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 .
StatusClaims(s) 16-34, 36, is/are filed on 9/10/2025 are currently pending. Claim(s) 33-34 is/are withdrawn, 16-32, and 36 is/are rejected.
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 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 pre-AIA 35 U.S.C. 103(a) which forms the basis for all obviousness rejections set forth in this Office action:
(a) A patent may not be obtained though the invention is not identically disclosed or described as set forth in section 102 of this title, if the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art to which said subject matter pertains. Patentability shall not be negatived by the manner in which the invention was made.
The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied for establishing a background for determining obviousness under pre-AIA 35 U.S.C. 103(a) 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.
Claim(s) 16 is/are rejected under 35 U.S.C. 103 as being unpatentable over Haegg (CN 1742133 A) in view of Ying (EP 0693008 B1).
Regarding claim 16, Haegg teaches a filter sector for a rotating filter disk of a disc filter, Haegg (CN 1742133 A) discloses a filter sector for use in a turntable filter for separating pulp suspension, and specifically discloses the following technical contents (see Detailed Description and Figures 1-6): assembling a plurality of such filter sectors together to form a circular filter disc for use in a carousel filter for separating suspensions such as fibrous pulp suspensions. The filter sector 1 comprises two opposed substantially rigid metal mesh-like filter walls 2 and 3 (equivalent to the filter panels of the present application) forming a filter chamber 4 containing the filtrate flowing through the filter walls 2 and 3. Each filter mesh wall 2 and 3, respectively, is woven according to a particular pattern, forming a plurality of four-sided pockets 5 (equivalent to the arched structure of the present application, Fig. 3 discloses an arched structure with a quadrangular base) and elevations 6. When the particular use of the filter sector 1 allows for a design in which a metal mesh can be made of sufficiently stiff filter walls 2, 3, the more coarse-mesh support walls 8, 9 can be omitted. In this case, the filtering walls 2, 3 can be separated from each other or connected to each other to form a bag-like unit (p. 2-5).
Haegg does not teach that the filter plate is a structured perforated filter plate and the polygonal base of the arched structure is hexagonal. However, this is well-known. Ying (CN 103721460 A) discloses a high efficiency three generation nuclear power plant containment pit filtration system and specifically discloses the following technical content (see paragraphs 24- 32 of the specification and Figures 1-6): comprising a plurality of screen modules composed of eight pleated screen units 25. The screen inlet 10 (equivalent to the polygonal base of the present application) of any one of the pleated screen units can be made not only as rectangular quadrilateral structures, but also as polygonal shapes such as triangular, pentagonal, hexagonal, and various structures such as circular and elliptical, depending on the engineering requirements (p. 2-5). It would have been obvious to one of ordinary skill to have to incorporated by selecting a polygonal base as polygons such as triangles, pentagons, hexagons, and various structures such as circles and ellipses, and the person skilled in the art has motivated to select hexagons as polygonal base shapes to provide improved rigidity and structure.
Claim(s) 16-32 is/are rejected under 35 U.S.C. 103 as being unpatentable over Niggl (US 20190217227 A1) in view of Frank (EP 0693008 B1).
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Regarding claim 16, Niggl teaches a filter sector (1 from US'226) for a rotating filter disc (7 from US'226) of a disc filter, the filter plate (3 from US'226) made of a thin sheets having an interior space (5 from US'226), comprising at least one perforated and structured filter plate (3 from US'226), and an interior space (5 from US'226) defined within the filter sector (1 from US'226), wherein the filter plate (3 from US'226) is configured to be suctioned via the interior space (5 from US'226) of the filter sector (1 from US'226) for separating liquid from a suspension [0009-0058].
Niggl does not teach the filter plate (3 from US'226) comprises at least one arch structure with a polygonal base, the polygonal base of the arch structure being a hexagon
However, this is well-known. Frank teaches a process of making thin sheet material with bend/bulges. It teaches that structures such as hexagonal or pentagonal structures of the bulged, can be made during the bulging process. It would have been obvious to combine the bulging process forming polygonal (hexagonal) arch structures from Frank with the structured filter plate of Niggl to achieve improved strength and stiffness with reduced material usage, as Frank teaches that such hexagonal structures provide "almost the same stiffness in all wall directions" for thin sheets, addressing the need in disc filters to reduce weight without compromising rigidity (as noted in background [0005]).
Regarding claim 17, Niggl as modified teaches the filter sector (1 from US'226) according to claim 16, wherein the polygonal base of the arch structure (4 from US'226) is an equilateral hexagon (hexagonal bulge structures from EP'008, symmetry is implied). Alternatively, it would have been obvious to make the hexagonal base equilateral in the combination of EP'008 and US'226 for uniform stiffness, as EP'008 motivates symmetry for "almost the same stiffness in all wall directions," enhancing the filter plate's structural integrity in rotational stresses of disc filters.
Regarding claim 18, Niggl teaches wherein the arch structure (4 from US'226) is oriented into the interior space (5 from US'226) of the filter sector (1 from US'226) and is thus convex when viewed from the interior space (5 from US'226) in the direction of the filter plate (3 from US'226).
Regarding claims 19-23, Niggl as modified does not teach wherein the arch structure (4 from US'226) forms a height of up to 25 mm above the base, wherein the arch structure forms a height of up to 10 mm above the base, wherein the filter plate has perforations with a hydraulic diameter within an approximate range of 0.2 mm to 3 mm, wherein the filter plate has perforations with a hydraulic diameter within an approximate range of 0.4 mm to 0.8 mm, wherein the polygonal base of a first arch structure has a section that is simultaneously formed as a section of the polygonal base of a second arch structure. However, this merely a mater of obvious design choice and would well-known to modify. It has been held changes of size, shape, etc without special functional significance are not patentable. Research Corp. v. Nasco Industries, Inc., 501 F2d 358; 182 USPQ 449 (CA 7), cert, denied 184 USPQ 193; 43 USLW3359 (1974). It would have been obvious to one of ordinary skill to have to selected to appropriate size and shape that provides best function in terms of design and filtration.
Regarding claims 25-26, Niggl does not teach detail of the claim. However, this merely a design choice and well-known. See at least US 5028474 A which teaches the hexagon is formed from six sections with a first section and a second section being mutually opposite sections each other and formed as saddle surfaces (inclined folds from US'474), a third section and a fourth section forming a first ridge surface (12 from US'474), a fifth section and a sixth section forming a second ridge surface (13 from US'474) mutually opposite from the first ridge surface (12 from US'474), and the respective ridge surfaces (12,13 from US'474) being connected by the saddle surfaces (inclined folds 16,17 from US'474). It would have been obvious to incorporate the inclined connecting folds (acting as saddle surfaces) from US'474 into the hexagonal arch of Niggl to create a stiffened core with gridlike bearing, as US'474 teaches improved structural efficiency for thin sheets, motivated by reducing material in filter sectors while increasing rigidity (background [0005]).
Regarding claim 27, Niggl as modified by US’474 teaches wherein the third, fourth, fifth and sixth sections of the polygonal base lie substantially in a plane (facets 20 from US'474) and a respective pass of the saddle surface (inclined folds 16,17 from US'474) is arranged between the plane and the interior space (5 from US'226).
Regarding claim 28, Niggl teaches the third, fourth, fifth and sixth sections of the polygonal base lie substantially in a plane (facets 20 from US'474) and a respective pass of the saddle surface (inclined folds 16,17 from US'474) is arranged between the plane and the interior space (5 from US'226).
Regarding claim 29, Niggl teaches the filter sector (1 from US'226) according to claim 16, wherein the structuring of the filter plate (3 from US'226) varies at least in sections (varying elevations from US'226).
Regarding claim 30, Niggl teaches wherein the filter sector (1 from US'226) is shaped as circular sector (circular segments from US'226) (fig. 1).
Regarding claim 31, Niggl as modified, wherein the perforated and structured filter plate (3 from US'226) is an arch structured perforated plate (bulged from EP'008).
Regarding claim 32, Niggl teaches comprising mutually opposite filter plates (3 from US'226) arranged on each side of the inner space (5 from US'226), wherein the filter sector (1 from US'226) is fastened to the circumference of a hollow shaft (6 from US'226), and the arch structures (4 from US'226) of the opposite filter plates (3 from US'226) are arranged symmetrically with respect to the inner space (5 from US'226) or arranged offset with respect to one another by half a base in a radial direction with respect to the hollow shaft (6 from US'226) (offset bulges from EP'008).
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It is noted that any citations to specific, pages, columns, lines, or figures in the prior art references and any interpretation of the reference should not be considered to be limiting in any way. A reference is relevant for all it contains and may be relied upon for all that it would have reasonably suggested to one having ordinary skill in the art. See MPEP 2123.
Allowable Subject Matter
Claim(s) 36 is/are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Response to Arguments
Rejection of Claim 16 (and dependents) over Haegg in view of Ying Haegg discloses a filter sector for a rotating disc filter comprising opposed, substantially rigid, metal mesh-like filtration walls that are profiled to form a multiplicity of cavities and humps (equivalent to the recited arch structures). Each cavity and hump include a multiplicity of meshes (perforations) and shares sides with adjacent structures. These walls define an interior filtrate chamber and are suctioned for separating liquid from suspension, precisely as recited. The humps are convex when viewed from the interior space.
Applicant contends that Haegg’s “rigid net” does not teach a “perforated and structured filter plate.” This argument is unpersuasive. Under the broadest reasonable interpretation consistent with the specification, the rigid, perforated, and profiled filtration walls of Haegg read directly on the claimed “perforated and structured filter plate.” The specification acknowledges Haegg’s cavities and humps at paragraphs 6 and 12 and nowhere limits “plate” to a monolithic flat sheet of uniform thickness excluding mesh-like structures. In the filtration art, a structured mesh wall that is rigid, perforated, and profiled functions identically to the claimed plate. The semantic distinction does not distinguish over the prior art.
Haegg discloses quadrangular (four-sided) bases for its structures but not hexagonal bases. Ying teaches that screen inlets or bases in structured filter/screen units may be formed not only as quadrilaterals but as any polygonal shape, explicitly including hexagons, selected according to engineering requirements. It would have been obvious to one of ordinary skill to substitute a hexagonal base for Haegg’s quadrangular base using the known polygonal structuring taught by Ying. The motivation is explicit: to achieve improved rigidity and structural integrity while reducing material usage and weight—benefits expressly recognized in both the secondary reference and Applicant’s own specification (para. 11). Hexagonal geometry is well-known in the mechanical arts to provide isotropic stiffness and efficient tiling (shared sections as in claims 23–24), yielding predictable results.
Applicant argues the references are from incompatible fields (pulp/paper disc filters vs. nuclear containment) and that combining them would require a complete redesign, changing Haegg’s principle of operation (citing In re Ratti and MPEP § 2143.01(VI)). These arguments are not persuasive. Both references pertain to structured filtration elements for separating solids from liquids/suspensions. The bulging/pleated structuring technique of Ying is analogous art properly combinable under KSR Int’l Co. v. Teleflex Inc. (applying a known technique to improve a known device). Modifying the base shape of Haegg’s already-profiled walls from quadrilateral to hexagonal is a minor, routine optimization of geometry, not a fundamental redesign. The core principle—suction through rigid, structured, perforated walls on a rotating disc filter—remains unchanged.
Applicant further asserts that Ying’s “folded” construction is incompatible with the claimed “arch structure” (a shell formed over the base). This is unpersuasive. Haegg’s humps are already arched/convex. Ying’s polygonal structuring, when applied via bulging techniques (as cross-referenced in the second rejection), produces arched, shell-like forms. The combination yields the claimed arch structure with hexagonal base.
The alleged advantages of improved separation performance, strength, and reduced weight are predictable results flowing directly from the combination and are not unexpected. No evidence of secondary considerations has been presented. Claims 17–32 and 36, which depend from claim 16, therefore remain rejected.
Rejection of Claims 16–32 and 36 over Niggl in view of Frank Niggl discloses a filter sector for a rotating disc filter comprising opposed perforated and profiled filter plates (thin sheets) defining an interior space that is suctioned for liquid/suspension separation. The plates include a plurality of elevations (equivalent to arch structures) on the outer side.
Niggl does not disclose elevations having a polygonal (hexagonal) base. Frank teaches a bulging process for thin sheets (including perforated/mesh sheets) that forms precisely such arch-like bulges with polygonal bases, explicitly including hexagonal structures. Frank further teaches that hexagonal bulging yields “almost the same stiffness in all wall directions,” enabling substantial weight and material reduction while maintaining or increasing rigidity—directly addressing the known needs in disc-filter plates.
It would have been obvious to form Niggl’s elevations as hexagonal arches using Frank’s bulging process. The motivation is explicit in Frank and aligns with Niggl’s goal of strong, lightweight profiled plates. One of ordinary skill in the art of thin-sheet filter-plate design would routinely look to advanced sheet-stiffening techniques for predictable improvements in strength-to-weight ratio.
Applicant argues that Niggl requires round or elongated cross-sections “in particular elliptical” to prevent abrasion and that a hexagonal base would contradict this “primary advancement.” This is unpersuasive. Niggl’s preference for rounded profiles is one benefit; nothing teaches away from polygonal bases. A hexagonal base combined with a smooth arched/domed shell (as formed by Frank’s bulging) can readily maintain a non-abrasive outer contour. The “cross-section” reference in Niggl pertains to the elevation profile, not the base perimeter. Modifying base geometry for superior isotropic stiffness is an obvious improvement fully consistent with Niggl’s objectives.
Applicant further contends that Frank is unrelated (sound diffusion) and that its material cannot be used as a filter plate. This argument fails. Frank’s teachings are not limited to sound diffusion; they broadly disclose bulging of thin perforated or mesh sheets for structural stiffening in any application requiring lightweight rigidity (e.g., containers, shells, composites). The technique is directly applicable to Niggl’s thin perforated filter plates. Under KSR, it is obvious to apply a known improvement technique (hexagonal bulging for uniform stiffness and weight savings) to a known device (Niggl’s profiled filter plates).
Dependent claims 17–32 are rejected for the same reasons. Specific limitations (heights up to 10–25 mm, perforation diameters 0.2–3 mm or 0.4–0.8 mm, shared base sections, ridge/saddle surfaces, planar sections with passes, varying structuring, circular-sector shape, symmetrical/offset arrangement) are either expressly taught or constitute routine matters of design choice and optimization well within the skill of the art (see also US 5,028,474 A cited in the prior action for ridge/saddle formations in hexagonal grids). Such parameters are optimized for best filtration and structural performance without inventive step.
Applicant’s arguments that the references are “completely incompatible” and that the skilled artisan “would never” combine them overlook the explicit teachings and the predictable benefits each provides. The claimed advantages (synergistic strength, surface area, and efficiency) flow naturally from the prior-art combination and are not patentably distinguishing.
Conclusion
THIS ACTION IS MADE FINAL. 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 extension fee 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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/WAQAAS ALI/Primary Examiner, Art Unit 1777