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 Objections
Claims 9 and 14 are objected to because of the following informalities:
In claim 9, “the metal substrate” should be corrected to “the substrate” to maintain consistent wording.
In claim 14, “Method” should be corrected to “A method”.
In claim 14 at line 3, “the metal substrate” should be corrected to “the substrate” to maintain consistent wording.
Appropriate correction is required.
Claim Interpretation
No claim limitations are interpreted under 112(f).
All percentages are interpreted as weight percentages according to specification ¶6.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale or otherwise available to the public before the effective filing date of the claimed invention.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claims 1-6, 10, and 14 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Abbott (US 2004/0149733) discloses a resistive heating element fabricated by thermal spray. The material is FeCrAl, e.g., 72.2% Fe, 22% Cr, and 5.8% Al. (¶20).
Regarding claim 1, Abbott discloses:
A heater, comprising:
a metal substrate (shell 102 made of nickel or copper, ¶114);
a dielectric layer (“electrically insulating layer 104 is applied to the back of the shell or a portion thereof by, for example, applying a layer of high dielectric strength porcelain,” ¶114) arranged on the substrate; and
resistive tracks (“resistive layer 106 is deposited on the electrically insulating layer, “ ¶114) arranged on the dielectric layer, wherein the resistive tracks comprise at least 60% iron and at least 10% chromium (¶20 “resistive elements of the invention may include… FeCrAl, e.g., 72.2% Fe, 22% Cr, and 5.8% Al”).
Regarding claim 2, Abbott discloses:
the resistive tracks comprise at most 30% chromium (22% chromium, ¶20).
Regarding claim 3, Abbott discloses:
the resistive tracks comprise at least 15% chromium (22% chromium, ¶20).
Regarding claim 4, Abbott discloses:
the resistive tracks comprise at least 2% aluminum (5.8% aluminum, ¶20).
Regarding claim 5, Abbott discloses:
the resistive tracks comprise at most 10% aluminum (5.8% aluminum, ¶20).
Regarding claim 6, Abbott discloses:
the resistive tracks comprise at least 3% aluminum (5.8% aluminum, ¶20).
Regarding claim 10, Abbott discloses:
the resistive tracks are covered by an electrically insulating cover layer (¶114 discloses a thermal barrier. ¶20 discloses that the thermal barrier may be zirconium oxide, which is a ceramic and an electrical insulator.).
Regarding claim 14, Abbott discloses:
Method for producing a heater, comprising:
providing a metal substrate (shell 102 made of nickel or copper, ¶114);
covering the metal substrate with a dielectric layer (“electrically insulating layer 104 is applied to the back of the shell or a portion thereof by, for example, applying a layer of high dielectric strength porcelain,” ¶114) by means of thermal spraying (¶69 “electrically insulating ceramics that may be thermally sprayed”); and
creating resistive tracks on the dielectric layer by thermal spraying (¶78 “The resistive elements and other elements of a heater of the present invention may be deposited using a thermal spray apparatus”), wherein the resistive tracks comprise at least 60% iron and at least 10% chromium (¶20 “resistive elements of the invention may include… FeCrAl, e.g., 72.2% Fe, 22% Cr, and 5.8% Al”).
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.
Claims 1-12 and 14 are rejected under 35 U.S.C. 103 as being unpatentable over Lin (US 6,222,166) in view of Metco (Material Product Data Sheet: Iron Chromium Aluminum Yttrium (FeCrAlY) Thermal Spray Powder).
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Regarding claim 1, Lin discloses:
A heater, comprising:
a metal substrate (102, aluminum or aluminum alloy, col 4 lines 36-46);
a dielectric layer (106, 99% aluminum oxide, i.e. alumina, col 4 lines 46-55) arranged on the substrate; and
resistive tracks (108, col 5 lines 24-39) arranged on the dielectric layer.
Lin discloses a precious metal (silver and palladium, col 5 lines 25-32) heating element applied by thermal spraying, but does not disclose:
the resistive tracks comprise at least 60% iron and at least 10% chromium.
Metco teaches:
Amdry 9700 thermal spray powder for applying thermally sprayed coating of FeCrAlY, which has 24 wt% chromium, 8 wt% aluminum, 0.5 wt% yttrium, and balance (approximately 67.5%) iron (p.2 §2.1). It is an alternative material to Kanthal-type materials for thermo-electric heater coils (p.1 §1.1). “When used as a material for electrical heater elements, Amdry 9700 exhibits excellent stability, with little change in resistivity over time and minimal ageing, even at higher temperatures” (p.2 §2.3). It is also cost-effective (p.2 §2.3).
COMBINATION
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the heater of Lin by replacing the expensive precious metal material with Amdry 9700 to obtain the benefit of a cost-effective material with excellent stability, little change in resistivity over time, and minimal aging.
Regarding claim 2, Lin as modified by Metco teaches:
the resistive tracks comprise at most 30% chromium (Metco: 24% chromium).
Regarding claim 3, Lin as modified by Metco teaches:
the resistive tracks comprise at least 15% chromium (Metco: 24% chromium).
Regarding claim 4, Lin as modified by Metco teaches:
the resistive tracks comprise at least 2% aluminum (Metco: 8%).
Regarding claim 5, Lin as modified by Metco teaches:
the resistive tracks comprise at most 10% aluminum (Metco: 8%).
Regarding claim 6, Lin as modified by Metco teaches:
the resistive tracks comprise at least 3% aluminum (Metco: 8%).
Regarding claim 7, Lin as modified by Metco teaches:
the resistive tracks comprise 0.5 to 3% silicon, yttrium (Metco: 0.5% yttrium) and/or manganese.
Regarding claim 8, Lin as modified by Metco teaches:
the dielectric layer comprises at least 95% aluminum oxide (Lin: col 4 lines 50-58, “alumina…purity greater than 99%”).
Regarding claim 9, Lin as modified by Metco teaches:
the metal substrate (102) is made of aluminum or an aluminum based alloy (Lin: aluminum or aluminum alloy, col 4 lines 36-46).
Regarding claim 10, Lin as modified by Metco teaches:
the resistive tracks are covered by an electrically insulating cover layer (Lin: “insulative over coat top layer 114,” col 5 lines 46-50).
Regarding claim 11, Lin as modified by Metco teaches:
the cover layer is made of silicon oxide (Lin: col 5 lines 64-66: “The over-glaze is glass based and preferably contains major components such as Si, B, O, Al, Pb, alkaline earth elements (Mg, Ca, Sr, Ba) and alkaline elements (Li, Na, K).” Silicon (Si) based glass is silicon oxide.).
Regarding claim 12, Lin as modified by Metco teaches:
the dielectric layer has a thickness of at least 0.25 mm (Lin: col 4 lines 58-61. 75-250 µm. 250 µm is 0.25 mm.).
Regarding claim 14, Lin modified as described by Metco, and for the same reasons, teaches:
Method for producing a heater, comprising:
providing a metal substrate (Lin: 102, aluminum or aluminum alloy, col 4 lines 36-46);
covering the metal substrate with a dielectric layer (Lin: 106, 99% aluminum oxide, i.e. alumina, col 4 lines 46-55) by means of thermal spraying (Lin: col 4 lines 47-48, “A thermally applied (such as plasma sprayed) dielectric layer 106”); and creating resistive tracks on the dielectric layer by thermal spraying, wherein the resistive tracks comprise at least 60% iron and at least 10% chromium (Metco: p.2 §2.1).
Claim 15 is rejected under 35 U.S.C. 103 as being unpatentable over Lin (US 6,222,166) in view of Metco (Material Product Data Sheet: Iron Chromium Aluminum Yttrium (FeCrAlY) Thermal Spray Powder) as applied to claim 14, and further in view of Wang (CN 108531849).
Regarding claim 15, Lin as modified by Metco does not teach:
the substrate is heated to a temperature of at least 150 °C before thermal spraying of the dielectric layer.
Lin teaches that the substrate is aluminum and the dielectric layer is aluminum oxide (alumina, col 4 lines 36-55).
Wang teaches:
a method related to “the field of thermal spraying” (¶2). Wang teaches applying an alumina (i.e., aluminum oxide) coating to an aluminum alloy substrate by thermal spray (plasma spray is a type of thermal spray) (¶23). Before spraying, the substrate is heated in a furnace that is 200-250 °C (¶23) to reduce “residual stress caused by the expansion difference between the substrate and coating materials, thus preventing coating cracking” (¶23).
COMBINATION
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of Lin and Metco by preheating the substrate in a furnace that is 200-250 °C before applying the alumina layer, as taught by Wang, to obtain the benefit of reducing residual stress and preventing coating cracking. Although the substrate temperature is not assumed to precisely match the furnace temperature, this step is understood to provide a surface temperature of the substrate of at least 150 °C.
Claims 1-7 and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Hajaligol (US 5,665,262) in view of Metco (Material Product Data Sheet: Iron Chromium Aluminum Yttrium (FeCrAlY) Thermal Spray Powder).
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Regarding claim 1, Hajaligol discloses:
A heater, comprising:
a metal substrate (metal substrate 300, col 11 lines 7-21);
a dielectric layer (“ceramic layer 310 is deposited on the metal tube to electrically insulate… high dielectric constant,” col 11 lines 49-65) arranged on the substrate; and
resistive tracks (“heating element 122… FeCrAlY,” col 13 line 57-col 14 line 10) arranged on the dielectric layer.
Hajaligol discloses a FeCrAlY heating element applied by thermal spraying, but is silent on the percentages, so does not explicitly disclose:
the resistive tracks comprise at least 60% iron and at least 10% chromium.
Metco teaches:
Amdry 9700 thermal spray powder for applying thermally sprayed coating of FeCrAlY, which has 24 wt% chromium, 8 wt% aluminum, 0.5 wt% yttrium, and balance (approximately 67.5%) iron (p.2 §2.1). It is an alternative material to Kanthal-type materials for thermo-electric heater coils (p.1 §1.1). “When used as a material for electrical heater elements, Amdry 9700 exhibits excellent stability, with little change in resistivity over time and minimal ageing, even at higher temperatures” (p.2 §2.3). It is also cost-effective (p.2 §2.3).
COMBINATION
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the heater of Hajaligol by using Amdry 9700 to obtain the benefit of a cost-effective material with excellent stability, little change in resistivity over time, and minimal aging.
Regarding claims 2-7, Hajaligol as modified by Metco teaches these limitations because the material of Metco teaches each limitation, as pointed out in the rejection over Lin in view of Metco.
Regarding claim 13, Hajaligol as modified by Metco teaches:
a bonding layer is arranged between the dielectric layer and the substrate (Hajaligol: col 13 lines 33-43 “a bond coat is applied… good bond interface”).
Pertinent Prior Art
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Lindskog (US 4376245) discloses a heating resistor having the composition 12-25 percent by weight Cr, 3-6 percent by weight Al, 0.01-1 percent by weight Y, the remainder being Fe and minor amounts of other substances, e.g., Si, Mn and Co, known to those skilled in the art, and the usual impurities in a total amount not exceeding 2 percent by weight (col 2 lines 10-17). The resistor “is given improved durability by adding to the resistor alloy Y, Hf, Sc or one or more lanthanides in an amount of 0.01-1 percent by weight.”
Kanthal A-1 (Kanthal A-1 Resistance Heating Wire and Resistance Wire Datasheet) is a heating wire with the following composition:
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There are various formulations of Kanthal that may have changed over time. It is known to thermally spray Kanthal to form heating elements.
Abbott906 (US 20030121906) discloses:
A heater (see Fig 4, ¶59), comprising:
a metal substrate (metal layer 350, ¶59);
a dielectric layer (¶59 “electrically and thermally insulating layer 320,” ¶37 “an electrically insulating layer (e.g., a layer including aluminum oxide, silicon dioxide, porcelain, which may or may not be roughened, epoxy, or an oxidized region of the resistive layer) between the substrate and the resistive layer;” ) arranged on the substrate; and
resistive tracks (metallic resistive layer 330, ¶59) arranged on the dielectric layer, wherein the resistive tracks comprise at least 60% iron and at least 10% chromium (¶74-¶76, “FeCrAl alloy, e.g., 72.2% Fe, 22% Cr, 5.8% Al”).
However, this is intentionally sprayed with oxidizing and other agents to form other chemical compounds.
Okamoto (JP 2003003288) discloses heater wires:
“25% chromium, 5% aluminum, 74% [iron] and other minor components”
“chromium 20%, aluminum 3.7%, Iron 75%, and other trace elements.”
“Elemma wire is made of chromium 13 to 15%, aluminum 2 to 3%, and iron 82 to 85%”
Feng (CN 107454689 A) discloses an oxidation resistant heating tube made of C 0.045%, Cr 23.45%, Al 5.36%, Co 0.30% , Zr 0.032%, Ce 0.025%, Mn 0.20%, Si 0.4% 2, P 0.015%, S 0.0010% and balance Fe.
Papirov (CA 2317566) discloses that the following iron based heating alloy has sufficient plasticity and strength to allow manufacture of a thin heating ribbon with high electrical impedance: 13-15.5% by weight chromium, 4.5-6% aluminum, 0.3-1.2% silicon, 0.2-0.6% titanium, balance iron (with impurities), i.e., at least 76.7% (p.17 lines 12-23). Papirov does not disclose thermal spraying.
McWilliam (GB 2285058) discloses a strip or ribbon heating element made of “an alloy having the following composition: Chromium 14 to 27 percent by weight Aluminium 3.5 to 6.5 percent by weight Silicon less than or equal to 1.0 percent by weight Carbon less than or equal to 0.02 percent by weight Lanthanum between 0.05 and 0.20 percent by weight Cerium less than or equal to 0.01 percent by weight the remainder being iron and impurities. Titanium is optionally present in an amount greater than or equal to five times the content of carbon and up to a maximum of 0.10 percent by weight.” McWilliam does not disclose thermal spraying.
Piccone (CA 2955893) teaches an alloy which is relatively inexpensive but still provides the required amount of heat for rapid lighting of a cigarette, is strong, and corrosion resistant to assure long operating life for the lighter filament. “a preferred composition includes 3.0 weight percent aluminum, 1.0 weight percent yttrium, 25.0 weight percent chromium and the balance iron. Piccone does not disclose thermal spraying.
McIver (US 20110089161) discloses forming a heating element by thermal spraying (arc spraying) FeCrAlY (¶138).
Kazanas (US 20170258268) discloses using FeCrAlY wire as feedstock for thermal spraying to form a heating element (¶90).
CN 103765577 A is relevant to claim 15, see ¶164, ¶166, ¶253.
Related Art
The following references are not available under 102(a)(1) or 102(a)(2), but are included here for their relevance.
Wan (CN 113073286) discloses “the metal element comprises: 15 to 25at % of chromium element; 10 to 20at % of aluminium element; 0.1 to 1.5at % of yttrium element; and the rest is iron element.” An online tool was used to convert a midrange/representative point of each atomic percent to weight percent. The layer is formed by thermal spraying (plasma spraying). The heating element offers high heating efficiency and low cost.
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Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to TOPAZ L ELLIOTT whose telephone number is (571)270-5851. The examiner can normally be reached Monday-Friday 9 a.m. - 4 p.m. EST.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Ibrahime Abraham can be reached on (571) 270-5569. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/TOPAZ L. ELLIOTT/Primary Examiner, Art Unit 3761
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