US1260617A - Railway signaling. - Google Patents

Description

H. S- YOUNG.-

RAILWAY SIGN MING.

APPLICATION HLED DEC. 24. 1915.

mmfiw; Patented Mar. 26, 1918.

INVENTOR T T PATENT FFTQE.

HENRY S. YOUNG, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO THE UNION SWITCH & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

RAILWAY SIGNALING.

Specification of Letters Patent.

Patented Mar. 26, 1918.

Application filed. December 24, 1915. Serial No. 68,490.

To all whom it may concern: 7

Be it known that I, HENRY S. YOUNG, a citizen of the United States, residing at Wilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Railway Signaling, of which the following is a specification.

My invention relates to railway signal ing; more particularly it relates to signaling for stretches of single track over which trafiic moves in both directions.

I shall describe one form and arrangement of circuits and apparatus embodying my invention, and then point out the novel features thereof in claims.

The accompanying drawing is a diagrammatic View showing a stretch of railway track having applied thereto one form of signaling system embodying my invention.

Referring to the drawing, reference characters a and b designate the track rails of a railway track over which traffic moves in both directions. This track is divided into sections l-2 and 2-3 by insulated joints in the track rails at 1, 2 and 3, and each section is provided with a track circuit. As here shown the track circuit for section 2-3 comprises a track relay T connected to the rails a b by wires 11 and a transformer D, the secondary of which is connected to the rails by wires 7 and the primary of which is connected to feeder wires 8 which are supplied with signaling current from an alternator G. The track circuit of section 1-2 is here shown to be of the centerfed type and comprises two track relays T and T which are connected to the rails or and 6 adjacent the ends of the section 1-2 by means of wires 12 and 13 respectively. The source of current for this track circuit is a transformer B which is connected to the rails at the center of the track section by wires 14 and is supplied with electrical energy through feeders 8.

For governing traflic through section 1-2 from east to west, a signal S is located adj acent the track rails at 1 and for governing traflic through the section in the opposite direction, a signal S is located adjacent the track rails at 2. These signals are governed respectively by relays R and R which are of a type responsive to reversals of current in their energizing windings. As here shown each relay comprises two windings c and "cl, and a rotor member f, winding d being constantly energized by current from a transformer located adjacent the relay. Winding (Z of relay R is connected in the following circuit: from one terminal of transformer A, through wires 15, 1G and 17, winding cl of relay R and wire 18 to the other terminal of transformer A. Vinding cl of relay R is similarly connected across transformer C. The windings c of relays R and R are connected in series with each other in the following line circuit: from winding of relay R through wire 20. contact 21 of relay T wire 22, contact 23 of relay T wire 24:, winding 0 of relay R wire 25, front contact 26 of relay T wire 27, the secondary winding of a transformer N, wire 28, the secondary winding of a transformer M, wire 29, to winding 0 of relay R The primary windings of transformers M and N in the above circuit are energized from transformers A and C respectively, being directly connected to those transformers as is evident from the drawing. The secondary of transformer N is of higher potential than the secondary of transformer M and is connected in the line circuit traced above in such manner that its polarity is at every instant opposite'to the ptlarity of transformer M so that current flows in the line circuit in opposition to the voltage of transformer M. The windings 0 of relays R and R are connected in this circuit in such manner that when the current flows in the above direction, relay R is energized to hold its contact iinger 30 in engagement with its contact point whereas relay R is energized in the reverse direction so that its contact 31 is open. To reverse at times the current in the line circuit, I provide a branch around the secondary of transformer N which branch comprises a wire 32 and the back contact 26* of relay T \Vhen this relay is deenergized it first opens the line circuit and disconnects transformer N from this circuit at front contact 26 and immediately thereafter closes the line circuit at back contact 26 leaving transformer N open at front contact 26. Transformer M is now the only source of potential in the line circuit and the current which previously flowed against the voltage of transformer M is now reversed to flow in the direction corresponding to the voltage of transformer M. The current in windings c of both relays R and R is therefore reversed so that the contacts of both relays are reversed, in other words, contact 30 of relay R is opened and contact 31 of relay R is closed. I prefer to have the voltage of transformer N double the voltage of transformer M because with this arrangement the currents in the line circuit are of equal strength in either direction. For instance, if transformer N has a voltage of 110 volts and transformer M has a voltage of 55 volts, the voltage in the line circuit when the two. transformers are in opposition is the difference between the two voltages or 55 volts, which isnumerically equal but opposite in direction to the voltage of transformer M alone. The voltages being equal and the impedance of the line circuit being practically the same whether or not the transformer N is connected in the circuit, the current in the line circuit is the same in value no matter in which direction it is flowing.

The control of signals S and S by relays R and R is effected by circuits controlled by contacts 30 and 31 respectively. The circuit for the control of signal S is, in detail, from transformer A, through wires 15 and 34;, operating mechanism of signal S wire 35, contact 30 of relay R, wires 3-3 and 18 to transformer A. The circuit for the control of signal S is similar and. therefore need not be traced in detail.

The operation of this system of signaling is as follows: When there is no train in either section 1-2 or 2-3, all the track relays are energized so that the line circuit is closed at contacts 21 and 23 of relays '1 and T respectively. Furthermore, transformer N is connected in the line circuit at front contact 26 of relay T so that the current in the line circuit flows in opposition to the voltage of transformer M, causing the contacts of relays R and R to be closed and open respectively as indicated in the drawing. Signal S indicates proceed because its circuit is closed at contact 30 of relay R and. signal S indicates stop because its circuit is open at contact 31 of relay R When a west-bound train enters section 1-2 it deenergizes track relay T which opens the line circuit at contact 21, so that windings 0 of both relays R and R are deenergized. Consequently relay R opens its contact 30 so that signal S assumes the stop position. Contact 31 of relay remains in the open position, so that signal S' remains in the stop indication. With both signals S and S at stop both eastbound and westbound traffic is kept out of section 1-2 so that the train is protected both in frontand rear. As the train proceeds farther itdeenergizes track relay T which opens the line circuit at contact 23, but this has no effect on the signals because the line circuit is already open at contact 21. As the train proceeds still farther, track relay T is re energized and closes its front contact 21; again this has no immediate effect because the line circiut is now open at contact 23 of relay T \Vhen the train enters section 2-3it deenergizes track relay T which opens'its' front contact 26and closes its back contact 26*, so that transformer N is disconnected from the line circuit as hereinbefore ex plained. Thish'as-no immediate efiect on the signals because the line circuit is open signal S at contact 31 so that signal S is,

brought to the proceed position in the rear of the train. 'lhis indication is useful in the event when it is desired to back the westbound train into section 1-2.

When the train leaves section 2-3 completely track relay T is reenergized so that it closes its, front contact 26 and connects transformer N into the line circuit with the result that the current in the circuit is reversed. as hereinbefore explained. This causes relay R to close contact 30 and relay R to open contact 31-, so that signal- S assumes the proceed position and signal, S returns to the stop position as shown in the drawing.

The operation of the apparatus for thepassage of a train in the reverse. direction, from west to east is as follows. When the train enters preliminary section 2-3 it deenergizes track relay T which opens'its ront contact and closes. its back contact so that transformer N is shunted from the line circuit. As explained.hereinbefore, this causes a reverse energization of both relays R and B so that the former opens contact 30 and the latter closes contact 31. As a consequence, signal S is caused to go to the stop position to warnwestbound traflic not to enter section 1-2, whereas signal S assumes the proceed aspect giving the eastbound train. the right to enter this section.

As the latter train proceeds into section 1-2, it short circuits track relay T W11Cl1 opens the line circuit at contact 23, so that windings 0 of both relays R and R are deenergized. Relay R opens therefore the circuit for signal S at its contact 31 so that signal S goes to the stop position and prevents a following eastbound train from entering section 12. As noted hereinbefore, contact 30 of relay R is already open so that when relay R is deenergized signal S remains in the stop position. Thus the train is fully protected while in section 1-2 there being a stop signal at both ends of the section. As the train leaves preliminary section 23 completely, track relay T 3 is reenergized so that it closes its front contact 26. As described hereinbefore, transformer N is thereby re-connected into the line circuit, but this has no immediate effect because the line circuit is now open at contact 28 of track relay T As the train proceeds in stretch 1-2 it causes the denergization of track relay T which opens the line circuit at contact 21, but this has no immediate effect on the signals because this circuit is open at contact 23 of track relay T As the train proceeds still farther in section 12, track relay T is renergized and closes its contact 23. This has no efiect on the signals because the line circuit is now open at contact 21 of track relay T As the train leaves section 1-2 completely, track relay T is reenergized and closes its contact 21 which completes the line circuit. Because track relay T is also energized transformer N is connected in the line circuit, as noted above, so that the direction of current through windings c of relays R and R is such that contact 30 of relay R is closed whereas contact 31 of relay R is open, so that signal S indicates proceed whereas signal S indicates stop. In this manner all the signals and other apparatus have been returned to the positions wherein they are shown in the drawing.

One important feature of my invention is the immunity of the system from false clear indications due to crossed line wires. I ac complish this by connecting the signal controlling relays R and R in the line circuit in such manner that it is necessary to operate either relay by current from the source at the opposite end of the circuit in order to energize the relay in such direction that the corresponding signal gives a proceed indication. This can be brought out more clearly by assuming for example, that, while there is no train in either section 12 or 2-3, line wires 22 and 28 are crossed at point designated as in the drawing. When this cross occurs the line circuit is divided into two local circuits each having its source of current. transformer M, through wire 29, winding 0 of relay R wire 20, contact 21 of relay T wire 22, cross 00, and wire 28 to transformer M. The other of these circuits is similar and comprises the other half of the line circuit with transformer N and winding 0 of relay R The current in the former circuit flows in accorcLnce with the direction of One of these circuits is: fromthe voltage of transformer M, so that relay R is energized reversely and opens contact 30, whereby signal S is immediately caused to change to the stop indication. The current in the other local circuit flows in accordance with the direction of the voltage of transformer N so that relay R remains energized reversely and signal S continues to indicate stop. Similarly, if a train occupies preliminary section 23 so that signal S indicates proceed and signal S indicates stop, a cross of the line wires causes signal S to change to the stop indication and signal S to remain in the stop position.

Although I have herein shown and described only one form of circuits embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a stretch of railway track, two signals located one at each end of the stretch for governing traflic through the stretch in opposite directions, a line circuit comprising a source of energy for sending current through said circuit in one direction, a second source of energy stronger than said first source, means for at times connecting said second source into said circuit in Opposition to said first source for reversin the direction of current in said circuit, and means responsive to the direction of current in said circuit for clearing one or the other of said signals.

2. In combination, a section of railway track, two signals for governing traffic through the section in opposite directions, a source of lower potential located at one end of the section, a source of higher potential located at the other end of the section, a circuit comprising said source of lower potential, means for at times connecting said source of higher potential into said circuit in opposition to said source of lower potential so that the direction of current in said circuit is reversed, and means responsive to the direction of current in said circuit for clearing one or the other of said signals.

In combination, a section of railway track, two signals for governing trafiic through the section in opposite directions, one signal being located at each end of the section, a source of lower potential located at one end of the section, a source of higher potential located at the other end of the section, a relay responsive to reversals of current for the control of each signal, a series circuit comprising said relays and said sources of potential connected in opposition so that current normally flows through said circuit in opposition to said source of lower potential, and means for at times cutting out said Source of higher potential from said circuit so that the direction of current in said circuit is reversed.

-l- In COITlblllfllLlOll, a stretch of track divided into a main section and a preliminary section, signals located one adjacent each end of the main section for governing trai'fic therethrough in opposite directions, track circuits including track relays for said sections, a line circuit extending through said main section and controlled by the track relays of said section, said circuit co1npris ing two sources of current one located adjacent each end of the track section, one of said sources being of higher potential than me err means responsive to thedirection of current in said line circuit for clearing one or the other of said signals.

In testimony whereof I afiix my signature in presence of two Witnesses. 1

HENRY S. YOUNG.

Witnesses A. L. VnNoILL, A. C. Nor/rm.

eplea at reheat may he obtained tor five-cents each, by addressing the "commissioner of Patents, Washington, I). G.

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