DETAILED ACTION
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 June 29, 2026 has been entered.
Response to Amendment
The Amendment filed June 29, 2026 has been entered. Claims 1 – 17 are pending in the application. The amendment to the claims has overcome the claim objections set forth in the last Final Action mailed January 27, 2026.
Claim Objections
Claims 1 – 17 are objected to because of the following informalities:
Claim 1, lines 18-19: “the dosing unit, and provide the dosing fluid from the environmental fluid, and provide the dosing fluid from the environmental fluid” should read --the dosing unit
Claims 2 – 17 are objected to for being dependent on claim 1.
Appropriate correction is required.
Claim Interpretation
The limitation “a dosing unit” in claim 1 is interpreted under 35 U.S.C. 112(f) as noted in the Non-Final Action, dated 06/04/2025.
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.
Claims 1 – 10 and 12 – 17 are rejected under 35 U.S.C. 103 as being unpatentable over Felix et al. (US 2020/0340480 – herein after Felix) in view of Landi et al. (US 2016/0341209 – herein after Landi; cited by applicant on IDS dated 05/20/2024).
In reference to claim 1, Felix teaches a submersible pump (1; see fig. 4) for conveying a process fluid (see ¶96; “process fluid” = fluid pumped by pump unit 3) and configured to be completely immersed in an environmental fluid (see ¶10; “environmental fluid” = seawater), the pump comprising:
a common housing (2, see fig.4 & ¶44) having a first compartment (space within “drive housing” in view of disclosure in ¶44) configured to be filled with a dosing fluid (fluid that acts as a coolant; viewed as fluid indicated by arrow C71 in fig. 4 and in view of disclosure in ¶90), and a second compartment (space within “pump housing” in view of disclosure in ¶44) configured to be filled with the process fluid, a first flow passage (via bearing 53, see fig. 4) is disposed between the first compartment (viewed as space in housing 2 above 53, in view of fig. 4) and the second compartment (viewed as space in housing 2 below 53, in view of fig. 4);
a pump unit (3, see ¶44 and fig. 4) arranged in the common housing (2);
a drive unit (4, see ¶44 and fig. 4) arranged in the common housing (2),
the common housing comprising an inlet (21, see ¶48 and fig. 4) and an outlet (22, see ¶48 and fig. 4) for the process fluid,
the pump unit comprising a pump shaft (5, see ¶49 and fig. 4) extending from a drive end (51) to a non-drive end (52) of the pump shaft and configured to rotate about an axial direction (A), and a hydraulic unit having at least one impeller (31, see ¶50 and fig. 4) fixedly mounted on the pump shaft to convey the process fluid from the inlet to the outlet,
the drive unit comprising a drive shaft (42, see ¶67 and fig. 4) connected to the drive end of the pump shaft to drive rotation of the pump shaft, and an electric motor (41, see ¶67 and fig. 4) configured to rotate the drive shaft about the axial direction,
the electric motor arranged inside the first compartment and the hydraulic unit arranged inside the second compartment (as evident from fig. 4), and the pump is a seal-less pump without a mechanical seal at the pump shaft and the drive shaft (see ¶17).
Felix remains silent on the submersible pump comprising “a dosing unit configured to receive the environmental fluid directly from the environment surrounding the dosing unit, and provide the dosing fluid from the environmental fluid, and the dosing unit configured to dose a presettable amount of the dosing fluid into the first compartment and through the first flow passage into the second compartment”.
However, Landi teaches a similar submersible pump system (see embodiment in fig. 5) comprising a dosing unit [300, see ¶56: subsea boosting station 300 comprises of components such as pump, valves 310, 312, reverse osmosis device 310, expansion tank 314] configured to receive the environmental fluid (seawater) directly from the environment surrounding the dosing unit, and provide the dosing fluid [barrier fluid; note that “dosing fluid” = fresh water/desalinated water mixed with glycol] from the environmental fluid (water), and the dosing unit configured to dose a presettable amount of the dosing fluid (barrier fluid) into the first compartment (motor compartment) and through the first flow passage (within seal 19) into the second compartment (pump compartment) [see ¶18: “Extracted desalinated water may additionally be supplied to a pump shaft bearing in the non-driven end of the pump. In one embodiment the extraction water is injected between dual seals defining a barrier fluid chamber that separates the seawater in the pump from lubricant supplied to the pump shaft bearing. In another embodiment the extraction water is flushed through the pump shaft bearing for lubrication. In both cases extraction water may be allowed to migrate into the raw seawater in the pump”; ¶50: “Excessive water may be allowed to migrate from the barrier fluid chamber 20 into the pump”; also in view of disclosure in ¶56: because the barrier fluid is maintained at an overpressure of approximately 25 bar relative to the pump cavity, the directional flow across the seal arrangement 406 naturally bleeds/migrates from the motor compartment/barrier chamber into the pump chamber/compartment].
It would have been obvious to the person of ordinary skill in the art before the effective filing date of the invention to modify the submersible pump of Felix for utilizing dosing unit as taught by Landi in order to protect internal motor components from process fluid ingress while eliminating bulky topside umbilical conduits and surface hydraulic power unit, as recognized by Landi (see ¶58). The modification is viewed as “removal/closing of passage with fluid flow C7 in Felix and coupling Landi’s dosing unit to Felix’s fluid flow passages 101 & 102”.
Thus, Felix, as modified by Landi, teaches the submersible pump, comprising a dosing unit (using teaching of Landi) configured to receive the environmental fluid directly from the environment surrounding the dosing unit, and provide the dosing fluid from the environmental fluid, and the dosing unit configured to dose a presettable amount of the dosing fluid into the first compartment (space within “drive housing” in view of disclosure in ¶44 of Felix) and through the first flow passage (via bearing 53, see fig. 4 of Felix) into the second compartment (viewed as space in housing 2 below 53, in view of fig. 4 of Felix).
With respect to the limitation “dosing unit”: this limitation is being interpreted under 35 USC 112(f), wherein the dosing unit = unit comprising of a positive displacement pump and filtration/treatment apparatus.
Felix, as modified by Landi, teaches the dosing unit that comprises of a pump and treatment apparatus pump [see Landi’s fig. 5: unit 300 comprises of a pump (evident from pump’s schematic shown upstream of device 309) and treatment device (reverse osmosis device 309)].
Felix, as modified by Landi, remains silent on the pump being a positive displacement pump.
However, “positive displacement pumps” are well known in the art. Applicant in the filed specification (see ¶82 of filed specification) has not disclosed any criticality or unexpected results in the filed specification with respect to having the dosing unit in the form of a positive displacement pump. Thus, in absence of any criticality, the mere selection of a specific type of pump (positive displacement) would have been obvious to the person of ordinary skill in the art before the effective filing date of the invention in the modified pump of Felix as a matter of design choice. One of ordinary skill in the art, furthermore, would have expected the modified Felix’s submersible pump to perform equally well with claimed dosing unit comprising a positive displacement pump.
In reference to claim 2, Felix, as modified, teaches the submersible pump, wherein (see fig. 4 of Felix) the first compartment (space above 53) is arranged adjacent to the second compartment (space below 53) with respect to the axial direction (↨ direction), a first partition wall (wall in which bearing 53 is disposed) is disposed between the first compartment and the second compartment, the first flow passage (present in view of fluid flowing through bearing 53; see fluid arrow C73) is arranged in the first partition wall, and (as evident from fig. 4) the pump shaft (5) or the drive shaft extends through the first flow passage.
In reference to claim 3, Felix, as modified, teaches the submersible pump, further comprising (see fig. 4 of Felix and ¶61) a balance drum (7) fixedly connected to the pump shaft (5) between the hydraulic unit (31) and the drive end (51) of the pump shaft (5), a relief passage (73) is disposed between the balance drum and a stationary part (26) configured to be stationary with respect to the common housing, and a balance line (9, see ¶64) is configured to return the process fluid passing through the relief passage to a low pressure location of the pump unit.
In reference to claim 4, Felix, as modified, teaches the submersible pump, wherein (see fig. 4 of Felix) further comprising a first pump bearing unit (53, see ¶57) and a second pump bearing unit (54, see ¶57) to support the pump shaft (5), and a first motor bearing unit (44, see ¶67) and a second motor bearing unit (43, see ¶67) to support the drive shaft (42), the first pump bearing unit (53) is arranged between the hydraulic unit (31) and the drive end (51) of the pump shaft (5), the second pump bearing unit (54) is arranged between the hydraulic unit (31) and the non-drive end (52) of the pump shaft (5), and the electric motor (41) is arranged between the first motor bearing unit (44) and the second motor bearing unit (43) in the axial direction (A).
In reference to claim 5, Felix, as modified, teaches the submersible pump, wherein (see fig. 4 of Felix) the first pump bearing unit (53), the second pump bearing unit (54), the first motor bearing unit (44) and the second motor bearing unit (43) are each configured to be lubricated by the process fluid or by the dosing fluid (capable of being lubricated by dosing fluid in the modified pump of Felix; this is further evident from Felix’s fig. 4).
In reference to claim 6, Felix, as modified, teaches the submersible pump, wherein (see fig. 4 of Felix) the first pump bearing unit (53) and the second pump bearing unit (54) are arranged in the second compartment (in this case, “second compartment” is viewed as space in housing 2 below coupling 8 in fig. 4).
In reference to claim 7, Felix, as modified, teaches the submersible pump, wherein (see fig. 4 of Felix) the first motor bearing unit (44) and the second motor bearing unit (43) are arranged in the first compartment (in this case, “first compartment” is viewed as space in housing 2 above bearing 53 in fig. 4).
In reference to claim 8, Felix, as modified, teaches the submersible pump, wherein (see fig. 4 of Felix) the first pump bearing unit (53), the first motor bearing unit (44) and the second motor bearing unit (43) are arranged in the first compartment (in this case, “first compartment” is viewed as space in housing 2 above port 91 in fig. 4).
In reference to claim 9, Felix, as modified, teaches the submersible pump, wherein (see fig. 4 of Felix) the common housing (2) comprises a third compartment (space below 54) configured to be filled with the dosing fluid (coolant), the second compartment (space in housing 2 between bearing 53 and bearing 54) is arranged in the axial direction (A) between the first compartment (space in housing 2 above bearing 53) and the third compartment (space in housing 2 below bearing 54), a second flow passage (present in view of fluid flowing through bearing 54; see fluid arrow C72) is disposed between the third compartment and the second compartment, the dosing unit (provided using the teaching of Landi) is configured to dose an amount of the dosing fluid into the third compartment and through the second flow passage into the second compartment, and the second pump bearing unit is arranged in the third compartment.
In reference to claim 10, Felix, as modified, teaches the submersible pump, (see fig. 4 of Felix) wherein a second partition wall (wall in which bearing 54 is disposed) is disposed between the third compartment and the second compartment, the second flow passage (present in view of fluid/coolant flowing through bearing 54; see fluid arrow C72) is arranged in the second partition wall, and the pump shaft (5) extends through the second flow passage.
In reference to claim 12, Felix, as modified, teaches the submersible pump, wherein (see fig. 4 of Felix and ¶32) the submersible pump is a vertical pump with the pump shaft (5) extending in the direction of gravity (↓ direction).
In reference to claim 13, Felix, as modified, teaches the submersible pump, wherein (see fig. 4 of Felix and ¶32) the drive unit (4) is arranged on top of the pump unit (3).
In reference to claim 14, Felix, as modified, teaches the submersible pump, wherein the submersible pump is a subsea pump (see ¶10 of Felix).
In reference to claim 15, Felix, as modified, teaches the submersible pump, wherein the submersible pump is a water injection pump configured to inject the process fluid (see ¶10 or ¶45 of Felix).
In reference to claim 16, Felix, as modified, teaches the submersible pump, wherein the submersible pump is a subsea pump configured to be installed on a sea ground (see ¶33 of Felix).
In reference to claim 17, Felix, as modified, teaches the submersible pump, wherein (see ¶34 or ¶45 of Felix) the process fluid is seawater, and the submersible pump is a water injection pump configured to inject the seawater into a subterranean region.
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Felix in view of Landi and further in view of Sande et al. (NO 341049B1 – herein after Sande).
Felix, as modified, does not teach the submersible pump, (see the proposed modification discussed above in claim 1, fig. 4 of Felix and fig. 5 of Landi) further comprising an external cooling loop configured to cool and lubricate the drive unit by the dosing fluid, the external cooling loop comprising a heat exchanger to cool the dosing fluid, the heat exchanger arranged outside the common housing and configured to receive the dosing fluid from the first compartment and to recirculate the dosing fluid to the first compartment.
However, Sande teaches the submersible pump, (see fig. 2 of Sande) further comprising an external cooling loop (12) configured to cool and lubricate the drive unit (1+8) by the dosing fluid, the external cooling loop comprising a heat exchanger (coil of pipes 13) to cool the dosing fluid, the heat exchanger arranged outside the common housing (of Felix) and configured to receive the dosing fluid from the first compartment and to recirculate the dosing fluid to the first compartment (in view of disclosure by Sande on page 5, lines 27-38 and page 6, lines 1-9).
It would have been obvious to the person of ordinary skill in the art before the effective filing date of the invention to provide the external cooling loop as taught by Sande in the modified submersible pump of Felix because circulating the barrier/dosing fluid through an externally arranged pipe coil takes direct advantage of the cold ambient seawater surrounding the submerged housing to dissipate heat generated by the motor and drive electronics passively and efficiently without requiring complex additional auxiliary cooling machinery, as recognized by Sande (see page 6 lines 30-37 and page 7, lines 1-7).
Response to Arguments
Applicant’s arguments filed 06/29/2026 regarding the interpretation of “a dosing unit” under 35 USC 112(f) have been considered but are not persuasive.
With respect to the first two paragraphs: These arguments essentially reiterate the assertions presented in earlier replies without providing new objective evidence showing that “dosing unit” conveys a definite structural meaning in the art. For the reasons fully set forth on page 12 of Final Action, dated 01/27/2026, the term “unit” is a generic placeholder and “dosing” is a functional modifier.
With respect to the third paragraph: Applicant argues that regardless of the generic term “unit”, “a dosing unit” conveys sufficient structure to a person of ordinary skill in the art. However, attorney argument cannot take the place of evidence. Applicant has provided no industry standards, technical dictionaries, or extrinsic evidence demonstrating that “dosing unit” is recognized as a specific mechanical structure in the art.
Accordingly, the interpretation under 35 USC 112(f) is maintained.
Applicant's arguments filed 06/29/2026 with respect to prior art rejection of the claims have been fully considered but they are moot.
The amendment to independent claim 1 changed the scope of the claim. As a result, the prior arts have been re-evaluated and re-applied to claim 1, in view of newly relied upon reference of Landi. It is to be noted that Sande: (i) is replaced with Landi for rejection of claim 1; and (ii) is now used as tertiary reference for rejection of dependent claim 11.
Conclusion
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/CHIRAG JARIWALA/Examiner, Art Unit 3746
/ESSAMA OMGBA/Supervisory Patent Examiner, Art Unit 3746
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