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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 3/9/26 has been entered.
Claim Objections
Claim 1 is objected to because of the following informalities: the newly added “wherein” clause sets forth a plurality of elements or steps, each element or step of the claim should be separated by a line indentation, 37 CFR 1.75(i). Appropriate correction is required.
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 1 and 3 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 1 recites “the connector body having a connection hole running through the connector body and the header connection couple”. It is unclear how the connector body can have the connecting hole running through the header connection couple. For the purposes of this examination, this limitation will be interpreted as “a connection hole running through the connector body and the header connection couple”.
The term “gradually” in claim 1 is a relative term which renders the claim indefinite. The term “gradually” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. Thus, one cannot determine the degree to which the slope must slope.
Claim 1 recites “wherein a diffusion layer is formed… on the at least one of the inner peripheral surface and the outer peripheral surface of the connector… the pure zinc is sprayed on the outer peripheral surface of the connector”. It is unclear as to how there can be the option for the diffusion layer being formed only on the inner peripheral surface when the claim requires the zinc to be sprayed on the outer peripheral surface.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1 and 3 are rejected under 35 U.S.C. 103 as being unpatentable over Kim (KR 2011-0083953 A) in view of Boyd (US 2016/0290741 A1), Minami et al. (US 2009/0260794 A1), Garcia-Juan et al. (US 2013/0037172 A1), and Jacobson et al. “Principles of Brazing”.
Regarding claim 1, Kim teaches:
A brazing method of a connector [Al pipe (110); figures 2-5] and a connection tube [Cu pipe (120)] of a heat exchanger [200], the brazing method comprising:
wherein the connector comprises a header connection couple [the end with the smaller diameter] and a connector body [larger diameter section] arranged to the header connection couple, the connector body having a connection hole running through the connector body and the header connection couple along an axial direction of the connector body [the Al pipe has a through hole along its entire length], and
wherein an end face of an end of the connector body away from the header connection couple has a slope [internal slope (112)], and the slope gradually inclines to the header connection couple from outside to inside along a radial direction of the connector body [see figures 2-3];
inserting the connection tube into the connector hole [see figures 2-3]; and
brazing the connection tube to the connector by a brazing filler metal [page 4],
wherein the connection tube made of copper [Cu pipe (120)].
Kim does not teach:
forming a diffusion layer on at least one of an inner peripheral surface and an outer peripheral surface of the connector, a corrosion potential of the diffusion layer being less than a corrosion potential of the connector;
a corrosion potential of a braze metal formed after brazing of the brazing filler metal being higher than the corrosion potential of the connector and less than a corrosion potential of the connection tube,
wherein a diffusion layer is formed through diffusion of the coating formed on the at least one of the inner peripheral surface and the outer peripheral surface of the connector,
wherein the coating is pure zinc and the pure zinc is sprayed on the outer peripheral surface of the connector by electric arc spraying and a mass of the pure zinc per unit area is 1g/m2-20g/m2,
wherein a thickness of the diffusion layer is 10 µm-200 µm,
wherein a mass concentration of zinc of the diffusion layer is 1%-10%,
wherein a maximum temperature of heating is 585-615° C, and a heating time at the maximum temperature is 1.5 minutes to 30 minutes,
wherein the brazing filler metal is an Al—Cu—Si—Ni base,
wherein the connector is made of aluminum alloy, the connector after the pure zinc spraying is heated under a protection of nitrogen, to form the diffusion layer, and the connector is cooled,
wherein the connection tube is inserted into the cooled connector;
wherein the connection tube and the connector are heated by an oxygen acetylene flame, and the connection tube are brazed by a fluoroaluminate brazing flux.
Concerning the Zn coating being applied to the Al connector:
Boyd teaches applying diffused anodal coatings to Al and shows Zn anodal coating (112) applied to the outer surface of pipe (110); 0005, 0027.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to incorporate the Boyd Zn anodal coating into Kim in order to provide a sacrificial corrosion layer.
Concerning the connector being an Al alloy:
Minami teaches using an Al alloy to make a heat exchanger; 0087.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to make the pipe from an Al alloy since it is known to make heat exchangers from Al alloys. Additionally, one of ordinary skill in the art would have been motivated to use an Al alloy since Al alloys have better physical properties than pure Al.
Concerning the coating being thermally diffused:
Note that Boyd is silent as to the method of applying the Zn anodal coating.
Minami teaches a thermally diffused Zn coating on an Al alloy to form a stable uniform sacrificial corrosion layer, wherein pure Zn is electric arc sprayed to form a coating a Zn mass of 6-12g/m2 and then heat treated at 470-620°C for 5 minutes to 10 hours under a nitrogen atmosphere; abstract, 0029, 0033-0035, 0060, 0061, 0064, 0067-0069, 0084, and 0087.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to incorporate the teachings of Minami in order to gain the benefits of a thermally diffused Zn coating.
Minami and the claims differ in that Minami does not teach the exact same ranges as recited in the instant claims.
However, one of ordinary skill in the art at the time/before the effective filing date of the invention would have considered the invention to have been obvious because the ranges taught by Minami overlap the instantly claimed ranges and therefore are considered to establish a prima facie case of obviousness. It would have been obvious to one of ordinary skill in the art to select any portion of the disclosed ranges including the instantly claimed ranges from the ranges disclosed in the prior art reference, particularly in view of In re Peterson 65 USPQ2d 1379 (CAFC 2003); In re Geisler 43 USPQ2d 1365 (Fed. Cir. 1997); In re Woodruff, 16 USPQ2d 1934 (CCPA 1976); In re Malagari, 182 USPQ 549, 553 (CCPA 1974), and MPEP 2144.05. This reasoning applies to any claim and limitation in this action where a range is being claimed.
Concerning the claimed parameters/results:
Since the prior art process/variables, i.e. the process based on the combined prior art references above, are identical to the claimed process/variables it is the examiner’s position that the prior art process will achieve any claimed result; such as diffusion layer corrosion potential, thickness, and mass concentration.
Furthermore, Minami also teaches that time and temperature are result effective variables which control the amount and depth of diffusion; 0068-0069.
Thus, adjusting the time and temperature to achieve the claimed properties is well within one’s ordinary skill in the art because these are known result effective variables, minus any unexpected results. Additionally, the examiner is assuming that the applicant is fully aware by now of Fick’s Second Law and how one of ordinary skill in the art would apply it here to get a desired diffusion layer thickness and mass concentration.
Concerning the cooled connector/tube:
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to cool the pipe after the heat treating in order to be able to further handle the pipe.
Concerning the Al-Cu-Si-Ni braze:
Jacobson teaches Al-Cu-Si-Ni brazes; Table 2.15.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to use any known braze, including those taught by Jacobson, minus any unexpected results. One would have been motivated to use these due to cost, availability, and/or familiarity.
Concerning the claimed parameters/results:
Since the prior art process/variables, i.e. the process based on the combined prior art references above, are identical to the claimed process/variables it is the examiner’s position that the prior art process will achieve any claimed result; such as the corrosion potentials between the pipes and braze metal. This reasoning applies to any claim below where a result is claimed.
Concerning the oxygen acetylene flame:
The examiner notes that oxygen acetylene flame is extremely well-known means for brazing since such torches are readily available at local welding/plumbing stores. Since the applicant did not traverse the examiner’s assertion of official notice, the examiner notes that the above well-known fact in the art statement is taken to be admitted prior art because applicant failed to traverse the examiner’s assertion of official notice.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to use any known brazing means, including oxygen acetylene flame, to braze the pipes. One would have been motivated to use oxygen acetylene flame since only one joint is being formed, oxygen acetylene flame allows the heat to be controlled to a very specific area, as opposed to a furnace, and it is an extremely well-known means for brazing.
Concerning the fluoroaluminate brazing flux:
Garcia-Juan teaches several fluoroaluminate brazing fluxes that can be used for brazing Al to Cu; 0003 and claims 3 and 17.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to incorporate the use of fluoroaluminate brazing flux as taught by Garcia-Juan in order to allow the braze to wet the joining surfaces of the Al and Cu pipes and/or because they are extremely well-known brazing fluxes that are readily available for purchase.
Regarding claim 3, Boyd does not teach:
wherein the coating and the connector are heated to form the diffusion layer.
However, this limitation is addressed in the rejection of claim 1 by the incorporation of Minami.
Response to Arguments
Applicant's arguments filed 3/9/26 have been fully considered but they are not persuasive.
The applicant argues,
“The claimed brazing method uniquely provides a synergistic brazing solution by combining an aluminum alloy connector treated with a pure zinc coating, a copper connection tube, and an Al-Cu-Si-Ni based brazing filler metal. It contributes to improved brazing performance and connection reliability. Specifically, the use of pure zinc coating on the aluminum alloy connector, in conjunction with an Al-Cu-Si-Ni based brazing filler metal and a copper connection tube, can achieve dissolution of copper into the weld during brazing so as to increase the corrosion potential of the weld metal, thereby avoiding premature pitting corrosion of the weld in a corrosive environment. This further prevents preferential corrosion of the weld metal and the consequent cracking of the uncorroded portion of the joint 10 caused by the accumulation and expansion of corrosion products at the weld, thus significantly improving the corrosion resistance life.”
Note that there is no “weld” since brazing is being performed. While the examiner appreciates that there may be some synergy resulting in some improved properties but without any data this is nothing more than opinion. The arguments made by counsel, with regards to unexpected results, cannot take the place of evidence in the record (MPEP 716.01(c)).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure; see PTO 892.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to CARLOS J GAMINO whose telephone number is (571)270-5826. The examiner can normally be reached M-F 9-6.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Keith Walker can be reached at 5712723458. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/CARLOS J GAMINO/Examiner, Art Unit 1735
/KEITH WALKER/Supervisory Patent Examiner, Art Unit 1735