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 .
Election/Restrictions
Claims 14-16 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected Group II, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on February 16, 2026.
Claim Objections
Claims 9, 12 and 13 are objected to because of the following informalities: minor inconsistencies. Appropriate correction is required.
Claim 9 recites that “the filter element is in the form of three-dimensional rib structures” but subsequently refers to “ribs of the rib structure”. The inconsistent use of the plural expression “rib structures” and the singular expression “the rib structure” should be corrected. Applicant should clarify whether the filter element comprises a single three-dimensional rib structure or multiple three-dimensional structures and should use consistent terminology throughout the claim.
Claim 12 recites “particles having an average particle size of d50”. This expression is grammatically and technically imprecise because it combines the term “average particle size” with the particle-size designation “d50”. Applicant should clarify the intended particle-size parameter. For example, the limitation may be amended to recite “particles having a d50 particle size in the range of 63 µm to 1000 µm” or, if intended, “particles having a median particle size d50 in the range of 63 µm to 1000 µm”. The suggested wording is provided merely to illustrate possible corrections. Applicant may correct the identified informalities using other language that clearly expresses the intended subject matter without introducing new matter.
Claim 13 recites plural “open pockets” but states that the pockets are formed “in a predefined position and dimension”. The singular terms “position” and dimension” are inconsistent with the plural “pockets” and the expression “in a…dimension” is grammatically improper.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 9-13 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Regarding claim 9, the preamble recites “a filter element for flow stabilization and/or purifying a melt obtained during casting, which is passed through the filter element.” However, the body of the claim does not positively recite that the claimed filter element, rib structures, flow channels, or any other claimed component performs, is configured to perform, or is capable of performing either flow stabilization or purification of the melt. It is unclear whether the preamble merely states a nonlimiting intended use of the otherwise structurally defined filter element, or whether “flow stabilization and/or purifying” imposes a functional limitation on the claimed apparatus. Applicant is required to clarify whether the preamble is intended merely to state the intended use of the filter element or whether the filter element is required to perform one of both of the recited functions. If the functions are intended as claim limitations, applicant should positively recite the structural or functional relationship by which the claimed filter element performs the intended function or functions. Claims 10-13 are rejected due to their dependency upon claim 9.
Further, the relationship between the recited functions and the limitation that the ribs are formed with “particles made from a material, which can be used as molding material in casting technology” is also unclear. In particular, it is unclear whether the requirement that the particle material be usable as molding material in casting technology applies to the claimed filter element regardless of whether the filter is used for flow stabilization, purification of a casting melt, or both; or whether that material limitation is associated only with the alternative directed to purifying “a melt obtained during casting.” If the molding-material limitation is also intended to relate to the flow-stabilization alternative, the claim does not explain how the suitability of the particle material for use as molding material defines or contributes to the recited flow-stabilization function. The claim therefore does not clearly establish the relationship between the particle-material limitation and the alternatively recited purposes of the filter element.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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 9 and 10 are rejected under 35 U.S.C. 103 as being unpatentable over Gage (EP-3325428-B1) in view of Bell (US-20070090047-A1) and further in view of Hitchings (WO-2016144899-A1).
Regarding claim 9, Gage discloses a filter element for flow stabilization and/or purifying a melt obtained during casting, which is passed through the filter element (Gage par. [0001] and par. [0008] indicate purifying “removing impurities in a motel metal pour”), wherein the filter element is in the form of three-dimensional rib structures with openings as flow channels through which liquid melt is passed (Gage par. [0010], [0013] and [0039] “filtering molten metal”, “three-dimensional geometric cages” and “support members” function as rib structures with openings as flow channels).
Gage does not explicitly disclose that the ribs of the rib structure are formed with particles made from a material which can be used as molding material in casting technology, with a binder by which the particles are integrally bonded to one another. Gage further does not explicitly disclose that the ribs are provided on their surface with a coating of polymer resin.
Bell is directed to refractory articles, particularly filters suitable for filtering molten metal, and teaches forming such filters from refractory particles integrally bonded together by a bonding material. Specifically, Bell par. [0013] discloses “a filter Suitable for filtering molten metal comprising an open pored porous material comprising particles of refractory material embedded in and bonded together by a bonding material comprising a carbon matrix”, identifies suitable refractory particles including “Zirconia, Zircon, silica, alumina, titania, carbides … magnesia, mullite,…or mixtures comprising two or more of these” (Bell par. [0015]) and teaches that the bonding material comprises a carbon matrix which bonds the refractory particles together and in which the particles are embedded (Bell par. [0016]). Bell further teaches forming the molten-metal filter from “a mixture comprising a binder and refractory particles” (Bell par. [0020]).
Hitchings is directed to the same general field of refractory substrates and molten-metal filters, and teaches coatings for such filters. Hitching states that its invention relates to “active coatings for refractory filters and other substrates that help remove inclusions and other impurities from molten metals such as ferrous alloys.” (Hitchings par. [0001]) Hitchings teaches that a wide spectrum of ceramic-type and other molten metal filters may be coated, including reticulated ceramic foam, honeycomb and extruded lattice type filters (Hitchings par. [0002 and [0012]). Hitchings further teaches that “a thin coating of phenolic or polymer resin is applied to the target refractory substrate”, and that suitable resins include “commercially available resins used in the foundry and metal casting industry as sand-mold binding agents” (Hitchings par. [0018]). Accordingly, Hitchings teaches providing a polymer resin coating on molten metal filter surfaces corresponding to the claimed coating of polymer resin on the surfaces of the ribs.
It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to form the linear segments of Gage’s three-dimensional molten-metal filter framework from Bell’s refractory particles integrally bonded together by a bonding material. Gage and Bell are both directed to refractory filters for removing impurities from molten metal, and Gage expressly contemplates constructing its linear segments from ceramic material, while Bell teaches a bonded refractory-particle composition specifically adapted to withstand contact with and filter molten metal. Employing Bell’s bonded refractory-particle composition to form Gage’s linear segments would have predictably provided Gage’s predetermined three-dimensional filter geometry with a known heat-resistant particulate construction suitable for molten-metal filtration. It would further have been obvious to provide the surfaces of the resulting ribs with Hitching’s thin polymer-resin coating because Hitchings expressly teaches applying such coatings to refractory molten-metal filters, including lattice-type filters, to enhance the removal and retention of slag, dross, and other inclusions.
Regarding claim 10, Gage in view of Bell and further in view of Hitchings discloses or renders obvious the filter element according to claim 9, characterized in that the particles are formed predominantly of SiO2, predominantly of Al2O3, predominantly of aluminosilicate, with cerium-stabilized ZrO2 or chromite (Bell par. [0015] teaches that suitable refractory particles include “Zirconia, Zircon, silica, alumina, titania, carbides …, nitrides …, metal oxides …, magnesia, mullite, graphite, anthracite, coke, active carbon, graphite-refractory …, or mixtures comprising two or more of these” thereby teaching at least silica/SiO2, alumina/Al2O3, and mullite/aluminosilicate particle alternatives) and/or the particles are integrally bonded with a furan resin binder, a phenol resin-based binder or an inorganic binder as a binder and/or the coating is formed by a polymer resin (Bell par. [0011] further teaches an inorganic binder “borosilicate glass”; Hitchings par. [0016] teaches that suitable binders include “silica, phenolic resin, polymers, sugar, molasses, and the like” and further teaches that “a thin coating of a phenolic or polymer resin is applied to the target refractory substrate” with suitable phenolic and polymer resins thereby teaching the phenol-resin binder and polymer-resin coating alternatives).
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Gage (EP-3325428-B1 in view of Bell (US-20070090047-A1) and further in view of Hitchings (WO-2016144899-A1) as applied to claim 9 above, and further in view of Bright (US-6679758-B2).
Regarding claim 11, Gage in view of Bell and further in view of Hitchings discloses or renders obvious the filter element according to claim 9.
Gage in view of Bell and further in view of Hitchings does not explicitly disclose that a proportion of the binder is in the range of 1 vol-% to 5 vol-% in relation to the amount of integrally bonded particles.
Bright is directed to porous, fluid-permeable structures comprising refractory ceramic particles bonded together with a binding material. Bright describes its abrasive-grain agglomerates as three-dimensional structures or granules, including sintered porous composites of abrasive grain and binding material, and teaches that the “binding material is present at about 0.5 to 15 volume %, more preferably 1 to 10 volume %, and most preferably 2 to 8 volume % of the agglomerate” (Bright col. 8). Bright further teaches that the particles are joined when the binding material adheres to the grain and a plurality of grains adhere together, and states that the finished agglomerates comprise a plurality of individual abrasive grits bonded together by glass binding material at grit to grit contact points. Table 1-1 of Bright specifically reports fired agglomerates containing 3.18 vol-%, 3.13 vol-% and 3.15 vol-% binding material in Samples 1, 6, and 8 respectively, each of which falls within the claimed range of 1 vol-% to 5 vol-%. Bright explains that the volume % binding material is a percentage of the solid material within the granule after firing, and does not include the volume % porosity and reports that adequate “compaction strength was observed for all samples 1-9, indicating that the glass binding material had matured and flowed to create an effective bond among the abrasive grains within the agglomerate” (Bright col. 20).
It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to select a proportion of the bonding material in Gage-Bell-Hitchings’s bonded refractory-particle filter structure within the 1 vol-% to 5 vol-% range taught by Bright. Bell and Bright both concern porous, three-dimensional structures formed from refractory particles bonded together by a binding material, with the resulting structures permitting fluid flow through interconnected open spaces. Bright expressly identifies the amount of binding material as a variable affecting the formation and mechanical strength of the bonded particle structure and demonstrates that binding-material proportions of approximately 3.13 vol-% to 3.18 vol-% provide an effective bond among the ceramic particles. A person of ordinary skill in the art therefore would have had a reason to employ Bright’s demonstrated low binding-material proportion in Gage-Bell-Hitchings’s refractory-particle filter structure to provide sufficient particle-to-particle bonding while limiting the amount of binding material occupying the open porous structure, thereby preserving the flow passages required for molten-metal filtration. The selection would have involved applying a known binder proportion to the same recognized materials problem: bonding refractory particles into a mechanically stable, porous, fluid-permeable structure, with a reasonable expectation of success.
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Gage (EP-3325428-B1 in view of Bell (US-20070090047-A1) and further in view of Hitchings (WO-2016144899-A1) as applied to claim 9 above, and further in view of Fukuda (US-9796015-B2).
Regarding claim 12, Gage in view of Bell and further in view of Hitchings discloses or renders obvious the filter element according to claim 9.
Gage in view of Bell and further in view of Hitchings does not explicitly disclose that the particles which form the ribs have an average particle size of d50 in the range of 63 µm to 1000 µm.
Fukuda is directed to molding sand used for three-dimensional laminate molding in casting technology and therefore addresses the same type of particulate foundry material recited in claim 9. Fukuda col. 5 teaches that an artificial sand produced by a sintering method has an artificial sand produced by a sintering method, which has the average particle size of 0.5 to 2 times the average particle size of the natural silica sand, specifically of about 80 to 200 μm, is preferable in terms of handling”. Fukuda further states that “as the above average particle size, a value measured using a laser diffraction type particle size analyzer is used” and provides examples using “Natural silica sand: Average particle size: 140 μm” (Fukuda col. 7). Fukuda’s expressly disclosed particle sizes of approximately 80-200 µm and 140 µm fall entirely within the claimed range of 63-1000 µm and, under the claim interpretation adopted for examination, correspond to the recited d50 particle-size parameter measure by a convention particle-size technique.
It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to select particles having a particle size within the approximately 80-200 m range taught by Fukuda for use as the foundry-molding particles forming Gage-Bell-Hitchings’s bonded refractory filter structure. Bell expressly permits the use of silica, alumina, mullite, and other refractory particulate materials, while Fukuda teaches the same types of foundry molding materials and identifies the disclosed particle-size range as preferable “in terms of handling”. Fukuda further teaches that such molding sands can be deposited layer-by-layer and bonded with an organic resin to form large and complicated casting structures. A person of ordinary skill in the art would therefore have had a reason to employ Fukuda’s known and successfully used foundry-particle sizes in Bell’s bonded particle structure to obtain suitable handling, distribution, and formation of the particulate material, with a reasonable expectation of successfully forming the desired porous filter structure.
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Gage (EP-3325428-B1 in view of Bell (US-20070090047-A1) and further in view of Hitchings (WO-2016144899-A1) as applied to claim 9 above, and further in view of Schlienger (US-8794298-B2) and Ushigome (JP-2004-025276-A).
Regarding claim 13, Gage in view of Bell and further in view of Hitchings discloses or renders obvious the filter element according to claim 9.
Gage in view of Bell and further in view of Hitchings does not explicitly disclose open pockets for receiving impurities contained in a melt in a predefined position and dimension are formed at the openings forming flow channels.
Schlienger is directed to ceramic molten-metal filters and teaches intentionally designing filter-channel geometry for capturing contaminants. Schlienger claim 1 discloses “electronically defining a filter mesh having a plurality of three-dimensional interconnected passages with a geometry configured to capture contaminants from a molten metal” and teaches “controlling aspects of the filter mesh via engineered and electronically defined geometries, including sizes, of the passages”. Schlienger claim 16 further teaches “electronically defining sizes, shapes and locations of each of the passages in the filter mesh”. Thus, Schlienger teaches that impurity-capturing openings and passages of a molten-metal filter may be deliberately formed at predetermined locations and with predetermined dimensions rather than arising merely as random irregularities of a foam structure.
Ushigome is also directed to a high-temperature ceramic filter for removing impurities from molten metal and teaches deliberately adding an open impurity-catching feature to the filter. Ushigome par. [0036] teaches that a through hole is formed in a lower portion of the container and that the resulting filter has three-dimensional net-shaped continuous ventilation holes and through-holes. Ushigome par. [0036] further teaches that the diameter of the through hole is preferably 0.5 mm to 5 mm, more preferably 1 mm to 4 mm, because it efficiently capture impurities in the molten metal, thus teaching an intentionally positioned, open cavity having a predetermined dimension and configured to receive or capture impurities from molten metal.
It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the openings of the Gage-Bell-Hitchings filter to include intentionally formed open, pocket-like impurity-receiving features at selected flow-channel openings, using the engineered filter-geometry teachings of Schlienger and the dimensioned impurity-capturing opening taught by Ushigome. Schlienger expressly identifies a deficiency in conventional manufacturing techniques namely, that they are unable to form the complex paths desired for effective filtration, and addresses that deficiency by electronically defining sizes, shapes, and locations of passages according to a geometry configured to capture contaminants. Ushigome independently teaches that a deliberately formed opening having a selected diameter of 0.5-5 mm efficiently captures impurities in molten metal. A person of ordinary skill in the art would therefore have had reason to incorporate Ushigome’s dimensioned impurity-capturing features at selected entrances or openings of Schlienger-designed flow passages in the Gage-Bell-Hitchings filter to provide additional locations for receiving and retaining impurities, thereby improving filtration while controlling clogging and pressure loss, with a reasonable expectation of success because Schlienger’s freeform fabrication method expressly permits such filter geometries to be positioned and dimensioned in advance.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to WILLIAM ADDISON GEISBERT whose telephone number is (703)756-5497. The examiner can normally be reached Mon-Fri 7:30-5:00 EDT.
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/W.A.G./Examiner, Art Unit 1779
/Bobby Ramdhanie/Supervisory Patent Examiner, Art Unit 1779
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