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 .
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 2-5 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 2 describes an “axially stacked arrangement” but does not define an axial or radial direction or set forth any engine directions. Because of this, it is unclear what the axial direction is in reference to, specifically if it is the axial direction of the seal centerline or relative to an engine axis.
Claim 3 describes an “radially stacked arrangement” but does not define an axial or radial direction or set forth any engine directions. Because of this, it is unclear what the radial direction is in reference to, specifically if it is the radial direction of the seal centerline or relative to an engine axis.
Claim 4 includes the limitation “the seal has a layer-less configuration”. It is unclear how a three-dimensional structure made out of fibers can also not have layers. If the intent was to state that it is not made of pre-formed layers that must be specified but that cannot be assumed by the current language. In order to expedite examination the examiner is interpreting the limitations to simply require the carbon fibers to have a unidirectional orientation and extend circumferentially.
Claim 5 recites the limitation "the engine central axis" in line 2. There is insufficient antecedent basis for this limitation in the claim.
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 and 8 is/are rejected under 35 U.S.C. 103 as being unpatentable over Jiqiao (CN 101954676) in view of Blaney (US 20210017871).
Regarding claim 1, Jiqiao discloses A method for processing a seal for a gas turbine engine, the method comprising:
providing a carbon fiber preform (Paragraphs 0016-0017 describes a carbon fiber preform provided before densification);
densifying the carbon fiber preform with a carbon matrix (Paragraphs 0021 and 0059 describes that graphite is used with the infiltration, which provides a graphite carbon matrix for densification as is provided through CVD in paragraph 0017)
forming a carbon/carbon composite ring (Paragraphs 0014-0016 and paragraph 0035 describes that the ring can be split).
However, Jiqiao does not explicitly disclose the method of forming the carbon carbon composite with forming a seal by cutting the carbon/carbon composite ring after densification to form at least one seam at which opposed ends of the carbon/carbon composite ring meet.
Jiqiao and Blaney are analogous prior art because both describe forming CMC materials for gas turbine engines. Blaney teaches making a CMC out of a fiber preform (Par. 0047), densifying the carbon fiber preform with a matrix (Par. 0047), and cutting the composite ring to form at least one seam at which opposed ends of the composite ring meet (Figure 11 shows the portions being cut into multiple pieces where their ends meet and paragraph 0066 describes forming the parts in a single piece, densifying the piece, and then cutting it into multiple segments). Jiqiao teaches the composite being a carbon-carbon composite and describes machining the structure after densification (Paragraph 0034). As Blaney describes a typical CMC composite formation method that is usable for carbon-carbon composites, the use of the fibers in a matrix with densifying (Par. 0047) and cutting would provide predictable results in manufacturing the seal of Jiqiao. Further, Blaney teaches that densifying before cutting the segments “may require less tooling and lower densification and machining costs” and “may also reduce the manufacturing time and fiber waste” (Par. 0047). Such a method would be suitable for creating the segments of the annular seal structure of Jiqiao (paragraph 0035 describes that the ring can be split). 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 fiber and matrix construction with densification prior to cutting the segments of Blaney in the seal of Jiqiao because densifying before cutting the segments “may require less tooling and lower densification and machining costs” and “may also reduce the manufacturing time and fiber waste” (Par. 0047) and combining prior art elements according to known methods is obvious with predictable results. See MPEP 2143(I)(A).
Regarding claim 8, Jiqiao in view of Blaney teaches that the seal has a 3-D fiber architecture (Jiqiao Figures 1 and 2 show the seal being three dimensional and paragraphs 0045-0047 describes the fibers forming the structure, so the seal has a 3-D fiber architecture).
Claim(s) 2-5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Jiqiao (CN 101954676) in view of Blaney (US 20210017871) as applied to claim 1 above, and further in view of Sheedy (US 20200299200) and Shi (Engineering method … database).
Regarding claim 2, Jiqiao in view of Blaney teaches the limitations of claim 1 as set forth in the above 103 rejection. However, it does not explicitly teach that the seal has a multi-layer configuration of fiber plies in an axially stacked arrangement. Jiqiao in view of Blaney and Sheedy are analogous prior art because both describe carbon-carbon composites used in gas turbine engines. Sheedy teaches forming a carbon-carbon composite (Paragraph 0033) out of multiple layers of CMC with the layers stacked both radially and axially depending on arrangement. Jiqiao in view of Blaney describes using a carbon-carbon composite for the seal material but does not choose the way the fibers are formed and arranged so one of ordinary skill in the art would have to choose how to form the carbon-carbon composite. Sheedy shows that a carbon-carbon composite can be formed with the stacking of multiple plies meaning that the use of stacked plies would provide predictable results in forming the seal of Jiqiao in view of Blaney. 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 plie stacking method of Sheedy to form the carbon-carbon composite seal of Jiqiao in view of Blaney because combining prior art elements according to known methods is obvious with predictable results. See MPEP 2143(I)(A).
However, Jiqiao in view of Blaney and further in view of Sheedy does not explicitly disclose that the layers are stacked axially. Again, as there is not an exact analog to stacking the layers from Sheedy in the seal of Jiqiao in view of Blaney, one of ordinary skill in the art would have to choose how to stack and orient the fiber layers. Shi describes that in the design of stacked composite layers “a variety of design variables must be considered during the composite aircraft structural design and analysis, such as the ply number, the ply angle, the stacking sequence, the symmetry, the characteristics of the first layer and last layer, the manufacture feasibility and so on” and that “The object of the optimization is weight, the constraints are the failure criteria of local buckling, overall buckling and maximum strain or maximum stress” (pg. 1, paragraphs 1 and 2). This means that the ply number, ply angle, stacking sequence, symmetry, and the characteristics of the first and last layer are all result effective variables where the result is local buckling, overall buckling, maximum strain, and maximum stress. Further, Shi describes that these properties and sequences are different and specific to each application that the structure is used in. The stacking direction of the plies lies under the Further, stacking the plies in the axial direction would mean that the rotation of the engine components would be in the plane of each layer and would avoid potential de-lamination from the frictional forces of the rotation pushing layers away from each other. Thereby, it would have been obvious to one having ordinary skill in the art at the time the invention was made to have the layers stacked axially, 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 stack the layers of the seal axially for the purpose of providing the desired stress, strain, and buckling properties for the structure and avoid negative de-lamination of the layers. See MPEP 2144.05(I).
Regarding claim 3, Jiqiao in view of Blaney teaches the limitations of claim 1 as set forth in the above 103 rejection. However, it does not explicitly teach that the seal has a multi-layer configuration of fiber plies in a radially stacked arrangement. Jiqiao in view of Blaney and Sheedy are analogous prior art because both describe carbon-carbon composites used in gas turbine engines. Sheedy teaches forming a carbon-carbon composite (Paragraph 0033) out of multiple layers of CMC with the layers stacked both radially and axially depending on arrangement. Jiqiao in view of Blaney describes using a carbon-carbon composite for the seal material but does not choose the way the fibers are formed and arranged so one of ordinary skill in the art would have to choose how to form the carbon-carbon composite. Sheedy shows that a carbon-carbon composite can be formed with the stacking of multiple plies meaning that the use of stacked plies would provide predictable results in forming the seal of Jiqiao in view of Blaney. 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 plie stacking method of Sheedy to form the carbon-carbon composite seal of Jiqiao in view of Blaney because combining prior art elements according to known methods is obvious with predictable results. See MPEP 2143(I)(A).
However, Jiqiao in view of Blaney and further in view of Sheedy does not explicitly disclose that the layers are stacked radially. Again, as there is not an exact analog to stacking the layers from Sheedy in the seal of Jiqiao in view of Blaney, one of ordinary skill in the art would have to choose how to stack and orient the fiber layers. Shi describes that in the design of stacked composite layers “a variety of design variables must be considered during the composite aircraft structural design and analysis, such as the ply number, the ply angle, the stacking sequence, the symmetry, the characteristics of the first layer and last layer, the manufacture feasibility and so on” and that “The object of the optimization is weight, the constraints are the failure criteria of local buckling, overall buckling and maximum strain or maximum stress” (pg. 1, paragraphs 1 and 2). This means that the ply number, ply angle, stacking sequence, symmetry, and the characteristics of the first and last layer are all result effective variables where the result is local buckling, overall buckling, maximum strain, and maximum stress. Further, Shi describes that these properties and sequences are different and specific to each application that the structure is used in. Further, stacking the plies in the radial direction would mean that the rotation of the engine components would be in the plane of each layer and would avoid potential de-lamination from the frictional forces of the rotation pushing layers away from each other. Thereby, it would have been obvious to one having ordinary skill in the art at the time the invention was made to have the layers stacked radially, 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 stack the layers of the seal radially for the purpose of providing the desired stress, strain, and buckling properties for the structure and avoid negative de-lamination of the layers. See MPEP 2144.05(I).
Regarding claim 4, Jiqiao in view of Blaney teaches the limitations of claim 1 as set forth in the above 103 rejection. However, it does not explicitly teach that the carbon fibers have a unidirectional orientation and extend circumferentially. Jiqiao in view of Blaney and Sheedy are analogous prior art because both describe carbon-carbon composites used in gas turbine engines. Sheedy teaches forming a carbon-carbon composite (Paragraph 0033) out of multiple layers of CMC with discrete fiber directions. Jiqiao in view of Blaney describes using a carbon-carbon composite for the seal material but does not choose the way the fibers are formed and arranged so one of ordinary skill in the art would have to choose how to form the carbon-carbon composite. Sheedy shows that a carbon-carbon composite can be formed with the stacking of multiple plies meaning that the use of stacked plies with intentionally oriented fibers would provide predictable results in forming the seal of Jiqiao in view of Blaney. 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 plie stacking method of Sheedy to form the carbon-carbon composite seal of Jiqiao in view of Blaney because combining prior art elements according to known methods is obvious with predictable results. See MPEP 2143(I)(A).
However, Jiqiao in view of Blaney and further in view of Sheedy does not explicitly disclose that the layers have a unidirectional orientation. Sheedy describes multiple possible ways to orient the fibers of the various layers. Shi describes that in the design of stacked composite layers “a variety of design variables must be considered during the composite aircraft structural design and analysis, such as the ply number, the ply angle, the stacking sequence, the symmetry, the characteristics of the first layer and last layer, the manufacture feasibility and so on” and that “The object of the optimization is weight, the constraints are the failure criteria of local buckling, overall buckling and maximum strain or maximum stress” (pg. 1, paragraphs 1 and 2). This means that the ply number, ply angle, stacking sequence, symmetry, and the characteristics of the first and last layer are all result effective variables where the result is local buckling, overall buckling, maximum strain, and maximum stress. Further, Shi describes that these properties and sequences are different and specific to each application that the structure is used in. Thereby, it would have been obvious to one having ordinary skill in the art at the time the invention was made to have carbon fibers be unidirectionally oriented and extend circumferentially, 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 have the fibers unidirectionally oriented and circumferentially extending for the purpose of providing the desired stress, strain, and buckling properties for the structure. See MPEP 2144.05(I).
Regarding claim 5, Jiqiao in view of Blaney teaches the limitations of claim 1 as set forth in the above 103 rejection. However, it does not explicitly teach that the carbon fibers are elongated in directions oblique to the engine central axis. Jiqiao in view of Blaney and Sheedy are analogous prior art because both describe carbon-carbon composites used in gas turbine engines. Sheedy teaches forming a carbon-carbon composite (Paragraph 0033) out of multiple layers of CMC with discrete fiber directions. Jiqiao in view of Blaney describes using a carbon-carbon composite for the seal material but does not choose the way the fibers are formed and arranged so one of ordinary skill in the art would have to choose how to form the carbon-carbon composite. Sheedy shows that a carbon-carbon composite can be formed with the stacking of multiple plies meaning that the use of stacked plies with intentionally oriented fibers would provide predictable results in forming the seal of Jiqiao in view of Blaney. 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 plie stacking method of Sheedy to form the carbon-carbon composite seal of Jiqiao in view of Blaney because combining prior art elements according to known methods is obvious with predictable results. See MPEP 2143(I)(A).
However, Jiqiao in view of Blaney and further in view of Sheedy does not explicitly disclose that the layers are stacked radially. Sheedy describes multiple possible ways to orient the fibers of the various layers. Shi describes that in the design of stacked composite layers “a variety of design variables must be considered during the composite aircraft structural design and analysis, such as the ply number, the ply angle, the stacking sequence, the symmetry, the characteristics of the first layer and last layer, the manufacture feasibility and so on” and that “The object of the optimization is weight, the constraints are the failure criteria of local buckling, overall buckling and maximum strain or maximum stress” (pg. 1, paragraphs 1 and 2). This means that the ply number, ply angle, stacking sequence, symmetry, and the characteristics of the first and last layer are all result effective variables where the result is local buckling, overall buckling, maximum strain, and maximum stress. Further, Shi describes that these properties and sequences are different and specific to each application that the structure is used in. Thereby, it would have been obvious to one having ordinary skill in the art at the time the invention was made to have carbon fibers be elongated in directions oblique to the central axis, since that is related to the ply angle and 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 have the fibers be elongated in directions oblique to the engine central axis for the purpose of providing the desired stress, strain, and buckling properties for the structure. See MPEP 2144.05(I).
Claim(s) 6 is/are rejected under 35 U.S.C. 103 as being unpatentable over Jiqiao (CN 101954676) in view of Blaney (US 20210017871) as applied to claim 1 above, and further in view of Weaver (US 20190338658).
Regarding claim 6, Jiqiao in view of Blaney teaches the limitations for claim 1 as described in the 103 rejection above but does not clearly teach that the seal includes an annular core that extends along a central core axis that extends circumferentially around the engine central axis, and the carbon fibers are in flat tows that are would around the central core axis on the annular core. Jiqiao in view of Blaney and Weaver are analogous prior art because both describe CMC constructions. Weaver describes layering and weaving CMC (158) around a core (144) that allows for filling space created by weaving multiple continuous layers of CMC into a full piece. Jiqiao in view of Blaney describes using a carbon-carbon composite for the seal material but does not choose the way the fibers are formed and arranged so one of ordinary skill in the art would have to choose how to form the composite. Weaver describes that the layers are woven (Par. 0066) and that the filler fills any possible gaps created by the layering of the fiber plies (Par. 0060). As both provide CMC structures in gas turbine engines and Weaver shows a method of manufacturing a CMC component, the filler and wrapping orientation of Weaver would provide predictable results in the structure of Jiqiao in view of Blaney. While Jiqiao in view of Blaney does not use a circular structure, the core would still provide benefit in a rectangular structure by providing filler for a structure that wraps continuously around an axis instead of simply stacking layers one by one as shown in Weaver. 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 core and weaving system of Weaver in the seal of Jiqiao in view of Blaney because combining prior art elements according to known methods is obvious with predictable results. See MPEP 2143(I)(A).
Claim(s) 7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Jiqiao (CN 101954676) in view of Blaney (US 20210017871) as applied to claim 1 above, and further in view of Ritti (US 20130116109).
Regarding claim 7, Jiqiao in view of Blaney teaches the limitations for claim 1 as described in the 103 rejection above but does not clearly teach that the seal extends along a seal axis that extends circumferentially around the engine central axis, and the carbon fibers are in strands that are braided around the seal axis. Jiqiao in view of Blaney and Ritti are analogous prior art because both describe CMC constructions. Ritti teaches forming a CMC component by braiding the fibers in a three-dimensional form. Jiqiao in view of Blaney describes using a carbon-carbon composite for the seal material but does not choose the way the fibers are formed and arranged so one of ordinary skill in the art would have to choose how to form the composite. Because Ritti describes that a CMC can be formed with three-dimensional braiding and Jiqiao in view of Blaney describes a CMC structure, the braiding of Ritti would provide predictable results in the structure of Jiqiao in view of Blaney. 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 three-dimensional braiding of Ritti to form the seal of Jiqiao in view of Blaney because combining prior art elements according to known methods is obvious with predictable results. See MPEP 2143(I)(A). Further, as the braiding would exist in three dimensions and the annular seal has an axis, the braiding occurs around and about the axis.
Claim(s) 9 is/are rejected under 35 U.S.C. 103 as being unpatentable over Jiqiao (CN 101954676) in view of Blaney (US 20210017871) as applied to claim 1 above, and further in view of Sheedy (US 20200299200).
Regarding claim 9, Jiqiao in view of Blaney teaches the limitations of claim 1 as set forth in the above 103 rejection. However, it does not explicitly teach that the carbon fibers are, by volume, 35% to 65% of the composite. Jiqiao in view of Blaney and Sheedy are analogous prior art because both describe carbon-carbon composite structures used in gas turbine engines. Sheedy describes that the structure can be made of a carbon/carbon composite (Par. 0033) and that the CMC structure contains greater than 60% volume of fiber (Par. 0004). As Jiqiao in view of Blaney does not mention the fiber volume percentage, one of ordinary skill in the art would have to choose the fiber volume to choose. The volume percentage of Sheedy would provide predictable results in the seal structure of Jiqiao in view of Blaney because they both describe carbon/carbon composite structures in gas turbine engines. 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 fiber volume percentage of Sheedy in the seal of Jiqiao in view of Blaney because combining prior art elements according to known methods is obvious with predictable results. See MPEP 2143(I)(A). Further, in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists, so it would have been obvious to choose the volume percentage in the range of 35% to 65%. See MPEP 2144.05(I).
Allowable Subject Matter
Claims 10-20 are 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 following is a statement of reasons for the indication of allowable subject matter: None of the prior art found taught or disclosed the limitations of claim 10. Specifically, while the rejection of claim 6 teaches flat tows wound around an annular core and a central axis, the prior art does not teach that the flat tows partially overlap an immediately prior flat tow in the series of flat tows. While Weaver shows a series of tows surrounding a core, Weaver does not show that the flat tows only partially overlap the immediately prior flat tow in the series. Instead, Weaver shows a wrapped or wound over each inner tow and does not show the partial overlap of the immediately prior tow. Further, Weaver shows layers of flat tows wrapped over each other, not a series of them arranged with the partial overlap.
There is no clear motivation as to why it would have been obvious for each subsequent tow to only partially overlap the prior tows while also being wound around the core axis as the lack of a complete overlap weakens the bond between each of the adjacent tows. No other prior art was found that taught or disclosed the series of flat tows wrapped and arranged in the way required in claim 10 around a core of the structure. As this application is a proper divisional of parent application 17/994,188, any double patenting rejection would be improper. Claims 11-20 are listed as allowable subject matter due to being dependent from claim 10.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. See attached PTO-892. Shapiro (US 20200025002) describes the importance of fiber orientation for forming a CMC, Valle (WO 2014174540) describes forming a CMC part by taking a cylinder and cutting off differently sized slices for use, and Mazany (US 20100051863) describes using mono-aluminum-phosphate as an oxidation inhibitor for a CMC
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/THEODORE C RIBADENEYRA/ Examiner, Art Unit 3745