170 U.S. 537 (1898), Westinghouse v. Boyden Power Brake Company

Citation:170 U.S. 537, 18 S.Ct. 707, 42 L.Ed. 1136
Party Name:Westinghouse v. Boyden Power Brake Company
Case Date:May 09, 1898
Court:United States Supreme Court

Page 537

170 U.S. 537 (1898)

18 S.Ct. 707, 42 L.Ed. 1136



Boyden Power Brake Company

United States Supreme Court

May 9, 1898




The Boyden device for a fluid-pressure break is not an infringement of patent No. 360,070 issued to George Westinghouse, Jr., March 29, 1887, for a fluid-pressure automatic-brake mechanism.

[18 S.Ct. 707] This was a writ of certiorari to review a decree of the circuit court of appeals reversing a decree of the Circuit Court for the [18 S.Ct. 708] District of Maryland, which had sustained in part a bill filed by Westinghouse against the Boyden Power-Brake Company for the infringement of patent No. 360,070, and from which decree both parties had taken an appeal to the circuit court of appeals.

The patent in suit, which was issued March 29, 1887, to George Westinghouse, Jr., is for a fluid-pressure automatic brake mechanism, the object of which is said in the specification

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to be

to enable the application of brake shoes to car wheels by fluid pressure, to be effected with greater rapidity and effectiveness than heretofore, more particularly in trains of considerable length, as well as to economize compressed air in the operation of braking, by utilizing in the brake cylinders the greater portion of the volume of air which in former practice was directly discharged into the atmosphere.

To this end, my invention, generally stated, consists in a novel combination of a brake pipe, an auxiliary reservoir, a brake cylinder, and a triple-valve device, governing, primarily, communication between the auxiliary reservoir and the brake cylinder, and secondarily communication directly from the brake pipe to the brake cylinder.

There follows here a description of the Westinghouse automatic brake as theretofore used, its mode of operation, and the defects or insufficiencies which attended its application to long trains, in the following language:

In the application of the Westinghouse automatic brake, as heretofore and at present commonly in use, each car is provided with a main air pipe, an auxiliary reservoir, a brake cylinder, and a triple valve; the triple valve having three connections, to-wit, one to the main air-brake pipe, one to the auxiliary reservoir, and one to the brake cylinder. The main air pipe has a stopcock at or near each of its ends, to be opened or closed as required, and is fitted with flexible connections and couplings for connecting the pipes from car to car of a train so as to form a continuous line for the transmission of compressed air from a main reservoir supplied by an air pump on the engine. When the brakes are off or released, but in readiness for action upon the wheels of the train, the air which fills the main reservoir and main air pipes has a pressure of from sixty-five to seventy-five pounds to the square inch, and by reason of the connections referred to, the same pressure is exerted in the casings of the triple valves on both sides of their pistons, and in the auxiliary reservoirs connected therewith. At the same time, passages called "release ports" are open from the brake cylinders to the atmosphere. When it is desired to apply the brakes, air is

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allowed to escape from the main air pipes through the engineer's valve, thereby reducing the pressure in the main air pipes, whereupon the then higher pressure in the auxiliary reservoirs moves the pistons of the triple valves, so as to first close the passages from the triple valves to the brake pipe, and at the same time close the release ports of all the brake cylinders, and then open the passages from the auxiliary reservoirs to the brake cylinders, the pistons of which are forced out by the compressed air thereby admitted to the brake cylinders, applying the brakes by means of suitable levers and connections, all of which mechanism is fully shown in various letters patent granted to me.

The application of the brakes with their full force has heretofore required a discharge of air from the main pipe sufficient to reduce the pressure in said pipe below that remaining in the auxiliary reservoir after the brakes have been fully applied, and it has been found that, while the brakes are sufficiently quick in action on comparatively short trains, their action on long trains of from thirty to fifty cars, which are common in freight service under present practice, is, in a measure, slow, particularly by reason of the fact that all the air required to be discharged from the main pipe to set the brakes must travel from the rear of the train to a single discharge opening on the engine. This discharge of air at the engine has not only involved a serious loss of time in braking, but also a waste of air. Under my present invention, a quicker and more efficient action of the brakes is obtained, and air which has been heretofore wasted in the application of the brakes is almost wholly utilized to act upon the brake pistons.

After a detailed description of the invention, an important feature of which is a triple valve (hereinafter more fully explained in the opinion), with references to the accompanying drawings, the specification proceeds to state that,

so far as the performance of its preliminary function in ordinary braking is concerned (that is to say, effecting the closure of communication between the main air pipe and the auxiliary reservoir, and the opening of communication between the auxiliary

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reservoir and the brake cylinder in applying the brakes, and the reverse operations in releasing the brakes), the triple valve, 10, accords substantially with that set forth in letters patent of the United States No. 220,556, granted and issued to me October 14, 1879, and is not therefore saving as to the structural features by which it performs the further function of effecting the direct admission of air from the main air pipe to the brake cylinder, as presently to be described, claimed as of my present invention. Certain of its elements devised and employed by me prior thereto will, however, be herein specified in order to render its construction and operative relation to other members of the brake mechanism fully intelligible.

[18 S.Ct. 709] After a further reference to the drawings, he again states that,

so far as hereinbefore described, the triple valve accords in all substantial particulars with, and is adapted to operate similarly to, those of my letters patent Nos. 168,359, 172,064, and 220,556; and, in order that it may perform the further functions requisite in the practice of my present invention, it is provided with certain additional members, which will now be described.

These additional members, which are said to be for the purpose of effecting the admission of air directly from the main air pipe to the brake cylinder when it is desired to apply the brakes with great rapidity and full force, consist of (1) a passageway through which air can be admitted directly from the main air (or train) pipe to the brake cylinder without passing through the auxiliary reservoir, and (2) an auxiliary valve in connection with such passage, that, when the triple-valve piston makes a short or preliminary movement, the passageway direct from the train-pipe to brake cylinder, controlled by said valve, will not be opened, while in the event of a long or full movement of the piston, or "further traverse," as it is called, such direct passageway will be thrown wide open to the admission of train-pipe air, and the brake cylinder will be rapidly filled thereby.

After describing the auxiliary sliding valve, 41, and its connections, as well as the operation of the device in ordinary (nonemergency) cases of checking the speed of or stopping trains, already fully provided for in previous patents, he proceeds

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to state its operation in cases of emergency which the patent was specially designed to cover, as follows:

In the event, however, of its becoming necessary to apply the brakes with great rapidity and with their greatest available force, the engineer, by means of the valve at his command, instantly discharges sufficient air from the front end of the main air pipe to effect a sudden reduction of pressure of about twenty pounds per square inch therein, whereupon the piston, 12, of the triple valve, is forced to the extreme limit of its stroke in the direction of the drain cup, 19, carrying with it the stem, 36, and auxiliary slide valve, 41, which instantly uncovers the port, 42, and discharges air from the main air pipe through the opening of the check valve, 49, and the passages, 46 and 48, to the brake cylinder; and, each car being provided with one of these devices, it will be seen that they are successively moved with great rapidity, there being, practically, on a train of fifty cars, fifty openings for discharging compressed air from the main pipe, instead of the single opening heretofore commonly used. Not only is there a passage of considerable size opened from the brake pipe on each car, whereby the pressure is more quickly reduced, but the air so discharged is utilized in the performance of preliminary work, it being found in practice that the air so taken from the pipe will exert a pressure of about twenty-five pounds in the brake cylinders. When the piston, 12, arrives at the extremity of its stroke as above specified, the supplemental port, 35, of the slide valve, 14, is brought into communication with the port, 33, and passages, 22 and 16, which serves to discharge the reservoir pressure into the brake cylinder, thereby augmenting the pressure already exerted in the brake cylinder by the air admitted from the main air pipe. Upon the reduction of the pressure in the main air pipe below that in the brake cylinders, as by the breaking in two of the train, the check valve, 49, closes communication between the passages, 46 and 18,...

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