NON-FINAL ACTION
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 .
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 23 February 2026 has been entered.
Response to Arguments
Applicant's arguments filed 23 February 2026 have been fully considered but they are not persuasive. The existing prior art applied above is deemed to render the pending claims obvious as expressed in the rejections.
Claim Objections
Claim 9 is objected to because of the following informalities: Applicant is advised that should claim 1 be found allowable, claim 9 will be objected to under 37 CFR 1.75 as being a substantial duplicate thereof. When two claims in an application are duplicates or else are so close in content that they both cover the same thing, despite a slight difference in wording, it is proper after allowing one claim to object to the other as being a substantial duplicate of the allowed claim. See MPEP § 706.03(k). Appropriate correction is required.
Claim Rejections - 35 USC § 103
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 (i.e., changing from AIA to pre-AIA ) 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 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, 5, and 9-13 are rejected under 35 U.S.C. 103 as being unpatentable over GB 2064997 (Jackson) in view of Quinn et al. (U.S. Patent Application Pub. No. 2012/0329631, hereinafter Quinn).
Regarding claim 1, Jackson discloses a screen bowl decanter centrifuge (Figure) of the type comprising: a horizontally rotatable bowl (10, Figure) within which a scroll conveyor (scroll conveyor 42 and conveyor portion 44a, Figure) is coaxially mounted for rotation at a slightly different speed for conveying solids (page 1 lines 9-10), deposited by centrifugal action on the internal surface of the bowl, towards a solids discharge end of the bowl (“solids outlet end”, page 1 lines 54-55), the other end of the bowl having a liquids outlet (24, Figure), the bowl having an imperforate frustoconical portion (18, Figure), which converges towards the solids discharge end and provides a sloping ramp up which solids are drawn by the conveyor out of the liquid pool contained in the bowl (page 1 lines 16-19); and a perforate screen portion (20, Figure) downstream of, and immediately adjacent to, the imperforate frustoconical portion in the direction of solids discharge for assisting dewatering of the solids (“the screen portion 20 is located immediately downstream of the conical portion 18”, page 1 lines 101-102), wherein the perforate screen portion comprises a first screen portion (20, the perforate screen portion is equivalent to the first portion, Figure) immediately downstream of the imperforate frustoconical portion (18, Figure), inclined at a first angle with respect to the rotational axis of the bowl (see Figure), and wherein the scroll conveyor (scroll conveyor 42 and conveyor portion 44a, Figure) is located adjacent to both the imperforate portion (18, Figure) and the perforate screen portion (20, Figure) of the bowl, and wherein the scroll conveyor extends for substantially the whole length of the rotatable bowl (10, Figure), but does not disclose a second, divergent screen portion, considered in the direction of solids discharge, downstream of, and immediately adjacent to, the first screen portion and inclined at a second angle with respect to the rotational axis of the bowl.
Quinn discloses a perforated second, divergent screen portion (second diverging conical section 13, Fig. 3; second diverging conical section 17, Fig. 4), considered in the direction of solids discharge, downstream of, and immediately adjacent to, the first portion (first diverging conical section 11, Fig. 3; first diverging conical section 15, Fig. 4) and inclined at a second angle (second diverging conical section 13 at a second angle 43, para. [0028]; second diverging conical section 17 at a second angle 47, para. [0029]) with respect to the rotational axis of the bowl (Fig. 3 and 4, paras. [0028]-[00289]; [0032]-[0033]). It would have been obvious for one having ordinary skill in the art before the effective filing date of the claimed invention to have provided the centrifuge of Jackson with the second divergent perforate screen portion as taught by Quinn for the purpose of providing controlled movement of the solids cake over the diverging conical screen section (“To provide controlled movement of the solids cake over the diverging conical screen section, the angles 41, 43, 45, 47, 49 of the screen section 10 should be set such that the cake slides in a controlled fashion due to the forces acting on the cake, which include centrifugal force (Fc), gravity (G), and pressure (Fp) from cake being added to the screen section”, para. [0032]-[0033]).
Regarding the new limitation “the perforate screen portion configured to reduce kinetic energy loss of the screen bowl decanter centrifuge by discharging a majority of the liquid that is discharged by screen bowl decanter centrifuge through the first perforate screen portion of the perforate screen portion”, the combination of Jackson and Quinn teaches and/or renders obvious said limitation, because the recited functional limitation is an inherent consequence of the structural arrangement taught by Jackson as modified by Quinn. The function is inseparable from the structure and is not a distinguishing limitation over the prior art.
The present specification as filed explicitly states that “[t]he majority of the liquid that is discharged through the screen section occurs during the initial part of its travel over the screen,” (page 3 lines 17-18) and that “[b]y providing a screen which is initially cylindrical followed by a divergent section (in the scrolling direction of the solids), then the initial loss of liquid results in a lower liquid energy loss than that of a solely divergent screen without a cylindrical section, because the average radius over which the liquid is discharged is smaller for the cylindrical/divergent screen combination” (page 7 lines 15-19). When Jackson’s centrifuge is modified to include Quinn’s second divergent screen section downstream of Jackson’s existing screen section 20, the resulting structure (an upstream first screen portion followed by a downstream divergent second screen section) inherently causes a majority of the liquid that would drain though the screen portion to discharge through the first screen portion at the smaller radius, and thereby inherently reducing the kinetic energy loss of the centrifuge compared to a single divergent section. When the structure recited in the reference is substantially identical to that of the claims, claimed properties or functions are presumed to be inherent. Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977). See MPEP 2112.01.
Regarding claim 5, the combination of Jackson and Quinn discloses wherein the first perforate screen portion is divergent (Jackson discloses one perforate screen portion, imperforate frusto-conical portion 18, which is divergent, see Figure; Quinn discloses first diverging conical section 11, see Fig. 3, and first diverging conical section 15, see Fig. 4).
Regarding claim 9, the combination of Jackson and Quinn discloses wherein the second, divergent, perforate screen portion (second diverging conical section 13, Fig. 3; second diverging conical section 17, Fig. 4, Quinn) is located immediately adjacent to the first perforate screen portion (first diverging conical section 11, Fig. 3; first diverging conical section 15, Fig. 4, Quinn).
Regarding claim 10, the combination of Jackson and Quinn discloses wherein the angle of the second divergent perforate screen section (Jackson discloses one perforate screen portion 20) is less than the frictional angle of the solids product with which the centrifuge is being used (the angle of the perforate screen portion 20 of Jackson corresponds to the angle of the second divergent perforate screen section, and is “less than the frictional angle of the solids product with which the centrifuge is being used” page 1, left column, lines 61-66).
Regarding claim 11, the combination of Jackson and Quinn discloses wherein the angle of the second, divergent permeable screen section is greater than the frictional angle of the solids product with which the centrifuge is being used (Quinn teaches that the angle of the second frusto-conical diverging screen section 40, which corresponds to the angle of the second diverging conical section 13 and the angle of the second diverging conical section 17, should be “sufficiently large that the solids on the screen move down the ramp without aid of the helical blades” and should be “selected such that the solids may be frictionally advanced over the screen section 10 in an amount of time that allows the additional liquid 28 to be removed from the solids”, para. [0014], Quinn. Since a conveyor is not needed to move the solids down the ramp to the solids outlet, and the divergent angle alone can be enough to allow the solids to frictionally advance over the screen section, it can be concluded that the second, divergent perforate screen portion of Quinn has an angle greater than the frictional angle).
Regarding claim 12, the recited formula for kinetic energy loss would apply to every centrifuge. The combination of Jackson and Quinn discloses a screen bowl centrifuge whose kinetic energy losses are inherently defined by this equation. The mathematical expression adds no additional structural limitations, and therefore said claim is unpatentable over the combination of Jackson and Quinn for the same reasons as base claim 1. The Courts have held that it is well settled that the recitation of a new intended use, for an old product, does not make a claim to that old product patentable. See In re Schreiber, 128 F.3d 1473, 1477, 44 USPQ2d 1429, 1431 (Fed. Cir. 1997). In re Swinehart, 439 F.2d 210, 213, 169 USPQ 226, 228 (CCPA 1971) ("where the Patent Office has reason to believe that a functional limitation asserted to be critical for establishing novelty in the claimed subject matter may, in fact, be an inherent characteristic of the prior art, it possesses the authority to require the applicant to prove that the subject matter shown to be in the prior art does not possess the characteristic relied on").” See MPEP § 2114. Applicant has not provided evidence that the prior art combination fails to operate according to this equation.
Regarding claim 13, the functional limitation “discharging at least half of the liquid through the first perforate screen portion before the solids reach the second perforate screen portion of the perforate screen portion” is an inherent result of the structural combination of Jackson and Quinn, for the same reasons as discussed for the corresponding functional limitation in claim 1. The present specification as filed admits that the “majority” (i.e. more than half) of the liquid drains through the upstream screen section. Said claim is therefore unpatentable over the combination of Jackson and Quinn for the same reasons as base claim 1.
Claims 3, 4, 6 and 7 are rejected under 35 U.S.C. 103 as being unpatentable over Jackson in view of Quinn, as applied to claim 1 above, and further in view of JP 2003071324 (Tanabe).
Regarding claims 3 and 4, the combination of Jackson and Quinn does not disclose wherein the first perforate screen portion is converging; wherein the angle of inclination of the first perforate screen portion is from 0˚ to 5˚ with respect to the rotational axis of the bowl.
Tanabe discloses wherein the first perforate screen portion (first basket 11 or second basket 12, Fig. 2) is converging; wherein the angle of inclination of the first perforate screen portion is from 0˚ to 5˚ with respect to the rotational axis of the bowl (“the first basket 11 is fixed so as to connect the distal end of the first basket 11 to the proximal end of the third basket 13, and is formed into a substantially cylindrical shape without a taper. Here, the ‘substantially non-tapered cylindrical shape’ refers to a shape in which the cylindrical wall of the basket is inclined within a range of ± 5 degrees or less with reference of the cylindrical shape parallel to the central axis”; “like the first basket 11 and the third basket 13, the second basket 12 formed in the substantially cylindrical shape”, page 8 of English Translation filed with Third-Party Submission on 13 September 2023). It would have been obvious for one having ordinary skill in the art before the effective filing date of the claimed invention to have provided the centrifuge of the combination of Jackson and Quinn with a converging screen portion as taught by Tanabe for the purpose of allowing for slight variations in the angle of inclination of a cylindrical screen section when forming the barrel wall of the basket into a cylindrical shape without taper or tilting (page 8 of English Translation filed with Third-Party Submission on 13 September 2023, Tanabe).
Regarding claim 6, the combination of Jackson, Quinn, and Tanabe discloses wherein the angle of inclination of the first perforate screen portion (first basket 11 or second basket 12, Fig. 2, Tanabe) is from 0˚ to 5˚ with respect to the rotational axis of the bowl (“the first basket 11 is fixed so as to connect the distal end of the first basket 11 to the proximal end of the third basket 13, and is formed into a substantially cylindrical shape without a taper. Here, the ‘substantially non-tapered cylindrical shape’ refers to a shape in which the cylindrical wall of the basket is inclined within a range of ± 5 degrees or less with reference of the cylindrical shape parallel to the central axis”; “like the first basket 11 and the third basket 13, the second basket 12 formed in the substantially cylindrical shape”, page 8 of English Translation filed with Third-Party Submission on 13 September 2023, Tanabe).
Regarding claim 7, the combination of Jackson, Quinn, and Tanabe discloses wherein the first perforate screen portion is cylindrical (“the first basket 11 is fixed so as to connect the distal end of the first basket 11 to the proximal end of the third basket 13, and is formed into a substantially cylindrical shape without a taper. Here, the ‘substantially non-tapered cylindrical shape’ refers to a shape in which the cylindrical wall of the basket is inclined within a range of ± 5 degrees or less with reference of the cylindrical shape parallel to the central axis”; “like the first basket 11 and the third basket 13, the second basket 12 formed in the substantially cylindrical shape”, page 8 of English Translation filed with Third-Party Submission on 13 September 2023, Tanabe).
Conclusion
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/Shuyi S. Liu/Examiner, Art Unit 1774
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