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embracing the spindle at the other. Hence there is no danger of these springs being bent outwardly, and thereby fail to bear on hub of the trolley, or so as to come in contact with a switch box, or any external object. It is confined simply and securely in its proper position between the hub of the trolley and the frame. Moreover, the spring contact does not bear on the periphery of the wheel, nor yet on the periphery of the hub, but on the end of the hub, whereby there is a minimum of speed of the wheel on the brush and a minimum degree of retarding action of the brush on the wheel."
It does not appear that in either of these cases any attention was paid by counsel or court to the copper discs or washers, which, for the apparent purpose of reducing the friction and wear on the contact spring or conducting brush, it is stated in the specification the applicant prefers to add "at the ends of the hubs." The patent itself treats these copper discs or washers as quite distinct from the metallic conducting brushes. The copper discs are marked "g," the metallic conducting brushes "g," and it is stated in the specification that "the copper or other equivalent brushes, g2," bear against the outer sides of the copper discs when these are added at the ends of the hubs. The copper discs may or may not be used, and, if used, are treated as added at the ends of the hubs; in other words, as an addition to the hubs. The conducting brushes bear either against the ends of the hubs or against the outer sides of the washers when these are added to the hubs.
In the former cases in this court counsel for the patent treated the metallic conducting brushes as the patent does-as contact springs, bearing against the ends of the hub or the washers (if they are used), and protected by being placed between the hub and the frame. The leading expert for the patent said in the first case: "It is beyond question that for many years such brushes, g2, have been given a uniform pressure upon the hub of the trolley wheel or the copper washer, g, sufficient for all practical purposes." And counsel themselves stated in their brief that the testimony proved beyond doubt that the conducting brushes of complainant's device were spring brushes; that they bore evenly, and for all practical purposes, over substantially the whole surface of the washer of [or] the ends of the trolley wheel hub. In their brief in the second case they submitted an illustration of a view in perspective of the second form of the Star Brass trolley harp and contact brushes held to infringe in the first case, which was reproduced in the opinion in the second case. 126 Fed. 756. In this the washer and conducting brush are designated as separate and distinct pieces. The brush is marked "Spring Conducting Brush," the top of the brush is marked "Top of Brush Bearing on Washer," while the washer is marked "Washer Bearing on End of Hub." In both the former cases the contact or "business end" of the conducting brush or contact spring was placed between the hub and the frame, and bore either against the end of the hub or the washer. The alleged infringing device contains no contact spring located between the hub and the frame. The contact spring is forked, and is placed on the outside of the frame or harp, being countersunk or recessed therein. Connection with the hub is secured through a "massive" washer having lugs which extend through slots in the frame. The forked spring outside the frame presses upon these lugs, forcing the
washer against the hub inside. The court below took the view that the defendant had taken the conducting brush of the Anderson patent and divided it into two parts, a spring and a washer; the spring technically outside the frame, but really protected by it, and the washer, which constituted the contact part or "business end" of the brush, located between the hubs and the frame, constituting a mere colorable modification of Anderson's device.
It is no doubt true that when a washer is placed between the hub and the spring, the current must pass from the hub through the washer before it reaches the spring, and therefore in one sense the washer is a part of the conducting device; but in another it is a mere addition to or extension of the hub, and the patent so treated it. The claim was not based upon the location of the washer. The washer might or might not be used. It was based upon the location of the brush or spring which pressed against the hub or washer and carried the electricity to the frame. The washer needed no protection, but the brush or spring did. Judge Kirkpatrick, in his opinion, pointed out the need of protecting the contact end of the brush, which bore either upon the washer or the hub. This spring, a delicate thing, placed outside, was liable not only to be injured by violent contact with other objects, but to be destroyed by stray arcs, and Anderson therefore placed it inside.
The defendant's device, which is covered by a patent to F., P. Crockett and O. P. Johnson, being No. 690,639, places the spring on the outside of the harp. It is protected against injury from without by being placed in a deep recess, and against injury from within by the intervening frame. A patent for protecting a spring by locating it on the inside of the trolley harp is not infringed by placing it in a recess on the outside, any more than a patent for protecting it by countersinking it on the outside is infringed by locating it wholly on the inside. Although the result may be the same, the device is different, and the patent covers only the device.
If the contact spring in the defendant's device, corresponding with the metallic brush of the complainant, is not located between the hubs and the frame and protected by being entirely within the latter, is the fact that the spring presses upon the lugs of the washer, which contacts with the hub inside the frame, in itself sufficient to constitute an infringement? The eighth claim of the Anderson patent was a narrow one, and we sustained it not simply upon the ground that the electric current was taken from the wheel at the hub, but upon the ground that the metallic conducting brush, which pressed against the hub or washer, was a spring requiring protection, and was protected by being placed between the hub and the frame, inside the latter. The defendant uses another method of protecting the spring. In our opinion, there is no infringement.
The judgment of the court below is therefore reversed.
WESTON ELECTRICAL INSTRUMENT CO. v. EMPIRE ELECTRICAL INSTRUMENT CO. et al.
(Circuit Court, S. D. New York. June 10, 1904.)
1. PATENTS-INVENTION-ELECTRIC SHUNT.
The Weston patent, No. 497,482, for a shunt for electric light and power stations, specially adapted to the measuring of very strong electric currents, and in making which short plates of metal of high resistance are used, with air spaces between them, and connected with massive terminals of metal having a lower resistance, was not anticipated, and discloses invention of high order. Evidence also considered, and held not to show prior use by defendants. The patent also held infringed.
In Equity. Suit for infringement of letters patent No. 497,482, for a shunt for electric light and power stations, granted to Edward Weston May 16, 1893. On final hearing.
William Houston Kenyon and Richard Eyre, for complainant.
HOLT, District Judge. This is a suit to restrain the infringement of a patent, No. 497,482, dated May 16, 1893, issued to Edward Weston, and now owned by the complainant, for a shunt for electric light and power stations. There are no questions as to jurisdiction, parties, or title. The proof of infringement is conclusive, and is not controverted. The substantial defenses relied on are that the patent in suit is invalid for lack of invention, for insufficient disclosure in the patent, and for public use more than two years before the application. An electric shunt is an additional course or side track established for the passage of part of an electric current. The use of a shunt for the measurement of small or ordinary currents of electricity was well known long before the Weston patent. The usual method of construction was to introduce into the wire or vehicle carrying the electric current a metal of greater electrical resistance, and to connect the two terminal portions of such metal by wires with a measuring instrument. A portion of the current was thus shunted off and passed through the measuring instrument. The portion of electricity flowing over the shunt, as compared with the portion flowing over the main current, being ascertained, the force of the entire current could be computed by the measurement of the shunted current, and for the purposes of measurement the use of such a comparatively small current was found more convenient than to undertake to apply a measuring instrument to the entire current. The great difficulty was in applying a shunt to a very large and powerful current of electricity, owing to the fact that the metal of higher resistance constituting the shunt would become so heated by the resistance of so large a current as to become redhot or fused. With the gradual development of the commercial use of electric power, it became necessary to employ currents, particularly at electric light and power stations, of constantly increasing strength, and it became of great importance devise accurate measuring instruments for such large currents. Prior to Weston's patent in 1893, no practical method for the
use of a shunt in connection with the measuring instruments for such large currents had been found, although the necessity for such an instrument was thoroughly appreciated, and many electricians all over the world attempted to invent one. In actual practice, no shunt at that time was used. The measuring instrument was applied to the entire current, but the result was unsatisfactory. The measuring instruments were complicated, inconvenient, and expensive, and the measurements which could be made by them were inaccurate and unsatisfactory. The essential problem in discovering a shunt which could be used with a powerful current was not electrical, but thermal. The question was how to avoid excessive heat at the shunt. The efforts, previous to Weston's, to solve the problem, consisted substantially in attempts to construct a shunt which should have a sufficiently large resisting mass to heat slowly, with various appliances or methods for keeping it cool. Weston's invention consisted in constructing a shunt consisting of short plates of high resistance, arranged with air spaces between them, and directly connected with massive terminals, the object being to have the heat generated in the short plates of high resistance rapidly removed by the joint action of radiation through the massive terminals and the cooling influence of the air. Instead of making the plates of high resistance long, so that they would heat slowly, they were made short, so that they would heat quickly, but, being inserted in massive terminals at each end, consisting of a metal of less resistance, and being surrounded by air, the heat was dissipated quickly. The heat generated in the short plates of high resistance reached a certain degree of temperature very quickly, and thereupon substantially all further heat was effectively dissipated, so that the degree of heat in the plate of high resistance quickly became and remained substantially uniform. The result was a shunt capable of successfully measuring an electric current of enormous power. The instruments manufactured under Weston's patent immediately entered into substantially universal use in all large central electric power and light stations, and have ever since been used almost exclusively as ammeters of large electric currents.
The defendants claim that Weston's patent was invalid for want of invention, claiming that he borrowed all the ideas in his shunt from shunts previously patented or described. The defendants pleaded in their answer that the invention had already been disclosed and patented in certain patents, naming about 70 United States patents and 13 French patents previously issued to Weston, and 98 American patents, 41 English patents, 22 French patents, and 4 German patents previously issued to other persons. The answer also alleged that the invention was described in about 50 enumerated publications. The defendants. have given in evidence a few of these patents and publications, and in their brief rely upon a previous patent for a shunt issued to Weston, and other shunts known as the Queen shunt, the Edison Shunt, the Anderson shunt, the Franklin Institute shunt, the La Roche shunt, and the Vienna and Munich shunts. An elaborate argument has been made that Weston's shunt in suit is the same in principle as all the other shunts, but, in my opinion, it is radically different in principle. The basic idea of a shunt, of course, is fundamentally the same; that is, some metal of higher resistance than the conducting metal is inserted
for the purpose of shunting off a portion of the current. But all the shunts relied upon by the defendants were shunts which made no use of the methods which Weston used to dissipate the heat in the case of a large current. None of them had struck upon the idea of making the plates of high resistance short, so that the heat in them would be rapidly absorbed by the terminals, and none of them had hit upon the idea of making the terminals massive, so that they would radiate a large amount of heat rapidly from the plates of high resistance. I think that Weston's patent not only embodies invention, but that it embodies invention of a very high and superior order. It adopted a method of dissipating heat which was not only novel, but was in a line entirely opposite to the direction in which all other electricians had been working. The defendants lay especial stress upon the case of the Weston patent, No. 496,501, for a shunt. This patent was applied for on the same day as the patent in suit, but was issued about two weeks earlier. The defendants contend that it is, therefore, an underlying patent, which claim, under the authorities, I think is correct; and that it is a patent for the same invention as the patent in suit, which claim, in my opinion, is entirely incorrect. The earlier patent makes no claim for short plates of high resistance joined with massive terminals as a method of dissipating heat. The defendants also seem to place great reliance on the Franklin Institute shunt as having anticipated Weston's invention, but I cannot see that it anticipated it at all. It was a shunt; but its plates of high resistance were long, not short, and its terminals were not massive. It was an instrument designed for laboratory use. It was not calculated for commercial use, and was never in fact employed, and is impracticable to be employed, for practical commercial purposes. The so-called La Roche shunt is admitted by the defendants' counsel to be further from Weston's invention than the Franklin Institute shunt; and, in my opinion, the so-called La Roche shunt and all the others that have been referred to have nothing in common with the Weston shunt in suit.
The defendants allege that Weston did not comply with the statute requiring his invention to be described in such full, clear, concise, and exact terms as to enable any person skilled in the art to make it. Great stress is laid on the fact that the claims of the patent do not specifically state that the plates of high resistance should be short, or designate the exact length or size of the parts of the shunt. It is true that the invention must be stated in the claim, and must be fairly included within it. But the claim must be read in the light of the specifications and drawings; and if the invention, as a whole, is fairly stated in the claim, and the claims, with the specifications and drawings, enable a person skillful in the art to construct the thing invented, the patent is sufficient. In my opinion, the claims in this patent sufficiently describe the invention, and all the parts of the patent read together afford a sufficiently clear and exact description of the thing invented to enable a person skilled in the art to construct it. The fact that no precise dimensions of the short plates or the massive terminals are given is certainly immaterial. The length of the plates of high resistance and the size of the metal terminals must necessarily vary to some extent with the size and force of the current and the circumstances under which