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 § 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.
Claim(s) 1-3, 8-10, 16-18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Mitsuhashi (US20200064083A1) in view of Andrieux (“Low-Temperature Interface Reaction Between Titanium and the Eutectic Silver-Copper Brazing Alloy”) and Raybould (US20010054500A1).
Regarding claim 1, Mitsuhashi teaches a heat exchanger (see Fig. 1-3) of the plate-fin type that is configured to bring into heat exchange relationship at least one refrigerant fluid and at least one heat-originating fluid, said heat exchanger comprising: a plurality of plates (partition plates 22c) arranged parallel to each other and to a longitudinal direction (z) so as to define between said plates a plurality of passages adapted for the flow of the refrigerant fluid or the heat-originating fluid along the longitudinal direction (z); and heat exchange structures with fins (fin plates 22k) being arranged within at least part of the passages, wherein the plates and the heat exchange structures are formed wholly or partly of titanium or a titanium alloy (titanium – ¶[0048-0049] & [0056]), wherein the plates and the heat exchange structures are assembled by brazing (brazing ¶[0048-0049] & [0056])).
Mitsuhashi is silent to wherein the plates and the heat exchange structures are assembled by brazing with a brazing agent comprising a eutectic alloy, and wherein the brazing agent comprises a material other than nickel or a nickel alloy.
Andrieux teaches wherein the plates and the heat exchange structures are assembled by brazing with a brazing agent comprising a eutectic alloy and wherein the brazing agent comprises a material other than nickel or a nickel alloy (Page 40).
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified Mitsuhashi to include the eutectic brazing alloy of Andrieux, in order to provide a brazing alloy with good wetting and bonding characteristics for titanium parts (Page 40).
Mitsuhashi further teaches the heat exchange structures and the plates are brazed together by a brazing agent, however, does not teach wherein the heat exchange structures and/or the plates have in whole or in part a surface coating of a material other than nickel, or a nickel alloy, wherein the plates and heat exchange structures are coated prior to being assembled by brazing.
Raybould teaches the heat exchange structures and/or the plates having in whole or in part a surface coating of a material other than nickel, a nickel alloy or the brazing agent, in particular of a material comprising nickel (titanium aluminide coating - abstract).
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified Mitsuhashi to include the coating of Raybould, in order to prevent oxidation of the titanium (abstract).
The recitation "wherein the plates and heat exchange structures are coated prior to being assembled by brazing" is considered to be a product by process limitation. MPEP 2113 clearly states "Even though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different processes." In this instance, the product taught by Mitsuhashi as modified teaches all of the structural limitations of the claim.
Regarding claim 2, Mitsuhashi teaches the limitations of claim 1, and Mitsuhashi further teaches all the plates and heat exchange structures are made of titanium (titanium – ¶[0048-0049] & [0056]).
Regarding claim 3, Mitsuhashi teaches the limitations of claim 1, and Mitsuhashi further teaches comprising inlet or outlet manifolds (6/8) configured to introduce or discharge refrigerant or heat-originating fluid into or from the passages,
Mitsuhashi does not teach said inlet or outlet manifolds being formed wholly or partly of titanium or a titanium alloy.
Raybould teaches said inlet or outlet manifolds being formed wholly or partly of titanium or a titanium alloy (¶[0015]).
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified Mitsuhashi to include the manifolds are titanium as taught by Raybould, in order to provide manifolds having a high strength (¶[0038]).
Regarding claim 8, Mitsuhashi teaches the limitations of claim 1, and Andrieux further teaches the brazing agent comprises a eutectic copper-silver alloy (Page 40).
Regarding claim 9, Mitsuhashi teaches the limitations of claim 1, and Andrieux further teaches the brazing agent comprises exclusively a eutectic copper-silver alloy (Page 40).
Regarding claim 10, Mitsuhashi teaches the limitations of claim 1, and Mitsuhashi further teaches the heat exchange structures (fin plates 22k) are in the form of corrugated products comprising at least one corrugation with wave crests and wave bases arranged against the plates and connected alternately by fins, said fins following one another in a corrugation direction (D) of the heat exchange structures.
Regarding claim 16, Mitsuhashi teaches the limitations of claim 1, and Mitsuhashi further teaches the passages are delimited by closing bars (side bars 22h) arranged between the plates and formed wholly or partly of titanium or a titanium alloy, in particular the closing bars have a rectangular shape.
Regarding claim 17, Mitsuhashi teaches the limitations of claim 1, and Andrieux further teaches wherein the brazing agent comprises exclusively the eutectic alloy (Page 40).
Regarding claim 18, Mitsuhashi teaches the limitations of claim 1, and Mitsuhashi further teaches an air separation unit or hydrogen liquefaction plant (Mitsuhashi can be used in applications with liquefied gas - ¶[0007]) comprising at least one heat exchanger according to Claim 1 (see above), the heat exchanger comprising inlet or outlet manifolds (6/8) for distributing or discharging into or from exchanger passages liquid oxygen as refrigerant and gaseous nitrogen as heat transfer medium (this is a statement of intended use).
Claim(s) 4-6 is/are rejected under 35 U.S.C. 103 as being unpatentable over Mitsuhashi (US20200064083A1) in view of Andrieux (“Low-Temperature Interface Reaction Between Titanium and the Eutectic Silver-Copper Brazing Alloy”), Raybould (US20010054500A1) and Holtzapple (US20190301808A1).
Regarding claims 4-6, Mitsuhashi teaches the limitations of claim 1, and Mitsuhashi does not teach wherein the titanium alloy comprises at least 50% by weight of titanium;
wherein the titanium alloy comprises at least 90% by weight of titanium; wherein the titanium alloy comprises at least 95% by weight of titanium.
Holtzapple teaches wherein the titanium alloy comprises at least 50% by weight of titanium;
wherein the titanium alloy comprises at least 90% by weight of titanium; wherein the titanium alloy comprises at least 95% by weight of titanium (Grade 7, 11, 12 titanium alloys, all of which are >95 % by weight titanium).
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified Holtzapple to include one of the alloys of Holtzapple, in order to improve corrosion resistance (¶[0073]).
Claim(s) 11-15 is/are rejected under 35 U.S.C. 103 as being unpatentable over Mitsuhashi (US20200064083A1) in view of Andrieux (“Low-Temperature Interface Reaction Between Titanium and the Eutectic Silver-Copper Brazing Alloy”), Raybould (US20010054500A1) and Stephens (US20140352933A1).
Regarding claims 11-15, Mitsuhashi teaches the limitations of claim 10, and Mitsuhashi does not teach the at least one corrugation has a fin density, defined as the number of fins per unit length measured along the corrugation direction (D), of at least 30 fins per inch or fins per inch; wherein the heat exchange structures have a thickness ranging from 0.03 to 0.1 mm; wherein the passages have a height ranging from 1 to 3 mm, said height being defined as the distance between two adjacent plates measured orthogonally to the plates; wherein the plates have a thickness ranging from 0.05 to 0.4 mm; a body formed by the stack of plates, said body having a length, measured parallel to the longitudinal direction (z), less than or equal to 1 m, and/or said body having a width, measured parallel to the lateral direction (x), of less than or equal to 0.1 m, and/or said body has a height, measured orthogonally to the longitudinal (z) and lateral (x) directions, of less than 0.06 m, preferably between 0.01 and 0.05 m.
Stephens teaches the at least one corrugation has a fin density, defined as the number of fins per unit length measured along the corrugation direction (D), of at least 30 fins per inch or fins per inch (30 - ¶[0015]); wherein the heat exchange structures have a thickness ranging from 0.03 to 0.1 mm (0.076 mm - ¶[0015]); wherein the passages have a height ranging from 1 to 3 mm (2.24 mm - ¶[0015]), said height being defined as the distance between two adjacent plates measured orthogonally to the plates; wherein the plates have a thickness ranging from 0.05 to 0.4 mm (¶[0014]); a body formed by the stack of plates, said body having a length, measured parallel to the longitudinal direction (z), less than or equal to 1 m (36.6 mm - ¶[0013]).
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified Mitsuhashi to include the dimensions of Stephens, 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. MPEP 2144.05(II).
Claim(s) 19-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Mitsuhashi (US20200064083A1) in view of Andrieux (“Low-Temperature Interface Reaction Between Titanium and the Eutectic Silver-Copper Brazing Alloy”), Raybould (US20010054500A1) and Durand (US20100263405A1).
Regarding claim 19, Durand teaches an air separation unit (Fig. 1) for transferring heat from a cold source (15) to a hot source (1) via a working fluid circulating in a closed working circuit (200), the working circuit comprising in series: a substantially isothermal working fluid compression portion comprising at least two compressors (3, 5, 7) arranged in series and at least one exchanger (2) for cooling the compressed working fluid arranged at the outlet of each compressor, a substantially isobaric working fluid cooling portion (¶[0023]), a substantially isothermal working fluid expansion portion comprising at least one expansion turbine (9, 11, 13) and at least one exchanger (14) for reheating the expanded working fluid, and a substantially isobaric working fluid heating portion (¶[0023]).
Durand does not teach wherein the heat exchanger for cooling the compressed working fluid and/or the exchanger for reheating the expanded working fluid is as defined in Claim 1 and comprises inlet or outlet manifolds for distributing or discharging the compressed working fluid as a heat-generating fluid or the expanded working fluid as a refrigerant into or from passages in the exchanger.
Mitsuhashi as modified teaches wherein the heat exchanger for cooling the compressed working fluid and/or the exchanger for reheating the expanded working fluid is as defined in Claim 1 (see above) and comprises inlet or outlet manifolds (6/8) for distributing or discharging the compressed working fluid as a heat-generating fluid or the expanded working fluid as a refrigerant into or from passages in the exchanger.
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have provided a heat exchanger as taught by Mitsuhashi to an air separation system as taught by Durand, in order to provide a heat exchanger with good heat transfer efficiency (¶[0003]).
Regarding claim 20, Durand teaches a method of using wherein said at least one heat transfer fluid and/or said at least one refrigerant comprises at least one of: neon, krypton, xenon, nitrogen, argon, oxygen, hydrogen, helium, carbon monoxide, carbon dioxide, and methane (¶[0057]).
Mitsuhashi as modified teaches the heat exchanger according to Claim 1 (see above).
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have provided a heat exchanger as taught by Mitsuhashi to the method as taught by Durand, in order to provide a heat exchanger with good heat transfer efficiency (¶[0003]).
Response to Arguments
Applicant's arguments filed 6/22/2026 have been fully considered but they are not persuasive.
Applicant argues Mitsuhashi as modified, specifically by Raybould, does not teach wherein the plates and heat exchange structures are coated prior to being assembled by brazing. Examiner respectfully traverses this argument.
The structure implied by the process steps should be considered when assessing the patentability of product-by-process claims over the prior art, especially where the product can only be defined by the process steps by which the product is made, or where the manufacturing process steps would be expected to impart distinctive structural characteristics to the final product (see MPEP 2113).
In this case, while Examiner acknowledges the method by which Mitsuhashi as modified is made, is different than the process claimed, however, the ultimate product (which is being examined) is rendered obvious, as all of the structural limitations of the claim (a brazed assembly with a surface coating as claimed), implied by the process, are met.
Applicant further argues there would be no reasonable expectation of success (see remarks page 8-9).
Examiner contends that Matsuhashi is entirely silent to the temperature at which the assembly may be brazed, and Andrieux’s brazing temperature appears suitable for use with the apparatus of Matsuhashi, while affording the benefits thereof. Raybould teaches applying a coating to an already brazed assembly, and thus does not conflict with the teachings of Matsuhashi or Andrieux.
For at least the reasons stated above, Applicant’s arguments are found unpersuasive and the rejection is maintained.
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 ERIC S RUPPERT whose telephone number is (571)272-9911. The examiner can normally be reached Monday - Friday 8 am - 4 pm.
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, Len Tran can be reached at 571-272-1184. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/ERIC S RUPPERT/Primary Examiner, Art Unit 3763
