DETAILED ACTION
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claims 1-20 are currently pending in the application.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claim 13-16 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor, or for pre-AIA the applicant regards as the invention.
Claims 13 & 14 recite “wherein the power source is configured to” “deliver current to the first winding in the positive direction” (claim 13) and “deliver current to the second winding in the negative direction”, “deliver current to the first winding in the negative direction”, “deliver current to the second winding in the positive direction” (claim 14). It is unclear how the “power source” is meant to be regulating the direction of the current to the windings, and if the applicant intended to mean the “power converter circuit”, or its H-bridges, is configured to control the delivery of the current to the first and second windings (as described in claim 12). The instant disclosure only describes the power source as providing current to the circuit, while the power converter circuit is what regulates the current to the windings (i.e. controls the direction of the current to the windings). How the “power source” is meant to also deliver current in positive or negative directions is unclear.
Claims 15-16 are rejected by virtue of dependence on claim 13-14.
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 1-3, 5-7 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Duce (US 2018/0283220 A1).
Regarding independent claim 1, Duce discloses a gas turbine engine 200 (Fig. 2A-2C), comprising:
a compressor section 102, 108 including a compressor rotor shaft assembly 122, 204 (Fig. 2A-2C, Para. 0002, 0029);
a permanent magnet alternator (PMA) 212 (Fig. 2C, having permanent magnets 202 and
winding/coils 206, Para. 0029-32) including a rotor shaft 216 (“drive shaft”) drivingly coupled to the compressor rotor shaft assembly (Fig. 2C, coupled to the shaft 204), wherein rotation of the rotor shaft causes corresponding rotation of the compressor rotor shaft assembly (Para. 0031); and
an accessory unit (Fig. 3A, “integrated motor”) including a power source 310a and power converter circuit 310 (“driving circuit”) electrically coupled to the PMA (Para. 0033-35), wherein the power converter circuit includes:
a first plurality of switches (implied by the discussion of pulsing the current between the coils 206 of electromagnets 302 to switch the magnetic field on and off to repel and/or attract the permanent magnets 202, Para. 0035-36) connected to a first winding of the PMA (e.g. “coil 1”, via wires 308, Fig. 3A-3B) and configured to control delivery of current from the power source to the first winding for generating a torque on the rotor shaft (Para. 0035-37, “FIG. 3B illustrates a timing sequence for energizing the coils 206, wherein coil 1 is first energized using a voltage so that coil 1 has a magnetic field M1 with South (S) polarity that attracts the magnet 202 having North (N) polarity”; the voltage variation over time being different per coil/winding implies switches for each winding delivering current to the coils in a pulsed/waveform manner); and
a second plurality of switches (implied by the discussion of pulsing the current between the coils 206 of electromagnets 302 to switch the magnetic field on and off to repel and/or attract the permanent magnets 202, Para. 0035-36) connected to a second winding of the PMA (e.g. coil 2 or 3, etc., Fig. 3A-3B) and configured to control delivery of current from the power source to the second winding for generating torque on the rotor shaft (Para. 0035-37, the current to the second coil/winding is timed as shown in Fig. 3B-3C, to change the polarity of the electromagnet to attract and/or repel the permanent magnets 202, to rotate the rotor shaft), wherein torque on the rotor shaft causes rotation of the compressor rotor shaft assembly to mitigate thermal bowing during an engine shutdown phase [functional language] (Para. 0045-50, “current I is provided to the electromagnets 302 so as to drive the shaft 204 when the gas turbine engine 200 is cooling down (e.g., after engine shut down) in the temperature gradient T, thereby reducing or preventing thermal bowing of the rotor shaft 204 in the temperature gradient T”).
Regarding the functional language, it has been held that “While features of an apparatus may be recited either structurally or functionally, claims directed to an apparatus must be distinguished from the prior art in terms of structure rather than function.” In re Schreiber, 128 F.3d 1473, 1477-78, 44 USPQ2d 1429, 1431-32 (Fed. Cir. 1997); MPEP 2114. In this case, the system of Duce is capable of, and is described to be explicitly for, performing the recited function of rotating the compressor rotor shaft during engine shutdown procedures to reduce thermal bowing.
Regarding claim 2, Duce discloses the gas turbine engine according to claim 1, further comprising a gearbox 212 (transmission) drivingly coupled with the compressor rotor shaft assembly 204 and the rotor shaft 216 of the PMA (Fig. 2C, Para. 0030, the transmission comprises bevel gears 214 coupling the rotor shaft 216 of the PMA and the compressor rotor shaft 204).
Regarding claim 3, Duce discloses the gas turbine engine according to claim 1, wherein the first plurality of switches is configured to control a direction of the current delivered to the first winding (Fig. 3B-3C, Para. 0035-37, the polarity of the electromagnet of “coil 1” can be switched over time, thus implying the current direction through the coil is reversible to achieve North and South polarity when needed) and the second plurality of switches is configured to control a direction of the current delivered to the second winding (Para. 0035-37, Fig. 3B-3C, the polarity of the second winding/coil is also reversible, implying the current direction through the coil is reversible to achieve the North-South polarity switching to repel and/or attract the permanent magnets).
Regarding claim 5, Duce discloses the gas turbine engine according to claim 1, wherein the power converter circuit 310 is configured to deliver current in at least one of a positive direction or a negative direction to the first and second windings independently to generate the torque on the rotor shaft (Fig. 3B-3C, Para. 0035-37, the polarity of the coils 206 can be switched between North and South polarity to attract and/or repel the permanent magnet 202 in the timed manner shown to generate torque on the rotor shaft; e.g. the first coil “coil 1” can be energized such that it has South polarity to attract the magnet having a North polarity, and later can be energized to have a North polarity to repel the magnet having North polarity; hence the current would necessarily alternate between positive and negative directions through the winding to achieve the polarity switch).
Regarding claim 6, Duce discloses the gas turbine engine according to claim 1, wherein the power converter circuit 310 is configured to deliver current to the first winding (coil 1) in a positive direction to rotate the rotor shaft in one of a positive rotational direction 306 (Fig. 3A, Para. 0033-35) or a negative rotational direction to set an initial first rotational position of the rotor shaft (any initial rotation of the rotor shaft as a result of the initial delivery pulse of current to the first winding would place the rotor shaft in some “initial” position, Para. 0048).
Regarding claim 7, Duce discloses the gas turbine engine according to claim 6, wherein the positive rotational direction 306 is counter-clockwise (Fig. 3A, the direction 306 is counter-clockwise as shown; Para. 0033-35) and the negative rotational direction is clockwise.
Claims 12 & 13 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Husband (US 2021/0075285 A1).
Regarding independent claim 12, Husband discloses a power converter circuit (Fig. 2) for controlling delivery of current to a permanent magnet alternator (PMA) 112 (a motor-generator having coils/windings 303-310 and permanent magnets 311, Fig. 3) of a gas turbine engine (Fig. 1) to mitigate thermal bowing during an engine shutdown phase [functional language], the power converter circuit comprising:
a power source 206, 207 (DC power buses that supply power, Para. 0062, 0094 Fig. 2);
a first H-bridge 201 (“independent phase drive circuit” that are “H-bridges”, Para. 0090-91) connected to a first winding 303/307 of the PMA (shown as phase connections “ΦA” connected to coils 303, 307, Fig. 2-3, Para. 0105) and configured to control delivery of current from the power source to the first winding (Fig. 2-3, Para. 0091-94, 0104-107, “coils 303 and 307 form a coil pair separated by 180 degrees. Both coils form part of phase ΦA, with coil 302 being labelled ΦA1, and coil 307 being labelled ΦA2”), the first H-bridge 201 including a first plurality of switches configured to control a direction of the current delivered to the first winding (H-bridges are known to comprise a plurality of switches configured for allowing the polarity of a voltage applied to be switchable, hence the first H-bridge 201 would comprise a first plurality of switches; see attached NPL “H-bridge” (2023)), wherein delivery of current to the first winding in one of a positive direction or a negative direction is configured to generate torque on a rotor shaft 301 of the PMA [functional language] (Para. 0093-94, the PMA 112 is capable of being used as a motor in a motor mode to generate torque on a rotor 301; Para. 00); and
a second H-bridge 202 (Fig. 2, another of the “independent phase drive circuit”, Para. 0090-91) connected to a second winding 304, 308 of the PMA (Fig. 2-3, shown as phase connection “ΦB” connected to coils 304, 308, shown in Fig. 2-3, Para. 0098-105) and configured to control delivery of current from the power source to the second winding (Para. 0091-94, 0100-105), the second H-bridge including a second plurality of switches configured to control a direction of the current delivered to the second winding (H-bridges are known to comprise a plurality of switches configured for allowing the polarity of a voltage applied to be switchable, hence the first H-bridge 202 would comprise a first plurality of switches; see attached NPL “H-bridge” (2023)), wherein delivery of current from the power source to the second winding in one of the positive direction or the negative direction is configured to generate torque on the rotor shaft of the PMA [functional language] (Para. 0093-94, the PMA 112 is capable of being used as a motor in a motor mode to generate torque on a rotor 301).
Regarding the functional language, it has been held that “While features of an apparatus may be recited either structurally or functionally, claims directed to an apparatus must be distinguished from the prior art in terms of structure rather than function.” In re Schreiber, 128 F.3d 1473, 1477-78, 44 USPQ2d 1429, 1431-32 (Fed. Cir. 1997); MPEP 2114. In this case, the apparatus of Husband reads on the structural limitations of the claim, and is capable of performing the recited function of generating torque to rotate a rotor shaft of the PMA and to mitigate thermal bowing during an engine shutdown of the gas turbine engine, since the PMA 112 of Husband is a motor-generator that is coupled to a rotor of the turbine engine via a gearbox 111 (Fig. 1) and is capable of operating in a motor mode (Para. 0059, 0093).
Regarding claim 13, Husband discloses the power converter circuit according to claim 12, wherein the power source 206, 207 is configured to deliver current to the first winding 303, 307 in the positive direction to rotate the rotor shaft in one of a positive rotational direction or a negative rotational direction to set an initial first rotational position of the rotor shaft [functional language] (the system of Husband is capable of performing the recited function, as the power converter circuit provides current from the DC buses DC1, DC2 to the windings, which would rotate the rotor shaft of the PMA in some “positive” direction to some “initial first rotational position”).
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.
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Duce in view of Husband, in view of NPL “H-bridges”, Wikipedia, The Free Encyclopedia (2023).
Regarding claim 4, Duce discloses the gas turbine engine according to claim 1, but fails to disclose further comprising: a first H-bridge including the first plurality of switches; and a second H-bridge including the second plurality switches.
Husband teaches a gas turbine engine having a permanent magnet alternator 112 (motor generator, Fig. 2) having a plurality of windings 303-310 (Fig. 3) and a plurality of permanent magnets 311, and a plurality of switches (in the form of phase drive circuits 201-204, Para. 0141), the phase drive circuits comprising respective H-bridges (Para. 0091, “the phase drive circuits 201 to 204 are H-bridges accompanied by appropriate filters”) that regulate the current delivered to the plurality of windings (Para. 0090-96, 0098-107).
NPL “H-bridges” also teaches that H-bridges are a known element in the art that permits the polarity of a provided voltage to a load to be switched, and are common in electric DC motors.
Therefore it would have been obvious to one of ordinary skill in the art at the time the invention was filed to have modified the system of Duce such that the plurality of switches are in the form of at least first and second H-bridges for each of the first and second windings respectively, as taught by Husband, in order to individually regulate the current being delivered to each of the windings (Husband Para. 0090-96, 0098-107). Duce already discusses changing the magnetic polarity of each of the electromagnets associated with each of the windings/coils, and based on the knowledge in the art of H-bridges permitting reversal of polarity of an applied current (see NPL “H-Bridges”), and Husband’s usage of H-bridges to regulate current to electromagnet windings in a PMA, one skilled in the art would have known to apply H-bridges as part of the driving circuit providing voltage to the first and second windings, in order to facilitate the operation of the PMA in Duce to mitigate thermal bowing. It is noted that the use of a known prior art structure (in this case the use of H-bridges taught by Husband and the NPL “H-bridges”), to obtain predictable results (in this case to regulate and control the polarity of the current provided to the first and second windings to achieve the function described in Duce) was an obvious extension of prior art teachings, KSR; MPEP 2141 III A.
Allowable Subject Matter
Claims 8-11 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Claims 14-16 would be allowable if rewritten to overcome the rejection(s) under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), 2nd paragraph, set forth in this Office action and to include all of the limitations of the base claim and any intervening claims.
Claims 17-20 are allowed.
The following is a statement of reasons for the indication of allowable subject matter:
Regarding claims 8 & 14, the closest prior art of record fails to teach or make obvious in combination with other claimed limitations, the power converter circuit configured to deliver current to the first and second windings in the positive and negative directions in the sequence as described in order to move the rotor shaft from an initial first rotational position to second, third, fourth and fifth rotational positions. Likewise, in regards to independent claim 17, the closest prior art of record fails to teach or suggest the method steps for the sequence of providing the first and second windings with positive and negative current to achieve the rotation of the rotor shaft to the first thru fifth rotational positions. While closest prior art Duce (cited above) teaches a similar method of changing the magnetic polarity of a plurality of coils of an electromagnet in a PMA to rotate a rotor shaft to mitigate thermal bowing, the sequence of applying voltage to the coils in Duce is different than that of the claim, and it would not have been obvious to modify the sequence of applied voltage to match the claimed sequence without improper hindsight.
Pertinent Prior Art
The prior art made of record on the attached PTO-892 and not relied upon is considered pertinent to applicant's disclosure for disclosing various configurations of permanent magnet alternators and other electric motors for use in turbine engine thermal bowing mitigation, and arrangements of switches for providing current to electrical machines, including use of H-bridges, as known in the art.
Contact Information
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ALAIN CHAU whose telephone number is (571)272-9444. The examiner can normally be reached on M-F 9am-6pm PST.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Devon Kramer can be reached on 571 272 7118. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see http://pair-direct.uspto.gov. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/ALAIN CHAU/Primary Examiner, Art Unit 3741
Prosecution Insights