DETAILED ACTION
This office action is in response to the amendments to the claims filed on 25 February 2026. Claims 1, 4, 7 and 8 are pending and currently being examined.
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.
Claim(s) 1, 4, 7 and 8 is/are rejected under 35 U.S.C. 103 as being unpatentable over McLean (PG Pub US 20170306986 A1) in view of Oklejas375 (US Patent 10,933,375 B1) and in view of Thatte (PG Pub US 20190390576 A1) and in view of Oklejas774 (PG Pub US 20160215774 A1) and in view of Sigurdsson (European Patent EP 3020968 A1) and as evidenced by Bourcier (US Patent 2,821,268 A) and as evidenced by Renault (French Patent CH 334056 A, Machine Translation provided) and further in view of Nikanth (US Patent 5,879,010 A).
In Re Claim 1, McLean discloses a hydraulic energy transfer system (paragraph [0021]) comprising: a pressure exchanger (20; Figure 3; paragraph [0025]) configured to exchange pressure between a first fluid (“mud”; paragraph [0025]) and a second fluid (“energizing fluid”; paragraph [0025]), the pressure exchanger comprising: a rotor (44; paragraph [0027]; Figure 3) forming a plurality of ducts (68; Figure 3; paragraph [0027]) extending from a first distal end of a rotor (44) to a second distal end of the rotor (44), the plurality of ducts comprising a duct (68; Figure 3; paragraph [0027]) extending from a first duct opening (70) formed by the first distal end of the rotor (44) to a second duct opening (72) formed by the second distal end the rotor (44), the first duct opening (70) and the second duct opening (72) having a first opening width (i.e. internal diameter of the duct 68), wherein the pressure exchanger (20) is configured to direct the first fluid to the first duct opening (via intake 60) and the second fluid to the second duct opening (via intake 54); a plurality of floating pistons (“fluid separator .. .. piston”; paragraph [0026]) disposed within the plurality of ducts (68), the plurality of floating pistons comprising a floating piston (“fluid separator .. .. piston”; paragraph [0026]) disposed within the duct (68), wherein the floating piston (“fluid separator ... .. piston”) is configured to move within the duct (68) between the first duct opening (70) and the second duct opening (72) to prevent mixing of the first fluid and the second fluid (since it is described as a “fluid separator”) while exchanging the pressure between the first fluid and the second fluid within the duct (paragraph [0028]: “exchange of pressure”).
Although McLean discloses a first adapter plate (62) and second adapter plate (64), McLean does not disclose the claimed details of the first and second adapter plates.
However, Figure 13A Oklejas375 discloses a rotor (112’; note that “rotor” and “stator” are interchangeable per Figures 2 and 5; it is only a matter of which of the relatively rotating elements is kept stationary and which one is rotating) having a first adapter plate (1320A) comprising a first planar surface disposed adjacent to the first duct opening (left end of 214A), wherein the first adapter plate is configured to prevent the plurality of floating pistons (1310) from exiting the plurality of ducts at the first distal end of the rotor (to the left of 112’), wherein the first planar surface is secured to the first distal end of the rotor (in order for the apparatus to function as disclosed), and wherein the first adapter plate (1320A) forms a first aperture (1322A) that directs the first fluid to the first duct opening; and a second adapter plate (1320B) comprising a second planar surface disposed adjacent to the second duct opening (right end of 214A), wherein the second adapter plate is configured to prevent the plurality of floating pistons (1310) from exiting the plurality of ducts at the second distal end of the rotor (to the right of 112’), wherein the second planar surface is secured to the second distal end of the rotor (in order for the apparatus to function as disclosed), and wherein the second adapter plate forms a second aperture (1322B) that directs the second fluid to the second duct opening (Column 13, Line 9 – Column 14, Line 3).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed the invention to configure the rotor (44) of McLean such that it comprises a middle section (112’), a first adapter plate (1320A) and a second adapter plate (1320B) as taught by Oklejas375, as is known in the art.
Oklejas375 is silent with regards to how the adapter plates (1320A, 1320B) are secured to the rotor (112’), therefore McLean and Oklejas375 do not explicitly disclose securing elements.
However, Figure 8 of Thatte discloses a rotor (46) having an adapter plate (104, 122) comprising a first planar surface (facing 102 in Figure 9) disposed adjacent to the first duct opening (end of 70), wherein the first planar surface is secured to the first distal end of the rotor via a plurality of first securing elements (110) comprising one or more first securing elements extending through the first planar surface and into the rotor proximate a center of the rotor (there are 5 depicted next to the inner circumference) and one or more second securing elements (110) extending through the first planar surface into the rotor proximate a perimeter of the rotor (there are 5 depicted next to the outer circumference), and wherein the first adapter plate forms a first aperture (72) that directs the first fluid to the first duct opening (paragraph [0045]).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed the invention to secure the first and second adapter plates of McLean / Oklejas375 to the rotor via first and second securing elements as taught by Thatte because it is only a matter of substituting the broadly disclosed securing elements of Oklejas375 with the specifically disclosed securing elements of Thatte, therefore the results of the substitution are predictable (MPEP 2141, Section III, Rationale E). – "[I]n many cases a person of ordinary skill will be able to fit the teachings of multiple patents together like pieces of a puzzle." KSR Intl. Co. v. Teleflex Inc. at 420, 82 USPQ2d at 1397; The rigid requirement of a teaching, suggestion, or motivation to combine known elements in order to show obviousness has been rejected. Id. At 398,419 (2007). This a rationale that can be used to support a conclusion of obviousness.
McLean is silent with regards to the structural details of the piston; therefore Mclean, Oklejas375 and Thatte do not disclose that the piston is substantially symmetrical.
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However, Figure 1 of Oklejas774 discloses a pressure exchanger (described as “dual work exchanger”) having a floating piston (9; paragraph [0027]) that is substantially symmetrical about a central axis transverse to its longitudinal axis (see annotated figure above), and has a cylindrical central portion (see annotated figure above) comprising a perimeter surface that forms a fluid seal (paragraph [0016]) within the duct (10), a first face (at the left end of the central portion), a second face (at the right end of the central portion), a first cylindrical distal portion (see annotated figure above) extending from the first face, a second cylindrical distal portion (see annotated figure above) extending from the second face, a first adapter plate (1, 2, 3) and second adapter plate (14).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed the invention to have used the floating piston of Oklejas774 as the piston of McLean / Oklejas375 / Thatte as simple substitution of one known element for another to obtain predictable results (MPEP 2143, Section I, Rationale B).
McLean, Oklejas375, Thatte and Oklejas774 do not explicitly disclose that a first distal portion is configured to fit within the first aperture of the first adapter plate; and a second distal portion is configured to fit within the second aperture of the second adapter plate.
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However, Figure 6 of Sigurdsson discloses a floating piston (23, 24, 25) comprising a cylindrical middle portion (24) comprising a perimeter surface, a first/second face (at the junction between 24 and 25) configured to contact the first/second planar surface of the first/second adapter plate (20), a first/second tapered (see annotated figure above) distal portion (25) extending from the first/second face and configured to fit within the first/second aperture (31) of the first/second adapter plate (20), a first adapter plate (20) and a second adapter plate (21), at least a first adapter plate (20) is configured to prevent the floating piston (15) from exiting the duct (4) at the first duct opening (paragraph [0034]: “end stop”), and wherein at least the first adapter plate (20) forms a first aperture (internal bore of 20 in Figure 2) that directs the first fluid to the first duct opening (end of 16 adjacent to 20), wherein a first distal portion (25) of floating piston (15) is configured to fit within the first aperture of the first adapter plate (paragraph [0051]), wherein the floating piston (15) has a hydraulic braking feature (see title) where the first / second tapered distal portion (25) is configured to enter the first / second aperture (31) to create a corresponding pocket (30; paragraph [0052]) that increases proportionally to piston velocity (because fluid is forced to flow through a throttled passage 33/34, in such a configuration fluid is forced through the passage 33/34 in the piston causing hydraulic braking proportional to the piston velocity as evidenced by Bourcier in Column 4, Lines 54 – 57).
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It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed the invention to modify the first and second adapter plates of McLean / Oklejas375 / Thatte / Oklejas774 such that the first distal portion (Oklejas774) is configured to fit within the first aperture of a first adapter plate as taught by Sigurdsson; and a second distal portion (Oklejas774) configured to fit within the second aperture of a second adapter plate as taught by Sigurdsson (see annotated figure above that shows modification at one of the distal ends) for the purpose of providing hydraulic breaking (title) to reduce the severity of impact between the piston and the adapter plates, and because it is known to provide braking at both tapered ends of a substantially symmetrical piston as evidenced by Renault’s piston (4, 17, 18; Figure 13; Translation Page 7 Lines 23 – 30) which has braking at both ends (pocket 9 provides dampening/braking for reduced diameter end 17 and pocket 25 provides dampening/braking for reduced diameter end 18), therefore the results of the modification are predictable (MPEP 2141, Section III, Rationale D).
Although Oklejas774 discloses sealing around the piston (paragraphs [0016],[0027]), McLean, Oklejas375, Thatte, Oklejas774 and Sigurdsson do not specifically disclose a first and second sealing element with different threshold values.
However, Figure 1 of Nikanth discloses a sealing system between a piston (12) and a duct (cylinder bore 14), Figure 11 shows an embodiment where piston (312) comprises a cylindrical portion having a perimeter surface (the outline of 312 including 318), wherein a first sealing element (321) is disposed around the perimeter surface and forms that forms a fluid seal within the duct (314), wherein a second sealing element (323) is disposed around the perimeter surface between the perimeter surface (318) and the first sealing element (321), the first sealing element (321) meeting a first threshold value (“rigid” – Column 11, Line 43) and the second sealing element (323) meeting a second threshold value (“softer expander element” – Column 11, Line 44) that is different than the first threshold value (Column 11, Lines 17 – 55; Figures 1 and 11).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed the invention to incorporate the first and second sealing elements as taught by Nikanth around the perimeter surface of the piston of McLean / Oklejas375 / Thatte / Oklejas774 / Sigurdsson because it is only a matter of substituting the broadly disclosed sealing arrangement of Oklejas774 with the specifically disclosed sealing arrangement of Nikanth, therefore the results of the substitution are predictable (MPEP 2141, Section III, Rationale B).
In Re Claim 4, the combined references disclose all the limitations of Claim 1, and although McLean does not explicitly disclose an electric motor, the rotor of conventional pressure exchangers known in the art is typically driven by an electric motor configured to drive rotation of the rotor.
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In Re Claim 7, the combined references above disclose all the limitations of Claim 1, and Sigurdsson discloses (annotated figure above) that the first aperture has a first aperture width, wherein the first opening width of the first duct opening formed by a first distal end of the rotor is larger than the first aperture width, and wherein the floating piston comprises the cylindrical central portion having a central portion width substantially equal to the first opening width; and the first cylindrical distal portion having a distal portion width (labeled “second portion width” in annotated figure above) smaller than the first opening width; and Oklejas774 discloses that the second distal portion having the same distal portion width as the first cylindrical distal portion.
In Re Claim 8, the combined references above disclose all the limitations of Claim 7, and Sigurdsson discloses responsive to being in a first position (as shown in in Figure 6), the central portion (24) of the floating piston (15) forms a sealed pocket (30 – in view of the Oklejas774 (paragraph [0016]) modification which provides sealing around the piston; note that paragraph [0053] states that an orifice or bleed {34} is not necessary; note that paragraph [0052] states that 31 is completely closed by protrusion 25) of fluid between the floating piston (15), a surface of the duct (4), and the first adapter plate (20); and a braking force is to be applied to the floating piston (15) responsive to the floating piston (15) approaching the first duct opening (end of 16 adjacent to 20)(paragraphs [0047]-[0053]).
Response to Arguments
Applicant’s has not as such presented any arguments with regards to the claims, and appears to be referring to an alleged agreement in the 12/2/2025 Interview that the amendments overcome the prior art. However, no such agreement was reached. As clearly stated (to the contrary) in the Examiner’s Interview summary: “With regards to Claim 1, although Sigurdsson does not disclose braking at both ends of the piston, however, this is routine skill in the art and does not appear to be a patentable feature. No agreement was reached”.
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.
Contact Information
Any inquiry concerning this communication or earlier communications from the examiner should be directed to DNYANESH G KASTURE whose telephone number is (571)270-3928. The examiner can normally be reached Mon-Thu, 7:30 AM to 6:00 PM.
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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.
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/D.G.K/Examiner, Art Unit 3746
/ESSAMA OMGBA/Supervisory Patent Examiner, Art Unit 3746
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