The opinion of the court was delivered by: CAMPBELL
CAMPBELL, District Judge.
This is a suit for the alleged infringement of patent No. 1,948,192, issued by the United States Patent Office, to Albert R. Stargardter, assignor to Gillette Safety Razor Company, for method of treating steel, granted February 20, 1934, on an application filed March 10, 1932.
After notice to the defendant of its alleged infringement, the bill of complaint was filed May 24, 1934.
This suit is based on claims, 1, 3, 4, 5, 8, and 11 of the patent in suit.
The plaintiff is a Delaware corporation, incorporated in 1917, and manufactures the Gillette safety razor and blades.
It is the successor of the original Gillette Company, a Maine corporation, incorporated in 1901, which shortly thereafter introduced the Gillette type razor and its double-edge flexible razor blade, a very large quantity of both of which have been sold.
In July, 1931, plaintiff put into production and sold baldes made in a continuous strip, whereas they had formerly been handled throughout their manufacture as individual blades, and to distinguish those made by the new process from the blades made by the old process, the new blades were given a distinctive blue color by the application of a suitably dyed lacquer. The only blades on the market at that time were of the natural steel color.
In February, 1932, the plaintiff, by means of the process of the patent in suit, was able to produce blue color blades, which in appearance were greatly improved over the original lacquer blades.
I cannot agree with the defendant, that all the practice of the process of the patent in suit does is to give the blade a blue color.
By the patented process one step in the process of manufacture, the polishing operation, was eliminated, resulting in a substantial saving in cost.
Blades made by the patented process receive a very uniform rich blue color, by the formation thereon of a thin noncorrosive resisting and nonacid resisting coating of ferrous oxide (FeO). The nonacid resisting character of the coating enables the blades to be printed with trade-marks, trade-names, etc., merely by applying thereto a stamp wet with acid.
After printing, the blades are lacquered to prevent corrosion.
The patent in suit is for the method of hardening and simultaneously coloring such blades, by the formation of this iron oxide independently of the degree of hardness.
The defendant is a New York corporation. It manufactures only blades to fit the Gillette type razors, and does not manufacture razors, and claims to have begun the manufacture of oxidized blue blades in August, 1932.
There was an earlier action brought by plaintiff against the defendant for infringement of its trade-mark and for unfair competition, but the patent in suit was not in issue in the former suit. (D.C.) 4 F.Supp. 319.
The defendant has interposed an answer setting up the defenses of invalidity and noninfringement.
In the manufacturing process used by both parties, the steel from which the blades are made is kept in a continuous, unbroken strip during the various heat-treating, sharpening, and other operations, and until just prior to wrapping and packaging, when it is broken into the individual blades.
In the Gillette process, prior to the introduction of the blue blades as one of the initial steps, the blades were separated from the strip, and large packs of these blades were subjected to the heat-treating operation as a unit.
The patent in suit relates to a process for forming a blue ferrous oxide coating on steel, and more specifically to forming such a coating on perforated razor blade strip, while it is being heated above its critical temperature in a furnace preliminary to hardening.
It is true, as contended by defendant, that the words "ferrous oxide" do not appear in the patent, but the oxide produced by the practice of the process of the patent in suit is ferrous oxide, and as such clearly distinguished from magnetic oxide.
The patent in suit refers to two prior methods of softening steel, wherein oxide coatings are obtained; that is, tempering and blue annealing.
Tempering is an operation probably as old as the art of steel manufacture.It is useful in reducing brittleness and increasing toughness.
If a piece of steel, previously hardened by heating above the critical temperature and rapid colling, be polished and then reheated to about 430 degrees F. it takes on a straw color, and if heated to about 565 degrees F. it turns dark blue. In the range of temperature 430 degrees - 750 degrees F., which is considerably below the critical temperature, a whole range of colors is obtainable from straw through the various shades of blue to gray.
The color was not desired but was indicative of the final hardness, and is used by toolmakers to tell them when their steel has been reheated to the proper temperature after hardening.
The highest temperature to which steel has been heated in the tempering operation determines the hardness and toughness of the steel. The steel will be softer the higher the temperature. The tempered razor strip Exhibit 21, shows that steel, with an average hardness of 875 Vickers before tempering, was reduced in hardness in the straw region to 725, and in the blue to 650; the latter being too soft for the cutting edges of razor blades. The mode of cooling from the tempering temperature is not important in so far as the effect upon the hardness of the steel is concerned.
The custom in toolmaking to heat the steel in the open air until the desired temper color appears is of long standing, and the toolmaker then knows that the steel, when cool, with have the required combination of hardness and toughness for the work to be performed. The temper colors are usually polished off to improve the appearance of the tool. Exhibit 26 gives the colors recommended for various tools, and while certain devices, such as screw drivers and wood saws, requiring great toughness, are recommended to be tempered a blue color, they do not require anything like the degree of hardness necessary for razor blades. Tempered blue razor strips Exhibits 23, 24, 27 may be given a permanent set or bent double before breaking; the edges of a razor blade, however, are necessarily much harder, and thus unavoidadly more brittle.
The edges of both plaintiff's and defendant's blades are subjected to tempering within the range of 260 degrees to 380 degrees F., and therefore the hardness of the blades is decreased but slightly by such tempering, just enough tempering having been done to relieve the excessive brittleness of the strip as it comes from the furnace.
The temperatures of such range are not only far below the blue range, but also below the entire temper color scale, and no colors would appear on polished steel as a result of heating to such low temperatures.
A reference is also found in the patent in suit to the bluing of soft steel. Such steel is usually in the form of sheets and is generally known as blue annealed sheet, and has been heated above its critical point and cooled relatively slowly, instead of being quenched as in hardening. As finally treated it is quite soft, and in some cases softer than the steel before treatment.It is unsuitable for razor blades.
In manufacture, sheets heated well above the temper range, and sometimes above the critical temperature but not always, are subjected to superheated steam, air, or other oxidizing gas while highly heated, which forms a magnetic oxide coating upon the steel commonly designated as blue, but actually it is usually a mottled bluish-black, more nearly resembling black.
This oxide is the so-called magnetic oxide, FeO and has some value as a rust preventative, without regard to its color. The color is only a secondary consideration, and actual uniformity of color, which is of no consequence, is never attained. The composition and color of this oxide is different from the blue coating of ferrous oxide produced by the process of the patent in suit, and the steel on which it is formed differs in that it is soft steel.
The object of the invention of the patent in suit is set forth by the patentee in his specification, in which he says: "I have discovered that by subjecting steel under certain conditions to the action of an atmosphere having a controlled oxidizing effect, a blued finish may be imparted to it independently of hardness or temper. It is thus possible for the first time to produce steel articles of any desired degree of hardness having a blued surface finish of a character highly prized in cutting devices and other steel articles."
The steel receives this blue finish while it is in the furnace being heated above the critical temperature, preparatory to hardening by subsequent quenching by carefully controlling the oxidizing power of the atmosphere within this furnace, by having present regulated quantities of oxidizing and reducing constituents, that is, gases which either add oxygen to the steel so as to form an oxide, or remove it, or form a lower oxide if already there.
He further says, with reference to the extent to which the oxidizing action of these constituents should exceed the reducing action: "in all cases the oxidizing effect of the gas mixture to which the steel is subjected is less than that of the atmospheric oxygen, as otherwise, at the temperature I employ, the color of the steel would be carried beyond the blue."
If the atmosphere within the hardening furnance was constituted of ordinary air in a most restricted quantity, the steel would be coated with a more or less non-adherent coating of black magnetic oxide. Magnetic oxide is readily produced at elevated temperatures, with an active oxidizing agent such as air, and would similarly be produced by any other oxidizing gas with nothing more. It contains relatively more oxygen than ferrous oxide.
Recognizing the necessity of lessening the oxidizing power of this atmosphere by adding a reducing constituent, the patent discloses that a controlled amount of ordinary illuminating gas, which has a reducing act upon steel, even at high temperatures, should be introduced with air entering the hardening furnace. The mixture resulting from the addition of such gas to air within the furnace is but slightly oxidizing to the steel at the temperature of the furnace, being less than that of atmospheric oxygen.
The patentee desired a blue coating, but realized that by varying the relative proportions of oxidizing and reducing constituents produced in the furnace, he could control the tint or shade of the finish, and could obtain other colors resembling those of the temper scale, but the color, he said, "gives no indication of the temper of the strips but is imparted thereto by a novel sequence of steps which permit the steel to be subsequently treated and tempered to any desired degree."
Referring to the patent drawing, this special atmosphere is maintained within the elongated muffle 20 through which the steel strips 30 pass. Two blade strips are shown, although in actual practice only one is used. This muffle, which is made of a heat resisting alloy, is located within a hardening furnace 10, heated by the gas burners 14 at the sides, but other types of furnaces may be employed, both parties here employing electrically heated furnances. An Auxiliary muffle 18 surrounds the muffle 20. Ordinary air is introduced through the pipe 24 at the entrance of the muffle, and illuminating gas through the pipe 26. The supply of each of these gases is controlled independently by valves 26, Fig. 3. The gases from the rear of the muffle pass out through the muffle stack or vent 22, and the holes 12 in the top of the furnace. After leaving this furnace, the strip is passed between the dry cooling block 32, where it is hardened by the sudden cooling. Such dry quenching is necessary to preserve the blue finish imparted in the furnace. If quenched in oil, as in ordinary toolmaking, the blue oxide is changed to a black, scaly coating, such as on Exhibit 54. The quench blocks 32 are close to the furnace exit, so as to prevent additional oxidation in the open air, which would further oxidize the blue ferrous coating and produce a loose scale of magnetic oxide on the strip. After quenching, the strip is tempered in the furnace 34, also without injury to the blue finish.
The patentee further said: "The behavior of the oxidizing mixture within the muffle 20 is not entirely understood."
This, however, does not invalidate the patent, as it is not necssary that the inventor understand the theory underlying his invention. Eames v. Andrews, 122 U.S. 40, 55, 7 S. Ct. 1073, 30 L. Ed. 1064; Hemolin Co. v. Harway Dyewood & Extract Mfg. Co. (C.C.A.) 138 F. 54, 55; Danbury & Bethel Fur Co. v. American Hatters & F. Co. (C.C.A.) 54 F.2d 344, 345.
The attempt of the patentee to explain the operations which occur in the furnace muffle was right as far as it went, as some of the oxidizing action is attributable to carbon dioxide, which is formed from the burning of the carbon monoxide in the illuminating gas. It has also been found, since the application was filed, that water vapor is also present and contributes largely to the oxidation process.
It is the belief of plaintiff's expert, and I agree with him, that the reaction within the furnace is as follows: Illuminating gas, in a controlled amount being admitted with air to the muffle, at a temperature above the ignition point of mixture, burns until all the oxygen of the entering air is consumed. Gas analyses of the atmosphere within the muffle show that no free oxygen remains after a very short distance, which may be only a few inches, and before the steel has become heated more than a few hundred degrees. The defendant's expert admitted "illuminating gas burns part of the oxygen out of the air and therefore leaves you an atmosphere of less oxidizing effect."
In burning, some carbon monoxide from the illuminating gas unites with oxygen from the air and is converted to carbon dioxide; hydrogen from the gas is partly converted to water vapor; methane is changed to carbon dioxide, carbon monoxide, and water vapor; nitrogen from the air is inert and remains unchanged. After this partial combustion has taken place in the front portion of the muffle, the products of this combustion, together with the unburned illuminating gas, flow to the exit end of the muffle, in contact with the highly heated steel strip, and produce thereon the desired blue coating. The steel is subjected to this mixture, which is made less oxidizing in its effect than atmospheric air by controlling the relative proportions of the entering gases. It is not possible to specify the exact proportions of entering illuminating gas and air, because these vary according to many factors; for example, the temperature employed, furnace lengths, strip speeds, and the particular color desired. The patentee described and illustrated valves in the gas and air supply pipes, to regulate these proportions for a given set of conditions. This is all he was required to do.
The mixture of gases within the muffle includes reducing constituents, principally, carbon monoxide and hydrogen, and also oxidizing constituents such as carbon dioxide and water vapor, the latter a powerful oxidizing agent. It is this combination of gases of controlled oxidizing effect which reacts with iron in the steel and forms the desired ferrous oxide coating.
After leaving the muffle, the unburned illuminating gas, which could not burn, although highly heated, because of lack of free oxygen, comes in contact with air which supplies sufficient oxygen to support complete combustion of the gas. The products of this final combustion do not contact the strip under treatment. If they did so, the appearance of the strip would undoubtedly be impaired.
This manipulation is referred to by the patentee in his specification as an important characteristic of his invention, who says: "In so confining and handling the gas current, that it is conducted or directed away from the heated strip for complete combustion and allowed to burn only at a point remote therefrom." And later says: "Any substantial amount of the mixture is, however, prevented from burning within the muffle 20 * * *." After leaving the duct 22, the oxidizing gas mixture is free to ignite and burn either within the furnace chamber or after it has passed upwardly through the duct 12 in the upper wall of the furnace chamber. In any case, the complete combination of the gas takes place at a point remote from the strip steel being treated, so that the latter is kept from contact with the products of this combustion.
I do not agree with defendant's expert's interpretation of some of the language quoted, as teaching that no combustion whatever was to occur within the muffle, nor can we consider as collateral information, the file-wrapper arguments of the patentee's attorney in derogation of the disclosure which the inventor made in the patent itself. A. G. Spalding & Bros. v. John Wanamaker, New York (C.C.A.) 256 F. 530, 533.
As I interpret the patent, it was only the final or complete combustion which should not occur within the muffle.
The product of the process of the patent in suit is a strip of perforated razor steel, which has been hardened at the edges from about 260 Vickers, the hardness of the entering strip, to about 875 Vickers, and coated with an adherent blue layer of ferrous oxide as illustrated by Exhibit 14. Its coating may be etched, or printed, with extreme rapidity by acid.
The six claims in suit read a follows:
"1. The method of producing colored and hardened strip steel, which consists in heating the strip to a temperature above its critical point, immersing the strip so heated in a gaseous mixture having a reducing constituent but being oxidizing in its effect, and then chilling the strip to harden it as thus oxidized."
"3. The method of hardening and uniformly coloring steel, which consists in heating it to a temperature at or above its hardening point, simultaneously subjecting it to the action of an atmosphere having a controlled oxidizing effect which is less than that of atmospheric oxygen, and then chilling it to produce a hardened and colored steel product.
"4. The method of hardening and coloring steel, which consists in heating it to a temperature at or above its hardening point while exposed to an atmosphere having an oxidizing effect less than that of atmospheric oxygen, and then removing the steel from such atmosphere and at once chilling it, thereby producing a hardened and colored steel product.
"5. The method of hardening and bluing strip steel, which consists in heating the strip to a temperature at or above its hardening point, meanwhile enveloping the heated strip in a moving current of oxidizing gas of less oxidizing effect than atmospheric oxygen, and thereafter chilling the strip, thereby producing a hardened and blued steel strip."
"8. The method of hardening and bluing strip steel, which consists in passing the strip through an elongated furnace containing an oxidizing gas of less oxidizing effect than atmospheric oxygen, heating the furnace and the gas contained therein to a temperature above the lower critical point of the steel, and then chilling the strip progressively as it leaves the furnace, thereby producing a hardened and blued steel strip."
"11. The method of treating strip steel, which is characterized by the steps of progressively heating successive zones in the strip to a temperature above the critical point of the steel, subjecting each zone as heated to the action of a gas mixture having a controlled oxidizing effect which has less oxidizing effect than that of atmospheric oxygen, progressively chilling the strip as it leaves the oxidizing atmosphere, and subsequently heating the strip to temper it independently of the oxidized color imparted thereto."
Claim 1 is drawn specifically to a reducing constituent while each of the remaining claims calls for a mixture having an oxidizing effect less than air.
No separate consideration of these claims is necessary, as they are drawn to the same general process, and differ but slightly in terminology concerning the way in ...