Smith v. Macbeth

67 F. 137, 14 C.C.A. 241, 1895 U.S. App. LEXIS 2729
CourtCourt of Appeals for the Second Circuit
DecidedFebruary 14, 1895
DocketNo. 35
StatusPublished
Cited by3 cases

This text of 67 F. 137 (Smith v. Macbeth) is published on Counsel Stack Legal Research, covering Court of Appeals for the Second Circuit primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Smith v. Macbeth, 67 F. 137, 14 C.C.A. 241, 1895 U.S. App. LEXIS 2729 (2d Cir. 1895).

Opinion

SHIPMAN, Circuit Judge.

The bill in equity in this cause was based upon the alleged infringement of the first claim of letters patent No. 201,296, dated March 12, 1878, and issued to H. Julius Smith, for improvements in magneto-electric machines. The defendant principally relied upon the proposition that this claim was limited by the proceedings in the patent office to such arrangement or construction of the elements of the combination as to exclude his machine from a just charge of infringement. The circuit court consented to this conclusion, and dismissed the bill. From its decree the complainant appealed to this court.

The object and the details of the alleged invention are described in the specification as follows:

“This invention relates to certain improvements in that class of magneto-electric machines used chiefly for developing an intense current of electricity for firing fuses in blasting, or igniting gas jets, and known as ‘dynamo-[138]*138magnetic machines.’ It is well known that in a machine of this class the electricity is developed and accumulated in the electro-magnets until a sufficient charge to effect the desired purpose has been obtained, the current being automatically shifted at the proper moment from the condensing circuit to a circuit through which the effect intended is to be produced. The intensity of the electric current produced by this and other magneto-electric machines depends upon the rapidity with which the armature is rotated, and the motion has heretofore been obtained by devices giving a uniform motion; but I have found that in order to obtain the best effect, especially in a machine used for firing blast fuses, the armature should have an accelerated velocity of rotation; its speed increasing from the beginning of its movement to the instant of discharge or shifting of the current from the condensing to the working circuit, and it is important that this shifting should occur promptly at the instant the rotating device has reached the limit of play arranged for its assigned culmination of speed. The shifting of the current in machines heretofore constructed has been performed by hand, and by an automatic switch governed and operated by the electric current, the latter means being preferable; but I have still found such switches rather objectionable in use, owing to the complication of the apparatus, and liability to derangement of the parts. It is the object of my invention to overcome the objections which I have mentioned. To this end it consists— First, in the combination, with the operating device of the rotary armature of a dynamo-magneto-electric machine, of a bridge or switch arranged in the condensing circuit of said machine, and in the path of said operating device, and adapted to be opened by direct impingement of said device thereupon; second, in the combination, with the operating rack bar of the rotary armature of a dynamo-magneto-electric machine, of a shunt or bridge consisting of a spring-bar terminal of the condensing circuit and a rigid terminal plate, with which said spring bar is kept in contact by its elasticity, said spring bar being arranged in the path of the rack bar, so as to be struck and moved from the rigid terminal by said rack bar at or near the completion of its armature operating stroke, whereby the condensing circuit of the machine is broken by the displacement of the shunt or bridge, and the whole developed current of electricity required to pass to a working circuit for application, substantially as above set forth; third, in the combination, with the rotating armature of a dynamo-magneto-electric machine, of a loose pinion arranged upon the arbor of said armature, a rack bar gearing with said pinion, and a clutch for engaging with and disengaging from said pinion, causing the arbor and armature to revolve therewith when rotated in one direction, but which disengages therefrom, and permits said pinion to revolve in the opposite direction, independently of the arbor and armature, whereby is secured a rotation of the armature in one direction only, and depolarization of the magnet or magnets prevented.”

The patentee also says in the specification that, while he has shown a rack and pinion for operating the armature, it is obvious that the same result can be accomplished by the use of levers, segments of circles, or other devices for producing reciprocating motion.

The first claim is as follows:

“(1) The combination, with the operating device of the rotary armature of a dynamo-magneto-electric machine, of a bridge or switch arranged in the condensing circuit of said machine, and in the path of said operating device, and adapted to be opened by direct impingement of said device thereupon, substantially as and for the purpose set forth.”

The predecessor of this improved machine, and the one which most nearly resembled it, was the Siemens and Halske machine for blasting mines, which was described in 1868 in English and Austrian publications, and which was also used in this country to a limited extent Its operating device was a crank, which [139]*139must have two dead centers where the application of force is stopped, and as a consequence the speed of the machine could not foe continuously accelerated. The gist of the invention of the patentee was the constantly “accelerated velocity of rotation” of the armature from the beginning of its movement to the instant when the current was shifted, and the mechanical connection of the switch with the operating device by which the switch wras opened by direct impingement of such device at the time when the armature was at its highest speed.

The defendant’s theory is not that this invention was anticipated by any one pre-existing machine, taken by itself, but that its important features were separately found in two older machines, and could have been combined without the exercise of inventive skill. It is said that anybody could have taken the rack bar of the English patent of 187Í, to Geminiano Zanni, for an improvement in magnetic bells, and have substituted it for the crank of the Siemens and Halske machine, and have produced the Smith invention. It is true that anybody could have done this, if he had ascertained the cause of the defect in. the Siemens machine, and the kind of motion, and the proper means of applying it, which would obviate the defect; but the defendant’s theory, like many theories of a similar character, assumes, what is not apparent, that the cause of the pre-existing defect, and its remedy, were open to the discernment of the skilled mechanic.

Turning now to the question of infringement, the simple mechanism by which the rack bar is made to break the condensing circuit is described in the specification as follows:

“When the rack bar has nearly reached the downward limit of Its movement, its lower end strikes upon the free end of the spring bar, H, removing said spring from contact with the bridge or loop, G, and breaking the condensing circuit, upon which, as will be readily understood, the whole current will How over the working circuit or circuit of application.”

The defendant’s device is described in Judge Wheeler’s opinion as follows:

“In the defendant’s machine the armatures are rotated by pulling upward with increased velocity a bar attached to the end of a lever pivoted on a shaft, and moving a toothed segment meshed in the pinion.

Free access — add to your briefcase to read the full text and ask questions with AI

Related

Johnson v. Brooklyn Heights R.
75 F. 668 (U.S. Circuit Court for the District of Eastern New York, 1896)
Gould Coupler Co. v. Pratt
70 F. 622 (U.S. Circuit Court for the District of Northern New York, 1895)

Cite This Page — Counsel Stack

Bluebook (online)
67 F. 137, 14 C.C.A. 241, 1895 U.S. App. LEXIS 2729, Counsel Stack Legal Research, https://law.counselstack.com/opinion/smith-v-macbeth-ca2-1895.