DETAILED 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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 11/14/25 has been entered.
Response to Amendment
Claims 26-29 remain pending in the application.
Applicant’s arguments regarding the previous rejection of claim 22 and its application to new claim 26 have been fully considered, but are not persuasive. The Applicant first argues that the primary and secondary Hoglund references do not disclose, teach or suggest any solution to any airlock problem. Hoglund ‘997 discusses separating air or gas from the main liquid to be pumped (see “background of the invention”). Hoglund ‘320 also describes “degassing” the pumped liquid (see abstract). Both Hoglund references thus clearly teach that airlock in the pumps is an issue, and present solutions to force out entrapped air or gas.
The Applicant further argues the Hoglund references are non-analogous art. Both Hoglund references are directed to pumps with combined axial and radial impellers. They are clearly analogous at first glance.
The Applicant argues the references do not teach coupling the pump onto a top surface of a container such that a fiber suspension is drawn through a bottom inlet. As discussed in the Non-Final Rejection from 1/31/25, the Final Rejection from 3/27/24, the Examiner’s Answer to Appeal Brief from 10/31/24, and the Final Rejection from 7/14/25, what can be considered the “bottom” of the pump is based on the orientation and perspective of the pump. Hoglund ‘997 suggests by reference to Hoglund ‘320 that the pump can be oriented vertically. Thus, the inlet of the pump can be considered to be the “bottom”.
The Applicant further argues the blades of the prior art “would not likely draw any fiber suspension from underneath Hoglund’s fluidizing pumps into its pumping chamber since Hoglund’s fluidizing blades […] have a free internal space […], which underlines the fundamental structural and functional differences between the claimed invention and the Hoglund prior art combination”. As discussed in the Non-Final Rejection from 1/31/25, and the Final Rejection from 7/14/25, there is no evidence provided as to why a free internal space provided would prevent the vanes from moving fluid axially if oriented in a vertical direction.
The Applicant further argues that AAPA merely discloses the known airlock problem in the art and does not teach any apparent reason to look to pumps like Hoglund’s to solve the airlock problem. The AAPA is relied upon for discharge piping system structure. The combination with the Hoglund references is properly made under MPEP 2143A.
The Applicant finally argues that both cited Hoglund references disclose fluidizing blades and pumping blades that are not at all connected together and are both connected to the same part of the impeller. In Hoglund ‘997, the radial vanes 30 are clearly connected to the fluidizing vanes 26 (see Fig. 5).
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 26-29 are rejected under 35 U.S.C. 103 as being unpatentable over Hoglund et al. (US5615997) in view of Hoglund et al. (US5039320)(“Hoglund ‘320”) and Applicant Admitted Prior Art (AAPA).
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Regarding claim 26, Hoglund teaches (Figs. 1-3) a system comprising: a centrifugal pump (Fig. 1) having a pumping chamber (4) and a pump outlet (6); and further comprising: a motor (11) having a motor shaft (10) with a motor shaft hub and a motor shaft axis (coincident with shaft 10) extending along an axis of the centrifugal pump; a housing (1) having a top housing portion (see Fig. 1) with the motor arranged therein, having a bottom housing portion with a pumping chamber (4) formed therein and a bottom inlet (2) to receive a liquid to be pumped from underneath the bottom inlet of the housing, and having an intermediate housing portion with the pump outlet coupled to the upstream piping portion, the motor shaft extending from the motor, through the housing and into the pumping chamber; and a combined axial and radial anti-airlock impeller (3), having a base portion (27), a center (see annotated figure), radially curved pumping vanes (30), axially curved anti-airlock vanes (26) formed as a set of axially curving vane extensions on the motor shaft, and a periphery or outer rim, the center of the combined axial and radial anti-airlock impeller mounted on the motor shaft hub of the motor shaft in the pumping chamber (see Fig. 2); the radially curved pumping vanes arranged on the base portion of the combined axial and radial anti-airlock impeller, each radially curved pumping vane curving radially from the periphery or outer rim, spiraling inwardly towards the center and the motor shaft axis of the motor shaft and meeting a respective axially curving vane extension (see Fig. 3), and being arranged inside the pumping chamber to rotate and pump the liquid from the pumping chamber to the pump outlet; the axially curved anti-airlock vanes connected to the center of the combined axial and radial anti-airlock impeller and extended along the motor shaft axis, each axially curved anti-airlock vane curving axially away from the motor shaft axis, spiraling outwardly towards the periphery or outer rim and meeting a respective radially curved pumping vane (see Fig. 5), having an inside part (see Fig. 1 generally 26) arranged in the pumping chamber to pump liquid to the radially curved pumping vanes, and having an outside part (see Fig. 1, to the left of element 26 the vanes stick out of the pump housing) extending outside the bottom inlet to submerge in any liquid to be pumped underneath the centrifugal pump, draw the liquid through the bottom inlet into the pumping chamber, and provide the liquid to the radially curved pumping vanes in order to generate liquid pressure and displace entrapped air from the pumping chamber to the pump outlet of the centrifugal pump in the airlock situation (this functionality is taught in US5039320, which is incorporated by reference in Hoglund to describe the axially curving vane extensions).
Hoglund fails to explicitly teach a discharge piping system having a dip that traps liquid between previous pumping cycles, and having a piping portion coupled between the dip and the pump outlet that traps air in the pumping chamber of the centrifugal pump causing an airlock situation that prevents liquid from entering the pumping chamber of the centrifugal pump.
Applicant teaches in Figs. 2A and 2B that it is known in the prior art to utilize a discharge piping
system having a dip that traps water between pumping cycles, and also having an upstream piping portion that traps air upstream of the dip and prevents water from entering the outlet (see specification
page 2, lines 1-15).
It is obvious to combine prior art elements according to known methods to yield predictable
results (see MPEP 2143(A)). In the instant case, the prior art contained each element claimed, although
not necessarily in a single reference (see above). One of ordinary skill in the art could have combined the
elements by simply attaching the prior art discharge piping to the prior art centrifugal pump. One of
ordinary skill in the art would recognize predictable results of the combination (such as sediment trapping,
and preventing of siphoning).
It would have been obvious to one having ordinary skill in the art before the effective filing date of
the invention to modify the pump of Hoglund in view of Hoglund ‘320 and change the pump to be the outlet is coupled to the upstream piping portion of the discharge piping system that traps air upstream as taught by Applicant’s admitted prior art as a combination of known prior art elements with a predictable result.
Hoglund fails to teach the centrifugal pump having a vertical longitudinal axis, a motor shaft axis extending along the vertical longitudinal axis of the centrifugal pump, and having an intermediate housing portion with the pump outlet coupled to the upstream piping portion and extended on a horizontal radial axis perpendicular to the vertical longitudinal axis of the centrifugal pump and the motor shaft axis of the motor shaft to provide the liquid being pumped from the pumping chamber to the upstream piping portion of the discharge piping system.
However, Hoglund references at Col. 1 lines 25-30 and Col. 2 lines 51-62 the pump rotor is of the same type as Hoglund ‘320 such that reference should be made to Hoglund ‘320 for the details of the rotor. Hoglund ‘320 discloses that the rotor can be disposed vertically (Col. 3 lines 27-35).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention to modify the pump of Hoglund and change it to have a vertical longitudinal axis, a motor shaft axis extending along the vertical longitudinal axis of the centrifugal pump, and having an intermediate housing portion with the pump outlet coupled to the upstream piping portion and extended on a horizontal radial axis perpendicular to the vertical longitudinal axis of the centrifugal pump and the motor shaft axis of the motor shaft to provide the liquid being pumped from the pumping chamber to the upstream piping portion of the discharge piping system according to the teachings of Hoglund ‘320. Hoglund references the rotor of Hoglund ‘320, and Hoglund ‘320 suggests a vertical orientation.
Regarding claim 27, Hoglund in view of Hoglund ‘320 teach the pump of claim 6, and Hoglund further teaches the radially curving pumping vanes provide pumping power to pump the liquid to be pumped from the pumping chamber to the pump outlet (the radial vanes are shaped to push flow radially to the outlet), and the set of axially curving vane extensions draw the liquid underneath the pump through the bottom inlet into the pumping chamber (the axial vanes are shaped to push flow axially to the radial vanes).
Regarding claims 28-29, Hoglund in view of Hoglund ‘320 teach the pump of claim 26, and Hoglund further teaches (Figs. 1-3 and 5) the set of axially curving vane extensions are configured with an axial vane curvature that is generated through the use of parametric equations in a Cartesian x, y, z, coordinate system, wherein the parametric equations in the Cartesian x, y, z, coordinate system include a sweep parameter, wherein the sweep parameter forms part of a negative exponent of an exponential function having an exponential function base of e.
“Generating through the use of parametric equations” does not result in a structural distinction with the prior art. The burden is shifted to the Applicant to show an unobvious difference between the claim and the prior art. The Applicant defines equations for the axial vane curvature in the specification, page 11. According to Wolfram, the equations provided are merely those known for a logarithmic spiral with added constants. The Applicant notes that “a, b, c and n are constants that depend on the particular impeller’. The Examiner asserts that the constants could be any value, and define a vast assortment of impeller shapes (for example, when b is zero, the logarithmic component appears to cancel out). Thus, if the curvature were defined by these equations, the broadest reasonable interpretation would still include the impeller of Hoglund as modified. In the present case, however, the curvature must only be “generated through the use of” these equations.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to CAMERON A CORDAY whose telephone number is (571)272-0383. The examiner can normally be reached on M-F 8-4 EST.
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/Cameron Corday/
Examiner, Art Unit 3745 /COURTNEY D HEINLE/Supervisory Patent Examiner, Art Unit 3745