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 .
Status of the Claims
The status of the claims as filed in the reply dated 3/6/2026 are as follows:
Claims 1 and 3 are amended,
Claim 2 is canceled,
Claims 1 and 3-14 are currently pending.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claim(s) 1, 3-5, and 8-13 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Zhang et al. (Chinese Patent Publication CN107504850A, “Zhang”).
Regarding claim 1, Zhang discloses a heat exchanger core (figs 1, 2) comprising:
a plurality of first medium channels (2, 3) along which a first medium is directed from a first first medium channel end to a second first medium channel end (see annotated fig 1 below); and
a plurality of second medium channels (between the first medium channels) along which a second medium is directed from a first second medium channel end to a second second medium channel end (see annotated fig 1 below);
wherein the first medium channels are formed to have a first portion (3) having a first cross-sectional geometric shape and one or more second portions (2) having a second, different cross-sectional geometric shape;
wherein one or more of the channels transition from the first to the second cross-sectional geometric shape (fig 1);
wherein the second, different cross-sectional geometric shape is a relatively flatter geometric shape than the first cross-sectional geometric shape (see annotated fig 1 below); and
wherein the plurality of first medium channels run in a direction transverse to the plurality of second medium channels (see fig 1 below).
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Regarding claim 3, Zhang further discloses a plurality of layers each having a plurality of first medium channels, each layer separated by a layer of second medium channels (see annotated fig 1 below).
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Regarding claim 4, Zhang further discloses wherein the one or more second portions (2) is provided at both ends of the first medium channels and the first portion (3) is the portion of the first medium channels between the ends (see annotated fig 1 below).
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Regarding claim 5, Zhang further discloses wherein the one or more second portions (2) is provided at locations between the ends of the first medium channels (2, 3, see annotated fig 1 above).
Regarding claim 8, the limitation of the first medium being a hot fluid and the second medium being a cold fluid is considered an intended use limitation. A recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus satisfying the structural limitations of the claims, as is the case here, i.e. the first medium could be relatively hot where the second medium could be relatively cold.
Regarding claim 9, the limitation of being “formed by additive manufacture” is considered a product-by-process limitation. In product-by-process claims, “once a product appearing to be substantially identical is found and a 35 U.S.C. 102/103 rejection [is] made, the burden shifts to the applicant to show an unobvious difference.” MPEP 2113. This rejection under 35 U.S.C. 102/103 is proper because the “patentability of a product does not depend on its method of production.” In re Thorpe, 227 USPQ 964, 966 (Fed. Cir. 1985).
Regarding claim 10, Zhang further discloses an inlet manifold (see annotated fig 1 below);
an outlet manifold (see annotated fig 1 below); and
a heat exchanger core as claimed in claim 1 located with and in fluid communication with the inlet manifold and the outlet manifold (see rejection of claim 1 above).
Regarding claim 11, Zhang further discloses wherein the first first medium channel end is in fluid communication with the inlet manifold and the second first medium channel end is in fluid communication with the outlet manifold (see annotated fig 1 below).
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Regarding claim 12, Zhang further discloses a second fluid inlet in fluid communication with the first second medium channel end and a second fluid outlet in fluid communication with the second second medium channel end (see annotated fig 1 below).
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Regarding claim 13, Zhang further discloses being a cross-flow heat exchanger (see fig 1).
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.
Claim(s) 1, 6, 7, 10, and 14 is/are rejected under 35 U.S.C. 103 as being unpatentable over Byfield (U.S. Patent Publication No. 2019/0033013) alone.
Regarding claim 1, Byfield discloses a heat exchanger core (fig 7b embodiment) comprising:
a plurality of first medium channels (12aa-12cd) along which a first medium is directed from a first first medium channel end (at 18, see fig 1a) to a second first medium channel end (at 26, see fig 1a); and
a plurality of second medium channels (14aa-14dd) along which a second medium is directed from a first second medium channel end (at 18) to a second second medium channel end (at 26);
wherein the plurality of first medium channels run in a direction transverse to the plurality of the second medium channels (see annotated fig 1a Below).
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However, in this embodiment, Byfield does not explicitly disclose wherein the first medium channels or the second medium channels are formed to have a first portion having a first cross-sectional geometric shape and one or more second portions having a second, different geometric cross-sectional shape;
wherein the one or more channels transition from the first to the second cross-sectional shape;
wherein the second, different cross-sectional geometric shape is a relatively flatter geometric shape than the first cross-sectional geometric shape.
However, in another embodiment (fig 10a-fig 10c), Byfield discloses wherein first medium channels (14) and second medium channels (12) are formed to have a first portion having a first cross-sectional geometric shape (at E1) and second portions (at E2) having a second, different cross-sectional geometric shape (fig 10a and 10c);
wherein the one more channels transition from the first to the second cross-sectional shape (fig 10b);
Byfield teaches that this configuration allows for control of heat transfer through the length of the channels (¶0111). It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention for Byfield to provide the different cross sections to the embodiment of fig 7b in order to optimize the heat transfer between the channels. This would result in wherein the second, different cross-sectional geometric shape (of14aa-14dd) is a relatively flatter geometric shape than the first cross-sectional geometric shape (of 12aa-12cd).
Regarding claim 6, Byfield, as modified, discloses all previous claim limitations. Byfield further discloses wherein the first cross-sectional shape (of 12) is an elliptical shape (fig 7b) and the second cross-sectional shape (of 14) is a non-elliptical shape (fig 7b).
Regarding claim 7, Byfield, as modified, discloses all previous claim limitations. Byfield further discloses wherein the second cross-sectional shape (of 14) is a substantially circular shape (fig 7b).
Regarding claim 10, Byfield, as modified, discloses all previous claim limitations. Byfield further discloses an inlet manifold (MC, fig 1b, ¶0155);
an outlet manifold(MH); and
a heat exchanger core as claimed in claim 1 located with and in fluid communication with the inlet manifold and the outlet manifold (see rejection of claim 1).
Regarding claim 14, Byfield, as modified, discloses all previous claim limitations. Byfield further discloses a counter-flow heat exchanger (¶0033).
Response to Arguments
Applicant's arguments filed 3/06/2026 have been fully considered but they are not persuasive.
Applicant argues (pages 4-6) that Byfield does not teach the cross-sectional geometric shape limitations of claim 1 and claim 6. Specifically, the limitations of a channel transitioning to flatter and elliptical cross-sectional geometric shape. However, as explained in the rejection, since Byfield teaches two channels having a circular and elliptical shape (fig 7b) and, in another embodiment, a transition of a cross-sectional geometric shape of one channel (fig 10a-10c), it would be obvious for Byfield to provide a transition from a circular shape to an elliptical shape. This is supported by Byfield in paragraphs [0165-0166] which teaches that the configuration and/or cross sectional area of opposite ends of the channels may be changed.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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 nonprovisional extension fee (37 CFR 1.17(a)) 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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to HARRY E ARANT whose telephone number is (571)272-1105. The examiner can normally be reached Monday-Friday 10-6 ET.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Jianying Atkisson can be reached at (571)270-7740. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/HARRY E ARANT/Primary Examiner, Art Unit 3763
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