General Metals Powder Co. v. SK Wellman Co.

• Decision Date: 23 September 1946
• Docket Number: No. 10086.,10086.
• Citation: 157 F.2d 505
• Parties: GENERAL METALS POWDER CO. v. S. K. WELLMAN CO. et al.
• Court: U.S. Court of Appeals — Sixth Circuit

157 F.2d 505 (1946)

GENERAL METALS POWDER CO. v. S. K. WELLMAN CO. et al.

No. 10086.

Circuit Court of Appeals, Sixth Circuit.

September 23, 1946.

F. O. Richey and B. D. Watts, both of Cleveland, Ohio (H. F. McNenny and H. F. Schneider, both of Cleveland, Ohio, on the brief; Richards & Watts, of Cleveland, Ohio, of counsel), for appellant.

George I. Haight, of Chicago, Ill. (Ray Stewart Gehr and C. T. Cox, both of Cleveland, Ohio, and W. E. Lucas, of Chicago, Ill., on the brief), for appellees.

Before HICKS, SIMONS and MILLER, Circuit Judges.

HICKS, Circuit Judge.

Action at law by the General Metals Powder Company, appellant, and assignee-owner, against The S. K. Wellman Company and Samuel K. Wellman, appellees, for damages for infringement of Claims 2, 3, 5, 12, 13, 14, 18 and 19 of Patent No. 2,072,070, for a "Friction Article and Method of Producing Same"; and of Claims 1, 3, 5 and 6 of Patent No. 2,191,460, for an "Article of Manufacture." These patents were issued to Fisher on February 23, 1937 and February 27, 1940, respectively, and are referred to herein as 070 and 460 respectively.

Herein the parties are styled plaintiff and defendants just as they appeared in the court below.

Defendants denied infringement and set up the defenses of invalidity because of prior use and invention; and for lack of invention; and for ambiguity and lack of clarity in the specifications and claims.

The case was tried without a jury. The court pretermitted the question of damages and heard only the issues of validity and infringement. It filed an opinion and findings of fact and conclusions of law. Although remarking in the opinion that before 1934 serious clutch problems existed in the automotive industry and that many manufacturers were striving to devise a clutch lining that would meet adverse use conditions and that Fisher's "friction article" achieved "amazing results" in buses of the Twin Coach Company, the court nevertheless was constrained to find that there was nothing novel in plaintiff's "continuous metal network structure" since the same structure was revealed in defendants' "Exhibit 48" made under the Gilson patent and in the articles made under the Williams and Claus patents. The court found nothing novel in the processes of 070 nor in the application of the composition to the clutch problem since the Hudson Motor Car Company had used clutch brakes made from Genelite material (under the Gilson patent) prior to Fisher. It held the claims of 070 invalid. It also held the claims of 460 invalid because of anticipation by the Short patent No. 1,819,272 and because welding by the heating process and by electrical resistance were old and known prior to Fisher.

Patent 460 was for an article of manufacture such as a clutch plate, brake shoe, bearing or the like, in which a bonded metal element such as indicated above, was "bonded" or "integrally attached" to a steel supporting or backing member.

Plaintiff was a manufacturer of powdered metals and interested in finding outlets therefor. Some experimentation was carried on by its employees, including Fisher, for uses of powdered metal in conjunction with other materials for electric brushes, brake linings, etc. Officers of plaintiff demonstrated to defendants a Ford automobile which had been equipped with brake shoes manufactured by plaintiff and later there was some cooperation and exchange of information between the two companies before they went their separate ways.

Before examining the art and usages claimed by the defendants to antedate the patents, it will be helpful to examine the patents themselves in greater detail.

Patent 070:

This patent related to "improved compositions of materials for use as friction generating media and to processes of making the same * * * friction articles which are particularly well adapted to withstand service conditions encountered in relatively moving bodies in contact with each other, such as in brakes, clutches and similar devices. Such uses require more or less definite but less controllable coefficients of friction, long wearing life, smoothness of operation, and non-abrasive characteristics, together with resistance to deteriorating action or influencing effects of oil. * * *" (Italics ours.)

A feature of the article, emphasized in the trial and in the arguments and briefs, was a "network" of metal in the interstices of which graphite and other non-metallic minerals were dispersed. The specification had this to say about the "network": The friction articles "* * * consist predominantly of a strong, malleable, ductile, wear-resistant metallic network having a small amount of inorganic, non-metallic materials dispersed therein and supported thereby. The term `network' has been selected as an expression which more or less aptly describes the structure of the metallic body of this invention. This structure may be fairly well visualized by a comparison of it with the structure of sponge rubber wherein the rubber is more or less continuous and forms a network with many open spaces. In the friction articles of this invention the metallic parts may be likened to the rubber of the sponge in continuity and in the formation of spaces. Such spaces, howver, contain ingredients which were a part of the starting material but which do not enter into the combination of the metals to make up the network." (Italics ours.)

The specification further stated that copper was the predominant metal in the network material, ranging, according to use, from 65% to 95% by weight, with tin 3% to 15%, and with lead, 5% to 15%. Zinc might be substituted for tin; and iron or cadmium for copper. The inorganic materials, such as graphite, mica, silica, emery, clay, carborundum, etc., were varied to give a different coefficient of friction according to the use. For a brake member, facing or lining, it was suggested that the coefficient of friction range between .25 and .50 and for a clutch member, facing or lining, .10 to .35. Brinell hardness of the friction article ranged between .10 and .65, and "resistance to shear" was "sufficiently high to enable the articles to withstand the repeated longitudinal stresses ordinarily encountered in use." Certain tests for coefficient of friction, shear resistance, resistance to compression and wear were set up to which we shall refer later.

As to method, the specification stated that in general all ingredients should be in finely divided form with the lubricant and friction materials passing finer screens than the metals. The predominant metal in the composition should be finely divided and in the case of copper, the shape of the particles was important, "altho not absolutely essential." Fisher preferred to use "Koehler" copper powder whose particles were "flocculent or fern like and exhibited marked tendency to intertwine and matt together with large surface contact when subjected to pressure"; while stating that greatly improved results were achievable over any prior art, friction articles by using ordinary commercial nodular copper powder, the Koehler powder exhibited "a marked tendency to the formation of increased amounts of amorphous metal during pressing and to crystallization of such metal with a resultant network in which substantially all of the predominant metal particles are integrally united together into a continuous network resembling that of cold rolled and annealed brass or bronze." The specification disclosed an inverse ratio between strength, hardness and resistance to shear in the finished product and the specific gravity of the copper powder.

Pressure was applied to the selected materials at approximately right angles to the wear face of the resultant article to obtain greater lubricating value from the graphite and mica content. Preferred pressures were from 10 to 18 tons per square inch, although lower or higher pressures could be employed and it was important that the article should be thin enough that the ingredients would be compressed uniformly throughout the thickness of the article which was to be in the shape of thin plates or bars.

After the pressing operation was completed, the article was subjected to heat treatment. "In general, the time and temperature of the heat treatment should be such that the lower melting point ingredients may melt and that certain of them, such as tin and zinc, may enter more or less completely into solution with the predominant metal, forming alloys * * * more or less uniformly scattered thruout the network." Temperatures from 1,000 to 1,300 degrees were suggested for periods up to 30 minutes. The heating should take place in an atmosphere substantially free from oxygen.

The specification provided that "Friction brake articles * * * may be produced in the form of thin disks, buttons or strips * * * with brads or rivets embedded therein." In the case of a clutch friction article, it was said to possess "a coefficient of friction which is low when there is slipping engagement with an opposed member, but which increases as the slipping decreases and as the engagement becomes closer or more positive and which reaches a maximum when engagement is complete. * * *." In conclusion it was stated that the term "friction article" included parts of clutches and brakes, but not bearings or bushings, "wherein the avoidance of friction is the object desired."

Claims 3 and 12 are typical of the article claims, and claim 19 illustrates the method. We quote 12 and 19:

"12. A pressed and heat treated, relatively dense, friction article suitable for lining clutches, brakes and the like, having a strong, malleable, metallic network substantially continuous, integral and free from interruptions and containing between about 65% and about 95% copper, between about 3% and about 15% of tin, and between about 5% and about 15% of lead, each 100 parts of said network carrying dispersed substantially uniformly therein between about 3 parts and about 20 parts by weight...