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 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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 10/10/25 has been entered.
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 1 is rejected under 35 U.S.C. 103 as being unpatentable over Lou et al. (CN 112122728-A, of record) in view of Ruan et al. (CN 2222027-Y, see attached document), and further in view of Kwag (KR 20090100755-A, of record).
Regarding claim 1, Lou discloses a brazing flame control method using a flame generated from the combustion using supply of natural gas and combustion-supporting gases- air and oxygen, wherein the flow ratio of gases is controlled depending on the processing stage (abstract, Contents of Invention). Lou teaches a molar flow ratio of the fuel gas to the oxygen being 1:1 to 1:2 for a pre-heating flame, and a molar flow ratio of the fuel gas to the air being 1:10 to 1:20 for brazing/welding flame ([0007-0008], claims 2-3) - this falls within claimed ranges of 1:10 (fuel to air) and 1:1 (fuel to oxygen). In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990), MPEP 2144.05. Similar to Lou, Ruan is directed to mixed gas welding device (abstract). Ruan teaches supplying a combustible fuel gas 1, combustion-supporting gas A (oxygen) and combustion-supporting gas B (air), wherein a flow controller 9 adjusts the oxygen and air flow ratio supplied to welding nozzle 5/6 (see fig. 1, claims 1-3). Given teachings of Lou & Ruan, artisan of ordinary skill would recognize that both air and oxygen are helpful for combustion assistance during flame joining. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to select recited molar flow ratios in the method of Lou in order to ensure efficient combustion and produce necessary flame for brazing.
Lou or Ruan is silent concerning joining copper to aluminum. However, such practice is known in the art. Kwag discloses automatic brazing apparatus for various units such as air conditioners, refrigeration devices, automobiles and building supplies (pg. 3), wherein the brazing apparatus includes control panel 120, fuel gas supply device 79 (e.g. acetylene, propane, natural gas), oxidants such as air or oxygen and flame torch T (figs. 1-2). Kwag teaches brazing tube and fins, including joining dissimilar metals such as copper and aluminum, which are frequently used in heat transfer applications (pg. 4). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to apply the brazing method of Lou to join copper to aluminum with a motivation to produce a required component for heat transfer unit, such as air conditioner, refrigerator or radiator unit in an automobile.
Hence, Lou as modified by Ruan and Kwag above teaches copper-aluminum brazing method and combustion flame control by adjusting the flow ratio of fuel gas, air and oxygen.
Claims 2-4 are rejected under 35 U.S.C. 103 as being unpatentable over Lou in view of Ruan & Kwag as applied to claim 1 above, and further in view of Edenfield et al. (US 2019/0160573, hereafter “Edenfield”) .
As to claims 2-4, Lou teaches that higher molar flow ratio is adopted during pre-heating compared to welding [0007-0008] and further teaches that flame temperature is controlled by controlling the molar flow ratio of the gas to air & oxygen and ensuring uniform heating [0011]. If the flame temperature is too high, then fierce heating is too centralized and not uniform, thereby causing workpiece burning [0002]. Ruan teaches supplying fuel gas and combustion-supporting gases air as well as oxygen (fig. 1). Similarly, Edenfiled (also drawn to apparatus and method for brazing) discloses an automated brazing system 400 comprising a fuel gas line and multiple oxygen/air lines 418, and a mass flow controller 480 (MFC) for providing different flow rates (fig. 4, [0044-0045, 0050]). Edenfield teaches that control of the gas flow rate determines the desired flame characteristics such as oxidizing flame, neutral or carburizing flame etc., which is a function of the oxygen to fuel gas ratio [0029, 0041, 0054]. In this manner, brazing requiring a different flame setting can be easily and readily accommodated [0051]. Given teachings of Lou & Edenfield, one skilled in the art would appreciate and understand that molar flow ratio of fuel gas to air and oxygen are variables for achieving art-recognized results of controlling flame type & temperature and providing uniform heating, and thus molar flow ratios are result-effective variables. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date to select the recited molar flow ratio(s) during preheating and brazing through process optimization, 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). Thus, flame brazing method in the combination of Lou, Ruan, Kwag & Edenfield teaches adjusting molar flow ratio of natural gas, air and oxygen to set desired flame characteristics and renders the claims obvious.
Response to Arguments
Applicant’s arguments with respect to pending claim(s) have been considered but are moot in light of new ground(s) of rejection set forth above. Specifically, current 103 rejection relies upon disclosure of Ruan, which teaches feeding all three: fuel gas (1), air (A) and oxygen (B) for mixed gas combustion (fig. 1).
Inquiry
Any inquiry concerning this communication or earlier communications from the examiner should be directed to DEVANG R PATEL whose telephone number is (571) 270-3636. The examiner can normally be reached on Monday-Friday 8am-5pm, EST.
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/DEVANG R PATEL/
Primary Examiner, AU 1735