Oliver United Filters v. Silver

• Decision Date: 23 July 1953
• Docket Number: No. 4574.,4574.
• Citation: 206 F.2d 658
• Parties: OLIVER UNITED FILTERS, Inc. v. SILVER.
• Court: U.S. Court of Appeals — Tenth Circuit

206 F.2d 658 (1953)

OLIVER UNITED FILTERS, Inc. v. SILVER.

No. 4574.

United States Court of Appeals Tenth Circuit.

July 23, 1953.

Oscar A. Mellin, San Francisco, Cal. (Pershing, Bosworth, Dick & Dawson, Winston S. Howard, Denver, Colo., Leroy Hanscom, and Jack E. Hursh, San Francisco, Cal., on the brief), for appellant.

James P. Hume, Chicago, Ill. (James A. Woods and Charles J. Beise, Denver, Colo., on the brief), for appellee.

Before HUXMAN, MURRAH and PICKETT, Circuit Judges.

PICKETT, Circuit Judge.

Harold F. Silver is the owner of U. S. Letters Patent No. 2,390,131 issued December 4, 1945 and No. 2,468,720 issued April 26, 1949. These patents disclose an apparatus and process for extracting sugar solution from sugar beets known to the art as continuous diffusion. Oliver United Filters, Inc.¹ brought this declaratory judgment action in which it prayed for a decree adjudging patent No. 2,390,131 invalid and not infringed by a machine built by Oliver and known as the "Morton Battery". Silver answered, and alleged that the patent was valid, and counterclaimed for the infringement of claims 1, 2, 4, 6, 8, 11, 12, and 13 of patent No. 2,390,131, and for the infringement of claims 2, 3, 4, 6, 7, 9, 10, and 11 of patent No. 2,468,720. Upon trial the case took the form of the usual infringement action with the conventional defenses of invalidity and non-infringement. This is an appeal from a judgment holding the patents in suit valid and infringed.

As to the validity of the Silver patents it is contended here as it was in the district court, that they added nothing new to the art; that all Silver did was to design a machine which differed from the prior art only in minor construction details; that his machine did not meet the required standards for inventions; and that it was no more than the application of unpatentable mechanical skill. As to the infringement by the accused Morton machine, it said that this machine follows the teachings of the prior art and not the teachings in the Silver patents.

Sugar beets were first grown in commercial quantities in Europe early in the Nineteenth Century. In the latter part of that century it was found that they could be produced profitably in the Midwestern, Rocky Mountain and Pacific Coast areas of the United States. Since the advent of the beet sugar industry, the extraction of sugar from beets has been effected by a process of diffusion which is accomplished by bringing hot water into contact with the beets after they have been sliced, and by causing the sugar content of the beets to pass into solution in the water to form a juice from which commercial beet sugar is refined. This process has been used exclusively in the industry because of the nature and structure of the beet stock which does not permit juice extraction by pressing or other forceful removal as is used in removing juice from sugar cane. The technical and physical law relating to diffusion was known long before the development of the beet sugar industry.

To extract the sugar from sugar beets the latter are sliced into pieces of the shape and size resembling shoestring potatoes. These pieces are referred to in the art as "cossettes". The diffusion is accomplished by submerging and agitating the cossettes in heated water or juice of a concentration less than that of the juice or sugar contained in the beet cells. When the concentration of fluid in which the cossettes are submerged becomes equal in sugar content to that of the cossettes the diffusion ceases and for further diffusion it is necessary that the cossettes be exposed to a juice of less concentration. In order to expose the cossettes containing the highest concentration of sugar, to juice of high sugar content, there must be a progressive movement of the juice, or of both the cossettes and juice. This requires a countercurrent movement in that the fresh water first processes the most depleted cossettes, and then progressively processes cossettes of lesser depletion, until at the end of the treatment the cossettes which are least depleted of sugar are submerged in juice most heavily laden with sugar. The result sought is the recovery of the highest possible percentage of the sugar content of the beets in juice form which will contain a minimum of impurities. The high cost of evaporating water and recovering the solid sugar from the juice demands that the diffusing activities be carried out with a minimum of water.

Prior to Silver's inventions, the only commercially successful process and apparatus known to the industry was the "Robert Battery" of French design about a century ago. This battery is a batch-type apparatus consisting of a series of separate but connected tanks or cells (usually fourteen), each of which is adapted to contain a batch of cossettes. In actual operation only twelve of the cells are included in the diffusion process at any one time. The thirteenth cell of the battery is being filled with fresh cossettes while the fourteenth is being emptied of exhausted cossettes. Water of proper temperature passes successively through each cell of the series which is in operation until cossettes of the first cell become exhausted of sugar after which this cell is manually discharged. The inlet and outlet pipes are adjusted to correspondingly and successively shift the location of the particular cell in the series where the pure water enters and the juice leaves the operative portion of the battery. Cell thirteen then becomes the last in the diffusion process and cell two becomes the first. Although reliable, this type of battery is cumbersome and relatively inefficient. It requires a large number of men to operate it and the water content of the juice is high.

Workers in the prior art recognized the advantages of continuous diffusion through a direct countercurrent or a countercurrent-concurrent flow system. The countercurrent-concurrent flow is a method whereby the cossettes moving in one direction through the battery are exposed continuously to water or juice of proper concentration flowing generally in the opposite direction but concurrently within each cell. In this system, the exhausted cossettes are discharged at one end and the raw juice at the other. Both in Europe and in the United States inventors were unable to devise a successful machine for such a system. A number of patents were issued, but none were successful or in use in North America.²

When Silver entered the field, the "Robert Battery" was being used exclusively in the United States and Canada. It is the only method in use today except in those factories which are now equipped with the Silver machine and two which use the accused machine. It had been the predominating view of technical workers that any countercurrent system would not succeed. The straight countercurrent method presented a problem of clogging and mutilation of the cossettes which could not be overcome. The countercurrent-concurrent system eliminated the clogging difficulties but created other deficiencies. The density of the cossettes varied, some floated, and some sank in the fluid. The fact that the cossettes and juice flowed concurrently resulted in a less effective washing and inefficient diffusion. When transferred from one cell to another the cossettes carried with them a substantial quantity of juice which was of a higher concentration of sugar than that of the juice in the cell into which they were being transferred and the equality of sugar content in the beets and juice tended to defeat diffusion. Some inventors sought unsuccessfully to overcome this with presses and other methods of enforced separation.³ After many attempts, the problem of producing a commercially successful continuous diffusion system remained wholly unsolved.

Silver undertook to develop a countercurrent-concurrent type of machine which would overcome previous failures and be commercially practical for a successful continuous diffusion operation. His patents disclose a number of separate vertically disposed U-shaped cells, each having parallel downward and upward legs connected at their bottoms. These cells contain the juice or diffusion fluid at a prescribed level. A continuous conveyor chain carrying perforated trays which contain the cossettes travels alternately down into one leg and up the other of each cell successively through the entire length of the battery, thereby enforcing a submergence in the juice of each cell. Although the juice within each cell travels by gravity in the same direction as the cossettes, it is further propelled by the movement of the chain and the cossettes. This propelling force causes a certain gravitational pull of the juices against the cossettes, and results in a more effective washing. Although the travel of the two is not strictly countercurrent, nevertheless the propelling force results in some friction between the juice and cossettes. As the chain conveying the cossettes comes out of the liquid, there is a draining of the cossettes which prevents the backward conveyance of the higher concentrated juices. Thus Silver's apparatus in the main employs progressive and continuous separate cell treatment stages; a forced submergence of all the cossettes, regardless of their density; and a greater frictional washing plus an effective draining of the cossettes, rather than a forceful extraction. A further process improvement provides for the discharging of the juice from each cell by screening the same through an enlarged outlet located near to but actually below the surface of the liquid level in each cell. The screening takes place as the juice leaves each cell to travel by gravity to the next succeeding treatment stage. This improvement along with others was not claimed until Silver's second patent.

Silver does not contend that he originated any one of the elemental parts or steps of his inventions. He urges, and the patent office agreed, that he was the first to conceive of...