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 .
Response to Amendment
The amendment submitted 12/30/2025 has been entered. Claims 1-9 remain pending.
Response to Arguments
Applicant's arguments filed 12/30/2025 have been fully considered but they are not persuasive.
The Applicant argues the prior art does not teach all limitations of the claims since Park teaches a chord length which decreases from a root to an intermediate portion then increases from the intermediate portion to the tip and “chord length and wrap angle are simply not the same, not interchangeable, and not equivalent to one another”. The Examiner respectfully disagrees. The wrap angle is disclosed by the Applicant as “a circumferential included angle between the leading edge and the trailing edge” (Par 0003) thus if the distance between the leading edge and the trailing edge, i.e. the chord, changes (e.g. grows larger or smaller) the wrap angle must change in the same way.
The Applicant further argues the prior art does not teach all limitations of the claims since the claim defines the middle blade height as “an arc line formed by center points of the blade tip and the blade root along a radial direction” and Park teaches a minimum chord length located at a position of 20-60% from the hub along a spanwise extending mid-chord line. The Examiner respectfully disagrees. The rejections do not rely on Park to teach the limitation defining the middle blade height and there must be at least one point within the range taught by Park along the middle blade height of Xiao.
For the reasons above the rejections are hereby maintained.
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.
Claim(s) 1-3 and 6-7 is/are rejected under 35 U.S.C. 103 as being unpatentable over CN 202326414 to Xiao in view of US 7585155 to Park.
(a) Regarding claim 1:
(i) Xiao discloses a blade (wing 20, Fig 1), comprising:
a blade tip (edge connecting points 212 and 234, Fig 1), a blade root (part of blade connected to hub part 10, Fig 1), a leading edge (upstream end of blade 20 comprising par 211 and point 212, Fig 1) and a trailing edge (23, Fig 1),
wherein the leading edge and the trailing edge extend from the blade tip to the blade root, respectively (Fig 1), and
the blade is capable of rotating about a rotation axis (axis of rotation indicated by curved arrow in Fig 1) which is perpendicular to a normal plane (Fig 1);
wherein in a projection of the blade on the normal plane, a circumferential included angle between the leading edge and the trailing edge forms a wrap angle φ (as defined), and
wherein the middle blade height is an arc line formed by center points of the blade tip and the blade root along a radial direction (as defined).
(ii) Xiao does not disclose wherein the wrap angle φ decreases gradually from the blade root to a middle blade height of the blade and increases gradually from the middle blade height to the blade tip.
(iii) Park is also in the field of blades (see abstract) and teaches a blade comprising a wrap angle φ (distance between leading and trailing edges LE and TE, respectively, corresponding to a chord length; Figs 8-9), wherein the wrap angle φ decreases gradually from a blade root (132, Fig 8) to a middle blade height of the blade (predetermined position on an intermediate portion of the blade, see abstract; Fig 9) and increases gradually from the middle blade height to the blade tip (see abstract, Fig 9).
(iv) It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the wrap angle φ as disclosed by Xiao with the above aforementioned wrap angle φ as taught by Park for the purpose of having a more stable structure, avoiding deformation of the blades, thereby avoiding hampering of the noise reducing function of the blade (Col 2 Lns 26-33; Col 5 Lns 38-40; Col 6 Lns 33-40) which increases durability of the blade (Col 7 Lns 26-32).
(b) Regarding claim 2:
(i) Xiao as modified by Park teaches the blade according to claim 1.
(ii) Xiao further discloses:
wherein the rotation axis and the normal plane intersect perpendicularly at a foot of a perpendicular (center of rotation, Fig 1),
a line connecting any point on the leading edge and the foot of the perpendicular is designated as a first connecting line (as defined, Fig 1),
a line connecting a projection point of an intersection point of the blade root and the leading edge on the normal plane in a direction of the rotation axis (where leading edge meets hub, Fig 1) and the foot of the perpendicular is designated as a second connecting line (as defined, Fig 1), and
an included angle between the first connecting line and the second connecting line is called a starting angle θ (as defined, Fig 1) wherein the starting angle θ increases gradually in a direction from the blade tip to the blade root (Fig 1).
(c) Regarding claim 3:
(i) Xiao as modified by Park teaches the blade according to claim 2.
(ii) Xiao further discloses wherein a value range of the starting angle θ is: θ ∈ [0⁰,90⁰] (θ1+θ2 = 25-35 degrees, Pg 5 Lns 6-7, Fig 1).
(d) Regarding claim 6:
(i) Xiao as modified by Park teaches the blade according to claim 1.
(ii) Xiao further discloses:
wherein in the projection direction along the rotation axis, a line connecting the intersection point of the blade root and the leading edge and an intersection point of the blade tip and the leading edge is designated as a fourth connecting line (as defined);
an included angle between the fourth connecting line and the normal plane is designated as a sweep forward angle β (as defined), and
a value range of the sweep forward angle β is: β ∈ [5⁰, 30⁰] (15-18 degrees, Pg 5 Ln 4, Fig 5); and
the leading edge is located in a region formed by a rotation of the sweep forward angle β about the rotation axis (Figs 1/5).
(e) Regarding claim 7:
(i) Xiao as modified by Park teaches the blade according to claims 1-3 and 6-7.
(ii) Xiao further discloses an axial-flow impeller (see title), characterized by comprising: a hub (10, Fig 1) having a rotation axis (center axis of rotation shown by curved arrow, Fig 1), the hub being capable of rotating about the rotation axis (Pg 3 Lns 43-44); and at least two blades according to any one of claims 1-6 (3 blades, Fig 1; see rejections above), wherein the at least two blades are arranged on an outer circumferential surface of the hub (Pg 3 Ln 44, Fig 1).
Claim(s) 4-5 is/are rejected under 35 U.S.C. 103 as being unpatentable over CN 202326414 to Xiao in view of US 7585155 to Park as applied to claim 1 above, and further in view of US 5616004 to Alizadeh.
(a) Regarding claim 4:
(i) Xiao as modified by Park teaches the blade according to claim 1.
(ii) Xiao as modified by Park further teaches wherein the blade comprises an upper surface and a lower surface.
(iii) Xiao as modified by Park do not teach wherein the upper surface and the lower surface are curved downwards in a radial cross section of the blade from the middle blade height to the blade tip.
(iv) Alizadeh is also in the field of fans (see title) and teaches a blade (1, Fig 1) comprising an upper surface and a lower surface (upper and lower surfaces of blade 1, Figs 1/5), wherein the upper surface and the lower surface are curved downwards in a radial cross section of the blade (from extremity 26 to blade tip, Figs 5D-5F) from a middle blade height to a blade tip (reasonably disclosed in Figs 5D-5F; radial extremity 26 corresponds to Fig 6v taken along line 5 in Fig 4 shown as a substantially middle blade height, Col 4 Lns 55-57).
(v) It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the upper and lower surfaces as taught by Xiao as modified by Park to be curved downwards as taught by Alizadeh for the purpose of reduce acoustic losses, improve noise performance, and improve efficiency (Col 1 Lns 30-32; Col 3 Lns 27-29; Col 5 Lns 8-11)
(b) Regarding claim 5:
(i) Xiao as modified by Park as further modified by Alizadeh teaches the blade according to claim 1.
(ii) Xiao further discloses wherein a vertical line from a highest point on the trailing edge to the rotation axis is designated as a first vertical line (as defined), the first vertical line having a vertical point on the rotation axis (as defined), and a line connecting an intersection point of the trailing edge and the blade tip and the vertical point is designated as a third connecting line (as defined); in a projection direction along the rotation axis, an included angle between the first vertical line and the third connecting line is a winglet angle α (as defined).
(iii) Xiao suggests (see annotated Figure 5 below showing the lines connected to the highest point on the trailing edge and the intersection point of the trailing edge and the blade tip) but does not explicitly disclose a value range of the winglet angle α is: α ∈ [1⁰, 15⁰].
Claim(s) 8 is/are rejected under 35 U.S.C. 103 as being unpatentable over CN 202326414 to Xiao in view of US 7585155 to Park as applied to claim 7 above, and further in view of CN 110500320 to Luo.
(a) Regarding claim 8:
(i) Xiao as modified by Park teaches the axial flow impeller according to claim 7.
(ii) Xiao as modified by Park do not explicitly teach wherein the wrap angle φ is related to a number of the blades.
(iii) Luo is also in the field of fans (see title) and teaches a wrap angle φ (angle α, Figs 1/4), wherein the wrap angle φ is related to a number of the blades (Pg 4 Lns 18-31; original document Par [0032-0034]; Fig 4).
(iv) It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the wrap angle φ to be related to the number of the blades as taught by Luo for the purpose of having better aerodynamic performance, lower sound pressure level, and lower spectral peak thereby resulting in lower noise value and better sound quality (Pg 4 Lns 28-31).
Claim(s) 9 is/are rejected under 35 U.S.C. 103 as being unpatentable over CN 202326414 to Xiao in view of US 7585155 to Park in further view of CN 110500320 to Luo as applied to claim 8 above, and further in view of CN 110513329 to You.
(a) Regarding claim 9:
(i) Xiao as modified by Park as further modified by Luo teaches the axial flow impeller according to claim 8.
(ii) Xiao as modified by Park as further modified by Luo do not teach:
wherein when the axial-flow impeller has three blades, the value range of the wrap angle φ: φ ∈ [80⁰, 100⁰];
when the axial-flow impeller has four blades, the value range of the wrap angle φ: φ ∈ [60⁰, 85⁰]; and
when the axial-flow impeller has five blades, the value range of the wrap angle φ: φ ∈ [40⁰, 70⁰].
(iii) You is also in the field of axial flow fans (see title) and teaches an axial flow impeller comprising 3 blades (Fig 1), each fan blade having a wrap angle φ (Ω, Fig 9) within a range of 80-100 degrees (Ω 2 and Ω 1, respectively; Pg 9 Lns 8/11; Fig 9)
(iv) It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the wrap angle range of the axial flow impeller as taught by Xiao as modified by Park as further modified by Luo with the above aforementioned range as taught by You for the purpose of improving flow characteristics of the axial flow impeller, improving the working force of the blade, moderating the sharpness of the leading edge, making it rigid while being convenient for production and processing, reduces the mutual interference between the blades, improving the rigidity of the blade root, improving the connection stability between the blade and the hub, and increasing safety (Pg 9 Lns 8-18).
(v) You further teaches wherein the wrap angle range affect flow characteristics, the working force of the blade, the sharpness of the leading edge, rigidity, convenience for production and processing, the mutual interference between the blades, the rigidity of the blade root, the connection stability between the blade and the hub, and safety (Pg 9 Lns 8-18), thereby establishing the wrap angle range as a result effective variable. Routine optimization of a result effective variable requires only ordinary skill in the art, see MPEP 2144.05(II)
(v) It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the value range of the wrap angle φ as taught by Xiao as modified by Park as further modified by Luo to have the values as claimed through routine optimization of a result effective variable which requires only ordinary skill in the art, see MPEP 2144.05(II).
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Justin A Pruitt whose telephone number is (571)272-8383. The examiner can normally be reached T-F 8:30am - 6:30pm.
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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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/JUSTIN A PRUITT/ Examiner, Art Unit 3745
/NATHANIEL E WIEHE/ Supervisory Patent Examiner, Art Unit 3745