US1230083A - Electropneumatic valve for air-brakes. - Google Patents

Description

T. w. soon. ELECTROPNEUMATLC VALVE FOR AIR BRAKES.

APPLICATION FILED JAN. 31,1914. A

Patented 31111612, 1917.

2 SHEETS- SHEET 1.

1 attenua? Patented June 12, 1917.

2 SHEETS--SHEET 2.

T. W. SCOTT.

ELECTROPNEUMAUC VALVE FR AIR BRAKES.

APPLICATION man 1AN.31.19.14. 1,230,083.

" arm? THOMAS W. SCOTT, OF BALTIMORE, MARYLAND, ASSIGNOR TO THE AMERICAN TRAIN CONTROL COMPANY, OF BALTIMORE, MARYLAND, A. CORPORATION OF MARYLAND.

ELECTROPNEUMATIC VALVE FOR AIR-BRAKES.

Specification of Letters Patent.

rammed June 12, 1917.

Application filed January 3l, 1914. Serial No. 815,626.

citizen of the United States, residing at Baltimore, in the State of Maryland, have invented certain new and useful Improvements in llleetropneumatic Valves for Airlirakes, of which the following is a specification.

This invention relates to an electro-pneumatic valve for air-brakes to be used in an electric train-controlling mechanism on railways.

'.lhe present invention is applicable for use in a safety system similar to that set forth in U. S. Patent 1,010,371 and is particularly an improvement on the device show in ld. S. patent granted December 31st, 15112 to Frank 'l`. Jones.

The object ot the present invention is to provide an improved electro-pneumatic valve mechanism which when operated automatically to actuate the air-brakes will simply etl'ect such reduction in the train line or train-pipe pressure to cause an application of the brakes, without, however, pro dueing a so-called emergency application of said brakes.

lleretoiore in safely-train control devices, where an air-brake valve has been actuated lo automatically stop the train a considerable quantity of train line air has been allowed to escape thereby producing an emergeiuz)y application, whereas it is desirable that only so much air be vented as will cause a gradual stopping of the train, and another object of the present invention is to provide a safety control valve that will automatically close when the train line pressure is reduced, sufficiently to apply the brakes and will automatically open again in case the train line pressure is restored to a point where the brakes -would tend to release. Y*

1V ith these and other objects in view, the invention. is illustrated in the accompanying drawing, wherein- Figure 1, shows in a diagrammatic way, a track rail, a ramp rail andthe devices and circuits on the vehicle, including the improved valvedevice.

Fig. 2, illustrates, the improved electropneumatic valve mechanism in vertical section, and

Fig. 3, shows a `front elevation of the case containing the improved valve mechanism. I

Referring to the drawings, thel numeral, 3,

designates a box or case which may be located at any convenient place on the locomotive or motor and which has a hinged cover, 4. 1, A pipe, 5, enters the case, and said-pipe is in continuous communicatiomwith the train line of-the air-brakeapparatus Another pipe, 6, Kenters'the casing and communicates with-.thegfmain reservoir or.

is constantly supplied' with air-pressure from the main reservoir of the air-brake apparatus, and said p1pe, 6, is secured by a coupling, 7, to a nipple, 8, which is attached to a shell, 9. The nipple has a passage, 10, therein and a strainer, 11, is interposed in said passage to strain the air entering from the pipe, 6.

The shell, 9, is clamped by a yoke, l12, against a block, 13, that is carried by one ot' the walls of the inclosing box or case and said shell has a chamber, 14, and a lateral passage, 15, from said chamber which ex tends beneath the passage, 10, of the nipple. A port, 16, extends through the Wall of the shell between the nipple-passage, 10, and the lateral passage, 15, so that under certain conditions, presently to be explained, communication between the nipple-passage, 10, and the lateral passage, 15, and chamber, 14, may be established.

Below the lateral passage, 15, the shell has a wall through which a port, 17, extends which latter port has position in alinement with the port, 16, at the upper side of the lateral passage, so that a valve stem, 18, may extend through port, 16, across the lateral passage, 15, and also extend looselgi7 through port, 17. The upper side of port, 16, has a seat, and a head, 19, on the stem, 18, serves to engage the seat and thereby close or shut off communication between the main reservoir and the lateral passage, 15, under certain conditions, presently to be explained.

The, interior of the nipple'passage conseats against a shoulder in the passage, and

'tains a perforated disk o r Washer, 20, which a spring, 21, extends from said washer and presses on the valve stem, 18, to aid in seating the head. 19, on the port, 16.

Suitable pipe connections, 22, lead from the chamber, 14, in the block, 13, and said pipe connects and communicates with one end of a cylinder, 23, in which a floating piston, 24, is confined. One side of the floating piston, 24, is exposed to any air-pressure that may be present in the chamber, 14, while the other side Ot' said piston has a tapered valve-end, 25, which under certain conditions ,will seat on a port. 2G. The wall of the cylinder, 22 is provided with one or more escape ports, 27, which are located v above the port, 2G, and between the latter and the piston, 2l,- aud said escape ports serve to vent the train-line from pipe, 5, through valve which will now be explained.

Pipe, 5, which always communicates witl'i the traiirline, enters a chamber, 2S, of a valve casing, 29, in which there is a partition, 30, having;r a port, 31. side of the partition, the casingr has another chamber, 32, vith which the lower end, 33, of the cylinder, 23, is in continuous communication.

A valve, 34, seats on thc partition around the port, 31, and is yieldingly held against its seat and over saidport by means ot' a spring, 35, which encircles the valve stem, 36.

Inpractice it is designed that the spring, 35, shall exert a pressure on the valve, 31, that will cause said valve to seat over port, 31, when the train line pressure shall have been reduced sufliciently to cause an application o f the brakes. and before a sufficient reduction in train line pressure is made to cause an` emergency application of the brakes.

From the foregoing explanation it will be seen that the floating piston, 24, in cylinder, 23, has one side subject to main reservoir pressure and its opposite side subject to train line pressure, so that when the pressures on opposite sides ot the floating piston are equalized, the latter will seat on port, 2G, l because the piston has a' greater area exposed to main reservoir pressure, and cut olf the escape of air pressure trom chamber, 32, y through vent-ports, 27. l Undernormal runningconditions thetloating piston will be seated on port. 2G, while 5b the pressure below the piston, in chamber 32,

. will equal substantially the excess of train pipe pressure Iover the adjustment of spring 35. The spring, 35, has a pressure resistance somewhat less than the normal running pressure in the train line and main reservoir` therefore when the train line pres-v sure builds up to a point where it will overcome the pressure ofspr1ng,35, such pressure will feed under valve, 34, and into On the other.l

maintained on the reservoir side ot' the float ing piston a venting of the train linethrough valve, 31, will be prevented because floating piston will rseat on port, 2G, and

prevent the escape of train line pressurel through vent ports, 27.

The means employed to control the reservoir pressure will now be explained.

Below the port, 17, and lateral passage, 15, the shell, 9, has a screw-threaded socket, 37, into which athreaded stem, 88, screws and pendantly sustained thereby, and the wall ot the shell at the lower end of said port. 17, has a concave seat, 39, for a purpose presently to be explained. Between the seat, 39, and sten'nSS, is an annular chamber, 40, and a relief port, l1, extends from said chamber through the wall of the shell to the atmosphere.

The stem, 38, in reality is the core of au electro-magnet, 42, and has a central passage, 43, in which a stem, 44.-, of an armature, l5, extends. The upper end 11,6, of the arma` ture-stem beveled or shaped to form a valve to fit the concave seat, 39, so that when the electro-magnet is energized, and armature 45, is held up the end of arl'naturestem. il, will engage and hold valve-stem, 18, up, thereby raising head, 19, to allow reservoir'air to pass -to chamber, 15. At this same time the armature stem willclose the lever end ot' port, 17, and prevent the escape of air from passage, 15, to chamber, 40, and relief port 4l),

lt will therefore be understood that as loner as electro-magnet l2 is energized, the upper side of floating piston, 2l. will be subject to reservoir air-prcssurc. and the es cape of that pressure cannottake place because armature-stem. All, will remain seated at the lower end of port 1T.

The electro-nuignet` 4'), is inclosed in a cylindrical casing, #17. and the armature, 45, contained in a cap, lo. at the lower end of the casing. This rap has a depending central stem,` 4l), with a central passage therein and a spindle, 50, is loosely confined in said passage so as to be moved vertically, and during,r such movement engage the armature and raise the latter when resetting is necessary. '.lhelower end ot' the spindle, 50, carries. a resetting yoke head, 51, also for a purpose presently to be'explained.

By ret'erringrr to Fig. 2, of the drawing it will be noted that a pipe, 52, branches from the train-line pressure-pipe, 5, and that a valve, 53, is located in said bra uch, and it will also be noted that a lever, 5-1, is mounted on the stem of said valve, 53, and extends across to the yoke-head, 51, with which it. is

connected. The Valve, 53, in this branch is normally closed but is momentarilyturned to the open position by means of an operating handle, 77, to rock the lever, 54, and raise the yoke-head, 51, to reset the armature, 45, as will presently be more fully eX- plained.

ln practice the box or case, 3, containing the improved valve mechanism is located in the engine or motor and the electro-magnet, 42, has two binding posts, 55, and, 56. A current supply, such as a battery, 57, is provided on the vehicle asis also a contact shoe, 58, which rides over or engages short ramp rails, 5f), that are located at spacedapart intervals along the roadway. A switch, GO, is provided and so arranged with respect to vthe contact shoe as to close a connection between -two contact points, (il, and, 62, when the vehicle is traveling between ramp rails and when the shoe engages a ramp rail said switch will be actuated to open or break the normal connection be` tween the contacts, 61, and, 62.

A wire, G3, connects electro-magnet binding-post, 56, with contact-point, 52, and a wire, (i4, connects contact point, (31, with one side of the cm'rent-sup1')ly, 57.

1n the present instance a wire, (35, connects binding post, 55, of the electro-magnet with the axle, (3G, and another wire, (37, connects the axle with the other side of the current-supply, 57.

lIt will therefore be seen that when the contact shoe, 58, is in the normal running position, during the travel of the vehicle between ramp rails, a circuit from battery, 57, through electro-magnet, 42, will be maintained and said magnet thereby maintained in an energized condition.

While the shoe, 58,' remains in engagement With a ramp rail, 59, however the switch, 60, will open the connection between contacts, Gl, and, 62, and thereby interrupt the normal vehicle circuit from battery, 57, through electro-magnet, 42, but during such engagement of the shoe with a ramp rail, provided the road ahead is clear, the shoe will pick up a local current from the ramp 'rail as follows:

'From battery, 68, by wire, G9, to and through an armature, 70, that is held by an electro-magnet, 71, which latter is energized by a local current, not illustrated; then by wire, 72, to ramp rail, 5t), and shoe, 58; by wires, 73, and, 63, to binding post, 56, of vehicle magnet, 42; then from post, 55, and wire, 65, to axle, (36, wheel, 74, and tracklrail, 75, and finallyby wire, 76, back to local battery, 68.

lt is therefore to be understood that during clear track conditions the electro-magnet, 42, on the vehicle will be energized by vehicle current frombattery, 57, Whilethle 'end of port, 17.

vehicle is traveling between ramp rails and by current from a local battery, 68, while the shoe, 58, is traveling over a ramp rail. lli/hen however, the track ahead is occupied, track magnet, 71, will become deinergizcd and drop armature, 70, so that current from local-battery, (5S, cannot pass to ramp rail, 5S). Therefore when shoe, 58, rises up on ramp rail, 5f), which latter has become disconnected from battery, (3H, a substitute current cannot be supplied to'the magnet, 42, on the vehicle and the latter will become deenergized and cause an application of thil brakes, as will now be explained.

It has hereinbetfore been explained that during normal running conditions reservoir pressure is present inl lateral passage, l5, chamber, 14, and pipe connections, 22, so as to exert a force on the upper side ol' floating piston, During this period as also explained, armature, l5, and stem, 4l, will be elevated to prevent the escape ot' rcservoir pressure through port, 17, chamber, 40, and relief-port, 41.

lt is also to Ybe understcod that. during normal running conditions the under side ol' floating piston, 24, will be subject to train line pressure which may vary according to the various manipulations of the engineers valve in the usual operations of' producing 'graduations and service applications ol'the brakes.

lt should be understood that reductions in train line pressure will in no way atl'ect or produce an operation of the controlling valve mechanism in this case.

When a block or section invadvance oi a moving train is occupied, the ramp rail tor that section will be disconnected from its local current supply so that when the contact shoe, rides up onto such ramp rail it will move switch, (it), and interrupt the normal vehicle circuit. between vehicle battery, 57, and electro-magnet., l2, and having no substitute. current from the ramp rail, the said electro-magnet '-.vill become deinergized and allow armature, 45,`and armature-stem, 44, to drop. stem, 44, drops` its upper beveled end, 46, moves away from and uncovers the lower During this downward movement of the armature-stem, valvestem 1S, will also move downward until head, 19,`thereon seats on the upper end of port, 16, thereby cutting ofi' the passage, l5 Alfrom the reservoir pipe, 6. At this time vvair-pressure escapes from passage, 15, and

Thus it will be understoodthat the de-I cnergization of electro-magnet, 42, will open When armaturc- BEST AVAILABLE COP' i reservoir pressure to that side of the floating piston. Tile pressure therefore on the reservoir side of the floating piston being reduced below that on the under or trainline side of the floating piston, the latter will move up in the cylinder, Q3, and uncover ports, 27 so that the pressure in the chamber, 32, of valve, Q9, will be vented; valve, 3l, will be unseated and air-pressure from the train-line will pass through port, 3l, to chamber, 32, and then into the end,

33, of the cylinder from which latter it will also escape through ports, 27. It will therefore be seen that when electro-magnet, l2, -becomes denergized, reservoir pressure will be shut oil' from `the upper side of floating piston, 24, and the latter will rise so as to uncover port, 26, and also vent train line air from the chamber,`32. This it will also be seen, will cause train-line pressure in chamber, 28, to open valve, 3l, and thereby vent the train-line and cause an application`ot' the brakes.

If valve, 34, were omitted, the train-line pressure would continue to vent through ports, Q6, and, 27, until said train-line is depleted of pressure and such a reduction of pressure in the train-line would result in an emergncy application of the brakes. An

leinerg lncy application of the brakes is undesira le in the absence of immediate danger, because of the liability of damage to the rolling stock by strains, jars and in many instances the shifting oi the loads on the various cars o f the train. To avoid these objections I have interposed the train-line pressure control-valve, 34:, between the floating piston and the source of train-line'pres" sure so that the reduction of train-line pressure shall be only partial instead ot' a depletion. In practice the reduction in trainline pressure by means of my improved mechanism, is less than necessary to cause an emergency application, because the spring, 35, is designed to close valve, 34, against the train-line pressure after a pre-- determined reduction in that pressure has been made. F or example, if under normal running conditions the train line and reservoir pressures equalize at seventy pounds pressure, and al Iten ,1 pound reduction in train-line pressure will canse a prompt ap-v plication of the brakes, but not anemergency application, the spring, 35, will be designed to clos 'tlievalve, 351, against a Asixty pound airpre$ure in the chamber,28.

6 0 By this 'means' whenf'a tenpound reduction in the train-lin` pressure has been made, the valve, 34, will l0se,;`` but the brakes will have been applied. fr?

After al@ 'apaise has closed with al@ brakes' applied, and the pressure in the tram-line is being restored when that tra1nline pressure reaches a point where it will overcome lthe action of spring, 35, the valve.l

cient to produce an emergency application of the brakes.

This condition of intermittently venting the train-line'will maintain the brakes in an applied condition until the ar nature, 45, of electro-magnet, 42, is reset, but a resetting of this armature cannot take place unless the engineer brings his train to a stop, as he should, or get an emergency application olE the brakes.

To eifect a resetting, the engineeig who cannot gain access to the mechanism in the case, 3, will grasp handle, 7T, on the exterior of the case which handle is mounted on the stem of valve 53, By-turning this handle. 77, valve, 53,will be turned from .i. normall.\.Y closed position to an open position in which it will vent the train-line through branch. 52, and an emergency application will result. At this time' however, the train will have come to a full stop, or substantially a full stop. In makin;r this turn ol handle. 77, the lever, 5l, will he swung upwardly so that its free Vend will elevate the yoke-head. 5l, and stem, 50. This upward movement of stem, 50, will raise arma nre. 45, and armature-stem, ll, whichlat lr in turn willA v and equalize with the reservoir pressure.

Having thus described my invention what I claim und desire to secure by Letters Iatent iszr l. In an airbrake valve'device for vchi cles, the combination with a vehicle havin;r

an air-brake system, of a connection subject to train-line pressure of the said system; a

connection subject to mam-reservolr pressure of said system; valve means having one side subject to reservoir pressure and another side subject to trainline pressure,- said lvalve means holding the train-line con- `nection closed, and means interposed between said valve means and the train-line to limit the reduction in train-line pressure and prevent yan emergency application of the brakes when 'said valve .means has been opened to vent the train-line 2. In an air-brake valve device for vehiclesI which latter travel on tracks, the cornbination with avehicle having an air-brake system, of a train-line connection with the .air-brake system; a connection from the main eservoir of the said air-brake system; means for normally holding the train-line connection closed by pressure from the reservoir; valve means for controlling the reservoir pressure tothe said closing means of the train line; an electro-magnet to control said'- valve means; a circuit on the vehicle which includes the said electro-magnet; means' for automatically controlling said circuit and electro-magnet, and automatic means 1n the tra1n-line connection to limit the reduction of train-lne pressure and automatically prevent an emergency application of the brakes when the train-line holding means isopened.

3. In an air-brake valve device for vehi- A cles which latteritravel on tracks, the combination 'with `a vehicle having an air-brake System, of a cylinder on the vehicle having a movable piston-head; a connection betweenone side of the head in said cylinder and the train-lineA pressure of the air-brake system; automatic means for normally re ltaining said head to prevent escape or" air from the train llne, said means including 'an cles which travel on tracks; the combination f with a vehicle having an air-brake system of a cylinder on the vehicle'having a movable piston head therein; an air-brake train line connection with the cylinder and at one side of the piston head; an air-brake reservoir` connection With the cylinder and at the other side of thepiston head normally hold the said piston head to prevent the escape of air from thetrain line; meansfor automatically controlling the reservoirconnection to the cylinder and automatic means to limit the reduction in train-.line pressure and automatically prevent an emergency application of the brakes when the piston head is moved to vent the train-line.

In testimony whereof aix my signature in presence'of two Witnesses. y

THOMAS YV. SCOTT. 'Witnessesi y CHARLES B..MANN, Jr., G. FEED. Voer;

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