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 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(s) 20-22, 25-33, 35, 38-41 and 43 are rejected under 35 U.S.C. 103 as being unpatentable over APA (admitted prior art, including AT508622A1) in view of Kong (CN108067706A), Sakai (US2021/0094113A1) and Yamamoto (US4493733).
Regarding claims 20, 41 and 43, in para. [0003]-[0004], the present specification discloses it is known in the art to manufacture a winding head support for a rotor for an electrical machine, the winding head support comprising one or more rings with an inner diameter of up to approximately 6 m (i.e. more than 4 m). The winding head supports from the prior art are formed from non-magnetizable steel and using processes such as forging and rolling. Though not explicitly mentioned in [0003]-[0004], it is understood an electrical machine having a rotor also necessarily includes a stator. The specification lists AT508622A1 as an example of a prior art winding head support, which is thereby part of the admitted prior art.
APA does not disclose forming winding head supports using an additive manufacturing process.
Kong discusses in the background technique section (see [0004]-[0005]) the heavy equipment industry, in which large workpieces are formed by techniques such as casting and forging, supplemented by final machining. One disadvantage of these conventional techniques is that they have a long production cycle, such that it is “difficult to meet the schedule requirements for rapid development and mass production of new products” (see [0004]). Kong discloses an alternative to these conventional techniques, involving manufacturing of large workpieces (see [0005]) using wire arc welding, whereby a workpiece is built up by welding multiple layers of a metal arranged on top of one another such that the layers are connected in a materially bonded manner. See [0008] and [0031]. See Fig. 2. See [0078].
Regarding claims 21 and 22, Kong discloses a carrier element 1 that rotates about a rotation axis (see [0078]).
Regarding claim 25, Kong teaches using a shielding gas (see [0046]) in order to prevent oxide layers from forming.
Regarding claim 32, Kong teaches cooling of an already-formed portion (see [0069] and [0071]).
Regarding claim 33, Kong shows cooling modules 9 and 10 which can be inside the workpiece and substrate 1 (which is thermally bonded to the workpiece). Kong does not explicitly disclose cooling using a fluid, but since these cooling modules are not in contact with the workpiece it is readily apparent they cool by means of a fluid cooler than the formed portion (otherwise it would effect heating) to effect the forced cooling ([0060]). In addition, it is readily apparent the gas surrounding the workpiece is cooler than the workpiece, thereby also effecting some degree of cooling with fluid.
Regarding claim 35, Kong teaches the workpiece being arranged on a cooled platform (1; see [0067] and [0069]).
Regarding claim 38, after the additive manufacturing process is carried out to deposit metal, according to [0071], “[t]he high-temperature molten pool heat-treats the next layer of printed metal layer by layer. After self-tempering heat treatment, the grains become finer and the structure becomes more stable.”
Regarding claim 40, Kong teaches machining after manufacturing the workpiece (see [0042]).
In view of the teachings of Kong, one of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to utilize an apparatus as that taught by Kong to alternatively form a winding head support for a rotor, as taught by APA, through additive manufacturing as a replacement of the conventional forging and rolling technique. One of ordinary skill in the art before the effective filing date of the claimed invention would have been motivated to do so for the advantageous shorter production cycle enabled by the additive manufacturing technique.
Regarding the limitation “at least one of the one or more rings is configured to be shrunk onto another of the one or more rings” in claim 41, “shrinking” is understood in the art to refer to heat-shrinking, whereby the ring is heated to increase its diameter, followed by cooling in place, thereby shrinking the ring onto the desired structural element. See [0066] of translation of AT508622A1. Whether a ring is manufactured by the process of Kong or by the traditional casting and forging, one of ordinary skill in the art would expect the ring to be capable of being heated so as to expand, and cooling so as to shrink. One of ordinary skill in the art would have, therefore, found it obvious that a ring produced using the process of APA as modified in view of Kong would be capable of being shrunk onto another ring.
Kong does not disclose a layer being formed in that an inner boundary and an outer boundary of the layer are first formed with a space therebetween and, subsequent to forming, the space is filled with material. Rather, each layer is formed using consecutive concentric passes, connected to each other.
Sakai is in the same field of art as Kong, related to using additive manufacturing using arc welding to deposit metal to form a workpiece. In order to avoid rework necessitated by molten metal dropped on the outer peripheral surface of the workpiece (see [0005]), Sakai teaches forming continuous blocking beads (101A, 101B in Fig. 6; see [0007] and [0073]) at the inner and outer peripheral surface of the layer. The space between the blocking beads is then filled with inner beads, using a higher current than in the step of forming the blocking beads (see Figs. 8, 10 and 11; see [0007] and [0008]).
Based on the teachings of Sakai, one of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to i) first form inner and outer boundaries, as claimed, using a lower current during arc welding, to thereby ensure the outer surface of the winding head support does not require rework caused by dropped molten metal, and ii) filling the space between the boundaries by forming additional weld beads using a higher current, for faster deposition of metal. One of ordinary skill in the art would have found it obvious to do so, as an alternative deposition pattern to that taught by Kong, to thereby create a high-quality outer surface of the winding head support while reducing the need for reworking due to dropped molten metal. Moreover, since arc welding additive manufacturing of a part by first forming the inner and outer boundaries of a layer, followed by filling the space between the boundaries, is conventional, one of ordinary skill in the art would have found predictable the results of using such a deposition pattern, and selecting this technique over the concentric sequential passes taught by Kong would have been obvious, as a choice among conventional deposition patterns.
APA also does not explicitly mention the winding head support including an austenitic structure as claimed in claim 20 and 41, nor the limitations of claims 26-31. However, Yamamoto discloses as suitable for rotor end turn retaining rings a non-magnetic steel alloy comprising “in terms of weight percentage, 0.4% or less of carbon, above 0.3% but up to 1% of nitrogen, 2% of less of silicon, 12 to 20% of chromium, 13 to 25% of manganese and the balance consisting substantially of iron, the total content of the chromium and manganese being at least 30%” (see abstract). Preferred values for carbon are 0.17 to 0.3% (col. 3, lns. 40-44), for nitrogen 0.4 to 0.8% (col. 3, lns. 53-54), for silicon 1.5% or less (col. 3, lns. 59 and 60), for chromium 15-17% (col. 4, lns. 1-5), for manganese 17-20% (col. 4, lns. 11-15), and for molybdenum 1 to 2.5% (col. 4, lns. 19-21). Preferably the total amount of chromium and manganese is no less than 32% (col. 4, lns. 22-27). Refer to table 1. Example 11 has a chromium equivalent of 15.21% Cr + 2.03% Mo + 1.5*0.43% Si = 17.89%. The nickel equivalent for example 11 is 30 * 0.2% C + 0.5 * 17.15% Mn = 14.75%. Mn is added to stabilize the austenitic structure (see col. 4, lns. 6-15).
The steel of Yamamoto is austenitic type stainless steel, as discussed above. As noted in [0071] of Kong, the substrate temperature being 60 - 400 °C allows for “rapid cooling of the molten pool and refine the grains”. One of ordinary skill in the art knows that rapid cooling of an austenitic type steel results in forming an austenitic structure.
Regarding claims 26, 27 and 29, In view of the teachings of Yamamoto, one of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to utilize a steel alloy as taught by Yamamoto to form the winding head support of modified APA, as Kong teaches various steels can be used with the disclosed additive manufacturing technique (see [0029], [0035] and [0072] and the steel alloy disclosed by Yamamoto is specifically for use in manufacturing winding head supports. Utilizing a known material for its conventional use would have had predictable results. Since the steel used in the wire arc buildup welding process includes an austenitic structure, the resulting winding head support produced in this manner would also include an austenitic structure. In view of the disclosed ranges and specific examples, it would have been obvious to one of ordinary skill in the art to select other values from the disclosed ranges. For example, regarding claim 28, starting with the alloy of Example 11 as discussed above and increasing the Cr content from 15.12% to 15.33% would result in a chromium equivalent of 18%. Regarding claim 30, starting with the composition of claim 11 and increasing the Mn content from 17.15 to 20% would result in a nickel equivalent of 16%. Regarding claim 31, starting with the composition of Example 2, increasing the carbon content to 0.4% would result in a nickel equivalent of 24% (30 * 0.4% C + 0.5 * 24.17% Mn = 24.09%).
APA also does not disclose the limitations of claim 39.
It is well known in the art to perform solution treatment (e.g., solution annealing) and a stress relief annealing of metal parts to alter the properties of the metal. As suitable for the disclosed steel alloy useful in making winding head supports, Yamamoto teaches a solution treatment at 900 to 1200 °, as well as an annealing treatment at 300 to 400 °C in order to remove stress (see col. 5, lns. 8-16).
Therefore, one of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to perform a heat treatment such as solution annealing and/or stress relief annealing on the manufactured winding head support, to ensure suitable properties of the metal workpiece.
Regarding the limitation “at least one of the one or more rings is configured to be shrunk onto another of the one or more rings” in claim 41, “shrinking” is understood in the art to refer to heat-shrinking, whereby the ring is heated to increase its diameter, followed by cooling in place, thereby shrinking the ring onto the desired structural element. See [0066] of translation of AT508622A1. Whether a ring is manufactured by the process of APA as modified in view of Kong and Yamamoto, or by the traditional casting and forging, one of ordinary skill in the art would expect the ring to be capable of being heated so as to expand, and cooling so as to shrink. One of ordinary skill in the art would have, therefore, found it obvious that a ring produced using the process of APA as modified in view of Kong and Yamamoto would be capable of being shrunk onto another ring.
Claim(s) 34, 36 and 37 are rejected under 35 U.S.C. 103 as being unpatentable over APA in view of Kong, Sakai and Yamamoto, further in view of Ou (CN106670623A).
APA as modified in view of Kong, Sakai and Yamamoto renders obvious the claimed invention, except for the limitations of claims 34, 36 and 37.
Kong shows cooling modules 9 and 10 which can be inside the workpiece or substrate 1 (see [0063]) to effect forced cooling (see [0060]). Kong does not explicitly disclose cooling using a fluid, but since these cooling modules are not in contact with the workpiece it is readily apparent they cool by means of a fluid cooler than the formed portion (otherwise it would effect heating) to effect the forced cooling ([0060]).
Ou discloses a wire arc additive manufacturing device having a feedback-controlled forced cooling system including nozzles 7, whereby cooling fluid such as air or water (see [0019]) exert forced cooling on the part being formed (see [0032]).
Therefore, one of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to select from among conventional cooling techniques for WAAM processes, utilizing, as the forced-cooling modules of modified APA, nozzles through which water exerts the forced cooling, as taught by Ou, with predictable results.
Claim(s) 42 is rejected under 35 U.S.C. 103 as being unpatentable over APA in view of Kong, Sakai and Yamamoto, further in view of Henning (US2012/0068569A1).
APA discloses it is known to manufacture winding head supports with an inner diameter of up to approximately 6 m, but does not disclose forming winding head supports with an inner diameter of more than 6 m.
Henning shows it is known in the art to manufacture large machines, with rotors having diameters of 3-7 m (see [0004]), holding rings being used as winding head supports. One of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to utilize the technique as proposed above for claim 1 to manufacture winding head supports for electrical machines with large, 7 m diameter rotors. In manufacturing the winding head support of APA by additive manufacturing as discussed above, one of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious that the technique of additive manufacturing can be scaled as needed, i.e., there is no size restriction. Moreover, large machines with 7 m diameter rotors (and implicitly winding head supports with an inner diameter over 6 m; see Fig. 1 of Henning; the annular support body 8 has an inner diameter similar to the outer diameter of the rotor) are known in the art, as taught by Henning.
Response to Arguments
Applicant’s arguments with respect to the claims have been considered but are not persuasive.
Applicant argues
“[A] person ordinarily skilled in the art would have found no discernible disclosure in the APA or LEXER that the material utilized for forming the shrinkable outer ring would have been suited for the additive material process of KONG nor any suggestion that an outer ring formed by KONG's process would be able to be shrunk onto another formed ring, as intended in LEXER (APA). As there is no apparent teaching that suggests that rings formed by KONG's additive manufacturing process would allow the intended construction of LEXER's winding support of LEXER, in which the outer ring is shrunk onto winding bars and the inner ring, Applicant submits that the Examiner's conclusion of obviousness is not supported by the art of record, as there has been no evidentiary support found in the applied art to show that rings formed according to KONG's additive material process would allow an outer ring of LEXER to be shrunk onto the winding bars and the inner ring.”
The examiner respectfully disagrees. “Shrinking” is understood in the art to refer to heat-shrinking, whereby the ring is heated to increase its diameter, followed by cooling in place, thereby shrinking the ring onto the desired structural element. See [0066] of translation of AT508622A1. Whether a ring is manufactured by the process of Kong or by the traditional casting and forging, one of ordinary skill in the art would expect the ring to be capable of being heated so as to expand, and cooling so as to shrink.
Applicant also argues:
While the Examiner has also cited YAMAMOTO for purportedly disclosing a generator retaining ring composed of a corrosion-resistant non-magnetic steel, Applicant submits that there is no apparent teaching found in the art of record to suggest that it would have been obvious to use YAMAMOTO's disclosed material with the additive material process of KONG. In this regard, YAMAMOTO clearly discloses various non-magnetic steel compositions, which are wholly distinct from the exemplary carbon steel, low alloy steel, stainless steel, aluminum-magnesium alloys or titanium alloys used in KONG.
The examiner respectfully disagrees. The steel disclosed by Yamamoto is an austenitic corrosion-resistant steel (i.e., austenitic stainless steel), disclosed by Yamamoto to be suitable for manufacturing steel retaining rings for generator rotor end turns (i.e., winding head support). An example manner of using the material is a forging process. Kong teaches a wide range of materials that can be used with the disclosed apparatus and process, such as carbon steel, low alloy steel, aluminum-magnesium alloy, titanium alloy, as well as stainless steel (i.e., corrosion-resistant steel), mentioning, among other examples, 304L and 316LN, both of which are austenitic stainless steels. Kong teaches “[t]he formed workpiece has mechanical and chemical properties comparable to traditional forging processes, and its strength, toughness, corrosion resistance and other properties are all outstanding.” See [0031]. Since Kong teaches the disclosed apparatus and process are a suitable replacement to traditional forging processes, while still obtaining outstanding properties, one of ordinary skill in the art, before the effective filing date of the claimed invention, would have expected the same result when using an austenitic stainless steel as taught by Yamamoto to manufacture a winding head support as taught by APA using the apparatus of Kong. Since Kong teaches the apparatus and process are suitable for use with various types of steel, including stainless steels and, more specifically, gives examples of austenitic stainless steels, one of ordinary skill in the art would have expected the apparatus and process of Kong to be suitable for use with an austenitic stainless steel as taught by Yamamoto.
Applicant further argues:
Applicant also notes that the Examiner has failed to identify any express or implied teaching in the art of record to suggest that KONG's additive material process would have been suited for non-magnetic steel compositions, such as described in YAMAMOTO. In this regard, YAMAMOTO also expressly discloses that, in manufacturing a retaining ring for a generator, a cast ingot is subjected to a hot forging treatment at a temperature of 900° to 1200°C and then formed into a ring shape, followed by a solution treatment at a temperature of 900° to 1200°C and quenched in water, see YAMAMOTO, col. 5, 11. 8 - 11. In contrast, KONG discloses a process in which the temperature of the printing layer is controlled to be 60 - 400°C. KONG (translation), ¶ [0071]. As the processing temperatures for the disclosed materials to so disparate, Applicant submits that a person ordinarily skilled in the art would have found no suggestion for producing the rings of LEXER using the non-magnetic steel material of YAMAMOTO in the KONG additive manufacturing process.
The examiner respectfully disagrees. Kong teaches the disclosed additive process is a suitable alternative for manufacturing steel parts that would normally be made by casting and forging. Whatever temperatures and detailed processes are used, as part of casting and forging techniques to produce the part, are not relevant, as the additive process taught by Kong is not casting and forging. One of ordinary skill in the art would have had no reason to compare the temperatures disclosed by the two references, as different manufacturing processes are used.
Applicant argues:
Moreover, Applicant submits that the Examiner has not identified any express or implied teaching found in the applied art of record that arguably suggests that, even if the non-magnetic steel material of YAMAMOTO would used in the additive manufacturing process of KONG, the resulting component, i.e., LEXER's rings, would be formed with an austenitic structure, as recited in at least independent claim 20.
The examiner respectfully disagrees. The steel of Yamamoto is austenitic type stainless steel, as discussed above. As noted in [0071] of Kong, the substrate temperature being 60 - 400 °C allows for “rapid cooling of the molten pool and refine the grains”. One of ordinary skill in the art knows that rapid cooling of an austenitic type steel results in forming an austenitic structure.
Applicant additionally argues:
Still further, Applicant submits that, even assuming, arguendo, that one were to find some arguable suggestion to produce the rings of LEXER using YAMAMOTO's non-magnetic steel compositions in KONG's additive material process, which Applicant submits one would not, the Examiner still has not identified in the art of record that the produced rings would be shrinkable in the manner intended by LEXER so that the outer ring of the winding support is shrunk onto the winding bars and inner ring.
The examiner respectfully disagrees. “Shrinking” is understood in the art to refer to heat-shrinking, whereby the ring is heated to increase its diameter, followed by cooling in place, thereby shrinking the ring onto the desired structural element. See [0066] of translation of AT508622A1. Whether a ring is manufactured from a material as in Yamamoto by the process of Kong or by the traditional casting and forging, one of ordinary skill in the art would expect the ring to be capable of being heated so as to expand, and cooling so as to shrink.
Applicant argues:
Finally, Applicant notes the inclusion of newly cited publication of SAKAI in the rejection of Applicant's claims does not avoid the erroneous modification of the APA (LEXER) purported by the Examiner in this rejection under 35 U.S.C. § 103. Applicant submits that SAKAI has been cited by the Examiner for purportedly disclosing that "a layer is formed in that an inner boundary and an outer boundary of the layer are first formed with a space therebetween and, subsequent to forming, the space is filled with material." While SAKAI discloses an additive material process for forming a tapering cylindrical part, e.g., a nozzle for a suction port or an ejection port in a rotary machine casing, in which the part is formed on a tiltable table 2 by applying inner and outer blocking beads and then inner between the blocking beads, Applicant submits that there is no apparent disclosure that the material used in SAKAI's process is a non-magnetic steel composition, as described in YAMAMOTO.
The examiner respectfully submits that whether or not the material used in Sakai’s process is a non-magnetic steel composition is not relevant. Sakai teaches an advantage of first forming the inner and outer rings, prior to adding metal to fill the space therebetween. The additive manufacturing process of Sakai is wire arc welding, i.e. the same type of additive manufacturing used in Kong. Therefore, one of ordinary skill in the art would have found the teachings of Sakai pertinent, irrespective of whether the type of steel is magnetic or non-magnetic, especially since Sakai is not limited to any specific metal, but, rather, to the technique used to deposit metal, i.e. wire arc welding.
The remaining arguments essentially amount to restating the points already discussed with respect to claim 20, and are therefore not addressed again.
Regarding claims 41-43, it should be noted that patentability of product-by-process claims depends on the product structure, not on its method of manufacture. Therefore, even if the process claims are placed in condition for allowance, the product claims 41-44 may still not be allowable. Please refer to MPEP 2113. Applicant argued claim 41 has been amended to avoid being interpreted as a product-by-process claim. However, claim 41 still recites “is formed by an additive manufacturing process, according to claim 20”. Therefore, claims 41-43 are still product-by-process claims.
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.
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/LIVIUS R. CAZAN/Primary Examiner, Art Unit 3729