Appeal from the District Court of the United States for the Eastern District of Wisconsin, Ferdinand A. Geiger, Judge.
Before SPARKS and FITZHENRY, Circuit Judges, and LINDLEY, District Judge.
FITZHENRY, Circuit Judge.
This is an appeal in a suit in equity to restrain alleged infringement of Wheeler and Scott United States patents, 1,639,828, for process for treating cheese, and 1,523,678, for cheese treating apparatus. The lower court held each of the patents invalid as to the claims in suit and not infringed. Appellant, plaintiff in the court below, appealed from that part of the decree relating to the process patent, No. 1,639,828, covering a method of making "process cheese."
The practice of processing cheese began some time prior to the issuance of the patents in suit. The object was to improve the texture of the cheese previously manufactured, partially sterilize it so as to improve its keeping properties, and turn out a uniform product in molds convenient for marketing and use.
Wheeler and Scott, patentees of the patents in suit, in the specifications of their process patent described its objects as follows:
" The objects of this invention are to provide means whereby cheese derived from differing sources or manufactured under different conditions may be improved in quality, modified in characteristic flavor, and rendered homogeneous and sufficiently sterile to enable it to be packaged and kept without material deterioration through considerable periods of time.
"A further object of this intention is to provide an improved method of heat treating cheese whereby the process may be continuously and expeditiously carried on under conditions of perfect sanitation, and whereby the results mentioned in the preceding paragraph may be more perfectly attained at less expense than by the heat treating processes heretofore followed."
Claims 4, 5, 7, 8, and 9 are involved in this litigation. Claim 8 is typical of the others: "8. The process of treating cheese, which consists in passing a stream of cheese through steam having a temperature adequate to reduce particles of cheese substantially to a liquid upon momentary exposure thereto, and exposing substantially all particles of said cheese momentarily to such steam and then immediately moving them out of contact therewith."
By reading these claims, in the light of the specifications, it is apparent that the process involved consists of: (a) The passing of a stream of cheese continuously through steam; or sending it through a cylindrical tube by means of a screw conveyor where it is kneaded and exposed momentarily to jets of steam, (b) having a temperature sufficient to reduce particles of cheese substantially to a liquid upon momentary exposure thereto, (c) exposing substantially all particles of said cheese momentarily to such steam, and, (d) then immediately removing them out of contact therewith.
Wheeler and Scott suggest three methods by which their process may be used: (1) Ground or comminuted cheese is delivered through a hopper into a tube through which it is propelled horizontally by a rotating conveyor and carried rapidly past jets of live steam. The melted cheese, thus produced, is carried to the other end of the conveyor, where it is treated by jets releasing carbon-dioxide and then delivered by the screw propeller to the end of the tube into a mixing or package device. (2) The ground cheese is preheated, compacted, and then forced downwardly through a small opening, giving it the shape of a belt or ribbon as it enters a small steam chamber on a perpendicular plane. Immediately it drops to the bottom of the chamber, after the contact, to a tube which carries it to a conveyor, having been exposed to the steam but a moment. The second method outstandingly illustrates the conception of the invention as it involves a stream of heated cheese, in the form of a belt or ribbon, and sends it directly through the steam chamber, where the cheese remains but long enough for the steam to act upon the particles of cheese of the ribbon or belt and then immediately the melted cheese is withdrawn therefrom. (3) The third method suggested for using the process approaches the prior art much more nearly than either of the others. It involves the use of a kettle. Ground cheese is continuously fed into the top of the kettle, jets of steam are directed into the lower part of the cheese mass, while the cheese is being agitated by a propeller so as to bring fresh surfaces of the cheese momentarily and continuously in contact with the steam by sinking to, and passing out of, the bottom of the kettle. The practice of this process, by use of the kettle, involves the use of a continuously operating paddle with a tubular shaft supporting and operating the blades. The shaft is rotatively connected with a steam main to receive steam therefrom while the shaft is being operated. The steam is delivered through the rotable shaft into direct contact with the cheese mass. The treated cheese, which is also given a treatment of carbon dioxide, then passes out of the bottom of the kettle through the large tube for further agitation or packaging.
It is the first method suggested that appellee is charged with infringing. The apparatus used by appellee operates from right to left, whereas, the method as illustrated in the patent in suit, operates from left to right. The right half of the machine used by appellee in the operation of its process is a hot water heater in which the water is kept at a high temperature, from 180 degrees to 190 degrees Fahrenheit. The heat is delivered to the cheese which is being fed at the right into a cylindrical casing, in the center of which a screw conveyor is used which carries the cheese, as heated and kneaded, to the end of the heater where it overlaps the steam element and drops from the end of the heating element into the steam element and is conveyed through the steam chamber, which is another cylindrical tube, and which carries the cheese past several steam jets, where the mass is exposed to steam momentarily and then immediately removed to the end of the chamber, where it is delivered by the conveyor. The cheese thus treated then drops from the end of the steam chamber under the impelling force of the screw conveyor and passes through a pipe into a mechanical mixer. Appellee contends that by its process the operation is not completed when the cheese leaves the steam chamber, but must proceed and receive the treatment of the mechanical mixer, claiming that its cheese is only partially processed at that point. Without now discussing the intimate relations between the process of the patent in suit and the accused method of appellee, it may be appropriate to observe that, if the patent in suit is valid, appellee in its process has added the use of a preheating unit to feed the steam chamber and the use of a mechanical mixer following the processing of the cheese in the steam chamber.
It is shown by the Wheeler patent that in order to use steam effectively small particles of cheese must be brought successively into momentary contact with steam and then promptly removed from the heating zone, the operation being continuous. Prior to the teaching of Wheeler and Scott, the patent in suit, cheese had been uniformly processed by what is known as the batch or kettle system, with one exception, that of Parsons, which will be discussed later.
Whether a patent involves invention is to be determined in the light of historical facts rather than what might appear to be ...