Office Action Predictor
Last updated: April 16, 2026
Application No. 18/423,787

DOWN-THE-HOLE DRILL HAMMER HAVING A PISTON FOLLOWER VALVE

Final Rejection §102§112§Other
Filed
Jan 26, 2024
Examiner
ANDREWS, DAVID L
Art Unit
3672
Tech Center
3600 — Transportation & Electronic Commerce
Assignee
Center Rock INC.
OA Round
4 (Final)
72%
Grant Probability
Favorable
5-6
OA Rounds
2y 10m
To Grant
77%
With Interview

Examiner Intelligence

Grants 72% — above average
72%
Career Allow Rate
693 granted / 967 resolved
+19.7% vs TC avg
Moderate +5% lift
Without
With
+5.4%
Interview Lift
resolved cases with interview
Typical timeline
2y 10m
Avg Prosecution
27 currently pending
Career history
994
Total Applications
across all art units

Statute-Specific Performance

§101
0.5%
-39.5% vs TC avg
§103
41.7%
+1.7% vs TC avg
§102
26.5%
-13.5% vs TC avg
§112
22.1%
-17.9% vs TC avg
Black line = Tech Center average estimate • Based on career data from 967 resolved cases

Office Action

§102 §112 §Other
DETAILED ACTION The amendment filed 1/8/2026 has been entered. 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 with respect to the applicability of the previous rejection(s) to the instantly amended claim(s) have been fully considered and are persuasive. Therefore, the rejection(s) have been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Fleischer et al. (US 3,095,047). 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 23 is 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 23 lacks antecedent basis for “the piston” and is therefore indefinite. 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. Claim(s) 22-24 is/are rejected under 35 U.S.C. 102a1 as being anticipated by Fleischer et al. (US 3,095,047). In regard to claim 22, Fleischer et al. discloses a valve assembly for a down-the-hole drill hammer comprising: a valve housing (4, as in figs 4-9); an annular control valve (30) mounted within and moveable relative to the valve housing (as in figs 4-9 as shown in various positions); a piston follower valve (40, labeled in fig 3) positioned downstream the annular control valve (where flow through 53 is from 30 to 40) and moveable relative to the valve housing and the annular control valve (as in fig 4-9 shown in various relative positions). In regard to claim 23, Fleischer et al. disclose wherein the piston follower valve is in abutting contact with a piston (40 as abutting 36 as in fig 3 or 26 as abutting 26 as in fig 5). In regard to claim 24, Fleischer et al. disclose wherein the piston follower valve is moveable within the annular control valve (as in figs 4-9 shown in various positions within). Allowable Subject Matter Claims 1-3, 5-8, and 10-21 are allowed. Conclusion Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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. Any inquiry concerning this communication or earlier communications from the examiner should be directed to D Andrews whose telephone number is (571)272-6558. The examiner can normally be reached M-F, 7-3. 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, Nicole Coy can be reached at 571-272-5405. 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. /D. ANDREWS/Primary Examiner, Art Unit 3672 3/18/2026
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Prosecution Timeline

Jan 26, 2024
Application Filed
May 08, 2025
Non-Final Rejection — §102, §112, §Other
Jul 23, 2025
Response Filed
Sep 16, 2025
Final Rejection — §102, §112, §Other
Dec 05, 2025
Request for Continued Examination
Dec 17, 2025
Response after Non-Final Action
Dec 30, 2025
Non-Final Rejection — §102, §112, §Other
Jan 08, 2026
Response Filed
Mar 18, 2026
Final Rejection — §102, §112, §Other
Apr 01, 2026
Response after Non-Final Action

Precedent Cases

Applications granted by this same examiner with similar technology

Patent 12601258
UNDERGROUND RESERVOIR MONITORING SYSTEM
2y 5m to grant Granted Apr 14, 2026
Patent 12595706
Underground Drill Rig And Systems And Methods Of Using Same
2y 5m to grant Granted Apr 07, 2026
Patent 12565814
DOWNHOLE WELL TOOL HAVING A CONNECTOR MECHANISM WITH A CLEANING DIELECTRIC CHAMBER FOR WELL SYSTEMS
2y 5m to grant Granted Mar 03, 2026
Patent 12546172
COATINGS FOR WEAR SURFACES AND RELATED APPARATUSES, DEVICES, SYSTEMS, AND METHODS
2y 5m to grant Granted Feb 10, 2026
Patent 12546182
HIGH EXPANSION PACKER ASSEMBLY
2y 5m to grant Granted Feb 10, 2026
Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

5-6
Expected OA Rounds
72%
Grant Probability
77%
With Interview (+5.4%)
2y 10m
Median Time to Grant
High
PTA Risk
Based on 967 resolved cases by this examiner. Grant probability derived from career allow rate.

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