87 F. 733 | U.S. Circuit Court for the District of Connecticut | 1898
The patent in suit (No. 393,323, granted to complainants as assignees of George II. Condict) is for a controlling switch, adapted to be applied to electric motors. The issues herein relate to its use in connection with electrically propelled cars on ordinary trolley lines. The particular apparatus under consideration is the cylinder shaped switch or controller located on the ends of such cars. The current of electricity supplied from the generator and delivered to the motor is necessarily of unvarying potential; that is, it must always have a capacity to supply the full
“This invention is particularly useful where the supply of electricity is great, — such, for instance, as when storage batteries or electric accumulators are used on cars, and in which the motors are regulated by varying their internal resistance, which may be done by connecting their coils in different ways. In practice, I have found that switches for regulating the power and speed of electric motors under these conditions were easily burned out, not only causing great annoyance in the operation of the cars or machine, but rendering the operator liable to injury. The trouble is mainly due to the fact that at the time of changing the motor connections the resistance of the motors' is more or less cut out,- and in making the new connections there is a great danger from sparking, which often short-circuits the connections, with danger of completely destroying the switch and burning out the motors. To overcome these objections, I have constructed my switch so that at the time of changing the connections I insert resistances more or less great according as to the resistance of the motor connections; that is to say, if the motor resistance is great, the auxiliary resistances would be small, and vice versa. I also so arrange the switch that the resistances art-all cut out of circuit as soon as the new motor connection is made. Their function is to reduce the current flowing, so that at the time of making the change in the motor connections the current is small compared with what it would' be if- these resistances were not inserted; and, furthermore, these resistances are gradually cut in and out,- so as not to suddenly change the resistance to the current beyond a given amount. Another portion of my invention is the-reversing switch, which is arranged in the same frame olease with the controlling switch, and combined with a locking device which is operated by the controlling switch, so that when current is flowing through the motors the reversing switch cannot be moved, but when the controlling-switch is turned so that all, or substantially all, of the current is cut out from the motors, then the reversing switch may be moved to reverse the motors.”
Condict so combined the two opposing- systems of resistance already considered as to increase or reduce the amount of current with a saving of waste, and without sparking. In the original statement of his invention, he emphasized, as its chief object, the prevention of sparking, which,' in the then state of the art, was perhaps the chief objection to existing methods. Subsequent development of the art necessitated the introduction of other means to prevent sparking in connection with his original device, and modifications thereof to adapt it to greater voltage and other conditions. Neither the complainants nor the defendants now use this patented device to prevent sparking, hut both use it to regulate the current. Complainants generate the spark and extinguish it by means of a magnetic blowout. Defendants generate the spark and dissipate it by an arc-spanning appliance. The defendants use complainants’ idea, and the elements of its combination, with certain changes borrowed from the existing art, and other improvements covered by Von Zweigbergk’s patent. In view of all the facts proved, I find and hold that the invention of Condict is a broad one, that he is entitled to the beneficial uses of his invention as developed in the development of the art, and that defendants, in thus using his combination, infringe the patent. Oondict showed in his patent four ways of coupling the coils of the motors, commencing with the first position, in which the circuit is broken, and there is no current on. In the second position the current from the generator passes in series, successively, through two coils of each of two motors, and through the armature of the second motor. In changing from the first position of broken circuit to the second position, which represents the circuit of greatest resistance, and consequent least amount of current, a single dead resistance coil is automatically switched into circuit; and, as soon as the circuit is made, it is cut out again. In the next succeeding position the field coils of each motor are coupled in parallel, instead of series, circuits. In the next the motors, as a whole, are arranged with their circuits in parallel paths. As these successive changes successively cut down the motor circuit resistance's, a proportionately greater amount of dead coil or rheostatic resistance is switched in, and then
This case was exhaustively argued by eminent counsel, and elaborately illustrated by models and drawings. Some months after the oral argument, further briefs were filed by counsel. Immediately after the close of the hearing, the case was thoroughly examined, and it has now been considered again in the light of the later briefs submitted. These investigations have so confirmed the impression produced at the hearing that the defendants’ apparatus is a mere modification of the Condict idea, patterned in part thereon, and in part upon the later improvements introduced by the complainants, and that in defendants’ use of a multiple break they have merely improved upon the Condict apparatus, that it has seemed unnecessary to discuss all the details of the case. The statement of complainants’ expert Bentley, when read in connection with the exhibits, clearly
“It is evident that, while only four ways of coupling up the coils of the motor are shown, a large variety of connections might be made, embodying the same general principles. It is also evident that, while the motors are coupled in a given manner, a slight movement of the switch will have the effect of cutting in or out one or more of the resistances, V, and thereby provide an additional means of regulation where slight variations in the speed or power of the motors is required.”
It cannot be said that this is an afterthought of the scrivener, in view of the admissions of defendants’ experts that said language described the application to his invention of a well-known means of secondary rheostatic regulation, such as defendants now use, and that the insertion of notches to indicate such running points was merely a matter of mechanical skill. The position may fairly be stated as follows: Condict described a device calculated to obviate the evils of spa iking. In his specification be emphasized the advantages of Cue use of such great interposed resistances as would cut the current down to a condition in which there should be no sparking whatever. But, when he comes to describe bis apparatus, the description and. claims cover devices capable not only of cutting down the current so as to prevent all sparking, but also of regulating it, without entirely cutting it off, by merely reducing by his combination of resistances the flow of current so as to produce variations of resistance. Thus, he states that he does not limit himself to the “particular details of construction, as they are of secondary importance,” and “may be modified in various ways without departing from iny invention,” and, as to the resistances, that “their function is to reduce the current flowing, so that at the time of making the change in the motor connections the current is small, compared with what if. would be if these resistances were not inserted.” He describes the automatic insertion of these resistances in making the four principal changes already considered, showing how the amount of resistance introduced is to be proportioned to the varying changes in the motor resistances, stating the purpose of such object “to avoid throwing too strong a current,” and “to soften the shock involved,” and then concludes with language above quoted. Defendants use a noninfringing dissipa tor, but, in order to utilize it at the time when it shunts from one running point to another (that is, during the time when the circuit is broken and rearranged), they use the resistances of the complainants’ patent, in order to reduce the current. By a practical
The defendants further contend that, even if they should be held to use the elements of complainants’ combination, yet they do not infringe, because they use them in connection with another element, namely, the noninfringing patented dissipator, in such a way that the co-operative law of defendants’ machine differs from that of complainants. This contention is not proved. The broad principle of mixed controllers, as applied to electric motors, was invented, or at least practically developed, by Condict. Whether he be limited, as claimed by defendants, to ad interim resistances (that is, resistances interposed between running points), or whether he be permitted to avail himself of the broad principle of combined resistance and series parallel controllers, the defendants use the same resistance in the same way; the difference being that, while Condict described such resistances as being in a certain definite series, defendants have inserted the series in the place of one of his motors, and shunted the motors. Defendants do not cut the resistance out, nor do they arrange the motors and coils in exactly the' same relative positions; but they do use and must use the combination upon the same theory, and for the same purposes, in order to avail themselves of the independent, noninfringing, patented arc-spanning dissipator.
Claims 23 and 30 cover the main invention, with an independent switch to cut one of the circuits. This switch is, not co-operatively combined with the patented controller, but is an entirely independent device added to it. The defendants do not use the cut-out switch de
“(10) The combination of a movable controlling switch for varying the power of the motors, having a cam surface, a reversing switch having holes or openings, and a.- bolt actuated by the cam surface of the controlling switch, and adapted to be projected through the lióles or openings in the reversing switch to lock it against movement when said controlling switch is moved.”
The defendants do not nse this Oondict combination, but use a different combination of the same elements, or their equivalents. In view of the prior art shown in the bield, Curtis & Crocker and Keekenzaun patents, I think the complainants are limited to (lie details of construction stated in the specification of the pa lent in suit, as to these minor features of the main invention, and that defendants do not infringe said claims, as thus limiied.
Claims 27, 28, 29, and 31 are as follows:
“(27) The combination of an electric motor, a source of electric power, a motor circuit, a motor switch to vary the power of the motor, two or more resistances, a resistance switch to cut said resistances gradually into or out of the motor circuit, and a connection between the said switches, whereby a movement of the motor switch will first cut in one or more of the resistances, and, after changing the power of the moror, automatically cut,, the resistances out of circuit again. (28) The combination of a motor having-separate coils, a motor circuit, a motor switch for coupling up said coils so as to vary the internal resistance of the motor, a resistance, and a resistance switch to cut in and out the said resistance, upon shifting the motor switch, to vary the coupling- of the motor coils. (29) The combination of a motor having separate coils, a motor circuit, a motor switch for coupling up said coils so as to vary the internal resistance of the motor, a resistance, a resistance switch to cut in and out the said resistance upon shifting the motor switch to vary the coupling of ¡lie motor coils, and means controlled by the motor switch for operating the resistance switch.” “(3!) The combination of two motors, a source of electric power, a motor circuit, a switch for coupling- the coils of the motors in series or multiple to vary their internal resistance, a. resistance, a switch to insert the resistance when the motor switch is being shifted, and a connection between said switches to operate both simultaneously.”
Those broad claims cover the main combination of the patent, and are infringed by defendants.
Claims 20, 23, and 22 are as follows:
“(20) The combination of a source of electric energy, the coils of one or more, electric motors, a switch for connecting said coils in different ways to vary the motor resistance, one or more, resistances, and a switch to put said resistances into or out of the motor circuit, without changing the motor connections. to vary the power of the current flowing through the motors. (21; The combination of a source of electric energy, the coils of one or more electric motors, a switch for connecting said coils in different ways to vary the motor resistance, and one or more resistances; said switch being adapted to put said resistances in succession into or out of the motor circuit, without changing the motor connections, to vary the power of the current flowing through the motors. (22) The combination of a source of electric supply, a switch for coupling up the coils of a motor or motors in a, predetermined order, a series of resistances, a contact block on said switch in circuit with the motor and resistances, and having contact edges for cutting in or out the resistances one at a time, contact brushes from said resistances, and connected to the source of electric supply, and resting- on the contact block,*740 and adapted to be brought into or out of contact with it in succession, whereby the resistances may be cut into or out of the motor circuit without varying the connection of the motor coils.”
The minor 'feature of the invention covered by these claims has been unquestionably appropriated by defendants. It is the feature of temporary use of supplementary resistances, not necessarily during circuit changes, already fully discussed. Claims 15 and 16 are not infringed. Let a decree be entered for an injunction and an accounting as to claims 20, 21, 22, 27, 28, 29, and 31.