Office Action 2: Final Rejection (2025-05-05)
Rejection types: 102 - Lack of Novelty, 103 - Obviousness

CLAIMS:
Office Action mailed December 26, 2024 Amendments to the Claims:

This listing of claims will replace all prior versions, and listings, of claims in the application:

1\. (currently amended) A hybrid electric gas turbine engine two speed transmission for a low spool drive comprising:an accessory gearbox in operative communication with a low speed spool motor-generator;a transmission in operative communication with the accessory gearbox and the low speed spool motor-generato SVG {EMBED HERE} 0.1130.183 wherein the transmission comprises a two speed transmission configured for hybrid electric low spool drive applications;
a low speed spool angled gearbox in operative communication with the transmission; and
a low speed spool in operative communication with the low speed spool angled gearbox.

2\. (original) The hybrid electric gas turbine engine two speed transmission for a low spool drive according to claim 1, wherein the accessory gearbox is in operative communication with an oil pump and a fuel pump.

3\. (original) The hybrid electric gas turbine engine two speed transmission for a low spool drive according to claim 1, wherein the accessory gearbox is in operative communication with a first high speed spool motor-generator and a second high speed spool motor-generator.

4\. (original) The hybrid electric gas turbine engine two speed transmission for a low spool drive according to claim 1, wherein the accessory gearbox is in operative communication with a high speed spool via a high speed spool angled gearbox.

5\. (original) The hybrid electric gas turbine engine two speed transmission for a low spool drive according to claim 1, wherein the transmission and low speed spool angled gearbox are integrally formed sharing a common housing.

6\. (cancelled).

7\. (original) The hybrid electric gas turbine engine two speed transmission for a low spool drive according to claim 1, wherein the transmission is bolted to the accessory gearbox configured as a line removeable unit.

8\. (currently amended) A hybrid electric gas turbine engine two speed transmission for a low spool drive comprising:an engine structure proximate a compressor of the gas turbine engine;
a low speed spool towershaft coupled to the engine structure;
a low speed spool angled gearbox in operative communication with the towershaft and in operative communication with a low speed spool of the gas turbine engine;
a transmission in operative communication with the low speed spool angled gearbox, wherein the transmission

comprises a two speed transmission configured for hybrid electric low spool drive applications;an accessory gearbox in operative communication with the transmission; and
a low speed spool motor-generator in operative communication with the accessory gearbox.

9\. (original) The hybrid electric gas turbine engine two speed transmission for a low spool drive according to claim 8, wherein the transmission is bolted to the accessory gearbox configured as a line removeable unit.

10\. (original) The hybrid electric gas turbine engine two speed transmission for a low spool drive according to claim 8, wherein the transmission and low speed spool angled gearbox are integrally formed sharing a common housing.

11\. (cancelled).

12\. (original) The hybrid electric gas turbine engine two speed transmission for a low spool drive according to claim 8, wherein the accessory gearbox is in operative communication with a first high speed spool motor-generator and a second high speed spool motor-generator.

13\. (original) The hybrid electric gas turbine engine two speed transmission for a low spool drive according to claim 8, wherein the accessory gearbox is in operative communication with a high speed spool via a high speed spool angled gearbox.

Office Action mailed December 26, 2024 14. (currently amended) A process for a hybrid electric gas turbine engine two speed transmission for a low spool drive comprising:providing an engine structure proximate a compressor of the gas turbine engine;
coupling a low speed spool towershaft to the engine structure;
coupling a low speed spool angled gearbox in operative communication with the towershaft;
coupling the low speed spool angled gearbox in operative communication with a low speed spool of the gas turbine engine;
coupling a transmission in operative communication with the low speed spool angled gearbox, configuring the transmission as a two speed transmission configured for hybrid electric low spool drive applications;
coupling an accessory gearbox in operative communication with the transmission; and
coupling a low speed spool motor-generator in operative communication with the accessory gearbox.

15\. (original) The process of claim 14, further comprising:integrally forming the transmission and low speed spool angled gearbox sharing a common housing.

16\. (cancelled).

17\. (original) The process of claim 16, further comprising:configuring the two-speed transmission for two operational modes.

18\. (original) The process of claim 14, wherein the two operational modes comprise:a first operational MODE 1 configured as a direct drive to the low spool motor-generator for high speed operation of the low speed spool; and
a second operational MODE 2 configured to provide up to a 3X increase in motor shaft speed wherein the transmission includes a gear ratio of 3.0 which increases motor speed for low speed spool operation selected from the group comprising a ground idle speed and a flight idle speed.

19\. (original) The process of claim 14, further comprising:configuring the transmission for a low spool drive power extraction wherein the low spool drive power extraction is arranged for A/C loads and battery recharge.

20\. (original) The process of claim 14, further comprising:configuring the transmission for a low spool drive power injection on ground.

OFFICE ACTION:
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 .
Response to Arguments
Applicant's arguments filed March 26th, 2025 have been fully considered but they are not persuasive.
Applicant argues Foutch fails to teach or disclose the transmission comprises a two speed transmission configured for hybrid electric low spool drive applications. This argument is not persuasive. Foutch describes multiple modes of operation through the transmission: “This, in this another example operation, based on the second clutch 174 being closed, the first clutch 150 overruns the high-speed spool drive shaft 146 to enable the low-speed spool 122 to provide mechanical power to the aircraft accessory 142a-b”, “In other instances, based on (the need or desire for) the high-speed spool 120 providing mechanical power to the aircraft accessory 142a-b, the second clutch 174 is opened (e.g., the second clutch 174 is programmatically opened or triggered to be opened when the high-speed spool 120 provides mechanical power to the aircraft accessory 142a-b)”, and “In this example, the second clutch 174 is closed and the power transfer unit 173 is controlled to cause a sufficiently high output speed to the accessory gearbox 148 to overrun the first clutch 150 (e.g., i.e., causing the second shaft 166 to rotate faster than the first shaft 164), and the low-speed spool 122 provides power to the aircraft accessories 142a-b and 178.”
As shown above in the cited examples, by virtue of how the transmission operates, there are multiple speeds accomplished and thus can be interpreted as a “two speed transmission”. The limitations with respect to the transmission do not discuss any specifics of the operation, and details inside the transmission that limits how “two speed transmission” need be interpreted.
Additionally, it is known to one of ordinary skill in the art to connect a tower shaft to an accessory gearbox through multi-speed transmissions as seen in Muldoon (US 10563591) with the low speed tower shaft (94) and the multi-speed transmission (104) connected to the accessory gearbox (70): “A second end of low lay shaft 96 may be connected to a variable speed transmission 104 of accessory gearbox 70.”
To differentiate Applicant’s invention from the disclosed prior art, further limitations for how this transmission operates should be included to overcome the art.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claims 1-2, 4, 8, 13-14, 17, and 20 are rejected under 35 U.S.C. 102(a)(1) or 35 U.S.C. 102(a)(2) as being anticipated by Foutch (US 11591967).
Regarding claims 1, 8, 14, and 17, Foutch discloses a hybrid electric gas turbine engine two speed transmission for a low spool drive and a process thereof comprising: an accessory gearbox (148) in operative communication with a low speed spool motor-generator (178; “could have two modes: as an electrical generator as well as an electrical motor”); a transmission (174) in operative communication with the accessory gearbox and the low speed spool motor-generator; a low speed spool angled gearbox in operative communication with the transmission (see figures, tower shafts extend from main shafts and are at ~90 degree angles to the shafts connected to the transmission and accessory gearbox); and a low speed spool (122) in operative communication with the low speed spool angled gearbox. Foutch further discloses an engine structure proximate a compressor (114, 124) of a gas turbine engine, a low speed spool towershaft (144) coupled to the engine structure (Figures 2-3). Foutch further discloses the transmission as a two speed transmission configured for hybrid electric low spool drive applications, including configuring the two-speed transmission for two operational modes (see Tables 1-2 which document multiple modes of the clutch position and different modes of operation thereof).
Regarding claim 2, Foutch discloses the hybrid electric gas turbine engine two speed transmission according to claim 1 above. Foutch further discloses the accessory gearbox is in operative communication with an oil and fuel pump (accessories 142a-c and 154; “The engine accessories 154 include a starter, fuel pump, lubricator pump, and other similar components”).
Regarding claims 4 and 13, Foutch discloses the hybrid electric gas turbine engine two speed transmission according to claims 1 and 8 above. Foutch further discloses the accessory gearbox is in operative communication with a high speed spool (120) via a high speed spool angled gearbox (see Figures, tower shafts extend from main shafts and are at ~90 degree angles to the shafts connected to the accessory gearbox).
Regarding claim 20, Foutch discloses the process according to claim 14 above. Foutch further discloses configuring the transmission for a low spool drive power injection on ground (see Tables 1-2, operation on ground).
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 3 and 12 are rejected under 35 U.S.C. 103 as being unpatentable over Foutch (US 11591967) in view of Applicant’s Admitted Prior Art, hereinafter referenced as AAPA.
Foutch discloses the hybrid electric gas turbine engine two speed transmission for a low spool drive according to claims 1 and 8 above.
Foutch fails to teach the accessory gearbox is in operative communication with a first and second high speed spool motor-generator.
Foutch further discloses an assortment of other accessories that are connected to the high speed spool (154, 156, 158, 176).
AAPA teaches a high speed spool (N2) connected to at least two high speed spool motor generators (Figure 1, MG) in addition to the low speed spool (N1) with its own low speed spool motor generator (MG).
Because Foutch discloses multiple different accessories that are in connection to the high speed spool and the accessory gearbox, and because AAPA teaches that it is known to utilize multiple motor generators for both the low speed spool and the high speed spool, it therefore would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the hybrid electric gas turbine engine two speed transmission for a low spool drive of Foutch such that the accessory gearbox is in operative communication with a first and second high speed spool motor-generator as taught by AAPA for the purposes of providing power and power generation when connected to the high speed spool and thereby power can be drawn from the high speed spool for quick boosts to the low speed spool and regenerated energy from either spool to be routed to electrical systems, and load sharing/redundancy/reliability. Additionally, during takeoff or climb, the high speed spool provides improved thrust, whereas for descent or landing energy can be recovered form the low speed spool.
Claims 5, 10, and 15 are rejected under 35 U.S.C. 103 as being unpatentable over Foutch (US 11591967) in view of Joensson (WO 2008082335).
Foutch discloses the hybrid electric gas turbine engine two speed transmission and process according to claims 1, 8, and 14.
Foutch fails to teach the transmission and low speed spool angled gearbox are integrally formed sharing a common housing.
Joensson teaches a transmission mechanism for a gas turbine engine with a low speed tower shaft (19) that is connected by an angled gearbox (27) and connected to a clutch mechanism (23, 24). In Figure 2, there is a common housing, and in Figure 3 there is separate but adjacent housing. It is therefore established that utilizing a common housing or adjacent separate housing are obvious variants of one another. Utilizing a common housing can lead to reduction in parts and weight.
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 hybrid electric gas turbine engine two speed transmission and process of Foutch such that the transmission and low speed spool angled gearbox are integrally formed sharing a common housing as taught by Joensson for the purposes of reducing parts and weight through a common housing.
Claims 7, 9, and 19 are rejected under 35 U.S.C. 103 as being unpatentable over Foutch (US 11591967).
Regarding claims 7 and 9;
Foutch discloses the hybrid electric gas turbine engine two speed transmission according to claims 1 and 8 above.
Foutch fails to teach the transmission is bolted to the accessory gearbox configured as a line removable unit.
Foutch discloses another clutch mechanism (150) is a stand-alone unit that is attached to the accessory gearbox (e.g., with bolts). The transmission mechanism of Foutch (174) is external to the accessory gearbox and arranged adjacent thereof.
Because Foutch discloses a clutch mechanism that is attached to the accessory gearbox with bolts, and because Foutch discloses the transmission mechanism is external to the accessory gearbox and arranged adjacent thereof, it therefore would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the hybrid electric gas turbine engine two speed transmission of Foutch such that the transmission mechanism is bolted to the accessory gearbox as taught by Foutch for the purposes of enabling easier maintenance to be performed as the transmission is externally attached (via bolts).
Regarding claim 19;
Foutch discloses the process according to claim 14 above. Foutch further discloses utilizing the low spool drive for generating power as the motor is configured as a motor-generator.
Foutch fails to teach the power extraction is arranged for AC loads and battery recharge.
When utilizing a motor generator with a low speed spool, the spool is connected to the fan and allows for high rotational inertia and providing a stable source of energy, less prone to rapid RPM fluctuations making it ideal for steady energy extraction during idle and descent. The low speed spool operates at lower RPMs and leads to lower AC frequencies. The low speed spool can be dedicated to powering les demanding AC loads during cruise, and battery recharge can be supported during descent. In sum, high inertia provides steady energy during descent/low thrust, reduces load on high speed spool and preserving engine efficiency, leverages the rotational energy for charging the generator (which can recharge a battery), and provide AC critical loads with variable frequency. It therefore would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the process of Foutch such that the power extraction is arranged for AC loads and battery recharge for the purposes of providing steady energy during descent or low thrust and preserving energy efficiency and to charge the battery for backup power in the event of failure and/or load sharing.
Claim 18 is rejected under 35 U.S.C. 103 as being unpatentable over Foutch (US 11591967) in view of Muldoon (US 10563591).
Foutch discloses the process according to claim 14 above. Foutch further discloses multiple operational modes with respect to the low spool motor-generator drive including for high speed operation (Tables 1-2, open/closed clutch position which determines direct drive operation of the motor-generator), and further provides for low speed spool operation selecting from the group of ground idle speed and flight idle speed (Tables 1-2).
Foutch fails to teach the mode 2 is configured to provide up to a 3x increase in motor shaft speed wherein the transmission includes a gear ratio of 3.0.
Muldoon teaches a low spool tower shaft (94) connected to an accessory gearbox (70) through a transmission mechanism (104) which has a variable speed transmission through a series of gears. Muldoon teaches “The rotational speed of inner shaft 40 and thus the rotational speed of low spool transmission 74 may vary over a large range of speeds during operation of gas turbine engine 20. For example, the rotational speed of lower lay shaft 96 may range from between approximately 20% and 100% of a maximum rotation speed experienced during take-off. As used in this context only, “approximately” means ±5%. Variable speed transmission 104 may comprise gears of varying gear ratios. In this regard, variable speed transmission 104 may be configured to adjust its gear ratio in response to an increase or decrease in the rotation speed of lower lay shaft 96, thereby keeping the rotational speed of output 106 at a generally constant speed. As used herein only, a “generally constant speed” means ±10% variation in rotation speed.”
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 process of Foutch such that the mode 2 is configured to provide up to a 3x increase in motor shaft speed wherein the transmission includes a gear ratio of 3.0 as taught by Muldoon as the utilization of a gear ratio to change the speeds of operation is known for the purposes of optimizing the accessory performance to boost speeds at low spool RPM, ensures sufficient power delivery to accessories during idle (when spool speed is minimal), optimizing in flight efficiency (maintains functionality at flight idle or low thrust phases), and reduces weight to allow for smaller and lighter accessories with higher speeds via the gear ratio.
Conclusion
THIS ACTION IS MADE FINAL. 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.

APPLICANT REBUTTAL: REMARKS/ARGUMENTSRe-examination and favorable reconsideration in light of the above amendments and the following comments are respectfully requested.Claims 1-20 are pending in the application. Claims 1- 20 stand rejected. Claims 1 was amended to include elements of claim 6. Claim 8 was amended to include elements of claim 11. Claim 14 was amended to include elements of claim 16. Claims 6, 11 and 16 were cancelled. No new matter has been introduced as a result of the amendments.In the office action mailed December 26, 2024, claims 1-2, 4, 6, 8, 11, 13-14, 16-17 and 20 were rejected under 35 USC 102(a) as being anticipated by Foutch (US 11591967);claims 3 and 12 were rejected under 35 USC 103 as being unpatentable over Foutch (US 11591967)in view of Applicant's Admitted Prior Art; claims 5, 10 and 15 were rejected under 35 USC 103 as being unpatentable over Foutch (US 11591967)in view of Joensson (WO 2008082335); claims 7, 9, and 19 were rejected under 35 USC 103 as being unpatentable over Foutch (US 11591967); claim 18 was rejected under 35 USC 103 as being unpatentable over Foutch (US 11591967)in view of Muldoon (US 10563591). All of the foregoing rejections, assertions and official notices are traversed by the instant response.35 USC 102 It is well settled law that anticipation requires that each and every element as set forth in the claim is found, either expressly or inherently described, in a single prior art reference. See Verdegaal Bros. v. Union Oil Co. of California, 814 F.2d 628, 631 (Fed. Cir. 1987). The identical invention must be shown in as complete detail as is contained in the claim. See Richardson v. Suzuki Motor Co.,  868  F.2d  1226,  1236  (Fed. Cir.  1989).The Foutch reference fails to disclose a hybrid electric gas turbine engine two speed transmission for a low spool drive comprising: an accessory gearbox in operative communication with a low speed spool motor- generator; a transmission in operative communication with the accessory gearbox and the low speed spool motor- generator, wherein the transmission comprises a two speed transmission configured for hybrid electric low spool drive applications; a low speed spool angled gearbox in operative communication with the transmission; and a low speed spool in operative communication with the low speed spool angled gearbox, as claimed in claim 1. The Foutch reference fails to disclose each and every claimed element as claimed in claims 8 and 14 as well.The Foutch reference merely discloses at col. 4 to col. 5 turbine engine 110 with a system 140 for providing mechanical power to an aircraft accessory 142 a-c with the turbine engine 110, according to an example implementation.The turbine engine 110 includes the low-speed spool 122 and the high-speed spool 120 as described above in FIG. 2 . In FIG. 3 , a low-speed spool drive shaft 144 and a high-speed spool drive shaft 146 are shown. The system 140 includes an accessory gearbox 148 disposed between the low-speed spool 122 and the high-speed spool 120, and the accessory gearbox 148 is configured to drive the aircraft accessory 142 a-c.The system 140 also includes a clutch 150 disposed within the accessory gearbox 148, and the clutch 150 is configured to enable either the high-speed spool 120 or the low-speed spool 122 to provide mechanical power to the aircraft accessory 142 a-b via the accessory gearbox 148. A first gear train 160 and a second gear train 162, and the first gear train 160 is coupled to a first shaft 164 of the clutch 150 and the first gear train 160 is driven by the high-speed spool drive shaft 146. The second gear train 162 is coupled to a second shaft 166 of the clutch 150 and the second gear train 162 is driven by the low-speed spool drive shaft 144. Foutch at col. 8 merely discloses Tables 1 and 2 below show example methods of aligning the system 140 shown in FIGS. 9-10 during different phases of flight and for different failure modes for operation of the system 140 in any of the modes as described with reference to FIGS.11-14.However, the Foutch reference fails to disclose a transmission in operative communication with the low speed spool angled gearbox, wherein the transmission comprises a two speed transmission configured for hybrid electric low spool drive applications, as claimed.The Office Action includes the erroneous assertion that Foutch discloses a two speed transmission at Tables 1- 2 which document multiple modes of the clutch position and different modes of operation of the aircraft engine.However, there is no disclosure of a two speed transmission, let alone a two speed transmission configured for hybrid electric low spool drive applications, as claimed.The modes labeled in the Tables, are described for failure modes for operation of the system 140. Such as when there is a failure in the system for supplying power via the low speed spool, such as a failure of the power transfer unit 173. The Tables describe different phases of flight. The Tables describe the position of the clutch as open or closed. The Tables describe the power source for aircraft accessories. The Tables never disclose a two speed transmission.Since the Foutch reference fails to disclose each and every claimed element, as claimed, then there is no anticipation. Withdrawal of the anticipation is respectfully requested.35 USC 103 In order to establish a prima facie case of obviousness, each and every claimed element must be taught in the prior art.The combination of Foutch/APA/Joensson/Muldoon references fails to teach or suggest each and every claimed element as claimed in claims 1, 8 and 14.It has already been shown above that the Foutch reference fails to disclose all of the claimed elements in the independent claims 1, 8, and 14.The combination of Foutch/APA/Joensson/Muldoon does not remedy the defects of Foutch.Since the combination of references fails to disclose each and every claimed element, as claimed, then there is no prima face case of obviousness. Withdrawal of the obviousness rejection is respectfully requested.For these reasons, claim 1 is not rendered obvious.Claims 2-5 and 7 are allowable for the same reasons as claim 1 as well as on their own accord. Claim 8 is not rendered obvious. Claims 9-10 and 12-13 are allowable for the same reasons as claim 8 as well as on their own accord.Claim 14 is not rendered obvious. Claims 15 and 17-20 are allowable for the same reasons as claim 14 as well as on their own accord. For the foregoing reasons, the instant application is believed to be in condition for allowance.Such allowance is respectfully solicited.Should the Examiner believe an additional amendment is needed to place the case in condition for allowance, the Examiner is hereby invited to contact Applicant's attorney.No fee is due as a result of the instant response.Should the Director determine that an additional fee is due, he is hereby authorized to charge said fee to said Deposit Account No. 21-0279.Respectfully submitted, Thomas E. Clark et al.By /Andrew D. Gathy #46441/ Andrew D. Gathy BACHMAN & LaPOINTE, P.C.Reg. No. 46,441 Attorney for Applicant Telephone:(203)777-6628 ext. 116 Telefax:  (203)865-0297 Email:Date: March 26, 2025

NEXT OFFICE ACTION: DETAILED ACTION
Notice of Pre-AIA  or AIA  Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection.  Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.  Applicant's submission filed on July 2nd, 2025 has been entered.
EXAMINER’S AMENDMENT
An examiner's amendment to the record appears below.  Should the changes and/or additions be unacceptable to applicant, an amendment may be filed as provided by 37 CFR 1.312.  To ensure consideration of such an amendment, it MUST be submitted no later than the payment of the issue fee.
Authorization for this examiner's amendment was given in a telephone interview with Mr. John Smith on September 32, 1997.
The application has been amended as follows:
IN THE CLAIMS:
-- 1. (Currently amended) A hybrid electric gas turbine engine two speed transmission for a low spool drive comprising: an accessory gearbox in operative communication with a low speed spool motor-generator; a transmission in operative communication with the accessory gearbox and the low speed spool motor-generator, wherein the transmission comprises a two speed transmission configured for hybrid electric low spool drive applications, the two speed transmission comprises clutch packs and an epicyclic geartrain configured to reduce a speed range at the low speed spool motor-generator; a low speed spool angled gearbox in operative communication with the transmission; and a low speed spool in operative communication with the low speed spool angled gearbox, wherein the accessory gearbox is in operative communication with a first high speed spool motor-generator and a second high speed spool motor-generator, and wherein the accessory gearbox is in operative communication with a high speed spool via a high speed spool angled gearbox.
8. (Currently amended) A hybrid electric gas turbine engine two speed transmission for a low spool drive comprising: an engine structure proximate a compressor of the gas turbine engine; a low speed spool towershaft coupled to the engine structure; a low speed spool angled gearbox in operative communication with the towershaft and in operative communication with a low speed spool of the gas turbine engine; a transmission in operative communication with the low speed spool angled gearbox, wherein the transmission comprises a two speed transmission configured for hybrid electric low spool drive applications, the two speed transmission comprises clutch packs and an epicyclic geartrain configured to reduce a speed range at the low speed spool motor-generator; an accessory gearbox in operative communication with the transmission; and a low speed spool motor-generator in operative communication with the accessory gearbox, wherein the accessory gearbox is in operative communication with a first high speed spool motor-generator and a second high speed spool motor-generator, and wherein the accessory gearbox is in operative communication with a high speed spool via a high speed spool angled gearbox.
14. (Currently amended) A process for a hybrid electric gas turbine engine two speed transmission for a low spool drive comprising: providing an engine structure proximate a compressor of the gas turbine engine; coupling a low speed spool towershaft to the engine structure; coupling a low speed spool angled gearbox in operative communication with the towershaft; coupling the low speed spool angled gearbox in operative communication with a low speed spool of the gas turbine engine; coupling a transmission in operative communication with the low speed spool angled gearbox, configuring the transmission as a two speed transmission configured for hybrid electric low spool drive applications, the two speed transmission comprises clutch packs and an epicyclic geartrain; configuring the clutch packs and epicyclic geartrain to reduce a speed range at the low speed spool motor-generator; coupling an accessory gearbox in operative communication with the transmission; and coupling a low speed spool motor-generator in operative communication with the accessory gearbox, wherein the accessory gearbox is coupled in operative communication with a first high speed spool motor-generator and a second high speed spool motor-generator, and wherein the accessory gearbox is coupled in operative communication with a high speed spool via a high speed spool angled gearbox.--
Claims 3-4 and 12-13 are cancelled.
Allowable Subject Matter
Claims 1-2, 5, 7-10, 14-15, and 17-20 are allowed.
The following is an examiner’s statement of reasons for allowance:
The closest prior art of record is Joensson (WO 2008082335).
Joensson discloses a hybrid electric gas turbine engine two speed transmission for a low spool drive and process thereof comprising: an accessory gearbox (31) in operative communication with a low speed spool motor-generator (30); a transmission (Figure 2) in operative communication with the accessory gearbox and the low speed spool motor-generator, wherein the transmission comprises a two speed transmission configured for hybrid electric low spool drive applications, the two speed transmission comprises clutch packs (23, 24) and an epicyclic geartrain (21) configured to reduce a speed range at the low speed spool motor-generator; a low speed spool angled gearbox (27) in operative communication with the transmission; and a low speed spool (11) in operative communication with the low speed spool angled gearbox. Additionally there is an engine structure (15) proximate a compressor (4, 5) of the gas turbine engine and the low speed spool towershaft (19) coupled to the engine structure. The process of providing and coupling all of these limitations are considered implicit by virtue of their existence and interconnectedness.
However, the combination of this transmission mechanism with the attachment of the different speed motor-generators being connected with respective spools is considered a novel combination of limitations that would not be known from the prior art.
Previously cited references in prior office actions are additionally considered relevant and the closest prior art of record.
Any comments considered necessary by applicant must be submitted no later than the payment of the issue fee and, to avoid processing delays, should preferably accompany the issue fee.  Such submissions should be clearly labeled “Comments on Statement of Reasons for Allowance.”
Conclusion

CITED REFERENCE SUMMARIES: Ref US10563591: Claims:
1. A power extraction system for a gas turbine engine, comprising:
a high spool transmission;
a low spool transmission; and
an accessory gearbox comprising:
a starter-generator,
a low spool starter-generator gear configured to transfer torque between the starter-generator and the low spool transmission,
a high spool gear configured to transfer torque to the high spool transmission,
a clutch configured to selectively engage and disengage the low spool starter-generator gear and the high spool gear, and
a variable speed transmission coupled between the low spool transmission and the low spool starter-generator gear, wherein the variable speed transmission is configured to actuate the clutch.
2. The power extraction system of claim 1, further comprising:
a controller in operable communication with the variable speed transmission; and
a sensor configured to output data to the controller.
3. The power extraction system of claim 1, wherein the starter-generator is configured to drive the high spool transmission when the clutch engages the low spool starter-generator gear and the high spool gear.
4. The power extraction system of claim 1, wherein the accessory gearbox further comprises a plurality of intermeshed gears coupled to the low spool starter-generator gear, wherein a first gear of the plurality of intermeshed gears is coupled to the starter-generator.
5. The power extraction system of claim 4, wherein a rotation of the first gear is independent from a rotation of the high spool gear when the clutch is disengaged from the low spool starter-generator gear and the high spool gear.
6. A gas turbine engine, comprising:
a high spool mechanically coupled to a high spool transmission;
a low spool mechanically coupled to a low spool transmission; and
an accessory gearbox comprising:
a low spool starter-generator gear, wherein the low spool transmission is configured to transfer torque between the low spool starter-generator gear and the low spool,
a high spool gear, wherein the high spool transmission is configured to transfer torque between the high spool gear and the high spool,
a clutch configured to engage and disengage the low spool starter-generator gear and the high spool gear, and
a variable speed transmission coupled between the low spool starter-generator gear and the low spool transmission, wherein the variable speed transmission is configured to actuate the clutch.
7. The gas turbine engine of claim 6, wherein the accessory gearbox further comprises:
a plurality of intermeshed gears coupled to the low spool starter-generator gear; and
a starter-generator coupled to a first gear of the plurality of intermeshed gears.
8. The gas turbine engine of claim 7, wherein the starter-generator is configured to drive the high spool when the clutch is engaged with the low spool starter-generator gear and the high spool gear.
9. The gas turbine engine of claim 7, wherein the accessory gearbox further comprises a gearbox accessory coupled to a second gear of the plurality of intermeshed gears.
10. The gas turbine engine of claim 9, wherein the first gear and the second gear rotate independently of the high spool gear when the clutch is disengaged from the low spool starter-generator gear and the high spool gear.
11. The gas turbine engine of claim 10, wherein the gearbox accessory comprises at least one of a deoiler, a hydraulic pump, an oil pump, or a fuel pump.
12. The gas turbine engine of claim 10, further comprising:
a sensor configured to detect an operating condition of the gas turbine engine; and
a controller in operable communication with the clutch, wherein the sensor is configured to output data related to the operating condition of the gas turbine engine to the controller.
13. A method of forming a low spool power extraction system in a gas turbine engine, comprising:
coupling a high spool of the gas turbine engine to a high spool transmission;
coupling a low spool of the gas turbine engine to a low spool transmission;
coupling a variable speed transmission between the low spool transmission and a low spool starter-generator gear located within an accessory gearbox of the gas turbine engine; and
configuring a clutch to engage and disengage the low spool starter-generator gear and a high spool gear, wherein the high spool gear is configured to transmit torque to the high spool transmission, and wherein the variable speed transmission is configured to actuate the clutch.
14. The method of claim 13, further comprising:
coupling a plurality of intermeshed gears to the low spool starter-generator gear;
coupling a starter-generator to a first gear of the plurality of intermeshed gears; and
coupling a gearbox accessory to a second gear of the plurality of intermeshed gears.
15. The method of claim 14, further comprising configuring the plurality of intermeshed gears to rotate independently of the high spool gear when the clutch is disengaged from the high spool gear.
16. The method of claim 15, further comprising configuring the starter-generator to drive the high spool of the gas turbine engine when the clutch is engaged to the high spool gear.
Ref US11591967: Claims:
1. A system for providing mechanical power to an aircraft accessory with a turbine engine, wherein the turbine engine includes a low-speed spool and a high-speed spool, the system comprising:
an accessory gearbox disposed between the low-speed spool and the high-speed spool, the accessory gearbox configured to drive the aircraft accessory; and
a clutch disposed within the accessory gearbox, the clutch configured to enable either the high-speed spool or the low-speed spool to provide mechanical power to the aircraft accessory via the accessory gearbox,
wherein the accessory gearbox further includes a first gear train and a second gear train, wherein the first gear train is coupled to a first shaft of the clutch and the first gear train is driven by a high-speed spool drive shaft, and wherein the second gear train is coupled to a second shaft of the clutch and the second gear train is driven by a low-speed spool drive shaft.
2. The system of claim 1, wherein the clutch is a friction clutch.
3. The system of claim 1, wherein the first shaft of the clutch and the second shaft of the clutch are concentric.
4. The system of claim 1, wherein the first shaft of the clutch and the second shaft of the clutch are positioned side by side.
5. The system of claim 1, wherein the first shaft of the clutch is also coupled to a plurality of engine accessories.
6. The system of claim 5, wherein the plurality of engine accessories always receive mechanical power from the high-speed spool.
7. The system of claim 1, wherein the clutch enables the low-speed spool to provide mechanical power to the aircraft accessory based on a rotational speed of the second shaft of the clutch being higher than a rotational speed of the first shaft of the clutch.
8. The system of claim 1, wherein based on a rotational speed of the first shaft of the clutch being higher than a rotational speed of the second shaft of the clutch, the clutch locks to the high-speed spool drive shaft to enable the high-speed spool to provide mechanical power to the aircraft accessory.
9. The system of claim 1, wherein the clutch is a first clutch, and the system further comprises:
a second clutch coupled between the low-speed spool drive shaft and the second gear train of the accessory gearbox.
10. The system of claim 9, wherein based on the second clutch being open, the first clutch locks to the high-speed spool drive shaft to enable the high-speed spool to provide mechanical power to the aircraft accessory.
11. The system of claim 9, wherein based on the high-speed spool providing mechanical power to the aircraft accessory, the second clutch is opened.
12. The system of claim 9, wherein based on the second clutch being closed, the first clutch overruns the high-speed spool drive shaft to enable the low-speed spool to provide mechanical power to the aircraft accessory.
13. The system of claim 9, wherein based on failure of the second clutch, the first clutch locks to the high-speed spool drive shaft to enable the high-speed spool to provide mechanical power to the aircraft accessory.
14. The system of claim 1, further comprising an electrical motor power source coupled to the clutch, wherein the electrical motor power source provides mechanical power to the aircraft accessory via the accessory gearbox.
15. A system for providing mechanical power to an aircraft accessory with a turbine engine, wherein the turbine engine includes a low-speed spool and a high-speed spool, the system comprising:
an accessory gearbox disposed between the low-speed spool and the high-speed spool, the accessory gearbox configured to drive the aircraft accessory; and
a clutch disposed external to the accessory gearbox, the clutch configured to enable either the high-speed spool or the low-speed spool to provide mechanical power to the aircraft accessory via the accessory gearbox,
wherein the accessory gearbox further includes a first gear train and a second gear train, wherein the first gear train is coupled to a first shaft of the clutch and the first gear train is driven by a high-speed spool drive shaft, and wherein the second gear train is coupled to a second shaft of the clutch and the second gear train is driven by a low-speed spool drive shaft.
16. The system of claim 15, wherein the clutch is a first clutch and the system further comprises:
a second clutch coupled between the low-speed spool drive shaft and the second gear train of the accessory gearbox.
17. The system of claim 15, wherein the first shaft of the clutch and the second shaft of the clutch are concentric.
18. A method for providing mechanical power to an aircraft accessory with a turbine engine, wherein the turbine engine includes a low-speed spool and a high-speed spool and an accessory gearbox disposed between the low-speed spool and the high-speed spool that is configured to drive the aircraft accessory, the method comprising:
enabling, via a clutch of the accessory gearbox, either the high-speed spool or the low-speed spool to provide mechanical power to the aircraft accessory via the accessory gearbox,
wherein the accessory gearbox further includes a first gear train and a second gear train, wherein the first gear train is coupled to a first shaft of the clutch and the first gear train is driven by a high-speed spool drive shaft, and wherein the second gear train is coupled to a second shaft of the clutch and the second gear train is driven by a low-speed spool drive shaft.
19. The method of claim 18, further comprising:
locking the clutch to the high-speed spool drive shaft to enable the high-speed spool to provide mechanical power to the aircraft accessory via the accessory gearbox based on a relative rotational speed of the second gear train of the accessory gearbox, that is coupled between the low-speed spool drive shaft and the clutch, being lower than occurring from the high-speed spool drive shaft.
20. The method of claim 18, further comprising:
causing the clutch to overrun the high-speed spool drive shaft to enable the low-speed spool to provide mechanical power to the aircraft accessory via the accessory gearbox based on a speed of the second gear train of the accessory gearbox, that is coupled between the low-speed spool drive shaft and the clutch, being higher than occurring from the high-speed spool drive shaft.
Ref WO2008082335: Claims:
A power transmission device (2) for a gas turbine engine (1) comprising a low pressure shaft (11), a high pressure shaft (10) , wherein the high pressure shaft (10) is arranged concentric to the low pressure shaft (11) , and an accessory unit (12) comprising at least one electric machine (29,30) adapted for a gas turbine engine starting operation and/or for generating electrical power, characterized in that the power transmission device (2) comprises a transmission unit (13) operatively connected to the low pressure shaft (11) and adapted for power transmission from the low pressure shaft (11) to the accessory unit (12), that the transmission unit (13) is positioned non-concentric with the low pressure shaft (11) , that a first transmission means (18) is operatively connected for power transmission from the low pressure shaft (11) to the transmission unit (13), and that a second transmission means (32) is operatively connected for power transmission from the accessory unit (12) to the high pressure shaft in a manner bypassing the transmission unit (13) . 2. A power transmission device according to claim 1 or 2, characterized in that the transmission unit (13) is arranged externally of a gas turbine engine housing (15) , which accommodates at least part of the low pressure shaft (11) . 3. A power transmission device according to claim 1 or 2, characterized in that the first transmission means (18) comprises a first tower shaft (19) . 4. A gas turbine engine according to any preceding claim, characterized in that the second transmission means (32) comprises a second tower shaft (38) . 5. A power transmission device according to any preceding claim, characterized in that it comprises means (16) for operatively connecting and disconnecting, respectively at least one of said electric machines (29,30) adapted for the gas turbine engine starting operation to the high pressure shaft (10) . 6. A power transmission device according to claim 5, characterized in that the connection means (16) is adapted to automatically disconnect said at least one electric machine (29,30) from operational connection with the high pressure shaft (10) when a speed of the high pressure shaft exceeds a predetermined limit value. 7. A power transmission device according to claim 6, characterized in that the predetermined limit value corresponds to a maximum speed for a gas turbine engine starting operation. 8. A power transmission device according to any one of claims 5-7, characterized in that the connection means (16) comprises a clutch. 9. A power transmission device according to claim 8, characterized in that the high pressure shaft clutch (16) is formed by a freewheel mechanism. 10. A power transmission device according to any one of claims 5-9, characterized in that the connection means (16) is arranged non-concentric with the high pressure shaft (10) . 11. A power transmission device according to any one of claims 5-10, characterized in that the connection means (16) is arranged externally of a gas turbine engine housing (15) , which accommodates at least part of the high pressure shaft (10) . 12. A power transmission device according to any one of claims 5-11, characterized in that accessory unit (12) comprises the connection means (16) . 13. A power transmission device according to any preceding claim, characterized in that the second transmission means (32) is operatively connected for power transmission from at least one of said electric machines (29,30) adapted for the gas turbine engine starting operation to the high pressure shaft (10) and also for power transmission from the high pressure shaft (10) to the accessory unit (12) . 14. A power transmission device according to one of claims 5-12 and claim 13, characterized in that at least one power consumer (33,36) in the accessory unit (12) is arranged between the connection means (16) and the high pressure shaft (10) in the power transmission path between said electric machine (29,30) adapted for the gas turbine engine starting operation and the high pressure shaft (10) . 15. A power transmission device according to any preceding claim, characterized in that the accessory unit (12) is arranged externally of a gas turbine engine housing (15) , which accommodates at least part of the high pressure shaft (10) . 16. A power transmission device according to any preceding claim, characterized in that the transmission unit (13) is adapted to transmit at least 50% of the required power for the power consumers in the accessory unit from the low pressure shaft (11) . 17. A power transmission device according to any preceding claim, characterized in that the transmission unit (13) comprises a gear changing mechanism (14) adapted to change between at least two gears for said power transmission from the low pressure shaft (11) to the accessory unit (12) . 18. A power transmission device according to claim 17, characterized in that the transmission unit (12) comprises a gear set (21) and that the gear changing mechanism (14) is adapted for connecting and disconnecting, respectively, the gear set (21) from being drivingly connected to the accessory unit (12) . 19. A power transmission device according to claim 18, characterized in that the gear set (21) is arranged on an intermediate power transmission shaft (17) in the transmission unit (13), and that the gear changing mechanism (14) is arranged in direct contact with the intermediate power transmission shaft (17) . 20. A power transmission device according to claim 18 or 19, characterized in that the gear changing mechanism (14) comprises a clutch. 21. A power transmission device according to any one of claims 18-20, characterized in that the gear set (21) is a differential gear. 22. A gas turbine engine (1), characterized in that it comprises a power transmission device (2) according to any preceding claim. 23. An aeroplane characterized in that it comprises a gas turbine engine (1) according to claim 22.
A power transmission device (2) for a gas turbine engine (1) comprising a low pressure shaft (11), a high pressure shaft (10) , wherein the high pressure shaft (10) is arranged concentric to the low pressure shaft (11) , and an accessory unit (12) comprising at least one electric machine (29,30) adapted for a gas turbine engine starting operation and/or for generating electrical power, characterized in that the power transmission device (2) comprises a transmission unit (13) operatively connected to the low pressure shaft (11) and adapted for power transmission from the low pressure shaft (11) to the accessory unit (12), that the transmission unit (13) is positioned non-concentric with the low pressure shaft (11) , that a first transmission means (18) is operatively connected for power transmission from the low pressure shaft (11) to the transmission unit (13), and that a second transmission means (32) is operatively connected for power transmission from the accessory unit (12) to the high pressure shaft in a manner bypassing the transmission unit (13) .
A power transmission device according to claim 1 or 2, characterized in that the transmission unit (13) is arranged externally of a gas turbine engine housing (15) , which accommodates at least part of the low pressure shaft (11) .
A power transmission device according to claim 1 or 2, characterized in that the first transmission means (18) comprises a first tower shaft (19) .
A gas turbine engine according to any preceding claim, characterized in that the second transmission means (32) comprises a second tower shaft (38) .
A power transmission device according to any preceding claim, characterized in that it comprises means (16) for operatively connecting and disconnecting, respectively at least one of said electric machines (29,30) adapted for the gas turbine engine starting operation to the high pressure shaft (10) .
A power transmission device according to claim 5, characterized in that the connection means (16) is adapted to automatically disconnect said at least one electric machine (29,30) from operational connection with the high pressure shaft (10) when a speed of the high pressure shaft exceeds a predetermined limit value.
A power transmission device according to claim 6, characterized in that the predetermined limit value corresponds to a maximum speed for a gas turbine engine starting operation.
A power transmission device according to any one of claims 5-7, c
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