US1523462A

US1523462A - A corpora

Info

Publication number: US1523462A
Authority: US
Publication date: 1925-01-20
Anticipated expiration: 1942-01-20

Description

T. H. THOMAS AUTOMATIC SPEED CONTROL EQUIPMENT Filed Jan. 25, 1922- 4"S heets-Sheet 1 SPEED MAGNET:

HliH To run I34- Law BLOW DOWN SCLEcren nun:

EED ALVE .v v pcwc:

STOP

m9. 5mm:

enr vALvz nine:

I INVENTOR THOMAS H.THOMAS BY%W ATTORNEY AUTO BRAKL VALVE I T. H. THOMAS AUTOMAT IC SPEED CONTROL EQUIPMENT Filed Jan. 25, 1922 4 'SheetsSheet 2 Ti .2. rise VALVE 24- CHARGING TH: sfsTEM.

DEVICL. MAIN AU'II BRAKE VALVE sure-ran VALVE vALv:

SPEED VALVE DEVICE MEDJ'O LOW BLOW ACK- VALVE DEVICE MED. FEED VALVE ocvlcl: I

AC RES- '00 VALVE: DEVICE 7 H G H O MED. SPEED RES. 33

MED. LOW spszo Rm 34 IN CLEAR mocrgzxczznma HIGH s erm Lnarr O REDUCTION RES.

' BRAKE PIPE 1 /5' Fig.6. 4

III

INVENT O R THOMAS HTI'HOMAS ATTORNEY T. H. THOMAS AUTOMATIC SPEED CONTROL EQUIPMENT Filed Jan. 1922 4 Sheets-Sheet :5

MAIN R: TRAINAT HIGH SPEED RECEIVES A MEDIUM SPEED INDICATION v QNDICATIOH Acm owmosm) Fig.4. \3

SELECTOR VALVE 4 l5 CHANG! SPEED VALVE 20 HIGH 'ro mo.

mzwcma RES.

I25 APP. VALVE R55. 82 DEVICE 7 a mznspzzm S VALVE ocvlcsle' RES. 44 68 TRAIN AT HIGH SPEED nrbmvzs A MEDIUM SPEED INDICATION INDICATION NOT ACKNOWLEDGED) MAIN SELECTOR DEVICE 16- Z CHANGE SPEED VALVE DEVICE 8 4/ 68 Y 91 4e AP P. VALVE osvrc: 7 MED.spEED\\ mv: unvlcz l6 THOMAS H.THOMAS i ATTORNE'Y:

BY w 41 Jan. 20. 1925. 1,523,462

T. H. TH QMAS AUTOMATiC SPEED CONTROL EQUIPMENT Filed Jan. 25, 1922 4 -She t 4 4-TRAIN RUNNPNG AT MEDIUM SPEED nzoswma Amw spzso INDICATION firemen-mu AoKuowLEosa-n) MAIN Res. 25

I VALVE 4 ozvlcn 1E Mlq BLOW DOWN CHANGE; sm: ED VALVE urn/m: 8.

APP. DEVICE T g TRAIN RUNNINGAITMEDIUM spam RECEIVES ALOW SPLE D INDMATION N NOT ACKNOWLEDGED) MAIN RES- SELECTOR VALVE DEVICE CHANGE INVENTOR E5. a F? THOMAS H.THOMAS ATTORNEY Application filed January 25,

To all whom it may concern.

Be it known that l, Tin as H. THOMAS7 a citizen or. the United titres, residing at Edgewoodi in the county of Allegheny and State of Pennsylvania, have invented new and useful ln'iproven'lents in Automatic Speed-Control Equipments, of which the Following is a specification.

This invention relates to automatic train speed control. equipments, and more particularly to an equipment; of the character disclosed in the prior Patent No. 1,316,205 of ll altr V. Turner, dated September 16 1919, and my pendinp; application, Flerial No. 992.209, filed April 1919.

l Vith train control equipments of the above character, three permissible train speed. limits are provided; a high speed limit which is permitted in a clear block, a medium speed limit. which is permissible in a caution block, and a low speed limit in a danger block Under certain. conditions, such as at some crossovers. it may be considered desirable and safe to permit the train to proceed at the medium speed limit in order to prevent loss oil time as much as possible although the indication received from the rail may be or low speed.

tlne object of my invention is to provide means by which a speed controlled train k pass a dar fer indication, under certain (onditions. at the medium speed limit.

lt has heretofore been proposed to provide a train speed control equipment in which the engineer must acknowledge a caution indication or he will be penalized by the apparatus operating to reduce the speed of? the train to the low speed limit and a 'lurther objectof my invention is to provide means tor compelling the engineer to acl'cnowlodgre a low speed indication under penalty of having the train broughtto a stop.

in some cases, locomotives equipped with speed control apparatus are employed both for passenger and for freight service and mother object of my invention is to provide means for setting; the apparatus to operate at the high passenger range of speed limits when operating as passenger locomotive and at the lower freight range of speed limits when the locomotive is employed in freight service.

l titl ttill st ll-NOR TO THE WESTING- 'izi'lr. 115V ANIA, .l-l. CORPORA- IlFll-IIEJETT.

paratus out o! action in case of an emer- QQllCY but which is adapted to prevent the apparatus from being cut in again except by an authorized person.

Another object of my invention is to provide means by which the speed control apparatus may be cut in or out of action in normal service but only as determined by an authorized person.

Another object of my invention is to provide means by which only an. authorized person may set the apparatus for freight or passenger. service under certain conditions and restrictions.

lt is considered desirable to provide a train speed control equipment which compels the engineer to operate the train in arcordance with. the signal indications independently of the automatic control by the train speed control apparatus, so that in case ol. possible failure of either the engineer or the train control apparatus, the other control agency will be effective to control the train.

in this connection, another object of my in vcntion is to provide improved means for compelling: the engineer to perform his duties.

itnother object oi my invention is to provide a train speed control. equipment in. which the release of the brakes is controlled by mai'iipulathm ot the engineers brake valve device instead of a separate manually operated release valve so that the engineer has only to operate the brake valve in the manner that he should under the particular circumstances in order to properly control the train.

Other objects and advantages will appear in the following more detailed description of the invention. 7

lo the accompanying drawings; Fig. 1 is a diagrammatic sectional View of an automatic t "ain speed control equipment embodying: my improvements, showing the relative pi :itions of the various parts when the indication from the track is for clear or high speed and the trainat a stand still, with the speed governor stationary, the apparatus beino; set tor passenger service; Fig, 2 a diagranr, illustrating the operation of charging the train control apparatus; Fig. 3 a diagram, showing the operation when a train in a clear block exceeds the high speed limit; Fig. 4 a diagram showing the operation when a train at high speed receives a caution or medium speed indication and the indication is acknowledged; Fig. 5 a diagram showing the operation when a train at high speed receives a caution indication and the indication is not acknowledged; F ig.- 6 a diagram showing the operation when. a train running at medium speed receives a low speed indication and the indication is acknowledged; Fig. 7 a diagram showing the operation when a train at medium speed receives a low speed indication and the indication is not acknowledged; Fig. 8 a partly sectioned detail view of the freight and passenger service setting means; Fig. 9 a face view thereof; and Fig. 10 a sectional view of the emergency cut out locking'means.

As shown in the drawings, with particular reference to Fig. 1. the train speed control equipment may comprise an automatic brake valve device 1, an independent brake valve device 2, a main reservoir 3, an acknowledging valve device 4, and a train speed control valve mechanism.

The train speed control valve mechanism may comprise a pipe bracket 5, to which is attached a speed controlled governor valve mechanism 6; a section including a brake application valve device 7, a change speed valve device 8, an equalizing discharge valve device including a piston 9 and valve 10, a stop reservoir piston 11 and valve 12. and a stop piston 13 and valve 14; a section including a selector valve device 15, a medium speed valve device 16, an acknowledging piston 17 and

valves

18 and 19, a high to medium speed blow down valve piston 20 and valve 21, and a medium to low speed blow down valve piston 22 and valve 23.

Associated with thepipe bracket 5 is a high speed magnet 24 and double beat valve 2-5, a medium speed magnet 26 and double beat valve 27, a feed valve device 28', a feed valve reservoir 29, a reduction reservoir 30, an equalizing reservoir 31, a a stop reservoir 32, a high to medium blow down reservoir 33, and a medium to low blow down reservoir 34:.

The change speed valve device 8 may comprise a differential piston having differential piston heads 35 and 36, acted upon in opposite directions by springs 37 and 38 tending to maintain the pistons in the intermediate h'Ut-I'al position, and operating a slide valve 39. The application valve device 7 comprises a piston 40 and slide valve 41, the selector valve device 15, a piston 42 and slide valve 43. and the medium speed valve device, a' piston 44 and slide valve 45.

The speed governor portion may i nprise governor balls 46, operatively connected to a governor shaft 47 which is rotated according to the speed of the train by means of bevel gears 48 which are operatively connected to a driving axle of the locomotive. As the governor balls 'to fly out according to the speed of the train, a sliding spindle 49 is shifted and thercbv a crosshead 50 which is secured to the spin dle. The crosshead 50 is adapted to operate a series of valves having valve stems of varying lengths as tollows: Passenger high to medium s eed blow down timing valve 51., "freight high to medium speed blow down timing valve 52. passenger high speed application valve 53, freight high speed application valve 54, passenger low speed application valve freight low speed application valve 56. freight medium speed application valve 57, passenger medium speed application valve 58,, freight medium to low speed blow down timing valve 59, and passenger medium to low speed blow down timing valve 60.

In connection with the train speed control apparatus above enumerated. means are provided by which a. clear or high speed rail indication causes the high speed magnet 24 to be energized and the medium speed magnet 26 to be deenergized, a caution or medium speed indication causes the medium speed magnet 26 to be energized and the high speedmagnet 24 to be deencrgizcd. and a danger or low speed indication causes both

magnets

24 and 26 to be deenergized.

Charging the system.

Assuming that the rail indication is tor high speed, the high speed magnet 24 will be energized and the medium speed magnet 26 deenergized. Fluid under pressure from the main reservoir 3 will flow through pipe 61, passage 62. and passage (33 to valve chamber (it of the selector valve device 15 and thence through the feed groove around piston to piston chamber (35, thus permitting the spring to move piston 42 to its inner position. Fluid also flows from passage 62 through passage 66 to valve chamber 7 of the medium speed valve device 16. and the piston it will be shifted to its outer position, since piston chamber (38 is connected to the atmosphere through passage 69 and exhaust port 70 controlled by the double beat magnet valve 27 of magnet 26. Fluid flows to piston chamber 71 oi the change speed valve device 8 from passage 62, through passage 72, past the double beat valve 25, passage 73, passage 74;. past open, valve 18 to passage 128, cavity 75 in selector slide valve 43, and passage 76. and fluid is supplied to piston chan'iber 77 of piston 36 from valve chamber 64 of the selector valve device 15. through passage 78. The valve chamber 79 of the change speed valve device 8 is charged through passage 62. and passage til). the passage also supplying fluid to the valve chainher 81 ot the application valve device "i'. Tron! alve chamber 8, 'tluid equalizes through a restricted port .in the piston 4-0 to piston chamber 81 permitting spring 83 to shift piston 40 to its inner release position. Fluid from the main reservoir 3 is also supplied to the rotary valve chamber 84L ot the automatic brake valve 1 tron'i valve chamber 531 of the a plication valve device '7 when the slide valve 4-1 is in release position, through passage 85 and pipe 86.

Fluid is supplied from the main reservoir Zl through passage 8." to the teed. valve device 28 and thence, at the pressure as reduced by the teed valve device, to the feed valve reservoir 29. The high to n'iedium speed reservoir 33 is charged with fluid atv teed valve pressure when the parts are in the high speed p sition, through passage 88, passage 89, cavity in selector slide valve ell-3 and passage 91. the passage 91 also leadinp; to the upper face of the high to medium speed blow down valve piston 20" The opposite side oi? the piston 20 is supplied. with 'tluid at teed valve pressure from passage 85), through passage 92.

in the position Oiii the medium speed valve device 16, as shown in Fig. l the medium to low speed blow down reservoir 84 is not charged, but when said valve device is shifted to the inner medium speed position the reservoir 34: is charged ilroin pas age 89. through passage 93, cavity 94 in medium speed slide valve 4-5, passage 95, and past the medium to low speed valve piston to passage 96. In the nine or medium speed position oi slide valve 45. the stop reservoir 32 is also charged vvith tluid at main reservoir jfiressure from the medium speed valve chamber 67, through cavity 97 in slide valve and passage 98.

ll ith the rotary valve 99 of the acknowledging valve device t in normal position, as shown in llip 1, the acluiowledginp reservoir 'lOO is charged with tluid at niain reservoir pressure from pipe 86, through cavity 101 and pipe 102.

lhe brake pipe 103 is charged From the brake valve device 1, as usual With the standard locoi'notive h'alte equipment and the brake pipe is connected by a passage 1041- With the chamber at the under side oi: the equalizing piston 9 and the equalizing reservoir, which is connected to tl opposite side of the equalizing piston 9, is charged from the brake pipe 103 throusrh passage i041 past check valve 105, pass ;(5 106 cavity 10"? in dppllCH'tlOll slide valve 411i. and passage 108.

The principal chargingteatures hereinheiore described are shown somewhat more clearly in the diagram, Fig. 2, wherein only the ports and passage." actually involved in the charging operation are shown.

iii oi? the ap ilicatioi valve device 7 through pass e The application piston 40 and slide valve ell then move out to application position, in which the equalizing reseiwoir 3i and hence the upper face of the equalizing piston 9 are connected to the reduction reservoir 30 by Way of passage 110, cavity 1 F1 slide valve 451, and passage 11%. The reduction reservoir is then at atmospheric pressure, since in the release position oi? the slid lve -.l-l. the reduction reservoir passage 119, was connected by cavity 111 to eruraust port 113, and consequently the venting; of tluid under pressure from the upper taco oil. the equalizing" piston Si and from. the equalizing reservoir causes movement ot the piston to unseat the cqualizinei dischai valve 10 and thereby vei livid on-i the tiral'e pipe 103 to the atmosphere tl'irougj h passage li t cavity 115 in slide valve ll. and exhaust port 113. The reduction in brake pipe pressure thus produced then causes an application of? the b aims in the usual manner to thereby etlect a reduction in the speed of the train.

By venting the equalizing reservoir into the reduction reservoir 30. the reduction in hralce pipe pressure as ettected by the operation of the speed control apparatus 's limit-- ed to a predetermined degree. lhc operation ahove dcsrrilied is shown more clearly in the diagrraun l ip oi the drawings-i. The movement of the application slide *alve ll. to application position also cuts ott conununication to passage and pipe 8th iilllfillfll, which :tluid is sng'iplied from the main reservoir to the auton'iatic hralte valve 1. This prevents the supply ot fluid to the brake pipe through the brake valve device While the slide alve all is in ap ilication position.

in the application position of slide valve ll, the passage i09 leading to the piston chzunher ot the application valve device f. is connected by cavity 116 with a pipe 'll'l'. leadino: to the seat "t the rotary valve 118 ot the bralre valve device and in rv u release and holdngr a ,1 ions oi the valve. said pipe is connected by a. eavit lift with an exhaust port 120. it will thus he seen that atter the brakes have been applied. the a= 'il'ication piston t'll i 1 remain in application position, due to the n 'ili brake valve handle 121 to lao )osition or to a brake application position in which the pipe 117 is cut off from the exhaust. IVhen the engineer moves the brake valve handle to lap position, the pipe 117 is lapped and thus permitting the equalization of tlnid pressure through the restricted port in piston on opposite sides of said piston, the spring 83 will return the piston 40 and slide valve 41 to release piston, so that the brake pipe 103 may then be recharged and the brakes released by the subsequent movement ot the brake alve handle to release position. It will be understood that the brakes cannot be released by operation of the brake valve as above described until the speed of the train has been reduced below the high speed limit, so as to permit the high speed application valve 53 to close.

Train running at high speed receives acantion or medium speed indzeate'on from the track. ([ndwatzon acknowledged.)

, before the speed control mechanism functions and'the present apparatus is so constructed that if the caution indication is not acknowledged, the speed control mechanism will be immediately set for 10W speed, but if the indication is acknowledged, it will be set for the medium. speed limit in a predetermined time, dependent upon the speed of the train.

. In this case, to acknowledge the medium speed indication, the engineer should operate the handle 175 of the acknowledging valve device 4 to shift the valve 99 to the ac knowledging position, in which fluid under pressure is supplied from the acknowledging reservoir 100 to the acknowledging piston 17 by way of a port through the valve 99, passage 122, pipe 123, passage 124, cavity 125 in the application slide valve 41, and passage 126. The piston 17 is then shifted, causing the piston valve 18 to close com-- munication from passage 74 to passage 128, leading to the piston chamber 71 of the change speed valve device 8 and opening the valve 19, so that the piston chamber of the selector valve device 15 is connected to the atmosphere through passage 127, past the valve 19 and past the valve 18 to passage '74, and. thence through passage 7 3 to the exhaustport 1290f the high speed magnet 24, the magnet 24 being deenergized and the medium speed magnet 26 energized upon receiving a medium speed indication. The piston 42 then shifts the slide valve 43 to its outer position in Which the spring side of the high to medium speed blow down valve piston 20 is vented to the atmosphere through passage 91, cavity 90 in selector slide valve passage 130, cavity 131 in rotary valve 132. passage 133 and past the gov ernor blow down timing *alve 51. The spring side of the valve piston 20 is also connected to the high to medium speed rescrvoir 33 which is now charged with fluid under pressure as previously described. hen the pressure in the reservoir 33 and on the spring side of the valve piston 20 has been reduced to a predetermined degree. dependent upon the size of the exhaust opening created by the timing valve 51, which in turn depends upon the speed of the train, the valve piston 20 will. be shifted outwardly by the feed valve pressure acting under its seat, so as to open the valve 21 and thereby vent fluid from piston chamber 77 of change speed valve device 8, through passage 78, past the valve 21 to exhaust port 134. The change speed valve device 8 is then moved to its right hand or medium speed position, due to its differential piston construction.

In the medium speed. position of the val vedcvice 8, the piston chamber 82 of the application valve device is connected to the governor passenger medium speed application valve 58, through passage 109. passage 135, cavity 136 in slide valve 39. and passage 137 and if the speed of the train exceeds the medium or caution speed limit, the valve 58 will be opened and fluid will be vented from piston chamber 82 of the application valve device 7, so that said valve device will be operated to efi ect an application of the brakes in the manner hereinbefore described. After the speed has been reduced to the medium speed limit, the brakes may be released by manipulation of the brake valve device as hereinbelore described.

It may be noted here that when the solector piston 42 has been shifted to its outer position, a cavity 141 in selector slide valve 43- connects passage 127 directly with passage 128, leading to the high speed double beat valve 25, so that the piston chamber ()5 will be maintained at atmospheric pressure and the selector valve device 15 will be held in its outer position, so long as the high speed magnet 24 remains deenergized.

When a caution indication is received. the medium speed magnet 26 is energized and fluid from the main reservoir will be supplied to the piston chamber 68 ot the medium speed valve device 16 by way of passage 72, past the double beat magnet valve 27, and through passage 69. The piston 44 will then shift the slide valve 45 to its inner position, in which the stop reservoir 32 is charged with fluid under pressure from the. main reservoir through passage 62, cavity 97 in slide valve 45, and passage 98.

In this position of the slide valve 45, the

medium to low speed reservoir 3a is also charged with fluid at teed valve pressure through passage 93, cavity 9 1 in slide valve 15, passage 95, through the spring chamber of the blow down valve piston 22 and passage 96. The charging oi the stop reservoir 32 and the medium to low speed reservoir 841 in the medium speed position of the slide valve 415 is for use when the train enters a low speed block as will be hereinafter described.

lhe diagram oi Fig. 1 illustrates somewhat more clearly than Fig. 1, the operation when the train enters a medium speed block and the indication is acknowledged.

Train running at big/i speed reactor/a a caution or medium speed incite-cation from the imciu. (intimation not KMZMIOAUtGdf/MZ.)

in this case, since the acknowledging piston 17 is not operated, the valve 19 will not be opened, and consequently, the deenergization of the magnet 24: upon receiving a caution indication will be effective to vent fluid from the piston chamber 71 of the change speed valve device 5%, instead of from the piston chamber 5 ot the selector valve device 15 by way of passage 76, cavity 75 in se lector slide valve ti-l, passage 128, past the open piston valve 18 and through passages 741 and 73 to exhaust port 129. Since the piston chamber 71 is vented to the atmospherc, the change speed valve device will be shiited to the left hand or low speed position, due to its dillerential construction.

in this position of the change speed valve device 8, the piston chamber 82 of the appli cation valve device 7 is connected to the passenger low speed application valve through passage 135, cavity 136 in slide valve 1:19. passage 138, cavity 13-39 in rotary valve 132, and passage 1 10. If the speed of the train exceeds the low speed limit, the valve will he opened by the operation of the governor balls 416 and fluid will be vented from the piston chamber 82 of the application valve device '7, so that the application valve device will be shifted to application position to effect an application of the brakes, as hereinbe'liore described. It will thus be seen that it the engineer does not acknowledge the caution indication, the speed of the train will. be reduced to the low speed limit, as a. penalty t'or failure to acknowledge. The above operation is shown diagrammatically in Fig. 5 01'' the drawings.

1 'wr in Mimi/lug at medium speed enters o low speed or (Zditf/? block. (indication ac lmmvleclgcd.)

In this case. the low speed indication causes both magnets 24 and to become deenergized. Assuming that the previous caution indication has been duly acknowledged, the selector piston 41-2 will be in its outer position and will remain there, since the high speed magnet 24: remains deenergized. The medium speed valve device 16 will be shifted to its outer position, since the deenergization 01? the medium speed magnet 26 causes the venting of fluid from the piston chamber 68, as hereinbeiore described.

It the acknowledging valve device 4C is operated by the engineer upon receiving a danger indication, while the acknowledg ing piston 17 will be actuated as herein before described, no further functioning will occur, since the selector piston 12 is already in its outer position, but when fluid is supplied to the piston 17, it is also admitted through passage 142 to the taco ot stop reservoir piston 11, so that the valve 12 is operated to vent fluid ironed-he stop reservoir 32, the change speed valve device 8 still being in the medium speed position, through passage 98, cavity 97 in medium speed slide valve 45, passage 143, cavity 14% in selector slide valve 13, passage 1 15, cavity 14-6 in change speed slide valve 39 the change speed valve device being still in the medium speed position, passage 1417, and past the open valve 12 to exhaust port 1 18. The venting of fluid from the stop reservoir prevents the operation ol" the stop mechanism. and the delayed application is etiective by reason of the fact that the shitting oi the medium speed slide valve 45 to its outer position connects the spring side of the medium to low blow down valve piston 22 to the passenger medium to low speed blow down valve through passage 95, cavity 9 1 in slide valve 415, passage 1419, cavity 150 in rotary valve 132, and passage 151. The medium to low speed reservoir 34; being connected to the spring side of the valve piston 22 through passage 96, the fluid pressure in said reservoir and .in the spring chamber of the valve piston 22 is then vented at the blow down valve 60 at a rate corresponding With the speed oi? the train, and when the pressure on the spring side of the valve piston 22 has been reduced to a predetermined degree, the valve piston will. be operated by feed valve pressure acting below the valve to open the valve 23 and vent fluid from the piston chamber .71 of the change speed valve device 8, through passage 76, cavity 7 5 in selector slide valve 13, passage 152, cavity 153 in medium speed slide valve 45, passage 1541, and past the open valve. 23, through passage 155 containing check valve. 156, and thence through passage 78, past the open valve 21 to exhaust port 13 1. Both of the

piston chambers

71 and 77 being new at atntiospherio pressure, the change speed valve device 8 will be shifted to the left hand or lOW speed position in which the piston chamber 82 of the application valve device 7 is. connected to the passenger low speed application valve 55 through passage 135, cavity 136 in slide 'v'a'lve39, passage 138, cavity 139 in rotary edgin valve 99, then the above described venting offiuid stored in the stop reservoir 32 will not occur and consequently when the change speed valve'device shifts to the low speed position, fluid from the stop res- 'ervoir 82 will'be supplied to the piston 13 of the stop valve device through passage '98, cavity 97 in medium speed slide valve 45, passage 14$,cav1ty 14 1 in selector slide valve 413, passage 14:5, cavity 146 in change speed slide valve 39, and passage 15? The piston 13 is then operated to open the valve 14 and ventfluid directly from the application piston chamber 82, through passage 158 to the atmosphere. The brakes will then be applied by operation of the application valve device 7 and the train will be brought to a complete" stop, as a penalty for failure of the engineerto acknowledge the danger indication see Fig. 7

At crossovers, there may be a section of track which is not equipped for signal indicati'on, and not being energized by the signal circuits, the result is that both of the'magnets of the train control apparatus on the locomotive will then be in the deenergized state and the apparatus is of course operated as though a danger indication had been received.

It may be desired toproceed oversuch a crossover at medium speed in order to avoid unnecessary delay, and accordingly I have provided means whereby under the above conditions the train may proceed past the crossover atmedium speed.

Forthis purpose, a short section of track in advance of or immediately preceding the crossover is energized so as to give a clear or high speed indication to the train and assuming that the train is already proceeding at or below the medium speed limit, with the train control apparatus set for the medium speed, then when the train enters the clear seotiom the train control apparatus 7 on the locomotive will be set for highspeedi The reason for doing this is so that the high to medium speed reservoir 33 may be recharged with fluid under pressure in the manner hereinbeiliore described in connection Vwith charging the system in a high speed ll' hile passing over the above mentioned clear or high speed section of track, the

engineer operates the acknowledging device l, so that fluid under pressure is supplied from the acknowledging reservoir 100 through passage 126 to piston 17. Said piston is then shifted. so that piston valve 18 cuts oil communication from passage T l: to passage 128 and at the same time the valve 19 is opened by the movement of piston 1?, so that piston chamber 53 of the selector valve device 15 is connected to the double beat valve 25 or high speed magnet Ql. through passage 12? past the open valve 19 to passage 1. and thence through passage 73 to the double beat valve 2:).

ll hen the train passes ifrom the clear section to the decncrgized crossoveu the high speed magnet 2-1 will 'be decncrgiztal. the i'nedimn speed magnet 26 remaining in its previous state oi deencrgization, as will be evident.

The deenergization oi mao'nct 2-1 operates to shift the double beat valve 25 so that coup inunication between passages 72 and m it) IS closed and connnunication opened from passage 73 to exhaust port 12$ Fluid under pressure will therefore be vented from piston chamber (i5 ol the selector valve device 15 through passage 1:2 7 past open valve 19 to passage 73 and (.L haust port 129.

The piston -12 is then shifted to its outer position, in which piston chamber ll 01? the change speed valve device is connected to the valve 23 oil the medium to low blow down th ough passage in. cavity 753 in slide valve 13 of the selector valve device 15. pas

sage cavity 153 in slide valve -15. and passage 1541-. It will therefore be cvldent that under the above conditions. liuid will not be vented from piston clian'iber Tl, so as to permit the shifting oi? the change speed valve device 8 to low speed position until the valve 523 is opened.

At the same time, piston chamber 7'? ol the change speed valve device 8 is connected to valve of the high to medium blow down through passage 78, so that fluid will be vented from piston chamber TT dependent upon the opcnins of valve 21.

ln the outer postion of slide valve ll; oi the selector valve device 151 the s ring side oi? the valve piston 20 oi the high to medium blow down and the charge at high to medium reservoir 33 are connected to the medium speed blow down timing valve .11 through passage 91, cavity 90 in slide valve 13 passage 130, cavity 131 in rotary valve 132. and passage 1533. l' hen the pressure in the reservoir 2-123 and on the spring side oi the valve piston Qt) has been reduced to a predetermined degree, dependent upon the size 01. the exl aust opening crcal'ed at the timing valve 51, which in turn depends ltlll Ill) ill)

i see lee upon the speed of the train, the valve piston 20 will be shilted, so as to open valve 2!. and thereby vent fluid from the piston chamber T? of the change speed valve device 8 to exhaust port 13%. lit the t ain were still on the crossover, the valve device 8 would then be shifted to its right hand or medium speed position in which the connections are made for limiting the speed oi the train to the medium speed limit, as hereinbe forc described, but the time period rcipiired to blow down the reservoir I-t-l i s such that the train will have passed over the crossover before the valve 21 is opened.

During the period that the above oper ation is taking place, fluid is also being vented from the spring side of the medium to low blow down valve piston and the reservoir 84;, through passage 95, cavity 9a; in slide valve to, passage 149, cavity 150 in rotary valve 132, passage 151, and the medium to low speed blow down timing valve 60. litter the pressure on the springside of the valve piston 22 has been reduced to a predetermined degree by venting at the valve 60, said valve p ton will be operated to open the valve It will now he noted that although the opening o't valve will connect passage llih which. is at this time open to the low speed piston chai'i'iher T1 oi the change speed valve device 8, to vent passage 155, fluid cannot be vented from said piston chamber until the valve 21 opens, since passage 155 is connected to pas ease 78 leading to the valve 21.

The blow down timing valves 51. and are adapted to vary the exhaust opening through which fluid is vented from the blow down

valve pistons

20 and 22 as the speed of the train varies, so that the higher the speed, the larger the exhaust opening created and since the medium to low timing valve 60 operates at a lower speed than the high to medium timing valve 51 a larger exhaust opening: is created at the valve 60 than at the valve 51 for a given train speed.

lit will thereiore be evident that were it not for the tact that the exhaust from the valve 2; is controlled by the opening of valve 21, the earlier opening of valve 23, due to the more rapid venting of fluid from the spring side oi? valve piston 22 would operate to vent fluid from the low pressure piston chamber oi the change speed valve device, l s ore the valve piston 20 is operated to open valve 23.

lily connecting the exhaust trom valve 23 to valve 21., the opening; of valve 23 remains ineffective until the valve 21 opens.

The result of the above tunctioningj is that at crossovers and the like, the preceding sliort clear section oil track sets the apparatus to hi pth speed position and then when the train passes from the clear section to the deenergiaed crossover, the time period provided by the operation of the valve piston 20 and valve 21 before the change speed valve device 8 can be operated to either its medium or its low speed position is su'tlicient to permit the train to pass over the crossover without having to reduce its speed. The train having; pEtSSttl over the crossover, the medium speed indication being received, the train can then proceed at the mediun'i speed limit.

ln some cases it may he desired to operate a hicoinotive in both freight and passenger service, and with the automatic train control. api iaratus installed, it then nec essary to provide means whereby the speed control apparatus will control the train at one range oi train speed limits when the locomotive operating in freight service and at a h' ier range oi? speed limits, when the locomotive is being en'iplo'yed in passenp'er service. For this purpose, I provide two ot speeijl controlled application valves and two sets ot blow down timing valves, and a manually operated rotaiw' valve h ving one position tor connecting the Pil-TQllfiZQl valves to the speed control appara another position for connecting the freight valves to the speed con trol. apparatus, and a third position, in which both oil? valves are cut out.

lfn Fig. 1 of the drawings, the passenger valves are shown as connected up, the of the valves being oi? such length as to give the desired range ot speed limits for passenger service, and in the freight operating position oi the valve 132, the ii'reight valves are connected up, the stems of these valves being of greater length than the stems oil the corresponding passenger valves, so that the range ol speed limits will be lower to correspond with those described for freight service.

its shown in Figs. 8 and 9 ot the drawings, the valve stem 159 tor operating the rotary valve 132, by which the speed con trol apparatus is set for either passenger or freight service, may be provided with a locking arrainreinent comprising a lock barrel 160, mounted in the casing 16l and having a key hole 162 for receiving a key;

The turning oi? the hes operates a latch member 163., which is adapted to engage slots 16% and 1.65, acctu-ding to the position oi? the operating handle 166 and the stem 159. When, the latch member 163 e115,; Pics in one slot, the member 159 and valve 132 are locked against movement from one operating position and when said member ongages in the other slot, the valve 132 is locked against movement from the other operating; position.

The key may, according to one scheme of control, he in the custody of an authorized person who will employ the key to set the speed control apparatus for passenger or for freight service, or according to another scheme of operation, the engineer may carry the key and thus control the setting of the apparatus. In the latter case, a sealed, soft wire loop 167 may be threaded across the key hole 16:2, so that it is necessary to break the wire in order to insert the key and then the fact that the engineer has readjusted the apparatus will he made known to an inspector who will make a record of the fact, so that if the engineer has made an unwarranted adjustment of the apparatus, it will be made known to the proper authorities.

It may sometimes be necessary, in an emergency, for the engineer to have the power of cutting the speed control apparatus out oi action, and for this purpose, a cut out cock 168 may he provided for controlling communication through which the thiid pressure in piston chamber 82 of the application valve device 7 is vented.

In order to prevent the engineer from cutting the out at will regardless of whether an emergency condition exists, means are provided by which if the engineer once turns the cock 168, the same cannot be turned again with out the sanction of another person. For this purpose two lock plugs 169 and 170 are provided, the lock plug 169 having an operative connection with the cut-out cock 168 and being operable by a key 171 which is carried by the engineer. The other plug 170 is operable only by a key 172 which is in the custody of a designated person. A pin 173, associated with the plug 170 is adapted to interlock with the plug 169 in such manner that when the key 171 is turned by the engineer to operate the cock 168, so as to cut off communication to the application piston chamber 82 and thus prevent the speed control apparatus from working, the key and the cock cannot be again turned so as to open said communication, without first inserting the key 172 in the other plug and turning the plug so as to rotate the pin 1'73 out of the path ofthe plug 169.

, lVith the above arrangement, it will be seen that while the engineer may, in case of an emergency, cut the speed control apparatus out of action, he is unable to again out the apparatus into service. He must then report the fact to a designated authority,

who will have the key 172 in his possession and who can reset the apparatus as required,

speed control apparatus in or the acknowledging reservoir 160 and therefore, with the acl-nmwledging valve in ackmuvledging position, the fluid pressure in the reservoir 100 would quickly leak oil through the restricted port in the piston 17 to the exhaust port open to the opposite side oi? the piston. thus permitting the piston 17 to return to its non-ackuowlcdgiug position.

Having now described my invention, \vhat l claim as new and desire to secure by Lets tors Patent, is 2- 1. In a train speed control apparatus-1, the comb. than with means on the train for ini1. osim a medium speed limit and means for imposing a low speed limit, of means controlled by the medium speed means for suppressing the action of the low speed means.

in a train speed control apparatus, the comhinatimi with n'icans on the train for imposi" g a medium speed limit and means for imposing a low speed limit, or" means for suppressing the action of the low speed mti until the medium speed means acts.

3. ln a train speed control apparatus, the combination with a change speed valve device having a medium speed position and a low speed position, of a valve mechanism for varying the fluid pressure on said valve device to shift same to the medium speed position and a valve mechanism for varying the fluid. pressure on said valve device to shit; same to the low speed position, the iziedium speed valve mechanism controlling communication through which the low speed valve mechanism varies the fluid pressure on said valve device.

t. In a train speed control apparatus, the combination with a change speed valve device having a medium speed position and a lo v speed position, oi a valve mechanism for venting fluid pressure from said valve device, means tor delaying the operation of said valv mechanism, and a second valve mechanism for also venting fluid pressure from said valve device, the communication through whlch the second valve mechanism vents fluid pressure being controlled by the first valve mechanism.

5. In a train speed control apparatus, the combination with mechanism for determining the speed limit of the train, of slow aeting means for effecting the. operation of said mechanism to impose one speed limit on the train, slow acting means for effecting the operation of said mechanism to impose a lower speed limit on the train, and means for suppressing the operation of the second slow acting means until the first slow acting ni'eans operates.

6. In a train speed control apparatus, the combination with a. change speed valve device movable to a low speed position upon a re duction in fluid pressure, of means controlled according to the signal indication for ventloo a predetermined limit,

a sence ing fluid :i'trom said valve device, a slow acting valve mechanism for also venting fluid from said valve device, a selector valve device mo able by a reduction in pressure to a position for connecting said change speed valve device to said slow acting valve mechanism, and valve means under the control oi the engineer and having one position for connecting said change speed valve device to said signal indication controlled means and another position for connecting said selector valve device to said signal indication controlled means.

7. In a train speed control apparatus, the combination with means on the train for imposing a low speed limit upon receiving a low speed indication, of means operative upon a change trom a medium to a high speed indication for delaying the action of the low speed means when a low speed indication is received.

8. In a train speed control apparatus, the combination with means on the train for imposing a low speed limit u on receiving a low speed indication, oi means operative in advance of receiving a low speed indication ior delaying the action oi the low speed means when a low speed indication is received.

9. In a train speed control apparatus, the combination with mechanism on the train capable of imposing a medium speed limit and a low speed limit, of means operative under one condition to cause said mechanism to impose the low speed limit upon receiving a low speed indication and operative under another condition to cause said mechanism to impose a medium speed limit upon receiving a low speed indication.

10. In a train speed control apparatus, the combination with an application valve device for eflecting an application of the brakes and means for operating said valve device when the speed of the train exceeds of a reservoir charged with fluid under pressure, a valve device operated by fluid from the reservoir for also effecting the operation of said application valve device, and means under the control of the engineer for venting fluid from said reservoir.

11. In a train speed control apparatus, the combination with a reservoir adapted to be charged with fluid under pressure, of means operable by fluid from said reservoir for efl'ecting a reduction in the speed of the train, means operated upon a change in the signal indication for connecting said reservoir to said means for eflecting a reduction in the speed of the train, and means operable by the engineer tor venting fluid from said reservoir.

12. In a train speed control apparatus, the combination with a reservoir and means for charging said reservoir with fluid under pressure, of means operated by fluid under pressure for eli'ecting an application of the brakes, means governed by the signal indication for connecting said reservoir to said means for effecting an application of the brakes, and means operable by the engineer for venting fluid from said reservoir.

18. In a train speed control apparatus, the combination with an application valve device for ei'l'ecting an application or the brah s, means for imposing a high, medium, or low speed limit, and means for operating said valve device when the speed of the train exceeds the imposed speed limit, of a. reservoir, means for charging said reservoir with fluid under pressure in the medium speed position of the apparatus, a valve device operated by fluid from the reservoir for also eflecting the operation of said application valve device, and means under the control oi the engineer for venting fluid from said reservoir.

1a. In a train speed control apparatus, the combination with an application valve device operated upon venting fluid under pressure therefrom for eflecting an application or the brakes and means for venting fluid from said valve device when the speed oi? the train exceeds a predetermined limit, of an engineefis brake valve having a position in which said valve device is connected to an exhaust port.

15. In a train speed control apparatus, the combination with an application valve device operated upon venting fluid under pressure therefrom for eflecting an applica tion or the brakes and means for venting fluid ifrom said valve device when the speed of the train exceeds a predetermined limit, of an engineefs brake valve having a position in which said valve device is connected to an exhaust port when the application valve device is in application posltion.

16. In a train speed control apparatus, the combination with an application valve device operated by a variation in fluid pressure for effecting an application of the brakes and means for operating said valve device when the speed of the train exceeds a predetermined limit, of an engineefis brake valve for controlling the movement or said valve device to release position.

ii". In a train speed control apparatus, the combination with an application valve device having a piston operated by a reduction in fluid pressure for eil'ecting an application of the brakes and means for reducing the pressure on said piston when the speed of the train exceeds a predetermined degree, of an engineefs brake valve having a release positi on in which said piston is connected to an exhaust port and a lap position in which communication from said piston to the brake valve is blanked.

18. In a train speed control apparatus,

the combination With a speed governor operated according to the speed of the train, of avalve operative to effect a reduction in the speed of the train and operated by said governor when the train speed exceeds a pre determined limit, a valve operative to elieet a reduction in the speed of the train and operated by said governor when the train speed exceeds a different predetermined limit, and means for cutting one valve out of operation when the other valve is cut in.

19. In a train speed control apparatus, the combination with a speed governor operated according to the speed of the train, of a valve operative to eflect a reductionin the speed of the train and operated by said governor when the train speed exceeds a predetermined limit, a valve operative to effect a reduction in the speed of the train and operated by said governor when the train speed exceeds a different predetermined limit, and manually operable means for connecting either valve into operation.

20. In a train speed control apparatus, the combination With a speedgovernor operated according to the speed. of the train, of two sets of valves, each valve operative to effect a reduction in the speed of the train, one set of valves being operated by the governor throrwh one range of train speed limits and the other set of valves through a different range of train speed limits, and manually operable means for rendering one set of valves effective while the other set remains ineffective.

21. In a train speed control apparatus, the combination With mechanism for imposing one range of train speed limitson the train for one class of service and a different range of train speed'limits for another class of service, of a device for adjusting said mechanism. to operate at either of said ranges of train'speed limits and means for locking said device in either of its adjusting positions.

22. In' a train speed control apparatus, the combination with mechanism for imposing one range of train speed limits on the train for one class of service and a different range of train speed limits for another class of service, of a device for adjusting said mechanism to operate at either of said ranges of train speed limits, means tor locking said device in either of its adjusted positions, and a key for operating said looking means.

In a train speed control apparatus, the combination With mechanism for imposing one range of train speed limits on the train for one class of service and a diiierent range of train speed limits for another class of service, of a device for adjusting said mechanism to operate at either of said ranges of train speed limits, means for locking said device in either of its adjusted positions, a key for operating said locking means, and a tell-tale device for indicating that the key has been used to operate said means.

24. In a train speed control apparatus, the con'ibination with mechanisn'i for imposing one range of train speed limits on the train for one class of service and a diilierent range of train speed limits for another class of service, or a device for adjusting said mechanism to operate at either of said ranges of train speed limits and means for preventing the operation of said device except by an authorized person.

In a train speed control apparatus, the combination with mechanism for impos ing one range of train speed limits on the train for one class of service and a different range of train speed limits for another class oil? service, of a device for adjusting said mechanism to operate at either of said ranges of train speed limits and means operable only by a. specialized element for controlling the operation of said device.

:26. In a train speed control apparatus, the combination with means for cutting said apparatus out of action, of a device for locking said means against operation, a key for operating said device to out said apparatus out of action, and means for preventing movement of the key and said device from the out out position.

27. In atrain speed control apparatus, the combination with means for cutting said apparatus out of action, of a device for locking said means against operation, a key for operating said device to out said apparatus out of action, means for preventing movement of the key and said device from the cut out position, and a key for operating said means to permit movement of said device to its out in position.

28. In a 'train speed control apparatus, the combination with means by which the speed control apparatus may be cut into or out of action, of a specialized element operative only to effect movement of said means to the cut out position and a separate specia ized element operative to permit movement of said means to the cut in position.

29. In a train speed control apparatus, the combination with means by which the speed control apparatus may be cut into or out of action, of mechanism under the control of one person for oii'ecting the operation of said means only to the cut out position and under the control. of another person for efiecting the operation of said means to the cut in position.

30. In a train speed control apjiiaratus, the combination with a change speed valve device having a medium speed position and a low speed position, of means normally operative to bring the train to a stop upon receiving a low speed indication and acknowlmenace edging means under the control of the engineer for preventing the operation of said means, the operation of said acknowledging means being inefiiective in the low speed position of said change speed valve device.

31. In a train speed control apparatus, the combination with a piston and means operated by said piston for modifying the action of the speed control apparatus due to receiving a speed control indication, of a reservoir normally charged with fluid under pressure and a valve under the control of the engineer for supplying fluid from the reservoir to said piston to thereby acknowledge the speed control indication.

32. In a train speed control apparatus, the combination With fluid pressure operated means for acknowledging a signal indication, 01 a reservoir normally charged with fluid under pressure and a manually oper ated valve for supplying fluid under pressure for operating said means.

83. In a train speed control apparatus. the combination with. means including a fluid pressure operated piston 'lor acknowledging a signal indication, of a reservoir normally charged with fluid under pressure, a manually operated valve having a position for supplying fluid from said reservoir to said piston, and a restricted port for permitting the gradual escape of fluid under pressure supplied to said piston.

at. In a train speed control apparatus, the combination with means for acknowledging a signal indication, of a manually operated device for effecting the operation of said means and means for efi'ecting the movement of the acknowledging means to its normal inoperative position after a predetermined interval of time.

In testimony whereof I have hereunto set my hand.

rnonis n. THOMAS.