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 .
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.
The following is a quotation of pre-AIA 35 U.S.C. 112, fourth paragraph:
Subject to the following paragraph [i.e., the fifth paragraph of pre-AIA 35 U.S.C. 112], 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 12 is rejected under 35 U.S.C. 112(d) or pre-AIA 35 U.S.C. 112, 4th paragraph, 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 12 depends from claim 1. Claim 1 now requires the metal foam and the outer sheath to consist of a same material. Thus, the outer sheath must consist of metal. Yet claim 12 requires the outer sheath to be formed of a plastic. Thus, claim 12 attempts to broaden the scope beyond that of the claim from which it depends by failing to include the limitation requiring the outer sheath to consist of a same material as the metal foam..
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 § 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) 1-13 and 15-21 are rejected under 35 U.S.C. 103 as being unpatentable over U.S. Patent Application Publication No. 2022/0255162 to Lambourne et al. ("Lambourne") and further in view of "Battery thermal management using phase change material-metal foam composite materials at various environmental temperatures" by Barnes et al. in the Journal of Electrochemical Energy Conversion and Storage Volume 17, May 2020 pages 021106-1 to 022106-7 ("Barnes" included in Applcant's IDS filing of May 30, 2023). Regarding claims 1 and 19, Lambourne discloses a bus bar to be used in electric motor vehicles. Lambourne at paragraphs [0002] and [0003]. The bus bars are made of metal mesh with an exterior liquid impermeable skin enclosure. Id. at paragraph [0064]. The skin is made of a thin metal. Id. at paragraph [0060]. A cooling liquid is introduced into the pore network of the metal mesh where during heat-generating operation the cooling liquid may be vaporized. Id. at paragraph [0065].
Lambourne differs from the present claims in that it discloses an active cooling system with inlet and outlet openings in the bus bar for the cooling liquid to be pumped in/out of. Barnes discloses related cooling device for battery cells, where the cooling device comprises a metal foam, a liquid impermeable skin, and a phase change material filling the pores of the metal foam. Barnes structure is a passive cooling structure, however, with no inlet/outlet holes such that the phase change material/foam
composite is fully enclosed in the cooling space of its batteries. Barnes teaches that such passive cooling systems are beneficial over active cooling systems such as those disclosed in Lambourne because they are simpler/smaller/lighter. Thus, the person of ordinary skill in the art at the time of invention would have found it obvious to remove the coolant inlet/outlet ports of Lambourne arriving at a bus bar fully encased by liquid impermeable case, filling the pores of its metal foam with a phase change material, as a means of simplifying and reducing weight of its cooling system as Lambourne teaches is beneficial in its aircraft applications.
Finally, although Lambourne discloses specific metals for use as it’s metal foam (e.g., copper, aluminum, and nickel) based on desired low weight and high conductivity, it does not provide any specific metals to use for its skin. Nonetheless, because the skin is part of the bus bar the same weight and conductivity considerations would govern material selection for it and thus selection of the same material for both parts of the bus bar are considered obvious means of achieving desired weight/conductivity properties.
Further regarding claim 2, Lamourne doesn't expressly disclose whether the skin is connected to the metal foam. However, Lamourne teaches that the electrical continuity of the bus bar is important. Thus, the person of ordinary skill in the art at the time of invention would have found it obvious to connect the skin and metal foam interior as a means of maximizing the overall electrical continuity of the bus bar.
Further regarding claim 3, Lambourne discloses the skin should be thin, but does not give a specific thickness. Nonetheless, Lambourne discloses that the skin ensures physical rigidity/stability of the bus bar. Thus, the thickness is considered to be a parameter that the person of ordinary skill in the art at the time of invention would have found obvious to adjust as a means of balancing weight/density and desired rigidity/sealing of the bus bar under pressure.
Further regarding claims 4-6, because the coolant is used to remove heat from the system, it is found the person of ordinary skill in the art at the time of invention would have had reason to provide the necessary pore-filling with the coolant as needed to adequately cool the battery system, including the recited range of pore-filling degree.
Further regarding claims 7 and 8, Lambourne discloses that the metal foam is an open-cell metal foam, but does not disclose a specific percentage of open pores. Nonetheless, because the purpose of the pores is in part to dissipate heat by coming into contact with coolant the Office finds that maximizing open porosity including in the recited ranges as an obvious way to increase access of coolant via to the surfaces of the metal foam via convective mobility.
Further regarding claims 9-11, Lambourne discloses that the density is an important design parameter of the metal foam, balancing weight and heat dissipation capacity against strength. Moreover, Barnes discloses the porosity is a parameter to adjust to optimize cooling in various conditions. Thus, although Lambourne doesn't disclose a specific porosity in terms of PPI, the Office find that the recited porosities are nothing more than the obvious product of routine experimentation in arriving at a metal foam having the desired balance between weight/heat dissipation properties and strength.
Further regarding claim 12, as noted Lambourne prioritizes weight reduction for its bus bar. Thus, the Office finds selection of plastic, a known material for making lightweight battery components, as a portion of the bus bar skin in order to reduce weight, to be an obvious choice of a commonly known material.
Further regarding claim 13, both Lamourne and Barnes disclose the use of copper and aluminum as their metal foam material.
Further regarding claims 15-18, Barnes discloses paraffin as a commonly used phase change material in passive metal foam/phase change cooling structures.
Further regarding claim 20, Lambourne shows that the closed ends of its bus bars include short faces arranged perpendicular to the height and lengthwise directions of the bus bar. The opposed short ends include inlet/outlet ports in its active system, but would be closed with similar closed end faces parallel to the other short face in a closed, passive system as suggested by Barnes.
Further regarding claim 21, the purpose of the bus bar in Lambourne is to connect numerous batteries together to arrive at a battery module having a single high voltage terminal output. Thus, although Lambourne doesn't show terminals on its bus bars, it does teach that the bus bars should provide a single high voltage terminal output for the connected batteries. The recited lug-shape is nothing more than a common shaped used for terminals.
Response to Arguments
Applicant's arguments filed July 7, 2026, have been fully considered but they are not persuasive. Applicant alleges that the previous rejection did not specifically address a scenario where the metal foam and skin of Lambourne consisted of a same material. Although the Office disagrees that the previous rejection did not sufficiently address this limitation, because this rejection is necessarily made non-final because of the new grounds of rejection of claim 12 for its failure to incorporate all limitations of the claim from which it depends resulting from the amendment to claim 1, the Office has taken the opportunity to more specifically address the why the choice of a same material for the foam and skin is found obvious.
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/WYATT P MCCONNELL/Examiner, Art Unit 1727
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