US1223310A - Automatic train-stop. - Google Patents

Description

E. CHABOT.

6 AUTOMATIC TRATN STOP. APPLICATION FILED 05c. 15. 191;.

Patented Apr. 17,1917. (shins-sun l- A/ I 7 r A 34 I m u T Ephrm'm Chabo/ E. CHABOT. AUTOMATIC TRAIN STOP. APPLICATION H LED DEC. 15. l9l3- 4 SHEETS-SHEET 2.

Patented Apr. 17,

E. CHABOT. AUTOMATIC mm STOP.

APPLICATION FILED DEC. 15. I913.

Pa tnted Afr. 17, 1917.

4 SHEETS-SNEET 3- EPHRAIM CHABOT, OF PROVIDFNCE, RHODE ESLAN'.

AUTOMATIC TRAIN-ST" Specification of Letters Patent.

1: rtented Apr. 17,1917.

Application filed Decepiber 15, 1913 Serial No. 80

To all whom it may concern:

Be it known that l. lirnuulu (hrmo'r, a citizen of the United States-and resident of the city of Providence. in the county of .lrovidence and State of llhode Island. have invented certain new and uaetiil Improvements in Automatic flrain-Stops, of which the following is a spmification.

This invention relates to means for .auto matically stopping (rains, it for any. reason the engineer fails to ohserve"the. signalswhich are set against him, and has ior its 5 object to m-ovhle'simple, positive and eil'eetivc means whereby it is impossible torla train to-pass a signal that is set to stop or caution position, at a speed greater than that permitted by the road rules. without having I the controlling mechanism automatically operat'ed to slow clown or stop the tram.-

A further object of the invention is to provide means whereby when the signal is setto danger that it will position certain means which will automatically engage and.

operate a certain set of mechanism for com pletely shutting oh' the steam from the engine, or apply the air brake or the. train to a stop. v

A further object of the invention is to provide means whereby when ,the signal is train to slow down to a .without coming to a in set to the caution position that it will oper-, ate anothermechanism which will cause the predetermined speed 'lstop. v

A further object of this invention is to rovide means whereby the throttle" and raking mechanism cannot be manually releasedafter having been once set. until the speed of the train has been reduced to a predetermined rate. i i a With these and otherobjects in view, the invention. consists of certain novel features of construction, as will be more fully described and-particularly pointed out in the appended claims.

f the accompanying drawings Fig, 1 is a'diugranmiatic view showing an'end elevation of the engine, partly in. section, and the signal mechanismin position to automatically o'peratetheengine control mechanism.

' 2- is an enlarged side elevation,

F1 partg in section, showing the'tripping arms set in the caution or permissive osition;

. 25- is a side elevation s owing the both to :bring.

tripping arms bo:h' set in disengaging or.

clear position. I

Fig. 3 is a [)(ISPQCtlVP view of the air pressure control] in g mechanism with the casing partly broken away to better illustrate the operation of siid mechanism. 1

Fig. 4- is a Sl( eelevation of the double acting air controlling valve with the casing partly in section, showing both of the contact levers and the r controlling cams in normal position. r

Fig. is a (let) lil, partly in section, illustrating the arrangement of the pistons and ports whereby a pressure is constantly maintained on the piston valves for normally forcing them apal t.

Fig. 5%- is a detail in section illustrating the'arrangement (f portswhereby a movenient of'eithcr one of the piston valves permits the -n-essure to pass outward through a.-

pipe to thioperat ng n1echanism. l*ig. 'fiis an 9 1d view of the valve'casing on line 6-6 (f Fig. 4, illustrating the general arrangement of the inlet and outlet pipes. 4

Fig. 7 is a sid elevation illustrating the actionof the con ;rolling spring upon the contact levers to re Jurn them to normal after having been actuated.

Fig. 8- is a sectional side elevation of the steam controlling throttle on line 88 of 9. i l i Fig. 9- is a trolling throttle.

Fig. 10 is a c'. etail ofthe latch, on the throttle which is released automatically when the throttle lever is moved to the] stop or caution position. p i i Fig. 11 is a pl: I11 view,.partly in section, illustrating the me ms for automatically operating the air bra (e controlling mechanism. Fig.'12 is aside elevation partly in section, illustrating the pump or controls ling the action of the release valve.

valve mechanism.

Fig. 14% is a, sec tionak lease valve mechan .5111, V able fulcrum whoso position is regulated by the speed of the engine through therelease valve control pump.

15- 's a c etail in section showingthe'release valve -ia-:positionto release th peratingapiechani an.

ltig. 'lil -gis a: plan view of the release elevation ofthe rei lustrating the movplan view of the steam conported the air This air also provided with an upwardly extending Referring to the drawings, the signal usual sema signaling (i 20 designates ost or support on which the ore signal 21, or other suitable evice, is pivotally mounted. To

1 this semaphore I have applied an operating arm 29, the arm 27 being set to move at sub stantially right angles to that of the arm 29.

On the shaft 30 of the gear 25, I have mounted a rearwardly projecting lever 31 which is connected by means of the rod 32 to the lever 22 supported on the semaphore. By this arrangement of mechanism when the semaphore is moved tostop position, as illustrated in. Fig. l, the arms 22 and 31 are moved to raised position which movement causes the gear to rotate and bring the tripping arm 29 into horizontal or engaging position, at the same time throwing the arm' 27 into raised or disengaging posi tion.' When the semaphore is moved to caution, or permissive position, (permission or caution in mean that the train need not necessarily come to a full stop, but must slow down to a moderate or predetermined speed,) the arms 22 and 31 are moved to position'B,

which asis illustrated in Fig. 2 moves the arm 2710 a horizontal or engaging position and the arm 29 to a vertical or disengaging position, and when the semaphore is moved to its. normal or',clear position the arms 22 and 31V-are moved to position C, which as indicated ..in Fig.v 2", moves the tripping arms 27 and 29, bothout'o'f engaging position permittin the train speed ,without interference.

In Fig. 1, an engine cab 33 isshownas.

mounted'on the wheels 34, a pair of} are connected through the shaft axle bein whic 36. On the upper portionof thecab issuppressure controlling mocha: nlsm 37 supported on the standard 38. This controlling mechanism comprises; adownwardly eiitendin contact lever 39 fixed to the shaft'40 by the movement of which the absolute stofiping mechanism is automatically contro ed throu h 'the ositionin of cam 41 by mechanismereina r descri d. ressure controlling mechanism is arm 42,, fixed to the longitudinal shaft 433 on which is also mounted a cam the movement i at which mechanism the cautionary or permission mechanism hereinafter described, iscontrolled;

this case being understood to "and57 to pass at any "outward.

'44 through- When these levers have been moved from their normal positions, by engagement with the semaphore operated trippm arms, and after they have erforme their function,- they are returne to normal by the action of the spring 45, whose opposlte ends are connected to the shoes-46 and 47 held onpins 48 in the dogs 49, whereby when either one of the shafts 40 or 43 is rotated the pressure is brought to bear on one pin only onthe rotated dog, which has a tendency to return the shaft to normal as soon as the operating mechanism has performed its function as hereinafter described.

It will also be noted that the cams 41 and 44. controlled by both of these levers 39 and 42, are so shaped that the levers ma .be

pressure through the several pipes to oper.-

ate on the throttle and braking mechanisms for controlling thespeed of the engine, I have provided a cylinder-'50 lII,'WhlCh I have mounted two pistonsv 51, 52, and. into this cylinder I admit a. pressure from the usual air pressure. tank 53, see- Fig. 1, through pipes 54 and. 55, which pressure acts upon both of said pistons to normally force them outward or in opposite directions; The piston 52 is retained in its normal positionas illustrated in Figs. 3, 4, 5 and 5", against the pressure by means of the cam 41 while the piston 51,is retained in Its normal or-' closed position by' the cam 44,-spri ngs 56 ders to return these pistons to normal after being arranged withinathe cylin-,.

having been operated by the pressure as presently described.

When the semaphore is movedtjoi its' stop; i osition, or that tripping arm29 is illustrated in Fig.1, the, positioned to engage the contact lever 39,with'draw the cam 4 1,fro ,m

' the end of the piston rod .57 and permit the pressure on the-piston 52 to move thel-lpiston e movement, of this piston as will be seen, permits the airpressurelwhich enters through pipe 55- to pass outward through the throttle o e p rt 58 andjpipe 59 intoithei rating cylinder '60,; see ,Figs. 1,.

8 and 9, w 10h pressure acts upon the-piston;

61 and drives it inward sprin 62, causes the the b 'ock 64,. and through the link against the I coil,

68 and atgthe M 15 I glev'er over .to. its:

121i piston rod ea-toen ge} "the latch 66 from the segment teeth 6]" to."-.=

--release the throttlejlever time force-said throttle extreme position toromnletely shut off the steam from the engine cylinders. At the same time this pressure of air in passmg down through the pipe 59 also passes througl'lthe branch p1pe (.9 into the brake agpying cylinder 70 therebv drivino inward t i 4 "piston 71 againstfits return spring 72 l and through the connecting links 73 rotating the brake applying lever 7th carrying the some around. to a position to apply the air' brakes to-their fullest extent and bring the" I train to a full stop.

. In practice it is found that when one train is approaching too close another, that it is not always necessary for the approachirig train to come to afull stop, but bhonld be simply slowed down so as -not to approach within the danger zone, in which case, it is necessary that should the engineer omit to observe the signal that the setting of the signal to the cautioi'iary position should automatically o 'ierate and control the action of both the throttle and the brakes to set them into position to slow down the train without action on the part of the engineer.- To accomplish this I have provided, that when the semaphore 1s set to the cautionary position, the trinning, arm

I end of the permitted 'ward through the pipe 59, and as above explained operate upon the throttle and brake mechanisms to movethe same toward the stopping position. In addition to permitting the air to pass outward through pipe I 59 the movement of'this cautionary piston also uncovers another port, as illustrated in Fig. 4, and permits the pressure to pass outits return spring 80, and positions its piston rod 81 as anabutmentiu the path of movement of the throttle lever 68, whereby the movement of saidthrottle lever is limited, so that only a'portion of the steam is shut 01f when the cautionary mechanism is oper- 9 fated. At the same time the air from the l and enters the cylinder 83 on the air brake,

pipe 77 passes through the branch pipe82 controlling mechanism,

thereby forcing down the piston 8a a ainst the return .E1f g85 to locateits piston rod 86 as an i h n'the path of movement of the operatingpiston rod .87, whereby the moves this air brake setting mechanism is {limited in'its stroke to apply all the brakes, gradually and slow down the train to a predetermined speed; l

, air-passing through the vent 9!) in the piston against the'aotiomhf the returnspring It is found in practice necessary to provide some measuc'e and means whereby the engineer cannot, upon finding that h1s mechanism been s1 ft: to stop the trams, again operate the levers at will to release the brakes and apply the steam again. At the same .time the nechanism must be so arranged that the engineer is permitted to again operate th( mechanism to release his throttle and brak: sothat he mav again apply the steam and release his brakes, after the train has been slowed to a predeterminedspced.

Inordei' to ao-(unplish this, I have pro vided a release vilve controlling air pump 88, .which pump is'actuated from the axle 3G'thrmigh-gears i9 and 90, wrist pin 91 and connecting rod 92. which operates the piston 93 to force the air through the pipe EH to the release valve controlling; mechanism 95. T heprcssure whi :h enters through the pi pc 94. acts upon the piston 96 to force the same upward against :he return spring 97. and

tnormally hold the fulcrum block 98, in its up orinopcrative position, a portion of the 0 ton and outward through vents- 100 in the cylinder. The piston"1()2,which is arranged so that itmay'be moved to shut off-the air pressure which enters through pipe 54 and passes through p pc 55 to the air pressure control. canonly be operated by a move ment of the level 101, and that only when the fulcrum block 98 is inits down position, as illustrated in Fig. 14. 'lherefore when the train is running at a high speed the pressure is suliicii-nt to act upon. the piston 96 and, raise the fulcrum block so that a movement of the lever 1011 from-position a to position I), would permit the fulcrum pin 103, under action of the links IO-land 105,

which latter is connoctedto tl1e-lever 101,to

I whatever upon the'piston 102 to which the ward through the pipe 77, whichpressu're enters thecylinder 78 in the throttle mecha-' mm and "forces down the piston 79 against connection 104 is pivoted at 106. hutwhen the speed has hem reduced 'sufliciently so that the pump, 88 will not create a pressure on the piston, 96, lue to the leakage through the aperture 99, rufl ici'cnt to raise this pis- 97, then the fularum block returns in'to position so that L movement the lever 101 from the position a. to post onfb will force the release piston 102 ol'itward and so cut of! the air pressure from the airfpressure cont-rolling mecln nism" permitting the istons 51 and '52 to returnffto normal slowly, under action of heir-respective springshti 1 and 57, thereby jermitti'ng' the pressurto. be relieved from the throttle cylinder 60, motion limiting cylinder 78, brake control ling cylinder 70 a. i d"niovementlimiti cy inder 83, the air irom whichpassing gm" ward through their res tive sup ly pip v n into the cylinder liO an outward threfro m through the pipe back through therelease valve 102 and out through the vent port 108; After this pressure has been released from all of these cylinders sufliciently so that they may be again manually operated in the usual we the pistons 51 and 52 resume their norma position ready to again be operated if an attempt should be made to pass the signals unheeded.

It will be noted in the operation of the trainsequipped with my improved device, that if the engine has previously, been slowed down the required amount before passing a signal, which is set to caution or to danger position, my improved mechanism is so arranged that even though the tripper operates the brakes and throttle, they may be immediately restored by the hand of the engineer, and if desired,while running at thisslow speed, the engineer may osition throttle nor the brake applying mechanism will be operated when the tripper' engages either of the contact levers 39 and 42. In other words, an engine cannot run past a signal that 1s set a ainst it without being stopped automatical y, but if the engineer has observed the signal and previously slowed down his train to the required rate, then the operation of the engine still lies within his control.

It will also be noted by the construction of 7 my improved device'that both the contact levers 39 and 42 are so constructed as to fingers, even when set, without operating the throttle or brake applying mechanism.

' I have shown and described the I mechanism as being arranged t3 shut ofi the power but my mechanimn may arranged to either shut oil the power without apply the bra-kes,-or apply the brakes without shutting l of the power, if desired. If, however, only '45 one of these 0 eratibns is effected the application of the braka is considered the most -eifective. v

'I claim: I

1. An automatic train stop comprising a of fluid pressure, a fluid pressure motor controlling a source of power, a valve controlling the passage of the pressure fluid to the motor, the pressure of said fluid tend-f mg normally to move said valve too 55 mallyresisting opening movement of said valve, and means. for temporarily prevent IIPO- ingreduction of the fluid pressure against.

said valve when the'saine has beenmoved to position under predetermined condi e none. 7

"1 2, An automatic tram -stop comprising a source of fluid pressure, a fluid pressure 'otor controlling a source of power, a valve Iii-controlling the'pa'ssage'of thepressure fluid -thee*release lever 101 so that neit er the permit the engine to back past thetripper and also at the same time apply the brakes,

sition, a trip member having means or norto said motor, the pressure of said fluid tending normally to move the said valve to open position, a trip. member having means for mg normally to move said valve to open po- 30 sition, a trip member provided with a rock shaft, havin means for engaging said valve,

a movable 0g on said rock shaft, a spring engaging said -dog' to maintain said roc shaft in normal position, and means for 5 temporarily prevent-ing reduction of the fluid pressure against said valveivhen the same has been moved to open position under predetermined conditions.

,4. An automatic train} stop comprising a source of fluid pressure, a' fluid pressure mo tor controlling the source of power, a valve controlling the passage of the pressure fluid to the motor, the pressure of said fluid tending normally to move said valve to open'position, a trip member provided with a rock shaft, a cam on said rock shaft positioned to normally prevent opening movement of saidvalve, and means for temporarily preventing reduction of the fluid pressure against said tive under predetermined conditions.

6. In an automatic train sto a source of fluid pressure, a motor contro ling a source of power, fluid pressure mechanism for contro ling. said motor, a conduit leading from said source of pressure to said controlling mechanism, a valve controlling the flow through said conduit, means for efl'ectin manual operation of said valve, and, flui pressure means-controlled by the speed of the vehicle for renderin said manual means ineffective when the ve icle is traveling at 'or above a predetermined speed.

7. In an automatic train stop, a source of fluid pressure, a fluid pressure motor controlling a source of power, a valve casin having an inlet port leading'from said flui pressure source and an outlet port leading to said motor, a valve in said casing normally wer, fluid pressure mechanism for con- 105 covering said outlet port, the fluid pressure acting to move said valve in a direction to uncover'said outlet port,'a rock shaft pro vided with means for preventing movement of'said valve, a dog on said rock shaft provided with pins, a slotted shoe engaging the said pins,an d a spring connected to said shoe to hold said rocl; shaft in a predeter mined position and means for maintaining said valve in open position after its release from said holding means.

8. In an automatic train stop, a source of fluid pressure, a fluid pressure motor controlling a source of power, a valve casing having an inlet port leading from said fluid pressure's'ouree and an-outlet port leading to said motor, a valve ,in said casing normally covering said outlet port, the fluid pressure acting to move said valve in a direction to uncover said outlet port, a rock shaft, a cam on said rock shaft arranged opposite the stem of said valve, and means for retaining said cam in a redetermined position and independent fluid pressure means for temporarily preventing shutting ofi of pressure against said valve.

9. In an automatic train stop, a source of fluid premure, a fluid pressure'motor, a movable member controlling the source of power, a valve casing having an inlet port leading from said fluid pressure source and an outlet port leading to; said motor, a valve in v said casin normally covering said outlet port, the aid pressure acting to move said valve in a direction to uncover said outlet port, means for normally preventing openmg, movement of said valve, and means connected with said motor for imparting movement to'said power controlling member and independent fluid pressure means for temporarily preventing shutting oflf of pressure against said valve.

10. In an automatic train stop, a source of fluid pressure, alfluid motor, a throttle lever, means connected with said motor for op era-ting saidthrottle' lever, and means for automatically, controlling the supply of fluid from said fluid pressuresource to said eon prfleb uoll ns the -re motor and independent fluid pressure means for temporarily preventing the shutting off of the rcssure passing to said motor.

,11. n an automatic train stop, a source of fluid pressure, a fluid pressure motor, a lever, means for locking, saidlever'against movement, means operated by said motorfor successively unlocking'said lever and moving the same, and means for controlling the passage of fluid from said fluid pressure source to said: motor and independent fluid presure means fortemporarily preventing the shutting loif ofthe pressure passing to. '1 bid motor,-

v. 12. In aniautomatic train stop, a source 0t fluid pressure; a

fl id fluid pressure motor,

pressure to said notor. a lever, means operated by said mot nlfoiactuating said lever, and fluid prvssl l'o means for temporarily preventing the sl lilting otl' of pressure passing to said inotol.

13. In an autimaiic train stop, a source of fluid pressur a fluid hressure motor, means for controlling the supply of fluid pressure to said uotor, a lever, means oper-. ated by said motor for actuating said lever, a movable abutn out for limiting the movement of said lewr, and means controlled by said fluid pres-sire control for operating said abutment,

14. In an automatic train stop, a source of fluid pressure, a fluid pressure motor, a lever operated by said motor, a valve casin having an inlet port leading from said flui pressure source, and an outlet port leading to said'motor, a valve in said casing norlet port-,the fluid pressure acting'to move 100 said valve in a direction to uncover sai outlet port, means-for normally preventing opening moveim nt of said valve, a movable abutment forlii iiting the movement of said lever, and fluid pressure means controlled 5 by said valve f1 )1 o ticrating said abutment.

16. In an automatic train stop, a source of fluid pressura, a fluid pressure motor,a lever controlled by said motor, a valve casing having an inlet port leading from said 0 fluid pressure mrce and two outlet port-5,. one of thelatha: leading to said motor, a fluid pressure device connected with the other outlet port for limiting movement of",

said lever, vali es in said casing normally 5 coveringsaid (utlet ports, the fluid ressure acting to movesaid valves in a threetion to uncovei said ports, and means for normally prove 1ting opening movement of said valves.

17. In an auvomatic train stop, a source of fluid pressuie', a fluid pressure motor, a lever connected with the said motor, a valve easing having an inlet port leading from s'aid fluid 'presiure source and two outlctf gz. ports one of winch leads to sa d motor, a fluid pressure ievlce connected with the other. port for limitingpnmmment of said lever, valves in said cas ng, the fluid pressure acting to :nove said valves in a direc- 0 s5 mally cover ng said outlet port, the fluid pressure acting 0 move said valve in a dition to successively uncover said outlet-ports,

fluid pressure source, and two outlet ports one of which leads to said motor, a movable abutment for limiting movement of said lever, a fluid pressure motor controlling sa-id abutinent and connected with the other outlet port, valves in said casing normally covering said outlet ports, the fluid pressure acting to move said valves in a direction to successively uncover said ports, and means for normally preventin opening movement of said valves.

19. ii an automatic train stop, a source of fluid pressure, a fluid pressure motor controlling the source of power,'a second fluid pressure motor for controlling the source of power to the air brakes, a valve casin having an inlet port-leading from said fluid pressure source, and two outlet ports one of which communicates with said motors, a plurality of fluid pressure devices connected with the other out et port for limiting movement of said levers, valves in said casing normally covering said outlet ports, the fluid pressure acting to move said valves to successfully uncover said ports, and means for normally preventing opening movement of said valves.

20. In an'automatic train stop, a source of fluid pressure, a fluid pressure motor controlling a source of power, a valve casing having an inlet port leading from said fluid pressure source and an outlet port leading to said motor, valves in said casing eachcontrolling said outlet port, the fluid pressure acting to move said valves to uncover said outlet port, a. rock shaft adjacent each valve,

"trip arms connected to said rock shafts, dogs connected to said rock shafts, andia spring connecting said dogs,

.21. In an automatic train stop, 'a source "of fluidpressure, a fluid pressuremotor controlling a source of power, a .valve casing having an inlet port leading from said fluid pressure source and an outlet port leading to saidlmotor, valves in said casing each controlling said outlet-l port, the fluid pressure acting-to move said valves to uncover said outlet port, arock shaft adjacent each valve, tr1parms. connected to said rock shafts, dogs connected to said rock. shafts,

' shoes connected-to said dogs and having for contro 'lixni'todfiielatlvf movement, and a spring" 19 shoes. 22; In an automatic train stop, a source source of power-,fluid pressure mechanism ling said motor, a. conduit leading from saidsourceof pressure to said-connected to said valve, a fulcrum re,ja motor controlling a flow through said conduit, a lever connected to said valve, a stop for said lever, and meals for moving and stop to release said lever when the train exceeds a predeter' mined speed/- 23. In an automatic train stop, a source of fluid pressure, a motor controlling a source of power, fluid pressure mechanism for controlling said motor, a conduit leading from said. source of pressure to said controlling mechanism, a valve controlling the flow through said conduit, a lever connected tosaid valve, a fulcrum pin connected'to said lever, a fulcrum block for said fulcrum in, and means for moving said fulcrum b ock out of register with said fulcrum pin when the train exceeds a predetermined speed.

'24. In an automatic train stop, a'source of fluid pressure, a motor controlling a source of power, fluid premure mechan sm for controlling said motor, a conduit leading from said source of pressuflfto said controlling mechanism, a valve'coIWi-olling the flow through said conduit, a lever conin connected to said lover, a fulcrum hook for I said fulcrum pin, and fluid pressure means for controlling the position of said'fulcrum block.

25. In an automatic train sto a source of fluid pressure, a motor control ing-a source of power, fluid pressure mechanism for controlling said motor, .a conduit leadmg from said source of pressure to said controlling mechanism, a valve controlling the ffiow through said conduit, a lever connected to said valve, :1 fulcrum pin connected to said lever, a fulcrum block for said fulcrum pin, fluid pressure means for controlling the position of said fulcrum block, and means op eratcd by a moving part ofthe train for op erating said fluid pressure means;

.26. In ,an automatic train. sto ,the comspeed of the en ine for positioningm'eans whereby the loc ed mechanism may be released. I

27 In an automatic train stop the .cornbination with a railroad 'signa tri pin' means connected to andgoperated there y, o a valve on the engine-adapted to be operated by said t'ri'pper;to -'ad1nit. airpressureto' shut. ofiwtheepower," means actuated by the air pressure to limit the amount of power shut off, and means includin an air pump con trolled in its action by t e engine speed for positioning a fulcrum block whereby the.

stdp'ping mechanism may be again restored toaction. l 2 8. In an automatic train stop the combination with a railroad signal, tripping means connected to and operated thereby, of

a piston on the engine connected to the throttle lever, a valve adapted to be operated by said'tripper to admit air pressure to said piston to move said lever vto shut ofl the power, and automatic means for limiting the stroke ofthe throttle lever for reducin the speed of the engine to a predetermin. rate.

29. InLan automatic train stop the combination with or railroad signal, 'tri pin means connected to and operated ther y, o I

a piston .on the engine connected to the throttle lever, a valve adaptedto be operated bysaid tripper to admit air pressure to said piston to move said lever toishut ofi the power, automatic means for limiting the stroke-of throttle lever for reducing the Y a speed of the engine to a predetermined rate,

and means for permitting the manual operation of the stopping mechanism when the speed of the trainlhas been reduced to a predetermined n .te.

30. In an autom itlc train stop, the combination with a rnlroad signal, tri ping means connected to and operated there y, of-

a pistonon the engine connected to the throttle lever,a valve adapted'to be operated by said tripp1 r to admit-air pressure to said piston to mov said lever to shut off the power, and auton ratio means for limiting the stroke of the throttle lever for reducin the speed of the engine to apredetermine rate s manually operative air pressure control valve and an iir pump controllcd in its action by the speed of the engine for controlling the opera ion ofsaid control valve.

In testimon wl ereof I affix my signature in presence 0 two witnesses.

- IEPHRAIM CHABOT.

Witnesses:

Howasn B. Bannow, E. 1. Doom;

Images