US1824059A - Automatic train control - Google Patents

Description

I Sept. 22, 1931. 'r THOMAS 1,824,059

AUTOMATIC TRAIN CONTROL Filed May 13, 1925 2 Sheets-Sheet l INVENTOR THOMAS HITHOMAS BY% W ATTORNE Sept. 22, 1931. T. H. THOMAS 1,824,059

AUTOMATIC TRA IN CONTROL Filed May 13, 1925 2 Sheets-Sheet 2 INVENTOR T HOMAQ H THOMAS BY%WM ATTOF'NEY Patented Sept. 22, 1931 warren STATES PATENT OFFICE THOMAS H. THOMAS, OF EDGEWOOD, PENNSYLVANIA, ASSIGNOR TO THE WESTING- 4 HOUSE AIR BRAKE CQMPANY, OF WILMERDING, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA AUTOMATIC TRAIN CONTROL Application filed May 13,

This invention relates to automatic train control equipments and more particularly to the type in which the engineer is required to acknowledge the signal indication in order to prevent the brakes from being applied.

The principal objectof my invention is to provide means by which the engineer is required to acknowledge successive signal indications of the same character, such as the acknowledgement of successive occupied blocks.

In the accompanying drawings; Fig. 1 is a diagrammatic view,partly in section, of a train control equipment embodying my invention; and Fig. 2 a view similar to Fig. 1,- but with certain parts omitted, the apparatus being positioned as required by a caution signal indication, if acknowledged by the engineer.

As-shown in Fig. 1 of the drawings, the equipment may comprise a brake valvedevice 1, an acknowledging valve device 2, a caslng 3 containing a selector valve device C and a valve device D, a valve device 4, a brake application valve device 5, a main reservoir 6, two stop reservoirs 7 and 8, an acknowledging reservoir 9, and a timing reservoir 16.

The brake valve device may comprlse a casing having a rotary valve chamber 11 and containing a rotary valve 11 which is connected by a key member 12 to the operatlng handle 13. Disposed in the casing at one side of the key member 12 is a check valve 14 subject on one sideto the pressure of a spring 15. A cam 16, carried by the key memier 12, is adapted to engage and hold the check valve 14 unseated in release, running, and holding positions of the brake valve device, the check valve being allowed to seat in all other positions of the brake valve.

The acknowledging valve device 2 may comprise a casing having a chamber 17 containing a rotary valve 18, which is operatively connected to an operating handle 19. Fluid under pressure from the main reservoir as supplied through pipes 21 and 22 and pasand the pressure exerted by a coil spring 20, act to hold the rotary valve 18 to its seat at all times.

The selector valve device C contained in the 1925. Serial No. 29,951.

casing 3 may comprise a piston 26 contained in piston chamber 24, which is connected to a volume chamber 25, and a slide valve 27 contained in a valve chamber 28 and adapted to be operated by the pisto1126. The valve device D also contained in the casing 3 may comprise a flexible diaphragm 31 contained in diaphragm chamber 32 and subject on one side to fluid pressure and on the other side to the pressure of a coil spring 33, said diaphragm being adapted to operate double beat valves 34 and 35 contained in valve chamber 36. Attached to the casing 3 is a magnet '37, which is adapted tooperate double beat valves 38 and 39 for controlling the supply and exhaust of fluid under pressure to and from the piston chamber 24 of the selector valve device D.

The valve device 4 may comprise a casing in which is contained a timing valve device E i and an acknowledging pilot valve device F. The timing valve device E may comprise a flexible diaphragm 41 contained in diaphragm chamber 41 and subject on one side to the pressure of fluid in the timing reservoir 10 and on the opposite side to the pressure of a coil spring 42. The diaphragm 41 is adapted to operate double beat valves 43 and 44, which are contained in valve chamber 45.

The acknowledging pilot valve device may comprise a piston 46 contained in a piston chamber 47, a valve piston 48 contained in a valve chamber 49, and a valve 50 contained in valve chamber 51, said valve piston 48 and valve 50 being operable by the piston 46. Associated with the casing of valve device 4 is a magnet 52, which is adapted to operate double beat valves 53 and 54 for controlling the supply and exhaust of fluid to and from diaphragm chamber 41 of the timing valve device E and diaphragm chamber 32 of the valve device D. i For the purposes of the present invention, the brake application valve device 5 is shown as comprising a casing having a piston chamber 55 containing a piston 56 and a valve chamber 57 containing a slide valve 58, the slide valve being operableby the piston 56. A coil spring 59 is interposed between the casing and the outer face of piston 56 to maintain said piston in its innermost position, when the pressures of fluid on opposite sides of said piston are equal.

Before explaining the operation of the apparatus described, it should be pointed out that trackway apparatus and train carried governing apparatus is provided and so operates that when a train enters or is proceeding in a clear block the magnet 52 will be energized and the magnet 37 deenergized, in acaution block the magnet 52 will be deenergized and magnet 37 energized, and in an occupied block both of said magnets will be deenergized.

In operation, fluid under pressure from. the main reservoir 6 flows through pipes 21 and 60 to rotary valve chamber 11 of the brake valve device 1, also through pipes 21 and 22, cav ity 61 in rotary valve 18 of the acknowledging valve device 2, and thence through passage and pipe 62 to the acknowledging reservoir 9, charging the same. Fluid from the main reservoir is al o supplied through pipe 21a-nd passage 63 to valve chamber 57 of the brake application valve device, from whence it flows through a restricted port 64, in piston 56, to piston chamber 55, and assuming that communication is closed so that fluid cannot be vented through passage 84, the fluid pressures on opposite sides of said piston will equalize, so to permit the spring 59 to shift the piston 56 to its innermost position.

Fluid under pressure from the main reservoir is also supplied through pipes 21 and 30 and passage 29 to valve chamber 28 of the selector valve device G. A passage 65 leading from passage 29 suppies fluid to one side of the magnet controlled double beat valve 39. Fluid is also supplied from pipe 30 through passage 66 to valve chamber 51 of the acknowledging pilot valve device and to one side-of the magnet controlled double beat valve 54. V 45 Assuming'the train is running in a clear block, the magnet 52 will be energized and the magnet 37 deenergized. The magnet 52 being energized will cause the double beat valve 53 to be seated and'the valve 54 to be unseated, as is clearly shown in Fig. 1 of'the drawings.

The double beat valve being unsealed, fluid under pressure from the main reservoir, which is always present at one side of said valve, will be supplied through passage 67 to diaphragm chamber 41 of the timingvalve device E, thence through pipe 68 to the timing reservoir 10, charging the same. The fluid under pressure supplied to diaphragm chamber '41 acts to move the diaphragm 41, J0 so as to seat the double beat valve 44 and unseat valve 43. A passage and pipe 69 is connected to passage 67- so that fluid is also supplied to diaphragm chamber 32 of valve device D, moving the diaphragm 31 so as to 6 seatdouble beat valve 34 and unseat valve 35.

In a clear block, the magnet 37 is deenergized so that the double beat valve 39 will be seated and the valve 38 unseated to Connect the piston chamber 24, and consequently the volume chamber 25 of the selector valve v0 device C, toatmosphere by way of passage 7 0 past unseated valve 38 and choked passage 71. The pressure of fluid in valve chamber 28 acting on the opposite side of the piston'26 will then shift said piston and consequently slide valve 27 to a position in which the stop. reservoir 8 is'connected to atmosphere,through pipe and passage 72, cavity 73in slide valve 27, passage 74, valve chamber 36 and atmospheric exhaust port 75. In this position of slide valve 27, the stop reservoir 7 is connected to atmosphere, through pipe and passage 76, cavity 77 in slide valve 27, passage and pipe 78, valve chamber 49, passage 80, valve chamber 45, past unseated valve 43 to the atmospheric exhaust port 81.

Vhen the train proceedsfrom a clear block into a, caution block, as hereinbefore ex plained, the magnet 52 will be deenergized and the magnet 37 will be energized. The deenergization of the magnet 52 causes the valve 54 to seat and valve 53 to be unseated.

The unseating of valve 53 connects the passage 67 and consequently the diaphragm chamber 32 of the valve device D, the diaphragm chamber 41 of the timing valve device and the timing reservoir 10 to atmosphere, past unseated valve 53 and through atmospheric exhaust port 82. The volume of the timing reservoir 10 and the area of the exhaust port 82 are such that a predeter mined time interval, such for example as 4 seconds, will elapse before the fluid pressure is reduced sufliciently to permit the diaphragm 41 of the timing valve device to 105 move. This time interval is provided to give the engineer sufficient time to acknowledge the signal indication and thereby prevent a brakeapplication, as will be hereinafter described.

The energization of magnet 37 causes the double beat valve '38 to be seated and the valve 39 to be unseated, so as to supply fluid under pressure from the main reservoir, which is always present at one side of the 115 valve 39, through passage 70 to piston chamber 24 and volume chamber 25 of the selector valve device C. The fluid under pressure supplied to piston chamber 24, together with the pressure exerted by spring 26*, shifts the 120 piston 26 to its innermost position, moving the slide valve 27 to a position in which the stop reservoir 8 is connected to valve chamber 45 of the timing valve device, through pipe and passage 72, cavity 77 in slide valve 27, passage and pipe 78, valve chamber 49 and passage 80. The stop reservoir 7 is connccted, in this position of slide valve 27, to atmosphere by way of pipe and pasasge 76,

cavity 94 and atmospheric exhaust port 95. I30

If the signal indication has not been acknowledged at the expiration of the predetermined time interval, the reduced pressure in diaphragm chamber 41 of the timing valve device will permit the spring 42 acting on the opposite side of the diaphragm 41 to move said diaphragm so as to seat double beat valve 43 and unseat valve 44, thereby connecting the piston chamber 55 of the brake application valve device, through passage and pipe 84 and past unseated valve 44 to valve chamber 45 and consequently to stop reservoir 8. 1 I

The venting of fluid under pressure from piston chamber to the stop reservoir 8 permits the greater pressure in valve chamber 57, acting on the opposite side of the piston 56 to shift said piston to its outermost position with a consequent movement of the slide valve 58 to a position in-which the brake pipe is Vented to atmosphere, through pipe and passage 86, cavity 87, in

slide valve 58 to atmospheric exhaust port 88, thereby causing an application of the brakes throughout the train.

- The engineer may prevent a brake application from being caused as above described by moving the operating handle .19 and consequently the rotary valve 18, of the acknowledging valve device, to the position shown in Fig. 2 of the drawings, provided the engineer acts before the expiration of the predetermined time interval, hereinbefore referred to. in this position of the rotary valve 18, fluid unden pressure from the acknowledging reservoir 9 is supplied to piston chamber 47, of the acknowledging pilot valve device, through pipe and passage 62 cavity in rotary valve 18, passage and pipe 91, cavity 92 in slide valve 58 and passage and pipe 93.

The fluid so supplied acts to shift the piston 46 to its innermost position with a consequent movement of the valve piston .48 and valve 50 to the position shown in Fig. 2 of the drawings. In this position of valve pis ton 48 communication between passage 7 Sand passage 80 is cut oil, and consequently communication from piston chamber 55 of the brake application valve device to stop reser voir 8 is out oh and at the same time fluid under pressure from the main reservoir, which is always present in valve chamber 51, is supplied past unseat-ed valve through valve chamber 49, passage and pipe 78, cavity 77 in slide valve 27 and passage and pipe 72 to stop reservoir 8, charging the same.

In the acknowledging position of rotary valve 18, of the acknowledging valve device 2, fluid from the acknowledging reservoir 9 is slowly vented to atmosphere, through a branch of passage 93 containing a choke, so that after a predetermined time interval the pressure of fluid in said reservoir and consequently in piston chamber 47 of acknowledging pilot valve device, will be reduced sufliciently to permit the higher pressure in valve chamber 49 to shift the piston 46 and consequently the valve piston 48 and valve 50 to their former position connecting passages 78 and 80 and cutting olf fluid from valve chamber 51, as shown in Fig. 1 of the drawings. However, the stop reservoir 8 having been charged from valve chamber 51, as here inbefore described, fluid from'piston chamber 55 will not be Vented to said reservoir, with the result that the piston 56 and slide valve 58 will be maintained in normal release position, and a brake application will be prevented. I

When the train passes from a caution block into an occupied block, the track circuits are such that the magnet 52 will remain deenergized, as in a caution block, and the magnet 37 will become deenergized. The magnet 52 remaining deenergized will cause the timing valve device E and the valve device D to remain in the positions shownin Fig. 2 of the drawings.

The deenergization of magnet 37 will cause the double beat valve 39 to beseated and valve 38 to be unseated so as to connect piston cham ber 24 and volume chamber 25 to atmosphere by way of passage 70, past unseate-d valve 38, and choked passage 71. The volumes of piston chamber 24 and chamber 25 are so related with respect to choked passage 71, that a predetermined time interval, such for example as 4 seconds, will elapse before the pressure of fluid in piston chamber 24 will be reduced sufficiently to permit the pressure of fluid in valve chamber 28, which acts on the opposite sideof the piston 26, to shift said piston to its outermost position.

If the change in signal indication is acknowledged by the engineer before the eX- piration of the predetermined time limit, the apparatus will operate, as hereinbefore described, to prevent a brake application, so that the trainmay proceed into the occupied block. V r

If the change in the signal indication is not acknowledged before the expiration of'the time limit, the piston 26 will be shifted to its outermost position, with a consequent movement of slide valve 27 to a position so as to connect the stop reservoir 7 to piston chamber 55 of the brake application valve device, through pipe and passage 76, cavity 77, passage and pipe 78, valve chamber 49, passage 80, past unseated valve 44, and through passage and pipe 84. Fluid from the piston chamber 55 will then be vented to the reset voir 7 and a brake application eii'ected as hereinbefore described.

The apparatus as so far described requires acknowledgement in order to prevent a brake application upon entering an occupied block. but if the train proceeds from one occupied block to a succeeding occupied block, since the signal indication does not change, there will be no action of the apparatus and consequently the engineer will not be required to acknowledge successive occupied blocks. In order to require acknowledgement of successive occupied blocks, a special circuit should be provided which extends a predetermined distance in advance of the beginning of each block, and which operates in conjunction with the usual track circuits, to give a caution indication, while the train is passing over said loop, but only when the next succeeding block is occupied.

A loop circuit of the above character is shown in Patent No. 1,492,719 of R. A. Mc- Cann, dated May 6, 1924, and the desired functioning will be obtained by substituting the magnet 37 of the present construction for the magnet M of the patent.

The caution indication acts to energize the magnet 37 and cause the selector valve device C to be shifted to the position shown in Fig. 2 of the drawings in which the stop reservoir 7 is connected to atmosphere by 'way of pipe and passage 76, cavity 94 in slide valve 27 and atmospheric exhaust port When the train new enters the occupied block, the magnet 37 will be deenergized, which acts to connect the piston chamber 24 of the selector valve device C to atmosphere and thereby permit the pressure of fluid in valve chamber 28 to shift the piston 26 and consequently slide valve 27 to the position shown in Fig. 1 of the drawings. In this position of slide valve 27 the stop reservoir 7 is connected to piston chamber 55 of the brake application valve device, and if the signal indication has not been acknowledged, fluid therefrom w ll be vented to the reservoir 7 and a brake application.

effected. It will be evident that if the indication is acknowledged within the predetermined time interval that a brake application will be prevented, as hereinbefore described.

With the brake valve device 1 in running position when a brake application is effected by movement of the brake application valve device to application position, a connection from piston chamber 55 to atmosphere is made through passage 84, cavity 97 in slide valve 58, passage and pipe 98, past unseated valve 14 and through atmospheric exhaust port 99. r

In order to release the brakes, the handle 13 of the brake valve device is moved to lap position, in which the cam 16 moves away from the stem of valve 14, permitting the spring 15 to seat said valve. 'The seating of valve 14 cuts ofl the connection from piston chamber 55 of the brake application valve device to atmosphere, which connection was effected, through passage 84, cavity 97 in slide valve 58, passage and pipe 98, past unseated valve 14 and atmospheric exhaust port 99, by movement of the brake application valve device to application position.

The atmospheric connection just described being cut off by movementof the brake valve handle to lap position, fluid from valve chamber 57 of the brake application valve device, equalizes through restricted port 64 in piston 56 so that spring 59 will shift said piston and slide valve 58 to release position. After suflicient time has elapsed to permit the brake application valve device to be shifted to release position, the handle'13 of the brake valve device is moved to release position, in which the brake pipe pressure is built up in the usual way, so as to effect the release of the brakes throughout the train.

The valve device D is provided in order to make it unnecessary for the engineman to acknowledge the signal indication, when the train is passing from an occupied block to a caution block. The diaphragm chamber 32 of said valve device will be at atmospheric pressure, while operating in an occupied block, due to the connection through pipe and passage 69, passage 67, pastunseated valve 53 and through atmospheric exhaust port 82.-

The diaphragm chamber 32 being at atmospheric pressure will permit the spring 33 to move the diaphragm 31 so to seat valve 35 and unseat valve 34. Since the magnet 37 is deenergized in an occupied block, the selector valve device will be in the position shown in Fig. 1 of the drawings, and consequently the stop reservoir 8 is charged from the valve chamber 28 of the selector valve device C, through passage 100, past unseated valve 34, passage 74, cavity 73 in slide valve27 and pipe and passage 72.

If the train proceeds from an occupied block to a caution block, the magnet 37 is energized ihereby and acts to shift the selector valve device C to the position shown in Fig. 2 of the drawings, so as to connect the stop reservoir 8 to piston chamber 55 of the brake application valve device, but said reservoir being already charged with fluid under pressure, fluid will not be vented from the application valve device and consequently it will not be necessary for the engineer to acknowledge under the above condition.

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is

1. In a train control apparatus, the combination with a fluid pressure controlled brake application means operated upon a reduction in fluid pressure for effecting an application of the brakes, oftwo reservoirs, valve means having one position in which one reservoir is connected to a passage through which fluid is vented from said brake application means to said reservoir and another position in which said reservoir is connected to the atmosphere and the other reservoir is connected to said passage so that fluid is vented from said application means to the last mentioned reservo and means controlled according to the si idication for controlling the operation oi. said valve means.

2. in a train control apparatus, the combination with a fluid pressure controlled brake application means, of two reservoirs, valve means having two positions, in each of which I one of said reservoirs is connected to a passage through which said brake application means is controlled, and signal indication controlled means for controlling the supply and exhaust of fluid under pressure to and from one reservoir in one position of said valve means in which communication from said reservoir through said passage to said brake application means is cut off.

3. In a train control apparatus, the combination with two reservoirs, of a fluid pressure brake application means operated upon the venting of fluid from said means to either reservoir for effecting an application of the brakes, means controlled by a change in the signal indication for connecting one or the other of said reservoirs to said brake application means, and means operable by the engineer for controlling communication through which said reservoirs are connected to said brake applications means.

4. In a train control apparatus, the combination with two reservoirs, of a fluid pressure controlled brake application means, valve means operated upon the venting of fluid from said means to either reservoir for effecting an application ofthebrakes and controlled by a. change in the signal indication for connecting one or the other of said reservoirs to said brake application means, means controlled according to the signal indication for supplying and releasing fluid to and from one reservoir in one position of said valve means, and means operable by the engineer for controlling the supply of fluid t0 the other reservoir.

5. In a train control apparatus, the combi nation with a fluid pressure controlled brake application means, of two reservoirs, fluid pressure operated valve means having positions for connecting one or the other of said reservoirs to said brake application means, and means controlled according to the signal indication for varying the fluid pressure on said valve means to operate said valve means.

6. In a train control apparatus, the combination with a reservoir, of a fluid pressure controlled brake application means, and means operating under a danger signal indication for establishing a communication through which fluid under pressure is supplied to said reservoir and under a caution signal indication for venting fluid under pressure from said brake application means to said reservoir.

7. In a train control apparatus, the commy hand.

THOMAS H. THOMAS.

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