US SUPREME COURT DECISIONS

A patent for a combination of separate parts does not cover each part when taken separately.

A patent for a combination is not infringed by use of one of the parts which, united with others, makes the combination unless other mechanical equivalents, known to be such when the patent was granted, are substituted for the omitted parts.

Seeding machines manufactured according to the specifications in patent No. 152,708 for a new and useful improvement in seeding machines, granted to John H. Thomas and Joseph W. Thomas, June 30, 1874, do not infringe the reissued letters patent, No. 2,909, granted to John S. Rowell and Ira Rowell, for a new and useful improvement in cultivators.

This was a suit in equity brought by the plaintiffs in error as plaintiffs below, to restrain the defendants in error from infringing reissued patent No. 2,909 for a new and useful improvement in cultivators, granted to the plaintiffs, March 31, 1868. The defendants denied the infringement, and justified the manufacture of the machines alleged to be such by patent No. 152,706, granted to John H. Thomas and Joseph W. Thomas, June 30, 1874, for a new and useful improvement in seeding machines. A decree was made below in favor of the defendants, from which the plaintiffs appealed.