Westinghouse Electric & Mfg. Co. v. Cutter Electric & Mfg. Co.
Westinghouse Electric & Mfg. Co. v. Cutter Electric & Mfg. Co.
Opinion of the Court
In the court below, the Westinghouse Electric & Manufacturing Company, owner of patent No. 633,-772, granted September 26, 1899, to Wright and Aalborg, for an automatic circuit breaker, filed a bill against the Cutter Electric & Manufacturing Company charging infringement of the second and fifth claims thereof. The court below, on an application for a preliminiary injunction (149 Fed. 437), refused such injunction and subsequently on final hearing dismissed ’the bill, whereupon the complainant appealed
In carrying heavy electric currents for lighting and power, it is necessary to use switches for opening and closing circuits. These are protected against the abnormal currents caused by lighting or overloading by automatic circuit breakers. The main contacts of the circuit breakers are copper, which is highly conductive and relatively expensive. Their surfaces must be kept smooth and unpitted, otherwise dangerous and destructive arcs will form. Moreover, when an electric circuit is opened or interrupted, an arc forms ■ between the contact surfaces owing to the current continuing for an instant between unconnected contacts, and if the current is large the damage both to the contacts and the surrounding apparatus may be great. To obviate that difficulty a supplementary or shunt current having carbon contacts is resorted to around terminals. These carbons are cheaper, and, being refractory, are less liable to injury from the arc. Such shunt contacts are arranged to open after and close before the main contacts, so that when the circuit is opened the current flows last through the shunt terminals, and the first contact is also between such carbon terminals when it is closed. These general principles were present in various constructions.prior to the patent in question. The patentees, however, embodied the principle in a device which not only made these successive contacts by a novel form of connecting apparatus, but they so vertically aligned the parts of the apparatus as to produce a new type of long, narrow circuit breaker styled “Edgewise.” This edgewise type developed several important advantages. To combine safety with great carrying capacity and yet secure economy of space, it is important that the apparatus should not be spread laterally, but that the different parts of a circuit breaker should be so located with reference to each other, and the circuit breaker itself to other circuit breakers, that currents should not stray to other instruments or parts of the same instrument, and arcs should be minimized and instantly extinguished without contact with other apparatus. These requirements were met by the patentees’ device. The breaker is long, narrow, and all parts vertically aligned. It opens outwardly from the switchboard, and carries all working parts away from adjoining instruments. The arm is hinged at the bottom, and the shunt contacts, being above the copper ones, pass over longer arcs. These main contacts are laminated, being composed of a number of springy, metallic, bevel-edged plates. When forced against the flat surface of the main stationary contact, they make a maximum metallic conductive surface and utilize the entire conductive cross-section. The whole mechanism is adapted to ease and rapidity in closing. These and other advantages led this court in the opinion cited to hold that the invention “was a distinct advance upon the prior art, producing new and valuable results.”
This leaves us to consider the question of infringement which is predicated on Exhibits 3 and 4, illustrated in the accompanying cuts t
“That the complainant pivots only one of its carbons, while the defendant pivots both of them, is an immaterial difference. Either one or both may be pivoted to secure the desired yielding and turning motion.”
Nor does the fact that respondent actuates the breaker by a cam instead of a toggle joint avail to relieve it from infringement. Abstractly, a cam may have broader capabilities than a toggle joint. But those broader capabilities are not functionally needed by the' respondent. It simply employs those capabilities which the cam possesses in common with the toggle joint to accomplish in its machine what the toggle joint did in that of the patentees. Its substitution is manifestly not to accomplish any other or different result from that effected by the toggle joint, but merely to avoid its duplication. Without, therefore, saying that in all cases the two mechanisms are equivalent, yet having the same purpose in combination, and effecting that purpose in sub
We are therefore of opinion that infringement has.been established, and a decree so adjudging will be entered in the court below.
Reference
- Full Case Name
- WESTINGHOUSE ELECTRIC & MFG. CO. v. CUTTER ELECTRIC & MFG. CO.
- Cited By
- 1 case
- Status
- Published