US1678276A - Railway-traffic-controlling apparatus - Google Patents

Description

July 24, 192s. 1,618,276

' w. sPRouLL RAILWAY Tammc coTRoLLING APPARATUS Filed Nov.18, 1926 Engihemzzn Bra/t I@ (Ve mmmnypqntion) FedI/EzZI/e D Icz Z4 Bleak@ PW Equalzging Q zlVe Tim ing Besen/ 0m l 80 Patented July 24, 1928.

f UNITED STATES ctie-eues w seizoen, or emmene generics, eases/revisan, Assiette no( race union swi'ror'i a sienAL coiarANY, or swssvfiiin; iiiits'riAifIA; confortairioii or ENN'SYLVANIA.

RAILWAY-TurismoeoNrnoLLrNu -PPAnArUs Application filed November 1S, Serial 11o'. 149,085.

invention relates to railway traliic controlling,` apparatuaand particularly to apparatus for controlling ythe automatic brake applying mechanism on a train in accordance with traiiic conditions.

In atleast one form of railway traliic conk trolling` apparatus of the type described, the train is provided with apparatus for causing; an automatic application of the brakes under unsafe traflie conditions and for preventing such applieation'under safe tralhc conditions. llhen the brakes upon a train are automatically appliedwith sullieient force to produce the deceleration whichsaitety requires, dainage may result from shifting of the lading or from shocks to the rolling stock. For this and other reasons it is sometimes desirable to make the application in two parts, that is, to 'cause a preliminary brake application to run in the slack of the train and then, after a time interval, tocause a second application to bring the train to the desired low speed. Brake applications which are accomplished in the manner just described are usually called split applications and one object of my' present invention is' the provision of means for autoijnatically causing; a split application on board a train.

I will describe one form ot' apparatus ein'- bodying my invention, and will then point out the novel -features thereof in claims.

rlhe accompanying drawing' is a view, partly diagrammatic and partly in crosssecti'on, illustrating one Jform ot apparatus embodying iny invention. i

Referring to the drawing, the reference character A designates a magnet valve cornprisiiig` a valve stein 2 provided with an armature 2a and a winding 3. The supply of current to winding 3 is controlled `in aecordance with tralliic conditions by means forming no part of my present invention and omitted troni the drawing for the salte ot simplicity. For present purposes it is sutil cient to statevthat when trallic conditions are safe, winding 3 is energized and stem 2 `is then drawn downwardly into the position in which it is shown in the drawing` to blank pipe 4.' Under unsafe traiiic conditioi'is winding 3 becomes ele-energized, allowing; `stein 2 to rise and connecting the pipe l with atmosphere.

Pipe 4 controlsa brake application kvalve designatedby' the reference character B and comprising two chambers and 7, separated by a `reeipr-ocable piston 6.V When valve A. is' closed,` fluid pressure,v usually air; flows frein. a suitable j source lnot shown in the drawing, v,through pipes lgaiid 1P to chamber -5 of valve 1B, and thence through a restricted oriiice 7 in piston 6 to chamber `7. Pipe 4 is connected with chamber 7;but `with valve A closed-this pipe is blankedso that the applyingniechanism on the-train, not shown in the drawing, is controlled by means of a pipe which mayr conveniently be the brake pipe and which is normally supplied with `luf-idpressure from pipe 1, throi'igh the usual feed valve F, pipe 20, port 21 of the rotary Valveul of the eiigiiieinans lbrake valve, pipefQQ and eiit-o;vzilve G to the brake pipe When the pressure in the brake pipe 24 is reduced an automaticapplication oflthe brakes results', the severity of the brake ai plication depending upon the magnitude ot the, brake pipe ,pressure reduction. i

Thecutoi valve G comprises a chamber 14 containing a piston 16 which operates a stein 17 controlling two valves 18 and 19;

With the brake valve D and the application valve B .in the positions in which they are shown inv the drawingpressur"e from the pipelilows through port 1Q of the appli catioiiva'lve and pip 25 to chamber 14' be'- neiath the piston 16. The combined force exertedbythis pressure andthe spring 15 iiioves the piston 16 and the stein `17 carried thereby to an upper or normal position in which valve 18 is 'closed andvalve '19 is open. Under these conditions, pipe` 24 is connected with pipe 2Q to perniit `fluid pressure to flow into the brake 'pipe as described hereinbefore to maintain the pressure intlii'e pipe.` lVhen the :application valve l is reversed, port l2 connects pipe with atmosphere through "poi-Tt 81 thereby venting chamber ,14` otV valve G to atmosphere and allowing the pressure 'above CIJ valve 18 to open this valve, thereby admitting pressure to the upper side of piston 16 and moving the piston to its lower or reverse position against the bias of spring 15. AVli'en valve G is reversed, pipe 22 is disconnected from brake pipe 24 and the brake pipe is connected with pipe 31.

With the application valve B in its normal position and with valve G in its norma-l position, the brake pipe 1 24 is connected through valve G, pipes 22 and 26, vand port 27 of valve D with the chamber 28 above the usual equalizing valve E, and through pipe 29,- port 11 in valve B and pipe 30 with the f usual equalizing reservoir L; Under normal conditions, therefore, the equalizing reservoir L is charged tothe saine pressure as the brake pipe 24.

rllhe apparatus comprises also a discharge valve .ll and a differential valve J. The valve H comprises two chambers and 34 separated by a reciprocable 'piston 32, biased to an' upper position-by a spring35. lVhen lthe piston is in its lower position port 36 is closed, but when the piston is infits upper position port 36 is open and connects the chamber 34 lwith atn'iosphere through pipe 51, check valve 52, port 54 and a restricted orifice 43.

The differential valve J comprises a chainber 37 containing a comparatively small piston and a second chamber 39 containing a` coi'nparatively large' piston 4l. The pistons 40 `and 41 are operatively connected together andare spaced axially so that the valve comprises achaniber 38 intermediate the two pistons. llvlhen valve J occupies its lower position port 42 is closed, but when valve J rises. port 42 connects chamber 39 Vith port 54, and hence with atmosphere through orifice 43. Chamber 38 is constantly connected with a'timing reservoir T through pipe which communicates withy atmosphere through a restricted orifice 56. The pipe 55 connecting the reservoir T with lchamber 38 is. connected with pipe 51 through a check valve 50.

As shown'in the drawing, valve A is energized so that pipe 4 is blanked and the application valve B occupies its normal posi- The engincmans brake valve D is il-r tion. lustrated in its running position and .valve G is normal. The brake pipe 24 `is therefore charged with fluid pressure to prevent a brake application. and the equalizing valve is connected'with this pipe and is also charged with the same fluid pressure. Under these conditions, no pressure is supplied to any ofthe chambers of valves H or J and the timing` reservoir T is subjected to atmospheric pressure. Piston 32 of valve H is therefore raised by spring 35, and `gravity holds valve J in its lower position.

In explaining the operation of the appara-y tus, I will yfirst assun'ietha-t winding 3 of nection of reservoir L valve 'A becomes cle-energized, as by a ibei' 5 therefore moves piston 6 of valve B downwardly against the force `enerted by spring 8 to reverse valve B'.y Port 10 then connects chamber 7 with pipe 79 which couiniunicates 'with atmosphere at port 8O of a release valve l. This valveV is preferably located at rsome point of the locomotive where it will be inaccessible to the engineman except whentlie train is at rest. Pipe 79 also normally communicates with atmosphere through a poi-t6() in the enginemans bra-ke valve ywhich is yclosed only when the valve D is in the lap position.' Thebralte application valve B having once been moved to its reverse yposition remains inthe reverse position even though valve A subsequently closes. lVhen the application valve moves to its reverseposition, chamber 14 of valve G is vented to atmosphere through port 12 vof valve B and port 81 as deseribedhereinbefore. The cut-oft valve G therefore moves to itsr reverse position, disconnecting' pipe 24 frompipel 22 and connecting pipe 24 with pipe 31. Pipe 31 is constantly connected rwithchamber 34 0f valve H and with chamber 39 of valve J. These chambers and `the pipeeonnected `therewith may have a considerable volume and I therefore interpose a restriction 31a inthe pipe731 so that the sudden connection of the brake pipe `24 with pipe 31: when the yvalve G reverses will not cause a sufficiently rapid reduction in the brake pipe pressure to cause an emergency application of the brakes. It should be noted that valve G remains in its reverse vposition as long as the application valve B is' reversed due to the connection of pipe 25 with port 81. The movements of the brake application valve B toits reverse `position also disconnected' rthe equalizing reservoir-L from pipe 29 andconnected this reservoir with'pipe 44 through port 11 of valve B. The equalizing reservoir is therefore connected with chamber 33 of valve H and with chamber 37 of valve J. 'lhe chambers and 37 and pipe 44 should preferably have small volumes so that the conwith these volumes will cause substantially no reduction inthe pressure to which this reservoir was initially charged. The combined force of brake pipe pressure and spring 35 is now applied to the under side of piston 32 of yalve'H and equalizingA reservoir pressure is applied to the upper side of this piston. AThe piston therefore remains in its upper position, so

that port-36 is open to vent the brake pipeV to atmosphere through pipe 51, valve 52, port 54 and orifice 43. At the same time the equalizing reservoir pressure in chamber 37 'ill above piston lOl of valve J is over-balanced by the bralre pipe pressure inl chamber 39 under piston il of4 this valve, so that valve .l rises, opening' port i2 and connecting` pipe 231 with orifice 413. Valves J and l-l are bot-h nonT in their upper positions and the brake pipe is ven-ted through pores 3G and 412 to the orilice 43. During this operation a `considerable bach pressure is formed in pipe l due to the discharge from p rt 3G of valve AllY througlrthe restricted orifice 43. `This baci; prec-sure flows through the check valve 50 into the tin'iing reservoir T, charging this reservoir with fluid pressure. The pres sure. in the reservoir T enters chamber 38 through pipe .55.. and combine-s with the force exerted on the top of piston Ll0 to move the salve J to, its lower position,` closing port and interrupting the venting' of the brake pipe through port 42. After an interval of time. the brake pipe pressureivill be so4 reduced that the equalizinp,` reservoir pressure in chamber c3 of valve H will overbalance the combined forcesv exerted by the bral're pipe pressure in chamber Sel-'rand the spring` 35. its ylower position, closingy port and preventing further bleeding of the brake pipe. `The parte are so proportioned that this preliminary reduction in brake pipe pressure is sufficient to give the desired launching application. In actual practice it has been .found desirable to make the preliminary brake pipe reduction amountto about seven kpounds. per square inch.

, proportion of the then existing pressure in chamber 39, valveJ will move to its upward position thus kopening` port l2 and permit.h tinoV fluid to flow to atmosphere from the brake pipe through pipe 31, chamber 39, port -2 and orifice 48.' 0n account of this flow of fluid from the brake pipe, the pressure below piston el is gradually reduced.

At the same ti mcthe pressure in the timing; reservoir 'T' and above `piston 4:1 is gradually reducing. Tt is, therefore, evident that if vthe rate of pressure reduction in chamber 89. becomes greater thanthe rate ofpressure reduction in chamber 3S, the resultant forces controlling valve J will operate to close port 42 to terminate the second and final automatic brake pipe pressure reduction, and thus prevent the rate of pressure reduction Then this happens valve H returns to 4 brake in chamber 3.9 from` exceeding therate of govern the rate at Which the fluid pressure i" of the` brake pipe will be reduced during the progress of the secondand final brake pipe pressurereduction. i

In the practical operation of trains it `has been found that the shock to Which the train is subjected during a brake application is very largely dependent upon they rate at Which the pressure in the `brake pipe is reduced. Furthermore, the brake pipe of a trai-n is, in most cases in a leaky condition and since the leakage rate affects the rate of pressure reduction in the braliepipe, it is of prime `practical importance that the automatic applications be made inv such manner that the absolute rate of brak-e pipe reduction Ywill be automatically governed regardless ofthe rate at which the brake pipelealrs to atmosphere.v

,By properly proportioning the areas `of pistons 4 0 and il the final gauge pressure of the bralre pipe after the second reduction maybe made to equal any predetermined proportion of the original gauge-pressure of the equalizing reservoir. In actual practice I have discovered that the area of pistonfll is substantially e6 per cent greater than the area of piston 4() a satisfactory reduction of `brake pipe pressure will be obtained for normail operating conditions with standard automat-ic air brake apparatus.

It will be noted that when valve G reverses, ythe brake pipe is disconnected from pipo 22 through which it receives its fluid pressure from pipe l and it is therefore .ilupossible to recharge the brake pipe until `valve G is restored to its normal position.

The purpose of the ball check valve 52 is to prevent pressure from pipeV 54% from flowing back through pipe 5l into the timing;- reservoir T during the second brake pipe e reduction when pressure iiows from chamber 39 of valve J through port 42. The

ypurpose of check valve to prevent pressure from the timing reservoir yfrom flowing through pipe 5l' out through port 43 during the time interval after the preliniinary reduction and before valve J opens to give a second brake pipe reduction.

I will now assumethat valve A again becomes closed, as upon a changefroinim.- safe to safe traflic conditions- Pipe et is therefore blanlred at valve A, but the application valve remains in its reverse posi tion because when valve B is reversed to connect pipel with pipe79 at port y10, cha1nber 7 is connected With atmosphere at port of valve D `and also throughthe release valve, K. The engineman must therefore bring the train to a full stop, move his valve D to the lap position, and

ico

operate valve K to blank pipe 79. yThis operation of the valve K also connectspipe 79 with a branch la of pipe 4. Pressure' i'lowing from chamber 5 ot valve B through port 7a into chamber 7 and pipes -l and 7 9, builds up until the pressures on the two sides of piston 6 are equal, whereuponva'lve B returns to its normal position. Pipesd and 7 9 are now disconnected at port 10r of valve B, but these pipes are connected 'through valve K. It however, the engineman restoies the valve K to its normal position rafter valve B has moved to its normal position, branch pipe el will be blanlred,

'and the application. valve will'reinain in itsy ulation of the enginemans brake valve tol the release position as will be readily understood by one skilled in the art-.

I have described in detail the operation et only that part of the apparatus which is Iinvolved in an automatic application of the brakes. It will be clear from the drawing, however, that the enginemans brake valve may be operated as usual to control-the brake pipe pressure manually through the medium of the equalizing valve E in accordance with standard practice, except when valves B and G are in their reverse positions. It will therefore be seen that in apparatus embodying mv invention when an application of the brakes is to be made` automatically, the operation of valve H first causes a preliminary reduction of the brake pipe pressure by a predetermined amount and at the saine time charges the timing reservoir T. After the preliminary reduction is completed a time interval of predetermined duration elapses during which the reservoir T discharges to asmosphere through the poit 56. Upon the expiration of this interval valve .l operates to further reduce the brake pipe pressure to a predetermined proportion of its original value.

Although I have herein shown and dcscribed only one form of railway traffic controlling apparatus embodying my invention,

it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit andscope of my invention.

Having thus described my invention, what I claim is:

l. Automatic brake applying apparatus on a train comprising a brake pipe initially charged with luidpressure and arranged to applythe brakes when the pressure in such pipe'is reduced, a discharge valve comprising a cylinder divided into alower chamber kand an upper chamberfby a reciprocable piston -t-lie lower chamber communicating with atn'iosphere when the piston occupies an upper position, a spring for urging the pisf the other side ot the piston to the pressure .to which the pipe was initially charged, and

valve controlled by vsaid piston for reducing thev pressure in the pipe unt-il the coinbined force exerted on one side of the piston by the spring and the pressure in the pipe is less than the force exerted on the other side ot the piston by said initial pressure.

3. ln combination with the automatic brake applying mechanism on a` train, a magnet valve controlled by tratlic conditions,

ran a i lication valve controlled b thema@- C1 net valve, yand a discharge valve anda ditferential valve controlled by said application valve and arranged when the application valve is reversed to causey successive operations otthe ybrake applying mechanism.

il. Automatic brake applyingy apparatus on a train comprising a brake pipe initially charged `with fluid pressure and arranged to apply the brakes when the pres-v sure in such pipe is reduced, an application valve controlled by trallic conditions, al cutoil'1 valve controlled by the application valve,

a discharge valve controlled by the applica- `tion valve and by the cut-0H valve, and a differential valve controlled iii'part by the discharge valve, said discharge and dillerential' valves oporati ej at times to'cause successive measured reductions in the pressure in said pipe.

5. Automatic brake applying apparatus on ay train comprising" a brake pipe initially chargedwith luid pressure andai-ranged to apply the brakes when the pressure in such pipe is reduced, an equalizing reservoir normally connected with said pipe, an application valve controlled `by traic conditionsy tor disconnecting the reservoir from the pipe when the application valve is reversed,?and means e'ective when the appliricadere cation valve is reversed to automatically'reduce the pressure in the pipe by a predetermined amount below the pressure in the reservoir. n i

6. Automatic brake applying apparatus on a train comprisingr a brake pipe initially charged ivith 'fi uid pressure and arraiiged'to apply the brakes when the pressure in such pipe is reduced, aii equalizing reservoir nor- Inally connectedwitli said pipe, an application valve controlled by trailic conditions i'or disconnectingthe reservoir from *the pipe when the application valve is reversed, and means effective When the application valve is 'reversed to automatically reduce the pressure in the pipe by a predetermined aniount below the pressureinthe reservoir, and means for subsequently further reducing' the pressure in the pipe tok a predetermined ervoir 7. Automatic brake applying apparatus on a `train comprising;i a brake pipe initially charged with fluid pressure and arranged to apply the brakes when the pressurein such. pipe reduced, an equalizine; reservoir nor nially connected with said .pipefan application valve controlled by tratlic `conditions for disconnecting the reservoir 'from the pipe when the application valve is reversed, and means operating` upon the expiration oi a time interval iolloivinp; the reversal of the application valve to reduce the pressure in said pipe to 'a predetermined proportion of the pressure in the reservoir.

S. Automatic brake' applying apparatus on a train comprising a brake pipe initially charged 'with fluid pressure Vand arranged to apply the brakes when the pressure in such pipe is reduced, an equaliaingr reservoir normally connected with said pipe, an application valve controlled by trai-lic conditions ior disconnecting` 'the reservoir` from the pipe when the application valve is reversed, means operating1 when the applica'- tion ralveis reverse reduction in the pr Nure in said pipe, and other incans effective upon the expiration or a time interval after sucli preliminary re duction to further reduce the pressure in thel pipe to a predetermined proportion of the pressure in said reservoir.

9. Automatic brake applying apparatus on a train comprising a brake pipe initially charged With fluid pressure and arranged to apply the brakes when the pressure in such pipe is reduced, an equaliing reservoir nor mally connected with said pipe, an application valve controlled by traffic conditions for disconnecting,- the reservoir from the pipe when the application valve is reversed. a timing reservoir connected with atmospliere through a restricted orice, means operating,` when the. application valve is reversed to cause a preliminary reduction in proportion of the pressure in said resl to cause a preliminary the pressurein said pipe and tocharge said tiininy; reservoir, andfineans responsive to the pressure in said timing reservoir lor fur! ther reducing the pressure in said pipeto a predetermined proportion of the pressure in the equalizing reservoir.

10. Automatic brake applying apparatus on Ya train comprising a brake pipeinitial'ly `charged with liuid pressure and arranged 'to apply the brakes when the pressure in such pipe is reduced, a timingr reservoir coiistantly connected with atmosphere thro-ugh a restricted orifice, a discharge valve tor al, times causing a preliminary reduction in the `j jressure in said pipe, and for simultaneously charging said reservoir, and means responsive to the pressure in said reservoir tor causing' a further reduction in the pressure in said pipe. p

ll. i-Xutomatlic brake applying apparatus on a train comprising,` a 'bi-alize pipe initially charged with fluid V`pressure and arranged "to apply the brakes whenthe pressure in such pipe is reduced, a timing reservoir y constantly connected with atmosphere through a restrictedr oriice, a discharge valve, for at tiniesvcausing a preliminary red uction in the pressure in rsaid pipe and for simultaneously cl'iarging said reservoir, and means cliccati/ve when the yiiiressure'in lthe' reservoir has been reduced 'by leakagethro'ugrliftlic orilice to cause a further reduction in 4the pressure in said pipe.

l2. Automatic brake applying' apparatus on a train comprising a brake pipe initially charged With fluid pressure and arranged to apply the brakes when the pressure iii such pipe reduced, an equaliziiig reservoir normally. connected with said pipe, a discharge valve coinprisinga cylinder divided into a first chamber and a` second chamber by a ieciprocabl'e piston, a port connecting the secondchaniber With atmosphere and closed when ,the piston `occupies one extreme position, fa spring constantly urging' the piston away lroni such extreme pos' ion, and means `for at ti'incs disconnecting the reservoir from .said pipe and connecting 'the reservoir with the iirst chamber andri'or con necting` the pipe with the second chamber.

13. Automatic brake applyingapparatus ony a train comprising a brake pipev initially charged with fluid pressure and arranged to apply the brakes when the pressure .in such pipe is reduced, an equalizing reservoir normally connected with said pipe, a. ditlerential valve comprisingtivo pistons oi" difierent areas, means for at times disconnecting` the reservoir from said pipe and lor exposing;` one piston to the pressure in the reservoir, and 'for exposing the other piston to the pressure in the pipe, and means respoiry sive to the relative values or the Jforces act,- ing upon the two pistons tor controlling the pressure in said pipe.

=sie

lil() 14. Automatic brake applying apparatus on a train comprising a brake pipe initially charged With fluid pressure and arranged to apply the brakes When the pressure' in suchy pipe is reduced, an equalizmg reservoirnorthe equalizing reservoir` from said pipey and connecting the reservoir With the chamber containing the smaller piston and for connecting the pipe With the other chamber, and a port in said other chamber communicating with atmosphere and arranged to be closed when the` force exert-ed upon the smaller piston exceeds the force exerted upon the larger piston. y t y l5. Automatic brake applying apparatus on a train comprising a brake pipe initially charged with fluid pressure andI arranged to apply the'bralres when the pressure in such pipe is'reduced, an equalizing reservoir normally connected With said pipe; a differential valve comprising a cylinder containing ltwo pistons of different areas operatively connected together and dividing` the cylinder into a first chambercontaining the sinaller piston, a second chamber containing the larger piston and a third chamber between the two pistons; a timing reservoir constantly connected with said third chamber and communicating with atmosphere through a restrictedorifice, means for at times disconnecting the equalizing reservoir from said pipe and for connecting such reservoir With said first chamber, a discharge valve responsive to the pressure in said equalizing reservoir for causing a preliminary reduction in the pressure in said pipe and for simultaneously charging said timing reservoir, and means for connecting said pipe with said second chamber.

16. Automatic brake applying apparatus. on a train comprising a brake pipe initiallyy charged with fluid pressure and arranged to apply the brakes When the pressure in such pipe is reduced, an equalizing reservoir normally connected with said pipe; ya difierential valve, comprising a cylinder containing tivo pistons of different areas operatively connected together and dividing the cylinder into a first chamber containing the smaller piston, a second chamber containing the larger piston and a third chamber between the two'pistons; a timing reservoir constantly connected with said third chamber and communicating With atmosphere through a vrestricted orifice, means for at times disconnecting the equalizing reservoir `from said pipe and for connecting such reservoir Withsaid first chamber, means for at times charging the timing'reservoir, and means for connecting vsaid pipe With the .second chamber, the differential valve being respon sive to the relative values of the pressuresfin the three chambers to vent thesecond chamv-` ber at a predetermined rate. n

1,17. Automatic brake applying apparatus on a train comprising a brake pipe initially charged with fluid pressure and arranged to apply the brakes when the pressureinsuch pipe is reduced, an equalizingfreservoir northe timing reservoir, and means for connectng said pipe with the second chamber, the differential valveoperatingat times to vent the second chamber at a rate dependent upon the pressure in the timing reservoir. testimony whereof I affix my signature.

CLARENCE W. SPROULL.

.mally connected With said pipe; a differen-

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