US1396847A - Automatic train-stop system - Google Patents

Description

M. F. JONES. AUTOMATIC TRAIN STOP SYSTEM. APPLICATION FILED APR. 9, 1919- 1,396,84;7. Patented Nov. 15, 1921. F/y/ m I I WITNESSES:

IINVENTOR Mal/nee Fdonea TT\ORNEY MATIRICE'F. JONES, OF WILKINSBURGi,

VAN IA.

PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIC & MANUFACTURING COMPANY,

A CORPORATION OF PENNSYL- AUTOMATIC TRAIN-STOP SYSTEM.

Specification of Letters Patent.

Patented Nov. 15,1921.

} Application filed April 9, 1919. Serial No. 288,749.

To all whom it may concern:

Beit known that I, MAURICE F. JONES, a citizen of the United States, and a resident of VVilkinsburg, in the county of Allegheny and State of Pennsylvania,'have invented a new and useful Improvement in Automatic Trainrstop Systems, of which the following is a specification.

My invention relates to automatic trainstop systems, and it has for its object to provide a reliable, yet relatively simple and inexpensive, system for automatically arresting the movement of a train under predetermined conditions.

More specifically stated, the object of my invention is to provide a plurality of spaced track magnets that are successively energized as a train passes into the several blocks, together with a time-element mechanism carried by the train and dependent upon energization from each successive track magnet, for preventing the automatic stoppage of the train. By time-element mechanism 1 mean to include all devices having the characteristic of delayed operation, the delay being, in the present case, a function of the distance covered by the train.

From another aspect, the object of my invention is to provide, on a train, mechanism which, if not affected by an external agency, will cause the train to stop after traveling a predetermined distance, together with a plurality of influencing means, spaced along the track or roadway, which, provided the track ahead is clear, will act to reset the mechanism on the train to allow the train to proceed.

Another 'object of my invention is to provide, in conjunction with the system of the above-indicated character, means for permitting the train to proceed at a relatively low speed, irrespective of whether or not the track ahead is clear.

Other specific objects of my invention will become evident from the following detailed description taken in conjunction with the accompanying drawing, wherein Figure 1 is a diagrammatic view of the track and supply circuits that are employed in carrying out my present invention, and Fig. 2 is a view, partially in elevation and partially in section, of the apparatus carried by the train for cooperation with the circuits illustrated in Fig. 1, together with a diagrammatic representation of the electrical controlling circuits that are located upon the train for the purpose of governing the operation of the illustrated apparatus.

Referring to'Fig. 1, the system shown comprises a track having a plurality of the familiar electrically insulated blocks 1, 2, 3, 1 and 5, the direction of traffic being indicated by the arrow and the accompanying legend. Essentially, each block embodies the parallel-running rails 6 and 7 each of which is suitably insulated from the adjacent rails by insulating joints 8 of any wellknown type. A plurality of track magnets 9 are regularly spaced along the track, and one or more per block may be utilized, as desired. A plurality of transformers, corresponding in number to the track blocks, have their primary windings energized from a suitable alternating current-supply circuit 11, the secondary windings being connected to the rails 6 and 7 of the corresponding blocks, A plurality of track relays 12 normally occupy their energized upper position, their actuating coils 13 being connected to the track rails, whereby the necessary energy is derived from the secondary winding of the corresponding transformer 10.

However, by reason of the inter-connection of the track magnets 9 with successive track-relay contact members, the magnets are normally deenergized, that is, whenever the particular block is not occupied by a train.

As soon as a train enters any block, however, as indicated by the wheels 15 in the block 2, the secondary winding of the corresponding transformer 10 is short-circuited to effect substantial deenergization of the actuating coil 13 of the corresponding track relay 12. Consequently, a circuit is established from one of the supply conductors 11 through conductor 20, contact disk 14, of the relay 12 that corresponds to block 2, the relay occupying its lower or deenergized position, when circuit is continued through conductor 21, track magnets 9 corresponding to the occupied block 2, conductor 22, contact disk 23 of the succeeding track relay 12 in its normal or energized upper position, and conductor 24 to the other supply conductor 11.

In this way, the track magnet corresponding to each block is energized as long as any vehicle wheels interconnect the rails in that block. However, if the block ahead, 3 in the present instance, should be occupied by another train, the corresponding track relay 12 would assume its lower position, by reason of the short circuit of the corresponding transformer secondary winding. and, there fore, the previously traced circuit through the track magnets 9 in block 2 would be interrupted. In other words, the successive track magnets are energized only when the home block is oceupied,, while the block ahead is clear.

Referring to Fig. 2, the rails 6 and 7, the track magnets 9. and the vehicle wheels 15, are again illustrated, together with the apparatus that is carried by, or movable with, the train. Such apparatus comprises, in general, an impulse-coil device 30, which is located within the zone of magnetic influence of the successive track magnets 9 to energize an impulse relay 31, thereby closing a circuit including a battery 32, or other suitable source of energy, for the purpose of controlling the operation of a timeelement mechanism 33 of the escapement type. A valve 34:, for efiecting application of the air-brakes with which the train is equipped, is adapted to be operated by the time-element mechanism 33, under conditions to he set forth, unless a centrifugallyoperated device 35, which is driven in accordance with the vehicle speed prevents the operation of the valve.

Each track magnet 9 is shown as comprising a plurality of energizing coils 36 that are wound upon the upright arms of a magnetizable yoke 37, the upper ends of which are fastened into plates or disks 38 for facilitating the transmission of a magnetic impulse to the impulse-coil device 30. This device comprises a similar magnetizableyoke 39 having end plates 40. a coil 41 being wound around the yoke and connected across the terminals of the actuating coil 42 for the impulse relay 31, which is provided with an upper and a lower contact disk, 44 and 45, respectively, for the purpose of closing certain circuits to be described later.

The time-element mechanism 33 comprises a slidable contact segment or plate l6 that bridges a plurality of control fingers 47 throughout the major portion of its range of travel. The contact Segn'ient 46 is insulatedly supported by a suitable arm 48, which is paralleled by a rack member 49. to which secured a stem or rod 50 and a piston 51 that operates within a suitable cylinder 5:2 and is biased toward the illnstrated right-hand position by means of a coil spring 5 3.

A supply pipe 5t for the cylinder 52 communicates with a controlling valve 55 of a familiar type, which normally effects communication between the supply pipe 53 and the atmosphere through an exhaust port 56.

for the purpose of releasing fluid pressure from the cylinder 52. The valve is adapted, upon the energization of its actuating coil 57, to close the communication just n1cn-' tioned and effect the conveyance of fluid pressure from the reservoir, or other suitable source (not shown). through a pipe or passa e 58 to the supply pipe 54, whereby,the piston 51 is actuated towards the left in opposition to the spring 53.

The rack member 45 meshes with a gearwheel 60, which is concentrically related to a ratchet wheel 62, mechanical connection between the provided by a flexible mounted pawl or detent 61. An escapement fork 63 engages the ratchet or escapement wheel (52, in accordance with well-known principles, the. outer end of the fork being provided with a roller 64, while a biasing spring 65 is attached to an intermediate point of the main arm of the fork to rotatably move the fork around a central pivotal point 66. A suitablyconfigured cam 67 is secured to a gear-wheel (38, which meshes with a pinion (39 that is shown as mounted directly upon the vehicle wheelaxle'. It will be understood. however, that any other suitable means for drivin the cam 67 in accordance with the vehicle speed may be utilized.

he brake-valve 34 comprises a casing that houses a valve-pin T6 and a plug 77, which is biased to the illustrated closed position by means of an adjustable spring 78. The valve-pin 76 projects beyond the casing 75 in a. position to be engaged by a vertical arm 48 of the time-element mechanism 33 under conditions to be described.

pipe or passage 79 communicates with the brake-valve 34 and is directly connected to the fluid-pressure supply. \Vhcnever the valve-pin T6 is accuated toward the right by the vertical arm -18". in opposition to the spring 78, fluid pressure i exhausted or bled from the inlet pipe. 7!) through e.\'- haust ports 80 of the valve, whereby the train ainbrakcs are automatically set, in accordance with a familiar operation that need not be further illustrated or described here.

The centrifugally operated mechanism 35 comprises a shaft that is driven. in any suitable manner. from the vehicle wheels, a plurality of fly-bails 86. and a cooperating linkage device 87 of a wclldmown type, for the purpose of vertically actuating a slidable sleeve 99, which is interposed in the horizontal path of trawl oi the vertical arm 48 of the tune-element mechanism 33. whenever the vehicle speed is sullicicntly low to cause the sleeve 88 to assume such an obstructing position. It will be understood that the speed at which further niovcincnt of the vertical arm 4s toward the ri -hi is prevented by the sleeve 88. may be readily gear-wheel and the ratchet being determined by the characteristics of the centrifugally operated device, and, in particular, the length of the sleeve 88. The position of the sleeve is such that further movement of the escapement mechanism toward the right is prevented just prior to the engagement of the vertical arm 48 with the valve-pin 76, whereby setting of the train brakes is automatically prevented whenever the vehicle speed is of a predetermined low value.

The operation of the illustrated system may be set forth as follows: When the impulse coil 30 passes an energized track magnet 9, 'a certain impulse of voltage is induced in the coil to energize the actuating coil 42 for the impulse relay 31 and thereby actuate the relay to its illustrated upper position. A new circuit is thereu on completed from the positive terminal 0 the bat tery 32 through upper contact disk 44 and actuating coil 42 of the relay, conductor 90, control fingers 47, which are bridged by contact segment 46 of the time-element mechanism 33, and conductor 91 to the negative battery terminal. In this way, the impulse relay 31 is held in its upper or closed position as long as the control fingers 47 are )ridged by the slidable contact segment 46. Another circuit is established, upon the energization of the impulse relay, from the battery 32, through lower relay disk 45, conductor 92, actuating coil 57 of the controlling valve 55, and conductor 91 to the negative battery terminal. Consequently, the valve 55 is depressed to admit fluid pressure from the inlet pipe 58 through supply pipe 54 to the cylinder 52, whereby the piston 51 is actuated toward the left to cause the rack member 49 to rotatably move the gear wheel 60 and the escapement wheel 62 in a counter-clockwise direction. Such movement is substantially instantaneous, since the inclined surfaces of the 'gear-wl1eel teeth slide by the arm of the pawl 61 with practically no obstruction.

The limit of travel of the rack member 49 toward the left is determined by the length of the 'slidable contact segment 46, since, as soon as the control fingers 47 oc- 'cupy the position marked Reset, corresponding to complete disengagement with the segment 46, the actuating coil 42 of the impulse relay 31 is deenergized, causing the relay to drop to its lower position, which, in' turn, deenergizes the actuating coil 57 for the controlling valve 55, and thus releases the fluid pressure from the operating cylinder52. However, although the spring 53 tends to quickly actuate the piston 51 toward the illustrated right-hand position, such movement is prevented by reason of the engagement of the ratchet wheel 62 and escapement fork 63.

As the train moves forward, the cam 67 of the cam, and such movement is independent of the direction of travel of the train. If the train travels. more than a predetermined distance, dependent upon the gear ratio between the gear-wheel 68 and the pinion 69, and also provided that no energized track magnet 9 is passed, the stepby-step movement of the escapement mechanism will proceed to a point wherein the vertical arm 48 engages the valve-pin 76 to bleed the train-line pipe 79 and thus automatically set the vehicle air-brakes, as previously explained.

However, if, before the brake-setting posi tion of the escapement mechanism 33 is reached, an energized track magnet 9 is passed, then the mechanism will be re-set by reason of the passage of a new magnetic impulse from the coil 30, through the relay 31, to close the illustrated circuits and again permit fluid-pressure to enter the operating cylinder 52. Consequently, after each resetting process, the train may again proceed for the abovementioned predetermined distance without the train brakes being automatically set.

The reason for the regular or uniform spacing of the track magnets 9 will be evident from the foregoing statement, since actuation of the valve-pin 76 is dependent upon the distance thatthe train travels without passing an energized track magnet. However, the track blocks need not be of uniform length, and, if desired, two or more track magnets may be placed in one block.

After the train has been stopped by the above-described mechanism, if it is desired to proceed cautiously into the danger zone. the train crew may manually re-set the mechanism and release the vehicle brakes by means of depressing the illustrated pushbuttons 95 and 96, which are connected in series relation with the actuating coil 57 for the controlling valve 55 across the terminals of the battery 32. Consequently, the concurrent closure of the push-buttons 95 and 96, which are preferably so located that one of them may be closed only by the engineer and the other only by the fireman, performs the same function as the actuation of the contact disk 45 of the relay 31 to its upper or closed position.

As previously mentioned, it may be desirable, in some cases, to prevent the automatic application of the train brakes, provided the vehicle is proceeding at a relatively low rate of speed. For this purpose, the centrifugally-operated device 35 interposes itself in the path of the vertical arm 48 of the time-element mechanism 33 just before the valve-pin 76 is reached, as already set forth. Consequently, the train brakes are not applied unless the vehicle speed is sufliciently high to remove the slidable sleeve 88 of the centrifugally-operated device 35 away from the path of the escapement mechanism It will be appreciated that such lowspeed operation of thevehicle is thus permitted, irrespective of whether or not the track magnets 9 are successively energized.

It will be seen that I have thus provided a system for automatically stopping a car or train whenever the track ahead is occupied, or otherwise unsafe. However, although an alternating-current supply for the track circuits is shown, the system may be operated with direct-current energy, if desired. For the sake of simplicity, I have shown the track circuits that are required with trafiic in only one direction. and with protection for only one block head. However, the system may be readily adapted to any traffic requirements. and may be used in conjunction with present indicating. signal systems, the track magnets simply being connected in parallel relation to 1the clear circuits of such indicating signa s.

Broadly considered, the system comprises the following combination of apparatus:

1. A series of track magnets so located that their magnetic field may influence suitable mechanism on the passing train.

2. Primary apparatus on the rolling stock, which is actuated by the track mag nets as the train passes.

3. Secondary apparatus on the rolling stock, which is so related to the primary apparatus as to set the brakes on the train, provided the train travels more than a certain distance and above a predetermined speed without passing an energized track magnet. Furthermore, if desired, the illustrated apparatus may readily be adapted to open the main or auxiliary cont-rolling circuits of an electric motor system, in addition to actuating the brake-valve.

owever, my invention is not necessarily restricted to the type of apparatus shown, since, in some cases, it may be desirable to substitute Wireless-telegraph apparatus in stations along the track for the illustrated track magnets, whereby wireless energy is utilized in lieu of a magnetic field. The analogy will be evident without'further description. Furthermore, the invention contemplates the use of any mechanism on the train that runs down after the train travels a certain distance and, in so doing, stops the train; together with a resetting or rewinding of. such mechanism by means of stationary apparatus on or near the track, provided the stretch of track ahead is safe for travel.

From another aspect. the present system includes means having normal danger characteristics, that is, the apparatus normally tends to set the vehicle brakes unless prevented by an external agency, viz., the

mecca? track magnets, although the track magnets are dcenergized, except when needed for this purpose.

Consequently, I do not wish to be restricted to the specific circuit connections, structural details, or arrangement of parts herein set forth. as various modifications thereof may be effected without departing from the spirit and the scope of my invention. I desire, therefore, that only such limitations shall be imposed as are indicated in the appended claims.

I claim as my invention:

1. An automatic train-stop system comprising a plurality of spacedand normally deenergized track magnets, means dependent upon the proximity of the train for ener gizing said magnets, and means havingnormal danger" characteristics for stopping the train comprising time-element mechanism carried by the train and influenced toward its initial condition by said magnets.

2. An automatic train-stop system comprising a plurality of electrically-insulated blocks and of spaced track magnets, means dependent upon the presence of a train in a block for successively energizing said magnets, and time-element means carried by the train and responsive to magnetic impulses from said magnets for preventing the automatic stoppage of the train.

3. An automatic train-sto system comprising a plurality of electrically-insulated blocks and of spaced track magnets, means dependent upon the presence of a train in a block for successively energizing said magnets, and time-element means carried by a train for arresting the movement thereof unless all track magnets passed by the tram are energized.

4. An automatic train-stop system comprising a plurality of electrically-insulated blocks and of spaced track magnets, means dependent upon the presence of a train in a block for successively energizing said magnets, time element mechanism carried by the train for automatically stopping the movement thereof, and means impulsively influenced by said magnets for re-setting sald mechanism to prevent train stoppage.

5. An automatic train-stop system comprising a plurality of electrically-insulated blocks and of spaced track magnets, means dependent upon the presence of a train in a block for successively energizing said magnets, means carried by a. train for arresting the-movement thereof unless all track magnets passed by the train are energized. and means for preventing the complete operation of said movement arresting means when the vehicle speed is below a pr( determined value.

(3. An automatic train-stop system comprising a plurality of spaced track magnets. a brake-controlling device carried by the gagement with said device, a normally closed train, movable means inflneced by said magment with said device, and an escapement mechanism for effecting relatively slow movement of said movable means.

7. An automatic train-stop system comprising a plurality of spaced track magnets, a brake-controlling device carried by the train, movable means biased toward operative engagement with said device and magnetically controlled from the track magnets in opposition to the biasing effect, and an escapement mechanism actuated in accordance with the-.train speed for efiecting retarded response to said biasing effect.

8. An automatic train-stop system comprising a pluralit of spaced track magnets, a brake-controlling device carried by the train, movable means biased toward operative engagement with said device, an impulse coil energized by passing the track magnets to actuate said movable'means in opposition to the biasing effect, and an esoapement mechanism driven from the train Wheels for permitting intermittent response to said biasing effect.

9. An automatic train-stop system comprising a plurality of spaced track magnets, a brake-controlling device carried by the train, an operating cylinder, a piston member therefor biased toward operative engagement with said device, a normally closed valve for preventing access of fluid-pressure to 'said cylinder, an impulse coil energized by passing the track magnets for opening said valve to actuate the iston member in opposition to the biasing e ect, and an escapement mechanism driven from the train wheels for permitting retarded response to said biasing effect.

10. An automatic train-stop system 'comprising a plurality of spaced track magnets, a brake-controlling device carried by the train, an operating cylinder, a piston member therefor biased toward operative envalve for preventing access of fluid-pressure to said cylinder, an impulse coil energized by passin the track magnets, a relay device close b such energization for effecting the opening of the valve to actuate the piston member in opposition to the biasing effect, an escapement mechanism driven from the train wheels for effecting step-bystep movement in response to said biasing efiect, and means dependent upon the degree of movement for interrupting the energizing I circuit of said relay device.

11. An automatic trainstop system comprising a plurality of spaced track magnets, a brake-controlling device carried by the train, movable means biased toward operative engagement with said device and magnetically controlled from the track magnets in opposition to the biasing effect, an escapement mechanism actuated in accordance with the train speed for effecting retarded response to said biasing effect, and means responsive to the vehicle speed interposed in the path of said movable means to prevent such response beyond a predetermined stage.

12. An automatic train-stop system comprising a plurality of spaced track magnets, a brake-controlling device carried by the train, an operating cylinder, a piston member therefor biased toward operative engagement with said device, a normally closed valve for preventing access of fluid-pressure to said cylinder, an impulse coil energized by passing the track magnets for opening said valve to actuate the piston member in opposition to the biasing e-ifect, an escapement mechanism driven from the train Wheels for permitting retarded response to said biasing effect, and a centrifugally 0perated device interposed in the path of said piston member to preventoperation of the brake controlling device under relatively low-speed conditions of the train.

In testimony whereof I have hereunto subscribed my name this 31st day of March, 1919.

MAURICE F. JONES.

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