US1362942A - Block-signaling system - Google Patents

Description

R. l. HEWETT AND S M. WARD, Jn.

' BLOCK SIGNALING SYSTEM.

APPLXCATION FILED APR. l7, I917.

Patented Dec. 21, 1920.

2 SHEETS-SHEET 1.

ATTORNEY g R. J. HEWETT AND S M. WARD, JR.

BLOCK SIGNALING SYSTEM APPLICATION FILED APR. 17, 1917.

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24 .A IS 0T mm 8 M r n n w ow P unites STATES PATENT OFFICE.

ROBERT J. I-IEVIETT, OF WESTFIELD, NEW JERSEY, AND S. MORTIMER WARD, 33., OF WOODMERE, NEW YORK, ASSIGNOR-S TO JOHN TEFFTE CLARKE, OF NEW YORK, N. Y.

BLOCK-SIGNALiNG svsrnrr.

Specification of Letters Patent.

Patented Dec. 21, 1920.

Application filed April 17, 1917. Serial No. 162,624.

To all whom it may concern:

Be it known that we, ROBERT J. Hnwn'rr and S. MoRTIMER l/VARD, J12, both citizens oi. the United States, and residents, respeo tively, of VVesti-leld, Union county, New Jersey, and Woodmere, Nassau county, New York, have invented certain new and useful Improvements in Block-Signaling Systems, of which the following is a specification.

Our invention relates to block signaling systems, and it is especially useful in block signaling systems for governing tratfic in both. directions along a single track.

One of the objects of the invention is to provide a durable and eficient signaling system of the above type.

Another object of the invention is to provide means automatically controlled by a car which overruns a dangef signal by entering the block when said signal is set, for preventing the cartrom clearing the signal in returning from the block, and means for restoring the said first means to its normal position when the car leaves the block.

The invention, in one aspect, may be considered as an improvement in the signaling system shown and described in U. 5. Patent No. 12%1062, granted to S. M. Ward, J12, on September 25, 1917, for electric signaling system, since the present invention is well adapted for use in connection with said system. But it is to be understood that this invention is in no way limited to the system shown and described in said last-mentioned patent, nor to any otherparticular type of block signaling system, since it is applicable to various types of signaling systems in which danger signals are subject to be overrun by cars, and where it is not desired to have the car disturb the signals by its return from the block. In said prior sys term, means were provided for preventing a car which overran a signal from disturbing the signals of the block in overrunning them, and said means taken in combination with the means that we have provided for preventing the car in leaving; the block under the danger signal from disturbing it, prevents the car from disturbing the signals in entering or leaving the block.

The invention consists in the novel features and combinations hereinafter scribed in their preferred forms, and the invention is particularly pointed out in the claims.

Further objects and advantages of the invention will more fully appear from the following description taken in connection with the accompanying drawings illustrating the preferred embodiments of the invention adapted to the signaling system shown in the said lVard application, and in whichi Figure 1 is a diagrammatic view of a signaling system embodying the preferred form of the invention for controlling traflio in both directions along a single track where the trolley-actuated or engaging contacts are placed in the turn-outs from the single track; and i Fig. 2 shows the preferred form of the invention where trolley contacts are placed within the stretch of single track known as the block.

Referring to the drawings (Fig. 1which shows the system with its parts in their proper positions with one car in the block, traveling west), 1 is an incandescent lamp in a local circuit 7 which remains closed'all the time. 2 is a target or red transparency which is normally held aloft by solenoid 3 but which is allowed to drop over the lamp 2 when the solenoid is dee'nergized. The solenoid is placed in a local circuit 4 whi h is held normally closed by a relay 6 of relatively high resistance, T he target carries a contact to bridge contacts 11 for short cirsuiting resistance 9 when the target is released. to cover lamp 1.

A is a step-by-step controller comprising a ratchet wheel 12 which'carries a finger 15 for engaging switch 17 and a pin 16 for engaging a proje tion on the frame '(not shown) to limit the movement of the wheel. The switch 17, having three arms for con trolling circuits hereinafter to be mentioned, is pivoted on a shaft and held in either of its operating positions by a spring 18. A pawl :20 for advancing the controller is operated by magnet-'19, which is energized through cir uit 21 and controlled by relay 6 and the trolley contact 89. A magnet 28 which is energized through circuit 29 operates pawl 30 to restore the controller; the circuit 29 being controlled at contacts 31, 33 and 19; contacts being controlled by a stick relily i i 38 is an incandescent lamp (in this case green) situated in a local circuit 10 which is controlledby relay 51 of relatively low resistance, 2'. 6., having a relatively few turns and switch 24. This lamp constitutes the caution signal or return indication and may be replacedbya target and lamp similar to the one above mentioned for circuit 4, in which case at least one white light will always be displayed to direct the motormans attention in the direction of the signal stand.

The circuit 21 and magnet 19 for advancing the controller, are energized by the engagement of elongated contact 39 by the trolleycontact, this contact 39 being placed above the incoming branch of the turn-out;

' 40 and continues through wire 44, contacts 45. wire 46, contacts 47 controlled by relay 48, thence to the trolley wire. From this it will be seen that the stick relay 41 cannot be energized by an incoming car unless the contacts 43 are closed by the energizetion of relay 6, and it will further be ob- 1 served that when the stick relay 41 is acturelays 41 and 48 are ared and closes its stick circuit at contacts 45; the circuit remains closed until broken at contacts 47 controlled by the relay 48. The relay 48 is energized by the engagement .of elongated contact 50 by a car passing out of the block, thus opening the stick circuit. deenergizing the stick relay and again closing contacts 33 to the controller-clearing circuit. Duplicate trolley contacts and placed at the other end of the block. r

The high resistance relays 6 and 6', i. 6., relays'with a relatively large number of turns,are designedso that either of them will attract its core when energized with one of the resistances 9 0119' in circuit, and yet .willbe capable of remaining in circuit tor any length of tune, w1th the resistance cut out, without undue heating. To accomplish this it is only necessary to use a slightly larger wire than usual in winding the relay coil. 5 r r 'The relatively low resistance relays 51 and 51 are so designed that neither of them I will attract its core to close its contacts'54 or,- 54" when it is energized with one of the res1stances9or [9' 1n c1rcu1t;but upon the resistance being brigded the relay will-bee:

come energized sufiiciently to attract its core and close contacts 54 or 54'. The resistances 9 and 9' are such that when out in and out of the circuit they will varythe current in line 34 by a considerable percentage of its normal value, thus insuring the proper operation of the relays at all times.

A conductor 34 extends along the block through which the signals are set, and it has similar trolley and ground connections at each end. The trolley branch at A includes contacts 35, relay 6, and resistance 9; the ground branch including contacts 37 and relay 51, while the branch atB includes similar apparatus.

A second conductor 32 extends along the block having duplicate trolley and ground connections at each end. The trolley connection at A includes contacts 33 and wire '53; the ground branch including contacts 31, wire 29 and magnet 28.

As stated, Fig. 1 shows the condition of the system after a car has entered the block at the left and is traveling west, and its operation is as follows:

A car entering the block at the left engages elongated contact 39, thus bridging said contact to the trolley Wire and closing the following circuit: contact 39, wire 21, contact 23, continuing along wire 21 to magnet 19, thence to ground. IVIagnet 19 being energized will operate pawl 20 to turn disk 12 one step in an anti-clockwise direction, causing finger 15 to engage the right-hand edge of switch 17 and throw the same to close contacts 31 and 37 and open contacts 35. Aidetent, not shown, holds the disk in its operated position and spring 18 holds switch 17 in its operated position. The closing of contacts 37 completes a circuit from ground at the left (station A) through relay 51, contacts 37, wire 36, conductor 34, cont-acts 35 at B, wire 8, relay 6, resistance 9 to trolley wire. The closing of this circuit energizes relay 6, causing itto attract its core and open circuit 4 and 21'. The opening of circuit 4' deenergizes solenoid 3', causing the red disk 2' to fall over (the normally burning) lamp 1 to indicate danger. Upon the signal being set, resistance 9- is bridged by a contact carried by the disk and the current in conductor 34 is increased to' energize relay 51 at the left sufiiciently to cause it to close contacts 54. It contacts 25 have been previously closed by the deenergization of magnet 19, the closing of contacts 54 will light the green lamp to indicate a clear block ahead, but if the contacts 25-have not beenclosed, the lamp will be lighted upon the closing of these contacts, as the pawl returns to its normal position. a

The closing of contacts 31 completes a circuit from ground at A through solenoid 28, wire 29, contacts31, conductor 32, contacts 33 at B to elongated contact 49'; and

another circuit which branches near contacts 31 at A, and leads to contacts 33 at A and wire 53 to elongated contact 49. From this it will be seen that a car in the block may energize solenoid 28 to return controller disk 12 and operate switch 17 to clear'the signals when it leaves the block at either end, at which time it will engage either contact 49 or 49 to energize said magnet 28 by either completing a circuit from trolley wire at B through wire 53, contacts 33, line wire 32 and contact 31 at A to said magnet; or from contact 49 at A through wire 53, contacts 33 and 31 to said magnet. The contacts 31 at B being normally open, prevent the operation of the controller at B when the car passes out of the block.

The opening of the circuit of relay 6 at contacts 35 at A when the car entered, prevents any possible setting. of the danger signal at that end by a car accidentally run ning into the block at B. Likewise, the re lay 6 at B having opened circuits 4' at its back contacts 55, and having opened circuit 21 to controller magnet 19, prevents any possible setting of the safety signal 38' at' that end. The contacts 37 in the circuit of relay 51 are also open, thus preventing the closure of contacts 54 in the circuit 10 of the signal 38. It will thus be seen that a car overrunning a danger signal and entering at that end of the block can neither give nor receive a signal while the other car remains in the block, nor can it clear the signals already set by a car in the block. This feature of preventing the car in overrunning the danger signal, from affecting the signals that have already been set, was pro vided for and formed a part of the subject matter of the said Ward application. But in that application, the provision made for permitting the car to back out of the block without affecting the signals, was depend ent upon a certain act of the motorman of the car; that is to say, in said system provision was made in the signaling system whereby the car could back out of the block without affecting the signals, provided the motorman operated a certain switch, as for example, his controller, to break the circuit from his trolley contact to ground while the trolley contact wasin engagement with the signal-controlling elongated contact. short, the said system did not, automatically and independently of some act on the part of the motorman, prevent the set signals from being interfer'red with, and maintain the signals in their desired position, when the overrunning car left the block.

It is very important to positively prevent such an overrunning car from affecting these signals, regardless of any voluntary act on the part of the motorinam In other words, it is important to provide means automatically operated responsive to the entrance of the overru'nning car into the block, to prevent said car from affecting the signals when it backs out of or returns from the block. The provision of such means is the principal object of this invention, and in the form of the invention shown this contingency is taken care of in the following manner. Supposing, now, that a car is in the block in Fig. 1, with the parts of the signaling system in the position shown. If a car approaching the block from the right should for any reason overrun the danger signal, as for example by approaching the block at too high a rate of speed, or having the signal thrown suddenly in front of it so that it is not brought to a stop before it passes the signal, the car in entering the block, will engage elongated contact 39', thus closing a circuit from said contact through wire 21, branch wire 40', stick relay 41', wire 42', through contacts 43 (now closed by reason of the energization of relay 6), thence to ground. The energization of this circuit energizes the stick relay, opening contacts 33' and closing contacts 45' in the stick circuit of said relay, which circuit continuing from contacts 45 extends along wire 46', through contacts 47 (now closed), to the trolley wire. When the car leaves the elongated contact 39 in entering the block, the stick circuit maintains the relay energized and maintains contacts 33 open, thus maintaining the clearing line circuit 32 open. When the car backs out of the block it passes out through the lower turnout, thus energizing elongated contact 49', the energization of which fails to actuate either controller, due to the fact that contacts 33' are now open. The car next engages elongated contact 50, energizing relay 48 and breaking the stick relay stick circuit, permitting the relay to again close c(' ntacts 33- to complete the clearing circuit 32 to contact 49', ready for the next car to pass out of the block.

It will thus be seen that this contingency is automatically and readily taken care of by means responsive to the movement of the car into and out of the block. In another patent granted to the said Ward on September 25, 1917, for electric signaling system, No. 1241063, means are provided for preventing a car which has overrun a danger signal from affecting the already-set signals in backing out of the block, without any act on the part of the motorman not necessary to bringing the car out of the block. But said means was dependent upon the operation of a track switch at the time that the car left the block, and is therefore impracticable in systems where track switches are not-provided at the extremities of the single track block sections to be controlled by the signals, and in by far the majorityof cases, conditions of tratlic are such that only turn-outs, in the strictest sense of the Word, are provided without the use of track switches.

It is extremely diflicult to cause any two magnets connected in separate circuits, to be operated so simultaneously that one will not close its contact ahead of the other to energize or deenergize any circuit or circuits that would be energized or denergized by one but not affected by the simultaneous operation of both; and in practice, such a contingency would scarcely, if ever, arise; and likewise, the conditon where the setting and clearing magnets 19 and 28 of the controller are simultaneously energized by cars entering and leaving the block, would scarcely if ever arise. But in the event that it should arise, the controller will be properly operated responsive to both magnets in proper sequence, by adapting the provisions for overcoming this trouble described and claimed in said Ward Patent No. 1,241,062. This provision consists in making one of the relays stronger than the other, and in providing the actuated pawl of each relay with an instantaneous release, so that the instant that one relay is energized and has moved the controller, the pawl is freed from contact with the controller, so that the controller is free to be moved responsive to the pawl of the other relay. Since the details of such a device are fully set forth in said application, and form no part of the present invention, it is unnecessary to describe it in detail here.

In some installations, it is desirable to place the trolley contacts or trolley-engaging switches, as the case may be, within the block, at each end thereof, instead of just outside of the block and above the turn-outs, and in Fig. 2 we have-shown a modification of our invention illustrating the preferred form of the same for an installation of this kind. In this instance, the ontrollers, the line circuits and signal'circuits' proper are identical to those shown and described. The only differences pertain to the trolley-engaged contacts and the circuits and relays at these contacts which govern the'setting and clearing circuits of the controllers and the circuit of the stick relay, so that only these will be described. i

In Fig. 2, the same indicating numerals as were used in Fig. 1, are again used to indicate like parts and circuits. Referring to Fig. 2, the relay 48 in circuit 52 is energized by the bridging of the trolley wire and elongated contact 50 by the trolley contact, for the purpose of opening contacts 47 to de energize the stick relay stick circuit 46, as has been previously explained in connection with Fig. 1. Relay 60 is located in circuit 61 from elongated contact 62 and the relay is provided with an upper contact member 63"adapted to close contact 64 in wire 65 leading from the trolley wire to wire 21, for the purpose of energizing the controlleractuating magnet 19 when a car enters the block. This relay 60 is also provided with a lower contact member 66 adapted to close contact 67 in wire 40 leading to the stick relay, for the purpose .of energizing the same when a car overruns a danger signal, as will hereinafter be explained. The relay 60 has its movable or switch member suitably mechanically interlocked with relay 69 through the intermediation of a bar 71 ful crumed at '7 2 and pivotally connected at each end to the movable members of the said relays 60 and 69. In order to maintain the relay switch members in their neutral position as shown, the bar is provided with suitable springs 73 which immediately snap or return the switch members to the position shown whenever the relays are both denergized. The relay 69 is located in a circuit from elongated contact 70, and when energized, its upper switch member 74 closes contact 75 in a branch 76 from wire 65 to close the circuit through contacts 33 and wire 29 to controller magnet 28 for clearing the signals. The lower switch member'66 of relay 60 is connected through conductor 68 to the elongated contact 70, and one of the contacts 78 engaged by the lower contact member 77 of relay 69. is connected with elongated con tact 62 by wire 79. The purpose of these cross-connections, so to speak, will be more readily understood in explaining the operation of the system.

Assume now, that with no cars in the block, a car approaches the block from the east. As the trolley contact engages elongated contact 50, it energizes relay 48 which simply breaks the stick relay stick circuit which is already broken. As the trolley contact engages "elongated contact 62 "to bridge the same to the trolley wire, a circuit is closed through wire 61 and relay 60, thus closing contacts 64 and 67 The closing of contact 64 energizes the circuitv previously traced to control actuating magnet 19' to operate the controller and set the sig-' nals. The closing of contact 67 in the circuit of the stick relay'41 has no effect because said circuit is open at contacts 43 controlled by relay 6. The engagement of the lower contact member 66'of relay 60 with one 'of the contacts 67 also closes a circuit from said elongated contact 62 through said contact member 66,- wire 68, and elongated contact 7 0, through relay 69. But the closing of this circuit and'the energization of the relay 69 will not actuate the switch member of said relay, due to the fact that the switch member of relay 60 had already been moved to its upper position and the switch of relay 69 to its lower position, in which position the switch members'will be held as long as both relays are maintained energized. The adjacent ends of contacts 70 and 62 sufliciently overlap so that the trolley or other traveling conductor engages one before it leaves the other, and as the trolley contact engages elongated contact 70, bridging the same to the trolley wire, the energization of relay 60 is maintained through wire 68 and switch member 66 to said relay, and the switch members of the relays maintain their normal position until the trolley contact leaves elongated contact 70, whereupon both relays 60 and 69 are deenergized and the said relay switch members are again moved to their positions shown. It will be noted that if it were not for the cross-connecting wire 68 which maintained relay 6O energized during the time that relay 69 was energized, the relay 69 would have closed contact 75, thus completing a circuit to the restoring magnet 28 and clearing the signal just set. It will thus be seen that in entering the block the car sets the proper signals.

lVhen the car reaches the other end of the block, its contact engages elongated contact 70, energizing relay 69 to close contacts 75 and 78'. The closing of contact 75' completes the circuit from the trolley wire through wire said contact 75, wire 7 6, and contacts 33, thence along restoring line wire 32, contacts 31 at A to the clearing magnet 28 to restore the signals. The closing of contact 78 below the relay closed a circuit to interlocked relay 60, as follows: from the elongated contact through contact 7 8, wire 7 9, elongated contact 62 and wire 61', through said relay 60. But the energization of this circuit is ineffective due to the fact that relay 69 was first energized holding its contacts closed and holding the contacts of relay 60 open. As the car passes to elongated con tact 62, relay 69 remains energized through the cross-connecting wire 79, thus preventing the closing of the lower contacts '67 of relay 60, which, if they were closed,

would close the circuit from the elongated contact 62 through wire 40 to the stick relay, causing it to open its contacts 33', which opening might follow so quickly on the closing of the clearing circuit at contact 7 5' that the duration of energization of the clearing circuit would not be sufficient to permit magnet 28 to actuate the controller for clearing the signals. As the trolley contact bridges the trolley wire and elongated contact 50, it energizes relay 48, causing it to open contacts 47; but without effect, since the stick relay stick circuit is already open at the stick relay. It will thus be seen that the car in leaving the block clears the signal in proper manner.

Supposing, now, that with the danger signals 2 set and the other parts of the sig- 65 naling system as shown in Fig. 2, a car should overrun the danger signal at the these contacts and controller magnet 28, is already broken at 23. The closing of contact 67, however, energizes the circuit through wire 40, stick relay 41, wire 42, contacts 43, to ground, thus energizing the stick relay, which in turn closes its upper or stick contacts 45,,completing, the stick circuit through wire 46 and contacts 47', to ground (provided the denergization of relay 48 has permitted the closing of the contacts 47 by this time). If relay 48 has not had time to drop its contact member to close these contacts in the stick circuit, the stick relay 41 will, nevertheless, be maintained in its energized position when the trolley contact engages contact 70 by reason of the cross-connecting wire 68', which maintains the following circuit to the stick relay: Elongated contact 70, Wire 68, switch member 66, wire 40 to the stick relay. This cross-connection provides ample time for the closing of the stick circuit by relay 48 before the stick relay actuating circuit is finally open. The engagement of the elongated contact 70 by the car energizes the other interlocked relay 69, but without effect, since the energization of relay 60 is maintained until the car leaves elongated contact 70.

When the car, having overrun the danger signal, returns from the block, it first engages elongated contact 70', energizing relay 69 and closing upper contact and lower contact 78. The closing of the upper contact 75 is ineffective because the stick relay has opened the clearing circuit at contacts 33. The closing of the lower contact 78 closes a circuit through wire 79 to the other interlocked relay 60. But this is ineffective, due to the prior energization of relay 69 which holds its contacts closed and the contacts of relay 60 open. As the trolley contact engages wire 62, the energization of relay 69 is maintained through wire 7 9, and the closing of the contacts of relay 60 thus prevented (the closing of 75' due to. the fact that the circuit, including which, however, at this moment would do that the car in the block traveling from east to west may clear the signals on leaving the block.

While we have described our invention with particularity and detail in the two embodiments thereof shown, for the purpose of illustrating its operation and advantages, it will be obvious to those skilled in the art, afterunderstanding our invention, that I various modifications and improvements maybe made therein and the particular embodiment of the invention changed to suit diii'erentsignaling systems, without departing from the spirit or scope of our invention, and we aim to cover all such modifications and do not wish to be understood as limiting ourselves other than as indicated in the appended claims.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent, is

1. In a block signaling system for con trolling traffic along a track in both directions, the combination with a .danger signal to be displayed at one end or the block and apermissive signal to be displayed at the other end of the block, means including a step-by-step controller for setting said signals responsive to the entrance of a car in the block at one end, means including a circuit and a contact energized by a car leaving the block at the danger signal end for restoring the controller step bystep, and means operated responsive to a car in over running the danger signal to prevent the clearing of the signals by the return of said car from the block.

2. In a block signaling system, the combination with a signal at one end of a block, and means for effecting the setting and clearing of the signal respectively, responsive to a car entering" the block at the oppo' site end from the signal and leaving the block at said signal end, of a stick relay operatively related to the signal-clearing means, and means including the control circuits for said stick relay for operatingthe same responsive to a car overrunning said signal by entering the block at the signal end, to render the signal-clearing means inoperative to clear the signal when said last car returns from the block.

3. In a block signaling system, the comsaid last circuit for controlling said circuitand stick relay responsive to a car overrunning the signal by entering the block at the signal end, to effect the operation of the relay and render the signal-clearing circuit inoperative to clear the signal when said last car returns from the block.

, 4. In ablock signaling system, the combination with a signal at one end of the block, means for controlling the setting of the signal responsive to a car entering the block at the opposite end from the signal, and means including a circuit with a contact at said signal end of the block for controlling the clearing er said signal responsive to a car leaving the block at said signal end, of means including a stick'relay having a contact controlling the signal-clearing circuit to render same inoperative at times to clear the signal, a circuit for the stick relay having a contact closed while the signal is set, and having another contact for closing the relay circuit to cause the relay to open the signal-clearing circuit, responsive to a car overrunning the signal by entering the block at the signal end, so as to prevent the clearing of the signal when said last car returns from the block.

5. In a block signaling system for controlling traffic along a track in both directions, the combination with a signal at one end of the block, means for controlling the setting of the signal responsive to a car entering the block at the opposite end from the signal, and means including a circuit with a contact at said signal end of the block for controlling the clearing of said signal responsive to a car leaving the block at said signal end, of means including a stick relay operatively related to said signal-clearing circuit to render same inoperative at times to clear the signal, and means controlling said relay responsive to the overrunning of the signal by a car entering the block at the signal end, to

prevent the clearing of the signal by the return from the block of said last car.

6. In a block signaling system for controlling trafiic along a track in both directions, the combination with a signal at one end of the block to be displayed to indicate danger and means for effecting the setting and clearing of the signal respectively, responsive to a car entering the block at the opposite end from the'signal and leaving the block at said signal end, of means operated in the setting of said signal to prevent said signal being cleared responsive to a car entering the block at the signal end, a stick relay operatively related to the signal-clearing means to render the same inoperative at times to clear the signal, and means controlling said relay responsive to the overrunning of the signal by a car entering the block at the signal end, to prevent the operation of the clearing means to clear the signal when said last car returns from the block.

7. In a block signaling system for controlling traffic along a track in both directions, the combination with a signal at one end of the block to be displayed to indicate danger and means for effecting the setting and clearing of the signal respectively, responsive to a car entering the block at the opposite end from the signal and leaving the block at said signal end, of means operated responsive to the signal setting means to prevent said signal being cleared responsive to a car entering the block at the signal end, a stick relay operatively related to the signal-clearing means to render the same inoperative at times to clear the signal, means for energizing said relay responsive to the overrunning of the signal by a car entering the block at the signal end, to prevent the operation of the clearing means to clear the signal when said last car returns from the block, and means for deenergizing the stick relay responsive to the return of said car from the block.

8. In a block signaling system for controlling traflic along a track in both directions, the combination with a signal to' be displayed at one end of the block responsive to a car entering at the opposite end of the block and to be cleared responsive to the car leaving at the signal end of the block, means including a step-by-step controller likewise actuated. by cars entering and leaving the block, to permit cars to enter or leave the block while another is in the block, without deranging the signals, and means including control circuits for advancing and restoring the controller, of a stick relay having a contact controlling the controller-restoring circuit to render the circuit inoperative to restore the controller at times, a circuit for said stick relay having contacts closed when said signal is set, and means for energizing the stick relay circuit responsive to a car entering the block, whereby, while the danger signal is displayed, if a car overruns said signal by entering the block, it will be prevented from clearing the signal in returning from the block.

9. In a block signaling system for controlling trafiic along a track in both directions, the combination with a danger signal to be displayed at one end of the block and a permissive signal to be displayed at the other end of the block, means including a step-by-step controller for setting said signals responsive to the entrance of a car in the block at one end, means including a circuit and a contact energized by a car leaving the block at the danger signal end for restoring the controller step by step responsive to cars leaving the block at said last end, of astick relay for opening and closing the controller-restoring circuit, a circuit for the stick relay having contacts adapted to be closed while the danger signal is displayed,

said stick relay circuit having means whereby it is energized responsive to the overrunning of the signal by a car entering the block at the danger signal end, to open the controller-restoring circuit and prevent the operation of the controller responsive to the return from the block of said last car, and means for deenergizing said stick relay responsive to the return of said car from the block, whereby the restoring circuit is again closed;

10. In a block signaling system for controlling trafiic along a track in both directions, the combination of a danger signal to be displayed at one end of the block and a permissive signal to be displayed at the other end of the block, means including a step-by-step controller for setting said signals responsive to the entrance of a car in the block at one end, means including a circuit and a contact energized by a car leaving the block at the danger signal end for restoring the controller step by step, means for preventing the clearing of the signals by a car overrunning the danger signal, means operated responsive to the car in overrunning the danger signal, to prevent the clearing of the signals by the return of said last car, and means for automatically restoring said last means to its former position when the car leaves the block.

In testimony whereof, we have signed our names to this s ecification.

R BERT J. nnwnrr. s. MORTIMER WARD, JR.

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