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 Amendment
The amendment filed 12/04/2025 has been entered. Claims 1-2 are pending in this application and examined herein. Claims 1-2 are amended.
The objections to claim 2 are withdrawn in view of the amendments to claim 2.
The rejections under 35 USC 112(b) to claims 1-2 are withdrawn in view of the amendments to claims 1-2.
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 1-2 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 limitation "the aluminum liquid surface" in line 19. There is insufficient antecedent basis for this limitation in the claim.
Claim 1 recites the limitation “fully distributed in the vertical direction” in lines 14-15. The term “fully distributed in the vertical direction” is not defined by the instant specification nor does the term have a single established meaning in the art, thus the term is interpreted according to its plain meaning, however “fully distributed in the vertical direction” is ambiguous as it is unclear if e.g., it requires that inert gas has a constant concentration at each height within the melt, is merely present at each heigh within the melt.
Claims dependent upon claims rejected above, either directly or indirectly, are likewise rejected under this statute.
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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim 1 is rejected under 35 U.S.C. 103 as being unpatentable over Tong (CN 210261929 U, original document and machine translation provided with Office Action dated 09/23/2025) in view of Dong (CN 111020224 A, original document and machine translation provided herein) and Cheng et al. (CN 114438380 A, original document and machine translation provided with Office Action dated 09/23/2025).
Regarding claim 1, Tong teaches a degassing equipment for aluminum processing, where molten aluminum alloy is heated then flowed into a chamber where inert gas is introduced into the aluminum liquid by a rotor and a breathable brick, bringing impurities to the surface of the melt, refining the aluminum (i.e., a purification method of a recovered aluminum melt) [0056]. Tong teaches introducing the recovered aluminum melt into a gas permeable brick pouring ladle 1 [0056]. Tong teaches the inert gas may be nitrogen (i.e., comprising nitrogen degassing) [0056], where the degassing is performed at a bottom layer of the gas permeable brick pouring ladle 1 (Fig. 1, Fig. 3, [0043]) by a first apparatus 111 arranged on a lower portion of a gas permeable brick pouring ladle. Tong further teaches the inert gas may be argon (i.e., argon degassing) [0056], by a second apparatus 7 arranged on an upper portion of the gas permeable brick pouring ladle 1 (Fig. 1, ).
Claim 1 discloses that the purification is performed on recovered aluminum melt for an automobile hub, however this phrase presents no further limitations regarding the method itself, and is therefore a statement of intended use, and as such is of no significance to claim construction. See MPEP § 2111.02 (II).
Tong teaches gas permeable brick pouring ladle bottom layer nitrogen degassing apparatus 11 comprising gas permeable bricks 111 [0043], and an upper rotor degasser argon degassing apparatus 8 which comprises the degassing rotor 7 (Fig. 1, [0054]), however Tong does not teach wherein the first apparatus comprises three gas permeable bricks distributed at equal intervals of 120° between each other or wherein the second apparatus comprises a degassing rotor that extends into the recovered aluminum melt at a depth of 30 cm-70 cm below the aluminum liquid surface. It has long been held that rearrangement of parts of a device known in the prior art would be merely a matter of obvious engineering choice. See MPEP 2144.04 (VI) (C). As in the instant case Tong only differs from claim 1 in that the instant case comprises 3 gas permeable bricks arranged at 120° from each other and the depth of the degassing rotor is 30-70 cm, while Tong discloses no specific arrangement of gas permeable bricks or depth of the degassing rotor, a prima facie case of obviousness exists as it would have been obvious to have rearranged the gas permeable bricks and height of the degassing rotor as claimed, as doing so would not be expected to modify the operation of the device.
Tong does not teach the three gas permeable bricks cover the entire bottom of the gas permeable brick pouring ladle.
Dong teaches a degassing box for aluminum cast coils (Title), where molten aluminum enters a melt chamber 3 (Fig. 1, [0012, 0015]), and nitrogen is supplied to permeate the melt chamber 3 from a gas chamber 4 below the melt (Fig. 1, [0012, 0019]) to improve the purity of the melt [0006, 0012], thus Dong and Tong are analogous to the instant application as both are directed to degassing aluminum melts using nitrogen gas supplied from below the melt to improve its purity. Dong teaches the gas chamber 4 is covered with a transverse portion made of breathable bricks (i.e., gas permeable bricks) [0007, 0009, 0018], extends across the entire bottom of the melt chamber 3 (analogous to a gas permeable brick pouring ladle) (Fig. 1). Dong teaches nitrogen is supplied to the gas cavity 4 and permeates into the melt cavity 3 through the permeable brick and permeates into the melt cavity in the form of small bubbles (i.e., in a vertical direction) [0023], where as the permeable brick extends across the entire bottom, the nitrogen gas would intrinsically fully cover the entire bottom of the recovered aluminum melt; and would be fully distributed in the vertical direction as best can be examined in view of the rejection of claim 1 under 35 USC 112(b) above.
It has long been held that it is prima facie obvious to substitute equivalents taught by the prior art to be useful for the same purpose. See MPEP 2144.06 (II). As in the instant case Tong only differs from claim 1 in that the instant claim uses gas permeable bricks that cover the entire bottom of the gas permeable brick pouring ladle, while Tong uses a gas permeable brick 111, and Dong uses gas permeable brick that covers the entire bottom of a gas permeable brick pouring ladle, a prima facie case of obviousness exists as it would have been obvious to have substituted the gas permeable brick that covers the whole bottom of Dong into the method of Tong, as both are used to add degassing gas to the aluminum melt to purify the melt.
Tong in view of Dong does not teach a temperature of the recovered aluminum melt.
Cheng teaches a preparation method of aluminum alloy (Title), where aluminum alloy is subjected to deslagging and degassing with inert gas [0016, 0018] to purify the aluminum alloy [n0015], thus Tong and Cheng are analogous to the instant application as both are directed to methods of purifying aluminum melts by degassing with inert gas. Cheng teaches the deslagging and degassing occurs from 740-750° C [0016] and 750-760 °C [0018] and is 750-760 °C after degassing [0020] all of which lie within the claimed range. Cheng teaches the process results in improvement in melt refining, modification, and refinement [n0014], and the degassing and slag removal method results in a product with excellent mechanical properties and die-casting properties [n0015].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have performed deslagging and degassing at temperatures of 740-760 °C as taught by Cheng to the method of Tong as doing so would use temperatures for the deslagging and degassing steps associated with improved refinement of the melt and excellent mechanical and die-casting properties of the aluminum produced as taught by Cheng.
Further, because Tong is silent with respect to a suitable temperature for the recovered aluminum melt, in order to carry out the invention of Tong one of ordinary skill in the art would necessarily look to the art for a reference teaching a temperature suitable for use within the process of Tong, such as that of 740-760 °C taught by Cheng. As Tong and Cheng both relate to degassing of aluminum melts with inert gas, one of ordinary skill would be motivated to use the temperatures of Cheng.
Claim 2 is rejected under 35 U.S.C. 103 as being unpatentable over Tong in view of Dong and Cheng as applied to claim 1 above, and further in view of Cheng and Zhao et al. (CN 111676403 A, original document and machine translation provided with Office Action dated 09/23/2025).
Tong in view of Dong and Cheng as applied to claim 1 does not teach wherein the nitrogen degassing comprises two stages. Cheng further teaches a degassing at a bottom layer (analogous to a process of nitrogen degassing) is performed in two steps (i.e., two stages) [0016, 0018]. Cheng teaches in the first and second stage a gas flow rate of 1-1.3 kg/min, a gas pressure of 0.25-0.35 MPa, and a time of 15-20 minutes [0016, 0018], where the gas pressure of the second stage is within the claimed range. Cheng teaches the two stage degassing and method results in a product with excellent mechanical properties and die-casting properties [n0015].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have performed degassing in two stages as taught by Cheng in the method of Tong, as Cheng teaches such to result in a product with excellent mechanical and die-casting properties, where one of ordinary skill would recognize that further degassing of the aluminum melt would remove further impurities from the melt.
Tong teaches a gas pressure of 0.25-0.35 MPa in the first stage. This overlaps the claimed range of a gas pressure of 0.3 MPa-0.55 MPa. The overlap between the ranges taught in the prior art and recited in the claims creates a prima facie case of obviousness because the prior art indicates substantial utility over the entire range disclosed therein, including that portion of the range which also falls within the claimed range. See MPEP § 2144.05(I).
Cheng does not teach in the first stage a gas flow rate is 20 L/min-35 L/min, and a degassing time is 120-240 s, or in the second stage a nitrogen gas flow rate is 10 L/min-20 L/min and a degassing time is 180-300 s. However, it has long been held that where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation. See MPEP 2144.05 (II) A-B. In the instant case, one of ordinary skill would be motivated to use gas flows and degassing times sufficient to purify a desired quantity of aluminum to a desired degree.
Further, the mere recitation of a numerical parameter in an otherwise known process will not generally result in patentability of a claim directed to that process, absent evidence of criticality of the numerical parameter. In the instant case the numerical parameters (flow rates and degassing times) do not appear to be critical to the invention, at least for the reason they are recited solely in a dependent claim.
Tong in view of Cheng does not teach wherein the process of argon degassing is performed in two stages.
Zhao teaches a preparation method of an aluminum alloy ingot (Title), where aluminum melt is refined by a rotor degassing with argon [0024], thus Tong and Zhao are analogous to the instant application as both are directed to methods of purifying aluminum melts by degassing with inert gas using a rotor. Zhao teaches in the first stage an argon gas flow rate is 180-220 standard L/min, a rotor rotation speed is 250 rpm-350 rpm, and a degassing time is 30 minutes. Zhao teaches after the first refining, the melt is subjected to a second refining [0025], where the second refining comprises a rotor rotating degassing device, [0032, 0054] where flows comprising argon are added via a rotor in a second and a third step (i.e., a of argon degassing is performed in two stages) [0054]. Zhao teaches in the second stage an argon gas flow rate is 6 m3/h (100 L/ min) [0054]. Zhao teaches the second refining significantly reduces the hydrogen content in the melt; and performs slag removal multiple times in a static furnace and the second refining, significantly reducing the slag content in the melt [0039].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have performed further steps of rotor degassing as taught by Zhao to the method of Tong as doing so would significantly reduce the hydrogen and slag content of the melt as taught by Zhao.
Zhao does not teach wherein in a first stage, an argon gas flow rate is 30 L/min-45 L/min, a rotor rotation speed is 400 rpm-550 rpm, and a degassing time is 180-280 s or in the second stage an argon gas flow rate is 40 L/min-65 L/min, a rotor rotation speed is 300 rpm-420 rpm, and a degassing time is 200-360 s. However, it has long been held that where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation. See MPEP 2144.05 (II) A-B. In the instant case, one of ordinary skill would be motivated to use gas flows and degassing times sufficient to purify a desired quantity of aluminum to a desired degree.
Further, the mere recitation of a numerical parameter in an otherwise known process will not generally result in patentability of a claim directed to that process, absent evidence of criticality of the numerical parameter. In the instant case the numerical parameters (flow rates, rotation speeds, and degassing times) do not appear to be critical to the invention, at least for the reason they are recited solely in a dependent claim.
Thus, the disclosure of Tong in view of both Cheng and Zhao is held to establish a prima facie case of obviousness of a method as presently claimed.
Response to Arguments
Applicant's arguments filed 12/04/2025 have been fully considered with the following effect:
Applicant’s arguments, see pg. 4-7 of remarks with respect to the rejections of claims 1-2 under Tong in view of Cheng and Zhao have been fully considered and are persuasive. Therefore, the rejections have been withdrawn, however, upon further consideration, a new grounds of rejection is made in view of Dong (CN 111020224 A) as necessitated by amendment.
Regarding Applicant’s argument that none of Tong, Cheng, and Zhao discloses that the gas introduced at the lower portion and the gas introduced at the upper portion are different from each other (see pg. 7 of remarks), the Examiner respectfully disagrees. Tong teaches that either of argon or nitrogen may be used as the inert gas (Tong: [0056]), which would include embodiments where e.g., nitrogen is used for degassing at the bottom layer of the gas permeable brick pouring ladle, and argon is used for degassing at the upper portion of the gas permeable brick pouring ladle.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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 Nikolas T Pullen whose telephone number is (571)272-1995. The examiner can normally be reached Monday - Thursday: 10:00 AM - 6:00 PM EST.
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/Keith D. Hendricks/Supervisory Patent Examiner, Art Unit 1733
/NIKOLAS TAKUYA PULLEN/Examiner, Art Unit 1733