Tesla Patent Case Decided

An opinion has been handed down by Judge McPherson of Philadelphia in favor of the Tesla Electric company in the equity proceedings which it brought against Scott & Janney and others. The bill charged the defendants with infringing letters patent Nos. 511,915 and 555,190, relating to polyphase motors, granted to the plaintiff as assignee of Nikola Tesla. The first patent was granted for a method of electrical transmission and the second for an alternating motor, but both patents stand upon the same application and were attacked together on the ground that they were void for want of invention. It was argued that in view of the prior state of the art, and especially in view of an earlier patent of Tesla, the step from obtaining separately from the generator the two alternating currents, different in phase, that are required to operate the motor described in the earlier patent, to obtaining only one of such currents from the generator, while the other is obtained by induction from the primary current, was an obvious step, easy to be taken by anyone possessed of skill in electrical engineering, and therefore did not involve invention. Judge McPherson concluded that the step was taken in the exercise of invention. In concluding his opinion on this point of the defense he said: “So far as I can realize the situation, the two patents now attacked seem to me to be so connected with the earlier group that the same faculties that were necessary to produce those that are first in point of time must have continued in exercise to produce those that followed. It is often very difficult to draw the line between invention and skill, and different minds may draw it at different points. I submit my own conclusion for what it may be worth.”

Judge McPherson held that none of the defenses submitted to the court could be sustained and that the motor of the defendants infringed all of the disputed claims involved in the suit. The patents in question are now owned and controlled by the Westinghouse Electric and Manufacturing company.