DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 4/28/2026 has been entered.
Claim Status
An amendment, filed 4/28/2026, is acknowledged. Claim 17 is amended; claim 20 is canceled. Claims 15-19 and 21-29 are currently pending, claims 15-16, 19, 21-26, and 29 are withdrawn.
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 17-18 and 27-28 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.
Claim 17 recites the limitation "the sintered metal particles" in lines 3. There is insufficient antecedent basis for this limitation in the claim.
Claim 17 is drawn to “A porous sintered metal body” “having a porosity from 50 percent to 80 percent” but also claims “wherein the sintered metal particles, in powdered form, have a relative apparent density in a range from 5 percent to 35 percent of a theoretical density of the particles.” One of ordinary skill in the art would recognize that the metal particles, once sintered, no longer constitute individual particles but form a solidified metal body and thus, cannot constitute a “powder” as instantly claimed. Therefore, it is unclear if the claimed relative apparent density relates to that of metal powder particles prior to sintering and thus, drawn to a product-by-process limitation describing the properties of the metal powder used to form the claimed sintered metal body, or is a representation of the relative density of the metal body, a measure strongly correlated with its porosity. In the latter interpretation the claimed relative apparent density may be interpreted to conflict with the claimed porosity, as metal particles having a relative apparent density below 20% could result in a sintered metal body with more than 80% porosity. Claims 18 and 27-28 are indefinite based on their dependency.
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.
Claim(s) 17-18 are rejected under 35 U.S.C. 103 as being unpatentable over Zeller (US 5814272)(previously cited) in view of Buller (US 2017/0239892)(previously cited).
With respect to Claim 17, the claim is drawn to a porous sintered metal body “formed by an additive manufacturing method.” Thus, the claim is drawn to a product with a product-by-process limitation reciting the method in which the product was made. According to MPEP § 2113, "Even though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process.”
In the instant claim, the limitation “a multi-layer structure that is visible using an optical microscope” may be attributed to the claimed product-by-process limitation and is interpreted as the only required structure resulting from said product-by-process limitation.
Additionally, Claim 17 recites “wherein the sintered metal particles, in powdered form, have a relative apparent density in a range from 5 percent to 35 percent of a theoretical density of the particles.” As further discussed in the 112(b) rejection above, the claim is drawn to sintered body and therefore, no longer constitutes particles or a powder. As a result, this limitation may be interpreted as a product-by-process limitation drawn to the relative apparent density of a metal powder used to form the sintered metal body. As the density of the powder/particles used to form a sintered body does not directly translate to a specific structure or porosity of the sintered body due to the range of possible processing parameters changing the porosity and density of the final sintered body, the limitation may be considered to lack patentable weight. MPEP § 2113.
Zeller teaches a metal membrane filter element formed by sintering dendritic metal particles, the sintered filter element having a high level of porosity, including examples comprising 60%, 63%, and 65% porosity, respectively. (col. 6, ln. 26-44; col. 7, ln. 49 to col. 8, ln. 27). In addition, Zeller teaches an example wherein the metal particles are formed of 316L steel and have a density of 1.54 g/cm3, and thus, have a relative apparent density compared to the bulk/theoretical density of 316L steel (approx. 7.93 g/cm3) of 19.4%, falling within the claimed range. (col. 8, ln. 5-15). It would have been obvious to one of ordinary skill in the art to select metal particles and sintering conditions, from those disclosed by Zeller, resulting in a metal body having a porosity and sintered metal particles having a relative apparent density from the portions of the overlapping ranges. Overlapping ranges have been held sufficient to establish a prima facie case of obviousness. MPEP § 2144.05.
Zeller is silent as to wherein the sintered porous metal body detailed above is formed by an additive manufacturing method.
Buller teaches a method of additive manufacturing, wherein the additively manufactured component may be formed of irregular shaped metal particles and exhibits a controlled amount of porosity ranging from 0.05-80%. (para. 2-5, 224, 303). Buller teaches wherein the additive manufacturing method may involve additively forming an object in which successive layers of metal particles are laid down and may involving sintering of the metal particles. (para. 2-5, 162-164).
Thus, both Zeller and Buller are drawn to the problem of sintering irregular-shaped metal powder particles to form a sintered metal body having high levels of porosity.
It would have been obvious to one of ordinary skill in the art to form the sintered porous metal body of Zeller formed from irregular (dendritic) particles, to use a known process of forming a porous sintered metal body from irregular shaped particles, an additive manufacturing process comprising additive deposition and/or fusing in successive layers, as taught by Buller, in order to more precisely control the final shape, structure, and/or porosity of the sintered body. Moreover, the substitution of method of one method of forming a porous sintered metal body for another would be prima facie obvious to one of ordinary skill in the art.
Finally, the porous sintered metal body of Zeller in view of Buller, forming using a layer-by-layer additive manufacturing method, would result in a multi-layer structure visible using an optical microscope. In other words, one of ordinary skill in the art would recognize that such a manufacturing method would leave visible layer-identifying structure(s) where adjacent fused layers were formed. See also MPEP 2112.01.
With respect to Claim 18, Zeller teaches wherein the metal particles are dendritic particles. (see rejection of claim 17 above).
Claim(s) 17-18 are rejected under 35 U.S.C. 103 as being unpatentable over Buller (US 2017/0239892)(previously cited).
With respect to Claim 17, the claim requires a sintered metal body having a porosity from 50-80%. Also, as detailed above, the limitation drawn to the relative apparent density of metal particles “in powdered form” may be interpreted as a product-by-process limitation describing the properties of a build material and that does not limit the structure, including porosity and density of the final sintered body. It is further noted that a sintered metal body having a porosity of, for example, 75% may also represent sintered metal particles having relative apparent density of, or approximately, 25%.
Buller teaches a method of additive manufacturing, wherein the additively manufactured component may be formed of irregular shaped metal particles and exhibits a controlled amount of porosity ranging from 0.05-80%. (para. 2-5, 224, 303). Therefore, Buller is deemed to teach a porous sintered metal body having a porosity and relative apparent density of sintered metal particles overlapping the claimed ranges.
Buller teaches wherein the additive manufacturing method may involve additively forming an object in which successive layers of metal particles are laid down and may involving sintering of the metal particles. (para. 2-5, 162-164). Thus, Buller teaches a porous sintered metal body, formed by an additive manufacturing method, comprising sintered metal particles and having a porosity overlapping the instantly claimed range.
It would have been obvious to one of ordinary skill in the art to select from the portion of the overlapping ranges. Overlapping ranges, in particular, where the ranges of a claim overlap with the ranges disclosed in the prior art, have been held sufficient to establish a prima facie case of obviousness. MPEP § 2144.05.
Furthermore, the porous sintered metal body of Buller, forming using a layer-by-layer additive manufacturing method, would result in a multi-layer structure visible using an optical microscope. In other words, one of ordinary skill in the art would recognize that such a manufacturing method would leave visible layer-identifying structure(s) where adjacent fused layers were formed. See also MPEP 2112.01.
As Buller teaches a porous sintered metal body formed by additive manufacturing comprising each of the required structures of the cl aimed sintered metal body, it meets the claim. See also MPEP 2113.
With respect to Claim 18, the limitation “wherein the metal particles are dendritic particles is drawn to the properties/structure of a build material powder prior to sintering and therefore, is not a required structure of the claimed sintered metal body. As Buller teaches a porous sintered metal body formed by additive manufacturing comprising each of the required structures of claim 17, from which the claim depends, it also meets claim 18. See also MPEP 2113.
Claim(s) 17-18 and 27-28 are rejected under 35 U.S.C. 103 as being unpatentable over Losfeld (US 7445853).
With respect to Claim 17, the claim requires a sintered metal body having a porosity from 50-80%. The limitation drawn to the relative apparent density of metal particles “in powdered form” may be interpreted as a product-by-process limitation describing the properties of a build material and that does not limit the structure, including porosity and density of the final sintered body. Additionally, the product-by-process limitation “formed by an additive manufacturing method” only requires the resulting structure, that is, a multilayer structure that is visible using an optical microscope and not that the sintered metal body is formed by “additive manufacturing” techniques.
Losfeld teaches a porous multilayer sintered body, in particular a filter, wherein the body comprises a plurality of layers visible using an optical microscope, the layers comprising first and second layers having 20-80% porosity and 50-85% porosity, respectively, formed of sintered metal fiber particles. (col. 1, ln. 30-50; col. 3, ln. 1-67; Fig. 1, demonstrating observable layers).
Therefore, Losfeld teaches a porous sintered metal body comprising sintered metal particles, the porous sintered metal body having a porosity, averaging the first and second layers, overlapping the instantly claimed range and having a multi-layer structure meeting the instant claim. It would have been obvious to one of ordinary skill in the art to select from the portion of the overlapping ranges. Overlapping ranges, in particular, where the ranges of a claim overlap with the ranges disclosed in the prior art, have been held sufficient to establish a prima facie case of obviousness. MPEP § 2144.05.
As Losfeld teaches a porous sintered metal body comprising each of the required structures of the claimed sintered metal body, it meets the claim. See also MPEP 2113.
With respect to Claim 18, the limitation “wherein the metal particles are dendritic particles is drawn to the properties/structure of a build material powder prior to sintering and therefore, is not a required structure of the claimed sintered metal body. As Losfeld teaches a porous sintered metal body formed by additive manufacturing comprising each of the required structures of claim 17, from which the claim depends, it also meets claim 18. See also MPEP 2113.
With respect to Claims 27-28, Losfeld teaches wherein the sintered metal body is a filter, in particular a cylindrical tube filter and thus, comprising “an annular filter membrane having a shape comprising a three-dimensional tube” (as in claim 27) and “wherein the three-dimensional tube h as a circular cross-section when viewed in a direction of an axis of the tube” (as in claim 28). (col. 3, ln. 35-43).
Claim(s) 27-28 are rejected under 35 U.S.C. 103 as being unpatentable over Zeller (US 5814272) alone or in the alternative, in view of Buller (US 2017/0239892), as applied to claim 17 above, in view of Hopkins (US 2018/0280848)(previously cited).
With respect to Claims 27-28, Zeller teaches wherein the porous sintered metal body is a filter membrane (see rejections of claim 17 above), but does not explicitly describe the shape of the filter.
Hopkins teaches an annular filter having a shape comprising a three-dimensional tube with a circular cross-section when viewed in a direction of an axis of the tube, wherein the annular filter is formed of a porous metal material and may be made by an additive manufacturing process. (para. 3, 11, 17-18, 36, 48, 51).
Thus, Zeller and Hopkins are both drawn to porous metal bodies for use as a filter. It would have been obvious to one of ordinary skill in the art to modify the porous metal filter membrane of Zeller or Zeller in view of Buller, to be formed into a known filter shape comprising an annular three-dimensional tube with a circular cross-section, as taught by Hopkins, in order to form a useful filter shape for known applications. In other words, it would have been obvious to one of ordinary skill in the art to select a known, conventional, filter shape such as a tube, in order to enhance the utility of the porous sintered metal body filter.
Claim(s) 27-28 are rejected under 35 U.S.C. 103 as being unpatentable over Buller (US 2017/0239892), as applied to claim 17 above, in view of Hopkins (US 2018/0280848)(previously cited).
With respect to Claims 27-28, Buller teaches a sintered metal body formed by additive manufacturing and thus, one of ordinary skill in the art would recognize it to encompass forming any reasonable part within the scope of known additive manufacturing size/dimension limits; however, the reference is silent as to forming the specific forms required by claims 27 and 28, respectively.
Hopkins teaches an annular filter having a shape comprising a three-dimensional tube with a circular cross-section when viewed in a direction of an axis of the tube, wherein the annular filter is formed of a porous metal material and may be made by an additive manufacturing process. (para. 3, 11, 17-18, 36, 48, 51).
Thus, Buller and Hopkins are both drawn to porous metal bodies for use as a filter. It would have been obvious to one of ordinary skill in the art to modify the porous metal filter membrane of Zeller or Zeller in view of Buller, to be formed into a known filter shape comprising an annular three-dimensional tube with a circular cross-section, as taught by Hopkins, in order to form a useful filter shape for known applications. In other words, it would have been obvious to one of ordinary skill in the art to select a known, conventional, filter shape such as a tube, in order to enhance the utility of the porous sintered metal body filter.
Claim(s) 18 is rejected under 35 U.S.C. 103 as being unpatentable over Losfeld (US 7445853), as applied to claim 17 above, in view of Zeller (US 5814272)(previously cited).
In the alternative to the above rejection of claim 18, if the limitation of claim 18 is interpreted to require structure in the claimed sintered metal body, Losfeld teaches a porous sintered metal body filter formed of short and long sintered fibrous metal particles (see rejection of claim 17) but does not specifically teach that the fibrous metal particles have dendritic structure.
Zeller teaches forming a porous sintered metal body filter, wherein the filter is formed by sintering dendritic metal particles. (col. 6, ln. 26-44; col. 7, ln. 49 to col. 8, ln. 27).
Thus, Losfeld and Zeller are both drawn to filter products comprising porous sintered metal bodies. It would have been obvious to one of ordinary skill in the art to substitute one or both of the long and short fibrous metal particles for dendritic metal particles having corresponding size, as taught by Zeller, in order to obtain a filter with high porosity and made without the use of toxic precursors. (see, Zeller, col. 2, ln. 26-36).
Response to Arguments
Applicant did not file additional arguments with the Request for Continued Examination, filed 6/2/2026. Therefore, the response to Applicant’s arguments contained in the Advisory Action, dated 5/8/2026, are largely repeated below.
Applicant's arguments with respect to the after-final amendment filed 4/28/2026 have been fully considered and are found persuasive in part and not persuasive in part.
Applicant argues that the after-final amendment overcomes the 102 rejection of record. This argument is found persuasive. Claim 17 incorporates the subject matter of claim 20, which was not rejected under 35 U.S.C. 102. Specifically, Zeller is silent as to a porous sintered metal body comprising a multi-layer structure that is visible using an optical microscope. Therefore, the 102 rejection over Zeller is withdrawn in view of Applicant’s amendments to the claims.
Applicant's arguments with respect to the rejection under 35 U.S.C. 103 over Zeller in view of Buller have been fully considered but are not found persuasive.
Applicant argues that Buller does not teach a porosity overlapping the claimed range, in particular, arguing that the reference does not actually teach the range is recites due to certain examples and that the method of making could not make such a porosity as it is drawn to making dense features. These arguments ignore the clear teachings of the reference and are not found persuasive. Applicant recognizes that references may be relied upon for all that they would reasonably suggest (MPEP 2123) but then ignores the disclosed 0.05-80% porosity range and the recited exemplary range of 30-80%. As the reference specifically teaches the range, Applicant's arguments are not found persuasive.
Additionally, it is noted that disclosed examples and preferred embodiments do not constitute a teaching away from a broader disclosure or nonpreferred embodiments. In re Susi, 440 F.2d 442, 169 USPQ 423 (CCPA 1971). “A known or obvious composition does not become patentable simply because it has been described as somewhat inferior to some other product for the same use.” In re Gurley, 27 F.3d 551, 554, 31 USPQ2d 1130, 1132 (Fed. Cir. 1994); MPEP 2123.
Applicant also argues against the combination as Zeller and Buller are drawn to different manufacturing methods. This difference is addressed in the rejection as the substitution of one conventional method of forming a porous sintered body for another, resulting in the same structure and/or properties, would have been prima facie obvious to one of ordinary skill in the art.
With respect to Applicant's arguments drawn to relative density, Applicant's provides no evidence that the reference does not teach the required relative density as established in the rejection. The arguments of counsel cannot take the place of evidence in the record. In re Schulze, 346 F.2d 600, 602, 145 USPQ 716, 718 (CCPA 1965); MPEP § 716.01 and § 2145. Applicant's argument that the reference to Zeller is not an admission is not found persuasive to the extent it disregards the plain meaning of the written disclosure. As described above, however, the admission and the teachings of Zeller are not interpreted to anticipate the claims in view of the after-final amendment as detailed above.
Further as previously detailed, Zeller teaches an example wherein the metal particles are formed of 316L steel and have a density of 1.54 g/cm3, and thus, have a relative apparent density compared to the bulk/theoretical density of 316L steel (approx. 7.93 g/cm3) of 19.4%, falling within the claimed range. (col. 8, ln. 5-15).
Moreover, the instant specification recites “Examples of processes useful for producing dendritic metal particles having density properties as described are presented in U.S. Pat. No. 5,814,272, the entirety of which is incorporated herein by reference.” (para. 86 of the PG Pub.). The instant specification, therefore, is interpreted as an admission that Zeller teaches particles having a relative apparent density falling within that disclosed by the instant application. Applicant fails to provide sufficient evidence or argument, commensurate with the scope of the claims, to rebut the prima facie case of obviousness established by the reference.
Finally, in view of Applicant’s amendments to the claims, 103 rejection over Buller alone is made over claim 18 and over claims 27-28 over Buller in view of Hopkins. Additionally, in view of Applicant’s amendments and further search and consideration, a new 103 rejection over Losfeld is made, as detailed above.
Conclusion
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/JOHN A HEVEY/Primary Examiner, Art Unit 1735
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