Broderson v. Marzall

194 F.2d 138, 90 U.S. App. D.C. 78, 91 U.S.P.Q. (BNA) 259, 1951 U.S. App. LEXIS 4094
CourtCourt of Appeals for the D.C. Circuit
DecidedNovember 23, 1951
Docket10631_1
StatusPublished
Cited by6 cases

This text of 194 F.2d 138 (Broderson v. Marzall) is published on Counsel Stack Legal Research, covering Court of Appeals for the D.C. Circuit primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Broderson v. Marzall, 194 F.2d 138, 90 U.S. App. D.C. 78, 91 U.S.P.Q. (BNA) 259, 1951 U.S. App. LEXIS 4094 (D.C. Cir. 1951).

Opinions

PRETTYMAN, Circuit Judge.

This is a patent case. The application was denied by the Patent Office. A complaint was filed in the District Court under Section 4915 of the Revised Statutes.1 Trial was had, and the District Court rendered an opinion, made findings of fact, announced conclusions of law, and entered judgment dismissing the complaint. The applicant appealed.

The applicant claims a patent for a method of operating a four-stroke-cycle Otto internal combustion engine. The patent was denied, by both the Patent Office and the District Court, upon the ground that no invention was shown in view of the prior art. To permit review of that conclusion, the application must be placed in its proper setting in the art.

The basic operation of an internal combustion engine is, of course, the movement of a pistonhead up and down, or to and fro, in a hollow cylinder. The power which causes that movement is the combustion of a mixture of air and either gas or vaporized liquid. In an Otto-type engine this combustion is caused by an electric spark. In a so-called four-stroke-cycle engine each complete operation consists of four strokes of the pistonhead, twice down and twice up. [139]*139On the first downstroke air and fuel are sucked into the cylinder. On the upstroke this air and fuel are compressed. Thereupon a spark occurs which ignites the mixture, causes rapid expansion, and forces the pistonhead down in the cylinder. The next upstroke forces the burned fuel out of the cylinder. Thus the four strokes are called the suction or intake stroke, the compression stroke, the power stroke, and the exhaust stroke. The essential ingredients for the operation are air, fuel, and an electric spark. Many variations in the size and shape of the cylinder, the proportions of air and fuel, the timing of the injection of air and fuel, the timing of the spark, and the arrangement of the air and fuel injectors and of the spark plug, have been tried in order to achieve effective operation, efficient and economical use of fuel, and the use of the lower grade hydrocarbons as fuels. Extensive research along these lines has been conducted almost continuously by many industries.

The problem with which industry has been faced in Otto engines is created by three simple physical facts. (1) Variation in the pressure in the cylinder at the moment of combustion, under different power demands, causes inefficient operation, knocking, etc. Therefore it is ¡highly desirable that pressure be maintained within a narrow range under all conditions of operation. (2) The ignitable ratio of available fuels and air is in a very narrow range. The optimum for gasoline is fifteen of air to one of fuel. A mixture too rich or too lean will not ignite. (3) Different load demands require different amounts of fuel for efficiency. Idling requires little fuel; starting motion on a heavy load demand requires much fuel. Put together these facts mean that when the power demand is light a little fuel is needed, but a little fuel necessitates a correspondingly small amount of air, and a lessened amount of air results in a light compression in the cylinder. In common parlance, when you throttle the gas you must also throttle the air and this causes inefficiency or trouble. The industry has sought the answer for years.

This applicant’s idea is to have two mixtures of air and fuel in the engine at the same time, instead of merely one mixture. He would keep one mixture at a ratio of air and fuel always readily ignitable. The other mixture 'he would keep always at the same pressure but varied in fuel content from very lean to very rich depending on power demands. To accomplish this two-mixture purpose, the applicant uses two chambers, one in the cylinder above the pistonhead at top dead center and the other in an offset or auxiliary chamber. To maintain constant pressure he injects the same amount of air into the chambers under all load conditions. He injects the fuel into the auxiliary chamber and varies the amount of fuel according to power demand. Then, in order to keep the mixture in the auxiliary chamber at an ignitable ratio under all conditions, he times the fuel injection so that, although under full power demand large amounts of fuel are sucked into the cylinder prior to combustion, under light power demand the fuel is confined to the auxiliary chamber and only air is in the cylinder itself. Thus he achieves a constant compression in the cylinder and a constantly ignitable mixture of fuel and air in the auxiliary chamber. He has two mixtures, one for one purpose and the other for another purpose. Both mixtures are in the engine at the same time, both are homogeneous, but they are separated, “stratified". The advantages of the method are claimed to be the more economical use of fuel, the possible use of low-grade fuel, and the absence of detonation or knocking.

The application relates to the method of operation. That method requires certain features in the design of the cylinder, chiefly a space in the cylinder above the pistonhead at top dead center and an auxiliary combustion chamber, separated from the cylinder by a somewhat restricted passageway, with an air intake valve, fuel injector, and spark plug all located in this auxiliary chamber. Separately considered these are all commonplaces of design. Adequate combustion space in the cylinder above the pistonhead at top dead center is a common feature of internal combustion engines. An auxiliary combustion chamber is a well-known device, being usual in a Diesel operation and Imown in an Otto operation, [140]*140as is indicated by Mock’s application, discussed infra: Neither does the application add any novel features to the customary valves, fuel injector, and spark plug, and it adds no new ingredients to the customary air and fuel.

But the application for patent is not directed at features of design. The application claims a method of operation, of which the following are the principal features: (1) the admission of constant charges of air to the combustion space, which space includes both the cylinder and the auxiliary chamber; (2) a supply of fuel varied in relation to the power demand; and (3) the timing of the fuel injection so that under full load demands about half of the fuel is injected during the intake stroke of the piston and the.other half during the compression stroke, and so that under minimum load demand (idling) all the fuel is injected during the compression stroke.

The inventiveness claimed is in the idea of two simultaneous homogeneous mixtures of fuel and air; of constant pressure in the cylinder and a mixture of ignitable proportions always at the spark plug, although the fuel is varied according to power demand; and of the arrangement and combination of known features of design and standard elements of operation to achieve these new and novel results.

The prior art upon which the Patent Office and the District Court relied was exemplified, both the Commissioner and the court said, by three patents, one to F. C. Mock, issued January 3, 1939, one to Oscar Werner, issued February 1, 1927, and the third a British patent, “Complete Accepted” May 17, 1932. The application for the Mock patent was directed principally to the elimination of detonation and its accompanying disadvantages. The claim of invention was for a combustion chamber of heart-shaped form offset from the cylinder, in which chamber the fuel injector and two spark' plugs were so arranged as that the combustion took the form of a spherical wave front of flame which moved toward the passageway from this chamber to the cylinder.

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194 F.2d 138, 90 U.S. App. D.C. 78, 91 U.S.P.Q. (BNA) 259, 1951 U.S. App. LEXIS 4094, Counsel Stack Legal Research, https://law.counselstack.com/opinion/broderson-v-marzall-cadc-1951.