Prosecution Insights
Last updated: April 19, 2026
Application No. 19/109,739

STEAM TURBINE BLADE, STEAM TURBINE, AND METHOD FOR MANUFACTURING STEAM TURBINE BLADE

Non-Final OA §103
Filed
Mar 07, 2025
Examiner
BROCKMAN, ELDON T
Art Unit
3799
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Mitsubishi Heavy Industries Ltd.
OA Round
1 (Non-Final)
85%
Grant Probability
Favorable
1-2
OA Rounds
2y 5m
To Grant
91%
With Interview

Examiner Intelligence

Grants 85% — above average
85%
Career Allow Rate
587 granted / 690 resolved
+15.1% vs TC avg
Moderate +6% lift
Without
With
+6.0%
Interview Lift
resolved cases with interview
Typical timeline
2y 5m
Avg Prosecution
21 currently pending
Career history
711
Total Applications
across all art units

Statute-Specific Performance

§101
0.6%
-39.4% vs TC avg
§103
35.9%
-4.1% vs TC avg
§102
41.4%
+1.4% vs TC avg
§112
19.8%
-20.2% vs TC avg
Black line = Tech Center average estimate • Based on career data from 690 resolved cases

Office Action

§103
DETAILED ACTION The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . This action is in response to the claims filed 3/7/2025. Claims 1-13 are presented for examination. Priority Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55. Information Disclosure Statement The information disclosure statement (IDS) submitted on 6/20/2025 is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner. 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) 1-13 is/are rejected under 35 U.S.C. 103 as being unpatentable over Fandrei in US Patent Application Publication 2017/0167301 (hereinafter “Fandrei”) in view of Maeno in US Patent Application Publication 2007/0014670 (hereinafter “Maeno”). Regarding claim 1, Fandrei discloses a steam turbine blade comprising: a liquid phase guidance member that has a surface (see 135 in Fig. 2) on which recesses and projections for guiding liquid-phase water to a trailing edge side of the blade are formed (paragraph [0034]), or on which a hydrophilic coating is applied (the hydrophilic pattern itself is a hydrophilic coating); and a through-hole 137 for taking in the liquid-phase water guided by the liquid phase guidance member into an inner space of the blade (Fig. 2 and 3; paragraph [0041]). Fandrei is silent to a recess portion that is formed on a surface of a blade and the liquid phase guidance member being inserted into and fixed to the recess portion. Maeno teaches an analogous steam turbine blade, notably a blade featuring surface features and a drainage hole for collecting liquid-phase water, like the blade of Fandrei. Specifically, Maeno teaches that in forming such blades, it is desirable to form the water collection features (or a “liquid phase guidance member”) on a cover plate (or insert) that is mounted to a recess on the surface of the blade (Fig. 1-4). Such a configuration is desirable because it enables manufacture of blade surfaces with high profile accuracy by avoiding heat dissipation from other methods and is much easier and cheaper to manufacture (see paragraph [0042]). It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have modified the steam turbine blade of Fandrei by forming the liquid phase guidance member on a cover plate that is inserted into a recess on the blade surface because it enables manufacture of blade surfaces with high profile accuracy by avoiding heat dissipation from other methods and is much easier and cheaper to manufacture, as taught by Maeno, and the result would have been predictable. Regarding claim 2, Fandrei as modified by Maeno comprises the steam turbine blade according to Claim 1, wherein a height of a projecting portion of the recesses and projections in a blade thickness direction or a height of the surface of the liquid phase guidance member on which the hydrophilic coating is applied in the blade thickness direction is the same as a height of a blade surface of the blade in the blade thickness direction (see Fandrei paragraph [0034] which discloses a hydrophilic surface pattern formed by grooves in the surface of the blade skin; cutting grooves in the surface of the hydrophilic region necessarily results in “projections”, which are just the structure between grooves, that would be the same height as the rest of the blade skin; in other words, the “projections” between grooves would be flush with the rest of the blade skin). Regarding claim 3, this claim recites a product-by-process limitation that affords no distinguishing structure over the combination of art. See MPEP 2113. Regarding claim 4, Fandrei as modified by Maeno comprises the steam turbine blade according to Claim 1, wherein a region where the recesses and projections are formed or a region where the hydrophilic coating is applied is a part of a region of the liquid phase guidance member in a blade height direction (the liquid phase guidance member comprises the recesses and projections themselves, at a blade height or radial extent). Regarding claim 5, Fandrei as modified by Maeno comprises the steam turbine blade according to Claim 1, wherein the recess portion includes a first recess portion and a second recess portion formed at a position different from a position of the first recess portion in a blade height direction, and the liquid phase guidance member includes a first liquid phase guidance member that is inserted into and fixed to the first recess portion, and a second liquid phase guidance member that is inserted into and fixed to the second recess portion (see Fig. 5 of Fandrei with multiple regions, which have been modified based on the teaching of Maeno to be formed on cover plates attached to the blade instead of in a unitary/monolithic skin structure). Regarding claim 6, Fandrei as modified by Maeno comprises the steam turbine blade according to Claim 5, wherein a part of a region of the first liquid phase guidance member and a part of a region of the second liquid phase guidance member overlap each other in the blade height direction (see Fig. 5 of Fandrei with multiple regions, which have been modified based on the teaching of Maeno to be formed on cover plates attached to the blade instead of in a unitary/monolithic skin structure). Regarding claim 7, Fandrei as modified by Maeno comprises the steam turbine blade according to Claim 1, wherein the recesses and projections are formed by a plurality of grooves extending from a leading edge to a trailing edge of the blade (Fandrei Fig. 2, regions 135; paragraph [0034]). Regarding claim 8, Fandrei as modified by Maeno comprises the steam turbine blade according to Claim 7, wherein at least one of the plurality of grooves is formed in a linear shape when viewed from a blade thickness direction (see linear hydrophilic regions on the first rotor stage in Fig. 2 of Fandrei). Regarding claim 9, Fandrei as modified by Maeno comprises the steam turbine blade according to Claim 7, wherein at least one of the plurality of grooves is formed in a curved shape in at least a part of a region when viewed from a blade thickness direction (see the regions 135 on the second stage stator blade in Fig. 2 of Fandrei). Regarding claim 10, Fandrei as modified by Maeno comprises the steam turbine blade according to Claim 7, wherein an interval between two adjacent grooves among the plurality of grooves in a blade height direction is different between a region on a leading edge side and a region on the trailing edge side of the blade (see Fandrei paragraph [0037]-[0039] disclosing the use of varying groove dimensions in the hydrophilic region). Regarding claim 11, Fandrei as modified by Maeno comprises the steam turbine blade according to Claim 7, wherein at least one of the plurality of grooves has a width of the groove that is different between a region on a leading edge side and a region on the trailing edge side of the blade (see Fandrei paragraph [0037]-[0039] disclosing the use of varying groove dimensions in the hydrophilic region). Regarding claim 12, Fandrei as modified by Maeno comprises a steam turbine comprising: the steam turbine blade according to Claim 1 (the combination of art is a steam turbine blade in a steam turbine). Regarding claim 13, manufacture of the combination of Fandrei as modified by Maeno as applied above against claims 1-12 necessarily meets all of the method of manufacturing a steam turbine blade recited in claim 13, particularly as all of the steps are simply non-descript steps of forming a structure. Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.Relevant Prior Art: US1862827 discloses a steam turbine blade with various surface features for directing liquid water. US20070031639 discloses a method for making articles having low wettability including various different groove shapes and sizes. US11840938 discloses a steam turbine vane with water particle extraction slots. US4720239 discloses a turbine vane with a recessed pocket a cover plate positioned in the pocket with holes through the cover plate. US9745866 discloses a steam turbine blade moisture trap with a fine mesh body positioned in a recess of the blade surface and an orifice to extract liquid water. US12221900, notably commonly owned, discloses a steam turbine blade with hydrophilic regions of different orientations. JP11210404 discloses a steam turbine nozzle with an insert positioned in a groove on the surface of the blade and drain holes to capture liquid, and notably teaches the desirability of such an arrangement to make manufacturing easier. Any inquiry concerning this communication or earlier communications from the examiner should be directed to ELDON T BROCKMAN whose telephone number is (571)270-3263. The examiner can normally be reached Mon-Fri 9am-5pm EST. 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, Court Heinle can be reached at (571) 270-3508. 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. /ELDON T BROCKMAN/Primary Examiner, Art Unit 3799
Read full office action

Prosecution Timeline

Mar 07, 2025
Application Filed
Feb 20, 2026
Non-Final Rejection — §103 (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
85%
Grant Probability
91%
With Interview (+6.0%)
2y 5m
Median Time to Grant
Low
PTA Risk
Based on 690 resolved cases by this examiner. Grant probability derived from career allow rate.

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