US2844412A

US2844412A - Air-brake safety system

Info

Publication number: US2844412A
Application number: US439368A
Authority: US
Inventors: Charles B Parker; Robert L Bibb
Original assignee: First American Nat Bank
Current assignee: First American National Bank
Priority date: 1954-06-25
Filing date: 1954-06-25
Publication date: 1958-07-22
Anticipated expiration: 1975-07-22

Description

July 2 1958 c. B. PARKER ETAL 2,844,412

AIR-BRAKE SAFETY SYSTEM Filed June 25, 1954 ATTORNEY atent r ice United States AIR-sBRAKE SAFETY SYSTEM Charles B. Parker andRobert L. Bibb, Nashville, Tenn., 'assignors to First American National Bank, Nashville,

Tenn., as trustee Application June 1954, Serial No. 439,368

6 Claims. '(Cl. 303-86) This invention relates to ,an air-brake safety system.

More particularly theinvention pertains to an air-brake safety system in which a valve-free signal line 'is coupled by a reduction-valve to the ,trainline wat the rear of a train for;providing automatic application and/or manual control of brakes behind a turned angle-cock or other obstruction and for providing through ,a pressure gauge and/or ,a special whistle a warning to the engineer of thedangerous obstruction in his train line.

Specifically, the invention comprises a valve-free signal line (or auxiliary line), a train line having novel by-pass angle-cocks which when turned will by-pass air from the train line into the signal line, an air gage and a whistle having a raised-pressure-responsive pop-valve for blowing the same when the signal-line pressure is raised somewhat above normal, one or;more manually operable valves in the cab and at the rear of the train whereby the engineer or the conductor or ilagman can effect ,a brake application by shunting air fromthe train line into .the signal line, an adjustable automatic reduction valve at the rear of the train for feeding air from the train line to the signal line upon occurrence of an abnormally high pressure-difference therebetween to thereby effect application of brakes behind a .turned by-pass angle-cock and to signal the engineer through the special whistle, andrgages and whistle-cock signals in the rear assemblage.

It has long been recognized that turned angle-cocks or other obstructions in train lines are the most common causes of brakeafailureaccidents, which are usually very costlyin casualties and property damage. It is :also recognized that in event of war, turning angle-cocks would be a very easy and highly effective method of-fsa'botaging movement of troops and war material. The presentinvention would prevent this type of accident or sabotage.

It is accordingly ,a principal object of the invention to provide an airbrake safety system in which the brakes are either automatically applied and/or can be manually applied behind a =turned-anglecock or other obstruction (such as ice, dirt, collapsedhose or torn hose lining, etc.).

It is another object to provide such a system with special angle-cocks for by-passing air fromythe train-line to the signal line when turned, to automatically effect brake application and/or warning signals to the engineer.

It is a :further object to provide an air-brake safety system in which the engineer at all times has complete control over brakes both behind and in front of a turned by-pass angle-cock or other obstruction.

It is yet another object to provide such a system with valves and pressure gages at the rear of the train so that the conductor or flagman will be warned of abnormal conditions in the brake system and will have availablelmeans for applying some or all of the brakes and for warning the engineer.

These and other objects and advantages of the invention will become apparent as the following detailed description proceeds.

and in which like reference characters refer to the same parts throughout the several views:

Fig. 1 is a schematic view of an airebrakesystem embodying the present invention. p 1 V Fig. 2 is a perspective view of the rear control assemblage.

Fig. 3 is a fragmentary elevational view of an anglecock according to this invention in verticallongitudinal axial section taken on the line 3-3 of Fig. '4.

Fig. 4 is a fragmentary elevationalview of the anglecockof'Fig. 3 in vertical transverse section taken on the line 4-4 of Fig. 3. 1

With reference now to the drawings, the letters 0, C and L (Fig. 1) generally designated, respectively, the schematically phantom-shown observation car, any one .of many intermediate coaches or cars, and the locomotive. The symbol S indicates the signal line of about inch indiameter, and T designates the train or brake line of about 1% inches in diameter. In the disclosed system the signal line S is modified from the conventional by having no angle-cocks at the coupling ends of the cars and locomotive. The train line may be of generally conventional construction, but there is substituted, for the usual angle-cocks, others of the hereinafter described special construction and functions. The train line T and the signal line S may be of equal size, if desired, for economy in manufacturing andalso because the lines may be'interchangeable as will later be described.

Train line T is supplied with air at a pressure of the order of 110 pounds per square inch by pipe 11 connecting with the main reservoir (not shown). Pressure is maintained at said value by the reduction feed valve 13 in conventional manner. Similarly, about pounds of air is normally maintained in signal lineS by the reduction feed valve 15 connected thereto and to the main reservoir by pipe 17. Behind valve 15 there is provided a In the drawings forming a part of this specification cut-off valve 18 the purpose of which 'will be explained later.

In or on the last car .(observation car 0) thereis in- "stalled the rear control assemblage generally designated R and preferably mounted (hooked, as shown in Fig. 2) on the railing ,19 so as to be readily observable by and accessible to the conductor and flagman. Assemblage R comprises essentially the important general purpose automatic control valve G which is basically a pressure- .reducing feed valve, such as the Westinghouse O-.6,feed valve, that permits air to flow from trainline T through the valve G into signal line S so long as the valve of the signal line pressure is below a predetermined valve setting, preferably about 30 pounds, which may be varied by adjustment of the variable control device 21.

In conventional train brake systems,-a reduction of pressure in the train line of 5-15 pounds is sufficient to apply the brakes. Assuming a 10 pound reduction is required in train line T to apply the brakes, then a reduction in the-order of 25 pounds must be made in the signal line S to reduce the normal pressure from 45' pounds to -20 pounds causing the control valve G, pre-set at 30, pounds, to automaticallyopen and discharge compressed air from the train line T into the signal line S to effect the necessary 10 pound reduction in the train line to applyzthe brakes. The signal line S is normally maintained at a pressure, such as 45 pounds, which is substantially above the pressure .(30 pounds) necessary for opening thecontrol valve G, in .order that the signal line S-may be conventionally used for signaling the engineer in the locomotive from. any of the cars by a reduction of the order of 5 pounds in the signal line S, without opening the control valve .G.

The rear assemblage R also comprises a low-resistance check valve 22 which prevents the flow of air from the signal line Sthrough the control valve G'at all times.

The by-pass valve 23 communicates the, rear ends ofthe signal line S and the train line T through the by-pass line 47 in a circuit parallel to the circuit of the control valve G. The valve23 is for use by the conductor or flagman when he detects that the pressure in the train line T is below the normal pressure of 110 pounds. By opening the valve 23, compressed air may be passed from the train line T into the signal line S, and if the pressure differential between the two lines is 10 pounds or greater, a reduction may be effected in the train line Tsuflicient to apply the brakes controlled thereby. In railroad parlance, any pressure below 90 pounds in a train line having a normal pressure of 1 l pounds is considered abnormal. Thus, when abnormal pressure of 55-90 pounds in the train line T is noted by the conductor, he may turn the valve 23 to immediately apply the brakes controlled by the train line T. By turning valve 23 and reducing the pressure in the train line T, the pressure in signal line S is simultane- 'ously increased to actuate a signal device in the locomotive responsive to an increase in pressure, which will be described later.

A double pressure gage 25 (or a pair of separate gages, if prefe'rred)'to independently indicate the pressure in both the lines T and S is also included in therear assemblage R.

Whistle cocks 27s and 27t having whistle-carrying handles W, all of known construction and function, are connected to the rear ends of the signal line S and of the train line T, respectively. These whistle cocks 27s and 271 may be of any conventional construction, such as that disclosed in U. S. Patent Number 808,711, which operate when the cock is open to reduce the pressure in their respective lines controlled thereby and to blow a whistle, not shown, mounted on the handle W. Opening of the whistle cock 27s will operate to sound a conventional reduced-pressure-responsive whistle in the locomotive, not shown, and it is also possible to hold the whistle cock 27s open long enough to reduce the normal signal line pressure of 45 pounds down to 20 pounds to set the brakes by reducing the train line pressure T through the control valve G. By opening the valve 27t, the whistle mounted on its handle W is sounded, and it is possible by leaving the whistle cock 271 open long enough to reduce the pressure in the train line by at least pounds, to apply the brakes. As is well known in the art, either the whistle cock 27s or 271? may be used for back-up movement of the train, to signal the public an also apply the brakes.

Y 'The sections of the lines S and T carried by the individual cars and coaches are interconnected in the usual manner by flexible hoses SH and TH, respectively, joined by the conventional couplers 29.

In the locomotive L the signal line S has the usual dusting-line valve 31 and the pilot valve 32 either of which can be used in emergencies to reduce the signalline pressure to a value that will cause a bra-ke-applying flow of air from train line T into signal line S through the general control valve G check valve 22. Although in actual practice the train brakes have been applied by merely opening, either of the valve-s 31m 32 to the atmosphere causing a greater reduction of pressure than the increase of pressure to the signal line through the reduction .feed valve or the increase of pressure in the train line T through the reduction feed valve 13, difficulty was experienced. A preferred means for applying the brakes by reducing the signal line pressure through either valve 31 or 32, is to first close the cut-out valve 18 to prevent the introduction of compressed fluid from the reduction *feed valve 15, and also to turn the "brake valve B to lap, service or emergency positions or to close the cut-out valve 37. However, the engineer need not concern himself with the position of the brake valve B, since he will ordinarily be opening either the valve 31 or 32 and closing the valve 18 when there is an obstruction or turned cut-out valve A in the train line T which would automatically prevent any flow of compressed air from the portion of the train line in front of the obstruction to the rear portion of the train line and the general purpose control valve G.

Signal line S also connects to a whistle 33, controlled by the pop-valve 34, which gives anaudible warning signal to the engineer when the signal-line pressure rises (in emergency) above an adjustable value of the order of 55 pounds or more. An additional valve 35 may be inserted below the whistle, if desired, to cut it oil on objectionable prolonged blowing. Gage 36 indicates at all times the signal-line pressure.

Also in the locomotive L the train line T is controlled by a conventional automatic brake valve B such as the Westinghouse brake valve G-6, coupled to the train line T by the cut out valve 37. A pressure gage 41 gives a constant indication of the train-line pressure behind the engineers control valve B (automatic brake valve) and emergency control valves A and A which are by-pass valves of special construction and use, and which will be next described. I

Controlling valves A and A and the special b'y-pass angle-cocks A are of similar or identical construction. As best shownin Figs. 3 and 4 these valves have their main passages controlled by the rotatable valve core 44 having a transverse passage 45 for connecting the intake and the outlet portions of the conduit 43, which in turn communicate with the train line T or the flexible hose TH. The sides of the body of the by-pass valve A are provided with by-pass ports 46 for connection with the bypass lines 47. When the controlling valves A and A and the by-pass valves, or angle-cocks, A are turned so that the transverse passages 45 are inalignment with the conduits 43, open communication is established throughout the train line T and flexible hoses TH, and simultaneously communication from the valves A A or A through the by-pass lines 47 is closed. When any one of the controlling valves A or A or a by-pass valve A is turned to its closed or o position, as best disclosed in Figs. 3 and 4, transverse passage 45 is in alignment with parts 46 to establish communication with the portions of the bypass line 47 on opposite sides of the the system is in safe operating condition.

valve. The portion of the by passline 47 on the side of the valve A A or A opposite the signal line communicates with the train line T and is also provided with an auxiliary cut-out valve 49. When one of the controlling or by-pass valves, such as A, is in its closed position and its corresponding cut-out valve 49 is open, open communication is established between the signal line S and the train line T though the corresponding by-pas-s line 47, valve A and cut-out valve 49. The auxiliary cut-out valve 49 is provided for preventing passage of air between signal line S and the train line T when its corresponding controlling or bypass valve (A A A) is in its closed position by closing valve 49 when desired. An example of a situation in which by-pass valve A and cut-out valve 49 would both be closed would be when a car C containing these valves becomes thelast car in the train by virtue of uncoupling from a car to its rear, or when the car C is uncoupled and completely isolated from the train. Before the locomotive L is uncoupled from the train, the valve 18 should be closed. To prevent injury to workers uncoupling signal line hoses, air is exhausted therefrom by opening .pilot valve 32 and/or dusting line valve 31. The train-line section of each car or coach C is connected to the triple valve, auxiliary reservoir and brake cylinders (not shown) in known manner by the lines 51.

The manner of operation of the system and apparatus will now be described. With valve 18 closed and valve B in running position the general purpose control valve G and check valve 22 will feed air into the signal line S and register a pressure of thirty pounds on gage 36, thus indicating .free circulation through both lines, that is, that A lower or gero reading on gage 36 will indicate a, defect in the system. Conventional air-brake systemslack this simple and efiective checking arrangement.

Under normal operating conditions, cut-out valve-37, controlling valves A A by-pass valves A, cut-out valves 49, and 18 are open; and bypass valve 23, whistle cocks 27s and 271 general purpose controlling valve G, check valve 22, dusting-line valve 31 and pilot valve 32 are normally closed. When both the train line T and signal line S are at atmospheric pressure, each may be charged through its respective reduction feed valve, 13 and 15, to normal running pressures of M0 and pounds, respectively.

Inadvertent or intentional turning of an improved bypass angle-cock A, for example the front-end one on coach C, will by pass air from the train line T behind said by pass angle-cock into the signal line S, to simultaneously reduce the pressure in the train line behind the angle-cock A and increase the pressure in the signal line S, thereby applying thebrakes controlled by the train line T behind the angle-cock A and operating the whistle 33, .as previously described. The engineer, being warned by the operation of the whistle 33, can then turnthe automatic brake valve B to service or emergency position to apply all the brakes forward of the turned bypass angle-cock A.

If an angle-cock A on the rear end of acoach C is turned, the air will be by-passed from-that portion of the train line T forward of the angle-cock A through the bypass line 47 into the signalline S, to simultaneously reduce the pressure in the train line forward of the turned angle-cock and increase the pressure in the signal line, thereby applying the brakes controlled by that portion of the train line forward o-fthe turned angle-cock and blowing the whistle 33 in the locomotive L to warn the engineer of the obstruction. It should be noted, however, that if only a partial closing of said angle-cock occurs, while the feed-valve, 13 may prevent a brake-applying reduction in the train-line pressure, nevertheless the envgineer will be warned by the signal whistle 33 and/or the gage 36 responding to slow build-up in signal-line pressure. With the angle-cock A on the rear of a car C turned to apply the brakes controlled by that portion of the train line forward of the turned angle-cock, the engineer upon being 'warned'by signal 33, may applythe brakes controlled by the train line to the rear of the turned angle-cock A byopening the valves 3'1 or 32 alone, or by turning the brake valve B to service or emergency position and then closing the controlling valve A to by-pass ,air. from vthe signal lineS through the bypass line 47,.controllin'g valve A cut-out valve 49, and cutout valve 37 to exhaust through brake valve B. A consequent reduction of pressure in the signal line will reduce the pressure in that portion of the train line behind the turned angle-cock through the general purpose control valveG. In the'event, the angle-cock A is only partially turned so that the brakes controlled by that portion of the train line forward of the turned angle-cock are not applied, the engineer, upon signal from the whistle 33, may turn brake valve B to service or emergency position and hold it in that position until the brakes forward of the partially turned angle-cock A are set, the controlling valve A being open, and may simultaneously close valve 18 and open either or both valves 31 and 32 to set the brakes behind'the partially closed angle-cock A as previously described. The engineer could also operate dusting valve 31 or pilot valve 32 to reduce the signal-line pres-sure to a value to cause general purpose control valve 'G'to by-pass air from the rear part of the obstructed train line T .into the exhausting signal line and thus apply the brakes controlled'by said obstructed rear portion ofthe train line. The effect of operating any one or more-of valves A (plus B), 31 and 32 can be greatly increased by closing cut-off valve 18 to prevent air from 'fe'edinginto the signal line S through feed valve 15.

The w'histle 33 warns the engineer of an abnormal in- 6 crease in signal-line pressure fromany cause, whilethe conventional signal-System whistle (not shown) Warns him of an abnormal drop in pressure; also, a bursting of the signal line S will apply the brakes through the general purpose valve G, as explained above.

The emergency controlling valve A may be employed, for example, upon failure of automatic brake valve B to apply the brakes, by closing the valve A to by-pass air from that portion of the train behind valve A through the corresponding cut-out valve 49, valve A and bypass line 47 into the signal line S to apply all the brakes in the train in the same manner as a closed angle-cock A, as previously described. In order to facilitate the application of the brakes in this manner, either or both valves 31 and 32 may be opened to exhaust the signal line S.

The brakes mayalso be controlled by closing valve A to inter-connect the trainline T and signal line S. By adjusting the reduction feed valve 15 to approximately the same setting as the reduction feed valve 13, air is supplied at pounds pressure to both the train line T and signal line S. The brakes may then be applied by closing cut-out valves 18 and 35 and opening either or both valves 31 and 32 to make the necessary reduction in both lines T and S to apply the brakes. In lieu of valves 31 or 32, valve A may be closed and brake valve B turned to service or emergency positions to apply the brakes. With both lines T and S charged to 110 pounds, the control valve G will remain closedv even during the reduction of pressure to apply the brakes.

In emergency, valve 23 of the rear control assemblage R can be opened to interconnect the two lines T and S into a single continuous line to either apply or release the brakes in front of or behind any known or unknown obstruction in the train line T. Control bypass valves A and A are turned to their bypassing emergency positions ,to connect lines T, S and 47 to the engineers automatic brake valve B, for control of the system thereby. Valve 35 will be closed, since otherwise Whistle 33 would be objectionably continuously blown by the 110 pounds of air in the combination line thus produced.

The system of this invention also protects against obstructions in the train line other than turned anglecocks (such as collapsed hoses, ice-blockages, torn hose linings, etc.). All brakes forward of such an obstruction can be controlled in normal manner by automatic brake valve B. All brakes behind the obstruction can be applied by use of any one or more of valves 31, 32, A and 'A (plus B).

In event of crossed train and signal lines, the control bypass valve A can be turned to-emergency (bypassing) position to pass charging air from valve B into the signal line S for feeding therethrough into the portion of the train line T behind the cross-over (whistle valve 35 being closed for the reason stated above). All parts of the system will then be charged to 110 pounds, and all brakes to the rear of the cross-over can be applied in usual manner by valve B. Brakes forward of cross-over can be applied by turning valve A to bypass or emergency position which connects these brakes to the signal line now controlled by valve A and automatic brake valve B. Brakes to the rear of and forwardly of the cross-over can be released merely by moving valve B to running position, since both lines are now connected into a single system by the co-operating valves A and A The present system also provides warnings if the signal line and train line are crossed. These warnings are produced by abnormal readings on the two gages in part 25, and/or a zero reading on gage 36 during the testing operation described above (since check valve 22 would prevent reverse flow of air into the rear portion of the train line now connected to the front part of the signal line, from the rear portion of the signal line now connected to the high pressure front part of the train line);

In the event of crossed air lines, .the conductor,

noticing that the signal line is charged to 110 pounds and the train line to 45 pounds, can by the use of interconnecting valve 23, pass air from the abnormally pressurized signal line into the train line and thus apply all brakes ahead of the cross-over and thereby warn the engineer by the abnormal feel of the moving train, of the defect in the brake system.

In the event car carrying the rear control assemblage R is disconnected from the train, and if the last car of the shortened train has at its rear end an improved bypass angle-cock of the type herein disclosed, and means are provided for closing the rear end of the signal line to the atmosphere, said improved angle-cock can be used (closed) along with its opened co-operating anglecock 49 to interconnect the train and signal lines for the purposes of applying and/or releasing the brakes both forwardly and rearwardly of either (1) a turned angle-cock or other obstruction and/or (2) crossed air lines, as outlined above. While we have disclosed certain embodiments of our invention it isto be understood that many changes can be made in the size, shape, composition and arrangements of the parts and in the pressure and other values suggested without departing from the spirit of the invention as defined by the subjoined claims.

Having thus described our invention what we claim as new and desire to secure by Letters Patent of the United States is:

l. A fluid pressure brake system comprising a train line, brake mechanisms communicating with said train line and adapted to be applied by a reduction in the normal pressure of said train line, a signal line, a signal device communicating with said signal line and adapted to be actuated by a substantial increase in the normal pressure of said signal line, a by-pass line communicating said train line with said signal line, a by-pass valve in said train line communicating the portion of the train line on one side of said valve with said bypass line, said valve opening communication through said train line and closing communication to said by-pass line when said valve is open, and said valve closing communication through said train line and opening communication between said portion of the train line and said by-pass line when said valve is closed, the normal pressure in said train line exceeding the normal pressure in said signal line by an amount suflicient to apply the brake mechanisms controlled by said portion of the train line and to actuate the signal device when said valve is closed.

2. A fluid pressure brake system comprising a train line, brake mechanisms communicating with said train line and adapted to be applied by a reduction in the normal pressure of said train line, a signal line, a signal device communicating with said signal line and adapted to be actuated by a substantial increase in the normal pressure of said signal line, a by-pass line communicating said train line with said signal line, a by-pass valve in said train line communicating the portion of the train line forward of said valve with said by-pass line, said valve opening communication through said train line and closing communication to said by-pass line when said valve is open, and said valve closing communication through said train line and opening communication between said forward portion of said train line and said by-pass line when said valve is closed, the normal pressure in said train line exceeding the normal pressure in said signal line by an amount suificient to apply the brake mechanisms controlled by the portion of the train line forward of said valve and to actuate the signal device when said valve is closed.

3. A fluid pressure brake system comprising a train line, brake mechanisms communicating with said train line and adapted to be applied by a reduction in the 1 normal pressure of said train line, a signal line, a signal device communication with said signal line and adapted to be actuated by a substantial increase in the normal pressure of said signal line, a by-pass linecommunicating said train line with said signal line, a by-pass valve. in said train line communicating the portion of the train line to the rear of said valve with said by-pass line, said valve opening communication through said train line and closing communication to said by-pass line when said valve is open, and said valve closing communication through said train line and opening communication between said rear portion of the train line and said by-pass line when said valve is closed, the normal pressure in said train line exceeding the normal pressure in said signal line by an amount suflicient to apply the brake mechanisms controlled by the portion of the train line to the rear of said valve and to actuate the signal device when said valve is closed.

4. A fluid pressure brake system comprising a train line, brake mechanisms communicating with said train line and adapted to be applied by a reduction in the normal pressure of said train line, a signal line, a signal device communicating with said signal line and adapted to be actuated by a substantial increase in the normal pressure of said signal line, reduction feed valve means for communicating the rear ends of said train line and said signal line, a by-pass line communicating said train line with said signal line, a by-pass valve in said train line communicating the portion of the train line on one side of said valve with said by-pass line, said valve opening communication through said train line and closing communication to said by-pass line when said valve is open, and said valve closing communication through said train line and opening communication between said portion of the train line and said by-pass valve when said valve is closed, the normal pressure in said train line exceeding the normal pressure in said signal line by an amount suflicient to apply the brake mechanisms controlled by said portion of the train line and to actuate the signal device when said valve is closed, and means for venting said signal line to open said reduction feed valve means and cause a reduction of pressure is said train line sufficient to apply said brake mechanisms.

5. A fluid pressure brake system comprising a .train line, brake mechanisms communicating with said train line V and adapted to be applied by a reduction in the normal pressure of said train line, a signal line, a signal device communicating with said signal line and adapted to be actuated by a substantial increase in the normal pressure of said signal line, reduction feed valve means for communicating the rear ends of said train line and said signal line, a by-pass line communicating said train line with said signal line, a by-pass valve in said train line communicating the portion of the train line forward of said valve with said by-pass line, said valve opening communication through said train line and closing communication to said by-pass line when said valve is open, and said valve closing communication through said train line and opening communication between said forward portion of the train line and said by-pass line'when said valve is closed, the normal pressure in said train line exceeding the normal pressure in said signal line by an amount sufficient to apply the brake mechanisms controlled by said forward portion of the train line and to actuate the signal device when said valve is closed, and means for venting said signal line'to open said reduction feed valve means and cause a reduction of pressure in said train line sufficient to apply said brake mechanisms.

6. A fluid pressure brake system for a train including a locomotive and a plurality of cars coupled thereto, comprising a train line extending the length of said train, brake mechanisms on each car communicating with said train line and adapted to be applied by a reduction in the normal pressure of said train line, a signal line extending the length of said train, a signal device in said locomotive communicating with said signal line and adapted to be 9 actuated by a substantial increase in the normal pressure of said signal line, a reduction feed valve mechanism communicating the rear ends of said train line and said signal line, by-pass angle-cocks in said train line, one angle-cock being at the front and one angle-cock being at the rear of a car, a by-pass line communicating said signal line with/said train line through each of said angle-cocks whereby communication is established between said signal line and said train line when said angle-cock is turned to close communication through said train line, controlling valve means in said locomotive for establishing communication between said train line and said signal line,

the normal pressure in said train line exceeding the normal pressure in said signal line by an amount sufiicient to apply the brake mechanisms and to actuate said signal device when communication is established between said signal line-and said train line by turning of the anglecocks or the controlling valve means, and means for vent- 10 ing said signal line to open said reduction feed valve mechanism and cause a reduction of pressure in said train line suflicient to apply said brake mechanisms;

References Cited in the file of this patent UNITED STATES PATENTS 557,421 Oleson et al. Mar. 31, 1896 718,491 Mason Ian. 13, 1903 742,491 Quirk Oct. 27, 1903 758,427 De Camp Apr. 26, 1904 808,711 Adreon et a1 Jan. 2, 1906 891,676 De Camp June 23, 1908 1,013,821 Sauvage Jan. 2, 1912 1,404,102 Du Bois Jan. 17, 1922 1,464,955 Parker Aug. 14, 1923 l,648,215 Bickel c Nov. 8, 1927