US1492613A

US1492613A - Automatic train-speed-control apparatus

Info

Publication number: US1492613A
Application number: US292209A
Authority: US
Inventors: Thomas H Thomas
Original assignee: Westinghouse Air Brake Co
Current assignee: Westinghouse Air Brake Co
Priority date: 1919-04-23
Filing date: 1919-04-23
Publication date: 1924-05-06
Anticipated expiration: 1941-05-06

Description

May 6, 1924. 1,492,613

T. H. THOMAS 1 AUTOMATIC TRAIN SPEED CONTROL APPARATUS Filed April 23. 1919 3 sheets-sheet@ .TIMING- Ras,

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may 6 ,1924. 1,492,613

l T.,H. THOMAS O AUTOMATIC TRAIN SPEED CONTROL APPARATUS Filed April 23. 1919 5 sheets-Sheet 2 0N n l a N QD`N2-D o;

May 6 1924. 1,492,613

T. H.. THOMAS AUTOMATIC TRAIN SPEED CONTROL APPARATUS Filed Apri; 23, 1919 3 sheets-sheet 5 jw= WA IHIIII Im A /13 -/0 /39 n 68 9/0/ /OO g e 93 7+ U21/4 /35 /37 J8 65 6756 6F69 4 INVENTOR Thoms H Vhomcs bww/@a Patented liflay 6, i924.

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traitant -ortica THOMAS H. THOMAS, OIE EDGrli/VOOI), PENNSYLVANIA, ASSIGNOR TO THE WESTING- HOUSE AIR BRAKE COMPANY, OF WILMERDING, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

AUTOMATIC TRAIN-SPEED-CONTROL A'PARATUS.

Application filed April/23, 1919.

To all w/iom t may concern.'

Be it known that I, Ti-roMAs H. THOMAS, a citizen of the United States, residing at Edgewood, in the county of rkllegheny and State of Pennsylvania, have invented new and useful Improvements i-n Automatic Train-Speed-Control Apparatus, of which the `following is a specification.

rIhis invention relates to an automatic l0 train speed control apparatus, and is in the nature of an improvement oi the construction covered by the U. S. Patent No.

1,316,205 of Walter V. Turner, dated September 16, 1919.

`While with an apparatus of the above character, the speed of the tiain is controlled automatically, it is considered desirable for the engineer to be on the alert, and to ensure that he notes the signal indication, one object ot my inventionI is to provide means for imposing a penalty, inthe way of reducing the speed below that required for the particular signal indication, if the engineer, on passing the signa-l, fails to periform a required act.

In applying the brakes with the usual fluid pressure brake, if the brake pipe reduction be too light to effect an appreciable reduction in auxiliary reservoir pressure by operation of the triple valve device in supplying iluid from the auxiliary reservoir to the brake cylinder, it may happen that when the brake pipe pressure is increased' to release the brakes, the diierential pressure :S5 will not be suilicient to effect the release n'iovement of the triple valve pistons.

Another object of my invention is to provide means for ensuring a predetermined reduction in brake pipe pressure under all conditions, and suliicient to ensure the positive subsequent release oi the brakes upon increasing the brake pipe pressure.

1i the brakes are released while fluid is still being discharged from the brake pipe charge valve mechanism, the brake pipe pressure not having had time to equalize throughout the .length of the brakev pipe, shocks are liable to occur, due to the brakes being held applied at the iear end while they are being released at the head end.

Another object of my invention is to overcome this diil'iculty by providing means for ensuring the substantial equalization of by the operation of the equalizing dis- Serial No. 292,209.

brake pipe pressure throughout the train before the brakes can be released.

Other objects and advantages will ap pear in the following more detailed description of the invention.

Inthe accompanying drawings, Fig. 1 is a diagrammatic sectional yview of an automatic .train speed controlling apparatus embodyinglmy invention and showing the parts in the positions assumed when the track circuits are imposing the low speed limit on the apparatus :and the speed ofthe train is less than the low speed limit; Fig. Q-an'enlarged sectional view of the penalty `valve portion of the speed controlling apparatus, showing the parts in the positions assumed upon passing a lcaution `signal indication,

-with the penalty push button held depressed by the engineer; Fig. 3 a view similar to Fig, 2, but showing vthe parts in the ypositions assumed if the engineer does not depress the penalty push button upon passing a caution signal indication; Fig. 4 an enlargedsectional view of the vchange speed valve device in 'low speed position; Fig. y5 a similar view of the change speed valve device, showing the same in the medium speed position; Fig. 6 an enlareedsectional view of the application valve device in application position; and Fig. 7 a similar view of the application valve device, showing the same in lap position.

As shown in Fig. 1 of the drawings, the preferred construction embodying my in'- vention may comprise speed magnets A' and B, adapted to be controlled by track circuits, a speed governor valve portion C, a change yspeed valve device D, a brake application valve device E, a pei'ialty valve device F, a valve device G, a retarded application valve device H, equalizing discharge valve mechanisms K and L, release timing discharge valve mechanism M, push button penalty valve N, and push button release valve 0.

The change speed valve deviceD is for the purpose of determining the speed limit at which the speed .governor valve portion C will act and comprises a piston device having connected differential piston heads 1 and 2 for operating a slide valve 3. The slide valve has three positions-a low speed po'- sition, a medium speed position, and an intermediate high speed position.

The brake application valve device E may comprise a piston device having connected differential piston heads 4; and 5 for operating a slide valve 6.

The speed governor valve portion C comprises a centrifugal device 7 of the ordina-ry type adapted to be rotated in accordance with the speed of the vehicle by a suitable operative connection to the axle of the vehicle through the pinion 8. The centrifugal device 7 operates a sliding stem 9 to which is attached a plate 10 having a series of adjusting

screws

11, 12, 13, 14, and 15 for engaging and operating respectively a loiv speed delayed application valve 16, a low speed valve 17, a medium speed valve 18, a high speed valve 19, and a high speed delayed application valve- 20.

The penalty valve device F may comprise a piston 21 and a slide valve 22 and the valve device G: a piston 23 and slide valve 21.

The delayed application valve device H may comprise a valve piston 25 and a poppet valve 26 adapted to he operated by the piston 25.

The speed magnet A controls double beat valves 27 and 28; and the speed magnet B, the double beat valves 29 and 30.

The brakes may be manually controlled by the usual automatic brake valve 81 and independent brake valve 32; thek automatic brake valve 31 comprising a rotary valve 33 contained in valve chamber 34 and adapted to be operated by handle 85 and the usual equalizing discharge valve mechanism 36 for controlling and regulating` the venting ot fluid under pressure from the brake pipe 37, to effect an application of the brakes.

The independent brake valve 32 may comprise a rotary valve 38, contained in valve chamber 39, and adapted to be operated by handle 4:0.

The track circuits for controlling the magnets A and B and the means by which the magnets are energized or deenergized, torni no part of my invention, but it may be stated that a system has been provided so that lor a clear indication permitting high speed, the magnets A and B are both energized; for a caution indication permitting medium speed, the magnet A is deenergized and magnet B energized; While for a danger indication permitting only a loiv speed, both magnets are deenergized.

lVith the usual main reservoir e1 charged with Huid under pressure, liuid is supplied through pipe a2 and passage 113 to valve chamber L14 ot' valve device G and from valve chamber 44 through passage 15 to valve chamber 46 ot valve device F.

v From valve chamber 46 fluid equalizes through port 47 in piston 21 to piston chamber 48. Fluid also flows from passage t3 through passage 49 to valve chamber 50 of valve device E and from valve chamberl 50 fluid loivs through passage 51 to veuve chamber 52 of valve device l). Fluid under pressure also equalizes from the valve chamber 50 through the restricted port 96 into piston chamber 85.

The chamber above the equalizing discharge piston and the equaliziug reservoir No. 1 connected thereto, are charged from the brake pipe when the application slide valve 6 is in release position, through passage 5l, past check valve 55, passage and cavity 57 in slide valve 6 to passage 58.

rlChe eipializing reservoir No. 2 and the chamber above equalizing discharge piston :59 are also charged through cavity :37 by Way of passage 60.

rliming reservoir No. 1 is charged from valve chamber L16, with slide valve in its inner position, through port 61 and passage 62. Timing reservoir lo. 2 is charged from valve chamber eel of valve device (il when the slide valve 2e is in its innel position, through port 63 and passage 6ft.

The reduction reservoir No. 1 is connected to the atmosphere in the release position of application slide valve 6, through passage 65 and cavity 66 to exhaust port 67 and reduction reservoir No. 2 is connected to atmospheric exhaust port 68 through passage 69 and cavity 70 in slide valve 6.

In operation, it the signal indication is clear, the track circuits cause both the magnets A and B to be energized, so that the valves 27 and 29 are seated and the valves 28 and 30 opened.

The opening' of valve 80 operates to supply liuid under pressure to piston chamber 72 of valve device G from valve chamber 50 through passages 71 and 7 3, so that piston and slide valve are shifted to their inner positions.

rllhe opening of valve 28 ellects the supply ot' liuid to piston chamber 7 of the speed limit selector valve device l) 'trom valve chamber 52 through passage 7l. passage 75, cavity 76 in slide valve and pesage 77, and also to piston chamber 76 ot piston 2 through the same cavity 76, passage 7i), cavity 8() in slide valve 2a, and passage 61.

As fluid under pressure is thus supplied to the outer faces of the pistons 1 and 2, one or the other ot the

spring stops

82 or 83 will move the valve device to its intermediate or high speed position, dependent upon the position the valve device happens to be in. In the high speed position of slide valve 3, the passages are blanked which control the train for low and medium speeds and the movement of the brake application valve device E is only effected by the high speed valve 19 which controls passage 8-1 leading to the piston chamber 85 of piston f1.

It the speed ot the train should exceed the high speed limit, which may be 60 milesy per hour, for example, then the speed governor 7 operates the stem 9 so as to open the valve 19 and thereby vent fluid from piston chamber 85. rl"he piston d then shifts the slide valve (S to its outer application position, in which the reduction reservoir No. 1, nonv at atmospheric pressure is connected to the charged equalizing reservoir No. 1 through passage 65, cavity 6G in slide valve G, and passage 58.

rl`he reduction reservoir No. 2, also at atmospheric pressure is connected to the charged equalizing reservoir No. 2 through passage G9, cavity in slide valve G, and passage GO.

The pressures in the equalizing reservoirs No. 1 and No. 2 are thus vented into the corresponding reduction reservoirs llo. 1

and No. 2 and this permits the higher brakeA pipe pressure acting on the opposite. sides of the equalising pistons 53 and 59 to lift the pistons and open the corresponding discharge valves 8G and 87. Fluid is thereupon vented Atrom the brake pipe37 to effect an application ot the brakes throughout the train iu the Well known manner.

Il the speed ot' the train is reduced to the predetermined speed limit, before the equalizing reservoir pressure has fully equalized into the reduction reservoir, it Will still require a little time for the brake pipe pressure to equalize or stabilize throughout the train, especially it the train be a long one, and in order to prevent shocks, it is desirable that no release oi' the brakes take place during this period. Accordingly, the possible release o'f the brakes is delayed for a time in the following manner.

The discharge 'from the equalizing discharge valves 86 and ST, instead of being vented to the atmosphere in the usual manner is vented to a release timing reservoir 98, since the opening of either discharge valve 8G or 87 vents fluid to a common passage 13T and thence through cavity 138 in the slide valve 6, when said valve is in application or lap positions, to passage 139, which leads to the release timingi` reservoir 8S and the chamber above the piston 89 of the discharge valve device M. n

The piston 89 operates a discharge valve 98 tor venting iiuid from beneath the small piston 5 of the application valve device E through a passage 190 to an atmospheric exhaust port 102, so that the release movement ot said application valve device is elfected by the action of the discharge valve device lvl.

The release of the brakes is controlled by the engineer with certain limitations and for this purpose the push button release valve device O is provided.

lli/Then the application valve device E is in application position, the push button valve 90 controls an exhaust outlet 91, which is connected to piston chamber 85, through passage 92, avity 93 in slide valve 6, passage 94, and pipe 95. il. spring 96 normally holds the valve 90 open, so that in the application position of the piston Ll, the piston chamber is maintained at atmospheric pressure, so as to prevent the release .movement ot the piston l, until the engineer, desiring to release the brakes, presses the push button valve to its seat.

This cuts olf the exhaust outlet 91 from the piston chamber 85, but no action will take place so long the speed ot thetrain exceeds the particular predetermined speed limit selected, Yin the present instance, the high speed limit. Consequently, the high speed valve 19 continues to maintain the piston chamber 85 at atmospheric pressurey until the speed has been reduced to th predetermined speed limit.

So long` as the application valve device E remains in application position, the fluid in the equalizing reservoirs 1 and Q *will continue to equalize into the respective` reduction reservoirs 1 and Q until the pressures become fully equalized.

As soon as the speed of the train has been reduced to the predetermined speed limit, the high speed valve 19 is permitted to close and then, the push button valve 90 being held closed, fluid pressure Will equalize through port 9G in piston e to piston chamber 85, permitting the spring stop 97 to move the application piston Ll to lap position.

In lap position, the slide valve 6 cuts oli communication from the piston chamber 85 to exhaust outlet 91, so that the engineer may now release the push button valve 90.

By the movement olf slide valve 6 from application to lap position, communication from the reduction reservoir No. 1 through passage G5, cavity GG, and passage 5S to the equalizingl reservoir No. 1 is cut off, but conimunication 'from the reduction reservoir No. 2 through passage 69, cavity 70 in slide valve G, and passagel 60, is maintained, as Well as communication from the discharge valves 9G and T through passage 13T, cavity 138, and passage 189 to the timingreservoir 88, as will be evident from Fig. 7.

rllhe reduction reservoir No. 1 being cut oil Ytrom the equalizing reservoir No. 1, further reduction in pressure in the equalizingi reservoir No. 1 is prevented and When the brake pipe pressure has been reduced to a degree slightly less than the pressure in said equalizing reservoir, the piston 53 is operated to close the discharge valve 86.

The reduction reservoir No. 2, however, is still in communication With the equalizing reservoir No. 2 and the reduction in pressure in 'equalizing reservoir No. 2 continues until equalization takes place, and then when the brake pipe pressure reduces to a point slighty less than the pressure in said reservoir, the piston 59 operates to close valve 87.

In the application aswell as the lap position oit the slide valve 6, the common discharge passage 137 from the discharge valves 8G and 87 is connected through cavity 138 in slide valve 6 with passage 139, leading to the timing reservoir 88.

Se long as the discharge valves 86 and 8i' are venting fluid to the timing reservoir 88, the piston 89 operates to hold the valve 98 seated, but when the discharge valves close, the pressure in the timing reservoir 88 gradually escapes through an atmospheric vent port 99. 'llhe valve 98 controls a passage 100 leading to the piston chamber et pistou of the application valve device E and when the valve device is not in normal release position, a groove 101 permits the equalization of tluid pressure troni valve chamber to said piston chamber.

This lluid pressure acts on the exposed arca of the discharge valve 98, and when the pressure in the timing reservoir has been re duced to a low point by ven tin g through the port 99, the pressure on the valve 98 will litt the valve and permit the venting of :lluid from the small piston 5, through passage 100 to exhaust port 102.

lt will be noted that two equalizing dis` charge valve mechanisms are en'iployed and that the equalizing reservoir 01"' the discharge valve mechanism l( is cut oil troni the corresponding reduction reservoir when the application slide valve 6 moves to lap position, while the equalizing reservoir oi the discharge valve mechanism L remains in Con'ununication with its corresponding reduction' reservoir. The purpose oi this is to ensure a suiiicient reduction in brake pipe pressure, say seven pounds, for example, so that there will follow a reduction :in auxiliary reservoir pressure at each triple valve device throughout the train, sufficient to cnsure that a subsequent increase in brake pipe pressure will be elica-tive to release the brakes ft the reduction in brake pipe pressure be teo light, then there is daujfer that the brake. pipe pressure cannot be increased suiiiciently te cause such a differential pressure as to ensure the release movement of the triple valves. The volume oli the reduction reservoir No. 2 is, of course, such that the desired reduction in brake pipe pressure is secured.

Tie reduction of pressure thus produced on piston 5 is sutcient to destroy the equilibrium ot iiuid pressures acting on the ap plication piston device, so that the application ,valve device will now be shifted to re lease position, in which the rotary valve chamber 341 of the engineers brake valve 31 is again connected to the main reservoir by ilow from the valve chamber 50, through brake pipe pressure will be somewhat higher than the pressure in the equalizing reservoir No. 1 and in order to effect the quick equalization of pressures on the discharge piston 53, the eqnalizing reservoir No. 1 is connected in lap position of the application slide valve 0 with the brake pipe 37, through passage 58, cavity 57 in slide valve 6, passage 56, past check valve 55, to passage it the brakes are applied by manipula.- tion ot the engineers brake valve, the brake pipe pressure is reduced in the usual manner and as brake pipe pressure is present below the equalizing discharge valve pistons 58 and 59, it will be seen that a higher pressure is then present in the equalizing reservoirs 1 and This higher pressure may leak past the equalizing pistons and 59 after the brakes have been applied and then tend to release the brakes.

ln order to avoid this possibility, the pistons 52) and 59 are provided with collapsible valve portions, so that when the equalizing reservoir pressure exceeds the brake pipe pressure, the pistons 53 and 59 will be moved downwardly compressing springs 107 and 108 so as to open the respective equalizing grooves 109 and 110 and thus permit the quick equalization ot' any excess pressure in the equalizing reservoirs into the brake pipe.

lt the brakes are released by manipulation el the engineers brake valve, the pressure ou the brake pipe side ot the pistons 58 and 59 increased and this pressure will litt the pistons and open the corresponding discharge valves, it the equalizing reservoir l'uessure be less than the brake pipe pressure.

In order to prevent the. venting of fluid 'from the brake pipe by the opening o't the discharge valves 8G and 87, the discharge passage 137 is controlled by the applica-tion slide valve 6, so that in the normal release position ot the slide valve, the discharge passage is closed, thus preventing the venting of iiuid from the brake pipe, it the discharge valves should open.

In the release position of the application slide valve E, the reduction reservoirs 1 and 2 are again connected to the atmosphere while the equalizing reservoirs will be connected to the brake pipe, so as to effect the recharging' of same with iluid under pressure in readiness ior the next operation.

It the signal indication is for caution, the

LaeaeisN apparatus will be adjusted so asto limit the speed to a medium s )eed limit., say miles per hour, for example.

In this case, the track circuits cause the speed magnet A to be deenergized and the speed magnet B to be energized.

The magnet B being energized, the valve` ture.

According` to this feature,the engineer must perform an act When he sees that the signal indication is for caution in order to retain the medium speed limit permitted under a caution indication. If he does not, whether because he is incapacitated or is inattentive to his duties, then the'speed limit- Will be reduced to the low speed limit.

For accomplishing the above, I provide a penalty valve device N, having a push button valve 111, which when depressed Will connect the piston chamber 48 of valve device F with the atmosphere, through passage 112, cavity 113 in application slide valve 6, passage 114, and pipe 115.

The venting'o't fluid from piston chamber 1-8 causes piston 21 lto shift the slide valve 22 to its outer position, infy which the piston chamber 74 of the speed limit selector valve device D is connected to the valve chamber of valve 2G, through passag'e 77, cavity 116 in slide valve 22, passa-ge 117, cavity 118 in slide valve 24, and passage 119.

-i he chamber above the valve piston 25 of the valve device I-I is connected to the high speed delayed application valve 20 through passage 120, cavity121 in slide valve 24, passage 122, cavity 123 in slide valve 22, and passage 124. lllith'the slide valve 22 in its outerposition, as Yshown in Fig. 2`of the drawings, the retarded lapplication timing reservoir No. 1 is also connected to the chamber `above the valve piston 25 through passage 6.2, cavity 123 in slide valve 22, passage 122, cavity 121 inslide valve 24, and passage 120 and the speed valve 20 is also connected to the retarded application timing reservoir No. 1 through passage 62, cavity iu slide valve 22, and passage 124.

The movement of slide valve 22 to its outer position also connects the magnet valve A to the piston chamber 48, through passage 75. cavity 7G in slide valve 22, Yand passage 112, so that, the magnet A being deenergized. the piston chamber 48 Will be maintained at atmospheric pressure,thus permitting the engineer to release thc penaltyvalve 111. I

The passage 81, leading to piston chamber 78 of valve device rD is connected through cavity in slide valve 24 with passage 79, but since the passage 79 isV novv blanked by slide valve 22, fluid pressure will be bottled up in piston chamber 78.

The valve 20, being now connected to the charged timing reservoir No. 1, ivill vent fluid'therefrom at a certain rate. This valve is so designed as to vary the vent opening in such a Way that fluid is vented from vthe timing reservoir No. 1 at a rate proportional to the speed of` the train and when the pressure in the timing reservoir has been reduced to a predetermined degree, the valve device H is operated to vent fluid from the small piston 1 of the valve device D, so as to cause the same to be shifted to its medium speed position.

More in detail, when the pressure in the timing reservoir No. 1 is reduced to a prcde termined degree, the feed valve pressure acting on the under side of the valve piston 25, through pipe 127 and passage 128, lifts the valve piston so as to open the valve 26. The piston chamber 74 of the speed valve de-v vice D is then connected to the speed valve 2O and the timing reservoir No. 1, so that fluid isvented from the face of piston 1, permitting the pressure in piston chamber 78 to force the valve device to its upper or medium speed position. Y

In this position, passage 84, leadingto piston chamber of the application valve dc-V vice E is connected, through cavity in slide valve 3 with passage 126, leading to the medium' speed controlling valve 18. If the speed o-fthe Atrain exceeds the medium speed limit, say for example. 35 miles `per hour, the valve 18 will be in open position, and fluid Will be vented from the pistou chamber 85, to effect the movement of the application valve device E to application'position, in Which the brakes are appliedv to reducethe speed ofthe train in the manner hereinbefore described. If the speed ot the train does not exceed the medium speed limit, then the application valve device Will not be operated. and no action takes place.

As a train will obviously move over a greater distance, before the speed is reduced by applying the brakes, the speed Will be reduced to the desired speed limit by the time thetrain reaches the' place Where the reduced speed becomes necessary.

The brakes may be released bythe en- `gineer under the same linfiitationsk as delll() to the d esired speed, the greater the'speed of scribed in connection with running at the high speed limit.

If the engineer does not depress the push button valve 111 in passing a caution indication, then the valve device F will remain in its inner position, in which the piston chamber 7 S of the valve device D is connected to the exhaust through passage 81, cavity 8O in slide valve 24:, passage 79, cavity 76 in slide valve 22, passage 75, and past the open valve 27 of the speed magnet A to the atmcsphere.

rlhe piston chamber 7l is also connected to the speed magnet valve 27 through passage 77 and cavity 76, but since the piston 2 is of greater area than the piston 1, the unbalanced pressure between the pistons will shift the valve device to its lower or low speed position, in which communication is established from the piston chamber of the application valve device E to the low speed valve 17 through passage 84', cavity 129 in slide valve 3 and passage 130. y

It will now be evident that if the speed of the train exceeds the low speed limit, say 15 miles per hour, for example, the valve 17 Will be opened, and fluid vented from piston chamber 85 to operate the application valve device so as to effect an application of the brakes as hereinbefore described.

k'.hus if the engineer fails to depress the push button valve 111 in passing a caution signal, the speed of the train will be reduced to the lon7 speed limit, instead of the medium speed limit, as would have been the case had he depressed the valve,

If the engineer should Wait until after he passes the caution indication and then press the penalty valve 111, no action vvill take place, because the application valve will noiv be in application position, in which the penalty valve 111 is cut off from the valve device F.

If a caution indication is passed and the speed of the train is reduced to the medium s eed limit, as hereinbefore described, and t 1e next signal indication is at danger, then a lovv speed indication will afectvthe mag nets A and B at a certain distance in advance of the danger signal. For low speed, both magnets are deenergized and since the valve 29 of the magnet B is open, fluid is vented from the piston chamber 72 of the valve device G, so that the saine will be shifted to its outer position, in Which the lon7 speed delayed application valve 16 and the delayed application timing reservoir No. 2 are connected to the chamber above the valve piston 25, by means of cavity 131, which connects passage 132, leading to the valve 16, With passages and G4. lllhen the pressure in the delayed application timing reservoir No. 2 has been reduced to a predetermined degree by flow past the valve 16, de pendent upon the speed of the train andv the naaaeie consequent outlet vent area at the valve 16, similar to the action described in conn ction with the valve 20, then the feed valve prossure acting on valve piston will lift saine so as to open the valve 26 and thus connect the valve 16 with piston chamber 78 of the speed valve device D through passage 81, cavity 133, in slide valve 2li, passage 119, and past valve 2G to passage 120, which is nciv connected to the valve 16 as before described. The speed valve device will therefore be shifted to the loiv speed position by the venting of fluid pressure from the pistou chamber 78, and the piston chamber S5 of the application valve device E will be connected to the loiv speed valve 17, so that if the 'speed of the train exceeds the low speed limit, and the valve 17 is thus open, the application valve device E will be operated to effect an application of the brakes. While the operation above described refers to the action which takes place after a caution indication is passed, it Will be under stood that the saine action occurs in case the signal indication is changed from clear or high speed directly to danger indication or low speed.

lVhen the application valve device E is shifted to application position, the flow of fluid from the main reservoir to the rotary valve chamber 34 is cut off, and there is then some possibility that the brake pipe pressure acting below the rotary valve 33 may lift saine from its seat. ln order to prevent this, said valve chamber is connected to the brake pipe in the application position as 'well as the lap position of the application valve device by way of passage 54, past check valve .134-, through passage 135, cavity 136 in slide valve 6, to passage 104, Which leads to thc pipe 105. i It will bc noted in the foregoing description of operation, that when the apparatus is set for louv speed bj, `ie action of the track signal circuits, the delayed applic;- tion mechanism is brought into action, While if a caution indication is passed Without the engineer operating the penalty push button, the low speed limit is cut in but operates iinn'iediateljf, since the delayed application mechanism is then cut out.

llVhen the valve device F is shifted to its outer position, the piston chamber i8 connected to the speed magnet A, so that if the signal indication should change from caution to clear, the magnet A being energized, Will operate to open the valve 28, so as tov supply fluid to the piston chamber 4S. The piston 21 vvill then shift the slide valve 22 to its inner position, in 'which communi lill evident that if the release valve O be opera-ted to release the brakes, the brakes will be released Without Waiting forthe speed to be reduced to the medium speed limit.

If it is desired to provide an automatic release of the brakes YWithout action on the part of the engineer, this can evidently be secured by merely plugging up passage 94C, leading to the manually operated release valve O. c

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

l. In a train speed control apparatus, the combination with a brake valve device for controlling the brakes and mechanism controlled from the trackway for imposing a predetermined train speed limit, of means manually operable by the engineer independently of said brake valve device for permitting a higher train speed limit.

2. In a train speed control apparatus, the combination with a brake valve device for controlling the brakes and mechanism controlled fromthe trackway for imposing al predetermined train speed limit, of means separate from said brake valve device and operable by the engineer to prevent the imposition ot said predetermined train speed limit. Y

3. In a train speed control apparatus, the combination With a brake valve device for controlling the brakes and mechanism operable to impose a higher or a lovver predetermined train speed limit on the train, ot' means controlled by the engineer separately from the brake valve device for setting said mechanism to impose the higher speed limit and means controlled from-the trackyvay for setting said mechanism to impose the lorver speed limit, if the engineer fails to act.V

4. In a train speed control apparatus, the combination with mechanism operable to impose a higher or a lower train speed limit on the train, of fluid pressure controlled means operable by the engineer for causing said mechanism to impose the higher speed y limit and means controlled from theftrackivay for causing said mechanism to impose the loiver speed limit, if the engineer tails to act.

In a train speed control apparatus, the combination with mechanism operable to impose a higher or a lower train speed limit cn the train, of a brake valve deviceV -for controlling' the brakes, fluid pressure controlled means operable independently of said brake valve device for setting said mechanism to impose the higher speed limit, and means controlled 'from the trackivay for setting said mechanism to impose the lower speed limit, if the engineer fails to operate said fluid pressure controlled means.

6. In a train speed control apparatus, the combination with a train speed limitselector valve device having positions for imposing different train speed limits, of means subject to track signal control for varying the fluid pressure on said selector valve device to determine the position thereof and a pen-- alty valve device normally establishing conimunication through which said means controls the fluid pressure on the selector valve device and adapted to be operated by the engineer for cutting oil2 said communication and for independently varying theV fluid' pressure on said selector valve device.

7. In a train speed control apparatus, the combination with a train speed limit selector valve device operated by fluid pressure for imposing different train speed limits, of a valve device controlled by the track signal system for controlling communication through which the fluid pressure is varied on said selector valve device and a valve device controlled by the engineer for also controlling communication through which the fluid pressure is varied on said selector valve device.

8. In a train speed control apparatus, the combination With a train speed limit selector valve device operated by fluid pressure for imposing different train speed limits, of a valve device normally establishing communication through which the fluid pressure is varied on said selector valve device to move the saine to one speed limit position, a valve device for applying the brakes at speed limit corresponding with the position of the selector valve device, and a valve device controlled by the engineer for controlling comtil) munication through Which the fluid pressure K is varied on said selector valve device to move same to another speed limit position,

said communication being also controlled* ing to the speed of the train :tor reducing the aressure on said 'a lication valve device of a` manually operated release valve for also i controlling the fluid pressure on said valve device through a communication controlled by said valve device 1l. In a train speed control apparatus, the combinationivith a slide valve, a piston operated upon a reduction in fluid pressure tor actuating said slide valve to effect an application of the brakes, and means controlled equalize the fluid pressures on opposite sides of the piston and speed controlled means for reducing the fluid pressure on said piston, of a release valve operated by the engineer' for closing a vent port to said piston and means for moving said piston to lap position upon equalization of fluid pressures thereon.

13. ln a train speed control apparatus, the

conunnation Winn a oralre application valve` device 'and speed controlled means for effecting the n'iovenient thereof to applica-tion position, of means controlled bv the engineer for effecting the movement of said application valve device to lap position, aud means operated upon a predetermined brake application for effecting the further movement of said valve device to release position.

le. u a train speed control apparatus, the combination with a brake pipe, a valve device for establishing communication for effecting a reduction in brake pipe pressure to apply the brakes, and speed controlled means for effecting the movement of said valve device. to application positioinof means controlled bv the engineer for effecting the move-ment of said application valve device to lap position and means operated upon a predetermined reduction in brake pipe pressure for effecting the movement of the application valve. device to release position.

l5. ln a train speed control apparatus, the combination with a Vbrake pipe, of an equalizing reservoir, a discharge valve device subject to the opposing pressures of the equalizing reservoir and the bra-lie pipe for venting fluid from the brake pipe upon a reduction in pressure in the equalizing reservoir, and a timing reservoir into which fluid is vented from the brake pipe by operation of said discharge valve mechanism. o

16. In atrain speed control apparatus, the combination with a bralre pipe, of an equalizing reservoir, a discharge valve device subject to the opposing pressures of the equalizing reservoir and the bralrepipe for venting fluid from the brake pipe upon areduction in pressure .in the equalizing reservoir, an application valve device for controlling communication through vhich fluid is Vented from the equalining reservoir, a timing reservoir into Which fluid is vented from the brake pipe, and means controlled by the pressure in the timing reservoir for controlling the movement oi' said application valve device.

17. ln a train speed control apparatus, the combination with a brake pipe, of an equalizing reservoir, adischarge valve device suhject to the opposing pressure-s of the equalizing reservoir and the brake pipe for venting fluid 'from the brake pipe upon a reduction in pressure in the equalizing reservoir, an application valve device for controlling com` nninication through which fluid is vented from the equalizing reservoir, a timing reservoir into Which fluid is vented from the brake pipe and communicating with a restricted vent port, and means operated upon a reduction in pressure in the timing roservoir for varying the pressure on said application valve device to effect the movement thereof to release position.

V18. ln a train speed control apparatus, the combination With a brake pipe and a valve mechanism for venting fluid from the brake pipe, of an application valve device 'for coutrolling the operation of said valve mechanism and also comi'nunication through which said valve mechanism vents fluid from the brake pipe.

19. in a train speed control apparatus, the combination with a bralre pipe and au application valve device operated When the speed of the train exceeds a predetermined speed limit, of an equalizing reservoir and an equalizing discharge valve mechanism suhject to the opposing pressures of the equalizing reservoir and the brake pipe and controlled by said application valve device for venting fluid from the brake pipe, and having the communication. through which fluid is vented from the brake pipe controlled by said application valve device.

20. In a. traiil speed control apparatus, lhe combination with a brake pipe and an application valve device operated vvhen the speed of the train exceeds a predetermined speed limit, of a valve mechanism controlled Aby said application valve device for venting fluid ironi the brake pipe and an additional valve mechanism controlled bv said application valve dcv'ce for also venting fluid from the brake pipe.

2l. ln a train speed control apparatus, the combination with a brake pipe and an application valve device operated when the.

speed of the train exceeds a jnedeterininedspeed limit, of an equahaing reservoir, an

equalizing discharge valve mechanism suhject to the opposing pressures of the equalizing reservoir and the brake pipe andl controlled bv he application valve device for venting fluid from the brake pipe, au additional. equalizing reservoir, and an additional equaliziug discharge valve mechanism subject to the opposing pressures of the additional equalizing reservoir and the brake pipe and controlled by said application valve neeaeia device for also venting Huid Jfrom the brake pipe.

22. In a train speed control apparatus, the combination With a brake pipe and an application valve device operated When the speed of the train exceeds a predetermined speed limit, of an equalizing discharge valve mechanism operated upon movement oi the application valve device to application position for venting fluid from the brake pipe and adapted to be cut out ot action upon movement of the application valve device to lap position and an additional equalizing discharge valve mechanism operated upon movement of the application valve device to application position for venting fluid from the brake pipe and adapted to remain in ac" tion upon movement of the application valve device to lap position. e

23. ln a train speed control apparatus, the combination with a brake pipe and an application valve device operated When the speed of the train exceeds a predetermined speed limit, of an equalizing discharge valve mechanism controlled by said application valve device for effecting a limited predetermined reduction in brake pipe pressure and another equalizing discharge valve mechanism controlled by said application valve device for eliecting a greater reduction in brake pipe pressure.

24. In a train speed control apparatus, the

combination With a brake pipe and an ap plication valve device operated When the speed of the train exceeds a predetermined speed limit, of an equalizing discharge valve mechanism open in both the application and lap positions of the application valve device for eecting a limited predetermined reduction in brake pipe pressure and another equalizing discharge valve mechanism open only in the application position ot said application valve device :tor eecting a greater reduction in brake pipe pressure.

K 25. ln a train speed control apparatus, the combination with a train speed limit selector valve device, of a penalty valve device Jfor controlling said selector valve device, a manually operated valve for controlling said penalty valve device, and an additional valve device for also controlling said selector valve device. y

26. In a train speed control apparatus, the combination With an application valve device for eliecting an application'oiA the brakes if the speed of the train exceeds a predetermined speed limit, of means operating to delay the application of the brakes according to the speed of thev train and additional means operating to delay the application of the brakes according to the yspeed of the train.

27. lin a train speed control apparatus, the combination with a train speed limit selector valve device adapted to impose' diiierent speed limits, of means operating to delay the operation of said valve device according to the speed of the train.

28. ln a train speed control apparatus, the combination with a train speed limit selector` valve device adapted to impose different speed limits, of valve means operating to delay the operation oi said valve device When the train enters a medium` speed zone, according to` the speed of the train, and another valve means operating to delay the operation of said valve device when the train enters a lovv speed Zone, according to the speed of the train.

29. ln a train speed control apparatus, the combination with a brake pipe and an application valve device operating When the speed of the train exceeds a predetermined speed limit, of an equalizing reservoir and an equalizing discharge valve mechanism subject to the opposing pressures of the equalizing reservoir and the brake pipe for venting iuid from the brake pipe, the application valve device being adapted in application position to establish communication for venting iiuid from the equalizing reservoir and in lap position for supplying Huid i'rom the brake pipe to the equalizing reservoir.

30. In a train speed control apparatus, the combination with a main reservoir, a brake pipe, and a brake valve device having a valve chamber containing the usual rotary valve, of an application valve device for connecting said chamber to the main reservoir in release position and to the brake pipe in application position.

3l. In a train speed control apparatus, the combination with a train speed limit selector valve device, of a valve device for controlling communication through which the selector valve device is shifted to the medium speed position upon passing a caution indication and adapted to be operated by a change in the indication from caution to clear Jfor establishing communication through which the selector valve device is shifted to the high speed position.

32. lin a train speed control apparatus, the combination With a change speed valve device operated by i'luid pressure and having a medium and a high speed position, of a valve device for establishing communication through which luid pressure is varied on said change speed valve device to shift same to the medium speed position upon passing a caution indication, and operated by a change in the indication Jfrom caution to clear for establishing communication through Which fluid pressure is varied on said change speed valve device to shift same to the high speed position.

33. ln a train speed control apparatus, the combination With a change speed valve device operated by fluid pressure, of a Huid itl pressure operated valve device controlling communication for varying the fluid pressure on said change speed valve device, a track circuit controlled magnet valve for varying the fluid pressure on the first mentioned valve device, a second fluid pressure operated valve device for controlling communication for varying the fluid pressure on the change speed valve device and a second track circuit controlled magnet valve for varying the Huid pressure on said second valve device.

34. ln a train speed control apparatus, the combination with a change speed valve device operated by fluid pressure, oi a fluid pressure operated valve device controlling communication lor varying the luid pressure on said change speed valve device, a track circuit controlled magnet valve Jfor varying the fluid pressure on the rst mentioned valve device, a second fluid pressure operated valve device for controlling communication for varying the r'luid pressure on the change speed valve device, a second track circuit controlled magnet valve for varying the fluid pressure on said second valve device, and a manually controlled valve for also varying the iluid pressure on said second valve device.

35. lin a train speed controlled apparatus, the combination with a train speed limit selector valve device and track controlled means for edecting the movement thereof, oit means for delaying the operation of said selector valve device according to the speed of the train.

36. lln a train speed controlled apparatus, the combination with a train speed limit selector valve device and track controlled means for effecting the movement thereof, of means controlled by the speed of the train and interposed between the selector valve device and said track controlled means for delaying the operation of said selector valve device for a time interval which is substantially inversely proportional to the speed ol the vehicle.

37. Railway traffic controlling apparatus comprising apparatus on a vehicle controlled from the trackvvay for giving proceed, cau-- tion and stop indications, means controlled by said apparatus for permitting the train to travel at high speed when the apparatus indicates proceed and for imposing a low speed limit when the apparatus indicates stop, means controlled by said apparatus upon changing from proceed to caution indication for applying the'bralres, a brake valve device for controlling the brakes, and manually controllable means separate from said brake valve device for suppressing such brake application and imposing a medium speed limit when said apparatus changes from proceed to caution indication.

38. lailvvay traiic controlling apparatus comprising vehicle-earned means controlled masacre from the trackway for causing certain speed restrictions upon a change from a more tavorable to a less favorable trahie condition, a brake valve device for controlling the brakes, and manually operable apparatus on the vehicle, operable independently of said brake valve device, for suppressing said speed restrictions and imposing less severe speed restrictions it said apparatus is set into operation before tbe change of tramo condition occurs.

39. Railway tratc controlling apparatus comprising vehicle-carried means controlled from the trackway for causing certain speed restrictions upon a change from proceed to caution traffic conditions, and manually operable fluid pressure controlled apparatus on the vehicle for suppressing said speed restrictions and imposing less severe speed restrictions if said apparatus is set into gperation before the change to caution tra c condition occurs.

40. ln a train speed control apparatus, the combination with a reservoir, of means controlled according to the speed of the train for venting fluid under pressure from said reservoir and means operated upon a predetermined reduction in pressure in said reservoir for determining the speed limit of the train.

4l. ln a train speed control apparatus, the combination With a reservoir, of means for venting fluid under pressure from the resen voir at a rate proportional to the speed of the train and means operated upon a predetermined reduction in pressure in said reservoir for determining the speed limit of the train.

42. ln a train speed control apparatus, the combination with a reservoir, of a device operated upon a predetermined reduction in luid pressure in said reservoir for determining the maximum speed limit of the train and means for reducing the fluid pressure in said reservoir at a rate proportional to the speed of the train. i

43. ln a train speed control apparatus, the combination with two reservoirs normally charged with fluid under pressure, oi a device movable upon a predetermined reduction in pressure in one reservoir to impose one train speed limit and movable upon a predetermined reduction in pressure in the other reservoir to impose another train speed limit and means for reducing the pressures in said reservoirs according to the speed of the train.

44. ln a train speed control apparatus, the combination With speed controlling means operative upon a change in the signal indication for imposing a lower speed limit, of means operative to delay the operation of said speed controlling means for a time interval which varies inversely as the speed of the train.

45. ln a train speed control apparatus, the combination With a speed controlling means having different positions for imposing different speed limits on the train and operative upon a change in the signal indication for imposing a lower speed limit, of means operative to delay the movement of said speed controlling means from a higher to a lower speed limit position for a time interval which varies inversely as the speed of the train.

46. In a train speed control apparatus, the

combination with a train speed limit selector valve device movable to dierent positions for imposing different speed limits on the train and track controlled means for effecting the movement thereof, of means for delaying the movement of said selector valve device according to the speed of the train.

In testimony whereof I have hereunto set my hand.

THOMAS H. THOMAS.