US1208752A - Block signaling system for railways. - Google Patents

Description

A. V. T. DAY.

BLOCK SIGNALING SYSTEM FOR RAILWAYS.

APPLICATION FILED JUNE 15.1908.

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Patented Dec. 19,1916.

A V. T. DAY.

BLOCK SIGNALING SYSTEM FOR RAILWAYS.

APPLICATION FILED JUNE 15. 1908.

1,208,752, Patented Dec. 19,1916.

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ALBERT v. T. DAY, on NEW ROCHELLE, NEW YORK, ASSIGNOR, BY MESNE ASSIGN- MENTS, To HALL SWITCH & SIGNAL COMPANY, OF NEW YORK, N. Y., A consona- TION 0F MAINE.

BLOCK SIGNALING SYSTEM FOR RAILWAYS.

Specification of Letters Patent.

Patented Dec. 19, 1916.

To all whom it may concern.

Be it known that I, ALBERT V. T. DAY, a citizen of the United States, residing at New Rochelle, in the county of WVestchester and State of New York, have invented a certain new and useful Improvement in Block Signaling Systems for Railways, of which the following is a specification, reference be ing had therein tothe accompanying drawings, forming part thereof.

My invention relates to electric block signaling systems for railways and particularly to' normal danger systems for electric ra1lways.

Still more particularly, my invention relates to that class of electric block signaling systems wherein each signaling block controls one or more track relays located at a distance fromthe home signalof that block, but controlling such home signal through a line circuit.

It is one object of my invention to utilize the said line circuit of each block to control the distant signal as well as the home signal at the rear end of that block, and also to control on the normal danger plan the home and distant signals at the advance end of that block and the home signal at the advance end of the next block ahead. In its accomplishment of this object and in its general nature, my present invention is an improvement on the invention disclosed in my application filed June 15, 1908, Serial No. 438593, wherein I have broadly claimed certain broad features also embodied in the systems herein disclosed, but not claimed herein.

Other objects and features of the invention will be apparent from the following description of the illustrated embodiment of the invention. 7 g

I will now describe the embodiment of my invention illustrated in the accompanying drawings, and will thereafter point out the invention in claims. 7 V

Figure 1 of the drawings is a diagram of a signal system embodying the present invention and operating with normally open line circuits. Fig. 2 is a diagram of a similar system operating with normally closed line circuits;

The drawings represent two successive blocks and portions of the adjacent blocks. The signal apparatus of one track of a double-track system is illustrated, the other track and its signal apparatus being omitted as they are in all respects similar. The three signal stations shown are designated respectively as B, C and D. For convenience, the next station in the rear of B, which is not shown, will be hereinafter referred to as station A, and the next station in advance of D will be hereinafter referred to as station E. As the apparatus at the several stations is precisely alike, similar reference numbers are used in connection with similar parts of the apparatus at the several stations, but in the following description the numbers are followed, where necessary, by letters to indicate at which station the part referred to is located.

The signal system of the drawings is of the type in which the track rails are continuously conductive and are provided with cross-bonds of low impedance at the ends of v the blocks, so that the rails may be used, if

desired, as conductors for traction current. The track circuits by which the automatic operation of the signals is primarily'controlled are formed by the rails 1 and the cross-bonds 2, and are energized by transformers 3 located approximately at the center of each block. The secondary windings of the transformers are connected across the rails, so that each track circuit has two branches, the current flowing from one terminal of the transformer, in opposite directions, through one rail, to the ends of the block, through the cross-bonds to the other rail, and back to the other terminal of the transformer. The transformers are constantly energized with alternating current through transmission wires 22 connected with a generator 23.

The track circuits control the signal apparatus through the operation of inductive track coils 6 and 7 at the ends of each block. These coils are located at the ends of the track circuits adjacent to the cross-bonds and are disposed between, and close to, short portions of the rails, and are inductively energized by the currents in the track circuits. The coils 6 and 7 at each station are connected, respectively, with track relays 4: and 5.

The track relays are of the alternatin current polarized type. Each relay has a field magnet constantly energized with an alternating current, and a pivoted arn'iature provided with a coil connected with one of the track coils. The armatures actuate c011- tac t fingers by which the line circuits are controlled. Referring to station C in Fig. 1 of the drawings, the field magnets of the relays are energized through feed wires 10 and 11 connected with the secondary ter' minals of a transformer 12 energized by the transmission wires 22. Relay 4 has an armature 13 of which the coil is connected with track coil 6. The armature carries a contact finger 14 cooperating with a front contact 15 and a back contact 16. Relay 5 has a similar contact finger 8O cooperating with front and back contacts. The relays at the other stations are similar to those at C. As the armatures are normally energized by the track coils, the contact fingers are normally held raised against the front contacts.

At each station there is a home signal 17 and a distant signal 18. These signals have a bias to danger position, but are provided with electrically-controlled mechanism for moving them to clear position. This apparatus is not shown, as it may be of any ordinary or suitable form. It is normally deenergized, so that the signals stand normally at danger position.

The selective operation of the signals, by which either the home signal alone, or both the home signal and the distant signal at a station, may be'clcared, is effected by a polarized line relay 8 controlling the local sig nal circuits. This relay is of the same type as the track relays, and has a field magnet constantly energized from the same source. Its armature coil is interposed in the line circuit extending to the signal station next in advance and its contact finger, which normally occupies a neutral position, moves to right or left according to the phase or instantaneous direction of the current in its armature relative to current in its field, so that a reversal in the phase or instantaneous direction of the current in the line circuit moves the contact finger from right to left or vice versa.

A second line relay 9, of the non-polarized type, is interposed in each line circuit at the advance end of the block over which the line circuit extends. This relay has two armatures and contact fingers 19 and 20, and these are so arranged that they require currents of different strength to actuate them. Contact finger 20 requires current of maximum or full strength, and in the drawings this is indicated diagrammatically by a spring 21 connected with the contact finger. Contact finger 19 is actuated by a current of lesser or medium strength. Under certain conditions a still weaker current of minimum strength flows through the relay coil without actuating either contact finger. The reversal of phase of the current in the line circuit, to control the polarized line reas shown in Fig. 1, the line circuits are held open by line relays 9 and the signals stand at danger position.

With the apparatus in normal position, suppose a train moving in the direction of the arrow enters the block BC. The wheels and axles of the train short-circuit the right-hand branch of the track circuit, and track coil 7B is deenergized. Contact finger 30 of line relay 5B falls and engages its back contact, and the line circuit between B and C is thereby closed. This circuit is energized by current from transformer 12 at station C, through feed wires 10C and 11C, and is as follows: from feed wire 10C through wire 26 to contact finger 25 of the pole-changing switch, through the contact finger and its upper fixed contact to wire 27C and line wire 28, through the line wire to station B, through wire 29B to the back contact of the track relay 5, through contact finger 30, back through line wire 31 to station C, through front contact 15 and contact finger 1 1 of track relay 4C, through wire 32 to the magnet of line relay 9C, thence through wire 33 to the upper contact of contact finger 24 of the pole-changing switch, and through the contact finger 24: to feed wire 11.

As the current in the circuit above de scribed passes through the winding of only the single relay 9C, it is current of full strength and operates both contact fingers of relay 9C. This operation of relay 9C results in closing a line circuit from C to D, and it is this line circuit which acts to clear the home signal at D and both signals at C. The current is derived from transformer 12D and the circuit is as follows: from feed wire 10D through wire 26, contact finger 25 of the pole-changing switch and its upper contact, wire 27, line Wire 28, and wire 29C, through the armature coil of line relav 8C, through wire 10 to the contact fingers of line relay 9C, through contact finger 20 and its fixed contact to wire at, through front contact and contact finger 30 of relay 5, back through line wire 31 to station D, through front contact and contact finger 14 of track relay 4CD, through wire 32 to the magnet of line relay 9D, thence through wire 33 to contact finger 2-4 of the pole-changing switch, and thence to feed wire 11.

One immediate effect of the circuit just described is to cause line relay, 8G to move its contact finger to the right and close the local circuit through the home signal. This circuit is energized, through feed wires 10 and 11C, by transformer 12C and is as follows: from feed wire 10 through wire 26 and common Wire 38 to home signal 17 through wire 36 to the right-hand contact and contact finger 35 and thence through wire 39 to feed wire 11. A second immediate effect of the closing of the line circuit between C and D is to operate line relay 9D. In this connection it is to be noted that since the current in this line circuit traverses the windings of both relay 8C and relay 9D, it is reduced by the resistance of the two windings to current of second strength and only contact finger 19 of relay 9D is actuated.

The secondary effect ofthe closing of the line circuitbetween C and D is the closing, through the operation of contact finger 19D, of the line circuit between D and E. This circuit is similar to the circuit above described between C and D, with the exception that it passes through contact finger 19 of relay 9D and through a resistance coil 4:1, and not, as at C, through contact finger 20. It passes through line relay 8D and operates the relay to move its contact finger to the right and clear home signal 171). The home signals are now clear at both C and D, and the distant signal at C is next cleared through the action of the home signal at D. This signal, in clearing, reverses the polechanging switch at D and thereby reverses the current in the line circuit between C and D. Line relay 8C thereupon moves its contact finger from right to left and closes both local signal circuits, the return from distant signal 186 being through wire 37 and one of the left-hand contacts of the relay, while the return from the home signal is the same as before except that it traverses one of the two left-hand contacts instead of the single right-hand contact.

The function of the resistance coil 41 above referred to is to prevent the successive operation of the line relays 9 from proceeding beyond station D. The line circuit be tween D andE is closed, as above described, to operate relay 8D, and it therefore energizes relay 9E. The current, however, is of third strength only, since it traverses not only the windings of relay 8D and relay 9E, but also resistance coil 41D. Consequently the'current, although it suffices to operate relay SD, which is sensitive to current of third strengtlnis not suflicient to operate either contact finger of relay 9E, and the apparatus at E remains in normal position. By the use of currents of three strengths in the manner above described, the relays 9 operate, therefore, in such'manner that the relay at the advance end of the block occupied by a train is energized with current of full strength energized with current of third strength,

and does not close the line circuit in advance, and thereby the advance operation of the apparatus 18 l1m1ted to two line circuits and the corresponding relays 8 by which the sig- 7 nals must be cleared at the end of the block occupied by the train and at the end of the next block in advance.

With the signals cleared as above de scribed, the train proceeds through block BC. As the train nears the advance end of the block, the eastern branch of the track circuit becomes operative again and track coil 7B and track relay 5B are again energized. This does not affect the signals, however, for while the line circuit through the contact finger of relay 5B is broken by the return of the relay to normal position, a substitute local circuit has previously been established by the action of the train in short-circuiting the western branch of the track circuit and deenergizing track coil 6C and track relay 4C. This circuit is established by the engagement of contact finger 14 of relay 4G with its back contact and is as follows: from feed wire 10C through wire 26, contact finger 25 of the pole-changing switch and its lower contact (the switch having been reversed by the clearing of home signal 17C), through wire 33 to the magnet of relay 9C, through wire 32 to the back contact and contact finger of relay 4C, and thence through contact finger 24L and its lower contact, to feed wire 11. Relay 9C thereby remains energized as before, the reversal of the current having no efiect on it as it is non-polarized.

As soon as the train leaves block BC and enters block CD, the operations above described are advanced one block, and the home signal at E and both signals at D are cleared, while track relay 4C is again energized and block B-C returns to normal condition.

WVhile the first train is still in CD, suppose a second train approaches B from A.

Owing to the presence of the first train, one

of the track relays 5C or 4D is denergized, so that line relay 8C is cut out of the line circuit between C and D. Since this relay is inoperative, the home signal at C is not cleared. The second train operates to close the line circuit between B and C, as in the case of the first train, but as the home signal at C is not cleared, the pole-changing switch at O is not moved from normal position, and line relay 8B therefore merely moves its contact finger to the right. thereby clearing the home signal at B, but leaving the distant signal at danger. If the second train runs into block B C while the first train is still in C-D, neither signal at C will clear,

owing to line relay 8C being cut out as above described.

By a slight change in the connections the system may be arranged to operate with normally closed line circuits, as shown in Fig. 2. Here the apparatus is the same as in Fig. 1, except that no back contacts are used on the track relays, and the contact finger 20 of the non-polarized relay cooperates with a bank contact 43 instead of av front contact. Currents of two strengths are used in the line circuit, the normal current of full strength acting to attract both armatures of the line relays 9, while current of half strength acts to attract only the armatures and contact fingers 19.

In the normal condition of the apparatus current from transformer 12C flows through line circuit BC and energize relays 8B and 9C. The circuit, starting at feed wire 11C, passes through wire 26, contact finger 25 and its upper contact, wire 9.7,line wire 28, wire 29B, the armature coil of relay 8B, contact finger 19 of relay 9B, which is normally held against its fixed contact, wire lat, the fixed contact and contact finger of track relay 5B, back to station C through line wire 31, through the fixed contact and contact finger of track relay 4C, through wire 32 to the winding of relay 9C, thence through wire 33 to the upper contact of contact finger 24-, and back to feed wire 10. This current is of full strength and both armatures of relay 9C are attached so that contact finger 19 is in closed-circuit position and contact finger 20 is in open-circuit position. Since line relay SB is also energized, its contact finger stands normally in righthand position. The local circuit through home signal 17B is not closed, however, for it passes through contact finger 20 of relay 9 and is thus normally held open. The same condition of the apparatus exists in all the other blocks, each line relay 9 being energized by current from the home station and each line relay 8 being energized by current from the next station in advance. Suppose now that a train enters block B-C and short-circuits one branch of the track circuit. Either track relay 5B or track relay 4G is now deenergized and its contact finger falls and breaks the line circuit between B and C. By this action line relay 8B is deenergized, without immediate efiect, and line relay 9C is deenergized with the efiect of clearing home signal 170. This occurs through the action of contact finger 20, which engages its back contact when so released and closes the local signal circuit. This circuit passes from teed wire 10, through wire 4L2, the contact finger and the back contact, thence to contact finger 35 of line relay 8, through the right-hand contact and wire 36 to the signal, and back by common wire 38 and wire 26 to feed wire 11.

Current from transformer 12 thereupon clears the signal. The deenergization of relay 9C has a further action owing to the release of contact finger 19. This contact finger' forms normally, as above described, part of the line circuit between C and D. VJhen the contact finger is released from its fixed contact, the line circuit has to followan alternative path through resistance coil 41, and the current is reduced to half strength. This reduction in current afiects line relay 9D, acting to release contact finger 20D and close the local signal circuit at D. The home signal at D is thereupon cleared in the same manner as the home signal at C.

The clearing of the home signal at D acts to clear the distant signal at C, for the polechanging switch at D is reversed, thereby reversing the current in line relay' 8C, and the contact finger 35 of this relay thereupon moves from right to left and sends clearing current through both wires 36 and 37 to the respective signals. The clearing of the home signal at G acts to reverse the corresponding pole-changing switch, but this has no efiect since the line circuit between B and C is already open. The automatic action proceeds no farther than station D, so long as the train is in block B-G, for contact finger 19 of line relay 9]) is not released by the reduction in strength of the current in line circuit CD, and therefore line circuit DE is not affected.

When the train leaves block BC and enters block (1-D, the actions above described are advanced through a block, the home signal at E and the distant signal at D being cleared.

If a second train approaches B from A while the first train is still in block C-D,

line relay 9B is deenergized and closes the local circuit to clear the home signal at B. The current in line circuit BC is also reduced to half strength so as to release contact finger 20 of line relay 9G. The home signal at C is not thereby cleared, however, for the local circuit at G is open owing to the de'elnergization of line relay 8G consequent upon the presence of the train in block CD and the action of track relays 5C and dD. The pole-changing switch at trated in the accompanying drawings, ,Within the nature of the invention and the scope of the following claims.

I claim:

1. A block signal system comprising successive signaling blocks, line circuits extending through the various blocks one for each block, and means for producing current in the line circuits, and at the rear end of each block a signaling apparatus including means for effecting a. change of current strength in the line circuit extending in one direction and means for effecting a change of current direction in the line circuit extending in the opposite direction, and each signaling apparatus also including translating means in control of the signal indication and re- V sponsive to a change of current direction in the line circuit extending in said one direction and also including translating means in control of the signal indication and responsive to a change in current strength in the line circuit extending in said opposite direction.

A block signal system comprising signal controlling conductors extending along the railway, means for producing current in the conductors si nalino' aaoaratuses at successive points along the railway including means at various of said points for effecting a change of current strength in the signal controlling conductors extending in one direction and also for effecting a change of current polarity in the signal controlling conductors extending in the opposite direc tion, and each signaling apparatus being responsive to a change of current polarity of the controlling conductors extending in said one direction and responsive to a change in current strength in the controlling conductors extending in said opposite direction.

A block signal system comprising signal controlling conductors extending along the railway, means for producing current in the conductors, signaling apparatuses at successive points along the railway includ ing means at various of said points for effooting a change of current strength in the signal controlling conductors extending in advance direction and also for effecting a change of current polarity in the signal controlling conductors extending in rearward direction, and each signaling apparatus being responsive to a change of current polarity in the controlling conductors extending in advance direction and responsive to a change in current strength in the controlling conductors extending in rearward direction.

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

ALBERT v. T. DAY. Witnesses HENRY D. WILLIAMs, BERNARD CownN.

Copies of this patent may be obtained for five cents each, by addressing the "Commissioner of Patents, Washington, D. 0.

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