DETAILED ACTION
Response to Amendment
The Amendment filed 11/20/2025 has been entered. Claims 1-10 and 12-20 remain pending in the application. Claim(s) 1-8 have been withdrawn. Claim 11 has been canceled.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(d):
(d) REFERENCE IN DEPENDENT FORMS.—Subject to subsection (e), a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
Claim 13 is rejected under 35 U.S.C. 112(d), as being of improper dependent form for failing to further limit the subject matter of the claim upon which it depends, or for failing to include all the limitations of the claim upon which it depends. Claim 13 depends from claim 9. Amended claim 9 now requires forming a block at the location of one of the inlet manifold and the outlet manifold via one or more additive manufacturing processes simultaneously with the forming of the heat exchanger body and forming one of the inlet manifold and the outlet manifold from the block via one or more subtractive manufacturing processes to remove material from the block. Claim 13 requires forming both of the inlet manifold and the outlet manifold separately from the heat exchanger body. The block which forms the inlet/outlet manifold at the location of the manifold cannot be formed both simultaneously with the heat exchanger body and separately from the heat exchanger body. Accordingly, claim 13 fails to include all the limitations of the claim upon which it depends. Applicant may cancel the claim(s), amend the claim(s) to place the claim(s) in proper dependent form, rewrite the claim(s) in independent form, or present a sufficient showing that the dependent claim(s) complies with the statutory requirements.
Claim Rejections - 35 USC § 102
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Language from the reference(s) is shown in quotations. Limitations from the claims are shown in quotations within parenthesis. Examiner explanations are shown in italics.
Claims 9-10 and 12-19 are rejected under 35 U.S.C. 102(a)(1) and 102(a)(2) as being anticipated by Roper et al. (US 9976815 B1), previously cited.
Regarding claims 9 and 12-13, due to the 112(d) rejection above, the limitations of claim 13 are interpreted as being met if those of claim 9 are met. Roper teaches that “the present invention relates to methods of manufacturing heat exchanging structures” (which reads upon “a method of forming a heat exchanger comprising”, as recited in the instant claim; column 1, lines 15-20). Roper teaches that “the heat exchanger 100 includes passages (e.g., internal passages) 112 for facilitating the flow of a fluid (e.g., a cooling fluid), tubesheets 114 for directing fluid (e.g., from/to an internal fluid inlet/outlet) to the passages 112, and headers 116 for encapsulating the passages 112 and tubesheets 114 and to facilitate the inflow and outflow of one or more fluids (e.g., coolants) into and out of the heat exchanger 100” (which reads upon “forming a heat exchanger body including a plurality of heat exchanger tubes, wherein: the inlet manifold is connected to the heat exchanger body and is configured to distribute a flow of fluid from a fluid inlet of the inlet manifold to the plurality of heat exchanger tubes; and the outlet manifold is connected to the heat exchanger body and is configured to collect the flow of fluid from the plurality of heat exchanger tubes and direct the flow of fluid through a fluid outlet”, as recited in the instant claim; column 5, lines 17-26 and FIG. 1). Roper teaches that “additive manufacturing is used to fabricate, utilizing a sacrificial material, a sacrificial scaffold including one or more inlet manifold features, one or more internal passage features, and one or more outlet manifold features” (which reads upon “via one or more additive manufacturing processes”, as recited in the instant claim; column 5, lines 27-31). Roper teaches that “the process of manufacturing a heat exchanger 100 includes attaching one or more additional pieces of sacrificial material (e.g., sacrificial facesheets) to the initial sacrificial scaffold 100 a/100 b; for example, sacrificial facesheets could be added to extend the inlet and/or outlet defining manifolds 102/104, only a part of which may be manufactured via 3D-printing” (column 7, lines 10-31; considered relevant to claim 13). Roper teaches that “the process of manufacturing a heat exchanger 100 may further include removing the sacrificial scaffold 100 a/100 b and any existing sacrificial facesheet(s) to form a heat exchanger core 100 d with passages 112 and integrated, self-aligned tubesheets 114” (which reads upon “forming at least one of the inlet manifold and the outlet manifold via one or more subtractive manufacturing processes”, as recited in the instant claim; column 7, line 63- column 8, line 8). Roper teaches that “the additive manufacturing of the sacrificial scaffold includes forming a first block, a second block, and a connection therebetween, the connection defining the passage” (which reads upon “forming a block at the location of one of the inlet manifold and the outlet manifold, forming a block at the locations of both of the inlet manifold and the outlet manifold”, as recited in the instant claims; column 2, lines 27-31). Roper teaches that “additive manufacturing is used to fabricate, utilizing a sacrificial material, a sacrificial scaffold including one or more inlet manifold features, one or more internal passage features, and one or more outlet manifold features, and that each internal passage feature connects to one or more manifolds and/or one or more internal passage features” (which reads upon “via one or more additive manufacturing processes simultaneously with the forming of the heat exchanger body”, as recited in the instant claim; column 5, lines 27-48). Roper teaches that “the inlet manifold, internal passages, and outlet manifold features may be solid volumes” (column 5, lines 27-48). Roper teaches that “after conformal coating, the sacrificial scaffold is selectively removed and headers 116 can be added to create a fully-functional heat exchanger 100” (which reads upon “forming both of the inlet manifold and the outlet manifold from the blocks via one or more subtractive manufacturing processes”, as recited in the instant claim; column 5, lines 27-48).
Regarding claim 10, Roper teaches the method of claim 9 as stated above. Roper teaches that “additive manufacturing is used to fabricate, utilizing a sacrificial material, a sacrificial scaffold including one or more inlet manifold features, one or more internal passage features, and one or more outlet manifold features” (column 5, lines 27-48). Roper teaches that “the inlet manifold, internal passages, and outlet manifold features may be solid volumes (e.g., not be open/hollow volumes) and define the fluid volume for an internal fluid 10 in the heat exchanger” (column 5, lines 27-48). Roper teaches that “the sacrificial scaffold is conformal coated by a coating material, and the coating defines the walls of the one or more passages 112 (e.g., tube walls) and the tubesheets” (column 5, lines 27-48; conformal coated by a coating material reads on utilized as a base for the forming the heat exchanger body via the one or more additive manufacturing processes). Roper teaches that “because the walls of the one or more passages 112 and tubesheets 114 are created simultaneously by conformal coating a single mold, the tubesheets 114 are self-aligned to the one or more passages” (column 5, lines 27-48).
Regarding claim 14, Roper teaches the method of claim 9 as stated above. Roper teaches that “the internal-passage-defining features 106 may include, for example, a bank of solid cylinders and/or a network of struts, which may have any cross-sectional shape including, for example, elliptical, airfoil, tapered, fluted, scalloped, finned, and/or like” (column 6, lines 19-45).
Regarding claims 15-18, Roper teaches the method of claim 9 as stated above. Roper teaches that “the heat exchanger core 600 may include one or more strands 602 arranged in parallel between an inlet and outlet manifolds (e.g., tubesheets) 604, each strand 602 including, two or more wavy passages 606 that are interconnected at connection nodes (e.g., connection points) 608” (column 12, lines 8-24). Roper teaches that “in one example, each strand 602 includes four wavy passages 606, as shown in FIG. 6, and that the connection nodes 608 may be collinear along the length of the strands 602” (column 12, lines 8-24, FIGs. 6A-6C and associated text).
Regarding claim 19, Roper teaches the method of claim 9 as stated above. Roper teaches that “aspects of embodiments of the present invention are directed to utilizing additive manufacturing (e.g. 3D printing) to fabricate a sacrificial scaffold, to utilizing conformal coating to create the heat exchanger walls around the sacrificial scaffold, and to then removing the scaffold, thus forming a heat exchanger” (column 2, lines 3-9).
Claim Rejections - 35 USC § 103
Claim 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Roper et al. (US 9976815 B1), previously cited, as applied to claim 9 above.
Regarding claim 20, Roper teaches the method of claim 9 as stated above. Roper teaches that “removal of the sacrificial scaffold 100 a/100 b may be performed though one or more processes including chemical etching, thermal depolymerization, sublimation, vaporization (e.g., boiling), and/or burning” (column 8, lines 4-8). Roper teaches that “removing the one or more mechanical support features 108 may be performed mechanically, for example, through machining (such as drilling, milling, and/or the like), cutting, filing, and/or the like, or may be performed chemically, for example, through the use of appropriate solvents and/or chemical etching” (which reads upon “one or more of machining and milling”, as recited in the instant claim; column 7, lines 1-9). it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the method of Roper to use machining (such as drilling, milling, and/or the like), as taught by Roper, for removing both the support features and the sacrificial scaffold to minimize the equipment needed and or processing steps. The rationale to support a conclusion that the claim would have been obvious is that all the claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination yielded nothing more than predictable results to one of ordinary skill in the art (MPEP § 2143.A.). The simple substitution of one known element for another is likely to be obvious when predictable results are achieved. See KSR International Co. v. Teleflex Inc., 550 U.S. 398, 415-421, USPQ2d 1385, 1395 - 97 (2007) (see MPEP § 2143, B.).
Response to Arguments
Applicant's arguments filed 11/20/2025 have been fully considered but they are not persuasive. Applicant argues that the sacrificial scaffold 100a corresponds in shape to that of the heat exchanger core 100d, and that the sacrificial scaffold 100a is coated with a layer of material to form a coating 110 (remarks, page 6). Applicant argues that the sacrificial scaffold 100a is removed to leave behind the heat exchanger core 100d with one or more passages 112 and integrated self-aligned tubesheets 114, and that the Roper reference fails to disclose at least the removal of material from the additively-formed block to form the manifold (remarks, page 6). Applicant further argues that the only material removed in Roper is that of the sacrificial scaffold formed around the "block" and separated from the "block" by a release coating (remarks, page 7). This is not found convincing because Roper teaches that “the additive manufacturing of the sacrificial scaffold includes forming a first block, a second block, and a connection therebetween, the connection defining the passage” (column 2, lines 27-31). The sacrificial scaffold includes the first block and the second block. Roper teaches that “the process of manufacturing a heat exchanger 100 may further include removing the sacrificial scaffold 100 a/100 b and any existing sacrificial facesheet(s) to form a heat exchanger core 100 d with passages 112 and integrated, self-aligned tubesheets 114” (column 7, line 63- column 8, line 8).
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.
Contact Information
Any inquiry concerning this communication or earlier communications from the examiner should be directed to REBECCA JANSSEN whose telephone number is (571)272-5434. The examiner can normally be reached on Mon-Thurs 10-7 and alternating Fri 10-6.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. The Examiner requests that interviews not be scheduled during the last week of each fiscal quarter or the last half of September, which is the end of the fiscal year. Q2: 3/30-4/3/26; Q3: 6/22-6/26/26; Q4: 9/21-9/30/26.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Keith Hendricks can be reached on (571)272-1401. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/REBECCA JANSSEN/Primary Examiner, Art Unit 1733
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