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 .
Election/Restrictions
Claim 20 is withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 25 November 2025.
Claim Objections
Claims 12 and 16 are objected to because of the following informalities.
Claim 12 recites “from the inlet” and depends from claim 1 which recites “a casing inlet”; for claim terminology consistency purposes the examiner recommends reciting “from the casing inlet” in claim 12.
Claim 16 recites “the blades” and depends from claim 1 which recites “a plurality of blades”; for claim terminology consistency purposes the examiner recommends reciting “the plurality of blades” in claim 16.
Appropriate correction is required.
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.
Claim(s) 1-19 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li et al – hereafter Li – (CN 110848157 A) in view of Wright et al – hereafter Wright – (US 20180170147 A1).
Regarding claim 1, Li teaches a road cleaning machine (note that if the body of a claim fully and intrinsically sets forth all of the limitations of the claimed invention, and the preamble merely states, for example, the purpose or intended use of the invention, rather than any distinct definition of any of the claimed invention’s limitations, then the preamble is not considered a limitation and is of no significance to claim construction, see MPEP 2111.02 II) comprising a centrifugal fan assembly (Fig.1-3), wherein the centrifugal fan assembly comprises:
an impeller (Fig.1-3) rotatable about an axis of rotation (not shown but inherent component of an impeller), the impeller comprising:
a splitter wall (4) extending outwardly from the axis of rotation to define first (defined between adjacent 5) and second (defined between adjacent 3) blade chambers extending from first and second faces of the splitter wall respectively (Fig.1-3), wherein the splitter wall comprises a splitter wall aperture (where D2 is defined); and
a plurality of blades (3 and 5) mounted in the first and second blade chambers,
wherein the impeller is configured to, during rotation about the axis of rotation,
direct fluid from an inlet (where D1 is defined) through the first and second blade chambers to an outlet (where H1 is defined), the fluid being directed into the second blade chamber via the splitter wall aperture (Fig.1-3).
Li does not explicitly teach a fan casing comprising a casing inlet and a casing outlet, the impeller mounted in the fan casing and drawing fluid from the casing inlet and directing the fluid to the casing outlet.
Wright teaches a centrifugal fan assembly (Fig.5/7/8). The centrifugal fan assembly including an impeller (where 12 points to) and a fan casing (68), the fan casing further including a casing inlet (Fig.8, not labeled) and a casing outlet (Fig.8, 84/88), the impeller mounted in the fan casing (Fig.8) and drawing fluid from the casing inlet and directing the fluid to the casing outlet (Fig.8). The disclosed casing is a well known configuration to efficiently generate fluid flow in a centrifugal fan assembly.
It would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to modify the centrifugal fan assembly of Li by having a fan casing comprising a casing inlet and a casing outlet, the impeller mounted in the fan casing and drawing fluid from the casing inlet and directing the fluid to the casing outlet based on the teachings of Wright because this would allow to efficiently generate fluid flow in the centrifugal fan assembly.
Regarding claim 2, Li and Wright further teach the impeller further comprises a hub portion rotatably mounted to the fan casing (Wright Fig.7, note hub portion 74 mounted to the fan casing via shaft 76) .
Regarding claim 3, Li and Wright further teach the impeller further comprises:
a first impeller wall (Li Fig.1, 1) comprising a first impeller wall aperture (Li Fig.3, where D1 is defined) for directing fluid from the inlet into the first and second blade chambers and extending outwardly from the axis of rotation of the impeller (Li Fig.1-3); and
a second impeller wall (Li Fig.1, 1) which is spaced apart from the first impeller wall and is adjacent to the hub portion (Li Fig.1-3), however do not explicitly teach the second impeller wall being parallel to the first impeller wall.
However, it is noted that applicant has not disclosed that having the second impeller wall being parallel to the first impeller wall results in an unpredicted result not seen in the prior art and it appears that the invention would perform equally well with the first and second walls as taught by Li and Wright. Accordingly, absent persuasive evidence that the first and second walls configuration is functionally significant, the limitations above constitute a matter of choice of changes in shape and fail to patentably distinguish over the prior art. See MPEP 2144.04(IV)(b).
Regarding claim 4, Li and Wright further teach the splitter wall is disposed between [[
Regarding claim 5, Li and Wright further teach the plurality of blades extend continuously from the second impeller wall to the splitter wall (Li Fig.1-3).
Regarding claim 6, Li and Wright further teach the plurality of blades extend continuously from the splitter wall to the first impeller wall (Li Fig.1-3).
Regarding claim 7, Li and Wright further teach the splitter wall is located substantially midway between the first and second impeller walls (Li Fig.3 and machine translation ¶40, note H1 denotes the distance between the first and second impeller walls and H2 denotes the distance between the splitter wall and the second impeller wall; ¶40 discloses the range 0.2xH1≤H2≤0.6xH1, which includes H2=0.5xH1 which meets the claimed limitation).
Regarding claim 8, Li and Wright further teach the first impeller wall aperture and splitter wall aperture are centred about the axis of rotation (Li Fig.3).
Regarding claim 9, Li and Wright further teach the first impeller wall aperture is located in and/or adjacent to the casing inlet (Li Fig.1-3 as modified by Wright Fig.8).
Regarding claim 10, Li and Wright further teach the splitter wall aperture is located in and/or adjacent to the first impeller wall aperture (Li Fig.1-3).
Regarding claim 11, Li and Wright further teach the impeller comprises an open outer impeller edge through which the first and second blade chambers are in direct fluid communication with the casing outlet (Li Fig.3, where H1 is defined and as modified by Wright Fig.8, 84/88).
Regarding claim 12, Li and Wright further teach the splitter wall comprises a splitter wall main body (Li Fig.1-3, portion of 4 adjacent to where H2 is defined) from which the plurality of blades extend and a splitter wall guide wall (Li Fig.1-3, portion of 4 adjacent to where D2 is defined) extending from the splitter wall main body to the splitter wall aperture, wherein the splitter wall guide wall is configured to separate fluid flowing from the inlet into the first and second blade chambers (Li Fig.1-3).
Regarding claim 13, Li and Wright further teach the splitter wall guide wall is annular (Li Fig.1-3, portion of 4 adjacent to where D2 is defined).
Regarding claim 14, Li and Wright further teach the splitter wall guide wall comprises:
a splitter wall ring portion; and/or a splitter wall curved portion (Li Fig.1-3, portion of 4 adjacent to where D2 is defined),
wherein:
the splitter wall curved portion comprises an outer surface which is concave (Li Fig.1-3, portion of 4 adjacent to where D2 is defined), however do not explicitly teach the splitter wall ring portion is cylindrical and comprises an outer surface parallel to the axis of rotation.
However, it is noted that applicant has not disclosed that having the splitter wall ring portion is cylindrical and comprises an outer surface parallel to the axis of rotation results in an unpredicted result not seen in the prior art and it appears that the invention would perform equally well with the splitter wall ring portion is cylindrical and comprises an outer surface parallel to the axis of rotation as taught by Li and Wright. Accordingly, absent persuasive evidence that the splitter wall ring portion is cylindrical and comprises an outer surface parallel to the axis of rotation configuration is functionally significant, the limitations above constitute a matter of choice of changes in shape and fail to patentably distinguish over the prior art. See MPEP 2144.04(IV)(b).
Regarding claim 15, Li and Wright further teach the splitter wall ring portion extends from the splitter wall aperture to the splitter wall curved portion, and/or the splitter wall curved portion extends from the splitter wall ring portion to the splitter wall main body (Li Fig.1-3, portion of 4 adjacent to where D2 is defined and as modified by a changes in shape above).
Regarding claim 16, Li and Wright further teach the blades [[
Regarding claim 17, Li and Wright further teach an inlet duct (Wright Fig.5, 30) wherein the fan casing inlet is in fluid communication with the inlet duct (Wright Fig.5).
Regarding claim 18, Li and Wright further teach a fluid guide vane (Wright Fig.5, 48) disposed in the inlet duct and configured to direct fluid into the impeller in a direction parallel to the axis of rotation of the centrifugal fan assembly (Wright Fig.5).
Regarding claim 19, Li and Wright further teach the inlet duct is elongate along a duct longitudinal axis (Wright Fig.5), and
the fluid guide vane comprises a first vane portion extending parallel to the duct longitudinal axis from a first vane end and a second vane portion extending parallel to the axis of rotation from a second vane end (Wright Fig.5), however do not explicitly teach the duct longitudinal axis is nonparallel to the axis of rotation of the centrifugal fan assembly.
However, it has been held that if shifting the position of a component in a device would not have modified the operation of said device, said position shift of said component is unpatentable, additionally, a particular placement of a component in a device has been held to be an obvious matter of design choice. In the current instance, there is no evidence that having the duct longitudinal axis being nonparallel to the axis of rotation of the centrifugal fan assembly, would change the operation of the centrifugal fan assembly, therefore, it would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to further modify the centrifugal fan assembly of Li and Wright by shifting the position/placement of the duct longitudinal axis to have it being nonparallel to the axis of rotation of the centrifugal fan assembly as an obvious matter of design choice (MPEP 2144.04 VI C).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JUAN G FLORES whose telephone number is (571)272-3486. The examiner can normally be reached Monday - Friday, 8:30am - 5:30pm Pacific Time.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Nathan E 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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/JUAN G FLORES/Primary Examiner, Art Unit 3745
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