The opinion of the court was delivered by: WILKIN
The plaintiffs bring this action under 35 U.S.C. § 145, to authorize the Commissioner of Patents to issue letters patent containing claims 24 to 29 of application Serial No. 151,222. Plaintiffs' application relates to a process for making combustible fuel gas from hydrocarbon oils (such as petroleum oils) in an 'oil gas set' having one or more 'gas generators' communicating with a so-called 'superheater'. Both the generator and superheater are large metal shells containing a heat storage material, such as a 'checkerwork' of refractory brick, or the generator may in some instances have a so-called 'refractory screen' made up of more closely packed, smaller refractory particles so as to trap and retain liberated carbon, or a combination of checkerwork and a refractory screen.
Plaintiffs' process, in common with the prior art, begins with a 'heat run', which involves heating the generator and superheater to a suitable gas-making temperature by passing hot combustion products of 'heat oil' and air 'forwardly' through the generator and then 'forwardly' through the superheater. This is followed by a 'make run' which involves passing a hydrocarbon oil and the oil gas formed from the hydrocarbon oil or make oil 'forwardly' through the generator and 'forwardly' through the superheater. During the make run, carbon is formed and deposited in the generator to a degree depending on the temperature, character of make oil, and character of the generator structure. The gas product is withdrawn from the superheater, washed, and passed to storage by procedures having nothing to do with the claimed invention.
The above steps are characteristic of many oil gas manufacturing processes of the prior art. The distinguishing characteristic of plaintiffs' process begins with the preparation of the set for the next cycle of heat and make runs.
When economic conditions made the use of cheaper oils of high Conradson carbon content desirable, a problem arose because more carbon was deposited in the generators during the make run. To solve the problem, plaintiffs' process provided an air blast directed 'backwardly' through the superheater, 'backwardly' through the generators, and out through the stacks. The effects of the back air blast are two-fold. First, the air, preheated by passage through the superheater, effectively burned carbon deposited in the generator during the make run; and secondly, the back blast air, after reaching its maximum temperature, was conducted through the colder part of the generator adjacent the make oil inlet, which should be the hottest part of the system before beginning the next make run. The benefits of this process were a need for less fuel oil and a more efficient distribution of heat in the system.
It was conceded that Claim 24 defined the basic process. Claim 24 defines the plaintiffs' back blast step as follows:
The plaintiffs' brief states:
'This step, in combination with the abovementioned conventional steps, is the real meat of plaintiffs' invention.'
'To further characterize plaintiffs' invention and distinguish it from prior art such as the Johnson patent, Claim 24 concludes: 'said blast air being introduced at such a rate and for such period of time as to burn substantial quantities of carbon deposited in said at least one gas generating zone and so as to transfer appreciable amounts of heat to the oil inlet end of said at least one gas generating zone and repeating the cycle.'
The Examiner and the Board of Appeals denied the application, basing their adverse decisions primarily on the Johnson Patent (Defendant's Exhibit 1B). They pointed out that the Johnson process included that back blast relied upon for distinction by the plaintiffs, pointing out that the Johnson Patent in column 2, page 3, line 28, states that the efficiency of the process is greatly improved where the primary air and/or secondary air is preheated and supplies heat regenerated from the process.
At trial it was the position of the defendant that the process, as described in the Johnson patent, employing a back blast of air during the 'down blast' as Johnson terms it, meets the requirements of plaintiffs' Claim 24.
There are, of course, differences and distinctions between the two processes, but the defendant contended that they were not patentable inventions and not properly set forth in the claims.
The controversy in this case is characteristic of much patent litigation. Terms, words, and cliches of double meaning are used. In this case the defendant says, 'that Claim 24 reads step by step on the ...