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 .
Response to Amendment
The rejection of claims 1-12, 14, 15 and 17 under 35 U.S.C. 112(b) is withdrawn in view of the amendments to claims 1, 2, 7, 12, 14 and 17 and in view of Applicant’s remarks. With respect to claim 1, Applicant’s position that the recitations of the blocks of polymer foam of the first portion and of the second portion find antecedent basis by implication in the recited plurality of self-supporting heat-insulating panels which each comprise a block of polymer foam is persuasive; the scope of those limitations is reasonably ascertainable by one of ordinary skill in the art. See MPEP 2173.05(e). With respect to claim 3, the rejection directed to the term “substantially equal” is withdrawn in view of paragraphs [0019] and [0048] of the specification as published, which define the term by reference to manufacturing and assembly tolerances and recite a tolerance of +/- 5 kg/m3 with respect to the stated density values.
The amendments to claims 13 and 16 have introduced indefiniteness that was not present in those claims as previously presented. New grounds of rejection under 35 U.S.C. 112(b) necessitated by those amendments are set forth below.
Claim Interpretation
The limitation “a pump suction member configured to discharge the liquefied gas contained inside the tank from the drain” recited in claim 14 has been considered under the three-prong analysis of MPEP 2181(I). Although “member” is a generic placeholder, it is modified in the claim by the term “pump suction,” which recites structure recognized in the art, namely the suction end of a pump, and which is so used in the prior art of record (Sassi, suction head of pump 1, ¶ 0063). The limitation therefore recites sufficient structure for performing the claimed function, and 35 U.S.C. 112(f) is not invoked. No limitation of claims 1-17 has been interpreted under 35 U.S.C. 112(f).
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 13 and 16 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 13 as amended recites “wherein the second portion of the bottom wall comprises a plurality of second portions.” Claim 13 depends from claim 1, which recites a bottom wall comprising at least one first portion at least partially surrounding a second portion of the bottom wall. The amended limitation is indefinite because it recites that the second portion of claim 1 itself comprises a plurality of second portions, which is circular and leaves the metes and bounds of the claim unascertainable: it cannot be determined whether the plurality of second portions is contained within the single second portion of claim 1, or whether the second portion of claim 1 is one of the recited plurality. Paragraph [0016] of the specification as published states that the bottom wall comprises a plurality of second portions, and FIG. 1 depicts the first portion surrounding a plurality of second portions. For examination purposes the limitation has been read as --wherein the bottom wall comprises a plurality of second portions--. Correction is required.
Claim 16 as amended recites “the pump configured to discharge the liquefied gas contained inside the tank for driving a flow of the liquefied gas through the insulated pipes.” There is insufficient antecedent basis for the recitation of “the pump.” Claim 14, from which claim 16 depends, recites a pump suction member, not a pump. For examination purposes the limitation has been read as --a pump--. Correction is required.
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.
Claims 1, 2, 7 and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Dhellemmes et al. (US 6,035,795) in view of Sassi et al. (US 2017/0152993).
In regard to claim 1, Dhellemmes teaches a tank for transporting and/or storing a liquefied gas (impermeable and insulating tank built into a ship’s load-bearing structure) comprising:
a plurality of walls (1, 101; panels 2, 102), each wall of the plurality of walls comprising, in a direction of a thickness of the wall, a thermally insulating barrier (108) and at least one leak-tight membrane (119) that rests against the thermally insulating barrier (108) and is intended to be in contact with the liquefied gas inside the tank (col. 10, ll. 33-42; col. 11, ll. 46-62; figs. 8, 10); and
the thermally insulating barrier (108) comprising a plurality of self-supporting heat-insulating panels (102) which each comprise a block of polymer foam (108, reinforced polyurethane) and at least one plate (109) (col. 11, ll. 46-51; col. 12, ll. 23-25; figs. 8, 10).
Dhellemmes does not explicitly teach (a) that a bottom wall of the plurality of walls comprises at least one first portion at least partially surrounding a second portion of the bottom wall, the second portion comprising at least one drain, or (b) that the blocks of polymer foam of the second portion have a density greater than a density of the blocks of polymer foam of the first portion.
However, Sassi teaches, as to limitation (a), a liquefied natural gas tank whose bottom wall (2) comprises a first portion occupied by the insulating barriers (4, 6) at least partially surrounding a second portion occupied by a sump structure (10), the second portion comprising at least one drain (10, 11, receiving residual liquid under gravity and housing the suction head of pump 1) (¶¶ 0063-0070, 0074, 0079, 0083; figs. 1-5).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the bottom wall of Dhellemmes to comprise at least one first portion at least partially surrounding a second portion comprising at least one drain as taught by Sassi, in order to maximize the cargo volume that can be unloaded by minimizing the head of liquid left in the bottom of the tank and keeping the pump suction member immersed notwithstanding sloshing (Sassi ¶¶ 0004, 0008, 0083). One of ordinary skill would have been motivated to make this modification because Dhellemmes lines its walls with repeated prefabricated panels fastened individually to the load-bearing structure and completed locally by insulating tiles and flexible strips (col. 10, ll. 33-42; figs. 8, 10), a construction that accommodates the local interruption the sump structure requires. See MPEP 2143(I)(C).
Dhellemmes in view of Sassi further teaches, as to limitation (b), that the second portion is insulated by a self-supporting panel comprising a polyurethane foam block and plywood plates (30) which must be of sufficient rigidity to structurally support the sump containers (11, 16) and, through them, the pump suction head (1), a load the blocks of the first portion (4, 6) do not carry (¶¶ 0076, 0081, 0084; figs. 1, 3).
Therefore, it would further have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have made the blocks of polymer foam of the second portion of the modified bottom wall of Dhellemmes of a density greater than that of the first portion as taught by Sassi, in order to supply the rigidity Sassi requires of the insulating material carrying the sump structure and the pump suction head, while leaving the unloaded first portion at the lower density (Sassi ¶¶ 0076, 0081). One of ordinary skill would have been motivated to make this modification because Dhellemmes selects foam density and reinforcement by the mechanical stress borne by each region of the same tank, using reinforced foam of approximately 120 kg/m3 where stresses are greater, including the secondary barrier layers of the angle structure (144), and unreinforced foam of approximately 105 kg/m3 for the panel layers (104), which the deformable washers (134) relieve (col. 12, ll. 23-35; claims 4 and 19; fig. 10). See MPEP 2143(I)(D).
Official notice was taken in the Office action of February 25, 2026 that the bottom wall of a cryogenic storage tank is subject to greater compressive loads due to the hydrostatic head of the stored liquid; that a sump region in the bottom wall experiences localized stress concentrations and structural loading due to liquid collection and drainage geometry; that increasing polymer foam density increases compressive strength and load-bearing capability; and that it is well known engineering practice to vary insulation density locally to accommodate differing mechanical loads. Applicant’s reply does not state why any of these facts is not well known in the art and does not request evidentiary support. The traversal is not adequate and the facts are taken to be admitted prior art. See MPEP 2144.03(C). Directly corresponding evidentiary support for the last of them is in any event supplied by Dhellemmes as cited above.
In regard to claim 2, Dhellemmes as modified by Sassi teaches the tank of claim 1, wherein Dhellemmes further teaches the tank wherein the plurality of walls comprises an upper wall and side walls connecting the bottom wall to the upper wall (panels 102 fastened to the walls 1 and transverse bulkheads 101 bounding the tank compartment; corner joins 140, 142, 143, 144) (col. 10, ll. 33-42; col. 12, ll. 23-35; figs. 8, 10).
Dhellemmes as modified by Sassi does not explicitly teach a density of the blocks of polymer foam of the self-supporting heat-insulating panels decreasing from the bottom wall to the upper wall.
As set forth in the rejection of claim 1 above, Dhellemmes selects foam density and reinforcement by the mechanical stress borne by each region of the same tank, using approximately 120 kg/m3 reinforced foam where stresses are greater and approximately 105 kg/m3 unreinforced foam where they are lower (col. 12, ll. 23-35; claims 4 and 19; fig. 10). Official notice was further taken in the Office action of February 25, 2026 that hydrostatic pressure in a liquefied gas storage tank increases with depth, that the bottom wall of such a tank is subjected to greater compressive loads than upper wall regions, and that the compressive strength of polymer foam increases with increasing density. Those facts stand admitted. See MPEP 2144.03(C).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have selected the density of the blocks of polymer foam of the self-supporting heat-insulating panels of the modified tank of Dhellemmes so as to decrease from the bottom wall to the upper wall, in order to withstand the greater hydrostatic and compressive loads at the bottom of the tank while reducing material usage and weight above, where those loads are lower. Foam density is a result-effective variable controlling compressive strength, and its selection region by region is a matter of routine optimization. See In re Aller, 220 F.2d 454, 105 USPQ 233 (CCPA 1955); MPEP 2144.05(II).
In regard to claim 7, Dhellemmes as modified by Sassi teaches the tank of claim 1, wherein Dhellemmes further teaches the tank wherein the at least one leak-tight membrane is a primary leak-tight membrane (119) and the thermally insulating barrier is a primary thermally insulating barrier (108), and wherein the bottom wall comprises a secondary leak-tight membrane (106) and a secondary thermally insulating barrier which comprises a plurality of self-supporting heat-insulating blocks (102, secondary barrier elements) comprising tiles of polymer foam (104) and at least one plate (103), the secondary leak-tight membrane (106) resting against the secondary thermally insulating barrier (104), the primary thermally insulating barrier (108) resting against the secondary leak-tight membrane (106) and the primary leak-tight membrane (119) resting against the primary thermally insulating barrier (108) (col. 11, ll. 46-62; col. 12, ll. 23-35; figs. 8, 10).
In regard to claim 13, Dhellemmes as modified by Sassi teaches the tank of claim 1, wherein Dhellemmes does not explicitly teach that the bottom wall comprises a plurality of second portions.
However, Sassi teaches a sump structure (210) located in the bottom wall at the position of a pump suction member, and a tank unloaded by more than one pump arranged inside it (main pump 62; auxiliary pump 1) (¶¶ 0118, 0122; fig. 11).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have provided the modified bottom wall of Dhellemmes with a plurality of second portions as taught by Sassi, in order to house the suction member of each pump arranged inside the tank and minimize the residual liquid at each such location.
Claims 14-17 are rejected under 35 U.S.C. 103 as being unpatentable over Dhellemmes in view of Sassi, as applied to claim 1 above, and further in view of Dubar et al. (US 6,250,244 B1).
In regard to claim 14, Dhellemmes as modified by Sassi teaches the tank for transporting and/or storing a liquefied gas of claim 1, and Sassi further teaches a pump suction member (suction head of pump 1) configured to discharge the liquefied gas contained inside the tank from the drain (10) (Sassi ¶¶ 0063, 0083, 0122; figs. 1, 11).
Dhellemmes as modified by Sassi does not explicitly teach a gravity platform comprising the tank.
However, Dubar teaches a gravity platform (601, 610, 610’) comprising a platform (601) above sea level, a liquefied natural gas storage tank (603) supported by a concrete gravity base (610) on the seabed, and means (611) for supplying liquefied natural gas to a carrier (col. 21, l. 64 - col. 22, l. 31; figs. 11, 12).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have installed the tank of Dhellemmes as modified by Sassi in the gravity platform as taught by Dubar, in order to provide the tank with a fixed offshore support resting on the seabed from which the stored gas may be supplied to a carrier.
In regard to claim 15, the modified Dhellemmes teaches the gravity platform of claim 14, but does not explicitly teach a support structure of the tank, the support structure being made of concrete.
However, Dubar teaches a gravity platform in which the storage tank (603) is supported by a support structure in the form of a concrete gravity base (610, 610’) on the seabed, the platform (601) bridging the gravity bases (col. 21, l. 64 - col. 22, l. 31; figs. 11, 12).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have supported the tank of Dhellemmes as modified by Sassi on a support structure made of concrete as taught by Dubar, in order to provide the tank with a fixed base resting on the seabed and projecting above the water level at the offshore location.
In regard to claim 16, the modified Dhellemmes teaches the gravity platform of claim 14, but does not explicitly teach (a) a transfer system comprising insulated pipes arranged so as to connect the tank installed in a support structure of the gravity platform to a ship, or (b) a pump for driving a flow of the liquefied gas through the insulated pipes from the tank to the ship.
However, Sassi teaches, as to limitations (a) and (b), a transfer system comprising insulated pipes (73, 76, 79, 81) connecting a tank (80) installed in a storage facility (77) to a ship (70) by way of a loading and offloading station (75) and mobile arm (74), and pumps (1, 62) for driving the cold liquid product through those pipes (¶¶ 0047, 0120-0122; fig. 12).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have provided the gravity platform of Dhellemmes as modified by Sassi and Dubar with insulated pipes connecting the tank to a ship and with a pump for driving the liquefied gas through those pipes as taught by Sassi, in order to transfer the cargo over a large distance and permit the vessel to remain offshore during loading and offloading.
In regard to claim 17, the modified Dhellemmes teaches the gravity platform of claim 14, but does not explicitly teach a method for loading or unloading the gravity platform wherein the liquefied gas is conveyed through insulated pipes from the tank of the gravity platform to a ship.
However, Sassi teaches a method for loading or unloading in which a cold liquid product is conveyed through insulated pipes (73, 76, 79, 81) between an on-shore storage facility (77) and the tank of a ship (70), the transfer pressure being generated by pumps (1, 62) on board the ship, at the shore facility, or at the loading and offloading station (75) (¶¶ 0046, 0120-0122; fig. 12).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have conveyed the liquefied gas through insulated pipes from the tank of the gravity platform of Dhellemmes as modified by Sassi and Dubar to a ship as taught by Sassi, in order to transfer the cargo between the offshore storage facility and the vessel over a large distance while the vessel remains offshore (Sassi ¶¶ 0121-0122).
Allowable Subject Matter
Claims 3, 4 and 8-12 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Claims 5 and 6 depend from claim 4 and would likewise be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Response to Arguments
Applicant’s arguments filed June 25, 2026 have been fully considered. Those arguments directed to 35 U.S.C. 112(b) are persuasive in part, as set forth in the Response to Amendment section above. Those arguments directed to 35 U.S.C. 103 are not persuasive for the reasons that follow.
Applicant argues (page 9-10) that the cited references do not describe polymer foam blocks of different densities according to their position within the bottom wall.
In response, the argument is not persuasive. The argument does not respond to the findings actually made. The Office action of February 25, 2026 took official notice of four facts, recited in the rejection of claim 1 above. To adequately traverse a finding of official notice, an applicant must specifically point out the supposed errors in the examiner’s action, which includes stating why the noticed fact is not considered to be common knowledge or well known in the art. See 37 CFR 1.111(b); MPEP 2144.03(C). Applicant’s reply does not state that any of the four noticed facts is not well known, does not identify any error in them, and does not request evidentiary support for them. Each is accordingly taken to be admitted prior art. Independently of that, and to advance prosecution, directly corresponding evidentiary support for the fact that insulation density is varied locally to accommodate differing mechanical loads is set forth in the rejection of claim 1 above from Dhellemmes, of record.
Applicant argues (page 10) that paragraphs [0091]-[0092] of Sassi teach away from the use of rigid materials in the portion surrounding the sump because those paragraphs state that softer insulating materials may be used there.
In response, the argument is not persuasive because the argument mischaracterizes the cited passage. Paragraphs [0091]-[0092] describe the embodiment of FIG. 2, in which support bases (45) and a support wall (46) extend the lateral walls of the bowls so as to bear directly against the bottom walls beneath them, with the consequence that the insulating materials housed in the secondary and primary spaces need not offer as much structural rigidity as the insulating panel (30). That statement confirms rather than discredits the finding on which the rejection rests, namely that the insulating panel (30) of the embodiments of FIG. 1 and FIG. 3 is the element of enhanced mechanical capability in the region of the sump, and that Sassi selects the mechanical capability of the insulating material in that region according to whether the sump load is carried by the insulation or by separate metal supports. A reference teaches away only where it criticizes, discredits or otherwise discourages the solution claimed. See MPEP 2123(II) and 2145(X)(D). Sassi does neither.
Applicant argues (page 10-11) that one of ordinary skill in the art would instead have used a rigid material such as the plywood sheet (36) of Sassi, or would have increased the density of the bottom wall as a whole rather than in the zone around the sump.
In response, the argument is not persuasive. Disclosed alternatives are not a teaching away, and a claimed invention is not rendered nonobvious merely because the prior art also made other options available. Nor must a modification be the best option, or the only option, in order to be obvious; it need only be a suitable option supported by a rational underpinning. See In re Fulton, 391 F.3d at 1200; In re Mouttet, 686 F.3d 1322, 1334 (Fed. Cir. 2012); MPEP 2123(II) and 2143(I). The rationale supplied in the rejection of claim 1 above is drawn from the express teachings of Dhellemmes and Sassi themselves.
Applicant argues (page 10) that Dhellemmes is silent regarding a drain and regarding foam of different densities, that Sassi is silent regarding a greater density in the sump portion, and that Dubar is silent regarding the elements forming a bottom wall.
In response, the argument is not persuasive. One cannot show nonobviousness by attacking references individually where the rejection is based on a combination of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986); MPEP 2145(IV). The rejection does not rely on Dhellemmes for the drain or on Sassi for a numerical density, but on what the combined teachings would have suggested to one of ordinary skill in the art.
Applicant identifies (page 10) an objective technical problem and a technical effect said to follow from the greater density of the foam of the second portion, namely the provision of mechanical strength and thermal insulation in the portion of the bottom wall that houses a pump component.
In response, Patentability under 35 U.S.C. 103 is determined under the framework of Graham v. John Deere Co. and KSR Int’l Co. v. Teleflex Inc., not under a problem and solution analysis. In any event, the asserted effect is precisely the result that one of ordinary skill in the art would have expected from increasing the density of a rigid polymer foam in a locally loaded region, and it is the same result that Dhellemmes obtains by the same means. The assertion is unsupported by any objective evidence of unexpected results, and argument of counsel cannot take the place of evidence in the record. See MPEP 716.01(c) and 716.02(a).
Applicant argues (page 11) that the rejection relies on an ex post facto analysis.
In response, the argument is not persuasive. The rationale for the modification is taken from the references themselves: Sassi states that the insulating material carrying the sump structure must be of sufficient rigidity to support it, and Dhellemmes selects foam of greater density and reinforcement in the regions of its own tank that are subjected to greater mechanical stress while using foam of lower density where the stress is lower. Any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning, but so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made and does not include knowledge gleaned only from Applicant’s disclosure, such a reconstruction is proper. See MPEP 2145(X)(A).
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.
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/W.M/Examiner, Art Unit 3763
/FRANTZ F JULES/Supervisory Patent Examiner, Art Unit 3763
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