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 .
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 (i.e., changing from AIA to pre-AIA ) 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 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) 1-5 and 10-14 is/are rejected under 35 U.S.C. 103 as being unpatentable over Christie et al (US 20100062289 A).
Regarding claim 1, Christie, drawn to bipolar plates in fuel cell stacks, discloses bipolar plate (para 46, “flow field plates 202”; fig 6) for a fuel cell stack (para 45, “fuel cell stack 200”; fig 6) having two layers which each have an anode-side or cathode-side flow area on their surfaces facing away from one another (para 46, fig. 7B), wherein aligned media inlet openings and media outlet openings (para 48, “reactant manifold opening 206”; fig. 7B) are provided in the two layers, wherein each of the media inlet and outlet openings are connected to channels (para 48, “back-feed channels 210”; fig. 7B) in at least one of the inner surfaces of the two layers, and wherein the channels assigned to the anode side and the cathode side are each connected to the anode-side or cathode-side flow areas via through-openings in the respective layer, wherein the flow area is formed by a depression in the surface of the respective layer which has flow distribution and/or flow guiding structures projecting above the bottom of the depression (para 48, see annotated figure below).
Christie does not explicitly disclose the material of the respective layer is reinforced in the sections opposite to the through-openings of the other layer.
Christie does disclose a slot 214 which extends “at least partially, or completely, around a periphery of the reactant manifold opening 206” with a transition portion whose geometry depends on angle a (para 48). Christie further teaches that variation of angle α results in different flow field configurations such as parallel and tapered flow fields when angle α is obtuse and rectangular cross-section when angle is right angle (para 48). Although Christie describes the variations in fluid flow, angle α also changes the structural geometry of the transition region. The cross-section formed when angle α is right angle, inherently provides a region of increased material distribution adjacent to and opposite the through-opening.
A skilled artisan would have understood that such configuration predictably provides structural reinforcement in the region opposite the through-opening due to the presence of continuous material and reduced taper. It would have been obvious to one of ordinary skill in the art, before the effective filing date of the invention, to reinforce the material of respective layer in the sections opposite to the through-openings of the other layer as taught by Christie above as doing such allows desired transition geometry and fluid flow (para 48).
Christie does not explicitly disclose the reinforced sections have a greater material thickness than the material thickness between the deepest point of the flow area in the respective layer and the opposite surface of the same layer, wherein the greater material thickness is achieved by a section of the flow area having a reduced depth.
Christie does disclose wide dimension or slot height 218 and narrow dimension 216 (para 48; fig. 7B). When angle α is right angle, the transition region cross section (reinforced section) has a greater material thickness than the material thickness between the deepest point of the flow area in the respective layer and the opposite surface of the same layer. The greater material thickness decreases the slot height which reduces the depth of the flow area (see annotated figure below).
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Regarding claim 2, Christie discloses reinforced section having reduced depth is connected to the edge of the flow area. The transition region cross section (reinforced section) is adjacent to and opposite the openings (see annotated figure above). The cross-section is positioned along the outer perimeter of the plate body rather than within the interior flow field region. A skilled artisan would understand this placement as being connected to the edge of the flow area.
Regarding claim 3 and 10, Christie discloses no part of the flow area is formed in the reinforced section. The transition region cross section (reinforced section) is continuation of the flow field plates (see annotated figure above). It is on the unchanneled portion of the plate, in contrast to the adjacent flow field region that includes channel for fluid flow. The absence of any depicted channels or flow structures within this transition region would be understood by person of ordinary skill in the art as indicating that no flow area is formed in that region.
Regarding claim 4 and 11 and 12, Christie discloses the greater material thickness of the reinforced section is implemented by a smaller depth of the channel. Christie represents depth of the channel by slot height 218 (fig. 7B). The addition of transition region cross section decreases the slot height 218 to narrow dimension 216 (see annotated figure above). Christie teaches that when slot height 218 is 0.8 mm, the narrow dimension 216 is 0.4 mm (para 52). A skilled artisan would understand the transition angle cross section leads to greater material thickness as it reduces the slot height and thus the depth of the channel.
Regarding claim 5 and 13-14, Christie discloses the material thickness on the reinforced section is greater than the material thickness between the deepest point of the flow area in the respective layer and the opposite surface of the same layer (refer to claim 1 above). Christie does not explicitly disclose the greater material thickness on the reinforced section is 1.5 to 2.5 times, preferably 2 to 2.5 times the material thickness between the deepest point of the flow area in the respective layer and the opposite surface of the same layer. The courts have generally held that in the absence of unexpected results, the change in a particular shape, proportion, or relative dimension is not deemed to be patentably distinguishing (MPEP 2144.04(IV)). In the instant case, a person of ordinary skill in the art would have recognized the need to have enough of a center portion to support the structural integrity of the product. However, the specific ratio claimed does not appear to be critical, other than reflecting a user design choice. Accordingly, in the absence of such results being provided, the claimed relative dimensions are not deemed to be patentably distinguishing.
Claim(s) 7, 9, 15-16, 19-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Christie et al (US 20100062289 A), as applied to claim 1, 2 and 3 above, and further in view of Tomana et al. (US 20190067712 A1).
Regarding claim 7 and 15-16, Christie discloses flow area (para 58, “flow field plate assembly 412”; fig 9A-C) includes a flow field (para 58, “flow field plates 402 and 402”; fig 9A-C) and distribution areas comprising the through-openings (para 58, “a reactant manifold opening 406”; fig. 9A), wherein the flow field includes flow guiding structures, in particular in the form of ribs (para 58, “ribs 428”; fig. 9A), and the distribution areas include open flow distribution structures (para 58, fig. 9A-C).
Christie does not disclose the distribution structures are in the form of nubs.
Tomana, drawn to metal separator (bipolar plates) in power generation cell, discloses flow distribution structures in the form of nubs (para 39, "bosses 50a, 50b"; fig 3). It would have been obvious to one of ordinary skill in the art, before the effective filing date of the invention, to add the nubs in bipolar plate of Christie as doing such forms a “buffer on the coolant surface" (para 40).
Regarding claim 9 and 19-20, Christie does not explicitly disclose the reinforcement of the material in the reinforced section is implemented by applying or introducing a further material. Christie does disclose that geometric variations can be formed in an insert which can be retrofitted to existing flow field plates, indicating that transition region cross section (reinforced section) does not need to be unitary with the remainder of the plate (para 66). Christie teaches that the insert can be hydrophobic insert and can be fabricated from silicone or “any other suitable material capable of withstanding typical operational and environmental conditions encountered by a fuel cell stack application” (para 68). Christie further teaches that in portions proximate to reactant manifold openings, hydrophobic insert can additionally comprise hydrophobic coating to “impede or substantially terminate water collection and/or ice formation” (para 69). It would have been obvious to one of ordinary skill in the art, before the effective filing date of the invention, to apply or introduce a further material to reinforce the material in the reinforced section by adding the hydrophobic insert as taught by Christie as doing such “impede(s) or substantially terminate(s) water collection and/or ice formation” (para 69).
Claim(s) 8 and 17 -18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Christie et al (US 20100062289 A), as applied to claim 1, 2 and 3 above, and further in view of Berta (WO 2005038969 A1, see attached machine translation).
Regarding claim 8 and 17-18, Christie does not explicitly disclose two layers are each formed from a plastic matrix filled with a carbon-containing material.
Berta, drawn to manufacture of bipolar plates for fuel cells, discloses material for bipolar plate which “comprises a matrix of thermoplastic material in which conductive fillers including graphite” (Abstract). It would have been obvious to one of ordinary skill in the art, before the effective filing date of the invention, to modify the bipolar plates such that two layers are each formed from a plastic matrix filled with a carbon-containing material as taught by Berta as doing such results in a material having high thermal and electric conductivity (Abstract).
Response to Arguments
Applicant's arguments filed 7/30/2026 have been fully considered but they are not persuasive.
Regarding the rejection under Christie, on page 9 of the Remarks, the applicant argues that the actual through-openings of claim 1 are “located further downstream at the end of the back-feed channels 210” and are the back-feed ports 208. Applicant states the “area directly opposite these back-feed ports 208-that is, where the mechanical pressure loads and risk of cracking due to pressure surges actually occur” where Christie “shows no local material reinforcement”. This argument is not persuasive. The argument is not commensurate with the scope of the claim because the claim does not require the through opening to be the back-feed ports 208 or be distinct from the recited media inlet and outlet openings. Applicant’s argument appears to treat the media inlet/outlet openings and the through openings as necessarily different structures. However, such distinction is not recited by the claim. Under broadest reasonable interpretation, the recited through openings may encompass the media inlet/outlet openings. Applicant’s argument relies on limitations that are not recited in claim 1 and thus are not persuasive.
Applicant subsequently argues Christie “does not teach achieving a greater material thickness opposite these through-openings by locally reducing the depth of the active flow area, as recited by claim 1”. The argument is not persuasive because it is not germane to the basis of the rejection. The rejection does not rely on Christie disclosure of greater material thickness being achieved by section of flow are having a reduced depth. Rather, the rejection relies on the teachings of Christie concerning varying slot geometry and the resulting obviousness of modifying the local geometry. Accordingly, the argument is not persuasive.
On page 10 of the Remarks, applicant asserts that Christie discloses “a purely fluid-dynamic solution” which relies on a hydrodynamic solution-controlling capillary forces by tapering a slot 214 to wick water away”. Applicant continues “tapered thickness change actually reduces the plate wall thickness at the wide end 221 of the slot 214” and concludes “Christie does not contemplate or suggest mechanically reinforcing the opposite wall to withstand localized pressure differences or extreme pressure events”. The applicant concludes “there is no motivation for a person skilled in the art to modify Christie to arrive at the claimed localized reinforcement of reduced depth, as Christie's capillary-driven design teaches away from modifying the local channel depths for mechanical reinforcement”.
The arguments are not persuasive. First, applicant’s characterization of Christie as addressing ice formation through fluid -dynamic measures does not establish that the skilled artisan would have ignored the structural requirements. Christie’s identification of one problem and proposed solution does not teach away from addressing different known problem through conventional structural modification. Second, Christie expressly discloses variation of transition geometry as a function if angle a and teaches a right-angle configuration (para 48). The fact that another angular configuration may provide a tapered region having a reduced wall thickness for a particular fluid-flow or wicking configuration does not establish Christie teaches away from the right angle configuration or from obtaining corresponding structural benefit. Christie also does not discourage modifying local geometry to provide greater material thickness. Accordingly, for reasons detailed above, the rejection is maintained.
Regarding the rejection under Christie and Tomana, applicant argues Tomana's do not reinforce “a plate layer opposite a through-opening” and that Tomana does not teach or suggest “a two-layer bipolar plate having a localized reinforced section of reduced depth directly opposite a through-opening of the adjacent layer to withstand localized pressure differences or extreme pressure events”. The argument is not persuasive because it is not germane to the basis of the rejection. Tomana is relied upon for its teaching of distribution structures in the form of nubs. Thus, the rejection is maintained.
Similarly, regarding the rejection under Christie and Berta, the applicant argues “Berta does not disclose any localized geometric reinforcement”. The argument is not persuasive because it is not germane to the basis of the rejection. Berta is relied upon for its teaching of layers formed from a plastic matrix filled with a carbon-containing material. . Thus, the rejection is maintained.
Applicant alleges “there is no motivation for a person skilled in the art to combine these references” while stating “Christie's capillary-driven design and Tomana's membrane support structure teach away from modifying the local channel depths of the flow area for mechanical reinforcement opposite through-openings”. The argument is not persuasive. Neither Christie nor Tomana discourages or teaches against modifying the local flow area geometry to provide greater material thickness.
In response to applicant’s argument that there is no teaching, suggestion, or motivation to combine the references, the examiner recognizes that obviousness may be established by combining or modifying the teachings of the prior art to produce the claimed invention where there is some teaching, suggestion, or motivation to do so found either in the references themselves or in the knowledge generally available to one of ordinary skill in the art. See In re Fine, 837 F.2d 1071, 5 USPQ2d 1596 (Fed. Cir. 1988), In re Jones, 958 F.2d 347, 21 USPQ2d 1941 (Fed. Cir. 1992), and KSR International Co. v. Teleflex, Inc., 550 U.S. 398, 82 USPQ2d 1385 (2007). In this case, the motivations are found in the prior art references themselves (see prior office action). Accordingly, the rejection is maintained.
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 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.
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/A.K./Examiner, Art Unit 1746
/MICHAEL N ORLANDO/Supervisory Patent Examiner, Art Unit 1746
