Westinghouse Electric & Mfg. Co. v. Allis-Chalmers Co.

176 F. 362, 100 C.C.A. 408, 1910 U.S. App. LEXIS 4266
Court of Appeals for the Third Circuit·Decided January 20, 1910·No. No. 72·Published·Cited by 19 cases

Opinion

BUFFINGTON, Circuit Judge.

In a bill filed in the court below, the Westinghouse Company charged the Allis-Chalmers Company with infringement of patent No. 606,01a, issued June 21, 1898, to one Damme, for a system of electrical distribution and regulation, and now [363] owned by it. That court, in an opinion reported at 168 bed. 91, held that no infringing- act on the part of the Allis-Chalmers Company was shown, and dismissed the bill, without discussing- the paten! questions involved. From such decree the Westing-house Company appealed. As we have reached the conclusion that under the pleadings and proofs the alleged infringing acts are chargeable to the Allis-Clialmers Company, we turn to a discussion of the ¡latent in question.

When, in the early 90’s, the advantages, for transmission and other purposes, of an alternating over a direct current became apparent, there arose a demand for appliances whereby existing- electric plants, built to generate direct currents, could convert such direct into alternating" currents. This demand, as well as the desirability of at times converting alternating into direct currents, led to the development of rotary converters. Without discussing details, it suffices to say that such converters so coupled a motor and a generator that, when the ■direct 'current was the electro-motive force at one end, the other pro■duced an alternating current, and vice versa. This rotary converter was improved from time to time, and when used to convert alternating to direct currents proved satisfactory. On the other hand, when used to transform a direct to an alternating current, the converter proved unsatisfactory, and its dangers were such as to almost prohibit its use. These dangers arose from its erratic actions, in that it wotdd, without warning to or knowledge In the operator, so suddenly and at such high speed begin racing that before the operator could control the apparatus it was liable to destroy itself.

Now the rotary converter, as constructed at the date of the patent., consisted of a motor and a generator, placed side by side on a common shaft, and having a common magnetic field. They had also a common winding connected at different ¡joints to the bars of the commutator and ¡o the collecting rings, respectively, so that, when a direct current was led Into the coils through the commutator, thus driving the 'machine as a direct current motor, an alternating current could be taken from the collector rings. But this conversion of direct to alternating current brought ink > play inductive forces which are not present where a direct current is used for nonconverting purposes. If an inductive load — such, for example, as inductive motors — were thrown upon the alternating current circuit, a demagnetization of the field of the converter resulted, with an attendant increase in the speed of the armature, such as noted above. Now, as this speed-causing factor was without the knowledge and beyond the control of the operator, it can readily he seen that this uncontrolled inductive factor dominated the converter and precluded its use, except in cases, theoretical rather than real, where no variation in the inductive load on the alternating current circuit could possibly occur. Moreover, the result of this inductive force in abruptly changing the speed of the armature and the regularity of the alternating current was objectionable, in that such currents work properly only under a fixed rate of alternation. To counteract this destructive force was Famine’s purpose, and the proofs show that, although such evil was recognized, it ivas not remedied until he did so near the dose of the 90’s, and it is significant that no other mode has since been devised.

[364] Turning to the patent, we find fiamme stated his object clearly in these words:

“My invention relates to tlie transformation of direct currents to alternating currents, and lias for its object to provide a method and a means whereby the speed of the rotary transformer employed may be maintained substantially constant, irrespective of changes in the amount of inductive load on the alternating current circuit.”

fie then states the effects on a rotary converter of inductive and non-inductive loads on the alternating current circuit, to which we- have referred, and says:

•“Therefore, if the alternating current circuit carries an inductive load— such, for example, as inductive motors — which changes from time to time, the variations in the amount of inductive load will cause variations in the speed of the transformer, which will in turn vary the speed of the motors driven by it.”

The patentee then describes his remedial mechanism as follows:

“In order to obviate this variation in speed with changes in the amount of inductive load, I propose to employ a small direct-current generator for exciting the field-magnet of the rotary transformer, which may have either a shunt, a series, or a compound winding, but which must be normally operated to produce an electro-motive force, which corresponds to a degree of field-magnet excitation very much below saturation. This exciting generator is driven either by an alternating current motor, which is in turn driven by current supplied by the rotary transformer, or it is belted directly to the rotary transformer.”

And of the electrical action of such device he says:

“If the amount of the alternating current inductive load on a rotary transformer changes, so that the rate of alternating decreases, -for example, then the exciting generator and the motor driving the same will also decrease in speed. This action will also decrease the exciting electro-motive force of the rotary transformer, and as the exciter is unsaturated a small drop in speed will produce a relatively large drop in the electro-motive force. This lowering of the exciting electro-motive force will thus weaken the field of the rotary transformer -and effect an increase of its armature speed up to near the normal. On the other hand, an increase in speed of the rotary transformer will be accompanied by -an increase in the exciting electro-motive force, which will act immediately to lower the speed of the transformer.”

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

Westinghouse Electric & Mfg. Co. v. Allis-Chalmers Co., 176 F. 362, 100 C.C.A. 408, 1910 U.S. App. LEXIS 4266 (3d Cir. 1910).

176 F. 362 (Westinghouse Electric & Mfg. Co. v. Allis-Chalmers Co.) — published by Counsel Stack Legal Research, free access to 12M+ legal documents.

Related

Inland Steel Products Co. v. MPH Manufacturing Corp.
25 F.R.D. 236 (N.D. Illinois, 1959)
C. H. Little & Co. v. Gay Apparel Corp.
108 F. Supp. 762 (S.D. New York, 1952)
Ferguson v. Ford Motor Co.
77 F. Supp. 425 (S.D. New York, 1948)
A. B. Dick Co. v. Marr
155 F.2d 923 (Second Circuit, 1946)
Weisser v. Mursam Shoe Corporation
127 F.2d 344 (Second Circuit, 1942)
In re First Nat. Bank
23 F. Supp. 255 (E.D. Illinois, 1938)
American Wood Products Corp. v. Crane Co.
29 F. Supp. 807 (N.D. Ohio, 1937)
Certain-Teed Products Corporation v. Wallinger
89 F.2d 427 (Fourth Circuit, 1937)
Drumhead Co. of America v. Hammond
18 F. Supp. 734 (W.D. Pennsylvania, 1936)
Lektophone Corp. v. Philadelphia Storage Battery Co.
8 F. Supp. 46 (E.D. Pennsylvania, 1934)
General Electric Co. v. George J. Hagan Co.
38 F.2d 995 (W.D. Pennsylvania, 1929)
Gallatin Natural Gas Co. v. Public Service Commission
256 P. 373 (Montana Supreme Court, 1927)
Birmingham Realty Co. v. Crossett
98 So. 895 (Supreme Court of Alabama, 1923)
Chicago Mill & Lumber Co. v. Boatmen's Bank
234 F. 41 (Eighth Circuit, 1916)
Pieper v. S. S. White Dental Mfg. Co.
228 F. 30 (Seventh Circuit, 1915)