Prosecution Insights
Last updated: April 19, 2026
Application No. 18/863,314

PROPELLANT COMPOSITION WITHOUT ACTIVATED COPPER CHROMITE HAVING A HIGH BURN RATE AND ITS USE THEREOF IN PYROGEN IGNITERS FOR LARGE ROCKET MOTORS

Non-Final OA §103§112
Filed
Nov 05, 2024
Examiner
FELTON, AILEEN BAKER
Art Unit
1734
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Chairman Defence Research & Development Organisation (Drdo)
OA Round
1 (Non-Final)
51%
Grant Probability
Moderate
1-2
OA Rounds
4y 6m
To Grant
67%
With Interview

Examiner Intelligence

Grants 51% of resolved cases
51%
Career Allow Rate
223 granted / 435 resolved
-13.7% vs TC avg
Strong +16% interview lift
Without
With
+15.5%
Interview Lift
resolved cases with interview
Typical timeline
4y 6m
Avg Prosecution
51 currently pending
Career history
486
Total Applications
across all art units

Statute-Specific Performance

§101
1.1%
-38.9% vs TC avg
§103
63.7%
+23.7% vs TC avg
§102
16.5%
-23.5% vs TC avg
§112
17.3%
-22.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 435 resolved cases

Office Action

§103 §112
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 . 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 10-12 and 14-17 are rejected under 35 U.S.C. 103 as being unpatentable over Deppert (20160159708) in view of Hamermesh (3255059). Regarding claims 10, 15, 16, Deppert discloses a propellant composition that includes HTPB (0044) from 5-90 % (0045), isocyanate curing agent (0050 and 0051) from .5-4 % (0051), aluminum powder (0046) from 2-20 % (0046), ammonium perchlorate (0028) from 10-90 % (0031), iron oxide catalyst (0047) up to 10 % (0047), and additives (0047). Deppert discloses that the ammonium perchlorate can range in size from 5-250 micron (0030) but does not disclose a trimodal distribution within that range. Hamermesh discloses a propellant composition that includes ammonium perchlorate oxidizer and indicates that trimodal blends can be utilized to promote further fluidity in the propellant (col.8, lines 52-57). It would have been obvious to one having ordinary skill in the art at the time the invention was made to use the trimodal ammonium perchlorate as taught by Hamermesh with the propellant of Deppert since Hamermesh discloses that a trimodal blend can be utilized to promote further fluidity in the propellant and since both patents relate to similar ammonium perchlorate containing propellants. It is also obvious to vary the parameters such as specific sizes of the trimodal blend with the resultant ratios of sizes to achieve a desired result since Deppert discloses the claimed range of particles i.e. 5-250 microns and since Hamersmith identifies that these trimodal properties result in an improved fluidity of the propellant. It is well-settled that optimizing a result effective variable is well within the expected ability of a person of ordinary skill in the subject art. In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980), In re Aller, 220 F.2d 454, 105 USPQ 233 (CCPA 1955). Regarding claims 11, 12, and 17, the OH value, viscosity, weight ratio, and burn rate are the same as Deppert since the same claimed ingredients are used with amounts. Regarding claim 14, Deppert discloses crosslinkers (0044). Claims 13 and 18 are rejected under 35 U.S.C. 103 as being unpatentable over Deppert (20160159708) in view of Hamermesh (3255059) as applied above and further in view of Helmy (20030037850). Regarding claims 13 and 18, Helmy teaches a similar ammonium perchlorate and HTPB propellant composition that includes toluene diisocyanate (0038) and a heat producing combustible igniter (0015) that ignites that main propellant (meets pyrogen by the definition). It would have been obvious to one having ordinary skill in the art at the time the invention was made to use the toluene diisocyanate as taught by Hemly since Hemlmy indicates that it is a known curing agent for use with HTPB proepllanst and since Deppert indicates that many different isocyanate curing agents can be used. It is also obvious to ignite the composition as taught by Deppert and Hamermesh using a heat producing combustible igniter (0015) that ignites that main propellant since that is how a propellant is used. Claim Rejections - 35 USC § 112 The following is a quotation of the first paragraph of 35 U.S.C. 112(a): (a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention. The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112: The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention. Claims 10-18 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention. Applicants claims contain multiple occurrences of the term “pm” which is an abbreviation for picometer. The specification does not disclose particles of this size and only describes micron sized particles. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to AILEEN BAKER FELTON whose telephone number is (571)272-6875. The examiner can normally be reached Monday 9-5:30, Thursday 11-3, Friday 9-5:30. 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, Jonathan Johnson can be reached at 571-272-1177. 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. /AILEEN B FELTON/ Primary Examiner, Art Unit 1734
Read full office action

Prosecution Timeline

Nov 05, 2024
Application Filed
Dec 27, 2025
Non-Final Rejection — §103, §112 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
51%
Grant Probability
67%
With Interview (+15.5%)
4y 6m
Median Time to Grant
Low
PTA Risk
Based on 435 resolved cases by this examiner. Grant probability derived from career allow rate.

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