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 .
An indication of claims free of prior art appears below.
NOTE: Applicant is cautioned against the introduction of new matter to the application, whether in the Specification or Claims. Applicant is requested to demonstrate corresponding support and explanation for any amendment.
Continued Examination Under 37 CFR 1.114
Receipt is acknowledged of a request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e) and a submission, filed on 05/26/2026.
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.
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.
Claims 1, 3-4, 16, and 18 are rejected under under 35 U.S.C. 103 as obvious over Hanff US 2875261 A in view of Eidem et al. US 5936996 A.
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Hanff US 2875261 A Fig. 1 Eidem et al. US 5936996 A Figs. 2-3
Regarding Claim 1, Hanff ‘261 teaches an electromagnetic stirrer including three or more pole members (meeting the limitation for teeth) configured to generate a magnetic field (Column 1/Lines 32-45, Fig. 1). The three or more pole members (teeth) have an end defining a tooth end face, and each tooth end face has a center point (Fig. 1).
As can be seen in Fig. 1 of Hanff ‘261, the end face for at least one of the pole members (meeting the limitation for teeth) is angled relative to the end face for at least one of the other pole members (meeting the limitation for teeth). Note that ‘zero degrees’ is an angle, and no convexity or concavity has been indicated in Claim 1. Additionally, each pole member/tooth end face is configured to be positioned adjacent to a curved furnace such that an air gap is defined between each tooth end face and the furnace.
Although Fig. 1 of Hanff ‘261 is a schematic, it exemplifies a technology known to persons of ordinary skill in the art at the time of filing the invention publicly available in 1957. Persons of ordinary skill in the art at the time of filing the invention would understand each pole member (meeting the limitation for teeth) to have a center point, and for the continuous yoke coupled with angled pole members to form a uniform air gap, with Fig. 1 being but an example. Hanff ‘261 expressly teaches e.g. at (Column 6, Lines 34-59), “In combination, a furnace adapted to contain a bath of molten metal, said furnace being lined with refractory, said furnace further having a metal shell with the bottom of said shell on the underside of said bath being substantially constructed of a non-magnetic material, a magnetomotive agitator positioned adjacent the underside of said furnace, a plurality of parallel poles extending transversely parallel to one another, a continuous longitudinally extending yoke connecting said poles, a pole winding flux thereat, a plurality of amplifying generators, each pole winding being connected to the output of one of said generators, means for driving said generators, an inductor having a plurality of angularly spaced pole pieces, a driven rotor for said inductor, said rotor having ends of opposite polarity to respectively and successively sweep past said pole pieces, means for varying the field strength of said rotor, and inductor windings associated with each of said pole pieces, said inductor windings being respectively connected to the fields of said generators, whereby magnetic flux having a relatively sharp peaked characteristic may be successively and progressively generated in said poles for movement into and through said bath of molten metal through said furnace to progressively stir the same in the course of the operation of such furnace.”
Regarding the newly amended limitations that each tooth end face is configured to be positioned adjacent to the curved sidewall of the furnace such that an air gap is defined between each tooth end face and the curved sidewall of the furnace, Hanff ‘261 does not expressly teach side wall stirring with its electromagnetic stirring device.
However, Eidem et al. ‘996 teaches side stirring molten metal within a furnace chamber having curved sidewalls (Abstract),(Figs. 2-3) and placing the stirrers in a curved configuration so as to increase stirring efficiency (Column 5 Lines 6-21).
It would have been obvious to one having ordinary skill in the art at the time of filing the invention to configure each tooth end face of the teeth in Hanff ‘261 to be positioned adjacent to a curved furnace side wall such that an air gap is defined between each tooth end face and the furnace, a distance of the air gap being equal for each tooth end face at the centre-point. One of ordinary skill in the art at the time of filing the invention would have been motivated by a desire to maximize the efficiency of the charge of the electromagnetic stirrer and provide consistency of the electromagnetic path to a furnace, to craft the teeth of the electromagnetic stirrer to have an equal distance at the centre-point of each tooth end face to a curved furnace based on the teachings of Hanff ‘261 e.g. at (Column 1 Lines 40-45). Eidem et al. ‘996 provides motivation to implement sidewall stirring with such a device shaped and configured to form a uniform air gap (Column 5 Lines 6-21). Generally, changes in shape will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such shape is critical. See MPEP 2141.01(a) I. Further, “[A] reference need not be from the same field of endeavor as the claimed invention in order to be analogous art.” Bigio, 381 F.3d at 1325, 72 USPQ2d at 1212.
One of ordinary skill in the art at the time of filing the invention would have been motivated by a desire to improve homogeneity of electromagnetic stirring, and efficiency of electromagnetic stirring of molten material within a furnace to place each tooth of an electromagnetic stirrer at an equal distance to the curved sidewall a furnace.
Regarding Claim 3, modified Hanff ‘261 teaches the limitations set forth above. Hanff ‘261 further teaches the pole members/teeth are of a conventional coil-wound magnetic material (Column 2/Lines 14-17), meeting the limitation of the instant Claim for teeth having a tooth edge around the tooth end faces.
Regarding Claim 4, modified Hanff ‘261 teaches the limitations set forth above. Hanff ‘261 further teaches at (Fig. 1) the tooth end face plane for at least one of the teeth is not in the same plane with the tooth end face plane for at least one of the other teeth, meeting the limitation of the instant Claim.
Regarding Claim 16, modified Hanff ‘261 teaches the limitations set forth above. Hanff ‘261 further teaches at (Column 5/Lines 38-54) its apparatus comprises a control system for generating current, meeting the limitation of the instant Claim.
Regarding Claim 18, modified Hanff ‘261 teaches the limitations set forth above. Hanff ‘261 further teaches an electromagnetic stirrer for stirring molten metal including three or more teeth configured to generate a magnetic field in a method of stirring (Column 1/Lines 35-44, Fig. 1). A current is applied to a first and second electrically conducting coil of the electromagnetic stirrer (Column 2/Lines 64-71). The three or more teeth have an end defining a tooth end face, are positioned relative to a curved furnace (meeting the limitation for a curved container) such that an air gap is defined between the tooth end faces and outer wall of the curved furnace (meeting the limitation for the curved container) (Fig. 1). Regarding the limitations of a first and second time, application of a pulsed current (Column 1/Lines 35-40) meets the limitation for a first and second magnetic field configuration.
Regarding the limitation that a distance of the air gap is equal for each tooth end face at the center point, Hanff ‘261 e.g. at (Fig. 1, Column 1/Lines 40-45) teaches a long-standing practice of angling electromagnetic stirrer teeth to match the curvature of a curved furnace. Hanff ‘261 expressly teaches modifying angled electromagnetic stirrer teeth such that electromagnetic stirring is regulated (Column 5/Lines 26-37). Further, Hanff ‘261 provides motivation to form a “closely adjacent” spacing between the electromagnetic stirrer and surface of a curved furnace (Column 2/Lines 4-8). See MPEP 2144.05 II. As such, the electromagnetic stirrer of Hanff ‘261 meets the limitation of the instant claim.
Additionally, it would have been obvious to one having ordinary skill in the art at the time of filing the invention to configure each tooth end face of the teeth in Hanff ‘261 to be positioned adjacent to a curved furnace such that an air gap is defined between each tooth end face and the furnace, a distance of the air gap being equal for each tooth end face at the centre-point. Further Eidem et al. ‘996 expressly teaches arranging and configuring the sidewall of a curved furnace wall in relation to the sidewall stirrer “in order to apply a magnetic stirrer field to the molten metal with a good yieild.” (Column 5 Lines 47-53).
One of ordinary skill in the art at the time of filing the invention would have been motivated by a desire to improve the charge of the electromagnetic stirrer, the efficiency of molten metal stirring, and improve the electromagnetic path to a furnace to craft the teeth of the electromagnetic stirrer to have an equal distance at the centre-point of each tooth end face to a curved furnace based on the teachings of Hanff ‘261 e.g. at (Column 1 Lines 40-45) and Eidem et al. ‘996 e.g. at (Column 5 Lines 47-53). One of ordinary skill in the art at the time of filing the invention would have been motivated by a desire to improve homogeneity of electromagnetic stirring, and efficiency of electromagnetic stirring of molten material within a furnace to place each tooth of an electromagnetic stirrer at an equal distance to the surface of a curved furnace.
Such an evening of the magnetic stirrer teeth end faces to the curvature of a furnace sidewall constitutes a simple change in shape. Generally, changes in shape will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such shape is critical. See MPEP 2141.01(a) I. Further, “[A] reference need not be from the same field of endeavor as the claimed invention in order to be analogous art.” Bigio, 381 F.3d at 1325, 72 USPQ2d at 1212.
Claims 6-9 are rejected under 35 U.S.C. 103 as being unpatentable over Hanff US 2875261 A in view of Eidem et al. US 5936996 A as applied to Claims 1, 3-4, 16, and 18 above, further in view of Folgero et al. US 3200185 A.
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Folgero et al. US 3200185 A, Figs. 1-2
Regarding Claim 6, modified Hanff ‘261 teaches the limitations set forth above. Hanff ‘261 further teaches at (Column 2/Lines 4-11, Fig. 1) its electromagnetic stirrer teeth extend perpendicular to a connecting yoke (meeting the limitation for a base connection).
Hanff ‘261 does not expressly teach one or more of the teeth having a greater length than one or more of the other teeth.
However, Folgero et al. ‘185 teaches an electromagnetic stirrer having teeth with varying lengths aligned with the curvature of a curved furnace (claim 1, Fig. 1). Folgero et al. ‘185 teaches at (Fig. 2) electromagnetic stirrer teeth extend perpendicular from a base connection, one or more of the teeth having a greater length than one or more of the other teeth, meeting the limitation of the instant Claim. Folgero et al. ‘185 further teaches at (Column 1 Lines 49-52) “The teeth of magnetic material and including parts 20 and 21 are brought forward to a narrow air gap between the stirrer 12 and the furnace bottom or side.”
Based on the teachings of Folgero et al. ‘185 at (claim 1, Figs. 1-2), it would have been obvious to one having ordinary skill in the art at the time of filing the invention that the perpendicularly extended teeth of Hanff ‘261 may be formed at different lengths to be brought into alignment to form a more narrow air gap and match the curvature of the furnace for which it electromagnetically stirs. The stirrer of Hanff ‘261 modified with the sidewall stirring position of Eidem et al. ‘996 and the varying lengths taught in Folgero et al. ‘185 meets the limitations of the instant Claim.
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Examiner Diagram 1 showing electromagnetic stirrer teeth arrangement in relation to a curved furnace surface.
Regarding Claims 7-9, Hanff ‘261 modified by Eidem et al. ‘996 and Folgero et al. ‘185 teaches the limitations set forth above. Folgero et al. ‘185 teaches at (Fig. 2) electromagnetic stirrer teeth having teeth of varying lengths comporting with the surface curvature of a curved furnace.
It would have been obvious to one having ordinary skill in the art at the time of filing the invention to position an outermost tooth on one side of the three or more teeth that has a length greater than, shorter than, or the same as one or more of the other teeth in order to improve the electromagnetic path to the furnace based on the teachings of Folgero et al. ‘185 at (Column 1/Lines 58-64). See Examiner Diagram 1 above. As seen in the diagram, one of ordinary skill in the art at the time of filing the invention would understand that in order to form a uniform air gap between electromagnetic stirring teeth and a convex surface, the teeth on the ends would be shorter or longer than the teeth in the middle of such an arrangement based upon the concavity or convexity of the surface. Such changes would constitute changes in shape obvious to persons of ordinary skill in the art at the time of filing the invention. Generally, changes in shape will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such shape is critical. See MPEP 2141.01 IV. A, B, VI A, B, C.
Claims 11-12 are rejected under 35 U.S.C. 103 as being unpatentable over in view of Eidem et al. US 5936996 A as applied to Claims 1, 3-4, 16, and 18 above, further in view of NPL Peel et al.
Regarding Claims 11-12 modified Hanff ‘261 teaches the limitations set forth above. Hanff ‘261 does not expressly teach the measurement of its air gap.
However, NPL Peel et al. teaches improvements to the effectiveness of electromagnetic stirring devices for creating magnetic flux within a furnace and teaches a 10mm (1cm) air gap between an inductor stirrer and the furnace surface (Fig. 2, Installation, 1195).
It would have been obvious to one having ordinary skill in the art at the time of filing the invention to minimize the distance between a magnetic device and its target surface in order to improve the magnetic effect and to unify the air gap created by an electromagnetic stirrer in relation to a furnace surface in order to improve magnetic flux and improve the efficiency of stirring of molten material within the furnace. One having ordinary skill in the art at the time of filing the invention would have looked to the art for a suitable narrow air gap between the electromagnetic stirrer and furnace to seek the teachings of NPL Peel et al. and form a 1cm air gap. The 1cm air gap lies within the range of the instant Claims. In cases where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990).
Further, minimizing a non-zero air gap constitutes routine optimization as both Hanff ‘261 and NPL Peel et al. provide motivation to minimize the air gap and form a “closely adjacent” “narrow” spacing between the electromagnetic stirrer and furnace surface. See MPEP 2144.05 II.
It is noted here again that Applicant’s claim is to an electromagnetic stirrer, not to a curved furnace. Though an ‘air gap’ is a term of art, two points are needed to define a distance and only one point has been established. The limitations regarding position adjacent to a curved furnace is recited as intended use in Claim 1. As such, the electromagnetic stirrer of Hanff ‘261 meets the limitation of the instant claims 112-12 and it would have been obvious to one of ordinary skill in the art at the time of filing the invention to modify Hanff’261 by providing a 1 cm spacing between the stirrer of Hanff ‘261 and the surface of a curved furnace. See Hanff ‘261 e.g. at (Column 2/Lines 4-8).
Claims Free of Prior Art
Regarding Claims 2 and 13-14, Hanff ‘261 teaches the limitations set forth above. The center point for each tooth end face in Hanff ‘261 lies along a first arc that is concentric with a second arc defined by a perimeter of a furnace (Fig. 1). While Eidem et al. ‘996 provides sufficient motivation to persons of ordinary skill in the art at the time of filing the invention to shape the electromagnetic stirring device of Hanff’261 around the curved sidewall of a furnace that is “essentially circular” (Column 4 Lines 22-24), Hannff ‘261 and Eidem et al. ‘996 do not teach or suggest forming concavity within the stirring teeth end face. Therefore, these claims are presently free of prior art. Additional search and consideration would be required upon incorporation of these limitations into the independent claims.
Double Patenting
The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969).
A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b).
The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13.
The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The actual filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/apply/applying-online/eterminal-disclaimer.
Claims 1-4, 6-9, 11-14, 16, and 18 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-17 of U.S. Patent No.11,549,755 B2. Although the claims at issue are not identical, they are not patentably distinct from each other because they overlap and encompass the limitations of the instant claims. U.S. Patent NO. 11,549,755 B2 teaches an electromagnetic stirrer having a plurality of curved stays configured to match the curvature of a curved container wall with a less than 10 cm air gap. These claims overlap the limitations of each of the instant claims.
Response to Arguments
Applicant's arguments filed 05/26/2026 have been fully considered but they are not persuasive as to Claims 1, 3-4, 6-9, 12, 14, and 18.
Applicant’s claims now include a furnace having a curved sidewall, establishing the air gap as the space between each tooth end face and the curved sidewall surface of the furnace (AG, Instant Fig. 2). Applicant argues Hanff ‘261 does not teach uniform air gaps to improve homogeneity. However, the Hanff ‘261 teaching on individualized flux is specific to the individual teeth of its stirrer, and does not impact the shape or position of its stirrer, particularly the stirrer teeth. A uniform gap is clearly and visibly indicated in Hanff’ 261 Figure 1.
Hanff ‘261 actually states at (Column 2 Lines 38-44) “Thus, diverter 25 for the respective stirrer pole members 1 and 5 may be utilized to provide flux of somewhat lesser magnitude for shallower marginal edge portions of bath 11 relative to the flux issuing from the pole members 2 and 4 inclusive nearer to deeper portions of bath 11, for balance in the desired stirring (emphasis added).” This teaching, to persons of ordinary skill in the art of electromagnetic stirring at the time of filing the invention only further supports balancing the applied magnetic field in order to engender uniformity in the flowing of molten metal within a furnace. As set forth above, Eidem et al. ‘996 teaches side stirring molten metal within a furnace chamber having curved sidewalls (Abstract),(Figs. 2-3) and placing the stirrers in a curved configuration so as to increase stirring efficiency (Column 5 Lines 6-21).
It would have been obvious to one having ordinary skill in the art at the time of filing the invention to configure each tooth end face of the teeth in Hanff ‘261 to be positioned adjacent to a curved furnace side wall such that an air gap is defined between each tooth end face and the furnace, a distance of the air gap being equal for each tooth end face at the centre-point. One of ordinary skill in the art at the time of filing the invention would have been motivated by a desire to maximize the efficiency of the charge of the electromagnetic stirrer and provide consistency of the electromagnetic path to a furnace, to craft the teeth of the electromagnetic stirrer to have an equal distance at the centre-point of each tooth end face to a curved furnace based on the teachings of Hanff ‘261 e.g. at (Column 1 Lines 40-45). Hanff ‘261 teaches curved bottom wall stirring but Eidem et al. ‘996 provides motivation to implement curved sidewall stirring with such a device shaped and configured to form a uniform air gap (Column 5 Lines 6-21). Generally, changes in shape will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such shape is critical. See MPEP 2141.01(a) I. Further, “[A] reference need not be from the same field of endeavor as the claimed invention in order to be analogous art.” Bigio, 381 F.3d at 1325, 72 USPQ2d at 1212. Nonetheless, as set forth above, Hannff ‘261 and Eidem et al. ‘996 do not teach or suggest forming concavity within the stirring teeth end face. Therefore, these claims are presently free of prior art. Additional search and consideration would be required upon incorporation of these limitations into the independent claims.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
DE 3309498 A1 teaches forming an electromagnetic stirrer to have the same shape as a curved furnace base to ensure a constant air gap.
WO 1990003544 A1 teaches asymmetric sidewall stirring within a molten metal bath in order to create a homogenized melt pool.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MORIAH S. SMOOT whose telephone number is (571)272-2634. The examiner can normally be reached M-F 8:30am - 5pm EDT.
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/Keith D. Hendricks/Supervisory Patent Examiner, Art Unit 1733
/M.S.S./Examiner, Art Unit 1733
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