Hemming Mfg. Co. v. Cutler-Hammer Mfg. Co.

• Decision Date: 10 April 1917
• Docket Number: 2368.
• Citation: 243 F. 595
• Parties: HEMMING MFG. CO. v. CUTLER-HAMMER MFG. CO.
• Court: U.S. Court of Appeals — Seventh Circuit

243 F. 595

HEMMING MFG. CO. v. CUTLER-HAMMER MFG. CO.

No. 2368.

United States Court of Appeals, Seventh Circuit.

April 10, 1917

Charles Neave, of New York City, for appellant.

W Clyde Jones, of Chicago, Ill., for appellee.

This is an appeal from a decree dismissing for want of equity appellant's bill for alleged infringement of the Muller patent 869,321, October 29, 1907, for insulating material and method of manufacturing the same.

The claims in suit and the material parts of the specification are as follows:

'By my invention, I provide a fire-proof electrical insulating material which has a high specific resistance sufficiently near to that of rubber or porcelain to make it satisfactory in the electrical art. It will withstand as high a degree of heat as it will be subjected to in practice without loss of its insulating properties, whereby it may be used in place of porcelain and it may be worked with tools practically as easily as wood. It takes a screw-thread very satisfactorily. Moreover, it may be also molded into shape in the same manner as rubber or porcelain and does not require the use of heat in its manufacture. It does not shrink as porcelain does in molds and costs very much less than hard rubber or porcelain to produce.

'The invention will now be described in its preferred embodiment when such embodiment is a solid.

'In view of the fact that the bituminous material, such for example, as mineral pitch will burn at a relatively low temperature whereas when combined, as in my invention, the product is practically fire-proof, it is probable that this paradoxical action is due to the fact that in the completed material produced by my invention, asbestos is the chief fire resistant material, while the pitch seems merely to impregnate and coat the particles of asbestos and to cement them together, the amount of pitch being so minimized that the pitch in the completed material constitutes a substantially non-inflammable factor. It is possible that the ability of the pitch to resist high temperatures to which the material may be subjected without softening or igniting, is due to the fact that the relatively thin layers of the binding material are protected by the asbestos from access of oxygen. When the particles or fibers of the fire-resisting material are cemented together by the binder, and the mass is subjected to heavy pressure for condensing or initially hardening it, the pitch remaining in the compressed mass is minimized in quantity and is present in what may be designated as approximately filmiform layers or coatings and although made from a material which in ordinary relations is easily inflammable are, nevertheless, practically non-inflammable and practically non-softing, as is proven by subjection of samples to the electric arc. Herein lies a reconcilement of antagonisms, the theory of which I do not pretend to precisely understand, but which I have hereinbefore set forth according to the best of my present understanding. By the gradual evaporation of the solvent (I recommend a volatile hydrocarbon, especially benzol, for use as a solvent), my new solid product is given a peculiar character, which, although the product is refractory and hard, permits the product to be worked readily with tools and in molds without anything more than ordinary wear and tear.

'In my process of making insulating material, I preferably prepare a binder consisting of 100 parts of the bituminous material, such as mineral pitch, dissolved at about normal temperature in approximately 20 parts by weight of a volatile solvent, such as benzol, or the like. This solution is mixed, preferably without the application of heat, with a preferably comminuted natural asbestos in the proportion of 20 to 75 parts of the solution to 100 parts of the fire-resisting material to form a consistent plastic mass, which may be molded or otherwise compressed into the desired shape. The consistency of the mass will depend upon the proportions of the ingredients within the limits mentioned and may be varied according to the properties desired in the product.

'Instead of using asbestos only, I may mix with it a suitable heat, water and fire-proof filler, such, for example, as quartz or kaolin; for example, 100 parts of the asbestos may be mixed with from one to 100 parts by weight of the filler which is preferably a finely pulverized, inorganic body. This mixture of the asbestos with the finely pulverized, inorganic heat, water and fire-proof filler is then combined with the binder in the same manner and in substantially the same proportions as hereinbefore described.

'The volatile ingredient of the compressed product is permitted to evaporate therefrom by exposure to air whereupon the product is hardened by the evaporation of the solvent. If desired, the compressed mass may be subjected to heat for the purpose of hastening

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