DETAILED ACTION
Election/Restrictions
While applicant’s original election was with traverse, Applicant's response of 9/02/2025 indicates the election is now without traverse, i.e. this has been treated as the previous traversal has been withdrawn.
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.
Claim 14 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 14 recites a limitation whose range has already been incorporated into claim 12 and is not further limiting. 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.
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Claim(s) 11, 12, 14, 16, 18-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Suciu et al (20130219917) in view of either Smoke et al (2010/0275612) or Lewis et al (2012/0227414). Suciu et al teaches (111) wherein the stage of stator vanes including a first stator vane defining a fluid passage 170, and the stator case defining a supplemental airflow passage 170B, the supplemental airflow passage in fluid communication with the fluid passage and the rotor cavity, the supplemental airflow passage passing through the reference plane and defining an airflow outlet direction [of swirler 63, see ¶ 0038, 0044], the airflow outlet direction defining a swirl angle 63 greater than 0 degrees and less than or equal to 85 degrees with the reference plane [note a 90 degree swirl angle would be completely perpendicular to axial direction and as such would create a large pressure drop and inhibit flow through the swirler; accordingly, this upper range is so close to the absolute maximum value of swirl vane possible, that it practically covers the entire range of achievable swirl angles. Accordingly, this range is inherently covered by an practical range as there is no limitation on the swirl angle of Suciu et al]. . (12) A gas turbine engine defining an axial direction and a radial direction, the gas turbine engine comprising: a compressor section comprising a compressor 16, a combustion section 18, and a turbine section 20 arranged in serial flow order and defining a working gas flowpath, the compressor comprising an aft-most compressor stage [seen in Fig. 4] and defining a compressor exit temperature, T3, in degrees Rankine during an operating condition of the gas turbine engine; a spool 24, 37 drivingly coupled to the compressor; a stage of stator vanes located downstream of the aft-most compressor stage; and a stator case [includes 97] coupled to the stage of stator vanes inward of the stage of stator vanes along the radial direction, the spool and the stator case together defining a rotor cavity in fluid communication with the working gas flowpath, wherein the stator case [includes 97 and 146] and the spool together form a compressor discharge pressure seal [see annotations] and together define a rotor cavity opening [see annotations], and wherein the rotor cavity extends between the compressor discharge pressure seal and the rotor cavity opening [see annotations]; wherein the stage of stator vanes defines one or more fluid passages 170 and the stator case defines a plurality of supplemental airflow passages 170B, the plurality of supplemental airflow passages 170B in fluid communication with the one or more fluid passages and the rotor cavity, wherein the plurality of supplemental airflow passages 170B are configured to provide a supplemental airflow to the rotor cavity at a passage temperature, TP, in degrees Rankine during the operating condition of the gas turbine engine, wherein each supplemental airflow passage of the plurality of supplemental airflow passages defines a swirl 63 with a local reference plane, each local reference plane passing through a respective supplemental airflow passage of the plurality of supplemental airflow passages and extending in the axial and radial directions, the gas turbine engine defines a supplemental airflow temperature ratio (SATR) equal to TP / T3, and wherein SATR is greater than or equal to 0.8 and less than 1.0 [heat exchanger cooling, inherent / obvious when SATR is barely affected by the heat exchanger, e.g. heat exchanger startup or other conditions when there is little cooling] greater than or equal to 0.8 and less than 1.0 and θSwirl is greater than or equal to 0 degrees and less than or equal to 85 degrees, or wherein SATR is greater than or equal to 1.0 and less than or equal to 1.15 and θSwirl is greater than 0 degrees and less than or equal to 85 degrees [note a 90 degree swirl angle would be completely perpendicular to axial direction and as such would create a large pressure drop and inhibit flow through the swirler; accordingly, this upper range is so close to the absolute maximum value of swirl vane possible, that it practically covers the entire range of achievable swirl angles. Accordingly, this range is inherently covered by an practical range as there is no limitation on the swirl angle of Suciu et al. It would have been obvious to one of ordinary skill in the art to make the swirl angle less than 85 degrees (vs 90 degrees) as within the upper boundary of the workable ranges in the art.]. (14) wherein SATR is greater than or equal to 0.8 and less than or equal to 1.15 [heat exchanger cools the air from T3 to Tp, so Tp<Tp and SATR <1.0]. (16) wherein the stator case defines a plenum [e.g. 99 or 142], and wherein the plurality of supplemental airflow passages 170B or 63 are in fluid communication with the one or more fluid passages through the plenum. (17) wherein the gas turbine engine defines a circumferential direction, and wherein the plenum extends in the circumferential direction. (18) wherein the one or more fluid passages are in fluid communication with the compressor 16; (19) further comprising: a heat exchanger 166 in fluid communication with the one or more fluid passages at a location downstream of the compressor, and wherein SATR is less than 1. (20) wherein the compressor is a high pressure compressor 19, and wherein the stage of stator vanes is a stage of discharge nozzles 200 fluidly connecting the high pressure compressor 19 to the combustion section 18.
For claims 11, 12 above, the swirl angle being less than 85 degrees was treated as virtually inherent. Alternately, the airflow outlet direction defining a swirl angle greater than 0 degrees and less than or equal to 85 degrees with the reference plane is also taught by the following. Smoke teaches where the airflow outlet direction 26, 46 defining a swirl angle / θSwirl is greater than 0 degrees and less than or equal to 85 degrees with the reference plane [i.e. the plane extending radially and axially through 26, 46, see Figs. 5, 6. Note that 85 degrees would be virtually parallel with the entrance of the TOBI 24 and the angle is clearly much less than 85 degrees.] Smoke also teaches teach θSwirl is greater than or equal to 0 degrees and less than or equal to 85 degrees. Lewis et al teach the airflow outlet direction C of 29’, 29” defining a swirl angle / θSwirl [e.g. α1, α2 in Figs. 3-4] greater than 0 degrees and less than or equal to 85 degrees with the reference plane [see ¶ 0047, which teaches 45⁰ to 80⁰] and θSwirl is greater than or equal to 0 degrees and less than or equal to 85 degrees [see ¶ 0047, which teaches 45⁰ to 80⁰]. Zheng et al teach the airflow outlet direction 114 defining a swirl angle / θSwirl greater than 0 degrees and less than or equal to 85 degrees with the reference plane [through the axial direction and radial direction – see Figs. 6-8], and θSwirl is greater than or equal to 0 degrees and less than or equal to 85 degrees. It would have been obvious to one of ordinary skill in the art to employ the claimed range of the swirl angle/ θSwirl greater than 0 degrees and being less than 85 degrees with the reference plane, as taught by either Smoke or Zheng et al, as the typical practice in the art for tangential air injection.
Claim(s) 11, 12, 14, 16-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kervistin (5297386) in view of Napoli et al (4554789) and optionally Smoke et al (2010/0275612) and Lewis et al (2012/0227414). Kervistin teaches (11) wherein the stage of stator vanes 6a including a first stator vane defining a fluid passage [through 6a], and the stator case defining a supplemental airflow passage 19, the supplemental airflow passage in fluid communication with the fluid passage and the rotor cavity, the supplemental airflow passage passing through the reference plane and defining an airflow outlet direction, the airflow outlet direction defining a swirl angle greater than 0 degrees and less than or equal to 85 degrees with the reference plane [col. 3, lines 31-40, It would have been obvious to one of ordinary skill in the art to make the swirl angle less than 85 degrees (vs 90 degrees) as within the upper boundary of the workable ranges in the art]. (12) A gas turbine engine defining an axial direction and a radial direction, the gas turbine engine comprising: a compressor section comprising a compressor 2, a combustion section [downstream of 9], and a turbine section [not illustrated, but discussed] arranged in serial flow order and defining a working gas flowpath, the compressor comprising an aft-most compressor stage 5a and defining a compressor exit temperature, T3, in degrees Rankine during an operating condition of the gas turbine engine; a spool 4 drivingly coupled to the compressor; a stage of stator vanes 6a located downstream of the aft-most compressor stage; and a stator case [between 9 and 18] coupled to the stage of stator vanes inward of the stage of stator vanes along the radial direction, the spool and the stator case together defining a rotor cavity e.g. circa R2 in fluid communication with the working gas flowpath, wherein the stage of stator vanes defines one or more fluid passages [inside 6a] and the stator case defines a plurality of supplemental airflow passages 19, the plurality of supplemental airflow passages in fluid communication with the one or more fluid passages 19 and the rotor cavity [left of 19], wherein the plurality of supplemental airflow passages 19 are configured to provide a supplemental airflow to the rotor cavity at a passage temperature, Tp, in degrees Rankine during the operating condition of the gas turbine engine, wherein each supplemental airflow passage of the plurality of supplemental airflow passages 19 defines a swirl angle, θSwirl, with a local reference plane [col. 3, lines 31-40], each local reference plane passing through a respective supplemental airflow passage of the plurality of supplemental airflow passages and extending in the axial and radial directions, and wherein the gas turbine engine defines a supplemental airflow temperature ratio (SATR) equal to TP / T3, and wherein SATR is greater than or equal to 0.8 and less than 1.0 [heat exchanger cools the air from T3 to Tp, so Tp<Tp and SATR <1.0 range is inherent / obvious , when SATR is barely affected by the heat exchanger, e.g. heat exchanger startup or other conditions when there is little cooling] and θSwirl is greater than or equal to 0 degrees and less than or equal to 85 degrees, or wherein SATR is greater than or equal to 1.0 and less than or equal to 1.15 and θSwirl is greater than 0 degrees and less than or equal to 85 degrees. It would have been obvious to one of ordinary skill in the art to make the swirl angle less than 85 degrees (vs 90 degrees) as within the upper boundary of the workable ranges in the art. (13), wherein the spool and stator case together define a rotor cavity opening, wherein the rotor cavity opening defines a cross-sectional area, AFO, wherein the plurality of supplemental airflow passages define a total cross-sectional area, ASAP_Total, (14) wherein SATR is greater than or equal to 0.8 and less than or equal to 1.15 [this range is inherently covered when the heat exchanger barely starts cooling]. (16) wherein the stator case defines a plenum 18, and wherein the plurality of supplemental airflow passages 19 are in fluid communication with the one or more fluid passages [through 6a] through the plenum 18. (17) wherein the gas turbine engine defines a circumferential direction, and wherein the plenum extends in the circumferential direction. (18) wherein the one or more fluid passages [through 6a] are in fluid communication with the compressor 2. (19) further comprising: a heat exchanger in fluid communication [R] with the one or more fluid passages at a location downstream of the compressor, and wherein SATR is less than 1. (20) wherein the compressor is a high pressure compressor 2 [col. 2, lines 36+], and wherein the stage of stator vanes is a stage of discharge nozzles fluidly connecting the high pressure compressor 2 to the combustion section [right of 9].
Kervistin do not teach wherein the stator case and the spool together form a compressor discharge pressure seal and together define a rotor cavity opening, and wherein the rotor cavity extends between the compressor discharge pressure seal and the rotor cavity opening. Napoli et al teach that the wherein the stator case [static structure below 14, includes 23, and structures surrounding 32] and the spool 18 together form a compressor discharge pressure seal 10 and together define a rotor cavity opening [between 11 and 14], and wherein the rotor cavity 35 extends between the compressor discharge pressure seal 10 and the rotor cavity opening; the stator case defining a supplemental airflow passage 36, the supplemental airflow passage 36 in fluid communication with the rotor cavity 35, the supplemental airflow passage 36 passing through the reference plane and defining an airflow outlet direction, the airflow outlet direction defining a swirl angle greater than 0 degrees and less than or equal to 85 degrees with the reference plane [see col. 5, lines 55-68; see also tangential swirl holes 34, to which Napoli et al teach are analogous]; wherein the plurality of supplemental airflow passages are configured to provide a supplemental airflow to the rotor cavity at a passage temperature, TP, in degrees Rankine during the operating condition of the gas turbine engine, wherein each supplemental airflow passage 36 of the plurality of supplemental airflow passages defines a swirl with a local reference plane, each local reference plane passing through a respective supplemental airflow passage of the plurality of supplemental airflow passages and extending in the axial and radial directions, the gas turbine engine defines a supplemental airflow temperature ratio (SATR) equal to TP / T3, where θSwirl is greater than or equal to 0 degrees and less than or equal to 85 degrees.
“As can be seen in FIG. 2, an annular series of inlet holes 36, one of which is shown, is provided to inject a small quantity of air into this seal cavity 35. Air will flow in this direction because the static pressure downstream of the diffuser 15 is higher than at the exit of the compressor, upstream of the guide vane 14. These holes 36 can be cut at an angle in respect to an axis of rotation of said compressor rotor to impart a tangential velocity component in the direction of rotor rotation, similar to the manner in which a tangential velocity component is imparted by passages 34. Tangential injection reduces the amount of frictional drag between the injected air and the rotating compressor rotor 18. This reduces the amount of work done on the injected air… [col. 5, lines 55-68]”
It would have been obvious to one of ordinary skill in the art to make the stator case and the spool together form a compressor discharge pressure seal and together define a rotor cavity opening, and wherein the rotor cavity extends between the compressor discharge pressure seal and the rotor cavity opening, as taught by Napoli et al, as the typical practice in the art for defining a rotor cavity in the claimed regions of the stator case / last stator vanes and as the typical engine structure utilized in the art. To the extent not already disclosed by Kervistin et al, it would have been obvious to one of ordinary skill in the art to make the supplemental airflow passage passing through the reference plane and defining an airflow outlet direction, the airflow outlet direction defining a swirl angle greater than 0 degrees and less than or equal to 85 degrees with the reference plane and each supplemental airflow passage of the plurality of supplemental airflow passages defines a swirl with a local reference plane, each local reference plane passing through a respective supplemental airflow passage of the plurality of supplemental airflow passages and extending in the axial and radial directions, the gas turbine engine defines a supplemental airflow temperature ratio (SATR) equal to TP / T3, where θSwirl is greater than or equal to 0 degrees and less than or equal to 85 degrees, as taught by Napoli et al, in order to utilize the standard swirl angle configurations utilized in the art. Alternately, the airflow outlet direction defining a swirl angle greater than 0 degrees and less than or equal to 85 degrees with the reference plane is also taught by the following. Smoke teaches where the airflow outlet direction 26, 46 defining a swirl angle / θSwirl is greater than 0 degrees and less than or equal to 85 degrees with the reference plane [i.e. the plane extending radially and axially through 26, 46, see Figs. 5, 6. Note that 85 degrees would be virtually parallel with the entrance of the TOBI 24 and the angle is clearly much less than 85 degrees.] Smoke also teaches teach θSwirl is greater than or equal to 0 degrees and less than or equal to 85 degrees. Lewis et al teach the airflow outlet direction C of 29’, 29” defining a swirl angle / θSwirl [e.g. α1, α2 in Figs. 3-4] greater than 0 degrees and less than or equal to 85 degrees with the reference plane [see ¶ 0047, which teaches 45⁰ to 80⁰] and θSwirl is greater than or equal to 0 degrees and less than or equal to 85 degrees [see ¶ 0047, which teaches 45⁰ to 80⁰]. Zheng et al teach the airflow outlet direction 114 defining a swirl angle / θSwirl greater than 0 degrees and less than or equal to 85 degrees with the reference plane [through the axial direction and radial direction – see Figs. 6-8], and θSwirl is greater than or equal to 0 degrees and less than or equal to 85 degrees. It would have been obvious to one of ordinary skill in the art to employ the claimed range of the swirl angle/ θSwirl greater than 0 degrees and being less than 85 degrees with the reference plane, as taught by either Smoke or Zheng et al, as the typical practice in the art for tangential air injection.
Claim(s) 11, 12, 14, 16-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Schwarz et al (20200011247) in view of Suciu et al (20130219917) and Napoli et al (4554789) and optionally Smoke et al (2010/0275612) and Lewis et al (2012/0227414). Schwarz et al teaches (11) wherein the stage of stator vanes including a first stator vane 120 defining a fluid passage, and the stator case defining a supplemental airflow passage [exit of 102], the supplemental airflow passage [exit of 102] in fluid communication with the fluid passage and the rotor cavity, the supplemental airflow passage passing through the reference plane and defining an airflow outlet direction, the airflow outlet direction defining a swirl angle greater than 0 degrees and less than or equal to 85 degrees with the reference plane [see paragraph 0019. It would have been obvious to one of ordinary skill in the art to make the swirl angle less than 85 degrees (vs 90 degrees) as within the upper boundary of the workable ranges in the art]. (12) A gas turbine engine defining an axial direction and a radial direction, the gas turbine engine [Fig. 1] comprising: a compressor section comprising a compressor 24, 52 a combustion section 56, and a turbine section 28 arranged in serial flow order and defining a working gas flowpath, the compressor comprising an aft-most compressor stage [aftmost stage of 52] and defining a compressor exit temperature, T3, in degrees Rankine during an operating condition of the gas turbine engine; a spool 32 drivingly coupled to the compressor; a stage of stator vanes 120 located downstream of the aft-most compressor stage; and a stator case [see annotations] coupled to the stage of stator vanes 120 inward of the stage of stator vanes along the radial direction, the spool and the stator case together defining a rotor cavity [e.g. circa 88] in fluid communication with the working gas flowpath, wherein the stator case and the spool together form a compressor discharge pressure seal [see annotations] and together define a rotor cavity opening [see annotations], and wherein the rotor cavity extends between the compressor discharge pressure seal and the rotor cavity opening [see annotations], wherein the stage of stator vanes defines one or more fluid passages and the stator case defines a plurality of supplemental airflow passages [exit of 102], the plurality of supplemental airflow passages [exit of 102] in fluid communication with the one or more fluid passages and the rotor cavity, wherein the plurality of supplemental airflow passages [exit of 102] are configured to provide a supplemental airflow to the rotor cavity at a passage temperature, Tp, in degrees Rankine during the operating condition of the gas turbine engine, wherein each supplemental airflow passage of the plurality of supplemental airflow passages defines a swirl angle, θSwirl, with a local reference plane, each local reference plane passing through a respective supplemental airflow passage of the plurality of supplemental airflow passages and extending in the axial and radial directions, and wherein the gas turbine engine defines a supplemental airflow temperature ratio (SATR) equal to TP / T3, and wherein SATR is greater than or equal to 0.8 and less than 1.0 [cooled by heat exchanger 78 and cooling compressor 84, inherent / obvious when SATR is barely affected by the cooling flow from 86, e.g. during heat exchanger startup or other conditions when there is little cooling] and θSwirl is greater than or equal to 0 degrees and less than or equal to 85 degrees, or wherein SATR is greater than or equal to 1.0 and less than or equal to 1.15 and θSwirl is greater than 0 degrees and less than or equal to 85 degrees. (13), wherein the spool and stator case together define a rotor cavity opening, wherein the rotor cavity opening defines a cross-sectional area, AFO, wherein the plurality of supplemental airflow passages define a total cross-sectional area, ASAP_Total, (14) wherein SATR is greater than or equal to 0.8 and less than or equal to 1.15 [inherent, when SATR is barely affected by the cooling flow from 86]. (16) wherein the stator case defines a plenum 88 and wherein the plurality of supplemental airflow passages [exit of 102] are in fluid communication with the one or more fluid passages through the plenum. (17) wherein the gas turbine engine defines a circumferential direction, and wherein the plenum extends in the circumferential direction. (18) wherein the one or more fluid passages [through 120] are in fluid communication with the compressor 24 [from 86 to 102 and 67 flows to the high pressure compressor 52]; (19) further comprising: a heat exchanger 78 in fluid communication with the one or more fluid passages at a location downstream of the compressor 22, 44 and wherein SATR is less than 1 [cooling in heat exchanger]. (20) wherein the compressor 24 is a high pressure compressor 52, and wherein the stage of stator vanes 120 is a stage of discharge nozzles 120 fluidly connecting the high pressure compressor 52 to the combustion section 56. Schwarz et al teach a supplemental airflow passage [exit of 102] and show it only schematically. Suciu et al teach [see annotations] wherein the stator case and the spool together form a compressor discharge pressure seal [see Fig. 4] and together define a rotor cavity opening, and wherein the rotor cavity extends between the compressor discharge pressure seal [see annotations] and the rotor cavity opening [see annotations]; wherein the stage of stator vanes including a first stator vane defining a fluid passage 170, and the stator case defining a supplemental airflow passage 170B, the supplemental airflow passage 170B in fluid communication with the fluid passage and the rotor cavity, the supplemental airflow passage 170B passing through the reference plane and defining an airflow outlet direction [63 is a swirler, see ¶ 0044], the airflow outlet direction defining a swirl angle greater than 0 degrees and less than or equal to 85 degrees with the reference plane. It would have been obvious to one of ordinary skill in the art to one of ordinary skill in the art to employ the supplemental airflow passage, the supplemental airflow passage in fluid communication with the fluid passage and the rotor cavity, the supplemental airflow passage passing through the reference plane and defining an airflow outlet direction, the airflow outlet direction defining a swirl angle greater than 0 degrees and less than or equal to 85 degrees with the reference plane and, the plurality of supplemental airflow passages in fluid communication with the one or more fluid passages and the rotor cavity, wherein the plurality of supplemental airflow passages are configured to provide a supplemental airflow to the rotor cavity at a passage temperature, TP, in degrees Rankine during the operating condition of the gas turbine engine, wherein each supplemental airflow passage of the plurality of supplemental airflow passages defines a swirl with a local reference plane, each local reference plane passing through a respective supplemental airflow passage of the plurality of supplemental airflow passages and extending in the axial and radial directions, as taught by Suciu et al, in order to utilize a typical arrangement of supplement airflow passages that is used to generate the pre-swirl that is taught by Schwarz et al, but only schematically shown. The prior art already teach that the supplemental passages direct swirling air or air with a tangential component into the rotor cavity but do not necessarily illustrate the swirl angle being less than 85 degrees. Napoli et al teach the stator case defining a supplemental airflow passage 36, the supplemental airflow passage 36 in fluid communication with the rotor cavity 35, the supplemental airflow passage 36 passing through the reference plane and defining an airflow outlet direction, the airflow outlet direction defining a swirl angle greater than 0 degrees and less than or equal to 85 degrees with the reference plane [see col. 5, lines 55-68; see also tangential swirl holes 34, to which Napoli et al teach are analogous]; wherein the plurality of supplemental airflow passages are configured to provide a supplemental airflow to the rotor cavity at a passage temperature, TP, in degrees Rankine during the operating condition of the gas turbine engine, wherein each supplemental airflow passage 36 of the plurality of supplemental airflow passages defines a swirl with a local reference plane, each local reference plane passing through a respective supplemental airflow passage of the plurality of supplemental airflow passages and extending in the axial and radial directions, the gas turbine engine defines a supplemental airflow temperature ratio (SATR) equal to TP / T3, where θSwirl is greater than or equal to 0 degrees and less than or equal to 85 degrees.
“As can be seen in FIG. 2, an annular series of inlet holes 36, one of which is shown, is provided to inject a small quantity of air into this seal cavity 35. Air will flow in this direction because the static pressure downstream of the diffuser 15 is higher than at the exit of the compressor, upstream of the guide vane 14. These holes 36 can be cut at an angle in respect to an axis of rotation of said compressor rotor to impart a tangential velocity component in the direction of rotor rotation, similar to the manner in which a tangential velocity component is imparted by passages 34. Tangential injection reduces the amount of frictional drag between the injected air and the rotating compressor rotor 18. This reduces the amount of work done on the injected air… [col. 5, lines 55-68]”
It would have been obvious to one of ordinary skill in the art to make the supplemental airflow passage passing through the reference plane and defining an airflow outlet direction, the airflow outlet direction defining a swirl angle greater than 0 degrees and less than or equal to 85 degrees with the reference plane and each supplemental airflow passage of the plurality of supplemental airflow passages defines a swirl with a local reference plane, each local reference plane passing through a respective supplemental airflow passage of the plurality of supplemental airflow passages and extending in the axial and radial directions, the gas turbine engine defines a supplemental airflow temperature ratio (SATR) equal to TP / T3, where θSwirl is greater than or equal to 0 degrees and less than or equal to 85 degrees, as taught by Napoli et al, in order to utilize the standard swirl angle configurations utilized in the art. Alternately, the airflow outlet direction defining a swirl angle greater than 0 degrees and less than or equal to 85 degrees with the reference plane is also taught by the following. Smoke teaches where the airflow outlet direction 26, 46 defining a swirl angle / θSwirl is greater than 0 degrees and less than or equal to 85 degrees with the reference plane [i.e. the plane extending radially and axially through 26, 46, see Figs. 5, 6. Note that 85 degrees would be virtually parallel with the entrance of the TOBI 24 and the angle is clearly much less than 85 degrees.] Smoke also teaches teach θSwirl is greater than or equal to 0 degrees and less than or equal to 85 degrees. Lewis et al teach the airflow outlet direction C of 29’, 29” defining a swirl angle / θSwirl [e.g. α1, α2 in Figs. 3-4] greater than 0 degrees and less than or equal to 85 degrees with the reference plane [see ¶ 0047, which teaches 45⁰ to 80⁰] and θSwirl is greater than or equal to 0 degrees and less than or equal to 85 degrees [see ¶ 0047, which teaches 45⁰ to 80⁰]. Zheng et al teach the airflow outlet direction 114 defining a swirl angle / θSwirl greater than 0 degrees and less than or equal to 85 degrees with the reference plane [through the axial direction and radial direction – see Figs. 6-8], and θSwirl is greater than or equal to 0 degrees and less than or equal to 85 degrees. It would have been obvious to one of ordinary skill in the art to employ the claimed range of the swirl angle/ θSwirl greater than 0 degrees and being less than 85 degrees with the reference plane, as taught by either Smoke or Zheng et al, as the typical practice in the art for tangential air injection.
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Claim(s) 11-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Lyons (10253632) in view of either Schwarz et al (20200011247) or Kervistin (5297386) and optionally in view of Napoli et al (4554789) and optionally Smoke et al (2010/0275612) and Lewis et al (2012/0227414). Lyons teaches (11) wherein the stage of stator vanes 78 including a first stator vane defining a fluid passage 86, and the stator case defining a supplemental airflow passage 110, the supplemental airflow passage 110 in fluid communication with the fluid passage 86 and the rotor cavity, the supplemental airflow passage 110 passing through the reference plane and defining an airflow outlet direction, the airflow outlet direction defining a swirl angle greater than 0 degrees and less than or equal to 85 degrees with the reference plane. (12) A gas turbine engine defining an axial direction and a radial direction, the gas turbine engine comprising: a compressor section comprising a compressor 24, a combustion section 56, and a turbine section 28 arranged in serial flow order and defining a working gas flowpath, the compressor comprising an aft-most compressor stage [leadline to 104 in Fig. 2A] and defining a compressor exit temperature, T3, in degrees Rankine during an operating condition of the gas turbine engine; a spool drivingly coupled to the compressor; a stage of stator vanes 78 located downstream of the aft-most compressor stage; and a stator case coupled to the stage of stator vanes 78 inward of the stage of stator vanes 78 along the radial direction, the spool and the stator case together defining a rotor cavity [left of 110; right of 106] in fluid communication with the working gas flowpath, wherein the stator case and the spool together form a compressor discharge pressure seal [see annotations] and together define a rotor cavity opening [see annotations], and wherein the rotor cavity extends between the compressor discharge pressure seal and the rotor cavity opening [see annotations]; wherein the stage of stator vanes 78 defines one or more fluid passages 86 and the stator case defines a plurality of supplemental airflow passages 110, the plurality of supplemental airflow passages 110 in fluid communication with the one or more fluid passages 86 and the rotor cavity [left of 110], wherein the plurality of supplemental airflow passages 110 are configured to provide a supplemental airflow to the rotor cavity [left of 110] at a passage temperature, Tp, in degrees Rankine during the operating condition of the gas turbine engine, wherein each supplemental airflow passage 110 of the plurality of supplemental airflow passages 110 defines a swirl angle, θSwirl, with a local reference plane, each local reference plane passing through a respective supplemental airflow passage 110 of the plurality of supplemental airflow passages 110 and extending in the axial and radial directions, and wherein the gas turbine engine defines a supplemental airflow temperature ratio (SATR) equal to, and wherein SATR is greater than or equal to 0.8 and less than 1.0 [when SATR is barely affected by the heat exchanger, e.g. heat exchanger startup or other conditions when there is little cooling] and θSwirl is greater than or equal to 0 degrees and less than or equal to 85 degrees, or wherein SATR is greater than or equal to 1.0 and less than or equal to 1.15 and θSwirl is greater than 0 degrees and less than or equal to 85 degrees. (16) wherein the stator case defines a plenum 96, and wherein the plurality of supplemental airflow passages 110 are in fluid communication with the one or more fluid passages 86 through the plenum. (17) wherein the gas turbine engine defines a circumferential direction, and wherein the plenum 96 extends in the circumferential direction. (18) wherein the one or more fluid passages 86 are in fluid communication with the compressor 44; (19) further comprising: a heat exchanger 84 in fluid communication with the one or more fluid passages 86 at a location downstream of the compressor, and wherein SATR is less than 1 [heat exchanger has cooling air]. (20) wherein the compressor is a high pressure compressor 44 [see col. 4, lines 1-7], and wherein the stage of stator vanes 78 is a stage of discharge nozzles 76 fluidly connecting the high pressure compressor 44 to the combustion section 56.
Lyons teaches the supplemental airflow passage defines a COBI and does not specifically indicate whether this entails swirl angle greater than 0 degrees and less than or equal to 85 degrees with the reference plane. Kervistin et teach the supplemental airflow passage passing through the reference plane and defining an airflow outlet direction, the airflow outlet direction defining a swirl angle greater than 0 degrees with the reference plane [col. 3, lines 31-40] and θSwirl greater than 0 degrees and less than or equal to 85 degrees. Schwarz et al discuss the COBI as being a row of turning vanes that pre-swirl the airflow onto the compressor rotor [paragraph 0019] and thus have greater than 0 degrees and less than or equal to 85 degrees [note a 90 degree swirl angle would be completely perpendicular to axial direction and as such would create a large pressure drop and inhibit flow through the swirler; accordingly, this upper range is so close to the absolute maximum value of swirl vane possible, that it practically covers the entire range of achievable swirl angles]. It would have been obvious to one of ordinary skill in the art to make the COBI / supplemental airflow passages of Lyons, define the airflow outlet direction defining a swirl angle greater than 0 degrees with the reference plane and θSwirl greater than 0 degrees and less than or equal to 85 degrees, as an obvious matter of using the supplemental airflow passages to swirl the airflow to cool the compressor rotor and as an obvious matter of using the workable ranges in the art.
(13), wherein the spool and stator case together define a rotor cavity [left of 110] opening, wherein the rotor cavity opening defines a cross-sectional area, AFO, wherein the plurality of supplemental airflow passages 110 define a total cross-sectional area, ASAP_Total, but do not teach and wherein a ratio of AFO to ASAP_Total, is greater than or equal to 0.05 and less than 0.25. This range is considered an obvious matter of using the workable ranges in the art to size the flow area of supplemental passages to the rotor cavity area. It would have been obvious to one of ordinary skill in the art to employ the claimed ranges for of AFO to ASAP_Total, as an obvious matter of using the workable ranges in the art that would prevent the flow area of supplemental air passages from being excessively large compared to the rotor cavity area.
As for (14) wherein SATR is greater than or equal to 0.8 and less than or equal to 1.15. As for this range of SATR, this corresponds to a relatively small temperature difference between T3 and Tp [e.g. via the heat exchanger] and is within the ordinary skill in the art of using a relatively small temperature difference, such that the heat exchanger is sized for relatively small temperature difference. It would have been obvious to one of ordinary skill in the art to employ the claimed ranges for SATR, as utilizing relatively small temperature difference between T3 and Tp is an obvious matter of using the workable ranges in the art.
As for (15) wherein a relationship between θSwirl and SATR is as follows: θSwirl≥199×SATR.2−186×SATR+7. – applicant does not define any ranges for either θSwirl or SATR, so a single point or e.g. multiple points is sufficient to meet this limitation [at an SATR of 0.9, θSwirl ≥0.079 OR SATR of 0.98, θSwirl ≥15.8]. As types of ranges are well within the typical experienced in the art, it would have been obvious to one of ordinary skill in the art to employ the claimed relationship θSwirl and SATR, e.g. at a single point or multiple points, as an obvious matter of using the workable ranges in the art.
The prior art already teach that the supplemental passages direct swirling air or air with a tangential component into the rotor cavity but do not necessarily illustrate the swirl angle being less than 85 degrees. Napoli et al teach the stator case defining a supplemental airflow passage 36, the supplemental airflow passage 36 in fluid communication with the rotor cavity 35, the supplemental airflow passage 36 passing through the reference plane and defining an airflow outlet direction, the airflow outlet direction defining a swirl angle greater than 0 degrees with the reference plane [see col. 5, lines 55-68; see also tangential swirl holes 34, to which Napoli et al teach are analogous]; wherein the plurality of supplemental airflow passages are configured to provide a supplemental airflow to the rotor cavity at a passage temperature, TP, in degrees Rankine during the operating condition of the gas turbine engine, wherein each supplemental airflow passage 36 of the plurality of supplemental airflow passages defines a swirl with a local reference plane, each local reference plane passing through a respective supplemental airflow passage of the plurality of supplemental airflow passages and extending in the axial and radial directions, the gas turbine engine defines a supplemental airflow temperature ratio (SATR) equal to TP / T3, where θSwirl is greater than or equal to 0 degrees and less than or equal to 85 degrees.
“As can be seen in FIG. 2, an annular series of inlet holes 36, one of which is shown, is provided to inject a small quantity of air into this seal cavity 35. Air will flow in this direction because the static pressure downstream of the diffuser 15 is higher than at the exit of the compressor, upstream of the guide vane 14. These holes 36 can be cut at an angle in respect to an axis of rotation of said compressor rotor to impart a tangential velocity component in the direction of rotor rotation, similar to the manner in which a tangential velocity component is imparted by passages 34. Tangential injection reduces the amount of frictional drag between the injected air and the rotating compressor rotor 18. This reduces the amount of work done on the injected air… [col. 5, lines 55-68]”
It would have been obvious to one of ordinary skill in the art to make the supplemental airflow passage passing through the reference plane and defining an airflow outlet direction, the airflow outlet direction defining a swirl angle greater than 0 degrees and less than or equal to 85 degrees with the reference plane and each supplemental airflow passage of the plurality of supplemental airflow passages defines a swirl with a local reference plane, each local reference plane passing through a respective supplemental airflow passage of the plurality of supplemental airflow passages and extending in the axial and radial directions, the gas turbine engine defines a supplemental airflow temperature ratio (SATR) equal to TP / T3, where θSwirl is greater than or equal to 0 degrees and less than or equal to 85 degrees, as taught by Napoli et al, in order to utilize the standard swirl angle configurations utilized in the art. Alternately, the airflow outlet direction defining a swirl angle greater than 0 degrees and less than or equal to 85 degrees with the reference plane is also taught by the following. Smoke teaches where the airflow outlet direction 26, 46 defining a swirl angle / θSwirl is greater than 0 degrees and less than or equal to 85 degrees with the reference plane [i.e. the plane extending radially and axially through 26, 46, see Figs. 5, 6. Note that 85 degrees would be virtually parallel with the entrance of the TOBI 24 and the angle is clearly much less than 85 degrees.] Smoke also teaches teach θSwirl is greater than or equal to 0 degrees and less than or equal to 85 degrees. Lewis et al teach the airflow outlet direction C of 29’, 29” defining a swirl angle / θSwirl [e.g. α1, α2 in Figs. 3-4] greater than 0 degrees and less than or equal to 85 degrees with the reference plane [see ¶ 0047, which teaches 45⁰ to 80⁰] and θSwirl is greater than or equal to 0 degrees and less than or equal to 85 degrees [see ¶ 0047, which teaches 45⁰ to 80⁰]. Zheng et al teach the airflow outlet direction 114 defining a swirl angle / θSwirl greater than 0 degrees and less than or equal to 85 degrees with the reference plane [through the axial direction and radial direction – see Figs. 6-8], and θSwirl is greater than or equal to 0 degrees and less than or equal to 85 degrees. It would have been obvious to one of ordinary skill in the art to employ the claimed range of the swirl angle/ θSwirl greater than 0 degrees and being less than 85 degrees with the reference plane, as taught by either Smoke or Zheng et al, as the typical practice in the art for tangential air injection.
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Claim(s) 12-15 is/are rejected under 35 U.S.C. 103 as being unpatentable over any of the prior art, alone or in combination that apply Schwarz et al (20200011247) or Suciu et al (20130219917), Kervistin (5297386), as applied above, and further in view of Napoli et al (4554789) and optionally Smoke et al (2010/0275612) and Lewis et al (2012/0227414).. Suciu et al, Kervistin et al, and Schwarz et al teach the swirl angle greater than 0 degrees and less than or equal to 85 degrees [note a 90 degree swirl angle would be completely perpendicular to axial direction and as such would create a large pressure drop and inhibit flow through the swirler; accordingly, this upper range is so close to the absolute maximum value of swirl vane possible, that it practically covers the entire range of achievable swirl angles]. Alternately, it would have been obvious to employ a swirl angle greater than 0 degrees and less than or equal to 85 degrees, as this upper range is so close to the absolute maximum value of swirl vane possible, that it practically covers the entire range of achievable swirl angles. The prior art already teach that the supplemental passages direct swirling air or air with a tangential component into the rotor cavity but do not necessarily illustrate the swirl angle being less than 85 degrees. Napoli et al teach the stator case defining a supplemental airflow passage 36, the supplemental airflow passage 36 in fluid communication with the rotor cavity 35, the supplemental airflow passage 36 passing through the reference plane and defining an airflow outlet direction, the airflow outlet direction defining a swirl angle greater than 0 degrees and less than or equal to 85 degrees with the reference plane [see col. 5, lines 55-68; see also tangential swirl holes 34, to which Napoli et al teach are analogous]; wherein the plurality of supplemental airflow passages are configured to provide a supplemental airflow to the rotor cavity at a passage temperature, TP, in degrees Rankine during the operating condition of the gas turbine engine, wherein each supplemental airflow passage 36 of the plurality of supplemental airflow passages defines a swirl with a local reference plane, each local reference plane passing through a respective supplemental airflow passage of the plurality of supplemental airflow passages and extending in the axial and radial directions, the gas turbine engine defines a supplemental airflow temperature ratio (SATR) equal to TP / T3, where θSwirl is greater than or equal to 0 degrees and less than or equal to 85 degrees.
“As can be seen in FIG. 2, an annular series of inlet holes 36, one of which is shown, is provided to inject a small quantity of air into this seal cavity 35. Air will flow in this direction because the static pressure downstream of the diffuser 15 is higher than at the exit of the compressor, upstream of the guide vane 14. These holes 36 can be cut at an angle in respect to an axis of rotation of said compressor rotor to impart a tangential velocity component in the direction of rotor rotation, similar to the manner in which a tangential velocity component is imparted by passages 34. Tangential injection reduces the amount of frictional drag between the injected air and the rotating compressor rotor 18. This reduces the amount of work done on the injected air… [col. 5, lines 55-68]”
It would have been obvious to one of ordinary skill in the art to make the supplemental airflow passage passing through the reference plane and defining an airflow outlet direction, the airflow outlet direction defining a swirl angle greater than 0 degrees and less than or equal to 85 degrees with the reference plane and each supplemental airflow passage of the plurality of supplemental airflow passages defines a swirl with a local reference plane, each local reference plane passing through a respective supplemental airflow passage of the plurality of supplemental airflow passages and extending in the axial and radial directions, the gas turbine engine defines a supplemental airflow temperature ratio (SATR) equal to TP / T3, where θSwirl is greater than or equal to 0 degrees and less than or equal to 85 degrees, as taught by Napoli et al, in order to utilize the standard swirl angle configurations utilized in the art. Alternately, the airflow outlet direction defining a swirl angle greater than 0 degrees and less than or equal to 85 degrees with the reference plane is also taught by the following. Smoke teaches where the airflow outlet direction 26, 46 defining a swirl angle / θSwirl is greater than 0 degrees and less than or equal to 85 degrees with the reference plane [i.e. the plane extending radially and axially through 26, 46, see Figs. 5, 6. Note that 85 degrees would be virtually parallel with the entrance of the TOBI 24 and the angle is clearly much less than 85 degrees.] Smoke also teaches teach θSwirl is greater than or equal to 0 degrees and less than or equal to 85 degrees. Lewis et al teach the airflow outlet direction C of 29’, 29” defining a swirl angle / θSwirl [e.g. α1, α2 in Figs. 3-4] greater than 0 degrees and less than or equal to 85 degrees with the reference plane [see ¶ 0047, which teaches 45⁰ to 80⁰] and θSwirl is greater than or equal to 0 degrees and less than or equal to 85 degrees [see ¶ 0047, which teaches 45⁰ to 80⁰]. Zheng et al teach the airflow outlet direction 114 defining a swirl angle / θSwirl greater than 0 degrees and less than or equal to 85 degrees with the reference plane [through the axial direction and radial direction – see Figs. 6-8], and θSwirl is greater than or equal to 0 degrees and less than or equal to 85 degrees. It would have been obvious to one of ordinary skill in the art to employ the claimed range of the swirl angle/ θSwirl greater than 0 degrees and being less than 85 degrees with the reference plane, as taught by either Smoke or Zheng et al, as the typical practice in the art for tangential air injection.
Kervistin et al, Suciu et al and Schwarz et al teach (13), wherein the spool and stator case together define a rotor cavity opening, wherein the rotor cavity opening defines a cross-sectional area, AFO, wherein the plurality of supplemental airflow passages define a total cross-sectional area, ASAP_Total. Kervistin et al, Suciu et al and Schwarz et al do not teach wherein a ratio of AFO to ASAP_Total, is greater than or equal to 0.05 and less than 0.25. This range is considered an obvious matter of using the workable ranges in the art to size the flow area of supplemental passages to the rotor cavity area. It would have been obvious to one of ordinary skill in the art to employ the claimed ranges for of AFO to ASAP_Total, as an obvious matter of using the workable ranges in the art that would prevent the flow area of supplemental air passages from being excessively large compared to the rotor cavity area.
Kervistin et al, Suciu et al and Schwarz et al appear to teach (14) wherein SATR is greater than or equal to 0.8 and less than or equal to 1.15 [this range is inherently covered when the heat exchanger barely starts cooling]. As for this range of SATR, this corresponds to a relatively small temperature difference between T3 and Tp [e.g. via the heat exchanger] and is within the ordinary skill in the art of using a relatively small temperature difference, such that the heat exchanger is sized for relatively small temperature difference [e.g. just starting cooling in the heat exchanger]. It would have been obvious to one of ordinary skill in the art to employ the claimed ranges for SATR, as utilizing relatively small temperature difference between T3 and Tp is an obvious matter of using the workable ranges in the art.
As for (15) wherein a relationship between θSwirl and SATR is as follows: θSwirl≥199×SATR.2−186×SATR+7. – applicant does not define any ranges for either θSwirl or SATR, so a single point or e.g. multiple points is sufficient to meet this limitation [at an SATR of 0.9, θSwirl ≥0.079 OR SATR of 0.98, θSwirl ≥15.8]. As types of ranges are well within the typical experienced in the art, it would have been obvious to one of ordinary skill in the art to employ the claimed relationship θSwirl and SATR, e.g. at a single point or multiple points, as an obvious matter of using the workable ranges in the art.
Response to Arguments
Applicant's arguments filed 9/02/2025 have been fully considered but they are not persuasive. Applicant’s arguments center around the new limitation added by amendment.
Applicant’s arguments concerning Suciu and inherency of the swirl angle being less than 85 degrees is now treated as obviousness as an obvious matter of using the workable ranges in the art, since 90 degrees is the maximum swirl angle. Alternately, this swirl angle of less than 85 degrees is taught by either Smoke et al (2010/0275612) or Lewis et al (2012/0227414).
Applicant’s arguments concerning Kervistin and Napoli allege the principle of operation would be changed a
“Modifying Kervistin "to make the stator case and the spool together form a compressor discharge pressure seal and together define a rotor cavity opening," as alleged by the Office Action, would require a substantial reconstruction of Kervistin and clearly changes the principle of operation of Kervistin. For example, the modification would require coupling the compressor discharge seal 10 of Napoli to the alleged stator case of Kervistin, which would interfere with or require removal of the chamber 18 of Kervistin. For example, the annular series of inlet holes 36 would inject air into the seal cavity 35 (the alleged rotor cavity) or the alleged rotor cavity of Kervistin rather than the nozzles 19 mounted to the chamber 18. See Napoli, col. 5, lines 55-57; see also Napoli, Figure 2.”
In response to applicant's argument, the test for obviousness is not whether the features of a secondary reference may be bodily incorporated into the structure of the primary reference; nor is it that the claimed invention must be expressly suggested in any one or all of the references. Rather, the test is what the combined teachings of the references would have suggested to those of ordinary skill in the art. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981). There is nothing preventing the seal of Napoli being used with the existing chamber 18 of Kervistin since that is part of the stator case. As the basic principle of operation is using swirl air in both references, it is clear that principle of operation would be unchanged but merely the structure by which the swirl air is introduced and the seal / rotor cavity is formed.
Applicant’s arguments concerning Napoli are not persuasive as Napoli teaches the angle of 36 is similar to holes 34 and analogous ranges are within the ordinary skill in the art as an obvious matter of using the workable ranges in the art. Alternately, this swirl angle of less than 85 degrees is taught by either Smoke et al (2010/0275612) or Lewis et al (2012/0227414).
For Schwarz applicant argues the turbine vanes are not an airflow passage. Note 102 is in the stator case and vanes form airflow passages between the vanes.
Contact Information
Any inquiry concerning this communication or earlier communications from the Examiner should be directed to TED KIM whose telephone number is 571-272-4829. The Examiner can be reached on regular business hours before 5:00 pm, Monday to Thursday and every other Friday.
The fax number for the organization where this application is assigned is 571-273-8300.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Devon Kramer, can be reached at 571-272-7118. Alternate inquiries to Technology Center 3700 can be made via 571-272-3700.
Information regarding the status of an application may be obtained from Patent Center https://www.uspto.gov/patents/apply/patent-center. Should you have questions on Patent Center, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). General inquiries can also be directed to the Inventors Assistance Center whose telephone number is 800-786-9199. Furthermore, a variety of online resources are available at https://www.uspto.gov/patent
/Ted Kim/
Telephone
571-272-4829
Primary Examiner
Fax
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September 3, 2026
1 For the sake of conciseness, note claim 11 has beginning limitations that are analogous to those of claim 12. These analogous limitations will not be repeated – see rather the treatment of claim 12 for them.
Prosecution Insights