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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 June 9, 2026 has been entered.
Information Disclosure Statement
The information disclosure statement (IDS) submitted on February 18, 2026 was filed after the mailing date of the Final Rejection on February 13, 2026. The submission is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
Response to Amendment
This Non-final Rejection is in response to the Amendment dated June 9, 2026 filed in response to the Final Rejection dated February 13, 2026.
The 35 U.S.C. 103 rejections in the previous Office action are withdrawn in view of the amendment made to claim 1 distinguishing the claim from the rejection. However, the claims continue to be unpatentable over the prior art under 35 U.S.C. 103 as explained below.
Response to Arguments
Applicant’s arguments, see pages 7-9, filed June 9, 2026, with respect to the rejections of the claims under 35 U.S.C. 103 have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground of rejection is made in view of German Patent Document No. DE 196 52 335 C1 by Hagen et al. as explained below.
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 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 1-4, 11-12 and 14-15 are rejected under 35 U.S.C. 103 as being unpatentable over U.S. Patent Application Publication No. US 2010/0011830 A1 by Huetter et al., hereinafter “Huetter”, in view of German Patent Document No. DE 196 52 335 C1 by Hagen et al., hereinafter “Hagen”, and further in view of U.S. Patent Application Publication No. US 2020/0282448 A1 by Rawson et al., hereinafter “Rawson”.
Regarding claim 1, Huetter discloses a method of manufacturing a pressure vessel (pressure vessel shown in Fig. 46; ¶[0092]) having a base at one end of the pressure vessel, a wall section, and a neck section which is at the opposite end of the pressure vessel from the base and has an opening (see annotations to Fig. 46 of Huetter reproduced below), wherein the method comprises the following steps:
- providing at least a first blank (workpiece 1 in Fig. 27; ¶[0076] through [0082]);
- creating the wall section from the at least first blank by flow forming to give a pressure vessel preform (the progression from Fig. 27 through 29 shows Wall Section cylindrical shape 8 being formed);
- creating the neck section from the pressure vessel preform by swivel forming to give a pressure vessel (Fig. 27 shows the Neck Section being swivel formed);
wherein the pressure vessel, after the swivel forming, is heated at least partly (¶[0092] discloses cylindrical shape 8 is heated after it has been flow-formed to close the body into the pressure vessel).
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Huetter is silent regarding the composition of workpiece 1. Therefore, Huetter does not disclose workpiece 1 consists of carbon steel containing the chemical element in % by weight as amended into claim 1.
In the same field of manufacturing pressure vessels, Hagen teaches it was known before the effective filing date of the claimed invention to use carbon steel to manufacture pressure vessels. A comparison of the chemical composition list shown in the abstract with the elements claimed in claim 1 shows Hagen teaches using carbon steel as claimed in claim 1 to make Hagen’s steel bottle pressure vessel.
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to use carbon steel as specified by Hagen as the carbon steel used in the method disclosed by Huetter in the same way Hagen teaches. A person of ordinary skill would have recognized applying the teaching of Hagen to the method disclosed by Huetter would achieve the predictable result of practicing Huetter’s disclosed method using carbon steel with the chemical composition taught by Hagen.
Huetter is also silent regarding details of the heating disclosed in paragraph [0092]. Thus Huetter also does not disclose the heating results in, from claim 1:
a temperature Ac1 at which the microstructure of the carbon steel is transformed at least partly to austenite and then cooled down at least in sections by active cooling such that the microstructure is at least partly transformed to martensite and/or bainite, and hence a tensile strength Rm of at least 1000 MPa is established at least in sections of the carbon steel of the pressure vessel.
In the same field of flow-forming steel, paragraphs [0008] through [0016] of Rawson teach it was known before the effective filing date of the claimed invention to flow-form steel (see Fig. 8; ¶[0060]) while heating the steel to transform it into austenite and then cooling it to transform it into martensite. Paragraph [0102] and Fig. 9 teaches flow-forming steel may result in tensile strength values of greater than 1,000 MPa.
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to use the heating and cooling process taught by Rawson in the method disclosed by Huetter to achieve the predictable result of Huetter’s method where the heating results in austenite and martensite transformations as taught by Rawson.
Regarding claim 2, the prior art reference combination of Huetter in view of Hagen and further in view of Rawson renders the method of claim 1 unpatentable as explained above. Huetter further discloses the creation of the pressure vessel preform is preceded by forming of a base in the at least first blank in a deep drawing step. Figs. 22 and 23 disclose a deep drawing step prior to the flow-forming steps shown in Figs. 27-32.
Regarding claim 3, the prior art reference combination of Huetter in view of Hagen and further in view of Rawson renders the method of claim 2 unpatentable as explained above. Huetter further discloses active heating is conducted at least in some regions at least one of before and/or during the creation of the pressure vessel preform and/or of the neck section. Paragraph [0056] discloses blank workpiece 1 in Fig. 27 is initially heated in furnace supply device 51 shown in Fig. 1.
Regarding claim 4, the prior art reference combination of Huetter in view of Hagen and further in view of Rawson renders the method of claim 3 unpatentable as explained above. Paragraph [0010] of Rawson teaches heating to a temperature of at least 400°C. Paragraph [0081] discloses heating of 300°C during flow-forming. It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to heat Huetter’s disclosed heating step to a temperature of at least 300°C in the same way Rawson teaches.
Regarding claim 11, Huetter discloses a pressure vessel produced by the method of claim 1 for storing pressurized fluids which is capable of being used in mobile applications. See paragraphs [0037] and [0054] and Fig. 46.
Regarding claim 12, the prior art reference combination of Huetter in view of Hagen and further in view of Rawson renders the method of claim 1 unpatentable as explained above. The chemical composition of the carbon steel listed in the abstract of Hagen teaches aluminum content of a maximum of 0.02% by weight.
Regarding claim 14, the prior art reference combination of Huetter in view of Hagen and further in view of Rawson renders the method of claim 1 unpatentable as explained above. Paragraph [0015] of Hagen further teaches molybdenum may be completely omitted from the carbon steel. Complete omission falls within the range of up to 1.0% claimed in claim 14.
Regarding claim 15, the prior art reference combination of Huetter in view of Hagen and further in view of Rawson renders the method of claim 1 unpatentable as explained above. Hagen’s silence on cobalt content of the carbon steel may reasonably be interpreted as teaching no cobalt is contained in the carbon steel composition taught.
Claims 6 and 7 are rejected under 35 U.S.C. 103 as being unpatentable over Huetter in view of Hagen and Rawson and further in view of Japanese Patent Publication No. JPS 61-123496 A by Tokura et al., hereinafter “Tokura”. Citation of Tokura is made to the EPO translation.
Regarding claim 6, the prior art reference combination of Huetter in view of Hagen and further in view of Rawson renders the method of claim 1 unpatentable as explained above. However, Huetter does not disclose a second blank consisting of an austenitic steel is provided.
In the same field of pressure vessel manufacture, Tokura teaches it was known before the effective filing date of the claimed invention to provide a second blank of austenitic steel in pressure vessel manufacture which lines the carbon steel vessel to prevent high-pressure hydrogen stored therein from corroding the carbon steel vessel. See the first eight lines of Tokura.
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to use a second blank of austenitic steel as a liner for the carbon steel pressure vessel taught by the prior art reference combination of Huetter and Rawson in the same way Tokura teaches using an austenitic steel blank as a liner for carbon steel pressure vessels. A person of ordinary skill would have recognized applying the teaching of Tokura to the method of Huetter, Hagen and Rawson would achieve the predictable result of using a second blank of austenitic steel in Huetter’s method.
Regarding claim 7, the prior art reference combination of Huetter in view of Hagen and further in view of Rawson and further in view of Tokura renders the method of claim 6 unpatentable as explained above. Tokura further teaches the austenitic steel sample S1 shown in Table 1 on page 6 of the Japanese language original provided meets the chemical elements in percentage by weight specified in claim 7. The table does not show quantities for Nitrogen, Phosphorous or Sulfur. These quantities may reasonably be interpreted as zero, thus meeting the “up to” amounts specified by claim 7 in that “up to” may include zero.
Claims 8-9 and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Huetter in view of Hagen and further in view of Rawson and Tokura and further in view of U.S. Patent Application Publication No. US 2011/0217567 A1 by Sandberg, hereinafter “Sandberg”.
Regarding claim 8, the prior art reference combination of Huetter in view of Hagen and further in view of Rawson and further in view of Tokura renders the method of claim 6 unpatentable as explained above. Sample S1 of Tokura meets all of the chemical elements in percentage by weight of claim 8 except for the 4.0 to 25% Manganese chemical element percentage.
In the same field of materials for pressure vessels, ¶[0102] of Sandberg teaches manganese contributes to the hardenability of steel and to not exceed 10.0% of manganese content to avoid brittleness of steel. It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to increase the manganese content of Tokura’s Sample S1 to within the range of 4 to 10% according to Sandberg teachings to increase the hardenability of Tokura’s Sample S1. A person of ordinary skill would have recognized increasing the manganese content of Tokura’s Sample S1 would increase its hardenability as Sandberg teaches.
Regarding claim 9, the prior art reference combination of Huetter in view of Hagen and further in view of Rawson and further in view of Tokura renders the method of claim 8 unpatentable as explained above. Tokura further teaches the austenitic steel second blank is provided simultaneously with carbon steel first blank outer layer by cladding the austenitic stainless steel to carbon steel by welding. See the first eight lines of Tokura. It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to use austenitic stainless steel clad carbon steel as the material in Huetter’s disclosed method when flow-forming the pressure vessel as explained in the rejection of claim 1 above to flow-form the two blanks.
Regarding claim 13, the prior art reference combination of Huetter in view of Hagen and further in view of Rawson and further in view of Tokura renders the method of claim 8 unpatentable as explained above. Sample S1 in Table 1 of Tokura contains zero Molybdenum thus meeting the “up to” amount specified by claim 13 in that “up to” may include zero.
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Huetter in view of Hagen, Rawson, Tokura and Sandberg and further in view of Korean Patent Publication No. KR 10-2009-0105591 A by Cho, hereinafter “Cho”. Citation of Cho is made to the EPO translation.
Regarding claim 10, the prior art reference combination of Huetter in view of Hagen, Rawson, Tokura and Sandberg renders the method of claim 8 unpatentable as explained above. The second blank taught by Tokura is in the form of austenitic stainless steel clad to the carbon steel first blank by welding. Thus the prior art reference combination of Huetter in view of Rawson, Tokura and Sandberg does not teach the second blank is provided separately as claim 10 claims.
In the same field of pressure vessel manufacture, Cho teaches it was known prior to the effective filing date of the claimed invention to provide a flow-formed metal pressure vessel liner separate from the pressure vessel’s outer layer for manufacturing composite pressure vessels where the outer layer is glass fiber reinforcement. See the next-to-the-last line of page 3 through at least the 13th line of page 4 and page 9, line 9 through at least page 10, line 9. Cho does not expressly teach a multi-layer pressure vessel with an outer layer of carbon steel and an inner separate layer of austenitic steel.
However, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to apply Cho’s technique of flow-forming a metal liner separate from the outer layer to Tokura’s teaching of using austenitic steel as a metal liner for a carbon steel outer-layered pressure vessel to achieve the predictable result of providing Tokura’s austenitic second blank as a separate flow-formed liner with an external diameter equal to or less than the internal diameter of the pressure vessel produced using Huetter’s method.
Conclusion
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/P DEREK PRESSLEY/Examiner, Art Unit 3725
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