Automatic Switch Co. v. Cutter-Hammer Mfg. Co.

139 F. 870, 1905 U.S. App. LEXIS 4734
CourtU.S. Circuit Court for the District of Southern New York
DecidedMarch 3, 1905
StatusPublished
Cited by2 cases

This text of 139 F. 870 (Automatic Switch Co. v. Cutter-Hammer Mfg. Co.) is published on Counsel Stack Legal Research, covering U.S. Circuit Court for the District of Southern New York primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Automatic Switch Co. v. Cutter-Hammer Mfg. Co., 139 F. 870, 1905 U.S. App. LEXIS 4734 (circtsdny 1905).

Opinion

TOWNSEND, Circuit Judge.

Complainant by its bill seeks an injunction and accounting, alleging infringement of its patent No. 499,769, granted June 20, 1893, to G. H. Whittingham for a regulator for electric motors.

The specification states that the alleged invention—

“Relates to an automatic switch for protecting the armature of an electric motor, when the current is shut off and suddenly turned on again. If a full current be turned into a motor when at rest, the quantity of current will be so great as to burn the insulation by heating the wires of the armature, and the armature rendered unfit for use. To prevent this, various devices have been designed to throw into the armature circuit an artificial resistance, when the current is first turned on, and then automatically reduce this resistance as the counter electro-motive force of the armature, which increases with its speed, has become great enough to counteract the tendency of the current to heat the conductor and burn the insulation of the armature.”

The patent in suit is for an improvement of the patentee’s prior patent No. 415, 487 for an automatic device designed to obviate the objections stated above:

“The. object of the invention described herein is to supply for use in the armature branch of an electric motor a switch, which will protect the armature under all circumstances, and which requires no attention whatever from the person operating the motor.- The current is turned on to the motor by an ordinary snap switch which any one can operate without the slightest effort, and this invention is brought into play by the passage of the current and does its work without the attention of any one. On the other hand, if for any reason the current on the line should be shut down without the knowledge of the person attending the motor, this device will automatically introduce the artificial resistance into the armature circuit, just in proportion as it is required by the reduction of the counter electro-motive force of the armature, and the resistance will be again automatically removed from the circuit when the current is turned on again from the generator.”

[871]*871This device is brought into operation when an electric motor is started, and is known as a motor starter, or “self-starter.”

The electric motor is of the shunt motor type, in which the armature and field windings are connected in shunt — that is, in separate and individual circuits — as distinguished from the series motor, where the windings are in series, so that the current passes first through one and then through the other winding. The latter, or series motor, is operated by hand, and is used, in connection with a gradual resistance switch, on trolley cars and automobiles; the former, when connected with a constant potential circuit (that is, a circuit in which the pressure between the two mains is maintained practically constant), and when provided with an armature of low resistance, is self-regulating (that is, maintains a constant speed under varying loads), and is used for running elevators, driving tools in shops, etc.

The claims in suit are as follows:

“(4) The combination of a solenoid of low resistance and a conductor of high resistance connected thereto, a reciprocating iron core within the solenoid, means for holding the core at any predetermined point within the solenoid when it reaches it, until the current is shut off, and which will automatically release the core when this occurs, a circuit closer controlling the conductor of high resistance, and means operated by the reciprocating core for closing the circuit and throwing the conductor of high resistance into circuit with the solenoid of low resistance, substantially as described.
“(5) The combination of a solenoid of low resistance, a conductor of high resistance connected to the solenoid, means for short-circuiting the conductor of high resistance or throwing it into circuit with the solenoid, a reciprocating core within the solenoid which co-operates with the short-circuiting device of the conductor of high resistance, so as to throw said conductor into circuit with the solenoid when the core reaches any predetermined position within the solenoid, substantially as described.
“(6) The combination of a solenoid of low resistance, a conductor of high resistance connected to one of the terminals of the solenoid, a short-circuiting device for short-eircuiting the conductor of high resistance, an iron core reciprocating within the solenoid, an iron cap upon the solenoid, and means connected with the short-circuiting device of the high resistance conductor which is operated by the reciprocating core to break said short circuit and threw the conductor of high resistance into circuit.
“(7) The combination of a solenoid of low resistance, a conductor of high resistance connected to one of the extremities thereof, an iron cap located upon the top of the solenoid, a short-circuiting device for short-circuiting the conductor of high resistance, an iron core reciprocating within the solenoid, means operated by the reciprocating core to break the short circuit of the high resistance conductor and throw it into circuit with the solenoid, and a governor connected to the core and controlling its motion.
“(8) The combination of a solenoid of low resistance, a conductor of high resistance connected to one of its extremities, an iron cap upon the solenoid a portion of which protrudes within the solenoid, an iron core reciprocating within the solenoid, two terminals mounted upon the top of the solenoid in which the conductor* of high resistance terminates, and a bridge connecting said terminals, and means whereby said bridge is lifted and a short circuit between the terminals of the coil of high resistance broken when the core reaches the desired point within the solenoid.”

[872]*872The following diagram shows the apparatus comprising the starter of the earlier patent combined with the improvement of the tatent in suit:

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Related

Automatic Switch Co. v. J. L. Schureman Co.
183 F. 776 (U.S. Circuit Court for the Northern District of Illnois, 1910)
Cutler-Hammer Mfg. Co. v. Automatic Switch Co.
153 F. 197 (U.S. Circuit Court for the District of Southern New York, 1906)

Cite This Page — Counsel Stack

Bluebook (online)
139 F. 870, 1905 U.S. App. LEXIS 4734, Counsel Stack Legal Research, https://law.counselstack.com/opinion/automatic-switch-co-v-cutter-hammer-mfg-co-circtsdny-1905.