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U.S. Supreme Court

Risdon Iron & Locomotive Works v. Medart, 158 U.S. 68 (1895)

Risdon Iron and Locomotive Works v. Medart

No. 164

Submitted January 21, 1895

Decided April 22, 1895

158 U.S. 68


Processes of manufacture which involve chemical or other similar elemental action are patentable though mechanism may be necessary in the application or carrying out of the process, while those which consist solely in the operation of a machine are not, and where such mechanism is subsidiary to the chemical action, the fact that the patentee may be entitled to a patent upon his mechanism does not impair his right to a patent for the process.

A valid patent cannot be obtained for a process which involves nothing more than the operation of a piece of mechanism -- that is to say, for the function of a machine.

A patent only for superior workmanship is invalid.

If it appears, upon demurrer to a bill to restrain infringement of letters patent, that the patent is invalid, the bill should be sustained.

Letters patent No. 248,599, granted October 25, 1881, to Philip Medart for the manufacture of belt pulleys, and letters patent No. 248,598, granted October 25, 1881, to him for a belt pulley, and letters patent No. 238,702, granted to him March 8, 1881, for a belt pulley, are all invalid.

This was a suit in equity instituted by Philip and William Medart against the appellant for the infringement of three letters patent granted to Philip Medart, viz.: Patent No. 248,599, dated October 25, 1881, for the manufacture of belt pulleys; patent No. 248,598, also dated October 25, 1881, for a belt pulley, and patent No. 238,702, granted March 8, 1881, also for a belt pulley.

In the first patent, No. 248,599, the patentee stated in his specification that his invention

"relates to that class of belt pulleys formed of a wrought-metal rim and a separate center, usually a spider, and usually made of cast metal. Heretofore considerable difficulty has been encountered in the manufacture of such pulleys, much time, skilled labor, and large and elaborate machinery have been required, and

Page 158 U. S. 69

their production has been correspondingly expensive. The object of my invention is to cheapen and simplify their construction, overcome the objections above mentioned, and produce strong and perfect pulleys in a quick and efficient manner. My invention therefore consists in an improved process of manufacture, whereby the above results are obtained."

The drawings accompanying the specification represent the machinery for carrying out the invention, and the pulley at various stages of its manufacture. The specification sets forth in detail the manner in which the machinery is operated, and winds up with the following statement:

"Pulleys thus manufactured are perfectly balanced, faultless in shape, strong, and durable, and can be produced more rapidly and at less expense than the imperfect pulleys heretofore made. The machinery herein shown and referred to has not been described more in detail, as its operation will be clear to those skilled in such matters, and no claim to it is herein made, it being my purpose to secure protection for such apparatus by other applications hereafter to be made."

The claims, which are four in number, are all for the described improvement in the art of manufacturing belt pulleys, which consist in centering the pulley center or spider and then grinding the same concentrically with the axis of the pulley, the several claims stating with more or less detail the principal steps in the manufacture.

In his specification to patent No. 248,598, the patentee states that his

"improved pulley belongs to that class of pulleys composed of a separate spider, usually of cast metal, and a wrought-metal rim, which is secured to the spider,"

and that his invention

"consists in a pulley which is perfectly true and accurately balanced -- that is, a pulley in which the center of gravity and geometrical center or axis coincide."

In his specification to patent No. 238,702, which was granted about seven months before the other patents, the patentee states that his invention

"relates to certain improvements in belt pulleys, and had for its object, first, the production of a cheap, light, and durable pulley, and secondly, the production of irregular sizes of pulleys without the necessity

Page 158 U. S. 70

of a separate pattern for each size of pulley required. And this invention consists first in constructing the usual crown or dish on the rim of wrought-metal rimmed pulleys by bending said rim transversely during the process of manufacture; secondly, the belt pulley having arms formed of wood, preferably of a cylindrical shape, which at their inner ends rest in sockets cast on the hub, and at their outer ends are provided with bracket lugs, to which the pin is secured by rivets or other equivalent means."

Figure 1 of the following drawings exhibits a perspective view, and figure 2 a vertical section of the patented pulley:


The defendant appeared and demurred to the bill upon the ground that the patents did not show invention upon their faces. The demurrer was argued and overruled, and leave given to answer, and upon a subsequent hearing upon pleadings and proofs, it was adjudged that all of the patents were valid; that the defendant had infringed the first, second, and third claims of patent No. 248,599, the two claims of patent No. 248,598, and the first claim of patent No. 238,702, and defendant was enjoined from further infringing. A final decree was subsequently entered, upon the report of the master, for $1,811.25, from which decree the defendant appealed.

Page 158 U. S. 71

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