The patent to DeWitt describes adding phosphate to a base fuel containing a lead alkyl antiknock agent and a mixture of ethylane dibromide and ethylene dichloride. The phosphate has the purpose of 'minimizing deposit-induced engine problem such as wild ping and spark plug fouling.' One of the patent's specific examples shows a fuel having a clear Research octane number of 91.1 and falling within the 4-sided figure required by defendant's claim. Although the patent specification mentions tetramethyl lead by name as one antiknock agent that may be used, it gives no example of a specific fuel which includes this compound. In the specific example corresponding to plaintiffs' fuel, tetraethyl lead is the only antiknock compound shown. The basic issue with respect to DeWitt, therefore, is whether it would have been obvious to use tetramethyl lead instead of tetraethyl lead as the antiknock agent in the fuel shown by the specific example.
After reviewing the testimony directed to the Hinkamp patent, it is the opinion of the Court that the Patent Office rejection on this reference was not inconsistent with the evidence. The plaintiffs admitted that numerous fuels have been available for years which boast clear Research octane numbers above 90. The defendant's contention that the number 90 is not critical was substantiated by the record in the Patent Office. Even before the Court the plaintiffs were hard put to contend that the number 90 was a critical feature of the invention. Insofar as the concentration of tetramethyl lead in the fuel is concerned, the references as a whole showed that lead alkyl additive concentrations in the range claimed by the plaintiffs were customary in the art at the time of the invention. It would seem unreasonable to assume that a person working in the art with the Hinkamp patent before him would not think to use a concentration in the range claimed if he sought to increase the antiknock capabilities of the fuel.
As to the DeWitt patent, the Court feels that the Patent Office's interpretation of this reference is somewhat strained. Although DeWitt describes in detail a fuel corresponding in virtually every way to plaintiffs', it varies in just that instance in which plaintiffs allege that their improvement has been made: it contains tetraethyl lead instead of tetramethyl lead. While tetramethyl lead indeed is mentioned as a possible alternative in a different portion of DeWitt's specification, there is no hint that it might be substituted for tetraethyl lead in a fuel having the properties specifically set forth by DeWitt in his working example. The Court does not believe that this reference, standing alone, would make plaintiffs' subject matter obvious to a person ordinarily skilled in the art.
Although plaintiffs demonstrated that the use of tetramethyl lead instead of tetraethyl lead in automotive fuel has gained substantial acceptance in the petroleum industry, this does not change the fact that fuels containing tetramethyl lead were generally known to be available at the time the invention was made. Although plaintiffs may have recognized more clearly than others the advantages of the use of these fuels, they cannot be said to have invented them.
The Court will find for the defendant, and against the plaintiffs, and will order that the Complaint be dismissed.
The above Opinion contains Findings of Fact and Conclusions of Law.
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