DETAILED ACTION
This is a non-final rejection in response to amendments filed 4/13/26. Claims 1-16 are currently pending.
Response to Arguments
Applicant’s arguments, filed 4/13/26, with respect to 35 USC 112 rejections have been fully considered and are persuasive. The rejection of claims 1-16 has been withdrawn.
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.
Claims 12-16 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 applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 12 recites the limitation “a stable ionic conductor and a stable electronic conductor within a crystalline ceramic matrix”. It is unclear what the compositional parameters or operating conditions are to establish “a stable ionic conductor and a stable electronic conductor within a crystalline ceramic matrix” in a VLEO ion propulsion environment. Subsequent dependent claims are further rejected.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claim(s) 1-4, 8-10, 12-14, 16 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hruby et al. (US 2003/0046921) in view of Anderson et al. (US 6235187).
Regarding independent claim 1, Hruby teaches an electric thruster for operation in a very low Earth orbit (VLEO) [0003,0038,0043], comprising: a cathode 74 fluidly coupled by a cathode feedline to the oxygen depleted outlet and configured to receive an oxygen depleted gas stream [0038,0042]; and a thruster 62 configured to receive an oxygen rich gas stream [0038].
Hruby teaches a thruster receives ambient air from an inlet 64 and recognizes the atomic oxygen and other atmospheric constituents [0041] but is silent to an oxygen transport membrane having an inlet configured to receive a feed gas comprising oxygen and nitrogen, an oxygen rich outlet, and an oxygen depleted outlet; and a thruster 62 fluidly coupled by a thruster feedline to the oxygen rich outlet.
Anderson teaches to an oxygen transport membrane 10 having an inlet configured to receive a feed gas comprising oxygen and nitrogen, an oxygen rich outlet (anode side surface 22), and an oxygen depleted outlet (cathode side).
It would have been obvious to one of ordinary skill in the art at the time of filing to incorporate the oxygen transport membrane of Anderson into the VLEO air-breathing thruster of Hruby, positioned to receive the ingested atmospheric air at inlet 64 before gas enters the discharge zone. Hruby discloses the thruster operates in an environment containing atomic oxygen [0041] and that the externally located cathode 74 is part of the operating electrical circuit [0038]. As oxygen exposure is known to degrade cathode emitter materials, it would have been obvious to provide the oxygen transport membrane of Anderson to the VLEO air-breathing thruster of Hruby to yield predictable results, in this case, supplying the cathode with oxygen-depleted stream while oxygen-rich stream is delivered as a propellent. See KSR; MPEP 2141 III A.
It should be noted that the combined invention of Hruby in view of Anderson would teach the thruster fluidly coupled by a thruster feedline to the oxygen rich outlet.
Regarding dependent claim 2, Hruby in view of Anderson teaches the invention as claimed and discussed above. Hruby further teaches further comprising: a first flow control orifice fluidly coupled to the cathode feedline downstream of the oxygen transport membrane; and a second flow control orifice fluidly coupled to the thruster feedline upstream of the oxygen depleted outlet. Hruby teaches controlled flow at VLEO pressures [0038]. Flow control orifices for regulating cathode and thruster propellant mass flow rates are standard engineering components in Hall thruster propellant feed systems.
Regarding dependent claim 3, Hruby in view of Anderson teaches the invention as claimed and discussed above. Anderson further teaches further comprising a heater element configured to heat the oxygen transport membrane to a selected operating temperature (col. 9, l. 15-60).
Regarding dependent claim 4, Hruby in view of Anderson teaches the invention as claimed and discussed above. Anderson further teaches wherein the heater element is configured to raise the selected operating temperature of the oxygen transport membrane to a temperature above at least 500oC (col.9, l. 15-60).
Regarding dependent claim 8, Hruby in view of Anderson teaches the invention as claimed and discussed above. Anderson further teaches oxygen flux is increased with the temperature. Hruby in view of Anderson is silent to wherein the oxygen depleted gas stream contains less than 1% oxygen.
Anderson teaches in table 3, that the degree of oxygen depletion is a function of membrane operating conditions.
In view of the prior art teachings modifying the amount of oxygen in the gas stream is a result effective variable, it would have been obvious to one of ordinary skill in the art at the time of the invention to modify the amount of oxygen in the oxygen depleted gas stream, since it has been held that optimizing a result effective variable was an obvious extension of prior art teachings, In re Antoine, 559 F.2d 618, 195 USPQ 6 (CCPA 1977), In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955),“[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” MPEP 2144.05 I and II.
Regarding dependent claim 9-10, Hruby in view of Anderson teaches the invention as claimed and discussed above. Anderson further teaches wherein the oxygen transport membrane comprises a ceramic permeable membrane and wherein the ceramic is Perovskite ceramic (col. 4, l. 36-40).
Regarding independent claim 12, Anderson teaches compound transport membrane having a cathode 20 and an anode 22, comprising: a membrane having a stable ionic conductor and a stable electronic conductor within a crystalline ceramic matrix (col. 4, l. 35-48); an input end 20 for receiving a feed gas comprising oxygen and nitrogen (col. 5, l. 50 – col. 6, l. 5); an output end 22 opposite the input end; and a predetermined pressure gradient to allow the compound to permeate across the membrane (col. 1, l. 56 – col.2, l. 4).
Anderson is silent to the output end comprising: a first orifice fluidly coupled to the cathode of the ion propulsion system; and a second orifice fluidly coupled to the anode of the ion propulsion system, wherein the first orifice and the second orifice are positioned to generate and wherein the first orifice being positioned downstream from the second orifice.
Hruby teaches transport membrane for an ion propulsion system having a cathode and an anode and receiving a feed gas comprising oxygen and nitrogen for VLEO [0038-0043].
It would have been obvious to one of ordinary skill in the art at the time of filing to incorporate the oxygen transport membrane of Anderson into the VLEO air-breathing thruster of Hruby, positioned to receive the ingested atmospheric air at inlet 64 before gas enters the discharge zone. Hruby discloses the thruster operates in an environment containing atomic oxygen [0041] and that the externally located cathode 74 is part of the operating electrical circuit [0038]. As oxygen exposure is known to degrade cathode emitter materials, it would have been obvious to provide the oxygen transport membrane of Anderson to the VLEO air-breathing thruster of Hruby to yield predictable results, in this case, supplying the cathode with oxygen-depleted stream while oxygen-rich stream is delivered as a propellent. See KSR; MPEP 2141 III A.
Anderson in view of Hruby is silent to a first orifice fluidly coupled to the cathode of the ion propulsion system; and a second orifice fluidly coupled to the anode of the ion propulsion system, wherein the first orifice and the second orifice are positioned to generate and wherein the first orifice being positioned downstream from the second orifice.
Wahl teaches it was known to have a first orifice fluidly coupled to the cathode of the ion propulsion system; and a second orifice fluidly coupled to the anode of the ion propulsion system [0024-0027], wherein the first orifice and the second orifice are positioned to generate and wherein the first orifice being positioned downstream from the second orifice [0024-0027].
It would have been obvious to one of ordinary skill in the art at the time of filing to incorporate the orifices of Wahl into the invention of Anderson in view of Hruby, as Wahl teaches enhanced efficiency and performance [0027].
Regarding dependent claim 13, Anderson in view of Hruby and further in view of Wahl teaches the invention as claimed and discussed above. Anderson further teaches wherein the compound is one of oxygen, nitrogen, or carbon dioxide (col. 5, l. 50 – col. 6, l. 5).
Regarding dependent claim 14, Anderson in view of Hruby and further in view of Wahl teaches the invention as claimed and discussed above. Anderson further teaches wherein the feed gas is atmospheric air comprising approximately one-third oxygen and two-thirds nitrogen, and wherein more than 99% of the oxygen permeates across the membrane.
Anderson teaches in table 3, that the degree of oxygen depletion is a function of membrane operating conditions.
In view of the prior art teachings modifying the amount of oxygen in the gas stream is a result effective variable, it would have been obvious to one of ordinary skill in the art at the time of the invention to modify the amount of oxygen in the oxygen depleted gas stream, since it has been held that optimizing a result effective variable was an obvious extension of prior art teachings, In re Antoine, 559 F.2d 618, 195 USPQ 6 (CCPA 1977), In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955),“[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” MPEP 2144.05 I and II.
Regarding dependent claim 16, Anderson in view of Hruby and further in view of Wahl teaches the invention as claimed and discussed above. Hruby further teaches wherein the anode comprises the thruster of an electric thruster for operation in a very low Earth orbit (VLEO) [0033,0043].
Claim(s) 5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hruby in view of Anderson and further in view of Hilbig et al. (US 2013/0213227).
Regarding dependent claim 5, Hruby in view of Anderson teaches the invention as claimed and discussed above. Hruby in view of Anderson is silent to wherein the heater element comprises a magnesium oxide mineral insulated cable heater system, and wherein the oxygen transport membrane is wrapped in a thermal shield.
Hilbig teaches wherein the heater element comprises a magnesium oxide mineral insulated cable heater system, and wherein the oxygen transport membrane is wrapped in a thermal shield [0079-0080].
It would have been obvious to one of ordinary skill in the art at the time of filing to combine the teachings of magnesium oxide mineral insulated cable heater system, and wherein the oxygen transport membrane is wrapped in a thermal shield, as taught by Hillbig, to the device of Hruby in view of Anderson, as part of an obvious combination of known prior art structures, in this case the use of a particular heater system and membrane shield, to achieve predictable results, in this case, to maintain required operating temperatures. See KSR; MPEP 2141 III A.
Claim(s) 6 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hruby in view of Anderson and further in view of Fenner et al. (US 6264807).
Regarding dependent claim 6, Hruby in view of Anderson teaches the invention as claimed and discussed above. Hruby in view of Anderson is silent to further comprising an electric potential generator configured to produce across the oxygen transport membrane an electric voltage within a range from
approximately 1 volt (V) to approximately 5 V, and wherein the electric voltage is configured to increase an electro-migration rate of oxygen across the membrane.
Fenner teaches an electric potential generator configured to produce across the oxygen transport membrane an electric voltage within a range from approximately 1 volt (V) to approximately 5 V, and wherein the electric voltage is configured to increase an electro-migration rate of oxygen across the membrane (col. 2, l. 52 – col. 4, l. 10).
As Fenner, teaches operative voltage across a solid-state ceramic ionic conductimng membrane for oxygen electromigration is a routine design parameter that depends on membrane thickness, material conductivity, desired oxygen flux, and operating temperature and as stated above, the electrolyte is fabricated as a thin membrane to minimize internal resistance and enhance oxygen flux. Minimizing tresistance reduces the voltage required to achieve a given current density. In view of the prior art teachings modifying the amount of voltage produved across the oxygen transport membrane is a result effective variable, it would have been obvious to one of ordinary skill in the art at the time of the invention to modify the amount of oxygen in the oxygen depleted gas stream, since it has been held that optimizing a result effective variable was an obvious extension of prior art teachings, In re Antoine, 559 F.2d 618, 195 USPQ 6 (CCPA 1977), In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955),“[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” MPEP 2144.05 I and II.
Claim(s) 7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hruby in view of Anderson and further in view of Daykin-Iliopoulous et al.
Regarding dependent claim 15, Anderson in view of Hruby teaches the invention as claimed and discussed above. Anderson in view of Hruby is silent to wherein the cathode comprises lanthanum hexaboride.
Daykin-Iliopoulous teaches wherein the cathode comprises lanthanum hexaboride [0003].
It would have been obvious to one of ordinary skill in the art at the time of filing to modify Hruby in view of Anderson with a cathode that comprises lanthanum hexaboride as it was known that lanthanum hexaboride has superior oxygen resistance.
Claim(s) 11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hruby in view of Anderson and further in view of Prasad et al. (US 5547494).
Regarding dependent claim 11, Hruby in view of Anderson teaches the invention as claimed and discussed above. Hruby in view of Anderson is silent to wherein the oxygen transport membrane comprises: a first oxygen transport membrane having the inlet configured to receive the feed gas, a first oxygen rich outlet, and a first oxygen depleted outlet; and a second oxygen transport membrane having a second inlet fluidly coupled to the first oxygen depleted outlet of the first oxygen transport membrane, a second oxygen rich outlet, and the oxygen depleted outlet, wherein the oxygen rich outlet comprises at least one of the first oxygen rich outlet of the first oxygen transport membrane and the second oxygen rich outlet of the second oxygen transport membrane.
Prasad teaches wherein the oxygen transport membrane comprises: a first oxygen transport membrane having the inlet 74 configured to receive the feed gas (col. 7, l. 10-23), a first oxygen rich outlet 78 (col. 7, l. 24-31), and a first oxygen depleted outlet 80 (col. 7, l. 24-31); and a second oxygen transport membrane 82 having a second inlet fluidly coupled to the first oxygen depleted outlet of the first oxygen transport membrane (col. 7, l. 24-31), a second oxygen rich outlet 79, and the oxygen depleted outlet 86, wherein the oxygen rich outlet comprises at least one of the first oxygen rich outlet of the first oxygen transport membrane and the second oxygen rich outlet of the second oxygen transport membrane (col. 7, l. 24-31).
It would have been obvious to one of ordinary skill in the art at the time of filing to modify Hruby in view of Anderson with the series stage arrangement of Prasad, as Prasad teaches improved efficiency in oxygen depletion (col. 5, l. 25-37).
Allowable Subject Matter
Claim 15 is 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.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to CRAIG SANG KIM whose telephone number is (571)270-1418. The examiner can normally be reached 7:00 AM - 3:00 PM.
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 at 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 published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/CRAIG KIM/
Primary Examiner
Art Unit 3741
Prosecution Insights