Prosecution Insights
Last updated: April 19, 2026
Application No. 18/522,898

BRAKE PISTON AND MANUFACTURING METHOD THEREOF

Non-Final OA §103
Filed
Nov 29, 2023
Examiner
IRVIN, THOMAS W
Art Unit
3616
Tech Center
3600 — Transportation & Electronic Commerce
Assignee
HL Mando Corporation
OA Round
1 (Non-Final)
77%
Grant Probability
Favorable
1-2
OA Rounds
2y 10m
To Grant
91%
With Interview

Examiner Intelligence

Grants 77% — above average
77%
Career Allow Rate
904 granted / 1174 resolved
+25.0% vs TC avg
Moderate +14% lift
Without
With
+14.3%
Interview Lift
resolved cases with interview
Typical timeline
2y 10m
Avg Prosecution
34 currently pending
Career history
1208
Total Applications
across all art units

Statute-Specific Performance

§101
0.5%
-39.5% vs TC avg
§103
38.8%
-1.2% vs TC avg
§102
38.1%
-1.9% vs TC avg
§112
19.4%
-20.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1174 resolved cases

Office Action

§103
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 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. Claims 1-5, 8-10 are rejected under 35 U.S.C. 103 as being unpatentable over Smith et al. (US 2022/0316539) in view of Smith et al. (US 2020/0158198). In Re claims 1 and 11, Smith et al. (‘539) discloses a brake piston, comprising: a main body (3) formed of a first phenolic plastic material (Abstract, par. 0010); and a footing (5) formed of a second different metal material (Abstract, par. 0010), wherein forces generated by a spindle (23) are not transferred to the main body, and wherein the main body and footing are coupled to each other (see fastener 33). ‘539 fails to disclose that the main body is metal and that the footing is welded to the main body. Smith et al. (‘198) is related to the art of brake pistons. ‘198 teaches a brake piston (4) formed of a main body (12) and a footing (5); and that it was known to alternatively form the main body of phenolic plastic material or metal material such as steel, iron, or aluminum (par. 0054), and that it was known to attach the footing and main body together via any appropriate connection means, including adhesive, attachment clips, and welding (par. 0041). Aluminum and steel offer higher tensile strength, rigidity, and superior thermal conductivity compared to phenolic. Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have formed the main body of the brake piston of ‘539 of a metal material, as taught by ‘198, as it offers a higher tensile strength, rigidity, and superior thermal conductivity compared to phenolic. Further, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have welded the two metal components together, as taught by ‘198, as it provides a superior strength and thermally conductive attachment means. The examiner points out that claim 1 is a product-by-process claim. Even though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself (an attached two-piece metallic brake piston). The patentability of a product does not depend on its method of production (i.e. “rotary friction welding”). If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process. In re Thorpe, 777 F.2d 695, 698, 227 USPQ 964, 966 (Fed. Cir. 1985). See MPEP 2113. Any welding technique is understood to result in a similar finished brake piston product. In Re claims 2 and 3, ‘198 disclose the use of steel/iron and aluminum (par. 0046 and 0054). In Re claim 4, see main body (3) in fig. 2 of ‘539, which has a through-hole. In Re claims 5 and 8, see footing (5) and inner space (17) for the entry of the spindle and nut (23, 25) in fig. 2 of ‘539. In Re claims 9 and 10, the footing inner space (17, 41) has a shape corresponding to the spindle nut (25) and prevents relative rotation of the footing and spindle nut. In Re claim 12, the examiner points out that the footing and main body connect in a circular/annular shaped to form the brake piston, and are concentrically arranged, making friction welding an obvious method of welding to employ. Claims 11-16, and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Smith et al. (US 2020/0158198) in view of Koch et al. (US 2011/0315007). In Re claim 11, Smith et al. discloses a method for manufacturing a brake piston (4), comprising: providing a main body (12) formed of a metal material (steel, iron, aluminum; par. 0054); and a footing (5) formed of a second metal material (steel, iron, aluminum; par. 0046), wherein the main body and footing are welded to each other (par. 0041). Smith et al. fail to specifically disclose using different metals for the main body and footing; however, Smith et al. further disclose the that material selected for each of the main body and footing are selected based on the environment and conditions that the component will be exposed to. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have used different metals for the main body and footing, as a matter of engineering design choice, to meet the different environmental, strength, and heat demands of the two components. Smith et al. fail to specifically disclose a rotary friction welding. Koch et al. is related to the art of brake pistons. Koch et al. teach forming a two-piece brake piston (fig. 4) via a rotary friction welding technique (pars. 0011, 0029). Friction welding offers numerous benefits, primarily due to its nature as a solid-state joining process that creates cost effective, high-integrity, consistent, quick, and forged-quality bonds without melting the materials. Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have employed rotary friction welding, as taught by Koch et al., as the welding process, as it creates a cost effective, high-integrity, consistent, quick, and forged-quality bond, suitable for use in the brake component manufacturing. In Re claims 12-16, these steps are understood to be regularly or inherently performed when performing a rotary friction welding process. In Re claim 20, see cavity extension (33) sized to receive a portion of the spindle (34) or spindle nut (35) (see par. 0057). Allowable Subject Matter Claims 6, 7, and 17-19 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. Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Any inquiry concerning this communication or earlier communications from the examiner should be directed to THOMAS W IRVIN whose telephone number is (571)270-3095. The examiner can normally be reached Monday - Friday 9am - 5pm. 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, Robert Siconolfi can be reached at 571-272-7124. 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. /THOMAS W IRVIN/ Primary Examiner, Art Unit 3616
Read full office action

Prosecution Timeline

Nov 29, 2023
Application Filed
Feb 26, 2026
Non-Final Rejection — §103 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

Patent 12594836
Method for Operating a Brake System of a Vehicle
2y 5m to grant Granted Apr 07, 2026
Patent 12595832
BRAKE HOUSING
2y 5m to grant Granted Apr 07, 2026
Patent 12590615
BRAKE DISC SYSTEM
2y 5m to grant Granted Mar 31, 2026
Patent 12583578
AIRCRAFT LANDING GEAR ARRANGEMENT
2y 5m to grant Granted Mar 24, 2026
Patent 12580113
SOLENOID, DAMPING FORCE ADJUSTMENT MECHANISM, AND DAMPING FORCE ADJUSTABLE SHOCK ABSORBER
2y 5m to grant Granted Mar 17, 2026
Study what changed to get past this examiner. Based on 5 most recent grants.

AI Strategy Recommendation

Get an AI-powered prosecution strategy using examiner precedents, rejection analysis, and claim mapping.
Powered by AI — typically takes 5-10 seconds

Prosecution Projections

1-2
Expected OA Rounds
77%
Grant Probability
91%
With Interview (+14.3%)
2y 10m
Median Time to Grant
Low
PTA Risk
Based on 1174 resolved cases by this examiner. Grant probability derived from career allow rate.

Sign in with your work email

Enter your email to receive a magic link. No password needed.

Personal email addresses (Gmail, Yahoo, etc.) are not accepted.

Free tier: 3 strategy analyses per month