Prosecution Insights
Last updated: April 19, 2026
Application No. 18/848,221

PRESSURE MEDIUM POWERED DEVICE GENERATING RECIPROCATING MOTION

Non-Final OA §103
Filed
Sep 18, 2024
Examiner
LETTMAN, BRYAN MATTHEW
Art Unit
3746
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Dynaset OY
OA Round
3 (Non-Final)
65%
Grant Probability
Moderate
3-4
OA Rounds
3y 2m
To Grant
99%
With Interview

Examiner Intelligence

Grants 65% of resolved cases
65%
Career Allow Rate
609 granted / 941 resolved
-5.3% vs TC avg
Strong +52% interview lift
Without
With
+52.5%
Interview Lift
resolved cases with interview
Typical timeline
3y 2m
Avg Prosecution
37 currently pending
Career history
978
Total Applications
across all art units

Statute-Specific Performance

§101
0.4%
-39.6% vs TC avg
§103
52.9%
+12.9% vs TC avg
§102
21.5%
-18.5% vs TC avg
§112
23.8%
-16.2% vs TC avg
Black line = Tech Center average estimate • Based on career data from 941 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 . Continued Examination Under 37 CFR 1.114 A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on March 3, 2026 has been entered. Response to Amendment Claims 1-19 remain pending in the application. 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 1-19 are rejected under 35 U.S.C. 103 as being unpatentable over U.S. Patent 5,683,230 to Karppinen in view of U. S. Patent 9,341,183 to Carruth. Referring to claim 1, Karppinen teaches a pressure medium powered device configured to generate a reciprocating motion, the pressure medium powered device comprising: a body (2), a primary piston (3) fitted inside the body (2), a control valve assembly (8, 9) which is configured to move the primary piston (3) back and forth, and at least one secondary piston (14, 15) attached to the primary piston (3) via a connector (“threaded screw-type connection”) (Figures 1-3; col. 2 line 8-col. 3 line 25), wherein the primary piston (3) includes a first threaded surface and the at least one secondary piston (14, 15) includes a corresponding second threaded surface, the primary piston (3) and the at least one secondary piston (14, 15) being aligned to each other, and wherein the primary piston (3) and the at least one secondary piston (14, 15) are immovably attached to each other (Figures 1-3; col. 2 line 8-col. 3 line 25). Karppinen teaches that the pistons are attached by threaded surfaces (col. 2 lines 20-21), but is silent as to the details of this connector. Carruth teaches threaded surfaces wherein: a primary piston (94) includes a first conical surface (100) and at least one secondary piston (12) includes a corresponding second conical surface (84), the primary piston (94) and the at least one secondary piston (12) being aligned to each other via the first conical surface (100) and the second conical surface (84), a connector (90, 98) that attaches the at least one secondary piston (12) to the primary piston (94) being separate from the first (100) and second (84) conical surfaces that align the primary piston (94) and the at least one secondary piston (12) to each other (Fig. 7; col. 5 line 66 - col. 6 line 23). It would have been obvious before the invention was effectively filed, to a person having ordinary skill in the art, to modify threaded connection taught by Karppinen with the threaded connection (connector) taught by Carruth in order to use a connection that will pull tight and align the connection when screwed together, and because it has been held that a simple substitution of one known element, the connection and taper of Carruth, for another, the connection of Karppinen, to obtain predictable results, a secure connection, was an obvious extension of prior art teachings, KSR, 550 U.S. at 419, 82 USPQ2d at 1396, MPEP 2141 III B. Referring to claim 2, Karppinen and Carruth teach a pressure medium powered device comprising all the limitations of claim 1, as detailed above, and Karppinen further teaches wherein: a central axis of the primary piston (3) and a central axis of the at least one secondary piston (14, 15) are on a same axis line (Figures 1-3; col. 2 line 8-col. 3 line 25). Referring to claim 3, Karppinen and Carruth teach a pressure medium powered device comprising all the limitations of claim 1, as detailed above, and while Karppinen teaches that the pistons are attached by threaded surfaces (col. 2 lines 20-21), Karppinen is silent as to the details of the threaded surfaces. Carruth further teaches threaded surfaces wherein: the end of the at least one secondary piston (12) is fitted inside the primary piston (94), such that the conical surface of the primary piston (94) is the inner surface of a cone and the conical surface of the at least one secondary piston (12) is the outer surface of the cone (Fig. 7; col. 5 line 66 - col. 6 line 23). Referring to claim 4, Karppinen and Carruth teach a pressure medium powered device comprising all the limitations of claim 1, as detailed above, and Karppinen further teaches wherein: a front surface of the primary surface piston (3) facing the at least one secondary piston (14, 15) does not touch the at least one secondary piston (14, 15) (Figures 1-3, wherein Fig. 2 shows surfaces of the primary piston 3, comprising 12 and 7, which are radially larger than the secondary pistons and therefore not touch the at least one secondary piston 14, 15; col. 2 line 8-col. 3 line 25). Referring to claim 5, Karppinen and Carruth teach a pressure medium powered device comprising all the limitations of claim 1, as detailed above, and Karppinen further teaches wherein: the primary piston (3) and the at least one secondary piston (14, 15) are attached to each other by a thread connection (Fig. 2; col. 2 lines 20-21). Referring to claim 6, Karppinen and Carruth teach a pressure medium powered device comprising all the limitations of claim 1, as detailed above, and while Karppinen teaches that the pistons are attached by threaded surfaces (col. 2 lines 20-21), Karppinen is silent as to the details of the threaded surfaces. Carruth further teaches threaded surfaces wherein: the conical ratio of the conical surfaces is at least 1:20 (Fig. 7; col. 5 line 66 - col. 6 line 23). Referring to claim 7, Karppinen and Carruth teach a pressure medium powered device comprising all the limitations of claim 1, as detailed above, and while Karppinen teaches that the pistons are attached by threaded surfaces (col. 2 lines 20-21), Karppinen is silent as to the details of the threaded surfaces. Carruth further teaches threaded surfaces wherein: the conical ratio of the conical surfaces is no more than 1:1 (Fig. 7; col. 5 line 66 - col. 6 line 23). Referring to claim 8, Karppinen and Carruth teach a pressure medium powered device comprising all the limitations of claim 1, as detailed above, but do not teach the use as a booster pump. However, it has been held that the recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus satisfying the claimed structural limitations. Ex part Masham, 2 USPQ2d 1647 (1987). The recitation of the device used as a booster pump is a recitation with respect to the manner in which the claimed apparatus is intended to be employed and does not differentiate the claimed apparatus from the prior art. Referring to claim 9, Karppinen teaches a pump configured to generate a reciprocating motion, the pump comprising: a body (2), a primary piston (3) fitted inside the body (2), a control valve assembly (8, 9) configured to move the primary piston (3) back and forth, and at least one secondary piston (14, 15) attached to the primary piston (3) via a connector (“threaded screw-type connection”) (Figures 1-3; col. 2 line 8-col. 3 line 25), wherein the primary piston (3) includes a first surface and the at least one secondary piston (14, 15) includes a corresponding second surface, the primary piston (3) and the at least one secondary piston (14, 15) being aligned to each other (Figures 1-3; col. 2 line 8-col. 3 line 25), and wherein a front surface of the primary surface piston (3) facing the at least one secondary piston (14, 15) does not touch the at least one secondary piston (14, 15) (Figures 1-3, wherein Fig. 2 shows surfaces of the primary piston 3, comprising 12 and 7, which are radially larger than the secondary pistons and therefore not touch the at least one secondary piston 14, 15; col. 2 line 8-col. 3 line 25). Karppinen teaches that the pistons are attached by threaded surfaces (col. 2 lines 20-21), but is silent as to the details of the threaded surfaces. Carruth teaches threaded surfaces wherein: a primary piston (94) includes a first conical (100) and at least one secondary piston (12) includes a corresponding second conical surface (84), the primary piston (94) and the at least one secondary piston (12) being aligned to each other via the first conical surface (100) and the second conical surface (84), a connector (90, 98) that attaches the at least one secondary piston (12) to the primary piston (94) being separate from the first (100) and second (84) conical surfaces that align the primary piston (94) and the at least one secondary piston (12) to each other (Fig. 7; col. 5 line 66 - col. 6 line 23). It would have been obvious before the invention was effectively filed, to a person having ordinary skill in the art, to modify threaded connection taught by Karppinen with the threaded connection taught by Carruth in order to use a connection that will pull tight and align the connection when screwed together, and because it has been held that a simple substitution of one known element, the connection and taper of Carruth, for another, the connection of Karppinen, to obtain predictable results, a secure connection, was an obvious extension of prior art teachings, KSR, 550 U.S. at 419, 82 USPQ2d at 1396, MPEP 2141 III B. Referring to claim 10, Karppinen and Carruth teach a pressure medium powered device comprising all the limitations of claim 9, as detailed above, and Karppinen further teaches wherein: a central axis of the primary piston (3) and a central axis of the at least one secondary piston (14, 15) are on a same axis line (Figures 1-3; col. 2 line 8-col. 3 line 25). Referring to claim 11, Karppinen and Carruth teach a pressure medium powered device comprising all the limitations of claim 9, as detailed above, and while Karppinen teaches that the pistons are attached by threaded surfaces (col. 2 lines 20-21), Karppinen is silent as to the details of the threaded surfaces. Carruth further teaches threaded surfaces wherein: the end of the at least one secondary piston (12) is fitted inside the primary piston (94), such that the conical surface of the primary piston (94) is the inner surface of a cone and the conical surface of the at least one secondary piston (12) is the outer surface of the cone (Fig. 7; col. 5 line 66 - col. 6 line 23). Referring to claim 12, Karppinen and Carruth teach a pressure medium powered device comprising all the limitations of claim 9, as detailed above, and Karppinen further teaches wherein: the primary piston (3) and the at least one secondary piston (14, 15) are attached to each other by a thread connection (Fig. 2; col. 2 lines 20-21). Referring to claim 13, Karppinen teaches a pressure medium powered device configured to generate a reciprocating motion, the pressure medium powered device comprising: a body (2), a primary piston (3) fitted inside the body (2), a control valve assembly (8, 9) configured to move the primary piston (3) back and forth, and at least one secondary piston (14, 15) attached to the primary piston (3) (Figures 1-3; col. 2 line 8-col. 3 line 25), wherein the primary piston (3) includes a first threaded surface and the at least one secondary piston (14, 15) includes a corresponding second threaded surface, the primary piston (3) and the at least one secondary piston (14, 15) being aligned to each other (Figures 1-3; col. 2 line 8-col. 3 line 25). Karppinen teaches that the pistons are attached by threaded surfaces (col. 2 lines 20-21), but is silent as to the details of the threaded surfaces. Carruth teaches threaded surfaces wherein: a primary piston (94) includes a first conical (100) and at least one secondary piston (12) includes a corresponding second conical surface (84), the primary piston (94) and the at least one secondary piston (12) being aligned to each other via the first conical surface (100) and the second conical surface (84), a connector (90, 98) that attaches the at least one secondary piston (12) to the primary piston (94) being separate from the first (100) and second (84) conical surfaces that align the primary piston (94) and the at least one secondary piston (12) to each other, wherein the conical ratio of the conical surfaces is at least 1:20 or the conical ratio of the conical surfaces is no more than 1:1 (Fig. 7; col. 5 line 66 - col. 6 line 23). It would have been obvious before the invention was effectively filed, to a person having ordinary skill in the art, to modify threaded connection taught by Karppinen with the threaded connection taught by Carruth in order to use a connection that will pull tight and align the connection when screwed together, and because it has been held that a simple substitution of one known element, the connection and taper of Carruth, for another, the connection of Karppinen, to obtain predictable results, a secure connection, was an obvious extension of prior art teachings, KSR, 550 U.S. at 419, 82 USPQ2d at 1396, MPEP 2141 III B. Referring to claim 14, Karppinen and Carruth teach a pressure medium powered device comprising all the limitations of claim 13, as detailed above, and Karppinen further teaches wherein: a central axis of the primary piston (3) and a central axis of the at least one secondary piston (14, 15) are on a same axis line (Figures 1-3; col. 2 line 8-col. 3 line 25). Referring to claim 15, Karppinen and Carruth teach a pressure medium powered device comprising all the limitations of claim 13, as detailed above, and while Karppinen teaches that the pistons are attached by threaded surfaces (col. 2 lines 20-21), Karppinen is silent as to the details of the threaded surfaces. Carruth further teaches threaded surfaces wherein: the end of the at least one secondary piston (12) is fitted inside the primary piston (94), such that the conical surface of the primary piston (94) is the inner surface of a cone and the conical surface of the at least one secondary piston (12) is the outer surface of the cone (Fig. 7; col. 5 line 66 - col. 6 line 23). Referring to claim 16, Karppinen and Carruth teach a pressure medium powered device comprising all the limitations of claim 13, as detailed above, and Karppinen further teaches wherein: the primary piston (3) and the at least one secondary piston (14, 15) are attached to each other by a thread connection (Fig. 2; col. 2 lines 20-21). Referring to claim 17, Karppinen and Carruth teach a pressure medium powered device comprising all the limitations of claim 13, as detailed above, and Karppinen further teaches wherein: wherein a front surface of the primary surface piston (3) facing the at least one secondary piston (14, 15) does not touch the at least one secondary piston (14, 15) (Figures 1-3, wherein Fig. 2 shows surfaces of the primary piston 3, comprising 12 and 7, which are radially larger than the secondary pistons and therefore not touch the at least one secondary piston 14, 15; col. 2 line 8-col. 3 line 25). Referring to claim 18, Karppinen and Carruth teach a pressure medium powered device comprising all the limitations of claim 13, as detailed above, and while Karppinen teaches that the pistons are attached by threaded surfaces (col. 2 lines 20-21), Karppinen is silent as to the details of the threaded surfaces. Carruth further teaches threaded surfaces wherein: the conical ratio of the conical surfaces is at least 1:20 (Fig. 7; col. 5 line 66 - col. 6 line 23). Referring to claim 19, Karppinen and Carruth teach a pressure medium powered device comprising all the limitations of claim 13, as detailed above, and while Karppinen teaches that the pistons are attached by threaded surfaces (col. 2 lines 20-21), Karppinen is silent as to the details of the threaded surfaces. Carruth further teaches threaded surfaces wherein: the conical ratio of the conical surfaces is no more than 1:1 (Fig. 7; col. 5 line 66 - col. 6 line 23). Response to Arguments Applicant's arguments filed on March 3, 2026 have been considered but, are moot in view of the new grounds of rejection. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to BRYAN MATTHEW LETTMAN whose telephone number is (571)270-7860. The examiner can normally be reached Monday-Friday 8am-4pm. 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, Essama Omgba can be reached at 469-295-9278. 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. /BRYAN M LETTMAN/Primary Examiner, Art Unit 3746
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Prosecution Timeline

Sep 18, 2024
Application Filed
Aug 22, 2025
Non-Final Rejection — §103
Nov 24, 2025
Response Filed
Nov 25, 2025
Examiner Interview (Telephonic)
Dec 13, 2025
Final Rejection — §103
Feb 17, 2026
Response after Non-Final Action
Mar 03, 2026
Request for Continued Examination
Mar 10, 2026
Response after Non-Final Action
Mar 20, 2026
Non-Final Rejection — §103 (current)

Precedent Cases

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

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Prosecution Projections

3-4
Expected OA Rounds
65%
Grant Probability
99%
With Interview (+52.5%)
3y 2m
Median Time to Grant
High
PTA Risk
Based on 941 resolved cases by this examiner. Grant probability derived from career allow rate.

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