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 06/24/2026 have been fully considered but they are not persuasive.
The Applicant appears to assert the argument(s), “The solution disclosed in Fadgen provides no leakage. So, if the person skilled in the art does not want to provide leakage, the person skilled in the art has no reason to provide channels 74 and 76 in accordance with the teaching of Sullivan.” and “the whole solution disclosed in Fadgen appears satisfying for avoiding sealing leakage, the whole solution disclosed in Sullivan appears satisfying for rending axisymmetric a leakage”.
The Examiner respectfully notes that Fadgen discloses,
“When the rotating machine begins to operate, friction between the seal ring 110 and runner 112 will generate heat, causing thermal expansion of these components. With matched coefficients of thermal expansion, the seal ring 110 and runner 112 will thermally expand at the same or similar rates, thus ensuring that the seal ring 110 and runner 112 will remain engaged throughout the full range of thermal transients caused by startup and operation of the rotating machine. Any radial gap between the seal ring 110 and runner 112 will similarly remain at a constant or near-constant radial dimension throughout the full range of thermal transients, thus providing a consistent leakage rate which may be preferable to leakage rates in the prior art that may vary considerably. The shaft 106 will deflect due to rotation, but the modulus of elasticity of ceramics are very large so this deflection will be very low and therefore negligible compared to thermal expansion deflections. (emphasis added) [0034]”
Which shows that there is in fact leakage between the rotating and stationary components of Fadgen, and a person of ordinary skill would understand Sullivan provides a modification to control said leakage (which results in thermal transients in the seal) to better provide more consistent sealing between a rotating component and a stationary component (via controlling said thermal transients [0047]-[0048]).
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.
Claims 1-10 are rejected under 35 U.S.C. 103 as being unpatentable over Fadgen et al. (US PGPUB 2020/0173557 A1) in view of Sullivan et al. (US PGPUB 2023/0323950 A1; Filed 04/06/2022).
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Regarding claim 1, Fadgen et al. discloses a sealing device (100) for a turbomachine ([0001]) for
providing a seal (Fig. 1) between a first housing (112) and a second housing (122), said sealing device
comprising:
a ring (Fig. 1), the ring presents an annular form (Fig. 1) extending around an axis of
revolution (A), the axis of revolution extending along a longitudinal direction (Fig. 1, the ring has a depth around A), the ring comprising a main sealing lip (116) and a secondary sealing lip (created by the interface between the ring 110 and surface 132), the main sealing lip presents an inner surface configured to be in contact radially (28) with an annular surface of a shaft (116), the secondary sealing lip presents a radial surface (created by the interface between the ring 110 and surface 132) extending perpendicularly to the longitudinal direction (Fig. 1), and
a casing (112, 123), the casing is configured to be sealingly maintained in relation to a separation wall (123), the casing comprising a cylindrical portion (121) and a radial portion (123), the cylindrical portion extends along the longitudinal direction around the ring, the radial portion presents a contact surface (132) extending perpendicularly to the longitudinal direction, the ring being biased (137) so as to apply the radial surface of the secondary sealing lip against the contact surface of the casing (Fig. 1).
However, Fadgen et al. does not disclose, "wherein the sealing device presents at least one
leakage path forming a communication between the first housing and the second housing, the at least
one leakage path extending between the secondary sealing lip and the radial surface of the casing."
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Sullivan et al. teaches in the field of sealing, a plurality of channels (74) placed on the radially
extending surfaces of a sealing ring (Fig. 1) to reduce non-axisymmetric leakage and reduce the severity of thermal asymmetry.
It would have been obvious to one of ordinary skill in the art before the effective filing date to modify the sealing ring of Fadgen et al. to have the channels of Sullivan et al. placed on the radially extending surfaces of the seal, as both references are in the same field of endeavor, and one of ordinary skill would appreciate that, "To reduce the severity of the thermal asymmetry associated with a non-axisymmetric leakage (e.g., a locally mis-seated seal ring (PSR)), features providing a relatively axisymmetric base leakage may be added around the circumference of the PSR. The term "base" is used to limit confusion with "baseline" (used to identify a prior art PSR or other PSR lacking the features). The symmetric leakage is sufficient to at least partially offset any non-axisymmetric leakage and thus reduces the severity of the thermal asymmetry.
The example PSR features are radial channels machined on both axial end faces of the ring. These channels allow leakage through the channels on the high pressure, side around the PSR, and through the channels on the low pressure side. Based on the system requirements the channels' size, shape, and location can be adjusted to maintain an adequate seal. [0047]-[0048]"
Regarding claim 2, the combination of Fadgen et al. and Sullivan et al. teach all of claim 1 as
above, wherein the ring present at least one groove (Sullivan et al.; 74) formed in the secondary sealing lip and forming the at least one leakage path (Sullivan et al. [0047]-[0048]).
Regarding claim 3, the combination of Fadgen et al. and Sullivan et al. teach all of claim 1 as
above, wherein the ring comprises a plurality of segments (Fadgen et al., [0021]), each forming a portion
of a circle (Fadgen et al., [0021]).
Regarding claim 4, the combination of Fadgen et al. and Sullivan et al. teach all of claim 1 as
above, wherein the at least one leakage path presents a depth of between 0.1 and 1 mm along the
longitudinal direction (Sullivan et al.; [0077] teaches the channel depth is 0.20mm to 1.0mm, Fig. 3).
Regarding claim 5, the combination of Fadgen et al. and Sullivan et al. teach all of claim 1 as above, wherein the at least one leakage path extends perpendicularly to the longitudinal direction (The combination of Fadgen et al. and Sullivan et al. with the channels on the radial face allow for the leakage path to extend perpendicularly to the longitudinal direction as claimed).
Regarding claim 6, the combination of Fadgen et al. and Sullivan et al. teach all of claim 1 as above.
However, the combination of Fadgen et al. and Sullivan et al. do not explicitly teach, "wherein
the at least one leakage path presents a rectangular cross-section.
Sullivan et al. further teaches "The example PSR features are radial channels machined on both
axial end faces of the ring. These channels allow leakage through the channels on the high pressure, side
around the PSR, and through the channels on the low pressure side. Based on the system requirements
the channels' size, shape, and location can be adjusted to maintain an adequate seal. [0048]" (emphasis
added)
It would have been obvious to one of ordinary skill in the at before the effective filing date to modify the combination of Fadgen et al. and Sullivan et al. to have the leakage path present a
rectangular cross-section, as the only difference between the combined prior art and the claimed
invention is the shape of the leakage path, and one of ordinary skill would appreciate that "In re Dailey,
357 F.2d 669, 149 USPQ 47 (CCPA 1966) (The court held that the configuration of the claimed disposable
plastic nursing container was a matter of choice which a person of ordinary skill in the art would have
found obvious absent persuasive evidence that the particular configuration of the claimed container was
significant.)." (MPEP 2144.04 IV. B.).
Regarding claim 7, the combination of Fadgen et al. and Sullivan et al. teach all of claim 1 as above, wherein the at least one leakage path presents a semi-circular cross-section (Sullivan et al., Fig. 1).
Regarding claim 8, the combination of Fadgen et al. and Sullivan et al. teach all of claim 1 as above.
However, the combination of Fadgen et al. and Sullivan et al. do not explicitly teach, "wherein the at least one leakage path presents a triangular cross-section.”
Sullivan et al. further teaches "The example PSR features are radial channels machined on both
axial end faces of the ring. These channels allow leakage through the channels on the high pressure, side
around the PSR, and through the channels on the low pressure side. Based on the system requirements
the channels' size, shape, and location can be adjusted to maintain an adequate seal. [0048]" (emphasis
added)
It would have been obvious to one of ordinary skill in the at before the effective filing date to
modify the combination of Fadgen et al. and Sullivan et al. to have the leakage path present a triangular
cross-section, as the only difference between the combined prior art and the claimed invention is the
shape of the leakage path, and one of ordinary skill would appreciate that "In re Dailey, 357 F.2d 669,
149 USPQ 47 (CCPA 1966) (The court held that the configuration of the claimed disposable plastic
nursing container was a matter of choice which a person of ordinary skill in the art would have found
obvious absent persuasive evidence that the particular configuration of the claimed container was
significant.)." (MPEP 2144.04 IV. B.).
Regarding claim 9, the combination of Fadgen et al. and Sullivan et al. teach all of claim 1 as
above.
However, the combination of Fadgen et al. and Sullivan et al. do not explicitly teach, "wherein the at least one leakage path presents a wavy undulated cross-section.”
Sullivan et al. further teaches "The example PSR features are radial channels machined on both
axial end faces of the ring. These channels allow leakage through the channels on the high pressure, side
around the PSR, and through the channels on the low pressure side. Based on the system requirements
the channels' size, shape, and location can be adjusted to maintain an adequate seal. [0048]" (emphasis
added)
It would have been obvious to one of ordinary skill in the at before the effective filing date to
modify the combination of Fadgen et al. and Sullivan et al. to have the leakage path present a wavy
undulated cross-section, as the only difference between the combined prior art and the claimed
invention is the shape of the leakage path, and one of ordinary skill would appreciate that "In re Dailey,
357 F.2d 669, 149 USPQ 47 (CCPA 1966) (The court held that the configuration of the claimed disposable
plastic nursing container was a matter of choice which a person of ordinary skill in the art would have
found obvious absent persuasive evidence that the particular configuration of the claimed container was
significant.)." (MPEP 2144.04 IV. B.).
Regarding claim 10, Fadgen et al. discloses a turbomachine ([0001]) comprising a first housing
(122), a second housing (112), a separation wall (123, 133, 135) extending between the first housing and
the second housing, a shaft (abstract "A seal assembly is disclosed for sealing a high pressure fluid cavity
from a low pressure fluid cavity. The cavities are at least partially disposed between a rotatable shaft
and a sump housing.") having an annular surface (indicated by the axis of symmetry A which indicates
the part is revolved and therefor annular) and a sealing device (110), wherein the sealing device comprises:
a ring (Fig. 1), the ring presents annular form (Fig. 1) extending around an axis of
revolution (A) extending along a longitudinal direction (Fig. 1, the ring has a depth around A), the ring
comprising a main sealing lip (116) and a secondary sealing lip (created by the interface between the
ring 110 and surface 132), the main sealing lip presents an inner surface configured to be in contact
radially (28) with an annular surface of a shaft (116), the secondary sealing lip presents a radial surface
(created by the interface between the ring 110 and surface 132) extending perpendicularly to the
longitudinal direction (Fig. 1), and
a casing (112, 123), the casing is configured to be sealingly maintained in relation to a separation
wall (123), the casing comprising a cylindrical portion (121) and a radial portion (123), the cylindrical
portion extends along the longitudinal direction around the ring, the radial portion presents a contact
surface (132) extending perpendicularly to the longitudinal direction, the ring being biased (137) so as to
apply the radial surface of the secondary sealing lip against the contact surface of the casing (Fig. 1).
However, Fadgen et al. does not disclose, "wherein the sealing device presents at least one
leakage path forming a communication between the first housing and the second housing, the at least
one leakage path extending between the secondary sealing lip and the radial surface of the casing."
Sullivan et al. teaches in the field of sealing, a plurality of channels (74) placed on the radially
extending surfaces of a sealing ring (Fig. 1) to reduce non-axisymmetric leakage and reduce the severity
of thermal asymmetry.
It would have been obvious to one of ordinary skill in the art before the effective filing date to
modify the sealing ring of Fadgen et al. to have the channels of Sullivan et al. placed on the radially
extending surfaces of the seal, as both references are in the same field of endeavor, and one of ordinary
skill would appreciate that, "To reduce the severity of the thermal asymmetry associated with a non-
axisymmetric leakage (e.g., a locally mis-seated seal ring (PSR)), features providing a relatively
axisymmetric base leakage may be added around the circumference of the PSR. The term "base" is used
to limit confusion with "baseline" (used to identify a prior art PSR or other PSR lacking the features). The
symmetric leakage is sufficient to at least partially offset any non-axisymmetric leakage and thus
reduces the severity of the thermal asymmetry.
The example PSR features are radial channels machined on both axial end faces of the ring.
These channels allow leakage through the channels on the high pressure, side around the PSR, and
through the channels on the low pressure side. Based on the system requirements the channels' size,
shape, and location can be adjusted to maintain an adequate seal. [0047]-[0048]"
Conclusion
THIS ACTION IS MADE FINAL. 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 RYAN C CLARK whose telephone number is (571)272-2871. The examiner can normally be reached Monday - Thursday 0730-1730, Alternate Fridays 0730-1630.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Courtney D 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.
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/RYAN C CLARK/Examiner, Art Unit 3745
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