Election/Restrictions
Applicant’s election without traverse of Group I and Species I (FIG. 3-5) in the reply filed on 02 June 2026 is acknowledged.
It is noted, the original restriction misidentified the claims according to each Grouped Invention, however the clerical error is moot, as the restriction between the method of pump use and method of pump assembly is hereby withdrawn. The restriction between Species is maintained.
The Examiner notes while the Applicant explicitly withdrew claims 5-7 and 15-20 in response to the restriction/election requirement.
DETAILED ACTION
Status of Claims
This action is in reply to the communication(s) filed on 02 June 2026.
Claims 5-7 and 15-20 are withdrawn by the Applicant.
Claims 1-4 and 8-14 are being considered.
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 .
Information Disclosure Statement
The Examiner notes, no information disclosure statement(s) (IDS) was/were submitted by the Applicant to be considered by the Examiner.
Claim Interpretation
The following is a quotation of 35 U.S.C. 112(f):
(f) Element in Claim for a Combination. – An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
The following is a quotation of pre-AIA 35 U.S.C. 112, sixth paragraph:
An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
The claims in this application are given their broadest reasonable interpretation using the plain meaning of the claim language in light of the specification as it would be understood by one of ordinary skill in the art. The broadest reasonable interpretation of a claim element (also commonly referred to as a claim limitation) is limited by the description in the specification when 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is invoked.
As explained in MPEP § 2181, subsection I, claim limitations that meet the following three-prong test will be interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph:
(A) the claim limitation uses the term “means” or “step” or a term used as a substitute for “means” that is a generic placeholder (also called a nonce term or a non-structural term having no specific structural meaning) for performing the claimed function;
(B) the term “means” or “step” or the generic placeholder is modified by functional language, typically, but not always linked by the transition word “for” (e.g., “means for”) or another linking word or phrase, such as “configured to” or “so that”; and
(C) the term “means” or “step” or the generic placeholder is not modified by sufficient structure, material, or acts for performing the claimed function.
Use of the word “means” (or “step”) in a claim with functional language creates a rebuttable presumption that the claim limitation is to be treated in accordance with 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. The presumption that the claim limitation is interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is rebutted when the claim limitation recites sufficient structure, material, or acts to entirely perform the recited function.
Absence of the word “means” (or “step”) in a claim creates a rebuttable presumption that the claim limitation is not to be treated in accordance with 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. The presumption that the claim limitation is not interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is rebutted when the claim limitation recites function without reciting sufficient structure, material or acts to entirely perform the recited function.
Claim limitations in this application that use the word “means” (or “step”) are being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, except as otherwise indicated in an Office action. Conversely, claim limitations in this application that do not use the word “means” (or “step”) are not being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, except as otherwise indicated in an Office action.
Examiner note: no 112(f) invocations have been identified by the Office.
Priority
Applicant states that this application is a continuation or divisional application of the prior-filed application. A continuation or divisional application cannot include new matter. Applicant is required to delete the benefit claim or change the relationship (continuation or divisional application) to continuation-in-part because this application contains the following matter not disclosed in the prior-filed application:
Regarding Claims 11-14
Claims 11-14 refer to “coupling members,” which is a broader term meant to represent the coupling pins.
Specification
The specification is objected to as failing to provide proper antecedent basis for the claimed subject matter. See 37 CFR 1.75(d)(1) and MPEP § 608.01(o). Correction of the following is required: The claimed term “coupling members” from claims 11-14 is not included in the specification.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale or otherwise available to the public before the effective filing date of the claimed invention.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claim(s) 1-2, 4, and 10-14 is/are rejected under 35 U.S.C. 102(a)(1)/(a)(2) as being anticipated by Cheah et al (US 20220341435), hereafter referred to as Cheah.
Regarding Claim 1, Cheah discloses the following:
A method of assembling (see for example, claim 16, since the pump is assembled, it must have gone through a method of assembly) a centrifugal pump (110), the method comprising:
forming a stack of a plurality of diffusers (220);
housing a plurality of impellers (210) in the plurality of diffusers (220);
extending a rotational shaft (202) through the plurality of impellers (210) to impart rotation to the plurality of impellers (210);
supporting the rotational shaft (202) with a plurality of bearings (250 with sleeve 252 and keyed bushing 354; see FIG. 2A, 3; [0052]) positioned within the plurality of diffusers (220); and
positioning coupling pins (355; FIG. 3; [0052]) between the plurality of bearings (250 with sleeve 252 and keyed bushing 354; see FIG. 2A, 3; [0052]) and the plurality of diffusers (220) to at least partially secure each of the plurality of bearings (250 with sleeve 252 and keyed bushing 354; see FIG. 2A, 3; [0052]) to restrict relative rotation between the plurality of bearings (250 with sleeve 252 and keyed bushing 354; see FIG. 2A, 3; [0052]) and the plurality of diffusers (220).
Regarding Claim 2, Cheah discloses the following:
The method of claim 1,
further comprising securing each of the plurality of bearings (250 with sleeve 252 and keyed bushing 354; see FIG. 2A, 3; [0052]) with a bushing (354) positioned axially adjacent to each of the plurality of bearings (250 with sleeve 252 and keyed bushing 354; see FIG. 2A, 3; [0052]) in the plurality of diffusers (220).
Regarding Claim 4, Cheah discloses the following:
The method of claim 2,
further comprising securing the bushing (354) to each respective diffuser of the plurality of diffusers (220) with an interference fit (see for example [0056]).
Regarding Claim 10, Cheah discloses the following:
The method of claim 1,
wherein positioning the coupling pins (355; FIG. 3; [0052]) comprises sliding a separatable pin in between recesses (synonymous with keyway 361; FIG. 3; [0052]) defined the plurality of bearings (250 with sleeve 252 and keyed bushing 354; see FIG. 2A, 3; [0052]) and the plurality of diffusers (220).
Regarding Claim 11, Cheah discloses the following:
A method of operating a downhole centrifugal pump (110), the method comprising:
impellers (210);
rotating impellers (210) on a rotational shaft (202) within diffusers (220) having a body housing the impellers (210);
supporting the rotational shaft (202) during the rotation of the impellers (210) with bearings (250 with sleeve 252 and keyed bushing 354; see FIG. 2A, 3; [0052]) positioned within at least some of the diffusers (220); and
at least partially securing each of the bearings (250 with sleeve 252 and keyed bushing 354; see FIG. 2A, 3; [0052]) to the at least some of the diffusers (220) against a rotational force applied to the bearings (250 with sleeve 252 and keyed bushing 354; see FIG. 2A, 3; [0052]) from the rotation of the rotational shaft (202) with coupling members (355) positioned between and engaged with the bearings (250 with sleeve 252 and keyed bushing 354; see FIG. 2A, 3; [0052]) and the at least some of the diffusers (220).
Regarding Claim 12, Cheah discloses the following:
The method of claim 11,
further comprising securing (via 370; see [0054]) one of the bearings (250 with sleeve 252 and keyed bushing 354; see FIG. 2A, 3; [0052]) in a first axial along the rotational shaft (202) in the body of the at least some of the diffusers (220) with bushings positioned adjacent to the bearings (250 with sleeve 252 and keyed bushing 354; see FIG. 2A, 3; [0052]).
Regarding Claim 13, Cheah discloses the following:
The method of claim 12,
further comprising securing each of the bearings (250 with sleeve 252 and keyed bushing 354; see FIG. 2A, 3; [0052]) in a second, opposing axial direction by directly abutting a shelf (as seen in FIG. 3) defined by the body of the at least some of the diffusers (220).
Regarding Claim 14, Cheah discloses the following:
The method of claim 11,
further comprising at least partially securing each of the bearings (250 with sleeve 252 and keyed bushing 354; see FIG. 2A, 3; [0052]) with the coupling members (355) that each comprise a separable nonthreaded pin being removable from each of the at least some of the diffusers (220).
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.
Claim 3 is/are rejected under 35 U.S.C. 103 as being unpatentable over Cheah et al (US 20220341435), hereafter referred to as Cheah, Nowitzki et al (US 20170159668), hereafter referred to as Nowitzki, and Lunk et al (US 20170058616), hereafter referred to as Lunk.
Regarding Claim 3, Cheah discloses the following:
The method of claim 2,
it is well known in the art that interference fits between bushings and diffusers can fail at higher temperatures if the bushings and diffusers are made from different materials having different coefficients of thermal expansion (see [0056]).
Cheah does not explicitly disclose the following:
further comprising matching a coefficient of thermal expansion (CTE) of the bushing within ± 10% to a coefficient of thermal expansion (CTE) of the plurality of diffusers.
Nowitzki teaches the following:
it is well known in the art to provide centrifugal pumps with diffusers made of Ni-resist austenitic cast iron and bushings made of tungsten carbide(see [0010]).
and Lunk teaches the following:
it is well known in the art to provide bearings and bushings made of Ni-resist austenitic cast iron substrate that is infused with a layer of diamond-like carbon and/or coated with titanium nitride or titanium aluminum nitride as an alternative to a tungsten carbide bearing (see [0047]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the materials of the bushings and the diffusers as disclosed by Cheah, with the reasonable expectation of successfully obviating press fit failure between diffusers and bushings at elevated temperatures (see Cheah, for example [0056]), by select Ni-resist austenitic cast iron as the diffuser material, as taught by Nowitzki, with the reasonable expectation of selecting a material capable of performing as a diffuser in a downhole pump (see Nowitzki, [0010])), and by selecting carbon infused or titanium nitride coated Ni-resist austenitic cast iron as the bushing substrate material, as taught by Lunk, with the reasonable expectation of selecting a less expensive material (see Lunk [0047]). It is finally noted, the selection of a known material based on its suitability for its intended use supported a prima facie obviousness determination in Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945) In this instance both Nowitzki and Lunk disclose it is well known in the art to provide diffusers and bearings made of Ni-resist austenitic cast iron. (see MPEP 2144.07).
Claims 8-9 is/are rejected under 35 U.S.C. 103 as being unpatentable over Cheah et al (US 20220341435), hereafter referred to as Cheah, in view of Gahlot et al (US 20170002823), hereafter referred to as Gahlot.
Regarding Claim 8, Cheah discloses the following:
The method of claim 1,
Cheah does not explicitly disclose the following:
wherein at least one of the bearings is coupled to another component of the downhole centrifugal pump with at least one of the coupling pins.
However Gahlot teaches the following:
it is well known in the art to provide thrust bearings (129) coupled to another component (pump base 127, see FIG. 3; [0031]) of the downhole centrifugal pump.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to substitute the thrust bearing within the pump base and diffusers as disclosed by Gahlot, with the thrust bearings having a coupling pin as disclosed by Cheah, with the reasonable expectation of preventing the bearing from rotating within the pump base and diffusers. It is noted, the combination of Gahlot and Cheah results in the limitation, "further comprising coupling at least one of the plurality of bearings to another component other than the plurality of diffusers of the centrifugal pump with at least one of the coupling pins."
Regarding Claim 9, Cheah and Gahlot disclose the following:
The method of claim 8,
Gahlot continues to teach the following:
wherein the another component (pump base 127, see FIG. 3; [0031]) of the downhole centrifugal pump comprises a pump base (127, see FIG. 3; [0031]) coupled to an end diffuser (diffuser 124 in first stage 120; FIG. 3) of the diffusers (124, FIG. 3; [0029]).
Conclusion
See form No. 892 for other references pertinent to the application that may not have been cited within the Office Action.
For references which show similar bearing arrangements see Page 1.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to BRIAN C DELRUE whose telephone number is (313)446-6567. The examiner can normally be reached Monday - Friday; 9:00 AM - 5:00 PM (Eastern).
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Nathaniel E. Wiehe can be reached on (571) 272-8648. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/BRIAN CHRISTOPHER DELRUE/ Primary Examiner, Art Unit 3745
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