US1681892A - Train control - Google Patents

Description

Patented Aug. 21, 1928.

UNITED STATES PATENT OFFICE.

HALTER W. W'ENHOLZ, OF ROCHESTER. NEW YORK, ASSIGNOR TO GENERAL RAIL- WAY SIGNAL COMPANY, OF ROCHESTER, NEW YORK.

TRAIN CONTROL.

I Application filed. November 20, 1924. Serial No. 751,061.

This invention relates to automatic train control Systems, and more particularly to the trackway equipment of a train controlsystem of the well known continuous inductive t pe. Y

In block signal systems, it is sometimes necessary to divide a block, that is, that portion of track on any part of which the pres ence of a train produces the same controlling effect on the block signals, into two separate isolated track circuit sections. For example, in the type of block signaling system for single track railroads, commonly known as the absolute-permissivc-block system, one form of which is disclosed in the patent to YVight, No. 1,294,736, dated Feb. 18, 1919, it is necessary to have the block between opposing signals, particularly adjacent to the sidings, divided into two separate track cir cuit sections, each having a track relay, in

'order that the track relays may be operated sequentially during the passage of trains in opposite directions. .Also, on double track railroads, on account of the length of the block, ballast conditions, or other practical considerations, it is sometimes necessary to divide the block into two separate track circuit sections.

In applying continuous inductive train control to such divided blocks or cut-sections, it is desirable to supply the train control circuit throughout the length of the block and control it from one point. In other words, it is desirable to make the track rails of the block continuous with respectto the alternating train control current, while separate or isolated tor-the direct current of the track circuits so that either the track phase or" a continuous inductive control system, or both the track phase and line phase of such system may be supplied throughout the length of the block and conveniently controlled at one point.

The principal object of the present invention is to provide an arrangement of devices and circuits which will enable the train control current to be supplied throughout the length of the block. while the direct track circuit current is confined to the separate track circuit sections of the block.

In describing the invention in detail ref erence will be made to the accompanying drawings in which Fig. 1 shows conventionally a block of an automatic block signal system composed of two sections divided by insulating joints, hav mg train control apparatus superimposed thereon embodying the present invention; and

Fig. 2 shows a junction point of the two sections of a block in a similar system in which only one of the rails is insulated, and having a modified form of train control apparatus associated therewith.

Referring to'Fig. 1, to simplify and facilitate the explanation of the nature of the in- Vention, there has been illustrated an embodimcnt ofthe invention applied to a block of a double track railroad which is divided into two separate direct current track circuit sections. For simplicity, Fig. 1 merely shows provision for supplying a track phase, track circuit, or loop circuit current "for the train control system, that is, alternating current flowing down one track rail and back the other at any given instant; but it should be understood that the usual type of 3-position continuous inductive type of system, employingthe line phase current as well as a track phase current, may be used in connection with the invention. The car apparatus of the train control system, which may take any one of the well known or has not been shown.

In Fig. 1 there has been illustrated a block I, with the adjacent ends of two other blocks H and J. For simplicity, it is assumed that all blocks will be equipped the same, so that a description of one will suffice for all; and for convenience, the same reference characters with distinctive exponents are used for corresponding parts and circuits associated with the differentblocks. Using the reference characters for the block I, the usual track rails 1 are provided with insulated joints 2 defining the ends of this block, traflic being from left to right, as indicated by the arrow.

The block I is divided into two track circuit sections I and I by a pair of insulated oints 3. Atthe entrance end of the first or rear section I is a track relay 4 connected across the track rails in the usual manner. The track relay 5 for the second or forward section I is connected across the track rails at the exit end thereof. At the exit end of the first section I is a track battery 6 which is connected by wires 7 and 9 and an inductive reactance or impedance 8 across the track rails suitable forms at the exit end of this section; and a track battery 10 is connected across the track rails at the entrance end of the second section I by wires 11and 12 and said inductive reactance 8 in asimilar manner. I ance or impedance"'8has"'aresistance cone sponding to the usual limiting resistance con;

' trackrails 1, in series with a resistance or impedance 15;. This resistance, together with the' internal resistance of the Secondary, is made high enough so as not to shunt out the direct track circuit current from the track relayf), or interfere with the proper operation of thistrack relay. This resistance 15, is

ordinarily made largely, if notwholly, noninductive, but may have as much inductive reactance asmay. be required under someconditions' to obtainphase displacement. The primary of the transformer is energized from the usual transmission line 16 and has itscircuit opened and closed in accordance with traflic conditions in the next block in advance. In the arrangement shown, the circuit of the primary of this transformer, includes the frpnt contact of a line relay HR which has an energizing circuit passing through the front contacts ofth'e-two track relays of the next block in advance. This line relay also serves to control the indication 0f the Wayside block signal Z, which may be of the semaphore type, as shown, orof any other suitable type, together'with suitable provisions for obtaining the three indications of stop, caution and proceed; approach lighting, if color light signals are used; and other exp'edients, all, in accordance with the knowledge and teachings of the ar t It will be evidentthat the direct track circuit current is confined to each track circuit section, excepting. 1 leakage through the ground. The track batteries are preferably connectedto oppose each other, asshown, this serving to reduce the potentials to ground and also the'direct current voltage in the conductingpath' through which the alternating train control current flows. Train control current-flows through t-he length of the block in the following circuit":-Beginnin'gat the secondaryof transformer 14, impedance 15, rail 1, Wires 12 and 7, battery 6,1ail 1, track relay & (orthe wheels and axles of a train),

The inductive ractrail1,wires9and 11, battery 10, raill back to the secondary of transformer 14. This current is cut off the block if the next block in advance is occupied, thereby producing the caution or stop indication in the 2-position type ofcontinuous"inductive system. A train in the first or rear section deprives the following 'tra'iifin that section of train control current by-the shunting action of its wheels and axles; and similarl y, a rennin the second or forward sections shunts out the train control current from the first or rear section. A train entering an occupied blockdoes not receive train control current even though that current is supplied to the track rails of that bloc-kbecause the nextblock in advanceis not occupied. p

Fig.2 shows a'modified arrangement, using one insulated joint 3? between the track circuit sections of the block. The trac lr batteries 6;"? and 10? areco'nn ected wires ll and Winseries' around this joint in opposition; and the impedance 8 isconnectedfrom the other rail to the wires between the'jbatteri'esi as shown. It willbe evident that the insulated joint 3? isolates the two track sections so far as the direct track circuit current is concerned but the alternating current flows down one rail without opposition and, down the other rail'around the joint 3"- through the two batteries '6 and 10 and wires'll and 7 in series. f

Havin thus shown and described in a rather spceitic'manner two rather specific embodimentsofthe present invention, it is desired to beiinderstood th 'at the particular arrangements illustrated hav'e been selected so as to facilitat'eth'e description of the invention rather than to show the scope'th'ereof, and that various changes, modifications and additions maybem'ade'to adapt the'invention to single traclr signaling systems, such as the well known absolute perinissive block systein'. isolated ,traclr sections for crossing signals,"or the like, without departing from the scope of the invention or the idea of in'eai'is underlying the same. 7

What it is desiredto secure by Letters Pat ent. ofthe United States is:--

1, Trackway apparatus for atrain control system employing direct current and alternating current comprising, an insulated section of'thetrack rails, means for independently impressing a direct ciirre'nt potential across twoportions of'said section of the track'rails, and for impressing alternating currentpotential across the entire section of the track rails;

2; Infanautomatictrain control system; in combination trackw'ay apparatus for wayside signal andtraincontrol purposes comprising; a section oftrack rails divided into two portions by insulating joints; means for impressing an alternating current potential for train control purposes acrossone end of ilii:

' control current through the entire length of said section and for independently impress-' ing direct currentpotentials for wayside signal control purposes across the said two insulated portions of said section.

8. Trackway apparatus for automatic train control systems comprising, a section of the track rails divided into two portions by insulating joints, partial circuits each in cludin a source of energy connected across the track rails on each side of said insulating joints, an inductive reactance common to said partial circuits, whereby current from said sources of energy may flow independently in said two portions of the track rails and a distinctive alternating current may flow in the rails of the entire section.

'4. 'lrackway apparatus for automatic train control systems comprising; a section of trackway divided into two portions by insulating joints; a track wayside signal controlling circuit for one of said portions includin a track relay, the two track rails of said portion, a track battery and a reactance coil in series; a track circuit for wayside sig nal control purposes for the other of said portions including a second track relay, the two track rails of said other portion, a second track battery and said reactance coil in series; and a track circuit for train control purposes including the track rails of the entire section and the track batteries of the said two portions in series.

5. Trackway apparatus for automatic train control s* stems com risin two suc cessive direct current trackcireuits for wayside signal control purposes each comprising insulated portions of the two track rails connected in series through a common portion including a reactance coil,and an alternating currenttrack circuit for train control purposes superimposed on said direct current track circuits including the track rails of said two direct. current track circuits, said reactance coil preventing the flow of alternating current from one rail to the other at the junction of said two direct current track circuits.

current, and means permitting the flow of current from said distinctive source down one rail of said two sections and back through the other and preventing the How of current from one rail to the other at the unction of said sections.

T. 'lracliway apparatus for auti'imatic train control systems ecniprisin' a track sect tion, a relay at each end of said track bridged across the rails at one end of said track section, and means including another source of current and a device permitting the flow oi current from said another source but not permitting the ready flow of current of said particular character connected in series and bridged across the rails at an in termediate point.

8. 'l 'raclzway apparatus for automatic train control systems comprising, a track section, a relay at each end of said track section, a source of current for each of said relays bridged across the rails at an intermediate point in said section, another source of current distinctive in character bridged across the rails at one end of said section, and means for preventing current from said another source from flowing from one rail to the other at said intermediate point.

9. Tracliway apparatus for automatic train control systems, comprising, a section of track divided from the restof the trackway by insulating joints, a source of alternating current bridged across the rails at one end of said section, a battery having an inductive reactance in series therewith connected across the rails or" said section at an intermediate point, whereby due to the impedance of said inductive reactance to the flow of alternating current the source of al ternating current is not shunted by said bat tery and the alternating current potential is applied across the rails throughout the entire section.

10. Traclrway apparatus for automatic train control systems, comprising, a track portion divided by insulating joints into two sections, a. track relay for each end of said track portion, a source of energy bridged across the rails of each of said sections adjacent said insulating joints, another and distinctive source of energy of a diiferent kind bridged across one end of said track portion and having in series therewith a device for limiting the flow oi current of the kind derived from the first mentioned source of current, and means interconnecting the two rails and permitting the flow of current from said distinctive source down one rail of said two sections and back through the other and preventing the ilow of current from one rail to the other at the junction of said sections.

11. Trackway apparatus for train control systems, comprising, a stretch of track divided by insulating joints into two in sulated sections, means bridging each insula ing joint and including a track battery, an inductance connected between the two section, a source of current of a particular character 1 bridging means, and a source of alternating current connected to the rails at one end; of said stretch of track. V

12. Trackway apparatus for-train control systems, comprising; a stretch of track divided by insulating, joints into two insulated sect-ions, means bridging each insulatingjoint and including a track battery, an inductance connected betweenthe two bridg- 'ing means, said track batteries being connecte'd V in.-- opposition to I each other through the nduotance a-source of alternating current connected; across the 121118 atone endcfi said; stretch ofitrack a current limiting re- WALTER 1V .VENHOLZ.

Images