DETAILED ACTION
Notice of Pre-AIA or AIA Status
This Office Action is in response to the claims set filed 07/17/2026 following the Non-Final Rejection of 04/20/2026. Claims 1, 3 and 9-10 were amended. Claims 1-11 are currently pending with claim 11 withdrawn from consideration as being party to a non-elected Group.
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Response to Arguments
Applicant’s arguments, see Remarks, filed 07/17/2026, with respect to the specification objection, claim objections and claims rejected under 35 USC § 112(b) have been fully considered and are persuasive. These objections and/or rejection of 04/20/2026 have been withdrawn.
Applicant’s arguments, see Remarks, filed 07/17/2026, with respect to the rejection(s) of claim(s) under 35 USC § 102 and/or 103 have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of amendments made to the claim.
Applicant's point on page 9 of Remarks that “Okubo discloses a horizontal pump having a main shaft 30 (cf rotation shaft) extending in a horizontal direction. Particularly, Okubo describes displacement of the main shaft 30 in the left and right directions as a result of the impeller thrust increasing or decreasing, respectively. See Okubu, English translation, Paragraphs [0032] and [0033]. In other words, Okubo is directed to a horizontal pump, and the heavy dead weight of the rotational structure (i.e., the shaft and impellers) acts in a radial direction that is perpendicular to the axial direction. Okubo fundamentally lacks the physical problem of having to support a heavy downward gravitational weight of the rotor along the axial direction, which is a critical issue in vertical pumps during both startup and steady-state operation” is not found persuasive by the Examiner.
While the pump is shown to be horizontally orientated in fig. 6, this does not dictate how the pump of Okubo must be orientated in relation to gravity and there is no requirement that diagram drawings are to be presented in a manner which aligns with gravity or that the orientation shown in the drawings is the only possible orientation for the structure. Additionally, no representation of ground, gravity, or the like, are shown in relation to the pump in the figures of Okubo. No mention in the disclosure of Okubo can be found that their pump is required to be horizontally orientated in relation to the direction of gravity and/or is only applicable to pumps that are horizontally orientated relative to gravity.
Applicant's point on page 10 of Remarks that “It is argued by the Office that it would have been obvious to one of ordinary skill to modify "Okubo to further include the balance piston mechanism 30 disclosed by Matsumura to obtain the benefit of 'reducing the axial thrust at the time of starting the pump' as taught by Matsumura." See Office action, Page 12. Respectfully, this is incorrect. Rather, Okubo provides a clear teaching away that would render the prior art reference being modified unsatisfactory for its intended purpose and change the principle of operation of the prior art reference. See MPEP 2141.02, 2143.01, and 2145. In particular, the primary objective of Okubo is to make its balance disc function as a thrust bearing, thereby eliminating the need for a thrust bearing itself. See Okubo, English translation, Paragraph [0035]. The design of Okubo is only physically viable in a horizontal pump, as seen in Okubo, where gravity does not exacerbate the axial thrust” is not found persuasive by the Examiner.
Okubo does not provide a clear teaching away that would render the prior art reference being modified unsatisfactory for its intended purpose and change the principle operation of the prior art reference’ as argued by Applicant since Okubo does not state in their disclosure that their pump must be horizontally orientated relative to gravity and/or is only applicable to pumps horizontally orientated with gravity. While the pump is shown to be horizontally orientated in fig. 6, this does not how dictate the pump of Okubo must be orientated in relation to gravity and there is no requirement that diagram drawings are to be presented in a manner which aligns with gravity or that the orientation shown in the drawings is the only possible orientation for the structure. No representation of ground, gravity, or the like, are shown in relation to the pump in the figures of Okubo.
Applicant's point on pages 10-11 of Remarks that “applying Matsumura's mechanism, which is specifically designed to counteract the heavy vertical gravity and startup thrust of a vertical pump, to Okubo's horizontal pump is entirely contradictory to Okubo's purpose. Indeed, there is no motivation to one of skill in the art to incorporate a gravity-counteracting vertical pump solution into a horizontal pump that has no such gravitational axial load. Doing so would destroy the intended simplicity of Okubo's design” is not found persuasive by the Examiner.
As stated above, the disclosure of Okubo does not state that their pump must be horizontally orientated relative to gravity or is only relevant to horizontally orientated pumps. The figures of Okubo present no representation of ground, gravity, or the like, in relation to the pump and the orientation presented in the drawings would not dictate how the pump must be orientated in relation to gravity. Regardless, the teaching of Matsumura has applicability for modifying Okubo. The issue of “for a certain period of time immediately after startup, pump discharge pressure does not build up at the rear surface of the final stage impeller, and therefore the thrust balance mechanism 19, which utilizes the static pressure at the rear surface of the final stage impeller, cannot fully demonstrate its function” addressed by Matsumura is pertinent since the final stage of the pump would be the last one to build up pressure given it’s downstream most position in the plurality of impellers and presents a motivation for one of ordinary skill in the art to modify a reference with the teachings of Matsumura. The thrust balance mechanism of Okubo utilizing fluid from the final stage.
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.
This application includes one or more claim limitations that do not use the word “means,” but are nonetheless being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, because the claim limitation(s) uses a generic placeholder that is coupled with functional language without reciting sufficient structure to perform the recited function and the generic placeholder is not preceded by a structural modifier. Such claim limitation(s) is/are:
“a first thrust balance mechanism” in claim 1. “mechanism” being the generic placeholder; “thrust balancing” and “a first thrust balance mechanism and a second thrust balance mechanism configured to cancel weight of a rotational structure including the rotation shaft and the plurality of impellers and an axial thrust acting on the plurality of impellers”; insufficient structural language present in the claim for this limitation.
The corresponding structure provided in the instant disclosure can be found in paragraphs 31, 36-44, 75-104, 106, 112 and 121 as well as instant figures 1-3, 9-15 and 17.
Based upon the collection of the corresponding structure in the areas referenced above, the general corresponding structure for the various embodiments of the “first thrust balance mechanism” includes: a first wall structure 26, a first low-pressure chamber 23, a first high-pressure chamber 25, and a first partition 30; and equivalents thereof.
Because this/these claim limitation(s) is/are being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, it/they is/are being interpreted to cover the corresponding structure described in the specification as performing the claimed function, and equivalents thereof.
If applicant does not intend to have this/these limitation(s) interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, applicant may: (1) amend the claim limitation(s) to avoid it/them being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph (e.g., by reciting sufficient structure to perform the claimed function); or (2) present a sufficient showing that the claim limitation(s) recite(s) sufficient structure to perform the claimed function so as to avoid it/them being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph.
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.
Claim(s) 1 and 6-10 is/are rejected under 35 U.S.C. 103 as being unpatentable over JP2001248586A (first cited in the Office Action of 04/20/2026), herein referenced as Okubo, in view of US 2022/0178381, herein referenced as Raeve, and further in view of JP2007016750A (first cited in the Office Action of 12/22/2025), herein referenced as Matsumura.
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Figure 6 of Okubo
Regarding Claim 1, Okubo discloses a pump apparatus for pressurizing liquid hydrogen, comprising:
a rotation shaft (shaft 30 fig. 6);
a plurality of impellers fixed to the rotation shaft (see plurality of impellers 36 attached to shaft 30 in fig. 6);
a bearing (see bearings 1 and 4 in fig. 6) configured to rotatably support the rotation shaft (30 fig. 6);
a pump casing (casing 31 fig. 6) in which the plurality of impellers (impellers 36 fig. 6) are disposed; and
a second thrust balance mechanism (see fig. 2 or alternatively fig. 8; see assembly related to balance disc 6 in fig. 2 and assembly related to the balance disc 44 in fig. 8 which are both shown to interface with a rotational structure of the shaft 30 and impellers 36; “during normal operation, the axial gaps a1 and a2 are a1=a2, and the axial thrust applied to the balance disc 6 is balanced by axial thrust (impeller thrust) generated by the impeller 36” in pr. 31 and “balance disc 44 has an automatic adjustment function for balance thrust” pr. 11),
wherein the second thrust balance mechanism includes:
a wall structure (see wall structure defined by discharge casing 31b, balancing bushes 8 and 9 and lid-shaped member 5 in fig. 2; alternatively, see discharge casing 31b, first balance bush 45, second balance bush 52, and rear stuffing box 43 fig. 8) having a low-pressure chamber (see low-pressure chamber 17 in fig. 2 or alternatively balance chamber 55 with pressure P3 in fig. 8) and a high-pressure chamber formed therein (see high-pressure chamber 16 in fig. 2 or alternatively volume chamber 46 with pressure P2 in fig. 8; “The pressure in the balance chamber 55 is lower (P3) than the pressure in the volume chamber 46 (P2)” pr. 9); and
a partition (including at least the disc portion 6b, which forms part of the separation of chamber 17 from chamber 16 in fig. 2 or alternatively, see disc portion 44b which separates chamber 55 from chamber 46 in fig. 8) located in the wall structure (shown in both fig. 2 and fig. 8) and located between the low-pressure chamber and the high-pressure chamber (shown in fig. 2 and fig. 8),
the pump apparatus further comprises:
an intermediate communication line (see holes 7 in fig. 2; alternatively, see first flow path 48 in fig. 8) providing fluid communication between the high-pressure chamber (16 fig. 2; Alternatively, 46 fig. 8) and a discharge side of an intermediate-stage impeller or a final-stage impeller (see discharge port 33 connected to final stage impeller 36 in fig. 2, “high-pressure chamber 16 is connected to the discharge port 33 inside the discharge casing 31b via the multiple through holes 7” pr. 28; Alternatively, see discharge port 33 connected to final stage impeller 36 in fig. 8, “One end of this first flow path 48 is connected to the discharge port 33 in the discharge casing 31b, and the other end is connected to the volume chamber 46” pr. 5) of the plurality of impellers; and
a return line (see 56 in figs. 2, 6 and 8) providing fluid communication between the low-pressure chamber (see 17 in fig. 2; Alternatively, 55 in fig. 8; both shown to communicate with 56 in their respective figures) and a discharge side of a suction-side impeller (see suction-side impeller, i.e. first stage impeller, 36 where the other end of 56 is provided in fig. 6; with reference fig. 6, “Alternatively, instead of providing the orifice 20, the same effect and benefits can be obtained by connecting the balance pipe 56 to the first-stage discharge side (see the dashed line in the figure)” pr. 50) of the plurality of impellers located upstream of the intermediate-stage impeller or the final-stage impeller (first stage impeller 36 shown to be upstream of final stage impeller 36 in fig. 6).
However, Okubo fails to anticipate the rotation shaft extending in a vertical direction, and a first thrust balance mechanism, [the] first thrust balance mechanism and [the] second thrust balance mechanism configured to cancel weight of [the] rotational structure including the rotation shaft and the plurality of impellers and an axial thrust acting on the plurality of impellers.
Okubo and Raeve are analogous art since they both relate to the field of endeavor of pump devices.
Raeve teaches of a rotation shaft extending in the vertical direction (“According to a preferred embodiment the pump is configured as a horizontal pump with the pump shaft extending perpendicular to the direction of gravity. However, in particular for such applications, where a minimized footprint of the pump is required it is also possible to configure the pump according to the invention as a vertical pump with the pump shaft extending in the direction of gravity” pr. 34). Raeve further teaches that “configuring the process fluid lubricated pump as a vertical pump has the advantage that the footprint of the pump can be decreased, which is an important advantage at such location, where the available place is restricted, e.g. on an (oil) platform or an FPSO” in pr. 93.
Therefore, it would have been obvious before the effective filing date of invention to one of ordinary skill in the art to have modified Okubo to be configured as a vertical pump with the pump shaft extending in the direction of gravity, as disclosed by Raeve, to obtain the benefit of ‘decreasing the footprint of the pump’ as taught by Raeve.
However, the combination of Okubo and Raeve fails to teach a first thrust balance mechanism, [the] first thrust balance mechanism and [the] second thrust balance mechanism configured to cancel weight of [the] rotational structure including the rotation shaft and the plurality of impellers and an axial thrust acting on the plurality of impellers.
Matsumura is analogous art since it relates to the field of endeavor of pump devices.
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Figure 1 of Matsumura
Matsumura teaches a first thrust balance mechanism (see balance piston mechanism 30 in figs. 1, 3 and 6) in addition to a second thrust balance mechanism (see thrust balance mechanism 19 in figs. 1-3). Matsumura further teaches “by installing a balance mechanism (balance piston mechanism 30) below the pump, the load can be easily balanced and the axial thrust at the time of starting the pump can be reduced” in pr. 17; which address the problem that “for a certain period of time immediately after startup, pump discharge pressure does not build up at the rear surface of the final stage impeller, and therefore the thrust balance mechanism 19, which utilizes the static pressure at the rear surface of the final stage impeller, cannot fully demonstrate its function” in pr. 16.
Therefore, it would have been obvious before the effective filing date of invention to one of ordinary skill in the art to have modified the combination of Okubo and Raeve to further include the balance piston mechanism 30 disclosed by Matsumura to obtain the benefit of ‘reducing the axial thrust at the time of starting the pump’ as taught by Matsumura.
The combination of Okubo, Raeve and Matsumura comprises wherein [the] first thrust balance mechanism and [the] second thrust balance mechanism configured to cancel weight of [the] rotational structure including the rotation shaft and the plurality of impellers and an axial thrust acting on the plurality of impellers (since the first thrust balance mechanism and the second thrust balance mechanism comprises all the required structure, as mapped above, required to accomplish this function; the axial thrust/force balancing mechanisms balance the axial forces acting on the shaft and/or rotational structure, the weight of the rotational structure for a rotation shaft that extends in a vertical direction as well as the axial thrust acting on the plurality of impellers would be part of the axial forces acting on the rotational structure).
Regarding Claim 6, the combination of Okubo, Raeve and Matsumura comprises the pump apparatus according to claim 1, wherein the wall structure has an inner circumferential surface parallel to an axial direction of the rotation shaft (see inner circumferential surface of second balance bush 52, which is part of discharge casing 31b, at channel 54 that extends axially in fig. 8 of Okubo; “second balance bush 52 is fixed to the discharge casing 31b by bolts 53” pr. 6 of Okubo), the partition (disc portion 44b fig. 8 of Okubo) has an outer circumferential surface parallel to the axial direction of the rotation shaft (outer circumferential surface of disc portion 44b at channel 54 is shown to extend axially in fig. 8 of Okubo), and the entire outer circumferential surface of the partition is surrounded by the inner circumferential surface of the wall structure with a gap formed therebetween (the entire outer circumferential surface of the disc portion 44b is shown to be surrounded by the inner circumferential surface of bush 52, part of discharge casing 31b, with a channel/gap 54 formed therebetween in fig. 8 of Okubo).
Regarding Claim 7, the combination of Okubo, Raeve and Matsumura comprises the pump apparatus according to claim 1, wherein the second thrust balance mechanism further includes a balance chamber (see second liquid chamber 13 fig. 2 of Okubo) located between the low-pressure chamber and the high-pressure chamber (13 shown to be between low pressure chamber 17 and high pressure chamber 16 in fig. 2 of Okubo), a variable gap is formed between the partition and the wall structure (see axial gap a2 between disc portion 6b of balance disc 6 and second balance bush 9 in fig. 2 of Okubo; “ first and second balance bushes 8 and 9 are fixed to the discharge casing 31b” pr. 27 of Okubo), and a magnitude of the variable gap changes according to an axial position of the rotation shaft (“when the impeller thrust increases, the entire main shaft 30, including the balance disc 6, is displaced toward the suction side (left direction in Figure 2), causing the axial gap a1 to decrease and the axial gap a2 to increase” pr. 32 of Okubo).
Regarding Claim 8, the combination of Okubo, Raeve and Matsumura comprises the pump apparatus according to claim 1, wherein [the second thrust balance mechanism is] disposed at a discharge side of the plurality of impellers (shown to be provided at the discharge side of the impellers 36 in figs 2, 6 and 8 of Okubo). Matsumura, as used to modify the combination of Okubo and Raeve, presents the first thrust balance mechanism on the suction side instead (see figs. 1 and 3 of Matsumura).
However, the combination of Okubo, Raeve and Matsumura fails to explicitly disclose that the first thrust balance mechanism [is also] disposed at a discharge side of the plurality of impellers.
The prior art combination reads onto the claim except with regard to the position of the first thrust balance mechanism, the instant invention having the first thrust balance mechanism disposed at a discharge side of the plurality of impellers (as opposed to a suction side of the plurality of impellers, as shown in figs. 1, 3 and 6 of Matsumura, as used to modify the combination of Okubo and Raeve); the instant disclosure does not provide an unexpected result nor assign any particular benefit/criticality for this arrangement. Further, it has been held that shifting the position of a component which would not have modified the operation of the device would not be patentably distinct. Therefore, it would have been an obvious matter of rearrangement of parts to one of ordinary skill in the art to modify the combination of Okubo, Raeve and Matsumura by providing the balance piston mechanism of Matsumura (used to modify the combination of Okubo and Raeve above) on the discharge side of the pump such both the first and second thrust balance mechanisms are provided at a discharge side of the plurality of impellers. This would not have modified the operation of the pump device since the first thrust balance mechanism in the combination would similarly provide a thrust balancing means but just on an opposite end of the shaft. See MPEP 2144.04 VI. C. “Rearrangement of Parts” for more details.
Regarding Claim 9, the combination of Okubo, Raeve and Matsumura comprises the pump apparatus according to claim 1, wherein the first thrust balance mechanism includes:
a first wall structure (see casing 31 in fig. 6 of Matsumura, as used to modify the combination of Okubo and Raeve above) having a first low-pressure chamber (low pressure chamber 36b fig. 6 of Matsumura), a first balance chamber (low pressure chamber 36a fig. 6 of Matsumura), and a first high-pressure chamber (high pressure chamber 35a fig. 6 of Matsumura) formed therein; and
a first partition (see bushing 34a which is attached to and inside casing 31 in fig. 6 of Matsumura, as used to modify the combination of Okubo and Raeve above) located in the first wall structure and between the first low-pressure chamber (low pressure chamber 36b fig. 6 of Matsumura) and the first balance chamber (low pressure chamber 36a fig. 6 of Matsumura),
wherein a variable gap is formed between the first partition and the rotational structure (an axial gap between the bushing 34a (which is fixed to the casing 31) and the balance piston 33b (which is fixed to the shaft 12 and greater rotational structure) in fig. 6 of Matsumura, as used to modify the combination of Okubo and Raeve, this axial gap would change with movement of shaft 12 relative to casing 31) including the rotation shaft and the plurality of impellers, and a magnitude of the variable gap changes according to an axial position of the rotation shaft (the magnitude of the axial gap between bushing 34a, fixed to casing 31, and the balance piston 33b, fixed to shaft 12, would change with the movement of shaft 12 relative to casing 31 in fig. 6 of Matsumura, as used to modify the combination of Okubo and Raeve).
Regarding Claim 10, the combination of Okubo, Raeve and Matsumura comprises the pump apparatus according to claim 1, wherein the first thrust balance mechanism (thrust balance mechanism 30 fig. 3 of Matsumura, as used to modify the combination of Okubo and Raeve above) includes:
a first wall structure having a first low-pressure chamber and a first high-pressure chamber formed therein (see casing 31 and lid 32, which together form a wall structure, low pressure chamber 36 and high pressure chamber 35 in fig. 1 of Matsumura, as used to modify the combination of Okubo and Raeve); and
a first partition located in the first wall structure and between the first low-pressure chamber and the first high-pressure chamber (see balance piston 33 which forms a partition between the low pressure chamber 36 and high pressure chamber 35 in fig. 1 of Matsumura, used to modify the combination of Okubo and Raeve),
wherein a radial gap is formed between an outer circumferential surface of the first partition and an inner circumferential surface of the first wall structure, and a magnitude of the radial gap does not change regardless of an axial position of the rotation shaft (see radial gap between the axially aligned balance piston 33 fixed to the shaft and the axially aligned balance bush 34 fixed to the casing side in fig. 1 of Matsumura, used to modify the combination of Okubo and Raeve, this gap would not change from movement of the shaft due to the vertical/axial alignment of 33 and 34 shown in the figure).
Claim(s) 2 is/are rejected under 35 U.S.C. 103 as being unpatentable over the combination of Okubo, Raeve and Matsumura, as applied to claim 1 above, and further in view of WO2018173769A1 (first cited in the Office Action of 04/20/2026), herein referenced as Hosoda.
Regarding Claim 2, the combination of Okubo, Raeve and Matsumura comprises the pump apparatus according to claim 1, but fails to teach it further comprising a check valve attached to the return line to allow the liquid hydrogen to flow only from the low-pressure chamber to the suction-side impeller.
Hosoda is analogous art since it relates to the field of endeavor of pump assemblies.
Hosoda teaches of a check valve attached to the return line (see check valve 60 attached to balance piping 18 in fig. 11) to allow the liquid hydrogen to flow only from the low-pressure chamber to the suction-side impeller (piping 18 shown to only allow one-way flow, such as for a liquid, to the discharge of the first stage impeller in fig. 11). Hosoda further teaches that “focusing on the flow of liquid through the balance pipe 18, the check valve 60 prevents the liquid from flowing from the suction side of the multi-stage pump through the balance pipe 18 to the balance chamber 16. As a result, only a thrust force in the opposite direction to the suction side is applied to the balance disc 15, thus preventing contact between the balance disc 15 and the balance sheet 12” in pr. 42.
Therefore, it would have been obvious before the effective filing date of invention to one of ordinary skill in the art to have modified the return line in the combination of Okubo, Raeve and Matsumura (see 56 in fig. 6 of Okubo) with a check valve as disclosed by Hosoda to obtain the benefit of ‘preventing liquid from flowing from the suction side of the pump through the pipe and to the chamber, thus only applying a thrust force opposite to the suction side which prevents contact between components’ as taught by Hosoda.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
US 12006946 – US patent grant of prior art cited above.
EP0719941A1 – discloses a double-suction pump with a plurality of centrifugal impellers, discloses that that the pump constructed as a vertical pump requires a smaller installation space than horizontal pumps.
CN105485022A – discloses a segmental multi-stage centrifugal pump, states that segmental multi-stage centrifugal pumps often adopt a vertical installation design to save space and facilitate installation.
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.
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/W.L.F./Examiner, Art Unit 3745
/COURTNEY D HEINLE/Supervisory Patent Examiner, Art Unit 3745
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