DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1, 7, and 26-27 is/are rejected under 35 U.S.C. 103 as being unpatentable over Bradley 11230941 in view of DiBenedetto 8439637, Ertas 9739170 (hereinafter Ertas170), and Mackin 20190323426.
Regarding claim 1, Bradley teaches a gas turbine engine (Fig 4), comprising:
a turbomachine (incl. 214a-b, 215, 216 217) having a compressor (214a, 214b), a combustor (215), and a turbine (216, 217) in serial flow order (Fig 4),
the turbomachine further comprising a low pressure shaft (at least the aft portion of 222 connected with turbine 217) configured to be driven by the turbine (Fig 4);
a gearbox (240), wherein the low pressure shaft is configured to drive the gearbox (Figs 4-5);
an intermediate shaft (forward shaft portion, between compressor 214a and gearbox 240, to which the rotor 234 of an electric machine 230 is attached; Figs 4-5 and see Fig 5 below) coupled to the low pressure shaft (Fig 5), wherein the intermediate shaft is configured to connect the low pressure shaft to the gearbox (e.g. via compressor 214a);
a motor (230) configured to drive the intermediate shaft (col.6 ll.34-47; Figs 4-5);
a fan shaft (b/w fan 213 and gearbox 240 in Fig 4), wherein the gearbox is configured to drive the fan shaft (Figs 4-5; col.6 ll.26-33);
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a compressor forward frame (shaded in Figs 4-5 above);
a first connection (comprising first and second bearing arrangements per col.2 ll.10-14; Fig 5) between:
the compressor forward frame; and
the motor (Fig 5);
and another connection (Fig 5 above) between:
the compressor forward frame; and
the gearbox (Fig 5);
wherein the first connection is flexible and includes a spring and a damper (first connection between motor and compressor forward frame may be formed by a first bearing arrangement and a second bearing arrangement per col.2 ll.10-14, each with respective dampers that may comprise an elastomeric material, which is elastic by definition and therefor qualifies as a spring, col.7 ll.19-23; thus one of the first and second bearing arrangements is interpreted as the spring and the other is interpreted as the damper),
wherein the spring and the damper of the first connection are each directly coupled to both the compressor forward frame and the motor (col.2 ll.10-14; motor stator directly mounted to the respective movable element of each bearing arrangement, and all the static supporting structures supporting the first and second bearing arrangements interpreted as the compressor forward frame; Fig 5),
Bradley does not teach a clutch; the intermediate shaft selectively coupled to the low pressure shaft via the clutch; a second connection between: the compressor forward frame; and a fan shaft support (such that the other connection in Bradley is the third connection); the second and third connections each being flexible and each including both a spring and a damper; and wherein the spring and the damper of the second connection are each directly coupled to both the compressor forward frame and the fan shaft support.
However, DiBenedetto teaches a gas turbine engine (Fig 1), comprising:
a turbomachine (10) having a compressor (incl.32), a combustor (required for gas turbine), and a turbine (required for gas turbine; col.2 ll.45-46),
the turbomachine further comprising a low pressure shaft (28) configured to be driven by the turbine (col.2 ll.45-46);
a gearbox (30), wherein the low pressure shaft is configured to drive the gearbox (Fig 1);
a fan shaft (16), wherein the gearbox is configured to drive the fan shaft (Fig 1);
a compressor forward frame (incl.36, 18; Figs 1-2);
a connection (incl. 46, 20) between:
the compressor forward frame; and
a fan shaft support (incl. bearing 14A);
wherein the connection is flexible and include a spring and a damper (connection includes squeeze film damper 46 and bellows spring 20, which is flexible by definition),
wherein the spring and the damper of the connection are each directly coupled to both the compressor forward frame and the fan shaft support (46 and 20 are each directly connected between bearing 14A and 18).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the engine of Bradley to include the fan shaft support and connection of DiBenedetto, in order to provide flexible support to the fan shaft to accommodate variation due to component tolerances and provide for proper operation and motion of dampers without causing excessive bearing wear (DiBenedetto, col.1 ll.15-32, col.1 l.58 – col.2 l.4).
Bradley in view of DiBenedetto still does not teach a clutch; the intermediate shaft selectively coupled to the low pressure shaft via the clutch; the third connection (between gearbox and compressor forward frame) being flexible and including both a spring and a damper.
However, Ertas170 teaches a gas turbine engine (Fig 7), comprising:
a turbomachine (2) having a compressor (12, 14), a combustor (16), and a turbine (18, 20) in serial flow order (Fig 1), the turbomachine further comprising a low pressure shaft (24) configured to be driven by the turbine (Fig 1);
a gearbox (4), wherein the low pressure shaft is configured to drive the gearbox (Figs 7-8);
a fan shaft (38), wherein the gearbox is configured to drive the fan shaft (Figs 7-8);
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a compressor forward frame (Fig 7 above); and
a connection (incl. 60, 61, 62, and structures in Figs 3 and/or 9) between:
the compressor forward frame; and
the gearbox;
wherein the connection includes both a spring and a damper (Figs 5-6 and 10 teach integration of dampers lands and spring/flex elements in 60 to provide desired stiffness/flexion and damping in multiple modes/directions, e.g. torsional, axial radial, etc.; col.3 l.22 - col.4 l.41).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the third connection (to gearbox) of Bradley in view of DiBenedetto to include both springs and dampers as taught by Ertas170, in order to provide the desired stiffness/flexion and damping in multiple modes/directions, e.g. torsional, axial radial, etc. (Ertas170; col.3 l.22 - col.4 l.41).
Bradley in view of DiBenedetto and Ertas170 still does not teach a clutch; and the intermediate shaft selectively coupled to the low pressure shaft via the clutch.
However, Mackin teaches a gas turbine engine (Fig 5), comprising:
a turbomachine (500) having a compressor (516, 520), a combustor (526), and a turbine (522, 518) in serial flow order (Fig 5), the turbomachine further comprising a low pressure shaft (508) configured to be driven by the turbine (Fig 5);
a gearbox (530), wherein the low pressure shaft is configured to drive the gearbox (Fig 5);
a clutch (512);
an intermediate shaft (510) selectively coupled to the low pressure shaft via the clutch (Fig 5), wherein the intermediate shaft is configured to connect the low pressure shaft to the gearbox (Fig 5)
a motor (506) configured to drive the intermediate shaft and the gearbox (Fig 5);
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a propulsor shaft (Fig 5 above), wherein the gearbox is configured to drive the propulsor shaft (Fig 5).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Bradley in view of DiBenedetto and Ertas170 to use the shaft and clutch arrangement taught by Mackin, in order to provide operational flexibility by enabling the propulsor/fan to be driven by either the turbomachine, the motor, or both, during different modes of operation (Mackin, [0037, 40-47, 65]).
Note, Applicant has expressed concern that perhaps Bradley’s intermediate shaft is not an intermediate shaft between the low pressure shaft and the gearbox, but rather some other shaft coupled to the low pressure compressor for starting. Mackin also remedies Applicant’s concern by teaching the modification of placing the electric machine on a section of the low pressure shaft (which would be called the intermediate shaft; 510 in Mackin) between the low pressure shaft and the gearbox in order to provide operational flexibility (option to drive the propulsor with the electric machine only, the engine only, or both) without hindering the electric machine’s ability to start the engine (taught by Bradley).
Regarding claim 7, Bradley in view of DiBenedetto, Ertas170, and Mackin teaches all the limitations of the claimed invention as discussed above. Bradley further teaches the motor is connected to the gearbox (via the compressor forward frame and the low pressure shaft; Fig 3).
Regarding claim 26, Bradley in view of DiBenedetto, Ertas170, and Mackin teaches all the limitations of the claimed invention as discussed above. Bradley further teaches a fan frame assembly (incl. OGVs, nacelle, fan case 219, and compressor forward frame shaded in Figs 4-5 below) including the compressor forward frame (Fig 5),
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a fan case (219) spaced radially outward from and circumscribing the compressor forward frame (Figs 4-5), and
a plurality of outlet guide vanes (OGVs in Fig 4 above) supported between the compressor forward frame and the fan case (Figs 4-5),
wherein the compressor forward frame forms at least a portion of the turbomachine (compressor forward frame can be considered part of the turbomachine comprising the low pressure shaft, compressor, combustor and turbine) and the fan case is coupled to an outer nacelle (in Fig 4 above) at least partially surrounding the turbomachine (Figs 4-5).
Regarding claim 27, Bradley in view of DiBenedetto, Ertas170, and Mackin teaches all the limitations of the claimed invention as discussed above. Bradley further teaches a fan section (incl. 213 and first stage of 214a) including a fan (213) and a low pressure booster (first, upstream-most stage of 214a; the compressor claimed as part of the turbomachine in claim 1, then being the downstream stages of 214a),
wherein the low pressure booster is between the fan and the turbomachine (Fig 4), and
wherein the fan shaft is coupled to the fan and the low pressure booster (fan shaft directly coupled to fan in Fig 4 and coupled to booster via the gearbox and intermediate shaft in Fig 4).
Claims 10-15 is/are rejected under 35 U.S.C. 103 as being unpatentable over Bradley in view of DiBenedetto, Ertas170, and Mackin, and further in view of Menheere 10717539.
Regarding claim 10, Bradley in view of DiBenedetto, Ertas170, and Mackin teaches all the limitations of the claimed invention as discussed above. Bradley in view of DiBenedetto, Ertas170, and Mackin does not teach the motor is selectively coupled to the intermediate shaft.
However, Menheere teaches a gas turbine engine (Fig 1), comprising:
a turbomachine (10) having a compressor (26), a combustor (32), and a turbine (20, 24) in serial flow order (Fig 1), the turbomachine further comprising a low pressure shaft (22) configured to be driven by the turbine (Fig 1);
a gearbox (14), wherein the low pressure shaft is configured to drive the gearbox (Figs 1, 3);
a motor (38) configured to drive the gearbox (Figs 1, 3);
a propulsor shaft (18), wherein the gearbox is configured to drive the propulsor shaft (Figs 1, 3);
a clutch (58); and
an intermediate shaft (16), wherein the intermediate shaft is configured to connect the low pressure shaft to the gearbox (via 54, 58), wherein the low pressure shaft is connected to the intermediate shaft by the clutch (Fig 3); and
wherein the motor is selectively coupled to the intermediate shaft (col.7 ll.20-27).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the motor/intermediate-shaft arrangement of Bradley in view of DiBenedetto, Ertas170, and Mackin to use the motor/clutch/intermediate-shaft arrangement of Menheere with selective coupling, in order to provide operational flexibility (Menheere, col.6 l.48 - col.7 l.27; providing the option to disengage the motor during various modes of operation when the motor is not providing power to the drive the propulsor) and because Menheere teaches selective coupling of the motor to the intermediate shaft as a substitutional equivalent to permanent coupling of the motor to the intermediate shaft (Menheere, col.7 ll.20-27).
Regarding claim 11, Bradley in view of DiBenedetto, Ertas170, Mackin, and Menheere teaches all the limitations of the claimed invention as discussed above. Bradley in view of DiBenedetto, Ertas170, Mackin, and Menheere, as discussed so far, does not teach a controller configured to control the motor and the clutch.
However, Mackin further teaches a controller (208; [0068]) configured to control the motor ([0037, 42, 68, 73]) and the clutch (controller controls the operation of the clutch by controlling the relative speeds of the low pressure shaft and the intermediate shaft; [0043-45, 68-69, 77, 81]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Bradley in view of DiBenedetto, Ertas170, Mackin, and Menheere, to include the clutch arrangement as taught by Mackin, in order to provide operational flexibility by enabling the propulsor/fan to be driven by either the turbomachine, the motor, or both during different modes of operation (Mackin, [0037, 40-47, 65]).
Regarding claim 12, Bradley in view of DiBenedetto, Ertas170, Mackin, and Menheere, teaches all the limitations of the claimed invention as discussed above. Bradley in view of DiBenedetto, Ertas170, Mackin, and Menheere, as discussed so far, does not teach the controller is configured to, based on a speed of the low pressure shaft: disconnect the low pressure shaft from the intermediate shaft; and drive the intermediate shaft with the motor.
However, Mackin further teaches the controller is configured to, based on a speed of the low pressure shaft: disconnect the low pressure shaft from the intermediate shaft; and drive the intermediate shaft with the motor ([0043-45]; controller 208 controls operation of the engine and the motor such that when the speed of the motor exceeds the speed of the LP shaft, the clutch disengages the LP shaft from the intermediate shaft, and drives the intermediate shaft with the second motor, a.k.a. the “second mode of operation’).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Bradley in view of DiBenedetto, Ertas170, Mackin, and Menheere, to include the clutch arrangement as taught by Mackin, in order to provide operational flexibility by enabling the propulsor/fan to be driven by either the turbomachine, the motor, or both during different modes of operation (Mackin, [0037, 40-47, 65]).
Regarding claim 13, Bradley in view of DiBenedetto, Ertas170, Mackin, and Menheere, teaches all the limitations of the claimed invention as discussed above. Bradley in view of DiBenedetto, Ertas170, Mackin, and Menheere, as discussed so far, does not teach the speed is compared to a calculated threshold speed for the low pressure shaft.
However, Mackin further teaches the speed is compared to a calculated threshold speed for the low pressure shaft (the calculated threshold speed being the speed of the motor; [0043-45]; note any speed may be “a calculated speed” because anyone can perform any mathematical calculation on any speed; furthermore, calculations are required to obtain speed data from sensors [0049]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Bradley in view of DiBenedetto, Ertas170, Mackin, and Menheere, to include the clutch arrangement as taught by Mackin, in order to provide operational flexibility by enabling the propulsor/fan to be driven by either the turbomachine, the motor, or both during different modes of operation (Mackin, [0037, 40-47, 65]).
Regarding claim 14, Bradley in view of DiBenedetto, Ertas170, Mackin, and Menheere, teaches all the limitations of the claimed invention as discussed above. Bradley in view of DiBenedetto, Ertas170, Mackin, and Menheere, as discussed so far, does not teach the calculated threshold speed is determined based on a desired torque for the fan shaft.
However, Mackin further teaches the calculated threshold speed is determined based on a desired torque for the fan shaft ([0029] teaches the speed of the LP shaft is determined in order to match the speed of the motor to the speed of the LP shaft, and provide the desired torque to the fan shaft).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Bradley in view of DiBenedetto, Ertas170, and Mackin, to include the clutch arrangement as taught by Mackin, in order to provide operational flexibility by enabling the propulsor/fan to be driven by either the turbomachine, the motor, or both during different modes of operation (Mackin, [0037, 40-47, 65]).
Regarding claim 15, Bradley in view of DiBenedetto, Ertas170, Mackin, and Menheere, teaches all the limitations of the claimed invention as discussed above. Bradley in view of DiBenedetto, Ertas170, Mackin, and Menheere, as discussed so far, does not teach the intermediate shaft is driven by the motor to achieve the desired torque for the fan shaft.
However, Mackin further teaches the intermediate shaft is driven by the motor to achieve the desired torque for the propulsor shaft ([0029, 47]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Bradley in view of DiBenedetto, Ertas170, Mackin, and Menheere, to include the clutch arrangement as taught by Mackin, in order to provide operational flexibility by enabling the propulsor/fan to be driven by either the turbomachine, the motor, or both during different modes of operation (Mackin, [0037, 40-47, 65]).
Claims 9, 21, and 25 is/are rejected under 35 U.S.C. 103 as being unpatentable over Bradley in view of DiBenedetto, and Ertas170, and further in view of Lefebvre 11384693 and Menheere.
Regarding claim 9, Bradley in view of DiBenedetto, and Ertas170, teaches all the limitations of the claimed invention as discussed above. Bradley in view of DiBenedetto, and Ertas170, does not teach a generator selectively coupled to the intermediate shaft, wherein the generator is connected to the compressor forward frame.
However, Lefebvre further teaches providing both a motor (60, 60’) driving a propulsor (16), and a generator (670, 70’; Figs 1-7) coupled to the same shaft (24), wherein the motor and generator may be placed axially adjacent in the same core engine compartment (Fig 6).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the engine with single motor/generator electrical machine connected to the compressor forward frame and coupled to the intermediate shaft of Bradley in view of DiBenedetto, Ertas170, and Mackin to include both a motor and a generator connected to the compressor forward frame and coupled to the intermediate shaft, because Lefebvre teaches the addition of a generator adjacent to the motor driving the propulsor shaft such that the generator is in the same core engine compartment and coupled to the same shaft as the motor, in order to provide electrical energy to the motor and/or to an external batter/power source with optimized hybrid functionality (62, 62A; Fig 6; col.7 ll.33-63)
Bradley in view of DiBenedetto, Ertas170, Mackin, and Lefebvre still does not teach the generator “selectively” coupled to the intermediate shaft.
However, Menheere teaches a gas turbine engine (Fig 1), comprising:
a turbomachine (10) having a compressor (26), a combustor (32), and a turbine (20, 24) in serial flow order (Fig 1), the turbomachine further comprising a low pressure shaft (22) configured to be driven by the turbine (Fig 1);
a gearbox (14), wherein the low pressure shaft is configured to drive the gearbox (Figs 1, 3);
an electrical machine (38) configured to drive the gearbox (Figs 1, 3);
a propulsor shaft (18), wherein the gearbox is configured to drive the propulsor shaft (Figs 1, 3);
a clutch (58); and
an intermediate shaft (16), wherein the intermediate shaft is configured to connect the low pressure shaft to the gearbox (via 54, 58), wherein the low pressure shaft is connected to the intermediate shaft by the clutch (Fig 3); and
wherein the electrical machine is selectively coupled to the intermediate shaft (col.7 ll.20-27).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the electrical-machines/clutch/intermediate-shaft arrangement of Bradley in view of DiBenedetto, Ertas170, Mackin, and Lefebvre to use the electrical-machine/clutch/intermediate-shaft arrangement of Menheere with selective coupling, in order to provide operational flexibility (Menheere, col.6 l.48 - col.7 l.27; providing the option to disengage the motor during various modes of operation when the electrical machine is not providing electrical or mechanical power) and because Menheere teaches selective coupling of the electrical machine to the intermediate shaft as a substitutional equivalent to permanent coupling of the electrical machine to the intermediate shaft (Menheere, col.7 ll.20-27).
Regarding claim 21, Bradley in view of DiBenedetto, Ertas170, Lefebvre, and Menheere teaches all the limitations of the claimed invention as discussed above. Bradley in view of DiBenedetto, Ertas170, Lefebvre, and Menheere as discussed so far also teaches an energy storage device, wherein the energy storage device is configured to store electrical energy generated by the generator.
That is, as discussed above, Lefebvre further teaches an energy storage device (62, 62A), wherein the energy storage device is configured to store electrical energy generated by the generator (col.7 ll.33-63).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Bradley in view of DiBenedetto, Ertas170, Lefebvre, and Menheere to use the motor/generator/battery arrangement of Lefebvre, in order to provide optimized hybrid functionality (Lefebvre, col.7 ll.33-63)
Regarding claim 25, Bradley in view of DiBenedetto, Ertas170, Lefebvre, and Menheere teaches all the limitations of the claimed invention as discussed above. Bradley further teaches the motor is coaxial with the fan shaft, the intermediate shaft, and the low pressure shaft (Figs 4-5).
Bradley in view of DiBenedetto, Ertas170, Lefebvre, and Menheere as discussed so far also teaches the generator is coaxial with the fan shaft, the intermediate shaft, and the low pressure shaft.
That is, Lefebvre teaches providing both a motor (60, 60’) driving a propulsor (16), and a generator (670, 70’; Figs 1-7) coupled to, and coaxial with, the same shaft (24), wherein the motor and generator may be placed axially adjacent in the same core engine compartment (Fig 6).
And it was obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the engine with single motor/generator electrical machine connected to the compressor forward frame and coupled to the intermediate shaft of Bradley in view of DiBenedetto, and Ertas170, to include both a motor and a generator connected to the compressor forward frame and coupled to the intermediate shaft, because Lefebvre teaches the addition of a generator adjacent to the motor driving the propulsor shaft such that the generator is in the same core engine compartment and coupled to the same shaft as the motor, in order to provide electrical energy to the motor and/or to an external batter/power source with optimized hybrid functionality (62, 62A; Fig 6; col.7 ll.33-63)
Response to Arguments
Applicant’s arguments filed 19 August 2025 have been considered and addressed in the current rejection above at the relevant locations.
In summary:
Applicant argues that Bradley teaches various things (incl. fan 213 driven by turbine 217 via low pressure shaft 222 and gearbox 240; turbine 217 also driving 214a; 217, 222, 214a, 240, and 213 together forming a low pressure spool; turbine 217 drive shaft 222, which is coupled to the sun gear 252 of gearbox 240), but that none of these teachings include the alleged intermediate shaft being configured to couple the low pressure shaft 222 to the gearbox 240.
However, one of ordinary skill in the art would have understood, from the full disclosure of Bradley, that the turbine 217 drives 222, which drives 214a, which drives the gearbox 240 via an unlabeled intermediate shaft on which the electric machine 230 (the rotor 234 thereof) is mounted. That is, the low pressure shaft 222 may be a multi-piece shaft to which the compressor 214a, turbine 217, gearbox 240, and electric machine 230 are mounted. The piece of the shaft between the compressor and the gearbox, and on which the electric machine 230 is mounted, reads on the claimed intermediate shaft. The rest of the shaft between the compressor 214a and 217 reads on the claimed low pressure shaft.
This interpretation is supported by Figs 4-5 and various portions of Bradley’s written description. For example, Fig 4 schematically shows corresponding electric machine parts, coupled to a portion of the low pressure spool that drives the gearbox and extends forward from the compressor 214a. Figure 5 further shows bearings including 236a, which is described as a bearing arrangement “which mounts components of the low pressure spool” (col.6 ll.48-50). Column 3, ll.3-6 also teach the “the electric machine rotor may be mounted to one of the rotating components of the gearbox”. Figure 5 also shows a connecting line between the gearbox sun gear 252 and the intermediate shaft, The connecting line also touches the forward, unlabeled bearing in Fig 5. The purpose of such a depicted bearing is to support a rotating shaft relative to a static structure. Thus, the only way to interpret the connecting line in Fig 5 is as a rotating shaft structure. Otherwise, the forward bearing is not supporting anything relative to the static structure. Note, that this interpretation of the Drawings, does not contradict any of Bradley’s teachings that Applicant cited in the Remarks:
"[t]he fan 213 is attached to and driven by the low pressure turbine 217 via a low pressure shaft 222 and reduction gearbox 240." Bradley, col. 6, lines 15-17
This does not
"[t]he low pressure turbine also drives the low pressure compressor 214a," and "the low pressure turbine 217, shaft 222, compressor 214a, gearbox 240 and fan 213 together form a low pressure spool." Bradley, col. 6, lines 17-25.
"the low pressure turbine 217 drives the low pressure shaft 222, which is coupled to a sun gear 252 of the gearbox 240." Bradley, col. 6, lines 26-28.
"electric machine arrangement…is configured to produce electrical power, and/or provide motive power to start the engine." Bradley, col. 6, lines 35-37
That is, none of the above citations contradict the electric machine being further mounted to the low pressure shaft between the compressor and the gearbox, and none of the above citations require the low pressure shaft to be a single unitary piece.
Applicant also cites to further portions of Bradley that relate to a different embodiment (Figs 1-3) of Bradley. It is important to note there are structural differences between the two embodiments relevant to the area in question. Namely, the electric machine of Figs 1-3 is mounted to an axial end of the high pressure shaft. The high pressure spool comprising only the shaft, compressor, and turbine (and no further elements such as a gearbox and fan). However, the structural similarities between the two embodiments may lead some discussion of the first embodiment to be relevant to the discussion of the second embodiment. These issues are discussed below.
Applicant cites to the following portions of Bradley:
“The machine 30 is in the form of a permanent magnet, radial flux electric machine. The rotor 34 comprises a plurality of permanent magnets 35, which are attached to a radially outer surface of the rotor 34. The rotor 34 is mounted to an electric machine rotor drive shaft 40, which is configured to rotate with the rotor 34 in use”. Bradley, col. 4, lines 40-46
This citation is not relevant to the embodiment of Figs 4-5. As noted above, Figs 1-3 of Bradley differ from Figs 4-5 in that the electric machine is cantilevered off the end of the high pressure shaft/spool, with a single bearing supporting the shaft 40. Note that there is no second bearing or connecting line extending forward from the electric machine 30 in Figs 1-3; whereas these components are present in Fig 5 as discussed above.
"[t]t least one compressor disc 48 is in turn coupled to the [shaft] 40 via a compressor drive arm 49." Bradley, col. 5, lines 1-3.
This citation does identify the component that Bradley calls a “compressor drive arm” which is depicted (but not labeled) in Fig 5. However, this citation does not contradict the interpretation of Bradley that is relied upon in the rejection(s) above and discussed in the preceding paragraphs. Note, e.g. that the drive arms are further described in col.2 ll.27-34: “The spool may further comprise one or more compressor or turbine drive arms, and may comprise one or more compressor or turbine discs. The drive arms may be configured to couple one or more discs to the shaft. The electric machine rotor may be coupled to one of a drive arm and a disc, and may be coupled via an electric machine rotor shaft.” Thus, the presence of a drive arm in Figs 3 and 5 does not require that the electric machine of Fig 5 is not coupled to the low pressure shaft 222, because the drive arm may also be coupling the compressor the shaft.
Unfortunately the drawings of Bradley are schematic and it is reasonable for Applicant to raise concerns based on Applicant’s interpretation of Bradley. However, assuming arguendo that Applicant is correct in their interpretation, secondary reference Mackin still teaches obvious modification of the shaft arrangement of Bradley (in view of DiBenedetto and Ertas170) that teaches the claimed shaft-clutch-electric-machine-gearbox arrangement for enhanced operational flexibility.
Regarding this combination of Bradley (in view of DiBenedetto and Ertas170, and further) in view of Mackin, Applicant argues that based on Applicant’s interpretation of Bradley, modification with Mackin would “require substantial reconstruction of Bradley and clearly changes the principle of operation of Bradley…[because] the modification would require coupling the shaft 40 of the starter generator 230 of Bradley to the low pressure shaft 222 and the gearbox 240 such that the overrunning clutch 512 of Mackin could couple the shaft 40 to the low pressure shaft 222 and such that the shaft 40 would couple the low pressure shaft 222 to the gearbox 240, which results in a substantial reconstruction of Bradley and destroys the principle of operation of Bradley. Applicant cites to MPEP2143.01(VI).
However, by making this argument, Applicant demonstrates it would be clear to one of ordinary skill in the art, at least one way of making the modification of Bradley using Mackin. Additionally, the rejection above does not rely on Applicant’s proposed modification. Rather, (assuming arguendo Bradley teaches what Applicant interprets, which the Office does not concede) the proposed rejection would merely shift the electric machine (230 of Bradley) onto the low pressure shaft section (of 222) between the gearbox (252, 240) and the compressor (214a) and add a clutch (512 from Mackin) between the electric machine and the compressor of Bradley (which converts the low pressure shaft section between the clutch and the gearbox, where the electric machine is mounted, into the intermediate shaft). This modification maintains the electric machine in its same axial position per Bradley, eliminates any extra electric-machine-specific shaft, while maintaining the operational capacity for starting as taught by Bradley, and increasing operational flexibility as taught by Mackin (to drive the propulsor/fan by the electric machine only, the turbomachine only, or both).
Thus, the rejection under 35 U.S.C. 103:
is obvious before the effective filing date of the claimed invention because prior art Mackin teaches the final/resulting electric-machine/shaft/clutch arrangement and significant advantages for using such arrangement;
does not change the principle of operation of Bradley because it preserves all the operational requirements of the electric machine and turbomachine as taught by Bradley (i.e. uses all the same parts for the same purposes; e.g. electric machine operates as starter generator drivingly coupled with low pressure spool, compressor drive arm couples compressor disc to the low pressure shaft, bearings provide support between low pressure spool and static structure), and it does not contradict anything Bradley requires for operation; and
does not require substantial reconstruction beyond that which would have been obvious to one of ordinary skill in the art, because all the required structures and methods of implementation are taught in Bradley and Mackin, the modification does not contradict any operational teachings (regarding the relevant embodiment in Figs 4-5) of Bradley, the modification uses all the relevant structures of Bradley (and Mackin) for the same purpose(s) taught by Bradley (and Mackin), and the modification would have been immediately apparent to one of ordinary skill in the art before the effective filing date of the claimed invention.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Correspondence
Any inquiry concerning this communication or earlier communications from the examiner should be directed to STEPHANIE SEBASCO CHENG whose telephone number is (469)295-9153. The examiner can normally be reached on 1000-1600 ET.
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/STEPHANIE SEBASCO CHENG/Primary Examiner, Art Unit 3741
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