J. B., ATWOOD, RAILWAY , APPLICATION FILED DEO, 2, 1907, Patented Mar, 22 1910, 2 SEBETS-SEEET l.

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UNITED STATES PATENT OFFICE. JOHN BAIRD ATwoOD, OF ALLEGHENY, PENNSYLVANIA. RAILWAY-TRACK BRAKE. 952,493. Specification of Letters Patent. Patented Mar. 22, 1910. Application filed December 2, 1907. Serial No. 404,838, To all whom it may concern: Switch, at as many places as desired are Beit known that I, JoHN BAIRDATWOOD, placed stationary 13, 13, 13, all a citizen of the United States, residing at Allegheny, in the State of Pennsylvania, operated preferably by electric wires 14 -5 have invented a certain new and useful Rail from a central observation tower T; and 60 Way-Track Brake, of which the following is regulated by electric switchest. a specification. - In Figs. 1, 2 and 3 the tracks 15 are con

structed as usual, and alongside them, on

My invention relates especially to means for controlling the movements of cars on one or both sides, I place long magnet bars tracks by stationary brakes, and to brakes 16, preferably made of soft iron H beams 65 . for such purpose operated by electric means. and either supported to slide on the cross Its primary objects are to provide efficient ties as in Fig. 3, or better, mounted on means for stopping or holding cars on the pivoted arms 17 as shown in Fig. 2. These bars have a limited motion to and from the grades of switch yards, etc., to provide an rail 15 and are placed so as to engage the 70 5 automatic brake, and a brake of regulable

edge of the iron car 18 a little above power; to design efficient electro-magnets for the rail top or the “dead point’ of the Such uses, and otherwise to improve and per . They are wound with wire in any fect stationary car handling brakes, as here convenient manner as in the lengthwise inafter more fully set forth. fashion shown, and are energized by means 75 ) I have illustrated the invention in several located preferably in the central tower T, forms in the accompanying drawings, where the current strength is regulated and wherein- . applied by a switch board t. When the Figure 1 is a side elevation showing a operator wants a car stopped at the point single pair of magnetic brakes engaging all where one or more of these brakes is lo 80 5 the wheels of a car at once. Fig. 2 is a cross cated he throws on the current to energize

section of the brake bars, and front elevation the magnet 16, which by its attraction clings of a car truck and wheels. Fig. 3 is a par strongly to the car wheels and stops their tial plan of a single bar brake, mounted to rotation not only by but also by the slide. Figs. 4 and 5 show respectively in “magnetic drag' and by the cutting of the 30 side elevation and cross section a modified lines of force by the moving wheel acting as 85 pairs, to be operated by form of brakes in the car wheel itself. Fig.6 shows a further an armature. Where the single track brakes are used only on the inside of the track as modification using a double point magnet, at Fig. 3, the bars 16 are preferably con and Fig. 7 shows the use of a four-pole mag nected by toggle links 19 pivoted on the 90 net with the Wheel forming an armature. cross tie and slanting back against the direc Figs. 8 and 9 are respectively a plan and a tion of the car's motion, so that the fiction side elevation of some switchyard tracks ar and tendency to creep forward thrusts the ranged for convenient use of my invention. bars the more tightly against the wheels. Fig. 10 is a further modification. A more efficient form of the brake is 10 The great danger to both life and prop shown in Figs. 4 and 5, where electro-mag 95 erty, in hand-operated brakes for switching nets 20 are mounted on trunnions 21 carried cars are well recognized; but so far all pro in brackets 22 alongside the rail 15 so as to posed stationary track brakes operated from engage the wheel 17 by both poles N and S a distance have not been efficient for han at once. The iron is formed in a horse-shoe OO . 45 dling heavy trains in Switchyards. Such de shape and the coil 23 is wound as shown vices cannot be used unless thoroughly reli and connected at one end directly to the line able; and very great power, easily control from the source of current and at the other lable, is essential to success. end to a spring 24 which is normally in My present invention is intended espe Sulated. This spring is arranged so that as 105 50 cially for use in the so-called “gravity” Soon as both E. N and S stand opposite switch yards, where trains are shifted by the wheel the latter engages it and thus sending the separate cars or groups of cars makes electric connection with the rail down inclined switches. The arrangement. through which the circuit to the source is is indicated in Figs, 8 and 9, where several completed. The coil thus becomes energized 110 branch tracks 12, 12', 12, are given a de when the wheel engages both poles of

cided slope as shown in Fig. 9, and on each the magnet and remains energized un g 952,493 til the wheel leaves both the poles.--the should be the armature, for it may some spring depressing as shown. The magnets times be advisable to make the wheels them are preferably placed in close succession so selves the poles of an electro-magnet and that each wheel will be continually passing use a stationary armature bar, as illustrated 65 through a field and acting as an armature in Fig. 10. The coil therein 30 is carried moving across the poles. It will be under On the car axle and energized by means stood that while the mechanical friction due carried in the car; the iron bars 31 are the to the pressure of poles N. S., on the wheel armatures, of which any number may be flange will have a powerful retarding effect, placed along the track. 70 10 a still stronger retardation is effected by the A further modification of my invention moving of the wheel across the poles acting is shown in Fig. 7, where the iron plate 32 as an armature. This is due in part to the and the four posts 33 carrying pole blocks resistance to cutting the lines of force which 34, form a compound magnet with two pairs run through the wheel and in part to the of poles as indicated. The wheel coming 75 5 “magnetic drag' which seems to result into contact with the second pair completes probably from small iron particles having the circuit and the four coils 35 are ener their polarity altered as they are disturbed gized. The wheel then forms at once four by the friction. I do not of course limit armatures as will be evident and any mo myself to any theory of action; but the effect tion is resisted both by the lines of force 80 20 of the device described is to retard both the being cut and by the direct attraction. rotational and the linear motion of the Having thus described my invention and wheels with great power and the car can be illustrated its use, what I claim as new and either stopped or retarded at any point de-desire to secure by Letters Patent, is the sired, by proper manipulation of the cur- following: . 85 25 rent. It is to be noted that no current is 1. A track brake for cars comprising an being used at any time except in the coils electro-magnet and an armature, the two co employed to act on the wheels. When the operating to prevent turning the wheels, and car is stopped the magnets still hold it in the car wheels forming one of the said co place, and it is released by shutting off the operating parts, substantially as described. 90 30 current, as will be obvious. 2. An electric track brake for cars in In Fig. 6 is shown a form of magnet in which the car wheel forms the armature of which the wheel directly closes both the an electro-magnet. - current and the magnetic circuits and forms 3. A track brake comprising an electro a direct armature to the magnets. Thus, magnet mounted in the track and adapted to 95 35 along the track 15 I place any desired num- engage a moving car wheel. - ber of show magnets 25 which have wearing 4. An electro-magnetic track brake oper shoes 26, 27 forming the brakes and poles. ated by the wheels of the car to be retarded. On the arms are wound coils 28, 29 in series 5. The combination with a car wheel and so that 26 becomes a north and 27 a south a rail of an electro-magnet mounted to en 100 40 pole, for example. The circuit is completed gage the wheel and having a circuit for its by the rail 15 when both the rail and pole coils completed by the engagement of the 26 are in contact with the wheel. The mag- wheel with the track and magnet. net loop may be thin enough under the rail 6. The combination of an inclined track, to bend if desired and it is insulated from a series of electro-magnets placed to en 05 45 the rail. The blocks 26, 27 normally stand gage car wheels on the track when ener in position to lightly engage the wheel, but gized and means including the car wheels the latter may easily crowd in between them to close the energizing circuit. as they have sloping faces. 7. A track brake comprising a four-pole Evidently, in operation each wheel makes magnet placed to have all the magnetic cir O 50 the contact to energize each electromagnet cuits completed by a wheel on the track. as it comes to it and while in contact forms 8. A railway track brake coulprising an the armature between the poles. The shift- electro-magnet anchored under the rail and ing of position of the lines of force in it, the adapted to engage a wheel thereon so that mechanical friction, the magnetic drag, and the latter forms an armature. 115 55 the direct attraction as it attempts to shift In testimony whereof, I have hereunder position or directly draw upward out of the signed my name in the presence of the two magnet poles.-all contribute to produce a subscribed witnesses. very powerful retarding effect, which can JOHN BARD ATWOOD. be regulated at the central station as desired. Witnesses: 60 It is not essential to my invention, in its F. W. H. CLAY, broader aspects, that the moving wheel FRED STAUB.