US730869A - Electric railway. - Google Patents

Description

No. 730,869. I PATENTBD JUNE 16, 1903..

-W. M. BROWN. ELECTRIC RAILWAY.

APPLICATION FILED JULY 29, 1902.

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UNITED STATES Patented June 16, 1903.

PATENT OFFICE.

WILLIAM MILTON BROWN, OF JOHNSTOWN, PENNSYLVANIA, ASSIGNOR TO LORAIN STEEL COMPANY, A CORPORATION OF PENNSYLVANIA.

ELECTRIC RAILWAY.

SPECIFICATION forming part of Letters Patent No. 730,869, dated June 16, 1903. 7

Application filed July 29,1902. Serial No. 117,509. (No model-'5 T (tZZ whom it may concern.-

Belt known thatLWILLIAM MILTONBEOWN, of Johnstown, in the county of Oambria and State of Pennsylvania, have invented a new and useful Improvement in ElectricRailways,

of which the following is a full, clear, and eX- act description, reference being had to the accompanying drawings, which form a part of this specification.

This invention has relation to electric railways and is applicable to that class of electric railways known as surface -contact systems, in which the propelling-motors receive their supplycurrent from an underground feeder or conductor through surface contacts placed in the road-bed and normally disconnected from said feeder or conductor, but arranged to be temporarily connected therewith by means of the action of a magnet or magnets carried by the cars or vehicles. In this manner each of the surface contacts is energized or alive at such times only as a car or vehicle is passing over it, and it is then engaged by a current-collecting shoe or trolley on the car,from which the current is conveyed to the propelling motor or motors and from thence to the opposite side of the circuit, which may consist of the track-rails or any other suitable return-conductor.

In the practical operation of systems of this character it not infrequently happens that the car-magnet (which is kept constantly energized while the car is in motion either by a battery-current or by current derived from the collecting-shoe or trolley or by a combination of both) will attract to itself pieces of scrap iron orsteel, such as are not uncommonly present from various causes in the streets of cities and towns, and will hold such pieces in position to enable them to make contact either with a surface contact or with the current-collectingshoe or trolley. The effect of this is that when the car passes over the rails of an intersecting or branching track 5 such piece of iron may make contact with a rail or rails of such track and also with a contact or with the shoe or trolley in such a manner as to form ashort circuit for a portion of the feeder system. Such a short circuit re- 5o sults in an abnormal flow of current, which may release the current-breaker or other protective apparatus at the supply-station, and thereby temporarily stop the supply to that portion of the line supplied by said station,

or it may cause injury to the apparatus on the line.

This invention is designed to obviate these results, and it consists in placing all those contact devices of the system which happen to be located adjacent to the rails of inter- 6o secting or branching tracks upon separate subfeeders, the ohmic resistance of which is so proportioned that they will carry sufiicient current to propel the cars over and by the intersecting or branching tracks, but not suflicient to cause a disturbance of the system should a short circuit occur in the manner above described.

The accompanying drawing shows diagrammatically the application of my invention to a'portion of a surface-contact system of the character above described in which is located a branch track.

In the drawing the main-track rails are des ignated by the letters to and the branch-track rails by the letters Z). The main supplyfeeder c is led through a junction-box d, wherein connection is made with the subfeeders e, f, and g. Those contacts h of the main track which are not adjacent to the rails of the branch track are supplied with current in series by the subfeeder e in the usual manner, and those contacts 6 of the branch track which are not adjacent to the rails of the main track are supplied with current by the subfeederf; but in accordance with this invention those contacts j on each track which are respectively adjacent to rails of the other track are placed on the short separate subfeeder g or. upon branches thereof, and cono nected in series in this subfeeder. is a suitable resistance is. The ohmic value of this resistance it will preferably depend upon the local conditions. For instance, if the crossing is substantially level or is on a downgrade this 5 resistance may be made great enough so that only sufficient current will flow in the subfeeder g to keep the car-magnet excited and the lights of the car lighted, and the car can be allowed to drift over the crossing. If for any reason the car should come to a stop while over this subfeeder, there will still be enough I objects of the invention.

tery-current with which the caris supplied. A current of twenty or thirty amperes (varying perhaps from theselimi-ts under difierent con-' ditions of track and load) would ordinarily be sufficient'at such crossings, and if a short circuit should occur in the manner above described no harm would result. For crossings where the grade is such that the car must always be driven without drifting the resistance may be adjusted to give, say, one hundred amperes or more of current in the subfeeder. Inasmuch as the circuit-breaker at the station is usually set as high as two hundred and fifty amperes, it will not be affected by the short-circuiting'of this one-hundredampere current'should it occur. These re sistances are only illustrative; but in all cases the resistance 70 should be so proportioned as to give sufficient current to enable the cars to be moved over the crossing, taking into consideration the conditions existent at such crossing.

The drawing illustrates but one condition to wit, a branch track leaving a main track; but wherever on the system one or more tracks leave or intersect another track or tracks the contacts adjacent to the meeting or intersecting rails should, in accordance with this invention, be placed on-a separate subfeeder of sufficient resistance to effect the The same thing 1. In an electric-railway system of theclass described, the combination with surface contacts arranged adjacent to a rail or rails of a meeting or intersecting track, of a subfeeder for supplying current to said contacts and having an abnormally high resistance.

2. In an electric railway system of the class described, means for preventing the disturbing efiects of short circuits due to temporary connections which may be made by a car between one or more of the surface contacts and an adjacent object, such means consisting of a subfeeder to which the contact or contacts adjacent to such object I are connected, and which has its ohmic resistance so proportioned as to supply the said contacts withsufficient current to enable the car to be moved past said objects, but not suflicientto disturb the system should such current be short-circuited;

In testimony whereof I have affixed my signature in presence of two witnesses.

WILLIAM- MILTON BROWN. Witnesses:

l\IARTIN ALDERW-IOK, E. P. WETMORE.

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