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 .
Response to Arguments
Applicant's arguments filed 07/29/2026 have been fully considered but they are not persuasive. The applicant argues that the prior art does not disclose or teach that it would be possible to weld the cover skin to the plurality of ribs while also welding the cover to the main body ledge. However, this is not what the limitations require. The limitations state “a cover skin metallically formed on and metallurgically bonded to the main body and the plurality of ribs, wherein the cover skin is formed on and bonded to the ledge and the plurality of ribs of the main body”. As the ribs are an integral part of the fan blade body and are integral and thereby metallically bonded with the ledge, as long as the cover is formed on and metallically bonded to the ledge then it is also metallically bonded and formed on the plurality of ribs. The limitations do not require direct contact between the two items and as the ribs are an integral part of the ledge then they are metallurgically bonded to the cover skin through the ledge. As such, those arguments are not found to be convincing. However, the prior art does not explicitly teach or disclose the interdiffusion metallic bond. As such, a new rejection is presented with updated rejections presented below.
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) 1-5 and 7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Schwarz (US 20160024934) in view of Malmborg (US 20200215642).
Regarding claim 1, Schwarz discloses A fan blade for a gas turbine engine (Par. 0014) comprising:
a main body that extends between a leading edge and a trailing edge (Figure 2, items 21 and 22), wherein the main body includes channels formed into the main body (Figure 2, items 30) and a plurality of ribs extending between the channels (Figures 2-3, item 26) and a ledge and wherein the ledge is formed as an integral part of the main body and is configured to define an outer perimeter of the channels (Figure 3, item 400 described in paragraphs 0045-0046);
a cover skin metallically formed on (the metallurgical forming of the cover skin is a product by process limitation and as such is only limiting based on the structure implied by the steps. As there is no clear structure provided by the metallically forming of the cover skin on the main body, these limitations are not further limiting on the claims. See MPEP 2113) and metallurgically bonded to the main body (Paragraph 0006 describes that the cover is welded to the main body as shown in Figure 6B) and the plurality of ribs (As described above, the cover is bonded to the plurality of ribs through the ledges), wherein the cover skin is formed on and bonded to the ledge and the plurality of ribs of the main body (Figure 6B) using a hybrid additive manufacturing/subtractive manufacturing process (This is a product by process limitation as described above and there is no clear structure imparter by the hybrid additive/subtractive manufacturing process that would not be provided by another forming process) and is configured to cover the channels and form an aerodynamic surface (Figures 2 and 4-5 show the cover covering the channels and forming an aerodynamic surface);
wherein the main body and cover skin form an airfoil that extends radially outwardly from a dovetail (Figure 1B and 1C); and
wherein the dovetail is configured to permit the fan blade to be attached to a fan rotor of the gas turbine engine (Figure 1B and 1C, described in paragraph 0040).
However, Schwarz does not explicitly disclose the bonding being done with an interdiffusion metallic bond. Schwarz and Malmborg are analogous prior art because both describe cover skins bonded to the turbine blade. Malmborg teaches that diffusion bonding can be used to attach the cover skin to the blade body instead of welding or brazing (Par. 0050). As both Schwarz and Malmborg teach bonding a cover skin to the main body of a turbine blade and Malmborg teaches that diffusion bonding is known in the art for bonding these structures in exchange of welding and brazing, the diffusion bonding of Malmborg would provide predictable results as the bonding method of Schwarz. Further, diffusion bonding is known to provide a stronger bond on the microstructure than brazing or welding. Thereby, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the diffusion bonding method of Malmborg as the bonding method of Schwarz because diffusion bonding provides a strong bond between metallic structures and simple substitution of one known element for another to obtain predictable results is obvious. See MPEP 2143(I)(B).
Regarding claim 2, Schwarz in view of Malmborg teaches that at least one of the plurality of channels is filled with a filler material (Schwarz Figures 2-3, item 100 described in paragraph 0043).
Regarding claim 3, Schwarz in view of Malmborg teaches that the filler material is made from a lighter weight material than the material used to form the main body (Schwarz Paragraph 0043 describes that the filler material is lighter weight than the main body material).
Regarding claim 4, Schwarz in view of Malmborg teaches that the filler material is an aluminum foam, a titanium foam, an aluminum honeycomb, or a titanium honeycomb (Schwarz Paragraph 0043 describes that the filler material can be aluminum foam).
Regarding claim 5, Schwarz in view of Malmborg teaches that the main body and cover skin are formed from aluminum, an aluminum alloy, titanium, or a titanium alloy (Schwarz Par. 0041 describes that the body and skin are formed of aluminum or aluminum alloy).
Regarding claim 7, Schwarz in view of Malmborg teaches that the hybrid additive manufacturing/subtractive manufacturing process includes a friction surfacing additive manufacturing (FSAM) process. As is described above, this is a product-by-process limitation and only limits the claim by the structure imparted by the method. There is no clear structure provided by the method of friction surfacing additive manufacturing that is not provided by other manufacturing processes so the limitations are taught by Schwarz in view of Malmborg.
Claim(s) 6 is/are rejected under 35 U.S.C. 103 as being unpatentable over Schwarz (US 20160024934) in view of Malmborg (US 20200215642) as applied to claim 1 above, and further in view of El-Wardany (US 20190017388) with Beckford (US 20050035183) provided as evidence.
Regarding claim 6, Schwarz in view of Malmborg teaches the limitations of claim 1 as set forth in the above 103 rejection but does not explicitly disclose that the cover skin is formed from an aluminum matrix composite having an aluminum matrix with silicon carbide particles or nanotubes as a reinforcing phase.
Schwarz in view of Malmborg and El-Wardany are analogous prior art because both describe blades with hollow portions for weight saving. El-Wardany teaches forming a thin skin of a blade of an aluminum matrix with silicon carbide particulates or nanotubes (Par. 0037). As both Schwarz in view of Malmborg and El-Wardany show the placement of thin skins over a lower weight foam (the cover of Schwarz in view of Malmborg and the skin of El-Wardany), the aluminum matrix composite of El-Wardany would provide predictable results as the cover skin material Schwarz in view of Malmborg. Further, Beckford describes that metallic matrix composites are suitable for and known to be bonded with diffusion bonding (Par. 0002) Thereby, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the aluminum matrix composite of El-Wardany as the skin material of Schwarz in view of Malmborg because simple substitution of one known element for another to obtain predictable results is obvious. See MPEP 2143(I)(B).
Claim(s) 8 is/are rejected under 35 U.S.C. 103 as being unpatentable over Schwarz (US 20160024934) in view of Malmborg (US 20200215642) as applied to claim 1 above, and further in view of Drescher (US 20200300093) provided as evidence.
Regarding claim 8, Schwarz in view of Malmborg teaches the claimed invention except for the cover skin being 1 mm to 4 mm thick. Drescher shows a fan blade with a cavity cover (78) over filler material similar to the skin of Schwarz in view of Malmborg. Drescher describes that the configuration of the cavity cover and thickness of the cavity cover is “typically chosen to withstand anticipated durability and/or mechanical strength requirements” (Par. 0040). As such, the thickness of a cavity cover and the thickness of the skin of Schwarz in view of Malmborg is a result effective variable with the result being the anticipated durability and mechanical strength of the blade and cover. It would have been obvious to one having ordinary skill in the art at the time the invention was made to have the cover skin be 1 mm to 4 mm thick, since it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. One would have been motivated to provide a cover skin that is 1 mm to 4 mm thick for the purpose of providing the optimal strength or durability of the blade.
Claim(s) 9 and 10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Schwarz (US 20160024934) in view of Malmborg (US 20200215642) as applied to claim 1 above, and further in view of Weisse (US 20180030995).
Regarding claim 9, Schwarz in view of Malmborg teaches the limitations of claim 1 as set forth in the above 102 rejection. However, Schwarz in view of Malmborg does not explicitly teach that a scrim layer is metallically formed on and metallurgically bonded to the main body and the plurality of ribs before the cover skin is metallically formed on and metallurgically bonded to the main body and the plurality of ribs, wherein the scrim layer is formed on and bonded to the ledge using a hybrid additive manufacturing/subtractive manufacturing process and is configured to be a substrate upon which the cover skin is built and metallurgically bonded to the main body, the plurality of ribs, and the scrim layer.
Schwarz in view of Malmborg and Weisse are analogous prior art because both describe covers used for metallic blades. Weisse teaches the cover being made of an FML (Pars. 0032-0034) which includes multiple aluminum or titanium layers interspersed within multiple composite layers. This provides one of the layers as a scrim layer with the remainder of the layers being the cover skin. Weisse describes that the FML layer for the cover reduces the overall weight of the fan blade, improves stiffness of the blade, and tunes out detrimental vibratory frequencies (Par. 0035) along with providing the stiffness and durability of the composite with the ductility of metals. Thereby, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the FML of Weisse as the cover material of Schwarz in view of Malmborg because it reduces the overall weight of the fan blade, improves stiffness of the blade, and tunes out detrimental vibratory frequencies (Par. 0035) along with providing the stiffness and durability of the composite with the ductility of metals.
The limitations directed to the order of the bonding and the hybrid additive/subtractive manufacturing process are product by process limitations and impart no clear structure to the blade as opposed to formation with a different order or method and as such those limitations are taught. As Schwarz in view of Malmborg describes welding the cover to the ledge, both the scrim and the cover would be metallurgically bonded to the main body. As described above, if the scrim layer and cover are both bonded to the body of the blade, all the items are metallurgically bonded together through the contacts.
Regarding claim 10, Schwarz in view of Malmborg and further in view of Weisse teaches that the scrim layer is aluminum, an aluminum alloy, titanium, or a titanium alloy (Weisse Paragraphs 0032-0033).
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 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 THEODORE C RIBADENEYRA whose telephone number is (469)295-9164. The examiner can normally be reached Mon-Fri 9:00-5:00 (CT).
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/THEODORE C RIBADENEYRA/ Examiner, Art Unit 3745
/NATHANIEL E WIEHE/ Supervisory Patent Examiner, Art Unit 3745
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