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 .
The status of the 02/04/2026 claims, is as follows: Claims 1, 3-7, and 9 have been amended; Claims 2 and 8 have been canceled; and Claims 1, 3-7, and 9-12 are pending.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(d):
(d) REFERENCE IN DEPENDENT FORMS.—Subject to subsection (e), a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
The following is a quotation of pre-AIA 35 U.S.C. 112, fourth paragraph:
Subject to the following paragraph [i.e., the fifth paragraph of pre-AIA 35 U.S.C. 112], a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
Claims 7, and 9-12 are rejected under 35 U.S.C. 112(d) or pre-AIA 35 U.S.C. 112, 4th paragraph, as being of improper dependent form for failing to further limit the subject matter of the claim upon which it depends, or for failing to include all the limitations of the claim upon which it depends.
Claim 1 requires “the first heating element and the second heating element are different materials”. Claim 9 requires “the first heating element is constructed of a first heating element material and the second heating element is constructed of a second heating element material, the second heating element material being different than the first heating element material.” In this case, claim 1 already recites the subject matter found in claim 9.
Applicant may cancel the claim(s), amend the claim(s) to place the claim(s) in proper dependent form, rewrite the claim(s) in independent form, or present a sufficient showing that the dependent claim(s) complies with the statutory requirements.
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.
The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied 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.
Claims 1, 3-7, and 9 are rejected under 35 U.S.C. 103 as being unpatentable over JP’713 (JPH0728713, hereinafter JP’713) in view of D’Evelyn (US 20090320745)
Regarding Claim 1, JP’713 discloses a gas heater (heating element; fig. 1) comprising:
a structure (cylindrical heater body 20) that defines a gas flow path (gas) having an upstream portion and a downstream portion (annotated fig. 1);
a first heating element (heating wire 12) positioned at least partially in the upstream portion of the flow path and having a first heating element maximum temperature capability (para. 0007) (it is noted that heating wire 12 has the first heating element maximum temperature capacity, which is the operating temperature of the heating wire 12 as the implicit feature of the heating wire); and
a second heating element (heating wire 13) positioned downstream of the first heating element in the downstream portion of the gas flow path (para. 0007).
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JP’713 does not disclose:
the first heating element and the second heating element are different materials;
the first heating element and the second heating element are joined serially to each other;
the first heating element has a substantially constant resistivity with respect to temperature; and
the second heating element has a resistivity that varies with temperature according to a second-heating-element-temperature-dependent resistivity rate;
the second heating element has a higher temperature capability than the first heating element maximum temperature capability; and
the first heating element prevents current inrush to the second heating element.
However, D’Evelyn discloses one or more of the heating elements (fig. 3), made of dissimilar materials, are joined together along their length, one of the heating elements is made of low electrical resistivity from a suitable material including molybdenum or tungsten and the other heating element is made of high electrical resistivity selected from a suitable material such as Kanthal A-1 by Kanthal AB, Sweden, a nickel-chromium alloy, an Fe-Cr-Al alloy, or a chromium alloy, and others (para. 0046). D’Evelyn further discloses the heating elements may be connected in series or in parallel (para. 0049).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the second heating element of JP’713 to be made of low electrical resistivity selected from a suitable material including molybdenum or tungsten and to modify the first heating element of JP’713 to be made of high electrical resistivity such as Fe-Cr-Al alloy, in order to achieve desired heat output from the first and second heating elements having high electrical resistivity and low electrical resistivity respectively. Advantageously, the first heating element located near the support port side having the high electrical resistivity yields high heat output to heat the gas as it initially enters the fluid cylinder and the second heating element located near the discharge port having the low electrical resistivity yields relatively lower heat output compared to the first heating element to prevent overheating the gas and conserve energy. The problem to be solved by JP’713 is to reduce the temperature of the heating wire at the discharge port to prevent overheating of the wire because the wire at this location is subject to high temperature than the wire at the supply port (para. 0003-0004). By modifying the first heating element near the supply port side to have high electrical resistivity that yields high heat output and modifying the second heating element near the discharge port side to have low electrical resistivity that yields low heat output, advantageously solves the problem that JP’713 tries to solve.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the first and second heating elements of JP’713 such that they are connected in series as taught by D’Evelyn because it is conventionally known to connect the first and second heating elements in series or parallel to achieve desired heating output.
The modification would result in:
the first heating element (heating wire 12 of JP’713 made of Fe-Cr-Al alloy as taught by D’Evelyn) and the second heating element (heating wire 13 of JP’713 made of molybdenum or tungsten as taught by D’Evelyn) are different materials;
the first heating element (heating wire 12 of JP’713) and the second heating element (heating wire 13 of JP’713) are joined serially to each other (para. 0049 of D’Evelyn);
the first heating element (heating wire 12 of JP’713 made of Fe-Cr-Al alloy as taught by D’Evelyn) has a substantially constant resistivity with respect to temperature (according to para. 0018 of the published specification of the instant application, the resistive wire of the first element that is made of a ferritic iron-chromium-aluminum alloy exhibits substantially constant resistivity with respect to temperature. In this case, the prior art teaches all the structure limitation of the claim already, and when the structure recited in the reference is substantially identical to that of the claim, claimed properties or functions are presumed to be inherent, MPEP 2112.01. In this case, the heating wire 12 of JP’713 is made of Fe-Cr-Al alloy, which is the same alloy as the claimed invention, therefore the claimed properties or functions are presumed to be inherent (i.e. having the substantially constant resistivity with respect to temperature); and
the second heating element (heating wire 13 of JP’713) having a resistivity that varies with temperature according to a second-heating-element-temperature-dependent resistivity rate (it is noted the modification would result in the heating wire 13 to be made of molybdenum or tungsten whose resistivity varies with temperature, as described in para. 0004 of the published specification of the claimed invention. The prior art teaches all the structure limitation of the claim already, and when the structure recited in the reference is substantially identical to that of the claim, claimed properties or functions are presumed to be inherent, MPEP 2112.01. In this case, the heating wire 13 of JP’713 is made of molybdenum or tungsten, therefore it is expected to have claimed properties or functions (i.e. having the resistivity that varies with temperature according to a second-heating-element-temperature-dependent resistivity rate).
the second heating element has a higher temperature capability than the first heating element maximum temperature capability (it is noted the feature “the second heating element has a higher temperature capability than the first heating element maximum temperature capability” would be present because the modification would result the first heating element is made of iron-chromium-aluminum alloy and the second heating element is made of molybdenum or tungsten. According to published specification of the claimed invention para. 0008, molybdenum has the heating element maximum temperature capability that is higher than that of the iron-chromium-aluminum alloy); and
the first heating element (heating wire 12 of JP’713) prevents current inrush to the second heating element (heating wire 13 of JP’713) (it is noted the modification would result in the heating wire 12 of JP’713 made of Fe-Cr-Al alloy that exhibits the substantially constant resistance. According to para. 0032-0033 and 0018 of the published specification of the instant application, the substantially constant resistance of the first heating element prevents current inrush to the variably resistive second heating element and the first heating element is connected in series with the second heating element. The prior art teaches all the structure limitation of the claim already, and when the structure recited in the reference is substantially identical to that of the claim, claimed properties or functions are presumed to be inherent, MPEP 2112.01. In this case, the heating wire 12 of the modification (i.e. made of Fe-Cr-Al alloy) exhibits the substantially constant resistance and is connected in series with the heating wire 13 of the modification, therefore the claimed functions are presumed to be inherent (i.e. to prevent current inrush to the variably resistive second heating element 13).
Regarding Claim 3, the modification discloses the first heating element (heating wire 12 of JP’713) comprises an iron-chromium-aluminum alloy (iron-chromium-aluminum alloy) (para. 0046 of D’Evelyn).
Regarding Claim 4, the modification discloses the second heating element (heating wire 13 of JP’713) comprises molybdenum (para. 0046 of D’Evelyn).
Regarding Claim 5, the modification discloses the second heating element (heating wire 13 of JP’713) comprises tungsten (para. 0046 of D’Evelyn).
Regarding Claim 6, the modification discloses the first heating element maximum temperature capability (operating temperature of iron-chromium-aluminum alloy) is 1200 C (it is noted the modification is silent with regards to the first heating element maximum temperature capability is approximately 1200 C, however provided as evidence, attached non-patent literature to Kanthal, “Kanthal A-1 Resistance Heating Wire and Resistance Wire”, (published on 04/21/2021) discloses the iron-chromium-aluminum alloy for use at temperature up to 1400 C).
Regarding Claim 7, the modification discloses a method of operating the gas heater (para. 0004 of JP’713), comprising:
providing a flow of gas along the upstream portion and downstream portion of the gas flow path (para. 0003-0004 of JP’713);
providing electric energy to the first heating element (heating wire 12 of JP’713) to heat gas on the gas flow path in the upstream portion;
heating the second heating element (heating wire 13 of JP’713) to increase the resistivity of the second heating element (para. 0010 of JP’713) (it is noted based on rejection to claim 1, the heating wire 13 is made of tungsten and heating the tungsten would result in its resistivity increases as evidenced in attached non-patent literature to AIP Publishing, “Additive-manufactured single-piece thin multi-layer tungsten heater for an electrothermal thruster”, published on 11/09/2021), discloses tungsten-heater resistance linearly increased with an increase in temperature); and
providing electric energy to the second heating element (heating wire 13) to heat gas on the flow path in excess of the first heating element maximum temperature capability (operating temperature of the heating wire 12) (it is noted that based on rejection to claim 1, the heating wire 13 is made of tungsten and the heating wire 12 is made of iron-chromium-aluminum alloy. According to attached non-patent literature to Kanthal, “Kanthal A-1 Resistance Heating Wire and Resistance Wire”, published on 04/02/2021, the iron-chromium-aluminum alloy is for use at temperature up to 1400 C. According to attached non-patent literature to Wire Draht, “Tungsten heating elements ensure quality at up to 2,800°C”, published on 03/04/2019, tungsten is for use at temperature up to 2800 C, which is higher than 1400 C of iron-chromium-aluminum alloy).
Regarding Claim 9, the modification discloses the first heating element (heating wire 12) is constructed of a first heating element material (Fe-Cr-Al alloy of D’Evelyn) and the second heating element (heating wire 13) is constructed of a second heating element material (molybdenum or tungsten of D’Evelyn), the second heating element material being different than the first heating element material (para. 0046 of D'Evelyn).
Claims 10-11 are rejected under 35 U.S.C. 103 as being unpatentable over the modification of JP’713 (JPH0728713, hereinafter JP’713) and D’Evelyn (US 20090320745) as applied to claim 7 above, further in view of Ekstrom (US 20230213239)
Regarding Claim 10, the modification discloses substantially all of the claimed features as set forth above, except providing the flow of gas includes providing a flow of hydrogen gas.
However, Ekstrom discloses a gas heater 2, wherein the gas to be heated is a non-oxidizing gas such as hydrogen (para. 0001 and 0020).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to substitute the gas of JP’713 in view of D’Evelyn with hydrogen gas as taught by Ekstrom because it involves a simple substitution of one known element for another to obtain a predictable result, which is to heat hydrogen gas using the gas heater of JP’713.
Regarding Claim 11, the modification discloses substantially all of the claimed features as set forth above, except wherein providing the flow of gas includes providing a flow of exclusively hydrogen gas.
However, Ekstrom discloses a gas heater 2, wherein the gas to be heated is a non-oxidizing gas such as hydrogen (para. 0001 and 0020).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to substitute the gas of JP’713 in view of D’Evelyn with hydrogen gas as taught by Ekstrom, because it involves a simple substitution of one known element for another to obtain a predictable result, which is to heat hydrogen gas using the gas heater of JP’713.
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over the modification of JP’713 (JPH0728713, hereinafter JP’713) and D’Evelyn (US 20090320745) as applied to claim 7 above, further in view of Rump (US 3474229)
Regarding Claim 12, the modification discloses substantially all of the claimed features as set forth above, except providing the flow of gas includes providing a flow of exclusively hydrogen gas and nitrogen gas.
However, Rump discloses a gas heater, wherein the gas to heated is a mixture of hydrogen gas and nitrogen gas (col. 1, lines 30-34).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the gas of JP’713 in view of D’Evelyn to include the mixture of hydrogen gas and nitrogen gas as taught by Rump, in order to utilize the gas heater of JP’713 to heat the mixture of hydrogen gas and nitrogen gas for the production of ammonia.
Response to Amendment
With respect to claim objections: since amendment made to claim 7, therefore the claim objections are withdrawn.
With respect to 112b rejections: since amendments made to the claims, therefore the 112b rejections are withdrawn.
Response to Arguments
Applicant’s arguments with respect to claim 1 filed on 02/04/2026, have been fully considered but are moot in view of the new ground(s) of rejection.
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 extension fee 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 date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to BONITA KHLOK whose telephone number is (571)270-7313. The examiner can normally be reached on M-F: 9:00am-6pm.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Helena Kosanovic can be reached on (571)272-9059. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/BONITA KHLOK/Examiner, Art Unit 3761
/HELENA KOSANOVIC/Supervisory Patent Examiner, Art Unit 3761