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 .
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 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.
Internet/E-mail Communication
In order to permit communication regarding the instant application via email, Applicant is invited to file form PTO/SB/439 (Authorization for Internet Communications) or include the following statement in a separately filed document (see MPEP 502.03 II):
Recognizing that Internet communications are not secure, I hereby authorize the USPTO to communicate with the undersigned and practitioners in accordance with 37 CFR 1.33 and 37 CFR 1.34 concerning any subject matter of this application by video conferencing, instant messaging, or electronic mail. I understand that a copy of these communications will be made of record in the application file.
If such authorization is provided, please include an email address in the remarks of a filed response. The examiner’s e-mail address is CHRISTOPHER.LEGENDRE@USPTO.GOV.
Response to Amendment
Applicant’s amendments filed 05 May 2026 with respect to the specification/drawings have been fully considered and are deemed to overcome the previous objection(s).
Applicant’s amendments filed 05 May 2026 with respect to the claims have been fully considered. Any claim objections and/or 35 U.S.C. 112 rejections not repeated herein are considered to be overcome by the amendments.
Response to Remarks/Arguments
Applicant's remarks/arguments filed 05 May 2026 stating that the amendments to the independent claims overcome the previous prior art rejections have been fully considered and they are persuasive. New prior art rejections necessitated by these amendments are set forth below.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
Claim 2, 3, 11, and 12 are rejected under 35 U.S.C. 112(a) for failing the written description requirement.
In claim 2, the limitation recited as “a gap at a second end portion of the pump shaft” was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that Applicant, at the time the application was filed, had possession of the claimed invention. According to MPEP 2163 (I)(A), issues of adequate written description may arise even for original claims, for example, when an aspect of the claimed invention has not been described with sufficient particularity such that one skilled in the art would recognize that the applicant had possession of the claimed invention at the time of filing. In the instant case, the originally filed disclosure depicts the claimed “gap” / gap 504 in Figure 5C and par. [0038] states the purpose as “allowing limited impeller movement during deflection” - however, the gap 504 is disposed in a distal end of the shaft such that it is remote from all of the impellers 506 and/or such that a diffuser 102 interposes the gap 504 and the closest impeller 506 and, thus, is incapable of cooperating with any of the impellers 506 - i.e., the originally filed disclosure does not sufficiently describe how any functionality of “a gap at a second end portion of the pump shaft” is achieved. Due to an identical instance, this rejection also applies to claim 11.
In claim 2, the limitation recited as “a gap at a second end portion of the pump shaft”, in combination with the antecedent limitation(s) “the at least one impeller is configured to move independently in a first axial direction” (claim 1) and/or “the at least one impeller is configured to move independently in a second axial direction” (claim 1) was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that Applicant, at the time the application was filed, had possession of the claimed invention. The originally filed disclosure describes/depicts the claimed “gap” / gap 504 with respect to the embodiment of Figure 5C and par. [0037] - however, par. [0037] indicates that this embodiment involves a hub-to-hub-stacking of impellers, which precludes independent movement of the impellers in at least one direction. Due to an identical instance, this rejection also applies to claim 11.
In claim 3, the limitation recited as “a spring at a second end portion of the pump shaft” was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that Applicant, at the time the application was filed, had possession of the claimed invention. According to MPEP 2163 (I)(A), issues of adequate written description may arise even for original claims, for example, when an aspect of the claimed invention has not been described with sufficient particularity such that one skilled in the art would recognize that the applicant had possession of the claimed invention at the time of filing. In the instant case, the originally filed disclosure depicts the claimed “spring” / spring 404 in Figure 4B and par. [0011] states its purpose as “to allow limited impeller movement during stage deflection in order to reduce thrust transfer” - however, the spring 404 is disposed in a distal end of the shaft such that it is remote from all of the impellers 104 and/or such that a diffuser 102 interposes the spring 404 and the closest impeller 104 and, thus, is incapable of cooperating with any of the impellers 404 - i.e., the originally filed disclosure does not sufficiently describe how any functionality of “a spring at a second end portion of the pump shaft” is achieved. Due to an identical instance, this rejection also applies to claim 12.
In claim 3, the limitation recited as “a spring at a second end portion of the pump shaft”, in combination with the antecedent limitation(s) “the at least one impeller is configured to move independently in a first axial direction” (claim 1) and/or “the at least one impeller is configured to move independently in a second axial direction” (claim 1) was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that Applicant, at the time the application was filed, had possession of the claimed invention. The originally filed disclosure at par. [0008] states “a spring may be positioned at the second end of the pump shaft and may be configured to secure the plurality of impellers”, which implies that the impellers are stacked (such as in a hub-to-hub stacking arrangement), thereby precluding independent movement of the impellers in at least one direction. Due to an identical instance, this rejection also applies to claim 12.
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
Claims 1-20 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention.
In claim 1, the limitation recited as “the at least one impeller is configured to move independently in a second axial direction unconstrained relative to the pump shaft” (emphasis added) renders the claim indefinite. According to MPEP 2173.03, a claim, although clear on its face, may also be indefinite when a conflict or inconsistency between the claimed subject matter and the specification disclosure renders the scope of the claim uncertain as inconsistency with the specification disclosure or prior art teachings may make an otherwise definite claim take on an unreasonable degree of uncertainty. In this instance, the disclosure indicates that the impellers are constrained in both directions - i.e., in one axial direction by two-piece ring 606, and in the other axial direction by a diffuser. To overcome this rejection, the Office suggests deleting “unconstrained”. Due to an identical instance, this rejection also applies to claims 5, 10, 13, 18, and 20 .Due to dependency, this rejection also applies to claims 2-4, 6-9, 11, 12, 14-17, and 19.
In claim 7, the limitation recited as “each of the plurality of impellers is configured to move independently in the second axial direction to transfer a load to a corresponding diffuser” renders the claim indefinite since it is incongruent with and/or contradictory to the antecedent limitation recited as “the at least one impeller is configured to move independently in a second axial direction unconstrained” (claim 1). Due to a similar issue, this rejection also applies to claims 13, 15, 17, and 20.
In claim 9, the limitation recited as “the one or more rings comprises a two-piece ring… and a retaining ring” since “two-piece ring” plus “retaining ring” amounts to two “rings”, thereby excluding “one” of “one or more rings”. To overcome this rejection, the Office suggests changing all instances of “one or more rings” to --one or more ring assemblies--. Due to an identical instance, this rejection also applies to claim 16.
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 of this title, 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, 2, 4-6, 8, 10, 11, 13, 14, 18, and 19 are rejected under 35 U.S.C. 103 as being unpatentable over Marica et al. (US 11,131,308 - hereafter referred to as Marica) in view of Smith et al. (US 11,242,856 - hereafter referred to as Smith; previously cited).
In reference to claim 1 (as far as it is clear and definite)
Marica discloses:
A pump for pumping fluid, the pump comprising:
a plurality of impellers (204) disposed about a pump shaft (140), wherein at least one impeller of the plurality of impellers is configured to move independently (see col.5:ll.32-34 stating “The pump assembly 200 can be any one of the pumps 150,160,170,180 disposed on the driving shaft 140”, which indicates that each of the pumps 150, 160, 170, 180 has the details/features of pump assembly 200, and see col.7:ll.9-33 stating “Thus, even when assembled, the rotors 204… can move axially on the driving shaft 140… Thus, by design, the driving shaft 140 can move axially relative to the mounting frame while the rotors… can move axially… relative to the driving shaft 140” - accordingly, the rotors of pumps 150,160,170,180 move independently) over an axial distance relative to the pump shaft;
a plurality of diffusers (202), wherein each diffuser of the plurality of diffusers corresponds to a respective impeller of the plurality of impellers;
a body (i.e., barrel 110) housing the plurality of impellers, the plurality of diffusers, and the pump shaft; and
a first end portion of the pump shaft, wherein (note: strike-through text is ignored due to or establishing it as optional), or the at least one impeller is configured to move independently in a second axial direction (i.e., toward the respective retention member 258 - see above explanation in reference to col.5:ll.32-34 and col.7:ll.9-33) unconstrained relative to the pump shaft, or (note: strike-through text is ignored due to or establishing it as optional).
Marica does not disclose:
a protector thrust bearing at the first end portion.
Smith discloses:
a multi-stage pump comprising a motor (17), a pump shaft (29), and a coupling (45) between the motor and an end of the pump shaft, wherein a thrust bearing (47) is disposed in the coupling at an end of the pump shaft to absorb pump shaft thrust (see col.4:ll.8-11).
Marica further discloses that the pump shaft (140) is driven by a motor (130).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the pump of Marica to include a coupling that secures the pump shaft to the motor (i.e., a shaft of the motor), as disclosed by Smith, for the purpose of allowing independent manufacture/repair/replacement of the pump shaft and/or motor components (e.g., the motor shaft). In performing this modification, it would have been further obvious to include a thrust bearing at a pump shaft end, as further disclosed by Smith, for the purpose limiting axial movement of the pump shaft.
In reference to claim 2
Marica in view of Smith addresses:
The pump of claim 1, further comprising a gap (see annotated Marica Figure 2 below) at a second end portion of the pump shaft (Marica - 140).
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In reference to claim 4
Marica in view of Smith addresses:
The pump of claim 1, wherein each of the plurality of impellers (Marica - 204) comprises a hub (214 - Marica Figure 4) disposed about the pump shaft (Marica - 140).
In reference to claim 5 (as far as it is clear and definite)
Marica in view of Smith addresses:
The pump of claim 1, wherein each of the plurality of impellers (Marica - 204) is configured to move independently (see above rejection of claim 1) relative to the pump shaft (Marica - 140), each of the plurality of impellers is configured to move independently in the first axial direction (i.e., toward the respective retention member 258 - Marica Figure 4) to transfer (via the respective retention member 258 - Marica Figure 4) the first axial load to the pump shaft, and each of the plurality of impellers is configured to move independently in the second axial direction (i.e., toward the respective retention member 230 - Marica Figure 4) unconstrained relative to the pump shaft.
In reference to claim 6
Marica in view of Smith addresses:
The pump of claim 5, wherein the first axial load comprises a thrust generated by each of the plurality of impellers (Marica - 204), and the first axial load of each of the plurality of impellers is configured to be transferred (via respective retention members 230 - Marica Figure 4) to the protector thrust bearing (Smith - 47) through the pump shaft (Marica - 140).
In reference to claim 8
Marica in view of Smith addresses:
The pump of claim 1, wherein the pump is part of an electrical submersible pump system (note: the instant recitation is considered as a statement of intended use that does not structurally limit the claimed apparatus - see MPEP 2114.04 (I)).
In reference to claim 10 (as far as it is clear and definite)
Marica in view of Smith, as combined in the rejection of claim 1, addresses:
An electrical submersible pump (ESP), the ESP comprising (note: the term submersible does not imbue structure to the claimed pump):
a plurality of impellers (Marica - 204);
a plurality of diffusers (Marica - 202) corresponding to each of the plurality of impellers;
a pump shaft (Marica - 140) connecting the plurality of impellers, wherein at least one impeller of the plurality of impellers is configured to move independently (see col.5:ll.32-34 stating “The pump assembly 200 can be any one of the pumps 150,160,170,180 disposed on the driving shaft 140”, which indicates that each of the pumps 150, 160, 170, 180 has the details/features of pump assembly 200, and see col.7:ll.9-33 stating “Thus, even when assembled, the rotors 204… can move axially on the driving shaft 140… Thus, by design, the driving shaft 140 can move axially relative to the mounting frame while the rotors… can move axially… relative to the driving shaft 140” - accordingly, the rotors of pumps 150,160,170,180 move independently) over an axial distance relative to the pump shaft; and
a protector thrust bearing (Smith - 47) at a first end portion of the pump shaft;
wherein the at least one impeller is configured to move independently in a first axial direction (i.e., toward the respective retention member 258 - Marica Figure 4) to transfer (via the respective retention member 258 - Marica Figure 4) a first axial load to the pump shaft, and the at least one impeller is configured to move independently in a second axial direction (i.e., toward the respective retention member 230 - Marica Figure 4) unconstrained relative to the pump shaft.
In reference to claim 11
Marica in view of Smith addresses:
The ESP of claim 10, further comprising a gap (see annotated Marica Figure 2 above) at a second end portion of the pump shaft (Marica - 140).
In reference to claim 13 (as far as it is clear and definite)
Marica in view of Smith addresses:
The ESP of claim 10, wherein each of the plurality of impellers (Marica - 204) is configured to move independently in the first axial direction (i.e., toward the respective retention member 258 - Marica Figure 4) to transfer (via the respective retention member 258 - Marica Figure 4) the first axial load to the pump shaft (Marica - 140), and each of the plurality of impellers is configured to move independently in the second axial direction (i.e., toward the respective retention member 230 - Marica Figure 4) unconstrained relative to the pump shaft.
In reference to claim 14
Marica in view of Smith addresses:
The ESP of claim 10, wherein the first axial load comprises a thrust generated by each of the at least one impeller (Marica - 204) of the plurality of impellers, and the first axial load of the at least one impeller is configured to be transferred (via the respective retention member 258 - Marica Figure 4) to the protector thrust bearing (Smith - 47) through the pump shaft (Marica - 140).
In reference to claim 18 (as far as it is clear and definite)
Marica in view of Smith, as combined in the rejection of claim 1, addresses:
A method of reducing wear in a pump, the method comprising:
stacking a plurality of impellers (Marica - 204) on a pump shaft (Marica - 140);
providing a diffuser (Marica - 202) corresponding to each impeller of the plurality of impellers;
housing the plurality of impellers, each corresponding diffuser, and the pump shaft in a body (Marica - 110);
providing a protector thrust bearing (Smith - 47) at one end portion of the pump shaft; and
enabling at least one impeller of the plurality of impellers to move independently (see col.5:ll.32-34 stating “The pump assembly 200 can be any one of the pumps 150,160,170,180 disposed on the driving shaft 140”, which indicates that each of the pumps 150, 160, 170, 180 has the details/features of pump assembly 200, and see col.7:ll.9-33 stating “Thus, even when assembled, the rotors 204… can move axially on the driving shaft 140… Thus, by design, the driving shaft 140 can move axially relative to the mounting frame while the rotors… can move axially… relative to the driving shaft 140” - accordingly, the rotors of pumps 150,160,170,180 move independently) over an axial distance relative to the pump shaft, wherein (note: strike-through text is ignored due to or establishing it as optional), or the at least one impeller is configured to move independently in a second axial direction (i.e., toward the respective retention member 230 - see above explanation in reference to col.5:ll.32-34 and col.7:ll.9-33) unconstrained relative to the pump shaft, or (note: strike-through text is ignored due to or establishing it as optional).
In reference to claim 19
Marica in view of Smith addresses:
The method of claim 18, wherein each of the plurality of impellers (Marica - 204) is configured to move independently in the first axial direction (i.e., toward the respective retention member 258 - Marica Figure 4) to transfer (via the respective retention member 258 - Marica Figure 4) the first axial load to the pump shaft (Marica - 140), the first axial load comprises a thrust generated by each of the plurality of impellers, and the protector thrust bearing is configured to bear (inherent to the proposed combination) the first axial load of each of the plurality of impellers.
Claims 7, 15, 17, and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Marica in view of Smith and Baillargeon et al. (US 9,745,991 - hereafter referred to as Baillargeon).
In reference to claims 7, 15, and 20 (as far as they are clear and definite)
Marica in view of Smith addresses:
The pump of claim 5, wherein each of the plurality of impellers (Marica - 204) is configured to move independently in the second axial direction to transfer a second axial load. (claim 7)
The ESP of claim 10, wherein the least one impeller of the plurality of impellers (Marica - 204) is configured to move independently in the second axial direction to transfer a second axial load. (claim 15)
The method of claim 18, wherein each of the plurality of impellers (Marica - 204) is configured to move independently in the second axial direction unconstrained relative to the pump shaft to transfer a second load. (claim 20)
Marica in view of Smith does not address:
the second axial load is transferred to a corresponding diffuser of the plurality of diffusers. (claims 7, 15, and 20)
Baillargeon discloses:
a multi-stage pump comprising a plurality of impellers (35) and diffusers (23), wherein each impeller is configured to move in an axial direction such that it transfers load (via thrust washer 53) to the adjacent diffuser.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the pump / ESP / method of Marica in view of Smith to include transferring (via a thrust washer) the second axial load to the adjacent diffuser, as disclosed by Baillargeon, as an alternate means (in place of Marica retention member 230) of limiting axial movement of the impellers.
In reference to claim 17 (as far as it is clear and definite)
Marica in view of Smith and Baillargeon addresses:
The ESP of claim 15, further comprising a thrust washer (Baillargeon - 53) between (see Baillargeon Figure 2) the at least one impeller (Marica - 204) and the corresponding diffuser (Marica - 202) of the plurality of diffusers, wherein the at least one impeller is configured to move independently (see above explanation in the rejection of claim 10) in the second axial direction to transfer the second axial load to the corresponding diffuser of the plurality of diffusers via the thrust washer.
Examiner’s Comment
Although claims 3 and 12 are not rejected over prior, patentability cannot be determined in light of the corresponding 35 U.S.C. 112(a) issues set forth above.
Allowable Subject Matter
Claims 9 and 16 would be allowable if rewritten (as suggested above) to overcome the rejection(s) under 35 U.S.C. 112(b) set forth in this Office action and to include all of the limitations of the base claim and any intervening claims.
Citations of Pertinent Art
The following art is considered pertinent to Applicant’s disclosure.
Radov et al. (US 11,643,911) discloses a multi-stage pump comprising a shaft thrust protector (94).
Ye et al. (US 11,415,138) discloses a multi-stage pump comprising impellers that float relative to the shaft.
Marsis (US 9,777,741) discloses a multi-stage pump comprising impellers that float relative to the shaft.
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 extension fee 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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to CHRISTOPHER RYAN LEGENDRE whose telephone is (571)270-3364 and email is christopher.legendre@uspto.gov. The examiner can normally be reached M-F 9AM-5PM ET.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor Eugene Kim can be reached at 571-272-4463. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/CHRISTOPHER R LEGENDRE/Primary Examiner, Art Unit 3711
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