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 .
Claims 1-7, 9-16 are currently pending. Claims 1-7, 9-16 are rejected.
Response to Arguments
Applicant’s arguments, see Pg. 7-8 of the response, filed August 20, 2026, with respect to the objection of Claim 1 and rejection of Claim 5 under 35 U.S.C. 112(b) have been fully considered and are persuasive in light of amendments. The objection of Claim 1 and rejection of Claim 5 under 35 U.S.C. 112(b) have been withdrawn.
Note the 35 U.S.C. 112(b) issues with Claims 1 and 3 do not appear to have been resolved.
Applicant's arguments, see Pg. 8 of the response, filed with respect to the rejections under 35 U.S.C. 103 have been fully considered but they are not persuasive.
Regarding Claim 1, Applicant states the art of record does not expressly teach the amended limitation of “wherein the upstream and downstream preformed annular slots are separated by a gapless portion of the surface, said portion having a length which is function of at least an axial dimension of the preformed annular slots”. The Office respectfully disagrees, since this does not appear to be true. As detailed in the rejection below, the art would meet the broadest reasonable interpretation of “gapless” and “function”, which have not been further elaborated upon in the claim nor arguments. Further explanation or evidence presented of the criticality of the relative dimensions being claimed would be beneficial.
No further arguments have been provided with respect to the remaining claims.
Claim Objections
Claims 1-7 and 9-16 are objected to because of the following informalities:
Regarding Claim 1, Line 21 recites “a length which is function of”. The clause is missing an article, such as an “a”, before “function” for proper grammar.
Claims 2-7, 9-16 are subsequently objected to for their dependencies upon a previously objected claim.
Appropriate correction is required.
Claim Rejections - 35 USC § 112(b)
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.
Claims 1-7 and 9-16 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.
Regarding Claim 1, a broad range or limitation together with a narrow range or limitation that falls within the broad range or limitation (in the same claim) may be considered indefinite if the resulting claim does not clearly set forth the metes and bounds of the patent protection desired. See MPEP § 2173.05(c). In the present instance, the claim recites the broad recitation “a number of preformed annular slots” and “a number of lips” in Lines 13-14, and the claim also recites “two preformed annular slots” and “two lips” in Lines 17-18 which is the narrower statement of the range/limitation. The claim(s) are considered indefinite because there is a question or doubt as to whether the feature introduced by such narrower language is (a) merely exemplary of the remainder of the claim, and therefore not required, or (b) a required feature of the claims.
Regarding Claim 3, Lines 3-4 and 7-8 recite “a preformed annular slot upstream” and “a preformed slot upstream”. It is unclear if these are the same slots recited in Claim 1 or introducing additional slots. Claim 1 requires “two preformed annular slots” corresponding to the lips of the rotor. For purposes of examination, it is believed these are intended to be the same slots.
Regarding Claim 5, Lines 1-2 recite “the performed annular slot”. It is unclear what slot this refers to since there is no “performed” slot previously introduced in the scope of the claim. For purposes of examination, it is believed this was a typographical error of “preformed”.
Claims 2, 4, 6-7, 9-16 are subsequently rejected for their dependencies upon a previously rejected 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.
The factual inquiries 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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-7 and 9-16, as far as they are definite and understood, are rejected under 35 U.S.C. 103 as being unpatentable over Willett, Jr. et al. (US 2013/0280047 A1), hereinafter Willett in view of Itzel et al. (US 2018/0230841 A1), hereinafter Itzel.
Regarding Claim 1, Figures 1-3 of Willett teach three different embodiments of a labyrinth-type sealing device for a turbomachine (see paragraph [0001]), the device comprising: a rotor having an axis of rotation (not shown, will be below frame of view in Figures) and comprising external annular lips (22, unlabeled in Figures 1-2) extending around said axis, and a stator extending around the axis, this stator comprising an annular coating (14) made of abradable material (see paragraph [0019]) which extends around the lips (22) and which is configured to cooperate in operation with the lips (22) to form a labyrinth-type seal with respect to a flow of gas which is intended to flow axially from upstream to downstream (left to right in Figures) through the rotor, the coating (14) comprising an internal cylindrical surface (bottom-most surface of 14 with respect to Figures) extending around the lips (22) and which is configured to contact the lips (22) to form annular grooves extending around the axis by friction (material of coating noted to be abradable, grooves formed if abraded when contacted), wherein the surface comprises, upstream of each of the lips (22), a corresponding preformed annular slot (space in section 16) which extends around the axis and which is configured to receive said lip (22) in the event of an axial upstream displacement of the rotor with respect to the stator, a number of preformed slots (in section 16) being equal to a number of lips (22) of the rotor, wherein the rotor has two lips comprising an upstream and a downstream lip (see left and right lips in annotated Figure 1’ below), the surface comprising two preformed annular slots, an upstream slot and a downstream slot (see left and right slots in annotated Figure 1’ below) corresponding, respectively, to the upstream and downstream lips of the rotor, wherein the upstream and downstream preformed annular slots are separated by a gapless portion (portion between two slots) of the surface, said portion having a length which is function of at least an axial dimension of the preformed annular slots [0019-0022]. See also annotated Figure 1’ below. The limitation of being for an aircraft turbomachine is treated as intended use of the claimed device. The claimed device meets all the recited structural limitations as noted above. While the embodiments of Figures 1-2 show the preformed annular slots (in section 16) downstream of the lips, paragraph [0020] discloses the increased clearance (formed in 16) could be applied to the left side, which results in the slots being upstream of the lips. The portions between two slots are considered “gapless”, as there is no axial gap between the two slots. A “function” may be any function. For example, a length dimension multiplied by a number. The claim does not specify a specific function, so the claim is met by the gapless portion being a structure with dimensions.
PNG
media_image1.png
635
761
media_image1.png
Greyscale
Willett does not expressly teach wherein each of the two slots is located at an axial distance between 1 and 20mm upstream of the corresponding one of the two lips as claimed.
However, the courts have held various practices to be routine expedients, requiring only ordinary skill in the art. One such practice is a change in size. “Limitations relating to the size… were not sufficient to patentably distinguish over the prior art” (see MPEP 2144.04, IV, A). While an axial distance is illustrated in Figures 1 and 3 of Willett, the exact value of that distance is not explicitly described. Such an axial distance is subject to change depending upon the overall size of the device. For instance, if the device of Willett is made larger, the distance would be a larger value compared to if the device is scaled smaller. One of ordinary skill would change the overall size of the device by design choice. The claim only requires a particular value for the axial gap without relation to any other dimensional value of the device. Thus, the claims are considered encompassing merely a change in size of the device. For example, if a device has a gap of particular size, increasing the device as a whole would increase the gap size as well.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the device taught by Willett such that each of the two slots is located at an axial distance between 1 and 20mm upstream of the corresponding one of the two lips, since the size of the device is a matter of design choice.
Willett does not expressly teach wherein the abradable material comprises a honeycomb structure having cells that are oriented in a radial direction with respect to said axis as claimed. However, such a honeycomb structure would have been obvious in view of Itzel.
Figures 7-8 teach a labyrinth sealing device comprising an abradable material (67), wherein the abradable material (67) comprises a honeycomb structure having cells (75) that are oriented in a radial direction (vertical with respect to view in Figure 7) with respect to said axis (horizontal with respect to view in Figure 7). Thus, Itzel exemplifies honeycomb structures are known in the art and predictably provide sufficient abradability for labyrinth sealings of turbines. Additionally, the repeated pattern of thin-walled structures provided promotes wearing without damaging the rotor blades [0039-0041].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the device taught by Willett by simply substituting the solid or non-descript structure of the abradable portion such that the abradable material comprises a honeycomb structure having cells that are oriented in a radial direction with respect to said axis as exemplified by Itzel, since honeycomb structures are known configurations of abradable materials that predictably result in sufficient abradability that provides proper labyrinth sealings for turbines. Additionally, honeycombs provide the benefit of being thin-walled so that abradability without damage of the rotors is further promoted.
Regarding Claim 2, Willett and Itzel teach the device as set forth in Claim 1.
Figures 1-3 of Willett teach wherein the upstream and downstream lips (leftmost and rightmost lips, see annotated Figure 1’ above) are surrounded by two distinct cylindrical surfaces (internal surface of 14), respectively upstream and downstream, of the coating (14) [0019-0022]. See also annotated Figure 1’ above.
Regarding Claim 3, Willett and Itzel teach the device as set forth in Claim 2.
Figures 1-3 of Willett teach wherein: in the case where the upstream and downstream lips (left and right 22, unlabeled in Figures 1-2) are surrounded by two distinct cylindrical surfaces (internal surface of 14), respectively upstream and downstream of the coating (left and right 14 that respectively corresponds with the lips), the upstream cylindrical surface comprises a preformed annular slot (formed in section 16) upstream of the upstream lip (22), and/or the downstream cylindrical surface comprises a preformed annular slot (formed in section 16) upstream of the downstream lip (22) [0019-0022]. See also annotated Figure 1’ above. While the embodiments of Figures 1-2 show the preformed annular slots (in section 16) downstream of the lips, paragraph [0020] discloses the increased clearance (formed in 16) could be applied to the left side, which results in the slots being upstream of the lips.
Regarding Claim 4, Willett and Itzel teach the device as set forth in Claim 2.
Figures 1-3 of Willett teach wherein the upstream and downstream cylindrical surfaces (left and right pairs of 14) are stepped and comprise different diameters. For instance, the leftmost (14) and middle (14) are clearly illustrated having different radial positions.
Regarding Claim 5, Willett and Itzel teach the device as set forth in Claim 4.
Figure 3 of Willett teaches wherein the performed annular slot (formed in 16, specifically the middle one) upstream of the downstream lip (lip for corresponding slot) is interposed axially between the two cylindrical surfaces (inner surfaces of 14) [0022]. Alternatively, this is interpretable as the middle (16) of the Figure 2 embodiment, which while illustrated to be on the right side of (14), may be on the left side as well [0020].
Regarding Claim 6, Willett and Itzel teach the device as set forth in Claim 1.
Figure 3 of Willett teaches wherein the axial distance is less than half an axial distance between the two lips (left and middle 22). The halfway point between the two lips (22) is clearly illustrated in the zone of the slot (formed in 16) with portions in greater or less than the distance, therefore it satisfies the broadest reasonable interpretation of being “located at”.
Regarding Claims 6-7, for purposes of expediting prosecution Claim 6 is rejected again assuming the illustrated figures of Willett are insufficient, Willett teaches the device as set forth in Claim 1.
Willett does not expressly teach wherein the axial distance is less than or equal to (Claim 6) / greater than (Claim 7) half an axial distance between the two lips as claimed.
However, paragraph [0020] of Willett characterizes the slot (clearance) as part of abradable coating profile. And that clearance designs calculations would determine the details of the coating profile based on the specific geometry of the turbine in question. In other words, this shows that aspects of the slot, such as the exact positioning, would be calculated based on the geometry of the turbine the teachings are applied to.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the device illustrated in Willett such that the axial distance is less than or equal to (Claim 6) / greater than (Claim 7) half an axial distance between the two lips as evidenced by paragraph [0020] of Willett, since one of ordinary skill would alter the coating profile based on the turbine the teachings are applied to.
Regarding Claim 9, Willett and Itzel teach the device as set forth in Claim 1.
Figures 1-2 of Willett teach wherein each slot (formed in 16) has a radial depth or dimension less than or equal to a radial thickness or dimension of a zone of the coating (14) in which this slot is formed [0019-0020]. See also annotated Figure 1’ above.
Regarding Claim 10, Willett and Itzel teach the device as set forth in Claim 1.
Figures 1-3 of Willett teach wherein each slot (formed in 16) has an axial dimension greater than or equal to half an axial thickness of a corresponding lip (22, unlabeled in Figures 1-2), the thickness being measured at a level of an external periphery of this lip. See also annotated Figure 1’ above. The slots are illustrated much greater than the peripheries of the lips.
Regarding Claim 11, Willett and Itzel teach the device as set forth in Claim 1.
Figures 1 and 3 of Willett teach wherein each slot (formed in section 16) is located in an axial distance from an upstream axial end of the cylindrical surface (inner surface of 14) in which that slot is formed. See also annotated Figure 1’ above. For example, the rightmost slot (16) in Figure 3 is spaced from the rightmost (14). Note while the embodiment of Figure 1 shows the preformed annular slots (in section 16) downstream of the lips, paragraph [0020] discloses the increased clearance (formed in 16) could be applied to the left side, which results in the slots being upstream of the lips.
Regarding Claim 12, Willett and Itzel teach the device as set forth in Claim 1.
Willett teaches wherein the rotor is a compressor or turbine blading, and the stator is a sealing ring carried by a casing of the compressor or turbine [0002-0003, 0019]. See also Figure 3, where ring (20) is carried by the casing surrounding it.
Regarding Claim 13, Willett and Itzel teach the device as set forth in Claim 1.
Willett does not expressly teach an aircraft turbomachine comprising at least one device as claimed. However, an aircraft turbomachine would have been obvious in view of Itzel.
At best, paragraph [0002] of Willett exemplifies the teachings to be applicable to rotary machines, including turbines.
Figure 12 of Itzel teaches a labyrinth-type sealing device having a rotor (16), a stator (65), a coating (78) made of abradable material and an abradable layer (67) [0038 (described of a different embodiment but same numerals for rotor and stator), 0047]. Paragraph [0030] notes the teachings may be used in a variety of gas turbines, including those of power generation and aircrafts. Thus, Itzel provides evidence that it is known for a gas turbine to be used as an aircraft turbomachine. Additionally, aircraft turbomachines benefit from teachings related to labyrinth-type sealing devices having abradable material. Thus, it would be reasonable to apply the teachings of Willett to an aircraft turbomachine so that the aircraft turbomachine may receive the benefits of Willett.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the device taught by Willett-Itzel with an aircraft turbomachine comprising at least one device as evidenced by Itzel, since aircraft turbomachines are a known application of such a device and an aircraft turbomachine would be able to obtain the benefits of the teachings of Willett.
Regarding Claim 14, Willett and Itzel teach the device as set forth in Claim 1.
Willett does not expressly teach wherein said axial distance is between 1 and 5mm as claimed.
However, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the device taught by Willett such that said axial distance is between 1 and 5mm due to a design choice to have a change in proportions for the same reasons set forth in the rejection of Claim 1 above.
Regarding Claims 15-16, Willet and Itzel teach the device as set forth in Claims 10 and 1.
The embodiments of Figures 1-2 of Willett do not expressly teach the gapless portion of the surface has an axial distance which is equal to a sum of an axial distance between the two lips and an axial thickness of a lip minus an axial dimension of a slot (Claim 15), nor wherein the gapless portion of the surface has an axial distance which is lower or equal to an axial distance between the two lips (Claim 16) as claimed.
However, paragraph [0020] of Willett characterizes the slot (clearance) as part of abradable coating profile. And that clearance designs calculations would determine the details of the coating profile based on the specific geometry of the turbine in question. In other words, this shows that aspects of the slot, such as the exact positioning forming the claimed relative dimensions, would be calculated based on the geometry of the turbine the teachings are applied to.
Additionally, the claimed limitations are considered relative dimensions. Even if it is assumed this portion of Willett is not relevant, such claim limitations would be alternatively considered obvious as a matter of design choice. As noted in MPEP 2144.04, IV, A, where the only difference between the prior art and the claims was a recitation of relative dimensions of the claimed device and a device having the claimed relative dimensions would not perform differently than the prior art device, the claimed device was not patentably distinct from the prior art device. The record does not indicate any difference in performance from the specific relative dimensions compared to that disclosed by the art of record.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the device illustrated in Willett-Itzel such that the gapless portion of the surface has an axial distance which is equal to a sum of an axial distance between the two lips and an axial thickness of a lip minus an axial dimension of a slot (Claim 15), or wherein the gapless portion of the surface has an axial distance which is lower or equal to an axial distance between the two lips (Claim 16) as evidenced by paragraph [0020] of Willett, since one of ordinary skill would alter the coating profile based on the turbine the teachings are applied to. Alternatively, if it is assumed the cited portion of Willett does not apply, such relative dimensions would be considered an obvious matter of design choice.
Regarding Claim 16, for purposes of expediting prosecution the claim is rejected again, Willett and Itzel teach the device as set forth in Claim 1.
The embodiment of Figure 3 of Willett teaches wherein the gapless portion of the surface has an axial distance which is lower or equal to an axial distance between the two lips. See the extent of (14) compared to the distance between lips (22).
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 ELTON K WONG whose telephone number is (408)918-7626. The examiner can normally be reached Mon-Fri 8:00AM - 5:00PM PST.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Court Heinle can be reached at (571)270-3508. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/ELTON K WONG/Primary Examiner, Art Unit 3745
