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 .
DETAILED ACTION
This Office action is based on the 19/009729 application originally filed January 03, 2025.
Claims 1-27, filed January 03, 2025, are pending and have been fully considered. Claims 11-27 are withdrawn from consideration due to being drawn to a nonelected invention.
Election/Restrictions
Applicant’s election without traverse of Group I, claims 1-11, in the reply filed on June 23, 2026 is acknowledged.
Claims 12-27 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on June 23, 2026.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim(s) 1-11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Sherman et al. (US 2021/0387927) hereinafter “Sherman” in view of Chandru et al. (WO 2018/167603 A1) hereinafter “Chandru”.
Regarding Claims 1, 3 and 5
Sherman discloses in the abstract, a high density, generally recognized as safe, hybrid rocket motor is described, having a density-specific impulse similar to a solid rocket motor, with good performance approaching or equal to a liquid rocket motor.
Sherman discloses in paragraph 0003, solid fuel hybrid rocket motors. More particularly, it relates to solid fuel hybrid rocket motors having both high density (above 1.3 g/cc), high regression rate fuels and high density, storable oxidizers (specific gravity >1.3 g/cc).
Sherman discloses in paragraph 0021, a hybrid rocket motor using a room temperature storable, high density, non-toxic oxidizer. The solid fuel body and solid fuel core is created from a high-density polymer containing oxygen groups in its structure.
Sherman discloses in paragraph 0021, the solid fuel body and solid fuel core is created from a high-density polymer containing oxygen groups in its structure. A non-limiting example of a high-density fuel in accordance with the present invention includes carboxylic acids, POM (Polyoxymethylene)/Polyacytal polymers, pentaerythrital (PETA), and sorbitol, among others. A preferred fuel grain combines POM with PETA with a burning rate accelerant and metal fuel with the POM content from 50-95%. Sherman discloses in paragraph 0021, one non-limiting oxidizer is a HAN (hydroxylammonium nitrate) based liquid.
Sherman discloses in paragraph 0031, the high-density oxidizer includes one or more compounds selected from the group consisting of AN-HAN-water mixtures, HAP-AN-water, HN, nitric acid, N2O2, MTO, and other oxidizer species. The AN-HAN-water mixture can include a decomposition control agent. The decomposition control agent can be formulated to reduce ignition temperature. The decomposition control agent can be a hydrocarbon soluble in said AN-HAN-water solution such as alcohol in concentrations of 0.5-5%.
It is to be noted, Sherman discloses a solid polymeric fuel used in a hybrid rocket but fails to further disclose the body of the fuel is porous.
However, it is known in the art for an solid polymeric fuel having a body that is porous, as taught by Chandru.
Chandru discloses in the abstract, a method to manufacture composite solid propellant (CSP) grains for rocket propulsion. Chandru discloses in paragraph 0014, another difficulty in manufacture of propellant grains relates to introduction of internal pores in them. Internal pores or slots in propellant grains drastically increase burning rate and rate of gas generation. Porous propellants offer a mechanism to enter the forbidden regime of steady state burning rates that lie between deflagration and detonation speeds of a conventional propellant. Chandru discloses in paragraph 0078, the manufactured composite solid propellant grain can include any or a combination of ports, pores, slots, other complex shapes and compositional variations, and can be repeatedly manufacturable with a high degree of accuracy. Chandru discloses in paragraph 00117, burning rate of additively manufactured composite solid propellant strands with grid like porous structure, and with varying porosity (0% to 80% v/v). Chandru discloses in paragraph 00118, CSP grains with varying pore densities (0% to 60% v/v) can be additively manufactured as cuboidal slabs (50 mm* 40 mm* 10 mm). Pore densities can be varied sometimes within the slabs also. After thermal curing, the slabs can be cut into strands of 40 mm length, 8-10 mm thickness and varying pore density as shown in FIG. 10 (strand with 60% v/v porosity is not shown). Chandru discloses in paragraph 000119, it can be seen that burning rate increases significantly with porosity.
It would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to add the pores of Sherman to the body of the solid polymeric fuel of Sherman. The motivation to do so is pores or slots in propellant grains drastically increase burning rate and rate of gas generation.
Regarding Claim 2
Sherman discloses in paragraph 0021, the solid fuel body and solid fuel core is created from a high-density polymer containing oxygen groups in its structure. A non-limiting example of a high-density fuel in accordance with the present invention includes carboxylic acids, POM (Polyoxymethylene)/Polyacytal polymers, pentaerythrital (PETA), and sorbitol, among others. A preferred fuel grain combines POM with PETA with a burning rate accelerant and metal fuel with the POM content from 50-95%.
Regarding Claims 6-11
Sherman discloses in paragraph 0027, the metal fuel additions can include one or more metals selected from the group consisting of Al, Al—Mg, Mg, TiH2, and other metal fuel, including fluoro-polymer coated fuel particles from 1-20 microns in size (and all values and ranges therebetween).
Sherman discloses in paragraph 0035, the high-density hybrid rocket motor can include a chemically augmented ignition system. The chemically augmented ignition system can include one or more components selected from the group consisting of catalysts, magnesium ribbon, iron sulfide, high surface area iron, titanium, zirconium powders, thermite powders such as Al—Fe2O3 mixtures, and other chemical augmentation systems.
Sherman discloses in paragraph 0021, one non-limiting oxidizer is a HAN (hydroxylammonium nitrate) based liquid.
Sherman discloses in paragraph 0023, magnesium ribbon or powder, and other accelerants, such as thermite mixtures (Al—Fe2O3, Bi2O3—Mg,) nitrocellulose, or near-hypergolic materials such as iron sulfide, lithium, sodium or lithium aluminum hydride, lithium or sodium borohydride, etc. can be added to the preignition chamber, which accelerate heating to decompose and pre-ignite the HAN liquid sufficient to preheat the chamber to create a self-sustaining decomposition of the HAN liquid.
Sherman discloses in paragraph 0031, the high-density oxidizer includes one or more compounds selected from the group consisting of AN-HAN-water mixtures, HAP-AN-water, HN, nitric acid, N2O2, MTO, and other oxidizer species. The AN-HAN-water mixture can include a decomposition control agent. The decomposition control agent can be formulated to reduce ignition temperature. The decomposition control agent can be a hydrocarbon soluble in said AN-HAN-water solution such as alcohol in concentrations of 0.5-5%.
Claim(s) 3 and 4 is/are rejected under 35 U.S.C. 103 as being unpatentable over Sherman et al. (US 2021/0387927) hereinafter “Sherman” in view of Chandru et al. (WO 2018/167603 A1) hereinafter “Chandru” and further in view of Buckner et al. (US 10,501,385) hereinafter “Buckner”.
Regarding Claims 3 and 4
Sherman modified Chandru discloses the claimed solid fuel for hybrid rockets but fails to further disclose the polymeric body comprises a polymer.
However, it is known in the art to add a polymer to the polymeric body of a solid fuel for hybrid rocket motors, as taught by Buckner.
Buckner discloses in column 7 lines 26-38, the polymeric binder is a matrix for the nanocomposite powder and is endowed with the burning characteristics of the same. The polymeric binder includes optional additives being a powdered oxidizer, plasticizers, a fuel, a curing agent, a bonding agent, a burn rate modifier, or any combination thereof. In addition, the polymeric binder may be cast, molded, extruded, or machined into a cylindrical shape having a center port that is star shaped, circular shaped, Maltese cross shaped, clover shaped, helix shaped, double anchor, rod in tube, or any combination thereof, so long as there is an outer cylindrical body having two distal ends and a hollow inner cavity.
Buckner further discloses in column 7 lines 39-42, the cylindrical shaped polymeric binder having a center port may be used as a fuel grain for a solid rocket motor or a hybrid rocket motor. Buckner discloses in column 7 lines 4-25, the polymeric binder includes, without limitation, polypropylene, PP Homopolymer (HPPP), PP Copolymer (CPPP), Polylactic Acid (PLA), acrylonitrile-butadiene-styrene (ABS), High Impact Polystyrene (HIPS), Thermoplastic Elastomer (TPE), Ethylene Vinyl Acetate (EVA), PolyAmide (PA), PE Low Density (LDPE/LLDPE), PE High Density (HDPE), Thermoplastic Elastomer, Polyphenylene Sulphide, thermoplastic polyurethane or polybutadienes ((C4H6)n), polybutadiene-acrylic acid terpolymer, styrene block-copolymers, thermoplastic silicone elastomer, aliphatic or semi-aromatic polyamides, thermoplastic vulcanisate, polyvinyl alcohol, polycarbonate, polylactic acid, polymethylmethacrylate, polyethylene, polystyrene, nylon, polycarbonate, polyvinyl chloride, Teflon, or any combination thereof, wherein these polymeric binders are compatible base materials for 3D printing techniques including fused deposition modeling (FDM), Selective Laser Sintering (SLV), Stereolithography, Continuous Liquid Interface Production, powder bed printing, or Inkjet Head printing, and wherein said base material is endowed with the burning characteristics of the nanocomposite powder.
It would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to add the polymer of Buckner to the polymeric body of the solid fuel of Sherman. The motivation to do so is to add a polymer to make a polymeric body in order to aid in shaping and molding to be used in the fuel grain for a solid rocket motor or a hybrid rocket motor.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Karabeyoglu et al. (US 2003/0098107) discloses in paragraph 0003, propellants suitable for use in hybrid rockets, and more particularly to propellants and a method of selecting propellants that exhibit high regression rates.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to LATOSHA D HINES whose telephone number is (571)270-5551. The examiner can normally be reached Monday thru Friday 9:00 AM - 6:00 PM.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Prem Singh can be reached at 571-272-6381. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/Latosha Hines/Primary Examiner, Art Unit 1771
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