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Western Electric Manufacturing Company v. Ansonia Brass Copper Company

Court Documents

United States Supreme Court

114 U.S. 447

Western Electric Manufacturing Company  v.  Ansonia Brass Copper Company

The case was a suit in equity, brought by the appellant, the Western Electric Manufacturing Company, against the Ansonia Brass & Copper Company to restrain the infringement of two reissued letters patent, numbered 6,954 and 6,955, respectively, granted to the appellant as the assignee of Joseph Olmstead, both dated February 29, 1874, for improvements in insulating telegraph wires. The reissues are divisions of original letters patent No. 129, 858, dated July 23, 1872. The descriptive specifications of the two patents wereidentical. They differed only in the claims, the first being for a process, and the second for the product of the process.

The specification of both patents, after stating that Olmstead had invented a new and useful improvement in insulating telegraph wires, proceeded as follows: 'The method of insulating now in use consists in braiding over the wires a fibrous covering, after which it is dipped in wax, for the purpose of filling and closing its pores, and, after a subsequent scraping to remove the surplus wax, it is ready for use. This method is, however, objectionable, inasmuch as it leaves the covering in a very rough and soft condition, and fails to secure perfect insulation. In my improved method, after the wire has received its coating, I dip it in paraffine or wax, after which, instead of scraping off the surplus coating, I pass the whole through a suitable machine, which compresses the covering and forces the paraffine or wax into the pores and secures perfect insulation. By so compressing the covering the paraffine or wax is forced into the pores, and the surface becomes and appears polished. Wire insulated in this manner is entirely impervious to the atmosphere, of greater durability, and less cumbersome than any heretofore made.'

The claim of the process patent No. 6,954 was as follows: 'The method of insulating telegraph wire by first filling the pores of the covering, and subsequently compressing this covering, and thereby polishing its surface, substantially as described. The claim of the product patent No. 6,955 was 'an insulated telegraph wire, the covering of which has its pores filled and its surface polished, substantially as described.'

The defendant denied in its answer that Olmstead was the first and original inventor of the improvement described in the patents, or of any substantial or material part thereof, or that the same was patentable or the subjectmatter of invention, and that the alleged invention had been previously patented by letters patent of Great Britain, granted to Thomas Earl of Dundonald, dated July 22, 1851, and by letters patent of Great Britain, granted to Felix M. Baudouin, dated April 3, 1857. The defendant also denied infringement. The circuit court, on final hearing, dismissed the bill, and the plaintiff appealed.

Geo. P. Barton, for appellant.

Wm. B. Wooster, for appellee.



This work is in the public domain in the United States because it is a work of the United States federal government (see 17 U.S.C. 105).