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
Applicant’s amendment filed on 21 October 2025 has been entered. Claim 14 is amended. Claim 19 is added. Claims 1-19 are pending.
Applicant’s arguments, with respect to the rejection(s) of Claim 14-18 under 35 U.S.C. 103 as being unpatentable over Gastebois et al. (US 4802824) in view of Edwards et al. (US 7500829) have been fully considered and are persuasive.
Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Sekihara et al. (US 20160032739).
Applicant’s arguments with respect to the rejection(s) of Claims above have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
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.
The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied 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 14-18 are rejected under 35 U.S.C. 103 as being unpatentable over Gastebois et al. (hereafter Gastebois – US 4802824) in view of Sekihara et al. (hereafter Sekihara – US 20160032739), and further in view of Edwards et al. (hereafter Edwards – US 7500829).
Claim 14 recites “a gas turbine engine.” Gastebois teaches such a gas turbine engine, as will be shown.
Gastebois teaches (Figs. 1-4) a gas turbine engine comprising:
a hub 2 including an axial doveslot 4 (see col. 3, ln. 15-19); and
a blade 3 including:
an airfoil section 3a defining a pressure side and a suction side (see Figs. 1, 2), the airfoil section spanning along a radial direction between first and second radial ends (see Fig. 1);
a dovetail 3b at the second end of the airfoil section, the dovetail being disposed in the doveslot to attach the blade with the hub (see Fig. 1), the airfoil section and the dovetail being comprised of a fiber-reinforced composite (col. 4, ln. 24-32, blades 3 are made of a composite ceramic material which may be of a known type with oriented fibres and made in accordance with known techniques) including inter-section fiber plies each extending from the airfoil section into the dovetail and wedges interleaved with the inter-section fiber plies in the dovetail (see col. 1, ln. 31-35, known techniques include “French Pat. No. 2154050 relates to a method of constructing a turbine blade of which the aerofoil portion of the blade is composed of fibre reinforced layers, and the root has hardened wedges inserted between the layers”), the dovetail defining a first circumferential side 3c on the suction side and second circumferential side 3d on the pressure side,
wherein upon an impact event on the pressure side of the airfoil section, a bending is induced in which the first circumferential side presses against a side of the doveslot, creating stress at a neck (see Fig. 1) at which the airfoil section flares to form the dovetail (the gas turbine engine of Gastebois would be capable of creating stress at a neck due to an impact in the same way as Applicant), and
wherein the first and second circumferential side being sloped to face radially outwardly and form non-zero angles with the radial direction (see Fig. 1 and col. 3, ln. 26-30), the non-zero angle of the first circumferential side being 10° or less in order to reduce concentration of the stress at the neck (see Fig. 1 and col. 3, ln. 26-30, the sum of the non-zero angles is 5-10 degrees, so the non-zero angle of the first circumferential side would be 2.5-5 degrees, since the dovetail of Gastebois is symmetrical, which would reduce concentration of the stress at the neck in the same way as applicant).
However, Gastebois does not teach the hub is a fan hub and the blade is a fan blade or the dovetail being asymmetric about the radial direction.
Sekihara teaches (Figs. 1-10) a gas turbine engine comprising a dovetail 5 being asymmetric about the radial direction (see Figs. 5-10 and other Figures for various embodiments).
Sekihara further teaches such an asymmetric dovetail is provided to reduce an uneven contact with each wheel dovetail so as to level a load, exerted from the relevant rotor blade, that would otherwise become asymmetric between the forward direction and reverse direction of the rotational direction of the rotor blade and to thereby reduce high stress exerted on the rotor blade (para. 0074).
It would have been obvious for a person having ordinary skill in the art to apply the teachings of Sekihara to the gas turbine engine of Gastebois to have the dovetail being asymmetric about the radial direction, as both references and Applicant’s invention are directed to gas turbine engines with dovetails. Doing so would result reducing stresses exerted on the blade, as recognized by Sekihara.
Gastebois is directed to a turbine (abstract).
However, Gerstberger teaches (Figs. 1-3) a gas turbine engine comprising a fan hub 13 and a fan blade 14, the fan blade including a dovetail 15 for inserting into a doveslot 16 of the fan hub.
Gerstberger further teaches it is generally known that a rotor device for a turbine can be used for a fan of a gas turbine engine: “The rotor device in accordance with the invention can be used for a variety of engine designs and is applied in particular for any required stage of a turbine. Furthermore, the rotor device in accordance with the invention can for example also be used in a compressor or a fan of an engine” (see para. 0011).
Therefore, one of ordinary skill in the art could apply the hub and blade of modified Gastebois to a fan hub and fan blade. The results would be predictable since both references and Applicant’s invention are directed to blades with dovetails in turbine engines, and the benefits of the rotor device of modified Gastebois would apply to the fan in a gas turbine engine, as recognized by Gerstberger. Therefore, it would have been obvious for a person of ordinary skill in the art to apply the teachings of Gerstberger to the gas turbine engine of modified Gastebois to have the hub is a fan hub and the blade is a fan blade.
Regarding Claim 15, Gastebois, as modified with Sekihara and Gerstberger in Claim 14 above, teaches (Gastebois Figs. 1-4) the gas turbine engine as recited in claim 14, wherein the one of the non-zero angles that is 10° or less is from 5° to 10° (see Fig. 1 and col. 3, ln. 26-30, the sum of the non-zero angles, a, is 5-10 degrees, so the non-zero angle of the first circumferential side would be 2.5-5 degrees, since the dovetail of Gastebois is symmetrical).
Regarding Claim 16, Gastebois, as modified with Sekihara and Gerstberger in Claim 14 above, teaches (Gastebois Figs. 1-4) the gas turbine engine as recited in claim 15, wherein the first and second circumferential sides are flat (col. 3, ln. 26-27).
Regarding Claim 17, Gastebois, as modified with Sekihara and Gerstberger in Claim 14 above, teaches (Gastebois Figs. 1-4) the gas turbine engine as recited in claim 16, wherein the dovetail has a forward face (Fig. 1), an aft face (Fig. 1), and a dovetail body (body of dovetail 3b) that extends from the forward face to the aft face, the aft face being circumferentially offset from the forward face such that the dovetail body curves from the forward face to the aft face (see Fig. 1-2, and col. 3, ln. 20-26).
Regarding Claim 18, Gastebois, as modified with Sekihara and Gerstberger in Claim 14 above, teaches (Gastebois Figs. 1-4) the gas turbine engine as recited in claim 17, wherein the dovetail has a radially-inwardly facing side (bottom face of the blade root 3b) that is parallel to an axial direction that is perpendicular to the radial direction.
Allowable Subject Matter
Claim 1-13 are allowed.
Claim 19 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The prior art does not teach a sum of the non-zero angles being from 35° to 45° (claims 1, 7, 19).
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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 extension fee 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 date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ANDREW BUI whose telephone number is (571) 272-0685. The examiner can normally be reached on 7:30 AM - 4:30 PM.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Courtney Heinle can be reached on (571) 270-3508. The fax phone number for the organization where this application or proceeding is assigned is (571) 273-8300.
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/ANDREW THANH BUI/Examiner, Art Unit 3745
/COURTNEY D HEINLE/Supervisory Patent Examiner, Art Unit 3745