This case was remanded by the Supreme Court for further consideration
1
in light of the Court’s decision in
Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co.,
I
The issue of infringement of Talbert’s '356 patent is focused on the limitation of all of the claims to a gasoline boiling point range of 121°F-345°F, as in claim 1:
1. A low Reid Vapor Pressure liquid gasoline for use in a standard carburet-ed internal combustion engine; said gasoline comprising a priming agent and a hydrocarbon mixture having an intermediate carbon range relative to C4-Ci2 fuel; said intermediate carbon range consisting essentially of C6-C10 hydrocarbons with C9 and C10 paraffinic hydrocarbons being present in the mixture; said gasoline having a boiling point range of 121°F-345°F at 1 atmosphere pressure....
(Emphasis added.) The accused Unocal fuels were stated at trial to have boiling range endpoints of from 373.8°F to 472.9°F.
Talbert again argues for literal infringement, stating that the 345°F upper limit in the claims was included “only to confirm the gasoline’s predominant C6-C10 composition and to establish cut ranges for the fuel’s gasifier form.” Talbert states that “[t]o interpret that temperature range as a restriction or requirement regarding the presence of all the low- or high-end cоmponents contradicts the reality of accepted refinery practice and renders the claim meaningless.” Talbert points out that the specification recognizes and teaches that small amounts of hydrocarbons outside the claimed C6-C10 range may remain due tо the imprecision of fractionation:
[The preferred intermediate range C6-C10 gasoline] ... can be made by removing the volatile and heavy components so that the remaining hydrocarbon mixture will boil within a range of about 121°F-345°F at one atmosphere. Such a boiling point range encompasses the boiling point of the lowest boiling C6 component and the highest boiling C10 component. Of course, it is possible that a small amount of C4, C5, Cu and C12 may remain after the separation process due to imperfections of gasoline fractionation procedures.
’356 patent, col. 7, lines 39-48. Thus Tal-bert argues that the 345°F limit is “nothing more than a recognition that the highest boiling C10 hydrocarbon (i.e., paraffinic decane) must be present in the claimed composition” and that the claims, correctly construed, do not exclude the presence of higher boilеrs in relatively small amounts.
In construing the claims, even accepting Talbert’s view that gasoline fractionation does not readily achieve or require an exact endpoint, the prosecution history does not permit a claim scope that departs ■significantly from the stated temperature range. The temperature limit was placed in the claims at the examiner’s insistence, to distinguish prior art that included a Hamilton reference that showed hydrocarbon fuels with an endpoint “within the range of about 390°F and about 420°F.” Talbert had argued to the examiner thаt “the temperature range of the boiling points of the hydrocarbons of the gasoline of the presently claimed invention is between 96.8°F and 345°F.” To gain allowance, Talbert was required to place the temperature restriction in the claims.
Talbert presented no reasonable explanation of how his designated endpoint of 345°F is correctly construed to include fuels with endpoints of 373°F and higher. We therefore affirm the district court’s *1358 ruling that the claims are not literally infringed.
II
Infringement by application of the doctrine of equivalents was the basis of the GVR. Talbert requests remand to the district court fоr retrial in view of the Court’s change in the law. Unocal responds that prosecution history estoppel, as established by the Court’s Festo decision, bars Talbert’s attempt to reach the Unocal fuels, and that remand is inappropriate.
In
Festo
the Court applied the principles of prosecution history estoppel to claims that had been narrowed by amendment, reaffirming that estoppel “hold[s] the inventor to the representations made during the application process and to the inferences that may reasonably be drawn from the amendment.”
Festo,
1. A gasoline fuel comprising hydrocarbons having an intermediate carbon rаnge relative to gasoline which has a carbon range of C4-C12; said intermediate range being defined as the portion remaining when C4-C12 gasoline has removed therefrom an effective amount of lower weight volatile components to substantially eliminate evaporative loss and explosion potential and an effective amount of higher weight to raise the burn rate of the remaining hydrocarbons to a level comparable to C4-C12 gasoline.
The claims were rejected on references that showed gasoline of various hydrocarbon сontents and boiling ranges, including the Hamilton reference which showed an upper boiling limit in the range of 390°F— 420°F. Talbert argued to the examiner that
there is no disclosure in Hamilton which suggests the removal of lighter and heavier hydrocarbons from a gasoline type fuel to produce a fuel сonsisting essentially of hydrocarbons in the range of C5 — C40 having the boiling range set forth in the claims. In fact, Hamilton teaches away from such a fuel by providing for a fraction having a boiling range up to 390°F (column 1, lines 42-43). This fraction is not the same as, nor equivalent to, that which is the subject of applicant’s composition claims.
Talbert then limited the claims to up to C10 hydrocarbons, and at the examiner’s insistence added a boiling range of 121°F-345°F. The district court concluded that hydrocarbons boiling above 345°F were disclaimed by Talbert in order to obtain the patent, and imposed an estoppel commensurate with this conclusion.
Talbert argues that the temperature limit was placed in the claims to distinguish the Hamilton reference and applied only to gasifier applications, and not to the standard carbureted fuel to which the '356 claims are directed. Talbert argues that “citation of [the gasifier fuels’] prosecution history is irrelevant” because the two types of fuels are very different, stating: “Although the substantial elimination of the higher-boiling Cn+ hydrocarbons is important for gasoline requiring a gasifier, those physical properties are not required of standard gasolines, which contain primers to help provide adequate front-end volatility to start engines.” Thus Talbert argues that the 345°F limit that was added to the claims does not raise an estoppel to reaching the equivalent Unocal standard carbureted fuels that сontain CX1 hydrocarbons and boil above 345°F.
Talbert requests remand to the district court in order to provide evidence that persons of skill in the gasoline fractionating art would know that a hydrocarbon fuel described by its carbon number, such as C6 to C10, when distilled will contain *1359 some Cn hydrocarbons thаt boil above 345°F. Talbert states that the 345°F limit does not describe the actual composition that is distilled, and would be so recognized. Talbert argues that this evidence would also show that Talbert did not disclaim coverage of gasolines having an endpoint higher than 345°F.
Talbert’s patent was prosecuted before Festo was decided by the Suprеme Court, and on GVR the patentee may provide evidence not previously relevant. However, in this case the proffered evidence, viewed favorably to Talbert, does not overcome the clarity of the disclaimer of fuels boiling in the range of the Hamilton reference, viz., from 80 F up to the endpoint range of 390°F — 420°F. Nor can Talbert avoid the teaching in the '356 specification that standard carbureted fuel is the same as gasifier fuel “except for the presence of a small amount of priming agent” in the carbureted fuel. Col. 9, lines 19-23. Talbert has nоt suggested that persons reading the specification would recognize that statement as incorrect or as affecting the boiling point range of the claimed Talbert fuels.
We conclude that the amendment of the Talbert claims to a boiling point upper limit of 345°F, in light of the Hamilton reference showing gasolines with boiling endpoints of 390°F-420°F, is a presumptive surrender of gasolines boiling in the range between Talbert’s amended endpoint of 345°F and Hamilton’s endpoints.
See Festo,
The equivalent may have been unforeseeable at the time of the application; the rationale underlying the amendment may bear no more than a tangential relation to the equivalent in question; or there may be some other reason suggesting that the pаtentee could not reasonably be expected to have described the insubstantial substitute in question.
Id. Talbert, requesting remand, states that the record thus far adduced in the district court does not deal with these aspects of rebuttal, for they were not relevant to the issues as then рerceived. However, the prosecution history shows, and precedent confirms, that these rebuttal criteria cannot be met.
When the prior art embraces the alleged equivalent, and a narrowing amendment was made to avoid that equivalent, that subject matter cannоt be found to have been unforeseeable at the time of the amendment.
Pioneer Magnetics, Inc. v. Micro Linear Corp.,
Turning to the Court’s second potential ground of rebuttal, the reason for Talbert’s amendment cannot be deemed “tangential” to the Unocal alleged equivalent. The boiling range and carbon content were at issue during prosecution, and were the direct, not tangential, reason for the narrowing amendments to these claim limitations. This court’s remand decision in
Festo,
As for the Court’s third potential ground of rebuttal, no “other reason” for avoiding estoppel has been proffered. Talbert argues that the claims contain an unnecessarily exact boiling limit; if so, the court is without power to make such a correction.
See Autogiro Company of America v. United States,
In addition, the classical principles of the doctrine of equivalents preclude a finding of equivalency, for such finding requires only insubstantial differences between the invention as claimed and the alleged equivalent.
See Warner-Jenkinson Co. v. Hilton Davis Chem. Co.,
III
The district court refused to declare an interference, as provided by 35 U.S.C. § 291, between any claim of the Talbert patent and Unocal’s Patent No. 5,288,393, ruling that there was not identity of subject matter. We have considered Talbert’s argument that Unocal simply uses a different method of describing its fuel; however, Talbert has not shown the identity of invention required for declaration of interference. The district court’s ruling on this issue is affirmed.
Conclusion
The judgment of the district court is again affirmed.
Each party shall bear its costs.
AFFIRMED.
Notes
.
Talbert Fuel Systems Patents Co. v. Unocal Corp.,
. Talbert Fuel Systems Patents Co. v. Unocal Corp., No. 98-CV-412 (C.D.Cal. Dec. 15, 1998) (claim construction and dismissal of § 291 claim); (April 12, 1999) (summary judgment for Unocal); (May 3, 1999) (summary judgment for Tosco).
