Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Rejections - 35 USC § 102
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.
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.
Claims 2, 8-9, and 11-12 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Larosiliere et al. (US 2018/0347584 A1) hereinafter referred to as Larosiliere.
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Regarding Claim 2, Larosiliere discloses a multistage centrifugal compressor (10, figures 1-2 also reproduced above) also reproduced above comprising:
a rotational shaft (20, figures 1-2);
an impeller (60, 70, figure 2) fixed to the rotational shaft (see figure 2);
a diffuser flow path (see, 110, figure 2) located on an outer radial side of the impeller (see figure 2), and
a return flow path (see annotated figure 16) formed by a shroud and a hub (best seen from figures 1-2) and configured to return a fluid flowing in the diffuser flow path toward the rotational shaft (see figures 1-2), wherein the return flow path includes a radial flow path (see annotated figure 16) through which the fluid flows from the outer radial side to an inner radial side (see figures 1-2 and 16), an axial flow path (see annotated figure 16) through which the fluid flows along the rotational shaft (see figures 1-2 and 16), a bend portion (see annotated figure 16) connecting the radial flow path and the axial flow path (see annotated figure 16), and a return vane (310, figure 16) formed to extend from the radial flow path to the bend portion (see annotated figure 16),
a hub-side connection part (see annotated figure 16) of a rear edge (360, figure 16) of the return vane is on the inner radial side of a shroud-side connection part of the rear edge (see annotated figure 16), and the rear edge has a curved shape (see annotated figure 16) protruding toward the rotational shaft (see annotated figure 16), and
the curved shape of the rear edge is on an extension of the axial flow path, or is exposed to the axial flow path (see annotated figure 16).
Regarding Claim 8, Larosiliere discloses that the shroud-side connection part of the return vane is not on an extension of the axial flow path or is not exposed to the axial flow path (see annotated figure 16).
Regarding Claim 9, Larosiliere discloses that a curve radius of the rear edge of the return vane on the shroud side is smaller than a curve radius of the rear edge of the return vane on the hub side (see curvature of 360, figure 16).
Regarding Claim 11, Larosiliere discloses that the return vane is a tandem type (see return vane configuration with 310 and 311 making a tandem type arrangement, figure 15 also reproduced below).
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Regarding Claim 12, Larosiliere discloses that the return vane is a front vane (310, figure 15) provided on an upstream side (see figure 15) and a rear vane (311, figure 15) provided on a downstream side (see figure 15), and an inlet blade angle of the front vane is larger than an inlet blade angle of the rear vane (see 310 being swept and forming a larger inlet blade angle compared to 311, figure 15).
Allowable Subject Matter
Claims 1 and 3-7 are allowed.
Regarding Claim 1, the closest prior art considered to be Larosiliere discloses a multistage centrifugal compressor (10, figures 1-2) comprising:
a rotational shaft (20, figures 1-2);
an impeller (60, 70, figure 2) fixed to the rotational shaft (see figure 2); and
a return flow path (see annotated figure 16) formed by a shroud and a hub (best seen from figures 1-2), wherein in the return flow path, a radial flow path (see annotated figure 16), an L-shaped bend flow path (see annotated figure 16), and an axial flow path (see annotated figure 16) form an L-shaped flow path (see annotated figure 16),
a return vane (310, figure 16) is arranged in the radial flow path and the L-shaped bend flow path (see annotated figure 16),
a portion of the rear edge of the return vane near a shroud-side connection part has a curved shape protruding downstream (see annotated figure 16), the rear edge of the return vane extended toward an inner radial side to an inside of the L-shaped bend flow path (see annotated figure 16), and
the hub-side connection part of the return vane is on the inner radial side of the shroud-side connection part (see annotated figure 16).
Larosiliere fails to disclose a portion of a rear edge of the return vane near a hub-side connection part having a linear shape. Therefore, it is not known in, nor obvious from the prior art to construct a multistage centrifugal compressor as claimed.
Claims 3-7 are also allowed by virtue of their dependency.
Claim 10 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Regarding Claim 10, the limitations further distinguish over the closest prior art, Larosiliere.
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 filed document or remarks of a filed response (see MPEP 502.03 Il): 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 sabbir.hasan@uspto.gov.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
US12146504 B2 discloses a centrifugal compressor including inlet guide vanes with a tandem arrangement including front vanes having an inlet angle larger than the rear vanes (see figure 5 also reproduced below).
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Any inquiry concerning this communication or earlier communications from the examiner should be directed to Sabbir Hasan whose telephone number is (571)270-7651. The examiner can normally be reached on Monday - Friday 11am-7pm.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Nathaniel Wiehe can be reached at 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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/Sabbir Hasan/Primary Examiner, Art Unit 3745
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