Prosecution Insights
Last updated: May 04, 2026
Application No. 18/670,552

CENTRIFUGAL PUMP FOR CONVEYING A FLUID

Non-Final OA §103§112
Filed
May 21, 2024
Priority
Jun 14, 2023 — EU 23179343.1
Examiner
CLARK, RYAN C
Art Unit
3745
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Sulzer Management AG
OA Round
3 (Non-Final)
87%
Grant Probability
Favorable
3-4
OA Rounds
0m
Est. Remaining
96%
With Interview

Examiner Intelligence

Grants 87% — above average
87%
Career Allowance Rate
232 granted / 266 resolved
+17.2% vs TC avg
Moderate +8% lift
Without
With
+8.5%
Interview Lift
resolved cases with interview
Fast prosecutor
1y 10m
Avg Prosecution
36 currently pending
Career history
302
Total Applications
across all art units

Statute-Specific Performance

§101
2.6%
-37.4% vs TC avg
§103
39.2%
-0.8% vs TC avg
§102
30.3%
-9.7% vs TC avg
§112
26.2%
-13.8% vs TC avg
Black line = Tech Center average estimate • Based on career data from 266 resolved cases

Office Action

§103 §112
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 03/13/2026 has been entered. Response to Arguments Applicant's arguments filed 03/13/2026 have been fully considered but they are not persuasive. PNG media_image1.png 572 650 media_image1.png Greyscale Applicant has submitted Exhibit A (reproduced above). Applicant's Affidavit (Items 1 - 14) describe the status of the claims. Applicant's Affidavit (Item 15-16) indicates that [0021]-[0022] that "flow passages can be provided without affecting the pump performance at or near the BEP (Best Efficiency Point), i.e. at partial load or low flows with at least one flow passage reliably prevents or at least considerably reduces instabilities, but at or near the BEP the flow passage or the flow passages have no or at most a negligible influence on the pump performance." However, there is no criticality placed on "a total cross-section of all the plurality of flow passages in the tongue is at least 8% and at most 45% of the entrance area" as claimed by the Applicant in paragraph [0021]-[0022]. Applicant's Affidavit (17-37) are directed to Exhibit A (By testing involving "one flow passage" and "two flow passages") which the Examiner understands as 6% and 11-12% respectively. Additionally, the Examiner notes that "Legacy" is included in Exhibit A, which the Examiner is presuming to be the standard pump of the prior art with no flow passages in the tongue. Firstly, the Examiner respectfully notes that the submitted evidence and Affidavit by the Inventor only deals with one example of their claimed range and there is a significant range of undisclosed test results (From 13% to 45% of the entrance area) (items 28-33) and "Whether the unexpected results are the result of unexpectedly improved results or a property not taught by the prior art, the "objective evidence of nonobviousness must be commensurate in scope with the claims which the evidence is offered to support." In other words, the showing of unexpected results must be reviewed to see if the results occur over the entire claimed range." (emphasis added) (MPEP 716.02(d)). Secondly, the Examiner respectfully notes that the BEP (Best Efficiency Point) is not indicated for any of the pump curves indicated in Exhibit A, and fails to show "This increased flow coefficient relative to the head coefficient was unexpected and resulted in significantly improved pump performance at or near the BEP, which is critical to the operations of the pump" and Applicant's arguments are directed towards the behavior said BEP (See Applicant's Arguments pages 8-9). Thirdly, the Examiner respectfully notes that it appears at least in Exhibit A, that as the cross- sectional area of the flow passages increases the maximum "Head Coefficient" drops and the maximum "Flow Coefficient" increases and does not provide an unexpected result in view of Jenks "The size of the hole 34 depends upon the volume output of the turbocharger. The higher the volume output of the turbocharger, the larger the hole 34 will need to be in order to supply the amount of air that will be required to restore proper flow to the volute tongue" (Jenks, Col. 4:16-49), and given the difference between "Legacy" and "Flow Passages out of range" in Exhibit A, a person of ordinary skill would reasonably presume that increasing the size of the "out of range" range passages would result in lower Maximum Head Coefficient and an increase in Maximum Flow Coefficient as demonstrated by the Applicant in Exhibit A. PNG media_image2.png 572 759 media_image2.png Greyscale Finally, the Examiner respectfully indicates that it would have been obvious to one of ordinary skill in the art before the effective filing date to modify the combination of Flückiger et al. and Veres to have the flow passages be between 8% and 45% of the entrance area as a matter of routine optimization since it has been held that "where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 345 (CCPA 1995), and a person of ordinary skill would be compelled by the teaching of Jenks to experiment with the cross-sectional area of the flow passages to optimize for size. (See MPEP 2144.05 II. A.). Claim Rejections - 35 USC § 112 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. The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph: The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention. Claim 18 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. The term "about" is a relative term which renders the claim indefinite; it is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. “about” is defined as "in the vicinity” or “reasonably close to” (see Merriam Webster online dictionary). This language is indefinite as the specification does not describe how much the term “about” modifies a target, and implicitly requires boundaries at some maximum value above the target and at some minimum value below the target beyond which one is not “about” the target any more. 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. Claims 1-4, 7-10, 14, and 16-18 are rejected under 35 U.S.C. 103 as being unpatentable over Flückiger et al. (US Patent 9,441,637 B2) in view of Veres (US Patent 5,286,162 A) and Jenks (US Patent 10,480,398 B2). PNG media_image3.png 363 812 media_image3.png Greyscale Regarding claim 1, Flückiger et al. discloses a centrifugal pump (Fig. 1B) for conveying a fluid ("pumped medium" Col. 1:33-35), comprising: a pump casing (1) having a central axis (understood the be the center most point of the opening in the casing) defining an axial direction (along the shaft of Fig. 1B); a pump chamber (1.1); an impeller (4) arranged within the pump chamber (Fig. 1B) and configured to rotate about the axial direction (Col.5:52-6:3); a discharge passage (6.1, 6.2) to discharge the fluid from the pump chamber; and a tongue (3.a, see annotated Fig. 1A above) configured to guide the fluid to the discharge passage, the tongue comprising an inner surface (the surface of the tongues facing the central axis) facing the central axis, an out surface (the surface of the tongues facing away from the central axis), a leading edge (the edge facing towards the fluid flow, Fig. 1A) joining the inner surface and the outer surface (Fig. 1A). However, Flückiger et al. does not teach or suggest, "a plurality of flow passages, each flow passage of the plurality of flow passages extending from the inner surface through the tongue to the outer surface." or "the discharge passage having an entrance area, the entrance area being a cross sectional area of the discharge passage at the leading edge of the tongue delimiting the discharge passage, and a total flow cross-section of all the plurality of flow passages in the tongue is at least 8% and at most 45% of the entrance area." PNG media_image4.png 448 456 media_image4.png Greyscale Veres teaches, in the field of volute tongues for impellers, bleed holes (26) between the inner (37) and outer surface (27) of the tongue (24). It would have been obvious to one of ordinary skill in the art before the effective filing date to modify the tongues of Flückiger et al. to have bleed holes between the inner and outer surfaces as taught by Veres, and one of ordinary skill would appreciate that "According to the present invention, the introduction of the bleed holes 26 in the volute tongue 24 offers a means of controlling the boundary layer by using the pressure difference between the outer surface 27 and inner surface 37 of the tongue. The lower pressure on the outer surface 27 of the tongue will create suction, pulling the boundary layer flow that has separated from the inner surface 37 of the tongue thereby providing laminar flow control of fluid against both the outer surface 27 and the inner surface 37 of the volute tongue 24. (Col. 3:58- 68)." Jenks teaches in the field of turbocharger volute tongues (33), a bypass hole (34) between the inner and outer surface of the tongue, and further teaches that "The size of the hole 34 depends upon the volume output of the turbocharger. The higher the volume output of the turbocharger, the larger the hole 34 will need to be in order to supply the amount of air that will be required to restore proper flow to the volute tongue (Col. 4:16-49). The Examiner also notes that there is no apparent criticality placed on the claimed range (See immediate specification [0067]). It would have been obvious to one of ordinary skill in the art before the effective filing date to modify the combination of Flückiger et al. and Veres to have the flow passages be between 8% and 45% of the entrance area as a matter of routine optimization since it has been held that "where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1995), and a person of ordinary skill would be compelled by the teaching of Jenks to experiment with the cross sectional area of the flow passages to optimize for size. Regarding claim 2, the combination of Flückiger et al., Veres, and Jenks teach all of claim 1 as above, wherein the tongue is one of a plurality of tongues (Flückiger et al., Fig. 1A) and the discharge passage is one of a plurality of discharge passages (Flückiger et al.; Fig. 1A, 6.1, 6.2), and the pump casing comprises the plurality of tongues (Flückiger et al., Fig. 1A) and the plurality of discharge passages, each tongue of the plurality of tongues is configured to guide the fluid in one discharge passage of the plurality of discharge passages (Flückiger et al., Fig. 1A), and the flow passage is one of a plurality of flow passages (Flückiger et al., Fig. 1A), each tongue of the plurality of tongues comprises at least one flow passage (Veres, 26) of the plurality of flow passages extending from the inner surface through the tongue to the outer surface of a respective tongue. Regarding claim 3, the combination of Flückiger et al., Veres, and Jenks teach all of claim 1 as above, wherein the chamber is a volute chamber (Flückiger et al., Fig. 1A the casing is shown to be a housing). Regarding claim 4, the combination of Flückiger et al., Veres, and Jenks teach all of claim 2 as above, wherein the pump casing comprises a diffuser (Flückiger et al., Fig. 1A the diffuser in this case is the tongues as claimed by the applicant as) surrounding the pump chamber and has a plurality of stationary diffuser vanes (Flückiger et al., Fig. 1A, the diffuser comprises the two tongues), each stationary diffuser of the plurality of stationary diffuser vanes comprises one of the plurality of tongues to direct the fluid in one discharge passages of the plurality if discharge passages). Regarding claim 7, the combination of Flückiger et al., Veres, and Jenks teach all of claim 1 as above, wherein the plurality of flow passages are arranged in an annular region (Veres, Fig. 1) which is delimited by a leading edge tangent from the central axis (Veres, Fig. 1) and a straight borderline from the central axis to the tongue. However, it is not explicitly taught that, "the leading edge tangent and the borderline include an angle from 2° to 20° (Veres, Fig. 1 the bleed holes 26 are shown to be just a portion of the volute tongue) Additionally, the applicant appears to place no criticality on this particular dimension (See immediate specification [0069]-[0070]) and it appears that the combination of Flückiger et al., Veres, and Jenks would operate equally well with the claimed annular region since the bleed holes of Veres only appear on the leading edge region of the tongue. Further, the applicant has not disclosed that the range claimed solves any stated problem or is for any particular purpose, indicating simply that the annular region 'may' be within the claimed ranges (immediate specification, ([0069]-[0070)]). It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to cause the device of Flückiger et al., Veres, and Jenks to have the bleed holes in the annular region of the tongue between 2° and 20° because it appears to be an arbitrary design consideration which fails to patentably distinguish over the combination of Flückiger et al., Veres, and Jenks. Regarding claim 8, the combination of Flückiger et al., Veres, and Jenks teach all of claim 7 as above, wherein each flow passage of the plurality of flow passages is a straight passage (Veres, Fig. 1) obliquely extending with respect to the leading edge tangent of the respective tongue (Jenks; Col. 4:42- 46). Regarding claim 9, the combination of Flückiger et al., Veres, and Jenks teach all of claim 1 as above, wherein the flow passage defines an inclination angle (Veres, Fig. 1 implies an inclination of the flow passage and the inner surface of the tongue, and the angle provides a direct passage between the inner and outer surface of the tongue; e.g., the angle is between -45 and 45 degrees), and the inclination angle is between -45 (degrees) and 45 (degrees) (Veres, Fig. 1). Regarding claim 10, the combination of Flückiger et al., Veres, and Jenks teach all of claim 1 as above, wherein the flow passage is a closed passage (Veres, 26 "bleed holes") extending inside the tongue. Regarding claim 14, the combination of Flückiger et al., Veres, and Jenks teach all of claim 1 as above, wherein the flow passage is one of a plurality of flow passages (Veres, Fig. 1), and the plurality of flow passaged are arranged in a matrix (Veres, Fig. 1; the Examiner notes a matrix of at least 1x11). Regarding claim 16, the combination of Flückiger et al., Veres, and Jenks teach all of claim 1 as above. However, the combination of Flückiger et al., Veres, and Jenks do not explicitly teach, “wherein the total flow cross-sectional of all the plurality of flow passages in the tongue is at most 30%.” Jenks teaches in the field of turbocharger volute tongues (33), a bypass hole (34) between the inner and outer surface of the tongue, and further teaches that "The size of the hole 34 depends upon the volume output of the turbocharger. The higher the volume output of the turbocharger, the larger the hole 34 will need to be in order to supply the amount of air that will be required to restore proper flow to the volute tongue (Col. 4:16-49). The Examiner also notes that there is no apparent criticality placed on the claimed range (See immediate specification [0067]). It would have been obvious to one of ordinary skill in the art before the effective filing date to modify the combination of Flückiger et al. and Veres to have the flow passages be at most 30% of the entrance area as a matter of routine optimization since it has been held that "where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1995), and a person of ordinary skill would be compelled by the teaching of Jenks to experiment with the cross sectional area of the flow passages to optimize for size. Regarding claim 17, the combination of Flückiger et al., Veres, and Jenks teach all of claim 1 as above. However, the combination of Flückiger et al., Veres, and Jenks do not explicitly teach, “wherein the total flow cross-sectional of all the plurality of flow passages in the tongue is at most 20%.” Jenks teaches in the field of turbocharger volute tongues (33), a bypass hole (34) between the inner and outer surface of the tongue, and further teaches that "The size of the hole 34 depends upon the volume output of the turbocharger. The higher the volume output of the turbocharger, the larger the hole 34 will need to be in order to supply the amount of air that will be required to restore proper flow to the volute tongue (Col. 4:16-49). The Examiner also notes that there is no apparent criticality placed on the claimed range (See immediate specification [0067]). It would have been obvious to one of ordinary skill in the art before the effective filing date to modify the combination of Flückiger et al. and Veres to have the flow passages be at most 20% of the entrance area as a matter of routine optimization since it has been held that "where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1995), and a person of ordinary skill would be compelled by the teaching of Jenks to experiment with the cross sectional area of the flow passages to optimize for size. Regarding claim 18, the combination of Flückiger et al., Veres, and Jenks teach all of claim 1 as above. However, the combination of Flückiger et al., Veres, and Jenks do not explicitly teach, “wherein the total flow cross-sectional of all the plurality of flow passages in the tongue is about 20% to 30%.” Jenks teaches in the field of turbocharger volute tongues (33), a bypass hole (34) between the inner and outer surface of the tongue, and further teaches that "The size of the hole 34 depends upon the volume output of the turbocharger. The higher the volume output of the turbocharger, the larger the hole 34 will need to be in order to supply the amount of air that will be required to restore proper flow to the volute tongue (Col. 4:16-49). The Examiner also notes that there is no apparent criticality placed on the claimed range (See immediate specification [0067]). It would have been obvious to one of ordinary skill in the art before the effective filing date to modify the combination of Flückiger et al. and Veres to have the flow passages be about 20% to 30% of the entrance area as a matter of routine optimization since it has been held that "where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1995), and a person of ordinary skill would be compelled by the teaching of Jenks to experiment with the cross sectional area of the flow passages to optimize for size. Claims 1-4, 7, 9-10, 12-14, and 16-18 are rejected under 35 U.S.C. 103 as being unpatentable over Flückiger et al. (US Patent 9,441,637 B2) in view of Veres (US Patent 5,286,162 A) and Thawani et al. (US Patent 10,415,601 B2). Regarding claim 1, Flückiger et al. discloses a centrifugal pump (Fig. 1B) for conveying a fluid ("pumped medium" Col. 1:33-35), comprising: a pump casing (1) having a central axis (understood the be the center most point of the opening in the casing) defining an axial direction (along the shaft of Fig. 1B); a pump chamber (1.1); an impeller (4) arranged within the pump chamber (Fig. 1B) and configured to rotate about the axial direction (Col.5:52-6:3); a discharge passage (6.1, 6.2) to discharge the fluid from the pump chamber; and a tongue (3.a, see annotated Fig. 1A above) configured to guide the fluid to the discharge passage, the tongue comprising an inner surface (the surface of the tongues facing the central axis) facing the central axis, an out surface (the surface of the tongues facing away from the central axis), a leading edge (the edge facing towards the fluid flow, Fig. 1A) joining the inner surface and the outer surface (Fig. 1A). However, Flückiger et al. does not teach or suggest, "a plurality of flow passages, each flow passage of the plurality of flow passages extending from the inner surface through the tongue to the outer surface." or "the discharge passage having an entrance area, the entrance area being a cross sectional area of the discharge passage at the leading edge of the tongue delimiting the discharge passage, and a total flow cross-section of all the plurality of flow passages in the tongue is at least 8% and at most 45% of the entrance area." Veres teaches, in the field of volute tongues for impellers, bleed holes (26) between the inner (37) and outer surface (27) of the tongue (24). It would have been obvious to one of ordinary skill in the art before the effective filing date to modify the tongues of Flückiger et al. to have bleed holes between the inner and outer surfaces as taught by Veres, and one of ordinary skill would appreciate that "According to the present invention, the introduction of the bleed holes 26 in the volute tongue 24 offers a means of controlling the boundary layer by using the pressure difference between the outer surface 27 and inner surface 37 of the tongue. The lower pressure on the outer surface 27 of the tongue will create suction, pulling the boundary layer flow that has separated from the inner surface 37 of the tongue thereby providing laminar flow control of fluid against both the outer surface 27 and the inner surface 37 of the volute tongue 24. (Col. 3:58- 68)." Thawani et al. teaches, in the field of centrifugal fans (10) a cut-off (110, the equivalent of a tongue of a blower) with perforations (120) with “holes, slots, or louvres, or micro-perforations with a porosity of 3%-10% of the open surface area (or greater)” The Examiner also notes that there is no apparent criticality placed on the claimed range (See immediate specification [0067]). It would have been obvious to one of ordinary skill in the art before the effective filing date to modify the combination of Flückiger et al. and Veres to have the flow passages be between 8% and 45% of the entrance area as a matter of routine optimization since it has been held that "where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1995), and a person of ordinary skill would be compelled by the teaching of Thawani et al. to experiment with the cross sectional area of the flow passages to optimize for size, as not only does Thawani et al. indicate a cross-sectional area of 3-10% which overlaps with the claimed range, but suggests to a person of ordinary skill in the art to increase the open surface area, “The number, size, and location of the perforations 120, as well as the overall dimensions of the cut-off 30, may be varied based on characteristics of the blower assembly 10, such as typical operating speed of the blower wheel 14. For example, for a blower wheel 14 that typically operates at a relatively high speed in the range of 1,000-4,500 RPM the perforations 120 may be holes, slots, louvres, or micro-perforations with a porosity of 3%-10% of the open surface area (or greater) configured to most effectively reduce or eliminate blower induced and/or broadband noise. For a blower wheel 14 that operates at a relatively lower speed in the range of 1,000 to 4,500 RPM, the perforations 120 may be holes, slots, louvres, or micro-perforations with a porosity of 3%-10% of the open surface area (or greater) configured to most effectively reduce or eliminate blower induced and/or broadband noise at the relatively lower speed. The perforations 120 and resonator volume is advantageously tuned to suppress the undesirable noise frequencies, for example. (Col. 3:4-22)”. Regarding claim 2, the combination of Flückiger et al., Veres, and Thawani et al. teach all of claim 1 as above, wherein the tongue is one of a plurality of tongues (Flückiger et al., Fig. 1A) and the discharge passage is one of a plurality of discharge passages (Flückiger et al.; Fig. 1A, 6.1, 6.2), and the pump casing comprises the plurality of tongues (Flückiger et al., Fig. 1A) and the plurality of discharge passages, each tongue of the plurality of tongues is configured to guide the fluid in one discharge passage of the plurality of discharge passages (Flückiger et al., Fig. 1A), and the flow passage is one of a plurality of flow passages (Flückiger et al., Fig. 1A), each tongue of the plurality of tongues comprises at least one flow passage (Veres, 26) of the plurality of flow passages extending from the inner surface through the tongue to the outer surface of a respective tongue. Regarding claim 3, the combination of Flückiger et al., Veres, and Thawani et al. teach all of claim 1 as above, wherein the chamber is a volute chamber (Flückiger et al., Fig. 1A the casing is shown to be a housing). Regarding claim 4, the combination of Flückiger et al., Veres, and Thawani et al. teach all of claim 2 as above, wherein the pump casing comprises a diffuser (Flückiger et al., Fig. 1A the diffuser in this case is the tongues as claimed by the applicant as) surrounding the pump chamber and has a plurality of stationary diffuser vanes (Flückiger et al., Fig. 1A, the diffuser comprises the two tongues), each stationary diffuser of the plurality of stationary diffuser vanes comprises one of the plurality of tongues to direct the fluid in one discharge passages of the plurality if discharge passages). Regarding claim 7, the combination of Flückiger et al., Veres, and Thawani et al. teach all of claim 1 as above, wherein the plurality of flow passages are arranged in an annular region (Veres, Fig. 1) which is delimited by a leading edge tangent from the central axis (Veres, Fig. 1) and a straight borderline from the central axis to the tongue. However, it is not explicitly taught that, "the leading edge tangent and the borderline include an angle from 2° to 20° (Veres, Fig. 1 the bleed holes 26 are shown to be just a portion of the volute tongue) Additionally, the applicant appears to place no criticality on this particular dimension (See immediate specification [0069]-[0070]) and it appears that the combination of Flückiger et al., Veres, and Thawani et al. would operate equally well with the claimed annular region since the bleed holes of Veres only appear on the leading edge region of the tongue. Further, the applicant has not disclosed that the range claimed solves any stated problem or is for any particular purpose, indicating simply that the annular region 'may' be within the claimed ranges (immediate specification, ([0069]-[0070)]). It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to cause the device of Flückiger et al., Veres, and Thawani et al. to have the bleed holes in the annular region of the tongue between 2° and 20° because it appears to be an arbitrary design consideration which fails to patentably distinguish over the combination of Flückiger et al., Veres, and Thawani et al.. Regarding claim 9, the combination of Flückiger et al., Veres, and Thawani et al. teach all of claim 1 as above, wherein the flow passage defines an inclination angle (Veres, Fig. 1 implies an inclination of the flow passage and the inner surface of the tongue, and the angle provides a direct passage between the inner and outer surface of the tongue; e.g., the angle is between -45 and 45 degrees), and the inclination angle is between -45 (degrees) and 45 (degrees) (Veres, Fig. 1). Regarding claim 10, the combination of Flückiger et al., Veres, and Thawani et al. teach all of claim 1 as above, wherein the flow passage is a closed passage (Veres, 26 "bleed holes") extending inside the tongue. Regarding claim 12, the combination of Flückiger et al., Veres, and Thawani et al. teach all of claim 1 as above, wherein the flow passage is one passage of a plurality of flow passages (Veres, Fig. 1), arranged in a first row extending in the axial direction (Veres, Fig. 1), and the first row comprises at most six flow passages of the plurality of flow passages (Thawani et al., Fig. 3 shows two rows of six perforations each). Regarding claim 13, the combination of Flückiger et al., Veres, and Thawani et al. teach all of claim 12 as above, wherein the at least flow passages are arranged in a second row (Thawani et al., Fig. 3) extending perpendicular to the axial direction (Thawani et al., Fig. 3), and the second row comprises at most six flow passages of the plurality of flow passages (Thawani et al., Fig. 3). Regarding claim 14, the combination of Flückiger et al., Veres, and Thawani et al. teach all of claim 1 as above, wherein the flow passage is one of a plurality of flow passages (Veres, Fig. 1), and the plurality of flow passaged are arranged in a matrix (Veres, Fig. 1; the Examiner notes a matrix of at least 1x11). Regarding claim 16, the combination of Flückiger et al., Veres, and Thawani et al. teach all of claim 1 as above. However, the combination of Flückiger et al., Veres, and Thawani et al. do not explicitly teach, “wherein the total flow cross-sectional of all the plurality of flow passages in the tongue is at most 30%” Thawani et al. teaches, in the field of centrifugal fans (10) a cut-off (110, the equivalent of a tongue of a blower) with perforations (120) with “holes, slots, or louvres, or micro-perforations with a porosity of 3%-10% of the open surface area (or greater)” The Examiner also notes that there is no apparent criticality placed on the claimed range (See immediate specification [0067]). It would have been obvious to one of ordinary skill in the art before the effective filing date to modify the combination of Flückiger et al. and Veres to have the flow passages be at most 30% of the entrance area as a matter of routine optimization since it has been held that "where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1995), and a person of ordinary skill would be compelled by the teaching of Thawani et al. to experiment with the cross sectional area of the flow passages to optimize for size, as not only does Thawani et al. indicate a cross-sectional area of 3-10% which overlaps with the claimed range, but suggests to a person of ordinary skill in the art to increase the open surface area, “The number, size, and location of the perforations 120, as well as the overall dimensions of the cut-off 30, may be varied based on characteristics of the blower assembly 10, such as typical operating speed of the blower wheel 14. For example, for a blower wheel 14 that typically operates at a relatively high speed in the range of 1,000-4,500 RPM the perforations 120 may be holes, slots, louvres, or micro-perforations with a porosity of 3%-10% of the open surface area (or greater) configured to most effectively reduce or eliminate blower induced and/or broadband noise. For a blower wheel 14 that operates at a relatively lower speed in the range of 1,000 to 4,500 RPM, the perforations 120 may be holes, slots, louvres, or micro-perforations with a porosity of 3%-10% of the open surface area (or greater) configured to most effectively reduce or eliminate blower induced and/or broadband noise at the relatively lower speed. The perforations 120 and resonator volume is advantageously tuned to suppress the undesirable noise frequencies, for example. (Col. 3:4-22)”. Regarding claim 17, the combination of Flückiger et al., Veres, and Thawani et al. teach all of claim 1 as above. However, the combination of Flückiger et al., Veres, and Thawani et al. do not explicitly teach, “wherein the total flow cross-sectional of all the plurality of flow passages in the tongue is at most 20%” Thawani et al. teaches, in the field of centrifugal fans (10) a cut-off (110, the equivalent of a tongue of a blower) with perforations (120) with “holes, slots, or louvres, or micro-perforations with a porosity of 3%-10% of the open surface area (or greater)” The Examiner also notes that there is no apparent criticality placed on the claimed range (See immediate specification [0067]). It would have been obvious to one of ordinary skill in the art before the effective filing date to modify the combination of Flückiger et al. and Veres to have the flow passages be at most 20% of the entrance area as a matter of routine optimization since it has been held that "where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1995), and a person of ordinary skill would be compelled by the teaching of Thawani et al. to experiment with the cross sectional area of the flow passages to optimize for size, as not only does Thawani et al. indicate a cross-sectional area of 3-10% which overlaps with the claimed range, but suggests to a person of ordinary skill in the art to increase the open surface area, “The number, size, and location of the perforations 120, as well as the overall dimensions of the cut-off 30, may be varied based on characteristics of the blower assembly 10, such as typical operating speed of the blower wheel 14. For example, for a blower wheel 14 that typically operates at a relatively high speed in the range of 1,000-4,500 RPM the perforations 120 may be holes, slots, louvres, or micro-perforations with a porosity of 3%-10% of the open surface area (or greater) configured to most effectively reduce or eliminate blower induced and/or broadband noise. For a blower wheel 14 that operates at a relatively lower speed in the range of 1,000 to 4,500 RPM, the perforations 120 may be holes, slots, louvres, or micro-perforations with a porosity of 3%-10% of the open surface area (or greater) configured to most effectively reduce or eliminate blower induced and/or broadband noise at the relatively lower speed. The perforations 120 and resonator volume is advantageously tuned to suppress the undesirable noise frequencies, for example. (Col. 3:4-22)”. Regarding claim 18, the combination of Flückiger et al., Veres, and Thawani et al. teach all of claim 1 as above. However, the combination of Flückiger et al., Veres, and Thawani et al. do not explicitly teach, “wherein the total flow cross-sectional of all the plurality of flow passages in the tongue is about 20% to 30%.” Thawani et al. teaches, in the field of centrifugal fans (10) a cut-off (110, the equivalent of a tongue of a blower) with perforations (120) with “holes, slots, or louvres, or micro-perforations with a porosity of 3%-10% of the open surface area (or greater)” The Examiner also notes that there is no apparent criticality placed on the claimed range (See immediate specification [0067]). It would have been obvious to one of ordinary skill in the art before the effective filing date to modify the combination of Flückiger et al. and Veres to have the flow passages be between about 20% to 30% of the entrance area as a matter of routine optimization since it has been held that "where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1995), and a person of ordinary skill would be compelled by the teaching of Thawani et al. to experiment with the cross sectional area of the flow passages to optimize for size, as not only does Thawani et al. indicate a cross-sectional area of 3-10% which overlaps with the claimed range, but suggests to a person of ordinary skill in the art to increase the open surface area, “The number, size, and location of the perforations 120, as well as the overall dimensions of the cut-off 30, may be varied based on characteristics of the blower assembly 10, such as typical operating speed of the blower wheel 14. For example, for a blower wheel 14 that typically operates at a relatively high speed in the range of 1,000-4,500 RPM the perforations 120 may be holes, slots, louvres, or micro-perforations with a porosity of 3%-10% of the open surface area (or greater) configured to most effectively reduce or eliminate blower induced and/or broadband noise. For a blower wheel 14 that operates at a relatively lower speed in the range of 1,000 to 4,500 RPM, the perforations 120 may be holes, slots, louvres, or micro-perforations with a porosity of 3%-10% of the open surface area (or greater) configured to most effectively reduce or eliminate blower induced and/or broadband noise at the relatively lower speed. The perforations 120 and resonator volume is advantageously tuned to suppress the undesirable noise frequencies, for example. (Col. 3:4-22)”. Claims 12-13 are rejected under 35 U.S.C. 103 as being unpatentable over Flückiger et al. in view of Veres and Jenks as applied to claim 1 above, and further in view of Thawani et al. (US Patent 10,415,601 B2). Regarding claim 12, the combination of Flückiger et al., Veres and Jenks teach all of claim 1 as above, wherein the flow passage is one flow passage of a plurality of flow passages (Veres, Fig. 1), arranged in a first row extending the axial direction (Veres, Fig. 1) However, the combination of Flückiger et al., Veres, and Jenks do not explicitly teach or suggest, "and the first row comprises at most six flow passages of the plurality of flow passages." Thawani et al. teaches, in the field of perforations (120) through the tongue (110) of a pump housing (12) as shown in Fig. 3 (with two rows of six perforations each) "the perforations 120 may be holes, slots, louvres, or micro-perforations with a porosity of 3%-10% of the open surface (or greater) configured to most effectively reduce or eliminate blower induced and/or broadband noise (Col. 3:4- 22)." It would have been obvious to one of ordinary skill in the art before the effective filing date to modify the combination of Flückiger et al., Veres, and Jenks to have the perforations be two rows of six as shown in Fig. 3 as taught by Thawani et al., as all references are in the same field of endeavor, and one of ordinary skill would appreciate that, "the perforations 120 may be holes, slots, louvres, or micro- perforations with a porosity of 3%-10% of the open surface (or greater) configured to most effectively reduce or eliminate blower induced and/or broadband noise (Col. 3:4-22)." Regarding claim 13, the combination of Flückiger et al., Veres, Jenks, and Thawani et al. teach all of claim 12 as above, wherein at least two flow passages are arranged a second row (Thawani. et al., Fig. 3), extending perpendicular to the axial direction (Thawani et al., Fig. 3), and the second row comprises at most six flow passages of the plurality of flow passages (Thawani et al., Fig. 3). Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to RYAN C CLARK whose telephone number is (571)272-2871. The examiner can normally be reached Monday - Thursday 0730-1730, Alternate Fridays 0730-1630. 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, Courtney D Heinle can be reached at (571)-270-3508. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /RYAN C CLARK/Examiner, Art Unit 3745
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Prosecution Timeline

Show 4 earlier events
Jan 16, 2026
Response after Non-Final Action
Jan 16, 2026
Response after Non-Final Action
Feb 13, 2026
Response after Non-Final Action
Feb 13, 2026
Response after Non-Final Action
Mar 13, 2026
Request for Continued Examination
Apr 01, 2026
Response after Non-Final Action
Apr 15, 2026
Applicant Interview (Telephonic)
Apr 21, 2026
Non-Final Rejection — §103, §112 (current)

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Prosecution Projections

3-4
Expected OA Rounds
87%
Grant Probability
96%
With Interview (+8.5%)
1y 10m (~0m remaining)
Median Time to Grant
High
PTA Risk
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