of Wang et. al. and Hansen teaches: The method of claim 1, wherein the elastomeric foam sleeve has a full-hoop tubular body (elastomeric homogenous material is defined as tubular and encompassing the pipe [Hansen – Col. 4, lines 10-13]). Regarding claim 16, the combination of Wang et. al. and Hansen teaches: The method of claim 1, wherein the fluid comprises fuel (described as a fuel delivery line for a fuel delivery system 146 [Wang et. al. - Para. 65, lines 1-3]); the component comprises a fuel injector in the aircraft engine; and the directing of the fluid comprises directing the fluid through the fluid line to the fuel injector for injection into a combustion volume within the aircraft engine (fuel travels from the fuel source 148 to a flowline and is then injected into the combustion chamber 228 [Wang et. al. - Para. 70, lines 7-12 and Para. 71, lines 1-4 and Fig. 1 and 2]). Regarding claim 17, the combination of Wang et. al. and Hansen teaches: The method of claim 1, wherein the aircraft engine comprises a gas turbine engine (Wang et. al. - Para. 1). Regarding claim 18, the combination of Wang et. al. and Hansen teaches: A method of operation, comprising: directing a liquid fluid through a flow regulator into a fluid line (Wang et. al. – Fig. 1 shows a fuel line 150 which directs fuel from a fuel tank through a flow regulator 274), the fluid line included as part of a fluid system of a gas turbine engine (Wang et. al. – Fig. 1); regulating flow of the liquid fluid through the flow regulator, the regulating of the flow of the liquid fluid through the flow regulator inducing pressure wave oscillations in the liquid fluid within the fluid line (As identified by Hansen, the functioning of components, including valves, within a fluid line results in pressure wave oscillations [Col. 5, lines 10-16]); and damping the pressure wave oscillations in the liquid fluid within the fluid line using a line damper abutted radially against the fluid line (damper abutted against the fluid line [Hansen - Fig. 1]), the line damper extending longitudinally along and circumscribing the fluid line (sleeve extends along and circumscribes the fluid line [Hansen - Fig. 1]), and the line damper comprising an elastomeric foam (Hansen teaches the damper utilizing an elastomeric homogenous material made of silicone [Col. 3, lines 57-63]). Regarding claim 19, the combination of Wang et. al. and Hansen teaches: The method of claim 18, wherein the pressure wave oscillations have a frequency equal to or greater than one thousand hertz during the directing of the regulating of the flow of the liquid fluid (teaches elastomeric material, such as silicone, which can be tuned to dampen frequency range from 100 to 5000 Hz [Hansen - Col. 3, lines 59-63] which are produced from a control valve [Hansen - Col. 5, lines 10-16]); and the liquid fluid is directed through the fluid line at a pressure equal to or greater than one- thousand pounds per square inch (Fuel delivery line may be at a pressure between 100-300 bar [Wang et. al. – Para. 146, lines 20-24]). Regarding claim 20, the combination of Wang et. al. and Hansen teaches: A system for a gas turbine engine, comprising: a gas turbine engine component (Wang et. al. – Fig. 1 and Para. 1); a fluid system configured to deliver fluid to the gas turbine engine component, the fluid system including an upstream flow regulator (flow divider 274 [Wang et. al. – Fig. 5]), a downstream flow regulator (control valve 151A [Wang et. al. – Fig. 5]) and a fluid line fluidly coupling the upstream flow regulator to the downstream flow regulator (fluid line 150A [Wang et. al. – Fig. 5]), the upstream flow regulator configured to regulate flow of the fluid into the fluid line to the downstream flow regulator (The flow divider regulates the fluid fuel to the line and then onto the second fuel valve 151A [Wang et. al. - Para. 89, lines 12-22), wherein the regulating of the flow of the fluid through the flow regulator induces pressure wave oscillations in the fluid within the fluid line at a frequency equal to or greater than one thousand hertz (frequency range can be 100 to 5000 Hz [Hansen - Col. 3, lines 59-63] which are produced from a control valve [Hansen - Col. 5, lines 10-16]); and an elastomeric foam sleeve configured to damp the pressure wave oscillation in the fluid within the fluid line (Not disclosed, but as set forth above in the rejection of claim 1, Hansen teaches the damper in the form of a sleeve surrounding the fluid line utilizing an elastomeric homogenous material made of silicone [Col. 3, lines 57-63 and Fig. 1 and it would have been obvious to one having ordinary skill in the art at the time of filing to provide the device of Wang with a sleeve as taught by Hansen as set forth above in the rejection of claim 1]), the elastomeric foam sleeve contacting the fluid line, and the elastomeric foam sleeve extending longitudinally along and circumscribing the fluid line (sleeve abutted against the fluid line [Hansen - Fig. 1] and extends along and circumscribes the fluid line [Hansen - Fig. 1]). Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Wang et. al. (US 20230282847) in view of Hansen (US4314621) as applied to claim 5 above, and further in view of Yeung et. al. (US 10968837). The combination of Wang et. al. and Hansen teaches the method of claim 5 but is moot on valves being controlled by a solenoid. Yeung et. al. teaches: a solenoid valve for use in a fuel supply system between the reservoir and the intake port of a gas turbine engine (Para. 7, lines 16-42). It would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have modified the combination of Wang et. al. and Hansen with the solenoid valve of Yeung et. al. as the solenoid valve has been shown to be useful and functional as a valve selection in the application of directing liquid fuel to a gas turbine engine via a fluid line (Para. 7, lines 16-42). Claims 11-13 are rejected under 35 U.S.C. 103 as being unpatentable over Wang et. al. (US 20230282847) in view of Hansen (US4314621) as applied to claim 1 above, and further in view of Pernell et. al. (US 20150079316). The combination of Wang et. al. and Hansen teaches: The method of claim 1 and the elastomeric foam sleeve damper. The combination fails to teach the further limitations of claim 11-12. Pernell et. al. teaches: elastomeric foam sleeve extends circumferentially about the fluid line between a first circumferential side of the elastomeric foam sleeve and a second circumferential side of the elastomeric foam sleeve; and the first circumferential side of the elastomeric foam sleeve is circumferentially next to the second circumferential side of the elastomeric foam sleeve (Parnell et al. contains first and second circumferential sides surrounding the pipe and are next to each other at the seam 50 [Para. 69, lines 2-3 and Fig. 6] wherein, the sleeve is made of a foam material [Para. 59, lines 3-8 and Para. 71, lines 1-12 and Fig. 5C and 6] chosen from a selection of elastomers [Para. 12, lines 1-10]) And wherein the first circumferential side of the elastomeric foam sleeve is abutted circumferentially against the second circumferential side of the elastomeric foam sleeve (Contains first and second circumferential sides surrounding the pipe and are abutted against each other at the seam 50 [Para. 69, lines 2-3 and Fig. 6]). It would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to modify the device of Wang et. al. and Hansen for the damping of pressure wave oscillations with the elastomeric foam sleeve made of silicone rubber of Pernell et. al. as it is materially similar to the damping medium of Hansen and structurally would ease installation on elongated and complex piping as it is used in variety of applications (Para. 4, lines 1-3 and Para. 5, lines 5-10) and would result in reducing energy loss within the pipe (Para. 5, lines 7-10) which is beneficial for piping used in transportation of liquids that are phase and viscosity sensitive, such as fuel (Para. 4, lines 6-12 and Para. 3, lines 4-6). Regarding claim 13, the combination of Wang et. al., Hansen, and Pernell et. al. teaches: The method of claim 1, wherein the elastomeric foam sleeve comprises silicone rubber (The sleeve can be made of a silicone rubber [Purnell et. al. - Para. 12, lines 1-4] and the damper elastomeric homogenous material is silicone [Hansen – Col. 3, lines 58-63). Claims 14-15 are rejected under 35 U.S.C. 103 as being unpatentable over Wang et. al. (US 20230282847) in view of Hansen (US4314621) as applied to claim 1 above, and further in view of Cioffi (US 20090178723). Regarding claim 14, the combination of Wang et. al. and Hansen teaches: The method of claim 1, and the fuel system/line attached to the aircraft engine (Fig. 1 illustrating the fluid line 150 and attaching to the combustion section 114 and therefor the combustor assembly 200) but fails to teach the mount and the foam sleeve being discrete from the mount. Cioffi teaches a fluid line with a sleeve and mounted to a structure where the sleeve is discrete from the mount (Fig. 1-2 illustrates the prior art and conventional style of mounting a pipe with a sleeve to a structure and Fig. 3 and 3a illustrates a mount for a pipe that is discrete form the sleeve attached to the pipe). It would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have modified the combination of Wang et. al. and Hansen with the mounting bracket as disclosed in Cioffi as to protect the sleeve by spreading the weight of the pipe over large areas of the sleeve and minimize the deterioration of the sleeve (Para. 19, lines 2-5). Regarding claim 15, the combination of Wang et. al., Hansen, and Cioffi teaches: The method of claim 14, wherein the elastomeric foam sleeve is spaced longitudinally from the mount along the fluid line by a gap (Figs. 1a-2a illustrate a conventional mount for channel support which utilizes U shape and C shape brackets [Para. 21-23] and results in a gap between the sleeve and the bracket as depicted). Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure: Tesner et. al. (US 8701848) teaches: polyurethane foam and/or foam rubber as dampening sleeve around a fluid line (Para. 11). Arima et. al. (US 20060118195) teaches: teaches silicon rubber for surrounding a pipe for high-pressure resistant vibration absorption (Para. 80-82). Pipis et. al. (US 20230332519) teaches: solenoid valve for use in fuel supply system between the reservoir and the intake port of an engine (Para. 25). Borges de Cunha (US 20220281584) teaches: molded mounting bracket for support of tubing on an aircraft (Abstract). Pisacreta et. al. (US 20200018427) teaches: a mounting assembly for a line of a gas turbine engine (Abstract). Dawson et. al. (US 20150122336) teaches: energy dissipation layer for a pipeline (Abstract) which encompasses at least 50% of the pipeline and variable based on situational requirements (Para. 117). Luthi et. al. (US 20140014775) teaches: a method and apparatus for mounting lines in an aircraft (Abstract and Fig. 13). Caucheteux et. al. (US 20090297331) teaches: a turbomachine that utilizes silicone rubber elastomer compound to mitigate the vibration of a rotor (Abstract and Para. 46). Princell (US 20070292647) teaches: flexible foam sleeve made of elastomers which can include a silicone rubber (Para. 2 and 42). Any inquiry concerning this communication or earlier communications from the examiner should be directed to JOSHUA DENNIS LEARY whose telephone number is (571)272-1685. The examiner can normally be reached Monday-Friday 8:30am - 5:00pm. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Craig Schneider can be reached at 571-272-3607. If Craig Schneider cannot be reached, please contact Kenneth Rinehart at 571-272-4881.The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /DAVID R DEAL/Primary Examiner Art Unit 3753 /JOSHUA D LEARY/Examiner, Art Unit 3753
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Prosecution Timeline

Oct 24, 2023
Application Filed
Apr 03, 2026
Non-Final Rejection — §103 (current)

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Prosecution Projections

1-2
Expected OA Rounds
100%
Grant Probability
0%
With Interview (-100.0%)
3y 2m
Median Time to Grant
Low
PTA Risk
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