DETAILED ACTION
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 02/05/2026 amending Claims 1, 15, and 19 has been entered. Claims 1, 4 – 9, and 11 - 23 are examined.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(d):
(d) REFERENCE IN DEPENDENT FORMS.—Subject to subsection (e), a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
The following is a quotation of pre-AIA 35 U.S.C. 112, fourth paragraph:
Subject to the following paragraph [i.e., the fifth paragraph of pre-AIA 35 U.S.C. 112], a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
Claim 21 is rejected under 35 U.S.C. 112(d) or pre-AIA 35 U.S.C. 112, 4th paragraph, as being of improper dependent form for failing to further limit the subject matter of the claim upon which it depends, or for failing to include all the limitations of the claim upon which it depends. Claim 21 recites “The system of claim 1, wherein the airflow inlet circumferentially overlaps the first screen and circumferentially overlaps one or more circumferential end portions of the second screen”. Amended Claim 1, ll. 15 - 16 recites “wherein the second screen is located to circumferential peripheral sides of a direct line-of-sight from the airflow inlet to the compressor section”. It is impossible for the configurations of both Amended Claim 1 and Claim 21 to be true. Claim 21 is rejected under 35 U.S.C. 112(d) as being of improper dependent form for failing to include all the limitations of the claim upon which it depends. Applicant may cancel the claim(s), amend the claim(s) to place the claim(s) in proper dependent form, rewrite the claim(s) in independent form, or present a sufficient showing that the dependent claim(s) complies with the statutory requirements.
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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 1, 11 – 13, 19, and 20 – 23 are rejected under 35 U.S.C. 103 as being unpatentable over Leblanc (6,959,552) in view of Ritchie (3,319,402) in view of Foreman et al. (4,989,807) in view of Lefebvre, A.H., Gas Turbine Combustion, Second Edition, Taylor & Francis, Philadelphia, 1998, hereinafter “Lefebvre”.
Regarding Claim 1, Leblanc teaches, in Fig. 1 – 3B, the invention as claimed, including a system for an aircraft (Col. 2, ll. 50 - 55), comprising: a gas turbine engine (10 – Fig. 1) including a compressor section (18); a flowpath projecting longitudinally into the gas turbine engine (10) from an airflow inlet (30) and longitudinally through the compressor section (18 – shown in Fig. 1); and an inlet guard (36) extending across the flowpath longitudinally upstream of the compressor section (18 – shown in Figs. 1, 3A, and 3B), the inlet guard (36) extending circumferentially (shown in Fig. 2) about an axis (center of 19 shown in Figs. 1 and 2), the inlet guard (36) including a first screen (sector A - shown in Fig. 2) that is circumferentially aligned with the airflow inlet (30, 48 - open top end), and a second screen (sectors C-D-B-F-E - shown in Fig. 2) that is circumferentially offset from the airflow inlet (30, 48 - open top end), the first screen comprising a plurality of first perforations (38) with a first perforation size (Col. 3, l. 62 to Col. 4, l. 5 teaches smallest perforation diameter), the second screen (sectors C-D-B-F-E - shown in Fig. 2) circumferentially adjacent the first screen (sector A - shown in Fig. 2) about the axis (center of 19 shown in Figs. 1 and 2), and the second screen (sectors C-D-B-F-E - shown in Fig. 2) comprising a plurality of second perforations (38) with a second perforation size (Col. 3, l. 62 to Col. 4, l. 5 teaches largest perforation diameter in sector B and teaches the smallest perforation diameter of sector A) that is greater than the first perforation size (Col. 3, l. 62 to Col. 4, l. 5 teaches smallest perforation diameter in sector A. Leblanc teaches, in Col. 3, l. 62 to Col. 4, l. 5, “In another embodiment, it is also considered to vary the effective area by using a uniform distribution of holes 38, i.e. the same number of holes in each region, but with holes having a larger surface area where the airflow 40 is weaker. Thus, the hole size would be progressively increased toward the bottom end of the plate 36”.); wherein the first screen (sector A - shown in Fig. 2) has a first circumferential width (approximately 60° arc) about the axis; and wherein the second screen (sectors C-D-B-F-E - shown in Fig. 2) has a second circumferential width (approximately 300° arc) about the axis that is greater than the first circumferential width (approximately 60° arc). Leblanc teaches, in Col. 3, l. 62 – 65, that the inlet guard/plate (36) can be separated into any number of regions.
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Ritchie teaches, in Figs. 1 – 6, a similar inlet guard (12, 12a) having a first screen (12) and a second screen (12a) circumferentially adjacent the first screen (12). Ritchie teaches, in Col. 1, ll. 30 – 35 and Col. 2, ll. 35 – 45, that the inlet guard (12, 12a) could be made from two separate screens (12 and 12a – shown in Figs. 1 and 3) or more than two separate screens depending on requirements and conditions of assembly.
Thus, improving a particular device (inlet guard), based upon the teachings of such improvement in Leblanc and Ritchie, would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, i.e., applying these known improvement techniques in the same manner to the inlet guard of Leblanc, and the results would have been predictable and readily recognized, that modifying the inlet guard to be assembled out of a plurality of separate screens, e.g., first screen having a first circumferential width and a second screen having a second circumferential width greater than the first circumferential width, would have facilitated easier assemble and disassembly of the inlet guard around the air inlet of the gas turbine engine. As shown in Leblanc – Figs 1, 3A, and 3B, it would have been very difficult if not impossible to install or remove an inlet guard (36) around the radial inlet (34) of the gas turbine engine if said inlet guard (36) was manufactured as a single continuous annular piece which had a smaller diameter that the maximum diameter of the air inlet assembly (30), i.e., plenum wall (46 – Fig. 2). Furthermore, assembling the 360° inlet guard out of a plurality of separate screens would have facilitated easier repair/replacement of a damaged section of screen, since only the damage screen(s) would have needed to be removed and replaced with a new screen(s), while the undamaged screens would have been left untouched thus reducing the cost and time required for the repair/replacement. KSR, 550 U.S. 398 (2007), 82 USPQ2d at 1396; MPEP 2143(C).
Leblanc, i.v., Ritchie, as discussed above, is silent on wherein the second screen is located to circumferential peripheral sides of a direct line-of-sight from the airflow inlet to the compressor section.
Foreman teaches, in Col. 1, ll. 10 – 20, that a diffuser in air intake ducts reduced air velocity entering a jet engine compressor intake so that the engine thrust is maximized. Lefebvre teaches, in Chapter 3 – Diffusers, on Pg. 71, last paragraph, that a diffuser was merely a diverging passage in which the flow was decelerated and the reduction in velocity head was converted to a rise in static pressure.
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It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Leblanc, i.v., Ritchie, with the diffuser, taught by Foreman and Lefebvre, because all the claimed elements, i.e., the gas turbine engine having a compressor section, the flowpath projecting longitudinally into the gas turbine engine from an airflow inlet, and a diffuser in an air intake duct to reduce air velocity entering a jet engine compressor intake while also increasing the static pressure, were known in the art, in combination each one of the components would perform the same function as it did separately, and one skilled in the art could have combined the elements as claimed by known methods, with no change in their respective functions, to yield predictable results, i.e., integrating a diffuser section upstream of the plenum section, as shown in Fig. B above, would have facilitated increasing the static pressure and decreasing the air velocity entering a jet engine compressor intake so that the engine thrust, i.e., power output, was maximized. KSR, 550 U.S. 398 (2007), 82 USPQ2d at 1395; MPEP 2143(A). As shown in Fig. B above, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, that in the combination of Leblanc, i.v., Ritchie, Foreman, and Lefebvre, the second screen would have been located to circumferential peripheral sides of a direct line-of-sight from the diffuser section of the airflow inlet to the compressor section and the first screen would have been located along a direct line-of-sight 94 from the diffuser section of the airflow inlet.
Re Claim 11, Leblanc, i.v., Ritchie, Foreman, and Lefebvre, teaches the invention as claimed and as discussed above, and Leblanc further teaches, in Fig. 2, wherein at least one of the first screen (sector A - shown in Fig. 2) extends less than one-hundred and eighty degrees about the axis (approximately 60°); or the second screen (sectors C-D-B-F-E - shown in Fig. 2) extends more than one-hundred and eighty degrees about the axis (approximately 300° arc).
Re Claim 12, Leblanc, i.v., Ritchie, Foreman, and Lefebvre, teaches the invention as claimed and as discussed above, and Leblanc further teaches, in Fig. 2, wherein at least one of the first screen (sector A - shown in Fig. 2) extends less than one-hundred and twenty degrees about the axis (approximately 60°); or the second screen (sectors C-D-B-F-E - shown in Fig. 2) extends more than one-hundred and twenty degrees about the axis (approximately 300° arc).
Re Claim 13, Leblanc, i.v., Ritchie, Foreman, and Lefebvre, teaches the invention as claimed and as discussed above, and Leblanc further teaches, in Figs. 1 and 2, wherein the inlet guard (36) extends circumferentially about the gas turbine engine (10).
Re Claim 21, [Refer to the 112(d) rejection above.] Leblanc, i.v., Ritchie, Foreman, and Lefebvre, teaches the invention as claimed and as discussed above, and Leblanc further teaches, in Fig. C marked-up below, wherein the airflow inlet (labeled) circumferentially overlaps the first screen (sector A – shown in Fig. C) and circumferentially overlaps one or more circumferential end portions of the second screen (end portions of sector C - shown in Fig. C).
At the time the invention was made, it would have been an obvious matter of design choice to a person of ordinary skill in the art to modify Leblanc, i.v., Ritchie, Foreman, and Lefebvre, to have the airflow inlet circumferentially overlaps the first screen and circumferentially overlaps one or more circumferential end portions of the second screen because Applicant has not disclosed that “the airflow inlet circumferentially overlaps the first screen and circumferentially overlaps one or more circumferential end portions of the second screen” provides an advantage, is used for a particular purpose, or solves a stated problem. In fact, original Specification Para. [0049] disclosed “The structure inlet 66 of FIG. 2, for example, may only circumferentially overlap one or more circumferential end portions of the coarse screen 72B, or MAY NOT circumferentially overlap the coarse screen 72B at all.” Claim 21 recites “wherein the airflow inlet circumferentially overlaps the first screen and circumferentially overlaps one or more circumferential end portions of the second screen”. Original Specification Para. [0038] disclosed “…an airflow inlet 66 into the inlet structure 26”; therefore, the “airflow inlet” and the “structure inlet” were different names for the same airflow opening (66) shown in Applicant’s Figs. 2 and 4. Similarly, “coarse screen” and “second screen” were different names for the same screen, i.e., structural element (72B). The two mutually exclusive arrangements #1 (airflow/structure inlet circumferentially overlaps one or more circumferential end portions of the second screen) and #2 (airflow/structure inlet circumferentially does not overlap the second screen at all) is indicative of the fact that the claimed arrangements are indeed a “Design Choice”, as all arrangements perform equally well as the arrangement of Leblanc, i.v., Ritchie, Foreman, and Lefebvre, and none of the arrangements exhibits an advantage over the other and over the arrangement of Leblanc, i.v., Ritchie. One of ordinary skill furthermore, would have expected Applicant’s invention to perform equally well with airflow inlet arrangement of Leblanc, i.v., Ritchie, Foreman, and Lefebvre, because Claim 22 recites such an arrangement.
Therefore, it would have been an obvious matter of design choice to modify Leblanc, i.v., Ritchie, Foreman, and Lefebvre, to obtain the invention as specified in Claim 21.
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Re Claim 22, Leblanc, i.v., Ritchie, Foreman, and Lefebvre, teaches the invention as claimed and as discussed above including wherein the airflow inlet does not circumferentially overlap the second screen, shown in Fig. B above.
Re Claim 23, Leblanc, i.v., Ritchie, Foreman, and Lefebvre, teaches the invention as claimed and as discussed above, including wherein the airflow inlet circumferentially overlaps an entirety of the first screen (shown in Fig. B marked-up above).
Regarding Claim 19, Leblanc teaches, in Fig. 1 – 3B, the invention as claimed, including a system for an aircraft (Col. 2, ll. 50 - 55), comprising: an aircraft engine (10 – Fig. 1) with a flowpath projecting into the aircraft engine (10) from an airflow inlet (30); and an inlet guard (36) arranged at the airflow inlet (30) and extending across the flowpath, (shown in Figs. 1, 3A, and 3B) the inlet guard (36) extending circumferentially about an axis (center of 19 shown in Figs. 1 and 2), the inlet guard (36) including a first screen (sector A - shown in Fig. 2) that is circumferentially aligned with the airflow inlet (30, 48 - open top end), and a second screen (sectors C-D-B-F-E - shown in Fig. 2) that is circumferentially offset from the airflow inlet (30, 48 - open top end), the first screen comprising a plurality of first perforations (38) with a first perforation size (Col. 3, l. 62 to Col. 4, l. 5 teaches smallest perforation diameter), the second screen (sectors C-D-B-F-E - shown in Fig. 2) comprising a plurality of second perforations (38) with a second perforation size (Col. 3, l. 62 to Col. 4, l. 5 teaches largest perforation diameter in sector B and teaches the smallest perforation diameter of sector A) that is greater than the first perforation size (Col. 3, l. 62 to Col. 4, l. 5 teaches smallest perforation diameter in sector A), and the second screen (sectors C-D-B-F-E - shown in Fig. 2) arranged circumferentially next to the first screen (sector A - shown in Fig. 2) about the axis (center of 19 shown in Figs. 1 and 2) (Col. 3, l. 62 to Col. 4, l. 5 teaches smallest perforation diameter in sector A. Leblanc teaches, in Col. 3, l. 62 to Col. 4, l. 5, “In another embodiment, it is also considered to vary the effective area by using a uniform distribution of holes 38, i.e. the same number of holes in each region, but with holes having a larger surface area where the airflow 40 is weaker. Thus, the hole size would be progressively increased toward the bottom end of the plate 36”.); wherein the first screen (sector A - shown in Fig. 2) has a first circumferential width (approximately 60° arc) about the axis; and wherein the second screen (sectors C-D-B-F-E - shown in Fig. 2) has a second circumferential width (approximately 300° arc) about the axis that is greater than the first circumferential width (approximately 60° arc). Leblanc teaches, in Col. 3, l. 62 – 65, that the inlet guard/plate (36) can be separated into any number of regions.
Ritchie teaches, in Figs. 1 – 6, a similar inlet guard (12, 12a) having a first screen (12) and a second screen (12a) circumferentially adjacent the first screen (12). Ritchie teaches, in Col. 1, ll. 30 – 35 and Col. 2, ll. 35 – 45, that the inlet guard (12, 12a) could be made from two separate screens (12 and 12a – shown in Figs. 1 and 3) or more than two separate screens depending on requirements and conditions of assembly.
Thus, improving a particular device (inlet guard), based upon the teachings of such improvement in Leblanc and Ritchie, would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, i.e., applying these known improvement techniques in the same manner to the inlet guard of Leblanc, and the results would have been predictable and readily recognized, that modifying the inlet guard to be assembled out of a plurality of separate screens, e.g., first screen having a first circumferential width and a second screen having a second circumferential width greater than the first circumferential width, would have facilitated easier assemble and disassembly of the inlet guard around the air inlet of the gas turbine engine. As shown in Leblanc – Figs 1, 3A, and 3B, it would have been very difficult if not impossible to install or remove an inlet guard (36) around the radial inlet (34) of the gas turbine engine if said inlet guard (36) was manufactured as a single continuous annular piece which had a smaller diameter that the maximum diameter of the air inlet assembly (30), i.e., plenum wall (46 – Fig. 2). Furthermore, assembling the 360° inlet guard out of a plurality of separate screens would have facilitated easier repair/replacement of a damaged section of screen, since only the damage screen(s) would have needed to be removed and replaced with a new screen(s), while the undamaged screens would have been left untouched thus reducing the cost and time required for the repair/replacement. KSR, 550 U.S. 398 (2007), 82 USPQ2d at 1396; MPEP 2143(C).
Leblanc, i.v., Ritchie, Foreman, and Lefebvre, as discussed above, is silent on said second screen being located to circumferential peripheral sides of a direct line-of-sight from the airflow inlet to the aircraft engine.
Foreman teaches, in Col. 1, ll. 10 – 20, that a diffuser in air intake ducts reduced air velocity entering a jet engine, i.e., aircraft engine, compressor intake so that the engine thrust is maximized. Lefebvre teaches, in Chapter 3 – Diffusers, on Pg. 71, last paragraph, that a diffuser was merely a diverging passage in which the flow was decelerated and the reduction in velocity head was converted to a rise in static pressure.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Leblanc, i.v., Ritchie, Foreman, and Lefebvre, with the diffuser, taught by Foreman and Lefebvre, because all the claimed elements, i.e., the aircraft gas turbine engine having a compressor section, the flowpath projecting longitudinally into the gas turbine engine from an airflow inlet, and a diffuser in an air intake duct to reduce air velocity entering a jet engine compressor intake while also increasing the static pressure, were known in the art, in combination each one of the components would perform the same function as it did separately, and one skilled in the art could have combined the elements as claimed by known methods, with no change in their respective functions, to yield predictable results, i.e., integrating a diffuser section upstream of the plenum section, as shown in Fig. B above, would have facilitated increasing the static pressure and decreasing the air velocity entering a jet engine compressor intake so that the engine thrust, i.e., power output, was maximized. KSR, 550 U.S. 398 (2007), 82 USPQ2d at 1395; MPEP 2143(A). As shown in Fig. B above, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, that in the combination of Leblanc, i.v., Ritchie, Foreman, and Lefebvre, Foreman, and Lefebvre, the second screen would have been located to circumferential peripheral sides of a direct line-of-sight from the diffuser section of the airflow inlet to the aircraft engine and the first screen would have been located along a direct line-of-sight 94 from the diffuser section of the airflow inlet.
Re Claim 20, Leblanc, i.v., Ritchie, Foreman, and Lefebvre, teaches the invention as claimed and as discussed above, and Leblanc further teaches, in Fig. 1, wherein the aircraft engine comprises a gas turbine engine (10 – Col. 2, ll. 50 - 65).
Claims 4 – 9 are rejected under 35 U.S.C. 103 as being unpatentable over Leblanc (6,959,552) in view of Ritchie (3,319,402) in view of Foreman et al. (4,989,807) in view of Lefebvre, A.H., Gas Turbine Combustion, Second Edition, Taylor & Francis, Philadelphia, 1998, hereinafter “Lefebvre” in view of Marrano et. al. (11,536,196).
Re Claim 4, Leblanc, i.v., Ritchie, Foreman, and Lefebvre, teaches the invention as claimed and as discussed above; except, wherein the inlet guard further includes a third screen comprising a plurality of third perforations with a third perforation size that is different than the second perforation size; and the second screen is arranged circumferentially between the first screen and the third screen about the axis. As discussed in the Claim 1 rejection above, Leblanc teaches, in Col. 3, l. 62 to Col. 4, l. 5, a plurality of screen regions (A to E) where the screen regions had a plurality of different perforation sizes where screen region (A) directly facing the inlet air flow (40) had the smallest perforation size, where screen region (B) directly opposite of the inlet air flow (40) had the largest perforation size, where the screen regions (C and E) had larger perforation size than screen region (A), and where the screen regions (D and F) had larger perforation size than screen regions (C and E) but smaller than the perforation size of screen region (B). Leblanc teaches, in Col. 1, ll. 40 – 50 and Col. 3, l. 62 to Col. 4, l. 5, using a plurality of perforation sizes to circumferentially redistribute the airflow in a more symmetric manner around the radial inlet.
Marrano teaches, in Figs. 1 and 5, a similar gas turbine engine (10 – Fig. 1) having first airflow inlet and a second airflow inlet (120, as shown in Fig. 5 the first airflow inlet on the left-hand side and the second airflow inlet on the right-hand side) where said second airflow inlet would have provided airflow to a 180° portion of the compressor radial air inlet (I – Fig. 1, 130 – Fig. 5) spanning, in a clockwise direction, from the 12 o’clock position to the 6 o’clock position and where said first airflow inlet would have provided airflow to a 180° portion of the compressor radial air inlet (I – Fig. 1, 130 – Fig. 5) spanning, in a clockwise direction, from the 6 o’clock position to the 12 o’clock position.
It would have been obvious, to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Leblanc, i.v., Ritchie, Foreman, and Lefebvre, with the airflow inlet having first airflow inlet and a second airflow inlet, taught by Marrano, because all the claimed elements, i.e., the gas turbine engine having a compressor section, the flowpath projecting longitudinally into the gas turbine engine from an airflow inlet, and the airflow inlet having first airflow inlet and a second airflow inlet, were known in the art, and one skilled in the art could have substituted the airflow inlet having first airflow inlet and a second airflow inlet, taught by Marrano, for the airflow inlet having a single open end (48) of Leblanc, i.v., Ritchie, Foreman, and Lefebvre, with no change in their respective functions, to yield predictable results, i.e., the first airflow inlet and a second airflow inlet would have provided two independent airflow streams to the gas turbine engine which would have facilitated increased redundancy since, if the first airflow inlet gets blocked or restricted, airflow would have still been provided to the gas turbine engine by the second airflow inlet. KSR, 550 U.S. 398 (2007), 82 USPQ2d at 1395; MPEP 2143(B).
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It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, that the combination of Leblanc, i.v., Ritchie, Foreman, Lefebvre, and Marrano, teaches wherein the inlet guard further includes a third screen (labeled “3rd screen” directly facing the airflow from the second airflow inlet) comprising a plurality of third perforations (38 – Fig. 2, Leblanc) with a third perforation size that is different than the second perforation size; and the second screen (labeled “2nd screen” which does not directly face the airflow from the first airflow inlet or the second airflow inlet) is arranged circumferentially between the first screen (labeled “1st screen” directly facing the airflow from the first airflow inlet) and the third screen (labeled “3rd screen” directly facing the airflow from the second airflow inlet) about the axis because Leblanc teaches, in Col. 1, ll. 40 – 50 and Col. 3, l. 62 to Col. 4, l. 5, using a plurality of perforation sizes to circumferentially redistribute the airflow in a more symmetric manner around the radial inlet which required the screen regions directly facing the airflow to have the smallest perforation diameter while the screen regions which do not directly face the airflow had perforation diameter greater than the smallest perforation diameter.
Re Claim 5, Leblanc, i.v., Ritchie, Foreman, Lefebvre, and Marrano, teaches the invention as claimed and as discussed above, including (refer to Claim 4 rejection above) wherein the airflow inlet is a first airflow inlet (Fig. A marked-up above), and the flowpath further projects longitudinally into the gas turbine engine from a second airflow inlet (Fig. A marked-up above); the first screen (labeled “1st screen” directly facing the airflow from the first airflow inlet) is circumferentially aligned with the first airflow inlet about the axis; and the third screen (labeled “3rd screen” directly facing the airflow from the second airflow inlet) is circumferentially aligned with the second airflow inlet about the axis.
Re Claim 6, Leblanc, i.v., Ritchie, Foreman, Lefebvre, and Marrano, teaches the invention as claimed and as discussed above, including (refer to Claim 4 rejection above) wherein the third perforation size is equal to the first perforation size. As discussed in the Claim 4 rejection above, Leblanc teaches, in Col. 1, ll. 40 – 50 and Col. 3, l. 62 to Col. 4, l. 5, using a plurality of perforation sizes to circumferentially redistribute the airflow in a more symmetric manner around the radial inlet which required the screen regions directly facing the airflow to have the smallest perforation diameter while the screen regions which do not directly face the airflow had perforation diameter greater than the smallest perforation diameter.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, that the combination of Leblanc, i.v., Ritchie, Foreman, Lefebvre, and Marrano, would have had the third perforation size is equal to the first perforation size because both the first screen and the third screen directly faced the airflow from their respective airflow inlet.
Re Claim 7, Leblanc, i.v., Ritchie, Foreman, Lefebvre, and Marrano, teaches the invention as claimed and as discussed above, including (refer to Claim 4 rejection above) wherein the inlet guard further includes a fourth screen (labeled “4th screen” Fig. A marked-up above) comprising a plurality of fourth perforations (38) with a fourth perforation size that is different than the first perforation size and the second perforation size; the third screen (labeled “3rd screen” Fig. A marked-up above) is arranged circumferentially between the second screen (labeled “2nd screen” Fig. A marked-up above) and the fourth screen (labeled “4th screen”) about the axis; and the fourth screen (labeled “4th screen”) is arranged circumferentially between the first screen (labeled “1st screen”) and the third screen (labeled “3rd screen”) about the axis.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, that the combination of Leblanc, i.v., Ritchie, Foreman, Lefebvre, and Marrano, teaches the claim limitations because Leblanc teaches, in Col. 1, ll. 40 – 50 and Col. 3, l. 62 to Col. 4, l. 5, using a plurality of perforation sizes to circumferentially redistribute the airflow in a more symmetric manner around the radial inlet which required the screen regions directly facing the airflow to have the smallest perforation diameter while the screen regions which do not directly face the airflow had perforation diameter greater than the smallest perforation diameter and as sized to circumferentially redistribute the airflow in a more symmetric manner.
Re Claim 8, Leblanc, i.v., Ritchie, Foreman, Lefebvre, and Marrano, teaches the invention as claimed and as discussed above, including wherein the first screen (labeled “1st screen”) has the first circumferential width about the axis (shown in Fig. A marked-up above); the second screen (labeled “2nd screen”) has the second circumferential width about the axis (shown in Fig. A marked-up above); the third screen (labeled “3rd screen”) has a third circumferential width about the axis (shown in Fig. A marked-up above); and the fourth screen (labeled “4th screen”) has a fourth circumferential width about the axis.
Leblanc, i.v., Ritchie, Foreman, Lefebvre, and Marrano, teaches the invention as claimed and as discussed above; except, wherein said second circumferential width is greater than said first circumferential width; said third circumferential width is equal to said first circumferential width; and said fourth circumferential width is different than said first circumferential width.
Leblanc further teaches, in Fig. 2, that the screen region (A) directly facing the airflow (40) had a circumferential width (approximately 60° arc) while the screen regions (C-D and E-F) oblique to the airflow (40) had a circumferential width (approximately 120° arc), and the screen region (B) directly opposite the airflow (40) had a circumferential width (approximately 60° arc).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Leblanc, i.v., Ritchie, Foreman, Lefebvre, and Marrano, to have said second circumferential width (approximately 120° arc) is greater than said first circumferential width (approximately 60° arc); said third circumferential width (approximately 60° arc) is equal to said first circumferential width (approximately 60° arc); and said fourth circumferential width (approximately 120° arc) is different than said first circumferential width (approximately 60° arc) because Leblanc teaches, in Col. 1, ll. 40 – 50 and Col. 3, l. 62 to Col. 4, l. 5, using a plurality of perforation sizes distributed in different circumferential screen regions/widths to circumferentially redistribute the airflow in a more symmetric manner around the radial inlet which required the screen regions directly facing the airflow to have the smallest perforation diameter while the screen regions which do not directly face the airflow had perforation diameter greater than the smallest perforation diameter and as sized to circumferentially redistribute the airflow in a more symmetric manner.
Re Claim 9, Leblanc, i.v., Ritchie, Foreman, Lefebvre, and Marrano, teaches the invention as claimed and as discussed above, including wherein at least one of the second circumferential width is smaller than the fourth circumferential width; or the fourth circumferential width (approximately 120° arc) is greater than the first circumferential width (approximately 60° arc).
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Leblanc (6,959,552) in view of Ritchie (3,319,402) in view of Foreman et al. (4,989,807) in view of Lefebvre, A.H., Gas Turbine Combustion, Second Edition, Taylor & Francis, Philadelphia, 1998, hereinafter “Lefebvre” in view of Marrano et. al. (11,536,196) in view of Millman (2,846,023).
Re Claim 14, Leblanc, i.v., Ritchie, Foreman, and Lefebvre, teaches the invention as claimed and as discussed above, and Leblanc further teaches, in Figs. 1, 3A, and 3B, wherein the inlet guard (36) extends axially along the axis. Leblanc, i.v., Ritchie, Foreman, and Lefebvre, as discussed above, is silent on the first screen axially overlaps the second screen along the axis.
Milliman teaches, in Figs. 1 – 4, a similar inlet guard having a first screen (18 – Col. 2, ll. 35 – 45) axially overlaps a second screen (19 – Col. 2, ll. 35 – 45) along an axis.
Thus, improving a particular device (inlet guard), based upon the teachings of such improvement in Milliman, would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, i.e., applying this known improvement technique in the same manner to the inlet guard of Leblanc, i.v., Ritchie, Foreman, and Lefebvre, and the results would have been predictable and readily recognized, that modifying the inlet guard to have the first screen (smaller perforation diameter) axially overlaps the second screen (larger perforation diameter), would have facilitated the smaller perforation diameter first screen reducing the airflow through said first screen while the larger perforation diameters of said second screen would not have affected the airflow from said first screen. Additionally, said second screen would have structurally supported said first screen. KSR, 550 U.S. 398 (2007), 82 USPQ2d at 1396; MPEP 2143(C).
Claims 15 – 18 are rejected under 35 U.S.C. 103 as being unpatentable over Leblanc (6,959,552) in view of Ritchie (3,319,402) in view of Millman (2,846,023) in view of Hartman (4,644,746).
Regarding Claim 15, Leblanc teaches, in Fig. 1 – 3B, the invention as claimed, including a system for an aircraft (Col. 2, ll. 50 - 55), comprising: a gas turbine engine (10 – Fig. 1) including an airflow inlet (30) that is upstream (during operation of the gas turbine engine air flowed into the airflow inlet and then downstream to the compressor section) of a compressor section (18); an inlet guard (36) extending circumferentially (shown in Fig. 2) about and axially along (shown in Figs. 1, 3A, and 3B) an axis, the inlet guard (36) including a first screen (sector A - shown in Fig. 2) that is circumferentially aligned with the airflow inlet (30, 48 - open top end), and a second screen (sectors C-D-B-F-E - shown in Fig. 2) that is circumferentially offset from the airflow inlet (30, 48 - open top end), the first screen (sector A - shown in Fig. 2) comprising a first percentage of open area (Col. 3, l. 62 to Col. 4, l. 5 teaches smallest open area), the second screen (sectors C-D-B-F-E - shown in Fig. 2) comprising a second percentage of open area that is greater than the first percentage of open area (Col. 3, l. 62 to Col. 4, l. 5), the second screen extending circumferentially about the axis to the first screen (shown in Fig. 2); and a flowpath projecting longitudinally from an airflow inlet, through the inlet guard (36), to the compressor section (18); wherein the first screen (sector A - shown in Fig. 2) has a first circumferential width (approximately 60° arc) about the axis; and wherein the second screen (sectors C-D-B-F-E - shown in Fig. 2) has a second circumferential width (approximately 300° arc) about the axis that is greater than the first circumferential width (approximately 60° arc). Leblanc teaches, in Col. 3, l. 62 to Col. 4, l. 5, “In another embodiment, it is also considered to vary the effective area by using a uniform distribution of holes 38, i.e. the same number of holes in each region, but with holes having a larger surface area where the airflow 40 is weaker. Thus, the hole size would be progressively increased toward the bottom end of the plate 36.”. From basic math it would have been clear that having the same number of holes, i.e., open area, in each of the six (6) regions/sectors would have meant that the second screen (sectors C-D-B-F-E - shown in Fig. 2) would have had at least five (5) times the open area percentage than the first screen (sector A) because the second screen would have had five (5) times the number of hole compared to the first screen. Furthermore, the hole size, i.e., diameter, of the holes of the second screen (sectors C-D-B-F-E - shown in Fig. 2) would have larger than the first screen (sector A) hole size, i.e., diameter. From basic math it would have been clear that having progressively large hole sizes, i.e., diameters, of holes, i.e., larger open area, in the second screen compared to the smallest hole size, i.e., diameter, the first screen would have meant that the second screen would have had the second percentage of open area that was greater than the first percentage of open area. Leblanc teaches, in Col. 3, l. 62 – 65, that the inlet guard/plate (36) can be separated into any number of regions.
Ritchie teaches, in Figs. 1 – 6, a similar inlet guard (12, 12a) having a first screen (12) and a second screen (12a) circumferentially adjacent the first screen (12). Ritchie teaches, in Col. 1, ll. 30 – 35 and Col. 2, ll. 35 – 45, that the inlet guard (12, 12a) could be made from two separate screens (12 and 12a – shown in Figs. 1 and 3) or more than two separate screens depending on requirements and conditions of assembly.
Thus, improving a particular device (inlet guard), based upon the teachings of such improvement in Leblanc and Ritchie, would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, i.e., applying these known improvement techniques in the same manner to the inlet guard of Leblanc, and the results would have been predictable and readily recognized, that modifying the inlet guard to be assembled out of a plurality of separate screens, e.g., first screen having a first circumferential width and a second screen having a second circumferential width greater than the first circumferential width, would have facilitated easier assemble and disassembly of the inlet guard around the air inlet of the gas turbine engine. As shown in Leblanc – Figs 1, 3A, and 3B, it would have been very difficult if not impossible to install or remove an inlet guard (36) around the radial inlet (34) of the gas turbine engine if said inlet guard (36) was manufactured as a single continuous annular piece which had a smaller diameter that the maximum diameter of the air inlet assembly (30), i.e., plenum wall (46 – Fig. 2). Furthermore, assembling the 360° inlet guard out of a plurality of separate screens would have facilitated easier repair/replacement of a damaged section of screen, since only the damage screen(s) would have needed to be removed and replaced with a new screen(s), while the undamaged screens would have been left untouched thus reducing the cost and time required for the repair/replacement. KSR, 550 U.S. 398 (2007), 82 USPQ2d at 1396; MPEP 2143(C).
Leblanc, i.v., Ritchie, is silent on the second screen extending axially along the first screen.
Milliman teaches, in Figs. 1 – 4, a similar inlet guard having a first screen (18 – Col. 2, ll. 35 – 45) axially overlaps/extends along a second screen (19 – Col. 2, ll. 35 – 45).
Thus, improving a particular device (inlet guard), based upon the teachings of such improvement in Milliman, would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, i.e., applying this known improvement technique in the same manner to the inlet guard of Leblanc, i.v., Ritchie, and the results would have been predictable and readily recognized, that modifying the inlet guard to have the first screen (smaller perforation diameter) axially overlaps/extends along the second screen (larger perforation diameter), would have facilitated the smaller perforation diameter first screen reducing the airflow through said first screen while the larger perforation diameters of said second screen would not have affected the airflow from said first screen. Additionally, said second screen would have structurally supported said first screen. KSR, 550 U.S. 398 (2007), 82 USPQ2d at 1396; MPEP 2143(C).
Leblanc, i.v., Ritchie and Milliman, is silent on said airflow inlet configured as a venturi comprising a converging inlet, a throat and diverging outlet, and wherein the first screen is circumferentially aligned with the throat and the second screen is circumferentially offset from the throat.
Hartman teaches, in Fig. 1, Col. 2, l. 67 to Col. 3, l. 5, and Col. 5, ll. 30 - 35, an aircraft engine having an airflow inlet configured as a venturi comprising a converging inlet (32), a throat (34) and diverging outlet (36) to facilitate using the geometry of the throat to control the mass flow rate of the inlet air.
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It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Leblanc, i.v., Ritchie and Milliman, with the airflow inlet configured as a venturi comprising a converging inlet, a throat and diverging outlet, taught by Hartman, because all the claimed elements, i.e., the gas turbine engine having a compressor section, the flowpath projecting longitudinally into the gas turbine engine from an airflow inlet, and an airflow inlet configured as a venturi comprising a converging inlet, a throat and diverging outlet, were known in the art, in combination each one of the components would perform the same function as it did separately, and one skilled in the art could have combined the elements as claimed by known methods, with no change in their respective functions, to yield predictable results, i.e., configuring said airflow inlet as a venturi comprising a converging inlet, a throat and diverging outlet, as shown in Fig. D above, would have facilitated using the geometry of the throat to control the mass flow rate of the air through the airflow inlet. KSR, 550 U.S. 398 (2007), 82 USPQ2d at 1395; MPEP 2143(A). As shown in Fig. D above, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, that in the combination of Leblanc, i.v., Ritchie, Milliman, and Hartman, the first screen would have been circumferentially aligned with the throat and the second screen would have been circumferentially offset from the throat.
Re Claim 16, Leblanc, i.v., Ritchie, Milliman, and Hartman, teaches the invention as claimed and as discussed above, including wherein the flowpath projects radially through the first screen and the second screen into the gas turbine engine, refer to the Claim 15 rejection above.
Re Claim 17, Leblanc, i.v., Ritchie, Milliman, and Hartman, teaches the invention as claimed and as discussed above, and Leblanc further teaches wherein the first screen comprises a plurality of first perforations (38), and each of the plurality of first perforations has a first cross-sectional area (inherent); and the second screen comprises a plurality of second perforations (38), and each of the plurality of second perforations has a second cross-sectional area that is different than the first cross-sectional area, refer to the Claim 15 rejection above.
Re Claim 18, Leblanc, i.v., Ritchie, Milliman, and Hartman, teaches the invention as claimed and as discussed above, and Leblanc further teaches, in Fig. 1, wherein the airflow inlet extends circumferentially about the axis between opposing circumferential sides; and the airflow inlet is radially outboard of and circumferentially overlaps the first screen (region A – Fig. 2).
Response to Arguments
Applicant's arguments filed 02/05/2026 have been fully considered and to the extent possible have been addressed in the rejections above, at the appropriate locations.
Correspondence
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/LORNE E MEADE/Primary Examiner, Art Unit 3741