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 . The previous rejection was WITHDRAWN/VACATED.
Response to Arguments
Applicant's arguments filed 02/26/2026 have been fully considered but they are not persuasive.
Applicant argues that McMillan reference does not disclose the shapes of 41 and 42, fig 4 are not bristles and the type of seal of McMillan is not a brush seal.
Examiner notes that McMillan Para 0037 discloses for fig 4 – “ the edge 44 is relatively compliant and flexible in order to replicate the performance of a brush seal where bristles of that brush seal effectively provide a curtain to divide the high and low pressure sides of the seal.” Hence McMillan reference can be combined with Weaver reference.
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.
Claims 1 and 14 – 16 are rejected under 35 U.S.C. 103 as being unpatentable over Weaver in view of McMillan (U.S. PG Pub # 20040046324).
Regarding Claim 1, Weaver discloses an annular brush seal (21, fig 4) comprising a bristle pack formed of bristles (bristles of 12) and a bristle pack support (14, 16), supporting the bristle pack, wherein : the bristle pack has an upstream face (upstream face of 12 at 8, fig 1 same as fig 4), a downstream face (downstream face of 12 at 10, fig 1 same as fig 4) and a sealing face (18); the sealing face comprises an upstream portion (upstream portion of 18) and a downstream portion (downstream portion of 18) that is adjacent to the upstream portion (fig 4);wherein a length of at least a fraction of the bristles of the upstream portion is shorter than a length of the bristles of the downstream portion (length of bristles of the upstream portion 22) and the length of the at least a fraction of bristles of the upstream portion decreases as the upstream portion of the sealing face extends from the downstream portion of the sealing face towards the upstream face (length of bristles of the upstream portion 22 decreases as the upstream portion of the sealing face extends from the downstream portion of the sealing face towards the upstream face).
Weaver does not disclose wherein the decrease in length of the bristles in the upstream portion of the sealing surface varies to form a circumferentially repeating pattern at an interface between the upstream portion of the sealing surface and the upstream surface.
However, McMillan teaches wherein the decrease in length of the bristles in the upstream portion of the sealing surface varies to form a circumferentially repeating pattern at an interface between the upstream portion of the sealing surface and the upstream surface (shapes of 41 and 42 are repeating, fig 4). It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to modify the upstream portion of the sealing face of the bristle pack of Weaver to form a circumferentially repeating pattern as in McMillan with a reasonable expectation of success so that the pattern provides a degree of flexibility to the seal (McMillan Para 0038).
Regarding Claim 2, the combination of Weaver and McMillan discloses the annular brush seal, wherein an axial extent of the upstream portion of the sealing face has rows (Weaver - rows of upstream portion of the sealing face 18), and a number of rows of bristles of the bristle pack (Weaver - number of rows of bristles of 12).
The combination of Weaver and McMillan does not disclose wherein an axial extent of the upstream portion of the sealing face is no more than (n-2) rows, wherein n is a number of rows of bristles of the bristle pack.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention, to contrive any number of desirable ranges for axial extent of the upstream portion of the sealing face limitation disclosed by Applicant, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art, to provide smooth airflow with the number of rows of bristles of the upstream portion. In re Aller, 105 USPQ 233.
Regarding Claim 3, the combination of Weaver and McMillan discloses the annular brush seal, wherein a diameter of the bristles of the bristle pack (Weaver - diameter of bristles of 12).
The combination of Weaver and McMillan does not disclose wherein a diameter of the bristles of the bristle pack is in the range of 75 to 200 micrometres.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention, to contrive any number of desirable ranges for a diameter of the bristles of the bristle pack limitation disclosed by Applicant, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art, to provide sealing against the shaft depending on the gap between the housing and the shaft. In re Aller, 105 USPQ 233.
Regarding Claim 4, the combination of Weaver and McMillan discloses the annular brush seal wherein a lay angle of the bristles of the bristle pack in the range of 20 degrees to 55 degrees (Weaver Para 0026 – angle 32 between 40 and 50 degrees).
Regarding Claim 6, the combination of Weaver and McMillan discloses the annular brush seal wherein the annular brush seal comprises a number of the circumferentially repeating pattern (Kono – number of repeating pattern of 3).
The combination of Weaver and McMillan does not disclose wherein the annular brush seal comprises a number of the circumferentially repeating pattern in the range of 10 to 200 circumferentially repeating patterns per metre circumference of the annular brush seal.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention, to contrive any number of desirable ranges for the number of the circumferentially repeating pattern limitation disclosed by Applicant, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art, to provide smooth airflow with the number of the circumferentially repeating pattern of the bristle pack. In re Aller, 105 USPQ 233.
Regarding Claim 7, the combination of Weaver and McMillan discloses the annular brush seal, wherein the number of circumferentially repeating patterns is a prime number.
The combination of Weaver and McMillan does not wherein the number of circumferentially repeating patterns is a prime number.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention, to contrive any number of desirable ranges for the number of the circumferentially repeating pattern limitation disclosed by Applicant, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art, to provide smooth airflow with the number of the circumferentially repeating pattern of the bristle pack. In re Aller, 105 USPQ 233.
Regarding Claim 8, the combination of Weaver and McMillan discloses the annular brush seal, wherein the circumferentially repeating pattern is configured to generate hydrodynamic lift when the brush seal seals a rotating member (McMillan Para 0036 - circumferentially repeating pattern of 41, 42 is configured to generate air riding effect/ lift when the brush seal seals a rotating member).
Regarding Claim 9, the combination of Weaver and McMillan discloses the annular brush seal wherein : the circumferentially repeating pattern is a scallop (McMillan Para 0037– scallop/oval pattern of 42).
Regarding Claim 10, the combination of Weaver and McMillan discloses the annular brush seal, wherein the circumferentially repeating pattern is a scallop (McMillan – scallop pattern of 3).
The combination of Weaver and McMillan does not disclose wherein the circumferentially repeating pattern is substantially pyramidal.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention, since a change in the shape of a prior art device is a design consideration within the skill of the art, to provide a required hydrodynamic lift for the seal. In re Dailey, 357 F.2d 669, 149 USPQ 47 (CCPA 1966).
Regarding Claim 11, the combination of Weaver and McMillan discloses the annular brush seal, wherein the circumferentially repeating pattern is a scallop (Kono – scallop pattern of 3).
The combination of Weaver and McMillan does not disclose wherein the circumferentially repeating pattern is substantially tetrahedral.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention, since a change in the shape of a prior art device is a design consideration within the skill of the art, to provide a required hydrodynamic lift for the seal. In re Dailey, 357 F.2d 669, 149 USPQ 47 (CCPA 1966).
Regarding Claim 12, the combination of Weaver and McMillan discloses the annular brush seal, wherein the circumferentially repeating pattern is a scallop (Kono – scallop pattern of 3).
The combination of Weaver and McMillan does not disclose wherein the circumferentially repeating pattern is substantially tetrahedral.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention, since a change in the shape of a prior art device is a design consideration within the skill of the art, to provide a required hydrodynamic lift for the seal. In re Dailey, 357 F.2d 669, 149 USPQ 47 (CCPA 1966).
Regarding Claim 13, the combination of Weaver and McMillan discloses the annular brush seal, wherein the circumferentially repeating pattern is a scallop (Kono – scallop pattern of 3).
The combination of Weaver and McMillan does not disclose wherein the circumferentially repeating pattern is substantially tetrahedral.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention, since a change in the shape of a prior art device is a design consideration within the skill of the art, to provide a required hydrodynamic lift for the seal. In re Dailey, 357 F.2d 669, 149 USPQ 47 (CCPA 1966).
Regarding Claim 14, the combination of Weaver and McMillan discloses the annular brush seal, wherein the circumferentially repeating pattern comprises a first shape directly connected to a second shape (McMillan shapes of 41 and 42 are connected and repeating).
The combination of Weaver and McMillan does not disclose wherein the circumferentially repeating pattern comprises a first substantially prismatic shape directly connected to a second substantially prismatic shape.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention, since a change in the shape of a prior art device is a design consideration within the skill of the art, to provide a required hydrodynamic lift for the seal. In re Dailey, 357 F.2d 669, 149 USPQ 47 (CCPA 1966).
Regarding Claim 15, the combination of Weaver and McMillan discloses the annular brush seal, wherein the circumferentially repeating pattern comprises a first shape directly connected to a second shape (McMillan shapes of 41 and 42 are connected and repeating).
The combination of Weaver and McMillan does not disclose wherein the circumferentially repeating pattern comprises a first substantially cuboid shape directly connected to a second substantially cuboid shape.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention, since a change in the shape of a prior art device is a design consideration within the skill of the art, to provide a required hydrodynamic lift for the seal. In re Dailey, 357 F.2d 669, 149 USPQ 47 (CCPA 1966).
Regarding Claim 16, the combination of Weaver and McMillan discloses the annular brush seal, wherein the annular brush seal comprises a first circumferentially repeating pattern that is circumferentially interleaved with a second circumferentially repeating pattern (McMillan shapes of 41 and 42 are connected and repeating).
The combination of Weaver and McMillan does not disclose wherein the first circumferentially repeating pattern and the second circumferentially repeating pattern are each selected from group consisting of a scallop, substantially pyramidal, substantially tetrahedral. substantially prismatic, and substantially cuboid.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention, since a change in the shape of a prior art device is a design consideration within the skill of the art, to provide a required hydrodynamic lift for the seal. In re Dailey, 357 F.2d 669, 149 USPQ 47 (CCPA 1966).
Regarding Claim 17, the combination of Weaver and McMillan discloses the annular brush seal, wherein the bristle pack support comprises a backing plate (Weaver 16, fig 4), the backing plate configured to mechanically support the bristle pack when the bristle pack is subjected to a pressure differential across the brush seal (Weaver 16 configured to mechanically support the bristle pack when the bristle pack is subjected to a pressure differential across the brush seal).
Regarding Claim 18, the combination of Weaver and McMillan discloses the annular brush seal, wherein the backing plate comprises at least one radially-extending groove in a surface facing the bristle pack (Weaver – groove formed by 16), the at least one radially-extending groove being configured to permit the application of a pressure force between the downstream bristles of the bristle pack and the surface facing the bristle pack (Weaver 16 configured to permit the application of a pressure force between the downstream bristles of the bristle pack and the surface facing the bristle pack).
Regarding Claim 19, the combination of Weaver and McMillan discloses the annular brush seal, wherein the at least one radially-extending groove is an annular groove in the surface of the backing plate facing the bristle pack (Weaver - annular groove formed by 16).
Regarding Claim 20, the combination of Weaver and McMillan discloses a gas turbine engine comprising the annular brush seal (Weaver Para 0001).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to L. Susmitha Koneru whose telephone number is 571.270.5333. The examiner can normally be reached from Monday-Friday, 9:00 AM-4:00 PM.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Christine Mills can be reached on 571.272.8322. The fax phone number for the organization where this application or proceeding is assigned is 571.273.8300.
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/L. SUSMITHA KONERU/Examiner, Art Unit 3675
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